Plutonium-239 builds up in reactor fuel at a rate that depends on the probability of neutron capture by
(all reactor fuel contains more
than
). Reactors designed specifically to make plutonium are called
breeder reactors . They seem to be inherently more hazardous than conventional reactors, but it remains unknown whether their hazards can be made economically acceptable. The four reactors at Chernobyl, including the one that was destroyed, were built to breed plutonium and produce electricity. These reactors had a design that was significantly different from the pressurized water reactor illustrated above.
Plutonium-239 has advantages over
as a reactor fuel — it produces more neutrons per fission on average, and it is easier for a thermal neutron to cause it to fission. It is also chemically different from uranium, so it is inherently easier to separate from uranium ore. This means
has a particularly small critical mass, an advantage for nuclear weapons.
Phet explorations: nuclear fission
Start a chain reaction, or introduce non-radioactive isotopes to prevent one. Control energy production in a nuclear reactor!
Test prep for ap courses
Which of the following statements about nuclear fission is true?
No new elements can be produced in a fission reaction.
Energy released in fission reactions is generally less than that from fusion reactions.
In a fission reaction, two light nuclei are combined into a heavier one.
Fission reactions can be explained on the basis of the conservation of mass-energy.
When
235 U is bombarded with one neutron, the following fission reaction occurs:
.
Find the values for
x and y.
Assuming that the mass of
235 U is 235.04 u, the mass of
141 Ba is 140.91 u, the mass of
92 Kr is 91.93 u, and the mass of
n is 1.01 u, a student calculates the energy released in the fission reaction as 2.689 × 10
−8 , but forgets to write the unit. Find the correct unit and convert the answer to MeV.
Nuclear fission is a reaction in which a nucleus is split.
Fission releases energy when heavy nuclei are split into medium-mass nuclei.
Self-sustained fission is possible, because neutron-induced fission also produces neutrons that can induce other fissions,
, where
and
are the two daughter nuclei, or fission fragments, and
x is the number of neutrons produced.
A minimum mass, called the critical mass, should be present to achieve criticality.
More than a critical mass can produce supercriticality.
The production of new or different isotopes (especially
) by nuclear transformation is called breeding, and reactors designed for this purpose are called breeder reactors.
Wayne and Dennis like to ride the bike path from Riverside Park to the beach. Dennis’s speed is seven miles per hour faster than Wayne’s speed, so it takes Wayne 2 hours to ride to the beach while it takes Dennis 1.5 hours for the ride. Find the speed of both bikers.
from theory: distance [miles] = speed [mph] × time [hours]
info #1
speed_Dennis × 1.5 = speed_Wayne × 2
=> speed_Wayne = 0.75 × speed_Dennis (i)
info #2
speed_Dennis = speed_Wayne + 7 [mph] (ii)
use (i) in (ii) => [...]
speed_Dennis = 28 mph
speed_Wayne = 21 mph
George
Let W be Wayne's speed in miles per hour and D be Dennis's speed in miles per hour. We know that W + 7 = D and W * 2 = D * 1.5.
Substituting the first equation into the second:
W * 2 = (W + 7) * 1.5
W * 2 = W * 1.5 + 7 * 1.5
0.5 * W = 7 * 1.5
W = 7 * 3 or 21
W is 21
D = W + 7
D = 21 + 7
D = 28
Salma
Devon is 32 32 years older than his son, Milan. The sum of both their ages is 54 54. Using the variables d d and m m to represent the ages of Devon and Milan, respectively, write a system of equations to describe this situation. Enter the equations below, separated by a comma.
please why is it that the 0is in the place of ten thousand
Grace
Send the example to me here and let me see
Stephen
A meditation garden is in the shape of a right triangle, with one leg 7 feet. The length of the hypotenuse is one more than the length of one of the other legs. Find the lengths of the hypotenuse and the other leg
however, may I ask you some questions about Algarba?
Amoon
hi
Enock
what the last part of the problem mean?
Roger
The Jones family took a 15 mile canoe ride down the Indian River in three hours. After lunch, the return trip back up the river took five hours. Find the rate, in mph, of the canoe in still water and the rate of the current.
Shakir works at a computer store. His weekly pay will be either a fixed amount, $925, or $500 plus 12% of his total sales. How much should his total sales be for his variable pay option to exceed the fixed amount of $925.
I'm guessing, but it's somewhere around $4335.00 I think
Lewis
12% of sales will need to exceed 925 - 500, or 425 to exceed fixed amount option. What amount of sales does that equal? 425 ÷ (12÷100) = 3541.67. So the answer is sales greater than 3541.67.
Check:
Sales = 3542
Commission 12%=425.04
Pay = 500 + 425.04 = 925.04.
925.04 > 925.00
Munster
difference between rational and irrational numbers
Jazmine trained for 3 hours on Saturday. She ran 8 miles and then biked 24 miles. Her biking speed is 4 mph faster than her running speed. What is her running speed?