IRSN comments on TG-76 Draft report - « Radiological Protection from Naturally Occurring Radioactive Material (NORM) in Industrial Processes »
This report provides general guidance for an integrated and graded approach for radiological protection of various categories of exposure (humans with workers and public; environment with non-human species) related to human activities linking to NORM industries. These activities are very diverse, and may be past (legacy sites issue), or present.
The great variety of activities and associated situations makes the framework complex but the latter is globally clearly explained. The reference to multiple hazards exposure situation and the need for an integrated and consistent exposure assessment and management is one of the major added values of the proposed guidance. As a TSO, IRSN is fully supportive of this integrated and graded approach encompassing multiple hazards.
To make the report more impactful, IRSN recommends a number of improvements as explained below:
(i) a more detailed explanation about the features supporting the categorization of a given industrial activity into existing or planned exposure situations, since this triggers the adoption of the corresponding assessment and management process for radiological protection; At present the focus is highly put on existing situations and planned ones are only presented very rapidly (e.g. point (13)). This may lead to confusion and even to misunderstanding when compared with e.g. the IAEA safety guidance or the EURATOM BSS, where the focus is clearly different (i.e. presented as planned exposure situations, with NORM exposure management being dealt as existing situations in the case of e.g. legacy sites). One way to solve this could be to limit the report to “NORM and existing exposure situations” OR to add a chapter dedicated to a discussion on this issue.
(ii) it is clearly stated that radon/thoron exposure management is not developed in the present report; however, the way it is articulated with NORM exposure management deserves a more detailed discussion than the one developed point (14).
(iii) Regarding « protection of workers » (chapter 4.1), one should pinpoint in item (69) that the panel of risks undergone by workers is not a specific issue of NORM facilities but also applies for nuclear activities other than NORM-related ones. The underlying rationale to justify a more graded and more flexible management for radiation protection where there is no or very low radiological safety issue because of a limited concentration of radionuclides in materials, is confusing. Moreover, as mentioned in our comment (ii), the document could have pointed out the internal exposure which is an actual specific issue of NORM activities (e.g., the combination of (radon + dusts + large amounts of NORMs to be managed) represents a tricky issue for confinement).
(iv) the EIA is only referred to in chapter 4.3 dedicated to protection of the environment; However, this integrated and graded approach is widely implemented in the international and national regulation and covers the impact assessment for the public and the environment and for the various types of stressors/pollutants (i.e. non-radiological and radiological). This should be corrected, at least by being also cited in the chapter dedicated to protection of the public (chapter 4.2). One main point should be added to the highlights list page 5 on this issue. Moreover in chapter 4.2, the sources of exposure of the public as detailed also apply to the environment (except building materials). This should be mentioned in chapter 4.3.
(v) more specifically the ICRP-promoted integrated approach regarding non-radiological and radiological risks should be illustrated (e.g. by the case of natural Uranium exhibiting both a chemical and radiological hazard for human and non-human species).
(vi) by adding “giving rise to enhanced exposure to human and non-human species” as done in the glossary, the definition of NORM becomes similar to the one dedicated to TeNORM. This should be solved in order to make clear that the report is dealing with situations where “activity concentrations of the naturally occurring radionuclides have been changed by some anthropogenic processes” (and not situations where activity concentrations of the naturally occurring radionuclides are undisturbed). The previous definition could also be kept instead of this one.
(vii) the way the system of protection has evolved throughout the various successive ICRP publications is summarized in the introduction but protection of the environment is omitted. Some short explanation should be added there on this like for the other categories of exposure. Now ICRP is explicitly moving towards a unique system of radiation protection, it is important to demonstrate the integration of protection of the environment into the system, with biota beside (beside public, workers and patients) in a balanced reasoning.
When taking these suggestions into account, abstract, main points and conclusions (chapter 5) should be revised accordingly.
