Переводы документов. Translations in English

NP-033-11. General safety provisions of nuclear research installations

Approved by

Approved by

Order of the Federal

Environmental, Industrial

and Nuclear Supervision Service

dated 30 June 2011 No. 348

 

FEDERAL RULES AND REGULATIONS

IN THE FIELD OF ATOMIC ENERGY USE "GENERAL

SAFETY PROVISIONS OF NUCLEAR

RESEARCH INSTALLATIONS"

NP-033-11

 

I. GENERAL

 

1.1. Purpose and scope

 

1.1.1. These Federal Rules and Regulations in the Field of Atomic Energy Use "General safety provisions of nuclear research installations" (hereinafter referred to as NRI Safety Provisions) were developed in compliance with Federal Law No. 170-FZ dated 21 November 1995 "On Atomic Energy Use" (Collected Acts of the Russian Federation 1995, N 48, art. 4552; 1997, N 7, art. 808; 2001, N 29, art. 2949; 2002, N 1, art. 2; N 13, art. 1180; 2003, N 46, art. 4436; 2004, N 35, art. 3607;  2006, N 52, art. 5498; 2007, N 7, art. 834; N 49, art. 6079; 2008, N 29,  art. 3418; N 30, art. 3616; 2009, N 1, art. 17; N 52, art. 6450).

1.1.2. The NRI Safety Provisions establish:

1) basic terms and definitions related to safety of nuclear research installations;

2) the purpose and basic principles of safety assurance for nuclear research installations;

3) general requirements for safety assurance at nuclear research installations of various types as well as specific requirements for reactor plants, critical and sub-critical test stands, sub-critical accelerator-driven systems as potential sources of radiation exposure for the workers (personnel), the public and the environment.

1.1.3. The requirements of the NRI Safety Provisions shall be applicable to designed, constructed, operated and decommissioned nuclear research installations.

1.1.4. The abbreviations used are given in Appendix 1, and terms and definitions are given in Appendix 2 to these NRI Safety Provisions.

 

1.2. Purpose and basic principles of safety assurance

of nuclear research installations

 

1.2.1. The purpose of NRI safety assurance is to limit radiation impact of the NRI on the workers (personnel), the public and the environment under normal operation conditions and in case of abnormal operation including accidents.

1.2.2. The NRI meets the safety requirements if its radiation impact on the personnel, the public and the environment under normal operation conditions and in case of abnormal operation including design basis accidents does not lead to exceedance of the established radiation exposure doses for the personnel and the public, releases (discharges) and content of radioactive substances in the environment and is also limited in case of beyond design basis accidents.

1.2.3. The NRI safety shall be provided by implementation of the defense-in-depth principle based on the system of physical barriers in the way of ionizing radiation and radioactive substances propagation into the environment and the system of technical and administrative measures for maintenance of the physical barriers efficiency as well as for protection of the workers (personnel), the public and the environment against radiation impact of the NRI.

1.2.4. The number and purpose of the NRI physical barriers shall be defined in the NRI design. Sufficiency of the physical barriers used at the NRI, technical and administrative defense-in-depth measures shall be substantiated in the NRI design and presented in the NRI SAR.

1.2.5. The system of technical and administrative defense-in-depth measures shall take into account potential radiation impact of the NRI on the workers (personnel), the public and the environment and shall form the following five levels.

The first level - the NRI location conditions, the NRI design quality and prevention of abnormal operation:

1) assessment and selection of the area and site suitable for the NRI location;

2) development of the design based on the conservative approach with maximum use of the inherent safety features;

3) application of verified and validated programs and methods for calculations of the NRI nuclear core, systems and equipment, experimental substantiation of the main design solutions;

4) quality assurance for the NRI systems (components) and any works performed in the course of the design development, manufacturing, installation and adjustment of equipment;

5) assurance of the required proficiency level for the workers (personnel);

6) operation of the NRI in accordance with the requirements of the RP process regulations and the NRI operation guideline;

7) maintenance of operable state for safety-related systems (components), replacement of faulty equipment or equipment with expired lifetime or its service life extension in accordance with the established procedure.

The second level - prevention of design basis accidents by the normal operation systems:

1) timely detection of any NRI operational occurrences and their elimination;

2) control during abnormal operation.

The third level - prevention of design basis and beyond design basis accidents by safety systems:

1) prevention of development of initiating events into design basis accidents and the design basis accidents into beyond design basis accidents;

2) mitigation and elimination of accident consequences through the use of LSSs.

The fourth level - beyond design basis accident management:

1) prevention of development of beyond design basis accidents and mitigation of their consequences;

2) bringing of the NRI into the controlled state.

The fifth level - emergency planning:

1) development and implementation of emergency action plans.

1.2.6. The defense-in-depth principle shall be implemented at all stages of activities related to the NRI safety assurance. In this case the strategy for prevention of adverse events shall be in priority especially for the first and the second level.

1.2.7. Technical and administrative solutions adopted for the NRI safety assurance shall be well proven by the previous experience or testing, studies, operation experience and shall comply with the requirements of federal regulations and rules in the field of atomic energy use. This approach shall be applied in the course of design, development and manufacturing of the equipment, construction, operation, refurbishment, retrofitting and decommissioning of the NRI.

1.2.8. All works affecting the NRI safety shall be accompanied with quality assurance activities, in this case the operating organization shall arrange development and implementation of the general quality assurance program for the NRI and supervise quality assurance by any organizations performing works and (or) rendering services to the operating organization.

1.2.9. Safety culture shall be formed and maintained in the operating organization and any organizations performing works and (or) rendering services to the operating organization by selection, training and preparation of the workers (personnel) in each area of safety-related activities, establishment and strict adherence to the discipline rules with clear distribution of personal responsibility among the managers and executives, development and strict adherence to the job instructions and their regular updating with due regard for the gained experience.

1.2.10. The operating organization shall ensure the NRI safety including development of measures for prevention of accidents and mitigation of their consequences, accounting, control and physical protection of nuclear materials, radioactive substances and radioactive waste, radiological control of the environment in the sanitary-protective area and the supervised area.

The operating organization shall bear full responsibility for the NRI safety, in this case it shall provide technical safety in operation of pressure vessels, hoisting, transportation and electrical equipment, complex technical devices, in the course of electrical installation, construction and erection works and shall prevent accidents accompanied with fires and explosions.

 

II. CLASSIFICATION OF SYSTEMS AND COMPONENTS OF NUCLEAR

RESEARCH INSTALLATIONS

 

2.1. The NRI systems and components including experimental devices are distinguished in accordance with:

1) purpose;

2) impact on safety;

3) nature of the performed safety functions.

2.2. The NRI systems and components are classified as follows in accordance with their purpose:

1) normal operation systems and components;

2) safety systems and components.

2.3. The NRI systems and components are classified as follows in accordance with their impact on safety:

1) safety-related;

2) non-safety-related.

2.4. Safety systems and components are classified as follows in accordance with the nature of performed safety functions:

1) protective;

2) localizing;

3) supporting;

4) control.

2.5. The NRI components are divided into four safety classes.

Safety class 1. Safety class 1 includes the NRI components failures of which represent initiating events for beyond design basis accidents resulting in damage of nuclear fuel and other NRI components and exceedance of the limits established for design basis accidents with the safety system functioning as per the design.

Safety class 2. The following NRI components are referred to safety class 2:

1) components failures of which represent initiating events resulting in damage of nuclear fuel and other components of the NRI core and also the primary reactor circuit within the limits established for design basis accidents with the safety system functioning as per the design taking into account the number of their failures specified for design basis accidents;

2) components of safety systems failures of which result in failure of the corresponding systems to perform their functions.

