As described above, a decommissioning plan has to be established and maintained throughout the plant’s lifetime and accepted by the regulatory body of the country. Adequate funds should be available. This gives the authorization for final shutdown and the first operation is then to unload the used fuel. The IAEA (2006c) Safety Standards Series document, Requirements for Decommissioning of Facilities Using Radioactive Material, WS-R-5, gives the precise ways of dealing with decommissioning.

The regulator has the responsibility for establishing the various criteria for the safety and environment of the decommissioning phase, for perform­ing regular inspections and for checking the handling of the produced wastes. It also has to produce criteria which have to be met for the end state allowing the release of the site from regulatory control; when this is not feasible the site has to continue to be controlled and adequate measures shall be taken.

Internationally the recommended strategy for dismantling of a nuclear plant is immediate dismantling. But some factors may induce delays (for example, availability of waste disposal and long-term repository, funds and competent personnel availability). In any case, the facility must at all times demonstrate its safety.

An organization for the management and implementation of decommis­sioning shall be established as part of the operating organization or dele­gated to contractors but the responsibility still lies with the operating organization. It is important at this stage to remember the Fundamental Safety Principle 1 on Safety Responsibility (see Section 2.4.1).

Decommissioning and dismantling involve:

• Radioactivity, which means protection of the workers and the environment

• Contamination, which induces use of chemicals and the necessity of containment.

Dismantling of an installation produces enormous quantities of wastes. The wastes generated must be disposed of or recycled when possible. The low — activity wastes can be disposed of in existing facilities that are usually avail­able in most countries. For the other kinds of wastes it is important to reduce the volume as much as possible by separating the non-radioactive ones. The radioactive part (intermediate and high level) should be packaged and stored safely while waiting for availability of appropriate repositories.

If waste is stored on the site, a revised or new, separate authorization, including requirements for decommissioning, shall be issued for the facility.