ML20149L578
| ML20149L578 | |
| Person / Time | |
|---|---|
| Issue date: | 02/22/1996 |
| From: | Cool D NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | Ilari O FRANCE |
| Shared Package | |
| ML20148P089 | List: |
| References | |
| FRN-61FR65120, RULE-PR-20 AF31-2, AF31-2-040, AF31-2-40, NUDOCS 9602270266 | |
| Download: ML20149L578 (29) | |
Text
.
AF3l-2 0; Ilari February 22,>1996 LOECD Nuclear Energy Agency J2 DR.
Le Seine St-Germain 12, Boulevard des lies
,92130 Issy-les-Moulineaux
~ France t
Dear. Colleague,
^
I am responding to your letter EN/S/1811, dated September 25, 1995,' forwarding the Report on Dose Constraints-and Reference' Levels for our review and approval. We have reviewed the report, as requested.
~ The U.S. Nuclear' Regulatory Commission.is considering the concept of dose constraint in a manner different than envisioned in the report.
For instance, NRC has proposed to establish a constraint of 10 millirem p;r year'for air-emissions from licensees other than power reactors.
This constraint would be applied to existing licensees, as well as future licensees, so its use is not 4
entirely " prospective," as the report recommends. Moreover, NRC's proposed s
constraint on' air emissions corresponds more closely to the "a~uthorized limit (AL)" described in the report, than to the meaning of " dose constraint" as a
used in the report.
In fact, on page 3 of the' report, effluent discharge is used as an example of an " authorized limit." As another example, it is highly z unlikely that NRC would ever apply dose constraints to the case of medical exposures of patients, because that would far exceed NRC's scope in regulating the U.S. medical community.
l Because NRC may apply dose constraints in a manner different than described in the report, it is inappropriate that we offer our endorsement of the report.
At the same time, we do not want to stop publication of the report, because we believe that the document offers valuable descriptions of concepts important to the radiation protection community. Thus, we abstain from approving the report.
In reviewing the -report, we did develop a number of comments that we offer for e
your consideration in finalizing the document. These comments are offered from our own perspectives in the use of dose constraints, so they should be considered.in that-light. Our comments and a mark-up of the report are provided-as Enclosures 1 and 2, respectively.
I Please contact'me at (301) 415-7197 if you have any questions.
We appreciate the opportunity to review and comment on the report.
Sincerely, DonaYdId.Yool, irector
)
g Division of. Industrial and Medical Nuclear Safety Office of Nuclear Material Safety and Safeguards-
Enclosures:
As stated' Distribution:11845-5134 :
Centra File IMDB r/f.
NMSS r/f-IMNS r/f
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CRaddatz,.RES-SSherbini CEstep 00CUMEN 8:NEAD00.SWM Cm ments coordinaued with CTrottier and CRaddatz. RES.
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l' COM4ENTS ON PROPOSED CRPPH REPORT ON DOSE CONSTRAINTS AND REFERENCE LEVELS
-j
- 3 i
[
! General Comments:~
f
(.
.The Executive Summary should be shortened.
1.
1 k
2.,
The paper unnecessarily complicates radiation protection.and "as low as
.is-reasonably achievable" (ALARA). ALARA has' been successful in reducing doses to small fractions ~ of limits. The suggestions in this paper do not reduce doses, but do reduce flexibility.
They may be a significant detriment to radiation protection.
l t
3.
. All' reference to' medical exposures should be deleted from the paper.
- Physicians and patients should make these judgments on dose benefit / detriment on a case-by-case basis.
l 4.
Consideration should be given to replacing the term " authorized limits" with a different ters. The term " limit" connotes a regulatory requirement, which does not appear to be the intent of the term.
5.
In referring'to dose to the critical group, the ICRP verbiage should be used, 'Mt is, " dose to the average member of the critical group" instead of "the mean dose to the critical group," as these terms may not be mathematically identical.
Further, the change from the ICRP text l
will cause_ confusion as health physicists attempt to discern:the reason for the changed language.
Specific Comments:
I Page 3 Paragraph 3.
Last sentence.
Replace "he/her" with "he/she."
Title 4.
Revise the title to state:
" Authorized Limits,
i Operational. Guides, and Reference Levels."
Page-4 Section 5, paragraph 4.
The sentence "Due to the spread of l
+
exposures in different fields of application of radiations, there i
is no possibility to establish a generic constraint for workers,"
should be replace with the following sentence:
"Due to the variability of exposures in different fields of applications, a generic constraint for workers is'not recommended."-
Page_8-Paragraph 4.
The paragraph is not clear and should be revised.
. In particular, the first sentence is incomplete.
Paragraph 4.
Move the parenthetical acronym (BSS) to follow the tern " Basic Safety. Standard" in the second sentence.
Page 9
.Last and secor.d to last paragraphs..The subject of the verbs considered, revised, and appeared is not clear.
l
' Paragraph'1.
It is recommended that a direct. quote from ICRP be Page110'
.added,to:the paragraph to support the statements presented.
I.
v
..~
Page 11 Paragraph 4.
The presentation on dose constraints goes beyond ICRP-60 concepts and as such should be revised or deleted.
Page 12 Paragraph 1.
The paragraph appears to suggest that all facilities achieve doses similar to the hypothetical "well managed facility" in addition to meeting generic source, task or practice constraints.
This requires performance of multiple analyses to determine if low doses are low enough.
This concept should be justified by a cost versus benefit analysis.
Paragraph 3.
The paragraph says that in some cases, no further optimization need be considered once ~a constraint is established.
This ignores potential improvements in technology or differences in achievable doses for individual facilities.
It is recommended that the text be revised to address potential improvements as a means of reducing dose.
l Paragraph 4.
Replace "he/her" with "he/she."
Page 13
. Paragraph 1.
The sentences in italics are confusing.
- Also, setting the source upperbound and the dose constraint for a source at the same numerical value results in no added protection, beyond the amount of the dose limit apportioned to the source. Thus, it would imply that generic optimization and experience have no
)
effect on reducing the dose constraint.
These sentences should be J
revised or deleted.
Page 14 Paragraph 4.
Insert the word "are" after Investiaation Levels in Section c).
In the parenthetical in the sixth bullet, delete the word "than."
Last paragraph.
Insert commas after " dosimetric records" and
" recording level" in Section d).
Page 15 Paragraph 4.
The last sentence of Paragraph 4 should be revised to read "A too restrictive public dose constraint may have a negative impact on occupational exposures."
