KOEBERG NUCLEAR POWER STATION.

A description is given of a nuclear power plant being built near Cape Town which will contain two nuclear reactors of similar design with a total generating capacity of approximately 2000 MW. The first reactor is scheduled to come into operation in 1982, and the second possibly two years later. The plant is supported on what is known as a nuclear island or raft, the lower foundation of which is a 36,000 m**3 concrete slab poured on top of the cement foundation. This slab contains 4700 tons of reinforcing steel. A total of 490 concrete columns support the upper foundation raft, which in turn will carry the entire load of the containment building. Each of the columns, which are 1. 5 m high, is topped with a neoprene rubber pad for shock absorption. On top of this is a leaded bronze mat which, in turn, is topped with a stainless steel plate (1000 tons of 18/18 stainless steel have been used for this purpose). This combination of shock absorber and sliding surfaces is known as a seismic filter. This support system will enable the station to withstand what would be a massive earthquake measuring 7 on Richter Scale, even though the station is not in an earthquake area, and the chances of such a disturbance occurring are rated at one in a million years.