Presentation to NRC Commission on Lessons from Fukushima

November 17, 2015 | 9:00 am
Dave Lochbaum
Former Contributor

The Nuclear Regulatory Commission invited me to share UCS’s perspectives on the status of lessons learned from the Fukushima accident during a November 17, 2015, briefing. This briefing was one in a series of briefings conducted every 3-4 months by the Chairman and Commissioners to hear from external stakeholders and the NRC’s senior staff.

The three primary points in my presentation were:

Inadequate Foundation for Flooding and Earthquake Re-evaluations: In March 2012, the NRC ordered owners to inspect their plants for flooding and earthquake hazards and then re-evaluate protection levels with the objective of properly managing these risks. But after these inspections were completed, serious flooding protection deficiencies were revealed by actual events at the Arkansas Nuclear One and St. Lucie plants. The inspections failed to identify deficiencies (over 100 deficiencies were revealed after the Arkansas Nuclear One event and nearly 50,000 gallons of water flooded a building at St. Lucie). It appears that the inspections failed to accurately assess flooding and earthquake hazards, significantly impairing the subsequent re-evaluation of the hazards.

Inadequate Protection Against Erosion of Safety Upgrades: Mitigation measures are being implemented to make U.S. reactors less vulnerable to Fukushima-styled challenges. These measures are not subject to the regulatory requirements imposed on equipment and training used to mitigate what are called design bases accidents (e.g., pipe breaks, equipment malfunctions, etc.). In recent years, the NRC staff identified dozens of times when owners have improperly and illegally lessened protection against design bases accidents by not first receiving NRC’s approvals. Because Fukushima’s mitigation measures are not similarly controlled, it seems extremely likely if not absolutely certain that upgrades implemented today will be lessened tomorrow by owners.

Huge Gap Between Industry and NRC Risk Perceptions: UCS reviewed the risks calculated by the NRC and the industry for serious safety events over the past 15 years. In all cases, the industry calculated much lower risks than did the NRC. The closest—repeat, closest—agreement was when the NRC’s risk was only twice as high as the owner’s calculation. This situation exacerbates the safety erosion problem. When owners calculate very low risks and do not have to engage the NRC, they can lessen or eliminate a safety upgrade.