-
Home
- College physics
- Medical applications of nuclear
- Fission
Conceptual questions
Explain, in terms of conservation of momentum and energy, why collisions of neutrons with protons will thermalize neutrons better than collisions with oxygen.
Got questions? Get instant answers now!
The ruins of the Chernobyl reactor are enclosed in a huge concrete structure built around it after the accident. Some rain penetrates the building in winter, and radioactivity from the building increases. What does this imply is happening inside?
Got questions? Get instant answers now!
Since the uranium or plutonium nucleus fissions into several fission fragments whose mass distribution covers a wide range of pieces, would you expect more residual radioactivity from fission than fusion? Explain.
Got questions? Get instant answers now!
The core of a nuclear reactor generates a large amount of thermal energy from the decay of fission products, even when the power-producing fission chain reaction is turned off. Would this residual heat be greatest after the reactor has run for a long time or short time? What if the reactor has been shut down for months?
Got questions? Get instant answers now!
Why can heavy nuclei with odd numbers of neutrons be induced to fission with thermal neutrons, whereas those with even numbers of neutrons require more energy input to induce fission?
Got questions? Get instant answers now!
Problem exercises
(a) Calculate the energy released in the neutron-induced fission (similar to the spontaneous fission in
[link] )
given
and
. (b) This result is about 6 MeV greater than the result for spontaneous fission. Why? (c) Confirm that the total number of nucleons and total charge are conserved in this reaction.
(a) 177.1 MeV
(b) Because the gain of an external neutron yields about 6 MeV, which is the average
for heavy nuclei.
(c)
Got questions? Get instant answers now!
(a) Calculate the energy released in the neutron-induced fission reaction
given
and
.
(b) Confirm that the total number of nucleons and total charge are conserved in this reaction.
Got questions? Get instant answers now!
(a) Calculate the energy released in the neutron-induced fission reaction
given
and
.
(b) Confirm that the total number of nucleons and total charge are conserved in this reaction.
(a) 180.6 MeV
(b)
Got questions? Get instant answers now!
Breeding plutonium produces energy even before any plutonium is fissioned. (The primary purpose of the four nuclear reactors at Chernobyl was breeding plutonium for weapons. Electrical power was a by-product used by the civilian population.) Calculate the energy produced in each of the reactions listed for plutonium breeding just following
[link] . The pertinent masses are
,
, and
.
4.81 MeV
0.753 MeV
0.211 MeV
Got questions? Get instant answers now!
The naturally occurring radioactive isotope
does not make good fission fuel, because it has an even number of neutrons; however, it can be bred into a suitable fuel (much as
is bred into
).
(a) What are
and
for
?
(b) Write the reaction equation for neutron captured by
and identify the nuclide
produced in
.
(c) The product nucleus
decays, as does its daughter. Write the decay equations for each, and identify the final nucleus.
(d) Confirm that the final nucleus has an odd number of neutrons, making it a better fission fuel.
(e) Look up the half-life of the final nucleus to see if it lives long enough to be a useful fuel.
Got questions? Get instant answers now!
The electrical power output of a large nuclear reactor facility is 900 MW. It has a 35.0% efficiency in converting nuclear power to electrical.
(a) What is the thermal nuclear power output in megawatts?
(b) How many
nuclei fission each second, assuming the average fission produces 200 MeV?
(c) What mass of
is fissioned in one year of full-power operation?
(a)
(b)
(c) 991 kg
Got questions? Get instant answers now!
A large power reactor that has been in operation for some months is turned off, but residual activity in the core still produces 150 MW of power. If the average energy per decay of the fission products is 1.00 MeV, what is the core activity in curies?
Got questions? Get instant answers now!
Questions & Answers
how does the planets on our solar system orbit
how many Messier objects are there in space
Astronomy (from Ancient Greek ἀστρονομία (astronomía) 'science that studies the laws of the stars') is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution.
Rafael
what is big bang theory?
Rosemary
what type of activity astronomer do?
Rosemary
the big bang theory is a theory which states that all matter was compressed together in one place the matter got so unstable it exploded releasing All its contents in the form of hydrogen
Roaul
I want to be an astronomer. That's my dream
Astrit
Who named the the whole galaxy?
what is the dark matter
Richard
what are the factors upon which the atmosphere is stratified
bigbang is the beginning of the universe
Sokak
but thats just a theory
Sokak
nothing will happen, don't worry brother.
Vansh
these are Rocky substances between mars and jupiter
GANGAIN
Comets are cosmic snowballs of frozen gases , rock and dust that orbit the sun. They are mostly found between the orbits of Venus and Mercury.
Aarya
hey can anyone guide me abt international astronomy olympiad
sahil
how can we learn right and true ?
why the moon is always appear in an elliptical shape
Because when astroid hit the Earth then a piece of elliptical shape of the earth was separated which is now called moon.
Hemen
Did you mean eye sight or sea level
Minal
oh sorry it's sea level
lidiya
according to the theory of astronomers why the moon is always appear in an elliptical orbit?
Gatjuol
hi !!! I am new in astronomy....
I have so many questions in mind ....
all of scientists of the word they just give opinion only.
but they never think true or false ...
i respect all of them...
I believes whole universe depending
on true ...থিউরি
Govinda
we're all stars and galaxies a part of sun. how can science prove thx with respect old ancient times picture or books..or anything with respect to present time .but we r a part of that universe
w astronomy and cosmology!
Michele
another theory of universe except big ban
there many theory to born universe but what is the reality of big bang theory to born universe
Asmit
what is the exact value of π?
Nagalakshmi
there are many theories regarding this it's on you believe any theory that you think is true ex. eternal inflation theory, oscillation model theory, multiple universe theory the big bang theory etc.
Aarya
I think after Big Bang!
Michele
from where on earth could u observe all the stars during the during the course of an year
I think it couldn't possible on earth
Nagalakshmi
in this time i don't Know
Michele
is that so. the question was in the end of this chapter
Karuna
in theory, you could see them all from the equator (though over the course of a year, not at pne time). stars are measured in "declination", which is how far N or S of the equator (90* to -90*). Polaris is the North star, and is ALMOST 90* (+89*).
So it would just barely creep over the horizon.
Christopher
Got questions? Join the online conversation and get instant answers!
Source:
OpenStax, College physics. OpenStax CNX. Jul 27, 2015 Download for free at http://legacy.cnx.org/content/col11406/1.9
Google Play and the Google Play logo are trademarks of Google Inc.