NukeWorker Forum
News and Discussions => History & Trivia => Topic started by: wlrun3@aol.com on Aug 08, 2007, 11:34
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The Hope Creek (1986 1100 MW BWR 4 Mark 1 Ctmt) reactor containment building looks like a PWR containment.
Why? Is it unique?
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Depends on how you mean "unique". The BWR 6 Mark III containments also look like PWR containments.
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Big Rock Point (don't know the model but it was AEC license #3, I think) had a spherical containment and it was a BWR (well, sort of... the boiling took place in a steam drum.) Clinton has a containment dome and is a boiler. So unique? No. Different, yes.
When Hope Creek was being built it, like many other single unit plants, was going to be two units. When they cancelled unit 2, they upgraded unit 1 to the next larger model reactor BUT THE DRYWELL WAS ALREADY BUILT! So they crammed a reactor and supporting systems into a drywell that was not designed to hold it. That is why there is no space inside. There are literally places a normal sized human being cannot get to in there. Very strange.
I did their first refueling outage and never went back. But I don't remembr it looking like a PWR from the outside.
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The Rx Bldgs at Hope Creek have two parts - actually only unit 1 has both parts. The square Rx bldg is outside a round building which extends above the roof of the square one. It does resemble a PWR from outside. The refuel floor even has a polar crane.
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The memory is the second thing to go and I can't remember what was first. Then again, the vast majority of the time I was at Salem, Hope Creek was just a drawing, not even a hole in the ground yet. I spent most of the outage at Hope Creek issuing instruments, keys, and respirators and covering waste solidification... long funny story.
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The Rx Bldgs at Hope Creek have two parts - actually only unit 1 has both parts. The square Rx bldg is outside a round building which extends above the roof of the square one. It does resemble a PWR from outside. The refuel floor even has a polar crane.
Thankyou Troy.
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BWR Containments...
Mark I is the Nitrogen inerted Drywell and Torus. The Lightbulb and the Donut inspired this design. These are inside an unremarkable pole barn called a Reactor Building. They are found at BWR 2s, 3s, and 4s. Dresden, Quad Cities, Pilgrim, Duane Arnold, Monticello and almost every body else have these.
Mark II is the vertical standpipe containment. They are also Nitrogen inerted. These are found at BWR 5s. In the Mark I and II the Drywell IS the Primary Containment. LaSalle, Columbia, NMP 2, and Susquehanna have these.
Mark III is the horizontal vent containment. These have a Drywell inside the Primary Containment. These are NOT inerted, you can tour the Primary Containment at power and look down (and hopefully see no bubbles) in the Suppression Pool. since they are not inerted, they have active Hydrogen control systems, such as igniters, mixers, and recombiners.
Some have Containment Spray (Clinton, Perry, Grand Gulf) Some do not (River Bend).
Why? Heck I don't know. Ask GE.
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http://en.wikipedia.org/wiki/Image:Hope_Creek-Salem_Nuclear.jpg#filelinks
This pic shows both HC and Salem. The BRT to the left is HC1. If HC2 had been completed, there would have been another to the left of it. The parts that were built are technically considered abandoned in place, mostly for property tax purposes, but they are still accessible and sometimes contain temporary office spaces and storage.
While several GE Bwr's have cylindrical Reactor Buildings, Hope Creek resembles a PWR containment mostly because of the curved, rather than flat, top of the building. This gives it the appearance of a dome structure that is usually associated with PWR's in the US.
Some totally useless trivia: The far northern tip of the artificial island (the part to the left of the HC cooling tower in the picture) is actually in Delaware by a few yards.
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BWR Containments...
Mark I is the Nitrogen inerted Drywell and Torus. The Lightbulb and the Donut inspired this design. These are inside an unremarkable pole barn called a Reactor Building. They are found at BWR 2s, 3s, and 4s. Dresden, Quad Cities, Pilgrim, Duane Arnold, Monticello and almost every body else have these.
