Safety Documentation for Research Reactors

IAEA International Atomic Energy Agency

Safety Documentation for Research Reactors

A. M. Shokr Research Reactor Safety Section

Division of Nuclear Installation Safety August 2016

IAEA

Contents

• Safety documents for research reactors (RRs) • Safety-related documents for RRs • Document control

IAEA

General

• Safety documents for RRs: • Safety Analysis Report (SAR) • Operational Limits and Conditions (OLCs) • Emergency Plan

IAEA

Safety Analysis Report

• Prepared by the operating organization for the justification of the site and reactor design, and is the basis for safe operation of the reactor.

• SAR is the comprehensive document produced concerning the safety of the facility.

• It is the most important link between the operating organization and regulatory body, and is the main document for licensing of the reactor.

• It should be reviewed and assessed by the regulatory

body, during different stages of the RR lifetime.

IAEA


• Preparation of the SAR begins as early as possible in the RR project. Successive updates to the SAR are anticipated as project proceeds.

• The amount of information provided will correspond to the project stage under assessment, and should be sufficient to allow for making a decision on the acceptability of the reactor for that stage.

IAEA


• The SAR also serves other purposes: To aid the designers in confirming that individual systems

are integrated correctly;

To ensure that the safety analysis has properly identified the safety issues related to the design;

To aid in training the reactor operating personnel;

To form the basis for the establishing the OLCs.

IAEA

SSG-20: Safety Assessment of RRs and Preparation of the Safety Analysis Report

• Provides guidance on the preparation, review and assessment of the SAR

• Provides guidance on the initial licensing process for new RRs, and also on re-licensing and periodic safety reviews of existing RRs

IAEA

Safety Analysis Report - Contents

Contents (from SSG-20): 1. Introduction and general description of the research reactor 2. Safety objectives and engineering design requirements 3. Site characteristics 4. Building and structures 5. The reactor 6. Research reactor cooling systems and connected systems 7. Engineered safety features 8. Instrumentation and control systems 9. Electric power 10. Auxiliary systems

IAEA

Safety Analysis Report - Contents

Contents (from SSG-20) – Continued: 11. Research reactor utilization 12. Operational radiation safety 13. Conduct of operations 14. Environmental assessment 15. Commissioning 16. Safety analysis 17. Operational limits and conditions 18. Management systems 19. Decommissioning 20. Emergency planning and preparedness

IAEA


• The level of detail of the information in the SAR is determined in accordance with the stage of the research reactor project, the reactor type and characteristics (design, power, utilization, etc.), and the site.

However, every topic provided in SSG-20 should be addressed.

• Some of the topics may be presented in separate documents (OLCs, operational procedures, etc.). In this case, these topics should be treated briefly in SAR and a reference is made to the appropriate document.

• Adequate technical references should be cited in SAR that may be necessary for a thorough review and assessment.

IAEA


• The SAR should be periodically reviewed to consider

operating experience feedback, including accidents, radiological information, modifications and new experiments, etc.

• The regulatory body will review and assess the SAR and

confirm (through inspection activities) that reactor operation is being conducted as described in the SAR.

IAEA

IAEA Safety Report Series No. 55

• Provides a set of suggested methods and practices for performing all steps of safety analyses.

• Discusses deterministic and probabilistic analysis methods for research reactor design and licensing.

• Useful for operating organizations, regulatory bodies and other organizations involved in the safety of research reactors.

IAEA

IAEA Safety Report Series No. 80

• Provides a set of suggestions and methods for performing safety reassessments for research reactors (to ensure harmonization of methods and approaches);

• Provides information on the use of the relevant IAEA safety standards in performing reassessments;

• Does not replace or supersede any of the existing IAEA safety standards.

IAEA

Operational Limits and Conditions

• The OLCs are established to prevent accidents and to mitigate their consequences should they occur.

• The OLCs should be derived from the results of the safety analysis.

• OLCs may be presented in a separate document. In this case, it should be briefly stated in the relevant chapter in SAR.

