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NUCLEAR FISSION

Date post: 29-Jan-2016
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NUCLEAR FISSION. gamma rays. gamma rays. High speed ‘fission’ fragment. Nuclear fission * the splitting of large nuclei into smaller fragment nuclei. High speed ‘fission’ neutrons. U - 235. There is a small loss in mass after fission has occurred. - PowerPoint PPT Presentation
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NUCLEAR FISSION Nuclear fission * the splitting of large nuclei into smaller fragment nuclei. There is a small loss in mass after fission has occurred. Einstein’s equation: E = mc 2 shows how much energy is release c = speed of light 300,000,000 m/s and c 2 = 9 x 10 High speed ‘fission’ neutrons High speed ‘fission’ fragment gamma rays gamma rays U - 235
Transcript
Page 1: NUCLEAR  FISSION

NUCLEAR FISSION

Nuclear fission * the splitting of large nuclei into smaller fragment nuclei.

There is a small loss in mass after fission has occurred.Einstein’s equation: E = mc2 shows how much energy is released. c = speed of light 300,000,000 m/s and c2 = 9 x 10 16 !!

High speed ‘fission’ neutrons

High speed ‘fission’ fragment

gamma rays

gamma rays

U - 235

Page 2: NUCLEAR  FISSION

Chain reaction * occurs when one fission event causes further fission events .

Fission neutrons cause

further fission

In a nuclear bomb two pieces of pure U 235 or Pu 239

are forced together to exceed the critical mass of 4.5kg.

Sub critical masses lose too many neutrons so the chain reactiondoes not take place

gamma rays

gamma rays

gamma rays

gamma rays

U - 235

Fissionable isotopes: Only Uranium -235 is fissionable in the nuclear reactor. Plutonium -239 is also fissionable and is created from the more common Uranium 238. ( 99% of natural uranium is U 238.)

Page 3: NUCLEAR  FISSION

Fuel rods with enriched Uhaving 3% U 235

instead of less than 1%( the rest is U 238)

A moderator slows down the fast moving neutrons to allow successful collisions with U235 nuclei

Boron/steel control rods absorb surplus neutrons.

Their depth allows one neutron per fission to produce

one further fission

A PWR REACTOR

Page 4: NUCLEAR  FISSION

a nucleus of U-235 or P-239 splits

U-235

P-239

A

C

B

A

Page 5: NUCLEAR  FISSION

If all the mass in a spoonful of sugar (5g) was converted to energyby Einstein’s equation: E = mc2

c = speed of light 300,000,000 m/s and c2 = 9 x 10 16

Q1. How much energy is released?Q2. If the UK needs 50GW of power and power stations are 30% efficient , how long could a spoonful of sugar keep the UK supplied with electricity?

E = m x c2

E = 5 x 10 -3 x 9 x 10 16

E = 45 x 10 13 J

Page 6: NUCLEAR  FISSION

If all the mass in a spoonful of sugar (5g) was converted to energyby Einstein’s equation: E = mc2

c = speed of light 300,000,000 m/s and c2 = 9 x 10 16

Q1. How much energy is released?Q2. If the UK needs 50GW of power and power stations are 30% efficient , how long could a spoonful of sugar keep the UK supplied with electricity?

E = m x c2

E = 5 x 10 -3 x 9 x 10 16

E = 45 x 10 13 J

Page 7: NUCLEAR  FISSION

If all the mass in a spoonful of sugar (5g) was converted to energyby Einstein’s equation: E = mc2

c = speed of light 300,000,000 m/s and c2 = 9 x 10 16

Q1. How much energy is released?Q2. If the UK needs 50GW of power and power stations are 30% efficient , how long could a spoonful of sugar keep the UK supplied with electricity?

