MATHEMATICAL MODELS OF COOLER FLOW THROUGH CRACS IN PIPES FOR APPLYING OF «LEAK BEFORE BREAK» CONCEPT (PREPRINT IBRAE-2001-13)

Preprint IBRAE-2001-13

Semenov V.N., Starodubtseva L.P., Filippov A.S.

The mathematical model for estimation of critical flashing water flow through channels with large length-to diameter ratio (cracks) is described. The problem of critical leak rate estimation arises when applying Leak Before Break (LBB) concept. This concept is an approach for demonstration of NPPs safety. Approximation of homogeneous non-equilibrium two-phase fluid is employed in described model. The comparison of model result with experimental data concerning critical two-phase water flow has been done. The model estimates critical leak rate correctly in general. The simple engineer formulas that are used in practice for estimation of crack opening displacement (COD) on straight pipe with circumferential crack are described as well.   

Bibliographical reference

Semenov V.N., Starodubtseva L.P., Filippov A.S. Mathematical models of cooler flow through cracs in pipes for applying of «Leak Before Break» concept (in Russian). Preprint IBRAE-2001-13. Moscow: Nuclear Safety Institute, July 2001. 35 p. — Refs.: 43 items.