Переводы документов. Translations in English

NP-029-17. Nuclear safety rules for ships and other floating craft with nuclear reactors

NP-029-17

Approved by
Order of the Federal
Environmental, Industrial and
Nuclear Supervision Service dated
September, 4, 2017 No. 352

 

FEDERAL RULES AND REGULATIONS
IN THE AREA OF ATOMIC ENERGY USE "NUCLEAR
SAFETY RULES FOR SHIPS AND OTHER FLOATING CRAFT
WITH NUCLEAR REACTORS"

(NP-029-17)

 

I. Purpose and scope of application

 

1. These Federal rules and regulations in the area of atomic energy use "Nuclear safety rules for ships and other floating craft with nuclear reactors" (NP-029-17) (hereinafter - the Rules) are developed in accordance with Federal Law dated November, 21, 1995 No. 170-FZ "On atomic energy use", Decree of the Government of the Russian Federation dated December, 1, 1997 N 1511 "On approval of Regulations on development and approval of federal rules and regulations in the area of atomic energy use" (Collected Acts of the Russian Federation, 1997, No. 49, art. 5600; 2012, No. 51, art. 7203).

2. These Rules shall be applicable to ships and other floating craft with nuclear reactors based on double-circuit pressurized water reactors including floating power units (hereinafter - the ships) at all stages of their lifecycle.

3. These Rules define the basic requirements for the design, characteristics and operating conditions for the systems and components of ship nuclear power units as well as principles and peculiarities of the technical and administrative arrangements for nuclear safety assurance in the course of design, construction, commissioning, operation and decommissioning of the ships and in the course of development and manufacturing of any systems and components for application in the ship nuclear power units.

4. These Rules are developed in accordance with the federal rules and regulations in the area of atomic energy use establishing the general safety assurance requirements for ships and other floating craft with nuclear reactors and also with due regard for the experience in design, construction and operation of the ship nuclear power units.

5. Nuclear safety of a ship nuclear power unit is defined by technical excellence of the design, the required quality of manufacturing, installation, adjustment and testing of its safety-related systems and components, their reliability in the course of operation, diagnostics of the state, quality and promptness of repair and elimination of failures, performance of the watch and scheduled maintenance, arrangement of the works in accordance with the flow sheets, qualification and discipline of the personnel.

Nuclear safety of a ship nuclear power unit shall be ensured by the system of technical and administrative arrangements, including:

use of the inherent self-protection properties;

application of the defense-in-depth principle;

usage of the safety systems based on the principles of redundancy, spatial and physical separation, functional independence and single failure;

application of reliable, field-proven technical solutions and substantiated methods;

scientific support of the design development, construction of nuclear power units, their start-ups and also scientific and technical support in the course of their operation;

compliance with the requirements of the federal rules and regulations in the area of atomic energy use, any regulatory documents governing nuclear safety assurance for ships and other floating craft with nuclear reactors and also adherence to the requirements of the operation documentation;

safety culture formation and maintenance.

6. Mutual coordination of the requirements for safety of the nuclear power unit and the ship shall be ensured in the course of the ship design development.

7. The procedure for bringing the ships into compliance with requirements of these Rules, including time limits and scope of the required activities shall be determined in each particular case under the conditions of construction, operation or decommissioning license.

8. The list of abbreviations is given in Appendix 1, and terms and definitions are given in Appendix 2 to these Rules.

 

II. Requirements for the safety-related systems of
ship nuclear power units

 

General requirements for the systems of ship nuclear
power units

 

9. The NPU and its systems and components shall ensure:

monitoring of neutron flux density (intensity) and its change rate;

monitoring of the process parameters in case of any potential operational occurrences including design basis accidents;

the NPU control in all operation modes;

generation of protection, emergency and warning alarm signals;

bringing of the reactor into the sub-critical state and its maintenance in the sub-critical state;

the NPU shutdown and the cooldown mode control;

information support for the operator under normal operation conditions and in case of any deviations from the operation limits and (or) conditions, exceedance of the safe operation limits and (or) conditions, including design basis and beyond design basis accidents as well as in the course of accident management;

emergency cooling of the nuclear core.

The NPU and its systems and components shall prevent:

any disturbances of the chain nuclear fission reaction control and monitoring function in the reactor nuclear core;

reaching of criticality in the course of the nuclear core refueling;

disturbances in the process of heat removal from the fuel elements in the course of the reactor power operation and residual heat removal in the course of shutdown and cooldown.

10. Any software tools used for the NPU safety analysis shall be certified. The lists of these programs shall be provided in the SAR, and their application scopes shall be specified.

11. Operability and characteristics of the safety-related NPU systems and components subject to control and testing in the course of manufacturing, installation, integrated testing of the NPU and also to periodic inspections in the course of operation in order to confirm the design parameters shall be substantiated in the NPU design and specified in the SAR.

The NPU design shall provide for the means and methods of the SRS checking for compliance with the design characteristics on the operating or shut-down reactor. The inspection means and methods shall not cause any deterioration of the NPU safety.

12. The NPU design, its safety-related systems and components shall be analyzed in order to detect their potential failures or malfunctions. Assessment of any failure or malfunction consequences, the possibility for any deviations from the safe operation limits and (or) conditions, development of the measures to mitigate these consequences and results of failure analyses shall be reflected in the ship SAR.

13. The list of initiating events for the analysis of design basis accidents, the list of beyond design basis accidents and results of their development and consequence assessment shall be presented in the NPU design. An accident with the nuclear core destruction and melting shall be considered among beyond design basis accidents.

The operation limits and conditions, safe operation limits and conditions and the design limits shall be specified in the NPU design.

14. The life characteristics and the life management methodology for the safety-related systems and components shall be substantiated in the NPU design.

15. Any quality assurance issues with regard to manufacturing of the NPU components in the course of the ship construction, commissioning and operation shall be solved by the relevant manufacturing plants, the shipbuilding and operating organizations. The shipbuilding and operating organizations as well as their subcontractors performing any activities in the area of atomic energy use shall develop quality assurance programs in accordance with the FRR requirements.

16. Safety-related NPU systems and components shall be subject to control and testing in the course of manufacturing, installation and adjustment and verification for compliance with the design characteristics in the course of operation. Ptograms, means and methods for such verifications shall be provided in the NPU design, and their frequency shall be specified and substantiated. Safety-related systems shall be equipped with the monitoring means. The monitoring means shall be redundant in cases prescribed in the NPU design documentation.

17. Monitoring of the following shall be provided in the NPU design:

radioactivity of the circuit coolants;

radioactive media at the points of their controlled discharge;

radioactive wastes accumulated in the course of the NPU operation at the places of their temporary storage prior to handover to the onshore storage and processing facilities.

18. The reactor room and the adjacent rooms or their sections shall be equipped with collision protection intended to protect the NPU and safety-related systems against any damages due to incidents and accidents considered in the ship design.

 

Requirements for the design and characteristics of the reactor nuclear core
and actuators of the control and protection
systems

 

19. The nuclear core and the reactor components affecting the reactivity shall be designed in such a way so that any reactivity changes due to movement of the control devices and reactivity effects in any operational states and in case of design basis accidents do not cause uncontrolled increase of energy release in the nuclear core resulting in damage of fuel elements above the established design limits. Values of the reactivity coefficients shall be negative within the operating nuclear core temperature range under normal operation conditions and in case of any operational occurrences including design basis accidents.

20. Characteristics of the nuclear fuel, the nuclear core, location of fuel elements, burnable absorber, control devices or reactivity members and any other reactivity control means shall eliminate any possibility for criticality reaching in case of the nuclear core destruction or fuel melting.

