3 ms·

> If you see it as flippant then that might reflect on you. It does reflect on me. It reflects the fact that I can't read minds. You gave a widely known quote

> If you see it as flippant then that might reflect on you. It does reflect on me. It reflects the fact that I can't read minds. You gave a widely known quote, and in your mind it was crystal clear what you meant. But to other people, who can't read your mind, it just sound flippant. It sounds like you think NuScale is a bunch of theoreticians. And that with your remark you are trying to put down their decade-long quest to achieve something. Maybe it does not sound flippant to you, but I assure you, it is flippant.

jacquesm 4y ago
The message, to expand on it is that they are in the earlier stages of their development and the safe bet is that by the time it is all said and done things will be much more in line with what we've come to expect from the nuclear industry, including any and all of the statements already in line with that today. So by the time it is done it will be more expensive, likely heavier, likely way late, more complex and narrower in its possible range of applications. It's not a law, it is an observation made over many nuclear deployments and to the best of my knowledge there isn't a single project that was an exception so I expect it to be true this time around as well. Which is why you can safely ignore any of the touted advantages until the product is ready to be fielded in quantity. Assuming it ever will be fielded in quantity, plenty of designs were slated for large numbers of deployment and ended up being one-offs or at best single digit runs because of unforeseen issues with the design.
- credit_guy 4y ago
  Fair enough. But although the most dangerous words in history are "this time is different", there are reasons to believe things could be different this time: 1. the Nuclear Regulatory Commission. NuScale got the design approval from them. That means this design is as good as frozen. The NRC is an extraordinarily conservative organization. If NuScale, or anyone who licenses their technology, will try to diverge from the approved design by a bit, ..., well that's not even a possibility, why should we think of consequences. So this design, by the time is in production, won't be heavier, more complex, or narrower in scope, because it will be this exact design. It may be more expensive, late, in fewer numbers than expected, however. 2. Conservativeness of the design. This reactor is just a pressurized water reactor design. The most widely used today. It's in a small form factor and modular, but otherwise there's nothing revolutionary or radical about it. 3. History. After about 70 years of reactor operation, the NRC has seen lots and lots of failure modes. The number of new failure modes to be discovered is not zero for sure, but it asymptotically approaches zero. The reason for a lot of past construction delays was the moving of the goalposts by the NRC, but that was due to the discovery of new failure modes, not to any malicious intent. The goalposts may still move between now and 2029, but much less. 4. Politics. In the past few decades, at least in the US, the left was against nuclear power, and the right was for it. Now it appears a large number on the left have embraced nuclear power, so some form of bipartisanship has been achieved. This is quite unprecedented. Will it last? Probably not forever, but it might last a few election cycles, and this could be enough for this SMR design to achieve some escape velocity.
  - jacquesm 4y ago
    Sure, but having the design frozen is one reason why this may never happen in the first place, after all any kind of deviation and it is back to a recertification and that gets expensive quickly. No such thing as 'move fast and break stuff' in the nuclear power business, your design works or you're history. And as you tacitly admit modular is revolutionary and there are a whole pile of challenges right there, having a single (large) point of failure may well be much easier to manage than several smaller ones, I never saw the modularity as the problem to solve, because existing (large) reactors are more often than not also created in sets to deal with downtime due to maintenance and overhauls. Your third point is accurate, but also may end up being this projects downfall: by changing some core design parameters (such as size) new failure modes may well pop up. MTBF is mostly a function of the number of components, if you increase the number of components, even if the components are smaller you will probably still see more failures. Four is true, but: here in NL we currently have the same situation and a new reactor was just greenlit (two, actually if I understood all of the material right). But this is a decade+ project and I suspect that given the fickle nature of these projects that there is a fair chance that it will eventually never see the light of day because of the dark horse of economics: a typical nuclear plant will generate power, but it will never generate any money. Without subsidies these are essentially dead ends.

jacquesm 4y ago

The message, to expand on it is that they are in the earlier stages of their development and the safe bet is that by the time it is all said and done things will be much more in line with what we've come to expect from the nuclear industry, including any and all of the statements already in line with that today. So by the time it is done it will be more expensive, likely heavier, likely way late, more complex and narrower in its possible range of applications. It's not a law, it is an observation made over many nuclear deployments and to the best of my knowledge there isn't a single project that was an exception so I expect it to be true this time around as well. Which is why you can safely ignore any of the touted advantages until the product is ready to be fielded in quantity. Assuming it ever will be fielded in quantity, plenty of designs were slated for large numbers of deployment and ended up being one-offs or at best single digit runs because of unforeseen issues with the design.

credit_guy 4y ago
Fair enough. But although the most dangerous words in history are "this time is different", there are reasons to believe things could be different this time: 1. the Nuclear Regulatory Commission. NuScale got the design approval from them. That means this design is as good as frozen. The NRC is an extraordinarily conservative organization. If NuScale, or anyone who licenses their technology, will try to diverge from the approved design by a bit, ..., well that's not even a possibility, why should we think of consequences. So this design, by the time is in production, won't be heavier, more complex, or narrower in scope, because it will be this exact design. It may be more expensive, late, in fewer numbers than expected, however. 2. Conservativeness of the design. This reactor is just a pressurized water reactor design. The most widely used today. It's in a small form factor and modular, but otherwise there's nothing revolutionary or radical about it. 3. History. After about 70 years of reactor operation, the NRC has seen lots and lots of failure modes. The number of new failure modes to be discovered is not zero for sure, but it asymptotically approaches zero. The reason for a lot of past construction delays was the moving of the goalposts by the NRC, but that was due to the discovery of new failure modes, not to any malicious intent. The goalposts may still move between now and 2029, but much less. 4. Politics. In the past few decades, at least in the US, the left was against nuclear power, and the right was for it. Now it appears a large number on the left have embraced nuclear power, so some form of bipartisanship has been achieved. This is quite unprecedented. Will it last? Probably not forever, but it might last a few election cycles, and this could be enough for this SMR design to achieve some escape velocity.
- jacquesm 4y ago
  Sure, but having the design frozen is one reason why this may never happen in the first place, after all any kind of deviation and it is back to a recertification and that gets expensive quickly. No such thing as 'move fast and break stuff' in the nuclear power business, your design works or you're history. And as you tacitly admit modular is revolutionary and there are a whole pile of challenges right there, having a single (large) point of failure may well be much easier to manage than several smaller ones, I never saw the modularity as the problem to solve, because existing (large) reactors are more often than not also created in sets to deal with downtime due to maintenance and overhauls. Your third point is accurate, but also may end up being this projects downfall: by changing some core design parameters (such as size) new failure modes may well pop up. MTBF is mostly a function of the number of components, if you increase the number of components, even if the components are smaller you will probably still see more failures. Four is true, but: here in NL we currently have the same situation and a new reactor was just greenlit (two, actually if I understood all of the material right). But this is a decade+ project and I suspect that given the fickle nature of these projects that there is a fair chance that it will eventually never see the light of day because of the dark horse of economics: a typical nuclear plant will generate power, but it will never generate any money. Without subsidies these are essentially dead ends.