The scope of radiological protection

Draft document: The scope of radiological protection
Submitted by Augustin Janssens, European Commission
Commenting on behalf of the organisation

Views of the Group of Experts established under Article 31 Euratom Treaty on the Draft ICRP Publication “The Scope of Radiological Protection Regulations” 20-21 June 2006 (1) Covering letter The Group of Experts discussed the attached document (= part 2 below) with general comments on the draft ICRP Publication and concluded that it reflects very well all the concerns that were raised. The Group invites the European Commission to forward the document to ICRP on behalf of the Group of Experts. The Group supports the deletion of many paragraphs and chapters that could be cause of confusion and hopes that this will contribute to the clarity of the remaining text. The Group nevertheless feels that much more work is needed to ensure that the slimmed down document offers all the clarity that is pursued, and that an editorial effort should be made to make it fit for use by a wide audience. The concepts relating to the definition of the scope of radiological protection are complex and need to be explained very well, in simple words, in order to serve this purpose. The Group invites ICRP to consider publication of the document after thorough revision. Nevertheless the Group also invites ICRP to reflect on whether it is for ICRP to give such detailed guidance on regulatory matters. The Group of Experts recommends leaving out the word “regulations” from the title of the Publication, and to focus in the text on the boundaries of effective radiological control measures, whether regulatory or not. (2) Comments document The EC welcomes the background offered in this document to the complex issue of the scope of regulations. The EC believes such a background is useful in better understanding the issue, but underlines that it is up to regulators to decide on the best way to implement the ICRP Recommendations and to define the boundaries of regulatory control. Hence there is no need for ICRP to propose numerical guidance. International consensus should be pursued, but this is rather within the remit of IAEA (cf. RS-G-1.7), WHO (drinking water) and FAO (Codex Alimentarius). As part of the background it is useful to put certain developments into a historical perspective. However, there is no need to dwell on dead branches of this evolution, nor on (possible) misinterpretations. Mentioning these often confuses rather than clarifies. In particular, the document should not argue why certain terms are maintained despite (alleged) linguistic problems. On substance, the European Commission has different views on the following topics: 1. EXEMPTION FROM INTERVENTION Exemption relates to the possibility for regulators not to impose certain requirements on legal persons. In an intervention situation it is for the same regulators/authorities to decide whether there is a need to intervene. There is no merit for the regulator to exempt its own authorities from intervention. In many countries it would be even very difficult to separate the two functions. This observation leads to the deletion of paragraphs (16) to (17), (21), (67) to (74). The exemption of commodities should, as a consequence, be looked at only within the system of radiological protection for practices. Paragraphs (117) and (119) should be revised [the last sentence of (117) and sentences 3 and 6 of (119) to be deleted]. 2. COSMIC RAYS The conclusion in (88) that cosmic radiation may be considered for exclusion or generic exemption is very poorly substantiated. Paragraph (87) is even dismissive. Chapter 6.2 makes no reference to the fact that in the EU the exposure of aircrew is regulated. Hence chapter 6.2 (84) to (88) should be deleted and replaced by a brief paragraph explaining, inter alia, that regulation may include monitoring and equitable distribution of individual doses, without actually reducing collective dose. 3. “DICHOTOMY” BETWEEN NATURAL AND ARTIFICIAL SOURCES The document makes interesting reflections on people’s different appreciation of natural and artificial radionuclides, and admits that regulations need to allow for such perceptions as a societal and cultural reality. On the one hand, these considerations should be formulated in a less dismissive way; on the other hand, the difference between natural and artificial sources should relate to different means of regulatory control, not to the scope of regulatory control. The document rightly argues that exemption and exclusion are not primarily a matter of triviality of exposure but rather of amenability to control. This is sufficient to explain the “dichotomy” on an objective basis. Hence it is proposed to delete paragraphs (25), part of (26), (28), and part of (31) and (33). 4. EXPOSURE SITUATIONS 'In paragraph (22) it is argued that the “type of exposure should not in principle influence the definition of the scope of the regulatory system”. This statement is not substantiated and one could find many examples to the contrary. One could very well exempt or exclude exposure situations within the three main classes of exposure separately, since the effectiveness of regulatory control and the allocation of responsibilities may be very different. Only the exclusion of exposures that are essentially not amenable to control should be stated a priori. The document fails in this respect to distinguish between two uses of the term exclusion. In ICRP-60 exclusion only related to exposures that were essentially not amenable to control and hence were not, on the one hand, in the scope of regulation, and on the other hand not included (i.e., excluded) in the assessment of total individual exposure. With the extension of the concept of amenability and in view of the fact that the new recommendations put more weight on source-related constraints for individual exposures from single controllable sources, there is still a need to subtract “background” exposures. In this context the document often makes no distinction between “existing” and “background” exposure situations and this gives rise to confusion. Existing exposure situations may, in a number of cases, merit regulatory control; it is only