The following news article originally appeared in NEI’s Nuclear Energy Overview.
The NRC has issued for public comment draft interim staff guidance for U.S. nuclear energy facility operators to perform certain flooding hazard assessments in response to a request for information the agency issued in March as part of its response to the Fukushima accident.
The March request calls for licensees to use the latest available information and analysis methods to analyze site-specific hazards, including stream and river flooding, hurricane storm surges, tsunamis, and dam failures.
Of those flooding hazards, the draft guidance issued last week focuses on giving the NRC staff an up-to-date technical basis to evaluate licensee assessments of hazards from tsunamis, hurricane storm surges and water body oscillations known as “seiche.” The guidance says all coastal nuclear energy facilities must perform assessments for these types of phenomena and provides a combination of allowable deterministic and probabilistic methods of analysis.
If the re-evaluated flooding hazards exceed the level a plant was originally designed to withstand, the operator must perform an “integrated assessment” of the plant’s specific vulnerabilities and its response capabilities, including physical barriers, temporary protective measures and operational procedures. The NRC issued draft guidance earlier this month on how to perform the integrated assessments (see Nuclear Energy Overview, Oct. 4).
The guidance says the agency will review licensee responses to the request for information and determine whether more regulations are required.
The guidance is not mandatory for licensees—the NRC said it will consider alternate approaches.
The draft guidance (JLD-ISG-2012-06) is available in the NRC’s ADAMS document control system under accession number ML12271A036. The NRC will accept comments until Nov. 26. Comments should be sent directly to the NRC via www.regulations.gov using Docket ID NRC-2012-0261, with a copy to Jim Riley at NEI (email@example.com). NEI is collecting significant generic comments to submit to the agency on behalf of industry.