21. Activation (switch-off) of the circulation pumps of the reactor coolant circuit and (or) the emergency cooldown system with the reactor shut down shall not upset its sub-critical state in case of any initiating event considered in the RP design.

22. It should be substantiated in the RP design and demonstrated in the SAR that no deformation and damage of fuel elements in excess of the design limits takes place in case of design basis accidents caused by reactivity increase.

23. The maximum damage limit for fuel elements and the corresponding values of the reactor circuit coolant volumetric activity with regard to reference radionuclides shall be established and substantiated in the nuclear core design.

24. Design of the nuclear core shall prevent any exceedance of the design limits with regard to damage of fuel elements under normal operation conditions and in case of any operational occurrences (including design basis accidents) taking into account the following:

the design number of modes and their design behavior;

thermal, mechanical and radiation deformation of the nuclear core components;

limit values of the thermotechnical parameters;

vibration, thermal cycles, fatigue and ageing of the materials;

impact of fission products and the coolant impurities on corrosion of the fuel element claddings;

impact of radiation and any other factors deteriorating mechanical characteristics of the nuclear core materials and integrity of the fuel element claddings.

25. Characteristics of the nuclear core and the reactivity control means shall prevent reactivity increase at any section of their travel in the course of insertion into the nuclear core in any combination of their positions.

26. Design of fuel assemblies and the reactor shall prevent any accidental movement and deformation of the nuclear core components, geometrical changes of the fuel elements and other FE components, deterioration of heat removal conditions resulting in damage of fuel elements above the design limits or impairing normal functioning of the CPS control devices under normal operation conditions and in case of any operational occurrences including design basis accidents.

27. The nuclear core, the reactor components and the CPS actuators shall be designed in such a way so that to prevent any blockage (impossibility to move in any direction through the use of electric motor and manual drive), ejection of control devices or spontaneous disengagement of the control devices and the components of the CPS actuators in any position of the ship including its capsizing.

28. The possibility to unload the nuclear core and its components after a design basis accident shall be substantiated in the RP design and demonstrated in the SAR.

29. Labeling of fuel assemblies shall have distinctive signs characterizing the fuel and poison content.

30. Fuel elements and absorber elements with different content of fuel and poison respectively shall have the relevant labeling.

 

Requirements for the reactor coolant circuit

 

31. The boundaries of the reactor coolant circuit shall be determined in the RP design.

32. It should be substantiated in the RP design and demonstrated in the SAR that safe operation of the reactor coolant circuit systems and components including the reactor pressure vessel is ensured within their service life defined in the RP design with due regard for corrosive, chemical, neutronic and physical, radiation, thermal, force and other impacts possible under normal operation conditions and in case of any operational occurrences and design basis accidents. Quantity and character of impacts considered in determination of the design service life shall be substantiated in the RP design and specified in the SAR.

The operation model for the RP and its components within the design service life shall be substantiated and presented in the SAR.

33. Heat exchanging equipment used in the RP shall have reserve of heat exchange surface in order to compensate for deterioration of its heat transfer characteristics in the course of operation. Values of the heat exchange surface reserve shall be defined in the RP design and specified in the SAR.

34. Layout of the reactor coolant circuit shall provide conditions for development of natural coolant circulation in the circuit so that to guarantee residual heat removal from the nuclear core without any exceedance of the operation limits with regard to damage of fuel elements, particularly in case of EP activation at any reactor power level.

35. The following methods and hardware shall be provided in the RP design:

for protection of the reactor coolant circuit against impermissible overpressure under normal operation conditions and in case of any operation occurrences including design basis accidents (application of safety valves connecting the circuit volume with the atmosphere is not permitted);

for detection of the reactor coolant circuit leak points and assessment of the leakage value.

36. Engineering features for compensation of the reactor coolant circuit leakage shall be provided in the RP design. The maximum leakage shall be substantiated in the RP design.

37. Installation of the leak restrainers on the reactor coolant circuit pipelines branching from the main circulation circuit shall be provided in the RP design.

38. Technical arrangements for protection of the reactor coolant circuit against unintended drainage of the coolant shall be provided in the RP design and presented in the SAR.

Any inlets to the reactor pressure vessel located below the upper boundary of the nuclear core shall be eliminated.

39. Quality parameters and chemical composition of the coolant as well as the requirements for the means of their maintenance in the course of operation, particularly the means for the coolant purification from radioactive fission and corrosion products shall be specified in the RP design.

40. Arrangements for hydrogen removal from systems and components aimed to prevent formation of detonating mixture and the hydrogen detection means shall be defined in the RP design. Engineering features for detection and warning on any hazardous hydrogen concentrations shall be used in any cases prescribed in the RP design.

 

Control of the ship nuclear power unit

General requirements

 

41. The NPU shall include the NPU control system consisting of NOCSs and CSSs.

42. The NPU control system shall ensure continuous state monitoring for the NPU systems and components and safe control of the RP equipment in all operation modes regardless of the position of the system control devices.

43. The NOCSs shall ensure control of the processes in all NPU operation modes with the quality and reliability parameters and metrological characteristics established in the NPU design.

The NPU control system shall provide technical state monitoring and safe control of the RP equipment in all operation modes.

44. The CSSs shall perform their functions automatically upon occurrence of the conditions specified in the RP design.

45. In case the RP control and protection system combines the NOCS and CSS functions its configuration, structure, characteristics and operation procedure shall be substantiated in the NPU design and specified in the SAR.

NOCSs and CSSs shall be designed in such a way so that to ensure the possibility to identify the initiating events of accidents, to determine actual operation algorithms for the safety-related RP systems and components, deviations from the regular algorithms and actions of the operating personnel in case of such deviations.

Diagnostics shall be provided for NOCSs and CSSs.

The following shall be established in the RP design:

permissible power of the reactor depending on the NOCS operability in case of partial loss of functions;

conditions for take-down of the NOCS, CSS and their parts for repair.

46. The reactor and hardware shall be controlled from the CCR equipped with telephone and loudspeaker communication with the reactor compartment (room) and other compartments (rooms). Surveillance over the reactor room shall be arranged through the use of the closed-circuit television system from the control room and visually from the repair control station (if any).

47. In case of impossibility to perform control from the CCR the ECS shall be provided with at least the following outputs arranged via independent lines (cables):

the physical protection button;

lower position indication for the reactivity control devices;

at least two RP state monitoring devices;

control of the emergency reactor cooldown systems.

48. The possibility for any common cause failure of the NPU control and monitoring circuits in the main CCR and the ECS in case of any initiating events considered in the NPU design shall be eliminated, and the possibility for simultaneous control from the main and emergency control rooms shall be prevented through the use of engineering features.

49. The IHCS design shall contain the analysis of:

responses of the control systems to any external and internal impacts (fires, flooding, electromagnetic noise);

responses of the systems to any possible malfunctions (short circuits, insulation quality loss, voltage drop, spurious activation, blockage of control devices, loss of control);

responses of the control systems to any failures of their components;

software reliability;

stability of the control and adjustment circuits;

technical solutions aimed to prevent unauthorized positive reactivity insertion and blocking of the EP signals not provided in the RP and NPU designs;

technical solutions aimed to prevent any human errors and to mitigate their consequences;

operability or operability maintenance period for the control system under extreme conditions (fire, steaming, flooding, pressure increase in the room);

information load for the operator;

as well as quantitative reliability analysis for the NOCS and CSS operation.

Analysis of the control system responses shall confirm absence of any responses hazardous for the RP. In case any responses hazardous for the RP are detected in the course of operation the reactor shall be brought into the sub-critical state, and measures shall be taken to eliminate these responses and to introduce the relevant changes to the RP design.

