Enough news space has been devoted over the years to the prospects for new reactors in the U.S. to lay waste to several small forests and countless electrons. However, there is a different means by which the nation’s share of nuclear-generated electricity can be increased, and it does not involve earth-movers, the construction of new buildings or other changes visible to the casual observer.
Another option available to nuclear power plant owners is to pursue a power uprate, which essentially means an increase in the maximum amount of power a reactor can generate. But before a power uprate can be implemented, it must first undergo a thorough review by the NRC.
Just last week, the NRC approved a 15 percent power uprate for the Nine Mile Point 2 nuclear power plant in upstate New York. That approval was the culmination of an NRC review that began with the submittal of the application on May 27, 2009.
During the course of the agency’s evaluation of the proposal, NRC staff scrutinized data regarding the proposal and posed dozens of technical questions to the plant’s owner, Constellation. They included queries about the effects of greater stresses on piping and the plant’s steam dryer, a component at the top of the reactor vessel, as a result of operations at higher power levels.
The NRC does not proceed to a final decision until all such questions are answered to our full satisfaction.
Uprates are not a new development. In fact, the NRC approved the first uprate back in 1977 and has to date okayed 140 such applications. All told, the uprates have led to an increase in power output nationwide of about 6,000 megawatts electric.
There are three different kinds of power uprates: “measurement uncertainty recapture” uprates, “stretch” uprates and “extended” uprates. Here’s a brief description of each:
Measurement uncertainty recapture uprates – They involve an increase of less than 2 percent and are achieved by implementing enhanced techniques for calculating reactor power levels. State-of-the-art devices are used to more precisely measure feedwater flow, which is used to calculate reactor power.
Stretch uprates – The increases are typically between 2 and 7 percent and usually involve changes to instrumentation settings but do not require major plant modifications.
Extended uprates – Power boosts of this type have been approved for increases of up to 20 percent. They usually involve significant modifications to major pieces of non-nuclear equipment, such as high-pressure turbines, condensate pumps and motors, main generators and/or transformers. The Nine Mile Point 2 uprate would fall into this category.
For more information on power uprates, visit the NRC web site at: http://www.nrc.gov/reactors/operating/licensing/power-uprates.html.
Neil Sheehan Region I Public Affairs Officer
U.S. NRC Blog 
Left unsaid by the nuclear industry and the NRC is that:
1. These “Up-rates” tend to cause much higher “wear and tear” on all critical components that carry reactor core coolant, something that is not usually disclosed to ratepayers, since they not the operating Utilities have to foot the bill to pay for them (which is termed maintenance) and/or their replacement, which could easily run into the Billions over time!
2. The transportation and long term storage of these Up-rated fuel rods is yet another area where the NRC has “put the cart before the cart” since they have not approved either as of yet. San Onofre, located in southern California, which is now being decommissioned due to an operator debacle involving in-house designed replacement steam generators that almost caused a near-miss nuclear accident, has identified these Up-rated fuel rods as needing much longer cool down times in spent fuel pools and no, as yet, approved transportation storage “caste”, so in effect, these Up-rated fuel rods will be stored on site for 60+ years, or until the NRC discovers a long term solution, neither of which had been disclosed to ratepayers!
They government ought to make a review on this proposition so the citizens won’t be suffering in the near future.
I thought that the uprates are some sort of new development. But anyway, the change in instrumentation settings is nice to hear.
I always thought that Under existing rules, a reactor design that commissioners have voted to approve must be published in the Federal Register for 30 days before it is legally effective.