Revision and expansion of the data base in the LEPRICON dosimetry methodology

The objective of this ongoing study is to develop and use an advanced methodology for reducing the uncertainties in estimates of the spectrum and total fluence in a pressure vessel of an LWR from analysis of dosimetry measurements performed at a surveillance position. This new methodology (code-named LEPRICON) has the power to supplant existing methods of spectral unfolding because it can be used to obtain not only better estimates of the fluence and spectrum in the pressure vessel but also of the uncertainties in these quantities, and these uncertainties are always less than those using existing methods. This report is the second in a series of interim reports demonstrating such an uncertainty reduction. It describes the completion of the analysis of thirty-seven measurements performed in four fields of high diversity whose purpose is to serve as dosimetry benchmarks. It is intended that LWR surveillance data will be simultaneously adjusted with these benchmark measurements to yield unfolded spectral fluences of high accuracy in the pressure vessel