Course: Chemistry 501

Test: Radiation Safety Exam

Instructor: Edwin Jackson RADIATION SAFETY EXAMINATION 1. Your Radiation Safety Manual should contain which of the following:

a. A List of authorized users b. PI User Authorization c. Facility Authorization d. User Certification for all authorized users, including the PI. e. All of the above f. a, b, g a, b, c

2. Which of the following records must be maintained by each laboratory using radioactive materials?

a. Inventory of radioactive material b. Records of disposal c. Records of laboratory surveys e. sealed source leak checks f. a, c, e g. a, b, c

3. You are working with tritium and wish to survey your laboratory for contamination, which of the following methods or instruments would be useful?

a. Geiger-Mueller Counter b. Liquid Scintillation Counter c Solid Scintillation Counter d. Gas Proportional Counter e. Ionization Chamber f. a, d, c, g. b, d

4. In checking for 32P contamination which of the following methods or instruments could detect the presence of the nuclide?

a. Geiger-Mueller Counter b. Liquid Scintillation Counter c Solid Scintillation Counter d. Gas Proportional Counter e. Ionization Chamber f. a, c, d g. a, b, c, d, e 5. In checking for 125I contamination which of the following methods or instruments would be the most efficient?

a. Geiger-Mueller Counter b. Open window flow through counter c Solid Scintillation Counter d. Gas Proportional Counter e. Ionization Chamber f. a, b, e g. a, b, c, d, e

6. 0.5 liters of tritiated water containing 0.5 Ci 3H is mixed with the water in a tank. A 1 ml sample of water is removed from the tank mixed with appropriate scintillation counting fluid and counted on a scintillation counter. You may disregard quenching effects. The efficiency of the counter is determined to be 55% and the observed count is 5000 counts per minute. What was the volume of water in the tank prior to the addition of the tritiated water?

a. 300,000 liters b. 244,200 liters c. 122,100 liters d. 3,765,000 liters e. 9,000 liters

7. ALARA is a term used with respect to radiation safety. Which of the following statements best describes the ALARA concept.

a. Keep the natural background radiation as low as possible b. Don=t eat in the laboratory c. Use all prudent means to reduce exposure to radiation d. Limit the waste produced when using radioactive material

8. Safety standards for handling radioactive material must be in compliance with The Utah Regulatory Code. The two sections of the code specifically addressing worker safety and notification are:

a. R313-13 b. R313-15 c. R313-17 d. R313-18 e. R313-16 f. a, b g. b, d

9. In case there is a spill of radioactive material which of the following would not be an important objective?

a. Clean it up as soon as possible. b. Limit the spread. c. Protect human life. d. Call the Radiation Safety Officer if it is during working hours. e. a, b, c f. a, b, d g. a, b, c, d

10. Which of the following would be the most serious external health hazard?

a. 3H b. 14C c. 32 P

11. Emissions from which of the following would have the highest specific ionization in tissue?

a. 3H b. 14C c. 32P d. 125I

12. In which of the following shielding materials will generation of bremsstrahlung be the highest given the same flux of a high energy beta particle beam?

a. Paraffin b. Copper c. lead d. glass

13. The Compton Effect is a means of transferring energy which occurs with:

a. gamma radiation b. alpha radiation c Neutrons d. -Beta radiation

14. Gamma radiation is generally produced in:

a. outer electron orbital b. inner electron orbital c. nucleus d. electrons moving between orbitals

15. Which of the following represents an equation demonstrating the decay of 32P ( you may ignore neutrinos and antineutrinos).

a. n + e => p b. p + e => n c. n => p + e d. e+ + e- => energy e. none of the above 16. You could expect a good thin window Geiger counter to have a 2 pi efficiency for 14C beta's of about:

a. 5% b. 10% c. 25% d. 50%

17. Which of the following would be appropriate disposal methods for 1 Ci of 14C at BYU?

a. Dump it down the drain. b. Burn it. c. Ship it out to a disposal site. d. Decay in storage.

18. Which of the following would be appropriate disposal methods for 10 mCi of 32P?

a. Dump it down the drain. b. Burn it. c. Ship it out to a disposal site. d. Decay in storage.

