Photo courtesy of Energy Northwest

Solution

Columbia Generating Station, Spent Fuel Pool

Newport Beach, CA

Completion

2017
Columbia Generating Station, Spent Fuel Pool

Photo courtesy of Energy Northwest

After the Fukushima Daiichi accident, the U.S. Nuclear Regulatory Commission (NRC) issued 10 CFR 50.54(f), a letter requiring licensees to perform a reevaluation of seismic hazard and take further actions if it exceeds their design basis. In response to this letter, Columbia Generating Station (CGS) undertook an evaluation of the spent fuel pool (SFP) integrity for the new seismic hazard.

Scope | Solutions

SGH performed the SFP seismic integrity evaluation in accordance with Electric Power Research Institute (EPRI) 1025287 Screening, Prioritization and Implementation Details for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic and EPRI 3002009564 Seismic Evaluation Guidance: Spent Fuel Pool Integrity Evaluation. EPRI 3002009564 specifies requirements for SFP integrity at higher seismicity sites, such as CGS. The USNRC has endorsed the requirements in these two EPRI documents. Highlights of our work included the following:

  • Evaluating Structural Integrity Requirements

  • Performing probabilistic analysis of the reactor building seismic soil-structure-interaction response using CLASSI and SASSI software

  • Determining high-confidence stress demands in SFP walls and floor

  • Calculating high-confidence low probability of failure (HCLPF) capacities

  • Demonstrating seismic margin above the ground motion response spectrum

  • Evaluating Non-Structural Integrity Requirements

  • Reviewing and performing a walkdown confirmation of piping penetrations

  • Performing a walkdown and evaluation of refueling gates

  • Completing a piping walkdown and review for siphoning requirements

  • Reviewing and screening of sloshing and boil-off requirements

  • Preparing NRC Submittal (Accepted, ADAMS Accession No. ML18106B119)

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