DETERMINATION OF CERENKOV LIGHT ABSORBTION BY FUEL POND WATER USING A CALIBRATION LIGHT SOURCE

Year
2011
Author(s)
B. Lindberg - LENS-TECH AB
M. Larsson - Swedish Nuclear Power Inspectorate
J.D. Chen - Channel Systems Inc.
D.A. Parcey - Channel Systems Inc.
R. Kosierb - Canadian Nuclear Safety Commission
E. Sundkvist - Mindcell AB, Falugatan
C. Vogt - Channel Systems Inc.
Abstract
Quantitative measurement of Cerenkov light generated by spent fuel assemblies requires an understanding of the absorbance characteristics of the spent fuel pond water. The presence of particulate or organic material can severely attenuate the transmission of the ultraviolet component of the Cerenkov spectrum. This can make the quantitative measurement of the Cerenkov light using a digital Cerenkov viewing device difficult or in some cases impossible. A calibration light source that can be inserted into the fuel pond has been constructed. This source generates a known ultraviolet light flux. Measurements of this source can be used to calculate the absorbance of Cerenkov light by the fuel pond water and in turn compensate for the absorbance when measuring the intensity of a spent fuel assembly. This paper discusses the challenges of constructing such a device and the results from measurements in two spent fuel ponds.