Key components installed at Chinese units

Friday, 16 June 2023

Together with the CA02 module, the CA03 makes up the in-containment refuelling water storage tank. The tank, which holds up to 500,000 gallons - nearly 2 million litres - of borated water, is positioned above the reactor, and relies on gravity as the only driving force needed to release water to keep the reactor core cool should the reactor experience an unexpected shutdown.

The CAP1000 reactor design - the Chinese version of the AP1000 - uses modular construction techniques, enabling large structural modules to be built at factories and then installed at the site. This means that more construction activities can take place at the same time, reducing the time taken to build a plant as well as offering economic and quality control benefits.

The CA02 and CA03 structural steel modules are known as super modules because they are too large to transport and require on-site assembly. The CA03 module - assembled from 17 sub-modules - is more than 35 metres long, 12 metres tall and weighs about 214 tonnes. The CA02 is about 12 metres tall and weighs more than 50 tonnes.

The CA03 module of Sanmen 3 was hoisted into place within the containment building on 10 June in an operation lasting 2 hours and 50 minutes, the Shanghai Nuclear Engineering Research and Design Institute announced.

The construction of two new reactors at each of the Sanmen, Haiyang and Lufeng nuclear power plant sites in China was approved by the country's State Council on 20 April this year. The approvals were for Sanmen units 3 and 4, Haiyang 3 and 4 and units 5 and 6 of the Lufeng plant.

The Sanmen and Haiyang plants are already home to two Westinghouse AP1000 units each, and two CAP1000 units were approved for Phase II (units 3 and 4) of each plant.

The first safety-related concrete was poured for the nuclear island of Sanmen 3 on 28 June 2022, marking the official start of its construction. The largest and heaviest module - the cuboid-shaped CA20 - was installed in August. That module comprises plant and equipment for used fuel storage, transmission, the heat exchanger and waste collection, among other things. The module measures 20.5 metres long, 14.1 metres wide and 20.9 metres high.

The CA03 module of Haiyang 3, construction of which began in July 2022, was installed on 31 May - 31 days ahead of schedule, China National Nuclear Corporation announced.

Xudabao 3 polar crane

The rail for the polar crane has been put in place at unit 3 of the Xudabao plant.

The crane is located under the containment dome on a trolley that moves 360° on a circular rail over the reactor shaft, enabling transport operations anywhere in the central hall of the reactor building. It can be used for installing large equipment, such as the reactor vessel and steam generators, as well as during maintenance work and the transportation of fuel.

The rail for the cricular crane for Xudabao 3 is lowered into place (Image: CNI23) 

Installation of the rail "lays a solid foundation for the subsequent overall hoisting of the ring crane and the overall hoisting of the dome", China National Nuclear Corporation subsidiary China Nuclear Industry 23 Construction Company Limited said.

Construction of Xudabao 3 - a Russian supplied VVER-1200 -began on 28 July 2021, with that of unit 4 starting in May 2022. The units are expected to be commissioned in 2027-2028.