Area 3 Smaller systems Flashcards
How do we put a CEA subgroup on the hold-bus?
We have 10 minutes to get it done
It is a make before break. Meaning that the CEA subgroup will be on its normal power supply and the hold bus at the same time. This will prevent an inadvertent dropped into the core.
How many CEA’s are there?
89
Where does the CEDMCS system receive power from?
NGN-L03 and NGN-L10
Where is the cooling water holdup tank?
40 foot aux building
Describe pumping the cooling water holdup tank to the chemical waste neutralizing tank.
Control Room gets a high level alarm AO's bump the pump for 2 minutes AO notifies Chemistry Chemistry samples Chemistry notifies CR that water is SAT AO notifies Demin operator (Make sure there is sufficient room in chem waste neutralizing tank) AO starts one pump Pump will automatically stop on low level
What is the hydrogen recombiner used for?
- thermally recombine water and oxygen to make water
- maintain containment hydrogen concentration
What is the low, normal, and high level on the WC expansion tank?
Low- 12”
Norm- 36”
High- 72”
What is the low, normal, and high pressure in the WC expansion tank?
Low- 5 psig
Norm- 15 psig
High- 45 psig
What is the low, normal, and high level on the NC expansion tank?
Low- 12”
Norm- 30”
High- 50”
What is the low, normal, and high pressure in the NC expansion tank?
Low- 1 psig
Norm- 5 psig
High- 8 psig
What is the minimum temperature for most of our heat trace for the H2 analyzers and PASS?
237 degrees F. (Some are 220)
At what pressure in either the span gas or reagent gas do we need to notify the SM/CRS to have the applicable bottle replaced?
Less than 250 psig
What is the design basis temperature for the EW system?
135 degrees F
What is the low, norm, and hi level in the EW expansion tank when the system is in standby?
Low- 20” (All of unit 3’s values are lower)
Norm- 25-30”
High- 50”
What is the low, norm, and hi level in the EW expansion tank when the system is operating?
Low- 20” (All of unit 3’s values are lower)
Norm- 25-50”
High- 50”
What are the normal loads on the EW system?
Essential Chiller and SDCHX
What provides makeup to the EW system?
Normally- DW
Alt- CST
Emergency- FP
What is the largest load on the EW system?
SDCHX
What will cause the EW pumps to automatically start?
- LOP (20 sec’s after DG output bkr closes)
- CSAS
- SIAS
- CREFAS or CRIVIAS
- AFAS 1 or 2
If we have the ‘A’ train of EW cross connected to NC; what will cause the cross connect valves to automatically close? Why?
EW 'A' surge tank low level (17") or SIAS It ensures the EW system can perform its class function
What causes the EW surge tank makeup solenoid valve to automatically close?
High level or low low level (14”)
It automatically closes on a low low level to prevent feeding a leak
Describe “stacking” in the Essential Chillers?
During winter months, a low cooling load and low EW temperature can cause liquid refrigerant to remain in the condenser due to there not being enough refrigerant pressure to drive the liquid through the flash economizer to the cooler. Temperature and pressure drop and the chiller trips on low temp.
How do we prevent stacking?
RHPCV
When should the bypass valve around the RHPCV be opened?
Degraded EW pump performance
EW aligned to the fuel pool cooling loads
What are the ways we override the RHPCV’s?
- Hydraulically using the pilot stem located on top of the valve
- manual override screw on the bottom of the valve (pilot bypass stem must be backed off first).
What are the loads off of EC?
LPSI, HPSI, CS, AF, EW pump rooms Control room ventilation ESF switchgear room DC equipment room Elect pen room
What is the N2 pressure on the EC expansion tank?
28 psig
What does the flash economizer do for us in the essential chiller?
subcools refrigerant before it gets to the flash economizer to add efficiency
What are the WC normal loads?
Containment HVAC Control Building HVAC Aux Building HVAC RW HVAC Non-nuclear Sample coolers Polishing demin Sample coolers Generator Collector housing
What is the limit for WC water entering the chiller?
100 degrees F
What is the limit for LO temperature leaving the WCN-E02 bearings?
170 degrees F
How many chillers can we have running at one time?
2 big chillers and the small chiller
What pressure does PCV-20 maintain on the WC expansion tank?
5-45 psig N2
What level does the WC expansion tank fluctuate between?
12-72”
What are the chillers without digital controls?
Unit 2 1A and 1C
Unit 3 1A
Why is it important to know which chillers have digital controls?
The ones without digital controls are susceptible to chilled water low flow trip when starting a 2nd chiller.
When starting a WC circ pump, what do you need to be careful of?
Don’t fully open the WC circ pump discharge valve completely without first starting that Chiller. This could cause WC rising temperature and rising amps on the running chiller; which could cause it to trip.
When do the Normal chillers trip on low water flow?
Big chillers- 800 gpm
Small Chiller- 215 gpm
When do the normal chillers trip on low condenser water flow?
Big chillers- 1600 gpm
Small chiller- 400 gpm
When will the normal chillers trip on compressor low oil pressure?
13 psig
What systems need to be in operation to start a WC?
NCW, DW, N2, IA, PB, NB, PH, NH, PK, NK
What is the essential cooling water systems mission time?
30 days
What do you look for in the CEDMCS room on rounds?
- Check voltage/amps on CEDMCS control panel
- No faults on control panel
- Walk by RTSG, SPLA
- Check coolers are running
- Leaks, squeaks, vibrations on any equipment
What are the normal voltage and amp values for logs in the CEDMCS room?
About 240 volts and 88 amps
How many room coolers are in the CEDMCS room?
Two, both normally running
What are the three CEA regulating groups?
- Shutdown groups
- Regulating groups
- Part Strength groups
If one motor generator set is secured what must the control room do?
Move CEAs with MI only to prevent overloading the MG.
What does CMA alarm in the CEDMCS system indicate?
Continuous motion alarm. Motion longer then preset time interval of 30 seconds in high rate or 60 seconds in low rate.
What does a timer failure in the CEDMCS system indicate?
CEA sequence took greater than 5 seconds or both the upper gripper and lower gripper had zero voltage at the same time. Can cause the affected CEA and the subgroup to have a low voltage upper gripper signal
What does a CGHV in the CEDMCS system indicate?
Continuous gripper high voltage- After a loss of subgroup logic, which causes a high voltage condition in the CEDM coils. (10 minutes to get it on the holdbus)
What is our concern with CEDM cooling loss?
With RCS temperature above 300 degrees F. Cooling must be restored within 10 minutes or a rapid cooldown must happen.
