USA: from leading to lagging the world in spent fuel management?10 November 2015
The USA is still the world leader in using nuclear power, but it is no longer a world leader in advancing nuclear technology. Throughout the nuclear fuel cycle the USA has lost its leading position. In providing nuclear facilities and services, countries like South Korea, Russia and China are moving in front, and the USA falling behind is especially pronounced in the case of spent fuel management. What happened? By Charles McCombie
National nuclear power programmes, and especially their waste disposal programmes, are strongly influenced by politics. Rarely, however, have the political impacts been as strong as in the USA.
The most recent example is the cancellation of the Yucca Mountain spent fuel repository programme, following a pre-election promise made by President Barack Obama to the Democratic leader, Harry Reid.
Equally important was the original selection of Yucca Mountain as the single preferred USA disposal site. This decision, taken by Congress in the light of growing cost estimates for characterisation of potential repository sites, is known as the "screw Nevada bill". But in fact Yucca Mountain was originally chosen as a top candidate not for political reasons, but on the basis of a structured technical multi-attribute analysis which had been reviewed and approved by the National Academy of Sciences. This approach was forgotten in the aftermath of political decisions taken in obscurity.
Along the way other very important political decisions altered the course of the US spent fuel disposal programme. One example is the rapid retraction of plans to look for a second repository site in the eastern part of the USA, in a host rock different from the volcanic tuff in Nevada. That would have examined the granites that lie primarily in those states with the most active nuclear power programmes. The political storm unleashed in the northern and eastern states by the stated intention to seek a second repository site led to hasty abandonment of the plans. An admirable and ethical approach -developing two national sites for reasons of geographical equity - was dropped for purely political reasons.
Industry or government led?
The most successful nuclear waste disposal programmes, those in Sweden and Finland, are those where the nuclear industry has been directly tasked with implementing waste disposal plans. In the USA, the decision was taken early that nuclear utilities could delegate all responsibilities for spent fuel disposal to the government. The only requirement placed on the owners of nuclear fuel was to contribute to a nuclear waste fund (at a rate of 0.1 cents per kilowatt hour). The initial satisfaction of the utilities with this arrangement disappeared as little progress was made on disposal and the huge sums accumulating in the waste disposal fund were not made available by Congress at sufficient levels to progress the programme. Today, the Department of Energy (DOE) is compelled to pay large sums to utilities that have sued it because it failed to accept their spent fuel, as promised in the nuclear waste policy act.
In addition, the pressure put on the government by nuclear utilities with growing quantities of spent nuclear fuel in temporary storage has forced the government, through the NRC, to retreat from its commitment to geological disposal facilities -- although they are recognised as the only way in which we can avoid passing on the burden of managing spent nuclear fuel.
The regulatory regime
The US Environmental Protection Agency is responsible for setting the framework and, because the EPA regulates all types of hazardous materials, there is an opportunity for objective risk-based regulations.
Specific nuclear rules are then set by the US Nuclear Regulatory Commission. Although the NRC is a large, competent and respected technical body, things have not always gone smoothly. After many years in which the EPA and NRC failed to develop regulatory criteria for high-level waste repositories, Congress lost patience and decided that the National Academy of Sciences must show the way forward.
When the Academy produced its recommendations in the report "A Technical Basis for a Yucca Mountain Standard", the EPA wasted a large amount of effort and many years arguing, unsuccessfully, that the Academy recommendations on the timetable for safety assessments for a repository were not binding. This was not the only occasion on which the administration did not respond positively to advice from the National Academies. The recommendations in a later report on phased siting approaches ("One Step at a Time") were disregarded by DOE, although their full-hearted adoption by other national programmes, in particular in Canada, has led to positive progress.
There have also been heated, but meaningless, debates between the EPA and the NRC on subjects such as repository dose limits and the relative merits of 15mrem per year versus 25mrem per year. In the context of safety assessments done over thousands of years and taking into account the state of knowledge on the effects of radiation on human beings, there is no real sense distinguishing between these numbers.
The most recent regulatory development is the reworking (and renaming) of the so-called waste confidence rule. Early versions included statements on the confidence of the ability of the USA to implement safe geological disposal facilities. The revised version restricts itself to assertions that on-site surface storage of spent nuclear fuel can be safely done "indefinitely."
The NRC says its responsibility is simply to assess whether proposed nuclear facilities can be safely implemented and not to frame a long-term policy for nuclear waste management or disposal. Nevertheless the ex-chair of the NRC emphasised that geological disposal is still required. The blue ribbon commission (BRC) set up by President Obama emphasised this, but little progress is being made.
