Page 154 - How It Works - Book of Amazing Answers To Curious Questions, 12

� AMAZIG ANSWERS TO CURIOUS QUESTIONS

What powers the 5. Steam generator G. Steam
The steam created in the secondary
The steam generator uses heat from the
loop turns the turbine, driving a
coolant in the primary loop to turn the generator that produces electricity.
water in the secondary loop to steam
USS Nimitz? ready to turn the turbine. Once the
coolant's heat is released at the steam
generator, the colder coolant returns to
the reactor to go round again. 7. Condenser
This device turns the
merica's Nimitz-class doesn't boil inside the core. This steam into liquid by cooling
aircraft carriers are superhot water is then passed it. The condensed water is
A powered by two small through a steam generator. The 4. Radiation shield then piped back into the
Concrete surrounds the steam generator to be
on-board pressurised water heated water in the primary radioactive materials, reheated again.
reactors IPWR), which drive the loop doesn't get converted to steam confining the dangerous
ship's four steam turbines that not itself !because it's under high radioactivity.
only power four five-bladed pressure), rather the intense heat of
propellers, but also generate it is used to convert the cooler water
electricity to power everything on in the separate secondary loop into
the ship. The nuclear reactions turbine-driving steam to power the
taking place in the PWRs can generator. And because the loops are
generate enough power to reach a separate and the water never mixes,
top speed of 30 knots. Inside the the radioactivity is safely contained
reactor cores a huge amount of in the reactor of the primary loop.
energy is given off due to fission-the The steam from the turbine is then
splitting of large atoms !uranium) cooled and condensed, converting it
Steam turns the
into smaller ones and releasing back into liquid waterready to run
turbine shaft,
kinetic energy in the process. the cycle again. driving the
There are two separate loops The reactors rarely require generator and
producing
inside each aircraft carrier's nuclear refuelling- maybe once every 25 3. Reactor 1. Primary 2. Pressurised electricity. A
power station. The primary loop years - offering carriers practically Nuclear fission of uranium coolant water Nimitz's two
contains superheated water, or unlimited range. Refuelling fuel takes place inside the pump (coolant) PWRs generate
tightly sealed reactor, Circulates coolant Natural water is enough
coolant lin liquid form). This coolant involves removing the used core superheated but electrical power
releasing huge amounts of around the
is pumped through the uranium­ and replacing it with a shiny new heat (between SOO'F and reactor and doesn't boil to supply a
population of
fuelled reactor- where it reaches up one replenished with enriched 900'F), which is through the because it is kept
transferred to the coolant. steam generator. under high pressure. 100,000.
to goo•r - under high pressure so it uranium nuclear fuel.
154 How It f.#Jrks WorldMags.net
WorldMags.net