Didcot Power Station - events and incidents, ongoing discussion

[whole diary]

[ChrisB]

If they are really worried about people watching from their homes ending up in a dust cloud, I hope they have plans to come round and clear it all up afterwards.

Apparently so - jet washers everywhere, including the railway if you believe some gumph I was reading earlier

[Electric train]

As long as the blasting don't disturb my slumber in East Berkshire .............. am I bothered ........................................... No 

[bobm]

From the BBC^» (British Broadcasting Corporation - home page)

Major fire at Didcot B power station
 
A major fire has broken out at Didcot B Power Station, Oxfordshire Fire and Rescue has said.

The gas-burning power station has been in operation since 1997 and can supply the power to up to one million households, according to energy company RWE npower.

The neighbouring Didcot A power station was closed last year, with three of its enormous cooling towers demolished in July.

[JayMac]

A Picture from the Oxford Mail:



Reported to be one of the row of cooling towers at Didcot B that is ablaze.

[JayMac]

According to Sky News, fire is now under control.

[TonyK]

Probably no effect on rail services tomorrow, then, but still worrying. That's 1.36GWe of capacity, needed for when Hurricane Gonzalo moves on and leaves the wind turbines alone, currently offline. Wind is showing nearly 20% of the share on Gridwatch - it rarely reaches double figures, and demand is low tonight. CEGB have been using the pumped storage at Dinorwig despite the low demand. More gas will be called for, but I should think extra shovels of coal, still the biggest source of energy, will be needed.

I have just read the earlier posts about the cooling towers demolition for the first time - interesting. I went to see a former bonded tobacco warehouse at Canons Marsh in Bristol get blown up, at 7am one Sunday. It was heaving with people. Friends had a breakfast barbeque. It went down eerily quietly compared to the maroon fired on the rooftop to frighten the birds away, and the whole place began to smell of old Woodbines. There was no attempt to stop people seeing it, and the footage was used as the title sequence for Children in Need's TV appeal. People will always gather to watch such epic demolitions.

The Didcot towers were demolished by explosion, not the style of the late Fred Dibnah. His way of demolishing a chimney was to make a hole at the foot of the chimney, shoring it up with timber. Once he reckoned he had done enough, he would simply light a fire to burn away the timbers. See this Youtube clip. It couldn't have worked on a cooling tower.

Didcot power station is, as was said, visible from miles around. It is marked on the southern England aeronautical chart as a visual reporting point, especially useful because of nearby (in aviation terms) Brize Norton. I'll watch for when it is withdrawn.

[JayMac]

I believe Didcot B can be run at half capacity. It is effectively two separate power stations each capable of generating 680MWe. As long as the fire was contained within one of the two cooling tower runs then the other half of the station should be able to continue generation.

[Chris from Nailsea]

Reported to be one of the row of cooling towers at Didcot B that is ablaze.

That's so not cool. 

[TonyK]

That's so not cool. 

And I'm not sure they are cooling towers either, but seemingly the turbine exhausts. It's hard to see what could burn in an undemolished cooling tower - they are typically brick built, and used to rapidly cool surplus hot water. BNM is right - there are two matched power generators. There always seems to be - I don't now if this means one can run independently, but there will be a big inspection of everything before anyone presses a start button.

[stuving]

That's so not cool. 

And they ain't no cooling towers either, but seemingly the turbine exhausts. It's hard to see what could burn in an undemolished cooling tower - they are typically brick built, and used to rapidly cool surplus hot water. BNM is right - there are two matched power generators. There always seems to be - I don't now if this means one can run independently, but there will be a big inspection of everything before anyone presses a start button.

If you have huge flames coming out of a turbine exhaust, does that not suggest the turbine is on fire? Or, rather a lot more on fire than it was designed to be?

[JayMac]

The turbine exhausts are the two large chimneys at Didcot B. The station is of a type known as a Combined Cycle Gas Turbine.

Gas/air mixture is fired in a combustion chamber which produces a force to turn the turbine connected to the primary generator. Heat from this process is then drawn off to make steam in a Heat Recovery Steam Generator, with remaining gases exhausted through the two large chimneys. A steam turbine connected to a secondary generator produces further electricity from this steam. Exhaust steam passes through a condenser producing water that is returned to the HRSG. The banks of cooling towers are used to cool this water.

Those cooling towers have large fans to draw in air. It could be (pure speculation on my part) that one of the motors for these fans caught fire.


Basic details of the generating process at Didcot B:
http://www.rwe.com/web/cms/mediablob/en/97532/data/97538/4/rwe-npower/about-us/our-businesses/power-generation/didcot/dl-leaf.pdf#page=12


EDIT to add: Just heard on the radio a spokesperson from RWE (Didcot's owners) saying that the fire was contained in one of the cooling modules and had not spread to any other part of the station.

