Memorandum submitted by Mr Gordon Thompson
(3 January 2002)
On 18 December 2001, the House of Commons Defence
Committee published a report, The Threat from Terrorism.
In the accompanying press notice, the Committee announced that
it will continue its work on the threat from terrorism, and indicated
that written submissions are welcome. Accordingly, the Institute
for Resource and Security Studies (IRSS) offers this submission.
The submission was prepared by Gordon Thompson, executive director
of IRSS. Dr Thompson was based in the UK during the period 1969-79
and has subsequently performed a number of studies on UK-related
This submission addresses the potential role
of civilian nuclear facilities as radiological weapons for an
enemy of the UK. That enemy might be a foreign state, a foreign
or domestic group of terrorists, or a malicious or insane individual.
A thorough analysis of the subject addressed
by this submission would require a book-length document, which
would cite a large body of technical literature. This submission
does not purport to provide a thorough analysis. Instead, it touches
on a few points and mentions a few pieces of literature. Its purpose
is to bring a neglected subject to the Committee's attention.
The Committee is welcome to contact IRSS if there is a desire
to pursue the subject in greater depth.
2. RELEVANT NUCLEAR
A civilian nuclear facility is a potential radiological
weapon if the facility contains a large amount of radioactive
material that can be released to the environment. Three types
of facility are prominent in this respect, namely: (a) commercial
nuclear reactors; (b) nuclear fuel reprocessing plants; and (c)
radioactive waste storage facilities. In the UK, there are facilities
in each of these three categories. Similar facilities exist in
France and other countries, many of them at locations such that
a release of radioactive material from the facility could have
significant impacts in the UK.
Experience shows that nuclear facilities can
release significant amounts of radioactive material to the environment.
Prominent examples are the Windscale reactor fire of 1957, the
Kyshtym radioactive waste storage tank explosion of 1957, and
the Chernobyl reactor explosion and fire of 1986. Studies show
that civilian facilities now operating could release large amounts
of radioactive material as a result of influences that include
human error, equipment failure, natural forces (eg earthquake),
and acts of malice or insanity.
A notable example of a potential radiological
weapon for an enemy of the UK is the B215 facility at Sellafield.
This facility houses 21 steel tanks and associated equipment in
above-ground concrete cells. The tanks contain high-level radioactive
waste (HLW) in the form of a self-heating, acidic liquid that
requires continuous cooling and agitation. This liquid HLW is
a product of nuclear fuel reprocessing at Sellafield. At present,
the tanks contain about 1,550 cubic metres of liquid HLW. The
radioactive isotypes in this liquid include about 8 million TBq
(2,400 kilograms) of caesium-137. For comparison, the 1986 Chernobyl
reactor accident released to the atmosphere about 90,000 TBq (27
kilograms) of caesium-137, representing 40 per cent of the inventory
of caesium-137 in the reactor core. Most of the offsite radiation
exposure from the Chernobyl accident can be attributed to caesium-137,
which has a half-life of 30 years.
3. USING A
In order to use a nuclear facility as a radiological
weapon, an enemy must obtain a release of radioactive material
from the facility. A variety of methods are available for this
purpose. Each facility has its particular vulnerabilities, which
are apparent to knowledgeable persons. If the enemy has an agent
in place inside the facility, the obtaining of a release might
not require violent action. In the absence of an inside agent,
the obtaining of a release would generally require violent action.
One potential method for obtaining a release
through violent action would be to arrange for the impact of a
fuel-laden commercial aircraft on the facility. For example, the
aircraft might be a Boeing 747-400, which has a maximum takeoff
weight of 360-400 tonnes and a fuel capacity of 200-220 thousand
litres. Complete combustion of 100,000 litres of jet fuelabout
half the fuel capacity of a Boeing 747-400will yield energy
equivalent to that from exploding 900 tonnes of TNT, although
with lower efficiency equivalent in converting combustion energy
into blast. Thus, the impact of a fuel-laden Boeing 747-400 on
a nuclear facility would unleash large forces, potentially causing
a significant release of radioactive material.
By way of illustration, consider the impact
of a fuel-laden commercial aircraft on the B215 facility at Sellafield.
According to press reports, more than 200 commercial flights pass
within 50 miles of Sellafield each day. The UK Nuclear Installations
Inspectorate (NII) stated in 1995 that the impact of a large commercial
aircraft on the B215 facility could breach one of the concrete
cells surrounding a liquid HLW tank, and the tank itself, leading
to a release of HLW to the environment. NII did not consider the
effects of the accompanying fuel-air explosion. Nor did NII consider
the implications of this event for cooling and containment of
the liquid HLW in the other tanks in the B215 facility.
The initial breaching of one or more liquid
HLW tanks, and the accompanying fuel-air explosion and fire, would
create severe radioactive contamination of the Sellafield site.
