|Dr. Landfermann, Dr. Helming
Federal Ministry of the Environment, Nature Conservation and Nuclear Safety of Germany
The draft ICRP-publication „The Scope of Radiological Protection Regulations“ is giving advice on conceptual and quantitative criteria for the definition of the scope of radiation protection legislations and the implementation of radiation protection control. Thus it deals with qualitative and quantitative criteria for exclusion, exemption and clearance.
Although this draft to a great extent repeats conceptual and numerical aspects established by other international bodies, it conceptually and with respect to the terminology deviates from the currently applied principles. The clear and proven triad of exclusion, exemption and clearance is replaced by a terminology mixing up “exclusion” and “exemption” and introducing new terms like “generic exemption” and “automatic exemption” while the term “clearance” is no longer recommended. The reasons for these changes are not visible. Furthermore the area of application of these principles is extended to unsuitable radiation protection matters like intervention. All this causes confusion and leads to misconception.
This draft defines the legal boundaries as well as the implementation and exception criteria to be considered by national radiation protection systems. It identifies unimportant and unwarranted radiation protection situations to be excluded, exempted or released from all or specific requirements of the legislation. Although especially the quantitative recommendations in this connection are put into perspective by allowing for national deviations this approach goes far beyond the assignment of the ICRP and interferes with the sovereignty of national legislation and the indispensable rights of the national regulators. The ICRP should strictly refrain from covering aspects that are exclusively bound to national rights and responsibilities.
The system of quantitative criteria given to define the boundaries between “inside” and “outside” the radiation protection regulations is neither consistent nor convincing. A clear and reasonable strategy to define these boundaries on the basis of a dose concept - as it is the common practice in radiation protection - is totally missing. Instead the values are taken from various sources using multiple arguments and explanations to justify the choice. Own estimates are not given. Several values are much too high to be accepted from health protection point of view.
Summarizing it is proposed to abandon this publication and to incorporate a consistent and convincing concept of general scope definition without recommending specific values into the new ICRP’s radiation protection recommendations.
Comments in more details:
1. Sovereignty of the National Administration
The draft ICRP-publication „The Scope of Radiological Protection Regulations“ is giving advice on conceptual and quantitative criteria for the definition of the radiation protection matters that “can and need be subject to national radiation protection regulation” and of “those” matters “that cannot or need not”. Thus it provides strong recommendations to state’s legislators and regulators how to design and implement national radiation protection regulations. Radiation protection regulations need not to be established for exposure situations that are deemed to be unamenable to control (exclusion) and regulatory requirements may be relinquished if they are unwarranted because the societal efforts are deemed to be disproportional to the saving of radiation detriment (exemption). While recommending criteria for exclusion and exemption, the ICRP-publication states that it is not the intention to “recommend to legislators and regulators how to phrase radiological protection legislation or regulations”. “Instead its recommendations focus on the definition of technical boundaries between what should be regulated and what may not and leave national preference the mechanism through which controls are applied or nor applied.”
It is understood that the ICRP’s motivation to develop and publish a recommendation on the scope of radiation protection arises from the fact that the hitherto existing recommendations are not limited in the extent of practical implementation and therefore cover all types of radiation exposure situations regardless of the size and the origin of the exposure. Obviously the Commission regards this situation as being incomplete and therefore requiring detailed amendments by this draft ICRP-publication on the qualitative and quantitative scope of radiation protection leaving only the mechanism of practical implementation to the national preference as stated above. The determination and recommendation of generic and universal technical boundaries is justified by international standardization and international consensus on the values recommended.
This position of the ICRP goes astray and is not shared from here. It is due to the nature of the ICRP’s general assignment and work that the so far existing recommendations deal exclusively with scientific and technical aspect e. g. with radiation effects and basic radiation protection concepts but strictly refrain from covering direct aspects of legislation and regulation like the definition of the legal boundaries and the practical implementation and exception criteria of national radiation protection systems.
