A first for Canada: New type of nuclear plant opening by 2028

Do you have a source hydro turbines “turning fish in to mulch”? I’ve been around lots of hydro projects and the main hazards for fish seemed to be either dewatering of habitat due to turbines reducing flows too quickly or I heard it is bad for them if the dam uses the spill way and makes the water all aerated

Does anyone understand this? "Some of the main differences that the MMR has from conventional nuclear plants is that the reactor cannot meltdown as the heat is passively released into the environment..."

300MW is a lot of energy to passively release into the environment. Does this design really fail safe? And if so, how?

The Fukushima issues were caused (IIRC) by failure of the backup generators to run the cooling system after the reactors were shut down. Do these small reactors really not need any external power when in that state? And do they get into this state by default? I.e. do they shut themselves down without external power and if the control systems fail? That would seem to be a massive safety advantage if it's true.

I remember reading about UK magnox reactors where the graphite control rods were held above the core by electrically powered actuators and which were designed to fall into the core (and stop the reaction) if there was a power failure. Perhaps these reactors are similar.

For getting an intuition on it, I would recommend the clip from HBO’s Chornobyl which ELI5’s a nuclear meltdown. [1]

If the reactor is air cooled, that can be translated as “the heat can just burn off” as there isn’t a liquid cooling system, reducing this failure mode.

As mentioned in the video, reactions are about balance. If a ‘safe’ SMR gets shut off or has its systems fail, you would want the accelerators / enablers of the reaction to disappear, and roll out the reaction.

This is unlike most fission reactors in use today which are a ‘balanced dance’ where lots of the design is focused on reducing the speed of the burn (like a constant stream of water on a fire) rather than say controlling the oxygen of a fire with limited fuel. SMRs aim be more of the “control the oxygen” type of reaction rather than “keep the fire cool” kind of reaction. (Forgive my vast oversimplification, but this is my intuition on it).

[1] https://youtu.be/TmIEI4ky-Zc

Solar/wind/storage is always a better option as long as the storage solution isn't replaced by burn fossil fuel, which like the tarsand oil detail, is the kind of detail that sadly pop up in practically all places where the solar/wind/storage solution is being promoted. The fossil fuel need to stay in the ground.

I am fairly enthusiastic about both renewables and nuclear, but I am a bit pessimistic about storage. The holy grail would be green hydrogen as storage, and that has been the political aiming for in the last 10 years. However in the mean time, everyone just got to rely on that Russian gas and oil. Solar/wind/fossil fuel is the current model and I just can't get enthusiastic about that.

My only question about nuclear is why is it okay to bury the nuclear waste?

I can understand that it might be fine to bury small amounts in specific stores but if countries slowly adopt nuclear energy at scale then over time won’t we be burying a lot of waste that, correct me if I’m wrong, has to be stored for thousands of years? I don’t understand how this can be sustainable long term. I also think it’s maybe arrogant of us to assume that it will always be safe to just store it and that something won’t happen that could disrupt that.

I’m no expert on this though so if someone has a great explanation I’d love to understand it.