Safety class 3. Safety class 3 includes the following components:

1) safety-related systems not included in safety classes 1 and 2;

2) components containing radioactive substances in case release of these substances to the rooms and the environment upon failure of these components exceeds the radiation exposure limits for the workers (personnel), the public and the environment established for normal operation conditions;

3) components performing the functions of radiological control and radiation protection of the workers (personnel) and the public.

Safety class 4. Class 4 includes non-safety-related normal operation NRI components not included into classes 1, 2 and 3. Components used for accident management and not included into safety classes 1, 2 and 3 shall be also referred to safety class 4.

2.6. In case any component has features pertaining to different safety classes it shall be attributed to a higher safety class.

2.7. Sections of the systems separating any components of different safety classes shall be referred to a higher safety class.

2.8. Safety class is an obligatory aspect to be considered in formation of any other classifications of the NRI components set in the regulatory documents. Other aspects of these classifications shall be established in accordance with the set of regulated characteristics for the NRI components.

2.9. Safety classes of the NRI components shall be determined in the design according to the requirements of the NRI Safety Provisions.

2.10. The quality requirements for the NRI components referred to safety classes 1, 2 and 3 and the requirements for quality assurance shall be established in the federal regulations and rules in the field of atomic energy use regulating arrangement and operation of the NRI components. In this case the above-mentioned regulatory documents shall set more stringent requirements for quality and quality assurance of the components referred to higher safety classes.

Components referred to safety class 4 shall be subject to the requirements of general industrial technical and regulatory documents.

2.11. Pertaining of components to safety classes 1, 2 and 3 and application of the requirements of federal regulations and rules in the area of atomic energy to these components shall be specified in the documentation for development, manufacturing and supply of the NRI systems and components.

2.12. Classified designation of the component reflects its pertinence to safety classes 1, 2, 3.

2.13. Classified designation shall be supplemented with the following symbol reflecting the purpose of the component and the nature of safety functions performed by this component:

N - normal operation component;

Z - protection component;

L - localizing component;

O - support component;

U - CSS element.

If a component has multiple purposes all the purposes are to be included in the component designation. Examples of class designations: 2N, 2Z, 2NZ.

 

III. REQUIREMENTS FOR THE DESIGN OF A NUCLEAR

RESEARCH INSTALLATION

 

3.1. General requirements

 

3.1.1. The following shall be provided in the NRI design:

1) normal operation systems and safety systems with the configuration and technical arrangement taking into account specific features of the NRI and complying with the requirements of the NRI Safety Provisions;

2) the site (room) for permanent and (or) temporary storage of nuclear materials, storage and preparation of experimental devices for use at the NRI;

3) the transportation and handling scheme and equipment for loading (reloading) of nuclear materials to the core and also for safe storage and removal of nuclear materials from the NRI site;

4) storage facilities or specially equipped areas (sites) for safe storage of radioactive waste;

5) methods and equipment for collection, processing, conditioning and storage of radioactive waste;

6) equipment for transportation of radioactive waste within the NRI site and for final disposal;

7) systems for purification of the air released into the environment and the discharged water from any contained radioactive substances;

8) equipment and administrative measures for protection of safety-related systems and information on safety-related parameters against any unauthorized access;

9) techniques for decontamination, fragmentation and dismantling of equipment in the course of the NRI decommissioning;

10) technical methods and means for explosion protection and fire protection of the NRI equipment and rooms including:

1. use of fireproof and (or) slow-burning structural materials;

2. restricted use of fire- and explosion-hazardous materials;

3. use of materials preventing sparking in case of any impact that can initiate detonation of explosion-hazardous medium;

4. use of fire- and explosion-proof electrical equipment;

5. use of fire-resistant cables in any systems  where ignition and fires are possible in the course of operation;

11) the range, amount and storage locations for the personnel protection equipment, medicines, radiological and dosimetric control devices, equipment for emergency response and recovery works at the NRI;

12) independent means for registration and storage of any information required for investigation of accidents, in this case the above-mentioned means shall be protected against unauthorized access and shall maintain their operability under design basis and beyond design basis accidents;

13) arrangements in case of any natural disasters, internal and external impacts including fires and accidents at the NRI;

14) a separate section containing the NRI vulnerability analysis and sufficiency substantiation for any physical protection measures provided in the NRI design.

3.1.2. The NRI design shall give preference to systems (components) with the structure based on the passive principle of action and inherent self-protection properties.

3.1.3. The NRI design shall provide for the possibility of direct and complete verification of SRS compliance with the design parameters in the course of commissioning, after repair and regularly within the entire service life of the NRI, and in case in it impossible - for indirect and (or) partial verification with substantiated frequency.

In the course of operation maintenance and inspections of safety systems and safety-related normal operation components shall be performed in compliance with the safe operation limits and conditions established in the design and specified in the NRI SAR. Frequency and permissible period of maintenance and inspections shall be justified in the NRI design.

3.1.4. Measures for protection of systems (components) against common cause failures shall be considered and substantiated in the NRI design.

3.1.5. The NRI design shall provide for application of technical solutions preventing human (personnel) errors or mitigating their consequences in particular during maintenance of safety-related NRI systems.

3.1.6. Absence of certain hardware, systems and equipment prescribed in the NRI Safety Provisions in the RP, CTS, STS or SADS design shall be substantiated in the NRI SAR with due regard for the results of analysis of any potential radiation impact of the NRI on the workers (personnel), the public and the environment.

3.1.7. The following shall be defined in the NRI design:

1) neutron and physical, thermohydraulic and other safety-related NRI characteristics;

2) the NRI operation modes, operation limits and conditions, safe operation limits and conditions for the NRI with due regard for all controlled neutron and physical, thermohydraulic and other safety-related characteristics;

3) the list of nuclear-hazardous works at the NRI and safety assurance measures in the course of these works;

4) conditions and frequency of the NRI neutron and physical characteristics checks for compliance with the design;

5) reliability parameters for normal operation NRI systems, safety-related systems and their components referred to safety classes 1 and 2 and also safety systems and their components;

6) the list of building structures, equipment, automation means and other systems (components) of the NRI subject to certification in accordance with the established procedure;

7) classification of the NRI rooms in accordance with their explosion and fire safety;

8) conditions, scope and frequency of maintenance and inspection for the safety-related NRI systems;

9) conditions for actuation of the NRI safety systems and levels of external impacts requiring fast shutdown of the research reactor (power reduction) and (or) bringing of the research reactor to sub-critical state in case of their exceedance;

10) the list of initiating events for design basis accidents and the list of beyond design basis accidents, assessment of accident probability and development scenarios;

11) probability of the maximum permissible emergency release from the NRI;

12) dose quota for the NRI with due regard for the peculiarities of the NRI location area;

13) the NRI service life, equipment lifetime and criteria for decisions on its replacement.

3.1.8. The following shall be substantiated in the NRI design and the NRI SAR:

1) safety of the NRI in case of any initiating event for design basis accidents at the NRI with a coincident (in accordance with the single-failure principle) single failure of any active component or passive component of any safety system with mechanical moving parts independent from the initiating event or a human (personnel) error independent from the initiating event;

2) frequency of the maximum emergency release from the NRI requiring any decisions on the public protection not exceeding base_1_118820_327681/year per a NRI;

3) absence of any radiation impact of the CTS beyond the sanitary-protective area under normal operation conditions and in case of abnormal operation and potential accidents;

4) absence of any radiation impact of the STS outside the sub-critical assembly rooms under normal operation conditions and in case of abnormal operation including accidents.

 

3.2. Normal operation systems of a nuclear

research installation

 

3.2.1. Nuclear core and reflector of a nuclear

research installation

 

3.2.1.1. The NRI nuclear core and the reflector shall be designed in such a way so that to ensure portion loading (reloading) of nuclear materials, and the NRI could be brought into sub-critical state in all operation modes and in case of design basis accidents.

