PART C: OTHER
WASTE MANAGEMENT ISSUES
CHAPTER 7: REPROCESSING, PLUTONIUM AND
7.1 The United Kingdom faces complex challenges in
nuclear waste management because of the variety and volume of
wastes that must be dealt with. These wastes have resulted from
the active role that the United Kingdom has played (and continues
to play) in both civil and military developments since the Second
World War. The United Kingdom has operated numerous different
commercial and research reactor types (including submarine reactors),
has had an active fuel reprocessing programme for military and
commercial purposes since the 1950s, is a world leader in nuclear
materials research and the application of nuclear materials for
medical purposes, and operates facilities for fuel fabrication.
The various programmes to clean up wastes from previous activities
also generate their own waste, albeit in more manageable forms.
Each operation often generates its own waste stream which may
require a unique management solution because of the physical nature
of the waste, or its chemistry, or its activity. The waste management
task for the United Kingdom is thus comparable to that of the
US, France, or the former Soviet Union, rather than to nations
such as Sweden, Canada, the Netherlands and others which have
only operated a limited number of different reactor types and
have no nuclear weapons programme.
7.2 In this chapter we look at some of the issues
for the United Kingdom which feed into the debate on longer-term
solutions to nuclear waste. These include plutonium and its uses
and the reprocessing of spent fuel. A description of the issues
is given under each heading and this is followed by a review of
what our witnesses told us. Our opinions are summarised at the
end of the chapter.
7.3 Whether a country reprocesses spent fuel or not
is a key factor in determining what types and volumes of waste
have to be managed. This, in turn, may have a bearing on the long-term
management strategy that can be used. Compared to a "once-through"
fuel cycle, reprocessing reduces the volume of HLW, but increases
the volume of ILW; this could have implications for the volumes
of storage or repository space (or both) that will be required.
Over the whole fuel cycle reprocessing can reduce the volume of
LLW because if uranium and plutonium are recycled less uranium
ore needs to be mined. This off-sets the small additional radioactive
discharges to the air and sea at the reprocessing plant. The following
table shows the volumes of LLW, ILW and HLW arising from 1 GW(e)
year power generation for a fuel cycle with reprocessing and complete
recycling of uranium and plutonium, and a once-through cycle.
If the uranium and plutonium produced by reprocessing are not
recycled the situation is very different because of the large
repository volume that is likely to be required to accommodate
these fissile materials (see para 7.42).
Table 4 Waste arisings
|Waste type||Waste volume (cubic metres)
7.4 Reprocessing involves the chemical and physical
separation of uranium and plutonium from spent nuclear fuel. The
fuel rods are first removed from their support structure and are
chopped into sections. These sections are then dissolved in nitric
acid in order to separate the fuel from its cladding. The resulting
liquor undergoes chemical processing (e.g. using ion-exchange
and organic solvents) and physical techniques (e.g. filtering
and centrifuging) to separate the plutonium and uranium, that
can be re-used, from various waste streams containing the fission
products and fuel cladding.
7.5 The initial impetus behind reprocessing was to
supply plutonium for research and the manufacture of nuclear weapons.
More recently, reprocessing has been linked with the more positive
image of recycling (e.g. in advertisements on British television
by BNFL) to show how nuclear power can be a sustainable alternative
to fossil fuels. There is a variety of reasons for reprocessing
spent nuclear fuel:
· To produce plutonium (e.g. for weapons,
fast reactors or mixed oxide fuel, MOX).
· As a waste management strategy for dealing
with otherwise unstable fuel or fuel assemblies (e.g. for dealing
with Magnox fuel).
· To reduce the environmental impact on
uranium mining areas, by reducing uranium demand.
· To recover uranium for use in the manufacture
of new fuel (which conserves supplies of uranium, may give a degree
of fuel supply security, may be cheaper if the price of mined
uranium is high, and can save on fuel enrichment).
· To maintain a technological and commercial
advantage over competitor nations.
· To generate income, much of which could
come from overseas customers.
· To create employment.
