I've seen quite a few SMR proposals over the last couple of years and not a single one that dared to address the whole cycle from deployment to eventual decommission as a function of the total revenues - costs to operate. Most of these projects seem to be made to bilk investors or governments rather than to actually produce power. The day Italy produces the first KWh that is net profitable to the operators without counting subsidies I will be highly amazed, and that's assuming they get to operational in the first place.
I agree, I tell everyone who will listen that no country, not Russia, China, Japan, France, USA etc has ever made nuclear power profitable. And you can't blame it on the environmentalists in China and Russia.
That being said, many countries consider it a national security issue not to be held hostage to foreign oil.
Profitable compared to what, that provides base load?
If energy prices are too high, industry suffers. If you let the price rise, maybe China just eats your lunch.
What's the option value vs risk of gas price rises? Gas sets the marginal price of electricity in Italy today for 60% of the year [1]
[1] <a href="https://www.terna.it/DesktopModules/AdactoBackend/API/directdownload/get?file=Terna_2025_Annual_Report_8de9f199b1840f9.pdf" rel="nofollow">https://www.terna.it/DesktopModules/AdactoBackend/API/direct...
"However, the electricity system remains significantly exposed to gas price
volatility, which in 2024 determined electricity prices for more than 60% of the hours."
Nuclear power plants need to be taken offline for multiple weeks to months at a time for refueling and maintenance over their lifespans making them a poor fit for base load without extremely costly redundancy in a small country.
Cutting out the “and maintenance” bit is misleading.
It’s commonplace for maintenance issues at non CANDU reactors to extend the “refelling” downtime. So no, CANDU can’t stay online for decades without maintenance and instead have similar downtime issues. The major benefit is when manufacturing plutonium due to shorter fuel cycles, but overall CANDU reactors are less cost effective which is why adoption fizzled out.
> So no, CANDU can’t stay online for decades without maintenance and instead have similar downtime issues.
There are several situations:
* refuelling occurs
* maintenance needs to happen
* refurbishment needs to be done
Some of these things take downtime, some do not, depending on the design of the reactor and other factors. A blanket statement of "refuelling forces a downtime" is a blanket statement which is incorrect in many situations. Depending on the maintenance (or inspections) needed, this may or may not need downtime. Refurbishment generally means tearing things apart, so usually means downtime, but if a site has multiple reactors they can be done one at a time, e.g.:
Eh, again, I disagree. As an example: Many CANDU reactors have insanely high availability. Example: Qinshan CANDU Unit 1 only had a planned outage of less than 27 days in 2023. There are many other examples. That is crazy uptime in the world of electricity production. And to be clear, if you come at me with "Oh, what about the major maintenance required every 10+ years?". Thermal (coal/gas) has the same issue.
jacquesm · · focus · HN ↗
asmodeuslucifer · · focus · HN ↗
That being said, many countries consider it a national security issue not to be held hostage to foreign oil.
barrkel · · focus · HN ↗
If energy prices are too high, industry suffers. If you let the price rise, maybe China just eats your lunch.
What's the option value vs risk of gas price rises? Gas sets the marginal price of electricity in Italy today for 60% of the year [1]
[1] <a href="https://www.terna.it/DesktopModules/AdactoBackend/API/directdownload/get?file=Terna_2025_Annual_Report_8de9f199b1840f9.pdf" rel="nofollow">https://www.terna.it/DesktopModules/AdactoBackend/API/direct... "However, the electricity system remains significantly exposed to gas price volatility, which in 2024 determined electricity prices for more than 60% of the hours."
Retric · · focus · HN ↗
throw0101c · · focus · HN ↗
CANDU reactors, for one, can be (and are) refuelled live:
* <a href="https://en.wikipedia.org/wiki/Online_refuelling" rel="nofollow">https://en.wikipedia.org/wiki/Online_refuelling
Every few decades they do need to be refurbished though.
Retric · · focus · HN ↗
It’s commonplace for maintenance issues at non CANDU reactors to extend the “refelling” downtime. So no, CANDU can’t stay online for decades without maintenance and instead have similar downtime issues. The major benefit is when manufacturing plutonium due to shorter fuel cycles, but overall CANDU reactors are less cost effective which is why adoption fizzled out.
throw0101c · · focus · HN ↗
There are several situations:
* refuelling occurs
* maintenance needs to happen
* refurbishment needs to be done
Some of these things take downtime, some do not, depending on the design of the reactor and other factors. A blanket statement of "refuelling forces a downtime" is a blanket statement which is incorrect in many situations. Depending on the maintenance (or inspections) needed, this may or may not need downtime. Refurbishment generally means tearing things apart, so usually means downtime, but if a site has multiple reactors they can be done one at a time, e.g.:
* <a href="https://news.ontario.ca/en/release/1006993/ontario-delivers-darlington-refurbishment-project-ahead-of-schedule-and-under-budget" rel="nofollow">https://news.ontario.ca/en/release/1006993/ontario-delivers-...
throwaway2037 · · focus · HN ↗
vegardx · · focus · HN ↗
throwaway2037 · · focus · HN ↗
Retric · · focus · HN ↗
vegardx · · focus · HN ↗
You said 27 days of planned outage is crazy uptime in the world of electricity production. Hydro routinely beats that by an order of magnitude.