Analysis of contact length distribution of superconducting strands with copper sleeves at cable-in-conduit conductor joints

Nakazawa, Shinobu*; Teshima, Shotaro*; Arai, Daichi*; Miyagi, Daisuke*; Tsuda, Makoto*; Hamajima, Takataro*; Yagai, Tsuyoshi*; Nunoya, Yoshihiko; Koizumi, Norikiyo; Takahata, Kazuya*; et al.

Teion Kogaku, 46(8), p.474 - 480, 2011/08

https://doi.org/10.2221/jcsj.46.474

It is observed that measured critical currents of a large current CIC conductor sample become lower than expected ones, since unbalanced current distribution is caused through contacting resistances between strands and Cu sleeves in CIC conductor joints. In order to evaluate the contacting length, we identify all strands 3 dimensional positions in the CIC conductor, and then we measure contacting number and lengths of strands which appear on surface of the cable for contacting with the Cu sleeves. It is found that some strands do not appear on the surface of cable and the contacting lengths are widely distributed with large standard deviation. We develop a numerical code which simulates strand positions in the CIC, and then compare the analyzed contacting strand number and contacting length with measured ones. It is found that the both results are in good agreement and hence the code is available for evaluating the contacting parameters. We vary twist pitches of sub-cables to search the contacting parameters and then show that all strands appear on the cable surface and have contacting lengths with small standard deviation. It is found that the twist pitches are a key parameter for optimization of the contacting parameters.

Rise-to-power test in High Temperature Engineering Test Reactor; Test progress and summary of test results up to 30MW of reactor thermal power

Nakagawa, Shigeaki; Fujimoto, Nozomu; Shimakawa, Satoshi; Nojiri, Naoki; Takeda, Takeshi; Saikusa, Akio; Ueta, Shohei; Kojima, Takao; Takada, Eiji*; Saito, Kenji; et al.

JAERI-Tech 2002-069, 87 Pages, 2002/08

JAERI-Tech-2002-069.pdf:10.12MB

Rise-to-power test in the HTTR has been performed from April 23rd to June 6th in 2000 as phase 1 test up to 10MW, from January 29th to March 1st in 2001 as phase 2 test up to 20MW in the rated operation mode and from April 14th to June 8th in 2001 as phase 3 test up to 20MW in the high temperature test operation mode. Phase 4 test to achieve the thermal reactor power of 30MW started from October 23rd in 2001. On December 7th it was confirmed that the thermal reactor power reached to 30MW and the reactor outlet coolant temperature reached to 850C. JAERI obtained the certificate of pre-operation test from MEXT because all the pre-operation tests by MEXT were passed successfully. From the test results of rise-up-power test up to 30MW, the performance of reactor and cooling system were confirmed, and it was confirmed that an operation of reactor facility could be performed safely. Some problems to be solved were found through tests. By means of solving them, the reactor operation with the reactor outlet coolant temperature of 950C will be achievable.

Surveillance system for radiation monitoring in HTTR

Nakazawa, Takashi; Kikuchi, Hisaki; Yasu, Katsuji; Yoshino, Toshiaki; Ashikagaya, Yoshinobu; Sato, Koichi; Minowa, Yuji; Nomura, Toshibumi

JAERI-Tech 2001-010, 125 Pages, 2001/03

JAERI-Tech-2001-010.pdf:7.4MB

no abstracts in English