Q82 — IR NIS TS 3.3.1.1 During Startup
APE 33 AA2.08 (3.4)
Given:
• Unit 2 is performing a reactor startup per S2.OP-IO.ZZ-0003, Hot Standby to Minimum Load.
• Reactor power is 1E-4%.
Subsequently, the following sequence of events occur;
• OHA E-6, LOSS OF IR, is LIT.
• 2N35, Intermediate Range (IR) NIS Channel, indicates zero on 2CC2.
In accordance with Technical Specifications LCO 3.3.1.1, Reactor Trip System Instrumentation, which ONE of the following identifies the required action, if any?
[REFERENCE PROVIDED]
Note: RTP – Reactor Thermal Power
• Unit 2 is performing a reactor startup per S2.OP-IO.ZZ-0003, Hot Standby to Minimum Load.
• Reactor power is 1E-4%.
Subsequently, the following sequence of events occur;
• OHA E-6, LOSS OF IR, is LIT.
• 2N35, Intermediate Range (IR) NIS Channel, indicates zero on 2CC2.
In accordance with Technical Specifications LCO 3.3.1.1, Reactor Trip System Instrumentation, which ONE of the following identifies the required action, if any?
[REFERENCE PROVIDED]
Note: RTP – Reactor Thermal Power
A. Immediately suspend the reactor startup and insert all control rods.
B. Reduce RTP below P-6 OR raise RTP above P-10 within a maximum of 24 hours.
C. Reduce RTP below P-6 within a maximum of 2 hours.
D. No action is required since RTP is below P-6.
▶ Show Answer & Explanation
✓ B. Correct. IAW Tech Specs 3.3.1.1 Functional Unit 5, Action 3, with only one IR NIS channel operable and Rx power above P-6 (1E-5% RTP per S2.OP-IO.ZZ-0003), then RTP will need to be reduced to below P-6 OR raise RTP above P-10 within 24 hours.
✗ A. Incorrect. Plausible because the SRO may believe this is the conservative action but not required by Tech Specs. Two IR channels inoperable will require the immediate suspension of adding positive reactivity and reducing RTP below P-6 within 2 hours.
✗ C. Incorrect. Plausible because the SRO may incorrectly apply the TS action. This action is required for two inoperable IR channels.
✗ D. Incorrect. Plausible because the SRO may incorrectly apply the TS action. This LCO is not applicable when RTP is below P-6. However, reactor power at 1E-4% is above P-6 (1E-5%).
Ref: Tech Specs 3.3.1.1 Action 3 | LO: NOS05ABNIS, Objective 1 | Source: Bank – Salem | Cognitive: Comprehension/Analysis
Connections
- Related systems: Excore NIs
- Related tech specs: TS 3/4.3 — Instrumentation
- Related procedures: AB.NIS-0001 — Nuclear Instrumentation System Malfunction
- Related exam: 2022 NRC Written Exam