It is certainly in line with the character of the ICRP’s work when - from scientific point of view - answers are given to questions like what in principle de-minimis exposures are and if there are further criteria for the purpose of defining the scope of radiation protection systems especially in the case of natural radioactivity. Similarly the modelling of principle concepts of radiation protection like the concept of justification, optimisation and limitation or the concept of exclusion, exemption and clearance belong to the scientific work of the ICRP. This may even include the identification of general radiation protection situation that are due to their nature not amenable to practical radiation protection control by any reasonable means.
But it is definitely far beyond the scientific and technical radiation protection matters of the ICRP and extends to the sovereignty of the national administrations when moving towards the identification and definition of unimportant or unwarranted radiation protection situations to be exempted or released from all or specific requirements of the legislation.
The decisions on where the boundaries between “inside” and “outside” the radiation protection regulations lie are indispensable rights of the national legislators. They decide whether a particular exposure situation depending on its qualitative or quantitative features is important and whether to include this situation into the national system of radiation protection control is warranted or not and under which conditions a release from the regulator’s control can be granted.
Of cause when doing this, internationally recommended concepts and principles on how to derive appropriate values are to be taken into account. But according to specific national conditions deviations are possible.
The draft ICRP-publication itself expresses that the decisions on legal and practical boundaries of national radiation protection systems cannot be made by exclusively focussing on scientific aspects like the de-minimis principle or on values internationally established and agreed e. g. within the principles of good and proven practices. Rather it also has to take into account that there are various specifically national factors like the particular environmental and health policy, the economical situation and culture as well as the perception of different risks in public life and occupation. These are factors that are only accessible to the assessment and decision making by the national governments and parliaments, respectively. The ICRP as an international scientific advisor is not supposed to anticipate these evaluations and decision making processes.
Although the quantitative recommendations of this draft ICRP-publication are all put into perspective by allowing for national deviations they would – once published - form hard to ignore statements putting legislators into difficult situations. Therefore the ICRP should focus on basic principles to be applied but abandon recommendations on aspects that are exclusively bound to national rights and responsibilities.
2. Terminology and Involved Radiation Protection Matters
The draft ICRP-publication is to a great extent a summary report and repetition of the already existing and well documented concept of exclusion, exemption and clearance as designed by the International Atomic Energy Agency (IAEA) in the Basic Safety Standards and in the Safety Guide No. RS-G-1.7 on the “Application of the Concept of Exclusion, Exemption and Clearance”. Many countries have adopted their radiation protection system to these principles and procedures.
The system of exclusion, exemption and clearance is also found in the Directive of the Council of the European Commission 96/29/EURATOM as of 13 May 1996 which is legally binding for all EU-countries and consequently reflected in their legislation. Practical aid to the implementation of this part of the directive is given by the guidelines of the Group of Experts established under the terms of Article 31 of the EURATOM Treaty published in the Radiation Protection 122 “Practical Use of the Concept of Clearance and Exemption, Part I and II”.
Although many conceptual and numerical aspects are repeated, the concept of this draft ICRP-publication also deviates from the terminology and the rules of application as established in the above mentioned references and as currently applied in the practical radiation protection systems of most countries. The clear and proven triad of exclusion, exemption and clearance is now replaced by a terminology mixing up “exclusion” and “exemption” and introducing new terms like “generic exemption” and “automatic exemption” while the term “clearance” due to its “ambiguous meaning” is no longer recommended (in some parts “authorized release” is used). The reasons and necessity of creating new terms are not visible. Furthermore the area of application of the above mentioned principles is extended substantially. All this may cause confusion and lead to misunderstandings. For example:
a) The radon concentrations in ambient air below 40 Bq/m3 or substances containing activity concentrations of artificial -emitting radionuclides around 1 Bq/kg or 10 Bq/kg for - and -emitters, respectively, are considered as candidates for exclusion from legal instruments although this conceptually clearly is an exemption (control not warranted due to the size of concentration/possible exposure or disproportion between control effort and possible exposure reduction).
b) For naturally occurring radioactive material (NORM) there is a choice given of either straightforward exclusion or generic exemption around activity concentration of 1000 Bq/kg of the radionuclides in the primordial uranium and thorium series. Since these exposure situations and even below these values are to a great extent amenable to control an exclusion does not seem to be justified. If such exposure situations are to be kept outside the regulations clearly exemption or clearance are the right term to be used.