[Chris from Nailsea]

I went to see a former bonded tobacco warehouse at Canons Marsh in Bristol get blown up, at 7am one Sunday. It was heaving with people. Friends had a breakfast barbeque. It went down eerily quietly compared to the maroon fired on the rooftop to frighten the birds away, and the whole place began to smell of old Woodbines. There was no attempt to stop people seeing it, and the footage was used as the title sequence for Children in Need's TV appeal. People will always gather to watch such epic demolitions.

Indeed they did.  It was 29 May 1988 - and I, too, was there (in an official capacity). 

[LiskeardRich]

http://www.bbc.co.uk/news/uk-england-29684205

Fire crews are battling a major blaze at Didcot B Power Station, Oxfordshire Fire and Rescue has said.

Twenty fire appliances are at the scene, which broke out in one of the cooling towers.

Energy company RWE npower, which owns the gas-burning power station, has said the fire is now under control and there have been no injuries.

Police have warned local people to stay indoors and close their doors and windows.

Oxfordshire Fire and Rescue said 60 firefighters were called to the site. The plant was shut down and all areas isolated before crews moved in to tackle the fire.

It is not being treated as arson, the fire service said.

A spokesman for RWE npower said: "We can confirm that no one is injured which is clearly the most important thing and also that the fire is now under control.

"Obviously the plant has been shut down."

He said it was "too early to say" how much damage had been caused, adding that there would have been "about a dozen" people on site when the fire broke out.


Local people were warned to stay indoors and close doors and windows
Georgina Miles, who lives half a mile away, said the fire was "huge" but the flames had become smaller since firefighters had arrived.

"It was pretty dramatic; there was a lot of damage," Ms Miles said.

Zainab Mirmalek, who lives opposite the power station, said: "There's lots of water gushing down on it, lots of smoke and steam but the fire is definitely under control now."

Fellow Didcot resident Leila Qureshi said: "We got quite near before the road was shut.

"The fire was ferocious. You could feel the heat and smell it."

Emergency service personnel from Buckinghamshire Fire & Rescue Service, Thames Valley Police and the National Police Air Service (NPAS) have all been called in to help with the blaze.

The power station has been in operation since 1997 and can supply power to up to one million homes, according to RWE npower.

The neighbouring coal-powered Didcot A power station was closed last year.

Hundreds of people gathered to watch when three of its enormous cooling towers were demolished in July.

[stuving]

The turbine exhausts are the two large chimneys at Didcot B. The station is of a type known as a Combined Cycle Gas Turbine.
...
Those cooling towers have large fans to draw in air. It could be (pure speculation on my part) that one of the motors for these fans caught fire.

Basic details of the generating process at Didcot B:
http://www.rwe.com/web/cms/mediablob/en/97532/data/97538/4/rwe-npower/about-us/our-businesses/power-generation/didcot/dl-leaf.pdf#page=12

Yes, I was trying to remember the layout of one of these CCGTs^▸ (Combined Cycle Gas Turbine) while in the bath - unsuccessfully. However I did conclude that a fault in a fan motor might start a fire, but I don't think it has enough fuel in it to give much of a blaze.

But that description says:

Warmed river water from the condenser passes to 31 low-level cooling towers. The river water passes through side radiators, cascades through plastic packing, and is cooled by a stream of cold air. The air is drawn in by low-noise fans, which are set in the top of the cooling towers.

"Plastic packing" ... and there is a picture of these "towers" - made of wood! Plenty to burn there.

(Note: these towers, like Didcot A's, cool river water not steam cycle water and use evaporation to do so.)

[JayMac]

(Note: these towers, like Didcot A's, cool river water not steam cycle water and use evaporation to do so.)

Indeed. I missed that bit when reading earlier then summarising here. The steam cycle water stays in the system in a continuous loop. Improved summary:

1. A gas/air mixture is combusted which powers a gas turbine connected to an electricity generator.
2. The majority of the hot gases from this combustion are captured rather than exhausted and used to make steam in a steam generator.
3. The steam drives a steam turbine, either connected to a second electricity generator, or on the same shaft as the gas turbine.
4. The steam then passes through a condenser.
5. Cold river water is pumped through the condenser, cooling the steam.
6. The cooled steam cycle water is then returned to storage tanks ready for use in the steam generator again.
7. The river water, now hot after heat transfer in the condenser, is pumped through the cooling towers.

All told it is a pretty clever system to get as much leccy as possible from the energy source.