PART A: the present
CHAPTER 2: NUCLEAR
WASTE MANAGEMENT IN THE UK
2.1 The development of methods for the long-term
management of radioactive waste is a necessity in all countries
which have had nuclear programmes (see Table 1). The scale of
the problem, in terms of volume, radioactive content and diversity
of physical and chemical forms of the waste, depends on the size
of the country's civil and defence nuclear progammes. The problems
are greatest in countries which have now, or had in the past,
a substantial civil programme and a substantial defence programme.
These countries are the US, the former Soviet Union, France and
the United Kingdom. In all these countries one important component
of the problem is the waste which already exists, especially that
arising from plants designed and processes carried out in the
1940s, 1950s, 1960s and early 1970s, when much less attention
was paid to long-term waste management than in more recent times.
A second important component is 'committed' waste, that is the
waste which is bound to arise from the operation or decommissioning
of plants which are operating now (and that which is expected
to arise from plants which are under construction or for which
there is a commitment to start construction).
2.2 This legacy of wasteexisting and committedis
very much greater than any current projections of wastes from
future nuclear programmes. It has to be dealt with, whether there
are future nuclear programmes or not.
Table 1 Nuclear Share of Electricity
Generation (as of March 1998)
|Country||Percentage of electricity generated by nuclear power stations
|Republic of Korea||34.1
Source: From IAEA Bulletin 40/3/1998.
UNITED KINGDOM WASTE
QUANTITIES AND CHARACTERISTICS
2.3 The United Kingdom maintains an 'inventory' of
existing and projected future radioactive wastes. This is a database
of information on waste volumes, radioactive contents and physical
and chemical characteristics. It is updated regularly (approximately
every three years) and is compiled by contractors for both UK
Nirex Ltd and the Department of Environment, Transport and the
Regions (DETR). The latest version of the inventory was issued
in 1996 and refers to wastes existing and projected to arise on
the basis of information available in 1994.
2.4 The United Kingdom inventory includes all civil
nuclear power and defence wastes, plus wastes which arise from
other sources, for example the production and use of radioactive
materials in research, health care and non-nuclear industries.
It does not include some materials which are held in store, for
example plutonium, uranium and some unreprocessed spent fuel.
These are considered to be a resource now, but may be declared
to be waste in future. Some of them are fissile and their inclusion
in the inventory could increase significantly the quantities of
waste requiring long-term management. We discuss these materials
in Chapters 4 and 7.
2.5 For the purposes of the inventory, and for general
description, wastes are divided into three categories according
to the concentrations of radioactive materials in them and the
way they arise: high level, intermediate level and low level.
2.6 High level waste (HLW) has the greatest concentration
of radioactive materials and produces substantial quantities of
heat. It arises mainly as a nitric acid solution containing fission
products separated from irradiated nuclear fuel during reprocessing.
This solution will be 'vitrified' (ie converted into a borosilicate
glass) and this process is already in operation. If unreprocessed
spent fuel and plutonium were declared to be waste, they would
also be classified as high level waste.
2.7 Intermediate level waste (ILW) is less radioactive.
It consists primarily of metals, with smaller quantities of cement,
graphite, organic materials and inorganic sludges. Most of these
arise from dismantling and reprocessing of spent fuel, including
treatment of effluents prior to discharge into the environment,
and from general operations and maintenance of radioactive plant.
ILW (for example, contaminated and activated metals) will also
be produced when nuclear plants are dismantled.