c) The principle of exemption is applied to radioactivity in foodstuffs referring to the values as given by the Codex Alimentarius Commission. This is conceptually completely misleading. The criteria for radioactivity in foodstuffs as provided by Codex Alimentarius Commission are maximum acceptable concentration in the aftermath of a radiological accident. They are only to be tolerated under very exceptional circumstances and for a limited period of time. They do not apply to regular circumstances and to the general exchange and consumption of foodstuffs. The concentration of radionuclides in foodstuffs under normal circumstances is very low and therefore usually not subject to direct radiation protection regulations. Drinking water may constitute an exception. However, the values of the Codex Alimentarius Commission could not be used if exemption values were to be designed. Rather a much lower dose criterion would be appropriate due to existing broad and adequate possibilities to control such exposure situations by legislators and regulators. Thus drinking water requirements for example are usually based on a 0.1 mSv/a criterion.
d) Intervention situation like the clean-up of site contaminated by past activities or accidents do not fit into the exemption concept either. A radiation protection system may, of cause, provide action levels above which intervention measures are to be thought about and below which an intervention is usually not deemed to be warranted. But generally the basic intervention principles require to assess whether an intervention is justified and - if answered with yes – what the optimum intervention procedure would be taking into account all relevant aspects and factors. Following this approach, intervention actions may end up with contamination values or dose values a little or even far below possible action levels depending on the particular circumstances (best achievable result under the given conditions). The respective sites would usually be released from control. Eventually even values above action levels would have to be accepted. This complex situation cannot be covered by fixed generic or universal exemption values.
A different situation exists when contaminated material from a remediation site is to be reused (e. g. as building material for roads) or to be disposed of on a dumpsite. This may well be treated under the exemption/clearance categories.
Having in mind all the repetition of the existing concepts of exclusion, exemption and clearance as already well documented in many publications on the one hand and the changes with their conflicting and misleading aspects introduced to this concept on the other hand, it is seriously questionable whether this ICRP-publication is desirable. Since many countries have integrated the existing concept into their national legislation this ICRP-publication would lead to misconception and manifold confusion.
3. Quantitative scope criteria
The draft ICRP-publication mentions or recommends various criteria and figures of different type and magnitude to be used or referred to when defining exclusion and/or exemption/clearance levels:
General dose criteria for exclusion/exemption/clearance (further aspects and factors to be considered):
- Some 10 uSv/a for artificial radionuclides
- about 1 mSv/a for naturally occurring radionuclides (including/excluding radon?)
- about 1 mSv/a for intervention situations (including/excluding radon?)
- about 1 mSv/a for commodities
- cosmic radiation at ground level in general,
- radionuclides that are natural constituents of the human body like K-40 in general,
- radon concentrations in ambient air below 40 Bq/m3,
- substances containing activity concentrations of artificial alpha-emitting radionuclides around 1 Bq/kg and
- substances containing activity concentrations of artificial beta- and gamma-emitting radionuclides around 10 Bq/kg.
Exclusion or generic exemption of
- naturally occurring radioactive material below activity concentration of 1 Bq/g of the radionuclides in the primordial uranium and thorium series and below 10 Bq/g for substances containing K-40 (values are supposed to correspond to about 1 mSv/a) and
- building materials containing naturally occurring radionuclides including industrial by-products and residues with enhanced concentrations of natural radioactivity on the basis of a more restrictive sum formula using the above mentioned values of the uranium and thorium series and the K-40 (sum is supposed to correspond to a few mSv/a in the worst-case scenario); if necessary further restrictions with respect to radon.
