19/04/23 radiation safety - level 5 1

Radiation safetyRadiation safetylevel 5level 5

Frits Pleiter

19/04/23 radiation safety - level 5 2

ContentsContents

atomic and nuclear physics (1) interaction with matter (3)

o sources and x-ray equipment (2)o shielding (3)o detection (4)o radiobiology (6)

• objective risk of radiation (6)• subjective risk acceptation (6)

quantities and units (5) regulations (7)

o practical health physics (8 - 10)o waste (11)

19/04/23 radiation safety - level 5 3

RiskRiskprinciplesprinciples

the risk of ionizing radiation is 0.05 per sievert

occupational risk > 1 in 1000 is unacceptableoccupational risk < 1 in 10 000 is acceptablerisks between these values are manageable

19/04/23 radiation safety - level 5 4

RiskRiskcomparison of riskscomparison of risks

type of work mortality / yearNational Health Council 17-07-

1984light industry 20 per millionindustry 40 per millionconstruction work 100 per millionheavy transport 170 per millionradiological work (20 mSv/y) 1000 per million high risk

natural radiation (2 mSv/y) 100 per millioncigarettes (20 per day) 4000 per million

the risk of 1 cigaret corresponds with the risk of 10 µSv

19/04/23 radiation safety - level 5 5

RegulationsRegulationsfrom recommendation to legislationfrom recommendation to legislation

ICRP recommendationInternational Commission on Radiological Protectionindependent commissionrecommendation not legally binding, but almost always accepted

European directivedirective must be implemented in national legislation

Dutch legislationNuclear Energy Act + decrees + regulationsWorking Conditions ActEnvironmental Protection ActGeneral Administrative Law Act

19/04/23 radiation safety - level 5 6

RegulationsRegulationslegislation and supervisionlegislation and supervision

supervision by the governmentInspectorate of Social Affairs and Employment (ISZW)Environment and Transport Inspectorate (ILT)Health Care Inspectorate (IGZ)

19/04/23 radiation safety - level 5 7

RegulationsRegulationssystem of dose limitationsystem of dose limitation

justificationbenefits must outweigh the health detriment it may cause

optimizationALARA = as low as reasonably achievable

limitationlimits are not a guide for the maximum permissible doselimits may never be exceeded

19/04/23 radiation safety - level 5 8

RegulationsRegulationsannual limitsannual limits

stochastic effects, exposed workerscategory A-workers 20 mSvcategory B-workers 6 mSv

stochastic effects, non-exposed workersnormal workers 1 mSvmembers of the public 1 mSvrequirement for permit holder 0.1 mSv outside location

these limits are meant to minimalize the risk of stochastic effects

19/04/23 radiation safety - level 5 9

RegulationsRegulationsannual limitsannual limits

harmful tissue reactions, exposed workerslens of the eye 150 mSvlimbs 500 mSvskin 500 mSv

harmful tissue reactions, non-exposed workerslens of the eye 15 mSvlimbs 50 mSvskin 50 mSv

these limits are meant to prevent harmful tissue reactions

19/04/23 radiation safety - level 5 10

RegulationsRegulationspermit and radioactivitypermit and radioactivity

a Nuclear Energy Act permit is required for possession and use of radioactivity if both the activity concentration and the activity exceed the exemption levels

nuclide concentration (Bq/g) activity (Bq)3H 106 109

14C 104 107

32P 103 106

35S 105 108

99mTc 102 107

125I 103 106

131I 102 106

226Ra 1 104

238U 10 104

19/04/23 radiation safety - level 5 11

RegulationsRegulationspermit and devicespermit and devices

an x-ray device must either be reported or be authorized

a permit is required fordevices with a maximum high voltage > 100 kVall devices used for

industrial radiographyprocessing of productsmedical therapy for humans and animalseducation

(almost all) other devices must be reported

19/04/23 radiation safety - level 5 12

RegulationsRegulationsrisk analysisrisk analysis

ionizing radiation may only be applied under supervision of a radiation safety expert level 2, 3, 4 or 5

the radiation expert must make (or commission) a risk inventory and evaluation before starting the application

the risk inventory and evaluation must be approved by a registered coordinating radiation safety expert

19/04/23 radiation safety - level 5 13

RegulationsRegulationsclassification of exposed workersclassification of exposed workers

a worker must be classified as an exposed worker if he can receive more than 1 mSv per year as a result of his work

exposed workers must be given appropriate instructions

exposed workers must receive a personal dose-monitoring device which they must (visibly) wear during radiological work

19/04/23 radiation safety - level 5 14

RegulationsRegulationsclassification of exposed workersclassification of exposed workers

exposed workers must be classified in categories

category possible annual dose medical check upA 6 - 20 mSv yesB 1 - 6 mSv no

19/04/23 radiation safety - level 5 15

RegulationsRegulationsclassification of work areasclassification of work areas

work areas must be classified in zones

zone possible anual dose warning 'no entry'sign sign

controlled 6 - 20 mSv required yessupervised 1 - 6 mSv required no

19/04/23 radiation safety - level 5 16

RegulationsRegulationstransport of radioactive substancestransport of radioactive substances

regulations are very complicatedsender is responsibleleave transport to a specialized companysending radioactivity by regular mail is prohibited