A possible neutron-induced fission reaction is

$^{235}_{92}\text{U}+^{1}_{0}\text{n}\to ^{141}_{56}\text{Ba}+^{92}_{36}\text{Kr}+3\,^{1}_{0}\text{n}+\Delta E$

The atomic masses are: $^{235}\text{U}=235.0439\ \text{u}$, $^{141}\text{Ba}=140.9144\ \text{u}$, $^{92}\text{Kr}=91.9262\ \text{u}$ and neutron $=1.008665\ \text{u}$. Use $1\ \text{u}=931.5\ \text{MeV}\ c^{-2}$.

A simplified nuclear reactor contains fuel rods, a moderator, control rods, a coolant circuit, a heat exchanger and shielding.

Spent nuclear fuel contains many different fission products.

Energy released in fission appears in several forms, including kinetic energy of fragments and neutrons, gamma photons and energy carried by antineutrinos from later beta-minus decays.

The graph shows the number of neutrons in a reactor core after successive fission generations for three different positions of the control rods.

The graph shows how binding energy per nucleon varies with nucleon number.

Some countries use nuclear fission power stations as part of their strategy to reduce carbon emissions.

A nuclear power station has an electrical output power of $900\ \text{MW}$. The overall efficiency for converting fission energy to electrical energy is $0.36$. Each fission releases $200\ \text{MeV}$. Use $1\ \text{MeV}=1.60\times 10^{-13}\ \text{J}$ and the molar mass of uranium-235 as $0.235\ \text{kg mol}^{-1}$.

After shutdown, a reactor continues to produce thermal power due to radioactive decay of fission products. A sample of spent fuel produces $480\ \text{kW}$ of decay heat from one isotope immediately after removal. The isotope has a half-life of $6.0\ \text{h}$. Assume the heat production from this isotope is proportional to its activity.

The graph shows the probability of neutron-induced fission in uranium-235 as a function of neutron kinetic energy.

A possible neutron-induced fission reaction of uranium-235 is shown.

$^{235}_{92}\text{U}+^{1}_{0}\text{n}\to ^{141}_{56}\text{Ba}+^{92}_{36}\text{Kr}+x\,^{1}_{0}\text{n}+\Delta E$

The table gives atomic masses for the nuclides involved.

The diagram shows part of a pressurized-water nuclear power plant. The primary circuit passes through the reactor core and a heat exchanger. The secondary circuit drives a turbine.

The graph shows the activity of two fission products, X and Y, in spent fuel after removal from a reactor. The initial number of nuclei of X and Y is the same.

The graph shows the relative yield of fission fragments from uranium-235 as a function of fragment nucleon number.

A sample of spent fuel contains equal numbers of nuclei of iodine-131 and strontium-90. Iodine-131 has a half-life of $8.0\ \text{days}$ and strontium-90 has a half-life of $29\ \text{years}$.

Some spent nuclear fuel can be reprocessed to separate uranium and plutonium from fission products before disposal.

A nuclear power station uses uranium-235 fission. The table gives the electrical output, the overall efficiency and the energy released per fission.

The graph shows binding energy per nucleon as a function of nucleon number. A fission of uranium-235 produces two fragments with nucleon numbers near the peaks shown on the graph.

A simplified neutron-economy table for a thermal reactor shows the average number of neutrons released per fission and the fraction of those neutrons that induce a further uranium-235 fission under three operating conditions.

The table gives data for three radioactive isotopes found in high-level nuclear waste. The proposed waste-management plan is initial pond storage followed by immobilization in glass and underground disposal.

A country is considering replacing part of its gas-fired electricity generation with nuclear fission. The table compares selected data for gas, wind and nuclear generation.

A possible neutron-induced fission reaction of uranium-235 is

$^{235}_{92}\text{U}+^{1}_{0}\text{n}\to ^{94}_{38}\text{Sr}+^{140}_{54}\text{Xe}+x\,^{1}_{0}\text{n}+\Delta E.$

The atomic masses are:

$\begin{aligned} ^{235}\text{U} &=235.0439\ \text{u}\\ ^{94}\text{Sr} &=93.9154\ \text{u}\\ ^{140}\text{Xe} &=139.9216\ \text{u}\\ ^{1}\text{n} &=1.008665\ \text{u} \end{aligned}$

Use $1\ \text{u}=931.5\ \text{MeV}\ c^{-2}$.

The graph shows the general variation of binding energy per nucleon with nucleon number.

Spent fuel removed from a reactor contains many radioactive fission products. One important isotope is strontium-90, which undergoes beta-minus decay with a half-life of $28.8\ \text{years}$.

The graph compares the mean fraction of kinetic energy retained by a neutron after one elastic collision with different moderator nuclei. A reactor design must reduce fission neutrons from MeV energies to thermal energies.

The graph shows the thermal power produced in a reactor after an emergency shutdown. The control rods are fully inserted at $t=0$. The fission chain reaction falls rapidly, but decay heat remains.

The diagram shows a simplified reactor core containing fuel rods, a moderator and movable control rods. Neutrons released in fission can either cause further fissions, escape from the core, or be absorbed without causing fission.

A nuclear power station has an electrical output power of $900\ \text{MW}$ and an overall efficiency of $0.36$. Each fission releases $202\ \text{MeV}$ of energy. Assume that all of this energy is transferred as thermal energy in the reactor core.

Use $1\ \text{MeV}=1.602\times10^{-13}\ \text{J}$ and $1\ \text{u}=1.661\times10^{-27}\ \text{kg}$.

The diagram shows a pressurized-water nuclear power station. The primary circuit passes through the reactor core and a heat exchanger. The secondary circuit produces steam for a turbine and generator.

Californium-252 can undergo spontaneous fission. One possible reaction is

$^{252}_{98}\text{Cf}\to ^{108}_{42}\text{Mo}+^{140}_{56}\text{Ba}+4\,^{1}_{0}\text{n}+\Delta E.$

The atomic masses are:

$\begin{aligned} ^{252}\text{Cf} &=252.0816\ \text{u}\\ ^{108}\text{Mo} &=107.9360\ \text{u}\\ ^{140}\text{Ba} &=139.9106\ \text{u}\\ ^{1}\text{n} &=1.008665\ \text{u} \end{aligned}$

Use $1\ \text{u}=931.5\ \text{MeV}\ c^{-2}$.

A reactor designer is comparing possible materials for use in a thermal reactor core. The table gives qualitative information about four materials.

A reactor operating at a thermal power of $3.0\ \text{GW}$ is shut down by fully inserting the control rods. The graph shows the thermal power produced by radioactive decay products after shutdown as a percentage of the original thermal power.

The graph shows how the activity of several isotopes in spent nuclear fuel changes with time after removal from a reactor.

In a reactor, a typical fission releases about $202\ \text{MeV}$. One possible approximate energy distribution is shown in the table.

The electrical output power is $1.20\ \text{GW}$ and the efficiency for converting recoverable thermal energy to electrical energy is $0.33$.

Use $1\ \text{MeV}=1.602\times10^{-13}\ \text{J}$.

A country is considering replacing a coal-fired power station with a nuclear fission power station. Both stations would provide a rated electrical power of $1.0\ \text{GW}$ with a capacity factor of $0.90$.

The coal station emits $0.85\ \text{kg}$ of $CO_2$ per $\text{kWh}$ generated. The estimated life-cycle emission for the nuclear station is $0.012\ \text{kg}$ of $CO_2$ per $\text{kWh}$ generated.