SP3:Radiation Safety Flashcards
Which of the following bodies regulates transportation of radiopharmaceuticals?
(a)NRC
(b) DOT
(c) TJC
(d) FDA
(b) The Department of Transportation is the controlling authority for the packaging and transport of all hazardous materials.
Which of the following bodies regulates the use of investigational pharmaceuticals?
(a)NRC
(b) DOT
(c) IRB
(d) FDA
(d) All the use of investigational pharmaceuticals is regulated by the Food and Drug Administration.
In the event of a spill of 99mTc to clothes, one should immediately:
(a)Enter a shower fully clothed.
(b) Remove and store the clothes until they decay to background.
(c) Wash the clothes in hot water and then survey them to determine remaining activity.
(d) Remove and destroy the clothing.
(b) The first priority in event of a spill is to contain the contamination, i.e., to keep it from being spread. In this case, that would be accomplished by removing the clothing and storing it until the activity has decayed to background level.
If a radiopharmaceutical is spilled on the floor, the first priority is to:
(a)Contact the Radiation Safety Officer.
(b) Pour a chelating solution over the area of the spill.
(c) Cover the area with absorbent paper and restrict access around it
(d) Call the housekeeping department to arrange for cleaning.
(c) The contamination must be contained as a first priority. Using a chelating agent may change the chemical structure of the substance spilled but will not affect the radioactivity of it. The Radiation Safety Officer should be notified, but first access to the area of the spill must be restricted.
The inverse square law, in words, says:
(a)If you double the distance from the source of activity, you reduce exposure to 25% of the original intensity.
(b) If you halve the distance from the source of activity, you decrease exposure to 25% of the original intensity.
(c) If you halve the distance from the source of activity, you decrease exposure to one-fourth of the original intensity.
(a) By doubling the distance, the intensity is reduced to one-quarter of the original activity, as shown in the formula below, where I1 is original intensity, I2 is the new intensity, d1 is the original distance from the source, and d2 is the new distance form the source.
I1 / I2 = (d2)^2 / (d1)^2
This can be rearranged to (I1)(D1)^2 = (I2)(D2)^2 for easy solving.
What is the best way to decrease the radioactive dose to visitors if a patient is surveyed to emit 3 mR/h at bedside?
(a)Have the patient wear lead aprons.
(b) Keep the patient well hydrated and encourage frequent voiding.
(c) Have the visitor sit or stand as far as possible from bedside.
(d) Have the visitor wear lead shielding.
(c) The best and simplest way to decrease exposure to a visitor would be to increase the distance form the patient. If the exposure rate is 3 mrem/h at bedside, we can estimate 1 ft. from the patient and we move the visitor to 2 ft. from the patient, the exposure rate at the new distance would be 0.75 merm/h. (The equation in solution to question 5 of this chapter is rearranged to read (I1)(d1)^2 = (I2)(d2)^2 and solved for the new intensity.)
Which of the following isotopes would be effectively shielded by a plastic syringe?
(a)67Ga
(b) 89Sr
(c) 99mTc
(d) 81mKr
(e) 133Xe
(b) Beta emitters can be effectively shielded by a few millimeters of plastic or Lucite. If shielded with lead, bremsstrahlung radiation will be produced from the slowing beta particles.
What is the NRC annual dose limit allowed to the lens of the eye?
(a)1.5 mrem
(b) 15 rem
(c) 50 rem
(d) 5 rem
(b) The NRC annual dose limit permitted to the lens of the eye is 15 rem. The skin of extremities is permitted to 50 rem, and the whole body total effective dose equivalent is limited to 5 rem (10 CFR 20.1201)
Which of the following should be used when administering an intravenous pharmaceutical to a patient?
(a)Lead syringe shield
(b) Leaded eyeglasses
(c) Gloves
(d) (a) and (b) only
(c) Gloves should be used when administering any pharmaceutical. Had the question stated a radiopharmaceutical, a syringe shield would also be needed, unless the radiopharmaceutical was a beta emitter.
Which of the following is the most effective means of measuring low levels of removable radiation?
(a)By performing an area survey
(b) By performing a wipe test
(c) With a pocket dosimeter
(d) With a TLD
(b) Wipe tests are used to detect removable contamination from surfaces such as packages, floors and counters and are achieved by wiping the area in question with a dry wipe and then counting the wipes along with a background sample in a well counter.
What is the dose rate limit at the package surface for a shipment of radioactive material bearing a Yellow-III label?
(a)200 mR/h
(b) 50 mR/h
(c) 200 rads
(d) 200 mrem
(a) DOT labeling categories are as follows: Radioactive White I, limited to packages with a dose rate of 0.5 mrem/h or less at the surface; Radioactive Yellow II, limited to packages with a dose rate of greater than 0.5 mrem/h but less than 50 mrem/h at the surface; Radioactive Yellow III, for packages with a dose rate of greater than 50 mrem/h but less than 200 mrem/h at the surface. Choice (d) is incorrect because it does not give a dose rate measured in mrem/h.
Which of the following measures absorbed doses?
