Fuel utilization improvement in PWRs using the denatured /sup 233/U-Th cycle

A number of changes in PWR core design and/or operating strategy were evaluated to assess the fuel utilization improvement achievable by their implementation in a PWR using thorium-based fuel and operating in a recycle mode. The reference PWR for this study was identical to the B and W Standard Plant except that the fuel pellets were of denatured (/sup 233/U//sup 238/U-Th)O/sub 2/. An initial scoping study identified the three most promising improvement concepts as (1) a very tight lattice, (2) thorium blankets, and (3) ThO/sub 2/ rods placed in available guide tubes. A conceptual core design incorporating these changes was then developed, and the fuel utilization of this modified design was compared with that of the reference case

Assessment of non-backfittable concepts to improve PWR uranium utilization

Seven non-backfittable improvements to light water reactors were assessed for Batelle/Pacific Northwest Laboratories in support of the Department of Energy's program on Advanced Reactor Studies. The objective was to provide industrial perspective as to which concepts have the best potential for development to improve fuel utilization. The concepts were rated against the assessment criteria while considering the key questions identified for each concept, and recommendations were made for further action on unresolved key questions. The concepts were subjectively ranked against each other in terms of relative investment potential. The ranking considered all criteria but, for example, weighted fuel utilization savings more heavily than development costs. Finally, conclusions and recommendations for future action were determined. The reference design for this study was the NASAP Composite Improved PWR

Qualification of the B and W Mark B fuel assembly for high burnup. First semi-annual progress report, July-December 1978

Five Babcock and Wilcox standard Mark B (15 x 15) fuel assemblies are being irradiated in Duke Power Company's Oconee Unit 1 reactor under a research and development program sponsored by the U.S. Department of Energy. Valuable experimental data on fuel performance characteristics at burnups of > 40,000 MWd/mtU will be obtained from these assemblies. This information, at a duty approximately 20% greater than that achieved by typical discharged assemblies, will be used to qualify standard Mark B fuel assemblies for extended burnups. Efforts during this period included fuel cycle design and reload licensing of Oconee 1 for cycle 5, in which the assemblies are being irradiated, and nondestructive examination of the assemblies during the refueling outage between cycles 4 and 5. The Oconee 1 cycle 5 startup tests proceeded in a routine manner, and the reactor has operated with a 92% capacity factor since completion of power escalation testing on November 10, 1978. Irradiation of the fuel assemblies is currently in progress