When the Nuclear submarines exploded, that released nuclear chemicals into the water, therefor poisoning the fish in the water. Also, when the submarines exploded, it sent lots of metal into the ocean, having a long term effect.
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The above answer is VERY odd. Only 2 nuclear submarines have ever been lost due to explosions. Neither released any nuclear materials.
The Skipjack had a torpedo battery explosion which caused sufficient damage that it sank below it's crush depth and imploded.
The K-141 Kursk also sank after an explosion in a torpedo tube.
Considering the details -
NOTE: The reactors in nuclear submarines are incapable of exploding - they would melt down first - at which point nuclear fission would stop. The reactors actually rely on control rods being positioned correctly in order to sustain the fission reaction and get the heat to run the turbines. If the control rods are pushed in too far, they shut down the reaction by absorbing too much radiation. If they are pulled out, the particles coming off the fuel go too fast to collide with other nuclei and fission stops. In the words of Goldilocks - they have to be "just right". In the case of a sunken sub, if seawater breached the reactor, it would flood the compartment and stop the reaction too.
Of course a submarine could be caused to explode if an on-board missile were to explode.
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The "negative effects" of nuclear submarines are the same ones shared by all submarines.
USA has the most nuclear submarines
Argentina had diesel-electric submarines while the British had nuclear-powered submarines.
A number of nuclear submarines sank, and the circumstances vary from accident to accident. Wikipedia has a list, and by going there and entering "List of sunken nuclear submarines" you can review that list.
Nuclear submarines are powered by a nuclear reactor and they are completely independent of air, so there is no need to surface frequently.
The US, Russia, Great Britain, France, China and (recently) India have nuclear submarines.
Yes, nuclear submarines generate nuclear power. There is a nuclear reactor on board (hence the tern nuclear submarine) which creates steam to drive the main engines to turn the screw(s).
Nuclear Energy
The PLA navy has more than 225,000 personnel and is thought to have as many as 70 submarines, 10 of them nuclear-powered
Plutonium can be used in nuclear reactors for nuclear propulsion of ships and submarines.
No - all submarines, be it nuclear or diesel-electric, use diesel fuel, either for primary engines (DE) or backup generator (nuclear).
It is a negative effect. While it might be a neat invention to some, it is going to end up destructive and causing a lot of major issues.
Since its free-fall nuclear weapons arsenal was decomissioned in 1998, the United Kingdom's only means of nuclear weapons delivery is via submarines and SLBMs.