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Operations & Power
Members focus on the dissemination of knowledge and information in the area of power reactors with particular application to the production of electric power and process heat. The division sponsors meetings on the coverage of applied nuclear science and engineering as related to power plants, non-power reactors, and other nuclear facilities. It encourages and assists with the dissemination of knowledge pertinent to the safe and efficient operation of nuclear facilities through professional staff development, information exchange, and supporting the generation of viable solutions to current issues.
Meeting Spotlight
Utility Working Conference and Vendor Technology Expo (UWC 2024)
August 4–7, 2024
Marco Island, FL|JW Marriott Marco Island
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The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
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BWXT will scout potential TRISO fuel production sites in Wyoming
BWX Technologies Inc. announced today that its Advanced Technologies subsidiary has signed a cooperation agreement with the state of Wyoming to evaluate locations and requirements for siting a potential new TRISO nuclear fuel fabrication facility in the state.
August W. Cronenberg, Michael A. Grolmes
Nuclear Technology | Volume 27 | Number 3 | November 1975 | Pages 394-410
Technical Paper | Fuel | doi.org/10.13182/NT75-A24313
Articles are hosted by Taylor and Francis Online.
To understand the phenomenology and consequences of a hypothetical mild (∼50¢ to $5/sec) overpower transient for a liquid-metal fast breeder reactor (LMFBR), a continuing series of in-pile fuel-failure experiments has been performed in the TREA T reactor for both fresh and preirradiated pins. The voiding history obtained from the failure of a fresh fuel element has been shown to result from a mild fuel-coolant-interaction process. However, preirradiated pins are accompanied by significant fission gas retention, which leads to a difference in failure criterion and voiding mechanism. Thus, the dynamics of coolant expulsion, following the failure of preirradiated pins under overpower transient conditions, must include the effects of gas discharge to the coolant channel. The flow transient for preirradiated fuel elements, brought to failure in a flowing sodium environment, was analyzed in terms of fission-gas-induced voiding. The analytic approach was based on single-phase isothermal expansion of the fis-sion-gas bubble, which was assumed to be ideal and to fill the coolant-channel cross section uniformly. Gas discharge through the cladding breach was calculated using either the equation for critical or for subcritical flow, depending on the pin-to-bubble pressure ratio. The coolant was considered incompressible. A parametric study indicates that the initial breach size is quite small, initiating a relatively slow rate of voiding without initial inlet-flow reversal. However, ∼100 msec after failure, rapid coolant expulsion and inlet-flow reversal occurs. To account for this condition, fission-gas communication between the storage plenum and core regions of the pin must be assumed, since the free gas inventory within the fueled section alone is quite small. At the time of flow reversal, however, significant melting and some vaporization of the fuel has occurred; thus, coolant expulsion by fuel-coolant interaction and/or fuel vapor pressure cannot be discounted. The release of such fission gas, however, will affect the energetics of fuel-coolant interaction and fuel sweepout; thus, gas effects must be taken into account in the analysis of LMFBR overpower transients.