Investigation on the Possibility of Tritium Self-Sufficiency for CFETR Using a PWR Water-Cooled Blanket

The neutron wall load ( \(P_{\mathrm{n}})\) of Chinese fusion engineering testing reactor (CFETR) will be less than 1 MW/m². To meet the net tritium breeding ratio (TBR) of the reactor, a new water-cooled blanket concept is considered. The blanket neutronics schemes are performed to explore the local TBR issues in the \(P_{\mathrm{n}}\) range of 1–5 MW/m², which aims at the effective design of the blanket concept considering the tritium self-sufficiency. As a result, the calculation results are compared with the local TBR values and the material fraction changes. It is found that the local TBR has the high value at low \(P_{\mathrm{n}}\) while the blanket size in radial direction is determined. It is mainly because of the total breeding area increasing due to the pipe pitch increasing in the model. This leads to the possibility for CFETR using a simplified blanket interior. In addition, to match the pressurized water reactor (PWR) water-cooled condition, a reduced size of blanket module in toroidal direction is achievable. It can be concluded that a PWR water-cooled blanket has more benefits to CFETR engineering implementation in the future.

I. Introduction

Chinese fusion engineering testing reactor (CFETR) is a 50–200-MW fusion power plant in the future [1]. It aims to realize an indeed fusion power plant with the implementation of blanket tritium self-sufficiency. Since the tritium self-sustaining issues are related to the steady-state operation of a real fusion reactor, how to satisfy the tritium breeding ratio (TBR) for the reactor is the key technology in the future. For this point, CFETR requires all the inner area of vacuum vessel to be installed with the breeding blanket modules except for the divertor region. Namely, overall TBR of all the breeding blanket modules must reach or exceed to 1.05 (the basic net TBR value). This is different from International Thermonuclear Experimental Reactor test blanket modules (TBMs) plan, which only has six TBMs for tritium generation in the three equatorial ports [2]. Therefore, the candidates of the breeding blanket concepts are in the tradeoff.