Design integration of the LHD-type energy reactor FFHR2 toward demo

Three candidates to secure the blanket space are proposed in the direction of reactor size optimization without deteriorating a-heating efficiency and with taking cost analyses into account. For this direction the key engineering aspects are investigated; on 3D blanket designs, it is shown that the peaking factor of neutron wall loading is 1.2 to 1.3 and the blanket cover rate over 90% is possible by proposing Discrete Pumping with Semi-closed Shield (DPSS) concept. On large superconducting magnet system under the maximum nuclear heating of 200W/m3, CICC and alternative conductor designs are proposed with a robust design of cryogenic support posts. On access to ignited plasmas, new methods are proposed, in which a long rise-up time over 300 s reduces the heating power to 30 MW and a new proportional-integration-derivative (PID) control of the fueling can handle the thermally unstable plasma at high density operations. (author)