Difficulties in ensuring review quality performed by committees under the Act on the Safety of Regenerative Medicine in Japan

自由診療で行われる再生医療の審査に関する課題を調査 今後の制度改正に期待. 京都大学プレスリリース. 2023-02-28.Questionable practices identified by an examination of therapeutic plan reviews performed by certified committees under the Act on the Safety of Regenerative Medicine. 京都大学プレスリリース. 2023-02-28.We outlined five studies regarding the quality of the review by committees based on the Act on the Safety of Regenerative Medicine. The findings raise serious concerns about the independence, integrity, and quality of reviews of therapeutic plans by these committees with inappropriately close relationships to medical institutions and companies

原型炉のための技術基盤確立に向けた日本の取組

The establishment of technology bases required for the development of a fusion demonstration reactor (DEMO) has been discussed by a joint effort throughout the Japanese fusion community. The basic concept of DEMO premised for investigation has been identified and the structure of technological issues to ensure the feasibility of this DEMO concept has been examined. The Joint-Core Team, which was launched along with the request by the ministerial council, has compiled analyses in two reports to clarify technology which should be secured, maintained, and developed in Japan, to share the common targets among industry, government, and academia, and to activate actions under a framework for implementation throughout Japan. The reports have pointed out that DEMO should be aimed at steady power generation beyond several hundred thousand kilowatts, availability which must be extended to commercialization, and overall tritium breeding to fulfill self-sufficiency of fuels. The necessary technological activities, such as superconducting coils, blanket, divertor, and others, have been sorted out and arranged in the chart with the time line toward the decision on DEMO. Based upon these Joint-Core Team reports, related actions are emerging to deliberate the Japanese fusion roadmap

Development of Strategic Establishment of Technology Bases for a Fusion DEMO Reactor in Japan

The strategic establishment of technology bases required for the development of a fusion demonstration reactor (DEMO) has been discussed by joint endeavors throughout the Japanese fusion community. The mission of Fusion DEMO is to demonstrate the technological and economic feasibility of fusion energy. The basic concept of Fusion DEMO has been identified and the structure of technological issues to ensure the feasibility of this DEMO concept has been examined. The Joint-Core Team consisting of experts from the Japanese fusion community including industry has pointed out that DEMO should be aimed at steady power generation beyond several hundred thousand kilowatts, availability which must be extensible to commercialization, and overall tritium breeding sufficient to achieve fuel-cycle self-sufficiency. The necessary technological issues and activities have been sorted out along with 11 identified elements of DEMO, such as superconducting coils, blanket, divertor, and others. These will be arranged within a time line to lead to the Japanese fusion roadmap

Conceptual Design for Higher Capability of the Tritium Production by the Honeycomb Structure Blanket of JA DEMO

The conceptual design of the breeding blanket with a honeycomb structure has been created with pressure tightness against in-box Loss-of-coolant accident based on a water-cooled solid breeder. In the previous design, the breeding area of the module was divided into 0.1-m-squared cells with rib structure. As a honeycomb structure is higher in pressure tightness than a square prism structure, the area for filling the mixed pebbles breeder of Li2TiO3 pebbles and Be12Ti ones can be enlarged. Then, the overall TBR is improved to increase the packing ratio of the tritium breeding material.In the created blanket, the capabilities of the pressure tightness, tritium breeding and heat removal are studied using interaction analyses of the neutronics, stresses and fluid dynamics analysis. As a result, a rib with the thickness of 0.015 m is needed to withstand the design pressure of 17.2 MPa by a stress analysis. The packing factor of the mixed pebbles breeder increase to 77 % from 68 % by changing the rib structure from a square prism structure to a honeycomb structure. From the 3D neutronics analysis results, the target of the overall TBR (>1.05) is achievable. The cooling system for the created blanket is designed by fluid dynamics analysis based on the PWR water conditions which are the coolant temperature of 290 - 325 ºC and the operation pressure of 15.5 MPa, respectively. In addition, the tritium extraction system in the created blanket is proposed together with the purge gas system which does not clog the holes. The saturated time of the tritium extraction is also estimated to grasp the tritium inventory in the breeding area.14th International Symposium on Fusion Nuclear Technology (ISFNT-14