Nuclear steam generators - Things are different in Canada

OVERKILL

$100 Site Donor 2021
Joined
Apr 28, 2008
Messages
50,184
Location
Ontario, Canada
Had an amusing exchange with an acquaintance of mine on Twitter this morning regarding the announcement of the 32 steam generators being shipped to Bruce B for the MCR project (refurbishment, life extension, uprates). Bruce Power had posted the below picture:
1601314277187.png


And he, being a former US plant operator, remarked at how small these were. He worked at a 2-unit plant with 2x940MWe reactors, each SG was good for roughly 500MWe, so 2xSG's per unit. The Bruce B units are 860MWe and each SG can support at least 108MWe, so 8xSG's per unit, 4 units per 4-pack.

I noted that if he thought these were small, at Pickering, each 516MWe unit has 12xSG's. He was gobsmacked. Hard to see, but in the below picture, #54, you can see 3x SG's in the cutaway on the right side with 6x in the non-cutaway section further back in the secondary containment structure.
E3CC08BA-80B1-45F6-9052-B57B93FAA3DA_1_105_c.jpeg


The CANDU 9's built at Darlington, which were based on the Bruce design, had an improved heat transfer loop configuration and half the number of SG's, so each unit at Darlington has 4 and they would of course be larger. Still twice the amount found in his US example. Interestingly, the SG's at Darlington were not replaced during the Unit 2 refurbishment and my understanding is that they were all deemed to be in sufficiently good condition to run until 2055 (targeted operating life at the moment) and beyond. But OPG hasn't pursued any uprates with Darlington, whereas Bruce is actively working to increase capacity to as close to 7,000MWe as possible.

Any nuke folks here, what's your SG config and count look like?
 
Joined
Sep 27, 2015
Messages
3,985
Location
USA
It's a different philosophy whether to (re)build the steam generator on site, as is necessary with a large one, or make it in a factory and install as a modular unit. Clearly those were designed to be just as large as they could transport by road on a flatbed truck.
 

OVERKILL

$100 Site Donor 2021
Thread starter
Joined
Apr 28, 2008
Messages
50,184
Location
Ontario, Canada
It's a different philosophy whether to (re)build the steam generator on site, as is necessary with a large one, or make it in a factory and install as a modular unit. Clearly those were designed to be just as large as they could transport by road on a flatbed truck.

That's a good thought. I assume the ones at Darlington, which are bigger, are also replaceable as my understanding is that they performed some extensive analysis on them prior to concluding that they would not need to be replaced as part of the refurbishment.

95% of the parts for both OPG's refurb of Darlington and Bruce's MCR project are produced in Ontario, so it's a pretty impressive industrial effort. These SG's are made in Cambridge, Ontario by BWXT Canada.
 
Joined
Sep 27, 2015
Messages
3,985
Location
USA
They really put a lot of writing on those. Somewhere on there it should say "Remove from wrapper before using."
 
Joined
Jul 8, 2012
Messages
4,541
Location
Nashville, TN via Memphis
Cool diagram! Thanks for posting that. Very educational for someone who's always been interested in how nuclear reactors work. I'll spend some time going through that site when I get a chance.
 
Top