Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Morita, Yoshihiro*; Suzuki, Hiroaki*; Naito, Masanori*; Nemoto, Yoshiyuki; Kaji, Yoshiyuki
Proceedings of 27th International Conference on Nuclear Engineering (ICONE-27) (Internet), 9 Pages, 2019/05
In this study, the SAMPSON code was modified to evaluate severe accidents in a spent fuel pool (SFP). Not only the SFP but also upper spaces of the SFP, walls of the reactor building, and the blowout panel were included. Air oxidation models obtained by the Zircaroy-4 cladding (ANL model) and the Zircaroy-2 cladding (JAEA model) were included in the modified SAMPSON code. Experiments done by Sandia National Laboratory using simulated fuel assemblies equivalent to those of an actual BWR plant were analyzed by the modified SAMPSON code to confirm the functions for analysis of the severe SFP accidents.
Suzuki, Hiroaki*; Morita, Yoshihiro*; Naito, Masanori*; Nemoto, Yoshiyuki; Nagatake, Taku; Kaji, Yoshiyuki
Proceedings of 27th International Conference on Nuclear Engineering (ICONE-27) (Internet), 7 Pages, 2019/05
In this paper, modification of the SAMPSON code was carried out to enable the analysis of spray cooling. The SAMPSON analysis of a spray cooling experiment was performed to confirm reproducibility of spray cooling behavior of fuel claddings. The modified SAMPSON code was applied to a hypothetical loss-of-coolant accident analysis of the SFP. Effectiveness of spray cooling on cladding temperature behavior was investigated. The SAMPSON analysis showed that spraying from the top of the SFP was effective for cooling the fuel assemblies exposed to the gas phase.
Someya, Takayuki*; Chitose, Hiromasa*; Watanabe, Satoshi*; Nemoto, Yoshiyuki; Kaji, Yoshiyuki
Proceedings of 27th International Conference on Nuclear Engineering (ICONE-27) (Internet), 9 Pages, 2019/05
In this study, CFD analysis has been conducted for the assessment of spent fuel integrity in large LOCA event and the maximum temperature of spent fuel assemblies has been evaluated. Then, it has been compared with the result of the simple assessment method. As a case study, additional CFD analysis has been conducted, where water level in SFP decreases to the Bottom of Active Fuel (BAF) due to boil-off. Since this scenario might be more severe than large LOCA scenario, the number of spent fuel assemblies, their decay heat and loading pattern to maintain spent fuel integrity are investigated.
Nemoto, Yoshiyuki; Kaji, Yoshiyuki; Onizawa, Takashi*; Kanazawa, Toru*; Nakashima, Kazuo*; Tojo, Masayuki*
Proceedings of Annual Congress of the European Federation of Corrosion (EUROCORR 2018) (USB Flash Drive), 8 Pages, 2018/09
The authors proposed oxidation models based on oxidation data which previously obtained in high temperature oxidation tests on small sample of Zircalloy-2 (Zry2) cladding in dry air and in air/steam mixture environment. The oxidation models were implemented in computational fluid dynamics (CFD) code to analyse oxidation behavior of long cladding sample in hypothetical spent fuel pool (SFP) accident conditions. The oxidation tests were conducted using Zry2 cladding sample 500 mm in length. The oxide layer growth in dry air was well reproduced in the calculation using the oxidation model, meanwhile which in air/steam mixture was overestimated atmosphere composition change anticipated in the spent fuel rack during the accident, and its influence on the oxidation behaviour of the cladding were discussed in consideration of the oxidation model improvement.
Otaka, Masahiko; Kato, Atsushi; Chikazawa, Yoshitaka; Uzawa, Masayuki*; Kaneko, Fumiaki*
no journal, ,
Reliability of JSFR spent fuel pool make-up system was improved through design study including related evaluation on the cooling capability under extreme high ambient temperature conditions.
Aihara, Haruka; Hinai, Hiroshi; Kitawaki, Shinichi; Nakajima, Yasuo; Taguchi, Katsuya
no journal, ,
no abstracts in English
Endo, Shinya; Motooka, Takafumi; Uehara, Hiroyuki; Obata, Hiroki; Kawamata, Yutaka; Ueno, Fumiyoshi
no journal, ,
no abstracts in English
Iwanami, Masaru*; Tanaka, Shigeaki*; Ueno, Fumiyoshi
no journal, ,
no abstracts in English
Tanaka, Shigeaki*; Iwanami, Masaru*; Ueno, Fumiyoshi
no journal, ,
no abstracts in English
Morita, Yoshihiro*; Suzuki, Hiroaki*; Naito, Masanori*; Nemoto, Yoshiyuki; Kaji, Yoshiyuki
no journal, ,
A new model including the spent fuel pool (SFP) or Zr oxidation behavior which is necessary to evaluate the SFP accident caused by cooling function loss was developed and implanted in the severe accident code SAMPSON in this work. Results of the evaluation using the improved code will be presented.
Higuchi, Toru*; Ishioka, Shinichi*; Tanaka, Shigeaki*; Morishima, Yasuo*; Ueno, Fumiyoshi; Maeda, Koji
no journal, ,
no abstracts in English
Nemoto, Yoshiyuki; Kaji, Yoshiyuki; Ogawa, Chihiro*; Nakashima, Kazuo*; Tojo, Masayuki*
no journal, ,
To cope with the hypothetical loss-of-cooling or lost-of-coolant severe accident in spent fuel pools (SFPs), it is important to understand the high temperature oxidation behavior of the Zirconium claddings exposed in the air or in the atmosphere of air/steam mixture which are presumed for the environment in spent fuel rack internal in the SFP accident. The authors have investigated the detail of high temperature oxidation behavior of the Japanese fuel cladding materials in dry air with flow rate in the hypothetical SFP accident condition, and proposed oxidation models as well. Since there is not enough knowledge about influence of air / steam mixing ratio in atmosphere on cladding oxidation in SFP accident condition, the authors conducted high temperature oxidation tests of claddings in atmosphere of air / steam mixture with flow rate of hypothetical SFP accident condition, and investigated the influence of air / steam mixing ratio on cladding oxidation behavior.
Ishimaru, Masaru; Maeda, Shigetaka; Miura, Yoshiyuki; Suzuki, Toshiaki
no journal, ,
no abstracts in English
Suzuki, Hiroaki*; Morita, Yoshihiro*; Naito, Masanori*; Kaji, Yoshiyuki; Nemoto, Yoshiyuki
no journal, ,
Severe accident code SAMPSON was upgraded by introducing the models of Zr oxidation in air, and spray cooling, etc, in this study. Analytical results on spent fuel pool (SFP) accident were obtained and effectiveness of the spray cooling system for the safety measure of the SFP was discussed in this study.