Babcock & Wilcox 125MW(e) reactor

  • Thread starter Thread starter mheslep
  • Start date Start date
  • Tags Tags
    Reactor
Click For Summary

Discussion Overview

The discussion centers on the Babcock & Wilcox 125MW(e) reactor, specifically its design, cost, and implications for nuclear energy production. Participants explore technical aspects, manufacturing challenges, and regulatory considerations related to small modular reactors (SMRs), including the use of enriched fuel and containment structures.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants note that the reactor is designed to use 5% enriched PWR fuel and is not yet certified, with costs around $5000/kW, though B&W claims it is less than that for larger designs.
  • There is a correction regarding the cost, with some suggesting it should be less than $5 million/MWe due to a potential translation error.
  • Participants discuss the casting of reactor vessels versus containment structures, with some asserting that reactor vessels are fabricated from forged plates rather than cast as single pieces.
  • One participant mentions that the reactor is intended to be built underground, speculating this may relate to NRC regulations regarding containment safety against jetliner impacts.
  • Concerns are raised about the practicality of building larger reactors like the AP1000 underground, particularly regarding air circulation for cooling and potential flooding issues.
  • There is discussion about the manufacturing capabilities of Japan Steel Works, Ltd, particularly in producing large forgings for reactor components.
  • Some participants express uncertainty about the implications of underground construction, including potential flooding and seismic impacts, as well as the need for effective emergency measures.
  • One participant questions the nature of a 'catastrophic fire' that would need to be smothered, suggesting it may relate to preventing radiation release similar to the Chernobyl incident.

Areas of Agreement / Disagreement

Participants express multiple competing views on the technical aspects of reactor design, construction methods, and safety considerations. There is no clear consensus on the implications of underground construction or the specifics of reactor vessel fabrication.

Contextual Notes

Participants highlight limitations in understanding the manufacturing processes and regulatory implications, as well as uncertainties regarding the safety measures associated with underground reactor designs.

mheslep
Gold Member
Messages
373
Reaction score
714
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" . 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
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:
Engineering news on Phys.org
Actually, that should read less than $5 million / MWe. The figure must be a translation error.
 
mheslep said:
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?)
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
 
Morbius said:
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
Yes as you say.
 
signerror said:
Actually, that should read less than $5 million / MWe. The figure must be a translation error.
Yep, thanks, corrected.
 
Morbius said:
A reactor vessel is cast;

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.

...a containment is not [cast] - it is built on site, and is not a single piece.

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.'
 
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/"

Here is what I wrote:
http://www.anupchurchchrestomathy.com/2009/06/babcock-wilcox-mpower-reactor.html"
 
Last edited by a moderator:
joelupchurch said:
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.
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.
 
mheslep said:
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.

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
mheslep said:
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.

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
gmax137 said:
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.

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
gmax137 said:
...

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.
Not to protect the structure, but to prevent a fire from venting radiation ala the Chernobyl fire, that's my guess
 
  • #13
Astronuc said:
Japan Steel Works, Ltd ...
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..
i.e. a garage hobby shop then? :wink: