Nuclear power may be ‘back 10 years’

Press, 28 November 1977, Page 25

Nuclear power may be ‘back 10 years’

PA Wellington. The very existence of tire Royal Commission on nuclear power may have influenced the Government to delay a start on nuclear power generation for at least 10 years, said the commission’s chairman (Sir Thaddeus McCarthy).

The final six of the 141 submissions received by the commission included suggestions by environmental groups that the commission was no longer relevant, because of the Government’s decision to delay the programme. However, Sir Thaddeus said the commission would continue to prepare its report unless the Government told it not to bother. This report is expected to be finished early next year.

In another submission the New Zealand Atomic Energy Committee said that New Zealand’s high earthquake risk would add up to SSOM to the estimated cost of a nuclear station — S6OOOM to S7OOOM at 1975 prices.

Its safety criteria subcommittee said in a 112page report that a nuclear station would have to be designed to withstand forces three times as great as those applicable to conventional buildings.

It would have to be able to withstand an earthquake in which houses were moved and their foundations and chimneys collapsed.

It would not withstand an earthquake in which houses were actually knocked off their foundations and there were conspicuous cracks in the ground.

Any site for a station would have to have a low risk of earth movements, volcanic activity, and subsidence. The committee had been asked to produce detailed conditions for the siting and design of nuclear power stations.

The reports said that the “choice of a level of seismic design might well be guided by the principle that the risk from an

earthquake at a nuclear power plant should not add significantly to the risks arising from accidents at the reactor from other causes.”

Soils would have to be compacted, because earthquakes often caused slips in uncompacted soils.

The foundations of various buildings at a station should be connected, so that equipment would not break if the soil moved more under one part than another. On the other hand, structures which could be separated should be. so that they did not collide during a tremor. But once an earthquake did hit a nuclear station, there would have to be automatic systems to shut down the plant and cool the reactor fuel. “To achieve required reliability, emergency core cooling is normally provided in the form of at least two completely independent systems of differing design principles, each with core cooling” said the report.