Development of simplified evaluation models for the first power peak during a criticality accident and its verification by the TRACE code simulated results based on CRAC experimental data

Nomura, Yasushi; Sakino, Takao*; Nikolaevna, S. O.*

JAERI-Research 2000-034, 95 Pages, 2000/07

JAERI-Research-2000-034.pdf:4.84MB

no abstracts in English

Current status and future plan for thermaI striping investigations at JNC

; kasahara, Naoto; ; ; Kamide, Hideki

JNC TN9400 2000-010, 168 Pages, 2000/02

JNC-TN9400-2000-010.pdf:8.78MB

Thermal striping is significant issue of the structural integrity, where the hot and cold fluids give high cycle fatigue to the structure through the thermal stress resulted from the time change of temperatur distibution in the structure. In the sodium cooled fast reactor, temperature change in fluid easily transfers to the structure because of the high thermal conductivity of the sodium. It means that we have to take care of thermal striping, The thermal striping is complex phenomena between the fluid and structure engineering fields. The investigations of thermal striping are not enough to evaluate the integrity directly. That is the fluctuation intensity at the structure surface is assumed to be temperature difference between source fluids (upstream to the mixing region) as the maximum value in the design. 0therwise, the design conditions are defined by using a mockup experiment and large margin of temperature fluctuation intensity. Furthermore, such evaluation manners have not yet been considered as a design rule. Transfer mechanism of temperature fluctuation from fluid to structure has been investigated by the authors on the view points of the fluid and structure. Attenuation of temperature fluctuation was recognized as a dominant factor of thermal fatigue. We have devdoped a numerical analysis system which can evaluate thermal fatigue and crack growth with consideration of the attenuation of temperature fluctuation in fluid, heat transfer, and structure. This system was applied to a real reactor and the applicability was confirmed. Further verification is planned to generalize the system. For the higher cost performance of the fast reactor, an evaluation rule is needed, which can estimate thermal loading with attenuation and can be applied to the design. An idea of the rule is proposed here. Two methods should be prepared; one is a precise evaluation method where mechanism of attenuation is modeled, and the other is simple evaluation method where ...

Preliminary analyses of critical experiments using 10% enriched uranium nitrate solution with the 800mm-diameter cylindrical tank of STACY

; Miyoshi, Yoshinori; Ono, Akio

JAERI-Tech 98-016, 88 Pages, 1998/05

JAERI-Tech-98-016.pdf:3.19MB

no abstracts in English

Simplified evaluation models for total fission number in a criticality accident

Nomura, Yasushi; Okuno, Hiroshi

ICNC 95: 5th Int. Conf. on Nuclear Criticality Safety,Vol. II, 0, p.11.25 - 11.28, 1995/00

no abstracts in English

Stress intensity factor analyses of surface cracks in three-dimensional structures; Comparison of the finite element solutions with the results obtained by the simplified estimation methods

; ; *; *

Int.J.Press.Vessels Piping, 15, p.37 - 59, 1984/00

https://doi.org/10.1016/0308-0161(84)90044-9

no abstracts in English

Comparison of evaluation methods of 1st peak power in slow transient

Yamane, Yuichi

no journal, , 

Simplified estimation methods and slow transient data of TRACY experiment are compared for the purpose of developing the method to estimate the first peak power in a criticality accident with a continuous reactivity insertion such as flowing of nuclear fuel solution into a vessel. It is shown that the estimated values are in the range between twice and a half of the experimental data.