In March 1992 George Galatis, a nuclear engineer at the Millstone nuclear power station in Waterford, Connecticut, became alarmed during a refueling. The reactor had to be shut down and the full radioactive core of the Unit 1 reactor, which held thousands of rods, was removed and then dumped into the spent fuel pool—a blatant violation of Nuclear Regulatory Commission (NRC) safety requirements.

The pool was already quite full. It wasn’t designed to suddenly hold those very radioactive and thermally hot fuel rods, which give off so much radiation that an unshielded person nearby would receive a lethal dose in seconds. In a previous incident around that time, a worker’s boots melted during this procedure. Because the pool could overheat, and possibly cause the pumps and cooling equipment to fail, the NRC had required reactor operators to wait for sixty-five hours before performing this task—with good reason. NRC studies over the past thirty years have consistently shown that even partial drainage of a spent fuel pool that exposed highly radioactive rods could release an enormous amount of radioactivity into the environment. Arnie Gundersen, a nuclear engineer with many years of experience at US nuclear reactors, describes this kind of accident as “Chernobyl on steroids.”

Northeast Utility (which sold the Millstone reactors to Dominion Power in 2000) was standing to lose about $500,000 a day for replacement power if it followed the rules calling for a shutdown that would last more than two months. It had taken this shortcut for many years, while the NRC deliberately looked the other way.

By this time, the corporations that owned the nation’s nuclear reactors were stuffing about four times more spent fuel into storage pools than the pools were designed to accommodate, with the NRC’s blessing. It took several years for Galatis to force the NRC to take action at Millstone, at the expense of his career. His whistleblowing landed him on the cover of Time and embarrassed the NRC into performing a more thorough inspection of the reactor. The agency found a host of problems and ordered Unit 1 closed in 1996. The reactor was permanently shut down in 1998, but the spent fuel remains in a pool while the reactor is still being decommissioned, thirteen years later.

In the tradition of no good deed going unpunished, the Republican-controlled Congress, led by then–Senator Pete Domenici, was outraged over Millstone 1’s closure and made sure that the NRC would never do this again. In his autobiography, Domenici proudly notes that he sought to cut 700 jobs at the NRC in 1999, effectively gutting its regulatory efforts. “While many NRC requirements had questionable impact on safety,” Domenici said, “their impact on the price of nuclear energy was far more obvious. This ‘tough love’ approach was necessary.”

Domenici had his way. By 2000, the NRC sharply curtailed its oversight activities and became more of an enabler of nuclear power than a regulator. To this day, it remains overly dependent on nuclear industry self-reporting of problems.

Nearly twenty years after George Galatis began his lonely struggle to improve safety of spent fuel pools, the Fukushima catastrophe in Japan has once again turned a spotlight on this serious hazard in the United States. The explosions at the Fukushima Dai-Ichi station left the spent fuel pools at three reactors exposed to the open sky, as Tokyo Electric Power (Tepco), the company that owns the crippled power station, desperately try to keep them cool with thousands of tons of water. Spent fuel in one pool is believed to have caught fire and exploded. American reactors have generated about 65,000 metric tons of spent fuel, of which 75 percent is stored in pools, according to Nuclear Energy Institute data. No other nation has generated this much radioactivity from either nuclear power or nuclear weapons production.

Nearly 40 percent of the radioactivity in US spent fuel is cesium-137. The 4.5 billion curies of radioactive cesium-137 in US spent reactor fuel is roughly twenty times more than what was released by all worldwide atmospheric nuclear weapons tests. American spent fuel pools hold about fifteen to thirty times more cesium-137 than the 1986 Chernobyl accident released. For instance, the pool at the Vermont Yankee reactor, a BWR Mark I (a boiling-water reactor, the same design as the four crippled reactors in Fukushima), currently holds nearly three times the amount of spent fuel stored at Dai-Ichi’s Unit 4 reactor. The Millstone reactors, which have the largest spent-fuel inventory in the United States, hold over five times more radioactivity than the combined total in the pools at the four wrecked Dai-Ichi reactors.