7.6 The United Kingdom currently has three reprocessing
plants: two major facilities at Sellafield for reprocessing uranium
oxide fuels and Magnox fuel, and a minor facility at Dounreay
for fuels containing a high proportion of plutonium or highly
enriched uranium (see Box 3). The United Kingdom reprocesses spent
fuel from its Magnox reactors, advanced gas-cooled reactors (AGRs)
and some research reactors. As yet it has not reprocessed any
spent fuel from submarine reactors or from the Sizewell B pressurised
water reactor (PWR). BNFL Sellafield is reprocessing substantial
quantities of fuel from overseas customers, particularly oxide
fuels from PWRs and other light water reactors in countries such
7.7 Because of the reprocessing programme, spent
reactor fuel in the United Kingdom is not considered to be a waste.
A similar policy in favour of reprocessing has also been adopted
by other countries including Japan, France, Belgium and India.
A number of eastern European countries also favoured reprocessing
in the past, although most of their contracts were with the former
Soviet Union and it is now not clear if or when reprocessing will
be carried out. The two principal countries engaged in commercial
reprocessing are now the United Kingdom and France.
7.8 Some countries (including Canada, Sweden, Finland,
and Spain) have decided not to reprocess their spent fuel; the
US does not reprocess the spent fuel from its civil reactor programme.
With no re-use envisaged, the spent fuel is declared as waste.
As it is not usually proposed to remove the spent fuel from its
support structures, the whole of the fuel assembly becomes what
in the United Kingdom would be termed high level waste (HLW).
7.9 For those countries which do reprocess, and regard
plutonium as an asset, one advantage is the reduced volume of
HLW that must be dealt with (see paragraph 7.3). Disadvantage
are the intermediate level waste generated by reprocessing, the
discharges of radioactive effluents to air and sea, and the effort
that must be devoted to the storage of plutonium.
Box 3: Reprocessing
in the United Kingdom
Magnox reactors use un-enriched uranium metal fuel
rods enclosed in a cladding of magnesium alloy. This fuel is reprocessed
in the B205 plant at Sellafield. Reprocessing of Magnox fuel started
at Sellafield in 1952 and more than 40,000 tonnes have been reprocessed
since then. Reprocessing is likely to continue for at least another
10 years as the remaining Magnox power stations are not expected
to close before 2007. One reason why the spent fuel is reprocessed
is because of the technical problems which result from contact
with water: the fuel cladding corrodes, and the fuel reacts with
water to produce uranium hydride (which can ignite spontaneously
in air). Contact with water occurs because the spent fuel is cooled
under water after being removed from the reactor. Contact with
water would also be likely in a repository. This suggests that
reprocessing of Magnox spent fuel will have to continue until
all of the fuel has been treated.
The Thermal Oxide Reprocessing Plant (THORP) treats
uranium oxide fuel from advanced gas-cooled reactors (AGRs) and
water-cooled reactors. The plant became operational in 1994 and
it completed the final part of the regulatory approval process
for commissioning in August 1997. After a steady build-up of activities,
the aim is to achieve and maintain a through-put rate (the rate
at which fuel is reprocessed) of 900 tonnes per year. It is expected
that 7,000 tonnes of fuel will be reprocessed in the first ten
years of operation. THORP cost £1.85 billion to build and
is designed to have a 25 year lifespan (PP 286, 292).
The fuel for AGRs and water-cooled reactors is ceramic
uranium oxide enriched with between 1.5 and 4 per cent fissionable
uranium-235. AGR fuel rods are clad with stainless steel. The
fuel for water-cooled reactors is clad in a zirconium alloy which,
like the fuel itself, is very stable. Spent AGR fuel is more of
a problem because of slow corrosion in the fuel rod cladding after
exposure to water. It is technically difficult to completely dry
the AGR fuel after immersion in water because the rods have graphite
sleeves which retain moisture; it is also difficult to remove
these sleeves without damaging the fuel itself (P 287, POST Report*,
The UKAEA site at Dounreay includes a small commercial
reprocessing facility. This deals with fuels from research reactors
including the Materials Testing Reactor (MTR) and Prototype Fast
Reactor at Dounreay, and MTRs owned by overseas customers. In
March 1998, approximately 5 kg of highly enriched uranium and
9 kg of low enriched uranium were delivered to the site from a
research reactor in Georgia (a former Soviet Republic). The transfer
was made because of concerns over its safety in the light of political
instability in the region. The material will be reprocessed and
the Government announced that some of it could be used for medical
purposes. Because of the circumstances of the transfer, the small
amount of waste from reprocessing will not be returned to Georgia.
