Bayesian statistical model for cladding high-temperature burst under loss-of-coolant accident conditions

Tasaki, Yudai; Narukawa, Takafumi; Udagawa, Yutaka

Journal of Nuclear Science and Technology, 61(10), p.1349 - 1359, 2024/10

https://doi.org/10.1080/00223131.2024.2321342

Formulation of high-temperature strength equation of 9Cr-ODS tempered martensitic steels using the Larson-Miller parameter and life-fraction rule for rupture life assessment in steady-state, transient, and accident conditions of fast reactor fuel

Miyazawa, Takeshi; Tanno, Takashi; Imagawa, Yuya; Hashidate, Ryuta; Yano, Yasuhide; Kaito, Takeji; Otsuka, Satoshi; Mitsuhara, Masatoshi*; Toyama, Takeshi*; Onuma, Masato*; et al.

Journal of Nuclear Materials, 593, p.155008_1 - 155008_16, 2024/05

https://doi.org/10.1016/j.jnucmat.2024.155008

Oxidation and embrittlement behavior of FeCrAl-ODS cladding tube under loss-of-coolant accident conditions

Narukawa, Takafumi; Kondo, Keietsu; Fujimura, Yuki; Kakiuchi, Kazuo; Udagawa, Yutaka; Nemoto, Yoshiyuki

Journal of Nuclear Materials, 587, p.154736_1 - 154736_8, 2023/12

https://doi.org/10.1016/j.jnucmat.2023.154736

Hierarchical Bayesian modeling to quantify fracture limit uncertainty of high-burnup advanced fuel cladding tubes under loss-of-coolant accident conditions

Narukawa, Takafumi; Hamaguchi, Shusuke*; Takata, Takashi*; Udagawa, Yutaka

Nuclear Engineering and Design, 411, p.112443_1 - 112443_12, 2023/09

https://doi.org/10.1016/j.nucengdes.2023.112443

Data report of ROSA/LSTF experiment IB-HL-01; 17% hot leg intermediate break LOCA with totally-failed high pressure injection system

Takeda, Takeshi

JAEA-Data/Code 2023-007, 72 Pages, 2023/07

JAEA-Data-Code-2023-007.pdf:3.24MB

An experiment denoted as IB-HL-01 was conducted on November 19, 2009 using the Large Scale Test Facility (LSTF) in the Rig of Safety Assessment-V (ROSA-V) Program. The ROSA/LSTF experiment IB-HL-01 simulated a 17% hot leg intermediate break loss-of-coolant accident due to a double-ended guillotine break of pressurizer surge line in a pressurized water reactor (PWR). The break was simulated by a long nozzle upwardly mounted flush with a hot leg inner surface. The test assumptions included total failure of both high pressure injection system of emergency core cooling system (ECCS) and auxiliary feedwater system. In the experiment, relatively large size of break led to a fast transient of phenomena. The primary pressure steeply dropped after the break, and became lower than steam generator (SG) secondary-side pressure. Break flow turned from single-phase flow to two-phase flow soon after the break. Core uncovery started simultaneously with liquid level drop in downflow-side of crossover leg before loop seal clearing (LSC). The LSC was induced in both loops by steam condensation on accumulator (ACC) coolant of ECCS injected into cold legs. The whole core was quenched owing to the rapid recovery in the core liquid level after the LSC. Peak cladding temperature of simulated fuel rods was detected almost concurrently with the LSC. During the ACC coolant injection, liquid levels recovered in the hot legs and SG inlet plena because of liquid entrainment from the hot leg into the SG inlet plenum by high-velocity steam flow. After the continuous core cooling was confirmed through the actuation of low pressure injection system of ECCS, the experiment was terminated. This report summarizes the test procedures, conditions, and major observations in the ROSA/LSTF experiment IB-HL-01.

Effects of azimuthal temperature distribution and rod internal gas energy on ballooning deformation and rupture opening formation of a 17 17 type PWR fuel cladding tube under LOCA-simulated burst conditions

Furumoto, Kenichiro; Udagawa, Yutaka

Journal of Nuclear Science and Technology, 60(5), p.500 - 511, 2023/05

https://doi.org/10.1080/00223131.2022.2116497

Engineering formulation of the irradiation growth behavior of zirconium-based alloys for light water reactors

Kakiuchi, Kazuo; Amaya, Masaki; Udagawa, Yutaka

Journal of Nuclear Materials, 573, p.154110_1 - 154110_7, 2023/01

https://doi.org/10.1016/j.jnucmat.2022.154110

Irradiation growth behavior and effect of hydrogen absorption of Zr-based cladding alloys for PWR

Kakiuchi, Kazuo; Amaya, Masaki; Udagawa, Yutaka

Annals of Nuclear Energy, 171, p.109004_1 - 109004_9, 2022/06

https://doi.org/10.1016/j.anucene.2022.109004

OECD/NEA benchmark on pellet-clad mechanical interaction modelling with fuel performance codes; Influence of pellet geometry and gap size

Soba, A.*; Prudil, A.*; Zhang, J.*; Dethioux, A.*; Han, Z.*; Dostal, M.*; Matocha, V.*; Marelle, V.*; Lasnel-Payan, J.*; Kulacsy, K.*; et al.

Proceedings of TopFuel 2021 (Internet), 10 Pages, 2021/10

Technical basis of ECCS acceptance criteria for light-water reactors and applicability to high burnup fuel

Nagase, Fumihisa; Narukawa, Takafumi; Amaya, Masaki

JAEA-Review 2020-076, 129 Pages, 2021/03

JAEA-Review-2020-076.pdf:3.9MB

Each light-water reactor (LWR) is equipped with the Emergency Core Cooling System (ECCS) to maintain the coolability of the reactor core and to suppress the release of radioactive fission products to the environment even in a loss-of-coolant accident (LOCA) caused by breaks in the reactor coolant pressure boundary. The acceptance criteria for ECCS have been established in order to evaluate the ECCS performance and confirm the sufficient safety margin in the evaluation. The limits defined in the criteria were determined in 1975 and reviewed based on state-of-the-art knowledge in 1981. Though the fuel burnup extension and necessary improvements of cladding materials and fuel design have been conducted, the criteria have not been reviewed since then. Meanwhile, much technical knowledge has been accumulated regarding the behavior of high-burnup fuel during LOCAs and the applicability of the criteria to the high-burnup fuel. This report provides a comprehensive review of the history and technical bases of the current criteria and summarizes state-of-the-art technical findings regarding the fuel behavior during LOCAs. The applicability of the current criteria to the high-burnup fuel is also discussed.