Fig. 2.12. Accelerator facilities at the Paul Scherrer Institute (PSI), Switzerland (image courtesy of PSI).

However, it should be noted that the concentration of radioactivity is more evenly distributed in the case of such an accelerator facility.

2.4.3. Military wastes

Military wastes arise from processes leading to the manufacture of nuclear weapons, depleted uranium weapons and armour, as well as other more mundane items such as thorium mantles used in gas lamps (the military have a tendency to stockpile, which leads to an accumulation of materials that cannot be disposed of in the same manner as household refuse).

Military wastes are physically no different to those arising from the nuclear fuel cycle, in that to produce nuclear weapons uranium must be mined to produce feed stock for enrichment to very high levels of uranium-235, or to produce fuel for reactors which provide the spent fuel from which plutonium is then extracted by reprocessing. This leads to reactor operational and decommissioning wastes, as well as reprocessing wastes of broadly similar types to those arising in the civilian programme. What is different is the spectrum of radioactivity associated with these wastes. For example, the operational wastes from the handling of plutonium consist of the same types of protective clothing used in the civilian programme for the manufacture of MOX, e.g., rubber gloves, overalls, overshoes, glove boxes etc., the difference being that the associated radioactivity consists of a different spectrum of plutonium isotopes and, of course, the volumes of these types of wastes are significantly higher in the case of military applications.

Information concerning the types of military wastes that arose within the British programme can be found in the UK inventory (Nirex, 2002).

2.5. Conditioning of radioactive wastes

Treatment and conditioning processes are used to convert radioactive waste materials into a form that is suitable for subsequent management, such as transportation, storage and final disposal.