ML20043C110
| ML20043C110 | |
| Person / Time | |
|---|---|
| Issue date: | 08/01/1988 |
| From: | Cunningham R NRC |
| To: | Bernero R, Congel F, Dragonette K NRC |
| Shared Package | |
| ML20042C963 | List:
|
| References | |
| FRN-53FR49886, RULE-PR-CHP1 NUDOCS 9006040053 | |
| Download: ML20043C110 (30) | |
Text
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porOtsense perCommesmon a gMomemos por coneamen Svesse 6 Opeunes perveurtagennsmon esesee Osament inussenses Stanswo E C-JueWr W;IA&RES Please replace the attached with the copy that you received at the meeting on Friday, July 29, 1988.
3 Thank you.
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4s Do Not use this term se e Recomo of approvels. eenounences, anspassam otseenoes, and e6 miter actions PROM:(Nemo, esp.symmel, ApenerN)
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9006040053 891130 FDR PR CHP1 53FR49886 FDC
'! ANIS ATION DE COOPsR ATION ET h
CRG ANIS ATION FCR - ECONOMIC AND DEVELOPMSNT W
COOPERATION d.
DE ' OfVELOPPEMENT (CONOhflQUES AGENCE POUR L'lNERGIE NUCLt. AIRE / NUCLEAR ENERGY AGENCY i
REFtRENCE 38.he= W Susen r
1M16 PARIS Tel. 45 24 82 to I
EN/S/1527 22nd July, 1988 l
TO ALL MEIllttS OF TER CSPPE Princieles for the Exemption of Radiation Sources and i
Practices from Reculatory Control l'
As you will recall, the IAEA had agreed in 1987 to an BEA proposal, i
supported by the CRPPH, to hold a joint meeting on the above-mentioned subject 1
in order to solve a number of pending issues. This meeting was held in Vienna on 21st-25th March 1988 under the form of an IAEA Advisory Group.
f.
This new Advisory Group, which included three seabers of the CRPPil Bureau, as well as a few other Consittee neebers, reached a full consensus on l
a revision of the previous IAEA-TECDOC-401.
The final draft of the nov document, which will be published by the IAEA, has been edited in close co-operation by the NEA and the IAEA Secretariats and is enclosed.'
The active contribution of several CRPPH acabers, including the Bureau, and the full involvement of the NEA Secretariat, have ensured that the concerns and remarks expressed by the CRPPH, during its review of the previous version in 1986, have been fully taken into account. We believe.that the document is now in good shape for publication, and we trust that you will agree on this.
Bovever, if you have.any major difficulties vitle the document, please let me know as soon as possible. If I do not receive any reaction from you by 25th Auaust 1988, I will assume that you agree with the text of the document.
Yours sincerely, I
.s lari i
Deputy llead, Radiation Protection and Waste Management Division L
L c.c.: National Delegations to the OECD Dr. A. Gontalet Mr. G. Linsley L
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~;g PRINCIPLES FOR THE EXEMP110N OF RADIATION SOURCES AND h:[,
PRAC11CES FROM REGULATORY CONTROL i
- 1. INTRODUCTION 1.
The IAEA/ILO/NEA(CECD)/WHO Basic Safety Standards for Radiation Protection (BSS) [1], published in IAEA Sefety Series No. 9, provide guidanco on regulations for radiation protection, based on the recommendations of the i
International Commission on Radiological Protection (ICRP) (2).
These includo a system of dose limitation which contains three basic principles, namely, justification of a prectice, optimitation of protection and limitation of individual risk.
2.
The basis of regulatory control in the BSS is a system of notification, registration and licensing, which makes it possible for the competent authority to impose appropriete requiromonts for protection.
Varying degrees of regulatory control are described in the BSS. 1he highest of these is the full' system of licensing of operations involving radiation.
Below that is a system of general authorization, in which the precise details
-of the operations, including the locations of radiation sources and radioactive material and the number of users may be lost, but in whjch the competent authority still has a general appreciation of the national situation.
It may achieve this through notification and, possibly, r99nt'tation, such that the general features of the operations, the total amount of sources or radioactive material in the country, and the designs of all devites approved for distribution are known.
It may even require that 1.The term ' control' is used in this document to mean ' restraint' rather than ' checking or verifying' (likewise for to'all derivations from the team such as ' controllable', ' controlled', etc.)
i 13832
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. i' l controls remain on stme Cspects Of trurce use, e.g. that disposal must be in g
[I an approved disposal facility.
In some cases, even this level of control is
,, f not required, and there are then reasons for esemption from all the controls recommended in the BSS.
3.
The purpose of this document is to recommend a policy on esemptions i
from the BS$ system of notification, registration and licensing.
4.
When reaching decisions on the basis of radiological protection l
considerations about exempting sources or practices involving radiativn exposure, the competent authority should be assured that the risk and 2
detriment connected with the sources or practices will be to snell as not i
to warrent the application of the sy6 tem of notification, registration, and licensing.
However, the formulation of esemptions from regulatory control j
should not allow the circumvention of controls that would otherwise be applicable by such means as deliberate dilution of material or fractionation of a prettice.
5.
The authority will also need to take account of the probability and severity uf possible consequunces of accidents or mit;se.