50. The methodology for determination of the actual reactor power shall be presented and substantiated in the RP design, the permissible and actual error for this determination shall be specified, and the requirements for the accuracy class of the power measuring instruments shall be stated. The methodology for definition of correlation between neutron and thermal power shall be presented.

51. Characteristics of the hardware shall prevent any possibility for:

simultaneous withdrawal of the reactivity control devices in the quantity exceeding the design value;

unauthorized lifting of the reactivity control devices in excess of the values defined in the RP design.

52. The following lists shall be provided in the NPU design for the NPU and safety-related systems:

the list of controlled parameters;

the list of remotely controlled hardware;

the list of control algorithms.

53. The lists of interlocks and protections of the NPU hardware as well as technical requirements for their actuation conditions shall be substantiated in the NPU design and presented in the SAR.

54. The NPU control systems and the NPU safety systems shall include the devices for generation of the following signals:

emergency warning (acoustic alarm signal) - in cases prescribed in the RP design;

alarm signals (light and acoustic) - when the parameters reach the EP actuation setpoints and conditions;

preventive warning (light and acoustic) - in case of any deviations from the operation limits and (or) conditions;

information - on position of the CPS control devices, availability of voltage in the power supply circuits, state of the hardware.

The scope and character of indication shall be defined in the NPU design.

55. Change ranges and rates for the regulated and controlled parameters under normal operation conditions and in case of any operational occurrences including design basis accidents shall be substantiated in the NPU design and specified in the SAR.

56. Prior to the reactor start-up the reactivity control devices shall be brought into the state described in the RP design.

57. Drives of the reactivity control devices shall have intermediate position indicators, end position detectors and limit switches actuated from the control devices. Rejection of installation of intermediate position indicators for the EP control devices shall be substantiated in the RP design.

58. Safe operation conditions in the course of testing, replacement and take-down of the reactivity control devices, the CPS actuators and any other reactivity control means for repair shall be substantiated in the RP design and specified in the SAR.

59. The NOCS shall ensure automatic and (or) automated diagnostics of state and operation modes, particularly for the hardware and software of the instrumentation and control system. Hardware and software failures and damages of the control systems shall result in generation of alarms in the CCR and initiate the actions aimed to ensure the NPU safety.

60. The control system shall provide for independent information recording and storage means ("black box") required to investigate the causes of any accidents (identification of the initiating events for the accidents, actual parameters and algorithms of operation for safety-related RP systems, deviations from the design algorithms, actions of the operating personnel, state of hardware, the radiation situation parameters, conversations of the personnel). The above-mentioned means shall be protected against unauthorized access and shall retain their operability in case of any design basis and beyond design basis accidents. The scope of information to be recorded and stored shall be substantiated in the RP design.

61. All automatic control systems of the NPU shall be subject to integrated testing prior to their delivery to the ship in order to check implementation of all algorithms with due regard for interaction of individual systems through the use of the mathematical NPU model.

The relevant requirements shall be presented in the acceptance testing program for the NPU control systems.

The NOCS and CSS components shall be subject to metrological evaluation.

 

Requirements for normal operation control systems
 of the ship nuclear power units

 

62. The NOCS structure shall include the NPU instrumentation and control system ensuring control of the process equipment and the CPS part ensuring reactivity control in all normal operation modes and in case of any operational occurrences including emergency situations.

63. The methodology and procedure for calibration of the monitoring channels with the prescribed frequency in the course of the NPU operation shall be defined and substantiated in the RP design.

64. The information support system for the operator shall be provided in the NPU NOCS. Configuration of this system and the scope of information support for the operator shall be substantiated in the NPU design and specified in the SAR.

65. The shipbuilding and operating organizations shall provide for the administrative arrangements and (or) engineering features preventing unauthorized access to the NPU NOCS.

66. Configuration, structure, basic characteristics, quantity and location of the NOCS control devices and actuators shall be presented and substantiated in the RP design. The number of the drives for the NOCS control devices and actuators, their efficiency, movement sequence and speed, their operation procedure shall be substantiated in the RP design documentation and presented in the SAR.

The RP shall be equipped with the neutron flux density monitoring channels; these channels shall ensure control of at least the following parameters within the entire neutron flux density change range in the nuclear core from 10-7 to 120% of the rated value:

the neutron flux density by two independent monitoring channels with indication devices;

the neutron flux density change rate (power doubling period) by two independent monitoring channels with indication devices.

67. The hardware shall ensure the average velocity of positive reactivity insertion in step-by-step mode through the use of the CPS control device (group of control devices) not exceeding 0.07 base_1_279073_32768/s (base_1_279073_32769 - effective delayed neutron fraction). Step-by-step movement of the CPS control device shall ensure alternated increase in reactivity and automatic termination of reactivity increase followed by a pause.

68. For the CPS control devices with the efficiency above 0.7 base_1_279073_32770 reactivity increase shall be incremental starting from sub-criticality of 3 base_1_279073_32771, with the increment not exceeding 0.3 base_1_279073_32772.

69. The RP design shall provide for the recording device for reactivity registration in the course of neutron and physical measurements.

70. In case the neutron flux density monitoring range is divided into several sub-ranges these sub-ranges shall overlap each other at least within one order of the neutron flux density measurement units; automatic switching of sub-ranges shall be also provided.

71. Permissibility to combine the measuring sections of the neutron flux density monitoring channels with the measuring sections of the neutron flux density change rate monitoring channels shall be substantiated in the RP design and demonstrated in the SAR.

72. In case the neutron flux density monitoring channels specified in par. 68 of these Rules do not ensure the neutron flux density control in the course of the first nuclear core loading the reactor shall be equipped with the additional neutron flux density monitoring system. This system may be removable and installed for the nuclear core loading and refueling periods; it shall include at least two independent neutron flux density monitoring channels with indication and recording devices.

The reactivity monitoring channels shall be equipped with the automatic operability checking means and malfunction warning alarms.

73. The reactivity meter with sensors, in-process display devices, recorders, with automatic switching of the neutron flux density and reactivity ranges shall be provided in the RP design for monitoring of reactivity changes. The methodology and error of reactivity determination through the use of the reactivity meter (number and location of sensors, algorithms and constants for calculations, errors and measurement ranges) shall be substantiated in the RP design and presented in the SAR.

74. The reactor shutdown system (not performing the EP function) shall ensure the following under normal operation conditions and in case of any operational occurrences including design basis accidents:

efficiency sufficient to bring the reactor nuclear core into the sub-critical state and to maintain the sub-critical state with due regard for potential reactivity release;

fast response sufficient to bring the reactor nuclear core into the sub-critical state without any exceedance of the design limits with regard to damage of fuel elements (taking into account operation of the emergency core cooling systems).

75. In case power is adjusted through the use of the automatic power controller the power adjustment range shall be determined. The reactor power increase with the period of less than 5 seconds shall be prevented automatically.

 

III. Requirements for safety systems
of the ship nuclear power units

 

General requirements for safety systems
of the ship nuclear power units

 

76. The RP and NPU designs shall provide for control, protective, localizing and supporting NPU safety systems.

The IHCS shall be equipped with the means for protection against erroneous intervention into the software algorithms substantiated in its design.

77. The possibility to insert the EP control devices into the nuclear core directly from the CCR and the ECS bypassing the logical circuits of the NPU control system shall be provided.

78. In case of the ship capsizing the EP control devices shall be inserted into the nuclear core, particularly in case of total blackout.

79. Sub-criticality of the nuclear core after lifting of the EP control devices with all other CPS control devices inserted into the nuclear core shall be at least 0.01 (Кeffbase_1_279073_32773 0.99) for the campaign moment and the nuclear core state with the maximum effective multiplication factor.

