Assessment of the computer code NAUA Mod 5 against a small-scale containment aerosol test

Abstract

The Committee on the Safety of Nuclear Installations (CSNI) of the Organisation for Economic Cooperation and Development (OECD) organized in 1992–1994, an International Standard Problem Exercise Number 34 (ISP-34), on aerosol behaviour in the primary circuit and the containment of a nuclear reactor. The exercise involved carrying out specific experiments in the Falcon Test facility at Winfrith Technology Centre, U.K., analysis of these experiments using different computer codes. Containment analysis of these tests was carried out by the Indian participants BARC using the computer code NAUA Mod 5. The present paper compares the code predictions with experimental measurements. The containment floor deposits are predicted closely, whereas the wall deposits are considerably under-predicted. The air-borne concentrations predicted by the code are well within the uncertainties of measurement. The possible reasons for the differences are brought out.