14.0 Instrumentation and Equipment

14.1 Radiation Detection Equipment

Authorized users must equip their laboratories with the appropriate survey instruments in good working order for each radioactive material use laboratory/facility.

The Radiation Safety Office is responsible for performing, or having performed, all portable radiation measuring instrument calibrations. The Authorized User is responsible for performing operability, and when appropriate, efficiency checks, on the equipment in their facilities/laboratories. All radiation measuring equipment must be calibrated annually.

GM and beta scintillation detectors are useful for monitoring medium-to-high energy beta radiation. These detectors are not capable of detecting H-3 due to its low beta energy. Liquid scintillation counters are used to monitor H-3. Gamma scintillation detectors are used to detect low-to-high energy gamma and x-rays.

Commonly used RAM at UNR
Radionuclide Radioactive half-life Radiation type, energy level Exposure rate at 1 foot from 1 mCi point source without shield Shielding requirement
H-3 12.3 years Beta, low Low None
C-14 5730 years Beta, medium Low None
P-32 14.3 days Beta, high 300 mrad/hr Plexiglas/plastic
S-35 87 days Beta, medium Low None
Ca-45 162.7 days Beta, medium Low None
Sc-46 83.8 days Gamma, high 12 mR/hr Lead
Cr-51 27.7 days Gamma, medium 0.2 mR/hr Lead
Fe-59 44.5 days Gamma, high 7 mR/hr Lead
I-125 60 days Gamma & xray, low 0.8 mR/hr Lead, leaded glass or plastic
I-131 8.3 days Gamma, medium 2.4 mR/hr lead
Detectors and their applications
Detector Type Detects Alpha Radiation Detects Beta Radiation Detects X-Ray and Gamma Radiation Radionuclides to Detect Portability
GM, metal cylinder No Yes Yes P-32, Cr-51, Sc-46, I-131 Yes
GM, pancake Yes Yes Yes Most RAMs used at UNR except H-3 Yes
GM, Thin end Yes Yes Yes Most RAMs used at UNR except H-3 Yes
Beta scintillation No Yes No C-14, P-32, P-33, S-35, Ca-45 Yes
Beta-gamma scintillation No Yes Yes C-14, P-32, P-33, S-35, Ca-45, Sc- 46, Cr-51, I-125, I-131 Yes
Ion chamber No No Yes Gamma (beta if equipped) exposure rate Yes
Liquid scintillation analyzer Yes Yes Yes All RAM used at UNR including H-3 Fixed
Gas Proportional counter Yes Yes Yes All RAM used at UNR Fixed