A nuclear submarine is a submarine which is powered by a nuclear reactor, but not necessarily nuclear-armed.

A nuclear submarine is far more superior to conventional submarines but the high cost of nuclear technology means that only few countries can afford them.  Here is a list of those countries

UNITED STATES

1

Total Nuclear Submarines - 68 Nuclear-powered ballistic missile submarines - 14 Nuclear-powered attack submarines - 54

RUSSIA

2

Total Nuclear Submarines - 29 Nuclear-powered ballistic missile submarines - 11 Nuclear-powered attack submarines - 18

CHINA

3

Total Nuclear Submarines - 12 Nuclear-powered ballistic missile submarines - 6 Nuclear-powered attack submarines - 6

UNITED KINGDOM 

4

Total Nuclear Submarines - 11 Nuclear-powered ballistic missile submarines - 4 Nuclear-powered attack submarines - 7

FRANCE

5

Total Nuclear Submarines - 8 Nuclear-powered ballistic missile submarines - 4 Nuclear-powered attack submarines - 4

INDIA

6

Total Nuclear Submarines - 1 Nuclear-powered ballistic missile submarines - 1 Nuclear-powered attack submarines - 0

AUSTRALIA

7

While Australia doesn’t have a nuclear submarine yet, it has signed an agreement called AUKUS with the US and UK to have a nuclear powered submarine by 2040.