Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Calculation of Np-237 and Am-241 Detector Calibration Constants from First Principles

Journal Article · · Journal of Radioanalytical and Nuclear Chemistry
The Analytical Development Section of Savannah River Technology Center (SRTC) was requested to determine the holdup of enriched uranium in a facility as part of an overall deactivation project of the facility. The facility was used to fabricate enriched uranium fuel assemblies, lithium-aluminum target tubes, neptunium assemblies, and miscellaneous components for the production reactors. The results of the holdup assays are essential for determining compliance with the Waste Acceptance Criteria, Material Control and Accountability, and to meet criticality safety controls. This report covers calibration of the detectors in order to support holdup measurements in the out-gassing ovens. These ovens were used to remove gas entrained in billet assembly material prior to the billets being extruded into rods by the extrusion press. A portable high purity germanium detection system was used to determine highly enriched uranium (HEU) holdup and to determine holdup of U-235, Np-237, and Am-24 1 that were observed in these components. The detector system was run by an EG and G system that contains the high voltage power supply and signal processing electronics. A personal computer with Gamma-Vision software was used to control and provide space to store and manipulate multiple channel spectra. The measured Np-237 and Am-241 contents were especially important in these components because their presence is unusual and unexpected in the facility. It was important to obtain a measured value of these two components to disposition the out-gassing ovens and to determine whether a separate waste stream was necessary for release of these contaminated components to a solid waste vault. This report presents determination of the calibration constants from first principles for determination of Am-241 and Np-237 using this detection system and compares the values obtained for Np-237 with the calibration factors obtained with a subsequent measurement using a point source of radioactive equilibrium Np-237/Pa-233.
Research Organization:
Savannah River Site (US)
Sponsoring Organization:
US Department of Energy (US)
DOE Contract Number:
AC09-96SR18500
OSTI ID:
824266
Report Number(s):
WSRC-RP-2003-01113
Journal Information:
Journal of Radioanalytical and Nuclear Chemistry, Journal Name: Journal of Radioanalytical and Nuclear Chemistry; ISSN 0236-5731
Country of Publication:
United States
Language:
English