核融合炉用トリチウム製造に対する高温ガス炉の特性

To start up an initial fusion reactor and for technical tests for tritium circulation and blanket system, it is necessary to provide sufficient amount of tritium from an outside device. We have proposed tritium production using a high temperature gas-cooled reactor [1,2]. The gas turbine high-temperature reactor of 300MWe nominal capacity (GTHTR300) [3] and high temperature engineering test reactor (HTTR) [4] have been assumed as typical calculation targets of gas-cooled reactor. On the basis of the continuous-energy Monte Carlo transport code MVP-BURN [5], the burn-up calculations for whole-core region have been carried out considering its unique double heterogeneity structure. The effectiveness of the use of the high-temperature gas-cooled reactor for tritium production for fusion reactors is presented.

To realize a proposed system, tritium handling technique in the reactor core is also important. If we can keep the Li-rod temperature below 800 K during the operation, the tritium outflow from the Li rods to He coolant can be suppressed to less than 1% of the amount of the tritium produced. When we attempt to operate the reactor at a higher temperature range (e.g. 1100-1200 K) from the viewpoint of electric power generation efficiency, the outflow will be increased. It is important to devise a way to reduce the outflow to further low level. The current status for development of Li-loading rod structure for tritium production and future plan for demonstration test are also shown.

[1] H. Matsuura, et al., Nucl. Eng. Des., 243 (2012) 95. [2] H. Matsuura, J. Plasma Fusion Res., 93 (2017) 457. (in Japanese) [3] X. Yan, et al., Nucl. Eng. Des., 222 (2003) 247. [4] S. Saito, et al, JAERI 1332 (1994). [5] Y. Nagaya, et al., JAERI 1348 (2005).