 

Requirements for control safety systems of
the ship nuclear power units

 

80. The RP and NPU IHCS designs shall provide for the control safety systems intended to activate safety systems and to carry out their control and monitoring in the course of the assigned function performance.

81. Structure, configuration, characteristics and the operation procedure for the CSSs as well as the quantity, efficiency, location, configuration of groups, movement sequence and velocity of the reactivity control devices and the number of their drives shall be substantiated in the RP design and presented in the SAR.

82. It should be substantiated in the RP design and demonstrated in the SAR that monitoring of the neutron flux density is ensured in the course of physical start-up, and the EP function is implemented in the course of all tests and modes requiring the EP actuation with the relevant parameters.

83. Methodologies of metrological validation and calibration of the reactivity monitoring channels shall be presented and substantiated in the RP design.

84. The CSSs shall be designed in such a way so that no operator's actions would be required within the first 10-30 minutes after the alarm signal generation with the possibility for the operator's further intervention into the CSS functioning in the course of the ship damage control. It should be substantiated in the RP and IHCS designs that the RP will remain in the safe state in case of any emergency signals provided in the design without the operator's intervention within the specified period.

85. The CSS shall perform the safety functions prescribed in the design with due regard for a single failure of any component and an additional non-detectable (hidden) failure of the non-controlled CSS component affecting the accident development.

86. The algorithm for safe lifting of the EP control devices (groups of EP control devices) shall be substantiated in the RP design and the NPU operation guidelines and presented in the SAR.

87. Lifting of the EP control devices in presence of any emergency alarms shall be prevented.

88. The CSS shall prevent insertion of positive reactivity through the use of the reactivity control devices in case of any warning signals; the list of these signals shall be defined in the RP design.

89. In case of any EP control channel failure in the CSS the emergency alarm signal from this control channel shall be generated automatically. Automated operability monitoring for the EP control channels shall be provided in the CSS. In this case the information on any channel malfunction or failure in the emergency alarm generation sub-system shall be displayed.

90. Permissibility and conditions for disabling of the EP control channels if their number is more than two shall be substantiated in the RP design and demonstrated in the SAR (duration, permissible RP power value).

91. The CSS shall provide for the possibility to check generation and traveling time of the alarm signals for each EP channel without the protection activation. In the course of checking the number of the operable protection channels shall be not less than two.

92. The NPU EP shall be activated automatically:

upon reaching of the EP setpoint with regard to the neutron flux density value;

upon reaching of the EP setpoint with regard to the neutron flux density increase rate (the power doubling period in the reactor start-up mode);

according to the process control signals;

in case of voltage loss on the CPS power supply buses;

in case of power supply loss for the ionizing chambers.

93. Parameters used as the basis for generation of the alarm signals, the EP actuation setpoints and conditions as well as the time interval from the alarm signal generation to complete insertion of the EP control devices shall be substantiated in the NPU design.

94. The alarm setpoint with regard to the neutron flux density (power) increase period shall be at least 5 seconds, and the warning setpoint - at least 15 seconds.

95. The CSS shall ensure the protection function for each process parameter with at least two independent channels using the majority logic (if the number of channels is more than two) within the entire design change range for the NPU process parameters.

96. Any failure of the display, recording and diagnostic components in the EP channel shall not affect performance of the protective functions by this channel.

 

Requirements for protective safety systems
of the ship nuclear power units

 

97. The PSS shall perform its protective function regardless of the power supply source presence or absence.

98. It should be substantiated in the ship design and demonstrated in the SAR that the EP control devices without one most efficient device have:

fast response sufficient to bring the reactor into the sub-critical state without any violation of the design limits in case of emergency situations and design basis accidents;

efficiency sufficient to bring the reactor into the sub-critical state and to maintain its sub-critical state in case of design basis accidents within the period sufficient to insert other reactivity control devices into the nuclear core.

99. Two reactor shutdown systems based on different activation principles shall be provided.

100. The reactor CPS shall be designed in such a way so that to ensure emergency protection via at least the following channels monitoring the neutron flux density:

in the start-up mode (up to 5% of the rated power) - at least two neutron flux density monitoring channels independent from each other and at least two neutron flux density increase rate (power doubling period) monitoring channels independent from each other;

in the power operation mode - at least two neutron flux density monitoring channels independent from each other.

101. The EP control devices shall be activated by the EP signal from any working or intermediate positions.

102. In case the "gross weight" of the EP control devices is insufficient for long-term maintenance of the reactor in the sub-critical state engagement of any other RP shutdown system (systems) with the neutron absorbing capacity sufficient to maintain the reactor in the sub-critical state with due regard for potential reactivity release shall be provided.

103. In case the reactivity control devices combine normal operation and emergency protection functions the procedure for their functioning shall be developed and substantiated, and the EP function priority shall be ensured.

104. The emergency cooldown system shall be provided for emergency cooldown of the NPU.

Configuration, structure and characteristics of the emergency nuclear core cooldown system shall be substantiated in the ship design.

105. The emergency nuclear core cooling system shall be provided to arrange heat removal from the nuclear core in case of any accidents with the reactor coolant circuit leakage. The instant rupture of the circuit pipeline with the maximum cross-section at the rated reactor power shall be assumed as the maximum design basis accident for calculations of the emergency cooling system. Damage of the nuclear core fuel elements shall not exceed the design safe operation limits.

Configuration, structure and characteristics of the emergency nuclear core cooling systems shall be substantiated in the ship design.

106. The ship design shall provide for the arrangements aimed to prevent the reactor transfer into the critical state and exceedance of the permissible pressure in the reactor coolant circuit upon activation and during operation of the emergency cooldown systems and the emergency reactor core cooling systems.

107. The PSS redundancy shall be substantiated in the ship design and demonstrated in the SAR.

108. The PSS components shall provide the possibility for periodic inspections in normal operation modes; in this case functional availability of these systems for performance of safety functions shall be ensured.

 

Requirements for localizing and supporting
safety systems of the ship

 

109. Localizing and supporting safety systems of the NPU shall perform their functional purpose to the full extent and comply with the requirements of regulatory documents in the area of atomic energy use. Redundancy of these systems shall be substantiated in the ship design and demonstrated in the SAR.

 

IV. Nuclear material handling system

 

General provisions

 

110. In case the NM handling and storage system providing for receiving and temporary storage of non-irradiated fuel assemblies, unloading of irradiated fuel assemblies from the reactor nuclear core and IFA loading into the storage tanks, preparation and loading of NIFA into the reactor nuclear core is present on the ship safety analysis in the course of fresh and irradiated nuclear fuel handling shall be presented in the SAR.

111. Basic nuclear safety principles and criteria implemented in the design and process flow diagram of the NM handling and storage system, the list of permissible values of the controlled system parameters in all operation modes of its components, compliance of the repositories and their systems (components) with the requirements of effective safety rules for storage and transportation of nuclear fuel in the storage facilities referred to safety class 3 shall be presented in the SAR.

112. Analysis of the NM handling system presented in the SAR shall contain:

description of functioning and nuclear safety assurance under normal operation and in case of any operational occurrences including emergency situations, design basis and beyond design basis accidents;

substantiation of the operation limits and conditions for nuclear safety assurance in the course of the NM handling and storage system operation. Assurance of integrity and leak-tightness prescribed in the design under static and dynamic loads in normal operation conditions and in case of emergency situations shall be demonstrated for safety-related systems.

