Whereas the 25-millirem figure may seem low, it would be hard for the average person to get that much. The NRC assumes that the most likely person to absorb such a dose is a farmer growing food on the site and irrigating the crops with a well drilled into the most contaminated spot.
But farming would horrify Foss, the redevelopment consultant, because agriculture would not pay much in taxes and the site is too valuable as industrial real estate. In fact, Maine has few people who grow all their own food. A person who worked at the site eight hours a day, 250 days a year, eating food grown elsewhere and drinking town water, would arguably have barely any additional exposure at all, probably less during that year than a passenger receives on a transpolar airplane flight. Still, the guiding principle of unrestricted release is that the land should be in good shape for any conceivable use.
The standard is so strict that checking for compliance becomes a technical problem. “You can’t measure it; you have to model it,” says Eric T. Howes, director of public and government affairs at the Maine Yankee plant. Radiation is customarily gauged in energy emissions per hour; to determine emissions per year in millirem, or thousandths of a rem, requires measuring hourly emissions in millionths of a rem. Adding to the complexity is that each isotope will persist for a different length of time. For example, among the most prevalent at the time of shutdown was cobalt 60, with its five-year half-life. Later, cesium 137, with a half-life of 30.2 years, will be the major concern. Eventually the remaining radioactive sources will be the trace amounts of isotopes that have half-lives in the thousands of years.
Paying the Tab Managers repeatedly declined to say how much extra it cost to meet the tougher Maine standard, as if the idea made them uncomfortable. But the General Accounting Office says Maine Yankee calculates the extra cost to be between $25 million and $30 million. In January 2002 Maine Yankee put the total decommissioning cost at $635 million. Low-level waste burial was $81.5 million of that amount; packaging and shipping accounted for another $26.8 million. Expenses at other plants should be in the same range. These are prodigious numbers compared with the $231 million that the plant cost to build in the 1960s and 1970s.
The Electric Power Research Institute estimates that for a plant that operates for 40 years, the cost of decommissioning will run 0.2 cent per kilowatt-hour produced in that period. Consumers today generally pay eight or nine cents for that much electricity, making it small by their standards, but the number is large for a company deciding what kind of plant to build.
The cost of decommissioning didn’t always matter so much. It was a communal obligation, and the only issue was intergenerational: whether enough would be collected from a utility’s captive customers for decommissioning or whether utilities would have to charge future users, not yet born when the benefits of the plant were enjoyed.
Now generating stations change ownership repeatedly, and somebody is going to be last. The GAO complained in a December 2001 report that the NRC was not paying enough attention to the financial qualifications of those entities buying plants. The NRC replied that it was, although some of the owners were not the entities to which it had granted operating licenses, as the builders had been. But the financial landscape has clearly changed; among the owners of today’s plants is Enron, which acquired a majority interest in the defunct Trojan reactor when it bought an Oregon utility, Portland General Electric.
In the end, money was not a problem at Maine Yankee, because the Federal Energy Regulatory Commission allowed the owners to bill the former customers.
At many plants, it is difficult to say when a shutdown will eventually occur—one of the other remaining questions that will influence the fate of aging reactors. The plants were originally licensed for 40 years from the issuance of a construction permit. The building of some dragged on so long that the NRC agreed to move up the start of the clock, to the time when operations actually began. Then it began offering 20-year license extensions. Most of the 103 plants running seem likely to apply.
Still, the economic life of old reactors is uncertain. They resemble older cars, worth an oil change but not a new transmission. Maine Yankee was retired because problems with its wiring and steam generators were becoming obvious. A sister plant, Yankee Rowe in Massachusetts, suffered from embrittlement of its reactor vessel. This condition, caused by years of neutron bombardment, makes the reactor vulnerable to thermal shock—that is, it could crack if the emergency core cooling system dumped in cold water. The extent of embrittlement at Yankee Rowe was not known, but the owners—a coalition of utilities that overlap with the owners of Maine Yankee—decided that it was not worth the price to find out.
Even those plants with 20-year life extensions will probably not run until the last day of their licenses. Capital improvements required for continued operation in the past few years would have to earn back their cost in a very short period of time.
The extent of decommissioning required is also uncertain. There are less drastic options than a return to green-field status. For example, when Northern States Power closed the
Pathfinder reactor in Sioux Falls, S.D., an early plant less than one tenth the size of Maine Yankee, it installed a conventional boiler powered first by coal and later by natural gas, and ran the turbine that way. Public Service Company of Colorado did the same with the Fort St. Vrain reactor, putting in natural gas turbines and using their waste heat to make steam to turn the old nuclear turbine. In both cases, only the nuclear components were removed.
Indian Point 1 in New York State, Millstone 1 in Connecticut, Dresden 1 in Illinois, and Peach Bottom 1 in Pennsylvania, among others, all adjacent to reactors that are still operating, were simply defueled, closed up and left to sit; they’ll be decommissioned later. So was Three Mile Island 2, the reactor near Harrisburg, Pa., that melted down its core in March 1979. Maine Yankee is not alone in decontamination, though. Yankee Rowe is undergoing the same process, as is Connecticut Yankee. The Shoreham reactor on Long Island, N.Y., which ran for only a few days, has been cleaned out, but many of its structures are still standing.
Another uncertainty is how much of the debris will require disposal. The NRC announced on November 6, 2002, that it would develop a rule for recycling contaminated metal. Proponents say that slightly radioactive metal would be fine for rebar encased in concrete; others worry that it could turn up in the braces on children’s teeth or in pants zippers. When the Energy Department tried to salvage nickel and other metals from its nuclear plants in the mid-1990s, public outrage was so great that the program was ended in 2000.
And the final cost will depend in part on how long the industry waits for permanent disposal of high-level nuclear fuel. Until that is resolved, there will be one large patch of concrete on the Maine coast where snow will not stick; the on-site storage ISFSI casks generate up to 17 kilowatts each, about as much as a dozen handheld hair dryers. Inside them is a latticework of 24 pigeonholes (each long enough for a 12-foot-long fuel assembly), vacuumed dry and welded shut in a steel wrapper 2.5 inches thick, set in a concrete silo 28.5 inches thick. They suggest an industrial-age Stonehenge, although their builders fervently hope no one will forget what they are for. Filling the casks began last August and will last well into 2003. When that job is finished, workers can tear down the spent fuel pool, the last remaining working system of the old plant.
Throughout the debate about decommissioning in Maine, opponents cut the owners no breaks, requiring a painstaking, expensive process. But the owners have demonstrated that, technologically speaking, this hill is not too high to climb.
Most of all, decommissioning standards have proved to be a response to uncertainty. One concern, looming large in the public’s mind, is the effect of small amounts of radiation. But this site, and others around the country, will be cleaned to a standard so that, whatever the future conclusion about the effect, there is little left to deliver a dose.
Subscription Center
See what we're tweeting about
1 Comments
Add CommentIt would be scientifically necessary to see a fully independant report by an international commission on this subject before the results could be accepted as refereed and sound.
Reply | Report Abuse | Link to this