Uncertainty quantification works relevant to fission yields and decay data

Go Chiba,Shunsuke Nihira

doi:10.1051/epjn/2018022

Abstract

In the present paper, firstly, we review our previous works on uncertainty quantification (UQ) of reactor physics parameters. This consists of (1) development of numerical tools based on the depletion perturbation theory (DPT), (2) linearity of reactor physics parameters to nuclear data, (3) UQ of decay heat and its reduction, and (4) correlation between decay heat and β-delayed neutrons emission. Secondly, we show results of extensive calculations about UQ on decay heat with several different numerical conditions by the DPT-based capability of a reactor physics code system CBZ.

Highlights

2.1 Development of numerical tools based on depletion perturbation theory (DPT)Generally there are two numerical procedures for uncertainty quantification (UQ) of reactor physics parameters induced by nuclear data uncertainty: the adjoint-based procedure and the stochastic-based procedure
There are two numerical procedures for uncertainty quantification (UQ) of reactor physics parameters induced by nuclear data uncertainty: the adjoint-based procedure and the stochastic-based procedure
We have focused mainly on nuclide transmutation problems such as nuclear fuel depletion and b-delayed neutrons emissions, and have developed numerical tools based on the DPT

Summary

Development of numerical tools based on DPT

There are two numerical procedures for uncertainty quantification (UQ) of reactor physics parameters induced by nuclear data uncertainty: the adjoint-based procedure and the stochastic-based procedure. The stochastic-based procedure has been adopted frequently by virtue of drastic advancements of computer resources, but the adjoint-based procedure is still powerful because it can yield sensitivity profiles of reactor physics parameters with respect to nuclear data without any statistical fluctuations with short computation time relative to the stochastic-based procedure. We have focused mainly on nuclide transmutation problems such as nuclear fuel depletion and b-delayed neutrons emissions, and have developed numerical tools based on the DPT. The present paper consists of two parts; the first part is to review our previous works on UQ based on DPT, and the second part provides some numerical results of UQ for decay heat in various conditions using our tools

Reviews of UQ works done at Hokkaido University

On linearity of reactor physics parameters to nuclear data

UQ of decay heat in various conditions with DPT

Conclusion