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Radiation safety level 5. Frits Pleiter. Contents. atomic and nuclear physics (1) interaction with matter (3) sources and x-ray equipment (2) shielding (3) detection (4) radiobiology (6)
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Radiation safetylevel 5 Frits Pleiter radiation safety - level 5
Contents • atomic and nuclear physics (1) • interaction with matter (3) • sources and x-ray equipment (2) • shielding (3) • detection (4) • radiobiology (6) • objective risk of radiation (6) • subjective risk acceptation (6) • quantities and units (5) • regulations (7) • practical health physics (8 - 10) • waste (11) radiation safety - level 5
Quantities and units activity = disintegrations / time (A) becquerel (Bq) exposure = charge / mass (X) röntgen (R) absorbed dose = energy / mass (D) gray (Gy) equivalent dose (H) sievert (Sv) effective dose (E) sievert (Sv) commited dose (E(50)) sievert (Sv) radiation safety - level 5
Quantities and units HT = wR DT wR = radiation weighting factor E = T wT HT wT = tissue weighting factor T wT = 1 E(50) = e(50) A e(50) = effective dose coefficient E(50) is summed over 50 year E(50) is attributed to the year of intake radiation safety - level 5
Quantities and unitsradiation weighting factor type wR -radiation 20 -radiation 1 -radiation 1 neutrons 5 - 20 (depending on energy) radiation safety - level 5
Quantities and unitstissue weighting factor organ wT gonades 0.20 bone marrrow 0.12 large intestine 0.12 lungs 0.12 stomach 0.12 bladder 0.05 breast tissue 0.05 liver 0.05 oesophagus 0.05 thyroid 0.05 skin 0.01 bone surface 0.01 remainder 0.05 radiation safety - level 5
Quantities and unitsappropriate language what is meant by a dose of 2 Sv on the thyroid an absorbed dose of 2 Gy on the thyroid ? for the unit of dose is gray an equivalent dose of 2 Sv on the thyroid ? in that case the effective dose was 0.05 2 = 0.10 Sv an effective dose of 2 Sv due to an irradiation of the thyroid ? in that case the equivalent thyroid dose was 2 / 0.05 = 40 Sv radiation safety - level 5
Quantities and unitsorders of magnitude activity in human body 8.5 kBq activity handled in radionuclide laboratory 1 kBq - 1 GBq activity used for medical diagnostics 10 MBq - 1 GBq activity used for medical therapy 100 MBq - 100 TBq annual dose from natural background 1.6 mSv annual dose from medical diagnistics 0.8 mSv annual limit for normal workers 1 mSv annual limit for exposed workers 20 mSv lethal dose > 5 Sv radiation safety - level 5
Quantities and unitsnatural background radiation radiation safety - level 5
Quantities and unitsradiation at large altitude radiation safety - level 5