> Do you have any sources about those being the true cause of the shutdown?

I don't, and I'm not sure it's possible to figure out exactly — since it's politically sensitive and possibly involved "back channel pressure" and other shenanigans.

That said, it has been a longstanding topic in German anti-nuclear circles, cf. list of articles (German) on:

https://www.heise.de/tp/thema/AKW-Fessenheim

I feel like, regardless of what the cause is, having numerous low-level incidents means it's not exactly "safe" as the title of the article suggests. Another user has commented that the plant is nearly 100 years old while the reactors are supposed to last only 40 years before being replaced.

Depends what's classified by an "incident". Aviation has "incidents" all the time. And yet we are not grounding planes based on this. We learn about them, and improve.

The key thing that makes aviation safe is not treating low-level incidents as OK just because they haven't turned into major incidents. One of the major, repeated root causes of catastropic failures in nominally robust, redundant and safe systems, across multiple industries, is the normalization of deviance - the acceptance of safety failings because they haven't lead to a critical disaster yet. The more I hear from nuclear advocates, the more convinced I've become that pro-nuclear advocacy is fundamentally incompatible with the existence of safe nuclear power plants, if that is even possible.

Do you trust the service with the statuspage that is 100% green for all of history or the one that reports the occasional degradation?

Reporting accidents isn't the issue. It's having them on the regular and being past the standard operational period that worries me. Not sure why that's contentious.

In an ideal world, you have your threshold for "incident" set low enough that you have a lot of them. Catching more of the distribution of problems let you increase the level of safety.

Exactly. This difference between "we're only going to update the status page if a customer comes screaming to us that the service has been unavailable for the past 24 hours and they've received no updates" and "we have automated systems in place to updated the status page if the p95 response time exceeds XXX (among other things)".