Xing was 19.9%-shareholder CGN Mining's nominee on the board, an entitlement the company gained when it increased its interest in Fission in January 2016 by subscribing to a number shares for C$82 million (US$58 million at the time).
CGN nominated its CFO and executive director Chen as Xing's replacement.
Chen has 22 years' experience in the financial field and previously held senior roles with CGNPC-URC and Ling Ao Nuclear Power Corporation.