Thermodynamics should dictate whether Millstone Power Station's nuclear reactors can safely keep operating even as they use warming waters to cool them.

Don't count Dominion, owner of Millstone station in Waterford, as among global warming deniers. Plant operators have witnessed average water temperatures in Long Island Sound steadily increase since the mid-1970s, when Millstone 2 went into operation. The heat up rate may seem marginal, .67 degrees per decade, but climatologically it's dramatic.

Last summer it got expensive. A spike sent water temperatures above 75 degrees, the highest temperature the Millstone 2 permit allows, forcing it to close for three weeks. That meant Dominion buying energy to meet its contractual power obligations, and resulted in operating losses (not disclosed). Millstone 3, which draws from deeper, cooler waters, continued operating. Millstone 1 is permanently shut down.

Forty years ago the 75-degree threshold used in the original engineering design specs appeared well within normal temperature ranges for the Sound, even in unusually warm years, but not anymore. Dominion is preparing a license amendment that if granted by the Nuclear Regulatory Commission would allow the plants to operate with water temperatures up to 80 degrees.

As we said, this is science. Engineers must demonstrate to the satisfaction of the NRC that the warmer waters are still adequate to safely cool the super-heated reactors, the steam from which spin the plants' generators and produce electricity. If granted, the new 80-degree threshold should remain viable for the life of the reactors. If waters in the eastern Sound start exceeding that number then there will be bigger things to worry about than electric generation.

The public can demand a hearing to challenge or question the application. The process should assure the safe operation of the reactors.

There is a certain irony here. Nuclear power generation does not produce greenhouse gases, which most climatologists now agree are accelerating climate change, yet nuclear plants have to adjust to that changing climate. Millstone is not the first to seek such a permit amendment.

The nation needs to take climate change seriously and pursue energy policies that reduce greenhouse-gas production, and that includes a new generation of nuclear plants.