QSPDS Flashcards
The unit is in Mode 1. The upper two sensors in the RVLMS Train ‘B’ have failed and are not functioning. All other RVLMS sensors are functioning normally. Based on these conditions, Technical Specification LCO 3.3.10 is…
A. not met, enter Condition C, Action C.1.
B. not applicable.
C. not met, enter Condition A, Action A.1.
D. met.
Answer: D
The plant is in Mode 3 and stable (post Reactor Trip). RVLMS Channel A, sensors 6, 7, and 8 fail and are not functioning. Based on these conditions, …
A. the crew must perform 3.3.10, Action A.1.
B. LCO 3.3.10 is met.
C. the crew must perform 3.3.10, Action C.1.
D. the crew must perform 3.3.10, Action G.1.
Answer: A
The reactor is tripped A LOCA is in progress Pressurizer level is 35% RVLMS is inoperable RCS voiding is occurring Which one of the following would be an indication that the RCS void has reached the outlet plenum?
A. Saturated conditions on RCS loop temperatures.
B. HPSI flow decreases.
C. Pressurizer level increases.
D. RCS pressure decrease when pressurizer heaters are energized.
Answer: A
The reactor is tripped. A small break LOCA is in progress. A loss of all Feedwater is in progress. Pressurizer level is 35%. Pressurizer pressure is 2275 psia and rising. Which one of the following would be an indication that RCS voiding is occurring?
A. RCS pressure increase when pressurizer spray is initiated.
B. Pressurizer level decrease when letdown flow is raised.
C. Pressurizer level increase when pressurizer spray is activated.
D. RCS pressure decrease when pressurizer heaters are energized.
Answer: C
Which of the following is part of the set of safety parameters monitored by QSPDS?
A. Containment Sump Level
B. Containment humidity
C. MFW flow to SG-1, SG-2
D. RCS narrow range pressure
Answer: A
Which of the following explains how QSPDS determines reactor vessel level?
A. QSPDS correlates a delta temperature between level sensor #1 and level sensor #2 to water level.
B. QSPDS looks for unheated thermocouple temperature to exceed a setpoint to determine water level.
C. QSPDS correlates CET temperature to reactor vessel level.
D. QSPDS uses a level input from the core monitoring computer.
Answer: B
A LOCA is in progress and the Reactor is tripped. SPTAs are complete. The CRS is implementing the LOCA ORP. RVLMS indicates 67% in the upper head and has been constant for the past 10 minutes.
Then:
The B02 indicator for reactor vessel level instantaneously drops to 41% in the upper head and stabilizes for another 10 minutes. The crew should relate this change in indication with the:
A. expansion of the void in the vessel head.
B. sudden increase of the RCS leak rate.
C. sudden decrease of the RCS leak rate.
D. expansion of the void into the outlet plenum.
Answer: A
QSPDS calculates upper head saturation margin using which of the following temperature inputs?
A. Highest upper head metal temperature.
B. Highest Th or Tc.
C. Representative CET.
D. Hottest of the top three (3) unheated junction thermocouple temperatures.
Answer: D
Describe how the Reactor Vessel Level Monitoring System determines Reactor Vessel Level?
A. RTDs (Resistance Temperature Detectors) fail open, indicating uncovery and lowering Vessel Level.
B. RTDs (Resistance Temperature Detectors) fail shorted, indicating uncovery and lowering vessel level.
C. Pairs of heated and unheated thermocouples respond to uncovery by indicating saturated/superheat conditions.
D. Pairs of heated and unheated thermocouples provide exact water conditions to COLSS, which calculates level.
Answer: C
A LOCA event is in progress at PVNGS Unit 1. At time 0, all Reactor Vessel Level Sensors indicate covered. At time +5 minutes, all Reactor Vessel Level Sensors indicate covered. At time +10 minutes, Sensor level 1 on both trains indicates uncovered. Based only on this information, what should the Reactor Operators infer about Reactor Vessel Inventory?
A. Reactor Vessel Level is at the #1 sensor and will take five minutes to lower to the #2 sensor.
B. The rate of Reactor Vessel Inventory loss is increasing (getting worse).
C. The rate of Reactor Vessel Inventory loss is decreasing (getting better).
D. Reactor Vessel Level is somewhere below the #1 sensor and above the #2 sensor.
Answer: D
Given the following conditions: A LOCA in progress. RVLMS is reading 67% in the upper head and has been constant for the past 15 minutes. HPSI flow is ~150 gpm/cold leg and constant. While looking at the B02 indicator for Reactor Vessel level, you observe level indication instantaneously drop to 41% and stabilize. This indication is due to the:
A. size of the LOCA having significantly increased.
B. heater on a HJTC has burned out.
C. expansion of the void uncovering the next lower RVLMS sensor.
D. initiation of simultaneous hot and cold leg injection.
Answer: C
Which one of the following is a relationship between QSPDS and the B02 post accident monitor recorders?
A. QSPDS sends an output to the B02 post accident monitor recorders to display information concerning pressurizer pressure
B. The B02 post accident monitor recorders provide class input to the QSPDS computer for subcooled margin calculations
C. The B02 post accident monitor recorders provide class input to the QSPDS computer for saturation margin calculations
D. QSPDS sends an output to the B02 post accident monitor recorders to display information concerning core exit thermocouple temperature.
Answer: D
Describe the configuration of a single train/probe of sensors used by the Reactor Vessel Level Monitoring System.
A. Two thermocouples at each sensor level, one heated and one unheated.
B. Sensors # 1-6 in the Upper Head, and # 7-8 in the Plenum.
C. Sensors # 1-2 in the Upper Head, and # 3-8 in the Plenum.
D. Four thermocouples at each sensor location, two heated and two unheated.
Answer: A
