Tiêu chuẩn iso 07503 2 2016

© ISO 2016 Measurement of radioactivity Measurement and evaluation of surface contamination — Part 2 Test method using wipe test samples Mesurage de la radioactivité — Mesurage et évaluation de la con[.]

Measurement ofradioacti vity -

Part 2:

Mesura e de la radioactivité — Me sura e et é alu tion de la

co tamination de surf c —

Partie 2: Méth de d’e ss ai utilisant de s éch ntillo s d’e ssai de frotis

S con edition

2 16-0 -1

Refer ence n mb r

ISO 75 3-2:2 16(E)

COPYRIGHT PROTECTED DOCUMENT

© ISO 2016, P blshed in Sw itz rlan

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F reword i v

Introduction v

1 Sc ope 1

2 Nor mati ve r eferenc es 1

3 Terms and definitio s, symbols and abbreviatio s 2

3.1 Te msan definitions 2

3.2 Symb ls and a br eviated te ms 3

4 So rc es of sur fac e c ontamination 3

5 Objecti ves of the sur fac e c ontaminatio evaluation 4

6 Strateg y 4

7 Metho s for evaluating sur face c ontamination 4

8 Wipe test material 5

9 Instrumentatio 5

9.1 General 5

9.2 Liq id scinti ation counte s 6

10 Calbratio 6

1 1 Calbration of instaled ins rument 6

1 2 Calbration of p rta le ins rument 6

11 Guidelnes o w ipe test samplng 6

1 1 General 6

1 2 Guidelnes on samplng r emo a le tritium contamination 7

12 Me surement proc ed r e 7

13 Evaluatio of me sur ement data .8

1 1 Calculation of the activity pe u it ar ea for measur ement r esult of ins aled ins rument 8 1 2 Calculation of the activity pe u it ar ea for measur ement r esult of p rtable instruments 9 1 3 A pplcation of ISO 11 2 9

14 Wipe test unc er tainties 9

15 Test rep rt 9

Biblog raphy 11

ISO (he Int ernational Org nization for Stan ardization) is a worldwidefede ation of national s an ards

b dies (ISO membe b dies) The work of pr p ring Int ernational Stan ards is normaly car ied out

through ISO t ech ical committ ees Each membe b dy int er st ed in a subje t for w hich a t ech ical

committ ee has be n es a lshed has the right t o be r pr sent ed on that committ ee Int ernational

org nizations, g ove nmental an non-g ove nmental, in laison with ISO, also take part in the work

ISO cola orat es closely with the Int ernational Ele trot ech ical C mmis ion (IEC) on al matt ers of

ele trot ech ical s an ardization

The proc d r s used t o develo this document an those int en ed for it furthe maint enanc ar

desc ibed in the ISO/IEC Dir ctives, Part 1 In p rticular the dife ent a pro al c it eria ne ded for the

dife ent ty es of ISO document should be not ed This document was draft ed in ac ordanc with the

edit orial rules of the ISO/IEC Dir ctives, Part 2 ( e www.iso.org dir ctives)

A tt ention is drawn t o the p s ibi ity that some of the element of this document ma be the subje t of

p t ent right ISO shal not be held r sponsible for identifying any or al such p t ent right Detais of

any p t ent right identified d ring the develo ment of the document wi be in the Introd ction an / r

on the ISO ls of p t ent de larations r c ived ( e www.iso.org p t ent )

Any trade name used in this document is information given for the convenienc of use s an does not

cons itut e an en orsement

F or an ex lanation on the meaning of ISO spe ific t erms an ex r s ions r lat ed t o conformity

as es ment, as wel as information a out ISO’ s adhe enc t o the WTO principles in the Te h ical

Bar ie s t o Trade (TBT) se the fol owing URL: F or word - Sup lementary information

The committ ee r sp nsible for this document is Te hnical Committ ee ISO/TC 8 , Nuclear ene g , n clear

techn lo ies, a d radiolo ic al protec tio , Subcommitt ee SC2, R adiolo ic al protec tio

This se on edition canc ls an r plac s the f irs edition (ISO 7 0 -2:1 8 ), which has be n

te h icaly r vised

ISO 7 0 consis s of the fol owing part , u de the g ene al title Meas ur ment o radio c ti v it y —

Meas ur ment a d ev lu tio o s urfc e c ontamin tion:

