1. 13/10/2015radiation safety - level 51 Radiation safety level 5 Frits Pleiter

2. 13/10/2015radiation safety - level 52 Excercises  Atomic and nuclear physics Atomic and nuclear physics  Sources and x-ray equipment Sources and x-ray equipment  Interaction and shielding Interaction and shielding  Detection Detection  Quantities and units Quantities and units  Radiobiology Radiobiology  Risk of radiation Risk of radiation  Regulations Regulations  Dose calculations Dose calculations  Open sources Open sources  Radioactive waste Radioactive waste

3. 13/10/2015radiation safety - level 53 Atomic and nuclear physics 1Which particles are the building blocks of the atomic nucleus? protons and neutrons 2The nucleus of a copper atom contains 29 protons. How many electrons are there in the electron cloud of a neutral copper atom? 29 3What is meant by excitation? What is meant by ionization? excitation = promotion of an electron to a higher energy level ionization = removal of an electron from the electron cloud

4. 13/10/2015radiation safety - level 54 Atomic and nuclear physics 4What are isotopes ? atoms with equal Z but different N 5What are isomers? atoms with equal Z and equal N 6What do you know about the Z-value of hydrogen ( 1 H), deuterium ( 2 H) and tritium ( 3 H)? all equal Z(Z = 1)

5. 13/10/2015radiation safety - level 55 Atomic and nuclear physics 7What do you know about the N-value of hydrogen ( 1 H), deuterium ( 2 H) and tritium ( 3 H)? all different N(N = 0, 1 and 2) 8What is the unit of activity? becquerel (Bq) 9How many disintegrations per second (dps) is 1 Bq? 1 dps

6. 13/10/2015radiation safety - level 56 Atomic and nuclear physics 10Would you call 1 kBq a strong or a weak source? weak 11Would you call 1 GBq a strong or a weak source? strong 12The initial activity is 100 MBq. The half-life is 24 hour. What is the activity after 1 day? 100 / 2 = 50 MBq(1 day = 24 hours)

7. 13/10/2015radiation safety - level 57 Atomic and nuclear physics 13And what is the activity after 5 days? How many percent of the initial activity is this? 100 / 32 = 3 MBq(2 5 = 32) 14What is the half life? 25 seconds about 3%

8. 13/10/2015radiation safety - level 58 Atomic and nuclear physics 15How change Z, N and the mass number A during  - -decay?  Z = +1,  N = -1,  A = 0 16How change Z, N and the mass number A during  + -decay?  Z = -1,  N = +1,  A = 0 17How change Z, N and the mass number A during electron capture?  Z = -1,  N = +1,  A = 0

9. 13/10/2015radiation safety - level 59 Atomic and nuclear physics 18How change Z, N and the mass number A during  -decay?  Z = -2,  N = -2,  A = -4 19How change Z, N and the mass number A during  -decay?  Z = 0,  N = 0,  A = 0 20How change Z, N and the mass number A during internal conversion?  Z = 0,  N = 0,  A = 0

10. 13/10/2015radiation safety - level 510 Atomic and nuclear physics 21Which secundary processes take place after electron capture? emission of x-ray photons and Auger electrons 22Which secundary processes take place after internal conversion? emission of x-ray photons and Auger electrons 23Which secundary process takes place after  + -decay? emission of annihilation radiation(E ± = 511 keV)

11. 13/10/2015radiation safety - level 511 Atomic and nuclear physics 24The desintegration energy is 1000 keV. Can  + -decay occur? no 25 Name the decay processes.  - -decay electron capture  + -decay  -decay  -decay

12. 13/10/2015radiation safety - level 512 Atomic and nuclear physics 26Can a nucleus show  - -decay as well as  + -decay? yes 27What is annihilation? e + + e -  2 photons, each with an energy of 511 keV

13. 13/10/2015radiation safety - level 513 Sources and x-ray equipment 1Sealed sources do or do not form a risk of internal contamination? they do 2Sealed sources do or do not form a risk of external irradiation? they do 3A Nuclear Energy Act permit is or is not required for possession of a sealed source? it is

14. 13/10/2015radiation safety - level 514 Sources and x-ray equipment 4The application of a sealed source is or is not restricted to a radionuclide laboratory? it is not 5A smear test on a sealed source does or does not make sense? it does: the source might leak 6An x-ray tube produces bremsstrahlung, or annihilation radiation, or both, or neither of them? bremsstrahlung

