Ontario Nuclear update

OVERKILL

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A few updates for those interested:

Darlington:
- DNGS Unit 2 refurbishment: Construction is 100% done, so the unit will now go through hot testing then brought back into service for the next 35-40+ years.
- DNGS Unit 3 refurbishment: Turn-down has been postponed due to the current pandemic, so the unit continues to operate. Unit 2 may be back online before Unit 3 goes down now and so DNGS may have 4x units operating again for a period.
- DNGS Unit 1: Is now at almost 800 days of uninterrupted generation:
[Linked Image]


Credit to @TomHess_ on twitter for the above graphic, former grid operations at Ontario Hydro.

Bruce:
- Some notable uptimes as well including 300 days for Unit 7, 320 for Unit 3 and 591 for Unit 1.
- Unit 6 is down for refurbishment, so it will be absent for the next ~2 years
- Unit 4 is down for maintenance, will be back before the summer.
- Unit 2 was just returned to service after a 2-day maintenance outage so that it can run uninterrupted during the peak summer period.

Pickering:
- Unit 4 is pushing 600 days. Pickering Unit 7 previously held the world record for uptime at 894 days which may be eclipsed by Darlington Unit 1.
- Unit 1 has been offline for quite a stint. This is a refurbished unit, I expect it will be back before the summer.
- Unit 5 continues to produce significantly above nameplate for reasons that cannot be disclosed, but demonstrate that there is some significant uprate potential if the government were to reverse the decision on not to refurbish the 4x B units. I expect 575MW is not unrealistic per unit, which is a ~60MW uprate.
- The 6 operating units produced 23.6TWh in 2019, which is a record for the site in its current configuration and puts CF at ~88%, also a record for the site. While 88% may sound low based on CF for some American sites, Pickering is one of the oldest operating nuclear power plants in the world with construction starting in 1966. Its economics were predicated on a minimum CF of ~60%, much lower than its more modern siblings.

Prior to the current pandemic reliable sources told me to expect an announcement from the province for Darlington B. That has now obviously been postponed, hopefully not indefinitely. Expectation is that there will be an MOU for DNGS B to be constructed using the first viable design to distill out of the Federal SMR program running at Chalk River. DNGS B will be the first commercial SMR project in Canada most likely. The 2nd will be something at Point Lepreau in New Brunswick is my bet.
 
Looks to me as the plant operators seem to think this is a competition. Numbers, percentages, days.. . When will it result in Canada's Chernobyl?
Joking!
 
Originally Posted by skyactiv
Looks to me as the plant operators seem to think this is a competition. Numbers, percentages, days.. . When will it result in Canada's Chernobyl?
Joking!


LOL! When the CANDU was first developed the expectation was that since it could be refuelled online that it would be the longest running design, since it would only have maintenance, not refuelling outages. That has generally aligned quite well with reality, though it is currently another PHWR in India, essentially a CANDU rip-off, that holds the record.

Pickering and Darlington both operate in 100% baseload mode, so their CF can only be further improved with improved parts and management, increasing the time between maintenance outages. Bruce CF is impacted by what are referred to as "maneuvers" which is flexible operation, or curtailment of output, though it does this far less now than it did in the past due to some grid operations changes curtailing wind before nuclear now. What this means is that even though certain Bruce units would have been capable of close to 100% CF during a 365 day period, the output for that period won't be anywhere near 100% CF because it was reduced at times through the use of steam bypass.

For 2019 for example:
[Linked Image]


Look at Unit 1 then look at Unit 3. Unit's 2 and 3 seem to be the most commonly curtailed at the A site, units 5 and 7 at the B site. Each of the A units have the potential to produce ~6.87TWh, each of the B units 7.16TWh.
So, CF for the non or least curtailed units:
Unit 1: 98.7%
Unit 4: 88.9%
Unit 6: 90.8%
Unit 8: 98.9%
 
Amazing. Still remember visiting DNGS in May, 1992, and being told that the multi-billion dollar plant, paying 8-10% (or higher) interest at the time, was not running because of cracks in turbines. Glad to hear they finally were able to turn that around.

Have they developed any 'permanent' fixes for the pressure tube cracking issues, or are they going to need to do another round of replacements before the next 40 years is up?

That's an awfully optimistic view of whether Ontario, let alone New Brunswick, will pursue new nuclear units.
 
Originally Posted by Y_K
Thank you. What are you paying per kW there please?


