Construction progresses at Shimane 3

27 July 2009

The reactor pressure vessel has been installed for unit 3 of Chugoku Electric Power Co's Shimane nuclear power plant in Japan, under construction by Hitachi using modular techniques.


Shimane 3 construction (Hitachi)
Shimane 3 under a forest of cranes (Image: Hitachi)

The vessel - with an inner diameter of about 7 metres and some 21 metres high - was lowered into position by one of the world's largest mobile cranes on 17 July. Weighing around 910 tonnes, the vessel was almost the maximum rated load of 930 tonnes for the large crawler crane.


It took nearly three hours for the crane to lift the vessel to about 35 metres above the ground, swing it into position, and lower it into the reactor building, the Japan Atomic Industry Forum (JAIF) reported.


Steel components for the reactor vessel were fabricated by Japan Steel Works at its Muroran plant. The component was then manufactured over a three year period by Babcock-Hitachi at its No.2 plant in Kure City, Hiroshima prefecture. It was completed and transported by sea on 7 July, and unloaded at the power plant site in Shimane prefecture on 14 July.


Hitachi is employing modular construction techniques in the construction of Shimane 3. The company has a dedicated factory for module production that was completed in 2000. Construction at Shimane 3 will use a total of some 190 modules.


One of the modules being manufactured by Hitachi is for the inside of the reinforced concrete containment vessel, which includes valves, pipes, large support structures, and the reactor shield wall to be placed in the upper dry well. This has a total weight of about 650 tonnes. Two hydraulic control unit (HCU) room modules (with a total mass of about 270 tonnes per module) have also been manufactured at the factory and delivered to the Shimane site.


Hitachi uses a large crawler crane to unload modules directly from ships delivering them to the Shimane site. Because construction site is located next to a wharf, the area between the wharf and buildings where the equipment is being delivered is set aside for the use of the crane.


Construction of Shimane 3 - a 1373 MWe advanced boiling water reactor (ABWR) - started in December 2005. It is scheduled to begin commercial operation in December 2011.


As of the end of June, the Shimane 3 unit was 69% complete, according to Chugoku.