IRRSP - Industrial Radiography Radiation Safety Personnel Personnel Dosimetry and Monitoring Questions and Answers — Questions and Answers
Question 1: According to 10 CFR 34, if a radiographer's direct-reading pocket dosimeter is found to be off-scale and radiation exposure cannot be ruled out, which of the following actions is required within 24 hours?
- The individual must be immediately removed from all radiation duties for 30 days.
- The individual's personnel dosimeter (e.g., TLD or OSL) must be sent for processing and evaluation. (Correct answer)
- A full recalibration of all survey meters on site must be initiated.
- The radiographer must complete a written report to be filed with the NRC.
Correct answer: The individual's personnel dosimeter (e.g., TLD or OSL) must be sent for processing and evaluation.
10 CFR 34.47(d) specifies that if a direct-reading dosimeter is off-scale (or an electronic personal dosimeter reads over 200 mrem) and exposure is possible, the individual's legal personnel dosimeter that requires processing must be sent for evaluation within 24 hours to determine the actual dose received. The individual is also restricted from work with licensed material until a dose determination is made by the RSO.
Question 2: Which of the following is a primary advantage of an Optically Stimulated Luminescence (OSL) dosimeter compared to a Thermoluminescent Dosimeter (TLD)?
- OSL dosimeters do not require an accredited NVLAP processor for evaluation.
- OSL dosimeters are significantly less expensive to manufacture.
- OSL dosimeters can be re-read to confirm a dose reading, while TLD readings are destructive. (Correct answer)
- OSL dosimeters provide an immediate, real-time audible alarm at a preset dose rate.
Correct answer: OSL dosimeters can be re-read to confirm a dose reading, while TLD readings are destructive.
A key feature of OSL technology is that the reading process, which uses a laser or LED light, is non-destructive. This allows the dosimeter to be re-analyzed multiple times to verify an exposure reading. In contrast, the process of reading a TLD involves heating the crystal, which erases the stored information, making a re-read impossible.
Question 3: A radiographer begins a shift and recharges their ion-chamber pocket dosimeter. At the end of the shift, they record the reading. How long must the licensee maintain the records of these daily direct-reading dosimeter readings?
- For 1 year
- For 3 years (Correct answer)
- For 5 years
- Until the commission terminates the license
Correct answer: For 3 years
According to 10 CFR 34.83(a), records of direct reading dosimeter readings required by § 34.47(b) must be maintained by the licensee for 3 years after the record is made. Records of the legal personnel dosimeter results, however, must be kept until the commission terminates the license.
Question 4: During radiographic operations, each radiographer and radiographer's assistant must wear several pieces of monitoring equipment. Which of the following combinations is required by 10 CFR 34.47?
- A survey meter, an alarming ratemeter, and a film badge.
- A personnel dosimeter, a survey meter, and a direct reading dosimeter.
- An operating alarm ratemeter, a personnel dosimeter, and a direct reading dosimeter. (Correct answer)
- A direct reading dosimeter, a Geiger-Mueller counter, and an OSL dosimeter.
Correct answer: An operating alarm ratemeter, a personnel dosimeter, and a direct reading dosimeter.
10 CFR 34.47(a) explicitly states that each individual acting as a radiographer or assistant must wear, on the trunk of the body, a direct reading dosimeter, an operating alarm ratemeter, and a personnel dosimeter (the legal dose of record, such as a TLD or OSL). A survey meter is required for surveys but is not part of the required wearable personnel monitoring equipment.
Question 5: A radiographer's film badge is due for exchange. According to 10 CFR 34, what is the maximum replacement frequency for a film badge?
- Weekly
- Bi-weekly
- Monthly (Correct answer)
- Quarterly
Correct answer: Monthly
As per 10 CFR 34.47(a)(3), film badges must be replaced at least monthly. Other types of personnel dosimeters that require replacement, such as TLDs or OSLs, must be replaced at least quarterly.
Question 6: An ion-chamber pocket dosimeter must be checked for correct response to radiation at specified intervals. What is the maximum allowable interval for this check, and what is the acceptable accuracy range?
- Every 6 months, within ±10% of the true exposure.
- Every 12 months, within ±30% of the true exposure.
- Every 6 months, within ±25% of the true exposure.
- Every 12 months, within ±20% of the true exposure. (Correct answer)
Correct answer: Every 12 months, within ±20% of the true exposure.
10 CFR 34.47(c) requires that pocket dosimeters or electronic personal dosimeters be checked for correct response to radiation at periods not to exceed 12 months. The regulation also states that acceptable dosimeters must read within plus or minus 20 percent of the true radiation exposure.
IRRSP - Industrial Radiography Radiation Safety Personnel Personnel Dosimetry and Monitoring Questions and Answers
According to 10 CFR 34, if a radiographer's direct-reading pocket dosimeter is found to be off-scale and radiation exposure cannot be ruled out, which of the following actions is required within 24 hours?