 

Storage facilities for new fuel assemblies

 

113. In case any room for temporary storage of non-irradiated fuel assemblies is present on the ship nuclear safety shall be ensured in the course of their storage and performance of any process operations for their receiving, temporary storage, preparation for loading and loading into the reactor nuclear core.

The NIFA storage facility shall be equipped with the hardware for radiation and nuclear safety monitoring.

114. Characteristics important for nuclear and radiation safety analysis to be checked at the incoming control station shall be specified for each NIFA type, and the incoming control techniques and methods shall be described.

115. The NIFA storage room shall be equipped with the systems for maintenance of the prescribed micro-climate complying with the technical specifications for their storage, the drainage system, the stationary SSCR alarm system. Arrangement of any steam pipelines in the storage room is prohibited. Pipelines with other working media shall have permanent joints.

116. The NIFA storage devices shall ensure fixed position of the NIFA in case of the ship heeling and trim differential, particularly in case of capsizing.

117. Safe quantity of non-irradiated fuel assemblies stored outside of the packages in the course of the NIFA preparation for loading into the reactor nuclear core and at the incoming control stations shall be defined in the NPU design.

118. The areas for incoming control of non-irradiated fuel assemblies, their preparation for loading into the reactor nuclear core (if any are present on the ship) shall be equipped with two-way double-channel communication with the reactor refueling control station.

119. The process equipment for handling and transportation operations in the NIFA storage facilities shall prevent any damage of the NIFA containers or NIFA themselves in the course of handling and transportation operations.

120. The NIFA storage facility shall have two-way double-channel communication with the CCR, the ECS and control stations for NIFA handling on the ship.

120. The NIFA storage facility shall be equipped with the engineering features aimed to ensure the NIFA storage conditions prescribed in the technical specifications.

 

Storage facilities for irradiated fuel assemblies

 

122. The on-board IFA storage facility (if any is provided on the ship) shall have radiation protection ensuring the equivalent dose rate on the external surfaces not exceeding the value established by the effective sanitary rules and regulations in the area of radiation safety assurance. It shall be equipped with locking devices for individual cells, sections and the entire storage facility aimed to prevent uncontrollable opening in case of any change of the ship spatial attitude. The capacity of the storage facility shall ensure the design number of the reactor refuelings within the specified service life. The IFA storage facility shall be equipped with the engineering features for storage of damages irradiated fuel assemblies and performance of any transportation and handling operations with them.

123. Design of the IFA storage facility shall ensure:

nuclear and radiation safety, prevention of  SSCR occurrence under any IFA storage conditions;

holding of the irradiated fuel assemblies within the period sufficient for reduction of their radioactivity and heat emission to the levels enabling their unloading; prevention of  temperature increase for the fuel element claddings in the course of storage and transportation and handling operations in excess of the normal operation values in case of any operational occurrences including design basis accidents;

location of the equipment for performance of all process operations with irradiated fuel assemblies in isolated rooms;

location of the independent exhaust ventilation channel;

prevention of any unintended releases of radioactive substances;

air sampling;

prevention of the room flooding.

124. The following shall be provided in the system for residual heat removal from the irradiated fuel assemblies in the course of their storage in the repository:

redundant heat removal channels and make-up of any coolant losses from the heat removal circuits;

redundant power supply of the instrumentation and control systems, pumps of the heat removal systems;

automatic and remote control of the pumps;

remote control of the valves;

state indication for the equipment in the control rooms;

the possibility for cooling water supply in the course of dockage;

radioactivity monitoring for the cooling circuit coolants with alarms in case of any deviations from the safe operation limits;

purification of the curcuits from radioactive and mechanical impurities through the use of regular means.

125. The IFA storage facility shall comply with the safety requirements - radiation exposure for the crew and the special personnel, the public and the environment under normal operation conditions and in case of any operational occurrences up to design basis accidents inclusive shall not result in any exceedance of the established exposure doses for the crew, the special personnel and the public, as well as norms for releases, discharges and content of radioactive substances in the environment.

 

V. Commissioning of the
ship nuclear power unit

 

General provisions

 

126. The NPU commissioning shall include:

obtaining of all necessary construction and mooring certificates with regard to the NPU and safety systems;

staffing, training and admittance of the trail crew personnel to performance of their duties;

inspection and testing of the NPU systems and components, preparation of the reactor and fuel assemblies for loading into the reactor;

fueling of the nuclear core, the set of potentially hazardous works for completion of installation of the reactor cover and the drives of the CPS actuators, adjustment and testing of the RP equipment, preparation for physical start-up.

physical start-up of the reactor;

integrated testing of the NPU in the course of the ship harbour acceptance testing;

the NPU testing in the course of the ship sea acceptance testing;

delivery of the transportable nuclear power unit for testing at the operation site (for FPUs);

testing of the transportable nuclear power unit at the operation site (for FPUs);

acceptance testing of the ship (in the shipbuilding organization or at the operation site);

issuance of the technical, operation, administrative and acceptance documentation.

127. Acceptance of the ship for operation, completion inspection for construction, adjustment and integrated tests of all NPU systems shall be performed by the acceptance committee.

 

Nuclear core loading

 

128. The systems and components ensuring the state monitoring for the reactor and the reactor coolant circuit shall be prepared prior to the nuclear core loading into the reactor. Inspection of the RP and organization preparedness for the nuclear core fueling shall be performed by the shipbuilding organization commission with involvement of the representative (representatives) of the  inter-regional territorial directorate for supervision of nuclear and radiation safety of the state regulatory authority for safety in atomic energy use (hereinafter - the ITD).

129. Loading of the nuclear core shall be carried out based on the positive results of the performed inspection with regard to preparedness of the shipbuilding organization, the ship equipment, the trial crew personnel engaged in the loading and subject to availability of the following documents:

the nuclear core loading program;

the list of systems and equipment required for the nuclear core loading (approved by the RP designer);

the shipbuilding organization certificate confirming readiness of the systems and equipment required for the nuclear core loading, availability of the technical documentation, preparedness of the ship trial crew and the shipbuilding organization departments for performance of the loading works;

nuclear safety guidelines for the reactor nuclear core loading;

orders of the shipbuilding organization on appointment of the manager in charge of the nuclear core loading and physical start-up of the nuclear reactor, admittance of the watch personnel to works, including participation of any external organization representatives particularly the operating organization, organizations of the research advisor and chief engineers;

guidelines on the trial crew personnel actions in case of any emergency situations.

The inspection results shall be registered in the certificate.

130. Loading of the nuclear fuel into the nuclear core shall be carried out in accordance with the nuclear core loading program and the nuclear safety guidelines. The program shall contain the information on any nuclear safety assurance measures in the course of nuclear fuel loading into the reactor, the loading procedure, characteristics of the neutron power monitoring channels.

131. The nuclear fuel loading shall be carried out through the use of neutron sources, with the CPS control devices inserted into the nuclear core, fixed reliably in the lower position and ensuring the reactor sub-criticality of at least 0.02 and with the neutron flux monitoring via at least two independent monitoring channels.

 

Physical start-up of the reactor

 

132. Inspection of the NPU readiness for physical start-up shall be performed by the shipbuilding organization commission with involvement of the ITD representative.

133. Physical start-up of the reactor shall be carried out based on the positive results of the performed inspection with regard to preparedness of the shipbuilding organization, the ship, the trial crew personnel and other workers engaged in physical start-up of the reactor.

134. The harbour acceptance (commissioning) testing of the systems and equipment shall be completed prior to commencement of the reactor physical start-up, and the relevant mooring certificates shall be obtained for:

the radiological control system;

the power supply system including backup and emergency power supply;

the emergency alert system;

the fire extinguishing system;

the airlock;

the controlled access area ventilation systems;

telephone and loudspeaker communication.

