Historical changes and Correspondence to Research and Test Reactors New Regulatory Standards for Monitoring Post in Oarai Research and Development Institute, JAEA

Hamaguchi, Takumi; Yamada, Junya; Komatsuzaki, Naoya*; Hatakeyama, Takumi; Seya, Natsumi; Muto, Yasunobu; Miyauchi, Hideaki; Hashimoto, Makoto

JAEA-Technology 2022-038, 65 Pages, 2023/03

JAEA-Technology-2022-038.pdf:4.3MB

New regulatory requirements were developed taking into account the lessons-learnt from the accident at Fukushima Daiichi Nuclear Power Station on March 2011. The new regulatory standards required that monitoring posts should be diversified in transmission systems and equipped with backup power supply equipment for design basis accidents. In this report, we look back on the history of monitoring posts in Oarai Research and Development Institute, explained the application for the permission of reactor installment license, application for approval of the design and construction method, pre-use operator's inspection and improvement design of monitoring posts. This report also includes about inspection based on act on special measures concerning nuclear emergency preparedness and the installation of KURAMA-II, which was carried out in conjunction with the improvement of monitoring post for new regulatory standards. As an appendix, application document for approval of the design and construction method are included.

Experimental investigation of Post-BT heat transfer and rewetting phenomena

Satou, Akira; Wada, Yuki; Le, T. D.; Shibamoto, Yasuteru; Yonomoto, Taisuke

Proceedings of ANS International Conference on Best Estimate Plus Uncertainties Methods (BEPU 2018) (USB Flash Drive), 12 Pages, 2018/00

Experiments were performed under the condition of AOO for BWRs to obtain Post-BT heat transfer rate, deposition rates of liquid droplets, and the rewetting behavior after the core dryout. Rewetting behavior was analytically investigated and a relation among the rewetting velocity, the hot wall temperature, and the heat transfer rates in the precursory cooling and wetted regions were obtained. In addition, experiments simulating the condition of ATWS were newly performed with simulated ferrule spacers especially to investigate the spacer effect. It was found that the heat transfer rates were enhanced by the spacers, which were compared with existing prediction models for the validation. The spacers also appeared to increase the rewetting velocity slightly. Since the precursory cooling was found to play an important role on the rewetting behavior through the series of prior experiments, new experiments are conducted focusing on the precursory cooling. In those experiments, the behaviors of liquid film and droplets around the rewetting front were observed to investigate the mechanism of the precursory cooling.

Calculation of conversion factor for estimation of I concentrations in the air from pulse-height distribution observed by NaI(Tl) detector in monitoring posts

Yamada, Junya; Hashimoto, Makoto; Seya, Natsumi; Haba, Risa; Muto, Yasunobu; Shimizu, Takehiko; Takasaki, Koji; Yokoyama, Sumi*; Shimo, Michikuni*

Radioisotopes, 65(10), p.403 - 408, 2016/10

https://doi.org/10.3769/radioisotopes.65.403

The purpose of this study is to develop a quick method for estimation of I concentrations in the air using data measured by monitoring posts. In this method, I concentrations were estimated by multiplying I count rates at the full-energy peak measured with a NaI(Tl) detector by a concentration conversion factor. The concentration conversion factor for monitoring posts in JAEA Oarai Center was calculated with an EGS5 Monte Carlo code. As a result, the concentration conversion factor for an infinite-air-source was 25.7 Bq/m/cps.

Optimization study on the normal conducting center post for the low aspect ratio tokamak reactor

Song, Y.*; Nishio, Satoshi

Fusion Engineering and Design, 72(4), p.345 - 362, 2005/01

https://doi.org/10.1016/j.fusengdes.2004.08.002

This paper presents detailed optimization results and design windows for the engineering design of normal conducting (NC) center post based on the analysis of thermal-hydraulic, static stress and critical buckling. At the same time a method to reduce the stress in the center post have been proposed, which can be applied to enhance the possibility of normal conducting center post in the future power plants. When the method of improvement for reducing the stress is applied in the system of the center post, the maximum magnet field can be improved from 8.6T to 15T.

Buckling analysis for the center post of low aspect ratio Tokamak

Song, Y.; Nishio, Satoshi

Proceedings of 20th IEEE/NPSS Symposium on Fusion Engineering (SOFE 2003), p.581 - 584, 2003/00

no abstracts in English

A Concurrent visualization system for large-scale unsteady simulations; Parallel vector performance on an NEC SX-4

Takei, Toshifumi*; Matsumoto, Hideki*; Muramatsu, Kazuhiro; Doi, Shun*

Kashika Joho Gakkai-Shi, 20(suppl.1), p.115 - 118, 2000/07

no abstracts in English

Expansion of material balance analysis function on nuclear fuel cycle

Ohtaki, Akira; ; ; *; *;

JNC TN9410 2000-006, 74 Pages, 2000/04

JNC-TN9410-2000-006.pdf:3.01MB

To evaluate materials balance in nuclear fuel cycle quickly and quantitatively the fuel cycle requirement code "FAMILY" was improved. And an accumulated TRU&LLFP quantity analysis code was developed. The contents are as follows: (1)A calculation ability of minor actinide production and expenditure was added to the "FAMILY" code. (2)An output program for the "FAMILY" calculation results was developed. (3)A simple version of "FAMILY" code was developed. (4)An analysis code for accumulated TRU&LLFP quantity in nuclear fuel cycle was developed.

None

*; Fusaeda, Shigeki*

JNC TJ1400 2000-004, 245 Pages, 2000/02

JNC-TJ1400-2000-004.pdf:8.57MB

no abstracts in English

Post processing system for multi-dimensionaI thermal-hydraulic analyses

Miyake, Yasuhiro*; *; ; Kimura, Nobuyuki

JNC TN9400 2000-016, 40 Pages, 1999/12

JNC-TN9400-2000-016.pdf:3.71MB

ln the conventional visualization system for the computational results, only Japanese (Nihongo) Line Printer (NLP) was available to print two dimensional cross sectional plots of vector and scalar fields. To evaluate the phenomena, an analyst had to print many plots on the NLP. This task makes difficult to check the computational results immediately after the calculation. Recently, as the visualization tools, we introduced Micro AVS and Field View which are utilized widely in the scientific and the industrial fields. ln order to show the numerical results on the visualization software, we constructed a post processing system which convert the results of the numerical code to "lntermediate files" which can be read by the visualization tools. As using this system, the examination of the numerical results can be executed on the display of the personal computer. Furthermore, the persuasive report and paper with high quality can be produced due to the color printing. As for the transient calculation, the change of the phenomena can be visually evaluated by using the animation function.

None

*

JNC TJ1400 99-016, 24 Pages, 1999/02

JNC-TJ1400-99-016.pdf:0.86MB

no abstracts in English