THE CASE OF SAFE DECOMMISSIONING

The case of decommissioning vis-à-vis these current radiation protection criteria can be analysed by assuming that an installation (e.g. a nuclear power plant (NPP)) is introduced in a given location where there is a given background extant dose. As a result of the introduction the background extant dose will increase, perhaps very little, but will not be zero. If the NPP is regulated following the international radiation protection system, the increase will be kept below the restrictions described above. After its lifetime, the NPP will require to be decommissioned and the site restored. As a result, presumably, the dose will go down. But since it is not feasible to reduce the residual dose to absolute zero, a residual dose, perhaps negligible but not nil, would remain as a lasting addition of dose, a ‘delta dose’, over the original

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background extant dose. The current problem of the international community is that it has been unable to reach a quantifiable consensus on what residual dose, what delta dose, is internationally acceptable when decommissioning a facility that was used during the performance of a practice (Fig. 8).

This, rather than dismantling techniques, is the real problem of decommissioning: if an international agreement on the radiation safety criteria for restoring sites used during practices is not reached soon, the current installations ending their lifetime would perhaps be ‘decommissioned’, i.e.

dismantled, but the real technical problem that the public is requesting to unravel would remain unsolved.

5.1. The issue of regulating commodities

The best indication that same basic radiation safety criteria are missing for decommissioning is the lack of resolution of the so-called issue of regulating commodities, which has engaged the international radiation protection community in a hot debate over past years. The problem is very simple: what is the level of radioactivity in goods, merchandise, products, etc., and, in general in

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FIG. 7. Summary: How the present system of radiation protection works.

any non-edible ‘commodity’, which requires regulation for radiation protection purposes. In order to illustrate the public importance of this issue, let us imagine the dilemma of a member of the public: he/she has probably learned some essentials about radioactivity, for instance that every product in the world contains some radioactivity. When shopping in a store he/she might ask, “Did the radiation protection regulator authorize this product that I am buying or not?” Surprisingly, the international community does not have a clear, non-convoluted answer to this simple dilemma. From what I heard today from the Conference President, it would be easier for such a curious member of the public if he/she lives in Germany because in this country that answer seems to be unequivocally available. But in most countries, and certainly internationally, there is no clear consensus as to when a radiation protection regulator should intervene regarding a particular commodity. Moreover, the situation is so irrational that while commodities such as nails, wood, bricks, etc., leaving a decommissioned nuclear power plant cannot be reintroduced into the market, a given foodstuff with the same level of radioactivity leaving the same installation can be sold commercially on the market because it would probably

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FIG. 8. The radiation safety issue of decommissioning.

comply with the international rules established by the Codex Alimentarius Commission that were incorporated into the BSS.

In summary, the current situation is that members of the public would be able to eat products that would normally not be allowed to be sent out from a decommissioned NPP into the market. This is because the Codex Alimentarius levels, which govern the regulations of edible substances, are internationally accepted and in addition are much higher than the levels that national regulators are using for releasing non-edible materials from NPPs. Many experts maintain that this is not necessarily a contradiction because, among other reasons, the models for human ingestion are straightforward, but human habits for the use of non-edible commodities can be extreme and require conservative models, etc. — all this seems to be logical, but for members of the public it is a logic that is difficult to digest.

6. OUTLOOK: BETTER COMMUNICATION?

The contradictions described above clearly indicate that in dealing with decommissioning safety criteria there is a serious problem of communication.

The Conference President has clearly indicated that this is one of the major issues that hopefully the conference will deal with. The technical community has been unable to inform the public convincingly that they are exposed to cosmic rays, to terrestrial radiation, to radon in their home, to radiation from naturally occurring radioactive material from the extractive industries, to fallout from past events, to normal commodities containing radioactive materials, to residues from accidents that have occurred, to normal releases from current practices — and that decommissioning may conceivably increase the extant dose due to all these causes by just a very small fraction. If the technical community is able to solve this problem of communication, I believe that we will be solving one of the major problems of decommissioning.

In closing, let me express my hope that this conference will provide solid findings, which are planned to be submitted to the Board of Governors of the IAEA and that they can be converted into an international action plan on the termination of activities that could be submitted to the Board at its meeting in September 2004. This international action plan might produce an international code of conduct on decommissioning.

I wish you a very successful conference, with constructive discussions, a fruitful information exchange and solid, far-reaching findings.

Thank you for your attention.

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