It was announced on 5 June 1998 that commercial reprocessing
at the Dounreay site would cease once existing contracts had been
completed. John Battle MP (then Minister for Science, Energy and
Industry) told the House of Commons that the decision was being
taken because there was no economic case for supporting commercial
reprocessing at Dounreay in the long term (Commons Hansard, 5
June 1998, Col 385).
*Radioactive Waste-Where Next?, Parliamentary Office
of Science and Technology, November 1997.
** Options for Disposal of Nuclear Fuel Waste: Alternatives
Evaluated Abroad or Internationally,
TJ Sumerling, Safety Assessment Management Ltd., Report for SKB
(Sweden), June 1997.
7.11 The discharges to the sea from Sellafield reached
their peak in the mid-1970s as a result of corrosion in Magnox
fuel assemblies which had been stored underwater for longer than
Since then, the introduction of new treatment plants has reduced
the activity of discharges to sea by about a factor of one hundred.
The radiation doses from these discharges to the most exposed
members of the public have decreased from a peak of about twice
the national UK average natural background dose in the mid 1970s
to about one tenth of the average natural background dose now.
At the 1998 Ministerial Meeting of the OSPAR Convention
in Portugal (22-23 July), the Government agreed to make further
reductions in radioactive discharges to the sea by 2020.
7.12 Discharges of the fission product technetium-99
(a long half-life beta-emitter) have increased recently as a backlog
at the Magnox reprocessing plant has been dealt with. BNFL are
looking at technology for reducing these discharges, while technetium-99
from THORP is already stored with other HLW and will be vitrified
(Commons Hansard, 28 July 1998, Col. 125).
of witnesses on reprocessing
7.13 Many witnesses, including the National Steering
Committee for Local Authorities (p 220), Friends of the Earth
(QQ 507, 526-529, pp 131-132, PP 319-321), Greenpeace (Q 417),
Cumbrians Opposed to a Radioactive Environment (CORE, pp 106-107),
the Consortium of Opposing Local Authorities (COLA, p 92), the
Nuclear Control Institute (pp 231-232) and CND (p 55) said that
reprocessing of spent fuel should be stopped. They argued that
the products of reprocessing (i.e. separated plutonium and uranium)
are not needed, and that reprocessing only compounds the existing
problems because it generates more waste and environmental pollution.
They also said that it creates further health and safety risks,
is costly, and increases the possibility of nuclear proliferation.
Greenpeace said, "The discharges from reprocessing to the
air and to the sea are causing substantial problems...This is
not a marginal problem. It is a major international problem and
we should end it" (Q 418).
7.14 The Irish Government (pp 187-189) told us that
it remained firmly opposed to any expansion of the nuclear industry
and described the facilities at Sellafield as "part of an
inexorable and increasing threat to Ireland's public health and
environment" (p 187). They said that nuclear waste management
policy should take more account of the effects on health and the
environment beyond national borders, the precautionary principle
should be observed at all times, and the polluters should pay
for the burden placed on society and economy in Ireland (p 188).
7.15 A report by SERA (the Socialist Environment
and Resources Association)
described reprocessing as a "powerful sacred cow within the
British nuclear industry". The report stated that reprocessing
creates over two thirds of Britain's annual arisings of ILW, large
volumes of LLW and about 9 tonnes of plutonium a year (the latter
requiring storage costing £1 million per tonne per year).
SERA concluded: "The end result is we are shackled with high
electricity bills and subsidies to support a process which has
no economic or technical justification, which saddles us with
more and more nuclear waste, which causes radioactive pollution
throughout Europe, and which creates highly dangerous plutonium.
It's time we stopped this nonsense." SERA's alternative to
reprocessing would be dry storage of the spent fuel.
7.16 In general, the views of the nuclear industry
are favourable towards reprocessing. British Nuclear Fuels told
us that only about ten per cent of the volume of ILW expected
to be accumulated by about 2050 would be avoided if nuclear power
generation and fuel reprocessing were to stop immediately. Waste
from past activities and decommissioning could not be avoided
(pp 34-35). BNFL also argued that the product of reprocessing
was useful: they told us that forty per cent of the fuel used
in the AGRs had come from reprocessed Magnox fuel (Q 127).