Such consideration may contra-indicate the exemption of a practice, even if it gives rise to very small doses under normal conditions.
6, It is recognised that competent authorities may have reasons different from those concerned with radiation protection for either exempting or not enempting particular sources or practices from regulatory control. Moreover, p
u 2 The terms ' risk' and ' detriment' are used as defined in the IAEA Radiation L
Protection Glossary (3).
Risk is the probability that a given individual will incur any given deleterious stochastic effect as.a result of radiation Detriment is the mathematical expectation of harm (damage to health exposure.
and other ef f ects) incurred f rom the esposure of individuals or groups of i
persons.in a human population to a radiation source, taking into account nut only the probabilities but also the the severity of each type of deleterious effect.
l 7
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, 1988-M 30 c[
r bearing in mind the principle of justification of a practice (2), they may want to prohibit uses of radiation sources or radioactive materials even if the associated doses are trivial, e.g., for frivolous uses, or in cases where the choice of solutions not requiring the use of a radiation source or
. radioactive material is equally effective, Further guidance will be issued by the 2AEA on the application of the 7.
enemption policy outlined in this document. 64owever, it is the responsibility of competent vetional authorities to formulate explicit rules for application of esemption policies in their own countries,
- 2. BASIC CONCEPTS 2.3. The system of dose limitatien 2.1.1. General The system of dose litnitation is applied in the BS5 to the regulation B.
of practices involving esposure to ionizing radiation and which are rubject to Therefore, the exemption of a practice or source from the control.
requirements of notification, registration and licensing must be seen in the content of this system and the application of its basic principles must be considered when granting an esemption.
The system of dose limitation comprises theee basic elements:
9.
- justification of a practice:
- optimization of radiation protection; and
- limitation of individual risk.
Decisions on the justification of a practice usually derive from considerations which are much broader that those based on radiation protection 1herefore, these decisions may well be made outside the content of alone.
regulatory control (or enemption f rom such control, as in the case of it>e For these reasons, the guidance in this document is present document).
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focused on practices which are d6 fined as justified, and the principle of e4 justification is not considered any further in the content of exemption criteria.
j 12.1.2. Optimization of protection 10.
Once a practice has been justified, it is necessary to design, plan and subsequently use the sources of esposure involved in the practice in such a way as to ensure that " exposures are as low as reasonably achievable, economic and social factors being taken into account". This means that, although the doses to the most exposed individuals, as a result of introducing a source of exposure, are below the_releva'nt dose limits, it is still necessary to "optimire" protection, that is, to reduce doses to as low as reasonably J
achievable" 11.
A concept used in the optimization of protection is health detriment.
j Detriment is defined in footnote 2 on p.2.
In the consideration of exempt
-practices, the datriment will be limited to stochastic effects (cancer deaths and serious genetic offects) [1].
The health detriniont is assumed, for the purpose of radiation protection, to be proportional to the collective dose equivalont commitmont [1].
We will refer to this quantity henceforth, as the collective dose commitment.
The unit of collective dose commitnient is the man sievert (man-Sv).
The collectivo dose commitment, rather than simply the l'
collective dose, is the appropriate quantity since the operation of a practico in a given year may give rise to doses in the future.
12.
Several techniques are available to carry out the analytical assessments required by the process of optimization of protection.
The choice of the appropriate technique depends on the kind of parameters involved in the process and their degree of quantification. One of the techniques suggested by the ICRP when a full quantification of parameters is possible is differential cost-benefit analysis (12).
13.
In differential cost-benefit analysis, the monetary values assigned to
' increasing levels of radiation health detrimont saved, i.e. by reducing the naR doses, Dr compared with the cost of increasing the level of protection 1he optimum level of protection is achieved when the next increment of expense on
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protection exceeds the value of health detriment thereby averted. This
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correct allocation of resources in protection against ionizing radiation.
The IAEA has recommended a procedure of assigning a cost to the unit j
14.
health detriment so that detriment can be " costed" and compared with costs of protection (1).
It has developed guidance on the minimum value to be assigned to unit collective dose in the context of the control of releases of radioactive materials into the environment that have transboundary radiological significance [13) and has proposed for this purpose the minimum J
L figure of US$3000 per man-Sv (in 1983 prices).
2.1.3. Limitation of individual risk The limitation of individual risk is carried out by controlling the 15.
radiation doses in a group of individuals most likely to receive the hi_ghes,t doses from the practice.
For this purpose, the concept of critical group is introduced. This group is chosen to be representative nf individuals receiving the highest levels of dose from the particular practice, and is defined so that it is reasonably homogeneous with respect to factors that affect 'he dose received.
It is also necessary to choose the time when theso t
doses are at their mariumum value. The assessment then proceeds in terms of the average individual dose in the critical group.
Unless otherwise stated, through this document the term " dose" refers 16.
to the sum of the effective dose equivalent from external exposure in a given-period and the committed effective dose equivalent from radionuclides taken into the body in the same period, 2.2. Excluded sources and practices L
1 17.
In the BSS (Anner I, para. A.1.3), it is suggested that competent authorities do not regulate the following:
Devices producing X rays of quantum energy not exceeding 5 kev;
"(a) 1 1
1.
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mq (b)
Radioactive substances in the form in which they occur in nature l
without preparation intended to increase the concentration of radioactive nuclides".
