Hemmed in by safety concerns along with political and financial risks, the U.S. nuclear industry hasn’t built a new power plant in 15 years.
But, as the Los Angeles Times reports, companies have still managed to generate more power through a little-known process called “uprating.”
Uprating refers to using more potent fuel rods and, sometimes, more highly enriched uranium. The materials enable plants to boil reactor water more quickly, sending more steam through the turbines and generating more power.
But the boost in power comes with increased risk: the stress on the reactor’s components is greater, which could cause a faster rate of deterioration.
Since being approved by the Nuclear Regulatory Commission in 1998, small uprates have long been common, but what is newer are the sharper increases in power output in the past several years. Some plants have experienced 20 percent increases in power, and 20 of the 104 American power plants have undergone “extended power uprates.”
Federal authorities have raised red flags about uprating. “This trend is, in principle, detrimental to the stability characteristics of the reactor, inasmuch as it increases the probability of instability events and increases the severity of such events, if they were to occur,” the Advisory Committee on Reactor Safeguards, a Congressionally mandated advisory group to the Nuclear Regulatory Committee, warned in a January letter.
Some defenders of the process argue that computer models show that when done properly, there is no increased risk to an uprated nuclear plant. Indeed, the advisory committee gives the practice a thumbs-up, despite its concerns.
However, others suggest that nuclear plants are far too complicated for either the smartest expert or a computer model to plan for all of the contingencies.
“It’s beyond the wit of mankind to identify all challenges to a nuclear plant,” John Large, a former researcher for the British atomic energy agency and the director of a nuclear consulting firm, told the Times.
In fact, three reactors in Illinois that were uprated in the past decade began showing increased wear and tear, including cracks in equipment, despite the calculations by the reactors’ operators that there was no greater risk.
