Speaker
Satoshi Konishi
(Institute of Advanced Energy)
Description
It is widely believed that fusion DEMO reactor will need significant amount of tritium at the beginning of its operation. However, the authors have pointed out that steady deuterium operation can produce sufficient tritium in a reasonable period of DD operation by DD reaction followed by exponential breeding in the blanket. The present study further suggests that realistic Power Ascension Tests (PAT) of DEMO can produce its tritium to be needed in the series of tests by its own program until reaching steady state full power operation, and thus no additional supply is needed. Closed tritium fuel plant was described by a system dynamics model, and analyzed considering realistic PATs of DEMO, that will be mainly pulsed DD and low concentration DT. Primary fuel cycle is composed of plasma exhaust evacuation, isotope separation by cryogenic distillation, storage and blanket tritium recovery. Secondary systems such as tritium recovery from water and solid waste, secondary confinement to capture permeated and leaked tritium is also analyzed to recycle tritium with longer time constants. Although no actual PAT plan for fusion DEMO is available, previous PATs for new fission reactors provides realistic scenarios. Typical PATs require years of operation from zero power criticality to full power, with pulsed power output and long dwell time between them. Output power is gradually increased in PATs to check the functions of reactor systems and components. In the case of fusion DEMO, zero power criticality corresponds to DD operation. While plasma may be fired in pulses, tritium plant is continuously operated to recover all the tritium produced by the DD and low DT burn. Depending on the different time constant of tritium retention in components, tritium is transferred by deuterium purge, and high concentration tritium is finally collected in the storage, to be available for the next tests.
Co-authors
Fumito Okino
(Institute of Advanced Energy, Kyoto University, Uji,Kyoto, Japan)
Ryuta Kasada
(Institute of Advanced Energy, Kyoto University, Uji,Kyoto, Japan)
Satoshi Konishi
(Institute of Advanced Energy, Kyoto University, Uji,Kyoto, Japan)