15. 13/10/2015radiation safety - level 515 Sources and x-ray equipment 7An x-ray tube produces bremsstrahlung, or characteristic radiation, or both, or neither of them? both 8The maximum bremsstrahlung energy does or does not depend on the anode voltage? it does 9The maximum bremsstrahlung energy does or does not depend on the anode current? it does not

16. 13/10/2015radiation safety - level 516 Sources and x-ray equipment 10The maximum bremsstrahlung energy does or does not depend on the cathode material? it does not 11The maximum bremsstrahlung energy does or does not depend on the anode material? it does not 12The maximum bremsstrahlung energy does or does not depend on the filtering? it does not

17. 13/10/2015radiation safety - level 517 Sources and x-ray equipment 13The energy of characteristic radiation does or does not depend on the anode voltage? it does not 14The energy of characteristic radiation does or does not depend on the anode current? it does not 15The energy of characteristic radiation does or does not depend on the cathode material? it does not

18. 13/10/2015radiation safety - level 518 Sources and x-ray equipment 16The energy of characteristic radiation does or does not depend on the anode material? it does 17The energy of characteristic radiation does or does not depend on the filtering? it does not 18The bremsstrahlung intensity does or does not depend on the anode voltage? it does

19. 13/10/2015radiation safety - level 519 Sources and x-ray equipment 19The bremsstrahlung intensity does or does not depend on the anode current? it does 20The bremsstrahlung intensity does or does not depend on the cathode material? it does not 21The bremsstrahlung intensity does or does not depend on the anode material? it does

20. 13/10/2015radiation safety - level 520 Sources and x-ray equipment 22The bremsstrahlung intensity does or does not depend on the filtering? it does 23The intensity of characteristic radiation does or does not depend on the anode voltage? it does 24The intensity of characteristic radiation does or does not depend on the anode current? it does

21. 13/10/2015radiation safety - level 521 Sources and x-ray equipment 25The intensity of characteristic radiation does or does not depend on the cathode material? it does not 26The intensity of characteristic radiation does or does not depend on the anode material? it does 27The intensity of characteristic radiation does or does not depend on the filtering? it does

22. 13/10/2015radiation safety - level 522 Sources and x-ray equipment 28Neutrons are effectively shielded by water, or paraffin, or concrete, or any of these materials? any 29Neutrons are effectively shielded by paraffin, or lead, or both, or none of these materials? paraffin

23. 13/10/2015radiation safety - level 523 Interaction and shielding 1The range of 5 MeV  -particles in air is about 0.3 mm 3 mm 3 cm 3 m 3 cm 2The range of 1 MeV  -particles in air is about 0.4 mm 4 mm 4 cm 4 m

24. 13/10/2015radiation safety - level 524 Interaction and shielding 3The range of 5 MeV  -particles in tissue is about 3  m 30  m 0.3 mm 3 mm 3 cm / 1000 = 30 µm because the density of tissue is 1000 times larger than the density of air 4The range of 1 MeV  -particles in tissue is about 0.4 mm 4 mm 4 cm 4 m 4 m / 1000 = 4 mm because the density of tissue is 1000 times larger than the density of air

25. 13/10/2015radiation safety - level 525 Interaction and shielding 5What is the photo-electric effect? ionization due to absorption of a photon 6What is the Compton-effect? scattering of a photon by an electrons 7What is pair formation?   e + + e -

26. 13/10/2015radiation safety - level 526 Interaction and shielding 8Which secundary processes take place after photo-electric effect? emission of x-ray photons and Auger electrons 9 Which secundary processes take place after pair formation? emission of annihilation photons(511 keV) 10Which material would you choose to shield  -radiation? no shielding needed(range is too small)

27. 13/10/2015radiation safety - level 527 Interaction and shielding 11Which material would you choose to shield  - -radiation? plastic(small Z-value to avoid bremsstrahlung) 12Which material would you choose to shield  + -radiation? plastic + additional lead(to shield 511 keV annihilation photons) 13Which material would you choose to shield  -radiation? lead (or concrete)

