[2D09-14] Fast Reactor

3:45 PM - 4:00 PM JST(6:45 AM - 7:00 AM UTC)

[2D13] Development of core deformation reactivity evaluation method(2) Sensitivity analysis on core reactivity in the FFTF LOFWOS#13 test

*Norihiro Doda¹, Shinya Kato¹, Kazuo Yoshimura¹, Tomoyuki Uwaba¹, Kenji Yokoyama¹, Masaaki Tanaka¹ (1. JAEA)

Keywords:

sodium-cooled fast reactor,reactivity feedback,core deformation reactivity,coupled analysis,FFTF

During a reactor power increase in ULOF and UTOP events in sodium-cooled fast reactors, core deformation due to thermal expansion of core elements is expected to cause a negative feedback effect to suppress this power increase. It is a complex phenomenon because of the interaction between reactor physics, thermal-hydraulics, and structural mechanics. To understand the phenomenon, JAEA has developed an evaluation method coupling the MARBLE code for reactor physics, the Super-COPD code for system-scale thermal-hydraulics, the ASFRE code for fuel-assembly-scale thermal-hydraulics, and the FINAS code for core structural deformation. This reports the sensitivity analysis results on core reactivity during a simulated ULOF test in FFTF as one of the validation tests for this evaluation method, and future development issues.