Fast Reactors and Accelerator Driven Systems Knowledge Base

Conference Article: The advances statistical hot spot analysis in gas breeder reactors

Abstract

The hot spot analysis on a pintype, gas-cooled breeder reactor has been the subject of this study. In this reactor type one has to expect a rather great temperature difference between the cladding and the coolant by the poor heat transfer behaviour of the gas. Furthermore, to decrease the nominal wall temperature, the heat transfer is increased over a substantial part of the core by the presence of artificial wall roughness on the cladding. The role of the local uncertainties, acting on the temperature difference between cladding and gas, is an important factor in the cladding hot spot calculations. Extra local uncertainties, due to tolerances in the roughness geometry, have to be taken into account only in the roughened part of the core. To introduce in the hot spot analysis these specific features of gas breeder reactors the advanced statistical method of A. Amendola 2 has been adopted and the necessary modifications in the computer code SHOSPA have been introduced, so that the new version of the code now applies to both sodium and gas cooled breeder reactors. Some calculations on a reference core have been performed to study the influence of the roughened length on the cladding hot spot factor. It followed that one can get a considerable gain in cladding hot spot temperature by taking the roughened length slightly greater than the value at which equal nominal peak-temperatures appear in the smooth and the roughened part of the core.

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Reference:

Summary report of a panel meeting held in Karlsruhe, 22-24 November 1973 on the recommendation of the International Working Group on Fast Reactors. 1974. p. 133-142

International Atomic Energy Agency, Vienna (Austria)

IAEA-TECDOC--166, pp:114-121