The NRC finding that the USA will be able to indefinitely ensure the safety of highly radioactive wastes stored on the surface may be true for the USA, as a large and rich country. But the example being shown to the rest of the world is dangerous. Despite US claims, the failure of the US disposal programme does not mean that geological disposal is impossible. Other countries such as Sweden, Finland and France are progressing steadily towards it.
Science and technology
The US capabilities in science and technology equal or exceed those in other countries. It was way back in 1957 that earth scientists in the USA agreed that the most promising way of managing highly radioactive materials in future was in deep geological disposal facilities. Scientists and engineers in the USA also got off to an early start in examining the necessary geological, material sciences, and engineering requirements.
However, the scientific community in other Western countries soon caught up or passed their US colleagues. This was partly because the choice for a potential host rock in the US was volcanic tuff, whereas in other countries the emphasis was on crystalline rocks, clays or salt.
The scientific questions to be answered for tuff involve difficult issues such as two-phase flow in partially saturated media, or probability of magmatic intrusion, whereas in the saturated low-flow environments investigated in other countries more important issues were those related to the geochemical environment in the repository.
In addition, the technical concepts for the US repository appeared to be subject to sudden and sometimes inexplicable modifications. Original proponents of the Yucca Mountain repository claimed that the environment was so dry that the system would be safe with effectively no engineered barriers. As the years went on, the engineered barriers in the proposed US disposal system became more complex and more expensive, culminating in a proposal for titanium drip shields which would be emplaced throughout the repository at the cost of billions of dollars.
With over 100 nuclear power plants providing funding for waste disposal planning, scientists and engineers involved in the US programme appeared to have no reservations about planning for enormous costs, which caused great apprehension in other national programmes with fewer resources available. The costs of characterising the Yucca Mountain site exceed the entire budget estimated by some other countries for siting, constructing, operating and closing a national waste disposal facility.
Security and non-proliferation
One area where the USA has retained its lead is in efforts to minimise concerns about nuclear security and weapons proliferation by means of restricting the spread of the technologies that could help develop nuclear weapons programmes.
These technologies are uranium enrichment, which can yield bomb-quality highly enriched material, and spent fuel reprocessing, which can yield weapons-capable separated plutonium. Here the USA leads in trying to persuade other nuclear power nations to renounce any intentions to enrich or reprocess.
Some success was apparent when the UAE publicly announced such a policy as part of cooperation agreements with the USA. But other nations have been reluctant to follow suit - not least because the efforts of the USA (and the other major nuclear nations) to keep the technology to themselves is often perceived as an attempt to divide the nuclear world into "haves and have-nots".
The current compromise on enrichment proposed for Iran might have been reached much earlier if the USA had been less fixed on an absolute ban and more open to a strictly controlled licence to enrich.
Can the USA regain its leadership?
The problems facing the US spent fuel management programme are recognised by those most closely involved. The blue ribbon commission was populated and staffed by some of the nation's greatest experts in this area. Some members of the commission have gone on to assume key positions in government related to the future of nuclear technology and nuclear waste management in particular. For example, Ernie Moniz is now energy secretary and Alison Macfarlane went on to head the NRC.
However, little progress is being made towards implementing the recommendations of the BRC. The most public DOE initiative that has as yet emerged from the recommendations of the BRC is a programme for testing the deep borehole concept for high-level wastes. This is an interesting technical concept, but has little or no direct relevance to the spent fuel management challenges facing the USA. Here are some more important steps that should be urgently taken.
- Move to implement the key recommendations of the BRC; i.e. establish a dedicated body outside the DOE with a clear mandate and a secured budget.
- Make clear that the administration decision to drop Yucca Mountain was a policy choice and not a generic judgement on the feasibility, safety or ethical justifiability of geological repositories. Re-affirm that geological disposal is recognised by the scientific and technical community as the safe ultimate solution.
- Acknowledge that, although safe surface storage of spent fuel can be carried out for many decades, it is not a final solution to disposing of long-lived radioactive wastes.
- Start a modern, staged repository-siting programme, taking on board the lessons learned from successful efforts in Sweden, Finland, France and Canada.
- Intensify international cooperation, acknowledging that some other countries are equal to or ahead of the USA in some of the technical areas involved in waste management and disposal
- Support multinational and regional approaches that could ensure safe and secure management on a global scale. This should be done without strengthening the fears of new or smaller nuclear power nations.