Readiness of the systems and equipment for physical start-up shall be confirmed, and the following documentation shall be prepared:

the physical start-up program;

the physical start-up methodology;

nuclear safety guidelines for physical start-up;

the NPU operation manual;

the list of systems and equipment required for the physical start-up (approved by the RP designer);

guidelines on the trial crew personnel actions in case of any emergency situations;

technical documentation of the NPU including descriptions of the equipment and safety-related systems;

operation documentation (daily logs, order books, maintenance records).

Orders of the shipbuilding organization on appointment and admittance of the following personnel shall be approved:

the physical start-up supervisor and his/ her deputy;

the trial crew personnel including participation of any external organization representatives particularly the operating organization, organizations of the research advisor and chief engineers;

the duty physicists (the representatives of the RP designer and the research advisor organization may be engaged as the supervisor in charge and the duty physicists subsequent to issuance of the work permits by the shipbuilding organization).

The following shall be approved:

protocols of exams passed by the trial crew personnel for admittance to the reactor control;

job descriptions of the trial crew personnel;

the provisions defining the liabilities of the physical start-up supervisor and his/ her deputy;

certificate of drilling carried out to check preparedness of the shipbuilding organization for implementation of any arrangements aimed to protect the workers (personnel) in case of any nuclear and radiation accidents with indication of the results.

135. The readiness certificates and construction certificates for the following equipment and systems shall be issued prior to commencement of physical start-up:

the reactor with the nuclear core;

the NPU reactor coolant circuit system;

instrumentation and control systems, safety systems (the CPS, the emergency reactor cooling system);

the start-up neutron source (in case of its absence in the nuclear core);

additional start-up equipment (in case of necessity);

other process systems within the scope required for physical start-up of the reactor.

The trial crew personnel shall adhere to the procedure for registration of the permit for the reactor bringing into the critical state in the order book prescribed in the NPU operation manual.

136. All orders and actions related to physical start-up of the nuclear reactor shall be registered in the order book and the daily log of the NPU control room.

137. Results of physical start-up shall be recorded in the report and registered in the nuclear core data sheet.

 

Integrated testing of the nuclear power unit
in the course of the ship harbour and sea acceptance testing

 

138. Integrated testing of the NPU shall be performed by the shipbuilding organization in order to confirm installation quality for the RP systems and equipment, to check their operability and operability of the NPU in general and also to determine the basic characteristics of the NPU and its supporting systems for compliance with the contractual specifications (the nasic design, technical specifications).

Inspection of preparedness for the integrated NPU testing shall be performed by the shipbuilding organization commission with involvement of the ITD representative.

Integrated tests of the NPU shall be carried out based on the positive results of the performed preparedness inspection and analysis of the following documents:

the list of joint resolutions issued in order to change the NPU design documentation in the course of the ship construction with indication of their implementation;

the NPU integrated testing program and schedule;

copy of the shipbuilding organization order on performance of harbour acceptance testing;

the report on the reactor physical start-up results with the neutron and physical measurement protocols;

the shipbuilding organization certificate defining the NPU and ship readiness for harbour acceptance testing confirmed by the representative of the ship construction customer.

139. The integrated NPU testing programs shall provide for verification of implementation of all preventive and emergency protection algorithms of the control system prior to the NPU start-up. The control systems shall provide technical possibility for such verification.

140.  Prior to the integrated testing the NPU operators of the prototype ships shall pass training and exercising on simulators with representation of the NPU control board as well as preparedness verification after the training course completion.

141. Preparedness of the NPU operators of the prototype ships for commencement of integrated testing shall be checked by the shipbuilding organization commission involving the representatives of the organizations of the research advisor and chief engineers, the main engineering organization and the RP designer.

142. The need for the methodology and the possibility to use any engineering features for registration of the NPU parameters in the course of integrated testing of prototype ships shall be defined by the main engineering organization and the research advisor organization.

143. Redundant power supply of the NPU and the ship from onshore power supply sources or auxiliary floating craft shall be arranged in the course of integrated testing.

144. The integrated testing results shall be registered in the report with indication of the list of any RP modifications affecting its safety. The RP and IHCS designers and the main engineering organization shall introduce any changes and supplements to the SAR based on this list as well as the integrated testing results. The final adjustment of the SAR shall be carried out subsequent to the acceptance testing results by the shipbuilding organization and the main engineering organization.

145. Safety assurance in the course of a non-self-propelled ship transportation for testing at the operation site and within the acceptance testing period till the acceptance certificate signing shall be arranged by the shipbuilding organization in accordance with the design documentation developed by the main engineering organization.

Transportation of a non-self-propelled ship shall be performed with the reactors in the sub-critical state provided that the required heat removal from the nuclear core is arranged.

146. The NPU testing in the course of the ship sea acceptance testing shall be carried out in accordance with the programs and methodologies developed by the main engineering organization with due regard for the nuclear safety requirements in all operation modes.

 

VI. Operation of the ship nuclear power unit

 

147. The ship NPU operation shall be carried out by the ship crew members and the special personnel having the required qualification and admitted to unsupervised works for the ship NPU maintenance and control.

148. Admittance of the ship crew members and the special personnel to performance of certain activities shall be arranged subject to availability of permits for works in the area of atomic energy use issued by the state regulatory authority for safety in atomic energy use in accordance with the established procedure.

149. The first start-up of the ship NPU shall be permitted subject to availability of the license for the nuclear power installation operation in the operating organization.

150. The NPU operation shall be permitted subject to availability of the complete operation documentation package updated in accordance with the results of integrated testing, sea acceptance and site acceptance testing of the ship. The time limits for adjustment of the complete operation documentation package shall be specified in the ship acceptance certificate.

151. The NPU operation shall be carried out in accordance with the FRR requirements, the operation documentation and the local regulations of the operating organization.

152. The operating organization shall ensure regular inspections of the safety-related systems based on the design materials and requirements of the technical operation rules.

153. The operating organization shall develop local regulations for nuclear safety assurance in the course of the NPU operation with due regard for the operation experience.

154. The reactor power level, the power increase rates as well as pressure and temperature increase rate in the primary circuit and the level in the pressurizers shall be monitored from the moment of fuel loading into the reactor.

155. It is permitted not to monitor the power level and the power increase rate in case of long-term standstill of ship RPs with the loaded nuclear core subject to the following conditions:

no works affecting the reactor reactivity change shall be performed;

the value of the reactor Кeff not exceeding 0.98 shall be ensured;

all regular reactivity control devices shall be inserted into the nuclear core and shall be in the lowest position;

drives of the reactivity control actuators shall be de-energized, and additional measures shall be taken to prevent unauthorized power supply or manual control of these drives;

the reactor shall be in the totally depoisoned, cooled-down sub-critical state.

156. The RP operation shall be stopped in case it is impossible to comply with the established safe operation limits and conditions.

157. In case of the ship operation in extreme situations associated with the risk of wreckage the NPU shall be operated with implementation of all technical and administrative arrangements required to rescue the ship crew, the special personnel and the public.

The decision on further operation of the RP in such situations shall be made in accordance with the official duties taking into account the ship state and potential radiation hazard for the crew, the special personnel, the public and the environment in compliance with the requirements of the operation documentation and guidelines on the usage of equipment in case of accidents.

In case the ship wreckage is inevitable the arrangements aimed to bring the RP into the safe state shall be implemented in advance.

158. In order to change configuration, design, parameters of the safety-related systems and (or) components as well as the design limits their impact on safety shall be analyzed, and changes approved by the state regulatory authority for safety in atomic energy use shall be introduced into the design and the SAR prior to their implementation on the ship in accordance with the procedure established by the ship operation license conditions.