18.
The phrase "in the fonn in which they occur in nature without preparation" requires careful interpretation.
Virtually all materials are radioactive, because they contain natural radionuclides or are contaminated with artificial radionuclides (e.g. from nuclear weapons fall-out), usually at very low levels. The nature of some of these materials and some other sources of exposure is such that control by competent authorities is not practicablo or even not possible.
Examples of these are potassiunr40 neiturally present in the human body, cosmic rays and radon out of doors.
Therefore, such sources are by their nature excluded from regulatory control.
19.
Although many naturally occurring sources are excluded from regulatory control, certain practices result in the inadvertent mobilitation and/or concentration of radionuclides, such that workers or the public might receive doses high enough to warrant regulatory control of these practices.
for example, radon daughters can concentrate in the air inside houses built on radium rich soil., leading to relatively high doses to the occupants breathing that air.
Other examples are concentration of nuclides of the uranium series
+
in phosphate fertilizers, building materials, mineral water factories, thermal spas, industrial uses of zircon sands, and coal fired power plants.
20.
Specific guidan:e for controlling practices that result in enhanced exposures to naturally occurring radionuclides is being considered
' internationally [1,4).
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- 3. THE DEFINITION OF PRACTICE AND SOURCE 3.1 General 21.
The term ' practice", usually associated with such terms a. " operation" and source", has been used very f requently in the last few years in radiation protection recommendations and regulations to charactorize the object of
specific guidance or assessment. Examples of this Cre t b definition of 1;
" justification of an operation or a practice", the concept of " collective dose per unit pfg3_jjf1", the "enemption of sources and practices from regulatory control", etc.
The guidance given in this report on the principles and criteria to be 22.
applied to exemption from regulatory control would be ambiguous and difficult to implement if a definition of what should constitute a " practice" and a
" source" in the concrete situations for which esemption is considered were not given.
'Ibe esemption principles recomniended in this report may be empeeted to 23.
find use in a variety of applications. These include, for example, the esemption from notification, registration and licensing of the disposal of certain types of low-level radioactive wastes in terrestrial and aquatic environments and the recycle of slightly contaniinated materials from the Also, in some applications the practice being considered nuclear industry.
for emenption may involve the whole cycle comprising the use and disposal of a In other cases, it er.ay be appropriate to consider the disposal source.
process itself as a separate practjee.
24 kt is clear, therefore, that the sources or practices may be of a however they should all correspond to the following widely varying nature; general definitions.
3.2. Practice 25.
A oractice may be defined as:
"a set of co-ordinated and continuing ge.t_i_vities involving radiation exposure which are aimed at a given purpose, or the combination of a number of similar such sets."
f Tne sire, scope and time duration of what is considerod as a I
26.
practice can bc different, depending on the purpose and the kind of radiation For protection assessment or regulatory action addressing the practice.
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i J.i enemple, these three features can be taken as different in the case of justification of the practice, or optimization Gf protection, or licensing or enemption of a given activity.
27.
In any event, when esemption from regulatory control is considered, the following features characterire any identified specific practice:
(a) the activities composing the practice should ~ be co-ordinated end aimed at a common objective; (b) the sources which are the object of the practjce should be clearly identified; (c) it should be possible to identify a specific critical group (or groups) uniquely linked tc the practice; (d) the dose to the individuals of the critical group (s) and the dose to the whole population exposed by the practice should not be significantly affected by other similar (or identical) practices (e.g.,
soveral waste disposal sites an tbo same region);
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the activities composing the practice should be easy to identify and describe, both in spatial and temporal terms, ar4d be sufficiehtly wel1 defined to facilitate impact analysis and regulatory assessments and to minimize the complomity of the procedures required for exemption from regulatory control.
I 3.3. Source 28.
The source can be defined as:
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"the physical __ entity whose use, manipulation, operetion, decommissioning and/or disposal, is a constituent of the co-ordinatea set of activities defined as ' practice' in paragraph 3.2"
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The " source" defined in this way is not equivalent to the " practice", but is the radioactive material, the equipment emitting radiation or containing radioactive material or the installation (or group of installations) producins or using radioactive material, which is the object of the practice.
3.4. Application 1
The application of the above definitfor,s to exemption from regulatory 29.
A few major cases control is liabic to be different for different practices.
are current 1'.of primary interest. They include the use of consumer products, s
the disposal of very Jow level solid radioactive wastes, the recyle and reuse i
j of materials resulting f rom decommissf oring of nuclear facilities, and the Examples of discharge of very small quantities of radioactive effluents.
to this
" practice" and " source" for these cases are discussed in the annea document.
t In the follo.ing sections, it is the exemption of practices which is 30.
this does not exclude the possibility of normally being considered.
- However, applying the exemption principles to a single source in some cases.
4, PRINCIrt.ES FOR EXCMP110N 4.1. General F rom a rad.ation orotection standpoint there are two basic criteria for 31.
detarmiting whether or no'. a practice can be a candidate for an exemption from the 855:
individual risks must be sufficiently low as not to warrant regulatory concern; and including consideration of the cost of regulatory radiation prottetion, control, must be optimited.
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' The first aspect is addressed by defining a level of individual dose that can
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be defined as " trivial".
