JPM RO-A2 — Determine Boration Time for 3 Stuck Rods and Final BAST Level
Admin | RO/SRO | G2.1.20 (4.6)
Location: Classroom
Time-Critical: No
Alternate Path: No
Estimated Time: 8 minutes
Initial Conditions:
- Unit 2 experienced an automatic Reactor Trip from an inadvertent Main Turbine 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.
- Current BAST levels:
- 21 BAST level: 94%
- 22 BAST level: 76%
Initiating Cue:
- You are the extra NCO.
- The CRS has directed you to 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?
- Assume the Rapid Boration flowrate remains at 40 GPM for the entire duration required in question 1, and Both BASTs lower equal amounts.
Time-Critical: No
Alternate Path: No
Estimated Time: 8 minutes
Initial Conditions:
- Unit 2 experienced an automatic Reactor Trip from an inadvertent Main Turbine 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.
- Current BAST levels:
- 21 BAST level: 94%
- 22 BAST level: 76%
Initiating Cue:
- You are the extra NCO.
- The CRS has directed you to 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?
- Assume the Rapid Boration flowrate remains at 40 GPM for the entire duration required in question 1, and Both BASTs lower equal amounts.
Task Standard:
1. CALCULATES the total boration time for 3 stuck control rods to be 105 minutes.
2. Calculates total amount of gallons injected to be 4200 gallons and final BAST levels are at 21: 67% +/- 2% and 22: 49% +/- 2%.
1. CALCULATES the total boration time for 3 stuck control rods to be 105 minutes.
2. Calculates total amount of gallons injected to be 4200 gallons and final BAST levels are at 21: 67% +/- 2% and 22: 49% +/- 2%.
▶ Show Critical Steps & Key Actions
| Step | Critical Element | Standard |
|---|---|---|
| 1 * | Determine boration time for 3 stuck rods using EOP-TRIP-2 Step 4 | 35 MIN x 3 rods = 105 minutes total Rapid Boration |
| 2.1 * | Determine total volume of boric acid injected | 105 MIN x 40 GPM = 4200 gallons total. Each BAST lowers by 4200/2 = 2100 gallons. |
| 2.2 * | Determine 21 BAST final level using S2.OP-TM.ZZ-0002 tank curve (Figure 2) | Start = 94% = 7400 gal. Used = 2100 gal. Remaining = 5300 gal. From tank curve: 5300 gal = 67% (+/- 2%) |
| 2.3 * | Determine 22 BAST final level using S2.OP-TM.ZZ-0002 tank curve (Figure 2) | Start = 76% = 6000 gal. Used = 2100 gal. Remaining = 3900 gal. From tank curve: 3900 gal = 49% (+/- 2%) |
Key Decision Point:
Step 1 is the primary discriminating step -- the applicant must correctly use EOP-TRIP-2 Step 4 to determine 35 minutes per stuck rod. The applicant must then correctly convert BAST levels from percent to gallons using the S2.OP-TM.ZZ-0002 tank capacity curve (Figure 2), subtract the volume used, and convert back to percent. The +/- 2% acceptance band accounts for readability errors when using the tank curve (each conversion from %→gallons or gallons→% has a +/- 1% readability error).
Step 1 is the primary discriminating step -- the applicant must correctly use EOP-TRIP-2 Step 4 to determine 35 minutes per stuck rod. The applicant must then correctly convert BAST levels from percent to gallons using the S2.OP-TM.ZZ-0002 tank capacity curve (Figure 2), subtract the volume used, and convert back to percent. The +/- 2% acceptance band accounts for readability errors when using the tank curve (each conversion from %→gallons or gallons→% has a +/- 1% readability error).
Ref: 2-EOP-TRIP-2 (Rev 41), S2.OP-TM.ZZ-0002 (Rev 8) | Task: N1150030501 | K/A: G2.1.20 — Ability to interpret and execute procedure steps | Source: New | View JPM PDF
Connections
- Related systems: CVCS
- Related EOPs: EOP-TRIP-2 — Reactor Trip Response
- Related procedures: S2.OP-TM.ZZ-0002 — Tank Capacity Data
- Related exam: 2022 NRC Operating Exam