159. In case of any refurbishment (repair) of the control system directly on the ship implementation of all protective algorithms of the control system shall be checked after completion of the works without the NPU start-up.

160. The following documents shall be available on the ship together with any other documentation:

the operation license for the ship with the NPU;

operation documentation for safety-related systems;

the list and methodology of regular SRS inspections;

the NPU operation manual;

accident management guidelines;

job descriptions of the NPU personnel;

programs and methods of the neutron, physical and thermotechnical measurements in the course of operation;

the chief mechanic engineer order book;

the lists of effective local regulations approved by the operating organization with indication of their validity periods;

nuclear safety rules, standards and guidelines;

the ship damage control guidelines.

161. The operating organization shall ensure control of all activities important for the NPU safety. Results of the annual nuclear and radiation safety inspection shall be submitted to the state regulatory authority for safety in atomic energy use and to the atomic energy use governing agency within the NPU safety analysis for the past year in accordance with the procedure established in the federal rules and regulations.

162. The crew and the special personnel performing the ship NPU maintenance and control shall obtain the permits for these works.

163. The NPU shut down for decommissioning shall be deemed in operation until all nuclear fuel (if any) is removed from the reactors and storage facilities.

164. Nuclear fuel shall be unloaded from the  reactor nuclear cores and storage facilities prior to the NPU decommissioning.

 

VII. Performance of potentially hazardous works

 

165. The main engineering organization of the ship shall develop the lists of PHW and technical requirements for their performance at all stages of the ship lifecycle (construction and commissioning, repair, the reactor nuclear core refueling, the nuclear core unloading in the course of decommissioning).

166. The operation documentation for the NPU safety-related systems shall include the lists of potentially hazardous works for maintenance of these systems and information on the required safety measures in the course of PHW.

167. Methods and means for the reactor state monitoring in the course of potentially hazardous works shall be specified in the technical requirements for PHW performance.

168. The main engineering organization shall compile the unified list of potentially hazardous works and technical requirements for their performance based on the input data provided by the RP and SRS developers.

169. The unified PHW list and technical requirements for their performance shall be agreed with the ship RP and IHCS designers and the research advisor organization in accordance with the established procedure.

170. The list of potentially hazardous works in the course of refueling and the technical requirements for their performance specified in the Unified PHW List shall be additionally agreed with the refueling equipment designer (unless it is the RP designer).

171. Simultaneous performance of several potentially hazardous works on the ship with the NPU and in the IFA storage facilites shall be prohibited.

172. Performance of any other works in the room where potentially hazardous works are carried out shall be prohibited.

173. Presence of any unauthorized persons in the reactor room and NM storage facilities and engagement of any personnel not specified in the administrative documentation of the operating organization shall be prohibited within the entire PHW performance period.

174. Commencement and completion of potentially hazardous works shall be announced via the ship annunciating system, and the relevant record shall be made in the daily logs of the NPU control room with indication of the NPU state.

175. Potentially hazardous works shall be performed in compliance with the following conditions:

the PHW shall be prescribed in the list of works;

the work supervisor and work performers having the permit of the chief mechanic engineer for admittance to unsupervised works shall be appointed by the ship captain's order;

the work performers shall be trained in safety measures with the personal signature in the training log;

the written permit of the officer in charge for performance of the works shall be available;

the watch in the NPU control room shall be present, monitoring of the reactor state shall be arranged in accordance with the technical requirements for the PHW performance, continuous monitoring of the radiation situation in the reactor room shall be ensured;

supervision of the PHW performance by the persons in charge of nuclear safety shall be arranged;

the action plan for protection of the workers (personnel), confinement and mitigation of any accident consequences shall be developed;

the relevant safety systems shall be ready for activation;

two-way communication between the NPU control room and the rooms where potentially hazardous works are carried out shall be arranged via two channels.

In case of any interruptions in the course of PHW the NPU shall be brought into the safe state.

No watch relief shall be performed in the course of potentially hazardous works. Watch relief shall be performed after completion of the work stage or process operation prescribed in the operation and process documentation or the procedure and the NPU bringing into the safe state with registration of the particular safety assurance measures in the daily log.

176. In case of any deviations from the PHW technique and occurrence of a nuclear-hazardous situation performance of the potentially hazardous works shall be stopped immediately. The potentially hazardous works may be resumed after issuance of a new written permit from the work supervisor and subsequent to elimination of the detected deviation and causes of the nuclear-hazardous situation.

 

VIII. Refueling of the nuclear core

 

177. Refueling of the reactor nuclear core is a potentially hazardous work.

178. The engineering operation documentation shall contain the section "Nuclear core refueling in the overhaul period" in order to perform refueling of the reactor nuclear core in the overhaul period. The section shall contain:

description of the state peculiarities for the systems and components ensuring power supply of the NPU;

the method for assessment of residual heat emission in the nuclear core planned for refueling, numerical heat emission criteria enabling to perform refueling of the nuclear core;

the guidelines on the nuclear core refueling works through the use of the on-board equipment;

the list of potentially nuclear-hazardous works and technical requirements for nuclear safety assurance in the course of these works.

179. The operating organization shall arrange preparation of the equipment, certification of the crew and the special personnel performing the works for the reactor nuclear core refueling and obtaining of the relevant permits by the officers and shall also inform the ITD on preparedness for the works and time limits for their performance.

180. The nuclear core refueling works shall be performed after inspection of preparedness for these works by the ITD with the inspection report issuance.

181. The refueling equipment shall be developed and used for each RP type which shall prevent any possibility for a nuclear or radiation accident in the course of dismantling and installation of the reactor equipment, the NF unloading and loading through the use of hardware (preferably mechanical one) together with the reactor and the nuclear core design.

182. Configuration of the refueling equipment and the requirements thereof in order to ensure safe handling of fuel assemblies in the course of refueling particularly in case of any failure and damage of the refueling equipment as well as after a design basis accident at the RP shall be specified and substantiated in the designs of the RP and refueling equipment.

183. Requirements for installation, operation and inspection of the refueling equipment as well as the requirements for its reliability shall be specified in the basic design of the refueling equipment.

184. The following measures shall be provided in the design of refueling devices:

for prevention of damage, deformation, breakage or falling of fuel assemblies as well as application of any unacceptable forces to the fuel assemblies in the course of their wirhdrawal or installation;

for prevention of IFA overheating in the refueling containers;

for diagnostics of the refueling equipment prior to each use;

for decontamination of the refueling equipment prior to each use and after use.

185. Means for display of information on end positions of the irradiated fuel assemblies shall be provided in the refueling equipment used for the IFA unloading and transportation.

186. The following shall be defined and substantiated in the RP design:

the refueling techniques;

the refueling frequency and technology;

engineering features and administrative arrangements for nuclear safety assurance in the course of refueling including the neutron flux density monitoring in accordance with the requirements of Chapter III of these Rules;

state of the safety-related systems;

the required IFA holding period prior to unloading;

the permissible period of IFA handling without cooling.

187. The reactor nuclear core refueling shall be performed by the trained personnel through the use of operable equipment.

188. The technology and procedure for the reactor nuclear core refueling shall be defined in accordance with the refueling process agreed with the designers of the RP and the refueling equipment and shall be approved by the operating organization. Work programs, schedules and the nuclear core refueling schemes shall be developed by the refueling organization based on the refueling process and the nuclear core documentation.

189. Refueling shall be carried out with the reactivity control devices (except for the EP) completely inserted and locked in the nuclear core. The minimum reactor sub-criticality in the course of refueling with due regard for any possible errors shall be at least 0.02.