The second aspect is usually addressed by usi g optimitation analysis technioues such as cost-benefit analysis, intuitive or formal, or other methods of analysis, t
I 32.
Under the assumption of proportionality between dose and risk, a given increment in the individual dose or collective dose will always result in the same increment in the individual risk or the collective health i
detriment, independent of other contributions to the individual or collective dose.
This maken it possible to assess the consequences of the exposure frva.
any arbitrary group of radiation sources, such as the group of sources subject to exemption from regulatory control, and to limit these consequences without consideration of oth&r sources..(plf@straLW$ However, in some instances the benefits derived from an enompt practice and the collective dose will bo directly proportional to the number of sources used within a practice, 33.
In consider 2ng the exemption of a par ticular practice from the radiological protection point of view, either a) the optimitation of practice, or b) the limitation of individual risk may turn out to be the mero restrictive factor, depending upon the nature of the practice.
34 In any event, it may be useful for the competent authorities.to havo guidelines about typical levels of individual and collective dose which are commonly believed-to be trivial and which can be used as a basis for
..in exemption without a great deal of detailed analysis.
35.
Some guidance is provided in the following on the derivation and i
application of these criteria and guidelines.
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3 The proportionality factor between dose and the probability of radiation r
induced lethal cancers and serious hereditary effects is taken to be of t'io order of md3nitude 10-2 per snevert.
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4 4.2. Individual related trivial risk 36.
In' individual related assessments, the concern is over the risk to which the individuals will be exposed. There appears to be agreement from it is many authors that, when considering a practice candidate for exemption, appropriate to apply the concept of a trivial level of risk, or dose, in a purely individual-related assessment: very small doses and the corresponding minute risk should not be of any concern for the individual himself or 'for the regulator in relation to the individual related assessment (1,b,6),
s 37.
f or the individual, therefore, there are two main considerations thet can be made in deciding upon a trivial level of risk or dose:
firstly, to choose a level of risk, and the corrosponding dose, which is of no significance to individuals; secondly, to use the existence of the exposure to the natural background, to the extent that it is normal and unavolcable, as a relevant reference levol.
4.2.1. The risk based considerations 30.
In the first consideration, it is widely recognized that values of individual risk which can be treated as insignificant by the decision-maker correspond to a level at which individuals who are aware of the risks they run would not commit significant resources of their own to reduce them [7).
1hi s is a difficult question to judge, because few individuals are conscious of tho magnitude of small risks and people have little opportunity to demonstrate their preferences in this field, There is likely to be a wide range of individual views on this subject and any decision is likely to leave some people feeling that they are exposed to risks calling for further control.
However, there is a widely held, although speculative view that few 39.
people would commit their own resources to reduce an annual risk of death of
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10 Most authors proposing values of trivial individual dose have set the level of annual risk of death which is held to be of no concern to the individual at
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Taking a rounded risk factor of 10
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invel of trivial individual effective dose equivalent would be in the range of 10-100 uSv per year.
4.2.2. Natural background radiation considerations i
40.
The level of natural background adiation has been estimated to give, as an average, an individual dose of about 2 mSv per year [11). This average conceals a wide variation due to different concentrations of radioactivo materials in the ground and in building materials, as well as differences due to different altitudes and habits of living. On a global average, about half of this dose is due to radon exposure, a source for which controls are suggested.
The other half cdmes frum esposure to cosmic rays, terrestrial gamma rays and radionuclides in the body, for which control is impractical.
41.
Individual mombers of the public do not generally take account of.tho variation in exposure to natural background radiation when considering moving from one part of the country to another, or when going on holiday.
It can, therefore, be judged that a level of dose which is small in comparison with the variation in natural background radiation can be regarded as trivial.
A figure'of whole body or effectivo dose equivalent of the order of one to a few per cent of natural background, i.e.20-100 uSv per year, has boon suggestod (9,10),
4.2.3. Conclusion of individual related trivial risk considerwt.hms 47.
The conclusion to be drawn is that a level of individual radiation dose, regardless of its origin, is likely to be regarded as trivial.if it is of the order of some 10's of uSv per year.
It is noted that this level of dose corresponds to a few per cent of the annual dose limit for members of the public recommended by the ICRP(2) and is much smaller than any upper bound set by competent authorities for practices subject to regulatory control.
4 The upper bound.is defined in Ref. [3] as a dose leve) established by a competent authority to constrain the optimization of protection fur a glvon source or source type.
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4.3. Optimiration of protection The trivial individual risk level is most helpful in putting radiation 43.
risks to. individuals into perspective.
In most practical situations, however, the regulatory need for an exemption arises in the consideration of source related assessments, where the total cetriment is the primary parameter of
- interest, In applying optimization of protection considerations to examining a 44, practice candidate for exemption, it should be borne in mind that the implementation of regulatory control may be costly in terms of regulatory time This f actor should be included among the paremeters considerd and resources.
in the optimitation assessment.
The assessment should address various possible options for regulatory control, from full licensing down to total exemption. The practice should be considered as appropriate for esemption if the result of the assessment shows that esemption is the option that optimites radiation protection.
In performing the optimiration i ssessment, the relevant quantity for 45.
the calculation of collective dosos should be the collective dose commitment oer year of oractice, since incremental costs for regulation will be incurred on an annual basis. The size of a practice, in terms of radiological impact, may also change from year to year.