Exemption, generic or universal exemption of
- radon in dwellings of less than a time average of 200 Bq/m3 (as a minimum exemption level equal to about 4 mSv/a),
- radon in workplaces of less than a time average of 500 Bq/m3 (as a minimum exemption level equal to about 3 mSv/a),
- action levels equal or higher than 200 and 500 Bq/m3, international standardized occupational action level of 1000 Bq/m3 (equal to about 6 mSv/a) as de facto exclusion or generic exemption level,
- foodstuffs containing activity concentrations smaller than specified by the Codex Alimentarious Commisson (1 mSv/a)
- drinking water containing activity concentrations smaller than specified by the WHO drinking water quality guidelines (0.1 mSv/a)
- apparatuses including sealed sources below 1 uSv/h in a distance of 0.1 m from the surface plus further criteria or maximum energy below 5 keV
- workplaces (occupational exposure) in the range of 1 – 10 Bq/g of the primordial uranium and thorium series (values are supposed to correspond to 1 – 2 mSv/a)
- releases from NORM-industries in the range of 1 – 10 Bq/g of the primordial uranium and thorium series (values are supposed to cause exposures smaller than 1 – 2 mSv/a for the public, usually in the range of 0.1…300 uSv/a)
The above listed values show that there is no consistent concept behind the now by the ICRP recommended boundaries of radiation protection systems, especially a clear and reasonable strategy to define those boundaries on the basis of dose assessments as it is the common practice in radiation protection is missing.
The recommended values are taken from various sources using multiple arguments and explanations to justify the choice. Some values are just referred to because they are reported by other international bodies. Own estimates as well as technical and scientific substantiations of recommended values – as genuine matters of the ICRP’s work – are not given. Partially values seem to be chosen as they fit to produce the desired results or comply with the current practice. Where appropriate the dose concept as the basic ground of radiation protection is even totally dropped.
Not all of the dose values given as approximate equivalents of the environmental media values, e. g. the activity concentration, can be confirmed from here. For example releases from NORM - industries containing naturally occurring radionuclides can cause high exposures for members of the public. Assessments for large dumps or waste rock piles with an average activity concentration of about 0.2 Bq/g of the primordial uranium series alone show that exposures to the public of more than 1 mSv/a may result (up to several mSv/a when ground water is affected). The underlying exposure scenarios are of cause chosen conservatively but not as worst case scenarios. Consequently the above recommended range of 1 - 10 Bq/g for the definition of exemption criteria with respect to NORM industry - releases like waste dumps can corresponds to exposures of the public of several 10 mSv/a up to even more than 100 mSv/a. Such exposure situation may surely be considered high enough to warrant control. Exemption does not seem to be justified for exposure situations above 1 mSv/a. Similarly problematic exposure situations can be shown for the recycling or reuse of NORM. Especially the above mentioned exemption criteria for using NORM as building materials seem to be inadequate because exposures of several mS/a may result depending on the circumstances and extent of NORM – material used. This is for example in strong contrast to the exemption level of 0.3 mSv/a excess gamma dose given by the guidelines of the group of experts under the terms of Article 31 of the EURATOM - Treaty. Furthermore the possible exposures can easily be reduced (without hampering the reuse NORM) by restricting the amount of NORM added to the building material. This situation seems to be accessible to legislation and practical radiation protection control. Exemption does not seem to be justified for exposure situations above 1 mSv/a, especially when simple, easy to control alternatives are available.
Substances containing naturally occurring nuclides used in the nuclear industry are - compared to the NORM-industries – relatively easy to control. Therefore it does not seem to be necessary to use the same exemption criteria as used for NORM (around 1 mSv/a). Rather lower exemption values could apply due to the given controllability with reasonable means.
Summarizing it is concluded that there is no benefit seen by publishing this ICRP-recommendation on the scope of radiation protection. It repeats well known concepts in a broad extent, but does not provide new ideas that are acceptable or make up the already existing concepts. In the contrary many aspects of this ICRP-publication are confusing, misleading and/or conflicting with proven and nationally implemented concepts. The definition of values in order to form the boundaries between exposure situations to be included into the radiation protection regulations and those to be excluded should - as a reflection of the national risk perception and of many other aspects - be left to the national legislations. The package of values as recommended by this draft ICRP-publication cannot serve as a navigation point for national regulators because it is neither consistent nor on a solid and consolidated technical basis. Some values are much too high.
Therefore it is recommended to abandon this publication and to incorporate a consistent and convincing basic concept of scope definition into the general ICRP-radiation protection recommendation without recommending specific values to avoid severe conflicts with national rights and responsibilities.