Too bloody much, LOL! Though that's mostly due to fixed-rate contracts signed by the previous two administrations that grossly overpay for unreliable supply and then reliable supply to back it up (gas). Current rate for OPG Nuclear is $0.09/kWh, Bruce Power is $0.077 and slated to remain at that price for decades, likely making it the cheapest form of electricity in the province at some point. Bruce has an official projected EOL of 2064, but that will almost assuredly get extended, as will Darlington's as the replacement fuel channels and pressure tubes being fitted to the units at Darlington and Bruce are of an improved design and are supposed to have a significantly longer service life. If that's the case, we may see 45+ years out of these new tubes. I don't think getting >100 years out of Bruce is being overly optimistic.

Average cost of supply in the province is $0.128/kWh, but 85% of that supply is at $0.09/kWh and below.

[Linked Image]
 
Originally Posted by pitzel
Amazing. Still remember visiting DNGS in May, 1992, and being told that the multi-billion dollar plant, paying 8-10% (or higher) interest at the time, was not running because of cracks in turbines. Glad to hear they finally were able to turn that around.

Have they developed any 'permanent' fixes for the pressure tube cracking issues, or are they going to need to do another round of replacements before the next 40 years is up?

That's an awfully optimistic view of whether Ontario, let alone New Brunswick, will pursue new nuclear units.


The big delay for Darlington was a post-Chernobyl pause put on the industry which also unfortunately stopped the B site from being built immediately after. It was supposed to be an 8-unit site like Pickering and Bruce.

Regarding pressure tubes, yes, all of that has been long sorted and never became a problem at Darlington. They introduced additional spacers between the calandria tubes and the pressure tubes, as it was them migrating to the far end due to water flow that caused contact between the two, which led to hardening and cracking and I believe resulted in a failure at Bruce A. They have probes now that go into the tubes during maintenance outages and check for the proper positioning of the spacers and use pulses to bump them back into place if they've migrated.

The pressure tube issues at Pickering (which led to one of the entire 4-packs getting a re-tube back in the 1980's IIRC) was a separate materials issue, and was therefore never was a problem at Bruce, Darlington or the other Pickering 4-pack AFAIK.

Regarding the pursuit of new nuclear units, this is a result of the Federal SMR initiative: https://smrroadmap.ca which OPG, Bruce Power, NB Power and myriad other entities are invested in. OPG-sponsored GFP/USNC is already at the Environmental Assessment stage for their MMR reactor, which will be the first design constructed at Chalk River and is designed to run mining sites and remote communities. NB Power has MOU's already with Moltex and another party for new builds at Point Lepreau.

While it tends to be a little out of date, the Canadian Nuclear Safety Commission maintains a list of the SMR's going through the design review process:
http://nuclearsafety.gc.ca/eng/reactors/power-plants/pre-licensing-vendor-design-review/index.cfm

NuScale and Terrestrial are speculated as being the front-runners for Darlington B, due to how far along they are in the design review process.
 
Originally Posted by OVERKILL
Originally Posted by Y_K
Thank you. What are you paying per kW there please?


Too bloody much, LOL! Though that's mostly due to fixed-rate contracts signed by the previous two administrations that grossly overpay for unreliable supply and then reliable supply to back it up (gas). Current rate for OPG Nuclear is $0.09/kWh, Bruce Power is $0.077 and slated to remain at that price for decades, likely making it the cheapest form of electricity in the province at some point. Bruce has an official projected EOL of 2064, but that will almost assuredly get extended, as will Darlington's as the replacement fuel channels and pressure tubes being fitted to the units at Darlington and Bruce are of an improved design and are supposed to have a significantly longer service life. If that's the case, we may see 45+ years out of these new tubes. I don't think getting >100 years out of Bruce is being overly optimistic.

Average cost of supply in the province is $0.128/kWh, but 85% of that supply is at $0.09/kWh and below.

[Linked Image]



Gee, those "green" technologies look like a great deal
smirk2.gif
 
Originally Posted by SubieRubyRoo

Gee, those "green" technologies look like a great deal
smirk2.gif



Don't get me started
lol.gif
We have something like 3,300MW of embedded solar that doesn't show up in the IESO controlled supply mix but is factored into that $0.479 cost. Assuming an 11% CF, that's $1.5 BILLION dollars of our $7.7 billion supply cost but at 3TWh amounts to less than half the output of one unit at Bruce
smirk.gif
whose 7TWh output would cost $500 million. In fact the cost of Bruce supplying >30% of Ontario costs only roughly 2x what we pay for solar to provide 2%.
 
I'm about 35 miles from a plant with a good track record and serious output … they are approved to add two modern domes and step down the the load on old domes. (have an oversized cooling lake) …
But, just can't work the massive investment with gas so cheap in the short term.
Have to stop there.
 
