2019 Fall Meeting

Presentation information

Oral presentation

III. Fission Energy Engineering » 301-1 Reactor Physics, Utilization of Nuclear Data, Criticality Safety

[2J01-05] Subcriticality Evaluation

Thu. Sep 12, 2019 9:30 AM - 10:50 AM Room J (Common Education Bildg. 2F D22)

Chair:Tomohiro Endo(Nagoya Univ.)

10:00 AM - 10:15 AM

[2J03] Improvement of reactivity estimation method based on behavior of power in subcritical quasi static state

*Yuichi Yamane1 (1. JAEA)

Keywords:subcritical, reactivity estimation, one-point kinetics, quasi steady state, fuel debris

For the purpose of estimation for the reactivity of an amount of the nuclear fuel which properties such as composition and inner structure are unknown, a method to estimate reactivity in dollar from neutron count rate in quasi steady state has been developed. One of the estimation steps in the method has been improved and reported.

In a step of the method, the value of reactivity is chosen so that a time series data fitting to the measured neutron count rate most is reproduced by the method of least squares. In the improved step, the reactivity value is chosen so that the time series data of the difference between the measured and reproduced fit to a line most.

It has confirmed that the estimation of the reactivity has been improved by adopting the improved step by applying the method to the data calculated by using one-point code AGNES.