Comments
From the conclusions of the OECD Nuclear Energy Agency's report on spent fuel pool loss-of-coolant accidents:
- All SFPs [spent fuel pools] are large robust monolithic structures. The pool walls are generally made of more than one metre thick steel lined concrete. Fuel assemblies are stored in racks that provide spacing for coolant flow and in some cases also for criticality control. The pools are filled with several additional metres of water above the spent fuel to provide biological shielding. An active cooling and purification system maintains optimal conditions for the stored fuel.
- The possibilities of loss of cooling and loss of coolant accidents are accounted for in the basic design of all SFPs. The cooling systems have built in redundancies and are connected to emergency backup power to maintain their function. Pool penetrations are kept to a minimum. The cooling systems either have siphon breakers or the depth of the inlet and outlet pipes are limited to prevent draining of the pool. The large volume of water provides a significant thermal mass, which slows the accident progression and gives respite for operator intervention.
- Following the Fukushima Daiichi accident, additional measures have been undertaken to improve SFP safety even further. These measures differ greatly due to the large variation on designs, but can be generally stated as improvements in accident response procedures, additional backup electricity or water supplies, and instrumentation improvements.
Humans and other animals across the world die from taking in poisonous radioactive isotopes. High levels of ionising radiation cause so much cell damage (modifications of complex chemistry process, DNA and RNA damage) that the persons get sick (nausea, digestion falters, hair loss) and then die over days or weeks.
I don't think an environmental radioisotope release can realistically give people across the world acute radiation syndrome.
moving nuclear fuel stored in pools into dry casket storage
The extent to which we can do this is limited because spent fuel must be stored for one to ten years in spent fuel pools while the shorter-lived isotopes decay before it's ready to be moved to dry cask storage.
This sounds quite conspiratorial and it comes from someone (Bret Weinstein) who is known to be far down the conspiracy rabbit hole and misrepresenting science (e.g. on COVID). So I am surprised we are paying any attention to it.
More substantively:
Regarding 1., I would value someone who has researched this give more insight into:
A. How long diesel generators could be expected to be supplied with diesel when there is some continental electricity outage of a year (or longer). This is hard to judge. My intuition is that society would be in chaos and that maintaining diesel supplies would be extremely tough to manage.
B. What is minimally required in the long process of shutting down a nuclear power plant? Including but not limited to diesel or other backup generator supplies.
Regarding 2., I do not see how a meltdown as happened with Chernobyl is not thought to be possible with current reactor designs. Even if current reactor designs have more safeguards, the fundamental problem still seems the same. You have constantly heating fissile materials that require cooling water to not overheat. And there are some potentially flammable substances in the area of the (used up) fuel rods too. Could you clarify more specifically what you think are important differences here?
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I felt a little confused about why the summary sounded conspiratorial to you. The way I meant to write it is “a chain of plausible-seeming but neglected events happen, and lead to catastrophe”. At most this seems a story of humans not being incentivised to act to prevent tail risks? Am I missing something?
Now, Bret Weinstein does seem to have a leaning toward potentially falsely identifying conspiracies. While I agree COVID vaccine negative side-effects seem underreported (I’ve seen it with family), I am also skeptical of Bret’s coverage. I also think there is another perspective on the Evergreen College situation, which is that the college had been slow to implement thoughtful reforms (whatever that means) to address structural discrimination and that tensions boiled over.
At the same time, I want to be careful about not dismissing explained reasoning outright because the person seems on the face of it unreasonable. There are people outside EA whom I talked with who initially seemed in some ways very unreasonable, until I probed their perspective enough, found a more comprehensive way of looking at the problem, and surprisingly changed my mind.
Would also want to encourage maintaining some openness around looking for conflicting perspectives. You have been advising a climate strategy of a developing a mix of energy solutions, including nuclear energy. You would adjust your recommendations if you ever found rigorous reasoning for there being an unacceptable risk of nuclear meltdown, right?
I'll address the rest later (hopefully this weekend), but just to clarify that I did not mean to call you or your summary conspiratorial, Remmelt!
I only meant the substantive claim and coming from Bret Weinstein, but I'll address this with more time and the rest of your comment later.
Apologies for the delay, Remmelt.
What I meant to say in my original comment is that when someone who has a bad reputation for being truth seeking / has a reputation for being a conspiracy theorist says something on an area outside their expertise we should not give a lot of credence to it.
The burden of this not being a credible scenario should -- in my view -- not lie with commenters and, at the time I was commenting, most comments seemed incremental instead of pointing to a strong skepticism on Weinstein's take to start as if it were a plausible situation that a guy on a podcast without specific relevant expertise has uncovered a mechanism that 50 years of anti-nuclear activism have not produced (or, more nuanced, something that is so implausible that even typical anti-nuclear advocates wouldn't lead with it because they know it won’t stand).
To the specific question -- we do have a long section on nuclear in our 2018 report and I've obviously also spent a lot of time on it though I haven't written it up, but it took me several years to turn from German anti-nuclear environmentalist to the positions I hold now.
Here is an article on why a Chernobyl-style event is not possible with modern reactors. And the diesel generators would not be refueled for a year, given in the scenario there would be a failure of the entire power grid you would just use them to have enough electricity to shut things down safely.
Hey, my apologies for taking even longer to reply (had family responsibilities this month).
I will read that article on why Chernobyl-style events are not possible with modern reactors. Respecting you for the amount of background research you must have done in this area, and would like to learn more.
Thanks, looking forward to reading your thoughts!