Steam Dumps (RQ-C-4742) Flashcards
On a turbine trip/load rejection what are the steam dump controls based on
- Auctioneered High Tavg
Which group(s) stagger open instead of opening all together? ***
- Group 1 only
Which steam dump groups are allowed to operate when the turbine trip controller is activated?
- Groups I and II
Which steam dump groups are allowed to operate when the load rejection controller is activated?
- Groups I, II, and III
What signals does the turbine trip ctrlr use to open steam dumps?
- Auctioneered High Tavg - Tno-load
What signals does the load rejection ctrlr use to open steam dumps?
- Auctioneered High Tavg - Tref
*** A Unit 2 reactor trip occurred from 90% power. The following plant conditions exist:
• Reactor trip breakers: OPEN
• Main turbine stop valve (C): OPEN
• Condenser vacuum: 21.4 in. Hg.
• RCS Tavg: 561°F
• Auto Stop Oil Pressure: 400 psig
Assuming all other equipment operated as designed and no operator actions are taken, the Steam Dump system is:
A. armed and dumping steam to the condenser with group 1 trip open solenoid bistables energized and group 2 modulating.
B. armed and dumping steam to the condenser with groups 1 and 2 trip open solenoid bistables energized.
C. armed but not dumping steam to the condenser because of a blocking signal.
D. not armed and not dumping steam to the condenser.
A. armed and dumping steam to the condenser with group 1 trip open solenoid bistables energized and group 2 modulating.
What are the trip open signals for Turbine Trip bistables for steam dumps? ***
- 10°F Group I
- 20°F Group II
(Direct 20# air to the trip/open valves)
What are the trip open signals for Load Rejection bistables for steam dumps?
- 9°F Group I
- 13°F Group II
- 17°F Group III
(Direct 20# air to the trip/open valves)
Load Rejection control will maintain temperature within ___ between Auctioneered High Tavg and Tref with no rod motion. ***
- 5°F
