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18/04/23 radiation safety - level 5 1
Radiation safetyRadiation safetylevel 5level 5
Frits Pleiter
18/04/23 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)
18/04/23 radiation safety - level 5 3
Sources and x-ray equipmentSources and x-ray equipmentdiscovery of radioactivitydiscovery of radioactivity
Henri Becquerel
In 1896 Henri Becquerel was experimenting with a uranium salt. At the end of the day, he used to put the uranium salt in a cupboard, next to some photographic material wrapped in brown paper.
On a day he noticed that the photographic material had been exposed at a spot close to the uranium salt.
18/04/23 radiation safety - level 5 4
Sources and x-ray equipmentSources and x-ray equipmentdefinition of a sealed sourcedefinition of a sealed source
radioactive substances that are•either embedded in or affixed to solid carrier material•or enclosed by surrounding material
in such a way that the carrier material or the enclosure offerssufficient resistance to prevent, under normal conditions of use,any dispersion of the radioactive substances
18/04/23 radiation safety - level 5 5
Sources and x-ray equipmentSources and x-ray equipmentapplications of sealed sourcesapplications of sealed sources
measurements or investigationswelds in pipelines 192Ir, 60Co 1 - 100 TBqthickness of steel 137Cs, 241Am 10 GBqthickness of cigarettes 90Sr / 90Y 40 MBq - 40
GBqfilling heights 137Cs, 60Co 1 - 10 GBq
chemical analysisx-ray fluorescence 241Am, 57Co 40 MBq - 40 GBqgas chromatography 63Ni 400 MBq
medical applicationsbrachytherapy 90Sr / 90Y, 125I 2 MBqbrachytherapy 137Cs, 192Ir 50 - 500 MBq
18/04/23 radiation safety - level 5 6
Sources and x-ray equipmentSources and x-ray equipmentISO 2919ISO 2919
sealed sources may be tested for the following 5 properties1.temperature and thermic shock2.pressure3.mechanical shock4.vibration5.puncture
classification runs from 1 (not tested) till 6 (most stringent test)gas chromatography 63Ni C32211industrial radiography 192Ir C43313
source with code C11111 has not been tested, but may be used
18/04/23 radiation safety - level 5 7
Sources and x-ray equipmentSources and x-ray equipmentapplications of open sourcesapplications of open sources
(bio)chemical analysislabelling 3H, 14C, 32P, 125I 1 MBq - 10 GBq
medical diagnosticsbone, heart 99mTc 500 MBqlungs 83Kr 600 MBqthyroid 123I 20 MBqtumor 111In 100 - 200 MBqPET 11C, 13N, 15O 500 MBq
medical therapyhyperactive thyroid 131I 100 MBq - 1
GBqthyroid tumor 131I 2 - 6 GBq
18/04/23 radiation safety - level 5 8
Sources and x-ray equipmentSources and x-ray equipmentapplications of open sourcesapplications of open sources
angioscan using 99mTccross-sections through the heartleft: septumright: wall of left atrium and ventriclebottom: apexdark spot at the bottom points to a bad blood circulation in the
apex
18/04/23 radiation safety - level 5 9
Sources and x-ray equipmentSources and x-ray equipmentdiscovery of X-raysdiscovery of X-rays
Wilhelm Conrad Röntgen
In 1895 Wilhelm Conrad Röntgen discoverd a magic radiationthat could penetrate solid objects. He called them x-rays, sincethey were a real mystery to him.
If the emerging x-rays hit photographicmaterial, a picture could be made ofthe inside such as the bones of a handor the contents of a suitcase.
18/04/23 radiation safety - level 5 10
Sources and x-ray equipmentSources and x-ray equipmentx-ray x-ray tubetube
negative cathodepositive anode
electron accelerationelectron deceleration (a lot of) heat
bremsstrahlungcharacteristic x-ray radiation
dose rate > 10 Gy/s possible !scattered radiation intensity is about a factor of 1000 smaller
18/04/23 radiation safety - level 5 11
Sources and x-ray equipmentSources and x-ray equipmentx-ray x-ray spectrumspectrum
a) bremsstrahlungb) characteristic x-ray radiationc) radiation emerging from the tubed) radiation after extra filtering
18/04/23 radiation safety - level 5 12
Sources and x-ray equipmentSources and x-ray equipmentx-ray x-ray spectrumspectrum
intensity of bremsstrahlung increases with:increasing anode voltageincreasing anode currentincreasing Z-value of anode materialdecreasing filter thickness
intensity of characteristic x-ray radiation increases with:increasing anode voltageincreasing anode currentdecreasing filter thickness
energy of bremsstrahlung increases with:increasing anode voltage
energy of characteristic x-ray radiation increases with:increasing Z-value of anode material
18/04/23 radiation safety - level 5 13
Sources and x-ray equipmentSources and x-ray equipmentapplications of X-raysapplications of X-rays
bitewing
18/04/23 radiation safety - level 5 14
Sources and x-ray equipmentSources and x-ray equipmentapplications of x-raysapplications of x-rays
CT-scan
18/04/23 radiation safety - level 5 15
Sources and x-ray equipmentSources and x-ray equipmentexamples of x-ray equipmentexamples of x-ray equipment
18/04/23 radiation safety - level 5 16
Sources and x-ray equipmentSources and x-ray equipmentneutronsneutrons
neutron = neutral particleinteraction with atomic nucleimaximum energy transfer in collision of particles with equal masses
good shielding material:paraffin H2-Cwater H2-Oconcrete chemically bound crystal water
bad shielding material:lead
leave safety measures to a real expert
18/04/23 radiation safety - level 5 17
Sources and x-ray equipmentSources and x-ray equipmentNORMNORM
NORM = naturally occuring radioactive materials
examples:uranium + daughtersthorium + daughterspotassium
sometimes everywhere (radon in dwellings)sometimes very large amounts with very low concentrationsometimes subject to Decree Radiation Protection
oil and gass industry produce 210Pb containing waste