Haiyang’s Third Phase Will Make It the World’s Largest Passive-Safety Nuclear Base

October 31 — Phase three of the State Power Investment Corporation’s Haiyang nuclear project in Shandong officially broke ground on 31 October. Units 5 and 6, approved by the State Council on 27 April 2025 and already licensed for construction, make this the first nuclear project to start in Shandong during the 15th Five-Year Plan period.

Phase three uses the domestically built CAP1000 third-generation passive pressurised water reactor. Compared with phase two’s CAP1000 units rated at 1.25 million kilowatts each, technical optimisation raises output to 1.3 million kilowatts per unit.

Shandong Nuclear Power says the change further improves energy and resource efficiency, and that the phase-three units can also supply clean heating to five county-level cities.

CAP1000’s “passive” safety systems do not depend on AC-powered pumps and valves: after losing all on-site and off-site power, they can keep the core cooled and the containment intact for 72 hours using gravity and natural circulation, without operator intervention.

The Haiyang site is planned in three phases for six million-kilowatt-class units, 7.6 million kilowatts in total. Units 1 and 2 came online in October 2018 and January 2019; phase-two units 3 and 4 are under construction and due in 2027. With phase three under way, Haiyang enters a stage of building and operating multiple units at once.

Once the two phase-three units are complete, Haiyang will be the world’s largest nuclear base using entirely passive pressurised water reactor technology: 60.9 billion kWh a year, heating capacity above 150 million square metres covering 25 county-level cities, saving about 18.56 million tonnes of standard coal and cutting 48.63 million tonnes of CO2 a year.

Haiyang has years of experience in nuclear heating. “Nuanhe No. 1”, built on the phase-one units, started in 2019 as China’s first commercial nuclear heating project; in 2021 phase two made Haiyang the first “zero-carbon” heating city; in 2023 phase three began cross-regional “twin city” heating, and it now heats about 400,000 residents in Haiyang and Rushan. Phase three will extend the radius and scale further.

The phase-three project adopts state-controlled ownership with private participation, described officially as a model exploration of private capital joining major national clean-energy projects in nuclear power.