Title:
PROBABILISTIC EVALUATION OF FASTENER DEGRADATION IN NUCLEAR POWER PLANTS
Document Type and Number:
WIPO Patent Application WO/2018/044366
Kind Code:
A3
Abstract:
A probabilistic method for determining an operability interval for fasteners in a nuclear power plant assembly is provided. The probabilistic method includes determining or assuming a geometric distribution of a given initial condition of fasteners in the nuclear power plant assembly at an initial time T0; determining a future fastener failure probability model of the geometric distribution over time; generating a plurality of random future fastener failure patterns by applying the fastener failure model to the geometric distribution at a given time T1 > T0; postulating fastener spacing rules designed to evaluate the acceptability of fastener failure patterns for the fasteners in the nuclear power plant assembly; applying the fastener spacing rules to a plurality of randomly generated fastener failure patterns for the given time Tl to determine the probability of the randomly generated fastener failure patterns passing the fastener spacing rules at the given time T1; iterating, by a processor of a computer, the applying step for a given range of time values T2, T3,..., Tx >T0 and determining a maximum future time Tmax at which a predetermined acceptable probability of the fastener failure patterns passing the fastener spacing rules is met, thereby justifying the acceptability of the fasteners for continued operation of the nuclear power plant assembly; and determining the operability interval as being Tmax-TO.
Inventors:
TROYER GREG (US)
HAIBACH BRIAN (US)
WIGER TIM (US)
HAIBACH BRIAN (US)
WIGER TIM (US)
Application Number:
PCT/US2017/032867
Publication Date:
April 12, 2018
Filing Date:
May 16, 2017
Export Citation:
Assignee:
AREVA INC (US)
International Classes:
G06F17/50
Foreign References:
| JP2002357690A | 2002-12-13 |
Other References:
WWW STRUCTINT COM ET AL: "A Probabilistic Approach to Baffle Bolt IASCC Predictions", 14 May 2012 (2012-05-14), pages 1 - 11, XP055452822, Retrieved from the Internet [retrieved on 20180221]
HURE J ET AL: "Intergranular stress distributions in polycrystalline aggregates of irradiated stainless steel", JOURNAL OF NUCLEAR MATERIALS, ELSEVIER BV, NL, vol. 476, 26 April 2016 (2016-04-26), pages 231 - 242, XP029560331, ISSN: 0022-3115, DOI: 10.1016/J.JNUCMAT.2016.04.017
AL MAZOUZI A ET AL: "PERFORM 60: Prediction of the effects of radiation for reactor pressure vessel and in-core materials using multi-scale modelling 60 years foreseen plant lifetime", NUCLEAR ENGINEERING AND DESIGN, AMSTERDAM, NL, vol. 241, no. 9, 25 January 2011 (2011-01-25), pages 3403 - 3415, XP028389217, ISSN: 0029-5493, [retrieved on 20110311], DOI: 10.1016/J.NUCENGDES.2011.01.054
HURE J ET AL: "Intergranular stress distributions in polycrystalline aggregates of irradiated stainless steel", JOURNAL OF NUCLEAR MATERIALS, ELSEVIER BV, NL, vol. 476, 26 April 2016 (2016-04-26), pages 231 - 242, XP029560331, ISSN: 0022-3115, DOI: 10.1016/J.JNUCMAT.2016.04.017
AL MAZOUZI A ET AL: "PERFORM 60: Prediction of the effects of radiation for reactor pressure vessel and in-core materials using multi-scale modelling 60 years foreseen plant lifetime", NUCLEAR ENGINEERING AND DESIGN, AMSTERDAM, NL, vol. 241, no. 9, 25 January 2011 (2011-01-25), pages 3403 - 3415, XP028389217, ISSN: 0029-5493, [retrieved on 20110311], DOI: 10.1016/J.NUCENGDES.2011.01.054
Attorney, Agent or Firm:
MEHALL, Clint, R. (US)
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