Tube Rupture/Small SG Tube Leaks Flashcards
What are entry conditions for Tube Rupture?
1) > 10 gpm leakage while performing small SG tube leaks
2) > 1 gpm leakage post trip
3) Numerous control room alarms dealing with N16, etc
What actions are taken when PZR level is 200” and above LL Limits? 100” and reactor critical?
CV-1206 in override, Open HPI Block, Isolate L/D, If one HPI block unable to maintain level then initiate RT-2.
If PZR level < 100” then trip RX.
What actions are taken if PZR level is or predicted to be less than 55”?
Initiate RT-2
What actions are taken per RT-14 for tube rupture?
RCS pressure maintained low within limits of figure 3 to minimize integrated leakage (Spray valve full open maintaining 40 - 50 deg F SCM). PZR cd limits do not apply during tube rupture.
What actions are taken in SG Tube rupture if lose SCM?
Trip RCPs if < 2 min (Leave running and go to LSCM if > 2 min)
RT-3 (If < 1 full train of HPI then go to LSCM)
Place EFW isol valves in manual and flow control valves in vector override
When will the bad SG be steamed per exhibit 1?
1) Maintain MSSVs closed
2) SG press < 990 with TBV or < 1040 with ADVs
3) SG level < 410”
4) tube shell Delta T < 100 deg F (tubes colder) during normal CD, < 150 deg F (tubes colder) during emergency cooldown.
5) CRS directed cooldown if good SG TBV/ADV full open
At what PZR level is RT-2 performed?
55”
What actions are taken when generator output < 350 MW and both MFPs operating?
Open FW discharge crosstie and trip the bad SGs MFP.
What conditions are required to perform emergency cooldown? What temperature do you stop and what is the rate?
If SG level approaching 410” or dose rate greater than alert criteria at site boundary. Actions are taken to cooldown using both SGs down to 540 deg F and then stop steaming the bad SG.
Cooldown rate limit is 240 deg F down to 500 deg F.
What actions are taken if ESAS occurs?
Actions are taken to throttle HPI and cycle ERV if pressure cannot be lowered by throttling HPI, if SCM adequate.
What conditions warrant isolation of the bad SG and what actions are taken?
> 410”, < 23’ in BWST, Dose at site boundary > alert criteria
If other SG is isolated initiate RT-4 (If no HPI pumps available then allow ERV to cycle in auto and trip RCPs if SCM adequate).
Isolate MFIV, EFW valves, ADV, and reduce RCS pressure to 1020 psig by maintaining CD rate < 240 deg/hr to 500 deg F, raising aux spray and letdown flow, throttling HPI, cycling ERV and opening RCS vents and then close MSIV
What are the loading restrictions per Attachment 1 of tube rupture?
What actions are taken if SG leakage is > 75 gpd and rate of change is greater than 30 gpd/hr?
Initiate shutdown to 50% within 1 hour at 1%/min and place unit in mode 3 within 2 hours at 0.5%/min or higher.
What actions are taken if SG leakage greater than 30 gpd and rate less than than 30 gpd/hr?
Initiate shutdown at 0.5%/min to be in mode 3 in 6 hours.
What major actions are taken for secondary system contamination?
Secure pumping trench, remove MSR DI from service, secure polishers to C and D, Isolate MSRs based on bad SG (A SG = B/D), Pump trench to NT