3.2.1.2. The design of the NRI nuclear core and the reflector shall prevent any unintended changes of their geometry and configuration.

3.2.1.3. Materials for fuel elements, fuel assemblies and other core components, the reflector and the CPS control devices shall be selected with due regard for any changes of their thermal and technical, mechanical, physical and chemical properties in the course of operation.

3.2.1.4. Nuclear materials used within the core, the design of the NRI core and the reflector shall prevent formation of secondary critical masses in case of any beyond design basis accidents with the NRI destruction.

3.2.1.5. The power coefficient of reactivity, reactivity coefficients with regard to the temperature of the coolant and nuclear materials in the RP and SADS core shall not be positive within the entire range of the RP and SADS parameter changes under normal operation conditions and in case of abnormal operation including design basis accidents.

3.2.1.6. The NRI design shall establish the operation limits for damage of fuel elements or radioactivity levels for the primary circuit coolant.

3.2.1.7. Deformation of the core components under normal operation conditions and in case of abnormal operation including design basis accidents shall not result in any deterioration of heat removal conditions and exceedance of the maximum permissible temperature of the core components.

3.2.1.8. The nuclear core and the reflector of the research reactor shall have such neutron and physical characteristics so that any reactivity changes under normal operation conditions and in case of abnormal operation including design basis accidents could not result in any damage of the core components and items located in the experimental loop exceeding the established limits or in exceedance of the specified coolant radioactivity level.

 

3.2.2. Primary circuit of a nuclear research installation

 

3.2.2.1. The design of the NRI primary circuit shall ensure heat removal from the nuclear core eliminating any temperature regimes for the core components, experimental devices and coolant deviating from the temperature and temperature change rate limits established in the NRI design for normal operation conditions and abnormal operation including design basis accidents.

3.2.2.2. Corrosive and chemical, neutron and physical, radiation, thermal, hydraulic and any other impacts possible under normal operation conditions and in case of abnormal operation including design basis accidents shall be taken into account in selection of the materials and determination of the service life for the NRI primary circuit.

3.2.2.3. The NRI primary circuit systems and components shall withstand static and dynamic loads and temperature impacts under design basis accidents.

3.2.2.4. The NRI design shall define the requirements for chemical composition of the coolant as well as the requirements for any means for the coolant purification from radioactive corrosion and fission products.

3.2.2.5. The design and layout of the NRI primary circuit shall eliminate any possibility for unintended coolant drainage from the nuclear core and experimental loops.

3.2.2.6. In development of the equipment layout and selection of the NRI primary circuit geometry it is necessary to strain after natural circulation development and assurance of its efficiency sufficient to prevent damage of fuel elements and other core components in excess of the limits established in the NRI design in case of any loss of the forced coolant circulation.

3.2.2.7. The NRI primary circuit with liquid-metal coolant and solution of nuclear materials shall not contain any non-draining dead zones.

3.2.2.8. The design of the NRI with solution of nuclear materials shall provide for the possibility to perform decontamination of the primary circuit in assembled state.

3.2.2.9. The NRI design shall provide for the means and methods aimed to ensure:

1) quality control for the basic metal and weld joints;

2) leak-tightness control of the primary circuit;

3) quality control for the coolant and its purification from any fission and corrosion products;

4) protection against impermissible overpressure in the primary circuit in case of any pre-accident situations and design basis accidents;

5) monitoring and registration of the parameters required to assess the residual lifetime for the primary circuit components.

 

3.2.3. Normal operation control systems of a

nuclear research installation

 

3.2.3.1. Normal operation control systems of the NRI shall ensure automated and (or) automatic control of the process equipment in order to achieve and maintain the NRI technical characteristics within the prescribed range.

3.2.3.2. The NRI design shall provide for the means and methods aimed to ensure:

1) neutron flux density control in all operation modes in particular in the course of the NRI core fueling (refueling);

2) the NRI control including control of the external neutron source; rising to the prescribed power level and maintenance of the power with the accuracy specified in the NRI design;

3) diagnostics of the equipment and automation devices of safety-related systems;

4) informational support for the NRI control room personnel for the purposes of accident management;

5) control of radionuclide releases and discharges as well as the radiation situation in the rooms and at the NRI site;

6) control of absence of any leaks of coolant (moderator) in the heterogeneous research reactor, moderator of the critical assembly, nuclear material solution in the homogeneous reactor;

7) control of compliance with the conditions for safe storage of nuclear materials and radiation sources.

3.2.3.3. The lists of controlled parameters of the NRI, the lists of regulated parameters and control signals as well as the list of the NRI parameters that determine activation of safety systems shall be given and substantiated in the NRI design.

3.2.3.4. In case an automatic power controller is used within the CPS the NRI design shall define the power range within which adjustment is performed through the use of the automatic controller; the automatic controller characteristics shall be also specified and substantiated.

3.2.3.5. The NRI design shall contain the following analyses:

1) responses of the normal operation control system to any potential failures in the system and external impacts;

2) reliability of functioning of the automation means and the normal operation control system in general;

3) technical measures preventing unauthorized insertion of positive reactivity and interlocking of the SS actuation signals.

3.2.3.6. The NRI normal operation control system shall generate light and acoustic signals on the control room panels (boards) in case of any exceedance of operation limits and conditions and safe operation limits and conditions.

3.2.3.7. Malfunction of the control and monitoring channels of the NRI normal operation control systems shall result in actuation of the alarm informing the control room workers (personnel) on the state of the normal operation control system.

 

3.3. Safety systems of a nuclear

research installation

 

3.3.1. General requirements

 

3.3.1.1. The NRI design shall provide for safety systems performing the following safety functions:

1) automatic shutdown of the NRI in case of any deviations from safe operation limits and conditions and maintenance of the NRI in sub-critical state for an infinite period of time;

2) emergency heat removal from the research reactor core;

3) confinement of radioactive substances within the established boundaries under normal operation conditions and in case of design basis accidents and limitation of their propagation into the environment in case of any beyond design basis accidents at the NRI.

3.3.1.2. The NRI safety systems shall be capable of performing safety functions within the scope specified in the NRI design with due regard for the impact of natural phenomena and external human-induced events typical for the NRI location area and any possible mechanical, thermal, chemical and other impacts under design basis accidents.

3.3.1.3. Safety systems shall comply with the single failure principle.

3.3.1.4. Safety principles aimed to enhance reliability of safety systems including the principles of safe failure, redundancy, independence as well as the principle of diverse ways for performance of the SS functions shall be applied in the course of SS development.

Application of the principles of redundancy, independence and diversity shall ensure operability of safety systems in case of any single failure.

3.3.1.5. Safety systems shall be separated from normal operation systems so that any malfunction or withdrawal of any normal operation system component (channel) from service could not affect the SS capability to comply with the prescribed safety assurance requirements.

3.3.1.6. Multi-purpose use of safety systems and their components shall be justified. Combination of functions shall not result in any violations of the safety assurance requirements and reduction of the prescribed reliability of the systems (components).

3.3.1.7. Safety systems shall be designed in such a way so that at least two sequential actions of the operator would be required in order to return the system to the initial state.

3.3.1.8. Conditions, scope and frequency of operability checks and testing of safety systems for compliance with the design characteristics shall be provided and substantiated in design of the safety systems.

3.3.1.9. The design shall provide for the arrangements aimed to prevent any unauthorized changes in the circuits, equipment and algorithms of safety systems.

 

3.3.2. Protective safety systems of a nuclear

research installation

 

3.3.2.1. The list of design basis accidents requiring application of protective safety systems including the shutdown system and the emergency heat removal system shall be defined in the design, and compliance of the PSS with the prescribed requirements shall be demonstrated.

