Study on loss-of-cooling and loss-of-coolant accidents in spent fuel pool, 1; Overview

Kaji, Yoshiyuki; Nemoto, Yoshiyuki; Nagatake, Taku; Yoshida, Hiroyuki; Tojo, Masayuki*; Goto, Daisuke*; Nishimura, Satoshi*; Suzuki, Hiroaki*; Yamato, Masaaki*; Watanabe, Satoshi*

Proceedings of 27th International Conference on Nuclear Engineering (ICONE-27) (Internet), 8 Pages, 2019/05

https://doi.org/10.1299/jsmeicone.2019.27.1343

In this research program, cladding oxidation model in SFP accident condition, and numerical simulation method to evaluate capability of spray cooling system which was deployed for spent fuel cooling during SFP accident, have been developed. These were introduced into the severe accident codes such as MAAP and SAMPSON, and SFP accident analyses were conducted. Analyses using Computational Fluid Dynamics (CFD) code were conducted as well for the comparison with SA code analyses and investigation of detail in the SFP accident. In addition, three-dimensional criticality analysis method was developed as well, and safer loading pattern of spent fuels in pool was investigated.

Uncertainty analysis of ROSA/LSTF test by RELAP5 code and PKL counterpart test concerning PWR hot leg break LOCAs

Takeda, Takeshi; Otsu, Iwao

Nuclear Engineering and Technology, 50(6), p.829 - 841, 2018/08

https://doi.org/10.1016/j.net.2018.05.005

Development of the severe accident evaluation method on second coolant leakages from the PHTS in a loop-type sodium-cooled fast reactor

Yamada, Fumiaki; Imaizumi, Yuya; Nishimura, Masahiro; Fukano, Yoshitaka; Arikawa, Mitsuhiro*

Proceedings of 25th International Conference on Nuclear Engineering (ICONE-25) (CD-ROM), 10 Pages, 2017/07

The loss-of-reactor-level (LORL) is one of the loss-of-heat-removal-system (LOHRS) of beyond-DBA (BDBA) severe accident. An evaluation method for the LORL which is caused by the coolant leakage in two positions of the primary heat transport system (PHTS) was developed for prototype JSFR which is loop-type sodium-cooled fast reactor. The secondary leakage in cold standby which occurred in different loop from that of the first leakage in rated power operation can lead LORL by excessive declining of the sodium level. Therefore, the sodium level behavior in RV was studied in a representative accident sequence by considering the sodium pumping up into RV, siphon-breaking to stop pumping out from RV and maintain the sodium level, and calculation programs for the transient sodium level in RV. The representative sequence with lowest sodium level was selected by considering combinations of possible leakage positions. As a result of the evaluation considering the countermeasures above, it was revealed that the LOHRS can be prevented by maintaining the sodium level for the operation of decay heat removal system, even in the leakages in two positions of PHTS which corresponds to BDBA.

The Effect of oxidation and crystal phase condition on the ballooning and rupture behavior of Zircaloy-4 cladding tube-under transient-heating conditions

Narukawa, Takafumi; Amaya, Masaki

Journal of Nuclear Science and Technology, 53(1), p.112 - 122, 2016/01

https://doi.org/10.1080/00223131.2015.1025884

Numerical investigation of heat transfer enhancement phenomenon during the reflood phase of PWR-LOCA

Onuki, Akira; Akimoto, Hajime

Journal of Nuclear Science and Technology, 36(11), p.1021 - 1029, 1999/11

https://doi.org/10.3327/jnst.36.1021

no abstracts in English

Applicability of REFLA/TRAC code to a small-break LOCA of PWR

Onuki, Akira; ; Murao, Yoshio

Journal of Nuclear Science and Technology, 32(3), p.245 - 256, 1995/03

https://doi.org/10.3327/jnst.32.245

no abstracts in English

Effect of fuel assembly configuration and fuel rod configuration on thermal-hydraulic behavior in core during reflood phase of PWR-LOCA

Onuki, Akira; ; Iguchi, Tadashi; Murao, Yoshio

JAERI-Research 94-012, 59 Pages, 1994/08

JAERI-Research-94-012.pdf:1.75MB

no abstracts in English

Assessment of one dimensional reflood model in REFLA/TRAC code

; Onuki, Akira; Murao, Yoshio

JAERI-M 93-240, 83 Pages, 1993/12

JAERI-M-93-240.pdf:1.94MB

no abstracts in English

Assessment of TRAC-PF1/MOD1 code for large break LOCA in PWR

; Onuki, Akira; Abe, Yutaka*; Murao, Yoshio

JAERI-M 93-028, 252 Pages, 1993/03

JAERI-M-93-028.pdf:5.98MB

no abstracts in English

Study of two-phase flow under low velocity in PWR-LOCA

Onuki, Akira

JAERI-M 92-150, 134 Pages, 1992/10

JAERI-M-92-150.pdf:4.08MB

no abstracts in English