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dc.creatorO'Kelly, David Seanen_US
dc.descriptionDue to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to, referencing the URI of the item.en_US
dc.descriptionIncludes bibliographical references (leaves 119-123).en_US
dc.descriptionIssued also on microfiche from Lange Micrographics.en_US
dc.description.abstractThe conversion of plutonium from a nuclear weapon to nuclear reactor fuel requires an evaluation of the residual gallium as a potential corrosive material within an operating nuclear fuel element. Homogeneous trace levels of gallium may remain following conversion and have the potential to migrate along the thermal gradient within the fuel and concentrate at the cladding-fuel contact zone. A system to investigate this material transport phenomenon was constructed using small diameter (0.18 inch), indirect electric heaters to simulate the centerline temperatures of operating nuclear fuel in a pressurized water reactor. The heater was inserted into annular surrogate fuel pellets containing depleted uranium, cerium oxide and trace quantities (10 ppm) of gallium to perform an initial study of the gallium migration using non-plutonium fuels and evaluate the performance of the simulation system. Heat was removed from the operating heaters by using an innovative liquid metal heat exchanger. The heaters were of a new design and were required to operate at a nominal temperature of 1000⁰C and for a minimum of 5000 hours. An evaluation of the expected heater lifetime and the thermal simulation system was needed in order to justify the high expense of a proposed full test using prototypic mixed-oxide fuel (MOX) containing plutonium from converted nuclear weapons. Bayesian reliability analysis methods were used to determine the expected heater failure rate because of the expected short test duration and the small sample size. Results from the operation of the simulation system and lifetime data indicate the current heater design is capable of producing the required temperatures and thermal gradients normally found in operating nuclear fuels. However, a design weakness in the heaters resulted in an unacceptably high failure rate of the heaters. The heaters were determined to have a reliability of 0.83 % at 5000 hours of operation with a Mean Time to Failure (MTTF) of 485 hours. The current heater design would require some modification and further testing prior to beginning a full scale test using prototypic MOX fuel pellets.en_US
dc.publisherTexas A&M Universityen_US
dc.rightsThis thesis was part of a retrospective digitization project authorized by the Texas A&M University Libraries in 2008. Copyright remains vested with the author(s). It is the user's responsibility to secure permission from the copyright holder(s) for re-use of the work beyond the provision of Fair Use.en_US
dc.subjectindustrial engineering.en_US
dc.subjectMajor industrial engineering.en_US
dc.titlePerformance testing and Bayesian Reliability Analysis of small diameter, high power electric heaters for the simulation of nuclear fuel rod temperaturesen_US
dc.typeThesisen_US engineeringen_US
dc.format.digitalOriginreformatted digitalen_US

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