Reactor Challenge : How to Split Aging Atom Splitters

They now arrive regularly here on the banks of the Ohio River, eager to see a dinosaur of the late 20th Century.

Church groups, Eagle Scouts, high school science classes and news media teams carefully pin radiation sensor badges on their collars, pull hard hats over their heads and step gingerly through a low-slung, rust-colored structure half-gutted and full of exposed piping.

When first turned on in 1957 and dedicated by President Dwight D. Eisenhower, the Shippingport Atomic Power Station was the nation’s first commercial nuclear power plant. Now, a victim of old age, it is in the process of becoming the first of its kind to be dismantled.

Information Sought

The events unfolding here, however, point as much to the future as the past, for another sort of visitor also frequents this site.

Government officials and utility company executives come regularly to see how the job is going. The attraction for them is not curiosity. They seek clues on how best to dismantle other nuclear reactors.

This is a matter that drew little thought in past years. When the first nuclear power plants were being built, hardly anyone asked what might happen when the structures wore out. Now they must. About 15 other reactors are due to reach the end of their lives by the year 2000, 53 by 2005, 70 by the year 2010.

Model for Dismantling

The decommissioning of the Shippingport reactor has come to be regarded, by the Department of Energy and some in Congress, as a model for how a dismantling can be done. Two House subcommittees held a special hearing last July 30 on the “lessons to be learned” at Shippingport. The DOE and the nuclear power industry expect to find answers to questions of cost, safety, demolition methods and waste disposal.

The lessons learned here, however, may not apply elsewhere--at least not for many years to come.

Shippingport is a relatively small plant, owned and operated not by a private utility, but by the federal Department of Energy. The conditions at Shippingport differ in critical ways from those at the large commercial plants due to go off line in coming years.

Because of these differences, it is not likely that any nuclear plant but Shippingport will be dismantled in this century. Instead, a dozen or more retired, shut-down reactors probably will decorate the countryside in the early 21st Century, surrounded by fences and manned by guards, costing utility companies an estimated $1 million each a year to maintain.

This is the picture painted by both the nuclear industry and its critics. The prospect, though, is far more troubling for the critics than it is for the industry.

“I sense the industry would just like to forget about this for a while, not spend the money and put it off. Whether the American public will allow this is another question,” said Cynthia Pollock, a researcher for the nonprofit Worldwatch Institute, a research organization funded by the United Nations and private foundations.

Special Paper

This year she wrote a special paper on nuclear plant decommissioning and testified at the congressional hearing in July.

“Nearly four decades and 400 power plants into the nuclear age, the question of how to safely and economically dispose of nuclear reactors and their wastes is still largely unanswered . . .” she told the legislators. “Nuclear engineers have been attracted to the exciting challenge of developing and improving a new technology, not to figuring out how to manage its rubbish.”

Nuclear power plants have finite life spans, generally about 30 years. They wear out mainly because the steel containment vessels and metal piping become too brittle after years of bombardment by neutrons, the product of fissioning atoms. Restoration rarely makes sense economically.

Power companies cannot, however, simply walk away from aging plants. Parts of a nuclear reactor become dangerously radioactive after years of use. Much of the radioactivity requires several decades to fade.

Three Options

Power companies have three options.

The first two essentially involve a waiting game. Plants can be entombed in concrete or mothballed behind fences and guards for dozens of years until the radioactivity subsides. In the short run, these methods are the cheapest and easiest, for they involve relatively little up-front money and allow dismantling after the plant has cooled off.

But the specter of dozens of aging, vacant, radioactive plants dotting the national landscape does not evoke enthusiasm among some, particularly those who live nearby. To them, a mothballed nuclear plant resembles in many ways a giant hazardous waste dump site.

The Pacific Gas & Electric Co., for example, intends to mothball its now-retired Humboldt Bay plant in Northern California but faces angry opposition from several citizen groups, including the Redwood Alliance. The utility’s critics worry about eventual costs of dismantlement to future generations. They worry about storing a dead reactor close to two geological faults. They want it torn down now.

Prototype Operation

That, as it happens, is the third option--immediate dismantlement. It is this option that is being tried at Shippingport. Three small research reactors have been dismantled in the past, but the present effort is seen as the prototype for how to handle a modern commercial reactor.

The contrast of images in this heavily industrialized river valley is striking. The 72-megawatt Shippingport plant sits on seven acres of land next to the modern, twin 833-megawatt Beaver Valley nuclear reactors owned by the Duquesne Power & Light Co. Shippingport’s long, two-story structure seems a mere shed, overwhelmed by the looming shadow of these reactors’ sleek, hourglass-shaped cooling towers.

