80 MW accident

In writing up the 1952 Canadian NRX nuclear accident, I naturally specify that the out-of-control reactor spikes to a huge power level. I assumed the Canadians somehow measured this spike during the accident. But in another of James Mahaffey’s intriguing footnotes (see my previous post), he clarifies:

…analysis of the accident found that the reactor power had peaked at 80 megawatts, far outside the designed power level. Most nuclear reactors have a digital simulator for training operators and investigating odd operations without the risks of using the actual system. In the case of NRX in 1952, no digital simulator existed, but they did have an analog electronic simulator built using vacuum-tube operational amplifiers. The Micromax recorder from the control room was connected to the simulator, and the accident was duplicated so as to give the instrument the same response it had given during the power excursion, running off scale. From this analysis along with the physical damage to the reactor, the 80-megawatt maximum power was confirmed.

Mahaffey, James. 2014. Atomic Accidents: A History of Nuclear Meltdowns and Disasters from the Ozark Mountains to Fukushima. Pegasus Books, New York, p. 151.

I find this fascinating.