3.3.2.2. The research reactor shutdown system and critical assembly shutdown system may include subsystems; one or several of these subsystems shall ensure fast transition of the research reactor or the critical assembly to the sub-critical state (emergency protection).

3.3.2.3. The NRI shutdown system shall ensure maintenance of the NRI in sub-critical state in any normal operation modes and in case of abnormal operation including design basis accidents.

3.3.2.4. Efficiency and fast response of the NRI shutdown system shall be sufficient to limit energy emission in the nuclear core to the level when no fuel element damage in excess of the established limits for normal operation or design basis accidents takes place ans to suppress positive reactivity resulting from manifestation of any reactivity effect or potential combination of reactivity effects under normal operation conditions, in case of abnormal operation and design basis accidents.

3.3.2.5. Absence of shutdown systems for the sub-critical assembly is permitted provided that the sub-critical assembly cannot reach the critical state in case of any initiating events of accidents and common cause failures.

3.3.2.6. Bringing of the NRI to sub-critical state through the use of the shutdown system shall not depend on power supply availability.

3.3.2.7. Apart from automatic actuation of the shutdown system the possibility for automated activation of individual shutdown system subsystems at the initiative of the personnel shall be provided.

3.3.2.8. The system for emergency heat removal from the research reactor core shall prevent damage of nuclear fuel and other core components in case of any initiating event considered in the design including any loss of integrity of the primary circuit boundaries.

3.3.2.9. Measures shall be provided for any research reactor in sub-critical state in order to prevent its transition to the critical state and exceedance of permissible pressure in the coolant circuit systems during actuation and operation of the system for emergency heat removal from the nuclear core.

3.3.2.10. Actuation of protective safety systems shall not result in failures of the equipment of any normal operation systems.

3.3.2.11. The design shall ensure operability of the protective safety systems under extreme conditions (for example fire, flooding of the rooms).

 

3.3.3. Localizing safety systems of a nuclear

research installation

 

3.3.3.1. Localizing safety systems in the form of leak-tight rooms, tanks, pans for storage and performance of works with radioactive substances shall be provided at the NRI in order to prevent releases of radioactive substances and ionizing radiation beyond the boundaries established in the design under normal operation conditions, in case of abnormal operation and accidents.

3.3.3.2. Permissible degree of untightness for the LSS rooms shall be substantiated in the NRI design, and the ways to achieve it shall be specified.

3.3.3.3. Compliance of actual leak-tightness of the LSS rooms with the NRI design shall be confirmed prior to the first fueling of the NRI core with nuclear materials and periodically verified at least once per a year.

3.3.3.4. All networks crossing the confinement periphery and capable of causing impermissible release of radioactive substances outside the LSS rooms in case of any accident shall be equipped with isolating devices.

3.3.3.5. Necessity to use LSS components in the potential accident localization area in order to perform the following basic functions shall be considered in the course of the LSS development:

1. pressure reduction;

2. heat removal;

3. RS concentration decrease;

4. monitoring of explosive gas concentrations;

5. maintenance of the concentration of explosive gases and aerosols below the lower concentration limit for flame propagation.

Application (non-application) of these or any other functions shall be defined in the NRI design and specified in the NRI SAR.

 

3.3.4. Control safety systems of a nuclear

research installation

 

3.3.4.1. Control safety systems shall ensure automatic and automated performance of safety functions and actuation of protective safety systems upon occurrence of the conditions specified in the NRI design.

3.3.4.2. The NRI design may provide for combination of the measuring channels of control safety systems and normal operation control systems; in this case it should be confirmed that any damage or failure in normal operation control systems will not affect the capability of control safety systems to perform safety functions.

3.3.4.3. Each CSS shall perform safety functions via at least two measuring channels of its process parameter within the entire design changing range for this parameter.

3.3.4.4. Acceptability and conditions for withdrawal of any CSS measuring channel from service shall be substantiated in the NRI design.

3.3.4.5. Data obtained from the CSS recording devices shall be sufficient for detection and registration of:

1) the initiating event having caused any deviations from the NRI operation limits or safe operation limits and the time of its occurrence;

2) changes of process parameters in the course of accident development;

3) actions of safety systems;

4) actions of the control room workers (personnel).

3.3.4.6. The NRI design shall minimize the possibility for any spurious actuation of control safety systems.

3.3.4.7. Any failure in the automatic actuation circuit shall not impair automated activation of the safety systems.

3.3.4.8. The following shall be provided for control safety systems:

1. continuous automatic diagnostics of operability;

2. regular diagnostics of good operating state for the CSS channels and diagnostics of the systems (components) from the control room panels (boards) in accordance with par. 3.1.3 of the NRI Safety Provisions.

3.3.4.9. Hardware and software failures and damages of control safety systems shall cause generation of alarms on the control room panels and initiate actions aimed to provide the NRI safety.

3.3.4.10. Failures of any display, recording, information and diagnostics components shall not affect performance of protective functions by the CSS.

3.3.4.11. Reliability of control safety systems shall be substantiated in the NRI design with due regard for the requirements for actuation of systems and any potential common cause failures.

3.3.4.12. Analysis within the scope specified in par. 3.2.3.5 of the NRI Safety Provisions shall be performed for control safety systems in the NRI design.

 

3.3.5. Supporting safety systems of a

nuclear research installation

 

3.3.5.1. The NRI design shall provide for the necessary supporting safety systems that perform the functions of power supply and supply of the working media to the safety systems as well as creation of required conditions for their operation.

3.3.5.2. Supporting safety systems shall have reliability parameters for performance of the specified functions sufficient to achieve the required functional reliability of the safety systems in combination with reliability parameters of the safety systems supported by them.

3.3.5.3. Performance of the functions specified in par. 3.3.5.1 of the NRI Safety Provisions by the supporting safety systems shall have unconditional priority over actions of the internal protections of SSS components unless it can result in more severe accident consequences.

3.3.5.4. Categories of the NRI consumers according to power supply reliability, the maximum permissible period of power supply interruption as well as the type of independent power supply sources of the emergency power supply system shall be specified and substantiated in the NRI design.

3.3.5.5. It should be demonstrated in the NRI design that emergency power supply ensures performance of safety functions in case of design basis and beyond design basis accidents on other safety systems.

3.3.5.6. The NRI design shall provide for the necessary and sufficient NRI fire protection means including the means for detection and extinguishing of the moderator and coolant fire.

 

3.4. Control room of a nuclear research installation

 

3.4.1. The NRI design shall include the control room where the workers (personnel) carry out automated control of the process, normal operation systems and safety systems.

3.4.2. The following shall be provided in the control room:

1) means for the neutron flux density and its change rate monitoring in all NRI operation modes including nuclear fuel loading (reloading) operations;

2) means for the neutron flux density control;

3) position indicators for the CPS control devices and control means for state of shutdown systems;

4) information support systems for the operator ensuring submittal of information on the current NRI state to the workers (personnel) of the control room; the scope and quality of this information shall be sufficient to make prompt reasonable decisions in all NRI operation modes;

5) warning and emergency alarms.

3.4.3. Sufficiency of the measures aimed to ensure normal activities of the control room workers (personnel) in all NRI operation modes and in case of design basis accidents shall be substantiated in the NRI design.

3.4.4. Instruments, displays, control keys in the control room shall be selected and arranged with due regard for the ergonomic requirements.

3.4.5. An emergency control room shall be provided for the research reactor and the critical assembly in order to be used in case of any impossibility to control the research reactor (critical assembly) systems from the main control room.

3.4.6. The technical measures shall eliminate any possibility for the NRI control from the main and the emergency control room at the same time.

