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 …

As petroleum-based fuels grow increasingly scarce and costly, nuclear energy may become an important alternative source of industrial energy. Initial applications would most likely include a mix of fossil-fired and nuclear sources of process energy. A means for determining the overall reliability of these mixed systems is a fundamental aspect of demonstrating their feasibility to potential industrial users. Reliability data from nuclear and fossil-fired plants are presented, and several methods of applying these data for calculating the reliability of reasonably complex industrial energy supply systems are given. Reliability estimates made under a number of simplifying assumptions indicate that multiple nuclear units or a combination of nuclear and fossil-fired plants could provide adequate reliability to meet industrial requirements for continuity of service.