Page 16 Paragraph 5.
Revise the first sentence to state:
"Due to the variability of exposures in different fields of application, a generic constraint for workers is not recommended."
Page 17 Paragraph 6.
The paragraph states that investigation levels would require a regulatory system for collation of dose information on a natiaal basis.
Supporting statements for this statement should be added to the paragraph.
Page 18 Paragraph 1.
Revise the last sentence to state:
... which, in fact should never..."
j i
7
lb Paragraph 2.
As mentioned.on the Page 13 comments, setting the dose constraint at the allocated fraction of the dose limit does not afford _ adequate protection. While the dose constraint will always be bounded by the apportioned dose limit, the text should be revised to indicate that generic optimization and experience should cause the dose constraints to fall below the bounds of the apportioned dose limit.
' Paragraph 4.
Revise the last sentence to read "If the investigation level is exceeded, a review of the circumstances that led to this situation may be appropriate to make sure that future discharges will not exceed derived constraint values."
Page 21 Paragraph 1, last sentence.
Change " common sense" to " care."
4 Paragraph 2.
Delete the reference to " medical domain."
Paragraph 7.
Change "a useful tool"' to "useful tools."
i r
s 1
3 i
AEN AGENCE DE NCMMTNEM NUCLfA;RE
'c""^"""^"
. NEA
Reference:
EN/S/1811 issy-les-Moulineaux,25 September 1995 To:
All members of the CRPPH All members of the Expert Group on Dose Constraints
Dear Colleague,
EXPERT GROUP REPORT ON DOSE CONSTRAINTS AND REFERENCE LEVELS Further to my letter EN/S/526 of 15th March 1995, the draft report that the CRPPH had examined at its meeting of let - 2nd March 1995, was submitted to another round of comments from CRPPH j
~
members and the Organisations of the 11SS Joint Scaetarist that had been invited to cosponsor the document.
The Chairman of the Expert Group, Dr. Kraus, in consultation with me, has prepared a new j
version of the draft that tries to accommodate as much as possible the comments we have received. A review of these comments " Explanatory Remarks to the 5th Draft of a Report of a Joint NEA/ CEC Group of.
Experts", prepared by Dr. Kraus, is attached for your information and to explain the rationale of the changes made in the document. 'the attached final draft of the report is now submitted to you for a final reading and approval by correspade= All changes from the previous version of NEA/ SAN / DOC (95)1 are findicated by the strikethrough of the parts which are deleted and by italics for all the parts which are added or snodified.
In the meantime, the draft is being forwarded to the CEC for the requested fortnal submission to their Article 31 Group, as well as to the IAEA and the PAHO which have expressed interest in co-sponsoring the report.
l 1
As soon as all these consultations are concluded, we intend to proceed to the publication, which is now long overdue, if I do not hear from you by the end of October, I shall assume that you agree to the publication of the report.
j l
. lhank you for your cooperation.
j i
Yours
- ely, f
CC:
' National Delegations o the OECD Encts.
Le seine se-oormaan 12. sousevard des ses 92130 issy-see Mowneaux r,ance Tot: (331)es 34 82 00 Fac (Sa-1)45 2411 to Telec 44004: Electronic mar: NEASFRNEA551
~. -
I o
ORGANISATION FOR ECONOMIC RESTRICTED CO-OPERATION AND DEVELOPMENT Paris,drafsed: 25 Septernber 1995 NUCLEAR ENERGY AGENCY OLIS:
dist:
i NEA/ SAN / DOC (95)1/REV1 English text only l
COMMITTEE ON RADIATION PROTECTION AND PUBLIC HEALTH Dose Constraints Operadca 1 Re:::riction:;
and Reference Levels
' (Report of a Jomt NEMCEC Group of Experts)
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EXECUTIVE
SUMMARY
2 1.
Introduction
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The conapt of " dose constraint" was
,,"d'y introdumd in ICRP Publication 60 as an i
additional mndition to the <=*i=8 **= of protection. This concept, however, is not new and its introduction d..W. rather, to an attempt to consohdate and ratinnalim a variety of concepts that were already existing in previous ICPJ guidance.
Moreover, whest the phase of protection planning for a source or practice or task is terminarut and the operational phase is started, it is appropriate to establish some practical level. Operenenal corresponding to values of memnnred quantities above which some l
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specioc action cr dutaion is to be taken.
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2.
Gamespe-ef Dame Constraint lhe objective of a Dose Constralpt is to be a ceding to the valum of individual doses from a source, practice or task whkh could be deesmined to he acceptable in the process of r9simienrinn of prnaudna in other words,' a Dose constraint is the value ofindividual does that shouldis sapected not so be a=raariart in the preitcaed individual dose distabution ennsidaed in the npalminasina process.
It can be established based on the results of a genede nprinusasinn or on the W from 4
well managed comparable operadons. Its we is.amegabs, being appened in the planning of protecdon in all situanons whese opei=<==ar= d prnsareinn is involved, e.g. In me design or.madiarmelons of plants, in the preparation of an operation, etc. Although it is espressed in terms of individual dose, it is a source-reisted quantity which remors no se source, practice or task so whke me tr n*= inn process a
is~being applied.
Once me ar=*'nn under nr==r=a= is made and me ar**n*a'i proaa'*an opdon is " alar 5a'i, it wm result in the choice of a leve of done ansar a duived quaesity to be used as e ?
t-6 Mie4e the value (or set of values) against which the design features or the OPassional perfbrmance me embejudged.
Dear values Asw. thereibre,
a gaggmaba character.
Although the constraint is pdmarHy expressed as an individual dose (Dose Constraint), it may also be expressed in terms of corresponens omtved operanonal quananes, such as an==i radioactive Y '
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Dame Constraint and Dese IJmit
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The Dose Constraint has the Ametion of setting a restriction on the dioice of protection options in emimina and does not have the nwaninF of a statutory limit. It shouki not be mahased with the Dose IJmit, which is a person-related quantity having the statute of an institutional barrier to the dose that ap individual could receive from the whole of practices to which Igcan be exposed in the T
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In this she case of nwelimI caposure, the concept of Dose IJmit does not apply, but the concept of Dose Constraint in optimisation in piaciple does apply. However, the practical implesnentatinn of 1
this concept is difficult because of the need to allow for the possibility of-Saa a constraint for a single patient if desired diagnostic information or therapeutic effect is otherwise not achievable.
