Sizewell B Nuclear Power Plant

Sizewell is a small village on the east coast of England and the site of Sizewell A, one of the UK’s first generation of Magnox power stations, constructed in the 1950s. The construction Sizewell B, a next generation 1,250 MW PWR (Pressurised Water Reactor) was commenced in the mid 1980s. Situated on the coast, and surrounded by wetlands, the underlying geology comprises Norfolk Crag, a medium to high permeability sand of about 3 x 10-4 m/s.

The reactor building was to be constructed within 400 m x 200 m ‘box’ formed by a diaphragm wall. The contractor, John Laing, required the box to be drained to enable the works ‘in the dry’.

WJ secured the contract to install the dewatering wells by reverse circulation techniques and install and commission the 22 kw borehole pumps before handing the system over to the contractor.

WJ has subsequently undertaken extensive pumping tests, ground and surface water pumping schemes and ongoing operations for the neighbouring Sizewell C plant between 2010 up to today.