While the overheated discussion of the ill-fated "nuclear renaissance" has cooled to near-Arctic levels, concern in the industry has shifted to discussing the woes of some nuclear senior citizens. More than half a dozen U.S. nuclear plants are approaching their original 40-year design lives—a figure whose origin had little to do with actual engineering—and some are drawing attention from regulators, local citizens, and activists wondering just how long these plants can and should run.

The March 2011 catastrophe at Japan’s Fukushima nuclear complex, which began with the destruction of a 40-year-old General Electric boiling water reactor, helped revitalize a discussion of aging rectors that began decades ago. Several of the older U.S. reactors that are the subject of discussions about when the plants should shut down are GE boilers with the questionable Mark 1 "light bulb and donut" containment structure.

The discussion is occurring despite decisions by the U.S. Nuclear Regulatory Commission (NRC) to extend the life of the plant licenses and upgrades—nuclear knee and hip replacements—that have increased the plants’ rated output. Is it time for the retirement home, or is there plenty of life left in these atomic geezers?

Vermont Yankee

The most discussion has centered on Vermont Yankee, the 620-MW GE Mark 1 unit that has operated for nearly 40 years on the Connecticut River in the southeastern corner of Vermont, cuddled up to New Hampshire and Massachusetts. Vermont Yankee began operating in November 1972 as a 500-MW unit and is now owned by New Orleans-based Entergy Corp. The NRC approved an upgrade to 620 MW in 2006 and extended the plant’s operating license to 2032. But, faced with a chronic problem of a tritium leak from underground piping, the state has been seeking to close the plant for years.

A federal court is now considering whether the NRC license extension trumps state authority over the operation of generating plants; the state is citing an agreement by Entergy to defer to state authority in 2008. Ironically, in 1978, the U.S. Supreme Court, in Vermont Yankee Nuclear Power Corp. v. Natural Resources Defense Council, Inc., ruled that state courts cannot impose themselves in cases involving the NRC, as federal law trumps state authority. The facts in the current case are considerably different, and the case is being watched carefully in the industry and by environmental and state groups.

Pilgrim

Down the road in Massachusetts, the Pilgrim nuclear plant, another elderly boiling water reactor (BWR) with a Fukushima-style Mark I containment, also is generating controversy. The 685-MW unit, commissioned about a week after Vermont Yankee, in December 1972, is also owned by Entergy. It was acquired in a nuclear buying spree during the industry restructuring of the 1990s. An application for a 20-year license extension at the plant on Cape Cod Bay has been pending at the NRC for some five years and continues to create controversy.

The operating license expires next year, and the NRC recently refused a request from Massachusetts Attorney General Martha Coakley to further delay the license proceedings. According to the Boston Globe, Coakley has raised the issue of the safety of onsite storage of spent fuel, in light of the spent fuel pool problems at Fukushima. Pilgrim has also faced problems of underground leaks of slightly radioactive tritium, which pose a public relations problem more than a health and safety issue. A local group, Pilgrim Watch, has been active in filing legal and procedural challenges.

Oyster Creek

In New Jersey, the nation’s oldest operating nuclear power plant, Oyster Creek, is also facing groundwater contamination problems. Owner Exelon Corp. is moving much of the plant’s underground piping above ground, under NRC direction, in order to monitor leaks in the aging systems.

The plant, another BWR with Mark I containment, went into service in late December 1969. In 2009, after a contentious four-year process, the NRC extended the plant’s original 40-year license to 2029. Workers at the plant found a tritium leak just a week after Oyster Creek got the 20-year life extension. This fall, the NRC voted to continue its program of increased groundwater monitoring from underground pipes. The NRC’s inspectors in 2009 found two cases of underground tritium leaks at Oyster Creek, although the accompanying radiation did not exceed the agency’s public dose limit. 

Crystal River

Industry insiders say they suspect that Progress Energy’s Crystal River plant, some 80 miles north of Tampa, Fla., may be the most likely of the older generation of plants to face premature shutdown. Crystal River, a Babcock & Wilcox 900-MW pressurized water reactor, went into service in 1976. The plant has been shut for more than two years, starting in September 2009, when operators began a steam generator replacement job. South Carolina-based Progress, now in merger talks with Duke Energy of Charlotte, N.C., had asked the NRC for a 20-year license extension in early 2009.

During the steam generator replacement, workers discovered a 25-foot-long crack in the reactor’s containment. After repairs, and as the company began bringing the unit back into service last March at the same time as the Fukushima disaster, technicians discovered what may be a second containment crack. The source of both cracks is unclear, although they may have to do with the tension of cables in the containment structure.

The utility has said it wants to repair the plant by replacing most of the containment at a cost of roughly $1 billion, plus another $1 billion in replacement power costs. The unit would not be back in service until 2014. But the utility’s plans have run into opposition in the state, and it is not clear how much of the repair and replacement power costs would be covered by the company’s insurance.

—Kennedy Maize is MANAGING POWER’s executive editor.