19. Which of the following tissues is most sensitive to damage due to ionizing radiation at a given level?

a. skin b. muscle c. fat d. blood cells and their progenitors

20. The Roentgen is defined as the amount of radiation needed to produce a specific number of ion pairs in:

a. tissue. b. water. c. air. d. man.

21. The Gray is equivalent to

a. 100 rad b. 100 rem c. 100 R d. .01 rem e. .01 R f. .01 rad

22. In order to convert roentgens to rads for a particular tissue you must: a. determine the average and maximum energy. b. multiply by the quality factor. c. know the density of the tissue d. none of the above

23. You have 2 mCi of 32P on April 5 and inadvertently forget it until April 29. What is the remaining activity? ( 2 life = 14.29 days)

a. 0.3 b. 0.62 c. 1.11 d. 1.50

24. Which of the following is true regarding free radical damage due to ionizing radiation.

a. Since ionizing radiation does so much direct damage free radicals are relatively unimportant b. There are relatively few molecules in living systems that can become free radicals c. the OH radical is the most important free radical created by ionizing radiation in biological systems. d. all of the above e. none of the above

25. Ionizing radiation can cause:

a. Inactivation of enzymes b. alterations in DNA c. alterations in RNA d. all of the above e. none of the above

26. Which of the following would be most sensitive to damage caused by ionizing radiation:

a. First trimester fetus b. 2 year old child c. 20 year old adult male d. 80 year old adult female

27. Normal background radiation in the Provo area is likely to cause an exposure of about:

a. 1 rem/year b. 1 sievert/year c. 1 rad/year d. 1 R/ year e. 200 mrem/year

28. Gamma radiation is:

a. very penetrating due to its lack of mass and charge b. Has very high specific ionization due to it's high energy c. best shielded with high atomic number materials d. not of concern since it does not react with tissue e. a, b, c f. a, c

29. Calculate the exposure rate in mrem/hr from a beta field producing a measurement of 100 counts/second with a pancake probe with 10 square centimeters of active surface area and an 80 % efficiency rate. The beta's have an average energy of 695 keV. You may calculate exposure for the soft tissue from the surface to one centimeter depth assuming that all of the energy is dissipated in one centimeter. (Hint: 1 erg = 6.24 X 1011 electron volts and soft tissue has unit density, one rad = 100 ergs/gram)

a. 0.25 mrem/hr b. 0.5 mrem/hr c. 3 mrem/hr d. 2.5 rem/hr e. 5 mrem/hr

30 Given that high energy betas dissipate energy at the rate of about 0.2 Mev/ 0.1 cm traveled in unit density material, calculate the dose to the first 0.1 cm of tissue from the same high energy beta field used in problem 28.

a. 10 mrem/hr b. 0.72 mrem/hr c. 1.44 mrem/hr d. 2.5 mrem/hr e. 5.5 mrem/hr

31. Which of the following must be labeled with the standard radiation symbol?

a. Room in which 32P is used. b. Refrigerator in which 14C is stored. c. Test tube currently in use. d. A centrifuge contaminated with a radioisotope. e. a, b, c f. a, b, d g. a, b, c, d

32. Which of the following is the permissible annual whole body exposure to ionizing radiation? a. 100 gray b. 100 becquerel c. .05 sievert d. 125 gray e. 100 mrem f. 1.25 rad

33. You are given 1 ml of 32P labeled dATP in solution. The labeled dATP is has an activity of 0.3 Ci/ml. You are performing an experiment in which the labeled dATP is added to a culture of E.Coli in log phase growth. The DNA from all of the cells is divided into the plasmid fraction and the chromosomal fraction via biochemical wizardry. Assume 50% incorporation of labeled dATP into the DNA and a 1/10 ratio of plasmid DNA (w/w) to chromosomal DNA. You add one tenth of the total chromosomal DNA from a single spiked culture to a vial filled with a suitable liquid scintillation cocktail and count using LSC. For good results you need at least 5,000 counts per minute from each fraction when counted on a scintillation counter with an efficiency of 95%. You may disregard quenching. How much label will you add to each separate culture in order to assure acceptable results without using excess material?

