All the rest of our incidents have also been known risks and I think all if not bar 1 or 2 down to human error or human refusal to follow best practice.
Human error makes sense and I guess that falls into a kind of third area of risks really. Avoidable and prepared for but still happens a lot because of people trying to take short cuts or not following procedures.
The issue with the nuclear plant and the deterioration of the core doesn't fall into that category. It falls into a category of monitorable plant deterioration, can and is modelled using measurement and inspection.
The other category is unexpected hazards like flooding, tidal waves, earthquakes, terrorists. Can also be planned for and try to prevent but there is always something new to come along and bite you I think in this category.
So, the risk consultancy... which I joined as a founding member 20+ years ago operates across all major high hazard industrial sectors, we have several large nuclear teams with individuals who have in excess of 40 years sector experience, civil or "other", commissioning, operating, maintaining, decommissioning and everything in-between.
I'm not sure how much I'm prepared to add to this topic, particularly on the nuclear side, but our 250+ consultants perspective you are A. wrong on claiming "risk assessors" are, what you really mean is "overly conservative" and B. wrong in seemingly claiming Hinkley B was shut unnecessarily.
What I mean by my initial statement is this... where is the counter challenge? So for example an experienced nuclear engineer comes along and identifies cracking in the core. He (his team) measures, models and evaluates the best they can and come up with a recommendation. Their recommendation will always be on the cautious side, perhaps rightly so. But where then is the challenge saying what if...what if we could extend. What are the options, mitigations, extra inspection and measurement regimes we could implement and how much does that change the risk? Maybe they have done this, but its not transparent that they have in this example.
Do you not think risk assessors are conservative? Isn't the main idea to prevent first, then mitigate if prevent isn't an option?
My point about Hinkley B is this:
* an inspection last year identified some deterioration in the core material.
* but nevertheless, it was considered ok to continue running for more than a year longer. An arbitrary date of July 2023 was set as a hard limit.
Does this not seem strange to you?
What would have made a lot more sense is, having identified deterioration of the core and yet accepting the plant could still be run longer at that point, would have been to set a further inspection perhaps at 3 or 6 month intervals. Then you make the decision to shut down the plant based on the results of that continued monitoring. If there is no change at the next inspection, you continue for another 3 or 6 months. If there is change, you make another decision based on that knowledge.
Having identified a problem in 2021, it makes no sense at all to basically say "run it until 2023 then we'll shut down no matter what".
Admittedly, we don't have access to all the facts unfortunately. Which is the point I was making about transparency of information and this applies everywhere not just this example.
Yes i know but it will be a fixed percentage over the current cap so its easy to do the math and figure out the cost if you are on already on the cap which most people who arent locked in are currently on. Just to reiterate of all the people in this thread im probably one of the best placed to understand all of this 