Final Report on the Research Project Ringhals Diagnostics and Monitoring, Stage 12

This report gives an account of the work performed by the Department of Nuclear Engineering (formerly Reactor Physics), Chalmers, in the frame of a research contract with Ringhals, Vattenfall AB, contract No. 578254-003. The contract constitutes Stage 12 of a long-term co-operative research work concerning diagnostics and monitoring of the BWR and PWR units. The work in Stage 12 has been performed between March 1st, 2007 and May 31st, 2008. In Stage 12 we have worked with four items as follows: Development of the beam mode core barrel vibration diagnostics; Investigation of the axial in-core neutron noise by measurements; Calculation of the conversion factor between core barrel displacement and the relative change in the ex-core detector signal; Evaluation of detector impacting. This work was performed at the Department of Nuclear Engineering, Chalmers University of Technology by Imre Pázsit (project leader), Christophe Demazière, Carl Sunde, Petty Bernitt and Augusto Hernández-Solís. Contact persons at Ringhals were Tell Andersson (project leader) and Henrik Nylén