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'Iherefore, the constraints in the optimiention of tnedical procedures on patients einM not be seen as rigid tipper boundaries to the process of apeia"--daa. but should rantwr have the meaning of GMann-l levds selected by appropriate proframinnal or regulatory agencies auf used - " ; - " -- * :::'
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NEA/ SAN / DOC (95)1REV1 i
J PREAMBLE i
- Ihe 1990 Reenmmendarinne of the Internadonal Comminaion on Radiological Protection 3
(ICRP Publication 60) propose a system of protection based on the Ituee prindples'of JustiScadon of a practice or an Amervention, Optimisation of protecdon and Danitadon ofindividual dose / risk.
j The concept of " dose constraint" was explicitly intrrwhired in Publication 60 as an additional i
condition to the antimia=*'on of protection. This concept, however, is not new and its introduction f
sm aipacds, rather, to an attempt to consolidate sad radnnalire a variety of concepts that were already existingin previous ICRPguidance.
Moreover, when the phase of potection,ntannine for a source or practice or task is terminated and the operational phase is started, it is appropriate to establish some C
- r.^.'."s;.M ; =d r
-.-.: z;;L; practical levels (Authorized Umits, Operational Guides, Reference levels) corTesponding to values of measured quantitics above which some specific action or dedsfon is to Le taken. ' It is to be noted that the name Reference levels is also applied by the ICRP to action levels and l
intervendon levels of certain manaured or menaseed quantities which, if eveerdad in meridantal or other unplannart exposure situadons, can trigger n'enerhal ac2 ions. 'Ihis report, however, only deals with the ai cf those reference levels esseerning which eply to the normal operspion of practices.
During the dimenesions carried out internadonally ; for the preparation of the pH. % IAEA/NEA/WHO/ILO/PAHOfFAO Basic Safety Standardsg Pinnaceann against lonAsing
- Ibis
,i - k.
-a n-n-
g 1__-__
- ____.g L r_
-"e"=
uppenhemnNRa[liation and the Safety of Radiasenn of the CEC " ' " _'a 985 j
i Stundnes. for the Ptnaartinn of ther Healtit of workers and the Public against the Danger Arising som lonising narna. inn (EURA'IOM Direcdwn i st appeared, howenr, est these concepts of Constraints and I.evels were far Aom enjoytag ibil understanding and homogensons interpretation of their meaning and Application in the regulseory and operational dnmaine '
'Ibe NEA cammienna on Radiation Protectim ami Public Health (CRPPH), therefore, decided in 1993, to set.up an Empert Group to deal with'this_ saatter i
._z
,. m,,,,
,,,,,,,,,, g j
ladinchad by the CBC,'It was also decided that eis Expert Groep abonid bejointly sponsound by the two i
ne semis o6fecahw of she aqperr Gro, war so~metow and elaborane the concepts.cf
-Dose Ommeraints N Ashoriand Useier, CF.-^'dGuidss'and Retrence i
Levels, daritytag their meaning, segulatory role and scope of appilcation ibr dif5erent types of prartir=
and expossue situadonal in this context, es assess the asemeinna of thene concuges with the concept of i
. Dose Unit and amendar how the'reguistory use of the Dose 1Jmien is men = read by the instruhirvinn of Dose anseraints imo the system of prreada=
r j
l l
6 6
9 4
8
9
~
NEA/ SAN / DOC (95)lREV1 2r Te-Maa It aus recognised that the definition of practical criteria for the' establishment of immerical values of Constraints and levels (in terms of dose or appropriate dedved quantities) for the different types of practices and exposure situations should be more qppropriately droit with by the
. IAEA and other internatwnal organisassons in their respective areas ofexmqpetence.
&,i T,
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r ='r. J ';,- r":2 2:=' =.
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~
1.
DOSE CONSTRAINTS As mentioned before, the concept of dose constraint is not completely new, but is rather the result of the consolidation and rationalization of some concepts which had been progressively intmduced in previous ICRP guidance.
1.1 Before4%blientien4GIF60 7he Develooment of the conemor o/Do.ne con.rrraint Prior to the issue of ICRP Publication 26, in 1977, the pnmary she of the CmmiMoe's remmmenrtarinna was to puutect the individual and, therefore, the emphaels was put on the person-related Mauermim Permissible Dose or Dose I.imit. *Ihis conczpt had, at the same time,*a gmgim2irc meanirig (for planning of protection in a practice) and a starnspective meaning'(for demonstration of man 88-~* with meanutory limits).
Progressively, =naHa=* with the done, limits.was and the concept of. <3. w:nn of protecnon began to be intrnrhvert intoally in Publication 22, of 1973, and, then, more formally, in Pubilcadon 26. 'this implied the inernrhreina of the. approach of sourco retarM N
mana==manen and prrearvion, and the need to introduce limitations to the dose to individuals 80m a given MN g7 acurce. In this context, the concern was raiaM that the distributions of beneSts and detriments fi )
considered and compared in the nrwi=ivatina process are not usually the same in a group of persons Q
N
)
- exposed. ' Ibis may create inequity in that the mnhination of these estrpmelana conssprmrtinF to the
\\/\\h.
optimum rrdiervive beneSt could result in rinare to some individuals wtich are not enreprehte.
It waL themfare. finit that a distribution of beneSts could be used in an agehnteseinn memessment to justify a distribution of detrimemen only if the detriment to cadt individual jg HmhM to Some ma=Imum value regarded as acceptable by modety. "Ihe concept of nnnstraint to ageln*=eina although not yet its name,-was, therefore, aheady included in the 1977 ICRP Ramanwsutmeanna, At that time, -
however, the value of the Dose Limit was seen as the only constraint to opetminnairm 6
9 4
_ _. ~. __
(.
NEA/ SAN / DOC (95)1REV1 A
T'L L e t._ _.
- _ _ fre n ra j
60 redefined the concept of Dose Umit as the lower boundary to
- A unacceptable risk. With this de8aition, the Dose Umit no longer ex)uld be seen to provide an adu===w restricdon on the possible inequity in the distribudon ofladividual doses resulting from the process of ar h apd""'ad= of protecdon. ~ 'Ihe concept of Dose Constraint was, therefore, explidtly introduced. By b
g,o analogy, a concept of Risk Constrafat was also intrndivwf igPnhaiention 60 in the area of control of the M
so called " potential exposures".
