JPM SRO-A2 — Determine Heat Stress Requirements for Containment Entry
Admin | SRO | G2.1.26 (3.6)
Location: Classroom (Administrative)
Time-Critical: No
Alternate Path: No
Estimated Time: 10 minutes
Initial Conditions:
- Unit 2 is at 100% power.
- 2PS3, PZR Spray Valve, is operating erratically and a decision has been made to enter containment to isolate the 2PS3 by closing the manual isolation valve (2PS28).
- The 2PS28 is located inside the PZR housing (dog house), upper elevation, and is known to be very physically demanding on the operators to operate. Two operators will be required to simultaneously operate the valve using a valve wrench during the entire valve operation. Operators will also have to climb ladders to access the 2PS28 in the dog house.
- The Shift Manager needs to determine the amount of resources needed to close this valve given the Heat Stress conditions.
- Rad Pro has provided a Wet Bulb Globe Thermometer (WBGT) temperature of 89 F for the work area.
- Rad Pro has determined that operators will need to wear double PCs.
- Cooling Garments will not be used.
Initiating Cue:
You are the Unit 2 Control Room Supervisor.
DETERMINE the following using SA-AA-111, Heat Stress Control for the two workers:
1. What is the Stay Time?
2. Assume the task will need more time. What is the Maximum Extended Stay Time?
3. Assume the task will NOT use the Maximum Extended Stay Time. What is the Recovery Time?
Time-Critical: No
Alternate Path: No
Estimated Time: 10 minutes
Initial Conditions:
- Unit 2 is at 100% power.
- 2PS3, PZR Spray Valve, is operating erratically and a decision has been made to enter containment to isolate the 2PS3 by closing the manual isolation valve (2PS28).
- The 2PS28 is located inside the PZR housing (dog house), upper elevation, and is known to be very physically demanding on the operators to operate. Two operators will be required to simultaneously operate the valve using a valve wrench during the entire valve operation. Operators will also have to climb ladders to access the 2PS28 in the dog house.
- The Shift Manager needs to determine the amount of resources needed to close this valve given the Heat Stress conditions.
- Rad Pro has provided a Wet Bulb Globe Thermometer (WBGT) temperature of 89 F for the work area.
- Rad Pro has determined that operators will need to wear double PCs.
- Cooling Garments will not be used.
Initiating Cue:
You are the Unit 2 Control Room Supervisor.
DETERMINE the following using SA-AA-111, Heat Stress Control for the two workers:
1. What is the Stay Time?
2. Assume the task will need more time. What is the Maximum Extended Stay Time?
3. Assume the task will NOT use the Maximum Extended Stay Time. What is the Recovery Time?
Task Standard:
Determines: Stay Time = 20 mins, Maximum Extended Stay Time = 30 mins, and Recovery Time = 60 mins.
Determines: Stay Time = 20 mins, Maximum Extended Stay Time = 30 mins, and Recovery Time = 60 mins.
▶ Show Critical Steps & Key Actions
| Step | Critical Element | Standard |
|---|---|---|
| 4.1.1 | Record WBGT temperature for work area | CRS records Wet Bulb Globe Temperature given from Initiating Cue as 89 F on Attachment 4. |
| 4.1.2 | Classify the work environment | CRS classifies work environment as High Temperature based on work area temperature of 89 F. |
| 4.2.1 * | Determine Work Rate using Attachment 2 | CRS determines Work Rate is HIGH. The 2PS28 valve operation is historically very hard to operate and physically demanding, requiring two operators with a valve wrench and climbing ladders inside the PZR dog house — this is High Work Rate activity (>50% of work time). |
| 4.3 * | Determine clothing ensemble adjustment factor | Determines the clothing ensemble to be Double Cloth Coveralls (double PCs) and the adjustment factor to add 9 F to the WBGT. |
| 4.4 * | Determine Stay Time using Attachment 3 | CRS uses: WBGT = 89 F, Work Rate = High, Clothing = Double PCs. Adds adjustment factor: 89 F + 9 F = 98 F. Using Attachment 3 with WBGT of 98 F and High work demand: Stay Time = 20 min. |
| 4.6 * | Calculate Maximum Extended Stay Time | CRS calculates Maximum Extended Stay Time (1.5 x ST): 1.5 x 20 mins = 30 mins. Check Times cannot extend beyond 1.5 times the established Stay Time. |
| 4.8 * | Determine Recovery Time | Stay Time (ST) = 20 mins. Actual Work Time = Stay Time. Recovery Time = (20/20) x 60 = 60 mins. |
Key Decision Point:
The applicant must correctly classify the work rate as HIGH based on the physical demands described in the initial conditions (valve wrench, climbing ladders, two operators simultaneously operating a valve in the PZR dog house). This drives the Stay Time determination. With WBGT of 89 F + 9 F clothing adjustment = 98 F effective WBGT, and High work rate, Attachment 3 yields a Stay Time of 20 minutes. The Maximum Extended Stay Time is simply 1.5x the Stay Time, and Recovery Time uses the formula (Actual Work Time / Stay Time) x 60 minutes.
The applicant must correctly classify the work rate as HIGH based on the physical demands described in the initial conditions (valve wrench, climbing ladders, two operators simultaneously operating a valve in the PZR dog house). This drives the Stay Time determination. With WBGT of 89 F + 9 F clothing adjustment = 98 F effective WBGT, and High work rate, Attachment 3 yields a Stay Time of 20 minutes. The Maximum Extended Stay Time is simply 1.5x the Stay Time, and Recovery Time uses the formula (Actual Work Time / Stay Time) x 60 minutes.
Ref: SA-AA-111 (Rev 12) | Task: N1220400302 | K/A: G2.1.26 — Knowledge of industrial safety procedures (SRO Only) | Source: New | View JPM PDF
Connections
- Related procedures: SA-AA-111 — Heat Stress Control
- Related systems: Pressurizer & PRT
- Related exam: 2019 NRC Operating Exam