Metastable Radioxenon Verification Laboratory (MRVL) Year-End Report

Technical Report · Fri Nov 07 00:00:00 EST 2014

DOI:https://doi.org/10.2172/1182947· OSTI ID:1182947

Cooper, Matthew W. ^[1]; Hayes, James C. ^[1]; Lidey, Lance S. ^[1]

---

1. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

This is the year end report that is due to the client. The MRVL system is designed to measure multiple radioxenon isotopes (¹³⁵Xe, ¹³³Xe, ¹³³mXe and ¹³³mXe) simultaneously. The system has 12 channels to load samples and make nuclear measurements. Although the MRVL system has demonstrated excellent stability in measurements of Xe-133 and Xe-135 over the year of evaluation prior to delivery, there has been concern about system stability over measurements performed on samples with orders of magnitude different radioactivity, and samples containing multiple isotopes. To address these concerns, a series of evaluation test have been performed at the end-user laboratory. The evaluation was performed in two separate phases. Phase 1 made measurements on isotopically pure Xe-133 from high radioactivity down to the system background levels of activity, addressing the potential count rate dependencies when activities change from extreme high to very low. The second phase performed measurements on samples containing multiple isotopes (Xe-135, Xe-133 and Xe-133m), and addressed concerns about the dependence of isotopic concentrations on the presence of additional isotopes. The MRVL showed a concentration dependence on the Xe-133 due to the amount of Xe-133m that was in the sample. The dependency is due to the decay of Xe-133m into Xe-133. This document focuses on the second phase and will address the analysis used to account for ingrowth of Xe-133 from Xe-133m.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1182947
• Report Number(s): PNNL-23843; NN2003000
• Country of Publication: United States
• Language: English