For the purpose of neking decisions about optimization, the year of relevance is that in which the practice roaches its maximum size.
As mentioned above, the undertaking of a formal optimitation assessment 46.
involves some cost and commitment of regulatory resources.
It can, therefore, be argued that where, in the absence of further protection measures, the individual doses are " trivial" and the residual collective dose commitment is sufficiently small, the cost of performing the optimization analysis may in itself outweigh the cost savings in terms of a further potential reduction in health detriment.
In such situations, the rigorous use of cost-benefit or other method of optimization analysis would not be justified and the initial assessment of levels of exposure may be sufficient for a decision to exempt the material or source.
This is not because the levels of dose and health detrinent are of no concern per se, but because they are already optimal.
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Practical emperience suggests that the cost of formal optimlration procedures will be at least several thousand dollars ($,9).
The use of the IALA minimum value of the man Sv suggested in [13) would lead to a practice related ' trivial
- collective dose for esemption purposes of the order of a few man Sv.
For continuing practices this can be interpreted as a commitment of about 1 man-Sv per year of practice.
S. APPLICA110N Of THE PRINCIPLES FOR EXEMPTION 10 A SINGLE PRACTICE
$.1. Individual dose considerations 40, for the purpose of esemption, it was concluded that a level of individual effective dose equivalent of some 10's of uSv in a year could reasonably be regarded as trivial by regulatory authorities (see para. 42).
Because an individual may be esposed to radiation doses from soveral practices that may have been judged esempt, in order to ensure that his total dose does not rise above the individual esemption dose criterion, each enempt practice should only utiltre a part of that criterion, and it may be reasonable for national authorities to apportion a fraction of that upper bound to each practice. This fractionation could lead to individual doses to the critical group of the order of 10 uSv in a year from each omempt practico,
$.2. Collective dose considerations 49.
Each practice should initially be assessed as if it were to be subjected to a formal optimitation procedure.
A. generic study of the available options (including various kinds of regulatory action) should be made by.the regulatory authority and the conclusion reached that exemption is the option that optimizes radiation protection.
If this generic study, in its early stages, indicates that the collective dose commitment resulting from one year of the unregulated practice will be less than about 1 man-Sv (see para, 47). it may be concluded that the total detriment is low enough to permit exemption without more detailed examination of other options.
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'5.3. Other.- i.1derations 50.
Exemption is intendal for sources and practices which 'are inherently safe.
Can-ption must not be granted if there is a possibility of scenarios leading to doses in excess'of those specified in granting the exemption.
In considering the exemption ci e practice, the regulatory authority 51.
should aim to exempt the practice as a whole. Where this is not feasible (as
-in defining exempt quantities of waste from one of many= institutions) the authority should have regard to the implications of the total effect of these exemptions across the whole practice.
Ths, f ormulation of an exemption should not allos the circumvention of l
52.
controls, that would otherwise be applicable, by such means as deliberato f
dilutio-of material or fractionation of the practice.
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- 6. PREPARA1 ION AND ADMINISTRATION us iXEMpTIONS i
1 6.1. General i
In general, the methodology to derive an exemption will be based on the
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l assessment of the individual and collectivo doses that may arise from the practice candidate for exemption M )'.
If a generic assessment, at its in i
early stages, indicates that the likely consequences of the exemption, terms of radiation exposure, are below the chosen criteria, the authorities i
may wall decide to grant the exemption.
In cases where such a simplified l
l procedure indicates that doses are not below the criteria, more detailed I
assessments, including comparisons wit h other available options, will bo required.
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$4 In both situations, the assessment should be carried out using calculational models which take account of:
the characteristics of the practice to be exempted;
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the characteristics of the sources involved in the practice.
Sufficient-flexibility should be allowed in the choice of models and their degree of sophistication in order to avoid the expenditure of resources out of proportion to the task involved. Thus, simple deterministic models may suffice for the_ purposes of a generic study addressing a well definod case for' exemption.
More elaborate models will be needed in other situations and these can be deterministic, covoring in detail a sufficient number of exposure scenarios, and/or probabilistie, which 6re designed to provide a measure of the.uncertair.ty inherent in the modelling and the database used.
55.
The choice of scenarios should be such as to cover all the likely pathways and exposure situations that arise from the practice candidate for exemption. 1he national authorities will have to exercise judgement in considering exposure situations, associated with low probability of occurrence, in which the chosen radiological protection criteria may be exceeded.
56.
In general, the models will be required to provide estimates of doses to workors and to members of the public.
Both normal and accidental oxposuro conditions should be envered; the latter, although unlikely, may have consequences serious enough to contra-indicate exemption.
This conclusion may also apply to cases of misuse of sources involved in the exempted practice, and, therefore, the possibility of such misuse will have to be considered.
6.2, Specifications for an exemption 57.
It is important clearly to define the terms of the exemption so thet regulatory authorities and persons in possession of exempt material have a common understanding about what is exempted.
Exemption levels are rarely, if ever, expressed in terms of individual or collectivo dose, since these paramoters are not practical to measure at the operational level.
