Brittle Fracture
DOE-HDBK-1017/2-93
OBJECTIVES
TERMINAL OBJECTIVE
1.0
Without references, EXPLAIN the importance of controlling heatup and cooldown rates
of the primary coolant system.
ENABLING OBJECTIVES
1.1
DEFINE the following terms:
a.
Ductile fracture
b.
Brittle fracture
c.
Nil-ductility Transition (NDT) Temperature
1.2
DESCRIBE the two changes made to reactor pressure vessels to decrease NDT.
1.3
STATE the effect grain size and irradiation have on a material’s NDT.
1.4
LIST the three conditions necessary for brittle fracture to occur.
1.5
STATE the three conditions that tend to mitigate crack initiation.
1.6
LIST the five factors that determine the fracture toughness of a material.
1.7
Given a stress-temperature diagram, IDENTIFY the following points:
a.
NDT (with no flaw)
b.
NDT (with flaw)
c.
Fracture transition elastic point
d.
Fracture transition plastic point
1.8
STATE the two bases used for developing a minimum pressurization-temperature curve.
1.9
EXPLAIN a typical minimum pressure-temperature curve including:
a.
Location of safe operating region
b.
The way the curve will shift due to irradiation
Rev. 0
Page v
MS-04