7.17 When evaluating the benefits and impacts of
reprocessing, BNFL and the Environment Agency said that the whole
fuel cycle, from mining uranium to eventual disposal, should be
considered. The Environment Agency added "one would be quite
justified in considering the (impact of the) totality of a nuclear
fuel cycle on the environment, not just your own environment but
other people's environment" (Q 560). BNFL estimated that
reprocessing resulted in only 75 percent of the LLW, and 80 per
cent of the ILW and HLW, that would be generated if virgin materials
were used and if spent fuel were disposed of directly (Q 127).
Hence, BNFL regarded reprocessing as "a best environmental
option" (Q 135).
7.18 The DETR told us that it was "not aware
of any definitive study which clearly identifies either the reprocessing
or direct disposal route for spent fuel management as being preferable
from an environmental point of view". Those studies which
had been undertaken depended on making a plethora of assumptions
and were complicated by there being no single measure for environmental
impact (PP 298-300). For AGR fuel, RWMAC compared the options
of early reprocessing, delayed reprocessing and not reprocessing
at all and concluded that "all three options have impacts
which are small and comparable within the bounds of the uncertainties
in the estimates" (11th Annual Report, 1990).
7.19 BNFL said that reprocessing gave various benefits
for the natural environment of the United Kingdom (P 287, PP 292-293):
· it allowed plutonium to be burnt in reactors
(thus reducing the total inventory of plutonium in the world when
compared to using fresh uranium fuel);
· it reduced the volume of highly active
waste that had to be disposed of;
· it conditioned wastes in forms that are
safe to dispose of or store;
· through overseas contract income, reprocessing
had substantially reduced the costs of treating the United Kingdom's
historic and future nuclear waste.
7.20 BNFL also told us that it would be technically
possible to construct a reprocessing plant which was designed
for waste management purposes, rather than for the recovery of
fuel quality uranium and plutonium. They said that a variety of
technologies had already been researched, but further development
would be needed if this were to be pursued. Such a plant would
only require a one-stage chemical separation process and, if this
was the desired objective, a new facility might make better economic
and safety sense than making modifications to THORP (P 287).
7.21 The UKAEA agreed that reprocessing was still
a safe and credible option for the United Kingdom and that it
should continue to be used to convert Magnox fuel into a more
stable form for the long term. The UKAEA also said: "in terms
of modern power stations then clearly there are the equally credible
options of either continuing to reprocess or to cease reprocessing
and store the irradiated fuel" (UKAEA, Q 240).
7.22 Long-term dry storage of AGR fuel had been considered
by Scottish Nuclear (now a subsidiary of the privatised British
Energy) as an alternative waste management option to reprocessing.
The company had started planning a storage site adjacent to its
Torness power station in Scotland, but, for economic reasons,
this was not pursued and Scottish Nuclear signed a contract with
BNFL in 1995 for the management of all of its spent AGR fuel (Q
782). Nuclear Electric (the British Energy subsidiary in England)
also made a similar deal. The combined contract is worth around
£1.8 billion and will cover the reprocessing of approximately
4,700 tonnes of uranium fuel, ie all the spent fuel produced by
AGRs over their expected lifetime (P 287, P 293). British Energy
said that it was now for BNFL to decide whether to store or reprocess
this fuel. The company was aware of the various arguments against
reprocessing voiced by environmentalists and interest groups,
but they had no reason to disagree with the original inquiry findings
which had said that THORP was environmentally sound (QQ 777-784).
7.23 The economic arguments for continuing with reprocessing,
and to continue operation of the THORP plant in particular, were
presented by BNFL and the National Campaign for the Nuclear Industry.
The economic base of west Cumbria is strongly linked to the fortunes
of BNFL: it is the largest employer in the area and many of these
jobs are linked to reprocessing activities (NCNI, pp 212-213).
