Hum... my first observation on that link is that the author 'evaluates' the colour coding, without noticing that the temperature scale changes... The second is that 'hot spot' locations don't seem to be fixed. The third is that according to the AREVA slides, the open reactor well is filled with water.

I also suspect that there is no direct temperature observation of the SFP on the thermograms (possibly due to the water vapour over it): the pond should be boiling or near boiling temperature, not 30-47°C.

_{*Lunatic*, n.
One whose delusions are out of fashion.}

lol

could be radiation powers EVERYTHING by then...
some lichens'll prolly make it ok

'The history of public debt is full of irony. It rarely follows our ideas of order and justice.' Thomas Piketty

Who says they are of iron?

"Rusty". Red coloured rust is the oxidation of iron. The oxides of other metals have different colours, for example, zirconium oxide (the oxide of zirconium, the material of the cladding of the fuel rods) is white. Zirconium itself and zircaloy is metallic (see photo in your link).

How long reactor rods would glow red?

They would glow red until short half-life breakdown products of uranium decay enough for surface temperatures to drop below c. 600°C. They would heat up way past that. For scale, according to slide 19 of the Mathias Braun/Areva presentation, the core of No. 3 reached 1,800°C when left exposed for 7 hours, and the core of No. 1, which was exposed for 27 hours, even reached 2,700°C.

The above is rods from the core; but I see now that your link hypothesizes rods from spent fuel pools, which is indeed more in line with the location of the photo next to No. 4. Those rods would likely not glow, but they would not be 'rusty' either. Also, I doubt that the fuel rod assemblies and the fuel rods themselves would stay intact upon impact after falling dozens of metres (again see the fuel rod photos in your link).

_{*Lunatic*, n.
One whose delusions are out of fashion.}