Status of gas-cooled reactors

PAPERS 158-161

J. R. M. Southwood Taper 158

A nuclear power station only exists to produce electricity economically, reliably and safely. The Magnox reactors, despite their modest parameters, have proved themselves on all three counts. The fuel, in particular, has been outstandingly successful and has performed well beyond the original expectations. Over the past 20 years, approximately 2 million fuel elements have been loaded into the reactors and the failure rate has been less than 0.1%. In addition, the irradiation limit of 3000 MWD/t channel average has been progressively raised to 5500 MWD/t. The Magnox programme was followed by the introduction of the advanced gas-cooled reactors. Some of the principal parameters increased significantly with the new design, following the Windscale prototype AGR design commissioned in 1963. These advances in parameters introduced a number of technical problems which prejudiced the early introduction of the first AGRs. It is not easy to predict what the outcome might have been if we had stayed longer with Magnox and steadily refined the design, but it is possible.that some real advances could have been made without incurring so many technical problems.