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Old 06-24-2019, 03:07 PM
Frankenstein Monster is offline
Join Date: Apr 2004
Location: Europe
Posts: 708
Originally Posted by jjakucyk View Post
At Chernobyl, I'm assuming the excursion happened either too quickly for the negative temperature coefficient to matter, or its overall effect was too weak in the face of the runaway reaction.
OK, I see what you mean. The ENS article indeed says exactly that.

Here is an article about the negative fuel temperature coefficient due to Doppler broadening in nuclear reactors. It says the effect is rapid / almost instantaneous but not very large. "In PWRs, the Doppler coefficient can range, for example, from -5 pcm/K to -2 pcm/K." That's small, and it's smaller when the fuel is hotter.