August 7 2003. Copyright 2003. Graphic News. All rights reserved.

ÒDr. StrangeloveÓ plan for new mini-nuclear weapons

LONDON, August 7, Graphic News: One day after the anniversary of Hiroshima, some 150 top U.S. scientists and senior officials are meeting in private at Offutt Air Force Base in Nebraska to plan the future of the American nuclear arsenal, including the development of so-called mini-nukes.

Last May the Bush administration won Senate approval for $15 million for continued research into the Robust Nuclear Earth Penetrator (RNEP), a plan to modify a nuclear weapon into a mini-nuke bunker-buster -- a weapon with up to 20 times the force of the Hiroshima bomb in 1945. That bomb, which had a yield of about 15,000 tones of TNT, killed an estimated 140,000 people.

Advocates say building so-called Òmini-nukesÓ is the only way to deter rogue states and terrorist groups. Critics say the weapons would inflict massive civilian casualties and undercut global efforts to quell the proliferation of nuclear arms.

Democrats have vowed to continue fighting what they describe as a determined effort by the Bush administration to produce new nuclear weapons. Such a move would abandon global arms treaties and violate the two cornerstones of current U.S. policy: to use nuclear weapons only as a last resort and never to use them against non-nuclear nations.

Opponents of nuclear bunker busters claim they are being portrayed by some in the Pentagon as less dangerous than existing atomic weapons. ÒNuclear earth-penetrating weapons lower the threshold for the use of nuclear arms,Ó says David Wright, a nuclear-weapons expert at the Union of Concerned Scientists in Washington DC. ÒIf youÕre really serious about trying to stop countries from developing nuclear weapons, itÕs not a very good idea.Ó

But military planners insist that Iraq, Iran and North Korea -- described by President Bush as an Òaxis of evilÓ -- are hiding chemical, biological or nuclear weapons beneath their vast deserts and mountains. Following the PentagonÕs limited success in destroying subterranean hideouts in Afghanistan with conventional bunker busters, nuclear warriors have argued that mini-nukes are becoming indispensable. ÒWithout having the ability to hold those targets at risk, we essentially provide sanctuary,Ó said Assistant Secretary of Defence J.D. Crouch.

The idea behind the RNEP is that powerful shock waves, like an earthquake, would rip apart even solid rock, pulverising the most deeply shielded enemy target. One RNEP option is to upgrade the PentagonÕs only existing nuclear bunker-buster -- the B-61 Mod 11 atomic bomb. 

The mini-nuke concept is not new: mini-, micro- and tiny-nukes were first suggested by weapon designers in 1991. The development of the B61-11 was kick-started by current Vice President Dick Cheney in one of his last acts as Defence Secretary during the administration of George Bush Sr. in 1993. Developed quietly at three Department of Energy (DOE) laboratories -- Lawrence Livermore in California, and Los Alamos and Sandia in New Mexico -- under the anodyne-named Stockpile Stewardship Programme, the first operational B61-11s were delivered to the Air Force in December 1997.

The deployment was controversial because of official U.S. policy not to develop new nuclear weapons. The DOE and the weapons labs have consistently argued, however, that the B61-11 is merely a ÒmodificationÓ of an older delivery system, because it used an existing Òphysics packageÓ. 

The B61-11 is constructed at the Oak Ridge National LaboratoryÕs Y-12 nuclear weapons plant in Tennessee. Ironically, the Y-12 plant is operated by Bechtel, the company awarded the contract to rebuild Iraq. Y-12 is responsible for putting the physics package -- the plutonium ÒpitsÓ which initiate the nuclear chain reaction, and the ÒcannedÓ subassemblies which make a bomb thermonuclear -- into a hardened steel casing with a new nose cone to provide ground penetration capability.

The Union of Concerned Scientists estimates the U.S. now has around fifty B61-11s in its stockpile. But tests with dummy bombs dropped from a B-2 stealth bomber in March 1998 showed these can only penetrate dry earth to a depth of six metres (20 feet). David Wright says this would not be nearly enough to contain the radioactivity. 

ÒEven for a 0.3-kiloton (equivalent to 300 tons of TNT) explosion, you would need a burial depth of about 70 metres (230 feet) in dry soil and about 40 metres (130 feet) in dry, hard rock to contain the blast,Ó Wright says. 

In addition to the immediate effects of blast, air shock, and thermal radiation, a nuclear explosion just six metres (20 feet) deep would produce especially intense local fallout. The fireball would break through the surface of the ground, carrying into the air large amounts of radioactive soil and debris.

A study by the Federation of American Scientists concludes that greater penetration with the RNEP is unlikely. A theory known as Òlong-rod penetrationÓ predicts the maximum penetration depth for typical values for steel and concrete to be roughly 10 times the missile length, or about 36 metres (118 feet) for a 3.6-metre-long (11.8-feet-long) B61-11 missile.

In addition an earth-penetrating nuclear weapon must protect the warhead and its associated electronics while it burrows into the ground. This severely limits the missile to impact velocities of less than about 3,000 metres per second (9,800 feet per second) for missile cases made from the very hardest steels -- increasing impact velocities would simply cause the warhead to deform and melt.
/ENDS

Sources: Federation of American Scientists, Union of Concerned Scientists, Project Plowshare