Ringhals Diagnostics and Monitoring, Final Research Report 2012-2014

Rapport, 2014

This report gives an account of the work performed by the Department of Nuclear Engineering, Chalmers, in the frame of research collaboration with Ringhals, Vattenfall AB, contract No. 630217-031. The contract constitutes a 3-year co-operative research work concerning diagnostics and monitoring of the BWR and PWR units. The work in the contract has been performed between January 1st 2012, and December 31st, 2014. During this period, we have worked with four main items as follows: 1. Development and application of the analysis method of core barrel vibrations, developed in the previous Stages, to three ex-core measurements performed during several cycles in R2, R3 and R4. What regards R2, this was the first attempt to analyze ex-core measurements taken at BOC, MOC and EOC, with the new curve-fitting procedure; 2. Investigation of the ultra-low frequency oscillations in reactor power in R4; 3. Development of the theory and simulations in order to determine the void content in R1 from the analysis of in-core measurements; 4. Evaluation of the measurements made in R1 with the use of 4 LPRMs and one TIP detector, for testing the velocity and void fraction profile reconstruction methods. This work was performed at the Department of Nuclear Engineering, Chalmers University of Technology by Victor Dykin, Cristina Montalvo (visitor from the Technical University of Madrid), Imre Pázsit (project co-ordinator) and Henrik Nylén, who was also the contact person at Ringhals.