Nuclear: Carbon Free, but Not Free of Unease

By HENRY FOUNTAIN

Next week, if all goes as planned, the 42-year-old nuclear reactor at the Vermont Yankee generating station will be shut down for the last time. The steam turbine at the plant, which at its peak could make enough electricity for about half a million homes with virtually no greenhouse gas emissions, will grind to a halt.

Vermont Yankee, in the river town of Vernon near the Massachusetts border, had been the target of years of protests and lawsuits by state officials, environmentalists and others concerned about safety and radioactive waste.

But in the end, the antinuclear movement didn’t kill the plant. Economics did.

“People are always surprised when we say that really wasn’t the driver in shutting it down,” said Bill Mohl, the president of a division of Entergy Corporation that operates Vermont Yankee and four other nuclear plants, including Indian Point north of New York City. Although Vermont Yankee produced power inexpensively, was upgraded recently and was licensed to operate until 2032, the plant had become unprofitable in recent years, a victim largely of lower energy prices resulting from a glut of natural gas used to fire electricity plants, Mr. Mohl said.

To its advocates, nuclear power is a potent force for fighting climate change, combining the near-zero emissions of wind and solar energy with the reliability of coal and gas. And nuclear power, which provides about 19 percent of all electricity in the United States and 11 percent worldwide, could be a greater source.

But as Vermont Yankee illustrates, the nuclear industry in the United States is having trouble maintaining the status quo, much less expanding. “It’s going nowhere quickly,” said Sharon Squassoni, who studies energy and climate change at the Center for Strategic and International Studies in Washington. Overseas, the outlook is not much better.

In addition to market forces, enormous design and construction costs, questions about new federal emissions rules, uncertainty about the long-term storage of waste fuel, and public perceptions about safety after the 2011 Fukushima disaster in Japan have all had an effect on the American nuclear industry.

Of the roughly 100 reactors in operation in the United States, four others have been permanently shut since 2012 because of market economics or the costs of repairs or safety improvements, and half a dozen or more are in jeopardy, industry analysts say. Safety concerns may eventually scuttle others close to large populations, including Indian Point.

Beyond five reactors under construction, few if any others are likely to be built anytime soon. And progress on a new generation of smaller, less expensive and potentially safer reactors has been slow.

Given that most of the still-profitable plants will reach the end of their useful lives by midcentury or sooner, it appears likely that nuclear power will play a diminishing role in the United States. “We’re going to be hard pressed just to replace those,” Ms. Squassoni said.

All of this is encouraging to opponents of nuclear power, who are concerned about the costs, the potential for a major accident — despite the industry’s relatively good safety record — and the hazards of storing spent fuel.

“These things are extremely expensive and prone to cost overruns,” said Grant Smith, the senior energy policy analyst with the Civil Society Institute, a Massachusetts research group that advocates solutions to climate change. “The high-level nuclear waste issue has never been addressed. You’re talking about indefinite costs into the future.” But the outlook for nuclear power dismays the industry and its supporters, including some environmentalists, who point out that replacing the lost electricity from Vermont Yankee and the other recently closed reactors with power from natural gas could result in the release of as much carbon dioxide as is produced yearly by two million cars or more.

“We can’t take a carbon-free source of energy off the table,” said Carol M. Browner, a former head of the Environmental Protection Agency who is now with Nuclear Matters, an industry-backed group.

Overseas, some nations have retrenched from nuclear power, out of necessity or by choice. Japan shut its 50 reactors for inspections and safety improvements after Fukushima, and although two were restarted briefly, all still remain shut down and not all are expected to reopen. Germany will eventually close all 17 of its reactors as part of an ambitious transition to renewable energy.

Even China, with more than two dozen nuclear plants under construction, faces uncertainties. If the country is able to exploit its abundant reserves of shale gas, its nuclear plans may be derailed, Ms. Squassoni said.

An even bigger question is whether China’s current rate of economic growth is going to continue. “If it doesn’t, what is that going to do to its energy demand?” she said. The impetus for developing more nuclear power may dissipate.

To people in the American nuclear industry, reactors do not get the respect they deserve for being both virtually emissions-free and a source of around-the-clock electricity for the grid. Experts point to the spell of extreme cold weather across much of the country last January, when nuclear plants kept working while many gas and coal plants had to shut down as the cold affected equipment and fuel supplies.

About half of the nuclear plants sell their electricity in competitive wholesale markets, which are relatively new and complex. Electricity from generators fueled by low-cost gas is priced so low that nuclear plants cannot compete, industry analysts say, and the markets also offer advantages to new power sources, especially wind turbines, over existing sources like nuclear and coal.

“The markets are quite simply not working,” said Richard J. Myers, the vice president for policy development at the Nuclear Energy Institute, an industry group.