3.4.7. Survivability and habitability of the control room and the possibility to perform the following functions from it shall be ensured:

1) bringing of the research reactor (critical assembly) into sub-critical state;

2) emergency cooldown of the research reactor in any cases prescribed in the NRI design;

3) monitoring of the research reactor (critical assembly) state and the radiation situation in the course of any accident mitigation arrangements.

3.4.8. It is permitted not to arrange an emergency control room for the critical assembly provided that the possibility to perform all functions specified in par. 3.4.7 of the NRI Safety Provisions from the main control room in case of abnormal operation and design basis accidents is demonstrated.

3.4.9. Common cause failures shall not result in a simultaneous failure of the monitoring and control circuits of the main and the emergency control room.

3.4.10. Modular arrangement shall be used in technical equipment of the control room and the emergency control room as well as in development of the normal operation control system and the control safety system in order to provide the possibility for their step-by-step improvement.

 

3.5. Experimental devices of a nuclear

research installation

 

3.5.1. The purpose, the procedure for installation (dismantling) and safe operation conditions for experimental devices shall be defined in the NRI design.

3.5.2. Experimental devices that can become an initiating event of an accident in case of their failure shall be designed with due regard for the requirements imposed on the NRI safety-related systems.

3.5.3. Design of experimental devices shall eliminate any possibility for unintended reactivity change in the course of their installation (dismantling) and operation.

3.5.4. Experimental devices shall have technical documentation (particularly calculations) approved by the operating organization and in case of necessity - experimental assessment of their impact on reactivity, power density field distribution in the nuclear core and efficiency of the NRI CPS control devices.

3.5.5. The basic parameters of experimental devices affecting the NRI safety shall be displayed in the main control room.

3.5.6. The NRI design shall provide for radiation safety assurance for the workers (personnel) maintaining the experimental devices.

3.5.7. Selection and planning of the rooms for the hot cell and the activation measuring laboratory, installation of their equipment and hardware, selection of the routes and development of handling appliances for transportation of any items irradiated in the experimental devices shall be arranged in the design from the viewpoint of dose burden minimization for the workers (personnel).

3.5.8. Safety assurance in operation of experimental devices shall be substantiated in the NRI SAR.

3.5.9. Issues related to decommissioning of experimental devices shall be taken into account in the NRI design.

 

3.6. Radiation safety of a nuclear

research installation

 

3.6.1. The scope of radiological control at the NRI, in the sanitary-protective area and in the supervised area under normal NRI operation conditions and in case of abnormal operation including accidents shall be defined in the NRI design with due regard for potential radiation impact of the NRI on the workers (personnel), the public and the environment.

3.6.2. The NRI design shall provide for the equipment, methods and techniques sufficient for:

1) detection of any physical barrier integrity breaks;

2) control of radioactive releases (discharges) to the environment (amount and radionuclide composition);

3) sampling of the steam and gas medium (gas, air) from the NRI rooms under normal operation conditions and in case of accidents;

4) definition, assessment and prediction of the radiation situation in the NRI rooms, the sanitary-protective area and the supervised area;

5) definition, assessment and prediction of equivalent doses of external and internal exposure for the workers (personnel) and all persons within the sanitary-protective area;

6) radiological control for the workers (personnel) as well as vehicles and materials on the NRI site border;

7) functioning of the necessary part of the NRI radiological control system under the conditions of a beyond design basis accident with the most severe radiation situation at the NRI;

8) prediction of the radiation situation in the field in the course of the NRI beyond design basis accident development;

9) recording and storage of any information required for the accident investigation.

 

IV. CONSTRUCTION AND COMMISSIONING OF A NUCLEAR

RESEARCH INSTALLATION

 

4.1. Construction of the NRI, manufacturing and installation of the NRI systems and equipment shall be performed in accordance with the detailed design.

4.2. Building structures, equipment, items and automation means including physical protection hardware subject to mandatory certification shall have compliance certificates.

4.3. Quality control and acceptance of the performed works and finished components, systems and equipment shall be arranged in accordance with the requirements of the regulatory documentation, the detailed design and quality assurance programs.

4.4. The purpose of administrative and technical arrangements for the NRI commissioning is to verify compliance of the constructed NRI technical characteristics with the characteristics established in the design.

4.5. Prior to the commissioning and in the course of the NRI operation the operating organization shall:

1) develop radiation safety guidelines and establish reference levels;

2) obtain sanitary and epidemiological inspection report, issue the NRI certificate and review them within the established time limits;

3) ensure recording of exposure doses for the workers (personnel), develop and implement the arrangements aimed to reduce exposure doses and the number of exposed persons;

4) arrange physical protection of the NRI, accounting and control of nuclear materials, radioactive substances and radioactive waste.

4.6. The operating organization shall arrange development of the NRI commissioning program defining the following aspects:

1) the main stages of works for the NRI commissioning;

2) initial state of the NRI before commencement of the future stage of works for the NRI commissioning;

3) the set and requirements for the documents necessary at each stage of the NRI commissioning.

4.7. The CTS and STS commissioning program shall provide consistent implementation of the commissioning work stage and the physical start-up stage.

4.8. Operability of each individual NRI system and its compliance with the design shall be checked and integrated verification of the systems in the course of their interaction shall be performed at the commissioning work stage.

4.9. Compliance of the neutron and physical NRI characteristics with the design shall be verified at the physical start-up stage including loading of nuclear materials into the core.

4.10. Apart from the commissioning work stage and physical start-up the RP and SADS commissioning shall also include the power start-up stage when the following main works shall be performed:

1) investigation of the power and temperature impact on individual neutron and physical characteristics measured in the course of physical start-up;

2) studies of characteristics of experimental devices (for example the neutron flux density at the outlet of the experimental reflector channels, the neutron flux density in the experimental core channel);

3) measurement of the radiation situation at the NRI site.

Rising of the RP and SADS to the rated parameters specified in the NRI design in the course of power start-up shall be arranged in several stages different in power, duration of power operation and power pulse parameters for the RP with a pulse reactor.

4.11. Subsequent to the results of the commissioning works, physical and power start-up of the NRI the operating organization shall arrange introduction of any changes to the design and engineering documentation, the NRI SAR, the RP and SADS process regulations and the NRI operation documentation.

 

V. NUCLEAR RESEARCH INSTALLATION OPERATION

 

5.1. General requirements

 

5.1.1. The operating organization shall develop the organizational structure including:

1) the NRI manager bearing direct responsibility for the NRI safety;

2) workers (personnel) maintaining the operational process at the NRI;

3) workers (personnel) providing maintenance and repair of the equipment and hardware, keeping of the equipment and  hardware in good operating state and their replacement in case of necessity;

4) the service ensuring metrological validation of the measuring means;

5) the services controlling the state of nuclear and radiation safety, general industrial safety and fire safety;

6) workers (personnel) supervising over development and implementation of quality assurance programs;

7) the security service ensuring functioning of the NRI physical protection system.

5.1.2. The operating organization shall ensure the NRI personnel proficiency and training level adequate for the performed functions.

5.1.3. Liabilities, authorities and scope of knowledge for the workers (personnel) and the NRI administration shall be defined in the relevant regulations and job descriptions.

5.1.4. The operating organization shall define the procedure for training of the workers (personnel) including the training and probation program, frequency of examinations and instructions, practical drills for the NRI control and operation of experimental devices, drilling of the personnel's actions in case of abnormal operation, pre-accident situations and accidents. The training program shall contain the section devoted to formation of safety culture for the workers (personnel).

5.1.5. The operating organization shall arrange development of the NRI SAR, the NRI operation guidelines and the RP and SADS process regulations where the design limits and safe operation conditions shall be specified, and also ensure performance of the operating procedures listed in Appendix 3 to the NRI Safety Provision.

