nuclear fission & fusion. fission: a heavy nucleus splits into 2 lighter nuclei some elements...
TRANSCRIPT
![Page 1: Nuclear Fission & Fusion. FISSION: a heavy nucleus splits into 2 lighter nuclei some elements undergo fission spontaneously some elements can be induced](https://reader030.vdocuments.site/reader030/viewer/2022032703/56649d095503460f949dba3c/html5/thumbnails/1.jpg)
Nuclear Fission & Fusion
![Page 2: Nuclear Fission & Fusion. FISSION: a heavy nucleus splits into 2 lighter nuclei some elements undergo fission spontaneously some elements can be induced](https://reader030.vdocuments.site/reader030/viewer/2022032703/56649d095503460f949dba3c/html5/thumbnails/2.jpg)
FISSION: a heavy nucleus splits into 2 lighter nuclei
some elements undergo fission spontaneously
some elements can be induced to undergo fission when bombarded with other particles (e.g. neutrons)
![Page 3: Nuclear Fission & Fusion. FISSION: a heavy nucleus splits into 2 lighter nuclei some elements undergo fission spontaneously some elements can be induced](https://reader030.vdocuments.site/reader030/viewer/2022032703/56649d095503460f949dba3c/html5/thumbnails/3.jpg)
FUSION: 2 nuclei combine to form a heavier nucleus
the sun is a tremendous fusion reaction; the major fusion reaction in the sun is thought to be:
both fission & fusion release large amounts of energy (fusion more than fission)
energy!nHeHH 10
42
31
21
![Page 4: Nuclear Fission & Fusion. FISSION: a heavy nucleus splits into 2 lighter nuclei some elements undergo fission spontaneously some elements can be induced](https://reader030.vdocuments.site/reader030/viewer/2022032703/56649d095503460f949dba3c/html5/thumbnails/4.jpg)
The Atomic Bomb (FISSION)
when the nucleus of U-235 splits, 2 isotopes are formed, plus neutrons are emitted
these neutrons collide with other U-235 atoms, causing them to undergo fission; they release neutrons, and so on…
The result - CHAIN REACTION!!
![Page 5: Nuclear Fission & Fusion. FISSION: a heavy nucleus splits into 2 lighter nuclei some elements undergo fission spontaneously some elements can be induced](https://reader030.vdocuments.site/reader030/viewer/2022032703/56649d095503460f949dba3c/html5/thumbnails/5.jpg)
FISSION
![Page 6: Nuclear Fission & Fusion. FISSION: a heavy nucleus splits into 2 lighter nuclei some elements undergo fission spontaneously some elements can be induced](https://reader030.vdocuments.site/reader030/viewer/2022032703/56649d095503460f949dba3c/html5/thumbnails/6.jpg)
CHAIN REACTION!!!
![Page 7: Nuclear Fission & Fusion. FISSION: a heavy nucleus splits into 2 lighter nuclei some elements undergo fission spontaneously some elements can be induced](https://reader030.vdocuments.site/reader030/viewer/2022032703/56649d095503460f949dba3c/html5/thumbnails/7.jpg)
The Atomic Bomb (FISSION)
![Page 8: Nuclear Fission & Fusion. FISSION: a heavy nucleus splits into 2 lighter nuclei some elements undergo fission spontaneously some elements can be induced](https://reader030.vdocuments.site/reader030/viewer/2022032703/56649d095503460f949dba3c/html5/thumbnails/8.jpg)
The Atomic Bomb (FISSION)
![Page 9: Nuclear Fission & Fusion. FISSION: a heavy nucleus splits into 2 lighter nuclei some elements undergo fission spontaneously some elements can be induced](https://reader030.vdocuments.site/reader030/viewer/2022032703/56649d095503460f949dba3c/html5/thumbnails/9.jpg)
CRITICAL MASS
The minimum mass of fissionable material that must be used to sustain a chain reaction
![Page 10: Nuclear Fission & Fusion. FISSION: a heavy nucleus splits into 2 lighter nuclei some elements undergo fission spontaneously some elements can be induced](https://reader030.vdocuments.site/reader030/viewer/2022032703/56649d095503460f949dba3c/html5/thumbnails/10.jpg)
One type of bomb…
Little Boy: U-235 (Hiroshima)
Fat Man: Pu-239 (Nagasaki)
subcritical mass of U-235
subcritical mass of U-235
TNT(dynamite)
![Page 11: Nuclear Fission & Fusion. FISSION: a heavy nucleus splits into 2 lighter nuclei some elements undergo fission spontaneously some elements can be induced](https://reader030.vdocuments.site/reader030/viewer/2022032703/56649d095503460f949dba3c/html5/thumbnails/11.jpg)
“Little Boy”
![Page 12: Nuclear Fission & Fusion. FISSION: a heavy nucleus splits into 2 lighter nuclei some elements undergo fission spontaneously some elements can be induced](https://reader030.vdocuments.site/reader030/viewer/2022032703/56649d095503460f949dba3c/html5/thumbnails/12.jpg)
![Page 13: Nuclear Fission & Fusion. FISSION: a heavy nucleus splits into 2 lighter nuclei some elements undergo fission spontaneously some elements can be induced](https://reader030.vdocuments.site/reader030/viewer/2022032703/56649d095503460f949dba3c/html5/thumbnails/13.jpg)
Nuclear Reactors (controlled FISSION)
![Page 14: Nuclear Fission & Fusion. FISSION: a heavy nucleus splits into 2 lighter nuclei some elements undergo fission spontaneously some elements can be induced](https://reader030.vdocuments.site/reader030/viewer/2022032703/56649d095503460f949dba3c/html5/thumbnails/14.jpg)
Nuclear Reactors (FISSION)
use subcritical masses of fissionable material CORE: contains fuel pins made of U-235;
interspersed among the pins are control rods control rods: absorb neutrons
– pull rods out of core: fission increases– push rods back into the core: fission decreases
Safety feature: if power is lost, rods will automatically fall into the core and shut the reaction down.
