Ex-core Detectors Research Articles

Noise investigations in boiling-water and pressurized-water reactors

Publisher Summary Reactor noise investigations, similarly to other scientific topics of engineering interest, can be divided into two categories: (1) the experimental and theoretical study of the phenomena, that is, the investigation of the information content of the different noise signals, and (2) the direct application of the technique aimed at the improvement of the safety and availability of nuclear power plants. Experts who are responsible for the direct application of the technique necessarily depend on the background research dealing with the information content of the signals. This chapter discusses some general features of the neutron noise measured by in-core and ex-core detectors. It also discusses specific problems related to boiling-water and pressurized-water reactors. In the point model approximation of neutron noise theory, one assumes that the fluctuations of the cross-sections do not drive the noise directly but rather through the fluctuations of the reactivity of the core. Point kinetics is frequently referred to as the “space independent model.”

Calculation of Spatial Weighting Functions for Ex-Core Neutron Detectors

A mathematical model for ex-core detector response in pressurized water reactor (PWR) configurations is presented, based on the use of a spatial weighting function that is independent of core power...

Monitoring of core support barrel motion in PWRs using ex-core detectors

Core Support Barrel (CSB) motion was quantified in a PWR using the following statistical descriptors: cross and auto power spectral density, coherence, and amplitude probability density. A scale factor was calculated for quantifying the CSB motion. We found it necessary to employ two-dimensional geometry complexity for the calculations of the scale factor. The statistical descriptors used for quantifying CSB motion had to be obtained from bandlimited signals. The frequency range used for bandlimiting was determined from the phase and the coherence between diametrically opposite excore power range monitors.

A Microprocessor-Based Four-Section Excore Detector System

The advent of microprocessors has added a new dimension to process measurement and control. Nuclear instrumentation has not been excluded. One system which has recently been introduced is an out-of-core detector system. This system provides continuous monitoring of the axial power distribution using four-section excore detectors. The microprocessor allows the system to be self-contained and provides the functions of data collection and analysis not possible through analog techniques. The hardware and software developed to achieve an intelligent monitoring system is presented.

Localization of In-Core Disturbances with Ex-Core Detectors

Localization of In-Core Disturbances with Ex-Core Detectors