5.1.6. The NRI administration shall arrange development of the operation manuals for the NRI systems, process equipment and experimental devices containing particular instructions for the workers (personnel) on the work practices under normal NRI operation conditions and in case of any pre-accident situation and defining their actions in case of design basis and beyond design basis accidents.

5.1.7. The procedure for maintenance and storage of the operation documentation shall be established with due regard for the quality assurance requirements specified in federal regulations and rules in the field of atomic energy use. The design, as-built documentation for the NRI equipment manufacturing, testing reports and as-built documentation for maintenance and repair of safety systems and safety-related systems referred to safety classes 1 and 2 shall be stored within the entire NRI service life.

5.1.8. Any deviations from the safe operation limits and conditions that have taken place at the NRI (including accidents) shall be investigated in accordance with the requirements of federal regulations and rules in the field of atomic energy use. The operating organization shall develop and implement the measures preventing recurrent deviations from the safe operation limits and conditions due to the same causes.

5.1.9. The operating organization shall ensure collection, processing, analysis, systematization and storage of the information on any NRI operational occurrences within the entire NRI service life and also its prompt submittal to any other organizations in accordance with the established procedure.

5.1.10. The operating organization shall arrange internal control of the NRI safety assurance and physical protection. The control results shall be specified in annual reports on the current NRI safety state assessment.

5.1.11. Upon expiry of the specified NRI service life and in case further experimental studies at the NRI are still important the operating organization shall settle the issue of the NRI service life extension.

 

5.2. Nuclear research installation operation

 

5.2.1. Start-up and power operation mode

 

5.2.1.1. The RP and SADS operation in the start-up and power operation mode shall be carried out in accordance with the process regulations and the operation guidelines and within the scope of the experimental research program approved by the operating organization administration.

5.2.1.2. The CTS and STS operation in the start-up mode shall be carried out in accordance with the NRI operation guidelines and within the scope of:

1) the basic experimental research program approved by the operating organization administration where the aims and objectives of each research stage different in the applied experimental devices and (or) methodological support shall be determined;

2) the working program approved by the NRI administration and covering one type of experiments provided in the basic experimental research program and related for example to application of certain experimental devices or start-ups with similar NRI power and reactivity characteristics. The working program shall contain the list of the applied experimental devices, the procedure and methods of the experiments, expected reactivity effects and safety measures with due regard for the peculiarities of the future works.

5.2.1.3. In case safe operation limits and conditions are not observed in the course of the NRI start-up or power operation the start-up and power operation mode shall be terminated and the NRI shall be brought into the temporary shutdown mode.

 

5.2.2. Temporary shutdown mode

 

5.2.2.1. In the course of the NRI operation in the temporary shutdown mode maintenance shall be performed in accordance with the manuals, programs and schedules developed by the NRI administration based on the design, engineering and operation documentation. In this case the requirements of the NRI design for conditions of the SS withdrawal from service for maintenance, repair and testing shall be taken into account. All the works shall be documented.

5.2.2.2. In the temporary RP shutdown mode in particular in the course of repair or replacement of the equipment and reactivity-affecting experimental devices the available engineering features shall ensure control of the neutron flux density and the main process parameters of the research reactor.

5.2.2.3. Subsequent to completion of the repair works the NRI safety-related systems shall be checked for operability and compliance with the design characteristics; the checking results shall be documented.

5.2.2.4. Safety measures in the course of nuclear-hazardous works at the NRI related for example to replacement of the components tested in the experimental loop of the research reactor, partial or complete replacement of the core fuel assemblies, repair (replacement) of the actuators of the CPS control devices shall be specified in the NRI operation documentation.

 

5.2.3. Long-term shutdown mode

 

5.2.3.1. The operating organization shall consider feasibility of the NRI transfer to the long-term shutdown mode in case any commenced experimental works are completed and no NRI operation in the start-up mode is planned up to the operation license expiry date.

5.2.3.2. If the decision on the NRI transfer to the long-term shutdown mode is made the operating organization shall develop and implement the arrangements to ensure the NRI safety in the long-term shutdown mode and lifetime management for the systems and equipment to be used in case of any recommencement of experimental research at the NRI or in the NRI decommissioning works.

5.2.3.3. The applied techniques for preservation of the systems and equipment and the NRI maintenance scope in the long-term shutdown mode shall comply with the NRI design requirements and shall be specified in the NRI SAR.

5.2.3.4. The operating organization shall inform the Federal Environmental, Industrial and Nuclear Supervision Service on the NRI transfer to the long-term shutdown mode.

 

5.2.4. Final shutdown mode

 

5.2.4.1. The final NRI shutdown mode shall be introduced via the resolution of the atomic energy use controlling agency.

5.2.4.2. In the final NRI shutdown mode the operating organization shall implement administrative and technical arrangements for preparation to the future NRI decommissioning works including:

1) unloading of nuclear materials from the nuclear core according to the technique specified in the NRI design and removal of nuclear materials from the NRI site;

2) performance of integrated engineering and radiation examination of the NRI systems, equipment, structures and buildings in order to assess their technical condition and also to develop maps of exposure dose rates and radioactive contaminations;

3) development of the basic NRI decommissioning program including the main administrative and technical arrangements for implementation of the selected NRI decommissioning variant;

4) development of the NRI decommissioning project defining particular types of works for the NRI decommissioning with indication of techniques and sequence of their performance, the required materials and equipment and the NRI site state after completion of the works;

5) development of the NRI SAR for the NRI decommissioning substantiating safety assurance for the workers (personnel) and the public during implementation of administrative and technical arrangements provided in the basic NRI decommissioning program and project.

5.2.4.3. Reduction of maintenance scope and the personnel size for the NRI operated in the final shutdown mode shall be arranged in accordance with the requirements specified in the NRI design and substantiated in the NRI SAR.

 

VI. MEASURES FOR PROTECTION OF THE WORKERS (PERSONNEL)

AND THE PUBLIC IN CASE OF ANY ACCIDENT AT A NUCLEAR

RESEARCH INSTALLATION

 

6.1. Action plans for protection of the workers (personnel) and the public in case of any accidents at the NRI with due regard for radiological consequences of any potential accidents shall be developed, agreed, approved and supported with the required material and technical resources prior to the NRI commissioning.

6.2. The action plan for protection of the workers (personnel) and the public in case of any accidents at the NRI shall be developed by the operating organization and shall provided for coordination of activities between the operating organization, the internal affairs agencies, the State Fire Protection Service, administrative bodies for civil defense and emergency situations, local government authorities and medical institutions within the protective action planning zone. The operating organization shall be responsible for preparedness and implementation of the plan.

6.3. The action plan for protection of the public in case of any accidents at the NRI developed by the competent local government authorities in accordance with the established procedure shall provide for coordination of activities between the head office for civil defense, emergency situations and disaster control of the relevant constituent entity of the Russian Federation and the federal executive authorities engaged in implementation of measures for the public protection and mitigation of the accident consequences.

6.4. Action plans for protection of the workers (personnel) and the public shall specify under what conditions, through what communication means and who should inform about the accident and commencement of the plan implementation and what organizations are to be informed.

6.5. The operating organization shall develop procedures and programs of emergency response drills in order to exercise the personnel's actions under accident conditions and ensure regular arrangement of the above-mentioned drills (at least once per two years) with due regard for the current activities at the NRI site.

6.6. The operating organization shall ensure preparedness of the workers (personnel) for actions in case of design basis and beyond design basis accidents. The top priority actions of the workers (personnel) for confinement of any possible accidents and mitigation of their consequences shall be described in the relevant guidelines.