• Format and contents of the OLCs may differ between

Member States (MSs), depending on the national safety regulations.

IAEA


• Provides guidance on all important aspects of developing, formulating and presenting the OLCs, including: • Safety limits; • Safety system settings; • Limiting conditions for safe operation; • Surveillance requirements; • Administrative requirements

• Provides guidance on development, content and implementation of operation procedures that should ensure that reactor operations in all modes and operations of experiments are consistent with the OLCs.

IAEA time

Safety Limit (SL)

Safety System Setting (SSS)

Limiting Condition for Safe Operation (LCO)

Relationship between the SL/SSS/LCO

Range of steady state operation

Practical margin to avoid reaching the LCO

Safety margin

Example: 220% Full Power



Example: Full Power

Example: Safety Margin is 2

Example of Surveillance Requirements: Calibration of neutronic channels every core configuration change, twice a year, etc.

IAEA time

SL

SSS

Alarm setting

Ran

ge o

f ste

ady

stat

e op

erat

ion

Same delay

system triggered earlier

Delay in response

system triggered Action taken

Measurement uncertainties: calibration, drift, instrument system

Operator corrective actions Margin to enable alarm to be infrequent

IAEA


• It is recommended that the OLCs are presented in terms of: Objectives of the specifications; Applicability of the specifications; Statement of the specifications; Bases of the specifications. Example: Safety limit on fuel cladding temperature Objective: To ensure integrity of the fuel cladding Applicability: Applicable to all reactor states and

operation modes Specifications: Fuel cladding temperature shall not

exceed 500 C Bases of specifications: Fuel blistering temperature. Description of

the calculation results, assumptions, considerations of uncertainties, etc.

IAEA


• All reactor operations shall be in accordance with the OLCs;

• Any proposal for change or modification of OLCs should be submitted by the operating organization to the regulatory body for review and approval prior to making the change or modification. Examples of modifications that involve changes to the OLCs:

• Core conversion; • Reactor power upgrade; • Replacement/modernization of the I&C systems; • Installation of new experiments.

IAEA


• NS-G-4.4, Appendix I: Factors to be Considered in Establishing Limiting Conditions for Safe Operation

IAEA

Emergency Plan

• Organization and responsibilities; • Emergency classification system; • Emergency declaration and notification ; • Arrangements for initial and subsequent assessment; • Action plan and emergency procedures; • Intervention levels and protective actions; • Emergency planning zones; • Emergency facilities and equipment; • Training on emeregncy.

IAEA

Safety-Related Documents

• Basic and detailed engineering design (systems descriptive reports, calculation reports, data sheets, operating values, drawings and diagrams, valve arrangements, etc.);

• Management system (for project phases and activities); • Commissioning documentation; • Operational procedures; • Maintenance, periodic testing and inspection programme; • Operational radiation protection programme; • Training and re-training programme; • Decommissioning plan.

IAEA

Commissioning documentation

• Commissioning documents include: - Management system for commissioning; - Commissioning programme; - Commissioning tests and procedures; - Commissioning results; - Working files and related documents; - Supporting documents including design

reports, as-built drawings, etc.

IAEA

Operating procedures

• Reactor start-up, operation, power level change and

shutdown;

• Determination of core reactivity to meet the OLCs (e.g. control rods worth, shutdown margin, excess reactivity, set-point calculations, etc.);

• Thermal power level determination;

• Handling (loading, unloading, transfer, storage, etc.) of fuel elements and other core components (e.g. reflectors, control rods, instrumentation, etc);

IAEA


• Core configuration changes;

• Reactivity measurement, loading, unloading, handling and safety evaluation of experimental devices;

• Performance of routine checks of reactor operation, system status, and facility conditions;

• Operation of reactor mechanical and electrical support systems and equipment;

• Special fuel handling (e.g. handling of failed fuel, preparation for and shipment of spent fuel);

IAEA


• Ion exchange replacement or regeneration;

• Operation of hoisting devices (cranes);

• Operation of beam tubes and other experimental devices;

• Reactor operator response to anticipated operational occurrences and DBAs;

• Shift turnover and logbook entries.