IcRP 4
j The principle of nr*1'al== don of protection is formniatut as follows.by the ICRP: "in relation to any particular sount within a practice, the magnitude of ladividual doses, the ranmher of people emp=d. and the likedibood o(incurring exposures where these are not certain to be received should all be kep,t as low as reasonably achievable, economic and social factors being taken into account. This procedure should be constrained by restrictions on the doses to ladividuals (dose constraints), or the I
risk to individuals in the case of potential exposures (risks constraints), so as to limit the inequity likely to result from the inherent economic and social jiutymants" (ICRP Publication 60, paragraph 112).
Hena, it appears clear that the concept of source-related dose constraints applies to the opumisation of protection for practices, in which the source is controllable, but not for :---Mons in situadons such as, fbr example, exposure after an accident.
Potential exposures are those that may, or may not occur. 'Ibe prnhahility of occurrence and the magnitude ofits ennenjwevvm have to be mamidned. However, the work of the ICRP in this area is
, still in its early stages and only general guidanm has been given. In contrast to dose limits, no risk i
. limits are cannmmand=1 It is not yet clear how risk cx)nstraints as mandanad in the ICRP nrineinta of i
optimintion wS1 be used,'since there are great damnades in de8ning powwimes fbr the oprimiention of j
safety of sources to prevent accidents. 'Iherefore in this paper, risk constraints are not dimenanwt i
1.2.
C ---- : -- "- " af " r
- = = in the - "
1.2.1 Conceptof Done Constraint
'Ihe objective of a Dose Constraint is to be a ceding to the val'oes,0findividual, doses from a source, pmcsice or task.whida could be deterndral to be acetytable $1 the process of apninisadan of
~
protection ibr that source, practice or task. In' otter mrds, a Dose Constraint is Gie'vaine oflindividual dose that shonid ir aspecand not so be armadad in the ptwared individual dose diairenesan maandared j
in the ngelmiennna process, 4
4 y
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.2 -
, _J 1,;
~
"5 L c _ ^ ' - M::: b -
' 3;" ; -
,L Wester its use h prospessivut betag appued in the plannlag of prnearnian in su situatkins where i
ap88mi=*86= cf preencdon is U ia, e.g. in the design or undincannns of plants, in the preparation of an operadon, etc. ' Although it is capressed in tens of intRvidual dose, it is 't sonroe selseed quantity whids refers to the ar
, pracsloe or task to v.tl:h the opriminadan process is betag appiled.
e 4
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- - =-
-~
l NEA/ SAN / DOC (95)1REV1 i
Once the nprimirneinn under constraim is made, the consinmit ceases to be operamonally
~
l relewsit and the rgelmised protection option it-aalassaA-it will result in the dioice of a level of dose
)
i and/or a derived quantity to be used as & ^ - ' '^^'y = e,
_ - 'seetriction-Dis 44he value (cr set of values) against whidi the design features or the operational per*u== are to be judged. 7hese values have.h'sno, a gaggggabs cher ii.
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. 1.2.2 "Ihe role of the Dome Constraint in the onfimbrinn promss
."Ihe Dose Constraint may be related to the protect on o persons against. exposures from a i
f l
couplete practice or from any part of a practice which is subject to optimisation,i.e. exposures due to:
a source such as a simple small one, a single machine, or a big installation;
=
a set of sourcesin aninstallation; 4
a particular task in connareinn with a source or set of sources, or a complete i
job, sudi as a specified mainamiance task, or a group of operations in a j
8Pedfac type ofindustry.
j la cedi case, those who establish constraints maast clearly describe the televant source and the magnitude of the constra'at senacead should be appropdsee to the purpose in hand.
A design or work procedure involving exposure of workers 'or manhas of the public to
. radiation wiu give rise to a distribudon of doses, and thestfore of desriment, and else usually to a d@rrent distribution of hansmen :' _.. _, i:.
. '- ^ ;- ~-"-~=5t 2:1 g
n_.
g
._..~
g.
y 3 -- gg y-y _ &_. 7--a 7
..m m.-
, 'Ihus, the Dose Constraint, as miling on the prec5cted individual doses in the dose snti-aaa9amid.,
.stributions resulting hem the aftlement options segssded considered during the,-
' ^' - process, k0,jo..
le meant to be used to restrict the inequity likedy to result tosa she above-mansioned.dgerence of o4 W,
dssrbnent and benefit distribuelone withm the exposed groep ofpeople.M p 49-
.p L
-_ _; e r,
. j in.ddidon io diet e to re..stribudons or beneses.and amerimanen Dom one source, practice or task, miceher Aind of 6esgedty Die-de-that susulting assyLresadt Bom practices of a same or almilar kind besag'theracterised by difament leruels of protection, wheueby a pracsics amids give rise to bisher ladividual (and perhaps coDessive) doses than a comparab e practice, if the & Dom well managed operseloos shours that a' givest level of preantvinn is practically addeved, thee are no a priori geasons to suggest ac,:spt for a similar practice a
- : = individual doses higher than gudesse shose addeved by the above-
~
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b k-NENSAN/ DOC (95)1REV1 memrinnati operadons. This roodod ansistency pfprotecaon Lewis between the two sindarpractices can be achieved by an appropriate chosce qf the Dose Constraint.
On the basis of these consideradons, the dioice of the value of the Dose Constraint for a given source, pracdce or task can result from one or a combinadon of the following approaches b8'N M 4 use of the nW of udi managed operation of practices or sources of the
~ heJua%ed iAmN same kind; eas+ w.bru44
- analg, use of the result of a generic up--- -- - Os of protection for the source, practice a
or task being considered-I' It should be stressed again that the applicadon of dose constraints puts emphasis on individual doses in the n,rvimimion of protection. Restrictions on collective dose per unit practice, which are used in some muntries in tenns of man Sv/GWa for nuclear power generadon or of collective dose per task (e.g., for fuel reloading in a nuclear power plant), are not dose constraints as discussed here. Such q
restrictions may be useful, and are indeed used in certain examtries to reduce the total and the average caposure of a group of workers Because, as it was already said, the nnnerraint is a ceding to the predicted individual doses in the opdmiastion, the actual npriminasion process has to be carried out in the region of individual rinnaa i
gu @-
below the Dose Constraint. Prne,rvina options remiting la individual dose disedbutions which indade L ggg values annariing the Done ennenraint ahmM be 88dminmaari tom the opumisadon process, which will gg gp - t nnemi=* to be applied among the semaining opdoes, However, these may be cases whese no additional M "t* b'"
- eftbrts for npriminarian are need to be made aner setting a Dose Constraint. Pardcularly fbr simple sources this might be a justified approach.
