The National Nuclear Safety Administration of China issued an operating license on August 20th for the demonstration high-temperature gas-cooled reactor plant (HTR-PM) at Shidaowan in the Shandong province of China. The next day, workers began loading the first spherical fuel elements into the first reactor at the plant.
The ceramic coated spherical fuel elements are sixty millimeters in diameter. Each of the fuel elements contains seven grams of uranium enriched to eight- and one-half percent. The core outlet temperature of the HTR-PM is seven hundred and fifty degrees Celsius for the helium gas coolant, steam temperature is five hundred and sixty-six degrees Celsius and the core inlet temperature is two hundred and fifty degrees Celsius. The reactor has a thermal efficiency of forty percent. The height of the core is eleven meters, and it has a diameter of three meters. Each reactor has two independent reactivity control system. The primary system consists of twenty-four control rods in the side graphite reflector. The secondary system has six channels for small absorber spheres which fall by gravity. These are also located in the side reflector. Fuel spheres are released into the top of the core one at a time as the reactor operates. As fuel spheres fall into the top, other spheres are removed from the bottom of the reactor. Broken spheres are separated out and the burnup is measured. Used fuel spheres are screened out and sent to storage. A forty-year operating lifetime is expected.
China Huaneng is the lead organization of the consortium to build demonstrations units. They said that the initial loading of fuel is divided into two stages. First, the fuel spheres are loaded into a temporary fuel storage tank and then transferred to the core through the fuel loading and unloading system. It will take about thirty days from the loading of the first fuel sphere until the reactor achieves first criticality. During this initial period, an estimated one hundred thousand fuel spheres will be installed. A full fuel load of one of the reactors at the plant will require about four hundred and twenty thousand fuel spheres. The first reactor has now entered the state of nuclear operation and will be connected to the Chinese grid sometime this year.
The HTR-PM has advantages such as inherent safety, a high equipment localization rate, modular design and adaptations to small and medium-sized power grids. It also has a wide range of potential commercial applications including power generation, cogeneration of heat and power and high temperature process heat applications.
Construction of the demonstration HTR-PM plant began in December of 2012. Two small reactors at the plant will drive a single two hundred- and ten-megawatt turbine. China Huaneng is working together with together with China National Nuclear Corporation subsidiary China Nuclear Engineering Corporation (CNEC) and Tsinghua University's Institute of Nuclear and New Energy Technology. Chingery, a joint venture of Tsinghua and CNED, is the main contractor for the nuclear island.
Cold functional tests aim to verify the reactor’s primary loop system and equipment as well as the strengths and tightness of its auxiliary pipelines under pressure higher than the design pressure. These tests were completed at the HTR-PM two reactors on the 19th of October and the 3rd last year, respectively. Hot functional tests which simulate the temperatures and pressures the reactor systems will be subjected to during normal operation will begin in January.
There are plans for another eighteen HTR-PM reactors for the site at Shidaowan. Beyond the HTR-PM reactor design, China has proposed a scaled-up version called the HTR-PM6000. Six of these reactors will drive one large six hundred- and fifty-megawatt turbine. Feasibility studies with respect to the deployment of HTR-PM6000 are being conducted for Sanmen, Zhejiang province; Ruijin, Jiangxi province; Xiapu and Wan'an, in Fujian province; and Bai'an, Guangdong province.