The headline on the story from the Mississippi Public Service Commission was that Grand Gulf Nuclear Station has been approved for a capacity “uprate” from 1,265 megawatts to 1,433 megawatts— making it the single most powerful reactor in America.

That’s fine, but there are other aspects that make the petition more significant.

First is that it will allow Entergy and all its subsidiaries to increase the share of nuclear-generated power in the mix of electricity it sells here in Warren County, across much of the rest of Mississippi and in Louisiana and Arkansas. Most of the plants supplying the grid are fired by fossil fuels, principally natural gas. Although experts assure us that gas reserves are plentiful for now, they are vulnerable to market forces, weather and, most significantly, perpetual supply. Fossil fuels are finite and nonrenewable. That isn’t going to change.

By increasing its reliance on a nuclear-fired plant, Entergy is assuring a reliable supply of power, and reliability is a key component in future economic growth.

The second aspect is cost.

When electricity made at Grand Gulf first went on the grid in 1985, there was sticker shock, to say the least. Ratepayers had to come up with more than $3 billion to pay for what is still the largest construction project ever undertaken in Mississippi.

Now, as the saying goes, the worm has turned.

Going forward, according to figures supplied to the Public Utilities Staff, the uprate is a less expensive option for Entergy and, thus, for ratepayers, than continued reliance on fossil fuels.

If federal clearances are given, the final phases in the $510 million plan will be completed during a planned spring 2012 refueling and maintenance shutdown.

This part of America needs electricity that is reliable and doesn’t cost any more than it has to cost.

The Grand Gulf capacity increase is a step in that direction. The PSC, after analysis, was correct to give its approval.