3 2.3. Done Constraint and DoneIJmit 1
It is important to recognize again that the Dose Constraint has the 'fhntving.cf setting a
,sestdction on the rhnine of protection options in apriminar6nn and best does not have the meaning of a statutory limit. It ahmM not be confheed with the Dose IJmit, whidt is ~a roo.nM cpantity having the statute of an tantitwinnal border to the dose that an individual conki secelve Bosn the whole
, of practices to whidt he$ned'can be exposed in the present and Azeseeable fbture.
N
'!he evolution Dom individualcisand to sourendeaed per*wwian Enhed,with One fbrmal j
intrrwkuttan of @minatinn in the 1970s gave rise to die' concern that the an=hinerinn.cf exposures hout several sources to the same individual could asceed the Dose'1Jait. '1his opeoarn was particularly sedened to the npnanre of manhn= of the puhtic Acnimultiple sources. The response to this was the proposal, developed dadng the 1980s, that es esposure of ladivideals Acen endt given source should be limiend by a Raction of the Does IJatt (emusd he she pasr " source-relased dose apperbound'*) sudt that the mm of the contrihudons of the exposure of those individuals Roni several sources cooki nat nenwri the Dose IJmit. 'Ihis apportionment of the thnit belongs taithe pdadple of 12 9
w o
e wm
=
v w
_m t
P t
i NEA/ SAN / DOC (95)IREV1 limitation of individual dnera and is tv==enarly different from the establishment of constraints for the l
oprimination of glven sources in seleckng a constraint the existence of a source apperbound should be taken into account However, this does not prevent Ant the' source q;--:ac: ' and the dose l
hf
. /
r constraint for a given source hagh same munerical value, if ;; ' .' ;;; b; - + = ' t; ho q
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1.2.4 Oiimatities for constrainte
,g grimarily the Dose Constraint is expressed as individual dose. In the case of public exposure, gpg/
this is th(mean dama to the critical aroup for the source or pracsim rymmedraed. It may also be y 7 C-expressed in terms of conesponding dedved operadonal quantrica such as annual radioacsive rmiazion gM.
60m a nuclear installation, caposure rate from a radiation device, ; ": "; -
1
-- ;; ;. ; ; -- -- oc. For these values the general term'"Dedved Constraint" is seenmmendad.w sonne exposure arvm and
.._m I
assumptions on exposure pathways shall be used for the meaMwanent of the Derived Constraints as for the aprimination process. Howeker, Derived Constraints may'also be disestly **=Mishad direcdy by investigating the =p=4== Dom wen managed opaminna 2.
PRACTICAL LEYELS i
As it was meadoned in k hm c---
k'
" --- W ' W ts,
^ * - - '
Operamonal Guides and Reference levels are values'of madamed or=====ad gnanths whidi, if
=madad in the operation of a practice, require some spedinc sisten or darinian to he'taken. 'Ibey are established as a result of oprimiastian and, in view of their retrospective use, are conceptuaBy ofkrest 60m the (prospeczive) donc constraires. Although these values are moent to tdsger actions if they are amadad, they may or may not mrrespond to regulasary requhmmrawn These levels can be expressed in terans of dose or done rate, but more citut in terms of derived quantitles (temenity of radiadon fleid, activity enn=aration, etc). *Ihey can be of the ibDowing types:
_- g 3,
j 4
-..m
..m_____
m___
__ __ m
-w
,.=
w wy w
+
13 o
N
4 NENSAN/ DOC (95)1REV1 3
a) psamadhad-levela Authorized Umits on opandon indicators, for awa-de on dscharge of eithseats, proposed by the operator / licensee and authorized by the licensing authorides, or directly estabushed by the regulatory authorides and-Ihey are uJually attached to an authorizadon as tedmical t
i preecr1pdons and are essentially used as checkpomts to assess congplumce with established restrictions on operation.
L b) '
Opendenallevain Guides related to of spedfic paramrears, estabildned by the management fer asintarnalune restrictionsfortheproperconductofoperations.
In view of the fact that the C
":x '
'il Audomed hmits are fixed on the basis r
of the results of opdmisadon of protecdon, taking into account past *=wi=* from well managed 4
operadons, their amnerical values are *==*d to vuugmd to an ladividual dose lower than, and at 4
most coual to, the rmmarical value of the Dose Constraint. Operational Guides are e.ipected to be usually lower than he corresponding Authorised Umits.
i w
eN A S.
f sr.
vs.
e
- ; ;---- --?: f. = = ; c:^. -% c' ?? ^t ;s~./ ;. '";;y ::: t :
Ort. '
c)
Investinatann 12v*h Aused as a morning of deteriorating operatumal conditions, if they are exceededwhich 7 hey are usually established by the managemanr fbr internal use. Fr a dine an lavestigation level ahmld tdggw one or more of the following actions:
enhanced annnrinn and monitoring of trends; -
investigation on the causes and the evolution of,the events leading to the cacceding of the investigados level; nanalA* ration and implamentarian ofcorrective areinas;-
reporting to the management and the regulsery authodties as appropriate.
'the value of an investigation lent can be marshnahnd ja the foDourlag ways:
as a firection of the@eae C 3
__.j C
__l- " * - _ " :; an Authorized Umit or Operuaonal Guide, as warning threshold against approaching or i
exceeding c::- -
,.1:. a marrestriedont or; i
1
. as a, multiple of, a normal operadonal vales M M the contsponding a
C, J'- -I * - ":- Auepriand UmisorOpetualonelGeddeTeo indicane a deviation, or a trend devisting fitout nonnel anadirlana Recxmkagh, wWdt assed as criteriajbr 6% M40sinestric -
7 hey are usually eaghn=had by the managenww or by a drainwarte service fbr use in te personal of wedsers. 'the critada to report la the daninwerie noords values of dose kmer1han the acording levet depend on marianal pracsicas.
y j
i 4
6 14 1
l 4
6
9 l
l*
NEA/ SAN / DOC (95)lREV1 l
They are usually sar J in tens of the ananal. dose limit or as a prorata fracdon of.the dose limit p
over a sivue domi=*1c recording paiod. Recordmg levels are not apa **ny relevant to the purposes j
of this report. They are meadoned hae for ss --- =
l y
THE APPLICATION OF CONSTRAINTS,OPERATIONAIr J
3.
---RESTRIGHONS AND REFERENGE OTHER LEVELS 3.1.
This chapter deals with Dose Constraints, v.;; '. :.'r Authorized Limits,
)
Operadorsal Guides and Refacoce Levels as they are applied to ampational, public, and medical exposures.
