On 26/02/2021 16:29, newshound wrote:
On 26/02/2021 14:25, Pancho wrote:
On 26/02/2021 14:00, newshound wrote:

The design was known to a) increase power output as the control rods
were inserted, b) take too long to insert the rods and


It wasn't widely know, it was "noticed", in a "how strange" sort of way.

These points only apply IF you drive it outside the envelope


One of the impressions you get from Chernobyl is that the operators
behaved the way they did because they felt they had a sure fire fail
safe, scram, to shut down the reactor.

No, this was considered a very important test to establish a different
aspect of safety. They were so focussed on this that they turned off
their brains.


It is slightly concerning to see the same over confidence in safety
systems reflected in this thread.

For the last couple of decades virtually all the focus for new designs
has been on passive safety.


The western systems are probably safer and better run, but to quote
Schiller:Â* "Against stupidity the gods themselves contend in vain."


I can't think of a significant engineering failure in the past 50 years
where no-one said "With hindsight, we knew that could happen".

You have probably got to go back to the Comet 1 failures in the 50's,
with fatigue initiated by fretting at rivets, and stress concentration
factors at window corners. The Liberty ship failures in WW2 led to the
science of fracture mechanics.

Even the Russians knew the RBMKs were an accident waiting to happen. In
Japan the question 'what if a tsunami hits' had been answered by ' the
seven meter wall will keep it out' , and if someone had said 'what if it
doesn't?' the answer would correctly have been - 'the loss of four
reactors with secondary containment will be the least of our worries
compared to the devastation and loss of life such a tsunami would wreak'.

Its a bit like saying our reactors need to be safe from nuclear attack.
Why? A few more mSv of radiation when ****loads has been dropped in bomb
form...

The point about safety in a quality controlled environement is that
every incident that us not in accordance with regulations is noted, and
its implications are considered. The procedures or parts are modified
and tested.

Rolls Royce is the best possible company to be doing this - they have a
track record in small PWRs from submarines. They have a track record in
power generations from OCGT and CCGT adaptations of aero engines,. They
also have the total quality approach in place for the jet engine
program. And they have manufacturing capable of high quality mass
production.



--
"When one man dies it's a tragedy. When thousands die it's statistics."

Josef Stalin