BNFL said that it thought there was a healthy future for THORP:
the company said it has a 16 year order-book for THORP worth over
£12 billion; there are good prospects that a further £5
billion of orders can be secured; and a nuclear renaissance was
expected in the next century, led by countries such as China (Q
127, P 292). A profit of at least £500 million (in 1992 money)
was expected in the first ten years of operation after accounting
for all capital and decommissioning costs (P 286). BNFL concluded
that THORP is justified on the basis of the economic benefits
and lack of serious environmental disbenefits (QQ 130-135).
7.24 An alternative view on the economics of THORP
was published during the course of our enquiry: Future THORP Available
Cash Flows, M.J. Sadnicki for the National Steering Committee
of Nuclear Free Local Authorities, April 1998. In this paper it
is calculated that THORP could only make a profit if several parameters
such as the fuel through-put rate and contract prices were at
the upper end of their possible range.
7.25 Mixed oxide fuel (MOX) is the principal means
by which plutonium, separated from spent fuel during reprocessing,
could be used for power generation. An alternative option, use
in fast breeder reactors, is discussed briefly in the next section.
MOX is important in waste management terms because it allows the
re-use of some of the material in spent fuel that would otherwise
be classified as waste. Using MOX could reduce the need for 'virgin'
uranium in reactor fuel, and thus could have an important impact
on those areas where uranium is mined. MOX could also have advantages
for decreasing the risk of nuclear proliferation: locking up plutonium
in MOX would make it less accessible for weapons production, although
still accessible by chemical means to the most determined.
7.26 Typically, MOX contains 5-8 per cent of plutonium
in oxide form mixed with uranium oxides. The isotope plutonium-239
is fissile and, like uranium-235 in standard reactor fuel, provides
the driving force for the fission reactions needed to generate
heat. A number of countries are operating reactors using MOX,
although the United Kingdom has not yet done so (see Box 4). No
reactors have yet been built with MOX specifically in mind from
the outset, but it has been used successfully in some water-cooled
reactors. Where MOX has been used it has been as part of a mixed
fuel load with normal reactor fuel, with up to one third of the
load being MOX. Extra safety procedures, and in some cases extra
radiation shielding, are required when MOX is used because spent
MOX fuel is more radioactive and more radiologically hazardous
than spent uranium metal or spent uranium oxide fuel due to the
presence of greater concentrations of actinides and fission products.
7.27 MOX can be used in a "once-through"
fuel cycle or in a cycle with reprocessing. The number of times
that MOX fuel can be reprocessed is limited by the build-up of
the heavier actinide elements in the fuel and the maximum is three
or four. Thus in both the once-through and reprocessing cycles
spent MOX fuel arises as waste; in the reprocessing case there
is also liquid HLW for solidification and disposal.
7.28 In 1996 the world-wide MOX fabrication capacity
was estimated by the nuclear industry to be around 124 tonnes
per year. Estimates for expected capacity in the year 2000 range
from 439 tonnes per year (by industry) to 229 tonnes per year
(by the World Information Service on Energy).
|Box 4: Some national policies for MOX
|Belgium||Two out of seven reactors are loaded with 20 per cent MOX. There is a commercial scale MOX fabrication plant at Dessel.
|France||16 out of 56 reactors are currently licensed to use MOX, and 12 of these have been loaded with 30 per cent MOX. France operates most of the world's capacity for MOX fabrication (including 'MELOX', the world's largest MOX plant). A further plant is planned.
|Germany||12 out of 20 reactors are licensed for MOX; seven of these are using this fuel. In January 1999 the coalition parties announced they would ban reprocessing fuel from January 2000 and would amend the existing law to allow a phasing out of nuclear power.
|Japan||Two out of 53 reactors have been partly fuelled with MOX for demonstration purposes. It is expected that MOX will be used in three or four reactors by the year 2000, and ten reactors by year 2010. One small MOX fabrication plant is in operation and a larger plant planned.
|Switzerland||It is expected that two out of Switzerland's five reactors will be partly loaded with MOX by the end of the century.
|U.K.||The UK has no present plans to use MOX. The Sellafield MOX fabrication plant is constructed but not yet licensed.
|U.S.||Investigating the possibility of using MOX in commercial reactors as a means of disposing of plutonium from their nuclear weapons programme.
|Others||The Netherlands, Sweden, and Canada have no plans to use MOX in their reactors.
|Sources: International MOX Assessment, 1997; Foreign Press Centre, Japan, 20 February 1998.
