Select Committee on Trade and Industry Written Evidence


Second supplementary memorandum by E.ON UK


  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".


  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.


  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.


  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%.


  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 WasteReplacement
Build Waste
Quantity of electricity produced by generation programme (GW.years) 350550
Radioactivity of irradiated fuel and vitrified high level waste 100 years after last replacement build reactor closes (EBq*) 518
Radioactivity of irradiated fuel and vitrified waste in the year 2090 (EBq*) 20180
Volume of packaged irradiated fuel (m3) 8,00032,000
Volume of vitrified high-level waste (m3) 1,3000
Volume of intermediate-level waste, including that linked with reprocessing (m3) 350,0009,000
Total volume of packaged waste for disposal in the repository (m3) 360,00040,000
Footprint for standalone intermediate level waste repository (m2) 1,200,00030,000
Footprint for standalone irradiated fuel and vitrified high level waste repository (m2) 3,000,0002,600,000
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) 5,000,0002,700,000

*EBq means Exa Bequerels; Exa = 1018

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

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