HPI Cooldown/ICC Flashcards
What are entry conditions for HPI Cooldown?
1) Prim to Sec heat transfer cannot be established and HPI cooling is adequate
2) Un-isolable steam leak on both SGs with one leaking into RB
3) SG tube rupture in both SGs with BWST < 23’, dose rate > alert criteria is projected at site boundary, or both SGs filled above 410”
What are entry conditions for ICC?
CET temps superheated and moving away from saturation
What conditions are required to restore letdown per RT-13?
1) Fuel damage does not exist
2) RCS to ICW leak not suspected
When in HPI cooldown and ESAS alarms are in what actions are taken?
DO NOT transition to ESAS.
1) If SCM adequate then throttle HPI, restore letdown and perform RT-10
With RCS solid what pressure change corresponds to 1 deg F temp change?
100#
What cooldown rate applies when SCM inadequate?
Cooldown rate limits do not apply
How is cooldown rate controlled in HPI Cooldown?
1) Adjust balance between HPI Injection and Letdown to maintain RCS pressure within limits of figure 3
2) Adjust TBVs/ADVs to maintain < 100 deg/hr if SGs available. If not, raise/lower HPI flow to raise/lower cd rate. (Tube shell delta T limit 150 deg F tubes colder)
What actions are taken in step 1 of ICC?
1) Verify RT-3 for full HPI, start 3rd HPI pump, fully open CV-1207, verify both LPI pumps in service and CFT outlets open.
What actions are taken if one HPI pump exists?
Leave ERV open
(If no HPI pump, cycle ERV from 2450# to within 100# of SG pressure or RCS pressure within 100# of next higher ICC region)
What SG pressure is plant lowered to if condensate pumps are only pumps available in ICC?
580 psig
What actions are taken in ICC if SW pumps are only pumps running?
Fully open TBVs/ADVs to keep SGs de-pressurized
What delta T is established for primary to secondary heat transfer in ICC?
Raise primary to secondary delta T to 90 - 110 deg F.
What transitions are made if RCS returns to region 1 of figure 4?
1) If prim to sec heat transfer established or uncontrolled RCS CD due to HPI/break flow regardless of SG status then go to ESAS if < 150# or Small break LOCA if > 150#
2) Go to HPI CD if HPI cooling in progress
What actions are taken if region 3 of figure 4 is entered?
Adjust TBVs/ADVs to reduce SG Tsat 100 deg F below current value and open Vents to vent non-condensables. If CFTs or LPI available then ensure ERV open.
What actions are taken in ICC if region 4 is entered?
Trip all RCPs, implement SAMGs, Leave ERV and high point vents open.
