Rip van Winkel wakes
By John Busby   
14 September 2006

Having done little to solve the radioactive waste problem for 50 years, a government wishing to awake a dormant nuclear power sector appointed an authority and a committee to provide a solution. If the public could be assured that the past problems were on the way to being resolved, while asserting that the improved technology of the new reactors would create minimal waste, public perceptions would be improved and the way cleared for the building of a new fleet of stations.

The onset of global warming presented a golden opportunity to claim that nuclear power offered carbon-free electricity generation, even though the actual fission in the reactor is the only element in the entire fuel cycle that emits no carbon dioxide. The depletion of Britain's gas (after the "dash-for-gas") also engendered a fear of the lights going out that has bolstered the nuclear lobby's spin.

The spin

Nuclear generation started in 1956 when HM Queen Elizabeth II threw the switch for the inauguration of the UK's first nuclear power station, Calder Hall on the Windscale site in Cumbria, since renamed Sellafield. A year later a neighbouring weapons plutonium generating reactor, Pile 1, caught fire, spreading a radioactive plume downwind over the surrounding countryside. Some years later, in 1986, Chernobyl contaminated a huge area of Belarus and Ukraine. Thus occurrences in both the defence and civil nuclear programmes contributed to a public perception of a brooding and latent horror waiting to threaten our wellbeing.

The parallel and interdependent defence and power generation pursuits produce a continuous flow of radioactive waste. It's piling up high level waste at Sellafield, intermediate level waste on the sites where it arises and low level waste stored at Drigg, also in Cumbria. Some of the radioactive elements in the nuclear waste will be with mankind until it ends.

Also nuclear power is an adjunct to the manufacture of nuclear weapons. With the need to replace the Trident nuclear deterrent, it will be essential to retain the ability to generate the plutonium needed and to maintain the skills in nuclear physics and engineering. 

The twin tasks

There are two major considerations,

  • the decommissioning of nuclear power stations and supporting functions on a variety of sites and
  • the disposal of the radioactive waste therefrom.

During its operation the components of a reactor deteriorate due to irradiation. Steels are embrittled and the graphite used to moderate the reaction disintegrates. Radioactive isotopes of hydrogen, carbon, iron and nickel are formed, which make demolition difficult. A Nuclear Decommissioning Authority (NDA) has taken responsibility on behalf of the government for the decommissioning of the weapons facilities and the generating stations with their supporting plants.

When the nuclear fuel charge in a reactor is no longer creating enough heat, i.e., it is spent, it is removed and held in a stirred and cooled pond of water. It is still dangerously radioactive and continues to generate heat. But the worst feature is that the fission creates highly radioactive and long-lasting isotopes of plutonium, neptunium and americium which remain a problem for thousands of years and with the spent fuel comprise the high level waste. The reactor components are classed as intermediate level waste, while clothing and used equipment adds to the low level waste.

The nuclear waste has been the subject of studies by a Committee on Radioactive Waste Management (CoRWM) arguing for the establishment of an "independent body" to oversee an "implementing body" which will deal with it. CoRWM recommends that in the interim, waste should be securely stored on the sites where it arises, followed by a final geological disposal.

Little having been done in the first 50 years of the nuclear era, intensive activity on the part of both will be required over the next 120 years to decommission the shutdown Magnox power stations and the nuclear installations. NDA has estimated the first tranche of costs as 70 billion.

Moreover, the NDA strategy fails to include the costs of decommissioning a further 12 nuclear plants still operating, viz., four Magnox reactors, the seven Advanced Gas-cooled Reactors (AGR's) and Sizewell B. The decommissioning of these in due course will add another 15 -20 billion to NDA's budget, so that rumours of its task costing 100 billion in total are probably well founded. NDA has not included in its strategy the eventual decommissioning of a new fleet of reactors.CoRWM has declined to cost its programme, but taking into account the need for interim measures and the excavation of an underground final disposal, it can be construed from the various consultation documents, that the implementation will cost around 50 billion.

CoRWM has also declined to study the waste arising from "new build". New designs of reactors are claimed to have extended operational life cycles over the present 35 years. If the operational cycles of the new types attain 60 years as claimed, decommissioning and waste management will extend well beyond the envisaged CoRWM timeline ending in 2120.

Meeting costs

The 2006 Energy Review  demanded that

"Any new nuclear stations would also meet full decommissioning costs and their full share of long-term waste management costs." (Paragraph 5.96).

As NDA and CoRWM have refrained from estimating the new build decommissioning and long-term waste management costs, it will be difficult to know what the full share will comprise that the new station builders are expected to cover. DTI have assumed that the "back-end" costs will be only 3% of the total nuclear costs and that

"only a relatively small annual contribution to a financial reserve which grows over time" of 1/MWh would suffice.

In the NDA financial analysis, the estimated station decommissioning costs exceed the original capital costs, reflecting the need for the cautious handling of the radioactive components. These, together with the CoRWM waste handling costs, will certainly exceed the 3% "back-end" nuclear life cycle costs assumed in the Energy Review and cycle costs around 50% would be more realistic. If the 1/MWh is based on a mere 3%, then it will be totally inadequate. If the operational cycle be interrupted for any reason, the annual contribution will fail to be paid. The station builder should instead put up a suitably-sized bond, at least equal to the capital cost of the station, to ensure that the taxpayer does not end up with the bill.