- 1he establishment of constraints een should be the result of an interaction between operators and re'gulators. Constraints may help the management of a licensee, of=.w or employer in optimising protection in design or in planning operations. Regulators may use it in a generic way for categories of similar souras, practices or tasks, or specifically in licensing individual sources, practices or tasks.
Although constraints can be established from a review of expaience from well==.=1 operations in comparable practices, or from a generic optimisation, thefinal &oice of the apeimiaad i
. prossedan option may'also be aflected by political, ant ial, or other reasons suggesting the need not to-
, exceed a given levd ofindividual dose. The need for trade offs between different exposure situations, for example between public exposure and <mparinaal exposure, may also be a fador in the tenirm of consumiata. A soo rusricevsconstraint may have a negasve k'
=L. +hana\\ espesores.
pp.%c' dese.,,
im Q an.ee upa N
once a protection opdon has been aniarteri by~ optimisation, the rnnarraint ceases to be seievant unless and until thee is a reoptimisadon needing to she masce of a new pre opdon. Tbis
===iar*= may be required by. chanses of opwating snadininna new==**=J adv=ar====*= 'new annanndral or social aanh or by SmEng that individual'anana do ohen emwrt an Operational Banaamalan Operadonal Gedde.
one of the appen=*an so seeing constraints is ao refer to the e resulting from "sood 4
praedcas". In order no fadittane this, the bodies hi charge of pasty = = analysis shouki draw up
" handbooks of good pracdoe senecsing the state of the art at a siven time for the various types of i
sources or pracdoes. A typical exanqple is she " Manual of Good Praedce in Wort Management",
currensty beingpublished by the NEA.
The laturwhreinn of constraints'wRI certainly annnaulige the developenet of databases of past arpadaar* t ' ' 2 7 d ; " d ;M ;" and the improvement of operational dnal=*y seisted en spedal'assip or sauces. - it is pere =Ma in emet,'that one df the nudor sidadects of.Ibe insona =>= of the concept of constaints wlR be to force authoddes and opdalma to analyse feedback
..o espadsace,in anler to avoid aesdag abitrary values for constraints.1 bis is one'of the ways in whidi f
the constraints can contdbujte to the dialogue betwest operators and mulhnrities.
s S
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NEA/ SAN / DOC (95)1REV1 1-1 A
- 7. p " --_'.,,,,. _ " _".c 2:
c' :. 0; C-:- -
'. '..?,,, _. :..d/c-
-^"
.,_m._
._ _.<_ indevkhealiteses
__m
.___.m---
_____m._--.&.
_ ___,_ m _
____ a
..__.___m,_.
--,m,
. - _g g m.,
g,m... _ _
_g___
g,_. 7 y _ _m
_,.m,____
m__m_
m,_
.,, __...._.m,m m_-
>m
. _ _ ~ _~
_ _ _ ~
m m,_,__
__m
,m m
___..,__m m
___.__,_m_
.m _.... _ < _. _
_ m......
.__.m_
4 4
It is to be noted, howver,that the ahnple act of compiling stadstical data on individual doses l
or other relevant data is not sufficient for buildmg up usefbl post-expedence data bases to be used in j
sesdag constraints. A sine 9:n-non medition is the iden#iftensinn of links between these data bases and j
the difftsent types of sources, practims or tasks. For this purpose,it is recommended that the data base of individual annual dnaes is mmplanad by a symesnatic review of past emedaaea including data on overall perforrnance (e.g. collective doses), operating diaracteristics (such as dose rates or exposure l
tirnes) and protecdve sneasures adopted i
Once a practice, task or operation has been nprimbed below the prnWined constraints,
{
- .,^
2 :'.
^.-2'i;.; :.:.:. '
^^ practwat nevels, as defined in Section 2., can be set by the
^
regulators, licennaes, and operators as yardsticks retrospemively used to dieck enmpiinnne with the perthr= =a~ expected froen the nprimle A prnserrian option.
It is to be noted that the estahlishment by reguissors of gentric coRetraints and refereOce
)
j levels for a givus casegory of sources or plaats ahnnld be niede ta'idag emnnnt of the possible nneristance of new facnities with existing farmelen fbr which the'prnearstan options were designed I-according to an earlier standard.
l
{
3.2.
- e....., -.>e..
' i i
l Dose Constraints for nernparannat exposure are set for the dose to aniindividual froen a particsalar source of exposure, froan a compiene job, sudi as a armad malnaananne task, or frorn a group of operations l'n a spedde type ofladustry. The Ooestraint can be expressed,as m' single don'e or as n' dose over a given tirne pedod. ~
var.Alk.
,/nmahretennmended
_1 2
. Due m sie W W exposwes in h m d p " '
- "' ^ - - -
a genedc constraint for M For=== ale, in medical radiology unmany,the constahss niay be very km. riowever, la sonne undergiound nines or in case of spedal malnannanne. operations or dannmaandamalan amiviales in a andeer power plant bigh asposses cannot easily be dimininhad '.Usually, however, dose annanaemen 8ar -:----,--J'-1-' exposure can be set'at levela significantly lower than the selevant Dose Lhnit.w e
)
s.su uw y-F gm
_.. g m,, _.... m,_ _ __...__
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i In the ennsart of upc s of workers the e= rima with wee managed opmalons is of partioslar kuportanz in setting constrairas. ~ National ingniries or international databases like the NEA/OECD Infbrmarina Syseesa on Occupational Exposure (ISOE) deliver a~ large amount of
=p R4 with exposures related to specific opertrions in nuclear power plants whidi can be used in establishing constraints.
