Conceptual framework and technical basis for clearance of materials with residual radioactivity

The primary impediment to the release of materials containing residual radioactivity from a controlled environment is the lack of a suitable framework within which release standards can be developed. Recently, the `risk-based` approach has been proposed as an appropriate means of setting standards. The term `clearance` has been introduced by the International Atomic Energy Commission as a regulatory process for releasing radioactive materials posing trivial risks. A `trivial` risk level has been determined to be on the order of 10[sup -6] to 10[sup -7] annual risk to an exposed individual, and a population risk of no more than 0.1 annually. Under these strict constraints, exposure scenarios may account for processing, disposal, and product end-use of materials. This paper discusses these scenarios and also describes the technical basis for deriving release levels under the suggested risk (or dose) constraints