Views of witnesses
7.29 BNFL is just completing a new MOX fabrication
plant, the Sellafield MOX Plant (SMP), which is expected to have
a production capacity of 120 tonnes of MOX per year. The Environment
Agency has decided that its discharges should be authorised (ie
that the plant can start operating) but the authorisation is awaiting
ministerial decision. The Environment Agency told us that it had
conducted a two month consultation exercise and had evaluated
the technical case presented to it by BNFL. It had also contracted
the PA Consulting Group to examine the economic case for the plant
(QQ 577-587). The public version of the economics report concluded
that the plant will produce significant levels of operational
profit: "very unlikely to be less than £100 million,
exceeds £300 million in many options, and on average amounts
to £230 million".
Friends of the Earth said that "the economic justification
presented for this plant [the SMP] is based upon information withheld
from the public domain and which does not consider alternatives"
7.30 BNFL told us that Japan would like all of its
plutonium from reprocessing returned in the form of MOX, and Germany
was heading the same way (Q 139).
MOX burnt in civil reactors might be a way of dealing with plutonium
stocks in the former Soviet Union (Q 140), although it would take
several decades to do so.
7.31 In the United Kingdom, British Energy said that
it might consider using MOX at Sizewell B although a number of
issues needed to be addressed. These included steps to minimise
radiation dose from the fuel assemblies, appropriate security
arrangements during fuel transport and handling, and addressing
all of the regulatory matters involved in licensing (P 277). The
short-term cost of using MOX at Sizewell would be higher (because
MOX fabrication is expensive), but there would be long-term savings
from reducing the amount of plutonium which would eventually require
disposal (QQ 809-810). The Cumbria and North Lancashire Peace
Groups disagreed, arguing that spent MOX posed greater problems
for ultimate management because it contained a higher proportion
of long-lived actinide elements (p 105).
British Energy concluded that "the economics of MOX use in
Sizewell B are not currently competitive with uranium fuel"
(P 277). Utilisation of MOX in AGRs had also been reviewed but
was not considered to be practicable (P 277).
7.32 Because of international agreements on nuclear
proliferation and the transfer of plutonium, MOX that is intended
for sale overseas can only be produced using plutonium supplied
by the country wishing to use that fuel. BNFL told us that there
would be a significant world market for nuclear power in the next
century even if only the most conservative estimates of energy
demand were to be met: "under these circumstances the plutonium
would represent a valuable potential source of energy" and
"the potential market [for MOX] exceeds the amount of plutonium
that will be available" (P 289). In contrast, the IAEA estimates
that under free market conditions for MOX the world stock of separated
civil plutonium could be reduced from the current level of 170
tonnes to about 50 tonnes by 2013.
Without a free market IAEA expects the world-wide rate of production
of plutonium and its rate of use as MOX to come into balance in
a few years' time; until then stocks will continue to increase.
7.33 BNFL also said the environmental advantages
of using MOX make it important when considering carbon dioxide
and other emissions: one tonne of plutonium when recycled as MOX
contains the same amount of energy as 2 million tonnes of coal
(P 293). The BNFL web site states: "The Sellafield MOX Plant
is a recycling plant. Using product from reprocessing, it will
have the capability, during its 20 years lifetime, to produce
around 2,000 tonnes of nuclear fuel creating the equivalent of
640 terawatt hours of electricityenough to provide electricity
to the whole of the United Kingdom for more than two years".
7.34 On the other hand the Royal Society report
noted that using MOX does not necessarily reduce the amount of
plutonium in existence. New plutonium will be generated from uranium-238
in the fuel as it captures neutrons released during the fission
of plutonium. The balance between consumption and creation would
depend on the isotopic content of the fuel, the fraction of the
fuel load that is MOX, and the fuel burn-up rate. Thus MOX fuel
itself could be reprocessed to recover plutonium for future use
(although the build up of higher mass actinide elements restricts
the number of times that MOX can be reprocessed, see paragraph
7.26). The report also stated: "Reprocessing of spent fuel
solely to produce plutonium for recycling as MOX is not economic.
