Technical Meeting on Deterministic Safety Analysis for Operational States and Accident Conditions for Nuclear Power Plants

The purpose of the meeting is to bring together designers, licensees, operators, and regulators to share information on current good practices, experiences, and new developments around performing DSA. This will cover all steps in performing the analyses, i.e. identification of initiating events, analysis methodology, acceptance criteria, selection of computer codes including their demonstration of code applicability and verification and validation (V&V), preparation of input data (e.g., plant parameters and modeling assumptions), assessment of uncertainties, and presentation of the analysis results.

The discussions during this Technical Meeting will provide inputs for the revision of the Safety Reports Series No. 23 (published in 2002), addressing the evolution of DSA over the last two decades. With an expanded scope to cover operational states and accident conditions, it will address the mature technologies and evolutionary and innovative reactor designs commensurately with the information available. It will ensure consistency with relevant IAEA safety standards published in the last few years, especially with GSR Part 4 (Rev. 1), SSR-2/1 (Rev. 1), SSG-2 (Rev. 1) and SSG-88.

Topics

The event will address aspects related to the DSA for NPPs including:

• Identification, categorization and grouping of Postulated Initiating Events (PIEs for anticipated operational occurrences and accident conditions).
• Acceptance criteria.
• Analysis approaches: conservative, best-estimate (realistic), combined, BEPU (best-estimate plus uncertainties) approaches.
• Types of analyses: design analysis, licensing analysis, validation of plant simulators, support for accident management and emergency planning including validation of emergency operating procedures and guidelines, analysis related to probabilistic safety assessment, analysis of operational events, regulatory oversight.
• Computer codes: selection and use of computer codes, process management, verification and validation (V&V), qualification of input data, documentation of computer codes.
• Preparation of input data for DSA.
• DSA for operational plant states and accident conditions.
• DSA in support of practical elimination of sequences that might lead to early or large radioactive releases.
• User effects.
• Treatment and evaluation of uncertainties.
• Presentation and evaluation of DSA results.

Key Deadline

30 June 2025 is the deadline for designations to be sent to IAEA through the official channels. For more information about designation and registration please refer to the Information Sheet.