Main points
Page 5, 117-119: precise this point concerns the public and the workers
Page 5, 120-122: complete as follows “..an issue of environmental contamination and therefore potential subsequent human health or ecological consequences”
Page 5, 123-124: enlarge the application of this point beyond workplace. This statement is also true for human health and environment (where strategies of exposure assessment and management generally deal with non-radiological exposure)
Introduction
Page 6, 140: add radioactive potassium (since it is an element and not a radioelement like thorium and uranium)
Page 6, 142: complete the scheme as follows: “…the radionuclides may be dispersed and/or change their physico-chemical properties so that they become unevenly distributed…”
Page 8, 125: complete “….to the environment with subsequent humans and non-human species exposure”
Page 8, 249-255: this point (16) contains some mistakes: Publication 108 describes the framework for protection of the environment, introduces the RAP and the DCRL concepts (not Publication 124 that deals with the applications of protection of the environment under different exposure situations ). Please correct and possibly complete with Publication 114, 136 and TG72 draft report under public consultation at present.
Page 8, 259: add “…applying the system of radiological protection…”
Page 8, 270: there, one perfect example to illustrate the key message of the para is the one of the dual toxicity of uranium (see general comment (iv) above)
Chapter 2
Page 14, 397: add “…and subsequent fauna and flora exposure”
Chapter 3
Page 15, 444: criterion instead criteria
Page 15, 448: complete “…to the expected level of risk”
Pages 16 to 20, 550-662: this entire chapter 3 is well detailed for people (workers and public) but environment as a category of exposure is not systemically and consistently mentioned when dealing with each of the principle to be applied (sub-chapters).
For example, 551-558: there is an apparent contradiction between the first two sentences to be solved: the first one suggests that optimization should apply also to the environment, but the next one only deals with the public. Another example is 587-633 where nothing is said about environment. There, an item should be added to explain the use of dose criteria for optimization, consistently with item 51)
Page 16, 449: complete “…commensurate to the expected level of risk”
Page 17, 534: complete “… after radiological characterization of the exposure situation (i.e. category of exposure, when, where, how) and taking into account human health and ecosystem health…”
Page 18, 554-557: Non-human species should be included there e.g., “…. Individual doses, the number of people exposed, the non-human species exposed,….guided by appropriate dose criteria (for human or non-human species respectively), taking into account….alongside ecological factors”
Page 19, bullet (54): there the structure and content of the paragraph should be revised in order to keep consistent with the fact the system of radiological protection is “one fits all categories of exposure”, and fully integrated. The way it is written in the draft report is only pointing out humans (non-human species are omitted).
Page 20, bullet (59): the “a”-step of the optimisation process should be completed as follows: “(a) the assessment of the exposure situation and the associated risk”
Chapter 4
Page 21, bullet (66): this is a repetition of bullet (23)
Page 22, bullet (75): there a few words about how articulation with Radon/thoron doses could be added
Page 23, 754: modify as follows “(a) eliminate the hazard and consequently the risk”
Page 23, 783: radon and thoron
Page 26, 914: complete : “…dose assessment and comparison with the ad hoc dose criteria”
Page 26, 935: change as follows “…radionuclides may also change their physico-chemical form; e.g., some may react with particles in the stream….”
Page 27, 944: modify as follows “(b) identification of potential exposure pathways taking account for environmental distribution of radionuclides in space and time “
Page 27, 952: in terms
Page 30, 1084-1086: modify as follows “…that mechanisms governed by physical, chemical and biological reactivity of radionuclides may lead to selective dispersion, ……impact over space and time”.
Page 30, 1086-1088: It could be said that this statement is also true for human risk assessment.
Page 30, 1092: complete”….informed by the prediction of dose for no-human biota in space and time.”
Page 30, 1094-1097: it is not clear “the relative contribution for different options” refers to. The meaning of the last sentence is also difficult to capture.
Page 30, 1102-1107: it should be stated that EIA encompasses human health risk assessment, consistently with non-human biota health (or ecological) risk assessment, alongside radiological and non-radiological impacts (the IAEA reference n°GSG-10 (2018) could be added).
Page 30, 1112: substitute “mobility of radionuclides” by “distribution of radionuclides in space and time”
Page 30, 1113: substitute “uptake” by “exposure”
Page 30, 1114: change into “modelling the dose and evaluation of the potential radiation effects
Page 31, 1129: delete “….chosen radionuclides….”
Page 131, 1136: …DCRL can be are considered…
Page 131, 1140: practically of the need to further restrict discharges or other options
Page 131, 1144: “special requisites” should be illustrated with some examples in brackets