— Part 1: G ene al princ iples

— Part 2 : Tes t meth d us in w ipe -tes t s amples

— Part 3 : Ap aratus c albratio

ISO 7 0 gives guidanc on the measur ment of surfac contamination This Int ernational Stan ard is

a plca le t o many situations w he e radio ctive contamination can oc ur C ntamination arises from

the r leaseof radio ctivity int o the local environment In mos cir ums anc s, the r lease is inadve t ent

but, on oc asion, ma be delbe at e Although the purp se and sco e of the inves ig tion ma dife , the

a pro ches taken t o measur the levels an ext ent of the contamination ar es entialy simiar

Radio ctive contamination can arise from a n mbe of activities or event such asthe folowing:

— routine la orat ory use of radiochemicals;

— medical tr atment ;

— in us rial a plcations;

— transp rt ac ident ;

— eq ipment malfu ctions;

— malev lent incident ;

— n clear ac ident

W ithout proc s know ledg e or documentation, it is not alway s p s ible t o identify or dis inguish the

dife ent radion cldes cons ituting a surfac contamination, an the ev luation of such contamination

cannot be made on a q antitative b sis Inst ead of using ins rument with n clde spe if ic calbrations,

it ma be ne es ary t o use othe ins rument w hich ar f it for such a purp se

Howeve , the e ma be cases (e.g a contaminat ed fuel mat erial transp rt containe ) w he e the

radion clde or the radion clde mixtur can be clearly charact eriz d A surfac contamination

ev luation ex ce ding a pur q altative as es ment of f ixed an r mo a le surfac contamination

ma then be ne ded Mor o e , folowing r q ir ment laid down in national r gulations an in

int ernational conventions, a measur d surfac contamination activity pe u it ar a has t o be comp r d

with surfac contamination guidelne v lues or surfac contamination l mit

Surfac contamination guidelne v lues ar radion clde-spe ific an th s r q ir complex

radion clde-spe ific calbrations of measur ment eq ipment C lbration q alty as uranc is c ucial

in orde t o a oid non-det ection ( i.e ty e I de ision e rors) leading t o incor e tly as uming compl anc

with given surfac contamination guidelne v lues or l mit Ev luation of surfac s contaminat ed b a

mixtur of radion cldes with k own ratiosr q ir s r spe tively pro ortionat ed calbration fact ors

ISO 7 0 is conc rned with the measur ment an es imation of radio ctivity levels It does not pro ide

advic on de ommis ioning, planning an survei lanc t ech iq es

Surfac contamination is spe ified in t erms of activity pe u it ar a an the lmit ar b sed on the

r commen ations b the Int ernational C mmis ion on Radiolo ical Prot ection (ICRP 1 3)

This p rt of ISO 7 0 deals with the ev luation of surfac contamination b in ir ct measur ment

using a wipe t es

Measurement ofradioacti vity - Measurement and

Part 2:

ISO 7 0 (al part ) an ISO 8769 ar ad r s ed t o the peo le r sp nsible for measuring the

radio ctivity pr sent on sold surfac s

This p rt of ISO 7 0 a ples t o theev luation of contamination on surfac s in t erms of activity pe u it

ar a b an indir ct method of measur ment

This part of ISO 7 0 is a plca le t o wel-defined surfac s, such as those of eq ipment an faci ities,

containe s of radio ctive mat erials, sealed sour es an buidings or lan

This p rt of ISO 7 0 can be used for la orat ory an eq ipment/ins al ation control an for r mediation

an monit oring activities t o comply with r lease c it eria

This p rt of ISO 7 0 also r fe s t o ins itutions/ uthorities control ing n clear mat erial transp rt

or mat erial/eq ipment clearanc ac ording t o national legislation guidelne v lues or int ernational

convention lmit

This p rt of ISO 7 0 does not a pply to contamination of the skin, clothing or lo se material, such as gra el

NOTE Direct evaluation of surface contamination from alp a-emit er , b ta-emit er an p oton emit er is

de lt with in ISO 75 3-1 The calibration of instruments for the evaluation of radio ctive surface contaminations

is de lt with in ISO 75 3-3

2 Normati ve r eferences

The folowing document , in w hole or in p rt, ar normatively r fe enc d in this document an ar

in ispensa le for it a pl cation F or dat ed r fe enc s, only the edition cit ed a pl es F or u dat ed

r fe enc s, the lat es edition of the r fe enc d document ( inclu ing any amen ment )a pl es

ISO 87 69, Refe enc e s ourc es — Calibration o surfac e co taminati on mo itors — Alp a-, beta- a d

p oto emitte s

ISO 9 98, Wate q alty — Determin tion o tritium acti v ity c onc entration — Liquid s c inti ation

c ou tin meth d

ISO 1 9 9, Dete min tio o the charac te i s tic lmits (dec i s io thr shold, detec tio lmit a d lmit o the

c onfidenc e inter val fr meas ur ments o ioni z in radiatio — Fu damentals a d a plc ation