The sub-criticality assurance conditions and the method of neutron and physical monitoring in the course of refueling shall be substantiated in the RP basic design.

190. Locking of the CPS control devices shall be ensured by the reactor design for dismantling of the reactor cover.

191. Subsequent to completion of the nuclear core refueling testing of the NPU systems and equipment shall be carried out, physical start-up and neutron and physical measurements shall be performed in order to confirm the design and estimated characteristics of the nuclear core; the relevant procedure shall be defined by the documents of the operating organization.

192. The refueling results shall be registered in the reactor data sheet and the nuclear core data sheet.

 

 

 

 

 

Appendix 1
to Federal rules and regulations
 in the area of atomic energy use
"Nuclear safety rules for ships
and other floating craft with nuclear
reactors" approved by Order of the
 Federal Environmental,
Industrial and Nuclear Supervision Service
dated September, 4, 2017 No. 352

 

ABBREVIATIONS

 

EP

- Emergency Protection

PSS

- Protective Safety Systems

IHCS

 - Integrated Hardware Control System

-

- Integrated NPU Testing

NIFA

- Non-Irradiated Fuel Assembly

SAR

- Safety Analysis Report for the nuclear power unit

SSS

- Supporting Safety Systems

IFA

- Irradiated Fuel Assembly

QCD

- Quality Control Department

ECS

- Emergency Cooldown Station

PHW

- Potentially Nuclear-Hazardous Work

FPU

- Floating Power Unit

AE

- Absorber Element

RW

- Radioactive Wastes

RSb

- Radioactive Substances

RP

- Reactor Plant (Nuclear Steam Generating Plant)

SRS

- Safety-Related Systems

CPS

- Control and Protection System

SSCR

- Self-Sustaining Chain Reaction

FA

- Fuel Assembly

FE

- Fuel Element

CSS

- Control Safety System

NOCS

- Normal Operation Control Systems

FRR

- Federal Rules and Regulations in the Area of Atomic Energy Use

CCR

- Central Control Room

NM

- Nuclear Materials

NF

- Nuclear Fuel

NPU

Nuclear power unit of the ship or any other floating craft with a nuclear reactor

 

 

 

 

 

Appendix 2
to Federal rules and regulations
 in the area of atomic energy use
"Nuclear safety rules for ships
and other floating craft with nuclear
reactors" approved by Order of the
Federal Environmental,
Industrial and Nuclear Supervision Service
dated September, 4, 2017 No. 352

 

TERMS AND DEFINITIONS

 

1. Nuclear core - the part of the reactor containing nuclear fuel, moderator, poison, coolant and structural components where the controlled chain fission reaction and energy transfer to the coolant take place.

2. Active system or component - a system or component functioning of which depends from operation of any other system or component.

3. Software tool validation - the regulated procedure for acknowledgment of the possibility to use the software tool within the specified scope/ limits of application and obtaining of the calculated parameters for the software tool with the certain error finished with issuance of the document (software tool validation certificate).

4. Safe failure - a failure of any system or component when the RP is switched to the safe state without any need for initiation of any actions through the use of control safety systems.

5. Commissioning of the nuclear power unit - a part of the ship lifecycle stage when the systems, equipment and the NPU in general begin to function, and their compliance with the design is verified.

6. Activation of the nuclear power unit - the set of process arrangements in compliance with the designer's operation manual aimed to bring the NPU into the active state according to its intended purpose.

7. Protective safety systems (components) - safety systems (components) intended for performance of the functions to prevent or limit damage of nuclear fuel, FE claddings, equipment and pipelines containing radioactive substances.

8. Integrated testing - testing of the NPU systems and components and the entire NPU in all design modes and power levels up to the rated power aimed to adjust the safe NPU operation limits and conditions.

9. Compensatory measures - process and administrative arrangements ensuring compliance of the NPU operation safety level with the design requirements in case of introduction of any additional requirements for the NPU operation conditions.

10. Nuclear safety assurance - the set of design and engineering solutions, administrative and technical arrangements implemented in the course of the NPU operation and handling of fissile materials in order to prevent (with certain probability) occurrence of any nuclear accident.

11. Nuclear core refueling (refueling) - nuclear-hazardous works at the NPU for withdrawal, loading and transportation of fuel assemblies including the associated works for the RP equipment dismantling and installation.

12. Personnel - the ship crew members and also any workers of the operating organization carrying out the NPU maintenance and operation.

13. Emergency cooldown station - a dedicated area or room of the ship containing the equipment and instruments intended for shutdown of the RP and its supporting systems in case of the CCR inoperability.

14. Design basis accident - an accident with the initiating events and end states defined in the design and the provided safety systems aimed to assure mitigation of its consequences to the limits established for such accidents with due regard for the single failure principle applied to the safety systems or a human error independent from the initiating event.

15. Design service (operating) life - calendar duration of the system (component) operation or restoration of service till the system (component) reaches the limit state specified in the design documentation.

16. Radiation safety - capability of the applied engineering features and actions of the ship personnel/ crew to reduce harmful radiation exposure for the people and the environment down to the established limits under normal operation conditions and in case of any accidents.

17. Safety-related systems and components - safety systems and components of the NPU and also normal operation systems and components in case their failures can disrupt normal operation of the NPU or impair elimination of any operational occurrences and can result in design basis or beyond design basis accidents.

18. Instrumentation and control system - the system intended for control and monitoring of the NPU process equipment and generation of the alarm signals for the process parameters.

19. Control and protection system - the system intended for control and monitoring of the reactivity control devices under normal operation conditions and in emergency modes.

20. Nuclear safety state - assessment of any deviations from the normal state of systems and components in the course of the NPU operation and NM handling.

21. Technical diagnostics - determination of the technical condition of the NPU, safety-related systems and their components by monitoring and prediction of this condition, detection of failure (malfunction) points and causes.

22. Severe accident - emergency conditions more severe that a design basis accident causing significant damage of the nuclear core.

23. Physical start-up - the NPU commissioning stage and also the process (process operation) within the ship operation period including reaching of the reactor critical state and performance of the required physical measurements at the power level when heat removal from the reactor is arranged due to natural heat loss (dissipation).

24. Physical protection - activity in the area of atomic energy use carried out in order to prevent any sabotage and theft in relation to nuclear materials, nuclear installations and storage facilities.

25. Central control room - the room where automated and remote NPU control and centralized state monitoring for its systems and equipment are carried out under normal operation conditions, in case of any operational occurrences, emergency situations and accidents.

26. Harbour acceptance testing of the ship - integrated pier-side inspection of the ship systems and equipment in service including system-by-system and integrated testing of the NPU in all operation modes.

27. Operation of the nuclear power unit - activity aimed to achieve the purpose of the ship (or any other floating craft with a nuclear reactor) NPU construction in a safe manner, including power operation, start-ups, shutdowns, testing, maintenance, repair, preservation, the nuclear core refueling.

28. Nuclear accident - any accident associated with the fuel element damages exceeding the established operation limits and (or) radiation exposure for the crew and (or) the special personnel in excess of the permissible limits caused by:

any disturbances of the chain nuclear fission reaction control and monitoring function in the reactor nuclear core;

criticality occurrence in the course of refueling, transportation and storage of fuel elements;

loss of heat removal from fuel elements;

any other causes resulting in damage of fuel elements.

29. Nuclear safety - the set of the NPU properties, conditions of the engineering features and administrative arrangements preventing any nuclear accident occurrence with certain probability.

30. Nuclear reactor - the part of the ship NPU intended for arrangement of the controlled chain nuclear fission reaction for the purpose of thermal energy generation.

 

 

 

 


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