where such controls are never warranted that the resulting exposures may be excluded in the same way as the old “background” radiation. As a consequence the 4th and 5th sentences of (22) ought to be deleted, as well as all current references to “background” in (17), (21), etc. 5. LOW INDIVIDUAL RISK It is true that the assumptions underlying the current BSS exemption values included consideration of extreme or even accidental situations to check that even in such cases the dose limits were not exceeded. It is not true that the exemption criteria were intended to refer to an average individual, which would imply that “some individuals” may be exposed to higher doses than “some tens of mSv per year”, (41). Hence this sentence in (41) should be deleted, as well as part of the last sentence in (44), the second and third sentences of (77), etc. 6. EXEMPTION AND EXCLUSION The conceptual difference between exemption and exclusion is rather clear from the document. However, it elaborates on a number of situations where the concept of exclusion would lead to rather low activity concentrations, and exemption is proposed at much higher levels. There is no benefit for the regulator in having two steps. Exemption is then the most appropriate regulatory tool. Even for the “exclusion” of the “background” fraction of the exposure, the values for exclusion are not meaningful if regulatory control is envisaged only at much higher exposures. This implies that the very low exclusion levels for radon (40 Bq m-3) and for artificial radionuclides (e.g., 1 Bq kg-1 for á-emitters) in non-edible commodities are not useful. Their inclusion may even be the source of confusion. Hence it is proposed to delete paragraphs (110), the first sentence of (111), all references to 40 Bq m-3 in (113) and (114) as well as (115). In addition, it is conceptually incorrect to equate action levels to “defacto exclusion levels or generic exemption levels. Therefore (115) should simply read: “In summary, for radon minimum exemption levels of 200 Bq m-3 (dwellings) and 500 Bq m-3 (workplaces) should be used.” For artificial radionuclides (123) should be deleted. Both references to radon and artificial radionuclides should be deleted from (134). 7. BUILDING MATERIALS The reference in (101) to the proposal by IAEA consultants for a summation formula is premature. There has not yet been any discussion on this matter by the IAEA Committees. While it is appropriate to exempt on the basis of a weighted sum, the proposed numerators are much higher than in similar formulae introduced in national law or in EC guidance (RP 112). Resulting doses could be unacceptably high. Hence only the first two sentences in (109) should be kept. 8. OTHER ISSUES There are a few other paragraphs that seem to elaborate a little too much on history, are not quite in the remit of a document on “scope”, or are rather confusing. It is proposed to delete as a consequence: – footnote 42 – paragraph (59), last sentence – paragraphs (60) to (62) and (66) – in (121), delete reference to natural radionculides (not included in the Codex Alimentarius) – paragraph (142): the summation rule was introduced for the current BSS exemption values and was considered for specific clearance levels, e.g., for metals; however, this practical rule is very conservative (each radionuclide may lead to different exposure pathways) and it is questionable whether it should be taken up by ICRP. The amendments above lead to the following corrections to the executive summary: (c) 4th sentence to be deleted: Exemption is not only for use by competent authorities, it can, and most often should, be written in the legislation. In particular for exemption from notification, the holder of radioactive substances needs to know from the law whether or not he should report. The next sentences of this paragraph may also be deleted (d) Terminology inconsistent with main recommendations: “prospective situations, extant...” Delete two last sentences: The scope of the regulatory system will depend on the category of exposed individuals; there are no arguments why the scope of radiation protection should be defined only in terms of properties of the radioactive substances. (e) 5th sentence to be deleted: the distinction between artificial and natural radionuclide should relate to objective features, not so much to perception (same observation in (f): delete reference to “cultural perceptions” and next sentence on “lack of consensus”). Also delete last sentence: "…such as the concerns…" (f) 2nd sentence: radon in “ambient” air should be understood as outdoors; delete “with activity concentration below 40 Bq m-3” (there is no need for such a value). 3rd sentence: do not exclude “substances”, but “radiation exposure situations involving substances” See observation under (e) on “cultural perceptions”. Last sentence: delete. (g) Replace “unjustifiable” by “unjustified” (consistency with main recommendations) Delete last sentence (out of place). (h) The dose criterion of 10 ìSv in a year was not introduced for the “average individual”; while it is true that the concept of “reference group” does not easily apply to the assessment of exposure scenarios for exemption and the “individual” is largely a hypothetical person, introducing the average individual here makes the criterion meaningless. Also change "around 10 ìSv" into "in the order of…" Last sentence: delete reference to “interventional situations”; see under (n). (i) 1st sentence: delete or allow for exceptions for flight at high altitudes/latitudes. Radon: explain the use of the concept of exemption (why is it “more elusive”? Exemption from what?). (m) 2nd sentence: “… to be freed from some or all regulatory requirements…” Delete considerations of language. Delete odd example of nuclear medicine patients Last sentence: while the exposure resulting from authorised discharges is not subject to controls, it is subject to environmental monitoring. This highlights the fact that “regulatory control” is not defined. Also "clearance" versus "authorised releases" need to the properly defined. (n) Delete this paragraph: the extension of the concept of exemption to intervention situations is extremely confusing. (o) Delete last sentence: out of context.