OT: Drax to be turned off whenever it's "too" windy or sunny

We used to build them where they were needed: Battersea, Bankside & Lot's Road in Central London for a start.

I was watching an interview with a chap (probably a nobody) who is proposing that Germany could recommission some of their nukes for under €1bn each

He also says the early German PWRs could ramp-up/down at about 12% of capacity per minute, and be run as "peaker" plants

What does Gridwatch show for Biomass overnight?

When does that happen ?

When does what happen?

Imagine sticking a 5GW nuclear power station in central london now.

Cant even get a third runway on heathrow after 30 years

Probably worth doing

All reactors can be run below max, but the nuclear reactions are difficult to manage if not designed for it

It runs flat out mostly, looks like power is reduced at around midnight

- 3 a m on some boilers

'Xenon poisoning makes it tricky' to run 'reactors in load following'.

And elsewhere, but I cant remember the source.

Yes, that mentions Xenon poisoning, extra control rods, transients when moving the control rods, but nothing about 'freshly fuelled' or 'until'.

Yup. It might have been something by Kathryn Porter TBH

This is more detailed- "Refuelling of fuel in the nuclear reactor is periodically performed for each fuel cycle. After each refuelling, the nuclear fuel needs to be conditioned. The conditioning of nuclear fuel limits the periods when load following is suitable. Therefore, the first period after a refuelling, only baseload operation should be performed. In addition, calibration of equipment is done during the conditioning. The conditioning typically takes around 7-14 days. Also, close to the end of the fuel cycle, flexible operation should be avoided due to a reduction in reactivity margins in the core and the conditioning of the existing fuel. This period can be up to a month or even longer. [4] It is also important to avoid load following when a fuel failure have been detected. This is due to previous experiences where even small temperature changes may lead to secondary damages of the fuel rods."

3 Load following is very uneconomic. The marginal cost of the fuel used to run the reactor is so low that nothing is saved by turning it down or off and it may well suffer increased wear.

So it can be done, but mostly if possible you dont.

That was before Mr Tesla 'invented' AC power distribution allowing them to be located away from where the electrons are needed.

The boilers run at nearly teh critical point for water, several hundred degC for best efficiency.

The generation of turbines of the vintage of Drax (660Mw) were built for a very small number of cold starts. they were generally used as base load (as nuclear are when they are working). For quick load changes they were sometimes run as rolling reserves (synced to mains but exitation reduced to give next to zero output). If turned off other than for major maintenance they were kept warm with steam.

Nearly right. T-hot is the temperature at which the boiler metalwork won't yield, T-min is teh temperature in the condenser. which is as close (or lower) than ambient as can be obtained. the condenser is cooled by sea water or river water, which is additionally cooled by evaporative cooling in the towers. I remeber when ferrybridge B (After C was in use) had its cooling towers removed (to reduce maintenance costs, the loss of cooling by just using river water was only a couple of percent, only in summer months with low river flow. As by then it was only used for peak winter demand it was insignificant.

That's why tehy use superheaters and reheaters, dry steam is essential.

If you look at the frenc hversion of gridwatch, the french often modulate their nuclear ouput down overnight, but only about the amount that we produce, about a tenth of their's. A problem of being mostly nuclear.

Your grasp of electrics is somewhat quaint, to say the least.

Battersea power station was first built in 1929 Tesla's AC machines were built in the late 1880s.

Long distance power transmission costs money. That fact has nothing to do with whether it's AC or DC.