The resulting radiation fields could preclude actions needed to
provide cooling and containment of liquid HLW in other tanks in
the B215 facility. Then, over a period of days, these tanks would
boil dry, after which the solid residue in the tanks would heat
up and release volatile radio-isotypesincluding caesium-137to
the atmosphere. The eventual release of caesium-137 to the atmosphere
might exceed 50 per cent of the inventory in the tanks. The present
inventory (see Section 2, above) is about 8 million TBq (2,400
kilograms). Thus, the release of caesium-137 to the atmosphere
might exceed 4 million TBq (1,200 kilograms).
The preceding discussion shows how an enemy
could use one eventin this instance, an aircraft impactto
trigger other events that yield a more significant outcome. This
amplifying effect is illustrated by the fire-induced collapse
of the World Trade Centre buildings in New York on 11 September
2001. It is likely that a sophisticated enemy would seek an amplifying
effect in a future attack. For example, an enemy possessing a
crude nuclear weapon would probably consider using this weapon
on a civilian nuclear facility, in order to amplify the weapon's
radiological impact. Detonation of a fission weapon will create
about 7 TBq of caesium-137 per kilotonne of yield, and a crude
weapon could have a yield in the 10-kilotonne range. The resulting
fallout of about 70 TBq of caesium-137 would be greatly amplified
if the weapon were used on the B215 facility at Sellafield, which
houses liquid HLW containing 8 million TBq of caesium-137.
4. EFFECTS OF
Radioactive material could be released from
a nuclear facility in two ways: (a) as an atmospheric release
composed of small particles and gases; or (b) as a liquid release.
An atmospheric release would create a plume that would travel
downwind. Particles in the plume would be deposited on the ground
and other surfaces. A liquid release would contaminate ground
water or surface water. For example, a liquid release at Sellafield
could contaminate the Irish Sea.
As an illustration of the implications of a
large release, consider a release to the atmosphere of 4 million
TBq (1,200 kilograms) of caesium-137. This release would represent
50 per cent of other present caesium-137 inventory in the B215
facility at Sellafield. The implications of such a release can
be illustrated by the area of land that would become uninhabitable
due to contamination by the caesium-137.
In this submission, the threshold of uninhabitability
of land is assumed to be a whole-body, groundshine-radiation dose
of 100 mSv over 30 years, representing about a three-fold increase
above the natural background level of radiation. A person residing
at the boundary of the uninhabitable zone would receive a radiation
dose of 100 mSv over the first 30 years. Thereafter, the dose
rate at this location would decline, due to radioactive decay
and weathering of the caesium-137. A person choosing to live within
the uninhabitable zone would experience a higher dose rate, potentially
orders of magnitude higher in the most heavily contaminated locations.
Contamination of food and water supplies, or the deposition of
radio-isotypes other than caseium -137, could cause additional
radiation doses, both within and outside the uninhabitable zone.
In typical weather conditions, an atmospheric
release of 4 million TBq of caesium-137 would, if the radioactive
plume travelled over land rather than the ocean, render uninhabitable
about 200,000 square kilometres of land. The use of a little imagination
shows that this event would be a disaster of historic proportions,
with health, environmental, economic, social and political dimensions.
As an indication of the significance of our
assumed threshold of uninhabitability, note that a radiation dose
of 100 mSv over 30 years corresponds to an average dose rate of
3.3 mSv per year. The health effects of radiation exposure at
this dose level have been estimated by the US National Research
Council (National Research Council, 1990). According to these
estimates, a continuous lifetime exposure of 3.3 mSv per year
would increase the incidence of fatal cancers in an exposed population
by about 8 per cent for males and 11 per cent for females. About
one person in five normally dies of cancer. In other words, in
a population residing continuously at the boundary of the uninhabitable
zonethereby receiving a whole-body, groundshine-radiation
dose of 3.3 mSv per yearabout 2 per cent of people would
suffer a premature death due to a fatal cancer that would not
otherwise occur. Ingestion of contaminated food and water, if
this occurred, would expose members of the population to internal
radiation, thereby causing additional cancer fatalities.
5. PRESENT UNDERSTANDING
The UK Government and the nuclear industry have
been warned on numerous occasions that civilian nuclear facilities
are tempting targets for enemy action. A Royal Commission discussed
this threat in a 1976 report (Flowers et al, 1976). The
author of this submission, Gordon Thompson, has made many attempts
to alert Government to the threat. For example, in June 1998,
at a briefing held within the Parliament buildings, the author
presented a report which addresses, among other matters, the potential
for an enemy-induced release of radioactive material from Sellafield's
B215 facility (Thompson, 1998).
The consistent response of Government and industry
to these warnings has been to ignore or rebuff them. Documents
and statements that have emanated from Government and industry
provide no indication that either entity has ever attempted a
thorough analysis of the threat or the options for reducing the
threat. Analyses of this kind may have been attempted in secrecy.
However, the author doubts that any thorough analysis has been
performed by industry or Government.