E = m x c2

E = 5 x 10 -3 x 9 x 10 16

E = 45 x 10 13 J

% Efficiency = useful power x 100% total power

total power = 50 x 10 9 x 100% 30%

= 167 x 10 9 W

Page 8: NUCLEAR  FISSION

If all the mass in a spoonful of sugar (5g) was converted to energyby Einstein’s equation: E = mc2

c = speed of light 300,000,000 m/s and c2 = 9 x 10 16

Q1. How much energy is released?Q2. If the UK needs 50GW of power and power stations are 30% efficient , how long could a spoonful of sugar keep the UK supplied with electricity?

E = m x c2

E = 5 x 10 -3 x 9 x 10 16

E = 45 x 10 13 J

Power = Energy transferred time

time (sec) = Energy transferred = 45 x 10 13 J = 0.27 x 10 4 sec Power 167 x 10 9 W = 45 Mins

% Efficiency = useful power x 100% total power

total power = 50 x 10 9 x 100% 30%

= 167 x 10 9 W

Page 9: NUCLEAR  FISSION

If all the mass in a spoonful of sugar (5g) was converted to energyby Einstein’s equation: E = mc2

c = speed of light 300,000,000 m/s and c2 = 9 x 10 16

Q1. How much energy is released?Q2. If the UK needs 50GW of power and power stations are 30% efficient , how long could a spoonful of sugar keep the UK supplied with electricity?

E = m x c2

E = 5 x 10 -3 x 9 x 10 16

E = 45 x 10 13 J

% Efficiency = useful power x 100% total power

total power = 50 x 10 9 x 100% 30%

= 167 x 10 9 W

Page 10: NUCLEAR  FISSION

If all the mass in a spoonful of sugar (5g) was converted to energyby Einstein’s equation: E = mc2

c = speed of light 300,000,000 m/s and c2 = 9 x 10 16

Q1. How much energy is released?Q2. If the UK needs 50GW of power and power stations are 30% efficient , how long could a spoonful of sugar keep the UK supplied with electricity?

E = m x c2

E = 5 x 10 -3 x 9 x 10 16

E = 45 x 10 13 J

Power = Energy transferred time

time (sec) = Energy transferred = 45 x 10 13 J = 0.27 x 10 4 sec Power 167 x 10 9 W = 45 Mins

% Efficiency = useful power x 100% total power

total power = 50 x 10 9 x 100% 30%

= 167 x 10 9 W

Page 11: NUCLEAR  FISSION

If all the mass in a spoonful of sugar (5g) was converted to energyby Einstein’s equation: E = mc2

c = speed of light 300,000,000 m/s and c2 = 9 x 10 16

Q1. How much energy is released?Q2. If the UK needs 50GW of power and power stations are 30% efficient , how long could a spoonful of sugar keep the UK supplied with electricity?

E = m x c2

E = 5 x 10 -3 x 9 x 10 16

E = 45 x 10 13 J

Power = Energy transferred time

time (sec) = Energy transferred = 45 x 10 13 J = 0.27 x 10 4 sec Power 167 x 10 9 W = 45 Mins

% Efficiency = useful power x 100% total power

total power = 50 x 10 9 x 100% 30%

= 167 x 10 9 W

Page 12: NUCLEAR  FISSION

If all the mass in a spoonful of sugar (5g) was converted to energyby Einstein’s equation: E = mc2

c = speed of light 300,000,000 m/s and c2 = 9 x 10 16

Q1. How much energy is released?Q2. If the UK needs 50GW of power and power stations are 30% efficient , how long could a spoonful of sugar keep the UK supplied with electricity?

E = m x c2

E = 5 x 10 -3 x 9 x 10 16

E = 45 x 10 13 J

Power = Energy transferred time

time (sec) = Energy transferred = 45 x 10 13 J = 0.27 x 10 4 sec Power 167 x 10 9 W = 45 Minsso 1Kg bag of sugar could keep the national grid running for 6 days!

% Efficiency = useful power x 100% total power

total power = 50 x 10 9 x 100% 30%

= 167 x 10 9 W

Page 13: NUCLEAR  FISSION

Nuclear Bombs

Sub critical masses

Page 14: NUCLEAR  FISSION

Nuclear Bombs

above critical mass

Page 15: NUCLEAR  FISSION

A PWR REACTOR


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