I. CROSSLAND, CrosslandConsultingLtd, UK

Abstract: This chapter provides a description of key issues in disposal of solid radioactive waste namely the nature of the waste itself, the measures needed to convert it to a form that is suitable for disposal, the institutional arrangements that allow disposal to take place and, finally, the disposal methods currently in use or proposed to be used. The chapter concludes with a discussion of possible future developments in this field.

Key words: radioactive waste disposal, high level waste (HLW), spent nuclear fuel (SNF), borehole disposal, vitrification.

18.1 Introduction

Industrial waste is an inevitable consequence of human exploitation of the environment. Today, the old tin and copper mines of Cornwall are tourist attractions but, when applying to have a group of mines registered as a World Heritage Site, the area was said to include some of the most polluted land in the UK1 and a warning was given that remediation could disturb areas associated with historic former mines. It seems that, given enough time, even industrial pollution can come to be seen as a form of heritage.

What our successors will think of radioactive waste — a by-product of twentieth and twenty-first century nuclear technology — is impossible to say but one of the key principles of its modern-day management2 states that its production should not place an undue burden, whether technical or financial, on future generations. This immediately rules out any form of storage as a potential solution, remembering that, according to the IAEA,3 all storage is temporary because it implies retrieval. What is needed is something permanent. Tasked with finding a solution for the long-term management of the UK’s radioactive wastes, the Committee on Radioactive Waste Management (CoRWM) examined every possible option, including firing the waste into space, sea dumping and deposition into subduction zones. After two years’ deliberation, the committee recommended4 geological disposal as ‘the best available approach’.

The aim of this chapter is simply to describe the nature of radioactive waste and the techniques developed for its safe disposal:

• Section 18.2 describes the various kinds and categories of radioactive waste and the manner of their arising.

• Section 18.3 covers pre-disposal, by which is meant processing and conditioning of radioactive waste for storage and disposal.

• Section 18.4 addresses the framework for disposal: the organisational arrangements needed to drive and control a disposal programme.

• Section 18.5 outlines modern practice in radioactive waste disposal and is divided into sub-sections on near-surface disposal, deep disposal and borehole disposal.

• Section 18.6 looks at possible future trends.

• Section 18.7 suggests some further reading.