Q94 — Refueling De-tensioning Requirements
G2.1.40 (3.9)
Given:
Select from the choices below that contains ONLY actions directed to be performed in accordance with S2.OP-IO.ZZ-0007, Cold Shutdown to Refueling, BEFORE Reactor Head De-tensioning would be initiated for a refueling outage starting on November 1st.
1. The Reactor shall be subcritical for at least 168 hours.
2. Verify each valve that isolates unborated water sources is secured in the closed position.
3. Any two of the Source Range and/or Gamma-Metrics neutron monitors are Operable.
4. Continuous communications between the control room and refuel floor is established.
Select from the choices below that contains ONLY actions directed to be performed in accordance with S2.OP-IO.ZZ-0007, Cold Shutdown to Refueling, BEFORE Reactor Head De-tensioning would be initiated for a refueling outage starting on November 1st.
1. The Reactor shall be subcritical for at least 168 hours.
2. Verify each valve that isolates unborated water sources is secured in the closed position.
3. Any two of the Source Range and/or Gamma-Metrics neutron monitors are Operable.
4. Continuous communications between the control room and refuel floor is established.
A. 1, 2, and 3 Only.
B. 1, 2, 3, and 4.
C. 2 and 3 Only.
D. 1 and 4 Only.
▶ Show Answer & Explanation
✓ C. Correct. In order to enter MODE 6 (de-tension the first Rx Head Stud), at least two source range neutron detectors are required to be operable (source or Gamma-Metrics), and per Technical Specification 3.9.2.1 and IOP-7, Attachment 1, the completion of S2.OP-ST.ZZ-0007(Q), Refueling Operations/Unborated Water Source Isolation Valves is required.
✗ A. Plausible because 2 and 3 are correct. Plausible because the candidate knows that Tech Spec 3.9.3 requires the reactor to be subcritical for at least 168 hours for a refueling starting between May 16th and Oct 14th. Incorrect as the date is outside that range in November and only 80 hours subcritical is required for the period between Oct 15th and May 15th. Also, incorrect because that spec is for movement of irradiated fuel, not de-tensioning.
✗ B. Plausible because the candidate may also remember that IOP-7 requires direct communications between the Control Room and personnel at the refueling station. Incorrect as this is a requirement, 1 hour prior to the start of CORE ALTERATIONS, not de-tensioning.
✗ D. Number 1 is plausible because the candidate knows that Tech Spec 3.9.3 requires the reactor to be subcritical for at least 168 hours for a refueling starting between May 16th and Oct 14th. Incorrect as the date is outside that range in November and only 80 hours subcritical is required for the period between Oct 15th and May 15th. Also, incorrect because that spec is for movement of irradiated fuel, not de-tensioning. Number 4 is plausible because the candidate may also remember that IOP-7 requires direct communications between the Control Room and personnel at the refueling station. Incorrect as this is a requirement, 1 hour prior to the start of CORE ALTERATIONS, not de-tensioning.
Ref: S2.OP-IO.ZZ-0007(Q), Cold Shutdown to Refueling, Technical Specifications 3.9.2.1 (Unborated Water Source Isolation Valves) and 3.9.2.2 (Instrumentation). | LO: N/A | Source: Modified – Salem 2015 NRC SRO Exam, Q20 | Cognitive: Fundamental
Connections
- Related systems: Refueling
- Related procedures: S2.OP-IO.ZZ-0007 — Cold Shutdown to Refueling
- Related tech specs: TS 3/4.9 — Refueling Operations
- Related exam: 2020 NRC Written Exam