SEISMIC FRAGILITY ASSESSMENT IN THE LEIBSTADT NPP, SWITZERLAND
The results from the seismic fragility analysis of the systems, structures, and components were the input to the seismic PRA (Probabilistic Risk Assessment) of the nuclear power plant. The activities of Rizzo Associates Czech were mainly to verify the seismic safety of the nuclear power plant by the determination of the seismic margin capacity of individual equipment. Rizzo Associates Czech engineers performed the seismic plant walkdowns of all mechanical and electrical equipment on safe shutdown equipment list, they performed calculations of seismic fragility parameters for individual components using proprietary software and developed a database to manage all the data relevant to the plant’s seismic safety re-evaluation.
Individual activities within engineering assessment and performed analyzes:
- Management and coordination of work tasks.
- Data acquisition and management.
- Preparation of plant seismic walkdowns.
- Performance of seismic plant walkdowns and development of walkdown report.
- Data review and screening analysis.
- Deterministic evaluation (determination of HCLPF values of selected mechanical and electrical equipment including I&C).
- Probabilistic evaluation: determination of seismic fragility parameters of selected mechanical and electrical equipment including I&C.
The total project level of effort was 8 000 man-hours.
All activities in the framework of the project were performed in accordance with the company’s quality policy. At the same time, documents EPRI NP-6041-SL rev1, EPRI TR-103959, EPRI TR-1002988, DOE EH-0545, ASME BPVC, ACI and other relevant normative technical documentation were used as acceptance criteria.