Feasibility Study for Field Monitoring of Water Supplies for Radioactivity.
Abstract
The feasibility study for field monitoring of water supplies for radioactivity has been completed. A detailed review of commercially available charged particle detectors was completed and a ruggedized silicon surface barrier (SSB) detector was selected for use in the engineering prototype field water radioactivity monitor (FWRM). A review of the fission products and daughter products was also conducted to identify the types and energies of particles of photons present in the environment after a bomb detonation. The review identified Sr-90/Y-90 and Cs-137 as the more dangerous of the radionuclides present in the environment following an event. In the case of seeded bombs, it was determined that cobalt (Co-60) is a dangerous element that must be considered for analysis in the design of the FWRM. Tests were conducted with both Cs-137 and Co-60 gamma ray backgrounds. Sr-90/Y-90 was identified as the charged particle emitter that the FWRM would be designed to detect, since Sr-90/Y-90 emits betas with average energies of 0.7 and 0.93 MeV and is representative of the range of beta energies from mixed fission products. Under the condition of a 100 mR/hr Cs-137 field, the signal (Sr-90 in water) to noise (Cs-137 background) with electronic discrimination against low energy electrons created by background gamma rays was > 100. Because of the much higher energies of gammas from C0-60, electrons created by gamma ray interaction in the water are much more energetic.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 20, 1986
- Accession Number
- ADA167028