Abstract
Fuel elements from three fuel bundles discharged from Bruce NGS A at burnups of 478 to 518 MWh/kgU were examined in the hot cell facilities at Chalk River Laboratories. The examination results show that the fuel operated at higher than expected temperatures, resulting in fission gas releases of up to (and probably exceeding) 24%. Sheathing strains of up to 3% were also observed, indicating a high level of pellet-clad interaction (PCI). This unexpected behaviour is believed to be related to a burnup-dependent reduction in UO{sub 2} thermal conductivity. All of the outer elements examined from two of the bundles apparently experienced stress corrosion cracking-related failures in the end cap weld region and sheath as a result of PCI. No failures were observed in the elements examined from the third bundle. The factors believed to have primarily influenced performance are end cap weld geometry and UO{sub 2} density. Pellet geometry, stack length and sheath properties may also have influenced performance. The results of these examinations may help to facilitate performance enhancements to existing and future fuel bundle designs. Until such an optimization takes place, the current bundle average burnup limit in Ontario Hydro reactors of 450 MWh/kgU is justified. (Author) (13
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Citation Formats
Floyd, M R, Leach, D A, Moeller, R E, Elder, R R, Chenier, R J, and O`Brien, D.
Behaviour of Bruce NGS A fuel irradiated to a burnup of {approx} 500 MWh/kgU.
Canada: N. p.,
1992.
Web.
Floyd, M R, Leach, D A, Moeller, R E, Elder, R R, Chenier, R J, & O`Brien, D.
Behaviour of Bruce NGS A fuel irradiated to a burnup of {approx} 500 MWh/kgU.
Canada.
Floyd, M R, Leach, D A, Moeller, R E, Elder, R R, Chenier, R J, and O`Brien, D.
1992.
"Behaviour of Bruce NGS A fuel irradiated to a burnup of {approx} 500 MWh/kgU."
Canada.
@misc{etde_10127747,
title = {Behaviour of Bruce NGS A fuel irradiated to a burnup of {approx} 500 MWh/kgU}
author = {Floyd, M R, Leach, D A, Moeller, R E, Elder, R R, Chenier, R J, and O`Brien, D}
abstractNote = {Fuel elements from three fuel bundles discharged from Bruce NGS A at burnups of 478 to 518 MWh/kgU were examined in the hot cell facilities at Chalk River Laboratories. The examination results show that the fuel operated at higher than expected temperatures, resulting in fission gas releases of up to (and probably exceeding) 24%. Sheathing strains of up to 3% were also observed, indicating a high level of pellet-clad interaction (PCI). This unexpected behaviour is believed to be related to a burnup-dependent reduction in UO{sub 2} thermal conductivity. All of the outer elements examined from two of the bundles apparently experienced stress corrosion cracking-related failures in the end cap weld region and sheath as a result of PCI. No failures were observed in the elements examined from the third bundle. The factors believed to have primarily influenced performance are end cap weld geometry and UO{sub 2} density. Pellet geometry, stack length and sheath properties may also have influenced performance. The results of these examinations may help to facilitate performance enhancements to existing and future fuel bundle designs. Until such an optimization takes place, the current bundle average burnup limit in Ontario Hydro reactors of 450 MWh/kgU is justified. (Author) (13 refs., 10 figs., tab.).}
place = {Canada}
year = {1992}
month = {Oct}
}
title = {Behaviour of Bruce NGS A fuel irradiated to a burnup of {approx} 500 MWh/kgU}
author = {Floyd, M R, Leach, D A, Moeller, R E, Elder, R R, Chenier, R J, and O`Brien, D}
abstractNote = {Fuel elements from three fuel bundles discharged from Bruce NGS A at burnups of 478 to 518 MWh/kgU were examined in the hot cell facilities at Chalk River Laboratories. The examination results show that the fuel operated at higher than expected temperatures, resulting in fission gas releases of up to (and probably exceeding) 24%. Sheathing strains of up to 3% were also observed, indicating a high level of pellet-clad interaction (PCI). This unexpected behaviour is believed to be related to a burnup-dependent reduction in UO{sub 2} thermal conductivity. All of the outer elements examined from two of the bundles apparently experienced stress corrosion cracking-related failures in the end cap weld region and sheath as a result of PCI. No failures were observed in the elements examined from the third bundle. The factors believed to have primarily influenced performance are end cap weld geometry and UO{sub 2} density. Pellet geometry, stack length and sheath properties may also have influenced performance. The results of these examinations may help to facilitate performance enhancements to existing and future fuel bundle designs. Until such an optimization takes place, the current bundle average burnup limit in Ontario Hydro reactors of 450 MWh/kgU is justified. (Author) (13 refs., 10 figs., tab.).}
place = {Canada}
year = {1992}
month = {Oct}
}