In the U.S., coal-fired power plants operate at around 60% capacity factor, and nuclear plants at nearly 90% (Source.)
The CF for nuclear is much more complex when compared to other sources. The article he refers to only talks about the Capacity Factor whilst it is operating which is dependent on its 'Availability' and 'Utilization' of the power source over it's life time. If it has a capacity factor of 90% and an availability of 50% over its lifetime, as people like to point out in solar's case, then Nuclear's Total Capacity Factor is only 45%. They mention refueling, but for maintenance I've heard of some terrible availability numbers for Nuclear of around 38%.
I'm not sure if that is what you are referring to, however I do know it is typical of the kind of intellectual dis-honesty we see from the nuclear industry's PR machine to 'not mention that bit'. I did a search on nuclear reactor availability and 'utilization' which produced nothing. I'm not saying it isn't there, but it is not as easy to find as 'Capacity Factor'.
The whole 'Capacity Factor' measure used there not only bypasses that the maintenance on some reactor plants can take them offline for years but also fails to point out that the plant becomes a net consumer of electricity to maintain cooling of spent fuel and other things, effectively a negative CF when it is offline.
From my understanding though it goes beyond the refueling cycle, maintenance and, a reactor's availability. It's CF cannot be assessed as simply as other sources because it's it is impacted by its energetic inputs. You have to include and measure energetic inputs such as mining, processing and enriching the ore however you will not have a complete idea of how much energy you have spent on it until after the reactor has been decommissioned, it cools, it is disassembled and, stowed so that the active and activated radio-isotopes don't end up bio-accumulating in the environment.
I think the true measure is Net energy return because it's measuring all of the inputs and outputs. That would be a comparison worth seeing. I think some people can't seem to accept that these losses are a tangible part of the 'Total Lifetime Capacity Factor' of Nuclear energy because they get so fixated on the reactor and none of the supporting technology it requires.
It's great news for Wind power which Investors prefer over Nuclear because wind is a lower risk, more scale-able than nuclear and can have frequent technology improvements over it's life time.