NRRPT Practice Study Guide
Exam Latest 2026/2027
Updated Verified Questions
and Solutions A+ Pass
Guaranteed
1. Given a gamma-energy value of 0.662 MeV, and a photon yield of
0.85 per decay, the exposure rate at 2 yards from an unshielded
10mCi Cs-137 point source is:
- ANS - 0.94 mR/hour
2. At what radius would you post a radiation area around an 8 curie
Cesium 137 (662 keV photon energy and a photon yield of 0.85
photons/disintegration) point source?
- ANS - 74 feet
3. Which of the following is equivalent to A=Aoe^-(.693/T1/2)t?
- ANS - A=Ao(1/2)^(t/T1/2)
4. As u in the equation I=Ioe^-ux is increased
- ANS - photon attenuation is increased
5. What would the time passing between the original activity and the
resultant activity have been if the original activity was 10 Curies,
, the resultant activity is 5 Curies and the half-life is 5 years?
- ANS - 5 years
6. If a floor contamination level of 666 dpm/100cm^2, in a room
measuring 10 m by 10 m by 10 m, becomes uniformly suspended
in the air of the room, using the Co60Y DAC value of 1E-8 uCi/ml,
what would the DAC fraction of the air in the room be?
- ANS - 0.3 DAC
7. An atom of a radionuclide that has a low neutron to proton ratio,
and an atomic rest mass energy that is 1.02 MeV greater than the
product atom's rest mass energy may decay by which of the
following?
- ANS - Either positron emission or electron capture
8. For an exclusive use vehicle that is transporting radioactive
materials, radiation levels on contact with any external surface of
the vehicle must not exceed:
- ANS - 2.0 mSv/hour
9. Which radioactive decay series includes Ra-226 as one of its decay
products?
- ANS - Uranium
10. Which of the following is incorrectly defined?
- ANS - 10CFR20, Appendix D, US Postal Service Regional Offices
, 11. Which of the following is not a label used for radioactive
shipments?
- ANS - Transport Index Label
12. A worker is to perform maintenance on a Reactor Coolant
Pump under the following radiological conditions; Dose rate on
contact with the pump - 350 mrem/hr, Dose rate at 30 cm from the
pump (working area dose rate) is 85 mrem/hr, and an airborne
concentration of .45 DAC. She will spend a maximum of 14 hours in
this area during the week. According to 10CFR20, how is this area
to be posted?
- ANS - Caution Radiation Area
13. A worker breathes air at a rate of 20 Liters/minute for 2000
hours in one calendar year. The air contains 1 DAC of a
radionuclide whose ALI is defined by the stochastic dose limit. The
worker's assigned 50 year committed effective dose equivalent is:
- ANS - 5 rem
14. An air sample is taken at a flow rate of 2cfm for 5 minutes
and counted using a 10% efficient frisker giving results of 190
ncpm...using a DAC of 3E-8 uCi/ml what is the DAC fraction of the
air sample?
- ANS - 0.3 DAC
15. The Bragg-Gray principal is based upon the relationship of:
- ANS - ionization of the gas in an ionization chamber to the dose in
the wall material
Exam Latest 2026/2027
Updated Verified Questions
and Solutions A+ Pass
Guaranteed
1. Given a gamma-energy value of 0.662 MeV, and a photon yield of
0.85 per decay, the exposure rate at 2 yards from an unshielded
10mCi Cs-137 point source is:
- ANS - 0.94 mR/hour
2. At what radius would you post a radiation area around an 8 curie
Cesium 137 (662 keV photon energy and a photon yield of 0.85
photons/disintegration) point source?
- ANS - 74 feet
3. Which of the following is equivalent to A=Aoe^-(.693/T1/2)t?
- ANS - A=Ao(1/2)^(t/T1/2)
4. As u in the equation I=Ioe^-ux is increased
- ANS - photon attenuation is increased
5. What would the time passing between the original activity and the
resultant activity have been if the original activity was 10 Curies,
, the resultant activity is 5 Curies and the half-life is 5 years?
- ANS - 5 years
6. If a floor contamination level of 666 dpm/100cm^2, in a room
measuring 10 m by 10 m by 10 m, becomes uniformly suspended
in the air of the room, using the Co60Y DAC value of 1E-8 uCi/ml,
what would the DAC fraction of the air in the room be?
- ANS - 0.3 DAC
7. An atom of a radionuclide that has a low neutron to proton ratio,
and an atomic rest mass energy that is 1.02 MeV greater than the
product atom's rest mass energy may decay by which of the
following?
- ANS - Either positron emission or electron capture
8. For an exclusive use vehicle that is transporting radioactive
materials, radiation levels on contact with any external surface of
the vehicle must not exceed:
- ANS - 2.0 mSv/hour
9. Which radioactive decay series includes Ra-226 as one of its decay
products?
- ANS - Uranium
10. Which of the following is incorrectly defined?
- ANS - 10CFR20, Appendix D, US Postal Service Regional Offices
, 11. Which of the following is not a label used for radioactive
shipments?
- ANS - Transport Index Label
12. A worker is to perform maintenance on a Reactor Coolant
Pump under the following radiological conditions; Dose rate on
contact with the pump - 350 mrem/hr, Dose rate at 30 cm from the
pump (working area dose rate) is 85 mrem/hr, and an airborne
concentration of .45 DAC. She will spend a maximum of 14 hours in
this area during the week. According to 10CFR20, how is this area
to be posted?
- ANS - Caution Radiation Area
13. A worker breathes air at a rate of 20 Liters/minute for 2000
hours in one calendar year. The air contains 1 DAC of a
radionuclide whose ALI is defined by the stochastic dose limit. The
worker's assigned 50 year committed effective dose equivalent is:
- ANS - 5 rem
14. An air sample is taken at a flow rate of 2cfm for 5 minutes
and counted using a 10% efficient frisker giving results of 190
ncpm...using a DAC of 3E-8 uCi/ml what is the DAC fraction of the
air sample?
- ANS - 0.3 DAC
15. The Bragg-Gray principal is based upon the relationship of:
- ANS - ionization of the gas in an ionization chamber to the dose in
the wall material
