25 years after Three Mile Island

25 years after Three Mile Island, concerns linger

Mar 23, 2004 - Reuters Power News
Author(s): Reuters

By Chris Baltimore WASHINGTON (Reuters) -

Twenty-five years after a near-catastrophe at the Three Mile Island nuclear plant exposed lax safety practices, owners and regulators of the nation's aging fleet of 103 reactors still face nagging questions about their ability to prevent mishaps. These concerns, worsened by recent findings of massive corrosion at a plant in Ohio, have so far kept utilities away from pursuing new nuclear plants for over two decades despite their potential to replace aging, air-polluting coal units. In a bid to change that trend, the Bush administration has promoted incentives to build new nuclear plants. But the outlook is uncertain because a Republican-written energy bill with some of the administration's proposals has long been stalled in the U.S. Senate. On March 28, 1979, Walter Cronkite opened his nightly news broadcast for CBS television, calling the accident at the Pennsylvania plant "the first step in a nuclear nightmare." That was the first time that many Americans heard of the mishap, the most serious accident in U.S. nuclear history. Early that morning, pumps feeding cooling water to the plant's reactor failed, and 32,000 gallons (121,000 litres) of radioactive, superheated water spewed from a dodgy valve into the domed concrete reactor housing. Without water to cool them, over half of the reactor's 36,000 nuclear fuel rods ruptured. Government scientists said that the 636,000 people living within 20 miles (32 km) of the plant got only minor radiation doses. A string of mechanical failures and human errors caused the Three Mile Island accident after operators with Metropolitan Edison Co. switched off crucial equipment that could have lessened the severity of the partial meltdown.

The near-catastrophe at the plant perched on an island in the Susquehanna River near Harrisburg effectively halted any expansion in the U.S. nuclear energy industry, which generates about 20 percent of the nation's electricity. The resulting cancellation of dozens of planned nuclear plants forced utilities to rely on decades-old nuclear and coal-burning plants for growing electric power demands. For the last decade, utilities have looked almost exclusively to natural gas plants to fill the gap, which has exacerbated the nation's shortage of that clean-burning fuel. And two years ago, massive corrosion found at an Ohio nuclear plant points to lingering safety questions.

"With plants aging and the number of checks dwindling, this is a troubling trend," said David Lochbaum, a nuclear safety engineer with the Union of Concerned Scientists. Activist groups also worry that current security measures cannot prevent a terrorist attack on a U.S. nuclear plant. OHIO PLANT RAISES FRESH CONCERNS Safety concerns continue to plague the industry. NRC inspectors in early 2002 found massive corrosion at a Ohio nuclear plant owned by FirstEnergy Corp . Leaking boric acid used as a coolant ate a football-sized hole in the steel outer hull protecting the company's Davis-Besse plant's reactor core.

No radiation was released, and the NRC allowed FirstEnergy to begin reviving the unit this month after the utility agreed to change its "safety culture." Nuclear Regulatory Commission Nils Diaz said the NRC "dropped the ball" by not spotting the corrosion sooner. "It was no way to do business, either on the part of operators or regulators," Diaz said. Nuclear industry officials bristle at any connection between the Three Mile Island and Davis-Besse incidents, and point to advances in operator training and plant design. But industry watchdogs say the aging U.S. nuclear utility fleet could be nearing the end of its trouble-free life, with incidents like Davis-Besse foreshadowing mishaps to come.

"We haven't seen a lot of near-misses in this country since (Three Mile Island)," Lochbaum said. "But the other end of the curve is what we're approaching, if we're not there already." The Bush administration, meanwhile, wants to jump-start the U.S. nuclear industry with an energy plan aimed at building at least one new nuclear power plant in the United States by 2010. One version of the energy bill stalled in the Senate would give tax incentives to build new plants, with a cost of $10 billion. The incentives could be stripped from the bill to appease budget concerns from the administration and others.

Nuclear advocates say such incentives can make nuclear generation competitive with coal and natural gas, and allow utilities to shift from their heavy reliance on fossil fuels. Utilities have relied on squeezing more megawatts from existing nuclear plants. Capacity factors went from 58 percent in 1980 to 92 percent in 2002, forestalling the need to build new plants, according to the Nuclear Energy Institute. The industry says that the NRC carefully reviews capacity increases to ensure safety. But with a dearth of new building, aging nuclear plants pose a risk, said Jim Riccio, an anti-nuclear advocate at Greenpeace.

"After Three Mile Island, the pendulum definitely swung in the direction of safety," he said. "In the last 25 years, it has swung in the other direction. They're running these plants to the verge of breakdown."