FR-P.1 & P.2 (Press Therm Shck) Flashcards
FR-P….
Which part of the Rx vessel is most susceptible to PTS?
Why?
What transient (H/U or C/D) produces the greatest total tensile stress on this component?
The Rx vessel inner wall
the pressure, residual, and transient stresses are cumulative (tensile) during the most limiting transient
Cooldown
FR-P…
What “event” is the least likely to cause a PTS event?
What “event is most likely to cause a PTS event?
LBLOCA (not likely to re-pressurize)
SBLOCA
- low vessel downcommer temp
- hi RCS pressure
Limit A Curve
What is T1? What is T1 based on?
What is T2? What is T2 based on?
T1 = 280 º F, minimum temp allowed preventing growth of an existing flaw in the vessel wall
T2 = 310 º F, 30 deg F greater than T1 to allow the operator time to take action if approaching Limit A
PTS
What is the greatest concern regarding the consequences of PTS?
What is the cooldown rate limit that prevents PTS?
An existing flaw is caused to grow and generate a crack through the reactor vessel wall
100 º F / hr
FR-P.1
Why is the SI termination criteria different for CET in this procedure?
ECCS flow may have contributed to the PTS => SI term is less restrictive only asking for
CET > 70 º F
RVLIS > X
CET are 20 deg (instrument inaccuracey) plus 50 deg because of the less restrictive SI term
Why do you start an RCP if you are unable to secure SI?
If SI cannot be secured the RCP start will mix relatively hot water in the loops with incoming SI flow, reducing the cooldown of the Rx vessel downcomer.
FR-P.1
When would you have to perform a soak in FR-P.1?
Why is a soak performed?
What is the cooldown limit after a soak is performed?
If a cooldown of 100 º F in any one hour is exceeded
to allow stresses accumulated during the cooldown to lower (temps equalize)
50º/ hr
