Systems Comp Study Sesh Flashcards
Explain the SDG sequence.
Senses UV
Opens MDS
Starts SDGs
First up to speed closes in
Second diesel auto synchs
Tie Breaker closes
If there is a differential on the BMC/CMC Transformer, how does the protective scheme work?
Both high and low side opens at the same time, then the creoss tie will close without any delay
How does the Degraded Bus Voltage work?
Sensed on A & D T Buses
9 sec delay for alarm. If SI or LoLo SG, then loadshed
+90 seconds of correction before Fast transfer to RATs
+21 seconds of RATs trying to correct before Load Shed
If sensed on A or D, that whole train will be loadshed
What is the normal source of power to the CRIDs?
250 vDC
What is the alternate power source to the CRIDs?
600 vAC
Which 600 v bus goes with which CRID?
C -1
D -2
A - 3
B - 4
What does the In Synch light being lit on the CRID tell you?
Alternate source is available
What does the ALT Source to Load PB on the CRID do?
electronically transfers on static switch to alternate source of power
How does the Auto Retransfer Lockout work on the CRID?
After transfer to the alternate load, if the event clears, and is normal for 30 seconds, the statis switch auto transfers the load back to the normal source. If a 2nd transfer to alt source occurs before the autoretransfer capability is reset manually, the alternate source supplies the load. The static transfer switch locks out on alternate source until reset.
What does a rectifier do?
Changes AC to DC
What normally powers the batteries?
Battery Chargers from 600 vAC
What is the order of starts with time delays for all the fire pumps?
Motor/Electric 140 psi for 2 secs
East Diesel 130 psi for 15 secs
West Diesel 120 psi for 25 secs
What are the SDGs sized for?
1 Unit, 1 Train of RCS Inventory Control
How does the LoadShed Scheme work?
Sensed on EACH T Bus at 94 (93) Volts and lowering for 2 seconds. Loadsheds that one bus
If there is a differential on the B/C bus 600 v transformer, will that bus be powered from the EDG?
NO. No high side disconnect, so entire bus is dropped
Who has command function?
Shift Manager
What is the fire protection provided to both Units CRCVs?
Auto Halon
Manual CO2
Auto Water for Unit 2 Only
Define the Modes of Operation Per Tech Specs
Mode 1 - Keff Greater than or equal to 0.99 and Rated Thermal Power > 5%
Mode 2- Keff Greater than or equal to 0.99 and Rated Thermal Power less than or equal to 5%
Mode 3 - Keff < 0.99 and RCS Tavg Greater than or equal to 350 degrees
Mode 4 - Keff < 0.99 and RCS Tavg btween 200 and 350 degrees
Mode 5 - Keff < 0.99 and RCS Tavg less than or equal to 200 degrees
What is the pressure safety limit?
2735 psi
If the safety limit for pressure is violated, what must be done?
Modes 1&2, Be in Mode 3 and restore within 1 hour
Modes 3-5, Restore within 5 mins
Whats the purpose of the safety limits in section 2 of Tech Specs?
Protect from fuel damage and maintain vessel integrity.
Who is responsible for overall safe operations?
Plant Manager
What are the Tech Spec credited sources for Offsite Power?
RATs and EP
SDGs are NOT credited
What is the normal Split Bus alignment?
BXfmr 5 to Train B
Xfmr 9 to Train A
BD is Open