[hef19898]

I am in the middle of INSAG-7, the revised Chernobyl accident report from the 90s. And the positive reactivity effect of the control rods was, as shown in the HBO series, known since 83. The RBMK chief engineer suggested changes, technical and in procedure, immediately after that. These have not been implemented, because it was considered to be an extreme edge case. Might have been nice to portray it that way.

After all, I love the HBO series, watched it three times by now. Still one of the best mini series ever produced. As shown by the fact that you have to dig that deep to find deviations from reality. In most other cases, you don't even have to scratch the surface.

[hef19898]

INSAG-7 includes a soviet report as annex. That report is really fascinating. Already in 1976 the soviet authorities and relevant institutes were aware of the design related issues of RBMK reactors and had identified necessary changes and modifications. Obviously, none were taken, but all these recommendations were included in the initial soviet report on the Chernobyl disaster.

And in my lay man eyes, the RBMK reactor (which was also found to violate soviet requirements from the 70s) was a disaster waiting to happen. Inherently unstable, optimized for grid stability instead of safety, lacking control and monitoring, erratic behaviour under certain conditions and no clear operating procedures.

Edit: Also nice is that the first reaction was to blame the operators and not the system as a whole. Kind of what always happens with aviation accidents as well, it always the pilots fault first.