1.9. Safety assessment “School for Drafting Regulations on Radiation Safety, IAEA - Module 1 Regulatory framework for safety, authorization and inspection October 2012

Notification & Authorization. Graded Approach Objective The objective of this lecture is to understand the importance for the establishment of requirements for safety assessment in the elaboration of radiation and nuclear safety regulations and the importance of safety assessment for all facilities or activities.

Notification & Authorization. Graded Approach Contents Scope and purpose of the safety assessment Assessment of safety functions, assessment of defence in depth Assessment of human factors Assessment of the provisions for radiation protection Assessment of safety over the lifetime of a facility or activity Documentation of the safety assessment an independent verification

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources Scope and purpose of the safety assessment GSR Part 3 The regulatory body shall establish a regulatory system for protection and safety that includes: … (b) Review and assessment of facilities and activities; …

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources Scope and purpose of the safety assessment GSR Part 1: Review and assessment of information relevant to safety This review and assessment of information shall be performed prior to authorization and again over the lifetime of the facility or the duration of the activity, as specified in regulations promulgated by the regulatory body or in the authorization. GRADED APPROACH

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources Scope and purpose of the safety assessment There is a graded approach to the information that should be assessed before granting the authorization. For example, the demonstration of safety or “safety case” submitted in support of an application for an authorization for industrial radiography needs to be much more detailed and comprehensive than the safety case submitted with an application for an authorization for an gas chromatograph electron capture detector.

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources Scope and purpose of the safety assessment GSR Part 1, Requirement 25: Review and assessment of information relevant to safety The regulatory body shall review and assess relevant information — whether submitted by the authorized party or the vendor, compiled by the regulatory body, or obtained from elsewhere TO DETERMINE whether facilities and activities comply with regulatory requirements conditions specified in the authorization

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources Scope and purpose of the safety assessment Safety Assessment for Facilities and Activities, Series No. GSR Part 4, Vienna, 2009

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources Scope and purpose of the safety assessment GSR Part 4, The primary purposes of the safety assessment shall be to determine whether an adequate level of safety has been achieved for a facility or activity and whether the basic safety objectives and safety criteria established by the designer, the operating organization and the regulatory body, in compliance with the requirements for protection and safety as have been fulfilled.

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources Scope and purpose of the safety assessment GSR Part 1, Safety assessments shall be conducted: To identify the ways in which exposures could be incurred, account being taken of the effects of external events as well as of events directly involving the sources and associated equipment; To determine the expected magnitudes and likelihood of exposures in normal operation and make an assessment of potential exposures; To assess the adequacy of the provisions for protection and safety.

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources Scope and purpose of the safety assessment

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources Necessary preparations for assessment Sufficient number of people with the necessary skills an and expertise available to carry out the work and funding; Background information relating to the location, design, construction, commissioning, operation, decommissioning and dismantling of the facility or activity, together with any other evidence that is required to support the safety assessment; The necessary tools, including the necessary computer codes for carrying out the safety analysis; The safety criteria defined in national regulations or approved by the regulatory body to be used for judging whether the safety of the facility or activity is adequate have been identified. This could include applicable industrial safety standards and associated criteria

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources Assessment of safety functions, assessment of defence in depth GSR Part 3, The safety assessment shall include, as appropriate, a systematic critical review of: (a) The operational limits and conditions for the operation of a facility; (b) The ways in which structures, systems and components, including software, and procedures relating to protection and safety might fail, singly or in combination, or might otherwise give rise to exposures, and the consequences of such events;

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources Assessment of safety functions, assessment of defence in depth GSR Part 3, The safety assessment shall include, as appropriate, a systematic critical review of (cont’d): (c) The ways in which external factors could affect protection and safety; (d) The ways in which operating procedures relating to protection and safety might be erroneous, and the consequences of such errors; (e) The implications for protection and safety of any modifications;

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources Assessment of safety functions, assessment of defence in depth Example of internal events: specific loads and load combinations, and environmental conditions (e.g. temperature, pressure, humidity and radiation levels) imposed on structures and components as a result of internal events, such as pipe breaks, impingement forces, internal flooding and spraying, internal missiles, load drop, internal explosions and fire

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources Assessment of safety functions, assessment of defence in depth Example of external events: natural and human induced external events in the region that have the potential to affect the safety of facilities and activities. This could include: natural external events (such as extreme weather conditions, earthquakes and external flooding) human induced events (such as aircraft crashes and hazards arising from transport and industrial activities)

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources Assessment of safety functions, assessment of defence in depth GSR Part 3, The safety assessment shall include, as appropriate, a systematic critical review of (cont’d): (f) The implications for protection and safety of security measures or of any modifications to security measures; (g) Any uncertainties or assumptions and their implications for protection and safety.

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources Assessment of safety functions, assessment of defence in depth GSR Part 3, The registrant or licensee shall take into account in the safety assessment : (c) Factors that could give rise to unintended operation of any radiation generator or a loss of shielding, and the measures available to detect and to prevent or control such occurrences; (d) The extent to which the use of redundant and diverse safety features, which are independent of each other so that failure of one does not result in failure of any other, is appropriate to restrict the likelihood and the magnitude of potential exposure.

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources Assessment of safety functions, assessment of defence in depth GSR Part 4, All safety functions associated with a facility or activity shall be specified and assessed. The safety functions associated with the engineered structures, systems and components, any physical or natural barriers inherent safety features any human actions necessary to ensure the safety of the facility or activity.

