Auto Depressurization System (ADS) Flashcards
What is the Time Delay to initiate ADS?
105 sec
What pressures are required for the ECCS pumps for ADS initiation?
CSL: 145#
RHR: 125#
What powers the ADS solenoids?
DIV1 DC: A/C solenoids
DIV2 DC: B solenoids
What differential pressure is the SRV tailpipe set at?
0.2psid, located in DW
How many blowdowns are the accumulators designed for?
1
What is the MAX temp on the temp element for the SRVs?
404F
What is the volume of the ‘C’ accumulators (relief)
2 cubic feet
What is the volume of the ‘A’ & ‘B’ accumulators (ADS)
10 cubic feet
What happens if Tk2 for nitrogen is <79#
SCRAM
What is the length of time the N2 yard can supply N2 for?
100 days
What is the length of time the N2 Tk 4 & 5 can supply N2 for?
5 days
How many hours can an accumulator supply N2 to an ADS valve if pressure is >160#
13.8 hrs
What must be done after any discharge of steam to the suppression chamber from the safety/relief valves?
DRYWELL VACUUM BREAKER OPERABILITY TEST, within 12 hours of any discharge per TSR 3.6.1.7.2
What does Relief Mode require to operate?
Both PT 5s functional (2 out of 2)
What provides Panel 601 indication for the relief/safety valves.
Acoustic monitoring, ‘C’ solenoids
What pressure must relief/safety valve accumulators be below and why?
<200#s or leakby may stroke valves.
What are SRVs meant to handle?
Pressure transient from MSIV full closure.
How many ADS valves are on N2 Tk 4?
3
How many ADS valves are on N2 Tk 5?
4
What pressure must be maintained in N2 Tk 4 & 5 for ADS?
> 334#
What does 1 SRV equate to in Rx Pwr and Steam Flow
approx 5% Rx Pwer
5% Steam Flow
What SRVs are the ADS valves?
121, 126, 127, 129, 130, 134, 137
