HTR-PM steam generator passes pressure tests

Tuesday, 2 October 2018

The test was completed on 29 September, one month ahead of schedule, CNNC said. Completion of the test "indicates that China has fully mastered the design and manufacture" of steam generators for high-temperature gas-cooled reactors, according to the company.

Work began on the demonstration HTR-PM unit - which features two small reactors and a turbine - at China Huaneng's Shidaowan site in December 2012. China Huaneng is the lead organisation in the consortium to build the demonstration units together with CNNC subsidiary China Nuclear Engineering Corporation (CNEC) and Tsinghua University's Institute of Nuclear and New Energy Technology, which is the research and development leader. Chinergy, a joint venture of Tsinghua and CNEC, is the main contractor for the nuclear island.

The demonstration plant's twin HTR-PM reactors will drive a single 210 MWe turbine. Helium gas will be used as the primary circuit coolant. The steam generator transfers heat from helium coolant to a water/steam loop. The design temperature of the HTR-PM reaches 750°C. "The overall structure is very complex, and the requirements for raw materials and manufacturing processes are extremely high," said CNNC.

The pressure vessel of the first reactor was installed within the unit's containment building in March 2016. The vessel - about 25 metres in height and weighing about 700 tonnes - was manufactured by Shanghai Electric Nuclear Power Equipment. The second reactor pressure vessel was installed later that year.

The first of the graphite moderator spheres was loaded within the core of the first reactor in April last year. In July, the thermal hydraulic parameters of the steam generator were validated. The demonstration HTR-PM is expected to be connected to the grid and start electricity generation this year.

A further 18 such HTR-PM units are proposed at Shidaowan.

Beyond HTR-PM, China proposes a scaled-up version called HTR-PM600, which sees one large turbine rated at 650 MWe driven by some six HTR-PM reactor units. Feasibility studies on HTR-PM600 deployment are under way for Sanmen, Zhejiang province; Ruijin, Jiangxi province; Xiapu and Wan'an, in Fujian province; and Bai'an, Guangdong province.