One of the more contentious issues in the Energy and Water Development
Appropriations bill last year was the funding of a program to study
nuclear earth-penetrator weapons. Also known as RNEP (Robust Nuclear
Earth Penetrator) or a nuclear "bunker buster," the proposed
weapon is designed to hold-at-risk deeply buried targets beyond the
range of conventional weapons. Last year, Congress voted to deny funding
for the study of this weapon. The House of Representatives recently
passed its version of the FY 2006 Energy and Water Development Appropriations
bill which did not include funding for such a nuclear weapon study (see
The House-passed version of the FY 2006 Defense Authorization bill worked
around this controversy by removing the nuclear component from a study
of earth penetrator weapons systems (see http://www.aip.org/fyi/2005/078.html)
and by shifting the proposed work from the Department of Energy to the
Department of Defense.
The Defense Authorization Act for FY 2003 mandated that a study be
performed on the health and environmental impacts of an RNEP weapon.
A National Research Council "Committee on the Effects of Nuclear
Earth-Penetrator and Other Weapons" conducted this study. Fifteen
experts from the university, private, and national laboratory communities
served on this committee, chaired by John F. Ahearne of Sigma Xi. The
committee released its study in a prepublication format in late April.
The study cites an estimate by the Defense Intelligence Agency that
there are approximately 10,000 hard and deeply buried targets in the
potential U.S. adversaries. Of these, about 20% "have a major strategic
function," of which more than a hundred could be targeted by an
RNEP weapon. These facilities are used to protect leaders, key personnel,
weapons, equipment, and other assets and activities. Some of the facilities
are located in the basements of multistory buildings in cities.
Much of the study is fairly technical. The committee summarized their
findings in nine "most important conclusions," which are available
at this NAS site: http://books.nap.edu/catalog/11282.html
Among them are the following:
"Many of the more important strategic hard and deeply
buried targets (HDBTs) are beyond the research of conventional explosive
penetrating weapons and can be held at risk of destruction only with
nuclear weapons. Many - but not all - known and/or identified hard
and deeply buried targets can be held at risk of destruction by one
or a few nuclear weapons."
"Current experience and empirical predictions indicate
that earth-penetrator weapons cannot penetrate to depths required
for total containment of the effects of a nuclear explosion."
"For attacks near or in densely populated urban areas
using nuclear earth-penetrator weapons on hard and deeply buried targets
(HDBTs), the number of casualties can range from thousands to more
than a million, depending primarily on weapon yield. For attacks on
HDBTs in remote, lightly populated areas, casualties can range from
as few as hundreds at low weapon yields to hundreds of thousands at
high yields and with unfavorable winds."
"For urban targets, civilian casualties from a nuclear
earth-penetrator weapon are reduced by a factor of 2 to 10 compared
with those from a surface burst having 25 times the yield."
Richard M. Jones
Media and Government Relations Division
American Institute of Physics