Chapter 1 - Introduction Flashcards
What is the pressure in a PWR?
15 MPa
What is the pressure in a BWR?
7 MPa
What is the temp at a PWR?
300
What is the temp at BWR?
280
Where are the controle rods in the PWR?
Up
Where are the control rods in the BWR?
Bottom
what is the irradiation level in a pwr in n/cm2-sec?
10^14
What type of steel is use for the RPV in a PWR”
308, 309 SS
material used for control rods in pwr?
ss cladding with b4c poison
what is the fuel cladding made of?
zr alloy
what is the fuel made of?
uo2
name fuel material issues?
fission gas release; fission product swelling; thermal conductivity decrease with burnup
name cladding material issues
waterside corrosion and hydriding, embrittlement, growth; pellet-cladding interaction; creep; fretting
name neutorn absorbers material issues
embrittlement; thermal mechanical failiure
name rpv material issues
radiation embrittlement
name the 4 main irradiation effects on structural materials
irradiation hardening and embrittlement
irradiation and thermal creep
volumetric swelling
he embrittlement (fusion)
What is dpa?
displacement per atom
how many dpa in a current gen 2 fission reactor
from 10 o 30 dpa
how many dpa in a msr?
100-190
what is creep?
tendence of solid material to move slowly or deform permanently under influence of persistent mechanical stresses that occurs in long-term exposure to high levels of stress.
Wha is moderate swelling
1-5% swelling leading to volume changes and distortion
what is large swelling
swelling of 10% causing severe embrittlement
What is embrittlement?
decrease of ductility of a material makingit brittle.
Why are SS not use in fast reactor?
14% swelling of 316 SS irradiated at 400 degrees