WASHINGTON (AP) _ U.S. nuclear experts became so worried about the chance of an accidental explosion of nuclear artillery shells that they ordered U.S. troops in Europe not to move them until they could be modified, The Washington Post reported in Wednesday editions.
The problem with the W-79 shell, designed for eight-inch howitzers, was one of three found recently by Energy Department experts, the newspaper said.
A special committee will be appointed to review the W-88 warhead atop the new D-5 missile undergoing deployment on Trident submarines this year, the Post said.
And it said special flight restrictions have been instituted pending review of the W-69 warhead on the short-range SRAM-A missile carried by some bomber aircraft.
The W-88 and W-69 warheads use the same volatile fuel that experts feared could explode in certain accidents and set off the conventional explosives that trigger the nuclear explosives.
Those conventional explosives surround a mass of plutonium and compress it from all sides to the point where the nuclear chain reaction begins and proceeds to cause a nuclear explosion in a split second.
The artillery shell problem was discovered by special computer studies using new, more powerful computers in 1988, the Post said.
Those studies raised the possibility that a bullet striking the conventional explosive could set off part of it, dispersing the highly toxic plutonium, though not necessarily causing a chain reaction. At least a dozen such accidents are known to have occurred in the nuclear age.
But if the bullet hit while the shell were in the artillery piece, the barrel of the weapon might reflect even neutrons back into the plutonium to cause a significant nuclear explosion, according to the experts’ thinking as described by the Post.
The W-88 was feared to be vulnerable to an accidental nuclear explosion, but the W-69 threat was dispersal of plutonium, the newspaper said.
An unidentified senior military official was quoted as saying, ″For a while, we were worried that these things might go off if they fell of the back of a truck and landed in a certain way.″
Special teams early in 1989 installed ″safing mechanisms,″ and the shells are being modified, the Post said.
Energy Secretary James D. Watkins, though declining to discuss specifics or confirm all details, was quoted as saying in an interview, ″Without any question, safety has been preserved″ for the artillery shell.