# Babcock & Wilcox 125MW(e) reactor

1. Jun 11, 2009

### mheslep

B&W just announced a small 125MW(e) LWR using 5% enriched PWR fuel. Not certified yet. Still not very cheap (at least in the US) at $5000/kW, though with 1/10th the investment of the Westinghouse AP1000 designs perhaps more utilities will line up. The catch would be insuring that the red tape costs per site also scale down, which I http://www.cleveland.com/ohio-utilities/index.ssf/2009/06/new_nuclearl.html" [Broken]. One aspect of the smaller scale that jumps out is that alleviates the problem of casting the huge containment vessels of 1100MWe designs (which, what, as discussed in PF only a foundry in Japan still has the online capacity to make?) http://www.babcock.com/library/pdf/mpower.pdf [Broken] http://atomicinsights.blogspot.com/2009/06/b-mpower-tm-reactor-who-says-america-is.html http://blogs.wsj.com/environmentalcapital/2009/06/11/honey-i-shrunk-the-reactor-small-nukes-arrive/ Correction: B&W says the price is less than the$5k/kW cited for larger designs, but says no more than that.

Last edited by a moderator: May 4, 2017
2. Jun 11, 2009

### signerror

Actually, that should read less than \$5 million / MWe. The figure must be a translation error.

3. Jun 11, 2009

### Morbius

mheslep,

I think you mean casting of the "reactor vessel" not the containment.

A reactor vessel is cast; a containment is not - it is built on site, and is not a single piece.

Even the containment vessels for university research reactors are not cast as a single piece.

Dr. Gregory Greenman
Physicist

4. Jun 11, 2009

### mheslep

Yes as you say.

5. Jun 11, 2009

### mheslep

Yep, thanks, corrected.

6. Jun 12, 2009

### gmax137

Whaaa? Reactor vessels are fabricated by welding up forged plates. Forging is required to get the required toughness.

An interesting note, the new replacement vessel heads coming out of Japan are ONE PIECE forgings - the older (original) heads by CE, B&W, and CB&I were welded up from several 'gores' and a top dome. The japanese must have forging presses that dwarf the ones we had in Chattanooga, etc.

That's right. Steel containments are also fabricated by welding up forged plate. I guess a concrete containment is 'cast' - but even most(?) of those have a welded up liner plate that actually forms the 'containment.'

7. Jun 19, 2009

### joelupchurch

I wrote about the mPower in my blog. I thought the fact that is supposed to built underground is interesting. I suspect this is in response to the NRC rule that the containment has to withstand a direct hit by a jetliner.

I think there are several companies that make reactor vessels, but the back log is about 3 years.

There is also an article about the mPower in the MIT Technology review.
http://www.technologyreview.com/energy/22867/" [Broken]

Here is what I wrote:
http://www.anupchurchchrestomathy.com/2009/06/babcock-wilcox-mpower-reactor.html" [Broken]

Last edited by a moderator: May 4, 2017
8. Jun 19, 2009

### mheslep

My take was not hardening to an attack, but rather placing the entire reactor under ground eliminated some of the containment structure and costs, as well as simplifying emergency cases - close the lid and a catastrophic fire must suffocate. This would be possible because of the size and elongated geometry of the B&W design, where as placing a full size AP1000 underground would be impractical.

9. Jun 19, 2009

### joelupchurch

I agree that the issue is cost. Assuming the containment has to jetliner safe, then you save even more money.

I'm a little concerned that building it underground will be problematical in some areas. If you build one here in Orlando, you better have one heck of a sump pump.

10. Jun 22, 2009

### gmax137

I'm not sure if building an AP1000 underground is even theoretically possible - the passive basis for the design relies on natural circulation flow of ambient air around (up) the containment outer surface to remove decay heat in the long-term. So if the unit is underground, the air flow would have to be down and then up - I guess maybe you could build it inside a huge "hill" with big air ducts to bring air in (radially) to the bottom of the containment, but then what would be the point?

Also, I'm not sure what is the 'catastrophic fire' that needs smothering? There isn't anything outside the structure necessary to prevent core damage.

11. Jun 22, 2009

### Astronuc

Staff Emeritus
Japan Steel Works, Ltd is the place to get one's PV head and PV. They are currently the one supplying the world industry.
http://www.jsw.co.jp/en/guide/product_steel.html
http://www.jsw.co.jp/en/guide/facilities.html

http://www.jsw.co.jp/en/guide/pdf/JSW_MuroranE.pdf

I believe the Muroran plant is the one that supplies NPV's and RCS components.
The have the big forging presses and big furnaces
l20-ton electric arc furnace / 100-ton electro-slag remelting furnace / 5-ton vacuum induction melting furnace / 3,000~14,000-ton forging presses / 30,000 horse power 4-thick plate reversing rolling mill / 12,000-ton pipe forming press / Low-frequency quenching equipment / Machining tools / 70~730-ton wharf cranes

Putting a small unit underground is not so bad. Putting a large unit like AP-1000 fully underground would raise concerns of flooding and seismic impact, depending on the location.

12. Jun 23, 2009

### mheslep

Not to protect the structure, but to prevent a fire from venting radiation ala the Chernobyl fire, that's my guess

13. Jun 23, 2009

### mheslep

i.e. a garage hobby shop then?