Q83 — EDG Lube Oil Trip and SR 4.8.1.1
068 Control Room Evacuation - G2.4.50 (4.2)
Given:
• Unit 2 is at 100% Reactor Power
• 2B EDG is supplying 2B 4KV Vital Bus in parallel with 23 SPT for a surveillance run
At time 09:30 on January 7th
• The crew evacuates the control room
At time 09:50 on January 7th
• The crew is successfully proceeding through S2.OP-AB.CR-0001 (CONTROL ROOM EVACUATION) when Local alarm "LUBE OIL HI TEMP" and "ENGINE GENERATOR TRIPPED" alarms in the EDG Control Room
At time 10:00 on January 7th
• The CRS declares 2B EDG inoperable and LCO 3.8.1.1 (AC SOURCES OPERATING) REQUIRED ACTION b is entered
At time 10:30 on January 7th
• LCO 3.8.1.1 REQUIRED ACTION b.1 (Demonstrate the OPERABILITY of the independent AC circuits by performing Surveillance Requirement 4.8.1.1.1.a) is completed for the FIRST time
Which ONE of the following completes the statements below?
The 2B EDG tripped when Lube Oil Temperature FIRST exceeded _(1)_.
The SECOND performance of SR 4.8.1.1.1.a must be completed within a MAXIMUM of _(2)_ hours after the 2B EDG is declared inoperable.
• Unit 2 is at 100% Reactor Power
• 2B EDG is supplying 2B 4KV Vital Bus in parallel with 23 SPT for a surveillance run
At time 09:30 on January 7th
• The crew evacuates the control room
At time 09:50 on January 7th
• The crew is successfully proceeding through S2.OP-AB.CR-0001 (CONTROL ROOM EVACUATION) when Local alarm "LUBE OIL HI TEMP" and "ENGINE GENERATOR TRIPPED" alarms in the EDG Control Room
At time 10:00 on January 7th
• The CRS declares 2B EDG inoperable and LCO 3.8.1.1 (AC SOURCES OPERATING) REQUIRED ACTION b is entered
At time 10:30 on January 7th
• LCO 3.8.1.1 REQUIRED ACTION b.1 (Demonstrate the OPERABILITY of the independent AC circuits by performing Surveillance Requirement 4.8.1.1.1.a) is completed for the FIRST time
Which ONE of the following completes the statements below?
The 2B EDG tripped when Lube Oil Temperature FIRST exceeded _(1)_.
The SECOND performance of SR 4.8.1.1.1.a must be completed within a MAXIMUM of _(2)_ hours after the 2B EDG is declared inoperable.
A. (1) 190 (2) 8
B. (1) 190 (2) 9
C. (1) 205 (2) 8
D. (1) 205 (2) 9
▶ Show Answer & Explanation
✓ D. Correct. For Part 1 and IAW 2B DG Alarm Response Manual, the 2B EDG tripped when Lube Oil Temperature FIRST exceeded 205 °F. For Part 2 and IAW Technical Specifications, the crew has 1 hour to perform SR 4.8.1.1.1.a for the first time then an additional 8 hours to perform SR 4.8.1.1.1.a for the second time (9 hours from entering the LCO).
✗ A. Incorrect but plausible. For Part 1, the local "LUBE OIL HI TEMP" comes in at 190 °F. Consequently, the candidate could incorrectly determine that the EDG tripped when the local "LUBE OIL HI TEMP" actuates. For Part 2, the candidate could incorrectly conclude that Surveillance Requirement 4.8.1.1.1.a needs to be performed every 24 hours after it was initially performed (25 hours from entering the LCO).
✗ B. Incorrect but plausible. For Part 1, the local "LUBE OIL HI TEMP" comes in at 190 °F. Consequently, the candidate could incorrectly determine that the EDG tripped when the local "LUBE OIL HI TEMP" actuates. Part 2 is correct.
✗ C. Incorrect but plausible. Part 1 is correct. For Part 2, the candidate could incorrectly conclude that Surveillance Requirement 4.8.1.1.1.a needs to be performed every 24 hours after it was initially performed (25 hours from entering the LCO).
Ref: S2.OP-AR-DG-0002 Alarms Manual | LO: NOS05TECHSPEC-12 — Describe the general component and parameter categories addressed by TS Sections 3/4.1 through 3/4.12 | Source: New | Cognitive: Higher
Connections
- Related systems: EDGs
- Related tech specs: TS 3/4.8 — Electrical
- Related abnormals: AB.CR-0001 — Control Room Evacuation
- Related exam: 2019 NRC Written Exam