PRESSURIZED THERMAL SHOCK
Locations of Primary Concern
Locations in the reactor system, in addition to the reactor pressure vessel, that are primary
concerns for thermal shock include the pressurizer spray line and the purification system.
The important information in this chapter is summarized below.
Pressurized Thermal Shock Summary
Definition of pressurized thermal shock (PTS)
Shock experienced by a thick-walled vessel due to the combined stresses
from a rapid temperature and/or pressure change.
Pressure in closed system raises the severity of thermal shock due to the additive
effect of thermal and pressure tensile stresses on the inside reactor vessel wall.
Plant transients with greatest potential to cause PTS include:
Excessive heatup and cooldown
Plant pressure excursions outside of normal pressure bands
Loss of coolant accident
Locations of primary concern for thermal shock are:
Pressurizer spray line