In that sense, had they been closing the plant with the expectation of drastically reducing energy demand, it might have made sense.
I really hate this kind of reasoning. Even if we do manage to reduce our energy consumption, closing the nuclear plant would still be more harmful to the environment because we could have closed fossil fuel plants instead. Unless, of course, we’d manage to reduce energy consumption so much that we wouldn’t need any non-renewable energy sources - which I don’t think is very realistic assumption. Certainly not realistic enough to make such a gamble on.
The only way closing the nuclear plant would have been beneficial to the environment would be if the act of closing it would have caused a reduction in our energy consumption that is greater than the energy the plant itself was producing (minus some extra energy from fossil fuel plants that take up its “emission budget” to increase their own energy production). Which is also quite unrealistic. I actually think it makes more sense that it achieved the opposite effect, since closing the plant took up activists’ effort and environmental publicity, which could have been used to push for reducing consumption instead.
The fine line between “I don’t want to do the thing” and “I don’t want you to be able to do the thing”.