Even though they contain some of the largest concentrations of radioactivity on the planet, US spent nuclear fuel pools are mostly contained in ordinary industrial structures designed to merely protect them against the elements. Some are made from materials commonly used to house big-box stores and car dealerships.

The United States has thirty-one boiling water reactors with pools elevated several stories above ground, similar to those at Dai-Ichi. As in Japan, all spent fuel pools at nuclear power plants do not have steel-lined, concrete barriers that cover reactor vessels to prevent the escape of radioactivity. They are not required to have back-up generators to keep used fuel rods cool if offsite power is lost.

For nearly thirty years, NRC waste-storage requirements have remained contingent on the opening of a permanent waste repository that has yet to materialize. Now that the Obama administration has canceled plans to build a permanent deep-disposal site at Yucca Mountain in Nevada, spent fuel at the nation’s 104 reactors will continue to accumulate and is likely remain onsite for decades to come.

Domenici and the nuclear industry have often said that spent nuclear fuel could be stacked on a football field ten feet deep. There’s a problem with this assertion. First, it’s not remotely feasible and, most certainly, ill advised to squeeze the largest concentration of radioactivity on the planet onto a field. This would unleash chain reactions involving enough plutonium to fuel about 150,000 nuclear weapons, and could ignite a radiological fire that would cause long-term land contamination that would make Chernobyl and Fukushima look like pimples on a pumpkin. It would deliver lethal radiation doses to thousands if not millions of people hundreds of miles away. In other words, storing the entire nation’s spent fuel in one place would be a mistake.

The nuclear catastrophe at Chernobyl illustrated the damage cesium-137 can wreak. Nearly 200,000 residents from 187 settlements were permanently evacuated because of contamination by cesium-137. The total area of this radiation-control zone is huge. At more than 6,000 square miles, it is equal to about two-thirds the area of the State of New Jersey. During the following decade, the population of the region declined by almost half because of migration to areas of lower contamination.

On June 7 the Japanese government reported to the International Atomic Energy Agency that the amount of radioactivity released into the atmosphere during the first week of the accident was twice its previous estimate. The government failed to mention that an equally large amount was discharged into the sea, indicating that the Fukushima accident may have released more radioactivity into the environment than was released at Chernobyl. Around the same time, the Nuclear Waste Management Organization of Japan reported that cesium-137 contamination from the accident had rendered an area about seventeen times bigger than Manhattan uninhabitable.

I co-authored a report in 2003 that explained how a spent fuel pool fire in the United States could render an area uninhabitable that would be as much as sixty times larger than that created by the Chernobyl accident. If this were to happen at one of the Indian Point nuclear reactors—located about twenty-five miles from New York City—it could result in as many as 5,600 cancer deaths and $461 billion in damages.

The US government should promptly take steps to reduce these risks by placing all spent nuclear fuel older than five years in dry, hardened storage casks—something Germany did twenty-five years ago. It would take about ten years and cost $3.5–7 billion to accomplish. If the cost were transferred to energy consumers, the expenditure would result in a marginal increase of less than 0.4 cents per kilowatt-hour for consumers of nuclear-generated electricity. Despite the destruction wreaked by the earthquake and tsunamis in Japan, the dry casks at the Fukushima site were unscathed.

Another payment option is available for securing spent nuclear fuel. Money could be allocated from $18.1 billion in unexpended funds already collected from consumers of nuclear-generated electricity under the Nuclear Waste Policy Act to establish a disposal site for high-level radioactive wastes.

After more than fifty years, the quest for permanent nuclear waste disposal remains illusory. One thing, however, is clear, whether we like it or not: the largest concentrations of radioactivity on the planet will remain in storage at US reactor sites for the indefinite future. In protecting America from nuclear catastrophe, safely securing the spent fuel by eliminating highly radioactive, crowded pools should be a public safety priority of the highest degree.

With a price tag of as much as $7 billion, the cost of fixing America’s nuclear vulnerabilities may sound high, especially given the heated budget debate occurring in Washington. But the price of doing too little is incalculable.