Card Set Information

2012-11-28 22:31:06

Show Answers:

  1. Who is the NCRP? are they advisory or regulatory
    • National Council on Radiation Protection and Measurement
    • Advisory
  2. Who believes that a radiation worker should be at no higher risk than a worker in other safe industries
    • NCRP
    • National Council on Radiation Protection and Measurement
  3. What is defined as one in which the annual accidental fatality rate is 10-4 or 1 in 10,000 year
    Safe Industry
  4. What is a measure of the genetic risk to a population as a whole from exposure to ionizing radiation of some or all members of that population?
    • GSD
    • genetically significant dose
  5. Why is it difficult for the NCRP to compare injuries, illnesses, and accidental deaths in regular jobs with ionizing rad jobs?
    Partly because of the latent period
  6. What are long term rad exposure effects which a threshold exists and for which the severity of the effect increases with dose
    non stochastic
  7. What are the long term effects of rad exposure which have no threshold and for which the probability of occurence is a function of dose.
  8. The effective dose equivalent which is the limit for stochastic effects is
    50mSv ( 5rem) per year
  9. The effective dose equivalent which is the limit for non stochastic effecs is ____ for the lens of the eye and ____ for all other tissues and organs minus the extermities
    • 150 mSv (15rem)
    • 500mSv (50rem)
  10. The NCRP recommends that the annual effective dose equivalent limit for this population is ____ for persons who are exposed continuously or frequently and ____ for those who are not
    • 1mSv (0.1 rem)
    • 5mSv (0.5 rem)
  11. The total dose equivalent for an embryo or fetus is _____ during gestational period
    5 mSv (0.5 rem)
  12. What should the total dose equivalent for an embryo or fetus be and should be done uniformly with respect to time____ and how much should not exceed ____ in any month
    • 5mSv (0.5rem)
    • 0.5mSv (0.05 rem)
  13. What are the purposes for monitoring radiation dose for rad workers
    • 1) allows the rad worker to know how much rad recvd at work
    • 2) allows employer to know if certain areas are receiving more than other areas
    • 3) provides permanent record of rad received if questions arise later
  14. The NRC and most state regulatory agencies require individuals to be monitored if it's expected that ____ of the effective dose equiv limit will be exceeded
  15. Who is the NRC
    Are they regulatory or advisory
    • Nuclear Radiation Commission
    • regulatory
  16. Name 4 personnel monitoring devices
    • film badge dosimeter
    • TLD
    • OSL (optically stimulated dosimeter)
    • Pocket ionization chamber or pocket dosimeter
  17. What is the most comonly used personnel monitoring device
    film badge
  18. The overall accuracy of the film badge is approx ____ and erroneous readings cann result if the badge is not read for a long time or exposed to heat or humidity
    +- 20%
  19. _____trap electrons in their internal crystal structure when exposed to rad
  20. When TLDs are heated at a later time, ____ is given off as the crystals rearrange themselves
  21. In TLDs, the amt of light emitted is ____ to the amt of rad absorbed
  22. What respond to radiation more like tissue than film does and results in readings that are potentially more accurate?
  23. Which dosimeter uses laser light to stimulate rearrangement of electrons trapped in aluminum oxide when irradiated
  24. ______can be read immediately but are subject to erroneous readings if exposed to humidity or mechanical shock
    Pocket Ionization chamber
  25. What are the time honored methods of radiation protection
    Time, distance, shielding
  26. If the radiation source is small, the inverse square law applies and doubling the distance from the souce reduces the exposure to ____ its original level
  27. If you triple your distance from a rad exposure, the reduction factor is
  28. What is the most important method for protection of operators and members of the general public in a rad therapy dept
  29. The choice of shielding material depends on the
    energy of the beam
  30. _____ is the preferred material for duperficial units because it is more effective than concrete or steel at stopping____ at these low energies, at which photo electric collision dominates
    • lead
    • photons
  31. At higher energies, at which ___ dominate, all materials ____ radiation equally gram for gram and the choice of material is usually based on ____
    • compton interactions
    • attenuate
    • economic space and factors
  32. What are the factors that are taken into acct when calculating shielding requirements for any radiation producing machine
    • W- workload
    • U-usefactor
    • T-occupancy of adjacent rooms to the therapy room
    • d-distance
    • P- effective dose limit for occupied area of public and rad workers
  33. Describe the effective dose factor for shielding
    P- limit for occupied area; rad worker equivalent limit or general public
