Progress report for the Division of Safeguards and Security: July--December 1976. [Development of nondestructive assay measurements, systems development, and applications]
- ed.
In the work on prediction of calorimeter equilibrium, a newly derived single-exponential prediction equation has been shown to yield results equal to those from previously reported work, but allows for more versatility in the instrumentation selection. A single-precision rather than a double-precision calculator is all that is required to predict reliable equilibrium values using this new equation. A double-exponential prediction equation has also been derived and tested using simulated data. Engineering refinements have been incorporated in the Automated Plutonium Assay System (APAS) to provide for improvements in the gamma-ray spectroscopy system and the container pickup device. In addition, evaluation tests on the assay instrumentation have been conducted. Calorimeter tests indicate that values within 1 percent of equilibrium can be obtained in 7 min. The Half-Life Evaluation Committee has completed measurements of the half-life of /sup 239/Pu. Preliminary results show that measurements by alpha and gamma counting, by mass spectrometry and by calorimetry agree sufficiently well that a recommended value with a relative standard deviation of +-0.1 percent will be reported. Papers describing these measurements are being prepared for journal publication. The committee concurs with the recent recommendation by Argonne National Laboratory representatives that the value 87.74 +- 0.04 yr be adopted for the half-life of /sup 238/Pu. Calorimetric assay has been used to prepare plutonium reference standards for use in verifying other NDA measurement systems. The reference samples contained plutonium oxide, nitride, and/or metal mixed with natural, depleted, and/or enriched uranium oxide, nitride, and/or metal. Eight samples have been certified, with plutonium uncertainties of less than 1 percent. They cover the weight range from 4.3 to 141.2 g of plutonium.
- Research Organization:
- Mound Lab., Miamisburg, OH (USA)
- DOE Contract Number:
- EY-76-C-04-0053
- OSTI ID:
- 7220362
- Report Number(s):
- MLM-2429; TRN: 77-015657
- Country of Publication:
- United States
- Language:
- English
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Nuclear safeguards progress report, January--June 1976
Progress report for the Division of Safeguards and Security: January--June 1977
Related Subjects
CALIBRATION STANDARDS
CHEMICAL PREPARATION
PLUTONIUM
GAMMA SPECTROSCOPY
PLUTONIUM 239
HALF-LIFE
SAFEGUARDS
RESEARCH PROGRAMS
CALORIMETERS
EQUILIBRIUM
SECURITY
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ACTINIDES
ALPHA DECAY RADIOISOTOPES
ELEMENTS
EVEN-ODD NUCLEI
HEAVY NUCLEI
ISOTOPES
MEASURING INSTRUMENTS
METALS
NUCLEI
PLUTONIUM ISOTOPES
RADIOISOTOPES
SPECTROSCOPY
STANDARDS
SYNTHESIS
TRANSURANIUM ELEMENTS
YEARS LIVING RADIOISOTOPES
055001* - Nuclear Fuels- Safeguards
Inspection
& Accountability- Technical Aspects