Mothballing Nuclear Reactors

Already staggering under bloated construction costs, the nuclear industry is now faced with decommissioning-the process of cleaning up, dismantling, burying, and disposing of retired nuclear plants in order to protect the public from radioactivity.

Nearly four decades and 400 power reactors into the nuclear age, the question of how to safely and economically dispose of nuclear reactors and their waste is still largely unanswered and unaddressed.

In most industries, the disposal of retired plants and equipment is a straightforward and relatively low-cost operation. But the high levels of radiation present in shut-down reactors will make the procedure uniquely complex and costly. Some radioactive elements will decay quickly, but others will remain hazardous for millennia. Decommissioning will require remote-controlled technologies and large work crews to limit individual exposure to radiation, as well as comprehensive strategies for safely transporting and disposing of radioactive debris.

The oldest commercial nuclear reactors are already nearing the end of their productive lives. Others have been closed prematurely because of accidents or faulty designs. In the United States, dozens of tiny research and military reactors and four small retired commercial units are awaiting decommissioning. The U.S. Nuclear Regulatory Commission (NRC) estimates that another 67 large commercial units will cease operations before the year 2010. Worldwide, more than a dozen power reactors have already been shut down, 66 more are likely to be retired by the year 2000, and another 162 will reach their thirtieth year of operation-the average life expectancy of a nuclear power plant-in the following decade.

Even in countries with advanced nuclear programs, managing the "back end" of nuclear power production (or practical decommissioning experience) is limited to very small reactors. Minnesota's tiny 22-megawatt Elk River reactor is the largest plant in the world that has been fully decontaminated and dismantled. The U.S. Department of Energy completed this three-year project in 1974 at a cost of $6.15 million. The plant had been in operation only four years. Modern reactors, many of which can produce 50 times more power than the Elk River plant, are expected to be in operation seven times as long. A larger plant poses a greater challenge since more radiation is accumulated.

In Europe, efforts to decommission several commercial reactors are just getting underway. The first three projects will be the 100-megawatt Niederaichbach unit in West Germany, the 33-megawatt Windscale advanced gas reactor in the United Kingdom, and the 45-megawatt French G-2 gas reactor in Marcoule. Although the French and U.K. plants are small, each was operated for approximately 20 years. The larger German reactor was in service for only two years before technical difficulties forced it to close.

Discussions about decommissioning usually ignore the topic of high-level nuclear waste disposal. But high-level wastes-spent fuel and the byproducts of fuel reprocessing-must be removed from the plant before decommissioning can proceed. Not one of the 26 countries that produce nuclear power now has a permanent disposal facility for high-level wastes and no such facilities are likely to be in operation before the turn of the century.

Few leaders have held power for more than several decades; the lifespan of most energy agencies is even shorter. But the toxicity of high-level waste requires that it be kept out of the biosphere for tens of thousands of years-longer than recorded history.

Since reliance on human management for such a long period of time is impossible, most countries have decided to bury their wastes in geologic repositories 300 to 1,200 meters below the earth's surface. Searching for stable sites is the current focus of most disposal programs. The characteristics of a good site include unfractured geology so groundwater will not migrate through the area and contaminate water supplies, low seismic activity, and the absence of mineral wealth so future generations will not want to drill in the area.

Removing the spent fuel is only the beginning of the decommissioning process. Few nations have independent commercial disposal facilities for low-level radioactive wastes, a much larger category that encompasses everything from work gloves and used equipment to contaminated water and soil. Although this waste is considerably less toxic than spent fuel and reprocessing wastes, it is produced in far greater volumes.

The average pressurized water reactor, the most commonly-used type of reactor, sends about 400 cubic meters of low-level wastes to burial sites each year. When these reactors are dismantled, they will each produce an estimated 18,000 cubic meters of low-level waste, one and one half times as much as will have been generated throughout a unit's 30-year operating life. This is enough to bury a football field under four meters of radioactive debris. Decommissioning just one large reactor will yield a volume of contaminated concrete and steel equal to one fourth of the low-level radioactive wastes now shipped to all commercial U.S. nuclear dumpsites in a year.

"Nobody really knows how much all this is going to cost," said Charles Komanoff, director of Komanoff Energy Associates, a New York-based consulting group. "Unfortunately with nuclear power, unknowns have a way of becoming very expensive."

