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Concept and Approaches Used in Assessing Individual and Collective Doses from Releases of Radioactive Effluents Iaea, Vienna, 1988 Iaea-Tecdoc-460

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Concept and Approaches Used in Assessing Individual and Collective Doses from Releases of Radioactive Effluents Iaea, Vienna, 1988 Iaea-Tecdoc-460 IAEA-TECDOC-460 CONCEPT AND APPROACHES USED IN ASSESSING INDIVIDUA COLLECTIVD LAN E DOSES FROM RELEASE RADIOACTIVF SO E EFFLUENTS A TECHNICAL DOCUMENT ISSUEE TH Y DB INTERNATIONAL ATOMIC ENERGY AGENCY, VIENNA, 1988 CONCEPT AND APPROACHES USED IN ASSESSING INDIVIDUAL AND COLLECTIVE DOSES FROM RELEASES OF RADIOACTIVE EFFLUENTS IAEA, VIENNA, 1988 IAEA-TECDOC-460 Printed by the IAEA in Austria June 1988 PLEASE BE AWARE THAT ALL OF THE MISSING PAGES IN THIS DOCUMENT WERE ORIGINALLY BLANK IAEe Th A doe t normallsno y maintain stock f reportso thin si s series. However, microfiche copie f thesso e reportobtainee b n sca d from INIS Clearinghouse International Atomic Energy Agency Wagramerstrasse5 P.O. Box 100 A-1400 Vienna, Austria Orders shoul accompaniee db prepaymeny db f Austriao t n Schillings 100,- in the form of a cheque or in the form of IAEA microfiche service coupons which may be ordered separately from the INIS Clearinghouse. FOREWORD n implementatioa s A e IAEth A f Basio n s Safety Standard r Radiatiofo s n Protectio Agence th ] y[1 ninitiate expanden a d d programme th 198n i en o 3 Radiation Protectio Generae th f o nl Public. This sub-programm Agence th f yo e has three components, namely (1) Limitation of the Releases of Radioactive Effluents into the Environment, (2) Monitoring for the Radiation Protection of the General Public, and (3) Application of the Radiation Protection Principles to the Sources of Potential Exposure. Unde e firsth r t component Limitatioe th n ,o f Releaseo n Agence th s y issue 198n i d 6Safeta y e PrincipleGuidth n o e r Limitinfo s g Releasef so Radioactive Effluents into the Environment, Safety Series 77. This Safety Guide was the revised version of the earlier issued Safety Series 45. In addition e Agencth , y issue 198n i d 5Safeta y Guide, Safety n Serieo , 67 s Assigning a Value for Transboundary Radiation Exposure. e applicationo guidT th n o ee principleth f o s r limitinfo s g radioactive releases contained in Safety Series 77, the Agency is in the process of preparing a number of safety guides. The first one is this present document which deals with the principles aspects of the methods for the assessment of e individuath d collectivan l e dose. Another document whic undes i h r preparation will be a safety guide on the detailed methdologies for the assessmen f individuao t d collectivan l e dose d thian ss documen beins i t g prepare y revisinb d e existinth g g Safet e Generiyth Serien o c7 5 sModel d an s Parameter Assessinr fo s Environmentae th g l Transfe f Radionuclideo r s from Routine Releases o safetTw . y guide e undear s r preparatio e applicatioth n o n n of the principles for limiting radioactive releases to specific cases. The first one is on the mining and milling of radioactive ores, which is now under publication nucleae th n o e other Th e .poweon r r plant reprocessind an s g plants, which is in an advance stage of completion. Another safety guide, which is under preparation is on the Establishment of Upper Bounds to Doses to Individuals from Global and Regional Sources. Several other documents are relate o thit d s present documen d thes an e tSafet ar e y Serie . 50-SG-SsMo n 3o the Atmospheric dispersio Nuclean i n r Power Plant Sitin Safetd an g y Serie. sNo 50-SG-S Hydrologican o 6 l Dispersio Radioactivf no e Materia Relation i l o t n Nuclear Power Plant Siting. e presenTh t document aim t givina s a generag l guidanc o thost e e responsible for establishing programmes for the determination of individual dose s wela ss collectiva l e dose n connectioi s n with licensina a sitgr fo e nuclear installation. This document will be supplemented by a series of document n guidanco s d specifian e c procedure r thosfo s e responsiblr fo e implementin e programmth g f doso e e assessmen e environmentth n i t . The document is concerned with the principles applied for calculating individual and collective doses from routine releases of radionuclides to the atmosphere and hydrosphere but not releases directly to the geosphere, as in waste management. These areas will be covered by other Agency publications. The document has been prepared with the help of two Advisory Group meetings and Consultants meetings. The final compilation of the document was the responsibility of Mr. J.U. Ahmed of the Division of Nuclear Safety. EDITORIAL NOTE preparingIn this materialpress, the International the for staff of Atomic Energy Agency have mounted and paginated the original manuscripts and given some attention to presentation. The views expressed necessarilynot do reflect governmentsthosethe of Memberthe of States or organizations under whose auspices the manuscripts were produced. The use in this book of particular designations of countries or territories does not imply any judgement by the publisher, the IAEA, as to the legal status of such countries or territories, of their authorities institutions and delimitation the of or theirof boundaries. The mention specificof companies theirof or products brandor names does implynot any endorsement or recommendation on the part of the IAEA. CONTENTS Chapte . 