'Ihe importance of the mmmitmant of management to y: : *+ of protection is to be emphaniard The management should be involved in the setting of dose constraints for apaemed 3
operadons and tasks in consultation with the worker.wa.Gyes and safety committees and, as appropriate, with the agreement of the regulatory body. 'Ihe mastraints, and the m Ag dioice of optimlard options, should be periodically reviewed in the light of what has been adileved and any changes in cir-aw i
One of the major conerns in nrmpatinaal radiation protection is that of transient workers, sudi as contractors for mainsemanne operations in noclear power plants, who do not belong to the staff of thelinannae SouraHelated dose constraints can be established for well danned tasks, but this may i
not prevent these starters Aom=== iia.= the dose limits. Cooperation of--@cyss and licennaea is a l
pramaation to ovescome the difDmities of npnminerinn of pensarvina ibr operations involving transient workers. 'niis should include the establishmant of spedSc Operational matrianiana Guides and Inycetigation levels to prevent these workers Aom bedag sym*=aneany exposed to dose levels close to the donelimits.
r l
'Ibe doses acenally received by wnders should be subject to statospective scrutiny to ename that individual doses are as low as reasonably adilevabis. 'Ibe concept of investigation level is of use '
3 in this nnamart Investigation levels ahnnld be ggt by ma3agessent, usuaDy as a taction of Dose Ilmits or of Operational Geddes. P - ' ":--
" "" f by 5.7 ^,
^^ - "^
- ; bj t --
itself, 'Ibey easy relate to doses received by individuals involved in a particular operation or to doses received by individuals within a place of work. If an invendgulion levd is ernaarled, there ahneld be an
. Investigation of the cirannmaar== whida led to the espoonre, to determine whedher doses west as now as l
- =nnahiy achievable, and a review of the operattag ammessants.
envkomment, may be useAd to check that there is so denennendon in working nr= Manna D
of an ladivia=rs espoeme. ' Ibis would require a renulasary syseien sor enn=nn= cf dose insormanna on a national basis.
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NEA/ SAN / DOC (95)1REV1 3.3.
Puhuc Exposure Accortkag to the ICRP, for pubHc exposure the conuraints are more important than the limits. With the widespread use of source-selated mastraints and prestleal restdctions on sources, of pukUc exposures are generally much lower than the Dase Limit,r. w "y,,"^^"^-:---^"L=
.-.'f " ; 5 ;;.c ^t However, haemuna the constraints on d acerce orprecsice-see is source-related, toy it might, at least in nrinciana fall to take adequam account of the exposures from other sources orprocaces, at present and in the ihture. Regnimenry authorities should take this into account when setdag dose constraints h the public whidi, in fact, power be as high as the value of the Dose IJmit.
e In pracdce, almost all public exposure is controued by the procedures of constrained optimiention and the use of presortsuHevels Asshorizedlimits. It is ones convenient to class together individuals who form a homoneneous arouD with remnant to their exposures to a single source. When pf4 *g such's group hAjpical of those most highly exposed by that source, it is known as a Wil===' > '
mie Dose cnauraine ahn.M he annHart to the maan dnas in die MHral amam frnmVsource for which KRMO M the protection is being opdmised. In some circumstances, this group 'may also incur some dose from other sources If the exposures to the nwenhers of any critical group are likely to approedt the Dose l
Ilmit for public exposure, the constraints applied to.cach source must be seleded to allow for any siFnifle="' contdbution Aom other sources ao the exposare of the critical group. This is done by heepiag-ensuring that the Dose Constraint for each source below dost not -ad he fraction of the t
I Dose Ilmit (" dose upperbound") allocated to that source. Critada for the emanhlishment of the Constraintfor wmhers of she public are suggested in IAEA 'IECDOC 664.
'#v'sdaaM** N o wir q ue.k & rh a u.
Does constraints genmany apply to en dangsom an esposure pamways.mverving.a siven artucal sroup. However,in some cases it may be approprints e use coesmaints for particular exposure pathways. One could, for example, set a constraint for te esposure of nwantwas of the puhuc to liquid
. releases aan a mideer inneanasir= For me abhorne aseenes anomer commaint may be appucable.
.s These sEf5erent pathway.spedfic coststraints would be es osmaps to eserdhndandnn process appued, respectively, so uquid and to airborne einuent nesament syseems.
kkM N
N'
=
msuharities set,
-5t" s.
- ' Anthorised IJsslar of discharge levels whidt should result 80sn the spghtcallon of tse openissalon process'to $le souros in question. These ipseested4evels Authorised I4 mis are gammaBy set la tenas of piinal tRa& aran roses, but also in )
ms of-esodo.s of ee amis.i h,.ei er mor r e.e pen a mwn ee. be appro,n= eo.
l set an Invesdsanon Imet at some encanon of ee psaa-a ma.ision Asmariand Idadr of. discharge. me 7,,___bO
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3.
Medical exponare Medical exposure is the exposure incurm! by patients as part of their own snedical or dental j
or treatment; by persons, other than those occupationally exposei knowingly and willingly di the support of patients; and by voluntess in a programme of hinnwtical research involving
. helping
- Ihe concept of Dose Constraint applies in a diffesent way to padents and to the other their types of ur-n 3.4.1 Pdan innsane Optim of protection should be applied to the planning of protection provisions in In this case, the diagnostic and tic practices involving radiation exposure of patients.
justificktion of causing medical exposure is a martri for medical fut-naat. but it is to be expected that the mc
'g benefit is directly enjoyed by the exposed patients, or, in Jpecial cases, by society, of Dose Lindt does not apply, but the concept of DoonConstraint in In this case, the prindple does apply. However, the practical i=naama=*=dna of this concept is difficult, because o j
()W need to allow for the of exceeding a constraint for a single podent if desired diagnostic infbrmation or therapeutic effect otherwise not achievable. 'Ibeitfore, the. constraints in the l
npeimineton of==nemi pr=dmes patients *mM not be seen as dgid upper boundaries to the process of a-maeina. but =hnh rather have the meaninf of Guidanac levels (see IAEA/NEA/ILQ/PAHO/WHO/FAO Safety Standards) selecsed by appropriate pro'essional or n,
4. V/
,. \\
. regulatory agencies using national and esperience thxn well managed operatioa, or using 4
are sivenin the i
genede npeimi-eian as appropriate. th 1mels for some diagnande &'tederred to each a standard siae petlest and are not Basic Safety Standards. They are derived Inevidual case.
.i For==nemi exposures in'dagnostic
' and dagnostic nadeer' Maa elswegh l
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Ouldance levels have rather the fhavenna of investi levels. An incarnal irrvestigation should be carried out by a==tical department if the average dose a standard slac patiend; for a spedfic type of aan=8aarina was.found rupestody and sign #lesady exceed or be 6siow the tuisvant Guidance level. Unless this is jnereG by's sound n= Meal appmplate steps shanM be taken by the department to improve practice;' ibis would involve changes earnairpa or equipeness to rednoe doses below the Guidanna level without a,--
' ;thequality of hdhr==sina in ca.c a ra.adon r.,y. -._ ie s be -,eo,dmai.
both in the' target and non-target tiasmes, shouldbe determined ind y}
"!he way of itsericting,exposses tri pedieses is mately quality assurance,induding quality ocatrol of the n=Ecal ievices, apet=las'd procedures and training and education of t
l n=He=8 personnel. For many years.m redacdon of doses to undergoing diagnostic amamiamstons has been wwi 'Ihere have been same local====
generaDytheresult has i
19 w-
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1 NENSAN/ DOC (9,5)1REV1 been
,W1 There is some hope that the u t
helpinimproving the situadon.
se of appropriately wirrteri Od'imana levels could 3.4.2 Other markt emnneres 4
[
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)
of exposure which fall into the category of inariie=f exposure. '!he I
boundades to opdmisadon, ashyposed to Ouldance Levelsexpos j
j i
in the spedal case of patients wh voluntarHy accept to undergo an - u = : i diagnostic or therapy giw4me, Dos o
h should be established case by case.
