The scope of radiological protection

Draft document: The scope of radiological protection
Submitted by Martin Pierre, Personal Comments
Commenting as an individual

The establishment of criteria for the purpose of determining whether or not a given situation should be subjected to radiation protection requirements is especially complex when dealing with natural radioactivity. Several concepts such as exclusion, exemption, clearance, action level and intervention level have been developed to facilitate the selection of the most appropriate way to address various situations involving natural radiation. This document as most guidance documents including the recent IAEA RS-G-1.7 recognize the need to consider other factors than dose to an individual in the establishment of such concepts. But I believe this draft "Scope of Radiological Protection Regulation" differs somewhat from past guidance and may prompt a new tendency to lower existing criteria unnecessarily by introducing the concept of a dose criteria of "in the order of 1mSv" as an exemption concept for naturally occurring radioactive material and introducing 40 Bq m-3 as the exclusion criteria for indoor radon concentration. Past guidance such as the IAEA BSS and RS-G-1.7 generally use the concept of exclusion for radionuclide of natural origin and provide values that limit the likelihood of individuals exceeding about 1 mSv in a year. This approach is less prescriptive and also importantly is often linked to the legal doctrine of de minimis non curat lex. With regards to indoor radon concentration the use of an exclusion criteria of 40 Bq m-3 does not seem to support the generally optimized action levels (usually in the order of 200 Bq m-3). In contrast the support for different exemptions for dwelling and workplace, in the context that work activities are not related to naturally occurring radioactive material and no specific consideration is given to radon exposure, is difficult to understand based solely on occupancy factor. In this case exposure of a working person spending 2000 hrs at work and 5000 hrs at home (occupancy of 7000 hours) may be significantly higher than a person spending most of the 7000 hours at home. Therefore, with some specific exceptions, recommended radon action levels should be the same for dwellings and workplace.