ECCS Flashcards
State 4 accident conditions that form basis of ECCS
Loss of Primary Coolant (greater than 125gpm)
Loss of secondary coolant (FW/MS)
SG tube rupture
Rod ejection accident
State 5 ECCS acceptance criteria
Peak cladding temp <2200F
Total Cladding oxidation <17% of thickness
Total hydrogen production <1% of max
maintain coolable geometry
Long term cooling
State what actuates SI
Low PZR pressure <1800# (2 of 4)*
Hi-1 containment pressure >4.3# (2 of 3)
Low MS line pressure <585# (2 of 3 on 1 of 4 S/G)*
Manual
* Blockable by P-11
Discuss SI reset
60 second timer after actuation
With SI reset all subsequent Auto SI actuations are blocked
With RX trip breakers open (P-4) auto SI blocked after SI reset
Define active failure and state worse case scenario for Seabrook
A failure of a powered component to act on demand
Worse case: EDG fails to start
Define passive failure and state worse case scenario for Seabrook
A structural failure of a static component which limits effectiveness in performing its design function (flanges, seals, packing)
Worse case: RHR pump shaft seal failure (50GPM leak)
State ECCS injection pressures
HHI: (CCP) 2600#
IHI: (SI) 1530#
Accumulators: 600#
LHI: (RHR) 200#
State SI accumulators T.S. basis
Low level: 6121 Gal, insufficient volume
High level: 6596 Gal, insufficient gas volume causing premature exhaustion
Low Pressure: 585#, insufficient gas volume causing premature exhaustion
High Pressure: 664#, premature injection and more water out break
Describe CCP recirc flow
min flow returns to pump suction via seal water return line
Recirc closes at >122.5 GPM
Recirc opens at <82.5 GPM
Describe SIP recirc flow
min flow returns to RWST vis SI-V-89,90 and 93
Describe RHR recirc flow
From the discharger of the RHR HX back to the pump suction
Auto open <750 GPM
Auto Closed >1403 GPM
State what PCCW supplies to ECCS components
CCP: oil cooler (65 GPM)
SIP: oil cooler (45 GPM)
RHR: Seal water HX (6 GPM)
RHR-HX
Discuss how HHI responds to a SI signal
CCPs start
CS-LCV-112D/E open, suction from RWST
CS-LCV-112B/C close, suction from VCT
SI-V-138,139 open, RCS injection header isolations
CS-V-142/143 close, Charging header isolation
CS-V-196/197 close, CCP minflow if >122.5GPM
Discuss how IHI responds to a SI signal
SIPs start
Discuss how LHI responds to a SI signal
RHR pumps start
CBS-V-2/5 open, RWST outlet, normally open
CC-V-145/272 open, PCCW to RHR HX, normally open
What happens if offsite power is lost after SI is reset
manual action may be required to restart safeguards equipment
Discuss interlock between SIP minflow and RHR to CCP/SIP isolation
SI-V-89 and 90 or 93 must be closed to open RH-V-35/36
AND
CBS-V-8/14 must be open
AND
RC-V-22 or 23 AND 87 or 88 must be closed
This prevents a loss of inventory to RWST
also prevents moving highly contaminated water to RWST.
State T.S. values for RWST per T.S. 3.5.4
Volume: 477,000 Gallons
Low Temp: 50F
High Temp: 98F
Boron concentration per COLR (2500-2600)
State T.S. actions for RWST inop
Restore the tank to operable within 1 hour or be in at least hot standby within 6 HRs and cold shutdown in the following 30 HRs.
State basis for RWST pH per T.S. 3/4.5.4
pH between 8.5 and 11 to keep Iodine in solution and prevent corrosion
When and why do we go to hot leg recirculation
5 hours after event to prevent boron precipitation
quench steam bubble and avoid boron precipitation
State RWST Lo-lo level and action
120,478 Gallons
- CBS-V-8/14 open
- have to manually close CBS-V-2/5
State reason for SI-V-93 control power switch and how to operate
Prevents single failure from causing valve movement and requires operator to perform 2 manipulations, this would inop both pumps
- turn CS to desired position and then turn control power (left to right)
