BELDO project: Contract research with the nuclear power plant Leibstadt KKL

by Dr Yohei Sato (PSI Computational Fluid Dynamics)

Thursday 27 Jun 2019, 14:00 → 15:00 Europe/Zurich

OHSA/B17 (Paul Scherrer Institut)

The overview of BELDO (BrennElemente Local Dry-Out) project, lasted from 2016 to 2018, is presented in the seminar. In 2014, KKL faced the problems, discoloration and oxide marks, in the fuel assemblies made by a specific fuel vendor. As a countermeasure, ENSI (nuclear regulation authority in Switzerland) did not allow KKL to run the power plant with full power, which suppressed the profit of KKL. In order to run the plant with full power, KKL needed to explain to ENSI how to avoid the problems. Then KKL ordered the contract research to the reactor vendor (GE-Hitachi), the fuel vendor (non GE-Hitachi), and PSI, separately. PSI was involved as a neutral; GE-Hitachi considered that the problem is caused by the fuel vendor, while the fuel vendor insisted that the problem comes from the reactor. PSI conducted large scale CFD (Computational Fluid Dynamics) simulations for the coolant flow in the entire lower plenum using 480 cores, and a new numerical model was also developed for the boiling flow in the fuel assembly. The conclusion of BELDO was exceeding the assumption, which will be shown in the seminar.