A reactor generating of thermal power is shut down after long operation at full power

PHYSICS · Multi-part · Fermi University Physics · Nuclear Physics · Fission, fusion and nuclear energy · Fission, fusion and nuclear energy

The Nucleus Resolved, Ch The reactor as a field equation: diffusion, criticality, feedback and burn-up

Problem

A reactor generating

1200\,\mathrm{MW}

of thermal power is shut down after long operation at full power. The residual fission-product decay heat follows

\frac{P(t)}{P_0} \approx 0.066\,t^{-0.2},

with

t

in seconds, valid from about a minute to a month after shutdown. ((a)) Estimate the reactor's thermal power one day (

t = 86400\,\mathrm{s}

) after shutdown. ((b)) Estimate it one week (

t = 604800\,\mathrm{s}

) after shutdown.