2.8 Low level waste (LLW) is the least radioactive.
Most of the LLW produced by the nuclear industry at present is
metals and organic materials, which arise largely as lightly contaminated
miscellaneous scrap. The metals are mostly in the form of redundant
equipment; the organic materials are mostly discarded protective
clothing, paper towels and plastic wrappings. When nuclear plants
are decommissioned there will be large volumes of LLW consisting
of building materials and big items of plant and equipment. Most
of the radioactive waste produced outside the nuclear industry
is LLW. This includes small volumes of waste arising at hospitals
and research establishments (eg contaminated glassware and plastic
containers). There are also rather larger volumes of waste from
industries that deal with materials that are naturally radioactive
(eg phospates used in the manufacture of fertilisers and detergents,
zircon sands used in making abrasives and refractories, sludges
and scales from the off-shore production of oil and gas). Some
of this waste is formally defined as "very low level"
(ie it has an activity level less than 4 Becquerels per gram)
and much of it is disposed of to landfills.
2.9 The term 'conditioning' is used to mean any process
by which raw waste is treated prior to disposal or long-term storage.
For liquid HLW the chosen conditioning process is vitrification.
For most ILW, conditioning consists of immobilisation in cement-based
materials, in steel drums. Most LLW is compacted to reduce its
volume, and in recent years LLW has been 'supercompacted': drums
of raw waste are compacted under high pressure to form 'pucks'
which are then loaded into large metal containers and concreted
2.10 Figure 1 shows the volumes of existing and committed
United Kingdom HLW, ILW and LLW given in the 1994 inventory (issued
in 1996) and the volumes of these wastes which were forecast to
arise ('uncommitted'). The total volume in stock in April 1994
was 71,000 cubic metres, of which 2.3 per cent was HLW, 86.6 per
cent ILW and 11.1 per cent LLW. Although LLW is produced in the
largest quantities most of it is disposed of (to Drigg)
soon after it arises, hence the relatively low volume in stock.
The uncommitted waste arisings shown in Figure 1 are based on
the following scenario:
· a national future nuclear power programme
with pressurised water reactors (PWRs), but without reprocessing
of spent PWR fuel,
· some future fuel manufacture for existing
power stations beyond that already committed, and
· operation of THORP beyond its first ten
years (ie beyond 2003).
2.11 As can be seen from the figure, the estimates
of total volumes of waste predicted to arise are not very sensitive
to the assumptions in this scenario. Of the total volumes, in
stock and predicted arisings, 65 per cent of HLW, 88 per cent
of ILW and 96 per cent of LLW are committed. (The effects on waste
volumes of differing assumptions about reprocessing are discussed
in Chapter 7.) On the basis of 1994 inventory information, the
cumulative volume of all waste in stock and predicted to arise
is 2.2 million cubic metres. Most of this is LLW (see Figure 1)
and about 90 per cent of this LLW will arise when present nuclear
plants are fully dismantled (see Figure 2).
2.12 Although it has the lowest volume, HLW has the
highest radioactive content. The total radioactive content of
all waste in stock in April 1994 was 40 million terabecquerels.
90 per cent of this was in the HLW and virtually all the rest
in the ILW. During about the first thousand years after production
of the HLW its activity falls by a factor of about one thousand
as the shorter-lived radionuclides decay (particularly caesium-137
and strontium-90, which have radioactive half-lives of about 30
years). Over about the next ten thousand years the activity of
the HLW decreases by about another factor of ten, as americium-241
(half-life about 430 years) decays. After this the activity of
HLW decreases more slowly until around three million years, when
the quantities of radionuclides such as neptunium-237 (half-life
2.1 million years) and caesium-135 (half-life 2.3 million years)
begin to fall substantially.
2.13 When it is first produced HLW emits substantial
amounts of heat. As its activity decreases so does its heat output.
By about fifty years after the fuel was reprocessed vitrified
liquid HLW should be sufficiently cool for it to be placed in
a geological repository without excessive temperature rise of
2.14 As the activity and heat output of HLW decreases
it becomes less hazardous. After two or three thousand years the
radiotoxicity of HLW is less than that of the uranium ore from
which it was derived. Uranium ore is itself hazardous and HLW
does not become innocuous when its radiotoxicity falls below that
of ore. Safety assessments of HLW disposal (see, for example,
the European PAGIS study)
indicate that potential risks to humans may still be significant
for hundreds of thousands of years.