a. 1. 4 *10-5 ml b. 1.7 *10 -7 ml c. 1.0*10-7 ml d. 1.0 * 10-8 ml 34. Under our license and Bureau of Radiation Control Rules we are obliged to maintain "adequate security for radioactive materials". What does this mean?

a. Stored radioisotopes must be either locked up or under the direct supervision of a qualified individual.

b. Experiments involving radioisotopes must be under the direct physical supervision of a qualified individual or the door to the laboratory must be locked.

c. Radioactive waste must be locked up or a qualified person must be able to see any tampering with the container at all times

d. all of the above e. a, b f. a, c g. b, c

35. The exposure limit set by regulation for an unborn child would be.

a. 100 mrem/ month b. 50 mrem/month c. 5 rem/year d. 1 rem/year e. 1 gray/month f. 1 sievert/month

36. In working with radioactive material what are the manipulable parameters which may be altered to minimize exposure.

a. time, shielding b. distance c. quantity d. a, c e. a, b f. a, b, c

37. Protective clothing that should be worn when working with .250 millicuries of liquid containing 35S includes.

a. gloves b. lab coat c. eye protection d. all of the above e. a, b f. b, c g. a, c 38. By virtue of both BYU policies and federal and state rules or regulations you are required to wear personal dosimetry badges whenever you are working with significant quantities of:

a. 32P b. 125I c. 3H d. 14C e. a, b f. a, d g a, b, d

39. The LD50 in humans for a single whole body ionizing radiation dose would be approximately:

a: .5 gray b. 5 gray c. 50 gray d. 500 gray

40. The minimum radiation absorbed dose to the skin sufficient to cause erythema would be about:

a. 1 gray b. 10 grays c. 100 grays d. 10 sieverts

41. Which of the following activities would be prohibited in a laboratory using radioactive material?

a. computer use b. sink disposal of radioactive waste c. eating or drinking d. all of the above e. none of the above

42. You should survey your laboratory:

a. once each month b. only when the RSO indicates that it is necessary c. at the end of each day that radioactive material is used d. none of the above

43. To prepare radioactive waste for disposal you should: a. remove all radioactive tags from tubes and containers b. place dry waste in a plastic bag and seal the bag c. not mix long half life waste with short (less than 90 days) half life waste. d. label the waste with the date, nuclide, and quantity in millicuries. e. use plastic containers for liquid waste. f. all of the above g. a, b, d h. b, c, d

44. Surveys should include surface scans or swipes of:

a. Floor b. Sinks c. Centrifuges d. Telephones e. Hands f. Door Handle g. All of the above

45. Surveys should be considered >positive= if:

a. They are at least 100 cpm above background b. They are at least 100 dpm above background c. They are above background d. None of the above

46. Survey meters should be checked with an appropriate check source:

a. Once each month b. Once each day c. Once each week d. Before the meter is used e. None of the above

47. When radioactive material is first received, it should be opened:

a. On a lab bench covered with soaker paper b. Only with a lab coat and gloves c. In a fume hood d. none of the above f. a, b g. b, c

48. The Linear No-Threshold theory of damage due to ionizing radiation is:

a. Well supported by experimental data b. Used by regulators in developing radiation protection policy c. Applicable to chronic symptoms of radiation exposure d. All of the above e. a, b f. a, c g. b, c

49. The User Certification that you sign indicates that:

a. You have read the applicable regulations b. You understand the ALARA concept c. You have a dosimetry badge d. All of the above e. a, b f. a, c g. a, c

50. Which of the following would have the highest radiotoxicity

a. gamma emitter with long physical half life and no target organ b. low energy beta emitter with long biological half life, that is preferentially concentrated in the bone c. low energy beta emitter with short biological half life that has no target organ d. alpha emitter with long biological half life, that is preferentially concentrated in the bone e. alpha emitter with short biological half life, that has no target organ f. gamma emitter with long biological half life that is preferentially concentrated in the bone