ISO 1 5 9- 2, Meas ur ment o radio c ti v it y in the env iro ment — S i — Part 2 : Guida c e fr the s elec tion

o the s ampln s trateg , s ampln a d pr -tr atment o s amples

ISO/IEC 1 0 5, G ene al r q ir ment fr the c ompetenc e o tes tin a d c albratio la oratories

IEC 6 3 5, R adiatio protec tion ins trumentatio — Alp a, beta a d alp a/beta (beta ene g >6 0 keV)

c ontamin tio mete s a d mo itors

3 Terms and definitions, symbols and abbreviations

3.1 Terms and definitions

F or the purp ses of this document, the folowing t erms an def initions an those given in ISO 7 0 -1

a ply

3.1.1

removable surface co taminatio

radio ctive mat erial that can be r mo ed from surfac s b non-des ructive means, inclu ing casual

contact, wiping, or washing

Not e 1t o entry: It should b not ed that u der the influence of moisture, chemicals, etc or as a result of cor osion

or difusion, f ix ed contamination may b come remova le or vice ver a without an h man action F rthermore,

surface contaminations may dec e se d e to evaporation an volatilization

Note 2 to entry: It should b emp asized that the ratio b tween f ix ed an remova le contamination can vary

over time, an that some decisions, such as those related to cle rance, should b b sed on t otal activity with the

potential t o b come remova le over time, not just the amou t hat is remova le at he time of a survey

3.1.2

wipe test

t es t o det ermine if r mo a le contamination is pr sent through wiping the surfac with a dry or wet

mat erial, folowed b ev luation of the wipe mat erial for r mo a le contamination

Note 1to entry: The ty e of wipe test, w et or dry, ne ds to b as es ed by a competent per on In some instances

(e.g tritium contamination) a w et wipe may b prefer ed In other , it may b more practical or ad isa le to

use a dry wipe

3.1.3

wiping ef iciency

ratio of theactivity of the radion cldes r mo ed from the surfac b one wipe sample t o the activity of

the radion cldes of the r mo a le surfac contamination prior t o this samplng

Not e 1t o entry: T e wiping eff iciency is def ined by the folowing relationship:

ε

w

R

T

=

a

a

w he e

a is the activity of the radion cl des r mo ed b wipe t est ;

a

T

is the t otal r mo a le activity of the radion cl des pr sent on the wiped ar a

Not e 2 t o entry: In practice, it is almost impos ible t o me sure the total amou t of remova le activity on the

surface; an in most cases,a value for “wiping eff iciency” can ot b as es ed but can only b estimated

Not e 3 t o entry: For important combinations of contaminant an surface material, the wiping eff iciency can b

determined e perimentaly using the method of “e haustive removal by repetitive wipe t ests” The step-by-st ep

ad ition of the removed activities results in an ap ro imation of the total remova le activity (a ), t o which the

activity removed by the f ir t wipe test (a )can then b related to yield the wiping eff iciency

Not e 4 t o entry: T e method of “e haustive removal by repetitive wipe t ests” is only ap lica le if it can b

guarante d that e actly the same are is wiped on e ch oc asion an e actly the same pres ure is maintained

u iformly over the are wiped More ver, results of this method are only valid for a specif ic nature an structure

of a surface an are not ransfera le t o other surface structures

3.1.4

tritium surface co taminatio

t otal activity oftritium adsorbed upon an a sorbed int o thesurfac

removable tritium surface contaminatio

fraction of surfac contamination w hich is r mo a le or trans e a le u de normal working con itions

Note 1t o entry: It should b not ed that

a) u der e ternal influences of a chemical nature (e.g moisture, cor osion) or of a p ysicalnature (e.g ambient

pres ure or temperature chang s, vibration, impact, e pansion an contraction), an also as a result of

dif usion, the total tritium activity may b transformed int o remova le contamination or non-remova le

The state is rever ible multiple times,

b) tritium surface contamination may b volatile or contain volatile fractions which may volatilize u der

normal working con itions - this also contributes to the remova le contamination an should b evaluated

ap ropriately (se also Clause 7), an

c) as a result of difusion of tritium int o the surface structure, removal of the tritium surface contamination by

e haustive wipes may b without efect as the removed tritium contamination may b replaced in short ime

(se also Clause 7)

