28x09 - Endoscopes, Megaphones, Uranium

[bunniefuu]

Narrator:
today on "how it's made"...

Endoscopes...

Megaphones...

And uranium.

An endoscope is a tube
with optical glass fibers

And lenses inside attached
to a video camera.

Doctors feed the endoscope
through the patient's mouth

Or other opening or insert it
through a tiny incision

Then watch what the camera
captures on a video monitor.

An endoscope lets the surgeon
see inside the patient

During an examination
or surgical procedure.

Its light-transmitting
optical fibers work

Like a flashlight
inside the body.

The optical fiber manufacturer
suspends glass rods

From the top of a tall oven,

Which heats them
to a melting temperature

Of 1,652 degrees fahrenheit.

Each rod drips downward
in the form of a thin strand.

A guide wheel turns this glass
fiber in a horizontal direction.

The fiber then winds
on to a drum,

Whose rotation speed
stretches it

To a specific
hair-thin diameter.

A worker combines several single
fiber spools on to a large

Winding wheel to make a bundle
containing thousands of fibers.

To make the cable
that connects a light source

In the operating room
to the endoscope,

A worker inserts
an optical fiber bundle

Into a silicon cable sheathing.

This one has nearly


She screws
a stainless steel fastener,

Called a ferrule on to each
threaded end of the sheathing.

After saturating the ferrules
and optical fibers

Inside with glue and curing
the adhesive with heat,

The worker trims
off excess fibers

And hands off the cable
to the next station,

Where a work polishes both ends.

Polishing
finalizes the dimensions

And enables light
to shine through.

This quality control test,
one of several,

Ensures the fibers can

Withstand a prescribed amount
of pressure without cracking.

The optical fiber manufacturer

Also supplies fiber spools

To the endoscope manufacturer

For the light transmission
system inside the endoscope.

Workers cut the bundle
of optical fibers

To the length required

For the endoscope model
they're making.

Endoscopes vary in length
and diameter,

Depending on the part of
the body they're designed for.

After verifying that
the diameter

Of the bundle is correct,

They tie the optical fibers
with string

To hold them together
during insertion.

Then workers insert
the fiber bundle

Between the inner and outer
stainless steel sheathes

That make up the main body
of the endoscope,

Pushing the fibers down
the length of the inner sheath.

They attach
a stainless steel adaptor.

This will connect
the light cable

From the operating room
light source

To the endoscope,

Transferring light
to the optical fibers

Inside the endoscope.

A worker inspects those fibers

Under magnification
for black spots.

Black spots indicate
broken fibers,

Which would interrupt
the transmission of light.

An endoscope transmits an image
much like a telescope does.

Optical lenses send reflected
light, which produces the image,

From inside the patient

All the way up to your eye
peering through the top.

The lenses in the endoscope
are glass rods.

After cleaning them
with chemical solution,

Workers line them up
in a fixture

With brass spacers
of various lengths in between.

Depending on the length
of the endoscope,

There are five to seven lenses.

The spacers create specific
distances between them.

Once workers have assembled
the image transmission system,

They gently slide it
off the fixture

Into the inner sheath
of the endoscope.

Then, they screw on
an ocular cap

To hold it all in place.

A worker cleans
the cap's glass top,

Then attaches an eyepiece.

This gives the surgeon
the option of either

Looking directly
into the endoscope

Or looking at an operating room
video monitor

Which receives the image
via a small camera

Attached to the eyepiece.

This demonstration shows
how it all comes together

In the operating room.

After securing the endoscope
in a holding fixture,

The surgeon attaches
the light cable

Coming from the nearby
light source.

The light travels down
and out the endoscope,

Illuminating the area
that surgeon's working on.

The lenses reflect the image

To the top of the endoscope,

Where a camera transmits
it to a video monitor

That's mounted in front
of the surgeon.

Narrator: in the beginning,

Megaphones were simply
cone-shaped devices

That focused sound forward
so it went further

And could be heard
more clearly.

In the 20th century microphones,
an amplifier and a speaker

Were added to the cone,

And that really
ramped up the volume.

With a megaphone,
there's no need to shout.

Just speak,
and you will be heard.

This waterproof version
is designed for coaching,

Law enforcement,
and military uses.

Production starts with a panel
of four digital circuit boards

That have little
gold pads on them.

An assembler places
a stencil over the panel

And aligns the stencil holes
with the gold pads.

He then squeegee's
solder paste down the stencil,

And it flows on to
the exposed gold pads.

This is before and after
the solder past application.

Robotic arms install
electrical components

On the solder-coated pads,
creating circuitry.

