Energy From Thorium Discussion Forum

It is currently Sep 26, 2018 5:56 am

All times are UTC - 6 hours [ DST ]




Post new topic Reply to topic  [ 94 posts ]  Go to page Previous  1 ... 3, 4, 5, 6, 7
Author Message
PostPosted: Jul 20, 2014 2:10 pm 
Offline
User avatar

Joined: May 24, 2009 4:42 am
Posts: 823
Location: Calgary, Alberta
jaro wrote:
Those Ansaldo isolation condensers do indeed look like Candu feeder headers.
Apparently they intend to use them on the Alfred lead-cooled fast reactor, to be built in Romania.
If this type of design does in fact do the job, then good for them.
But it doesn't look like the right kind of technology for much larger power plants (Alfred is only 150MWe/400MWth). Relatively few tubes of large diameter, instead of large numbers of small tubes..... the latter requires different technology.

This looks very intriguing, but I really don't like the large diameter heavy wall headers top and bottom that is a bad design from the thermal stress/strain/low cycle fatigue perspective. Much better to have just one row of tubes per small bore header (use same dia as supply pipe), and then add header/tube sets to achieve the required thermal capacity.


Top
 Profile  
 
PostPosted: Jul 22, 2014 3:23 am 
Offline

Joined: Jul 14, 2008 3:12 pm
Posts: 5045
Quote:
in those conditions NACC would actually float to the top, for two reasons, one is the marginal efficiency of NACC on gas is very high rivalling the most efficient CCGT plants today


Point granted - if natural gas prices are still reasonable compared to competitors. If natural gas costs too much the whole concept may sink because we don't want to use gas peaking at all. There may be a point where hydro, pumped hydro, adiabatic CAES and such will be more attractive. On the other hand we may methanize coal if natgas prices are consistently high so then it might work (with the climate being the big loser).

Quote:
For NACC you need to recall this analogy, Cyril and Lindsay walking in the beautiful Canadian wilderness, they stumble across a very mean and hungry Grizzly Bear. Does Cyril have to run faster than a grizzly to survive, no, just faster than Lindsay


In that case, you've had it, I'm a pretty fast sprinter. :lol:

Still, better to shoot the bear so that we can have a beer together and laugh.

Joking aside, I really hope this NACC concept (especially PB-FHR Mk1) gets funding, its better than endlessly building CCGTs and hope for gas prices to stay low.


Top
 Profile  
 
PostPosted: Jul 22, 2014 3:27 am 
Offline

Joined: Jul 14, 2008 3:12 pm
Posts: 5045
Lindsay wrote:
jaro wrote:
Those Ansaldo isolation condensers do indeed look like Candu feeder headers.
Apparently they intend to use them on the Alfred lead-cooled fast reactor, to be built in Romania.
If this type of design does in fact do the job, then good for them.
But it doesn't look like the right kind of technology for much larger power plants (Alfred is only 150MWe/400MWth). Relatively few tubes of large diameter, instead of large numbers of small tubes..... the latter requires different technology.

This looks very intriguing, but I really don't like the large diameter heavy wall headers top and bottom that is a bad design from the thermal stress/strain/low cycle fatigue perspective. Much better to have just one row of tubes per small bore header (use same dia as supply pipe), and then add header/tube sets to achieve the required thermal capacity.


I believe such a design is perfectly feasible, as the headers can be fully (and perhaps even doubly) thermally sleeved without excessive cost or complexity.

However, Jack Devanney pointed out a potential problem for power generation with this arrangement: the tube length varies with big drums. Not a problem for ECCS/PCCS (isolation condenser, passive cooling condenser in ESBWR). Nor for CANDU since they headers don't transfer heat. But a downside for power generation HX application where we really want uniform temperature. Still I suppose you can have efficient mixing since hot water has low viscosity and if you thermally sleeve everything, high freq. thermal cycling/fatigue would be eliminated.


Top
 Profile  
 
PostPosted: Jul 29, 2014 11:30 pm 
Offline
User avatar

Joined: May 24, 2009 4:42 am
Posts: 823
Location: Calgary, Alberta
Cyril R wrote:
Joking aside, I really hope this NACC concept (especially PB-FHR Mk1) gets funding, its better than endlessly building CCGTs and hope for gas prices to stay low.
I'm confident that you'd be safe, and the bear well fed :lol: . Re PB-FHR, I wish them every success, it has always been my hope that they would get a foot in the regulatory door that we can follow with fluid fuelled reactors based on molten salts.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 94 posts ]  Go to page Previous  1 ... 3, 4, 5, 6, 7

All times are UTC - 6 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group