WASHINGTON – The earthquake and tsunami that rocked Japan five years ago causing many deaths and a meltdown at the Fukushima Daiichi nuclear power plant has left a lasting legacy for the nuclear industry. The disaster sparked a worldwide response, with some countries shutting down all of their nuclear power plants and others creating detailed plans for improvements.

The United States has put in place industry-wide safety guidelines based off lessons learned in Japan. The response has focused on upgrading power plants so that safety mechanisms could be maintained even if all power sources are lost, said Scott Burnell, a Nuclear Regulatory Commission spokesman.

But nuclear experts say the regulations are not thorough and are hampered by high costs.

The Fukushima disaster on March 11, 2011, occurred after electric power was completely cut off at the power plant. Without electricity, the plant could not carry cooling water to the reactors, which overheated and caused a nuclear meltdown – the largest meltdown after Chernobyl in the amount of radioactive material released.

It was the first meltdown caused by a major natural disaster, said Dale Klein, chairman of the Tokyo Electric Power Company’s nuclear reform monitoring committee, during a briefing about the new safety regulations. TEPCO owns the disabled Fukushima power plant.

“This was the first accident that we’ve seen in the nuclear business that was initiated by a very strong external event and all the safety systems that we thought would be in place failed,” said Klein, who is also the former chairman of the U.S. Nuclear Regulatory Commission.

What happened in Japan is considered to be a rare and severe event, said Rosa Yang, vice president of innovation with the Electric Power Research Institute. But, some reactors in the U.S. are boiling water reactors – the same reactors as the ones at Fukushima. Many nuclear reactors are also concentrated on the eastern coastline.

Source: Nuclear Engineering International

A key component of the new U.S. safety plan is the FLEX strategy, which addresses the loss of power scenario.

Under FLEX, a nuclear power plant threatened by a loss of power, would have portable equipment stored in a protected site that could generate electricity and pump water until long-term power could be restored. The stand-by equipment would function without connecting to the power grid or back-up generators. If necessary, additional equipment would be provided from two national response centers located in Tennessee and Arizona.

“FLEX was probably the single-most significant piece of action that came out of the NRC’s review of Fukushima,” said Burnell, in a phone interview.

The FLEX strategy should be implemented at all U.S. nuclear power plants by the end of 2016, with other new requirements expected to be completed by 2019, said Burnell. The nuclear industry is expected to spend $4 billion on the post-Fukushima enhancements.

More than half of the nation’s 61 nuclear plants have implemented the FLEX strategy.

The NRC is also requiring improved venting systems to be installed in containment facilities – areas designed to mitigate the impact of a nuclear accident. In Fukushima, the containment structure leaked radioactive material and hydrogen, which caused the explosions and further damaged the plant.

“Some of the plants similar to Fukushima in the United States already have systems in place to vent pressure from containment, which allows the containment structure to continue to do its job and hold in radioactive material,” Burnell said. “Fukushima demonstrated that those systems needed to be more robust.”

Additional enhancements include updating existing emergency plans to improve crisis response, such as communication both within a plant and with outside agencies, such as the Nuclear Energy Institute, the Institute of Nuclear Power Operations and the Electric Power Research Institute – all nuclear research organizations.

Other countries such as the United Kingdom, South Korea and France followed the United States in assessing plants and making investments in safety improvements.

Although the new U.S. plans seem to cover the bases, the NRC softened or left out safety regulations that it deemed unnecessary, said Edwin Lyman, a global security scientist with the Union of Concerned Scientists, a non-profit research organization.

“To fix that problem is to brainstorm all the ways that challenge all the assumptions about safety, and really think hard about what the vulnerabilities are and address those appropriately,” Lyman said. “We feel that the NRC’s response hasn’t done that. It’s been a very limited and targeted response.”

The NRC is tasked with determining what safety regulations are vital for power plants to provide adequate protection of health and safety – all nuclear sites are required to do that much by the Atomic Energy Act.

If regulations are important enough to safety, then the NRC does not consider costs of implementation, said Burnell.

Costs for additional safety enhancements – such as replacing metal fuel rods and adding radiation filters on venting systems – were considered and determined to not be cost-effective. That was a mistake, said Lyman.

“Obviously we’re not happy with the notion that cost should be a factor,” he said. “You can’t go chasing after every very low probability event with very expensive safety measures, so there is some logic behind it. But we think that that method has been abused partly by what is considered a cost and a benefit.”

A report [hyperlink: http://www.ucsusa.org/sites/default/files/attach/2016/03/Preventing-American-Fukushima-full-report.pdf] released by the Union of Concerned Scientists also raised concerns about the FLEX strategy, such as whether the equipment would actually be usable and available during an emergency.

“It leads to the argument about how robust does that equipment have to be and how frequently do you have to inspect it or maintain it,” Lyman said. “Those things are cost factors and the industry is really interested in not spending a lot of money on maintaining this equipment.”

Some countries, like Germany, decided to decommission all nuclear reactors and focus on developing other sources of renewable energy, said Arjun Makhijani, president of the Maryland-based Institute for Energy and Environmental Research.

“Germany had a structured response to get out of nuclear, which has consequences for expenses and carbon emissions, but I think in the long term it was a sound decision,” Makhijani said.

As the U.S. energy industry moves toward clean power, the nuclear sector is vital to meeting emissions standards set by the Clean Power Plan, said Maria Korsnick, chief operating officer with the Nuclear Energy Institute, a nuclear research group. The plan aims to reduce carbon emissions 32 percent by 2030 compared to 2005 levels.

“We learned the lessons well and I’m confident in how well prepared we are today,” said Korsnick at the briefing, which was hosted by the institute.

But increasing reliance upon nuclear energy means that safety is even more important, said Lyman.

“In order for nuclear power to maintain itself as an option for climate change mitigation it has to be viable and that means it has to be safe, secure and economical,” he said.