3.1.6

in irect ev aluatio of remo able tritium surface co tamination

ev luation of the r mo a le tritium activity b means of a wipe t es

Note 1 to entry: An wipe used for tritium can only b analysed relia ly using liq id s intilation cou ting Direct

me surements of tritium contaminated wipes may have larg u certainties or are not pos ible

3.2 Symbols and abbr eviated terms

F or the purposes of this p rt of ISO 7 0 , the folowing symbols an those given in ISO 7 0 -1 a ply:

ε

w

wiping efficiency

a activity of the radion cldes r mo ed b wipe t es in Bq

a

T

t otal r mo a le activity of the radion cl des pr sent on the wiped ar a in Bq

a

r

activity pe unit ar a of the r mo a le contamination of the wiped surfac in Bq·cm

–

a

w

activity of the wipe sample in Bq

S

w

wiped surfac ar a in cm

2

C(A )

i nd

activity calbration fact or for wipe sample in (Bq·cm

–

)/s 1

4 Sources of sur face c ontamination

A surfac can be contaminat ed with naturaly oc ur ing or man-made radion cldes

The main natural radion cl des ar

40

K an radion cldes originating from

2 8

U an

2 2

Th de a

se ies Natural radio ctivity ma v ry conside a ly from one ty e of natural mat erial t o anothe (e.g

buiding mat erials)

La orat ories that int entional y han le natural y oc ur ing radio ctive mat erial, such as radium or

thorium, should anticip t e surfac contamination from these radion cldes

The sour es of surfac contamination b man-made radion cldes can arise from a n mbe of activities

such as the folowing:

— routine la orat ory use of radio chemicals;

— medical tr atment ;

— in us rial a plcations;

— transp rt ac ident ;

— eq ipment malfu ctions;

— malevolent incident ;

— n clear ac ident

5 Objecti ves of the surface c ontamination evaluation

The ultimat e g oal is t o prot ect he worker an the g ene al p pulation from dir ct an in ir ct radiation

ex osur s, such as inhalation, ing es ion, skin contact, an skin a sorption pathway s This is done b

measuring surfac contamination t o as es the imp ct of r lease an t o pr vent r suspension an

r mo i ization of radio ctive mat erials

Radiation prot ection depen s on k ow ledg e of the surfac activity an of the r mo a le fraction of

activity

The r mo a le fraction ma v ry o e time ( e Clause 7) an should be conse v tively a pled,

depending on the int ent of the surfac contamination charact erization

Prior t o any measur ment , q alf ied an ex e ienc d radiation profes ionals should develo the

r q ir d pro ram of work t o ensur that the bes p s ible information is g the ed t o charact eriz the

ty e an spr ad of contamination

6 Strateg y

A s rat eg for the det ermination of surfac contamination is normal y es a l shed b q alf ied

in ivid als that ha e a pro riat e ex e ienc an ex e tise in the measur ment and as es ment of

surfac contamination The s rat eg should be b sed on

— ran om an / r sy st ematic sc e ning

[1][2][7]

— che k of c itical p sitions (e.g st orag ear as of radio ctive sour es, do r han les, or the surfac s of

any containe or buiding in w hich radio ctive mat erials ar st or d), an

— complet e monit oring of the surfac

A r mediation monit oring proc s (e.g R efe enc [7]) or a sy st ematic monit oring s rat eg as outlned

in ISO 1 5 9- 2 ma be the b sis for the spe if ication of surfac contamination measuring p int in a

la orat ory, on an ext ended containe or on a sit e Such s rat egies, howeve , do not r plac a complet e

monit oring of surfac s, on w hich radio ctive contaminations ar as umed

A s rat eg for surfac contamination control at an o e ating faci ity ma also be the analy sis an

identification of c itical o e ational seq enc s p t entialy leading t o surfac contamination

7 Methods for evaluating surface c ontamination

The a plca i ty an the r l a i ty of dir ct measur ment or indir ct ev luation of surfac

contamination ar s rongly depen ent on the p rticular cir ums anc s [e.g the phy sical an chemical

form of the contamination, the ad e enc of contamination on the surfac (fix ed or r mo a le), the

ac es ibi ty of the surfac for measur ment or the pr senc of int erfe ing radiation fields ]

Dir ct measur ment as dealt with in ISO 7 0 -1 is used w hen the surfac is r adi y ac es ible,

r asona ly clean an w hen no int erfe ing radiation, such as a high b ckgrou d, is pr sent Dir ct

measur ment is used t o es a lsh the pr senc of b th fix ed an r mo a le contamination