The International Atomic Energy Agency’s (IAEA’s) Scientific Forum in September, attended by delegates from more than 50 countries and organisations, heard that spent fuel inventories are growing, with a total of 180,000 tonnes of heavy metal (tHM) stored around the world in addition to 88,000t from reprocessing. The amount of new spent fuel accumulating annually from nuclear electricity generation and other activities stands at about 11,000tHM. A panel of international experts reviewed the situation, looking at different strategies and approaches including interim storage, reprocessing, and planned long-term disposal in deep geological repositories.

CLOSING THE CYCLE

In his address to the forum, Patrice Bernard, director of nuclear development and innovation at the French Commissariat à l’Energie Atomique (CEA), said closing the fuel cycle has a major impact on minimising waste, resources extension, and the optimal use of energy sources. In December 1991, the French government had drafted a law, subsequently passed by parliament, which called for research and development (R&D) into solutions and processes for: minimising the quantity and the radiotoxicity of high-level wastes through partitioning and transmutation; waste conditioning and storage; and deep geological disposal.

A decision is to be taken in 2006 following research by CEA, the French National Agency for Radioactive Waste Management (Andra), in cooperation with Electricité de France (EdF), Areva, the French National Centre for Scientific Research (CNRS) and various universities in Europe and internationally. Among significant conclusions drawn from research, development and industrial experience are that reprocessing: significantly reduces the high level waste radiotoxicity and volume; allows recovery of valuable materials, in particular plutonium; and conditions the final waste (vitrification) to be safe, durable and of very small volume.

Recycling of plutonium in existing LWRs has been demonstrated on a large scale, and third generation reactors – such as the European Pressurized Water Reactor (EPR) – would bring further possible improvements, Bernard said. To date some 18,000t has been reprocessed at France’s La Hague facility and 20 reactors in France are now recycling plutonium. For the future, advanced partitioning processes and transmutation in advanced reactors could make it possible to recover and recycle all actinides (uranium, plutonium, americium, curium, neptunium) and reduce waste to fission products, the radiotoxicity of which drastically decreases after a few hundred years.

REDUCING WASTE

Professor Alexander Mayorshin, deputy general director of the Russian Institute for Atomic Reactors (RIAR), also stressed the importance of a closed fuel cycle to reduce the release of substances dangerous to the environment. He also emphasised the need to optimise processes to achieve the required maximum results without unnecessary operations and stages and to maximise the level of the inherent safety. With these basic principles in mind he described work being done at RIAR on reprocessing of spent fuel using dry pyroelectrochemical processes involving molten salts. Since 1964 RIAR has been performing large-scale studies for:

  • Development of dry fuel production and reprocessing technologies for different nuclear reactor types.
  • Development and testing of the fuel rod designs for different nuclear reactor types.
  • Investigation of ways for managing the waste generated using dry technologies.
  • Investigation of the actinide and fission product properties in different ion liquids.

RIAR’s work with molten salt systems resulted in the development of processes for production of granulated uranium and plutonium oxides and mixed uranium and plutonium oxides (MOX). This technology makes it possible to perform all the production operations using one piece of apparatus – a chlorinator-electrolyser. Equipment has been developed for oxide fuel reprocessing and fabrication using these techniques. In addition, new dry processes are being studied for: obtaining of oxide fuel with neptunium and americium (for transmutation); reprocessing nitride fuel (for the planned BREST fast reactor closed fuel cycle); reprocessing uranium fuel from research reactors; and metallisation of oxide fuel for long-term storage.

SPENT FUEL MANAGEMENT

Les Shephard, vice president of Sandia National Laboratories (SNL) in the USA, said there was a “wealth of success and experience” with spent fuel management, although critical issues remained. “In today’s world, spent fuel management, as one element of the nuclear fuel system, cannot be relegated to the back end of the fuel cycle as only a disposal or storage issue,” he said. New ‘management paradigms’ were needed that take account technological, economic, environmental, and non-proliferation challenges.

A half-century ago, US president Eisenhower, in his 1953 Atoms for Peace speech, offered nuclear technology to other nations as part of a broad nuclear arms control initiative. In the years that followed, however, the growth of nuclear power, while providing many benefits, also contributed to an increasing global challenge over safe and secure spent fuel management. Nevertheless, with the finite resources and challenges of fossil fuels, nuclear power would become more prevalent in the future, Shephard said. “We must address this inevitability with new paradigms for managing a global nuclear future. Over the past 50 years, the world has come to better understand the strong interplay between all elements of the nuclear fuel cycle, global economics, and global security. In the modern world, the nuclear fuel cycle can no longer be managed as a simple sequence of technological, economic and political challenges. Rather it must be seen, and managed, as a system of strongly interrelated challenges.” Shephard offered a number of suggestions for the coming 50 years, including:

  • Pursuing a multinational nuclear fuel system that fully integrates standardised reactor designs and fuel forms, approaches to reprocessing and ultimately disposal.
  • Pursuing a multi-national repository that provides significant safety, security, economic and non-proliferation advantages.
  • IAEA-led efforts to develop standards and approaches for confidence building through public involvement and enhanced transparency measures consistent with approaches developed for reactor safety, proliferation prevention, and nuclear materials management.

Credit: Dean Calma/IAEA


IAEA director general Mohamed ElBaradei at his opening statement at the Scientific Forum. (Austria Center, Vienna, Austria, 21 September, 2004)

MULTINATIONAL SOLUTIONS

Panel discussions at the end of the forum centred on the question of multinational, or international repositories for spent fuel and highly radioactive waste, particularly for countries having small nuclear programmes. The emerging view was that countries first need to demonstrate the successful launch and operation of national waste repositories, to build confidence in geological solutions. Leading nuclear countries in radioactive waste and spent fuel management have a responsibility to be engaged in multinational approaches, Shephard said.

This issue had been addressed by IAEA director general Mohamed ElBaradei in his opening statement to the forum. He said it would be “a major milestone when the first geological repository for high-level, long-lived radioactive waste is up and operating.”

However, earlier in his statement to the General Conference, he said that while he welcomed developments in Finland, the USA and Sweden where positive steps were being taken towards the construction of repositories, he also welcomed “the renewed interest in multinational approaches to spent fuel management and disposal,” noting that more than 50 countries had spent fuel, including fuel from research reactors, stored in temporary sites, awaiting disposal or reprocessing.

“I am encouraged that the Russian Federation has expressed interest in an international approach to spent fuel storage and reprocessing, and has agreed to work with the agency in giving consideration to its feasibility. We intend to hold a conference in Russia next year to discuss ways of moving forward with international cooperation on such an initiative,” he said.

ElBaradei added that the IAEA had appointed a group of senior experts to look into various options for multilateral control. “In my view, the group could focus initially on how to guarantee the supply of technology and fuel for nuclear generated electricity, and how to set up one or more international repositories for spent nuclear fuel. The agency could play an important role in this regard, particularly as a guarantor of supply, a role envisaged under the agency statute. The group plans to submit a report next March on the results of its study.”


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