900 Ton Containment Vessel Bottom Head Installed At Vogtle 3

Yesterday, Georgia Power announced that they successfully lifted the first part of the Vogtle Unit 3 containment vessel into place. From World Nuclear News: "The component — measuring almost 40 meters wide, 12 meters tall and weighing over 900 tons — was assembled on-site from pre-fabricated steel plates. The cradle for the containment vessel was put in place on the unit's nuclear island in April. The completed bottom head was raised by a heavy lift derrick and placed on the cradle on 1 June, Georgia Power announced." Georgia Power has a pretty cool gallery of high resolution construction photos (the bottom head is the background on my XBMC machine). Below the fold there is a video of the crane moving the bottom head into place.

Comments

Bottom head?

[MetalliQaZ]

Am I supposed to know what they are talking about here? Where is this going? Why? What is a bottom head used for? Vogtle Unit 3?? I feel like Lord Helmet in Spaceballs shouting "WHO??" in confusion just before his mask falls.

Re:Bottom head?

[cheesybagel]

Unit 3 means it is the third reactor in the power plant. Vogtle is the name of the power plant (probably the name of the place it is located in). Apparently there are already 2 units installed there with Generation II reactors and they are now in the process of construction another two units with Generation III reactors of the Westinghouse AP1000 design.

Re:Bottom head?

[firewrought]

Unit 3 means it is the third reactor in the power plant. Vogtle is the name of the power plant (probably the name of the place it is located in). Apparently there are already 2 units installed there with Generation II reactors and they are now in the process of construction another two units with Generation III reactors of the Westinghouse AP1000 design.

Vogtle was President/Chairman of Southern Company, Georgia Power's parent company. (Southern tends to name most of their plants after company bigwigs.) Apparently, he was a real POW who inspired the motorcycle dude in The Great Escape.

Re:Nuclear Wessel?

[flayzernax]

http://en.wikipedia.org/wiki/Vogtle_Electric_Generating_Plant#Units_3_and_4

http://en.wikipedia.org/wiki/AP1000

http://www.ap1000.westinghousenuclear.com/

I'm glad their going ahead with this design. Hopefully it's good. I live on the same geographic sub unit. Though I won't benefit from this probably because the energy produced there is never coming this way.

It is not the perfect design perhaps. But its updated compared to the ones people were raving about in the 60's and 70's.

What? Where?

[wonkey_monkey]

Yesterday, Georgia Power announced that they successfully lifted the first part of the Vogtle Unit 3 containment vessel into place.

Ah, good. What? This is presumably something to do with nuclear power - as it's come from Nuclear World News - but are they building a reactor or a waste site?

Is this Georgia, the U.S. state? Or Georgia the country, perhaps? Or is it actually somewhere completely unrelated to anywhere called Georgia, but where the company called Georgia Power just happen to be working?

When I was a rugrat, "bottom head" was just something I called my brother when he was being mean.

Re:What? Where?

[malakai]

The key points missing from this summary is that this is the first Generation III+ reactor being built in the US. The only reason it was allowed to be built was it's an existing site, and had already planned reactor 3 and 4. There's still a general no build moratorium on new reactor sites in the US.

This is the AP1000 which is sort of the "So you want to run a nuclear reactor, For Dummies" type of reactor.

They are very difficult to break. Even if operators do nothing, the reactor will go through a set of procedures ( at times with explosive bolts) to disable the reaction and cool for 72 hours. After that, a helicopter will need to drop water on the top of the tank to keep the gravity well fed.

See more info here on wiki .

Re:What? Where?

[Antipater]

The Vogtle complex is a group of nuclear reactors in Georgia, the US state, at the border with South Carolina. There are 2 older-generation plants operating there already (1.2GW capacity each), and Georgia Power is building two more using Westinghouse's AP1000 design. These are the first new nuclear power plants built in the US since Three Mile Island.

The bottom head is, more or less, the reactor's "floor".

Re:Crane

[Antipater]

/highfive

As someone who works on cranes myself, I was more interested in the lift than in the actual thing being constructed. Got any specs on that sheerleg? It looks like a monster. My eyes aren't good enough to count the number of falls, but just the boom structure has me ballparking its capacity at what, 2000 tons?

Re:On time and on budget

[cheesybagel]

About the only place that builds nuclear power plants on time is South Korea. This is probably because of permission issues. It also helps they have a large naval construction industry that can build the required steel pressure vessels. Sometimes the problems are due to licensing issues, and lawsuits stalling construction. Other times there isn't enough financing to build it at the originally planned speed. Then there are the issues with happen when you are building any new kind of reactor with untrained personnel. This is the first AP1000 reactor being built in the US (although there are a couple under construction in China for quite some time now).

Re:Crane

[Antipater]

Let's not forget the advanced fluginflappin or the over _200_ thonkcount on that sucker! Also, another thing that's advanced and in the know crane related talk!

A sheerleg is a floating crane - basically a flat barge with lots of ballast tanks to keep itself balanced while it lifts superheavy things. Rather than a previously-constructed ship that then has a crane stuck on top, the ship is the crane.

The number of falls is the number of times (plus one) that the cable is wrapped around a sheave (a pulley). Simple machines - a 2-fall crane can lift twice as much as a 1-fall crane, but uses a longer cable to do so. So cranes that have to lower things down to the seafloor generally have only one or two falls, while cranes for land or low-depth heavy lifting can have as many as 32.

The boom is the big ol' steel truss structure that everything hangs off of.

A note on capacities and this lift - 900 tons is a big lift, but not an amazingly big one. The average capacity of a heavy-lift mast crane is 600-800 tons in my experience, but can easily go into the thousands. Anything above 1000 is pretty sizeable, 2000 or more is pretty darn huge. The largest I've seen is 5000, the largest I can Google is 8700.