The Nuclear Option

Is Nuclear Power Worth It? Link goes to a Scientific American article. It's definitely worth the read. Definitely some pro's and con's to this energy source.

A pro, as odd it may seem by reading this quote:

And nuclear power plants have been operating in the U.S. for 50 years without exposing workers or residents in surrounding areas to excessive radiation. "Radiation is mundane, it's a weak carcinogen," says Rod Reed, a senior health physicist at the NRC. "It leads to very mundane changes, not three-eyed fish."

In fact, a typical coal-fired power plant exposes local residents to as many as 18 millirems of radiation yearly, whereas a nuclear power plant emits less than six millirems per annum, according to researchers at Oak Ridge National Laboratory.

Reed adds: "Radiation should be respected, not feared."

And a con?

At issue in the failure at Davis–Besse is the alloy metal used to craft the nozzles—known as Inconel 600 or Alloy 600. The alloy of nickel, chromium and iron is resistant to corrosion generally—but slowly cracks when exposed to boric acid and stress.

But it isn't just reactor heads that are made from the stuff. The steam generators that transfer the heat from the solution of water and boron, which comes into contact with the nuclear reactor, to the water heated into steam that turns the turbines to produce electricity also employ the alloy. "The tubes in the steam generators were susceptible to cracking," says Ken Karwoski, senior level advisor for steam generators and material inspection at the NRC's Office of Nuclear Reactor Regulation. "It's a combination of the temperature and the water chemistry."

So is this an issue dealing with all nuclear power plants? Fortunately no.

As early as the late 1950s there was some suggestion that this metal would crack under pressure but "the decision was made to go with this material," Karwoski says. "The perspective was that it should last but it didn't." And, as of today, there are still 15 nuclear power plants, including Davis–Besse, employing their old steam generators made from the alloy.

The U.S. fleet of 104 nuclear reactors—most built in the 1960s and 1970s—produced 806.5 billion kilowatt-hours of electricity in 2007, a record, and ran almost 92 percent of the time.

Speaking of issues with nuclear energy infrastructure, here is another article from Sci Am about nuclear mishaps.

In all, there were 10 incidents at U.S. nuclear plants last year [2006] that merited ratings of 2—"significant spread of contamination / overexposure of a worker" and "incidents with significant failures in safety provisions," as the INES handbook puts it—or above, Jones says. "Two reactor events and eight nonreactor events."

Overall, I'm still of the opinion that nuclear energy is a reasonable source of energy for the United States.

Nuclear Power

I'm not sure that many people actually consider this, but ... nuclear power is going to be as finite as fossil fuels are. Current estimates peg nuclear power as being capable of powering the world at current rates for the next 200 years. Then, that's it folks.

According to the NEA, identified uranium resources total 5.5 million metric tons, and an additional 10.5 million metric tons remain undiscovered—a roughly 230-year supply at today's consumption rate in total.

There are a couple more options though ...

Two technologies could greatly extend the uranium supply itself. Neither is economical now, but both could be in the future if the price of uranium increases substantially. First, the extraction of uranium from seawater would make available 4.5 billion metric tons of uranium—a 60,000-year supply at present rates. Second, fuel-recycling fast-breeder reactors, which generate more fuel than they consume, would use less than 1 percent of the uranium needed for current LWRs. Breeder reactors could match today's nuclear output for 30,000 years using only the NEA-estimated supplies.

That's a bit more comforting. The question is ... would future developers actually develop these technologies sometime other than the 11th hour like we're currently experiencing with oil?

Worried about Nuclear Power?

You shouldn't be ... or at least, you should be more worried about coal-burning power plants.

Seems as if the coal-burning process concentrates the radioactive elements naturally found in coal. In some places, the ash (the waste from coal-burning) contains up to 100x the amount of radioactivity than a similar amount of nuclear waste.

At issue is coal's content of uranium and thorium, both radioactive elements. They occur in such trace amounts in natural, or "whole," coal that they aren't a problem. But when coal is burned into fly ash, uranium and thorium are concentrated at up to 10 times their original levels.

It's not really much of an issue though. Researchers long ago figured out that being within close proximity of a coal-burning power plant raised your yearly exposure by about half a percentage point (0.5%).

McBride and his co-authors estimated that individuals living near coal-fired installations are exposed to a maximum of 1.9 millirems of fly ash radiation yearly. To put these numbers in perspective, the average person encounters 360 millirems of annual "background radiation" from natural and man-made sources, including substances in Earth's crust, cosmic rays, residue from nuclear tests and smoke detectors.

So, the moral of the story? Of all the things to worry about, nuclear and coal based energy aren't worth the effort.