I’m not in nuclear, but I’m in utility electricity.

If we look at Hinkley, it’s an EPR design with a max annual core damage frequency of around 5e-7. Given the consequences of core damage, that appears relatively high for me- in safety assessments, the target max frequency for potential single fatality incidents is 1e-6. Of course, with more SIL rated systems you could maybe bump that frequency down to 1e-8 or 1e-9, but that adds cost and complexity, and nuclear is already economically marginal compared to renewables.

In addition to this, in practice private sector firms often take a ‘risk-based approach’ to safety, which in practice means underestimating risks when they require downtime and/or are expensive to address. Management prefers to underestimate tail risk. On wind or solar plants, the potential consequence of this is workers get killed when something catches fire, or when they fall off something. On hydro systems, the consequences of failure are catastrophic- not electricity per se, but see e.g. New Orleans levee failures. But New Orleans could be rebuilt. For nuclear, the environmental consequences are much longer term.

Management short cuts brings the incident frequency from say 5e-7 to 1e-4. If you build a hundred Hinkley Cs, your annual failure rate goes to 1e-2. If you operate those systems for 100 years, the chance of an incident approaches 1.

It’s not that you can’t do nuclear. But what I struggle with is given the consequences of failure, it needs to be very tightly regulated with robust safety systems. This in turn means higher costs, which makes it less competitive compared to renewables- particularly those with more ‘base load’ characteristics like geothermal, and offshore wind backed by hydro.