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CANDU reactor

Hacker Approved

Nuclear reactor

Recommended as a proven, safe reactor design with high availability and on-time refurbishments; critics cite heavy maintenance costs and weak proliferation resistance.

Recommended as a proven, safe reactor design with high availability and on-time refurbishments; critics cite heavy maintenance costs and weak proliferation resistance.

15 people gave an opinion

recommend it
12
criticize it
3
approval share
80%
Each figure is one person. RecommendsCriticizes

Recommended in 6 of 13 months

  1. November 2025: recommended
  2. December 2025: not recommended
  3. January 2026: recommended
  4. February 2026: not recommended
  5. March 2026: not recommended
  6. April 2026: not recommended
  7. May 2026: not recommended
  8. June 2026: recommended
  9. July 2026: recommended
  10. August 2026: not recommended
  11. September 2026: recommended
  12. October 2026: recommended
  13. November 2026: not recommended (month in progress)

Why it carries the badge

  • 12 people recommend itNeeds 10 or more, met.
  • 4 recommenders for every criticNeeds 2 to 1 or better, met.
  • Recommended in 6 of 13 monthsNeeds 4 or more, met.

The same three rules apply to every product, and the badge can’t be bought. How the badge works

What people say about it

The reasons people give, with the number of comments that give each one. Open a reason to read what they said.

Why people recommend it

Each mark is one comment

  • Proven, safe and reliable design

    “Multiple installations already exist, and it is a very good design.”

    Comment from 4 Oct 2026 in “NRC issues first U.S. construction permit for a BWRX-300 small modular reactor”

    “a well respected and safe nuclear design in CANDU”

    Comment from 22 Jun 2026 in “Canada is looking to build up to 10 new nuclear reactors over the next 15 years”

    “Canada has a proven, safe reactor technology”

    Comment from 16 Sep 2026 in “EU chief opens door for Canada to become 'associate member'”
  • High availability and on-time refurbishments

    “Canada had Candus, an own authentic design that doesn't rely on enriched fuel and they did some very serious refurbs recently on time and on budget.”

    Comment from 23 Jan 2026 in “In Europe, Wind and Solar Overtake Fossil Fuels”

    “Many CANDU reactors have insanely high availability.”

    Comment from 24 Sep 2026 in “Italian parliament votes for return to nuclear energy”

    “they do it on-time and under budget”

    Comment from 22 Jun 2026 in “Canada is looking to build up to 10 new nuclear reactors over the next 15 years”
  • Runs without enriched fuel

    “Canada had Candus, an own authentic design that doesn't rely on enriched fuel and they did some very serious refurbs recently on time and on budget.”

    Comment from 23 Jan 2026 in “In Europe, Wind and Solar Overtake Fossil Fuels”

    “The CANDU reactors Canada has been operating for decades can run on spent fuel from legacy reactors”

    Comment from 8 Jul 2026 in “GAO: DOE Is Prematurely Excluding Less Expensive Options for Nuclear Cleanup”

What people warn about

Each mark is one comment

  • Plutonium and proliferation concerns

    “the design has no built in proliferation resistance”

    Comment from 23 Jun 2026 in “Canada is looking to build up to 10 new nuclear reactors over the next 15 years”

    “One design limitation that I have heard about it is that is can be used as source for weapons grade Plutonium”

    Comment from 1 Oct 2026 in “NRC issues first U.S. construction permit for a BWRX-300 small modular reactor”

What people recommend instead

The same counts for each, so you can compare like for like. The tick on each bar marks the 2 to 1 line the badge needs.

CANDU reactor compared with 1 alternative
ProductRecommendCriticizeApprovalMonthsOwnedBadge
Westinghouse AP1000 reactor13765%8——
CANDU reactorThis page12380%6—Approved

What people said

18 of the 20 comments that mention it, newest first. Each links to the original comment.

“Multiple installations already exist, and it is a very good design.”

RecommendsComment from 4 Oct 2026 in “NRC issues first U.S. construction permit for a BWRX-300 small modular reactor”

“One design limitation that I have heard about it is that is can be used as source for weapons grade Plutonium”

CriticizesComment from 1 Oct 2026 in “NRC issues first U.S. construction permit for a BWRX-300 small modular reactor”

“It's very safe and reliable.”

RecommendsComment from 1 Oct 2026 in “NRC issues first U.S. construction permit for a BWRX-300 small modular reactor”

“Many CANDU reactors have insanely high availability.”

RecommendsComment from 24 Sep 2026 in “Italian parliament votes for return to nuclear energy”

“Canada has a proven, safe reactor technology”

RecommendsComment from 16 Sep 2026 in “EU chief opens door for Canada to become 'associate member'”

“It's not what you would actually use for a new project, it's an empirical demonstration”

MixedComment from 8 Jul 2026 in “GAO: DOE Is Prematurely Excluding Less Expensive Options for Nuclear Cleanup”

“the CANDU are famously bad designs known to develop heavy maintenance costs even to remain operational”

MixedComment from 8 Jul 2026 in “GAO: DOE Is Prematurely Excluding Less Expensive Options for Nuclear Cleanup”

“The CANDU reactors Canada has been operating for decades can run on spent fuel from legacy reactors”

RecommendsComment from 8 Jul 2026 in “GAO: DOE Is Prematurely Excluding Less Expensive Options for Nuclear Cleanup”

“i still hope it'll be candus even if lot of bwrx supply chain is in Canada”

RecommendsComment from 23 Jun 2026 in “Canada is looking to build up to 10 new nuclear reactors over the next 15 years”

“The Candu reactor program is so defunct that the feds have been trying to sell it for about a decade.”

CriticizesComment from 23 Jun 2026 in “Canada is looking to build up to 10 new nuclear reactors over the next 15 years”

“the design has no built in proliferation resistance”

MixedComment from 23 Jun 2026 in “Canada is looking to build up to 10 new nuclear reactors over the next 15 years”

“in so many ways the world has moved on”

CriticizesComment from 22 Jun 2026 in “Canada is looking to build up to 10 new nuclear reactors over the next 15 years”

“they do it on-time and under budget”

RecommendsComment from 22 Jun 2026 in “Canada is looking to build up to 10 new nuclear reactors over the next 15 years”

“CANDUs are cool, hope to see more in the world”

RecommendsComment from 22 Jun 2026 in “Canada is looking to build up to 10 new nuclear reactors over the next 15 years”

“a well respected and safe nuclear design in CANDU”

RecommendsComment from 22 Jun 2026 in “Canada is looking to build up to 10 new nuclear reactors over the next 15 years”

“I have no problem with getting more CANDU reactors”

RecommendsComment from 19 Jun 2026 in “Swiss parliament lifts ban on new nuclear power plants”

“Canada had Candus, an own authentic design that doesn't rely on enriched fuel and they did some very serious refurbs recently on time and on budget.”

RecommendsComment from 23 Jan 2026 in “In Europe, Wind and Solar Overtake Fossil Fuels”

“our grid is in more need of 'bulk power'”

RecommendsComment from 16 Nov 2025 in “UK's first small nuclear power station to be built in north Wales”

Counts come from 1,795,640 Hacker News comments, November 2025 to November 2026. How we count. Report a mistake.