This scheduled regularity may appear mundane, nevertheless it’s fairly the feat that operational reactors are as dependable and predictable as they’re. It leaves some huge sneakers to fill for next-generation know-how hoping to hitch the fleet within the subsequent few years.
Typically, nuclear reactors function at fixed ranges, as near full capability as potential. In 2024, for industrial reactors worldwide, the common capability issue—the ratio of precise vitality output to the theoretical maxiumum—was 83%. North America rang in at a mean of about 90%.
(I’ll word right here that it’s not at all times truthful to simply have a look at this quantity to check totally different sorts of energy vegetation—natural-gas vegetation can have decrease capability components, nevertheless it’s largely as a result of they’re extra prone to be deliberately turned on and off to assist meet uneven demand.)
These excessive capability components additionally undersell the fleet’s true reliability—a variety of the downtime is scheduled. Reactors must refuel each 18 to 24 months, and operators are inclined to schedule these outages for the spring and fall, when electrical energy demand isn’t as excessive as once we’re all operating our air conditioners or heaters at full tilt.
Check out this chart of nuclear outages from the US Power Data Administration. There are some days, particularly on the top of summer time, when outages are low, and practically all industrial reactors within the US are working at practically full capability. On July 28 of this 12 months, the fleet was working at 99.6%. Examine that with the 77.6% of capability on October 18, as reactors had been taken offline for refueling and upkeep. Now we’re heading into one other busy season, when reactors are coming again on-line and shutdowns are coming into one other low level.
That’s to not say all outages are deliberate. On the Sequoyah nuclear energy plant in Tennessee, a generator failure in July 2024 took considered one of two reactors offline, an outage that lasted practically a 12 months. (The utility additionally did some upkeep throughout that point to prolong the lifetime of the plant.) Then, simply days after that reactor began again up, your complete plant needed to shut down due to low water ranges.
And who can overlook the incident earlier this 12 months when jellyfish wreaked havoc on not one however two nuclear energy vegetation in France? Within the second occasion, the squishy creatures obtained into the filters of kit that sucks water out of the English Channel for cooling on the Paluel nuclear plant. They compelled the plant to chop output by practically half, although it was restored inside days.
