Development and Validation of Burnup Library for PWR

Abstract

Burnup calculation is an important field in the nuclear physics calculations by which the changes in the isotopic composition of materials is computed. Burnup calculation is of significant importance for a wide range of applications in various stages of design, licensing, operation, waste management and decommissioning. The role of the nuclear data library is very important to the accuracy of burnup calculations. CINDER90 is a widely used point nuclear depletion code and its library was released in the year 2000. The raw data which are used for processing CINDER90 library are primarily from ENDF/BⅤ、ENDF/BⅥ and EAF3. It is necessary to update this library with newly released evaluated nuclear data. In this paper, a CINDER90 burnup library for PWR was developed based on nuclear data library ENDF/BⅧ0 and EAF2010, which consists of three parts: neutron cross section, decay data and fission product yields. The processing of neutron cross section was divided into two parts, firstly the branching ratios of EAF-2010 were integrated into ENDF/B-Ⅷ.0 library using the inverted-stack algorithm and CRECTJ6 program, and then the pointwise cross section was processed into 63group infinitely diluted cross sections by the opensource nuclear data processing code NJOY2016. The crosssection data were Doppler broadened at 2936 K and the midlife PWR flux spectrum with a fusion peak added (IWT=5) was applied as weighting function. Decay data and fissionproduct yields data were processed based on the MF8/MT457 and MF8/MT454 separately. Continuum delayed photon emission data was converted into a series of discrete lines by defining a set of energy bins with a width of 10 keV that spans the range of the continuum. Fissionproduct yields data contain 60 datasets from 36 fissionable actinides. When yield data are not available for an isotope identified in the library as fissionable, 239Pu fast yield set is given for neutron induced fission and 252Cf spontaneous fission yield set is given for spontaneous fission. The Takahama-3 benchmark from SFCOMPO-2.0 database was used to validate the new library. For most of the nuclides, the inventory calculation results obtained by using the new library and the old library are in well agreement except for 242Amm, of which the calculated value using the new library is closer to the experimental value. After investigating the 63group neutron cross sections, we believe that the inelastic cross sections in the old library are unreasonable. It can be concluded that the processing method proposed in this paper is correct and the calculation accuracy is improved for some important nuclides.

Keywords

• cinder90
• burnup library
• takahama-3