Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Takeda, Takeshi
JAEA-Data/Code 2023-012, 75 Pages, 2023/10
JAEA-Data-Code-2023-012.pdf:4.45MB
An experiment denoted as TR-LF-15 was conducted on June 11, 2014 using the Large Scale Test Facility (LSTF) in the Rig of Safety Assessment-V (ROSA-V) Program. The ROSA/LSTF experiment TR-LF-15 simulated accident management (AM) actions during a station blackout transient with TMLB' scenario with pump seal loss-of-coolant accident (LOCA) in a pressurized water reactor (PWR). This scenario is featured by loss of auxiliary feedwater functions. The pump seal LOCA was simulated by a 0.1% cold leg break. The test assumptions included total failure of both high pressure injection system and low pressure injection system of emergency core cooling system (ECCS). Also, it was presumed non-condensable gas (nitrogen gas) inflow to the primary system from accumulator (ACC) tanks of ECCS. When steam generator (SG) secondary-side collapsed liquid level dropped to a certain low liquid level, the primary pressure turned to rise. After the SG secondary-side became voided, the safety valve of a pressurizer cyclically opened which led to loss of primary coolant. Core uncovery thus took place owing to core boil-off at high pressure. When an increase of 10 K was confirmed in cladding surface temperature of simulated fuel rods, SG secondary-side depressurization was started as the first AM action. At that time, the safety valves in both SGs were fully opened. Primary depressurization was initiated by completely opening the pressurizer safety valve as the second AM action with some delay after the first AM action onset. When the SG secondary-side pressure lowered to 1.0 MPa following the first AM action, water was injected into the secondary-side of both SGs via feedwater lines with low-head pumps as the third AM action. A reduction in the primary pressure was accelerated because the heat removal from the SG secondary-side system resumed shortly after the third AM action initiation.
Takeda, Takeshi; Otsu, Iwao
Science and Technology of Nuclear Installations, 2018, p.7635878_1 - 7635878_19, 2018/00
Times Cited Count：2 Percentile：20.93(Nuclear Science & Technology)Doda, Norihiro; Hiyama, Tomoyuki; Tanaka, Masaaki; Ohshima, Hiroyuki; Thomas, J.*; Vilim, R. B.*
Proceedings of International Conference on Fast Reactors and Related Fuel Cycles; Next Generation Nuclear Systems for Sustainable Development (FR-17) (USB Flash Drive), 10 Pages, 2017/06
In sodium-cooled fast reactors, a natural circulation is expected to remove the core decay heat when the plant gets into a station blackout. From a perspective of reactor safety, the core hot spot temperature arising in the natural circulation should be evaluated accurately. To this end, Japan Atomic Energy Agency is trying to couple a 1-D plant dynamics analysis code Super-COPD and a 3-D CFD code AQUA to solve the thermal-hydraulic field in the whole plant under natural circulation condition. As a validation study, the coupled code was applied to an analysis of EBR-II shutdown heat removal test. The obtained numerical results reasonably agreed with the measured data, which demonstrated the validity of the coupled code.
Chikazawa, Yoshitaka; Kato, Atsushi; Hayafune, Hiroki; Shimakawa, Yoshio*; Kamishima, Yoshio*
Nuclear Technology, 192(2), p.111 - 124, 2015/11
Times Cited Count：1 Percentile：9.74(Nuclear Science & Technology)Evaluation of severe external hazards on JSFR has been analyzed. For seismic design, safety components are confirmed to maintain their functions even against recent strong earthquakes. For tsunam, hypothetical station blackout has been evaluated.
Takeda, Takeshi; Otsu, Iwao
Mechanical Engineering Journal (Internet), 2(5), p.15-00132_1 - 15-00132_15, 2015/10
Takeda, Takeshi; Otsu, Iwao
Journal of Energy and Power Sources, 2(7), p.274 - 290, 2015/07
Takeda, Takeshi; Otsu, Iwao
Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 10 Pages, 2015/05
Hidaka, Akihide; Maruyama, Yu; Nakamura, Hideo
Proceedings of 6th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, Operations and Safety (NUTHOS-6) (CD-ROM), 15 Pages, 2004/00
Severe accident studies showed that Direct Containment Heating issue was resolved for PWRs because a creep rupture at pressurizer surge line would occur prior to the melt-through of Reactor Pressure Vessel during station blackout (TMLB'). However, it was recently concerned that, if the secondary system is depressurized during TMLB', the creep rupture at SG U-tubes would occur earlier than the surge line. This pressure- and temperature-induced SG U-tube rupture (PTI-SGTR) is not preferable because of the increase in offsite consequences. The SCDAP/RELAP5 analyses by USNRC showed that the surge line would fail earlier than the U-tubes. However, the analyses used a coarse nodilization for steam mixing at the SG inlet plenum that could affect the temperature of U-tubes. To investigate the effect of steam mixing, an analysis was performed with MELCOR1.8.4. The analysis showed that the surge line would fail earliest during TMLB' while the U-tubes could fail earliest during TMLB' with secondary system depressurization. Further investigation is needed for occurrence conditions of PTI-SGTR.
Suzuki, Mitsuhiro
JAERI-Tech 2002-071, 171 Pages, 2002/10
JAERI-Tech-2002-071.pdf:11.26MB
no abstracts in English
Hidaka, Akihide; Soda, Kunihisa; Sugimoto, Jun
Journal of Nuclear Science and Technology, 32(6), p.527 - 538, 1995/06
Times Cited Count：3 Percentile：36.75(Nuclear Science & Technology)no abstracts in English
Anoda, Yoshinari; Katayama, Jiro*; Kukita, Yutaka; R.Mandl*
Power Plant Transients,1992; FED-Vol. 140, p.89 - 96, 1993/00
no abstracts in English
Kukita, Yutaka; Anoda, Yoshinari; ; F.Serre*
Power Plant Transients; 1990, p.7 - 14, 1991/00
no abstracts in English
*; Iwamura, Takamichi; Okubo, Tsutomu; ; Murao, Yoshio
JAERI-M 90-047, 37 Pages, 1990/03
no abstracts in English
; ; ; *; *
Source Term Evaluation for Accident Conditions, p.733 - 744, 1986/00
no abstracts in English
; *; ; *
Nihon Genshiryoku Gakkai-Shi, 27(1), p.56 - 65, 1985/00
Times Cited Count：1 Percentile：24.17(Nuclear Science & Technology)no abstracts in English