$6-Million Study

The Shippingport decommissioning project began with a $6-million, 12-volume engineering and cost study, completed by the DOE in 1983. The spent fuel rods were removed the next year, and contractors--headed by a team from General Electric--began the physical dismantling in September of 1985.

Taking apart Shippingport will cost an estimated $98.3 million and require five full years--twice as long as it took to build the plant. The mammoth effort involves thousands of hours of tedious manual labor and complicated logistics.

Workers wearing protective overalls and radiation sensors move through yawning, vacant expanses that once formed the heart of the reactor’s activity. They crawl through winding passageways and climb into the four cavernous containment vessels, set below ground level. They scrub walls, strip asbestos insulation, cut about 21 miles of metal pipe. They slice up tanks and knock down walls. They sort out contaminated materials and box them for shipment to the federal waste disposal site at Hanford, Wash.

They work at times behind protective shielding, with saws attached to the pipes with straps. For other tasks, they wear masks or respirators.

“Our feeling is this is not a high-tech job,” said Bill Murphie, project manager at DOE headquarters in suburban Maryland. “We need nuclear engineers only to write the specs. After that you don’t need master’s degrees. These are demolition workers. It’s much harder to assemble a plant. This is just ripping out stuff. Our only safety concern is really with the workers. There is no way it can contaminate the community.”

But the climax of the DOE’s efforts will involve a tricky bit of business.

The workers eventually must deal with the heart of the reactor--the pressure vessel, a steel cylinder 25 feet high and 10.5 feet across, with walls more than eight inches thick. A used pressure vessel remains highly radioactive even with the fuel removed, so it requires a protective shielding. Getting rid of this hot behemoth will be the decommissioning team’s greatest challenge.

Sometime in the early spring of 1989, workers will build a tower above the Shippingport pressure vessel. They will fill its insides with other radioactive elements from the plant, then pour cement into the cavity. A winch will hoist the 870-ton package to a specially tracked transporter, which will slowly roll it to a barge at a dock to be built on the nearby Ohio River.

7,800-Mile Journey

From there, the barge will begin a 7,800-mile journey down the Ohio and Mississippi rivers, into the Gulf of Mexico, through the Panama Canal, north along the Pacific Coast to the state of Washington, and east into the Columbia River. One month after leaving Shippingport, it will dock at the federal waste depository in Hanford.

“People are already asking if they can watch us make the move to the river,” said John Schreiber, the DOE’s project manager here. “I ought to sell tickets.”

Schreiber proudly shows visitors through his plant. With him often are Frank P. Crimi, General Electric’s project manager, and William W. Scott, project manager for another subcontractor, UNC Nuclear Industries.

They point to the multistage safeguards that protect workers from excessive radiation. They produce printed timetables that show they are on schedule for every task. They report that they are well below budget.

Basic Techniques

Although Shippingport is far smaller and less radioactive than the big commercial plants, DOE officials argue that the basic techniques can be applied on any scale. They hope to show that a nuclear plant can be dismantled easily and safely at a reasonable cost.

“If you have something that’s contaminated, you go through all the same procedures no matter what the level of radioactivity,” Schreiber said. “How you take the plant apart, store it and ship it can all be applied elsewhere.”

This is a view others cannot share, for several reasons.

Because the Shippingport pressure vessel is small enough to be removed and transported intact by barge, the DOE achieves a 10% reduction in worker radiation exposure while saving $7 million, a year’s worth of work, and 80 cross-country truck shipments of low-level waste.

Yet at larger plants, this method won’t work. The pressure vessels there will have to be cut up into pieces and shipped by land.

Opposition to Method

“This method they’re using is shortsighted,” said Pollock, the Worldwatch Institute researcher. “By employing cost-cutting measures now, DOE is depriving the international nuclear industry of invaluable lessons. The most difficult task decommissioning crews of the future face is dismantling the pressure vessel and its contents . . . . Cutting it up is costly and dangerous, and the technology for it has not even been developed.”

There are also differences between Shippingport and other plants in matters of cost and who will pay.

The DOE’s estimates for dismantling larger plants approach $150 million, but other projections range all the way to $400 million. In some of these estimates, a full 40% is alloted to the cost of waste disposal. If disposal costs rise significantly--as many expect--so will the costs of decommissioning. Predicting dismantling costs a decade or two from now is problematic.

The federal government is picking up the tab at Shippingport. Will current utilities, Pollock and others ask, even be around in 50 years to pay the bill at their plants? Will a future generation suddenly face a sharp rate hike to fund what is essentially a hidden cost of a plant built decades before?

Disposal Problem

None of these issues, though, represent the most glaring difference between Shippingport and other plants. The greatest difference involves radioactive waste disposal. Shippingport, being federally owned, has places to send its waste. Other plants face a tougher situation.

