Retiring reactors: what's the cost?

Retiring reactors: Whaths the cost?

Nuclear reactors don't live forever. Once their owners decide to shut them down permanently - a procedure known as decommissioning--there are three basic options: dismantling the plant and burying its parts; "mothballing," or storing, the plant for 10 to 50 years before dismantling; and permanently "entombing" the plant in concrete walls where it stands. Today, none of these options is inexpensive or politically attractive. Moreover, the growing need to choose among them and to resolve their relative costs "is getting less attttention than it deserves," according to a report released this week by the Washington, D.C.-based Worldwatch Institute.

More than a dozen power reactors have already been retired worldwide. Within 15 years, says the report's author Cynthia Pollock, 66 more are likely to be decommissioned. Dismantling has just begun on the 72-megawatt Shippingport Atomic Power Station outside Pittsburgh--the first commercial U.S. nuclear plant and the world's largest dismantling project to date.

However, despite the apparent readiness to decommission Shippingport, which the Energy Department says is not a typical dismantling project, Pollock reports that not one of the 26 nations using nuclear power "is adequately prepared" to cope with decommissioning today. Theprimary issues facing the owners of retired plans are high costs and locating communities willing to accept their radioactive refuse.

Right now, the report notes, no country has a plan for disposing of the high-level wastes now stored at any reactor. And then there is the additional issue of where to send the more than 3,000 cubic yards of low-level radioactive wastes that would result from the dismantling of a used plant. In the United States, home to most of the world's nuclear plants, low-level-waste sites are prohibited from accepting materials contaminated with long-lived radioactive species. Moreover, all three U.S. low-level-waste sites currently in operation are seeking to limit the volume of wastes they must accept in the near future, especially from out-of-state generators (SN: 1/11/86, p. 22).

In the long run, Pollock expects that the financial uncertainties -- not only how much it will cost to decommission a large commercial plant but also whether a utility will be able to afford those costs when a plant's retirement time arrives--will prove less important than the radwaste issue. However, with cost estimates ranging from $50 million to $1 billion or more per reactor, the report says, "nuclear decommissioning could be the largest expense facing the utility industry." Pollock asserts that the industry's lack of decommissioning experience with the large 1,000-mega-watt plants that are typical today makes most current decommissioning-cost projections little more than guesses based on "varying degrees of wishful thinking." For this reason, her report recommends that uitilities begin collecting money from their users as soon as possible and hold it in escrow to fund the plant's decommissioning costs.

While few argue with the report's general interpretation of the radwaste issue, some criticize its assessments of uncertainties--both technical and financial -- associated with decommissioning. For example, the report asserts that further research and new technologies will be necessaary for the dismantling of large-scale plants. But Robert shaw, a manager in the Palo Alto, Calif.-based Electric Power Research Institute's nuclear division, told SCIENCE NEWS that after analyzing this issue, "we came to the conclusion that nuclear plants can be dismantled in a very safe way with techniques and technologies that have already been proven."

Moreover, he says, the industry's experience in repairing large plants -- like Shippingport--involves activities "that in many instances would parallel the kinds of things that one would need to do in order to decommission a large plant." By piecing together these experiences, utilities "can come up with very reasonable cost estimates," ones that are much smaller than some of those considered in the Worldwatch report. Dave Harward of the Bethesda, MD.- based Atomic Industrial Forum, an industry group, put "reasonable" utility estimates of decommissioning a large plant at only up to about $170 million.

Pollock counters that current decommissioning technology involves many technologies that are still in their infancy and often almost prohibitively costly -- like robotics for remote handling of very radioactive equipment. As to hr citation of potentially exaggerated cost estimates, she says that at least one of her surces was from within the nuclear industry itself. The French Atomic Energy Commission's decommissioning director, she says, reported at an international meeting last year that his cost estimates for decommissioning, using available techniques, "would be at least 40 percent of the cost to build a plant]"--a figure that for new U.S. plants could easily exceed $1 billion.