Originally Posted by OVERKILL
Originally Posted by SubieRubyRoo

Gee, those "green" technologies look like a great deal
smirk2.gif



Don't get me started
lol.gif
We have something like 3,300MW of embedded solar that doesn't show up in the IESO controlled supply mix but is factored into that $0.479 cost. Assuming an 11% CF, that's $1.5 BILLION dollars of our $7.7 billion supply cost but at 3TWh amounts to less than half the output of one unit at Bruce
smirk.gif
whose 7TWh output would cost $500 million. In fact the cost of Bruce supplying >30% of Ontario costs only roughly 2x what we pay for solar to provide 2%.
Wind and solar are a good complement to hydroelectric - the hydro operation can pond water when wind and solar are generating. The water stored in the forebay serves as a hydraulic battery.

But agreed, on their own, wind and solar have a storage problem.
 
Originally Posted by OVERKILL

The big delay for Darlington was a post-Chernobyl pause put on the industry which also unfortunately stopped the B site from being built immediately after. It was supposed to be an 8-unit site like Pickering and Bruce.


Ontario's electricity demand didn't warrant the extra capacity either. And there was obviously a lot of political mismanagement of the government entity responsible for the plant. The issues became extreme in the late 1990s.

Quote

Regarding pressure tubes, yes, all of that has been long sorted and never became a problem at Darlington.


I thought Darlington was re-tubed? Wasn't there some issue with neutron bombardment of the materials? IIRC, the design included a so-called "annulus gas" system that was supposed to detect failure, but previous pressure tube failure incidents were very sudden, not gradual slow failures.

What about steam generators? Were Darlington's somehow immune to the problems that required their replacement at Bruce? And at so many other PWR's in the US?


Quote
While it tends to be a little out of date, the Canadian Nuclear Safety Commission maintains a list of the SMR's going through the design review process:
http://nuclearsafety.gc.ca/eng/reactors/power-plants/pre-licensing-vendor-design-review/index.cfm

NuScale and Terrestrial are speculated as being the front-runners for Darlington B, due to how far along they are in the design review process.


I didn't realize that there had been any proposals advanced for Darlington B, aside from the process that was unfolding in the mid 2000s.

Still neat, to see that it has become a productive asset. I remember the tour guide describing the continuous pour of the vacuum building, using quantities of concrete rivalling that of SkyDome.
 
Originally Posted by Number_35
Originally Posted by OVERKILL
Originally Posted by SubieRubyRoo

Gee, those "green" technologies look like a great deal
smirk2.gif



Don't get me started
lol.gif
We have something like 3,300MW of embedded solar that doesn't show up in the IESO controlled supply mix but is factored into that $0.479 cost. Assuming an 11% CF, that's $1.5 BILLION dollars of our $7.7 billion supply cost but at 3TWh amounts to less than half the output of one unit at Bruce
smirk.gif
whose 7TWh output would cost $500 million. In fact the cost of Bruce supplying >30% of Ontario costs only roughly 2x what we pay for solar to provide 2%.
Wind and solar are a good complement to hydroelectric - the hydro operation can pond water when wind and solar are generating. The water stored in the forebay serves as a hydraulic battery.

But agreed, on their own, wind and solar have a storage problem.


Almost all hydro in Ontario is some form of run-of-river, so there's VERY little storage capacity in our system, despite hydro making up ~25% of our generating capacity. The amount of hydro required to firm wind is insane, since wind can be AWOL for weeks. At least solar has a somewhat predictable cycle to it and with limited penetration can depress daytime peaking requirements.
 
Originally Posted by pitzel
Ontario's electricity demand didn't warrant the extra capacity either. And there was obviously a lot of political mismanagement of the government entity responsible for the plant. The issues became extreme in the late 1990s.

Yes, we'd have had to shutter Nanticoke for DNGS B to have made sense in the 1990's. Of course the price of the A plant due to the construction pause and accrued interest and the "hide and seek for 2 grand a week" or whatever the slogan was for the lads working on the plant at the time... Government mismanagement and contractors capitalizing on a project that seemed to have an infinite budget, it didn't make for a healthy situation for yet another new build.

Originally Posted by pitzel
I thought Darlington was re-tubed? Wasn't there some issue with neutron bombardment of the materials? IIRC, the design included a so-called "annulus gas" system that was supposed to detect failure, but previous pressure tube failure incidents were very sudden, not gradual slow failures.

Nope, the ONLY plant that was re-tubed prematurely were 4 units at Pickering. All of the pressure tubes at Darlington are original, same with Bruce 3 and 4 and all of Bruce B. Pickering A 1 and 4 have been refurbished, so their tubes are new(er), same with Bruce A 1 and 2. The annulus gas system, present at Pickering, Bruce and Darlington is supposed to sense the presence of moisture, and thus a leak, and no, it would not be helpful in a situation where there was a sudden and dramatic failure. It was designed to indicate there was a leaking seal, small leak, or similar; water getting somewhere it wasn't supposed to. They use probes and materials sampling to check for hardness (embrittlement) in the tubes now which has given them the ability to much better gauge their condition as well as the noted locating of the annulus spacers and moving them back into place when necessary.

