Analysis of small breaks at Framatome

For several years Framatome has been working on the development of a small-break code for the analysis of its reactors on the basis of a version of RELAP 4. A number of adaptations have been made. This work has produced a new code: FRARELAP. The basic phenomena attendant upon a small break are predicted satisfactorily, as is shown by the calculation-experiment comparisons for the LOFT L.3.1. test and the preliminary tests on the LOBI loop. With considerable support from separate-effect experiments the elementary models of FRARELAP can be improved continually. Many reactor calculations have already been carried out and have led to the definition of post-accident procedures specific to small breaks. (author)