Another category of medical exposug: refers to the exposure of reladves an hospital or when they are released from the hospitabloccupa i
applicadon of constraints may be useful for the pMprotection in these situations, thes{
i should be appued flexibly and caudously dmen<S I
S on w
~
i welfare of thepadent. It should be possible to exceed a constral <x>nsidered to be ofimportan fnom a medical point of view a net benetlt arises. Values ofdose these cases after confin i
recommended in the IAFDNENILO/PAH0/iVHO/FA O Basic Sqfety S tromtsfor these situa 4
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NEA/ SAN / DOC (95)1REV1 4.
CONCLURVE REMARKS Dose Constraints may be an important tool for lagproving optimisation in practical rmention protecdon andforfacilitating communication betwen operators, enqployers an a
authohties. Obviously there is a danger of over-sophistiredan in radianon protection leads n e dose hq$ndon of terms and' concepts of dgicsdt qplication in practical day.kHiay work, constraints may be misinterpreted and misused as a new category of limits.
- Derdore, the n concept has to be qplied with ~~===
- Lste, At the present stage in the ingplementation of optimisation of radsological protecti Firstly, in many sectors, especially in legal qplication of such an approach remains limited.' L, a structured optim industr] :! t Secondly, the economic and so:ial criteria which are used in the optimisation process largely dependent on value judgements, for which no consensus exists. ne adopti qproach, based on reference values of the man. sievert, which eglicitly takes into and social considerations, remasns an exception in view of this situatson, referring to goodpr i
seems to be the most suitable altensativefor setting dose constraints.
To-date, radsological protection optimisation has been implemented in a very gener manner, and dose constraints, as defEned above, have not been included in operakonal o s
1
" procedures. Consequently, the intro ction of dose constraints must be seen as one o a
}
l in inqproving she implementation of the optimisation principle.
I It is ingportant to ensure that the introducuan of a anstraint is not seen at a means to avoid the Jkrsher improvement of protection that can be achieved 'by a'fulf mplientinn 2
optimisation process. Den dose constraints muld qpear to be an induret means of ge f the
. same results shat should reasonably be aapected pom a strucaued ingplementanon o op"="m epproach.
In procacal terms, the efectiveness ofdone constraints depends on their adequate so the sources. In this consent, she cperators andpeople ranponsible fur she sources are still in i
best position so set the dose constraints.
in regulatory terms, dose constraints mpear so be a powrfld soolfor the evalunnn
^
encuram betwen the control of the quality of rodsological protection, as. wu at a vecsor for aushorines and operators, so ensure efective applicadon pfshe C'^ ^^'^ prhaciple.
~When the planning ofprosecdon by g' '-^? nader constraint is made and operational activkies are usartex a us+d sqpors to ingplement the resulu of+e ;- '-- ' = process can be Proiided by she essablishment ofAuthorized ibnits, Operadonal Geddes and Jtgerence Le aresunqM achieve and check compliance wkh opdmised preencsion reqadrements.
k S
9 21 a
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~.
4
=
NMM(95)!REV1 applicability of this concept in radiation protecaon
& ofconstraints is left to other Internanonal Organisanons, such as LAE their respective areas ofconpetence.
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1
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NEA/ SAN / DOC (95)!REV1.
l l
1 APPENDIX 1: REFERENCES (TO BE COMPLETED) l R===aadations that Doses be lept as low as Readily Achievable, ICRP Publicadon 1
(1) 22.Pergamon Press,1973 ICRP, R==nmendations of the ICRP, ICRP Publication 26. Pergamon Press,1977 j
(2) l ICRP, Cost Benefit Analysis in the Optimisation of Radiation Protection. ICRP (3)
Publicadon 37, Pergamon Press,1983 1AEA - Safety Series n*77: Principles for Limiting Releases of Radioacdve Effluent, into (4) the Environment,IAEA, Vienna 1986 1AEA - Safety Series n*92. Pdnciples for the Establishment of Upper Bounds to Doses to (5)
Individuals from Global ani Regional Sources, IAEA, Vienna,1989 ICRP, Optimisadon and Decision - Making in Radiological Protection, ICRP Publication (6) 55, Pengamon Press,1989 ICRP,1990 R====tations of the laternational Cn==h:sion on Radiological Protection (7)
}
ICRP Publication 60, Pergamon Press 1991, j
Dunster HJ.: The use of constraints by ICRP, J. Radiol. Prot 12 (1992) p.219' (8)
L.EA-TECDOC-664: Establishment of $ource Related Dose Constraints for,' Members of (9) -
the Public, Interim Report for nmment, IAEA Vienna 1992 e
NRPB: Board Stanament on the 1990 Rey =-- i"ons of ICRP, Drnments of the (10)
NRPB,Vol.4 No 1 (1993) -
(11)
NRPB:. Occupational, Public and Medical Exposure, LWimnts of the NRPB, Vol 4 No 2 (1993) f (12)
.Sugieri A., Cancio, D., Frittelli, I., Hubert, Ph.: Source Related Dose' Onnenraints,'
Congres " Harmonization in radiation protection: fiera theory'to practical appilcations"..
Taormina,Italie,10-13 October 1993
.(13)
Lochard, J., Schneider, T.
Sugler, A'., Hubert, Ph.: The Concept of Dose Constraint.-
Contract CEC DG XI n*93 ET-016,' April 1994 4
e 4
23
gp 3 /-. ;)
~
j o e>=a. 20, M & PQgQ PD R-From:
Anne M. Schramm <SCHRAMM_A@a1.eop. gov >
To:
Troy S. Hillier < HILLIER _T@a1.eop. gov >
Date:
2/15/96 3:09pm
Subject:
3150-0014 OMB NOTICE OF ACTION NOTICE OF OFFICE OF MANAGEMENT AND BUDGET ACTION -
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