 

VII. DECOMMISSIONING OF A NUCLEAR

RESEARCH INSTALLATION

 

7.1. The NRI decommissioning works may be commenced subject to implementation of the following arrangements:

1) removal of nuclear materials from the NRI site;

2) provision of special-purpose equipment ensuring safe dismantling works, decontamination and RW handling for the operating organization divisions and organizations performing works and rendering services for the NRI decommissioning to the operating organization;

3) completion of the personnel's training.

7.2. In case no technique and equipment for unloading of nuclear materials from the research reactor core are provided in the NRI design or preliminary partial dismantling of its structures is required, the works for unloading of nuclear materials from the core and removal of nuclear materials from the NRI site may be performed within the works prescribed in the NRI decommissioning project. In this case the NRI shall be considered as operated in the final shutdown mode up to removal of nuclear materials from the NRI site.

7.3. In the course of the NRI decommissioning works the operating organization shall ensure minimization of RW amounts and dose burdens for the workers (personnel), eliminate any radiation impact of the NRI on the public and arrange accounting, control and physical protection of radioactive waste.

 

 

 

 

 

Appendix 1

to General provisions on safety assurance

for nuclear research

installations approved by

Order of the Federal

Environmental, Industrial

and Nuclear Supervision Service

dated 30 June 2011 No. 348

 

ABBREVIATIONS

 

PSS - Protective Safety System

NRI - Nuclear Research Installation

CTS - Critical Test Stand

LSS - Localizing Safety System

SAR - Safety Analysis Report

SSS - Supporting Safety Systems

STS - Sub-critical Test Stand

SADS - Sub-critical Accelerator-Driven System

RW - Radioactive Waste

RSb - radioactive substances

RP - Reactor Plant

SS - Safety System

SRS - Safety-Related System

CPS - Control and Protection System

CSS – Control Safety System

- - Operating Organization

 

 

 

 

 

Appendix 2

to General provisions on safety assurance

for nuclear research

installations approved by

Order of the Federal

Environmental, Industrial

and Nuclear Supervision Service

dated 30 June 2011 No. 348

 

TERMS AND DEFINITIONS

 

Accident - abnormal operation at the NRI with release of radioactive substances and (or) ionizing radiation in the amounts exceeding the specified safe operation limits beyond the boundaries established in the design for normal operation conditions. The accident is characterized by the initiating event, development scenarios and consequences.

Beyond design basis accident - an accident caused by initiating events not considered for design basis accidents or accompanied with additional failures of safety system components as compared to design basis accidents in excess of a single failure and implementation of erroneous decisions of the workers (personnel).

Nuclear accident - an accident caused by loss of supervision over chain nuclear fission reaction in the NRI nuclear core and (or) loss of control over chain nuclear fission reaction in the NRI nuclear core; formation of the critical mass in the course of handling, transportation or storage of nuclear materials; damage of any components containing nuclear materials.

Design basis accident - an accident for which initiating events and end states are determined in the NRI design and safety systems are provided in order to minimize its consequences down to the limits established for such accidents with due regard for the safety system single failure principle or a single human (personnel) error independent of the initiating event.

Nuclear core of the nuclear research installation - the part of a research reactor, a critical assembly or a sub-critical assembly with nuclear materials (nuclear fuel) and other components required to sustain chain fission reaction located inside it.

The NRI nuclear core may include: moderator, coolant, reactivity control devices, experimental devices.

Active system (component) - a system (components) functioning of which depends on normal operation of any other system (component).

Safety of the nuclear research installation - the NRI property under normal operation conditions and in case of abnormal operation including accidents to restrain radiation impact on the workers (personnel), the public and the environment within the established limits.

Commissioning of the nuclear research installation - the type of activity when compliance of the systems, equipment and the entire NRI with the design is verified including the commissioning works, physical start-up of the NRI, power start-up of a research reactor.

Decommissioning of the nuclear research installation - the type of activity performed after removal of nuclear materials from the NRI site and aimed to achieve the prescribed end state of the NRI and its site.

nuclear research installation - a nuclear installation including a research reactor, a critical assembly or a sub-critical assembly and the set of rooms, systems, components and experimental devices with the necessary workers (personnel) located within the territory established in the design (the NRI site) and intended for use of neutrons and ionizing radiation for research purposes.

External neutron source - a neutron emitting device periodically installed into the nuclear core (withdrawn from the nuclear core) in the course of the NRI operation in the start-up and power operation mode and intended to increase the neutron flux density in the NRI core.

System channel - a part of the system performing the system function within the scope specified in the NRI design.

Dose quota for the nuclear research installation - the part of the dose limit established in order to limit exposure for the public in case of external exposure as well as in case of internal exposure due to RS ingress with air, food and water under normal operation of the NRI.

Conservative approach - the approach when  the values of parameters and characteristics  knowingly leading to prediction of less favorable results are used in safety analysis for the facility.

Safety culture - professional and psychological preparedness of the workers (personnel) when safety assurance is a priority and inherent need that leads to understanding of the personal responsibility and self-control in performance of all safety-related works.

Operational occurrence at the nuclear research installation - any abnormal operation of the NRI with deviation from the established operation limits and conditions; in this case any other limits and conditions specified in the NRI design can be violated including the safe operation limits.

Quality assurance - planned and systematically implemented activities aimed to perform any works at the stages of site selection, design, development and manufacturing of equipment, construction, commissioning, operation and decommissioning of the NRI in the duly established manner and to ensure compliance of their results with the prescribed requirements.

Shutdown of the nuclear research installation - operation of the RP and CTS in sub-critical state and operation of the STS and SADS after removal (disabling) of the external neutron source.

Common cause failures - failures of systems (components) caused by the same failure, or the same human error, or internal or external impact.

Note. Internal impacts or causes - impacts resulting from initiating events of accidents including shock waves, jets, missiles, changes of the medium parameters (for example pressure, temperature, chemical activity), fires, structural, process and any other internal causes.

External impacts or causes - impacts of any natural phenomena and human activities typical for the NRI site, for example earthquakes, high and low level of surface and underground water, hurricanes, accidents with air, water and land transport, fires, explosions at any facilities adjacent to the NRI site, loss of external power supply.

 

Safety analysis report for the nuclear research installation - the document substantiating the NRI safety assurance at all stages of its life cycle.

Human error - any untimely or inaccurate performance (failure to perform) of any required single action (single omission of a correct action) in the course of installation, testing or operation of safety-related systems (components).

Passive system (component) - a system (component) with the functioning associated only with the event initiating its actuation and independent from operation of any other active system (component).

Note. In accordance with their design features the passive systems (components) are classified into passive systems (components) with mechanical moving parts (for example check valves) and passive systems (components) without mechanical moving parts (for example pipelines and vessels).

 

Primary circuit of the research reactor - the set of channels (cavities) in the nuclear core of a heterogeneous research reactor, pipelines and heat exchangers containing the coolant for the nuclear core cooling, or the pressure vessel of a homogeneous research reactor with the nuclear material solution and pipelines for circulation of the nuclear material solution.

Pre-accident situation - the NRI state characterized by deviation from safe operation limits and (or) conditions that did not develop into an accident.

Safe operation limits - values of the process parameters established in the NRI design any deviations from which can lead to an accident.

Design limits - values of parameters and characteristics of the systems (components) and the entire NRI established in the NRI design for normal operation and abnormal operation including pre-accident situations and accidents.

Operation limits - values of parameters and characteristics of the systems (components) and the entire NRI established in the NRI design for normal operation.

Maximum permissible emergency release from the nuclear research installation - numerical values of radionuclide releases into the environment in case of beyond design basis accidents at the NRI that do not cause any exceedance of the exposure dose for the public within the protective action planning zone and outside it above the values specified in the effective radiation safety standards and necessitating any decision making on the public protection measures in case of an accident with due regard for the worst weather conditions.

