Engineers check the heating system at Shandong Nuclear Power Co in Haiyang. JIANG TAO/FOR CHINA DAILY

In addition to supplying power, nuclear energy has been used for decades for heating and seawater desalination around the world.

Nuclear energy developers are now using new models of this form of clean energy to increase efficiency and reduce costs.

In Haiyang, Shandong province, a nuclear power plant on the Yellow Sea shore completed a mission this year to provide clean heating to all urban districts of the city throughout the winter.

Shandong Nuclear Power Co, a subsidiary of State Power Investment Corp and also the plant's operator, said the facility provided carbon-free heating for 143 consecutive days, serving an area of 5 million square meters and benefiting 200,000 residents in Haiyang, a county-level city under the jurisdiction of Yantai.

The plant's heating system is connected to the nuclear unit, making it the first commercial attempt in China to supply heat from traditional nuclear power.

Xiu Yaping, a Haiyang resident who lives about 20 kilometers from the plant, said clean heating keeps her family warm and contributes to a healthier environment.

"The temperature in our home remained at about 24 C during the winter," Xiu said, adding that when she turned all the heating appliances in the property on, the temperature rose to around 28 C, so she had to turn one or two of them off.

"The heating came on several days before the scheduled start of the winter heating season, and due to cold weather it was turned off days after the scheduled end of this period," she said.

Living near a thermal power plant, Xiu used to be worried by smoke pouring from its chimneys in winter when the plant started to burn coal to provide heating. She needed to clean her window sills every day to prevent soot forming.

"Now, I feel that our living environment is much cleaner," she said.

Hongyanhe Nuclear Power Co in Dalian, Liaoning province, is scheduled to put the initial phase of a heating project into operation next winter. CHINA DAILY

Safety a priority

Zhou Dadi, a senior researcher at the National Development and Reform Commission's Energy Research Institute, said that for more than three decades China has conducted research on using nuclear energy to provide heating, and has developed mature technologies.

Wu Fang, chairman of Shandong Nuclear Power Co, said, "Safety is the first prerequisite we need to consider when we develop nuclear power."

In 2019, trials to use steam from nuclear power for winter heating began in Haiyang, when more than 7,000 households started to use this new system, followed by a second phase last year that covered the entire urban area of the city.

The heating system extracts nonradioactive steam from the secondary circuit of the nuclear unit. The steam is then fed through a multistage heat exchanger at the plant.

Heat is subsequently channeled to a thermal power supply company to heat water flowing to consumers through municipal pipelines.

Wu said, "During this process, only heat is transferred, with no hot water being exchanged, ensuring the safety and reliability of nuclear energy heating."

Smart devices are used in the heating system to guarantee safety and efficiency.

Li Changke, assistant to the general manager of Fengyuan Thermal Power Co, which is cooperating with Shandong Nuclear Power Co, said, "Devices have been installed on the pipeline network to monitor any water leakage or damage to insulation layers."

The heating system at the nuclear plant is included in the city's smart heating platform.

"We use smart equipment to adjust the heating supply according to the weather," Li added.