2.15 For the purpose of description, ILW is often
divided into two categories: short-lived and long-lived. The activity
of short-lived ILW is dominated by radionuclides such as caesium-137
and strontium-90, so it falls to very low levels within a few
hundred years. Ion exchange materials that are used for treatment
of liquid effluents are one example of short-lived ILW. In long-lived
ILW there are substantial quantities of radionuclides such as
plutonium-239 (half-life 24,000 years), americium-241 and its
daughter product neptunium-237 (half-life 2.1 million years),
or fission and activation products such as technetium-99 (half-life
210,000 years) and chlorine-36 (half-life 300,000 years). Assessments
carried out by UK Nirex Ltd show that long-lived ILW could still
give rise to significant risks to humans at times longer than
one hundred thousand years after its disposal (see, for example,
Figure 4.6 in the POST Report1).
2.16 Although the radiotoxicity of waste constituents
is the main concern, some of them are also chemically harmful
to humans and other organisms. For example, most of the heavy
metals are chemically toxic if sufficient quantities are ingested
or inhaled. In a few cases, for example depleted uranium, chemical
toxicity is of equal or greater concern than radiotoxicity.
THE WASTES ARE
2.17 Most HLW arises and is stored at BNFL's Sellafield
site; the remainder is at UKAEA's Dounreay site. Most of the HLW
is still in liquid form (see 2.6). At Sellafield the vitrification
plant began operation in 1996. The canisters of vitrified HLW
are kept in a purpose built store (the 'Vitrified Product Store',
VPS), which has passive cooling and a back-up forced cooling system.
The liquid HLW is stored in cooled tanks. In mid-1998 the VPS
contained some 1,600 canisters of HLW and BNFL estimated that
it would take until about 2015 to vitrify all the liquid HLW in
stock. At Dounreay all the HLW is in liquid form but its volume
has been reduced through a process of evaporation. Conversion
of this into solid form will not start for some years.
2.18 Around 65 per cent of ILW is currently held
at Sellafield (p 175). Much of this is still in raw form but a
number of plants are operating, or are planned, to condition this
waste. The main conditioning plants, with the dates at which they
did or will start operating, and the wastes which they deal with,
· the Magnox Encapsulation Plant (1990,
for Magnox cladding);
· the Waste Encapsulation Plant (1994, for
THORP wastes and retrieved solids/sludges);
· the Waste Packaging and Encapsulation
Plant (1994, for flocs and sludges);
· the Waste Treatment Plant (1996 for plutonium
contaminated material) and
· the Drypac plant (2003, for swarf, sludge
and miscellaneous beta/gamma waste).
At Sellafield there are several stores in use and
planned to hold the conditioned waste, all of which meet modern
safety standards. The stores have design lives of the order of
50 years and BNFL estimate that they could continue to be used
safely for 80-100 years (QQ 81, 83-87).
2.19 The remaining ILW is held at various nuclear
sites. Much of it is held at nine licensed Magnox power stations,
at Dounreay and Harwell, and at Aldermaston (see pp 177-179).
Again, most of this waste is in raw form and will need to be conditioned.
Waste stores, with design lives of several decades or more, are
in operation, under construction or planned at several sites,
including Dounreay, Harwell, Winfrith and Rosyth. At the Magnox
and advanced gas-cooled reactor (AGR) power stations the preferred
strategy is not to build new stores for conditioned wastes. Instead
the aim is to place such wastes in the 'safestores' which BNFL
(at the former Magnox Electric sites) and British Energy (Nuclear
Electric and Scottish Nuclear) plan to build around the reactor
and other major buildings when they are decommissioned (Q 752).
The safestores would also hold wastes arising from clearance of
peripheral plant and buildings. The safestores would remain in
place for about 130 years, to allow radioactive decay, then all
wastes would be removed and disposed of, and the buildings demolished.
