Seismically induced core-damage accidents in the Clinch River Breeder Reactor Plant

An estimate of the occurrence frequency of seismically induced core-damage accidents in the Clinch River Breeder Reactor Plant (CRBRP) was made using readily available data and techniques. Site seismicity was determined through statistical analysis of a historical listing of earthquakes surrounding the site. Component fragilities were based on analyses conducted by CRBRP vendors and information presented in light water reactor risk assessments. Seismically induced accident sequences leading to core damage were developed by event tree and fault tree analysis.

The total seismically induced core-damage frequency was determined to be 3.2 x 10^-5 per year, which comprises 90% of the total core-damage frequency of the CRBRP. Earthquakes that cause the peak ground acceleration at the CRBRP site to exceed 0.25 g (the design-base earthquake) were found to be major contributors to the total frequency.