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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.
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JNC TN9400 2000-066, 52 Pages, 2000/06
JNC-TN9400-2000-066.pdf:1.82MB
Phase I of feasibility studies on commercialized fast reactor system is being peformed for two years from Japanese Fiscal Year 1999. In this report, results of the study on fluid fuel reactors (especialiy a molten salt fast breeder reactor concept) are described from the viewpoint of technical and economical concerns of the plant system design. ln JFY1999, we have started to investigate the fluid fuel reactors as alternative concepts of sodium cooled FBR systems with MOX fuel, and selected the unique concept of a molten chloride fast, breeder reactor, whose U-Pu fuel cycle can be related to both light water reactors and fast breeder reactors on the basis of present technical data and design experiences. We selected a preliminary composition of molten fuel and conceptual plant design through evaluation of technical and economical issues essential for the molten salt reactors and then compared them with reference design concepts of sodium cooled FBR systems under limited information on the molten chloride fast breeder reactors. The following results were obtained. (1)The molten chloride fast breeder reactors have inherent safety features in the core and plant performances, ad the fluid fuel is quite promising for cost reduction of the fuel fabrication and reprocessing. (2)On the other hand, the inventory of the molten chloride fuel becomes high and thermal conductivity of the coolant is inferior compared to those of sodium cooled FBR systems, then, the size of main components such as lHX's becomes larger and the amount of construction materials is seems to be increased. (3)Furthermore economical vessel and piping materials which contact with the molten chloride salts are required to be developed. From the results, it is concluded that further steps to investigate the molten chloride fast breeder reactor concepts are too early to be conducted.
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PNC TJ9381 93-001, 158 Pages, 1993/02
Present nuclear power reactor adopts a forced circulation system. But, the natural circulation studies for light water reactor are recently preceeding. So, on purpose to examine possibility of ATR natural circulation reactor in 1000Mwt class, we evaluated the natural flow and core cooling characteristic for ATR. In this study, the sensitivity analyses for the natural circulation characteristic by change inlet pipe diameter, outlet pipe diameter, core length, and downcomer pipe height were executed. Then the sensitivities are as follows. (1)Influence of inlet pipe diameter. From analyses of the case which was executed using 3B as inlet pipe diameter, against using 2B in the base case, it was clarified that channel flow of the case using 2B is more stable than that of the another. (2)Influence of outlet pipe diameter. From analyses of the cases which were executed using 4B and 5B as outlet pipe diameter, against using 3B in the base cases, it was clarified that the cases using pipes of a large diameter have more natural flow than the other cases, because of decreasing pressure loss at outlet pipes. (3)Influence of core length. From analyses of the cases which were executed using 3.2m and 2.7m as core length, against using 3.7m in the base case, it was clarified that the cases using short core length have more natural flow than the other cases, because of decreasing pressure loss at the core. (4)Influence of downcomer height. From analyses of the cases which were executed using 20m and 30m as downcomer against using 15m in the base case, it was clarified that the cases using high downcomer height have more natural flow than the other cases, because of increasing driving head which is the diferential pressure between the core and the downcomer. And, from the analyses results of (1) to (4), it was crarified that the item of the most largest sensitivity was downcomer height. And then, using the combination which have most natural circulation flows for ...
; Matsuki, Takuo*; Hiroi, Hiroshi*; Himeno, Yoshiaki
PNC TN9410 88-092, 82 Pages, 1988/08
Post-test calculations of the large-scale sodium leak demonstration test, Run-D2, were performed using the ASSCOPS code in order to validate the applicability of the code to the evaluation of the fire suppression function of the PNC-type smothering tank. In the analysis, radiation coefficients between aerosols in the gas phase and structures and a pool surface in the smothering tank defined in the code were varied as parameter. The following three cases were calculated. (a)No aerosols suspending was assumed in the gas phase and thus, 1.0 was used as the coefficient between the structures and the pool surface. (b)The coefficient between the aerosols and the pool surface was 0.65, and that between structures and the aerosols was 0.73. (c)The coefficient between the aerosols and the pool surface was the same as case (b) and 0.5 was used as that between structures and the aerosols. The comparison between analysis and experiment with regard to the temperature of the various parts showed that the agreement was within +30% and -20%. From these results, it was concluded that the code was available for the evaluation of the fire suppression function of the smothering tank.