Each year of its operation, an average pressurized-water reactor sends about 400 cubic meters of low-level wastes--everything from torn-up concrete blocks to used gloves and tools--to one of three commercial disposal sites operating in this country. By comparison, a dismantled reactor will produce an estimated 18,000 cubic meters of such waste.

Shippingport is sending its huge volume of dismantled waste to the federal reservation at Hanford. Private power companies for the time being must hope that the three existing private sites, one each in Nevada, South Carolina and Washington, possess the capacity and inclination to handle their greatly increased loads.

Limits on Waste

This is not likely. Each of the sites in recent times has set limits on the volume of waste it will accept and has instituted substantial surcharges for future shipments from outside its own region.

Congress in 1980 passed the Low-Level Radioactive Waste Policy, requiring each state to be responsible for its own low-level waste by the start of 1986 and encouraging bordering states to form regional disposal sites. But local politicians, looking at public protests and technical problems, did not rush to meet this deadline. An amendment to the law passed in 1985, allowing a seven-year extension.

The plants face an even greater problem with high-level waste, which is composed mainly of spent fuel. Shippingport sent its spent fuel to a federal military facility in Idaho. Private companies have no place at all to send their spent fuel.

At every nuclear power plant in this country, the spent fuel--now comprising some 12,000 metric tons--is being stored on site in temporary water-filled “swimming pools.” The utilities have no other choice. There are no permanent high-level radioactive waste disposal sites operating anywhere in this country.

Squabbles Over Dumps

This void was dealt with only recently. In 1982, Congress passed the Nuclear Waste Policy Act, mandating that the federal government develop two such permanent sites, the first by 1998. But political and legal squabbles over where they will be located threaten to delay their creation well into the next century.

Plans for a temporary high-level storage site in Tennessee have also faced legal and political opposition.

The DOE does not see the problem of spent fuel as one lying at the feet of the decommissioning team. Spent fuel, they point out, comes from a plant’s operation, not its retirement.

But power companies will not be able to dismantle their nuclear plants and walk away from their sites until they have a place to send their spent fuel.

As it happens, this situation does not particularly trouble the power companies or the DOE. There is considerable logic in waiting dozens of years to dismantle the plants.

Reduction in Radiation

Cobalt, the chief radioactive element in a shuttered plant, has a five-year half-life. If the utility waits 30 years--six half-lives--the radioactivity will be reduced to less than 3% of its original level. After 50 years, it will be down to one-tenth of 1%.

While they wait, the utilities can be gradually setting aside, in interest-bearing accounts, the sums they will eventually need to finance dismantling.

For these reasons, mothballing promises to be the fate of most nuclear plants as they are retired, not dismantlement.

Three other commercial nuclear power plants besides Shippingport have been retired and await decommissioning of some sort--Humboldt Bay, Indian Point 1 in New York and Dresden 1 in Illinois. Pacific Gas & Electric project manager Robert T. Nelson told the congressional hearing in July that his company had no option for Humboldt Bay but mothballing.

“I don’t think there is a ghost of a chance any commercial reactor operator will be lifting out within two years of shutting down, as we are at Shippingport,” the DOE’s Murphie said. “They have no place to ship the fuel pool at the present time. And they have no reason to do so anyway. If they wait 30 to 40 years, the radiation levels will be much lower.”

DOE Sees No Threat

The DOE does not believe mothballed plants present a health or safety threat to surrounding communities.

Mothballing involves the removal of all resins and storage tanks. The plant is decontaminated and flushed, then left at room temperature under no pressure, protected by eight- to nine-inch-thick steel walls and several feet of reinforced concrete.

“Would you be scared?” said Ed DeLaney, director of the DOE’s decommissioning program. “Not me. I could sit right next to it.”

But Pollock sees potent problems beyond the issue of immediate danger.

“You need constant, high-quality surveillance, which you don’t always get. There are threats of leakage, of natural disasters, of sabotage by terrorists. Cars and cigarettes are more dangerous to a community, but a mothballed plant is not a pleasant prospect. It is, at the least, a political and economic problem.”

By 1990, the seven-acre plot occupied by the Shippingport plant will be a level, grassy knoll, suitable, DOE officials say, for any use. There could be a park, or a school, where once there was a nuclear reactor.

In this sense, Shippingport for a good long time promises to be more an oddity than a model.

“We haven’t thought about all this much before, but now we are addressing it,” said the DOE’s Murphie one morning recently. “It could be argued we were not ready in time. You could say waste sites are not ready. You could say funding is not there. But you must look at when these things really will be needed.”