Dimensional Behavior of Fuel Channels - Recent Experience and Consequences
- AREVA NP Inc., VA 24506 Lynchburg (United States)
- AREVA NP GmbH, 91050 Erlangen (Germany)
- AREVA NP Inc., WA 99354 Richland (United States)
Fuel channels in boiling-water reactors (BWR) undergo distortions like bow, bulge, and twist due to their operating conditions. These distortions may adversely impact planned operating strategy, and therefore need to be adequately addressed during various stages of fuel channel design and manufacturing, core design and operation monitoring. Fuel channel distortion may lead to interference between the fuel channel and adjacent control blade. If severe, such interference can impair both positioning of control blades during normal operations and rapid control blade insertion during a reactor scram. During the last five years, unexpectedly high fuel channel distortions leading to problems in control blade operations have been observed in some C- and S-lattice BWR plants in the U.S. operating on 18 - 24 month cycles. As a result, U.S. operators have implemented costly surveillance programs to detect the onset of high distortions and have declared control blades inoperable when unacceptable control blade operation occurs. This unusual fuel channel distortion has not been observed with AREVA NP fuel supplied in Europe in this scale. Nevertheless fuel channel distortion-related problems were recently observed in reactors outside the U.S. with early control blade operation. The mechanisms causing this unexpected fuel-channel distortion and the influencing factors are not completely understood worldwide for the time being. Therefore, a prediction of channels which will exhibit high bow is very challenging. A status is given from the AREVA NP perspective on: - The existing fuel channel distortion database, - The understanding of the phenomenon, - Measures to gather further information and improve existing tools, materials, and designs, and - Customer actions to reduce potential high channel bow and associated control blade issues. (authors)
- Research Organization:
- American Nuclear Society, 555 North Kensington Avenue, La Grange Park, IL 60526 (United States)
- OSTI ID:
- 21229270
- Resource Relation:
- Conference: 2007 LWR Fuel Performance Meeting / TopFuel 2007, San Francisco, CA (United States), 30 Sep - 3 Oct 2007; Other Information: Country of input: France; 3 refs; Related Information: In: Proceedings of the 2007 LWR Fuel Performance Meeting / TopFuel 2007 'Zero by 2010', 683 pages.
- Country of Publication:
- United States
- Language:
- English
Similar Records
Z4B, AREVA NP's most recent material for structural fuel assembly components
Impact of Control Blade Insertion on the Deformation Behavior of SiC-SiC Channel Boxes in Boiling Water Reactors