![Page 15: Nuclear Fission & Fusion. FISSION: a heavy nucleus splits into 2 lighter nuclei some elements undergo fission spontaneously some elements can be induced](https://reader030.vdocuments.site/reader030/viewer/2022032703/56649d095503460f949dba3c/html5/thumbnails/15.jpg)
Nuclear Reactors (FISSION)
“The energy produced by breaking down the atom is a very poor kind of thing. Anyone who expects a source of power from the transformation of these atoms is talking moonshine.”
Ernest Rutherford
![Page 16: Nuclear Fission & Fusion. FISSION: a heavy nucleus splits into 2 lighter nuclei some elements undergo fission spontaneously some elements can be induced](https://reader030.vdocuments.site/reader030/viewer/2022032703/56649d095503460f949dba3c/html5/thumbnails/16.jpg)
Nuclear Reactors (FISSION)
![Page 17: Nuclear Fission & Fusion. FISSION: a heavy nucleus splits into 2 lighter nuclei some elements undergo fission spontaneously some elements can be induced](https://reader030.vdocuments.site/reader030/viewer/2022032703/56649d095503460f949dba3c/html5/thumbnails/17.jpg)
Nuclear Power Plants
![Page 18: Nuclear Fission & Fusion. FISSION: a heavy nucleus splits into 2 lighter nuclei some elements undergo fission spontaneously some elements can be induced](https://reader030.vdocuments.site/reader030/viewer/2022032703/56649d095503460f949dba3c/html5/thumbnails/18.jpg)
Nuclear Power Plants
![Page 19: Nuclear Fission & Fusion. FISSION: a heavy nucleus splits into 2 lighter nuclei some elements undergo fission spontaneously some elements can be induced](https://reader030.vdocuments.site/reader030/viewer/2022032703/56649d095503460f949dba3c/html5/thumbnails/19.jpg)
Nuclear Power Plants
![Page 20: Nuclear Fission & Fusion. FISSION: a heavy nucleus splits into 2 lighter nuclei some elements undergo fission spontaneously some elements can be induced](https://reader030.vdocuments.site/reader030/viewer/2022032703/56649d095503460f949dba3c/html5/thumbnails/20.jpg)
TO GENERATE ELECTRICITY:
1) Fission heats up water in vessel and heat is carried away.
2) This heat is used to heat up water in a second system, which turns into steam.
3) Steam turns turbine of a generator.
4) Generator makes electricity.
![Page 21: Nuclear Fission & Fusion. FISSION: a heavy nucleus splits into 2 lighter nuclei some elements undergo fission spontaneously some elements can be induced](https://reader030.vdocuments.site/reader030/viewer/2022032703/56649d095503460f949dba3c/html5/thumbnails/21.jpg)
PROS OF NUCLEAR ENERGY:
no air pollution enormous amt. of energy released alternative to using our rapidly decreasing
fossil fuels
![Page 22: Nuclear Fission & Fusion. FISSION: a heavy nucleus splits into 2 lighter nuclei some elements undergo fission spontaneously some elements can be induced](https://reader030.vdocuments.site/reader030/viewer/2022032703/56649d095503460f949dba3c/html5/thumbnails/22.jpg)
CONS OF NUCLEAR ENERGY
containers for waste products may erode or break
thermal pollution (heated water returned to rivers, etc.)
potential theft of fuel (Pu-239) for use in weapons
![Page 23: Nuclear Fission & Fusion. FISSION: a heavy nucleus splits into 2 lighter nuclei some elements undergo fission spontaneously some elements can be induced](https://reader030.vdocuments.site/reader030/viewer/2022032703/56649d095503460f949dba3c/html5/thumbnails/23.jpg)
Controlled Nuclear FUSION
PROS:– A very abundant supply of energy world wide.– Environmentally clean– No creation of weapon materials– No chance of runaway reactions leading to
accidents
CONS:– It doesn’t work; at least not yet…
![Page 24: Nuclear Fission & Fusion. FISSION: a heavy nucleus splits into 2 lighter nuclei some elements undergo fission spontaneously some elements can be induced](https://reader030.vdocuments.site/reader030/viewer/2022032703/56649d095503460f949dba3c/html5/thumbnails/24.jpg)
Nuclear Fusion
"Every time you look up at the sky, every one of those points of light is a reminder that fusion power is extractable from hydrogen and other light elements, and it is an everyday reality throughout the Milky Way Galaxy."
Carl Sagan, Spitzer Lecture, October 1991
![Page 25: Nuclear Fission & Fusion. FISSION: a heavy nucleus splits into 2 lighter nuclei some elements undergo fission spontaneously some elements can be induced](https://reader030.vdocuments.site/reader030/viewer/2022032703/56649d095503460f949dba3c/html5/thumbnails/25.jpg)
Nuclear Fusion
Obstacles…– HOT – plasma at least 100 million C– High density plasma– Containment of plasma– Confinement time