The industry is pushing for changes that would help marginal plants stay in operation. Federal price supports would be one, perhaps temporary, solution. Another would be to grant a premium to power sources, like nuclear, that can keep running under almost any circumstances.

“All of this is fixable,” Mr. Myers said. “The question is: Do the fixes come quickly enough?”

Other help could come as the federal government and the states develop policies under new carbon-emission rules for the power industry that were proposed by the E.P.A. in June in its Clean Power Plan. They could lead to the development of new programs, and expansion of existing ones, that put a price on greenhouse gas emissions as a means of limiting them.

“The biggest thing that is going to drive people to clean solutions is going to be a cap on carbon,” said Christine Todd Whitman, a former New Jersey governor and E.P.A. head who is now an industry advocate.

The industry’s recent struggles represent something of a reversal from the previous decade, when there was talk of a nuclear revival in the United States after nearly 30 years without any new reactor construction permits being issued. Even then, however, some experts questioned just how much nuclear power could grow in the United States and abroad, and how much it could contribute to the effort to reduce carbon emissions.

In a report she prepared in 2009, Ms. Squassoni wrote that in light of steep construction costs, only a handful of new reactors would come on line by 2015, even in the best of circumstances.

“If you really wanted to reduce carbon emissions through nuclear, it was going to be incredibly expensive,” she said. “You’d have to build an incredible number of power plants.”

Now plants are even more expensive, in part because of new safety requirements in the wake of Fukushima. So-called small modular reactors have been proposed as a lower-cost alternative. There are many different designs — at least one is meant to run on waste fuel — but the federal Department of Energy has provided significant development money only for two designs that are smaller variations of the most common kind of reactor.

Ashley Finan, an analyst with the Clean Air Task Force, which focuses on technologies to fight climate change, said that the Nuclear Regulatory Commission had not made it easy for alternative designs to win backing from private investors.

“There’s a lack of a clear and predictable regulatory pathway,” Dr. Finan said. “You’re really not able to attract funding without a clear regulatory process.”

As a result, small modular reactors are many years from reality in the United States. Overseas, there are only a few isolated small-reactor projects underway, including one under construction in China.

Most modular designs have features that are intended to make them safer than existing reactors. Safety, as always, looms large in the debate about nuclear power. Although some watchdog groups point to incidents like leaks of radioactive water from some plants, the industry in the United States promotes its safety record, noting that events like unplanned reactor shutdowns are at historical lows. And the American industry’s one major accident, at Three Mile Island in Pennsylvania in 1979, pales in comparison with Fukushima or the 1986 Chernobyl disaster in the Soviet Union.

But Peter A. Bradford, a former member of the Nuclear Regulatory Commission, said that in discussions of adding more nuclear power to help curb emissions and fight climate change, the issue of safety takes on a new dimension.

“You can’t rationally bet a big part of your climate change abatement plan on a technology that you may suddenly find you don’t want to use anymore,” Mr. Bradford said. A major accident, for example, might force the entire industry to shut down, at least temporarily. “There’s no other low-carbon alternative with the potential to develop a large hole like that.”

不敵天然氣競爭 美42年核廠關門

紐約時報報導，有四十二年歷史的佛蒙特洋基（Vermont Yankee）核電廠的反應爐下周將永久關閉，並非為了核能安全，而是不敵天然氣發電的低價競爭。

這座位於佛蒙特州弗農市的核電廠在鼎盛時期的發電量足供五十萬戶使用，多年來一直是州政府官員、環保人士和其他憂心核能和核廢料安全人士抗爭和控告的對象。但最終，讓核電廠關門的不是反核運動，而是經濟因素。

雖然這座核電廠能以低成本生產電力、並獲准營運到2032年，但這幾年不賺錢，主因是火力發電廠使用的天然氣生產過剩，導致能源價格下滑。

主張核能發電的人士指出，不會產生溫室氣體的核能發電是對抗氣候變遷的利器，兼具風力和太陽能發電的零排放，以及燃煤和天然氣發電的可靠性優點。他們認為，應該增加核能發電的比重。

目前核能發電提供全美百分之十九的電力，提供全球百分之十一的電力。

美國約有一百座正在商轉的反應爐，自2012年以來已有另外四座永久關閉，關閉的因素包括市場經濟、維修和改善安全成本過高。另外有六座以上停機，安全顧慮也會讓靠近人口密集區的反應爐被淘汰。除了五座正在興建的反應爐之外，沒有新建反應爐計畫，顯示美國核能發電的重要性遞減。

原文參照：
http://www.nytimes.com/2014/12/23/science/nuclear-carbon-free-but-not-free-of-unease-.html

2014-12-24．聯合報．A13．國際．編譯田思怡