But given that reprocessing has been carried out and the plutonium
is available, then the extra cost of fabricating MOX fuel (as
compared with enriched uranium fuel) might be justified in view
of the savings in uranium and enrichment costs".
7.35 As discussed above, plutonium is one of the
products of reprocessing spent nuclear fuel. In the United Kingdom,
plutonium is separated out from the recovered uranium during reprocessing,
it is converted into insoluble plutonium dioxide, and it is kept
in secure storage at Sellafield.
7.36 The Royal Society estimated that the United
Kingdom now has 53.5 tonnes of separated civil plutonium in stock.
This includes plutonium held by BNFL for its overseas reprocessing
customers (thought to be less than 5.5 tonnes). Most of the current
stocks have been generated from the reprocessing of Magnox fuel.
By 2010 the stock will have risen to over 100 tonnes and, at that
time, the United Kingdom will hold about two thirds of the world's
separated civil plutonium. The overall global inventory of plutonium
by 2010 will be over 2,000 tonnes, but almost all of this will
be locked up in spent fuel or MOX and thus it will not be readily
7.37 In terms of waste management, plutonium is a
special case because of the nuclear proliferation risk that it
poses. Also, if it were to be disposed of or stored indefinitely,
there is a remote risk of a non-explosive critical nuclear reaction
occurring should enough plutonium come together in the right physical
configuration. Plutonium also presents a relatively high radiological
hazard because of the damage it can cause (through alpha-particle
radiation) if it is inhaled into the human body.
7.38 The United Kingdom does not categorise plutonium
as a waste, but it is given a zero value in BNFL's balance sheet.
The potential for using plutonium in MOX has already been discussed
and there could be an even greater potential for future use in
fast breeder reactors. Fast reactors use a fuel rich in plutonium
(20-35 per cent)
plus non-fissile uranium-238. In theory, fast reactors are around
sixty times more efficient than other reactors and, in the 1970s
they were expected to be a major source of power for the future.
However, there have been a number of technical and economic problems
with fast reactors which has made their future uncertain.
7.39 The United Kingdom shut down its prototype fast
reactor at Dounreay in 1994. Development of fast reactors in Japan
has hit problems following a sodium leak at the Monju prototype
fast reactor in December 1995. In 1998 the new French Prime Minister,
Lionel Jospin, confirmed that France was permanently shutting
down its Superphenix fast reactor for "economic reasons".
of witnesses on plutonium
7.40 BNFL told us that storage of separated plutonium
for possible future use was not a problem. They spend £10
million annually on security and safeguards associated with plutonium
on the Sellafield site and that, "guarding one tonne of plutonium
is as costly as guarding 50 tonnes". Over 35 per cent of
these costs were currently being met by overseas reprocessing
customers. BNFL said, "The issue surrounding plutonium is
not the quantity stored, but the international safeguards and
security regime to which the stored material is subjected. The
better funded the regime then the better the safeguards"
7.41 The UKAEA told us that it did not see fast reactors
being required for the next 50 to 100 years (Q 291). This, and
the fact that MOX is not yet used in the United Kingdom, means
that currently there is no significant demand being placed on
our plutonium stocks; indeed stocks are increasing. It has been
argued that plutonium might therefore be more of a liability than
an asset. Some witnesses, including Friends of the Earth, consider
that plutonium is a waste product from reprocessing (P 319). The
Science Policy Research Unit at the University of Sussex estimated
that managing our plutonium stocks as HLW would cost the United
Kingdom around £2.3 billion (in 1997 money) by the year 2105.
7.42 Again, if plutonium is regarded as a waste,
and if disposal is advocated, then some witnesses suggested that
this could cause problems. Sir John Knill and others told us that
natural processes could re-concentrate plutonium, so the best
option would be to distribute it as small particles within other
wastes and then distribute these wastes throughout a repository.
The amount of plutonium in normal wastes was not thought to present
too much of a problem, but the safe disposal of separated stocks
would be another matter entirely. Sir John thought that some special
method of disposing of plutonium may be required in the future
7.43 The DETR is also considering what the implications
would be if plutonium is classified as a waste in the future.
