Transcript bunkerbu - Stanford University

Bunker-busters:
Effectiveness and
Implications
Michael May
Stanford University
WIIS Symposium
March 12, 2004
Acknowledgement
• This presentation is based on work by
Zachary Haldeman and myself.
• References and acknowledgements
can be found at:
http://cisac.stanford.edu/
• Some pictures and other material are
from Zachary Haldeman, “New Roles
for Nuclear Weapons: Bunker Busting
and Agent Defeat” Stanford University
2
Questions
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What are the targets?
How well can they be located?
How effective are the weapons?
What are the other effects?
What does this have to do with
deterrence?
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What Are the Targets?
• Perhaps 1400 “strategic facilities”
mostly in the former Soviet Union
• A few dozen chem-bio warfare facilities
outside Russia (Iran, DPRK, Libya, ...)
• Mostly “cut and cover” facilities, a few to
ten meters underground (Natanz)
• A number of more deeply-buried tunnellike facilities (Kumchang-ni)
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Natanz
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Cut and Cover Target
QuickTime™ and a
Photo - JPEG decompressor
are needed to see this picture.
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Kumchang-ni
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How Well Can Targets Be
Located?
• Large, permanent facilities can be
located by overhead photography to
within a few meters
• But their depth, extent and layout (and
hence vulnerability) may not be known
• Small, temporary storage and other
sites, and deployed weapon systems
are hard to locate accurately
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How Deep Can Nuclear
Weapons Penetrate?
• Specially designed weapons delivery
systems today can penetrate:
– A few meters in granite
– Perhaps ten meters in other rocks
– Up to thirty meters in soil, alluvia, etc.
• Nuclear weapons would have to be
specially designed and perhaps tested
to withstand the shock of penetration
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How Effective Are Nuclear
Weapons Against Buried Targets?
Underground nuclear explosions produce
• A hot “cavity” that contains most of the
heat and radioactivity until venting
• Outgoing underground shocks that
fracture rock and destroy structures
• Surface effects such as radioactive
fallout, shock, and others
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A Cavity: 1 Kiloton at 30 m
DOB in Alluvium
QuickTime™ and a
Photo - JPEG decompressor
are needed to see this picture.
• Note asymmetric cavity,
fracture zone around it,
outline of a possible
bunker (60 m * 10 * 10)
in dotted line. Bunker
would not have retained
original shape.
• Bubble about 30x40 m.
• Time is approximately
200 + milliseconds after
explosion time.
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Effects on Biological and
Chemical Agents
• The time before the bubble vents varies
from a few milliseconds for shallow
depths to a few hundred milliseconds
• The longer time is enough to destroy
agents exposed during that time, the
shorter time may not be (little data)
• After venting, both temperature and
radioactivity decrease rapidly
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Effects on Biological and
Chemical Agents (cont’d)
• Even for the longer exposure times
(deeper penetration), not all the agents
may be exposed, depending on layout
• Additional agent destruction may take
place after venting and in fracture zone
• In general, detailed knowledge of the
target layouts and much more data are
needed to assure complete destruction
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Effects on Underground
Structures
• Destructive shocks extend further than
bubble dimensions
• Peak stresses of sufficient to destroy
very hard structures will reach out 100
m for a contained 10 kt explosion in
rock, half of that in soil.
• Data for cratering bursts are not
adequate for accurate prediction.
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Surface Effects
The main surface effects are:
• Radioactive fallout
• Blast and seismic
• Surface effects from underground
explosions are less than those from
surface bursts of the same yield
• But they still affect large areas
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Radioactive Fallout
• For 1-10 kt yields, the initial 24-hour
dose exceeds the LD50 dose of 450
rads over about 10 square kilometers.
• For yields in the sub-1-kiloton range,
this area is about 1 square kilometer
• (for 5 m burial in rock or 20 m in soil)
(Frank Serduke, UCRL-ID-146937, 2001)
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Above Surface Effects of
Cratering Nuclear Explosion
• Danny Boy at H+1
• 0.43 kt at 33 m DOB
in dry basalt
• Pointy contour (3rd
in, ~ 4 km long) is 1
r/hr, 100 r/hr contour
is ~ 1 km
• From ground and
aerial surveys (Teller
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et al. p. 209)
Blast and Seismic
• For 1-10 kt a few to 20 m underground,
severe blast damage may be expected
to a few hundred meters, minor damage
to a few miles
• Seismic damage may be expected to a
few miles depending on construction
• The seismic signal will be picked up
around the world
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Bottom Lines 1
• Nuclear bunker-busters are more
effective against buried targets than
penetrating conventional weapons.
• But complete inactivation of biochem
agents can probably not be assured.
• Targets buried below a few tens of
meters are likely to be unaffected.
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Bottom Lines 2
• Location of targets within meters is
essential, which opens up alternatives.
• Surface effects (radioactivity and blast)
will be significant over square miles,
perceptible over much wider areas.
• Release of active biological and
chemical agents may occur.
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Operational Comments
• Integrating a nuclear strike(s) into a
military operation has major logistics,
security, and training implications.
• U.S. projection forces and bases in
allied territories are more vulnerable
than dispersed hostile forces: U.S.
casualties in a two-sided nuclear war
will escalate greatly over conventional
casualties.
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Bunker-busters and the
National Security Strategy
• According to the NPR, the New Triad
will have four primary missions: to
assure, dissuade, deter, and defeat.
The National Security Strategy added a
fifth mission, “preemption,” which was
called “proactive counterproliferation.”
• Bunker-busters may be relevant to
defeat and to preemption. Deterrence?
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Bunker-busters and
Deterrence
• If what’s to be deterred is protecting
command and control or storage
facilities, those can still be protected.
• If what’s to be deterred is use in war,
the BW delivery systems are likely to be
dispersed and ready to use.
• If war itself is to be deterred, that’s best
done by the threat of defeat.
• So the effect on deterrence is unclear. 23
Bunker-busters and the NPT
• The U.S. advertising new missions for
nuclear weapons lessens the value of
the NPT and nuclear restraint for
everyone in return for marginal gains.
• The U.S. cannot deal with the nuclear
threat by itself. It needs a more, not
less, effective agreement.
• That calls for a different approach to US
nuclear policy than the NPR embodies. 24