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources Assessment of safety functions, assessment of defence in depth GSR Part 4, All safety functions associated with a facility or activity shall be specified and assessed. An assessment is undertaken to determine whether the safety functions can be fulfilled for: all normal operational modes (including startup and shutdown where appropriate), all anticipated operational occurrences and the accident conditions to be taken into account; these include design basis accidents and beyond design basis accidents (including severe accidents).

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources Assessment of safety functions, assessment of defence in depth Safety functions are functions that are necessary to be performed for the facility or activity to prevent or mitigate radiological consequences of normal operation, anticipated operational occurrences and accident conditions. Example: these functions can include: control of reactivity, removal of heat from radioactive material, confinement of radioactive material and shielding

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources Assessment of safety functions, assessment of defence in depth In the assessment of the safety functions, it has to be determined whether they will be performed with an adequate level of reliability It has to be determined whether the structures, systems, components and barriers have an adequate level of reliability, redundancy, diversity, separation, segregation, independence and equipment qualification,

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources Assessment of safety functions, assessment of defence in depth The necessary layers of protection, including physical barriers to confine radioactive material at specific locations, and the necessary supporting administrative controls for achieving defence in depth have to be identified in the safety assessment. This includes identification of: Safety functions that must be fulfilled; Potential challenges to these safety functions; Mechanisms that give rise to these challenges, and the necessary responses to them; Provisions made to prevent these mechanisms from occurring;

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources Assessment of the provisions for radiation protection GSR Part 3, The registrant or licensee shall take into account in the safety assessment: (a) Factors that could precipitate a substantial release of radioactive material, the measures available to prevent or to control such a release, and the maximum activity of radioactive material that, in the event of a major failure of the containment, could be released to the environment;

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources Assessment of the provisions for radiation protection GSR Part 3, The registrant or licensee shall take into account in the safety assessment (cont’d): (b) Factors that could precipitate a smaller but continuing release of radioactive material, and the measures available to detect and to prevent or to control such a release; GSR Part 4 - that radiation exposure of workers and members of the public within relevant dose limits and protection is optimized

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources Assessment of the of engineering aspects GSR Part 4, Taking into account robust and proven design. Relevant operating experience, including results of root cause analysis of operational occurrences, accidents and accident precursors where appropriate, have to be taken into account. The design principles that have been applied for the facility are identified in the safety assessment. The design principles could give rise to requirements to incorporate defence in depth, multiple barriers to the release of radioactive material, and safety margins, and to provide redundancy, diversity and equipment qualification in the design of safety systems.

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources Assessment of safety over the lifetime of a facility or activity GSR Part 3, Registrants and licensees shall perform additional reviews of the safety assessment as necessary to ensure that the technical specifications or conditions of use continue to be met when: (a) Significant modifications are envisaged to the facility or to its operating procedures or maintenance procedures; (b) Significant changes occur on the site that could affect the safety of the facility or of activities on the site;

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources Assessment of safety over the lifetime of a facility or activity GSR Part 3, Registrants and licensees shall perform additional reviews of the safety assessment as necessary to ensure that the technical specifications or conditions of use continue to be met when: (c) Information on operating experience, or information about accidents and other incidents that could result in exposures, indicates that the current assessment might be invalid; (d) Any significant changes in activities are envisaged; (e) Any relevant changes in guidelines or standards are envisaged or have been made.

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources Assessment of safety over the lifetime of a facility or activity GSR Part 1: Review and assessment of information relevant to safety at different stages of regulatory process: Initial review ( development of the design; construction of the facility or implementation of the activity; commissioning of the facility or activity; commencement of operation of the facility or conduct of the activity; normal operation of the facility or normal conduct of the activity); Periodic safety reviews; Modification of the design or operation; Review of changes to safety related issues Reviews of operation experience

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources Assessment of safety over the lifetime of a facility or activity GSR Part 1: Review and assessment of information relevant to safety at different stages of regulatory process (cont’d): Review of life extension of the facility beyond its original design life; Review of long term operation Review of decommissioning and dismantling of a facility; Review of the release from regulatory control; Changes in ownership or management of the facility; Closure of a repository for the disposal of radioactive waste and the post-closure phase; Remediation of a site and release from regulatory control

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources Assessment of human factors The safety of facilities and activities will depend on actions carried out by the operating personnel, and all such human interactions with the facility or activity are to be assessed: whether personnel competences, the associated training programs and the specified minimum staffing levels for maintaining safety are adequate. whether requirements relating to human factors were addressed in the design and operation of a facility: human factors relating to ergonomic design in all areas human–machine interfaces where activities are carried out. aspects of safety culture are to be included in the safety assessment as appropriate

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources Documentation of the safety assessment an independent verification GSR Part 3, Registrants and licensees shall ensure that the safety assessment is documented where appropriate, that it is independently reviewed under the relevant management system.

Notification & Authorization. Graded Approach Further Reading and References Radiation Protection and Safety of Radiation Sources, International Basic Safety Standards, Interim Edition, No. GSR Part 3, 2011 Safety Assessment for Facilities and Activities, Series No. GSR Part 4, Vienna, 2009

Notification & Authorization. Graded Approach Questions?

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources IAEA requirements on safety assessment GSR Part 3, If as a result of a safety assessment, or for any other reason, opportunities to improve protection and safety appear to be available and improvement seems desirable, any consequential modifications shall be made cautiously and only after favourable assessment of all the implications for protection and safety. The implementation of all improvements shall be prioritized so as to optimize protection and safety.

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources Components of the safety case should include the following: the context; the safety strategy; the facility description; safety assessment; limits, controls and conditions; iteration and design optimization; uncertainty management; integration of safety arguments.

Notification & Authorization. Graded Approach IAEA Training Course on Effective and Sustainable Regulatory Control of Radiation Sources