Various reels unwind to deliver
these little parts.

The robotic arms
suction them off liners

And transfer them to precise
locations on the boards.

The parts will run
the megaphone's sirens,

Horns, and microphones.

A technician clamps

One of the completed
circuit boards in a tester.

Spring-loaded pins underneath
make electrical contacts

With the components
and probe their performance.

The system runs a full test
of the circuitry.

At the next station,
an assembler attaches

A part known
as the front can

To the end
of a flared speaker cone.

He then turns his attention
to the speaker.

The assembler
inserts screws in the base.

He threads wires
from the speaker

Through a hole in the cone

And through the front can.

The assembler then places
the speaker in the cone,

And he screws it in place.

He attaches a connector
to the protruding speaker wires.

The worker places
a mesh metal screen

Over a hole in the rear can.

The assembler taps a nut driver

With a hammer to force
the mesh into the hole,

And this shapes the mesh
into a microphone cover.

He removes the newly-formed mic
cover and fits it to the mic,

Manually crimping it around
the sides for a snug fit.

He now tucks the microphone
into a tube

That has a sliding inner sleeve.

The assembler inserts the tube
into the microphone hole

In the rear can.

He slides the inside tube down

To push the microphone
in the hole.

He secures the knob
for turning the megaphone on

And for adjusting the volume.

The assembler installs
a mini-circuit board

That's linked to the siren
and horn button.

These small spring pins
will mate to a battery

To power
the megaphone's circuitry.

He tucks the pins
into molded protrusions

Inside the rear can

And waterproofs them
with rubber o-rings.

This megaphone subassembly
is now ready

For the main circuit board.

The assembler threads wires

For this switch trigger,
microphone, siren,

And horn through holes
in the board.

He then screws the board
to the rear housing.

He fits a silicon
o-ring around

The rim of the rear
can to seal it.

The assembler then joins
the rear can

With all the working parts

To the front can
and cone assembly.

He connects the speaker wires
to the circuit board.

This megaphone is now ready
for a sound test.

The technician connects it
to a temporary battery

And powers it up.

Check, one, two.
One, two.

Check, testing,
testing.

One, two, test.

More sensitive
testing is needed.

He encloses the megaphone
in an insulated chamber

To shut out background noises.

A computer runs the megaphone
at different frequencies

And analyzes its performance.

Once the megaphone passes
these tests,

They install handles.

And now it's ready for
anything you have to say.

Narrator: uranium is
a metallic element

That was discovered by
a german chemist in 1789.

The significance
of this discovery

Wasn't understood
for a century and a half.

In 1938, scientists figured
out that uranium atoms

Could be split
to produce energy.

The size of a fireplace log,

This nuclear fuel bundle
generates a lot more heat.

It's packed with enough uranium

To power 100 homes for a year.

To obtain the uranium,

The tunnel 1,640
feet underground

At this site in
northern saskatchewan.

This mine is the largest source

Of high-grade uranium
in the world.

The uranium ore lies
beneath a bed

Of water-saturated sandstone.

To reach it, they use
drill bits studded

With tungsten carbide buttons.

Like knuckles on a fist,

The button bits punch
into the rock face.

These first holes are for pipes

That will pull heat
out of the ground

And freeze it around the ore.

The miner operates the equipment
by remote control.

It transfers a new piece of pipe
to the end of the drill

Roughly every five feet

To penetrate 426 feet
into the sandstone bed.

It takes up to eight days

To install just
one length of pipe,

And there are 200 of them.

Workers configure the pipes

So they surround
the ore deposit.

These freeze pipes
will stabilize the ground,

And they'll also turn
high-pressure ground water

To ice, so it won't interfere
with the actual mining.

A freeze plant above
ground chills

Calcium chloride brine
to minus-22 degrees fahrenheit

And sends it through
the freeze pipes.

The brine absorbs heat
as it freezes the ground

And loops back
to be chilled again.

Above the uranium deposits,

Workers now gear up
to mine the ore.

They'll use this bit
to chew into the ore body

In order to make an initial
small-diameter hole

Known as a pilot hole.

The pilot hole maps out
the drill route to ore,

And it creates an entry point
for larger mining equipment.

From a raised position,

The bit bores vertically
into the rock

To drill the pilot hole

And reach a specific
level below the ore body.

They're now ready
for the reamer bit.

The reamer has numerous

Button-encrusted
wheel tentacles.

As this animation shows,

The drill pulls the reamer up
the pilot hole, widening it.

And the broken ore falls
into what's known

As an extraction chamber.

Here, a tram operated
by remote control

Scoops up the rock.

