Lawrence Livermore National Laboratory Experience Using 30-Gallon Drum Neutron Multiplicity Counter for Measuring Plutonium-Bearing Salts.

Dearborn, D. M. ; Keeton, S. C.

Technical Information Center Oak Ridge Tennessee

关键词: Inventories;    Radiation detectors;    Plutonium;    Accountability measurements;    Monitoring;   

RP-ID  :  DE200515014324

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

Lawrence Livermore National Laboratory (LLNL) has been performing accountability measurements of plutonium (Pu) -bearing items with the 30-gallon drum neutron multiplicity counter (NMC) since August 1998. A previous paper1 focused on the LLNL experience with Pubearing oxide and metal items. This paper expands on the LLNL experience with Pu-bearing salts containing low masses of Pu. All Pu-bearing salts used in this study were measured using calorimetry and gamma isotopic analyses (Cal/Iso) as well as the 30-gallon drum NMC. The Cal/Iso values were treated as being the true measure of Pu content because of the inherent high accuracy of the Cal/Iso technique, even at low masses of Pu, when measured over a sufficient period of time. Unfortunately, the long time period required to achieve high accuracy from Cal/Iso can impact other required accountability measurements. The 30-gallon drum NMC is a much quicker system for making accountability measurements of a Pu-bearing salt and might be a desirable tradeoff. The accuracy of 30-gallon drum NMC measurements of Pu-bearing salts, relative to that of Cal/Iso, is presented in relation to the mass range and alpha associated with each item. Conclusions drawn from the use of the 30-gallon drum NMC for accountability measurements of salts are also included.