Q84 — EOP-FRCC-1 SG Depressurization / RCP Start
T1G2 EPE 74 EA2.12 (3.8)
Given:
• Salem Unit 2 is performing 2-EOP-FRCC-1, Response to Inadequate Core Cooling
• All steam generators are intact and at approximately 1040 psig
• MSIVs are open
• The crew is preparing to depressurize the steam generators in order to inject accumulators
• Containment Pressure is 5 psig
Which of the following completes both statements?
1. The operators will depressurize the steam generators using steam dumps at a (1).
2. Following SG depressurization, the SG NR levels are as follows:
Per 2-EOP-FRCC-1, step 18, RCP Start for Temporary Core Cooling, what is the MAXIMUM number of RCPs that the CRS will direct to be started (assume CETs remain above 1200 F)?
• Salem Unit 2 is performing 2-EOP-FRCC-1, Response to Inadequate Core Cooling
• All steam generators are intact and at approximately 1040 psig
• MSIVs are open
• The crew is preparing to depressurize the steam generators in order to inject accumulators
• Containment Pressure is 5 psig
Which of the following completes both statements?
1. The operators will depressurize the steam generators using steam dumps at a (1).
2. Following SG depressurization, the SG NR levels are as follows:
| 21 SG | 22 SG | 23 SG | 24 SG |
| 7% | 12% | 16% | 10% |
Per 2-EOP-FRCC-1, step 18, RCP Start for Temporary Core Cooling, what is the MAXIMUM number of RCPs that the CRS will direct to be started (assume CETs remain above 1200 F)?
A. (1) maximum rate while attempting to avoid a Main Steam Isolation — (2) One
B. (1) maximum rate while attempting to avoid a Main Steam Isolation — (2) Three
C. (1) rate not to exceed 100 degrees F per hour — (2) Three
D. (1) rate not to exceed 100 degrees F per hour — (2) One
▶ Show Answer & Explanation
✓ A. Correct. Part 1 is correct. Part 2 is correct. Per 2-EOP-FRCC-1 step 11, the crew will depressurize the intact SGs by using the steam dumps or MS10s at a maximum rate. At step 18 with CETs above 1200 degrees F, then the crew will determine how many RCPs can be started to reduce CETs. With containment at adverse conditions, the required NR level to start RCPs will be 15%, therefore, after performing step 18, only one RCP meets the requirements in step 18 to be started.
✗ B. Plausible because if use normal containment conditions, the required NR level is 9% and then three RCPs would be started.
✗ C. Part 1 is incorrect. Plausible because this RCS cooldown rate is used on other EOPs to avoid violating tech spec limits. Part 2 is incorrect. Plausible because if use normal containment conditions, the required NR level is 9% and then three RCPs would be started.
✗ D. Part 1 is incorrect. Plausible because this RCS cooldown rate is used on other EOPs to avoid violating tech spec limits. Part 2 is correct.
Ref: 2-EOP-FRCC-1 (R41) | LO: NOS05FRCC00-06, Obj 2.a — Describe the EOP mitigation strategy for the following: Response to Inadequate Core Cooling | Source: Modified Bank - Diablo Canyon 2019 NRC SRO84 | Cognitive: Comprehension/Analysis
Connections
- Related systems: Steam Generator & Blowdown, RCPs, Containment
- Related procedures: EOP-FRCC-1 — Response to Inadequate Core Cooling
- Related concepts: Containment
- Related exam: 2023 NRC Written Exam