Transient behaviour of high burnup fuel (KOTO): Coupling of FRAPTRAN Fuel Rod for Transient Analysis with GENFLO Thermal Hydraulic Code (KOTO & READY)

Jan-Olof Stengård, Anitta Hämäläinen, Jaakko Miettinen

Research output: Chapter in Book/Report/Conference proceedingChapter or book articleProfessional

Abstract

Reactor analyses are becoming more and more challenging. Due to pursuing higher fuel discharge burnups, fuel designs and operational conditions are subject to constant upgrading. Advances in hardware have removed many of the limitations on detail of analyses, and best-estimate type applications have become a commonplace, a practice now increasingly adopted even in safety cases. At the same time there is a regulatory trend extending the range of events the licensee is to consider. Neutronics, thermal hydraulics, and fuel behaviour are closely interlinked during a reactor transient and cannot be generally separated in a realistic description. However, attempts to combine these into coupled models have been, even at their best, impracticably heavy to use. At VTT, in consent with the USNRC, an in-house general flow model GENFLO has now been coupled with the NRC's FRAPTRAN fuel performance code. The combination takes benefits of a fast-running non-iterative thermal hydraulic model and an updated fuel performance code validated for burnups of up to 65 MWd/kgU. A code description and results of two types of analyses are given. One is a hypothetical large break loss-of-coolant accident (LBLOCA) in a VVER reactor, the other is an instability transient in a Boiling Water Reactor (BWR), for which system conditions were separately available. A systematic validation and international peer review will follow.
Original languageEnglish
Title of host publicationFINNUS: The Finnish Research Programme on Nuclear Power Plant Safety 1999-2002
Subtitle of host publicationFinal Report
Place of PublicationEspoo
PublisherVTT Technical Research Centre of Finland
Pages104-111
ISBN (Electronic)951-38-6086-8
ISBN (Print)951-38-6085-X
Publication statusPublished - 2002
MoE publication typeNot Eligible

Publication series

SeriesVTT Tiedotteita - Research Notes
Number2164
ISSN1235-0605

Fingerprint

Transient analysis
Hydraulics
Loss of coolant accidents
Boiling water reactors
Hydraulic models
Hot Temperature
Hardware

Cite this

Stengård, J-O., Hämäläinen, A., & Miettinen, J. (2002). Transient behaviour of high burnup fuel (KOTO): Coupling of FRAPTRAN Fuel Rod for Transient Analysis with GENFLO Thermal Hydraulic Code (KOTO & READY). In FINNUS: The Finnish Research Programme on Nuclear Power Plant Safety 1999-2002: Final Report (pp. 104-111). Espoo: VTT Technical Research Centre of Finland. VTT Tiedotteita - Research Notes, No. 2164
Stengård, Jan-Olof ; Hämäläinen, Anitta ; Miettinen, Jaakko. / Transient behaviour of high burnup fuel (KOTO) : Coupling of FRAPTRAN Fuel Rod for Transient Analysis with GENFLO Thermal Hydraulic Code (KOTO & READY). FINNUS: The Finnish Research Programme on Nuclear Power Plant Safety 1999-2002: Final Report. Espoo : VTT Technical Research Centre of Finland, 2002. pp. 104-111 (VTT Tiedotteita - Research Notes; No. 2164).
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Stengård, J-O, Hämäläinen, A & Miettinen, J 2002, Transient behaviour of high burnup fuel (KOTO): Coupling of FRAPTRAN Fuel Rod for Transient Analysis with GENFLO Thermal Hydraulic Code (KOTO & READY). in FINNUS: The Finnish Research Programme on Nuclear Power Plant Safety 1999-2002: Final Report. VTT Technical Research Centre of Finland, Espoo, VTT Tiedotteita - Research Notes, no. 2164, pp. 104-111.

Transient behaviour of high burnup fuel (KOTO) : Coupling of FRAPTRAN Fuel Rod for Transient Analysis with GENFLO Thermal Hydraulic Code (KOTO & READY). / Stengård, Jan-Olof; Hämäläinen, Anitta; Miettinen, Jaakko.