The threat posed by civilian nuclear facilities
should be addressed in the UK's defence strategy. These facilities
are potential weapons with strategic implications. Yet, defence
planners lack a thorough understanding of the threat and the options
for reducing the threat. This deficiency should be corrected at
the earliest opportunity. A two-step process of technical analysis
The first step would be to perform a thorough
analysis of the nature of the threat. This analysis would assess
the vulnerability of each relevant nuclear facility to potential
enemy actions, and the consequences of the releases of radioactive
material that could be caused by those actions.
The second step would be to identify, for each
significant facility, a range of options for reducing the probability
or magnitude of a release of radioactive material from the facility
due to enemy action. Among these options would be measures for
active or passive defence of the facility. Other options would
include measures for reducing the inventory of radioactive material
at the facility.
A substantial part of the threat arises from
the reprocessing of spent nuclear fuel at Sellafield and La Hague.
Large amounts of radioactive material are concentrated at these
sites, much of it in readily-mobilisable forms. At Sellafield,
liquid HLW stored in the B215 facility could be mobilised as described
in Section3, above. At La Hague, spent nuclear fuel is stored
in water-filled pools in a high-density configuration; loss of
water from these pools could cause the fuel to burn, thereby releasing
radioactive material to the atmosphere.
In view of the substantial threat arising from
reprocessing, special attention should be given to the merit of
continuing this activity. If reprocessing lacks merit, then it
should be stopped immediately. At Sellafield, the stopping of
reprocessing would prevent the further production of liquid HLW,
and would expedite the rundown of the liquid HLW inventory through
vitrification. At La Hague, the stopping of reprocessing would
remove the rationale for accumulating spent fuel at this site
in high-density pools. At both sites, the stopping or reprocessing
would allow resources to be redirected to enhancing the robustness
and safety of facilities for managing radioactive material.
Numerous analysts have determined that reprocessing
lacks merit from the perspectives of economics, radioactive waste
management, and international security. For example, the Royal
Society has concluded that the assumptions underlying the UK's
reprocessing programme "no longer obtain" (Royal Society,
1998). Moreover, reprocessing separates plutonium from spent fuel,
thereby increasing the world's inventory of weapon-ready fissile
material. The Royal Society and many other observers have expressed
concern that separated plutonium might be used by hostile states
or terrorist groups to make nuclear weapons. Although plutonium
inventories at Sellafield and La Hague are comparatively secure,
reprocessing at these sites provides legitimacy for the accumulation
of plutonium at less-secure locations. Thus, reprocessing poses
a double treat. It provides enemies with pre-deployed radiological
weapons, while helping enemies to gain access to nuclear weapons.
A high-level group advising the US Government
has examined the security of nuclear weapons and fissile material
in Russia, concluding (Baker, Cutler et al, 2001):
"The most urgent unmet national security
threat to the United States today is the danger that weapons of
mass destruction or weapons-usable material in Russia could be
stolen and sold to terrorists or hostile nation states and used
against American troops abroad or citizens at home. This threat
is a clear and present danger to the international community as
well as to American lives and liberties."
This warning was directed to the US Government,
but is equally applicable to the UK. In view of the potential
for an enemy to amplify the impact of a crude nuclear weapon by
using it on a civilian nuclear facility, the UK defence strategy
should assign a high priority to improving the security of nuclear
weapons and fissile material in Russia and around the world. Moreover,
the UK policy on nuclear fuel reprocessing and plutonium management
should be compatible with the UK defence strategy.
IRSS recommends that the Defence Committee assign
a high priority to informing itself about the threat posed by
civilian nuclear facilities. The Committee should not rely upon
the Government or the nuclear industry to provide the relevant
information. Experience shows that these entities are reluctant
to address the threat, and cannot be trusted to provide a thorough
analysis of the threat and the options for reducing the threat.
The Committee should take direct responsibility for obtaining
The Committee should call upon the Parliamentary
Office of Science and Technology (POST) to conduct a thorough,
independent analysis of the threat and the threat-reducing options,
using the two-step approach outlined in Section 6, above. To perform
the analysis, POST should assemble an expert group with members
from inside and outside the UK, and should sponsor specialist
studies as necessary. Employees of the government and the nuclear
industry could serve on the expert group, but should be personally
accountable for their input.
POST should be tasked with providing the Committee
with an interim report in 6 months and a final report in 12 months.
These reports should be presented to the Committee at hearings
where Government, industry, academia and citizen groups are also
able to make presentations. After these hearings, the Committee
would be in a position to formulate its own recommendations for
The subject to be addressed in the proposed
POST analysis and the proposed hearings is central to the future
security of the UK. In the UK, the traditional approach to addressing
this subject would be to do so in secrecy. However, experience
shows that a climate of secrecy will stifle the development of
the information that the Committee needs in order to do its duty.
Accordingly, the analysis and the hearings should eschew secrecy,
with some limited exceptions. The exceptions would cover detailed
technical information that could be useful to an enemy.