The NRC estimates decommissioning costs for the large, 1100 megawatt plants to be between $125 million and $175 million. Other studies put the cost of decommissioning the hundreds of units in service and under construction around the world at from $50 million to $3 billion per reactor; the latter figure equals the cost of building a modern U.S. facility.

According to NRC spokesman Keith Steyer, "The cost of decommissioning will be covered under the operating costs of the plant, [which are] passed on to the consumer.'

If decommissioning costs, adjusted for inflation, equal only half the original construction price tag, the results could be a "financial catastrophe," for the nuclear industry. Komanoff said.

The reactor ordering binge prior to 1980 means that much of the decommissioning bill will fall due shortly after the turn of the century. Although engineers are trying to lengthen the life expectancy of reactors. numerous technical difficulties, including the constraints radiation buildup places on routine maintenance and the inevitable embrittlement of the reactor pressure vessel, are likely to limit their chances of success.

Cost estimates for the two reactors awaiting decommissioning amount to more than $1 million per megawatt. The small, 72-megawatt Shippingport facility in Pennsylvania, despite its unique transportation arrangement and federally subsidized waste disposal, is expected to cost up to $98 million to decommission-$1.36 million per megawatt. Unlike other plants, however, decommissioning Shippingport will be paid for by the federal government.

Shippingport is also considerably less contaminated than other reactors will be, not only because it is small, but because it has already been thoroughly decontaminated once during its operating life and has had several reactor cores. Decommissioning the smaller Windscale reactor is expected to cost close to $2 million per megawatt, for a total price tag of $64 million.

To ensure that adequate funds will be available for decommissioning, utilities may start setting money aside early in a reactor's life. It has been suggested that monthly surcharges on household electric bills be used to build individual retirement accounts for nuclear reactors. If money is not collected from ratepayers during the years the plant produces power, future electricity customers, or taxpayers in general, will suffer the "aftershock" of paying to dismantle plants from which they derived no benefit.

Of the four retired commercial reactors in the United States, only one managing utility had the foresight to begin a fund to cover decommissioning costs before the unit was taken out of service. In that case, the Pacific Gas and Electric Company in California collected only about $600,000 to decommission its small, 65-megawatt Humboldt Bay reactor. This amount is less than one percent of the company's estimated cost for decommissioning.

In 1984, the Critical Mass Energy Project reported that at least 11 L.S. reactors had gone through one third of their operating lives without collecting any funds for decommissioning from ratepayers. Nationwide, only $600 million had been collected. This lack of financial foresight has prompted ten states to require mandatory periodic deposits by utilities into external savings accounts.

But the amount collected in these decommissioning accounts has so far been woefully short of even the lowest estimates of decommissioning, according to Ruth C',aplan, director of Environmental Action.

"I think that [utilities] should be looking at a cost in constant dollars for decommissioning that is half the construction costs." said Caplan. "A lot of the numbers used by utilities are irresponsibly low."

In Sweden. utilities pay an annual decommissioning fee to the federal government. A separate account has been established for each reactor and utilities may withdraw it when their plants are retired. Less formal funding arrangements exist in West Germany and Switzerland. In countries where the electricitygenerating system is government-owned, such as France, the "when-needed" principle of funding has frequently been adopted. Utility managers assume that the national or provincial treasury will dole out enough money at the right time to cover the expense of decommissioning. The burden is placed squarely on the shoulders of future taxpayers. Third World governments, many already on the edge of insolvency, will be particularly hard-pressed to pay the decommissioning bills for their 23 operating reactors.

The formidable issue of decommissioning is getting far less attention than it deserves. Utility companies and ratepayers balk at yet another large expense associated with using nuclear power. Politicians are reluctant to tackle an issue that will not come to the forefront until after their political careers have ended.

But the nuclear industry is not viable without a sound decommissioning strategy. More than 30 years after the first nuclear plant started producing electricity, such a strategy has yet to be formulated. And even if reactor orders cease tomorrow worldwide, more than 500 reactors, including those currently under construction, will still have to be decommissioned.

Cynthia Pollock is a researcher at the Worldwatch Institute and author of Decommissioning: Nuclear Power's Missing Link.