2.20 The only LLW which is stored is that which cannot
be disposed of to Drigg (because of its volume, alpha activity
or chemical composition). Most of this is at Sellafield but there
are small amounts elsewhere (for example at Aldermaston).
2.21 Towards the end of our enquiry the Health and
Safety Executive (HSE) published a report that reviews ILW storage
in the United Kingdom.
The review, carried out by the Nuclear Installations Inspectorate
of HSE, confirms the evidence previously given to us that a delay
in providing a repository will not cause immediate safety problems
for ILW storage. It also concludes that up to 20 modern ILW stores
will be required for wastes currently accumulated on major nuclear
licensed sites if an operating repository is not available within
the next 15-20 years, and that a delay of more than 50 years will
require a further costly and difficult programme of store replacements
or extensive refurbishments, possibly with the repackaging of
2.22 The reactor compartments of decommissioned nuclear-powered
submarines are a particular type of ILW. At present 11 defuelled
submarines are being stored afloat; seven of these are at Devonport
and four at Rosyth. By the year 2020 there will be about 20 defuelled
submarines to store and this could rise to 50 by 2050. The storage
capacity at Devonport will be full by 2016 (Q 352). The spent
fuel from submarines is being stored in purpose built ponds at
Sellafield, where a new pond is under construction to hold future
arisings. This spent fuel has not been declared to be waste because
MoD intend to have it reprocessed. RWMAC has raised doubts as
to whether it will be technically feasible to reprocess submarine
fuel in current plants at Sellafield and has suggested that the
fuel may have to be disposed of with other HLW (p 261). For
reasons of national security there are no published estimates
of the volume or activity content of this fuel but the Ministry
of Defence (MoD) have told us that there are at present 51 used
submarine reactor fuel cores in store at Sellafield.
2.23 In a report published in 1996, AEA Technology
estimated that there will be 75,000 tonnes of uranium in stock
by the year 2010.
This includes irradiated uranium separated during reprocessing,
and depleted uranium produced in fuel fabrication. None of this
uranium is included in the United Kingdom inventory because it
is not yet considered to be waste. The corresponding quantity
of separated civil plutonium is expected to be about 100 tonnes.
More recently, in a study for DETR, QuantiSci estimated that there
could eventually be 100,000 tonnes of uranium and 150 tonnes of
plutonium in store.
2.24 The United Kingdom military stocks of uranium
and plutonium were announced in the recent Strategic Defence Review
(Cm 3999, July 1998). Various amounts of surplus fissile material
were also declared. These surpluses will be placed under EURATOM
safeguards and will be made subject to inspections by the International
Atomic Energy Agency (IAEA) of the United Nations.
2.25 There are also other materials in store, or
which may arise in the future, that contain uranium and plutonium
and which may in due course be declared to be waste. These include
the spent fuel from the Sizewell B PWR, for which no reprocessing
contract has yet been signed, and small amounts of fuel from other
reactors which does not meet the specifications for reprocessing
in current plant.
FUTURE NUCLEAR POWER PROGRAMME
2.26 It can be seen from the above that the volumes
of long-lived waste which exist now, and which will be generated
by the present nuclear power programme if reactors continue to
operate until the end of their useful lives, are substantial.
Closing all existing reactors over the next few years would have
little effect on these volumes, nor would the construction of
a small number of new reactors. Decisions about the future civil
nuclear programme will have little effect on waste volumes and,
in this sense, are not strongly linked to the choice of long-term
waste management option. The same is true of the future defence
programme. This is not to say that there is no link between long-term
waste management and future nuclear programmes: as we shall see
in Chapter 5 there certainly is a link in terms of the attitudes
of some sections of society. The situation for reprocessing, of
United Kingdom and of foreign spent fuel, is discussed in Chapter
of Waste Management in the UK
2.27 The first major Government review of nuclear
waste management in the United Kingdom was carried out in the
late 1950s and its results published in 1959 in Command Paper
884, The Control of Radioactive Wastes. The next review did not
take place until the 1970s, when the Royal Commission on Environmental
Pollution issued its sixth report Nuclear Power and the Environment
(Command Paper 6618, the "Flowers Report", published
in 1976). The following summary of events since then starts with
the Government's response to the Flowers Report.