28. 13/10/2015radiation safety - level 528 Interaction and shielding 14Which material would you choose to shield Auger electrons? no shielding needed(range is too small) 15The maximum range in water of the  -particles emitted by 32 P is 0.8 cm. What is the maximum range in air? about 1000  0.8 cm = 800 cm = 8 m

29. 13/10/2015radiation safety - level 529 Interaction and shielding 16What is the half-value thickness of lead for the  -radiation emitted by 131 I 137 Cs 60 Co 123 Sb 24 Na 0.2 cm 0.6 cm 1.3 cm 1.7 cm 17Why is the transmission curve for 198 Au not a straight line? because  -photons with different energies are emitted (284 keV, 364 keV and 637 keV)

30. 13/10/2015radiation safety - level 530 Interaction and shielding 18The half-value thickness for shielding  -radiation is 1 cm. How much shielding material is needed to reduce the radiation level to 3% of the initial value? 5 × 1 = 5 cm(3% = 1 / 2 5 = 1 / 32) 19The linear attenuation coefficient for shielding  -straling is 1 cm -1. How much shielding material is needed to reduce the radiation level to 3% of the initial value? 5 × (0.7 / 1) = 3.5 cm(d ½ = 0.7 / µ)

31. 13/10/2015radiation safety - level 531 Interaction and shielding 20When shielding  -radiation, the build-up factor of concrete is larger or smaller than the build-up factor of lead? larger

32. 13/10/2015radiation safety - level 532 Detection 1The voltage over an ionization chamber is relatively low or relatively high? relatively low 2The voltage over a proportional counter is relatively low or relatively high? neither low nor high, but in the intermediate region 3The voltage over a Geiger-Müller counter is relatively low or relatively high? relatively high

33. 13/10/2015radiation safety - level 533 Detection 4A gas-filled ionization chamber can or can not measure radiation energies? it can not(signals too small) 5A proportional counter can or can not measure radiation energies? it can 6A Geiger-Müller counter can or can not measure radiation energies? it can not(all signals are equal)

34. 13/10/2015radiation safety - level 534 Detection 7Which material is more suited to detect γ-radiation: Si (Z=14) or Ge (Z=32)? Ge(because of larger photo-electric effect) 8Which material is more suited to detect β-radiation: Si (Z=14) or Ge (Z=32)? Si(small photo-electric effect, therefore less sensitive to background  -radiation) 9A Ge-detector is a scintillation detector or an ionization chamber? ionization chamber

35. 13/10/2015radiation safety - level 535 Detection 10TLD is a scintillation detector or an ionization chamber? scintillation detector 11Why must scintillation material be transparant? scintillation light must be able to escape from the detector material and reach the photocathode of the photomultiplier tube 12A scintillation detector can or can not measure radiation energies? it can

36. 13/10/2015radiation safety - level 536 Detection 13A source with an activity of 400 kBq gives rise to a count rate of 100 counts per second (cps). What is the counting efficiency? 100 / 400  10 3 = 0.025% 14Which detector would you use to identify low-energy (20 keV)  -radiation? proportional counter or NaI(Tl) with a thin window 15Which detector would you use to identify high-energy (2 MeV)  -radiation? NaI(Tl) or Ge-detector

37. 13/10/2015radiation safety - level 537 Detection 16Which detector would you use to identify low-energy (20 keV)  -radiation? liquid scintillator, proportional counter or plastic scintillator 17Which detector would you use to identify high-energy (2 MeV)  -radiation? liquid scintillator, plastic scintillator or Si-detector 18Which detector is commonly used as dose rate monitor? Geiger-Müller counter

38. 13/10/2015radiation safety - level 538 Detection 19Which detector is extremely well suited to measure a contamination with a soft (20 keV)  ‑ emitter? large-area proportional counter or NaI(Tl) with a thin window 20Which detector is extremely well suited to measure a contamination with a hard (2 MeV)  ‑ emitter? NaI(Tl) or Ge-detector combined with smear test 21Which detector is extremely well suited to measure a contamination with a soft (100 keV)  -emitter? Geiger-Müller counter with a thin window (not for tritium) or liquid scintillator combined with smear test

39. 13/10/2015radiation safety - level 539 Detection 22Which detector is extremely well suited to measure a contamination with a hard (1 MeV)  ‑ emitter? Geiger-Müller counter or proportional counter with a thin window or liquid scintillator combined with smear test 23Which quantity is usually measured with a TLD-detector? equivalent dose

