"The U.S. Navy has sailed ships around the world for 60 years with nuclear power plants on them and we've never had an accident."

John McCain on Monday, June 2nd, 2008 in a speech in Nashville, Tenn.

Navy's record unblemished

In making his pitch for more nuclear power plants as one way to address global warming, Sen. John McCain is fond of citing a military statistic.

"My friends, the U.S. Navy has sailed ships around the world for 60 years with nuclear power plants on them and we've never had an accident," McCain said in Nashville, Tenn., on June 2, 2008. "That's because we have well-trained and capable people."

Indeed, the U.S. Navy turned to nuclear power in the 1950s to make its submarines faster and able to stay submerged longer. They are also quieter, more stealth. Since commissioning the world's first nuclear-powered submarine, the USS Nautilus , in 1954, the Navy has steamed 139-million miles around the world on various nuclear-powered vessels. Currently, there are 102 nuclear reactors aboard 80 Navy combat vessels, mainly submarines and aircraft carriers.

"We have never had an accident or release of radioactivity which has had an adverse effect on human health or the environment," said Lukas McMichael, a public affairs officer for Naval Reactors, the U.S. government office that oversees the operation of the Navy's nuclear propulsion program. "His (McCain's) statement is correct."

Now, two nuclear subs still sit on the Atlantic floor, having sunk in the 1960s.

The first to go down was the USS Thresher in April 1963 during deep-diving tests 200 miles off the coast of Cape Cod. All 129 officers, crewmen and military and civilian technicians aboard were killed.

The USS Scorpion submarine went down about 400 miles southwest of the Azores in May 1968. All 99 crewmen aboard died.

While there is some disagreement about the cause of the accidents, neither went down as a result of problems with the nuclear reactors.

The Navy has done some environmental monitoring over the years of the ocean floor around where the subs sank, and has determined there has been no significant impact to the environment. The low levels of radioactivity close to the submarines, McMichael said, were no different than the background levels of radioactivity found anywhere on the ocean floor.

While environmental and nuclear watchdog groups agree with McCain's statement about the Navy's accident-free record, many take issue with its significance as it relates to expanding the number of commercial nuclear power plants in the United States.

"The Navy, they train their people well," said Kurt Zwally, National Wildlife Federation global warming solutions manager. "The Navy's safety record is admirable. But there is a different safety record with plants in the U.S."

Edwin Lyman, a senior staff scientist at the Union of Concerned Scientists in Washington, D.C., said commercial nuclear power plants have at times been run haphazardly and sloppily.

The Navy is one thing, Lyman said. "Are they going to be able to run the commercial sector with that kind of discipline? I doubt it."

The Navy's good safety culture is certainly one reason for its success, said Thomas B. Cochran, senior scientist in the nuclear program at the Natural Resources Defense Council. But there are other reasons. The Navy's reactors are much smaller and more robust than reactors used commercially. They are designed for combat and to take jolts from being in a submarine. So the comparison isn't entirely fair, he said.

In short, while there is debate about the relevance of McCain's statistic, McCain is right when he says there have been no reactor accidents aboard the U.S. Navy's nuclear-powered vessels. We rate his statement True.