Requests to NDA to complete their cost analyses have met with refusal. CoRWM compared estimates of various options to assist in determining its recommendations, but has not provided a figure for the total cost of its programme, though it has estimated the additional volume of waste for "new build". So the Energy Review team has no basis for its assumption that the "back-end" costs are only 3% of the new type reactor overall costs. The construction of an adequate financial mechanism constraining developers to meet the full decommissioning and waste management costs requires a more comprehensive analysis than has yet been performed. Perhaps NDA and CoRWM have been asked to defer the missing cost calculations lest their publication proves the non-viability of nuclear power.

If a developer is to meet the full costs of decommissioning and waste management in an acceptable financial mechanism, its scope cannot be judged without an idea of the "new build" costs.

It has to be emphasised however that to estimate the cost of a programme extending over more than a century is likely to be somewhat problematic. NDA describes its burden as a "legacy"; it is enough of an inheritance without adding to it. Future generations will deplore their unsolicited dowry.

Timeline

In a period up to 2035, CoRWM proposes that the interim arrangements will be defined, communities willing to accept the disposal arrangements will be identified and site investigations and selection will take place. The planning and construction of the repository would be affected over the following ten years from 2035 to 2045, then followed by 65 years when the waste would be placed and a further ten years for the closure of the repository, taking the programme up to 2120.

Assuming the energy contribution of nuclear power remains at 8% of the UK's total energy, then around 90% of the available energy to perform the decommissioning and waste handling tasks will be from fossil fuels. As oil and gas supplies rapidly deplete as the century progresses, it is highly unlikely that in 2035, when CoRWM proposes that the excavation of the geological disposal commences, that the necessary energy will be available.

The procurement of sufficient energy to perform the excavation of the repository in 30 years time will prove problematic and although the decommissioning timescale would not require it to be usable before then, it would be better to start the excavation immediately while the diesel needed for the machinery is still available.

Reprocessing, mixed oxide fuel and breeders

Given that the supply of raw uranium is limited, the nuclear industry has come up with three main solutions in an attempt to secure a longer-term future. Natural uranium is enriched to increase its fissionable component, leaving depleted uranium as waste, so that only around 10% of the raw uranium is burned in the reactor.

The spent nuclear fuel elements are very radioactive and have to be kept in stirred and cooled ponds for from 5 to 25 years after removal from the reactor. They are then cut up and dissolved in nitric acid allowing the depleted uranium and plutonium to be separated. Some of the uranium is returned to the enrichment plant for fuel manufacture, while the plutonium goes to the mixed oxide plant where it is combined with another part of the depleted uranium to make a mixed oxide fuel, MOX.

The UK Thermal Oxide Reprocessing Plant (THORP) and the Sellafield Mixed Oxide Plant (SMP) are located at Sellafield on the Irish Sea. The operation of the plants has been an unmitigated disaster. THORP is currently closed because of a massive radioactive leak, while the MOX plant has never met its production rate. Both plants add to the radioactive high level waste and feature in the NDA strategy. The two plants were to have provided some revenue to alleviate the decommissioning costs, but both are like to be closed and will add to the costs rather than reduce them.The long-term future of nuclear power relied on the fast breeder reactor, which was supposed to "breed" new fuel while generating electricity. There have been many attempts to develop a successful one, but all have failed despite massive investment. The high operating temperatures require special coolants and the containment materials, such as nickel steels, are extremely weak at the elevated temperatures. They are also embrittled by the radiation. It is highly unlikely that a successful breeder reactor will ever be developed.

Once-through operation

Nuclear power is therefore destined to

  • run out of economically mined uranium and
  • meanwhile will continue to add to the accumulating waste.

 

For comparison, in the USA reprocessing has been banned and the spent fuel from over 100 reactors languishes in ponds awaiting its transfer to dry storage casks, which are stored in guarded open yards, until the promised repository is built. Meanwhile the ponds are practically full and are dependent on a secure supply of electricity to prevent them evaporating, uncovering the highly radioactive spent fuel, then drying out and catching fire.

In the UK the spent fuel comprising the high level waste, reactor components as intermediate level waste and copious quantities of low level waste such as clothing and process equipment mounts up. The deployment of the NDA strategy relies on bids from the private sector for its decommissioning contracts. The adoption of the CoRWM recommendations awaits a government decision.

If the UK nuclear lobby succeeds in its aims, the "new build" will remain as a "once-through" operation and the waste stream will be little diminished by reprocessing and supplies of MOX.

Uranium is first taken from the earth, enriched to make it fissionable, then by its fission it creates long-enduring radioactive new elements and may end up under the earth once again, where its new deadly nature will hopefully be retained. If during this centuries' long process it is allowed to escape, it will spread its deadly radiation over the earth instead of being put under it. If disturbed after a few thousand years it will still menace future generations.

Rip van Winkel wakes

The fabulous Rip van Winkel slept for 20 years. My Rip is human awareness, lulled to sleep by promises of cheap power when the first nuclear electricity left Calder Hall by Royal Command in 1956. If van Winkel wakes up in the 22nd Century after 200 years, what will he see? Will there be any nuclear power stations running? Or, will mounds of earth covering former nuclear stations be evident? Will the nuclear waste be safely treated and put underground? Or, did the fossil fuels run out before the CoRWM recommendations could be carried out? Did some of the spent fuel ponds run dry, contaminating lands? Did sense prevail and nuclear power was abandoned before the problems became totally insurmountable?

What sort of UK lifestyle remains? Was global warming avoided by Kyoto 2? Is most of what was the UK under water? Or, did the carboniferous fuels run out before the climate "tipping point" was exceeded? What proportion of the world's population at the beginning of the 21st Century survives?

What a nightmare he had. I share it.