3 ms·

Sure, I'm just saying the power increase did happen, according to both INSAG-1 and INSAG-7. Neither INSAG-1, INSAG-7 nor Legasovs report claims there is a rapid

Sure, I'm just saying the power increase did happen, according to both INSAG-1 and INSAG-7. Neither INSAG-1, INSAG-7 nor Legasovs report claims there is a rapid increase in power before AZ-5 is pushed. The claim in INSAG-1 is that this power increase was the start of a positive-feedback loop that caused the explosion. The claim in INSAG-7 was that the power increase was not a safety problem, except to the extent it caused the operator to push AZ-5.

man8alexd 5mo ago
The AZ-5 button was pushed as normal shutdown procedure as the test had been completed, not as a reaction to some event.
- sehansen 5mo ago
  I can't find any description of the test across the three reports mentioning that that emergency stop button is supposed to be pressed as part of the test. AFAICT the test wasn't even completed when the button was pressed as the purpose of the test was to demonstrate that the emergency core cooling system could run for at least 40 s (INSAG-1 page 17) after closing the turbine emergency stop valve. That valve was closed at 01:23:04 and AZ-5 was pressed at 01:23:40.
  - man8alexd 5mo ago
    For the rundown test, after the valve cut-off, it is irrelevant whether the reactor was shut down or not. The working plan for the test only specified that it was supposed to run before a planned maintenance period, so the shutdown was implied. During previous tests, the AZ-5 signal was wired to the valve cut-off signal and was sent automatically at the same moment. It is not clear why this changed in 1986, but the outcome would have been the same if AZ-5 had been pressed 35 seconds earlier.
    - sehansen 5mo ago
      Can you point to anywhere in INSAG-7 where they talk explicitly about that? Because if not your point about the show ignoring INSAG-7 falls a bit flat.
      - man8alexd 5mo ago
        This information is not discussed in INSAG-7. It is from trial testimonies sourced from the book by Nikolai Karpan (deputy chief engineer of Chernobyl NPP), who was present at the trial and made notes himself.

man8alexd 5mo ago

The AZ-5 button was pushed as normal shutdown procedure as the test had been completed, not as a reaction to some event.

sehansen 5mo ago
I can't find any description of the test across the three reports mentioning that that emergency stop button is supposed to be pressed as part of the test. AFAICT the test wasn't even completed when the button was pressed as the purpose of the test was to demonstrate that the emergency core cooling system could run for at least 40 s (INSAG-1 page 17) after closing the turbine emergency stop valve. That valve was closed at 01:23:04 and AZ-5 was pressed at 01:23:40.
- man8alexd 5mo ago
  For the rundown test, after the valve cut-off, it is irrelevant whether the reactor was shut down or not. The working plan for the test only specified that it was supposed to run before a planned maintenance period, so the shutdown was implied. During previous tests, the AZ-5 signal was wired to the valve cut-off signal and was sent automatically at the same moment. It is not clear why this changed in 1986, but the outcome would have been the same if AZ-5 had been pressed 35 seconds earlier.
  - sehansen 5mo ago
    Can you point to anywhere in INSAG-7 where they talk explicitly about that? Because if not your point about the show ignoring INSAG-7 falls a bit flat.
    - man8alexd 5mo ago
      This information is not discussed in INSAG-7. It is from trial testimonies sourced from the book by Nikolai Karpan (deputy chief engineer of Chernobyl NPP), who was present at the trial and made notes himself.