Taking a Look at an Independent Review of Spent Fuel Pool Safety and Security

Scott Burnell
Public Affairs Officer

 A recently published National Academy of Sciences report includes the academy’s latest thoughts on enhancing the safety and security of spent nuclear fuel storage. The NRC gave NAS the funding for the study at the direction of Congress. This report is Phase 2 of the NAS work; we’ll recap Phase 1 in a moment.

The agency sponsored the two-phase NAS study to identify lessons learned from the Fukushima accident and to follow up on previous NAS recommendations on spent fuel safety and security. The earlier NAS work looked at these same topics after the Sept. 11, 2001, terrorist attacks, and led to a 2004 report (our response to Congress about the 2004 report is on the agency’s website).

As the NAS gathered information for the latest report, they talked with NRC staff and received NRC documents related to relevant regulatory programs and requirements.

Our first look at the Phase 2 NAS report did not identify any safety or security issues that would require immediate action by the NRC. U.S. nuclear power plant security is extremely robust; the plants are some of the best protected facilities in the world. We have a long record of studying and analyzing the safety and security of spent fuel storage. Some of these studies have resulted in security enhancements. For example, after the 9/11 terrorist attacks, the NRC’s security assessments resulted in improvements to security at nuclear power plants, and strengthened the plants’ coordination with other federal and state agencies in responding to security threats.

Our post-Fukushima requirements for U.S. reactors have enhanced spent fuel pool safety. For example, we required plants to improve the ability of operators to monitor the water level in spent fuel pools. We also required plants to develop new strategies for adding water to these pools to keep them cool, even under the conditions that might exist following an extreme natural event, like a severe earthquake or flood.

Looking at all the available information, we remain confident U.S. spent fuel is safely and securely stored. The Phase 2 NAS report looks ahead to some areas that NAS believes warrant further study or action. We’ll evaluate the NAS report and its recommendations to see if we need to take any further action in the long run. The staff plans to provide the Commission with its assessment of the NAS Phase 2 report later this year.

We know the public has questions about safely and securely storing spent nuclear fuel, so the NRC website includes key points and frequently asked questions and answers. We expect to update this information once we’ve finished assessing the NAS report.

We looked at the NAS Phase 1 report in 2014. That report looked at the causes of the Fukushima accident and also identified lessons for improving nuclear power plant safety systems and operations. The staff provided the Commission an assessment of the Phase 1 report in SECY-15-0059. In our final assessment of the Phase 1 report, we determined that all of the NAS recommendations were being addressed by completed and ongoing NRC activities.

Inspector General Report on Spent Fuel Pools Makes Recommendations To Improve Oversight

Stephen Dingbaum
Assistant Inspector General for Audits

oigAn Office of the Inspector General audit regarding the NRC’s oversight of spent fuel pools is now available here. The audit set out to determine if the NRC’s oversight of spent fuel pools — and the nuclear fuel they hold — provides adequate protection for public health and safety, and the environment.

The NRC is responsible for developing the regulatory framework, analytical tools, and data needed to ensure safe and secure storage, transportation, and disposal of spent nuclear fuel. In the U.S. today, there are 93 spent fuel pools currently storing spent fuel. Recent NRC staff studies demonstrating the safety of spent fuel pools and the safety of continued storage of spent fuel at reactor sites highlight the need to make sure the pools operate safely for longer periods than originally envisioned.

The OIG found the NRC does provide adequate oversight of spent fuel pools and the fuel they contain, but opportunities exist for improvement. Specifically, we found that regulatory uncertainty exists in the NRC’s evaluation of the analytical methods used to prevent a chain reaction in the spent fuel pools. In addition, there are gaps in NRC’s spent fuel pool inspection program as inspections of spent fuel pools greatly vary between licensee sites and are limited in scope.

As part of its mission, the NRC must inspect and assess licensee operations and facilities to ensure compliance with its regulatory requirements. The NRC should also regulate in a manner that clearly communicates requirements and ensures regulations are consistently applied and practical. The OIG believes an absence of effective spent fuel pool guidance for both licensees and NRC staff may reduce program efficiency and effectiveness.

The report makes four specific recommendations to improve NRC oversight, including developing and issuing new guidance for licensees and developing new NRC inspection procedures. NRC management stated their general agreement with the findings and recommendations.

 

Keeping Proper Track of Spent Fuel Pool Conditions

Lauren Gibson
Project Manager
Japan Lessons-Learned Directorate
 

While “spent fuel pool #4” at Fukushima Daiichi did keep its contents safe during the March 2011 accident, no one could confirm that during the accident. The plant’s staff and other experts, including the NRC, simply didn’t have enough information to know what was going on in the pool. Why not? There was no reliable way to measure the pool’s water level.

SFP_instrKnowing the water level is important because if the pool had boiled dry, it would have damaged the fuel and added to the accident’s radiation release. The Japanese plant’s staff did the right thing in assuming the worst and making many attempts to add water to the pool. They even dropped water from helicopters. If they had known the pools were OK, however, they would have been able to focus on addressing the real problem: the damaged reactors.

This experience led the NRC to order U.S. nuclear power plants to add instrumentation to their spent fuel pools. That way, if an accident occurs at a U.S. reactor, plant staff will be able to tell when the spent fuel pool needed attention. Spent fuel pool instrumentation will help plant staff properly prioritize their accident response and keep the public safe.

U.S. reactors already monitor a small fraction of the water level in the spent fuel pool. However, this system may not work if power is lost, as it was at Fukushima, and can’t provide advance warning of low water levels.

The NRC’s order requires U.S. reactors to be able to tell whether water is at or above certain important levels. The highest level means enough water is available for the normal cooling system to work. The second level marks the level of water needed to protect someone standing next to the pool from the fuel’s radiation. The lowest level is still enough to cover the fuel, but the plant staff should begin adding more water to the pool.

Of course, water may be added—and most likely would be—prior to reaching this point. The order also requires that plant staff must be able to read these levels from somewhere away from the pool, such as in the control room.

U.S. reactors must install the new instruments no later than two refueling cycles after they submit their plan to the NRC or by the end of 2016, whichever comes first. All U.S. plants submitted their instrumentation plans in February 2013. We’ve been reviewing the plans and we recently issued interim staff evaluations. These documents give the plants feedback so they can continue on the right track for implementing the order.

The evaluations also ask plants for additional information we need to complete our review. While the agency’s final approval is yet to come, the interim evaluations give plants the confidence to order equipment and move forward with installing the instruments. We’ll provide the plants a final staff evaluation when we can conclude that they’ll comply with the order by the deadline by following their plan. We’ll continue inspecting plants to confirm they’ve finished complying with the order.

Our website’s Japan Lessons Learned section has a page with more information about the order and related guidance.