Posted on 01/12/2017 11:45:30 PM PST by greeneyes
An explosion of Unit 1 of the J.M. Stuart Station shut down the coal-fired Ohio plant and injured six people. Officials at Dayton Power and Light have said they’re still determining the cause of the explosion at the 2,318-MW plant in Aberdeen, Ohio, reported the Ledger Independent.
(Excerpt) Read more at power-eng.com ...
What I have heard from others that work with that plant is it is looking like a steam explosion, but in a system outside the boiler.
This and the plant up river are both being targeted. No replacement facility is planned. This is one of the newest electric generating stations in America. We are in deep doo doo. (JMSS generates 0.5% of US total electric output.)
Judging from the damage outside, the explosion was underneath of the main turbine. This would indicate some sort of pipeline rupture, main steam or reheat line. This unit is 42 years old, the design life was 30 years.
I agree, it is all torn up under the turbine. The front wall is blown out in front of the maintenance pod. No one is saying much so it is hard to know. The whole plant may close because of this.
This is like our own Gov. Cueball raving that Indian Point in NY will be closed by 2021. It supplies about 1/4 to 1/3 of the power to NYC and surrounding areas.
It will be replaced by “Non CO2 producing Generation with no attending cost increases for the power”
LOL
Hell, some of the idiots here think the electric power from it is radioactive.
Creep failure on a main or reheat line?
The concept for NY is that they plan to buy power from Ontario Hydro and think the cost will not go up.. but as these Coal Fired units die or are forced off line, the crap is going to hit the fan. Stuart Station uses a technology that was introduced in the late 1950’s and 1960’s called Super Critical steam or Universal Pressure.
Stuart has Boilers designed by Babcock & Wilcox. Only about 120 of these units were ever built but they represent perhaps 20% - 25% of all of the generation in the United States. Unit 4 at Stuart Station is UP 106! This is what I mean. Unit 1 which blew up is UP 54, I believe. Unit 1 was built in 1965, Unit 4 - 1969. Most American coal fired generation is about this age or older.
Happened day before yesterday. The plant is on the Ohio river about an hour east of Cincinnati.
Well, it is more likely that it is a sort of stress/corrosion creep that occurs at corners and junctions where the stress intensity can be just a tad higher. You will see this form as radial cracks around opening for pressure sample points and such.. but if the crack is aligned with the run of the pipe then it can open up like a hot dog in time.
The steel used to make these high pressure lines has 2.5% Chrome and it is pretty creep resistant at temperatures around 1000 degrees which is the design temp for this sort of line. In the boiler itself, this material is run as high as 1150 but at a reduced life expectancy. To have a failure down near the Turbine would require some additional stress amplifier or stress/corrosion mechanism to get the ball rolling even at 40+ years. Unfortunately, this sort of thing is all too common.
This is not necessarily suspicious. There are a lot of explanations for an explosion at a coal fired power plant.
The Russians again
Methane is usually the ‘source of ignition’ and the real deadly punch is provided by the coal dust. As the explosion proceeds it gains strength as it proceeds outside the mine. The coal dust gains power as picks up more dust on the way out.
No, this is not at all suspicious. But, oddly, this event could prove devastating politically. Funny how that sort of thing is. This plant was already in trouble, facing being closed due to Obama’s promise to make the cost of Electric energy go up. This might be the nail that closes this plant permanently and almost a year early.
The impact of this on Ohio Congressional District #2 - Brad Wenstrup could be enormous. This is part of why Obama targeted these units along the Ohio River for closure. This is where all of those “bitter clingers” live. Stuart and Killen Station are about 1000 direct jobs in the two poorest Ohio Counties. There are about 2000 indirect jobs in Southern Ohio dependent on these Units and perhaps another 500-1000 Coal mining jobs as well.
Brown and Adams Counties are Purple not Red. Ohio 2nd for the moment is dominated by Clermont Country which is still BLOOD RED. But, Ohio 2nd also has a large number of voters in Hamilton County who are splitting 50/50 but trending blue. If Brown and Adams go Blue.. Ohio 2nd will flip. And, as this tragedy was designed to blow up in Wenstrup’s face, regardless of the explosion, this is now almost baked into the cards. Someone better wake up.
Or fairy dust in Bath House Barry’s case.
Gotta make ya wonder why there wasn’t at least a catastrophe per week back when miners were using carbide headlamps . . .
This wasn’t a coal explosion, at least not likely. That would have blown out the back of the plant where the coal grinding equipment is. It is right below the boiler and the coal pipes go up outside of the part of the plant where all of the damage is.
The damage is in an area below the main turbine floor called the mezzanine. Lots of pipes and stuff there but not really much machinery. There are high pressure feedwater heaters in this zone but they run cooler than the main steam and reheat steam lines or the turbine.
But, lots of things could be the cause, just not coal.. this is the least likely.
In the old days mines had fire bosses. The fire boss would go in first and would look for a high spot in the top, he would then burn off the methane with his lamp. I am 3rd generation miner and have heard all the old stories, and have done some dangerous stuff myself.
If it is a steam line it is possibly a high pressure steam to the turbine line or a reheat line to a low pressure turbine. Lots of pressure in them needs to be bled off through a dump line. If overpressure, he pop valves should have lifted first unless a bad weld gave way.
Other causes could be starting a coal pulverizer mill, hydrogen explosion in the generator.
***This unit is 42 years old, the design life was 30 years.***
At the end of their life such units are often rebuilt for another 30 years. Every five years we had a “Major” overhaul on our unit and every year a shut down for a “minor” overhaul of various equipment.
***called Super Critical steam or Universal Pressure.***
Would that be called a “Once Through” boiler with no reheat system? Lots of pressure and heat in them. Way more than than a regular “two stage” high press-reheat type boiler.
Always had big respect for the work they/you did, and was fortunate enough to not have to follow those footsteps.
Glad you're still with us.
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