Power Plant Fire In Missouri

It was reported on the news tonight that the coal-fired Ameren power plant in Labadie Missouri had caught fire and a portion would be off line for some time. The cause was reported as a hydrogen leak.

Anthracite, is the Hydrogen a by-product of combustion or is this perhaps a gasification plant? I think that’s the correct term. Or perhaps the news reports are just incorrect?

Nope. The hydrogen is used to cool the generators. Hydrogen works great as a gaseous coolant (it’s not liquid hydrogen, it’s just normal hydrogen gas) and is not explosive…until it leaks and combines with air.

I know quite a bit about that plant - I’ll be calling there tomorrow in fact to see what the “Straight Dope” is on the incident…

First off, you are wondering…why use hydrogen to cool the generator? Simple:

  1. A gaseous coolant is needed, and
  2. Hydrogen gas has a very high specific heat. Meaning, it can soak up more heat per pound than any other common gas that can be used. Thus, it makes for efficient, high-performance coolant.

Now…what does a hydrogen cooling system consist of? Well…I’m glad you asked.
(public domain document, US Nuclear Regulatory Commission)

An example from a nuclear plant’s generator cooling, but coal systems are identical.

The business of consulting has involved me with much of the activity that surrounds a turbine deck during maintence periods. The pickle (rotor) will usually only be removed when recorded vibration has neared certain limits. Bearings, seals and such can be serviced without removing the pickle.

When a full disassembly is required, plus the servicing, and then reassembly, it is absolutely captivating for those who love mechanisms. Huge cranes, tremendous rigging, frightfully heavy components, and large burly men (petite women sometimes too) who manage to work as if repairing a Swiss watch.

Many pairs of eyes watch all aspects of the reassembly. Truly precise measurements are taken. Vast documentation occurs. The “what ifs” and “how abouts” require charts and tables and calculations to resolve. Items are x rayed. New, and verified hardware replaces some of the old. Asses, customers, and the NRC are covered and satisfied seven ways from Sunday. After final button-up, tests are performed.

But “stuff” happens.

Electronic “sniffers” can catch gas leaks in time, almost every time.

Sometimes, fault cannot be placed on human shoulders. The sequence of events that lead to mechanical failure are not always found in their entirety.

Looking forward to Anthracite’s findings.

Thank you both for the answers. I had no idea that the generators were cooled by hydrogen. I have passed the Labadie plant many times, usually across the river and it’s quite a landmark. Do most power plants use the same type of system?

As soon as I heard the report on the news, I knew where to go for answers.

I have visited both Bagnell Dam and Hoover Dam and cooling the generators was never mentioned, although a little thought would have made me realize it’s required.

Thanks again and I await further developments.

Most plants use hydrogen, but not all. The high-performance ones do.

My “sources” tell me there was a hydrogen fire and small explosion near the boiler feed pump turbine at the plant, and (reputedly) there is a hole in the turbine casing. If so, the unit will be down for some time…if I hear anymore info that I can repeat, I will post.

I’m glad I read this because I’m supposed to get samples of fly ash from Labadie on a regular basis (so they can keep selling it for TxDOT jobs) and I’ve had a whole lot of trouble in the past getting them to send me the samples they were supposed to (or getting them to return my phone calls even), and now I know why they won’t be sending me any for a while.

Well, it looks like the damage is a lot less severe than thought at first. The “hole” in the turbine magically changed into a hole in the hydrogen system, and supposedly there is a section of the turbine hall roof that is missing. The plant says they may get the Unit back online by the end of the week, however.

OK…my last post here unless someone else has a question. This is “unofficial” (but not confidential) from a friend at Amren, with some editing for clarity and emphasis added: