1/3D MODELING OF THE CORE COOLANT CIRCUIT OF A PHWR NUCLEAR POWER PLANT

CORZO SANTIAGO; RAMAJO DAMIAN; NIGRO NORBERTO

ANNALS OF NUCLEAR ENERGY

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Melbourne,Florida; Año: 2015 vol. 83 p. 386 - 397

0306-4549

Ms. Ref. No.:  ANUCENE-D-14-00707R1 Title: 1/3D MODELING OF THE CORE COOLANT CIRCUIT OF A PHWR NUCLEAR POWER PLANT Annals of Nuclear EnergyAbstract:A multi-dimensional computational fluid dynamics (CFD) model to simulate the in-core coolant circuit of a Pressure Heavy Water Reactor (PHWR) of a nuclear power plant wasperformed. Three-dimensional (3D) detailed modeling of the upper and lower plenums, thedowncomer and the hot-leg and cold-leg nozzles was linked with a finite volume one-dimensional (1D) one-phase code for modeling the behavior of all the 451 coolant channels.Suitable functions for introducing the distributed pressure drop (friction losses) andconcentrated losses (spacer grids, inlet restrictors and outlet throttles) allowed to obtain thepressure variation along the channels. The axial power distribution for each hydraulic zonewas also taken into account. Results were compared with those previously obtained with azero-dimensional (0D) code getting more realistic temperature patterns at the upper plenum.Although the present model is one-phase, the prediction of the local pressure and temperaturealong the channels allows to a preliminary identification of the location of incipient boiling bycomparing with the local saturation temperature. The present model represents an advancerespect to the previous 0/3D model and is the necessary step before to achieve a 1/3D two-phase model to accurately evaluate the in-core steam generation and void fraction distribution.