Response Functions of Four Criticality-Dosimetry Detectors
H-H. Hsu, K. J. Kearfott
The neutron spectra for given types of criticality accidents, such as those involving metallic, liquid, or reactor-based critical masses with a variety of shielding materials, can be determined experimentally. By folding a known neutron spectrum with the relevant activation cross sections for a given material, the amount of activation induced per incident neutron flux in the material can be determined. This factor would then enable the computation of the neutron flux due to a criticality from a measurement of the activity in the dosimeter element (e.g. foil) following its exposure under accident conditions. The usage of different dosimeter elements having different energy-dependencies of neutron activation response would assist in validating that the assumed criticality spectrum was correct. This paper explores the possibilities of such an approach using gold, salt, nickel, and phosphorous detector elements with the neutron spectra from Godiva, Sheba, HPRR and the shielded HPRR experimental arrangements. Results show that sufficient activation will occur without limiting interference from competing reactions and that substantive variations in the responses of the tested materials exist to allow reasonable application of the method.
This abstract was presented at the 34th Annual Midyear Meeting, "Radiation Safety and ALARA Considerations for the 21st Century", Personnel Surveillance Applications Session, 2/4/2001 - 2/7/2001, held in Anaheim, CA.