Probabilistic Safety Assessment (PSA)-based Seismic Margin Assessment (SMA) for JRTR

The purpose of the Probabilistic Safety Assessment (PSA)-based Seismic Margin Assessment (SMA) is to identify potential vulnerabilities and to demonstrate that the seismic margin is greater than 1.67 times the design basis safe shutdown earthquake (SSE). The PSA-based SMA shall be conducted in accordance with Korea Institute of Nuclear Safety (KINS) - Regulatory Guide (RG) No. 4.29 and the recommendation of SECY- 93-087 approved by NRC for a seismic risk evaluation. This paper describes the work and the results of the PSA-based SMA for the JRTR that is operating by Jordan Atomic Energy Commission (JAEC). The PSA-based SMA was conducted for the JRTR in accordance with EPRI NP-6041. As a result, it quantitatively revealed the most vulnerable structures, systems and components (SSCs), and probable accident scenario extended to the direct core damage under a seismic event. Also, it demonstrated that the HCLPF magnitudes of SSCs required for safe shutdown and the accident scenarios leading to the core damage were greater than 0.5g as shown in Table 1. This indicated that the seismic margin of the JRTR was greater than 1.67 times the design basis SSE. Consequently, the JRTR plant could meet or exceed the requirement to withstand a reference earthquake of 0.3g, and an explicit seismic analysis or design for the SSCs subjected to OBE load was not needed in terms of KINS-RG No.4.29.