The first of two reactor pressure vessels was installed at China’s demonstration HTR-PM high-temperature gas-cooled reactor unit under construction at China Huaneng's Shidaowan in Shandong province.

The first of two reactor pressure vessels was installed at China’s demonstration HTR-PM high-temperature gas-cooled reactor unit under construction at China Huaneng’s Shidaowan in Shandong province.

Work began in December 2012 on the demonstration HTR-PM unit, which will have two small 100MWe reactors driving a single 210 Mwe turbine. The gas-cooled HTR-PM is a Generation-IV reactor design. Its fuel comprises thousands of six-centimetre graphite pebbles containing uranium enriched to 8.9% uranium-235. Instead of cooling water, the reactor’s graphite core is bathed in inert helium gas with an outlet temperature of up to 750 °C. In line with the Generation-IV concept, the HTR-PM reactor can shut down safely in the event of an emergency without causing a core meltdown or significant leak of radioactive material, Xinhua said.

China Huaneng is the lead organization in the consortium to build the demonstration units together with plant constructor 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 twin-reactor unit is scheduled to start up next year.

CNEC said the operation to lift the vessel over the reactor building and lower it onto its support ring took seven hours to complete. The 700t vessel – about 25 metres in height – was manufactured by Shanghai Electric Nuclear Power Equipment. It successfully completed factory acceptance on 29 February and was dispatched from the manufacturing plant on 2 March, arriving on site on 10 March. China Huaneng said the second RPV is scheduled to be installed in May. The unit is expected to start commercial operation in late 2017. An earlier proposal was for 18 further 210MWe units to be installed at the Shidaowan site, but this has been dropped.

A proposal to construct two 600MWe HTR plants – each featuring three twin reactor and turbine units – at Ruijin city in Jiangxi province passed a preliminary feasibility review in early 2015. The design is based on the Shidaowan demonstration HTR-PM. Construction of the Ruijin reactors is expected to start next year, with grid connection in 2021.