# CANDU reactor

Hacker Approved page: https://hackerapproved.com/p/candu-reactor/

9 people recommended CANDU reactor in Hacker News comments, 3 had mixed feelings and 3 criticized it, November 2025 to October 2026. It was recommended in 5 of 12 months, in 8 threads. It does not meet the Hacker Approved badge rule.

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

Summary written by Claude from 18 comments.

## Why people recommend it

- Proven, safe and reliable design (4 comments in the sample): "Multiple installations already exist, and it is a very good design." ([source](https://news.ycombinator.com/item?id=49954969)) "a well respected and safe nuclear design in CANDU" ([source](https://news.ycombinator.com/item?id=48635599)) "Canada has a proven, safe reactor technology" ([source](https://news.ycombinator.com/item?id=49726246))
- High availability and on-time refurbishments (3 comments in the sample): "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…" ([source](https://news.ycombinator.com/item?id=46729818)) "Many CANDU reactors have insanely high availability." ([source](https://news.ycombinator.com/item?id=49830063)) "they do it on-time and under budget" ([source](https://news.ycombinator.com/item?id=48636248))
- Runs without enriched fuel (1 comment in the sample): "The CANDU reactors Canada has been operating for decades can run on spent fuel from legacy reactors" ([source](https://news.ycombinator.com/item?id=48827733))

## What people warn about

- Plutonium and proliferation concerns (2 comments in the sample): "the design has no built in proliferation resistance" ([source](https://news.ycombinator.com/item?id=48638811)) "One design limitation that I have heard about it is that is can be used as source for weapons grade Plutonium" ([source](https://news.ycombinator.com/item?id=49918646))

## What people recommend instead

- [Westinghouse AP1000 reactor](https://hackerapproved.com/p/ap1000-reactor/): 7 recommend, 3 mixed, 7 criticize

## The badge

A product earns the Hacker Approved badge when at least 10 people recommend it, recommenders outnumber critics at least 2 to 1 (mixed feelings count toward neither side), it was recommended in at least 4 of the 12 months and in at least 5 different threads, and no single thread supplies more than half of the people who recommend it. Health and money products are never badged.

## Cite as

Hacker Approved, "CANDU reactor", https://hackerapproved.com/p/candu-reactor/ (9 recommend, 3 mixed, 3 criticize; Hacker News comments, November 2025 to October 2026).

Counts updated 2 Nov 2026, with data through October 31, 2026.