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s esemptions should be empressed in terms of derived quantities that are 9,
directly measurable so that compliance with the provisions of the exemption can be determined..For example, exemptions related to waste streams or recycle scrap are usually expressed in terms of concentrations of specific radionuclides. In the case of consumer products containing radioactive materials, the exemptions are often in terms of total activity of a specific radioisotope in the product, Approaches to setting the derived quantities using models may involve 68.
either an iterative process, whereby representative values of these quantitles are selected and modelling carried out to demonstrate compliance with the criteria chosen, or a normalization process, in which doses ars computed-corresponding to a unit exempt quantity, which subsequently leads to the evaluation of the total amounts of sources that may be exempted in a given practice in compliance with the chosen criteria.
In both cases, the ultimate fate of the sources involved,-and their likely reutilization, must be adequately covered.
In addition to the basic terms of the exemption, it may be prudent to 59.
make additional provisions to enhance the probability that the assumptions about individual and collective doses will not be invalidated and to minimite the possibility of accidents and misuse.
Examples of these additional provisions include:
a constraint on the total activity which may be released in a year from (a) a reaulated activity in a exempt waste stream:
the chemical and physical form of the radionuclides permitted in the (b) exempt waste stream as well as a specification of the origin or the nature of the waste stream, e.g. contaminated oil from reactor pumos; the chemical and physical form of the radionuclides contained in sealed (c) sources employed in consumer products, as well as design of the source and quality assurance requirements; i
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(d) the identification of the person or enterprise to whom recycled' scrap may be sold, e.g. an automobile parts manufacturer,-in order better to i
assure that.' recycled scrap will not enter products giving rise to high individual exposures during the period of first recycle.
6.3.'The transition from control to exemption 60.
-Radiation sources and practices involved in an exemption frequently pass from a stage where they are regulated, under a~ system of notification, registration or licensing, to an exempt status.
In other words, there is a transfer of status from being a controlled activity to an exempt activity.
61.
Once the conditions of an exemption are clearly specified, the next
'j step is to establish a method whereby the regulatory authority can determine compliance with the exemption conditions as transfers aro made m m a controlled status to an exempted status.
One practical method to accomplish this objective is to include in the regulated user's licence an authoritation i
to transfer the material to a recipient exempted from regulation.
1he
. application for a licence providos the regulatory authority with an opportunity to review in advance the procedures and methods by which the licensee will assuro compliance with the provisions of the exemption.
1 1
62.
The licence can contain specific provisions which also enhanc e compliance with the provisief5 of the exemption.
For example, the license can contain record keeping o.g.uirements which are subject to inspection.
In the case of contaminated scrap to be recycled, the license can specify the person or enterprise to whom the scrap can be sold.
In the case of waste streams, the license can identify a specific landfill in which the exempt wastes can be placed.
It can also contain reporting requirements regarding the amounts released under the exemption so that the regulatory authority can monitor the status of use of the exemption, thereby providing data for revalidation of the initi&l assessment which formed the basis of the exemption. While not
~
necessarily appropriate in all cases, these types of techniques can be used in the licensing process to botter understand and control the ultimate impact of the exemption.
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6.4. Retrospective review
' Finally, good radiation protection practice involves a periodic review 63.
of the original assessment which formed the basis of the exemption to
' determine if adjustments are appropriate. The-foundation of such a reanalysis should include reports of quantities released under the exemption, results of compliance inspections of licensees making the transfer from a regulated to ari exempt status, reports of misadventures with exempt materials, environmental sampling where appropriate, as well as testing of radioactive consumer products purchased on the market.
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F Annex 1
EXAMPLES OF DEFINITIONS OF SONE PRACTICES AND-SOURCES
.A 1, Consumer products lhe term " consumer products" covers a large variety of items of generel use that emit radiation or contain radioactive substances.
They include, for example, smoke detectors, time-pieces, static eliminators, optical lenses, glassware, electronic tubes, etc.
7he sale and distribution of a number of consumer products are subject in Member countries to notification, registration and, ofton, licensing, There may be, however, some types of consumer products whose associated radiation risk-and detriment are so small that their sale and distribution could be, exempted ~from licensing and, perhaps, even from notification and ~
i registration.
The general-definitions and conditions given in Sections 3.2 and.3.3 are expressed in the following way for consumer products:
The " practice" is defined as the sale, distribution, use and disposal of a given type of consumer product on a national scale (the
- 4 production of these items is considered as a separate practice, which is usually subject to regulatory control).
The " source" is defined as the total of individual radioactive sources represented by the single items of the consumer product being considered.
,L 5 For example, smoke detector;
' type' does not mean 'model number'
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- - W As far as-the correspondence to the features indicated in Section 3,2
-is concerned, the situation is the following:
t conditions a) and b) are obviously satisfied by the definition given hS 9 f9r the practice; condition c) can be fulfilled (the identified critical group can be a t
' specific group of users, a group of transport and distribution workers, or other);
condition d) can generally be fulf!11td. The other "similar practices" '
to be considered for the assessment of their fractional contributien to the doses associated with the practice under consideration are the sale and distribution of other types of consumer products; condition e) can be fulfilled without significant difficulties if the practice covers se type of consumer product. This would be more difficult from the technical viewpoint and complicated from the administrative viewpoint if the definition of the practice, in ordor to comply with condition d), had to cover several different types of consumer products.
