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. Last Updated: 07/27/2016

U.S. H-Bomb Heads for Graveyard

WASHINGTON -- The United States will soon begin to dismantle the 35 remaining B-53s, the most powerful thermonuclear bombs it ever built, 40 years after the weapons first became operational and five years after they were withdrawn from active service, according to Energy Department officials.

With a yield of 9 megatons (the equivalent of 9 million tons of TNT), each B-53 has the power of more than 400 Hiroshima atomic bombs. The weapon was originally designed to destroy the Soviet Union's deeply buried bunkers built during the Cold War to protect top Communist Party leaders and Moscow's military command posts.

The 4,000-kilogram bomb remained in the active stockpile until 1997 because it was the only giant thermonuclear weapon, or H-bomb, that Strategic Command planners felt confident could destroy Russian, North Korean and Iraqi hardened targets hidden in mountains or buried underground, according to active and retired Defense and Energy department specialists.

It was only in 1997, when the newer B-61 Mod 11 nuclear bomb, with a special earth-penetrating warhead, became operational, that the Strategic Command during the Clinton administration put the B-53 into secure storage warehouses.

An unplanned lag has developed over the years in the Energy Department's ability to dismantle its older, retired nuclear weapons at its Pantex plant in Texas, the only facility where U.S. nuclear weapons have been assembled and disassembled. Like the B-53, a line of other nuclear weapons has developed waiting to be taken apart in a highly technical and potentially dangerous process.

This little-publicized delay, along with the growing number of refurbished nuclear bombs and warheads in line to go through the Pantex plant and be returned to operational status, is the reason there will be no immediate dismantling of the warheads removed under the new Bush administration strategic reduction treaty with Russia.

For example, the W-79, the 20-centimeter nuclear artillery shell that in the 1970s was to provide a neutron radiation effect that would kill people but leave buildings intact, still has not been completely dismantled.

The 500 so-called neutron artillery shells were retired in 1991 by President George H.W. Bush, but there still is "ongoing dismantlement work'' on the W-79 "that's been under [way] for several years,'' Everet Beckner, deputy administrator for defense programs of the National Nuclear Security Administration, told the Senate Armed Services Committee last week.

The W-79 program was supposed to have been completed in August 2000 but was held up when complications developed.

Another weapon retired by Bush and still being dismantled is the W-56, the warhead for the Minuteman II intercontinental ballistic missile. The 500 W-56 warheads were supposed to have been dismantled by September, but Beckner told the committee the process "will continue through fiscal year 2005.''

Also in line to begin disassembly soon are the tactical B-61 nuclear bombs that first came into the inventory in 1963.

Dismantling nuclear bombs and warheads takes years of planning, Beckner told the committee, "since we must safely and securely handle the thousands of parts that will be generated by the process.'' Radiation hazards must be analyzed and safety standards approved. Transportation from secure storage areas must be programmed; storage at Pantex arranged; and each weapon radiographed to see if its critical safety components are operational, all before any dismantling.

Each weapon has to be taken apart in a separate, secure work bay. The primary chemical high explosive must carefully be separated from the plutonium and special radioactive materials that cause the thermonuclear blast.

The chemical high explosives are burned at Pantex and the plutonium is stored there because no plant exists to take that section apart. Other special nuclear materials can be disposed of under the existing material disposition programs. Some other subassemblies can be retained for use in other weapons, while highly enriched uranium from the dismantled bombs and warheads could be sent to the Energy Department's Y-12 plant at Oak Ridge, Tennessee, for storage or further processing.

The dismantling system is so complex and the plans for refurbishing weapons so large that the Pantex plant, with its limited number of secure work bays, will not be able to take on new dismantling without expanding the workforce, Beckner told the senators.