Safe immobilization of high-level radioactive waste in waste forms for geological repositories

Abstract

The idea that spent fuel and other hazardous radioactive high-level wastes (HLW) would need to be dealt with arose soon after the first experimental demonstration of nuclear reactors in 1942. HLW is spent nuclear power plant fuel or waste deriving directly from reprocessing or recycling of spent fuel. This latter waste consists of mainly fission products (FPs), as well as minor actinides such as Np, Pu, Am and Cm. Table 1 shows the main components and relevant half-lives of reprocessing waste from the well-known Purex process. Also, there are abundant wastes from the production of Pu for nuclear weapons, mainly in the US and Russia. These wastes (Table 2), although designated as HLW in the US, have only around 0.1- 1% of the radioactivity per unit volume of the Purex-type HLW, and if they were located in most other countries would be categorised as intermediate-level waste (ILW). Current HLW inventories around the world run into tens of millions of tonnes. The manageability of HLW impacts directly on the sustainability of nuclear power. © 2011 Elsevier Ltd.