A.2.' Low level solid radioactive wastes In principle, the activity being considered for exemption is tho disposal-of very low level solid radioactive wastes to municipal landfill, or incineration facilities, or into the sea at coastal disposal sites.
- However, it is approprie.e,for practical reasons, to deal with exemption from each site at which these operations are carried out.
in this case, the " practice is defined as the disposal of T he re f ore,
very low level solid radioactive wastes at a given municipal landfill, or incineration facility, or coastal disposal site. This includes the operation of the site and the period of its remaining in existence after discontinuation if two or more disposal sitos were located at a short of disposal.
- However,
. distance from each other and gave comparable contributions to the dose of a
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1988-06-30 *
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ll' i:q same_ critical-group, the practice should be defined to cover the combination 5((r,,
p.y of these disposal sites in order to satisfy condition d).
The'" source" is defined as the radioactive wastes disposed of in the considered site (or group of sites).
4 As far as the correspondence to the features indicated in Section 3.2 is concerned, the situation is.the following:
condition a) is obviously satisfied by the definition given here for the practice; condition b) may be less easy to fulfil.
Infact, although the definition proposed above for the source refers to the entirety of the
~
waste streams terminating in the disposal site, the regulatory authority could find it more practical to consider as the " source" the installation (or group of installations) from which the wastes are generated; condition c) can be fulfilled (the identified critical group can be the workers at the disposal site or a specific population group);
condition d) can be satisfied by a judicious choice of the site or sites to be included in a given practice and the installations from which the relevant wastes are generated; condition e) may be less easy to fulfil due to the potential. complexity and the variability of the set of installations ano waste streams composing the source.
It is to be noted that a practice defined as in this case could cover one disposal facility or a small group of such facilities out of a much
~
greater total number of potential disposal facilities existing in a country.
In this case, therefore, the national authority should apply the recommendation of paragraph 51 and take due account of the potential impact of the totality of disposal f acilities in the country when deciding on its exemption policy.
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According to another proposal.which suggests a full application of the above mentioned recommendation of paragraph 51, the " practice" to be considered for exemption should encompass the whole of low level solid waste 4
disposal activities across a country.
In this case, the " source" should bo lity of radioactive wastes disposed of in all sites in the
. defined as the tota country.
This definition of practice would certainly better comply with the recommendation of paragraph 51.
However, its correspondonce with the features indicated in Section 3.2 would be incomplete and the practical application of-the regulatory, assessment and procedures for excmption would be difficult.
In fact, as far as the above mentioned features are concerned:
conditions a) and b) would continue to be fulfilled:
It is, in condition c) would be very difficult to apply in practice.
fact, unlikely that a unified critical group could be identified for the comploy of disposal sites in the country; condition d) would not be relevant any further; 1
condition e) would be very difficult to fulfil in practice.
A 3.
Low level radioactive effluents In principle, the activity being considered for exemption is the discharge of very small quantities of airborne or liquid radioactive effluents from certain types of facilities where radioactive materials are produced or Examples of such facilities may include some radiochemical manipulated.
laboratories, research and educational institutions, hospitals, manufacturing or other industries, etc.
however, be permitted for installations such as Exemptions should not, nuclear reactors where the discharge may be at a low level only by virtue of l
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".% 0 the application'off t.ltirert.iem ~ and where there otherwise would exist the possibilityofasignificantrelease(para,fM.
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.(herefert,.MthkWi"the " practice" is defined as the discharge of low level, radioactive effluents into the atmosphere or the aquatic environment p
at a given site. This covers the whole duration of the discharge operations.
i If more than one installation 2. ore discharging their effluents into the same environment and gave comparable contributions to the dose of a same critical group, the practice should be defined to cover the combination of the
-f discharges from these installations in order to satisfy condition d),
The source" is defined as the installation (or group of installations) discharging the +ffluents considered.
As far as the correspondence to the features indicated in Section 3.2 is concerned, the following considerations apply:
conditions a) and b) are satisfied by the definitions given here for the practice and the source;
- condition c) can be fulfilled (the critical group is usually a specific population group living in the surrounding of the installation or having particular living or dietary habits);
- i condition d) can be satisfied by a judicious choice of the i
installation (s) to be defined as the " source";
i condition e) may be more or less easy'to fulfil depending on the features of the environment receiving the discharges and of the characteristics of the population exposed.
A.' A. Recycle or reuse of meterials Activated or contaminated materials (steel, aluminium, concrete, etc.)
resulting, for example, from decommissioning of nuclear facilities could be a
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recycled or reused without radiological restrictions if a regime of enemption
'?S were applicable to them.--
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In this case, the " practice" is defined as the set of activities starting from the release of the material'(or materials) out of the boundary within which regulatory control applies (for esemple, the boundary-of a nuclear. site) and _ including all the operations, manipulations and uses which lead to exposure of a critical group (or groups).
The " source" can be defined as the radioactive material (s) to be-recycled or reused or as the nuclear f acility(f es) releasing the material for recycle or reuse.
