Safety objectives for research reactors

The safety objectives for research reactors are defined in Ref [1], which is complemented by two Safety Guides [2-3]. These Safety Guides provide recommendations to Member States and support the IAEA as it reviews the safety of research reactor facilities. 

The safety objectives for research reactors which are vulnerable to external events [16] define the acceptable radiological consequences to workers and the public under accident conditions. Other safety consequences, such as chemical hazards posed by research reactors, do not fall within the scope of this publication according to the relevant criteria for nuclear installations set forth in Refs [1,4]. 

Section 2 introduces the general safety objectives, concepts and principles for the safety of nuclear installations with emphasis on the radiation safety and nuclear safety aspects of research reactors. This section draws on Ref. [1]. 

The technical safety objectives aim at preventing accidents in research reactors and mitigating their consequences if they occur. It is necessary to show that any radiological consequence would be below prescribed limits, with a high level of confidence and for all design basis accidents. For research reactors this means the following ... 

The main objective of this Safety Requirements publication is to provide a basis for safety and a basis for safety assessment for all stages in the lifetime of a research reactor. Another objective is to establish requirements on aspects relating to regulatory control, the management of safety, site evaluation, design, operation and decommissioning. 

Technical and administrative requirements for the safety of research reactors are established in accordance with these objectives. This Safety Requirements publication is intended for use by organizations engaged in the site evaluation, design, manufacturing, construction, operation and decommissioning of research reactors as well as by regulatory bodies. 

The main safety objective in evaluating the site for a research reactor is the protection of the public and the environment against the radiological consequences of normal and accidental releases of radioactive material. Information shall be collected in sufficient detail to support the safety analysis to demonstrate that the research reactor facility can be safely operated at the proposed site. For low power reactors, the amount of detail to be provided can be substantially reduced below that required for a medium or high power reactor (see also paras 1.11-1.14). The results of the site evaluation shall be documented and presented in sufficient detail to permit an independent review by the regulatory body. This may constitute the first part of the development of the SAR for the research reactor. 

Technical safety objectives have to be developed for any research reactor with reference to the three main safety functions that also need to be ensured for external event scenarios [1] ... 

The requirements for the organizational aspects of research reactor facilities are established in Ref. [1], which covers all aspects of the safety of research reactors, including those relating to radiation protection. The organizational structure of the research reactor facility should be such as to ensure proper fulfilment of the objectives for radiation protection. 

See Basic Safety Standards for Radiation Protection, 1982 Edition, IAEA Safety Series No. 9, and the 1990 Recommendations of the International Commission on Radiological Protection, Publication 60, Pergamon Press (1991), for the radiation protection principles. See also Basic Safety Principles for Nuclear Power Plants, IAEA Safety Series No. 75-INSAG-3, for the technical safety objective. (See the Selection of IAEA Publications Related to the Safety of Research Reactors at the end of this book.)... 

Although during normal operation of research reactors exposure of the public due to the release of radioactive materials in the environment is expected to be negligible, a site-related assessment of such exposure should be performed prior to operation. The main objective of this assessment is to demonstrate compliance with the system of dose limitation as described in detail in IAEA Safety Series No. 9 "Basic Safety Standards for Radiation Protection 13). These evaluations are normally required by regulatory authorities and include estimating the effective dose equivalent for the most exposed members of the public (critical group) and collective effective dose equivalent commitment of the population ("collective dose"). 

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