40. 13/10/2015radiation safety - level 540 Quantities and units 1What is the unit for activity? What is the symbol of this unit? bequerel 2What is the unit for exposure? What is the symbol of this unit? Bq röntgen R

41. 13/10/2015radiation safety - level 541 Quantities and units 3What is the unit for absorbed dose? What is the symbol of this unit? gray 4What is the unit for equivalent dose? What is the symbol of this unit? Gy sievert Sv

42. 13/10/2015radiation safety - level 542 Quantities and units 5What is the unit for effective dose? What is the symbol of this unit? sievert 6What is the unit for commited dose? What is the symbol of this unit? Sv sievert Sv

43. 13/10/2015radiation safety - level 543 Quantities and units 7Which quantity is expressed in becquerel (Bq)? What is the symbol of this quantity? activity 8Which quantity is expressed in röntgen (R)? What is the symbol of this quantity? A exposure X

44. 13/10/2015radiation safety - level 544 Quantities and units 9Which quantity is expressed in gray (Gy)? What is the symbol of this quantity? absorbed dose 10Which quantity is expressed in sievert (Sv)? What is the symbol of this quantity? D equivalent dose, effective dose and committed dose H T, E en E(50)

45. 13/10/2015radiation safety - level 545 Quantities and units 11The radiation weighting factor w R for  -radiation is 1 5 20 100 20 12 The radiation weighting factor w R for  -radiation is 1 5 20 100 1

46. 13/10/2015radiation safety - level 546 Quantities and units 13The radiation weighting factor w R for  - radiation is 1 5 20 100 1 14What is the equivalent dose, if the absorbed dose is 1 mGy and the radiation weighting factor is w R = 20? 20  1 = 20 mSv

47. 13/10/2015radiation safety - level 547 Quantities and units 15The tissue weighting factor for the thyroid is w T = 0.05. The equivalent dose in the thyroid is 2 Sv. What is the effective dose? 0.05  2 = 0.10 Sv = 100 mSv 16Is this peanuts or a lot? a lot 17Is 1 Sv a large or a small effective dose? a very large dose(50  annual dose limit)

48. 13/10/2015radiation safety - level 548 Quantities and units 18Is 1  Sv/h a large or a small equivalent dose rate? small equivalent dose rate (maximum effective dose = 2000  1 = 2000 μSv = 2 mSv per year) 19A large value of e(50) means a large or a small radiotoxicity? large radiotoxicity 20The value of the effective dose coefficient does or does not depend on the radionuclide? it does

49. 13/10/2015radiation safety - level 549 Quantities and units 21The value of the effective dose coefficient does or does not depend on the chemical composition of the radioactive substance? it does 22The value of the effective dose coefficient does or does not depend on the contamination route? it does

50. 13/10/2015radiation safety - level 550 Radiobiology 1Damage produced by ionizing radiation is mainly due to direct breaks of biomolecules or to ionization of water molecules? ionization of water molecules 2Which cells are most sensitive to radiation? frequently dividing cells 3Which cells are least sensitive to radiation? cells that do not divide anymore

51. 13/10/2015radiation safety - level 551 Radiobiology 4What happens if the unborn embryo is irradiated during the first week of the pregnancy? either nothing or the embryo dies 5Is it possible that malformed organs develop if the unborn embryo is irradiated during the first week of the pregnancy? no 6Is it possible that malformed organs develop if the unborn embryo is irradiated during the second month of the pregnancy? yes, during this period the organs are formed

52. 13/10/2015radiation safety - level 552 Radiobiology 7Is it possible that malformed organs develop if the unborn foetus is irradiated during the second half of the pregnancy? no, organ formation is completed 8What might happen if the unborn foetus is irradiated during the second half of the pregnancy? growth retardation 9Is there a threshhold dose for stochastic effects? no 10Is the severity of a stochastic effect dose dependend?

53. 13/10/2015radiation safety - level 553 Radiobiology 11Is there a threshhold dose for harmful tissue reactions? yes 12 Is the severity of harmful tissue reactions dose dependend? yes 13Leukemia is a stochastic effect or a harmful tissue reaction? stochastic effect harmful tissue reaction 14Cataract is a stochastic effect or a harmful tissue reactions?

