Estimation of shutdown heat generation rates in GHARR-1 due to reactivity insertion accident

Abstract

Fission products decay power and residual fission power generated after  shutdown of Ghana Research Reactor-1 (GHARR-1) by reactivity insertion accident were estimated by solution of the decay and residual heat equations. A Matlab program code was developed to simulate the heat generation rates by fission product decay and resi-dual fission processes. Immediately after the shutdown, the residual heat generated was ~ 3.2 kW and reduced to 0 kW after 80 s, while the decay power of 1.8 kW reduced to 1.34 kW after 80 s. Twelve seconds after shut-down, the decay power dominated the reactor heating, indicating that the long term shutdown heating in the reactor system was generated by decay of fission products.