JPM SRO-A2 — Boration Time for Stuck Rods and BAST Level Evaluation
Admin | SRO | G2.1.20 (4.6)
Location: Classroom
Time-Critical: No
Alternate Path: No
Estimated Time: 10 minutes
Initial Conditions:
- Unit 2 experienced an automatic Reactor Trip from an inadvertent Main Turbine Trip.
- 2SJ2 was tagged for emergent repairs prior to the trip.
- SI is not required and the crew is implementing 2-EOP-TRIP-2, Reactor Trip Response.
- Three Control Rods from Control Bank Delta have failed to FULLY insert.
- RWST Concentration is 2350 ppm, and BAST concentration is 6650 ppm.
- Unit 2 remains in Mode 3 throughout the boration.
- Current BAST levels:
21 BAST level: 70%
22 BAST level: 70%
Initiating Cue:
- You are the CRS.
- Determine the amount of time Rapid Boration is required IAW 2-EOP-TRIP-2 Step 4 for the Three Control rods that have failed to insert on Control Bank Delta:
1. How many total minutes of Rapid Boration is required?
2. What will be the final BAST levels in percent IAW S2.OP-TM.ZZ-0002?
- Assume the Rapid Boration flowrate remains at 40 GPM for the entire duration required in question 1, and Both BASTs lower equal amounts.
3. Based on plant conditions after completion of the boration, identify any Tech spec(s) and Tech Spec action statement(s) required related to the boric acid system.
Time-Critical: No
Alternate Path: No
Estimated Time: 10 minutes
Initial Conditions:
- Unit 2 experienced an automatic Reactor Trip from an inadvertent Main Turbine Trip.
- 2SJ2 was tagged for emergent repairs prior to the trip.
- SI is not required and the crew is implementing 2-EOP-TRIP-2, Reactor Trip Response.
- Three Control Rods from Control Bank Delta have failed to FULLY insert.
- RWST Concentration is 2350 ppm, and BAST concentration is 6650 ppm.
- Unit 2 remains in Mode 3 throughout the boration.
- Current BAST levels:
21 BAST level: 70%
22 BAST level: 70%
Initiating Cue:
- You are the CRS.
- Determine the amount of time Rapid Boration is required IAW 2-EOP-TRIP-2 Step 4 for the Three Control rods that have failed to insert on Control Bank Delta:
1. How many total minutes of Rapid Boration is required?
2. What will be the final BAST levels in percent IAW S2.OP-TM.ZZ-0002?
- Assume the Rapid Boration flowrate remains at 40 GPM for the entire duration required in question 1, and Both BASTs lower equal amounts.
3. Based on plant conditions after completion of the boration, identify any Tech spec(s) and Tech Spec action statement(s) required related to the boric acid system.
Task Standard:
1. Calculates the total boration time for 3 stuck control rods to be 105 minutes.
2. Determines final BAST tank levels for 21 tank at 43% +/-2% and 22 tank at 43% +/-2%.
3. Determines that TS LCO 3.1.2.6.a.1 is not met and action is required.
1. Calculates the total boration time for 3 stuck control rods to be 105 minutes.
2. Determines final BAST tank levels for 21 tank at 43% +/-2% and 22 tank at 43% +/-2%.
3. Determines that TS LCO 3.1.2.6.a.1 is not met and action is required.
▶ Show Critical Steps & Key Actions
| Step | Critical Element | Standard |
|---|---|---|
| 1 * | Determine boration time for 3 stuck rods IAW 2-EOP-TRIP-2 Step 4 | Determines 3 control rods failed to fully insert. Boration time = 35 min x 3 rods = 105 minutes. |
| 2.1 * | Determine total volume of boric acid added | 105 min x 40 GPM = 4200 gallons total. Both BASTs lower equal amounts: 4200 / 2 = 2100 gallons per tank. |
| 2.2 * | Determine 21 BAST final level using S2.OP-TM.ZZ-0002 tank curve | Start level = 70% = 5500 gallons. Final volume = 5500 - 2100 = 3400 gallons. Using tank curve, 3400 gallons = 43% (+/-2%). |
| 2.3 * | Determine 22 BAST final level using S2.OP-TM.ZZ-0002 tank curve | Start level = 70% = 5500 gallons. Final volume = 5500 - 2100 = 3400 gallons. Using tank curve, 3400 gallons = 43% (+/-2%). |
| 3 * | Evaluate Tech Specs for boric acid system after boration | With RWST boron concentration of 2350 ppm and BAST boron concentration of 6650 ppm, TS 3.1.2.6 Figure 3.1-2 requires BAST level > 96.5%. Final combined BAST level is 86% (43% + 43%), which is below the required level. Determines LCO 3.1.2.6.a.1 is NOT met — Action a: restore storage system to OPERABLE within 72 hours or be in Hot Standby within next 6 hours. |
Key Decision Point:
Step 3 is the discriminating step — after completing the boration calculations, the applicant must recognize that the final BAST levels (43% each, 86% combined) fall below the required level from TS 3.1.2.6 Figure 3.1-2 (> 96.5% at the given RWST/BAST boron concentrations). This requires the applicant to enter the TS figure with both the RWST concentration (2350 ppm) and BAST concentration (6650 ppm) to determine the minimum required level, then compare it against the post-boration tank levels. The applicant must then identify the correct LCO and action statement.
Step 3 is the discriminating step — after completing the boration calculations, the applicant must recognize that the final BAST levels (43% each, 86% combined) fall below the required level from TS 3.1.2.6 Figure 3.1-2 (> 96.5% at the given RWST/BAST boron concentrations). This requires the applicant to enter the TS figure with both the RWST concentration (2350 ppm) and BAST concentration (6650 ppm) to determine the minimum required level, then compare it against the post-boration tank levels. The applicant must then identify the correct LCO and action statement.
Ref: 2-EOP-TRIP-2 (Rev 40), S2.OP-TM.ZZ-0002 (Rev 8), TS 3.1.2.6 | Task: N1150510502 | K/A: G2.1.20 — Ability to interpret and execute procedure steps | Source: New | View JPM PDF
Connections
- Related systems: CVCS
- Related procedures: EOP-TRIP-2 — Reactor Trip Response, S2.OP-TM.ZZ-0002 — Tank Capacity Data
- Related tech specs: TS 3/4.1.2 — Boration Systems
- Related exam: 2022 NRC Operating Exam