Researchers hope to extend reactor lifetimes with advanced methods and materials that guard against degradation caused by harsh conditions
by Mitch Jacoby
Forty years of hard labor in punishing conditions sounds like an interminable sentence. Imagine finding out near the end of that period that the sentence has been extended for another 20 years and maybe another 20 beyond that.
That’s the plight of nuclear reactors. These giant metal contraptions were typically designed to generate electricity for about 40 years, day after day resisting damage from a corrosive, watery world of extreme temperatures, pressures, and ionizing radiation. Now many are being asked to soldier on for at least another 20 years.
To extend reactors’ lifetimes, scientists and engineers are continually improving methods for monitoring and predicting the integrity and strength of these multibillion-dollar metal structures. And they are developing corrosion-resistant replacement materials to keep nuclear reactors operating safely and reliably for 60 years or longer.
Roger Hannah and Neil Sheehan, public affairs officers for US Nuclear Regulatory Commission operations in the Southeast and Northeast US, respectively, confirm that the Turkey Point Nuclear Plant, 40 km south of Miami, and Peach Bottom Atomic Power Station, 80 km southeast of Harrisburg, recently received additional extensions that would allow them to continue operating for a total of 80 years each. Hannah and Sheehan add that other plants are seeking to do the same.
“There’s even talk in the industry of going to 100 years,” Was says.
The trend to keep reactors running longer and longer is not limited to the US. The 440 or so reactors located throughout the world are 30 years old, on average, and getting older. And although some of them are scheduled to be shut down and decommissioned, many are being upgraded with new parts to greatly extend their years of operation.
That mode of damage, which Toloczko says is generally considered “the main life-limiting degradation mechanism” for commercial reactors, wreaked havoc at the Davis-Besse Nuclear Power Station near Toledo, Ohio. The corrosion problems detected there and at other plants and the analyses that followed led to a better understanding of damage mechanisms in nickel-based alloys and the implementation of more corrosion-resistant materials.