1. SUBMARINE Nuclear Reactors Friend or Foe?
Part 1: How A Nuclear Reactor Works
Part 2: Diesel Subs V. Nuclear Subs
Part 3: Health Risks (Short Term & Long)

2. PART 1: First, What Is A Nuclear Reactor?
    
                                
                    
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“Nuclear reactors are basically heat engines. As uranium fissions, the breaking apart of atoms releases energy, much of it in the form of heat, which can then be used to do work. In a nuclear-powered submarine, reactor heat produces steam to drive the turbines that provide the submarine's actual power. The development of compact, safe, and highly reliable pressurized water reactors for naval use in the early 1950s was the major technological achievement that made nuclear-powered submarines possible.” (1)

3. But How Does it Work?! The First Half of the Process….
Standard nuclear submarines, like those used in the U.S. Navy use pressurized water reactors. These reactors include both a primary and secondary cooling system. “The primary system circulates water, which is pressurized to keep it from boiling, in a closed loop.” As water moves through the actual reactor, it is made extremely hot. The heated water travels through the steam generator where the water transfers the heat to generate steam (In the second cooling system). The water then travels back to the initial reactor chamber where the process is repeated.
Quote taken from

4. But How Does it Work?! The Second Half of the Process….
While in the steam chamber, described during the first half of the process, the heat is sent through a “watertight boundary to the secondary system, also a closed loop. The unpressurized water in the secondary system turns to steam when heated. The steam, in turn, flows through the secondary system to the propulsion turbines, which turn the propellers, and to the turbine generators, which supply electricity. As it cools, it condenses to water and is pumped back to the steam generator.” (3)

5. Nuclear Reactor Demonstration
The final process should look like This.

7. PART 2: Diesel V. Nuclear Subs
There are two main types of submarines.
Type One: Nuclear Submarines
Type Two: Diesel Powered Submarines
Objective: To find which is more efficient and safe

8. DIESEL FUEL: TYPE 1
Before Nuclear Submarines were created, Diesel Fuel was used to both…
A) Power the batteries which ran all the mechanics on the submarine…
B) And run the sub’s propellers.
For this reason, multiple engines were needed.

9. Diesel Fuel: Type 1
When submarines run off of Diesel fuel, another OXYGEN is needed in order for the engine to run.
Because submarines generally run underwater, oxygen is not easily accessible unless the ship submerges to restock.
This could put a sub in the sights of an enemy ship. Submarines, using diesel fuel, use massive amounts of energy for their multiple engines.
Also remember, the crew has to breathe. In this respect, it is known that diesel subs must rise often.
In addition to this, diesel fuel can be very harmful to personnel aboard the ship if ever there was a problem.
On the other hand, diesel fuel is extremely easy to get at lower costs than nuclear components.

10. Nuclear Fuel: Type 2
Nuclear Fuel is nearly tenfold more efficient than diesel submarines, one of the reasons they are so regularly made.
Nuclear reactors usually use a single engine which can moderate itself to split power to both the propellers and energy needed to run sub’s internal mechanisms.
Also, NO OXYGEN is needed.
Nuclear Reactors run off of water pressure and a base reactor element (usually uranium)

11. Part 3: Health Risks
If a nuclear submarine is built carefully and maintained/serviced regularly, there crew should not be affected by it.
One possible risk is a ‘nuclear meltdown’