1 INTRODUCTIOr N ..............................................................................7 . 1.1. General principle f sourco s individuad ean l related dose assessments .........7 . 1.2. Principle f assessino s g radiation exposure ...........................................9 . Chapter 2. ASSESSMENT OF DOSE TO THE CRITICAL GROUP .............................. 19 2.1. Principle f calculatinso g exposure criticae th o t s l group ..........................9 1 . assessmene 2.2Th . f exposureo t s from radionuclides released to the atmosphere .......................................................................... 19 2.3. The assessment of exposures from radionuclides released to the aquatic environment ............................................................... 26 Chapter3. ASSESSMEN COLLECTIVF TO E DOSE ...............................................1 3 . 3.1. The concept of collective dose .......................................................... 31 3.2. Methods for calculating collective doses .............................................. 33 Chapte . 4 rAPPROPRIATENES MODEF SO L SELECTIO UNCERTAINTIED NAN S IN DOSE ASSESSMENTS ................................................................... 41 4.1. Introduction ................................................................................1 4 . 4.2. General problems encountere dosn di e assessments base modeln do s ..........2 4 . 4.3. Factors affectin uncertainte th g f resultyo s ..........................................4 4 . 4.4. Sensitivity analysis .......................................................................6 4 . 4.5. Uncertainty analysis ......................................................................7 4 . REFERENCES .................................................................................................. 49 LIS PARTICIPANTF TO S ..................................................................................5 5 . Chapter 1 INTRODUCTION l.1 General principles of source and individual related dose assessments A practice involving exposure o radiatiot s n usually gives a ris o t e distribution of doses, and thus of detriment, and to a distribution of benefits fropracticee th m n generaI . l thes o distributiontw e e quitar s e different and, therefore e distributio,th f benefit o nusee b o justif t dn ca s y e distributioth f detrimento n e sris th o onleac t kf i yh individua s smalli l , not exceeding levels which could be regarded as acceptable. The dose limits recommende e ICRth P y b d[11 e intende]ar o ensurt d e this leve f protectioo l n even for the most highly exposed individual. The dose limits, however, are not intended to be values used for design installations, or for planning operations, but are rather the lower boundary regioa f o unacceptablf o n e value norman i s l circumstances. Values above th e limits are specifically not permitted, but values below the limits are not automatically permitted. In this sense, the limits are only the constraints with the overriding consideration that the radiation doses should be kept as low as reasonably achievable, economic and social factors being taken into account ("Optimizatio protection)f o n . dose th e f o limit e constraints us a s e Th r optimizatiofo s n presents some conceptual difficulties, especiall e cas th f genera o en i y l exposuref o s membere publicth e dosf Th o s.e n individual-relatelimia s i t d requirement, while optimizatio source-relatea s i n d requirement. Becaus e dosth e e limit appliee combineth o t s d exposure from many practices cannot i , usee tb o t d limit a given single practice even when it is more restrictive than results of optimization. In fact, exposures at the limit from one single practice would leav margio en r othefo n r practices which expose r coul,o d expos e samth ee critical group. e probleTh f overlamo f exposurepo s from different practicet no s i s restricte y givean o nt d instan f timeo t . Each yea f operatioo r a f o n continuing practice can cause exposures which would be delivered in the future and which would add to the contributions of other years of operation e practiceoth f e dosTh e. rate resulting froe combinemth d l effecal f o t such annual discharges will increase, eventually reachin a steadg y state. This maximu me annua valuth f lo e dose from continuing practices could occur far in the future, and could also be maintained over considerable periods
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