Shares of NuScale Power (SMR -5.34%) have risen 350% over the past year. That's an impressive stock advance for a company that loses money and is likely to keep losing money for at least several more years. Growth like that is likely to have minted a few millionaires if they bought in early and invested enough.

But smart investing is more about looking toward potential future growth rather than betting on past performance. Investors now shouldn't be betting on today's performance when they buy NuScale Power, they are betting on the future of nuclear power. And if the future is as bright as seems possible today, NuScale Power has real potential to help make more millionaires in the years to come.

What does NuScale Power do?

NuScale Power is working toward being the first to market with a small-scale modular nuclear reactor. It is a pretty exciting advance in the nuclear power sector, which has historically only produced very large reactors. Large-scale nuclear power plants have advantages, but they also come with a host of negatives -- most notably, cost, construction time, and accident risk.

Image source: Getty Images.

Small modular reactors, or SMRs, address all three issues. Because they are smaller and built in a factory setting, SMRs are cheaper to build and can be built quickly. The economies of scale and construction efficiencies that can be created with SMRs are virtually unattainable in the one-off construction projects that produce large-scale nuclear reactors. As for safety, SMRs are, again, smaller and thus less risky. But they also make use of the most modern safety protocols. They are an elegant solution.

There's one more benefit, however, that can't be overlooked. SMRs are also more easy to locate. Their small size means they can operate closer to population centers. And they can actually be placed directly next to a facility, such as an AI data center, that needs the power. Assuming NuScale Power can successfully deploy its SMRs, there is great potential here.

NuScale Power has a head start

One of the big reasons to like NuScale Power is that it appears to be much further along in the process of building a commercial SMR than any other company. This first-mover advantage could make it the go-to source for SMRs even as competitors attempt to get their own reactors on the market.

The big story here, however, is going to come to a head at the end of 2025. That's when the final green light for a nuclear power installation in Romania is expected. Assuming that power plant moves forward, it will be the first customer for NuScale Power's technology.

The plant, to be operated by RoPower, will consist of six NuScale Power reactors chained together. This is a very big deal for a company that hasn't yet produced a single commercial reactor. It will represent a massive turning point for the business and put its entire business model to the test.

Data by YCharts.

A lot of good news is priced in already

That said, this single deal isn't the end of the game. It is just the beginning. In fact, NuScale Power is already preparing for sales beyond this one. It has placed enough orders for parts that require long lead times to build 12 of its SMRs. Management claims that this decision is justified by the positive conversations it is having with potential customers.

There's just one small problem with all of the good news here -- it is already well-reflected in the massive stock price advance. Even if the Romanian power plant gets approved, it probably won't be up and running until the end of the decade. That suggests that NuScale Power will continue to be a money-losing nuclear power upstart for several more years. If you buy this stock you need to be thinking in decades, not days.

NuScale Power's technology is exciting, but it isn't going to be an overnight success. Moreover, companies like NuScale often chart an irregular path higher when they are successful. So share price volatility is highly likely along the way. In the end, assuming NuScale is successful with its SMRs, it could be a millionaire-maker stock -- but only if you are willing and capable of sticking around for a long time.