They have commissioned QuantiSci to conduct a study into the disposal
of HLW, spent fuel and other materials, including plutonium and
uranium from reprocessing. A concern that is being investigated
is whether more than one deep repository would be required in
order to cope with the potential waste volumes (Q 161). This could
have significant implications for the United Kingdom's nuclear
waste management strategy. The interim report from QuantiSci
states that if these materials are classified as wastes and are
designated for disposal in a repository, then "there would
be a substantial impact on the required repository design and
thus size of the supporting R&D programme, particularly if
safeguards and criticality issues become more important, due to
the inclusion of more plutonium". QuantiSci added that, "Whilst
it would be possible to include additional wastes late in a deep
repository development programme, this could result in sub-optimal
decisions being taken, so the types of waste to be included in
the programme should be specified as early as possible".
7.44 In 1998 the United Kingdom became the first
nuclear weapons state to declare the size of its defence-related
stocks of fissile materials. Our stock of defence-related plutonium
was said to be 7.6 tonnes. In the Strategic Defence Review, when
these figures were released, it was announced that there was a
surplus of 4.4 tonnes of plutonium including 0.3 tonnes of weapons-grade
7.45 In its report on The Management of Separated
Plutonium, the Royal Society considered that there was an international
consensus against having a large stock of separated civil plutonium
because this posed a significant environmental and security risk,
and left "an open-ended legacy for future generations".
The Royal Society concluded that the Government should review
its strategy and options for stabilising and then reducing the
stocks of plutonium, subject the options to independent review,
and maintain R&D capabilities so that competing options could
be evaluated. The various options discussed included: use of MOX
in current reactors, building new reactors specifically designed
for MOX, using plutonium from United Kingdom stocks in MOX sent
abroad, disposal of plutonium in a repository, and use as fuel
in some advanced (fast) reactor whose fuel cycle eliminates plutonium.
54 From Butler, Gregg, Nuclear fuel: recycle or
dispose? How? Where? When? Interdisciplinary Science Reviews
Vol.23 No.3 p292-297 (1998). Back
Where reactor fuel enriched with uranium-235 is used, the spent
fuel is still enriched relative to naturally occurring uranium.
Thus, less re-enrichment is required to produce new fuel from
this material. Back
RWMAC, 11th Annual Report, 1990. Back
BNFL Annual Report and Accounts, 1998. Back
MAFF and SEPA, Radioactivity in Food and the Environment in
1997, report RIFE-3, 1998. Back
The Convention on the Protection of the Environment of the North-East
A Nuclear Waste: how ending reprocessing can benefit public
health, protect the environment and save up to £6 billion.
Report by SERA, Labour Environment Campaign, January 1998. Back
Evidence given in February 1998. Back
The IMA Report: Comprehensive social impact assessment of
MOX use in light water reactors. Final report of the International
MOX Assessment, for the Citizens' Nuclear Information Centre,
Japan, November 1997. Back
Assessment of BNFL's Economic Case for the Sellafield MOX
Plant, PA Consulting Group for the Environment Agency, December
Since taking that evidence, there has been a change of policy
in Germany. Back
Spent MOX also has a higher thermal load than standard uranium
spent fuel and thus requires a longer period of cooling before
it can be reprocessed or put in storage. In addition, the beta
and gamma activity is up to six times higher and the plutonium
content five times higher than spent uranium fuel (Nuclear
Fuel, Volume 23, No. 4, February 1998). Back
IAEA Bulletin 40/1/98. Back
The Management of Separated Plutonium, The Royal Society,
February 1998. Back
The Royal Society, ibid. Back
The Royal Society, ibid. Back
Alternative fuel cycles using thorium and uranium could also
be used. Back
Royal Commission on Environmental Pollution 6th Report,
1976, Nuclear Power and the Environment. Back
General Policy Statement given by Lionel Jospin, 19 June 1998. Back
Managing United Kingdom Nuclear Liabilities, SPRU, October
QuantiSci, High-Level Waste and Spent Fuel Disposal Research
Strategy: Project Status at the Half-Way Point, report DETR/RAS/98.006,
May 1998. Back
UK stocks of other nuclear materials were also announced including
highly enriched uranium (1.61 tonnes) and depleted, natural and
low enriched uranium (84,000 tonnes). HC Hansard, 2 June 1998,
col. 163-164. Cm 3999, Strategic Defence Review. Back