Megawatts output has a direct correlation to heat output of the reactor. Watts can be easily converted to BTU’s. 450,000 watts equals 25613.84 BTU/hours.
Oops, BTU/minutes, not hours.
But they’re talking about MW of heat generated vs MW of electrical power rating. A plant is not 100% efficient so the old power rating is not necessarily the same as the total heat generated. Not to mention, we don’t know at what percent of total capacity the plant was being run at at the time.