This post is from February 2005. Facts and links may have changed since. See more from that month

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RNEP Returns


Post-test B61-11 mock-up (source)

The Washington Post is reporting the the FY2006 budget due out in a few days will request $10.3 million to restart study of the Robust Nuclear Earth Penetrator (RNEP)— a “bunker busting” nuclear weapon.

The RNEP would convert existing B61 or B83 nuclear bombs to an earth penetrator configuration, replacing the B61 Mod 11 for bunker busting duties.

There are some misconceptions about RNEP—it is not a low yield nuclear weapon. The yield of the weapon under study could be as large as one megaton—about 75 times as powerful as the nuclear weapon that destroyed Hiroshima.

The National Academies has completed a study, Effects of Nuclear Earth-Penetrator Weapon and Other Weapons, undergoing classification review that is expected to conclude that nuclear earth penetrators require insanely accurate intelligence about the location of buried facilities and still pose significant fallout risks.

Can’t wait for the National Academies? Check out Lisbeth Gronlund and David Wright, Earth-Penetrating Weapons: Underlying Principles and other Technical Aspects (June 2002).

Jonathan Medalia recently authored a helpful CRS report on the subject, Robust Nuclear Earth Penetrator Budget Request and Plan, FY2005-FY2009.

Note: The photograph of the B61 Mod 11 mock-up was taken by military photojournalist Mark Farmer.

The Post has corrected this story.

Jeffrey Lewis

Writing on ACW 2004–2026

Dr. Jeffrey Lewis is the founding publisher of Arms Control Wonk.com. He is the Director of the East Asia Nonproliferation Program at the James Martin Center for Nonproliferation Studies at the Middlebury Institute of International Studies at Monterey. His also a non-resident affiliate at Stanford's Center for Security and International Cooperation and a Contributing Editor to Survival.

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