Three interesting takes on America’s complicated energy puzzle showed up in national papers in the last couple of days:
- A report in the Los Angeles Times on Monday suggesting that geothermal power could be on the verge of a renaissance after decades of decline, not only in geyser-rich California but across the country.
- A pair of reports in The New York Times on Sunday portraying our so-called renaissance in nuclear power as a limp-along effort to extend the lives of old-technology plants, equipment and designs beyond their normal spans, with all of the safety concerns you can imagine.
Both are worth careful study, I think, by anyone who wants a little better grasp on these two industrial sectors and also the factors that will shape America’s energy future.
Taking the nukes first, it certainly is not news that utilities all across the United States — including Xcel Energy in Minnesota — have sought federal approval for programs to refurbish nuclear reactors as they come to the end of their operating licenses and then to have those licenses renewed.
Still, it was striking to read in Sunday’s Times that officials in charge of seven plants in Pennsylvania, Virginia and South Carolina “are preparing to ask for permission to run them until they are 80 years old.”
Working past retirement age
The plants, that is, would be 80 years old; the utility executives will have retired at a much younger age. In terms of total design lifespan, the Times noted, the extensions could mean that certain plants would be running on plans drawn 90 or even 100 years earlier.
Back in the 1990s, when the idea of getting 20-year license extensions for 40-year-old reactors was gaining traction, it may have seemed like a sensible short-term fix in an era when electricity demand was rising steeply and steadily, the chances of putting a new nuke plant on line were tiny, and the writing was on the wall, however faintly, about the need to phase out coal-fired generation.
Since setting the rules for relicensing in 1991, the Times reports, the Nuclear Regulatory Commission has granted 70 license extensions and rejected none.
Now it has to figure out how to handle expected applications for additional 20-year extensions that it anticipates will go on the docket starting about four years from now.
I don’t know about you, but I didn’t find terribly comforting to be reminded that, “To win a license extension, the plants do not have to show that they will be safe for 80 years, only that they have monitoring programs in place to promptly detect problems as they emerge.”
Exposed to decades of radiation, some metal parts grow brittle and more likely to crack under stress. One potential source of stress is the emergency core cooling system; if the system sensed a leak in the piping, it could start up and dump huge volumes of cold water into a reactor, keeping it at operating pressure but at a far lower temperature. Engineers say that could lead to a condition called “pressurized thermal shock,” in which a reactor vessel would crack open.
To measure embrittlement, the plants use extra samples of the metal from which their reactor vessels were made, called coupons, stored for years in irradiated areas inside the reactors. These have been removed at various intervals and analyzed for brittleness, in a test that usually destroys the coupon.
A few of the reactors have run out of these coupons, and engineers are trying to draw conclusions about their conditions by extrapolating from coupons in other reactors. In others, they have moved the coupons closer to the center of the reactor, to age them faster, so they have an idea of what the vessel’s metal will look like in a few years, not just its current condition.
Like old cars, they’re paid for
However, extending the operation of the old plants has a significant advantage over replacing them, whether with a new nuclear plant or a natural-gas plant or, for that matter, renewable power.
“If you’ve effectively paid off the plant, this is very cheap power,” said Neil Wilmshurst, a nuclear engineer at the Electric Power Research Institute, a nonprofit utility consortium that has been researching how to keep old plants running. “The whole basis of license renewal is that the plants are being well maintained — that at the component level, things are being replaced when needed and maintained when needed.”
A handful of new nuclear plants are under construction in the U.S. right now, in most cases bedeviled by cost overruns and compliance issues. But even a brand-new plant doesn’t necessarily employ the latest designs, or the most modern equipment — even of the simplest sort.
Matt Wald, who wrote the Times piece quoted above, also reported Sunday on his recent visit to the Tennessee Valley Authority plant nearing completion near Spring City, Tennessee. It may become our first new nuclear plant of the millennium, but it is the product of an on-again, off-again building program stretching back to 1970.
For proportion’s sake, Wald helpfully points out that the Panama Canal and the Great Pyramid of Cheops were built in less time.
The new plant, known as Watts Bar 2, is being built to match the plant known as Watts Bar 1, right down to the control switches. And here’s the passage that made me feel for a moment as if I were reading a subtle satire rather than a sober news report:
Watts Bar 2 is something of an oddity. New industrial plants of any kind have computerized controls; this one still has computer monitoring, but the gauges and switches are all hard-wired in the style of the 1970s, partly because the managers want it to resemble Watts Bar 1 as closely as possible. The plan is for operators to be licensed on both plants, which share a control room, and to switch seamlessly from one to the other.
When work resumed in 2007, engineers decided that the mechanical switches in the control room, although they had never been used, were too old. But nobody manufactured mechanical switches of that type anymore, so the TVA sent them back to the manufacturer for reconditioning.
And that’s the news from the utility sector that, we are routinely reminded, is our only realistic hope of meeting future power demands as coal-fired generation continues to decline.
A fresh look at geothermal
But this just in from California: After decades in the doldrums, companies making electricity from geothermal heat are saying that their time has come again, and that new technologies can distribute this form of power generation well beyond the zones traditionally thought suitable.
Like so many of today’s new energy sources — solar gardens, wind farms, small hydro, biomass — geothermal has old roots, especially in California, where the Los Angeles Times recalls how
Pacific Gas & Electric completed the nation’s first commercial geothermal power plant at the Geysers in 1960. Wells driven 12,000 feet into the ground tapped into magma and swirling steam that was piped to the surface to drive turbines.
The vast energy trove in the Mayacamas Mountains north of San Francisco produced clean, seemingly limitless power at a time when Americans’ appetite for energy was growing insatiable…. But the industry’s lack of discipline became its undoing. By the mid-1980s, more than 20 energy companies crowded into the 45-square-mile field, pumping out steam with abandon.
In the frenzy to harvest cheap energy, too many companies drew too much water from underground reservoirs. By 1987, steam production was in rapid decline and electric generation from the Geysers plummeted to almost nothing.
Note that it wasn’t the below-ground energy that was depleted but only the vehicle — water — for carrying it to the surface.
According to the L.A. Times’s Julie Cart, researchers are now working on ways to pump surface water into deep wells and bring heat to the surface in efficient, closed-loop system.
Meanwhile, the U.S. Department of Energy is funding research into whether such facilities couldn’t also make use of “produced water” — the wastewater returned to the surface by fracking operations, and in volumes that create a major disposal problem.
Cart’s story is a little light in the financial dimension, I thought, and she reports without challenge the geothermal executives’ explanation that their continued low rankings in market share and public awareness are traceable to their lack of savvy when it comes to promoting their product.
However, she got my renewed attention with reference to an MIT study suggesting that with a little more government research support and development incentives, geothermal sources could provide 10 percent of the nation’s electric-generation needs.
That doesn’t solve the whole problem, but according to my notes, its just over half the amount we’re getting from a nuclear fleet that appears creaky and growing creakier.