Since the 1950s, U.S. nuclear power has commanded immense taxpayer and consumer subsidy based on promises of economic and environmental benefits. Many of these promises are unfulfilled, but new ones take their place and more subsidies follow.

Today, the nuclear industry claims that keeping all operating reactors running for many years, no matter how uneconomic they become, is essential in order to reach U.S. climate change targets.

Economics have always challenged U.S. reactors. After more than 100 construction cancellations and cost overruns costing up to $5 billion apiece, Forbes magazine in 1985 called nuclear power “the greatest managerial disaster in business history … only the blind, or the biased, can now think that most of the money [$265 billion by 1990] has been well spent.” U.S. Atomic Energy Commission Chair Lewis Strauss’ 1954 promise that electric power would be “ too cheap to meter” is today used to mock nuclear economics, not commend them.

As late as 1972, the Atomic Energy Commission forecast that the U.S. would have 1,000 power reactors by the year 2000. Today, we have 100 operating power reactors, down from a peak of 112 in 1990. Since 2012, power plant owners have retired five units and announced plans to close nine more. Four new reactors are likely to come on line. Without strenuous government intervention, almost all of the rest will close by midcentury. Because these recent closures have been abrupt and unplanned, the replacement power has come in substantial part from natural gas, causing a dismaying uptick in greenhouse gas emissions.

The nuclear industry, led by the forlornly named lobbying group Nuclear Matters, still obtains large subsidies for new reactor designs that cannot possibly compete at today’s prices. But its main function now is to save operating reactors from closure brought on by their own rising costs, by the absence of a U.S. policy on greenhouse gas emissions and by competition from less expensive natural gas, carbon-free renewables and more efficient energy use.

Only billions more dollars in subsidies and the retarding of rapid deployment of cheaper technologies can save these reactors. Only fresh claims of unique social benefit can justify such steps.

When I served on the U.S. Nuclear Regulatory Commission from 1977 through 1982, it issued more licenses than in any comparable period since. Arguments that the U.S. couldn’t avoid dependence on Middle Eastern oil and keep the lights on without a vast increase in nuclear power were standard fare then and throughout my 20 years chairing the New York and Maine utility regulatory commissions. In fact, we attained these goals without the additional reactors, a lesson to remember in the face of claims that all of today’s nuclear plants are needed to ward off climate change.

Nuclear power in competitive electricity markets

During nuclear power’s growth years in the 1960s and 1970s, almost all electric utility rate regulation was based on recovering the money necessary to build and run power plants and the accompanying infrastructure. But in the 1990s, many states broke up the electric utility monopoly model.

Now a majority of U.S. power generation is sold in competitive markets. Companies profit by producing the cheapest electricity or providing services that avoid the need for electricity.

To justify their current subsidy demands, nuclear advocates assert three propositions. First, they contend that power markets undervalue nuclear plants because they do not compensate reactors for avoiding carbon emissions or for other attributes such as diversifying the fuel supply or running more than 90 percent of the time.

Second, they assert that other low-carbon sources cannot fill the gap because the wind doesn’t always blow and the sun doesn’t always shine. So power grids will use fossil-fired generators for more hours if nuclear plants close.

Finally, nuclear power supporters argue that these intermittent sources receive substantial subsidies while nuclear energy does not, thereby enabling renewables to underbid nuclear even if their costs are higher.

Nuclear power producers want government-mandated long-term contracts or other mechanisms that require customers to buy power from their troubled units at prices far higher than they would pay otherwise.

Providing such open-ended support will negate several major energy trends that currently benefit customers and the environment. First, power markets have been working reliably and effectively. A large variety of cheaper, more efficient technologies for producing and saving energy, as well as managing the grid more cheaply and cleanly, have been developed. Energy storage, which can enhance the round-the-clock capability of some renewables is progressing faster than had been expected, and it is now being bid into several power markets — notably the market serving Pennsylvania, New Jersey and Maryland.

Long-term subsidies for uneconomic nuclear plants also will crowd out penetration of these markets by energy efficiency and renewables. This is the path New York has taken by committing at least $7.6 billion in above-market payments to three of its six plants to assure that they operate through 2029.

Nuclear power versus other carbon-free fuels  While power markets do indeed undervalue low-carbon fuels, all of the other premises underlying the nuclear industry approach are flawed. In California and in Nebraska, utilities plan to replace nuclear plants that are closing early for economic reasons almost entirely with electricity from carbon-free sources. Such transitions are achievable in most systems as long as the shutdowns are planned in advance to be carbon-free.