Dangerous nuclear waste in Pa. and N.J. should be stored more safely| Perspective

The partial meltdown of the Fukushima Daiichi nuclear plant in Japan in 2011 roused scientists and regulators in our country to reconsider the risks of nuclear facilities. I was part of a high-level panel that examined the tragedy and warned government officials to prepare these plants for rare but "extreme events" like the earthquake and tsunami that hit Japan or a terrorist attack.

Now the political leaders in New Jersey – and soon those of Pennsylvania – have a unique opportunity to do just that, reducing the risk from the thousands of tons of radioactive waste sitting at nuclear plants in both states.

New Jersey's lawmakers are nearing a deal that would provide billions of dollars in subsidies to three nuclear reactors owned by PSEG and Exelon at the Salem and Hope Creek plants. That aid, which may total $300 million a year, would allow those plants to continue operating, protecting jobs and communities that would be harmed by their abrupt closure. In Pennsylvania, Exelon has been seeking similar subsidies to keep Three Mile Island's Unit 1 on line.

But, in exchange for that aid, legislators should also demand that the utilities move their older radioactive waste from dangerous dense-packed pools to safer dry-cask storage containers.

Just as was the case in Fukushima, spent fuel at U.S. nuclear stations is stored in cooling pools. If one of the three pools at those sites were cracked by an earthquake or punctured by a terrorist attack, the result could be a loss of cooling water and a radioactive fuel fire. Millions might have to be relocated due to the radioactive contamination, and the damage could cause large parts of the state to become uninhabitable.

In Japan, had water not leaked into one of the storage pools (at Unit 4), the spent fuel would have overheated, caught fire and released enough radiation that Tokyo might have had to be evacuated.

"In the committee's judgment, the events in the Unit 4 pool should serve as a wake-up call to nuclear plant operators and regulators," our report concluded.

The risks are huge. A study done for the Nuclear Regulatory Commission estimated that, on average, a spent fuel pool fire in the United States would lead to the relocation of 3.5 million people from an area bigger than New Jersey. (My analysis shows this may understate the risk, and in either case, the number of people affected in our densely populated area could easily be greater.)

Even without a permanent repository for this waste in the U.S., nuclear plant operators can keep it safer. Right now, when the fuel rods that power a nuclear reactor are depleted (or "spent"), they are moved to adjacent deep pools of water to cool. They continue to generate heat at a declining rate over the subsequent years.

The NRC found that the risks of dense-packed pools could be greatly reduced if the utilities moved spent fuel into air-cooled casks after five years. The industry balked at the estimated $50 million per reactor cost and complained to Congress, threatening that this would cause the shutdown of more reactors.

So, the federal regulators backed off the requirement, offering the thin reassurance that an earthquake strong enough to crack a pool was highly unlikely and that the threat from terrorists was nonexistent.

As we learned in Fukushima, however, rare or seemingly impossible events can happen. And a spent-fuel fire would, in the words of one Japanese political leader, be the "devil's scenario."

So, this is where our state leaders have a chance to step in.

Ordinarily, states like New Jersey and Pennsylvania do not regulate nuclear safety; that's the responsibility of the NRC. But, these are not ordinary times. If New Jersey's or Pennsylvania's legislature decide to provide billions of dollars in new subsidies to PSEG and Exelon, the utilities ought to agree to move their older spent fuel from pools to casks. The states' residents deserve this protection in exchange for their support of nuclear power.

Frank von Hippel is a professor of public and international affairs emeritus and senior research physicist at Princeton University. He was a member of the congressionally mandated National Academy of Sciences panel on lessons learned from the Fukushima nuclear accident.