A lot of attention has been given in recent years on the subject of partitioning and transmutation of the actinides and some long-lived fission products contained in the spent fuel as it has the potential of easing operational and safety requirements of a repository. Some would even like this to become an important alternative to direct disposal of spent fuel. Separation of the long-lived isotopes and transmutation of these into less hazardous materials have several advantages. It allows a reduction of the volume, toxicity, and fissile content of waste and supports a simpler repository. The issues related to long-term disposal of spent nuclear fuel is attributable to only ~1% of its content, namely plutonium, neptunium, americium, and curium (the transuranic elements) and long-lived isotopes of iodine and technetium. When transuranics are removed, the toxic nature of the spent fuel drops below that of natural uranium ore within a period of several hundred years. The removal of neptunium, technetium, and iodine also makes the waste safer for the biosphere. Removal of plutonium eliminates the relevance of the waste from the point of view of nuclear proliferation. Thus if the nuclear waste can be partitioned and transmuted economically to more benign materials, the waste can be disposed of in controlled environments having time scales of a few centuries rather than millenniums.

Partitioning and transmutation requires advanced reactor and fuel cycle technologies, including multiple recycle strategies. That is the spent fuel must be reprocessed. Partitioning of waste can be accomplished by both aqueous and non­aqueous methods. The Argonne National laboratory in the US has developed an electrometallurgical non-aqueous process that can separate fissile material from fission products. This process can be used for both metallic and oxide fuels. For transmutation, both accelerator driven systems (ADS) and fast reactors are being considered for actinide burning. The ADS has the potential of providing both plutonium and minor actinide utilization, and enhanced safety of sub-critical operation. It has been recognized that a pure accelerator driven system for transmutation of waste is too costly, and hence a dual concept of power production and transmutation is being envisioned. This option combines the accelerator and fission reactor technologies; neutrons are generated by directing a beam of high — energy protons from an accelerator against a heavy target such as lead or lead — bismuth eutectic and these neutrons are then used in a surrounding blanket to fission the actinides and transmute the long-lived fission products. Unlike a conventional reactor the blanket is sub-critical and cannot sustain a chain reaction without the

accelerator generated neutrons. Power is generated from this sub-critical facility while transmuting the waste.

Various ADS schemes are being studied in several countries: the OMEGA (Option Making Extra Gain from Actinides) project in Japan, Advanced Accelerator Applications (AAA) program in the US, HYPER (Hybrid Power Extraction Reactor) project in the Republic of Korea, European Industrial Partnership and other projects at CERN, and CEA, France, and China. Russia is also participating in international collaboration activities. Carlo Rubbia’s “Energy Amplifier” is one ADS design that provided a strong, early impetus in developing a system to generate more energy than needed for the accelerator.

There are many technical problems to be solved; ADS is only at the beginning stage of investigation. It is very likely that the best results in terms of high level waste radio-toxicity reduction will be achieved by symbiotic systems, including critical fast reactors and hybrid systems (e. g., accelerator driven concepts).

6. CURRENT ISSUES

Although fuel diversity and energy security are important items for a country, economic competitiveness with alternate sources of electricity has been recognized as the critical element for the survival of nuclear power. Hence consorted efforts are being made with design, construction, operation and maintenance of new nuclear power plants to reduce its capital and operation costs. Currently nuclear production costs (fuel and O&M) of existing plants are low, approaching 1 cent/KW-hr; hence the critical issue is capital cost for new plants. Also, investors expect a short-term payback of capital costs such as within 20 years of operation. It appears that capital costs in the range of $1000 — 1200 per KWe are needed for competition with natural gas. In this regard, construction of large nuclear power plants, if allowed by the infrastructure of a country, provides an advantage. At the same time, new generation of small, innovative plants are needed for specific markets and especially for developing countries.

Non-proliferation and physical protection have become more important for nuclear power plants since the September 11, 2001 terrorist event in New York. In spite of the demonstrated effectiveness of the international safeguards regime, the risk of proliferation of nuclear weapons remains a social and political concern. A significant deployment of nuclear power would lead to building a large number of reactors in many different countries and sites, and there may not be sufficient resources to safeguard all reactors. Therefore, gaining acceptance will require specific efforts of designers to enhance the proliferation resistance characteristics, particularly for the SMRs. It has also been argued that since no country has made nuclear weapons from the civilian nuclear power program and we surely have the international, scientific and regulatory mechanisms to handle the proliferation question, we should move forward as rapidly as possible to build nuclear power where it can meet human and environmental needs. In any case, the world must remain vigilant and the suppliers, verifiers, and buyers must assure safeguarding of nuclear materials.

The September 11, 2001 event has highlighted the importance of protecting nuclear facilities from sabotage and stealing of nuclear material by terrorist organizations. Even if the actual impact of a potential terrorist activity is very minimal, the occurrence of such an event will create havoc from the public perception point of view; hence nuclear facilities including spent fuel storage facilities must be secured. An issue here is how to achieve this in a cost-effective manner and how much security effort is good enough.

Disposition of spent fuel is a challenge and a roadblock for nuclear power. However, great progress has been made this year when the governments of Finland and USA have approved the construction of geologic repositories in Olkiluoto in Eurajoki, Finland and at Yucca Mountain, Utah, USA. Finland is now set to become the first country in the world to build a final repository for spent fuel from nuclear power plants. Sweden and the US are also well ahead with similar plans.