What are the differences between thermal slow neutron reactors and fast neutron reactors?

Distribution of slow and fast neutrons in a PWR: Slow neutrons are responsible for most of nuclear fission and therefore help sustain the chain reactions. Fast neutrons, on the other hand, play a small role in fission but can transform nuclei of uranium 238 into fissile plutonium 239.

What is the thermal neutron fluence rate of the reactor?

For 1-year reactor operation, the thermal and fast neutron fluence in the reactor vessel is 5.75x 015 n/cm2 and 5.65×1015 n/cm2 respectively. When the reactor is operated for 60 years, the fast neutron fluence in the reactor vessel is 3.4×1017 n/cm2.

What is thermal neutron and fast neutron?

A free thermal neutron has energy in the order of 0.025 eV (minor deviation possible). Fast neutron has significantly higher energy, in a range of 1 – 20 MeV. Velocity of thermal neutron is close to 2.2 km/s. Fast neutron has very high velocity, typically in the order of 2×104 km/s.

What is the difference in the size of the thermal reactor and fast reactor?

What is the difference in size of thermal reactor and fast reactor? Explanation: The moderator to fuel volume ratio for thermal reactor lies between 20 to 80. Same ratio for fast reactor is very less that’s why the size of thermal reactor is very much greater than size of fast reactors. 3.

What is the difference between thermal neutrons and fast neutrons?

These terms have to do with the energy of neutrons: thermal neutrons, as their name suggests, have the energy of the order kBT, whereas fast neutrons have much higher energies. You may check here for an even finer classification. Both types of neutrons can be used in nuclear reactions: fast and thermal.

What is the difference between flux and fluence?

is that flux is (physics) the rate of transfer of energy (or another physical quantity) through a given surface, specifically electric flux, magnetic flux while fluence is (physics) a measure of particle flux (or that of a pulse of electromagnetic radiation).

What is fast neutron flux?

Within a nuclear fission reactor, the neutron flux is the primary quantity measured to control the reaction inside. The higher the neutron flux the greater the chance of a nuclear reaction occurring as there are more neutrons going through an area per unit time.

How slow neutrons are more effective than fast neutrons?

Answer to Question #73479 in Atomic and Nuclear Physics for Adnan Rafi. show neutrons are more effective than fast ones in inducing fission. why? It is because slow neutrons have a highest fission probability (called cross-section) to be captured by a fissile nucleus then to trigger fission.

Why does a slower neutron initiate nuclear fission?

In one of the most remarkable phenomena in nature, a slow neutron can be captured by a uranium-235 nucleus, rendering it unstable toward nuclear fission. A fast neutron will not be captured, so neutrons must be slowed down by moderation to increase their capture probability in fission reactors.

What is thermal neutron flux?

The neutron flux, φ, is a scalar quantity used in nuclear physics and nuclear reactor physics. It is the total length travelled by all free neutrons per unit time and volume. Equivalently, it can be defined as the number of neutrons travelling through a small sphere of radius in a time interval, divided by.