Five Years After Fukushima, U.S. Reactors Still Vulnerable

March 11, 2016 | 11:40 am
Lisbeth Gronlund
Former Contributor
Radiation hotspot in Kashiwa, February 2012

Radiation hotspot in Kashiwa, February 2012

Five years ago today, the Fukushima Daiichi nuclear power plant in Japan was hit first with a 9.0 magnitude earthquake and then with a 50-foot tsunami.

The reactors shut down as they were designed to do, but the nuclear core of a shut-down reactor remains hot and needs to be cooled to prevent a meltdown of the fuel. In addition, the radioactive spent fuel stored in pools of water needs to be cooled. Cooling requires electrical power—but the electric grid was destroyed and the backup diesel generators, located in the basements, were flooded and rendered useless.

In the following days, the three operating reactors suffered melt-downs and released radiation into the environment, significantly contaminating hundreds of square miles. Fortunately, Fukushima is located in a rural area, but some 100,000 evacuees remain unable to return to their homes.

Japan has been cleaning up the surrounding region by removing contaminated soil and placing it in large plastic bags, but has no long-term storage facility to accommodate the millions of waste-containing bags. The ultimate cost to Japanese taxpayers for the cleanup and compensation is estimated to be $100 billion.

A U.S. Fukushima?

But what has this got to do with nuclear power in the United States? A lot, it turns out.

There are many ways a reactor can lose offsite and backup electrical power—triggering a “station blackout” and disabling cooling equipment. Many U.S. reactors are more vulnerable to earthquake and flooding risks than was assumed when the reactors were built. For example, 34 reactors—one-third of the U.S. fleet—could face flooding hazards greater than they were designed to withstand if an upstream dam fails. The Nuclear Regulatory Commission (NRC), the agency that oversees the nuclear industry, has known about these risks for over 15 years and has failed to adequately address them.

Similarly, seismologists have determined that the earthquake risk in the central and eastern parts of the U.S. is greater than was understood when most reactors in those areas were built. The NRC now requires new reactors built in these areas to be designed with protection against the greater hazard—but has done nothing about existing reactors. The agency has identified 27 reactors that were not built to withstand the local earthquake risk based on current seismic information.

The NRC receives a wake-up call but falls back asleep

Following the Fukushima accident, the NRC understood that the United States needed to do a better job of preparing for natural disasters and other events that a reactor was not built to withstand. The NRC calls these “beyond design-basis” or “severe” events.

The agency appointed a task force of senior staff to determine how to make U.S. reactors safer if they were to confront an accident like that at Fukushima. In July 2011 the task force released a report with a dozen detailed multi-part recommendations.

So far, so good. But what has happened since then?

My colleague Ed Lyman, a senior scientist here at UCS, has just released a report assessing what the NRC and industry have done to carry out these recommendations: Preventing an American Fukushima: Limited Progress Five Years after Japan’s Nuclear Power Plant Disaster.

The bottom line is that the NRC “has rejected or significantly weakened many of the commonsense recommendations made by the task force.” And while “the NRC and the nuclear industry have devoted several billion dollars and much time and labor to addressing [some] of the task force recommendations … it is difficult to assess to what extent that considerable effort will reduce the risk to the public from severe nuclear accidents.”

Perhaps most disturbing is that the NRC rejected the top recommendation made by the task force—to overhaul what it called a “patchwork” of NRC regulations and industry voluntary guidelines for “beyond-design-basis” events.

A half measure

The main industry response to the Fukushima accident has been the FLEX program (short for “diverse and flexible coping capability”). The goal of this program is to stockpile extra emergency equipment, including diesel-powered pumps and backup power supplies, to allow cooling during a prolonged loss of alternating current power. But as Ed’s report details, the industry got out ahead of the NRC and began buying equipment before the NRC developed any requirements for the equipment. One result is that the industry bought commercially available equipment, which is cheaper but may not be able to survive a severe accident of the sort it would be needed for.

So, the more than 100 million people living within 50 miles of a U.S. reactor may—or may not—be safer than they were five years ago. They certainly aren’t as safe as they would be had the NRC followed more closely the recommendations of its own task force.

Time to wake up

To improve the safety of U.S. reactors in the event of a severe accident, the NRC must revamp its regulatory framework for beyond design-basis events. UCS hopes that future NRC commissioners will revisit the decision not to do so.