U.S. Nuclear Industry Largely Safer After Fukushima Accident

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By Rebecca Kern

March 10 —The U.S. nuclear industry is safer after making fleet-wide improvements over the past five years since the meltdown of three nuclear reactors at the Fukushima Dai-Ichi nuclear plant in Japan, industry, regulators and safety advocates say.

The Nuclear Regulatory Commission mandated safety improvements as a result of lessons learned from the 2011 nuclear plant disaster in Japan.

“I think the plants are safer than they were five years ago,” NRC Chairman Stephen Burns told Bloomberg BNA. “A lot of the things we've done, I believe, have made a safe situation safer.”

He said the NRC has focused on how plants can safely shut down a reactor during a “beyond-design-basis event,” such as a natural disaster.

“If I lose the ability to control the plant, even with the equipment that is robustly designed and available, if I lose that, how can I recover? That's what a lot of this is focused on,” Burns said.

The Nuclear Energy Institute, an industry group, said the industry is safer since it has followed the NRC requirement of buying and installing second sets of backup equipment, including diesel generators, batteries and pumps, to ensure power during an unexpected outage.

“When you boil it down to its basic, root causes, they lost electricity and they lost the ability to cool the [reactor] core, to maintain the containment integrity and to cool the spent fuel,” said Tony Pietrangelo, NEI's senior vice president and chief nuclear officer. Damage to the reactors caused a release of radiation.

“We believe we've added another layer of safety protection,” Pietrangelo told Bloomberg BNA. He said the industry's response has been focused on solving problems that led to the reactor meltdown at Fukushima.

NRC Inspections Just Started

However, because NRC has only inspected and approved two of the 61 U.S. plants for their compliance with the new post-Fukushima safety requirements, safety advocates say it's too early to say the system is safer.

Dominion Resources' North Anna nuclear plant passed the inspection earlier this year, and Tennessee Valley Authority's Watts Bar plant passed in April 2015, Scott Burnell, a spokesman for the NRC, told Bloomberg BNA.

The NRC estimates the inspections will continue until next year, but there is no estimate of when they will be completed, Burnell said.

“I don't think you can say the industry is safer,” Ed Lyman, a senior scientist at the Union of Concerned Scientists' Global Security Program, told Bloomberg BNA.

“They may be on the path to being safer, but from a formal point of view, until all of the procedures are done, until NRC has approved these plans, we don't have regulatory assurance they they're going to be effective,” he said.

“Maybe some plants, if they had a tsunami tomorrow, they'll be glad they have the equipment on site, but it hasn't been fully validated,” Lyman said. 

FLEX Buildings, Equipment and Spent Fuel Pool

One of the first actions the NRC took after the Fukushima accident was to form a “Near-Term Task Force” to assess the U.S. industry and provide recommendations on actions to make it safer in the event of beyond-design-basis events, such as earthquakes. The group issued 12 recommendations in a July 2011 report.

The NRC commissioners at the time agreed to implement several of the recommendations, including the Mitigating Strategies Order, which required plants to enhance their ability to maintain safety during a prolonged power outage. To comply with this order, the nuclear industry created a program known as the “diverse and flexible coping capability program” or FLEX for short.

Nuclear plants are required to purchase backup power equipment in case they lose electrical power and can't operate pumps to keep water levels high enough to cool the reactor, as happened at Fukushima. The backup equipment includes diesel generators, pumps, hoses, batteries and cables in a new building that was designed to withstand an earthquake.

Twenty-one of the 61 plants have backup equipment, and the rest are expected to have it by the end of the year, Burns said.

Checking Spent Fuel Pools

The second order issued by NRC was on spent fuel pool instrumentation outside the spent fuel facility, showing water levels inside it. At Fukushima, there was no external instrumentation for Unit 4 and inspectors were unable to get inside to assess the level, Burns said.

Approximately 80 percent of the operators of U.S. reactors have told NRC that they have installed spent fuel pool instrumentation, and the rest plan to install it by the end of 2016, Burns said.

The NRC also issued an order that applies to just 30 boiling water reactors which must improve venting systems that help prevent or mitigate damage to the reactor core in the event of a serious accident. The agency said all of these reactors are expected to meet the venting requirements by 2019 .

As another precaution, the industry created two national response centers, in Memphis, Tenn., and Phoenix, which also have an extra set of backup equipment that can be sent to a plant located anywhere in the U.S. within 24 hours. The industry has spent $4 billion on post-Fukushima safety enhancements, NEI's Pietrangelo told Bloomberg BNA.

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Expected Completion of NRC's Post Fukushima Requirements

Concerns With Equipment Requirements

Lyman said he has concerns with the performance-based requirements for the FLEX program, which was originally proposed by the nuclear industry and adopted by the NRC. The requirements say to purchase the equipment, but don't specify the types of equipment or minimum standards, he said.

He said performance-based regulation focuses more on meeting high-level objectives without detailed requirements as to how they should be met.

An alternative is a compliance-based system, in which there are minimum requirements.

“If there is a compliance-based system, at least there are standards and you can check things off. It's not guaranteed to be better, but at least it's clearer,” he said

He said the NRC should have had at least minimum compliance standards that licensees have to meet for equipment.

Dave Lochbaum, director of the Union of Concerned Scientists’ Nuclear Safety Project, told Bloomberg BNA that without compliance-based, or prescriptive, requirements, there’s no assurance the equipment will work.

NRC Commissioner William Ostendorff, one of the two current commissioners who was serving during the time of the Fukushima accident, said he supported the performance-based requirements for the FLEX program. He told Bloomberg BNA that every plant is different and so to have the same requirements for all of them in a compliance-based system would not work.

Seismic, Flooding Hazard Assessments

The NRC also issued requests from industry to provide feedback on the new evaluations they had to complete on seismic and flooding hazards.

About a quarter of plants have completed the seismic analysis, and the remainder are expected to complete the analysis by the end of 2019. This involves assessments as to whether the plant's buildings and equipment can withstand a certain seismic event, Burns said.

About 90 percent of plants have completed the reevaluation of their flooding hazards. The remaining plants have to receive additional information from the Army Corps of Engineers, which are expected to be completed by the end of 2018.

All of the plants have completed the requirements of NRC staff to “walk down” the plant to verify existing seismic and flooding protection is in place as originally designed at the plant, Burns said.

The NRC staff issued a proposed rulemaking that codifies these post-Fukushima safety requirements and makes them applicable not only to existing plants but to new nuclear plants as well. A final version is expected at the end of 2016 .

To contact the reporter on this story: Rebecca Kern in Washington at rkern@bna.com

To contact the editor responsible for this story: Larry Pearl at lpearl@bna.com