FINNUS: The Finnish Research Programme on Nuclear Power Plant Safety 1999-2002: Final Report. Espoo : VTT Technical Research Centre of Finland, 2002. p. 104-111 (VTT Tiedotteita - Research Notes; No. 2164).

Research output: Chapter in Book/Report/Conference proceedingChapter or book articleProfessional

TY - CHAP

T1 - Transient behaviour of high burnup fuel (KOTO)

T2 - Coupling of FRAPTRAN Fuel Rod for Transient Analysis with GENFLO Thermal Hydraulic Code (KOTO & READY)

AU - Stengård, Jan-Olof

AU - Hämäläinen, Anitta

AU - Miettinen, Jaakko

PY - 2002

Y1 - 2002

N2 - Reactor analyses are becoming more and more challenging. Due to pursuing higher fuel discharge burnups, fuel designs and operational conditions are subject to constant upgrading. Advances in hardware have removed many of the limitations on detail of analyses, and best-estimate type applications have become a commonplace, a practice now increasingly adopted even in safety cases. At the same time there is a regulatory trend extending the range of events the licensee is to consider. Neutronics, thermal hydraulics, and fuel behaviour are closely interlinked during a reactor transient and cannot be generally separated in a realistic description. However, attempts to combine these into coupled models have been, even at their best, impracticably heavy to use. At VTT, in consent with the USNRC, an in-house general flow model GENFLO has now been coupled with the NRC's FRAPTRAN fuel performance code. The combination takes benefits of a fast-running non-iterative thermal hydraulic model and an updated fuel performance code validated for burnups of up to 65 MWd/kgU. A code description and results of two types of analyses are given. One is a hypothetical large break loss-of-coolant accident (LBLOCA) in a VVER reactor, the other is an instability transient in a Boiling Water Reactor (BWR), for which system conditions were separately available. A systematic validation and international peer review will follow.

AB - Reactor analyses are becoming more and more challenging. Due to pursuing higher fuel discharge burnups, fuel designs and operational conditions are subject to constant upgrading. Advances in hardware have removed many of the limitations on detail of analyses, and best-estimate type applications have become a commonplace, a practice now increasingly adopted even in safety cases. At the same time there is a regulatory trend extending the range of events the licensee is to consider. Neutronics, thermal hydraulics, and fuel behaviour are closely interlinked during a reactor transient and cannot be generally separated in a realistic description. However, attempts to combine these into coupled models have been, even at their best, impracticably heavy to use. At VTT, in consent with the USNRC, an in-house general flow model GENFLO has now been coupled with the NRC's FRAPTRAN fuel performance code. The combination takes benefits of a fast-running non-iterative thermal hydraulic model and an updated fuel performance code validated for burnups of up to 65 MWd/kgU. A code description and results of two types of analyses are given. One is a hypothetical large break loss-of-coolant accident (LBLOCA) in a VVER reactor, the other is an instability transient in a Boiling Water Reactor (BWR), for which system conditions were separately available. A systematic validation and international peer review will follow.

M3 - Chapter or book article

SN - 951-38-6085-X

T3 - VTT Tiedotteita - Research Notes

SP - 104

EP - 111

BT - FINNUS: The Finnish Research Programme on Nuclear Power Plant Safety 1999-2002

PB - VTT Technical Research Centre of Finland

CY - Espoo

ER -

Stengård J-O, Hämäläinen A, Miettinen J. Transient behaviour of high burnup fuel (KOTO): Coupling of FRAPTRAN Fuel Rod for Transient Analysis with GENFLO Thermal Hydraulic Code (KOTO & READY). In FINNUS: The Finnish Research Programme on Nuclear Power Plant Safety 1999-2002: Final Report. Espoo: VTT Technical Research Centre of Finland. 2002. p. 104-111. (VTT Tiedotteita - Research Notes; No. 2164).