The following story originally appeared in NEI’s Nuclear Energy Overview.
NEI is urging the NRC to remain focused on the high-priority recommendations from the agency’s Fukushima task force before proceeding with implementation of the lower-priority items.
“Preliminary industry assessments indicate that the Tier 1 items, when completed, will achieve as much as 90 percent of the safety benefit from all recommendations,” NEI said in a comment letter last week. “At this time, the safety benefits derived from proceeding with implementation of the Tier 2 or Tier 3 recommendations are unclear.”
Last October the NRC staff grouped the task force’s recommendations into three tiers, with the first tier consisting of those recommendations to be begun “without unnecessary delay.” Tier 2 and 3 recommendations cover issues that require more assessment, depend on the resolution of Tier 1 issues, or depend on the availability of critical skill sets.
NEI’s letter follows a meeting last month at which NRC staff, while acknowledging that the Tier 1 recommendations would give the greatest safety benefit, said they were planning to move forward on the lower-priority items.
The letter reminds the agency of the burden the Fukushima regulations are placing on industry and regulator alike.
“Neither the industry nor the NRC has infinite financial or staffing resources,” the letter said. “The industry’s resources are fully committed to implementing Tier 1. While the industry understands the need for planning, it does not support nor does it have the resource capability to start work on non-Tier 1 activities before the Tier 1 scope and implementation details are reviewed and approved.”
The letter said completing work on Tier 1 issues would allow for a clearer understanding of both their safety benefits and of the lower-priority actions.
“Once the path forward on the Tier 1 items is clear and implementation plans have been approved, better assessments of the benefits of proceeding with Tier 2 and Tier 3 can be made. At that time, the safety benefits of Tier 1 will be known and the significance of the Tier 2 and Tier 3 actions can be better assessed.”
The letter added that the Tier 2 and 3 issues should follow several guiding principles:
- Directly link with the progression of the accident at Fukushima.
- Take into account the safety benefit from implementing Tier 1 actions, based on holistic risk-informed insights.
- Be directly applicable to U.S. plants, while taking into account differences in design, training and plant management practices at Japanese plants, including severe accident management procedures.
The letter also provides the industry’s detailed comments on certain aspects of the Tier 3 recommendations, including:
- Seismic and flooding re-evaluations should be conducted when new and significant information is identified, rather than on a fixed 10-year update schedule.
- The need for hardened containment vents for designs other than Mark I and Mark II boiling water reactors should be further evaluated.
- Hydrogen leakage should not be evaluated in isolation from other Fukushima-related issues—such as non-BWR I and II hardened vents—and needs further public discussion and evaluation.
NEI’s full comment letter can be found here.
—Nuclear Energy Overview