IAEA

Maintenance, Periodic Testing and Inspection Programmes

General description of the programmes; Management system; Maintenance organization; Training of maintenance personnel; List of structures, systems and

components (SSCs) covered by the programme;

Maintenance procedures; Administrative controls; Review and verification of the

programme; Maintenance facilities; Procurement and storage of spare parts.

IAEA

Operational Radiation Protection Programme

• The operational radiation protection programme should include

the policy statement of operating organization that includes the radiation protection objectives and commitment to the radiation protection principles, in particular the optimization principle.

• It should include procedures to be enforced and followed by

the reactor staff, temporary personnel and visitors.

• The procedures should ensure that all the activities that could

lead to radiation exposure are planned, supervised, and executed in a way that meets the radiological protection objectives.

IAEA

Operational Radiation Protection Programme

Area classifications and access procedures; Routine monitoring (of areas, air, contamination of

personnel, surfaces and objects, etc.); Environmental monitoring; Monitoring of operation and maintenance tasks; Calibration and test procedures for radiation protection

equipment; Decontamination procedures; Use of protection equipment; Detection and recording of radioactivity releases; Radioactive waste monitoring and management; Use of radioactive sources.

IAEA

Radiation Protection and Radioactive Waste Management in Design and Operation of RRs

• Identifies and provides guidance on important components that should be considered in the design stage to facilitate radiation protection and waste management

• Provides international practices to be followed in operational radiation protection and radioactive waste management programmes and their optimization

IAEA

Training and Retraining Programme

• Training organization and administration: Structure of the training organization; Requirements for qualifications of instructors; Provision of resources for training support; Description of training materials; Procedures for selection of personnel.

• Training System:

Training method (class room instructions, on-the-job training, self-study).

• Initial training programme: Training programme for each position; Training curriculum; Training of operating personnel, support personnel and users.

IAEA

Training and Retraining Programme

• Qualification: Requirements for qualifications and certification; Qualification process of the trainees (assessments, examinations,

etc.); Procedures for training validation and verification of its effectiveness.

• Retraining programme: Requirements for retraining and re-qualification; Retraining programme; Requalification examinations.

• Training records

IAEA

The Operating Organization and the Recruitment, Training and Qualification of Personnel for RRs

• Provides guidance on the following topics: • The nature of the operating

organization and how to establish the operating organization;

• The recruitment process and required qualifications for reactor personnel ;

• The initial training and re-training programmes for reactor personnel;

• The authorization process for individuals whose duties have immediate effects on safety

IAEA

Decommissioning plan

• A decommissioning plan should be prepared to ensure safety during decommissioning process.

• Decommissioning should be considered in the design stage of the reactor project.

• During the operational stage, a plan should be developed for the eventual decommissioning.

• The plan should be amended from time to time on the basis of the operating experience and the latest developments in decommissioning techniques.

IAEA

Decommissioning plan

Important technical components of the decommissioning plan are: • Decommissioning organization and responsibilities; • Management system for decommissioning; • Decommissioning strategy; • Initial radiological survey to determine the extent and magnitude of the

radioactivity and contamination; • Decommissioning procedures (handling, dismantling, disposal of

experimental facilities and other equipment, radiological protection, storage , required disposal, etc.);

• Final radiological survey of the facility before its relief of licensing and release for unrestricted use.

IAEA

Document control

• Control of documentation includes preparation, change, review, approval, release and distribution of documentation.

• The record administration and documentation system should be established to ensure the retention and preservation of all safety-related documents.

• Particular care should be taken to ensure that only the correct, up-to-date versions are in use.

• The safety documentation should be periodically reviewed to account for facility modifications/changes and to incorporate operating experience feedback.

IAEA

Thank you for your attention.