Radioactive release and discharge limits - numerical values of radionuclide releases and discharges to the atmosphere and the surface water specified in the NRI design and complying with the established public exposure quota.

Single failure  principle - the principle stating that the system shall perform the preset functions in case of any initiating event requiring its operation and a failure of any active component of passive components with moving mechanical parts independent from the initiating event.

Safe failure principle - enhancement of reliability in performance of SS functions by application of technical solutions providing the system transfer to safe state in case of any system (component) failure without any need for initiation of protective actions via the control safety system.

Physical start-up of the nuclear research installation - the NRI commissioning stage including loading of nuclear materials to the nuclear core and experimental determination of the NRI neutron and physical characteristics.

Power start-up of the nuclear research installation - the NRI commissioning stage including experimental investigation of the temperature and power impact on the NRI neutron and physical characteristics, investigation of the radiation situation in the course of the NRI power operation and rising of the NRI to the rated parameters specified in the NRI design.

Control device of the control and protection system - a reactivity control device which provides reactivity changes through changes of its position or state in the NRI nuclear core or the reflector.

nuclear research installation designers - organizations developing the NRI design.

Nuclear research reactor - the device for experimental research with the configuration and geometry enabling to sustain controllable nuclear fission reaction operated at the power level requiring forced cooling and (or) affecting its neutron and physical characteristics.

Reactor plant - a NRI with a nuclear research reactor.

Temporary shutdown mode - the NRI operation mode including performance of the NRI maintenance works and preparation of experimental devices.

Long-term shutdown mode - the NRI operation mode including performance of preservation works on individual systems and equipment and maintenance of the NRI operability within the period when no experimental research is planned.

Final shutdown mode - the NRI operation mode when preparation for the NRI decommissioning is arranged including unloading of nuclear materials from the NRI nuclear core and their removal from the NRI site.

Start-up and power operation mode - the NRI operation mode including the NRI power raising through the use of the CPS control devices and (or) external neutron source and performance of experimental studies.

Inherent self-protection - the property of NRI to provide safety based on natural responses, processes and characteristics.

Critical assembly - the device for experimental studies of characteristics and parameters of the neutron multiplying medium with the configuration and geometry enabling to sustain controllable nuclear fission reaction operated at the power level not requiring any forced cooling of the medium and not affecting its neutron and physical characteristics.

Sub-critical assembly - the device for experimental studies of characteristics and parameters of the neutron multiplying medium with the configuration and geometry providing attenuation of the chain fission reaction in the absence of any external neutron sources.

System - the set of components designed for performance of the specified functions.

Shutdown system - the system intended for fast termination of the nuclear chain fission reaction and maintenance of the NRI in sub-critical state through the use of reactivity control devices.

Safety systems (components) - systems (components) intended to perform safety functions.

Safety-related systems (components) - safety systems (components) and also normal operation systems (components) failures of which can disrupt normal operation of the NRI or impair elimination of deviations from normal operation and can lead to design basis or beyond design basis accidents.

Protective safety systems (components) - systems (components) intended to prevent or limit any damage of nuclear materials, equipment and pipelines containing radioactive substances.

Localizing safety systems (components) - systems (components) intended to restrict propagation of radioactive substances and ionizing radiation beyond the boundaries established in the NRI design and to prevent their release to the environment.

Supporting safety systems (components) - safety systems (components) intended to supply the safety systems with power and working media and to create the required conditions for their functioning.

Control safety systems (components) - systems (components) intended to initiate actions of safety systems and to carry out their monitoring and control during performance of the prescribed functions.

Normal operation systems (components) - systems (components) intended for normal operation.

Normal operation control systems (components) - systems (components) forming and implementing control of the process equipment of the NRI normal operation systems in accordance with the prescribed process objectives, criteria and restrictions.

Control and protection system - the system intended for safe maintenance and termination of the chain fission reaction combining the normal operation functions and the functions of a safety system and including the components of the control and monitoring systems, protective, control and supporting safety systems.

Initiating event - a single failure in the NRI systems (components), an external impact or a human error resulting in an operational occurrence and capable of leading to deviation from safe operation limits and (or) conditions; includes all dependent failures resulting from it.

Critical test stand - a NRI including a critical assembly.

Sub-critical test stand - a NRI including a sub-critical assembly.

Process regulations of the reactor plant - the document containing the rules and main methods of safe operation, the general procedure for performance of safety-related operations as well as safe operation limits and conditions for the RP.

Accident management - actions aimed to prevent development of a design basis accident into a beyond design basis one and also to mitigate the accident consequences.

Automated control - control performed by the workers (personnel) through the use of automation equipment.

Automatic control - control performed by the automation equipment without any involvement of the personnel.

Safe operation conditions - the minimum conditions with regard to quantity, characteristics, operability state and maintenance conditions for safety-related systems (components) established in the NRI design and ensuring compliance with safe operation limits.

Operation conditions - conditions with regard to quantity, characteristics, operability and maintenance of systems (components) established in the NRI design and required and sufficient for functioning without any deviations from the operation limits.

Sub-critical accelerator-driven system - a nuclear research installation consisting of a sub-critical assembly with a converter target producing primary neutrons in the course of irradiation with charged accelerator particles.

Physical protection of the nuclear research installation - the set of administrative arrangements, engineered features and actions of the security personnel aimed at prevent sabotage or theft of nuclear materials, radioactive waste and radioactive substances.

Safety function - specific particular purpose and actions ensuring its achievement and intended to prevent accidents and to mitigate their consequences.

Experimental loop of the nuclear research installation - an independent circulation circuit of the NRI intended for experimental studies and testing of new fuel element types and other components.

Experimental device of the nuclear research installation - a device or appliance intended to perform experimental research at the NRI.

Operation of the nuclear research installation - activities aimed to achieve the aim of the NRI construction in a safe manner including the critical mass gathering, operation at the prescribed power level, performance of experiments, the NRI shutdowns, handling of nuclear materials and radiation sources, maintenance, repair and any other associated activities.

Normal operation - the NRI operation within the operation limits and conditions defined in the NRI design.

Components - equipment, instruments, pipelines, cables, building structures and others items ensuring performance of the prescribed functions independently or within the systems and considered in the design of NRI as structural units for reliability and safety analysis.

Nuclear-hazardous works at the nuclear research installation - any works that can result in uncontrolled reactivity changes related for example to any modifications of the NRI core geometry and configuration and replacement of experimental devices.

 

 

 

 

 

Appendix 3

to General provisions on safety assurance

for nuclear research

installations approved by

Order of the Federal

Environmental, Industrial

and Nuclear Supervision Service

dated 30 June 2011 No. 348

 

LIST

OF OPERATIONAL PROCEDURES TO BE CONSIDERED

IN THE PROCESS REGULATIONS FOR A NUCLEAR

RESEARCH INSTALLATION

 

1. Procedure for the core loading and transition to the critical state.

2. Procedure for the core refueling.

3. The NRI start-up, power variations, power operation.

4. Calibration of the CPS control devices.

5. Reactivity margin measurement and monitoring.

6. Calibration of the neutron flux density control channels.

7. The NRI power determination and adjustment of the CPS ionizing chambers.

8. The personnel's actions in case of any warning signals.

9. The personnel's actions in case of the emergency protection actuation.

10. Scheduled shutdown and disabling of the NRI equipment.

11. Handling of nuclear materials.

12. Handling of radioactive substances and radioactive waste.

13. Any other procedures reflecting the NRI peculiarities in the course of nuclear- and radiation-hazardous works.

 

 

 

 


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