Mark II is the vertical standpipe containment. They are also Nitrogen inerted. These are found at BWR 5s. In the Mark I and II the Drywell IS the Primary Containment. LaSalle, Columbia, NMP 2, and Susquehanna have these.
Mark III is the horizontal vent containment. These have a Drywell inside the Primary Containment. These are NOT inerted, you can tour the Primary Containment at power and look down (and hopefully see no bubbles) in the Suppression Pool. since they are not inerted, they have active Hydrogen control systems, such as igniters, mixers, and recombiners.
Some have Containment Spray (Clinton, Perry, Grand Gulf) Some do not (River Bend).
Why? Heck I don't know. Ask GE.
Excellent description. Thankyou.
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Big Rock Point (don't know the model but it was AEC license #3, I think) had a spherical containment and it was a BWR (well, sort of... the boiling took place in a steam drum.) Clinton has a containment dome and is a boiler. So unique? No. Different, yes.
When Hope Creek was being built it, like many other single unit plants, was going to be two units. When they cancelled unit 2, they upgraded unit 1 to the next larger model reactor BUT THE DRYWELL WAS ALREADY BUILT! So they crammed a reactor and supporting systems into a drywell that was not designed to hold it. That is why there is no space inside. There are literally places a normal sized human being cannot get to in there. Very strange.
I did their first refueling outage and never went back. But I don't remembr it looking like a PWR from the outside.
Actually when they upgrade to the next bigger reactor in a BWR the RPV size stays pretty much the same. The real reason many BWR Mark I Containments are so tight was TMI Mods. Fermi which is Hope Creeks size actually has a smaller drywell and was always designed to be a big plant.
Mike
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BWR Containments...
Mark I is the Nitrogen inerted Drywell and Torus. The Lightbulb and the Donut inspired this design. These are inside an unremarkable pole barn called a Reactor Building. They are found at BWR 2s, 3s, and 4s. Dresden, Quad Cities, Pilgrim, Duane Arnold, Monticello and almost every body else have these.
Mark II is the vertical standpipe containment. They are also Nitrogen inerted. These are found at BWR 5s. In the Mark I and II the Drywell IS the Primary Containment. LaSalle, Columbia, NMP 2, and Susquehanna have these.
Mark III is the horizontal vent containment. These have a Drywell inside the Primary Containment. These are NOT inerted, you can tour the Primary Containment at power and look down (and hopefully see no bubbles) in the Suppression Pool. since they are not inerted, they have active Hydrogen control systems, such as igniters, mixers, and recombiners.
Some have Containment Spray (Clinton, Perry, Grand Gulf) Some do not (River Bend).
Why? Heck I don't know. Ask GE.
In the Mark II the vertical standpipes would discharge into a suppression pool.
In the Mark I diagonal standpipes would discharge into the torus.
Am I right?
Please help me understand the phrase "horizontal vent containment" in the Mark III.
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Please help me understand the phrase "horizontal vent containment" in the Mark III.
Follow pathway 11-12-10 on the last page of the below pdf file. High pressure in the drywell pushes down on suppression pool water contained by the weir wall within the drywell, exposing a pathway through the horizontal vents into the suppression pool water of containment.
http://www.nrc.gov/reading-rm/basic-ref/teachers/03.pdf
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In the Mark II the vertical standpipes would discharge into a suppression pool.
In the Mark I diagonal standpipes would discharge into the torus.
Am I right?
Please help me understand the phrase "horizontal vent containment" in the Mark III.