54. 13/10/2015radiation safety - level 554 Radiobiology 15After a total-body irradiation dies half of the irradiated persons if the effective dose is about 0.4 Sv 4 Sv 40 Sv 4 Sv 16After a total-body irradiation to an effective dose of 4 Sv there is a 50% chance to die because of damage to the bone marrow gastro-intestinal tract nervous system the bone marrow

55. 13/10/2015radiation safety - level 555 Radiobiology 17After a total-body irradiation to an effective dose of 10 Sv there is a 50% chance to die because of damage to the bone marrow gastro-intestinal tract nervous system the gastro-intestinal tract or, at survival, the bone marrow 18After a total-body irradiation to an effective dose of 50 Sv there is a 50% chance to die because of damage to the bone marrow gastro-intestinal tract nervous system

56. 13/10/2015radiation safety - level 556 Radiobiology 19What is the risk factor for stochastic effects after exposure to ionizing radiation? 5% per sievert

57. 13/10/2015radiation safety - level 557 Risk of radiation 1What is meant by: the risk factor for stochastic effects is 0.05 per sievert? if a million people are exposed to 1 Sv, about 0.05  1 000 000 = 50 000 of them will eventually die 2The annual natural radiation background in The Nederlands is approximately 2 µSv per year 20 µSv per year 2 mSv per year 20 mSv per year 2 mSv per year

58. 13/10/2015radiation safety - level 558 Risk of radiation 3The annual dose limit for exposed workers is 2 µSv per year 20 µSv per year 2 mSv per year 20 mSv per year 4The annual dose limit for normal workers is 0 mSv per year 0.1 mSv per year 1 mSv per year 20 mSv per year 1 mSv per year

59. 13/10/2015radiation safety - level 559 Risk of radiation 5Regular exposure to the dose limit of 20 mSv per year is a relatively small or a relatively high occupational hazard? (very) high hazard 6The risk factor for ionizing radiation is 0.05 per Sv. The average annual dose is about 2 mSv. Nearly 17 million people live in The Netherlands. How many persons will die each year due to ionizing radiation? 17 000 000  0.002  0.05 = 1700 (each year about 44 000 people die of cancer!)

60. 13/10/2015radiation safety - level 560 Risk of radiation 7What is wrong with this newspaper clipping, and why? the boy is at least 4 years old and was already born at the moment of the Chernobyl accident the malformations must be due to something else A Chernobyl victim one year after the nuclear disaster.

61. 13/10/2015radiation safety - level 561 Regulations 1The ICRP is an independent committee of experts advisory board of the Dutch government advisory board of the American government advisory board of the European Community an independent committee of experts 2Radiological workers must comply with the dose limits ALARA principle principle of justification all these principles with all principles

62. 13/10/2015radiation safety - level 562 Regulations 3The ALARA principle means that the effective dose must be as low as reasonably achievable zero less than 2 mSv per year less than 20 mSv per year as low as reasonably achievable 4The annual effective dose limit for an exposed worker is 2  Sv 20  Sv 2 mSv 20 mSv

63. 13/10/2015radiation safety - level 563 Regulations 5The annual dose limit for the lens of the eye of an exposed worker is 2 mSv 20 mSv 150 mSv 500 mSv 150 mSv 6The annual dose limit for hands, feet and skin of an exposed worker is 2 mSv 20 mSv 150 mSv 500 mSv

64. 13/10/2015radiation safety - level 564 Regulations 7The tissue weighting factor for the gonads is 0.20. The maximum permittable annual gonade dose is 4 mSv 20 mSv 100 mSv 500 mSv 20 / 0.20 = 100 mSv 8Radiological workers must comply with the Nuclear Energy Act Working Conditions Act Environmental Management Act all of them

65. 13/10/2015radiation safety - level 565 Regulations 9The Decree Transport of Fissile Materials, Ores and Radioactive Substances is a recommendation of the ICRP Decree under the Nuclear Energy Act Decree under the Working Conditions Act none of these Decree under the Nuclear Energy Act 10The Decree Radiation Protection is a recommendation of the ICRP Decree under the Nuclear Energy Act Decree under the Working Conditions Act none of these Decree under the Nuclear Energy Act

