An Interpretation of Fukushima-Daiichi Unit 3 plant data covering the two-week accident-progression phase based on correction for pressure data

Sato, Ikken

Journal of Nuclear Science and Technology, 56(5), p.394 - 411, 2019/05

https://doi.org/10.1080/00223131.2019.1588798

Water columns were adopted in the pressure measurement system of Fukushima-Daiichi Unit-3. Part of these water columns evaporated during the accident condition jeopardizing correct understanding on actual pressure. Through comparison of RPV (Reactor Pressure Vessel) and S/C pressures with D/W pressure, such water-column effect was evaluated. Correction for this effect was developed enabling clarification of slight pressure difference among RPV, S/C and D/W. This information was then integrated with other available data such as, water level, CAMS and environmental dose rate, into an interpretation of accident focusing on RPV and PCV pressurization/depressurization and radioactive material release to environment. It is suggested that dryout of in-vessel and ex-vessel debris was likely causing pressure decrease. S/C water poured into pedestal heated by relocated debris was the likely cause of pressurization. Cyclic reflooding of pedestal debris and dryout was likely.

Modeling of reflooding

G.Yadigaroglu*; R.A.Nelson*; V.Teschendorff*; Murao, Yoshio; J.Kelly*; D.Bestion*

Nucl. Eng. Des., 145, p.1 - 35, 1993/00

https://doi.org/10.1016/0029-5493(93)90056-F

no abstracts in English

Evaluation report on SCTF core-III test S3-22; Investigation of water break-through and core cooling behaviors under alternate ECC water delivery from hot legs to upper plenum during reflooding in PWRs with combined-injection type ECCS

Okubo, Tsutomu; Iguchi, Tadashi; Iwamura, Takamichi; ; Onuki, Akira; Abe, Yutaka; *; Murao, Yoshio

JAERI-M 91-104, 108 Pages, 1991/07

JAERI-M-91-104.pdf:2.38MB

no abstracts in English

Accident analyses for a double-flat-core type HCLWR

Okubo, Tsutomu; Iwamura, Takamichi; *; *; Murao, Yoshio

6th Proc. of Nuclear Thermal Hydraulics, p.79 - 86, 1990/11

no abstracts in English

Analysis of SCTF/CCTF counterpart test results

Okubo, Tsutomu; Sobajima, Makoto; Iwamura, Takamichi; Onuki, Akira; Abe, Yutaka; Adachi, Hiromichi; Murao, Yoshio

JAERI-M 90-083, 155 Pages, 1990/06

JAERI-M-90-083.pdf:3.6MB

no abstracts in English

Evaluation report on SCTF core-III test S3-9; Investigation of CCTF coupling test results under an evaluation model condition in PWRs with cold-leg-injection-type ECCS

Okubo, Tsutomu; Iguchi, Tadashi; Iwamura, Takamichi; ; Onuki, Akira; Abe, Yutaka; *; Adachi, Hiromichi; Murao, Yoshio

JAERI-M 90-046, 114 Pages, 1990/03

JAERI-M-90-046.pdf:2.26MB

no abstracts in English

Evaluation report on SCTF core-III tests S3-7 and S3-8; Investigation of tie plate water temperature distribution effects on water break-through and core cooling during reflooding in PWRs with combined-injection-type ECCS

Okubo, Tsutomu; Iguchi, Tadashi; Iwamura, Takamichi; ; Onuki, Akira; Abe, Yutaka; *; *; Adachi, Hiromichi; Murao, Yoshio

JAERI-M 90-035, 143 Pages, 1990/03

JAERI-M-90-035.pdf:3.07MB

no abstracts in English

Reflood experiments in single rod channel under high-pressure condition

G.Xu*; Kumamaru, Hiroshige; Tasaka, Kanji

JAERI-M 89-178, 35 Pages, 1989/11

JAERI-M-89-178.pdf:0.74MB

no abstracts in English

Two-dimensional fall back flow and core cooling in the slab core test facility: SCTF

; ; ;

Proc.2nd Int.Topical Meeting on Nuclear Power Plant Thermal Hydraulics and Operations, p.2 - 129, 1986/00

no abstracts in English

Experimental modeling of steam-water countercurrent flow limit for perforated plates

Journal of Nuclear Science and Technology, 22(9), p.723 - 732, 1985/00

https://doi.org/10.3327/jnst.22.723

no abstracts in English