  34. Describe the distance factor for shielding
    d- distance from the source of radiation to occupied area
  35. Describe occupancy factor for shielding
    T-fraction of time area will be occupied
  36. Describe primary beam use factor for each wall when factoring shielding
    U-Fraction of time the beam is aimed at a particular wall
  37. Describe workload factors for shielding
    W- # of patients per week times amt of rad for each
  38. Consideration must be given to ____ from the patient and ____ from the head, as well as the primary beam
    • scatter radiation
    • leakage radiation
  39. Why does special shielding consideration need to be taken with techniques like cyber knife and IMRT, where many small beams and oblique angles are used
    Because beams go everywhere so every wall and door have to be shielded.
  40. For a typical linear accelerator, 200 paitents may be treated per week (40) per day and isocenter dose may be 300 cGy, so the workload figure would be ___
    60,000 cGy at isocenter but will be more if IMRT
  41. What is the fraction of time an area adjacent to the therapy room is occupied
    occupancy factor
  42. Radiation worker (restricted areas) do not have as much shielding as the areas where the general public are but the shielding design for restricted areas is based on the limits for unrestricted areas in the name of
  43. If the rad level in a room can exceed 1mSv (100rem) in 1 hour, what does the sign posted on the entrance door have to say
    Caution High Radiation Area
  44. If the rad level in a room can exceed 5Gy (500cGy) in 1 hour, what does the sign posted on the entrance door have to say
    Grave Danger, Very High Radiation Area
  45. Where are the beam on light indicators required
    • on the control panel
    • at the entrance door
    • on the treatment unit itself
  46. Entrance doors to therapy rooms must be equipped with a/an ____ that will shut off the machine if the door is open during treatment
  47. The patient must ____ be seen through out treatment
  48. Visual and aural communication are required at all times because
    it allows the patient to notify the therapist if he or she is in distress
  49. High energy therapy units are required to have an independent ____ in the room to alert the therapist if he or she enters the room when the beams on
    beam on monitor
  50. If someone turns on the beam by mistake while you are in the treatment room, there are ____ located at several points within the room that will remove all power
    emergency push buttons
  51. How often are the visual and aural communication systems tested
  52. Safety equipment must be tested ____to ensure that it operates properly
  53. What is required to receive, possess, and use implants for radiation
    license from NRC or have to be an agreement state
  54. SOurces must be stored in heavily shielded "safes" in an area secure from theft or loss in keeping with requirements of
    Dept of Homeland Security
  55. Before an implant is prepared, a ___ must be completed by the requesting physician and ____ must be made that the implant was assembled in accordanace with the ____
    • Written directive
    • certification
    • directive
  56. How often are inventories of implants done even if no sources were removed during that time
    at least weekly
  57. Because it is possible for the material encapsulating the radioactive material in implant sources to get damaged or leak, brachytherapy sources must be ____ at intervals not to exceed ____
    • leak test
    • 6 months
  58. What are the 2 major sources of rad exposure in the rad therapy dept
    • megavoltage treatment machines(linear accelerators)
    • brachytherapy souces
  59. Practical rad protection from external beam radiation should include
    • time
    • distance
    • shielding
  60. If a paitent with an implant is in the hospital, a caution sign is posted on the entrance door and visits should be limited to ____ per visitor per day and the visitor must stay behind the line made by the radiation safety officer and the patient will have signs on their wrist band, bed, and chart to notify people of radiation exposure
    20 minutes
  61. What is the rate of nuclear decay
  62. What is the source of ionizing radiation that contributes the most to exposure of the general population in the US and how much
    • Natural background radiation
    • 82%
  63. Which type of device is best suited for output measurements of rad therapy equipment
    ionization chamber
  64. Exposure of a ____ year old women would contributer to the most genetically significant dose
  65. What is the annual effective dose equivalent limit for rad workers?
  66. What is energy absorbed per mass
    absorbed dose
  67. What is ionization per unit mass of air by photons
  68. What is short range, relatively heavy mass, and a high LET particle
    Alpha particle
  69. What does ALARA stand for
    as low as reasonably achieveable
  70. What is an agreement state
    States that have enetered into an agreements concerning licensing, inspections, and enforcement with the NRC