On 17/02/2021 17:03, michael adams wrote:
"Steve Walker" wrote in message
...
On 17/02/2021 14:59, michael adams wrote:
"Tim Streater" wrote in message
...

At Chernobyl it was:

1) ignorance of the possible behaviour of the reactor when run outside its
normal operating envelope, combined with removing or shutting down all the
computers and other safety equipment so the reactor could be forced into what
turned out to be a dangerous and unstable mode.

2) Poor operating procedures for running this sort of reactor test

3) Poor emergency procedures and lack of coordination with local fire
services.

4) The usual communist culture of secrecy which led to delays and made the
problem worse.

At Fukushima it was:

1) The assumption that the sea wall could contain the tsunami (they were
nearly right on that one).

2) Not siting the backup power generators and their fuel tanks where they
wouldn't be overwhelmed by a worse rsunami.


Hindsight is such a wonderful thing.

Not only can it tell us how mistakes we made the past could and should have been
avoided, but it will also be able to tell us how mistakes we are inevitably bound
to make in the future, could and should have been avoided as well.

We have moved on to passively cooled reactors, so that loss of power, fans, pumps,
electricity, generators, etc. are not a problem.

That eliminates the common risks of external problems.

Neither the Russians nor the Japanese were, or are, particularly stupid.

The Russians knew of the risks and chose not to address them.

The Japanses underestimated the height of a possible Tsunami and left
the generators vulnerable.

In pointing out the "mistakes" that they made Tim Streater is merely reinforcing
the point - of how easy it is, without the benefit of hindsight for people who aren't
particularly stupid to make "mistakes".

Chernobyl was not a mistake, it was known bad design, there was reliance
on operators to avoid a particular operating regime due to that design
constraint, there was no safety system to prevent such operation and
someone chose to carry out an unauthorised test, within that regime,
outside even the test's pre-determined parameters.

That was not an accident, it really was stupidity - that Western
regulation simply would not permit.

And that basically there's no reason to believe that people, who aren't particularly
stupid aren't going to continue making mistakes in the future of a kind and in areas
we can't even predict. The possible consequences of which may be similarly
difficult to predict.

The point is that with removing the reliance on active safety systems
and relying upon passive ones, you don't have to worry if you've
predicted the highest tsunami correctly; got enough generator fuel on
site; kept the batteries charged for starting them; protected the
control system and cabling sufficiently; maintained access for
operators. They can all be swept away and it still remains safe.

That alone really does remove most of the risks.