66. 13/10/2015radiation safety - level 566 Regulations 11Is a Nuclear Energy Act permit needed if the activity concentration is lower, but the total activity is larger than the exemption level? no 12Is a Nuclear Energy Act permit needed if the activity concentration is larger, but the total activity is lower than the exemption level? no 13No Nuclear Energy Act permit is required if and only if both the activity concentration and the total activity are below the exemption level. This is true or not true? not true: it is either-or

67. 13/10/2015radiation safety - level 567 Regulations 14The annual effective dose limit for an exposed A worker is 1 mSv 2 mSv 6 mSv 20 mSv 15The annual effective dose limit for an exposed B worker is 1 mSv 2 mSv 6 mSv 20 mSv 6 mSv

68. 13/10/2015radiation safety - level 568 Regulations 16The annual effective dose limit for a normal worker is 0 mSv 0.1 mSv 1 mSv 2 mSv 1 mSv 17An area in which the annual effective dose is larger than 1 mSv but smaller than 6 mSv, must be qualified as controlled area ("gecontroleerde zone") or supervised area ("bewaakte zone")? supervised erea

69. 13/10/2015radiation safety - level 569 Regulations 18An area in which the annual effective dose is larger than 6 mSv must be qualified as controlled area ("gecontroleerde zone") or supervised area ("bewaakte zone")? controlled erea the next three questions are only for level 5A: 19Is a permit needed for x-ray equipment with a maximum anode voltage of more than 100 kV? yes

70. 13/10/2015radiation safety - level 570 Regulations 20Is a permit needed for x-ray equipment that is used for medical radiotherapy? yes 21Is a permit needed for x-ray equipment that is used for teaching? yes

71. 13/10/2015radiation safety - level 571 Dose calculations 1How many working hours are there in a standard working day? 8 hours 2How many working hours are there in a standard working week? 5  8 = 40 hours 3How many working hours are there in a standard working year? 50  40 = 2000 hours

72. 13/10/2015radiation safety - level 572 Dose calculations 4The received dose is reduced by working faster or slower? faster 5The received dose is reduced by increasing or decreasing the working distance? increasing 6The received dose is reduced by applying more or less shielding? more shielding

73. 13/10/2015radiation safety - level 573 Dose calculations 7The dose rate is reduced by working faster or slower? makes no difference 8The dose rate is reduced by increasing or decreasing the working distance? increasing 9The dose rate is reduced by applying more or less shielding? more shielding

74. 13/10/2015radiation safety - level 574 Dose calculations 10The dose rate is 2 mGy/h. The received dose in a standard working week is 16 mGy 16 mSv 80 mGy 80 mSv 40  2 = 80 mGy 11The dose rate at 1 m is 1 mGy/h. The dose rate at 10 cm is 0.01 mGy/h 0.1 mGy/h 10 mGy/h 100 mGy/h (100 / 10) 2  1 = 100 mGy

75. 13/10/2015radiation safety - level 575 Dose calculations 12The received dose can be reduced by working twice as fast or by doubling the working distance. What is the best option? Why? doubling the working distance 13The received dose can be reduced by working four times as fast or by doubling the working distance. What is the best option? Why? inverse square law doubling the working distance never rush

76. 13/10/2015radiation safety - level 576 Dose calculations 14The source constant for 60 Co is Γ = 3.6  10 -13 Gy m 2 Bq -1 h -1. What is the dose received in 1 hour at 1 m from a source of 40 MBq? 3.6  10 -13  40  10 6  1 / 1 2 = 14  10 ‑ 6 Sv = 14 µGy 15What is the dose received in 1 standard working year? 2000  14 = 28  10 3 µSv = 28 mGy 16According to the granted Nuclear Energy Act permit, an accelerator must automatically shut down if the quivalent dose rate in the hal is 1  Sv/h. What is the maximum annual effective dose that workers in the hal may receive? 2000  1 = 2000  Sv = 2 mSv

77. 13/10/2015radiation safety - level 577 Dose calculations 17A  -source gives rise to a much larger or a much smaller skin dose than a γ-source with the same activity at the same distance and within the same period of time? much larger the next four questions are only for level 5B: 18Is the biggest risk of internal contamination due to the occasional uptake of a large amount of activity or to the regular uptake of small amounts of activity? the regular uptake of small amounts of activity