The scope of the defined practice and the definition of source depend on the features of those activities with reference to Section 3.2 and on the partie.ular exemption policy preferred by a national authority, If it is preferred, for practical reasons, to deal with exemption from each site producing material for recycle or reuse (e.g., an exemption for each nuclear power station to be decommissioned), then the " practice" would be defined lto cover only the material released from a given site and it should be made sure that the critical group and population doses relative to that practice are not significantly affected by the contribution of_ materials released (for the same kind of uses) from other nuclear sites in the country.
On the other hand, it could be considered that, because different materials-(e.g. steel, concrete, aluminium) are likely to be used in largely different ways and expose different groups of workers and population, it may be sensible to define each material as a different " source".
In this case, the-recycle and reuse of each separate stream of materials could be defined as a separate practice, because it would have a different purpose and would involve different exposure pathways and critical groups.
Moreover, some material (e.g. steel) released in one year could well add to the exposure of the same group (s) as the same type of material released in another year from a same site or group of sites, so the " source" could comprise all the material of one type from one site, irrespective of the time
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of its production and' release, and 'the " practice" defin! tion could. refer to-(,,
the' recyle and reuse of all that material irrespective of the time of its US '
production (e.g.. all' the steel from decommissioning of one or more power stations).
The correspondence to the features indicated in Section 1,2 can be seen in tho'following way:
condition a)- can be fulfilled for any of the above-mentioned possible definitions of the source and practice; condition b) can be more or less easy to fulfil, depending on the choice adopted for the definition of the source and practice; condition c) can be fulfilled with different degrecs of difficulty and spocificity depending on the definition adopted for the source and-practice:-
l condition -d) can be fulfilled by a judicious choice of the material (s) and site)(s) comprising a practice; condition e) can be more or less easy and complex to satisy depending on the choice of the material (s) and sito(s) comprising a practico,
- l Once again as for example 2 of this Annex, another possible proposal 1'
would be to consider as the " practice" to be exempted the whole recycle or reuse of materials going on-in a country,
]
In this case,'the " source" would be the totality of radioactive materials being recycled or reused, or all nuclear sites from which these
{
materials. originate.
Once again, as previously noted, this broader definition of the f
practice would certainly satisfy the recommendation of paragraph $1, but it would only partially fulfil the conditions of section 3.2 and-introduce difficulties and complications in the practical implementation of the t-regulatory assessment and procedures required for the exemption.
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REFERENCES
[1]
INTERNATIONAL ATOMIC ENERGY AGENCY, Basic Safety Standards for Radiation Protection, Safety Series No. 9, jointly sponsored by IAE A, ILO, OECD/NEA, WHO, published by IAEA, Vienna (1982).
[2]
INilRNAllIONAL COMM3SSION ON RADIOLOGICAL PRolEC130N, Recommendations of' the ICRP, Publication 26, Ann ICRP 13, Pergamon Press, Oxford,1977.
[3]
IN1ERNA13ONAL A10MIC ENERGY AGENCY, Radiation Protection Glossary, Safety Series No. 76, IAEA, Vienna,-1906.
[4]
IN1ERN4110NAL COMMISSION ON RADIOLOGJCAL PROTEC110N, ICRP. Publication 39
[5]
INTERNATIONAL COMMISSION ON RADIOLOGICAL PRO 1EC110N, The Application of Radiological Protection Principles to Radioactive Waste Disposal.
Publication 46.
[6]
OECD NUClFAR ENERGY AGENCY, Long lerm Radiological Protection Objectives for Radioactive Waste Disposal.
Exports report for the NEA Radioactive Waste Management Committee and the Committee on Radiation Protection and Public Health, Paris (1984).
[7]
Royal Society of London.
Risk Assessment:
A Study Group Report by the Royal Society, London (1983).
[8]
- BAKER, R.E.,
COOL, W.S.,
and MILLS, W.A., NRC Draft revision of 10 CFR Part 20.
Cut-of f level for Regulatory Concern (De Minin.is) p.17 (1983).
[9]
- CLARKE, R.H.,
FLEISHMAN, A.
The Establishment of de minimis radioactive wastes, IRPA 6th Congress, West Berlin, May (1984).
3
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[10)
MENHOLD, C.B.
Criteria'for a de minimis level. US Health Physics j
-Society, New Orleans 3-8 June (1984),
[11)-
UNSCEAR.
Report of the Unit 6d Nations Scientific Committee on the
-Effects of Atomic Radiation, Ionizing Radiation: Sou nes and-Biological Effects, United Nations, New York (1982).
'[12)
INTERNATIONAL COMMISSION Cid RADI0LOGICA;. PRO 1ECTION, Cost-Bonefit Analysis'in the Optimization of Radiation Protection.
Publication 37 (1983).
[13]
IN1LRNh110NAL ATOMIC ENERGY AGENCY, Costing Transboundary Radiation Exposure (The minimum value applied to unit collective dose in dif ferential cost-benefit analysis) (1984).
[14)
- IRAVIS, C.C.,
- RICHTCR, S.A.,
- CROUCH, E.A.C,, WILSON, R.,
Kl.EMA, D.,
" Cancer risk management". Environ. Sci lechnol. 21 (1987) 415-420.
[15]
SPANGI.ER, M.B.,
"De minimis risk concepts in the US Nuclear Regule!' s Commission, Part 1: A's low as reasonably achievablo", Project Apprejsal 24 (1987) 231-242.
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