APPENDIX 24
Second supplementary memorandum by E.ON
UK
RADIOACTIVE WASTE AND REPLACEMENT NUCLEAR
BUILD
1. Much has been said about the impact of
new nuclear build on the amount of radioactive waste requiring
management and disposal. Selecting figures to illustrate the issues
often results in questioning the viewpoint propounded. In reality,
the description of the quantities and categories involved is complex;
data is generally only meaningful in the context of the use to
which it is put.
2. This note seeks to provide a broad overview
of the main figures which are more fully documented elsewhere,
most recently in March 2006 by the Sustainable Development Commission
(SDC) in its paper "The role of nuclear power in a low carbon
economy".
OPERATIONAL AND
DECOMMISSIONING WASTES
3. It is generally agreed that the incremental
quantity of radioactive waste resulting from a 10 GW programme
of advanced pressurised water reactors (PWRs) operated for 60
years is small, 9,000 m3 of intermediate-level waste (ILW) and
80,000 m3 of low-level waste (LLW), accounting for an additional
2.5% and 3.0% respectively of the UK's legacy wastes. These estimates
are based on Westinghouse's AP1000 reactor design.
RADIOACTIVITY CONTAINED
IN IRRADIATED
NUCLEAR FUEL
4. Broadly, the energy which produces the
heat used to generate electricity come from the fission of atoms
of uranium; the more heat produced the more fission products are
produced. Over its life, a replacement build programme of 10 GW
would generate around 550 GW(e)years of electricity, more than
the 350 GW(e)years of the UK legacy programme. Consequently, the
new radioactivity created would be around 160% of that we have
already seen.
5. The effect of decay of the radioactive
products of the initial fission is very great. Some of the isotopes
spontaneously decay, almost immediately, and disappear by the
time the nuclear fuel is discharged from the reactor. At the other
extreme, others have very long half-lives, are present in the
discharged fuel and persist for hundreds of thousands of years.
Although these very long-lived radioactive isotopes include actinides
which have a high toxicity to life and constitute a hazard almost
indefinitely, they commonly have low solubility and mobility and
can be readily isolated in geological repositories. There are
many other isotopes which have intermediate lives and some of
these are more difficult to isolate in repositories due to their
high solubility and mobility in groundwater. Other wastes are
created by activation of metals and other materials used in reactors.
6. At a specific date shortly after the
planned closure of the replacement build reactors, say 10 years,
in 2090, the radioactive waste from the reactors would account
for a dominant proportion of the national radioactive inventory;
SDC's data indicates that the radioactivity contained in 14,000
tHM irradiated fuel from Westinghouse's AP1000 new build reactors
would be 30 times that of 4,700 tHM legacy irradiated fuel. However,
after 100 years, the multiplying factor reduces to 3, about in
proportion to the quantity of irradiated fuel involved.
VOLUMES OF
RADIOACTIVE WASTE
7. Whereas radioactive materials from the
legacy power programme comprise both irradiated fuel and vitrified
high-level waste (HLW) produced by reprocessing, replacement build
would be expected to generate only irradiated fuel. Reprocessing
concentrates most of the activity in irradiated fuel into a smaller
volume of HLW. It also creates large volumes of ILW, mainly the
reprocessing plant itself, which becomes contaminated by the fission
products and long-lived actinides. SDC figures show that the legacy
power programme generates 1,290 m3 of HLW and 353,000 m3 of ILW[86].
8. The packaged volume of irradiated fuel
for disposal produced by a 10 GW replacement build programme will
depend on the reactor type that is used. Estimates for the packaged
volume are in the range 21,000-31,900 m3, for use of Areva's European
Pressurised Water Reactor (EPR) and the AP1000 respectively. The
packaged volume of legacy fuel is 8,150 m3. This represents an
increase by a factor of about 3.
9. Although the packaged volume of irradiated
fuel and HLW is increased by a factor of 3 over that from the
legacy power programme, the effect of ILW is much reduced. The
SDC report shows the volume of ILW from a new build programme
of AP1000 reactors as 9,000 m3, compared to 353,000 m3 from the
legacy programme. Hence, the packaged volume of ILW from the replacement
build programme would amount to less than 4% of the equivalent
wastes from the legacy programme, and the overall increase in
the volume of repository wastes would be approximately 10%.
10. The irradiated fuel and HLW would need
to be distributed in a repository to ensure that the heat it was
producing did not result in the underground temperatures exceeding
levels that might affect the performance of the materials it contained.
11. The SDC report shows the impact from
a new build programme of AP1000 reactors on the footprint of a
repository compared to that for current ILW and irradiated fuel/HLW
volumes would be to approximately double the footprint of a stand
alone irradiated fuel/HLW repository, but only slightly increase
the footprint of a stand alone ILW repository (slightly less than
the 2.5%). Overall, the impact on the footprint of a co-located
ILW and irradiated fuel/HLW repository would be to increase the
repository footprint by about 50%.
FURTHER COMMENT
ON VOLUMES
12. The incremental volumes of waste for
disposal in a deep geological repository, produced by a 10 GW
replacement build programme, are small on the total scale of modern
industrial activity such as mining or non-radioactive waste disposal.
13. A suitable repository would probably
be located around 500 m beneath the surface of the earth. Once
closed, the physical evidence of the increased volume required
to accommodate the new-build arisings would solely be the excavated
spoils.
| (indicative figures) |
Legacy Waste | Replacement
Build Waste
|
| Quantity of electricity produced by generation programme (GW.years)
| 350 | 550 |
| Radioactivity of irradiated fuel and vitrified high level waste 100 years after last replacement build reactor closes (EBq*)
| 5 | 18 |
| Radioactivity of irradiated fuel and vitrified waste in the year 2090 (EBq*)
| 20 | 180 |
| Volume of packaged irradiated fuel (m3) |
8,000 | 32,000 |
| Volume of vitrified high-level waste (m3) |
1,300 | 0 |
| Volume of intermediate-level waste, including that linked with reprocessing (m3)
| 350,000 | 9,000 |
| Total volume of packaged waste for disposal in the repository (m3)
| 360,000 | 40,000 |
| Footprint for standalone intermediate level waste repository (m2)
| 1,200,000 | 30,000 |
| Footprint for standalone irradiated fuel and vitrified high level waste repository (m2)
| 3,000,000 | 2,600,000 |
| Footprint for co-located intermediate level waste and irradiated fuel/vitrified high level waste repository (includes about 750,000 separation between the two repositories) (m2)
| 5,000,000 | 2,700,000 |
| | |
*EBq means Exa Bequerels; Exa = 10 18
86
Of the legacy power programme ILW, about 40% is associated with
reprocessing and 30% with the final decommissioning of the legacy
programme gas-cooled reactors. Back
|