78. 13/10/2015radiation safety - level 578 Dose calculations 19A drum filled with mud containing an amount of activity that is 10 time the exemption level is or is not a direct risk of internal contamination? is not (it is impossible to ingest or inhale that much mud) 20Ingestion of activity is or is not more risky than inhalation? can't say: it all depends on the radionuclide and the chemical composition 21It is or is not true that activy can penetrate skin and gloves? true

79. 13/10/2015radiation safety - level 579 Open sources the next seven questions only for level 5B: 1The design requirements for a B-type laboratory are more strict or less strict than for a C-type laboratory? more strict 2The maximum allowed activity in a B-type laboratory is larger or smaller than that in a C-type laboratory? larger

80. 13/10/2015radiation safety - level 580 Open sources 3The maximum allowed activity in a D-type laboratory is larger or smaller than that in a C-type laboratory? smaller 4Specific requirements in the Nuclear Energy Act permit do or do not prevail over general requirements in the Guideline for Radionuclide Laboratories ("Richtlijn Radionucliden­laboratoria")? the most restrictive requirement prevails

81. 13/10/2015radiation safety - level 581 Open sources 5Is pipetting of 50 MBq allowed outside the fume hood, in a C-type laboratory? yes (p = -1, q = 2, r = 0) 6Is boiling of 50 MBq until dryness allowed inside a fume hood that complies with NEN-EN 14175, in a B-type laboratory? allowed (p = -4, q = 3, r = 2) 7Is breaking of a quartz tube containing 500 MBq powder and subsequent transfer of the powder into a glass beaker allowed inside a glove box, in a B ‑ type laboratory? allowed (p = -4, q = 3, r = 3) effective dosiscoefficient is e(50) inh = 2,9 × 10 -9 Sv/Bq see also p,q,r-table

82. 13/10/2015radiation safety - level 582 Open sources pphase of material / type of work -4simple work with gases mixing or grinding powders liquid close to boiling point highly splashing activities -3labelling with volatile nuclide ( 3 H, iodine) storage of gas in a dispenser simple work with enclosed powders boiling of enclosed liquids centrifugation, mixing on a vortex -2simple chemical manipulations (RIA) labelling with non-volatile nuclide elution of a Tc-generator labelling or other work in a closed system labelling of non-dispersible compounds pulling up a syringe qlaboratory class 0outside the radionuclide-laboratory 1D-laboratory 2C-laboratory 3B-laboratory rlocal ventilation 0outside fume hood 1fume hood (not NEN-EN 14175) 2fume hood (NEN-EN 14175) laminar flow cabinet (safety class 2) 3air-flow isolator (safety class 3) glove box back

83. 13/10/2015radiation safety - level 583 Radioactive waste the next eleven questions only for level 5B: 1A surface area is considered to be contaminated if the activity is 1 Bq/cm 2 4 Bq/cm 2 4 Bq/m 2 100 Bq/m 2 4 Bq/cm 2 (according to the "Richtlijn Radionucliden­laboratoria") 2Must waste be treated as radioactive waste if the activity concentration is below the exemption level? no

84. 13/10/2015radiation safety - level 584 Radioactive waste 3Must waste be treated as radioactive waste if the total activity is below the exemption level? no 4In order to dispose of waste as normal industrial waste, both the activity concentration and the total activity must be below the exemption level. Is this true or not true? not true: it is either-or

85. 13/10/2015radiation safety - level 585 Radioactive waste 5Radioactive waste must be disposed of as industrial waste disposed of dangerous industrial waste disposed of chemical waste handed over to COVRA 6Labels with the text "radioactive material" must be put in the regular waste bin blue ­box for environmental waste bin for industrial waste bin for radioactive waste

86. 13/10/2015radiation safety - level 586 Radioactive waste 7May objects with a surface contamination of less than 4 Bq/cm 2 be disposed of as industrial waste? yes 8May the contents of a counting vial always be discharged in the sink? no (never throw chemical waste into the sink) 9May the contents of a counting vial always be disposed of as chemical waste? no (if activity concentration and total activity are both above the exemption level, the waste must be handed over to COVRA)

87. 13/10/2015radiation safety - level 587 Radioactive waste 10The costs of disposing of radioactive waste are or are not exorbitant? they are 11The costs of disposal of 1 drum (100 l) solid radioactive waste amounts to about € 10 € 100 € 1000 € 10 000 about € 1000