Resonances Flashcards
What happens at larger energies in heavier isotopes in terms of resonances?
resonances get to be so closely spaced that they can no longer be resolved into separate peaks experimentally.
What is the unresolved resonance range?
At higher energies and in heavier isotopes, the resonances get to be so closely spaced that they can no longer be resolved into separate peaks experimentally
What is the tensile strengh of aluminium?
276 MPA
What is the tensile strength of ss?
500MPA
What is the temperature of msr?
600 to 700 C
What is the temperature of fast reactors?
500 to 600 C
What is the melting point of MSR?
460 C
Why use Zr instead of SS for cladding?
- lower capture xs for thermal neutrons
- SS suffers embrittlement
What is the thermal cross section for Zr
0.07 barns
What is the thermal cross section for Iron
2.58 barns
Why use Fe instead of Zr for cladding?
- Zr accelerated oxidation reaction
- ## Better corrosion resistance at high temp up to two orders of magnitude
How can you improve resistance to IGSCC?
- By reducing carbon content to a maximum of 0.03% as in the case of 316L
- Addition of of Ti, Nb, AND Ta can prevent the precipitation of MC precipitates in the grain boundaries to avoid depletion of chromium
How do you stabilize austenite?
With elements having a similar crystal strcuture FCC
What is the effect of austenite stabilizers in the phase diagram?
It raises the A4point and decreases the A3 point.
What is the effect of austenite stabilizers in the phase diagram?
It decreases the A4 point and increases the A3 point.
What is the effect of ferrite stabilizers in carbon solubility?
Lower the solubility of carbon in austenite causing increase of amount of carbides in the steel that can be retained.
What is the effect of carbides in steels?
Increasing steel hardness and strength
What are three common elements used for corrosion resistance by oxide film
Al, Si, Cr
What is the primary determinant of swelling in steel?
The nickel level