As part of its response to the Flowers report, the
Government made the Department of the Environment responsible
for radioactive waste management policy (Command Paper 6820).
It also increased research into the disposal of HLW and recognised
the need for a national disposal facility for ILW. In 1978, it
established the Radioactive Waste Management Advisory Committee
(RWMAC) and in 1979 published an expert report reviewing Cmnd
As part of the research on HLW disposal, the drilling
of boreholes began at a site in Scotland (Altnabreac) in 1979
and later at Harwell in Oxfordshire. The aim of these and planned
drilling programmes at other sites was to investigate the properties
of various types of rock. The research drilling programme was
discontinued in 1981, as a result of public opposition.
In 1982 the Government published another White Paper
on radioactive waste management. This established the Nuclear
Industry Radioactive Waste Executive (NIREX), which later became
United Kingdom Nirex Limited (shortened to Nirex). The remit of
Nirex was mainly to construct and operate new land disposal facilities
for LLW and ILW, but it was also to run the annual sea dumping
operation for LLW and some ILW. The Government stated that it
was envisaged that HLW would be stored for about 50 years.
Sea dumping was halted in 1983 when the meeting of
the international London Dumping Convention passed a non-binding
resolution intended to establish a moratorium on sea dumping.
Three international reviews of sea dumping of radioactive wastes
were carried out, none of which precluded further dumping but
all of which implied changes to dumping practices. In 1985 the
London Convention meeting extended the moratorium on dumping indefinitely.
In 1983, Nirex announced its initial choice of potential
new land disposal sites: a clay site at Elstow (owned by the Central
Electricity Generating Board) for a near-surface facility for
LLW and short-lived ILW, and a disused anhydrite mine at Billingham
(owned by ICI) for long-lived ILW. There was a great deal of local
opposition at Billingham and ICI became unwilling to allow the
site to be investigated. In 1984 the Government announced that
Nirex would be required to investigate at least three possible
sites for a new near-surface facility and at least three sites
for a deep repository, excluding Billingham. In 1986 Nirex announced
that they wished to investigate four sites for the near-surface
facility: Killingholme, Fulbeck, Bradwell and Elstow. Special
Development Orders were made for geological investigations at
In 1986 the House of Commons Environment Committee
published a report on radioactive waste.
The Government issued its response (Cmnd 9852), which stated that
only LLW would be placed in the Nirex near-surface facility, and
which reaffirmed the policy of storing HLW for 50 years.
The Government and Nirex decided in 1987 that the
investigations at the four potential sites for a near-surface
facility should cease, and that both LLW and ILW should be disposed
of in a deep repository. The reason given was economic. After
publication of a discussion document, responses to it, and a preliminary
safety assessment report, Nirex announced in 1989 its intention
to investigate Sellafield and Dounreay as potential sites for
the repository. Drilling began at both sites and in 1991 the decision
was made to focus on Sellafield. In the White Paper This Common
Inheritance (Cm 1200, published in 1990) the Government confirmed
the choice of disposal in a deep repository as the long-term management
option for ILW.
During this period the United Kingdom ceased its
research programme on the disposal of HLW beneath (and on) the
bed of the deep ocean. The Government also stated that there would
be no resumption of sea dumping of ILW and LLW but the option
would be kept open for disposal of large items of waste from decommissioning
of nuclear plant.
