There's been a lot of debate here in Fooldom on the facts that both demystify nuclear energy as well as those that sink it. The real fact is that until the zombie apocalypse arrives, nuclear energy is here to stay, whether we like to or not. Further, as long as it's here, utilities will continue to look for ways to grow their own nuclear capacity.

Right now only one utility in the country is building a new nuclear reactor. Given the long lead time, regulatory hurdles, and frighteningly high capital requirements, it's not an easy undertaking. However, adding nuclear capacity is something that many in the industry view as being a profitable endeavor, and many utilities have highlighted that as an area they plan to grow. Here's where it gets interesting. Most utilities are investing to add nuclear capacity without building new generation. Before we get to how that's possible, let's look at the industry's economics.

Southern (NYSE:SO), which is the first company in the country to break ground on new nuclear generation, is doing so because it believes nuclear power to be 15% to 40% less expensive than wind and 50% to 80% less expensive than solar. That's saying a lot, considering that its project, which has been in the planning stages for almost a decade and won't begin commercial operations until 2016, comes with a price tag of more than $14 billion. Even with cost overruns and lengthy delays, Southern believes nuclear expansion is critical for future. 

It also says a lot when wind-driven NextEra Energy (NYSE:NEE) is looking to grow its own new nuclear capacity. It even has plans to build a new generator, even though it is estimated to cost between $12 billion and $18 billion. The project would add 2,200 MW of generating capacity to NextEra's fleet. However, before the company ever moves forward with that project, it'll already have increased its nuclear capacity by 400 MW while spending a fraction of the cost. That's because NextEra, along with most of its nuclear generating peers, has turned to using nuclear uprates to boost capacity. 

Uprates, which increase generating capacity by installing components necessary to increase the generating power of a reactor, are the only real way to grow nuclear capacity these days. NextEra, for example, is spending $1.5 billion on an uprate program to add 400 MW of generating capacity. While that's not on the level of the $16 billion the company has spent to build its 10,000 MW of wind capacity, it's still more cost-effective than those new nuclear reactors. The other big difference to consider here is that the life of a wind farm is estimated at 20 to 25 years, while nuclear generators can keep the juice on for more than 40 years.

Top nuclear generator Exelon (NYSE:EXC) has been in the process of adding 1,300 MW of capacity via uprates. The eight-year, $2.3 billion plan has now been put on hold because of low natural gas prices, which have really hit Exelon hard. Still, the company has added 310 MW of nuclear capacity since 2009 by way of uprates, and they'll continue to deliver a much bigger long-term bang for the buck. 

This is especially true when you consider the cost of other renewables. Last year, Exelon bought a 230 MW solar farm from First Solar (NASDAQ:FSLR) for $1.36 billion, which included a $646 million loan guarantee from the federal government. While government programs and subsidies make renewables very attractive right now, if those end, uprates will again top the list of priorities at utilities looking to grow clean generating capacity.

The debate over nuclear energy isn't going to go away in our lifetime. While few new reactors are likely to be built anytime soon, uprates will continue to be the quiet way that utilities to grow generation capacity. It's really the only realistic way to grow nuclear power these days.