The Low-Risk Pool
Herschel Spector
The New York Times
October 17, 2004

The Connecticut attorney general is pressing the Nuclear Regulatory Commission to require units 2 and 3 at the nuclear power plants at Indian Point to transfer much of the spent fuel out of pools where they are now stored and be placed into casks. These casks would remain on site in Buchanan, N.Y., until they are taken to a national nuclear waste repository that may eventually open at Yucca Mountain in Nevada. Officials in Westchester County are also seeking such a transfer. But these officials are misguided - and they are basing their decisions on outdated information.

Nuclear fuel elements are clusters of fuel rods about 12 feet long. Used fuel elements at each operating Indian Point power plant are placed on the bottom of a pool of water adjacent to the plant's containment building, which shields the pool from many directions. This water is about 40 feet deep and inside a huge reinforced-concrete structure with more than six-foot-thick walls and a stainless-steel liner. The pools rest on bedrock and are largely below ground. They can withstand earthquakes and natural forces. Studies also show that Indian Point's spent fuel pools can withstand a direct hit by the largest commercial aircraft traveling at top speed without causing drainage.

When units 2 and 3 first began operating in the early 1970's, used fuel was stored in the pools in a configuration called an open array; if there was an accident that somehow drained the pool, the widely spaced used fuel could be cooled by air. It was assumed that there would be a national nuclear waste repository ready to take the used fuel before these pools would be full.

But long delays in opening Yucca Mountain forced nuclear utilities to go from the open-array configuration to more compact arrangements. Now even these compact arrangements are reaching capacity, prompting utilities to remove the oldest fuel elements and place them into steel and concrete casks on site.

In this age of terrorism, this compact pool arrangement has come under scrutiny. The concern is that a terrorist attack might somehow drain the water from these pools, causing the fuel to overheat and release radioactive material.

In February 2003, some scientists associated with Princeton University published a draft study calling for 80 percent of the oldest spent fuel in the pools in the nation's nuclear plants to be transferred to casks. The remaining 20 percent of the spent fuel would be returned to the original open-array configuration. The study proposed a 10-year, multibillion-dollar national cask program.

But the proposal did not provide adequate safety. Debris from a terrorist attack might block the air flow in an open array, and any attack powerful enough to drain this huge structure could also crush some of the spent fuel. These scientists now acknowledge that this air cooling design was insufficient, and that a small water spray system would also be needed to prevent crushed fuel from overheating.

Moreover, studies by the Nuclear Regulatory Commission show that the present compact fuel loading can be retained. Rearranging the older spent fuel would allow adequate air cooling of undamaged fuel if a pool was drained. Under this arrangement, older and cooler spent fuel elements would surround the newer and hotter spent fuel, absorbing their heat in the very unlikely event that the water drained out.

As it turns out, safety is better served by having the older spent fuel in the pool, not in casks. Authors of the Princeton report now agree with the commission that no enlarged cask program is warranted. By calling for an expensive and unnecessary cask plan, Westchester and Connecticut officials indicate that they are unaware of up to date research.

Even if the pools drained, new research from the Nuclear Regulatory Commission indicates that it may be physically impossible for all the radioactive material from the spent rods to escape. A 10 percent or smaller release seems more plausible. Verification of this, however, awaits the publication of a report by the National Academy of Sciences, which, at Congress's request, has reviewed the Princeton study and other analyses. The report is due out by year's end.

The Princeton study's authors have also responded to criticisms that they made serious errors, including miscalculating the size of the population at risk in an improbable terrorist attack. Correcting this error resulted in a reduction in their calculated worst-case health predictions, to 5,600 from 250,000 long-term cancer fatalities. But even the 5,600 figure is highly inflated. By comparison, cancer fatalities from non-nuclear causes that are certain to occur in the same population would be about 1.2 million.

While we await the publication of the academy's report, we can take comfort from the security systems in place at Indian Point, which make successful land or water-based terrorist attacks quite unlikely. The structural strength of the pools makes it difficult for a terrorist attack to drain the pools. Improving the spent-fuel configuration and adding a small water spray system would reduce the danger posed in the unlikely event that the pools went dry.

Herschel Specter was the federal regulator in charge of reviewing the licensing of Indian Point 3.

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