(a)mCi
(b) Becquerel
(c) Gray
(c) The gray (Gy) is an international unit (SI) measuring absorbed radiation dose and is equal to 100 rad. The millicurie (mCi) and the Becquerel (Bq) measure radioactivity according to disintegrations per time. The Becquerel is equal to 1 disintegration per second (dps), and the mCi is equal to 37 MBq.
If the dose rate at 3 m from a radioactive source is 100 mrem/h, what will the dose rate be at 6 m?
(a)25 mR/h
(b) 50 mR/h
(c) 75 mR/h
(d) 12.5 mR/h
(a) This can be solved using the inverse square law ((I1)(D1)^2 = (I2)(D2)^2) to find 25 mrem/h. Or one can recognize that the distance has been doubled, so the intensity is reduced to one-fourth of the original
The philosophy of the ALARA program is to keep the radiation dose:
(a)As low as recently authorized
(b) As long as reasonably attained
(c) As long as reasonably acceptable
(d) As low as reasonably achievable
(d) ALARA is the mnemonic for the NRC’s radiation protection philosophy that one should keep radiation exposure as low as reasonably achievable.
All of the following are critical factors in keeping radiation exposure to a minimum except:
(a)Time spent near the radioactive source
(b) Geometry of the container holding the source of radiation
(c) Distance from the source of radiation
(d) Shielding of the radioactive source
(b) Time, distance, and shielding are the most important factors to consider when attempting to reduce exposure to radiation.
Gaseous radiopharmaceuticals may only be used in rooms that:
(a)Have at least one window
(b) Contain an oxygen supply
(c) Are at a positive pressure compared to surrounding rooms
(d) Are at a negative pressure compared to surrounding rooms
(d) Airborne radiation, such as aerosols or gases, should be administered in rooms that are at negative pressure to surrounding areas. Depending on the amount of activity and the length of time it is present, special posting may be required (10 CFR 20.1902)
If the exposure rate at 4 m from a radioactive source is 5 mR/h, what will the exposure rate be at 3 m?
(a)2.8 mR/h
(b) 6.5 mR/h
(c) 7.4 mR/h
(d) 8.9 mR/h
(d) (I1)(D1)^2 = (I2)(D2)^2
A spill of 99mTc increases the exposure rate in a room from 1.7 to 3.15 mR/h. The room is posted with a sign reading “Caution-Radioactive Materials.” What would be the ideal solution?
(a)Change the sign to one reading “Caution-Radiation Area.”
(b) Call the NRC.
(c) Decontaminate the floor with water and cleanser.
(d) Place absorbent paper over the spill and close the room until the activity has decayed.
(d) A sign reading “Caution Radioactive Materials” is required wherever radioisotopes are used. The sign reading “Caution Radiation Area” sign is required if the dose rate exceeds 5 mrem/h, so no change in sign posting is needed. However, the spill should be contained, so restricting access to the area until the activity has decayed to background is the best course of action.
A technologist has 500 mrem registered on his ring badge in 1 month. What should be done to decrease exposure in the future?
(a)Use lead pigs and syringe shields when preparing radiopharmaceuticals.
(b) Have another technologist elute the generator.
(c) Wear lead aprons.
(a) All technologists should use lead vials and syringe shields when working with radiopharmaceuticals.
OSHA requires that personnel exposure records be provided to employees:
(a)Monthly
(b) Quarterly
(c) Annually
(d) Biannually
(c) OSHA requires that employees are advised at least yearly about their exposure records.
A room containing a 57Co sheet source is posted with a sign reading “Caution-Radioactive Materials.” The exposure rate measured next to the source is 5.2 mR/h. What should be done?
(a)Change the sign to one reading “Caution-Radiation Area.”
(b) Store the source in a leaded container.
(c) Monitor the length of time a technologist can work near the source.
(d) None of the above.
(b) According to the NRC regulations for sing posting, the sign should be changed to “Caution Radiation Area,” but a simpler solution would be to store the source in its leaded container.
A technologist discovers that a patient in the room next to a radioiodine therapy will receive 2.5 mrem/h when lying in his bed which is against the shared wall. What should be done?
(a)Move the bed to the other side of the room.
(b) Discharge the therapy patient.
(c) Discharge the non-therapy patient.
(d) Calculate how long visitors to the non-therapy patient can stay.
(e) Calculate how long the patient may stay in bed each hour.
(a) Time, distance, and shielding are the most important factors in reducing exposure; in this case, the simplest solution is to employ an increase in distance to the source of the radiation.
What is the dose rate limit at the surface of a package bearing a DOT Class I White label?
(a)0.5 mR/h
(b) 2 mR/h
(c) 50 mR/h
(d) 100 mR/h
(e) 200 mR/h
(a) A package with such a label may have an exposure rate that does not exceed 0.5 mR/h at the package surface, and there must be no detectable radiation at 1 m from the package.
A type A package bears a DOT Class II Yellow Radioactive label, has a transport index of 0.8, and contains 10 mCi of 111In oxine. What is the exposure rate at 3 ft from the package?
(a)0.4 mR/h
(b) 0.8 mR/h
(c) mR/h
(d) 7 mR/h
(e) Cannot be determined from the information given
(b) The transport index is the dose rate measured at 1 m (roughly 3 ft) from the surface of the package.