On the Mark 1 NOT exactly. Coming from the Drywell into the Torus there are 8 Downcomers that are open to the airspace in the drywell. The number MIGHT vary, I just know the number from the later BWR 4s. These downcomers penetrate the torus and connect to what is called the Ring Header. The Ring Header is a 360 degree pipe inside the Torus. FRom the Ring Header there are 80 pipes each connect on the air side to the Ring Header and the Open End under water in the Torus. We called these pipes the Spider Legs. IIRC they connected to the Ring Header at about 135 Degrees and 225 Degrees as you looked at the Ring Header. They then left at about a 45 degree Angle then changed directions to straight down. NOW I'm stretching my memory here but IIRC the Tech Spec Torus level was based on maintaining the open end of the spider legs at least 3 feet 3 inches below minimum allowed Torus Level.
The Dynamics worked like this
Time zero: Big LOCA
T+5 Seconds: Steam Entering the Drywell starts forcing the Nitrogen in the Drywell into the Downcomers.
T+15 to 25 Seconds: The Nitrogen clears the bottom of the Spider Legs. Drywell reaches Max Pressure. The Nitrogen creates a large gas bubble on the bottom of the Torus which displaces all the water to the top which causes the torus to try to lift. The supports for the spider legs, ring header and vacuum breakers were based on the stresses this caused. The Torus itself was anchored to the floor of the Reactor Building every 90 degrees.
T+25: The Water then displaces the gas bubble, Steam from the Drywell starts condensing. Condensate Oscillations and Chugging starts Occurring at the ends of the spider legs causing them to sway.
T+30 to 35 Seconds: Drywell Pressure drops below Torus Pressure, Vacuum Breakers on the Top of the Ring Header Open to start transferring the Nitrogen gas in the top of the Torus back to the Drywell Via the Downcomers. You'll actually see these Vacuum Breakers cycling at Random due to Chugging in the Spider legs.
By about T+60 seconds at the LATEST you should see Drywell Pressure Stabilize at about 25 Pounds with Torus Pressure at about 23#. How fast it goes down from there depends on how much RHR is available for torus cooling and torus spray.
I might be off around 5 seconds on the later numbers.
Mike
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Follow pathway 11-12-10 on the last page of the below pdf file. High pressure in the drywell pushes down on suppression pool water contained by the weir wall within the drywell, exposing a pathway through the horizontal vents into the suppression pool water of containment.
http://www.nrc.gov/reading-rm/basic-ref/teachers/03.pdf
Exactly what I was looking for. Thankyou.
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Hope Creeks "can" is like few other Boilers because the original plans had it to built in a highly populated area of North Jersey. Word has it that there will be a fourth unit constructed on the island! Build it and they will come! Cant wait for another round of the Island 500!
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BWR Containments...
Mark I is the Nitrogen inerted Drywell and Torus. The Lightbulb and the Donut inspired this design. These are inside an unremarkable pole barn called a Reactor Building. They are found at BWR 2s, 3s, and 4s. Dresden, Quad Cities, Pilgrim, Duane Arnold, Monticello and almost every body else have these.
Mark II is the vertical standpipe containment. They are also Nitrogen inerted. These are found at BWR 5s. In the Mark I and II the Drywell IS the Primary Containment. LaSalle, Columbia, NMP 2, and Susquehanna have these.
Mark III is the horizontal vent containment. These have a Drywell inside the Primary Containment. These are NOT inerted, you can tour the Primary Containment at power and look down (and hopefully see no bubbles) in the Suppression Pool. since they are not inerted, they have active Hydrogen control systems, such as igniters, mixers, and recombiners.
Some have Containment Spray (Clinton, Perry, Grand Gulf) Some do not (River Bend).
Why? Heck I don't know. Ask GE.
"3,4,5 Kiss Hymies Ass" 3 kW = 4 HP = 5 Amps at 480vac ...
"Hymie Rickover's Thumbrule for Interplanetary Power Conversion is more correctly 3,4,5,12,Kiss Hymies Ass Daily, with the 12 corresponding to DC Amps at Battery Voltage." rblinc
Thankyou, again.
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I can verify that is sux in that drywell!
Have not been in a worse one than Oyster Creek!
So they are on PAR with each other..same w/ the Area!