Research and Development Program in Reactor Diagnostics and Monitoring with Neutron Noise Methods, Stage 16

This report gives an account of the work performed by the Dept. of Nuclear Engineering, Chalmers Univ. of Technology, in the frame of a research contract with the Swedish Radiation Safety Authority (SSM), contract No. SSM 2009/2093. The present report is based on work performed by Imre Pazsit, Victor Dykin, Anders Jonsson and Christophe Demaziere, with Imre Pazsit being the project leader. This report describes the results obtained during Stage 16 of a long-term research and development program concerning the development of diagnostics and monitoring methods for nuclear reactors. The long-term goals are elaborated in more detail in e.g. the Final Reports of Stage 1 and 2 (SKI Report 95:14 and 96:50, Pazsit et al. 1995, 1996). Results up to Stage 15 were reported in (Pazsit et al. 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2003a, 2003b; Demaziere et al, 2004; Sunde et al, 2006; Pazsit et al. 2008, 2009). A brief proposal for the continuation of this program in Stage 17 is also given at the end of the report. The program executed in Stage 16 consists of four parts as follows: - An overview of the present status of experience with BWR stability; - An investigation of the significance of the properties of the noise source for BWR instability; - Study of the dynamics of molten salt systems: construction of the adjoint and calculating the space dependent noise induced by propagating perturbations in the fuel; - A specific study of some novel methods of analysis of non-linear and non-stationary processes.