In 1992 Nirex stated its intention to construct a
Rock Characterisation Facility (RCF) at Sellafield. Its timetable
was to submit the planning application for the RCF in 1993 and
then the planning application for the repository in 1998. Nirex
hoped that the repository would be operational by 2007. The RCF
planning application was eventually submitted in 1994, following
delays in gaining approvals to drill more boreholes. The target
date for repository operation was stated to be 2010. The application
was called in and the Public Inquiry into the RCF was held in
A Government review of radioactive waste management
policy was carried out, in parallel with a commercial and economic
review of nuclear power in the United Kingdom. The conclusions
of this review were published in 1995 as Cm 2919. They were that
the policy for radioactive waste management should be, and is,
based on sustainable development. Disposal was favoured over indefinite
storage and it was concluded that there was no advantage in delaying
the development of a repository for ILW. The Department of the
Environment was to carry out work on a research strategy for HLW.
In March 1997 the Secretary of State completed his
consideration of the Inspector's report on the Public Inquiry
into the RCF at Sellafield.
In his report the Inspector recommended that the
planning application be refused. He put forward two types of reason:
one type concerned straightforward planning matters, which might
apply to any type of development; the other type was particular
to the RCF and to the repository which might have followed it.
The straightforward planning matters included the adverse visual
impact of the above ground RCF buildings and spoil heaps, criticisms
of road traffic and parking plans, and possible harm to the habitat
of a badger clan. The main particular reason was that the proposal
to build the RCF was premature. More needed to be known about
the hydrogeology and geology of the site before disturbing the
rock and groundwater conditions by sinking the shaft for the RCF.
Also, the location of the RCF had not been shown to be the best
one from the point of view of the location of the repository,
and the 'potential repository zone' might be damaged by constructing
Underlying these particular reasons were concerns
about the process by which the Sellafield site had been selected
and about the suitability of the site itself. The Inspector concluded
that the site had not been selected in an objective and methodical
manner. His Technical Assessor was of the view that the site was
more geologically and hydrogeologically complex than would be
expected of a choice based principally on scientific and technical
grounds. He pointed out that while the preliminary safety case
for a repository at the site was certainly not a patent failure,
nor were its results so clearly within targets as to command any
substantial degree of confidence.
The Secretary of State decided that Nirex should
not be allowed to construct the RCF at Sellafield, citing in his
letter to Nirex both straightforward planning matters and reasons
particular to the RCF. His decision, the Public Inquiry and the
events leading up to it hold lessons for the future of nuclear
waste management in the United Kingdom which we will address later
in this report.
The DETR project to develop a research strategy for
HLW disposal began in the spring of 1997. An interim report on
the project was issued in 1998. This dealt with work during the
first stage of the project: a review of past and present national
and international R&D and identification of a potential HLW
repository development strategy, in terms of a series of key milestones
and the questions that must be answered to achieve these milestones.
In the summer of 1997 the Government announced that it accepted
the London Dumping Convention moratorium on sea dumping: the United
Kingdom would not seek to use this method for disposal of any
solid radioactive waste. In November 1997 the Parliamentary Office
of Science and Technology (POST) published its report Radioactive
Events during 1998, the period of our enquiry, are
discussed throughout the remainder of this report.
6 The 110 acre low level waste disposal site in West
Cumbria, owned and operated by BNFL. Back
See glossary for explanation of terabecquerels and other units. Back
Review of Radioactive Waste Management Policy, Final Conclusions.
Command Paper (Cm) 2919, 1995. Back
Commission of the European Communities, PAGIS, Performance
Assessment of Geological Isolation Systems for Radioactive Waste,
report EUR 11775, 1988. Back
WHO, Guidelines for drinking water quality, 2nd
Edition, Volume 1, Recommendations, 1993. Back
Health and Safety Executive Nuclear Safety Directorate, Intermediate
Level Radioactive Waste Storage in the UK: A Review by HM Nuclear
Installations Inspectorate, November 1998. Back
R. Cummings, R P Bush et al, An assessment of partition and
transmutation against UK requirements for radioactive waste management.
Report DoE/RAS/96.007 for the UK Department of the Environment,
1996. See also QQ 1141-1211. Back
The Royal Society: Management of Separated Plutonium, February
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
Radioactive Waste, House
of Commons Environment Committee, First Report 1985-86, HC 191 Back
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