Z. L O VA SIC, International Atomic Energy Agency (IAEA), Austria

Abstract: This chapter considers the types of nuclear reactor and the spent fuel waste produced. The various technologies for spent fuel storage, reprocessing, recycling and disposal are reviewed. The vitrification of high-level radioactive waste (HLW) is described.

Key words: spent nuclear fuel storage, vitrification, high level nuclear waste.

15.1 Types of nuclear reactors and nuclear fuel arisings

Since 1960 when the first commercial pressurized water reactor (PWR) of 250 MWe, Yankee Rowe, designed by Westinghouse, and the boiling water reactor (BWR), designed by General Electric, were put into operation in the USA, the quantities of spent fuel occupying the spent fuel pools of commercial reactors have steadily increased. While, from the beginning, PWR and BWR designs used enriched uranium fuel, Canada adopted a different approach using natural uranium fuel with heavy water moderator and coolant; its first commercial CANDU unit started operating in 1962. The Soviet Union also developed a pressurized water reactor, known as the VVER, and later (1973) the RBMK high power channel reactor. In contrast, the magnesium-clad fuel from the first generation of gas-cooled reactors, a number of which were also built between 1958 and 1971, was generally sent for reprocessing recognizing that it was unsuitable for long-term storage in water. In addition, over this same period, several experimental or prototype fast reactors operated. All but one of these (BN-600 in Russia) are now shut down. Many countries have chosen light water designs so that today 60% of the world nuclear capacity is PWRs and 21% BWRs.

Table 15.1 shows the types of nuclear reactors that make up the current total of 441 operating nuclear reactors (another five reactors are in a long-term shutdown condition). As PWR and BWR spent fuels are predominant in the quantities of arising spent fuel, most examples in this chapter are related to these two types of fuel. Yearly discharge from all these reactors was about 10 200 tonnes of heavy metal in 2010 and was about 10 500 t (HM) during several years prior to that year.