Now, there was a sudden tube failure at Pickering A (I just checked Wikipedia as I couldn't remember whether it was A or B, and it is on there, lol), but that was due to the annulus spacers all sliding down to one end (this is an issue that pre-dates Darlington) and resulted in localized embrittlement that led to serious failure. That was never a problem at Darlington or Bruce from what I recall as they learned to check for it once they figured out what was going on. This event is what resulted in all of the Pickering A units getting retubed in 1983.

Originally Posted by pitzel
What about steam generators? Were Darlington's somehow immune to the problems that required their replacement at Bruce? And at so many other PWR's in the US?

SG's are replaced during the refurbishment so they are rolled into that cost. SG's at Darlington are all original, as I believe they are at Bruce B and Pickering B as well. Unit 2 at Bruce had its SG replaced due to damage from a lead blanket, but I don't recall premature replacement of any other SG's pre-refurbishment. Pretty much every possible wear component is replaced during the refurb and Bruce is rolling uprates into theirs, whilst OPG has indicated that they have no intention of pursuing increased output from the units at Darlington. That said, will be interesting to see if Unit 2 comes back at 878MW or if it is higher with the new generator and turbine assembly.

Originally Posted by pitzel
I didn't realize that there had been any proposals advanced for Darlington B, aside from the process that was unfolding in the mid 2000s.

DNGS B wasn't officially shelved (again) until Wynne put it on "permanent hold" in 2012. However, OPG has been maintaining the EA granted to build the B site issued in I believe 2009? in anticipation of a more receptive administration. The current group has been receptive of the plan to build the B site, but with SMR's, and as I said, my source at OPG indicated that there was supposed to be an official announcement soon, though I expect that's been delayed now due to COVID-19.

Originally Posted by pitzel
Still neat, to see that it has become a productive asset. I remember the tour guide describing the continuous pour of the vacuum building, using quantities of concrete rivalling that of SkyDome.

Yes, Darlington is one of the best performing sites in the world, as is Bruce. Operations at OPG have greatly improved in the last couple of decades and we are seeing the results of those efforts now. Kind of sad that Pickering has never performed so well and yet is slated to close in 2024. Also quite incredible how long those pressure tubes have lasted
lol.gif
What's really wild is that while the Darlington refurbishment started with a unit which is roughly 30 years old, many of the Bruce units will be well into their 40's before they go down and as I noted in the OP, the new tubes are supposed to last longer still, so I expect 100 years is quite possible. Of course there's also nothing preventing a 2nd refurbishment except of course the cost. Not sure what things will look like in the late 2060's early 2070's.
 
Originally Posted by Papa Bear
Thanks for the info, Chris. The lights are still on in Leamington
smile.gif



You are quite welcome!
cheers3.gif
 
pitzel, just found this video which discusses pressure tube inspection, operating criteria and briefly touches on the single pressure tube failure experienced in the 1980's and resultant complete tube replacement where they note that the material used to construct those tubes is not in use in any of the tubes in services today:
 
Always enjoy reading your Nuclear posts, Overkill. Like I've mentioned before, if one didn't know any better, they'd swear you worked there and in a PR role.

Regarding the steam generators, which we referred to as just the turbine(s), (SG's to me means Standby generators, which we have 4, or 1 per unit) that have blades of course, and due to not being able to reduce the amount of moisture in the steam, have cutting issue on the tips/ends (steam cut) and need to be inspected/replaced during outages.

Our MSR's, (although things might have changed since the last time I was involved back in 09?), aren't efficient enough to remove all the steam in order to stop this completely due to a variety of factors and issues.

Also, someone back mentioned our vacuum bldg and the Skydome and the amount of concrete within per. I have never heard that comparison before so I can't comment on it but being involved with the vacuum bldg pour back in 83 (9 days straight,12 hr shifts night and day) when I was just 18, I can say there is a pile of concrete in it, and not just what you see on the outside.

Being retired now, Overkill, I don't think it is possible to get anymore of those pictures that I told you I would. There was a huge file with over a 1,000 pictures on it that I tried to send home a couple times but my computer just wasn't big enough to handle it.

I do have these but I am pretty sure you have seen them all?

Concrete pouring on Vacuum Building roof, Oct 24 1985.jpg


Darlington concrete pouring.jpg


Darlington construction-234-.jpg


Darlington Emergency Service Water intake, May 23 1984.jpg


Darlington ESW Intake from Forebay, looking East SCI 27100.jpg


Darlington site from West to North to East, October 1986 (1).jpg


Darlington View from top of Vacuum Bldg looking East, October 18 1984.jpg


Darlington.jpg
 
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