3 ms·

IIRC the control rods were also bizarre and had graphite bottoms, so the first part of a trip (scram) was adding reactivity. Prompt critical is prompt.

• gotocake 8y ago
  I believe the rods were graphite, just like the moderators. Of course the problem with that was that by the time they were inserted the reactor was already out of control. All the graphite rods did was burn, which certainly didn’t help matters! Worse, after a while the blocks of graphite used as the moderator also burned, and was difficult to extinguish. What they needed (other than better reactor design) was a ready store of neutron poisons that would have flooded the reactor vessel before rod insertion. Unfortunately, by the time they were using neutron poisons the explosion and fire had already destroyed anything like containment.
  • cladari 8y ago
    Chernobyl didn't have a containment or shield building. Manually disabling the safety systems didn't help.
  • pfdietz 8y ago
    The control rods had a plug of graphite on their ends, I believe, which made reactivity briefly increase as they were first inserted.