This remote control system keeps
miners a safe distance away

From falling rock hazards.

It also minimizes their exposure

To the radioactive uranium
in the ore.

As another precaution,

Workers continuously
ventilate the mine,

Introducing fresh air
every 20 minutes.

Steered by
the operator's joystick,

The tram delivers
the ore to a scanner.

By measuring the amount
of radioactivity in the ore,

The scanner determines

The uranium content
is about 15%.

In much of the ore, the uranium
content is even greater --

On average, around 18%,

And that's considered
to be very high-grade.

The train now empties
the ore into a chute.

Cameras follow the rocks'
journey to the next station.

Then from a control room,

An operator manipulates
a hydraulic hammer

To smash the ore to bits.

The broken ore
then migrates to a mill

That grinds it into a fine sand.

They add water,
and it becomes slurry,

Which they then pump
to the surface.

Trucks then transport
the uranium ore slurry

To a mill nearly 50 miles away.

They pull into a special
off-loading facility.

The support for a vacuum system
aligns with the tote

That encases the slurry tank.

Once in position, a vacuum pipe
drops into the tank

And suctions up the slurry.

Cameras provide a live feed
of the unloading progress

To a control room
almost 23 feet away.

After a wash
and a radiation check,

The truck leaves.

Stay tuned for
the transformation

Of uranium into nuclear fuel.

Narrator: just one fuel bundle
of uranium contains

The same amount of energy

As just over


But uranium can't
simply be chipped away

From the rock it resides in.

It must be chemically
separated and processed

To make it into usable fuel
for a nuclear reactor.

Acid dissolves the uranium,
but not the rest of the rock.

It settles to the bottom
of these tanks.

The uranium-acid
solution flows forward,

Leaving the unwanted
minerals behind.

Using a series
of chemical reactions,

They further purify the uranium.

They then roast it
at 1,562 degrees fahrenheit.

This concentrates it into
a jet-black powder.

The uranium powder flows
into 55-gallon steel drums.

A worker taps
the lip of the drum

To remove residual powder.

He then puts the lid
on and activates a press

That secures it
tightly to the drum.

As an extra precaution,
he seals it with a steel ring.

He labels it to indicate
the drum's contents,

Weight, and radioactivity.

Workers stack the drums
in a warehouse

To await shipment to the next
processing plant.

There, the uranium goes
from black to yellow

As they convert it
to uranium trioxide,

An interim chemical form
in the processing chain.

They ship the uranium
trioxide in specially

Designed inverted cones.

Upon arrival at
the next facility,

A valve opens at the bottom

And the powder flows
into conveyor tubes

That take it into the plant.

Inside, workers dissolve

The uranium trioxide
powder in acid.

A worker takes a sample
to test the density

And the chemistry and confirms
that both are acceptable.

They then add a chemical
to turn the dissolved uranium

Back into a solid.

After more processing,

The uranium trioxide
becomes uranium dioxide,

The chemical form required
for nuclear fuel.

Spinning the uranium
dioxide mixes

The different sized particles

To make it
a more h*m* blend.

The chemical processing has
also caused the uranium

To change color again.

It is now a fine black powder.

Using several tons of pressure,

Tools shape the uranium dioxide
into pellets.

A revolving wheel
with protrusions

Guides the pellets
into a channel conveyor.

The conveyor takes
the pellets into a furnace.

Over 24 hours, the heat
removes pores in the pellets.

The pellets shrink, increasing
the density of the uranium.

The particles fuse together
and harden into a ceramic.

Here's a pellet before
and after baking.

A robot arm now loads
the pellets

On to a tray and levels them.

A conveyor moves
the tray forward.

Ahead, another robot places
zirconium fuel tubes on a rack.

Zirconium is a metal
that's highly resistant

To both heat and corrosion,

But neutrons will pass
freely through it

During the fission reaction.

The rack of tubes meet up

With a tray of incoming pellets.

A robotic loader pushes
the stack

Of 30 pellets into the tube.

Another robot delivers
the rods one at a time

To an automated welder
that caps the ends.

The next robot retrieves
the completed uranium fuel rods

And transfers it
to an assembly fixture.

It arranges a total of 37 rods

In an upright position
within the fixture.

After the rods
have been welded

And the bundle capped
at both ends,

A robot transfers it to a scale.

This weigh-in confirms

That there is the correct amount
of uranium in the bundle.

Prior to burn up in a reactor,

The amount of radioactivity
emitted by nuclear fuel bundles

Is very low,
and they're safe to handle

As workers prepare them
for shipping.

They're now on their way
to the power plant,

Where they'll be sure
to generate a reaction.