ML21137A330
| ML21137A330 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 02/18/2021 |
| From: | Gregory Roach NRC/RGN-III/DRS/OLB |
| To: | FirstEnergy Nuclear Operating Co |
| Roach G | |
| Shared Package | |
| ML20136A260 | List: |
| References | |
| Download: ML21137A330 (3) | |
Text
Davis-Besse 2021 Initial License Exam Outline Review Comments 1
Simulator Scenario Outline Comments o NRC: With regards to CT-1 on a Loss of Subcooling Margin as a result of a large LOCA, DB-OP-02000 Specific Rule 2, step 2 indicates that tripping all 4 RCPs is a Time Critical Action = 2 minutes. Based on the spare scenario from 2020, the measurable performance standard this CT is graded against indicates that the applicants must complete this step in 10 minutes to be considered successful. If the 10-minute completion time is adopted for this exam, explain the difference from the time listed in DB-OP-02000.
Facility:
From the Bases and Deviation Document for DB-OP-02000 Step 5.1:
-Analyses were performed which used both conservative and acceptable for best estimate Appendix K assumptions with the objective of meeting the requirements of 10CFR50.46.
-Using conservative Appendix K assumptions, it was shown that RCPs must be tripped within two minutes after losing adequate SCM to prevent the RCS from evolving to a high enough void fraction such that the core would be uncovered if the RCPs were tripped at a later time.
-Using realistic Appendix K assumptions, the maximum allowed time for tripping the RCPs was determined to be 10 minutes.
o NRC: ES 301-4 indicates that 4 EOPs are entered with substantive actions. What four EOPs are specifically entered? These should not include the contingency EOPs of which there are two (SR 6 for SBO and LOSCM).
Facility:
As noted above, 4 total EOPs with substantive actions are entered.
- 1. Specific Rule 6, Power For C1 And D1 Buses (Contingency)
- 2. Attachment 28, RESTORE POWER TO C1 OR D1 BUS FROM THE SBODG (Contingency)
- 3. Section 5.0 LACK OF ADEQUATE SUBCOOLING MARGIN (Contingency)
- 4. Attachment 8, PLACE HPI/LPI/MU IN SERVICE The ES 301-4 has been changed as requested. In addition, following validation, no substantive actions are taken in SR 6 in this scenario, therefore it will not be counted. The 301-4 has been updated as follows.
EOPs entered/requiring substantive actions 1-Attachment 8, PLACE HPI/LPI/MU IN SERVICE Entry into a contingency EOP with substantive actions 1-Specific Rule 6, Power for C1 And D1 Buses and Attachment 28, Restore Power to C1 or D1 Bus From the SBODG.
2-Section 5.0, Lack of Adequate Subcooling Margin
Davis-Besse 2021 Initial License Exam Outline Review Comments 2
o NRC: Abnormal Operating Procedure DB-OP-02523, Component Cooling Water System Malfunctions RNO step 4.3.1 states in part, IF an EDG is running without CCW cooling, THEN stop the affected EDG using the local Emergency Shutdown Pushbutton. (emphasis added) How is this step meeting the NUREG guidance requiring verifiable action to be counted as 1) a component failure for the ATC applicant and 2) a Critical Task action for the crew associated with CT-A to emergency shutdown the EDG on a loss of Component Cooling Water?
Facility:
A Review of the CT Methodology per NUREG 1021 does address the act of directing an action meeting the CT.
This failure was designated by Davis-Besse as a Critical Task to Prevent Degradation of Mitigative Capability of the Plant based on established DB Operations expectations and standards for previously identified Critical Task.
Following validation, this critical task has been changed such that the CCW Pump will start when the operator turns the switch. This will negate the need for a local emergency shutdown of the EDG.
Davis-Besse 2021 Initial License Exam Outline Review Comments 3
JPM Outline Comments o NRC: Explain how In-Plant JPM P2 is linked to Safety Function 8 for plant systems.
Be specific as to which plant systems associated with this Safety Function are manipulated.
Facility:
JPM P2 is linked to Safety Function 8 from RO Task 086-016-04-0100, Perform Required Actions for Fire in the Plant. This JPM was previously used on NRC Exam 2013 which also credited Safety Function 8. Multiple systems components are manipulated during this JPM, PORV, Makeup, Decay Heat, Aux Feed, and electrical line-ups including Component Cooling Water (CCW) CC1407A disconnect switch o NRC: Potential overlap exists between SRO Admin JPM A.3 which covers approving a waste gas release permit and SRO written exam question 23 which is written to Tier 3 K/A 2.3.6 ability to approve a release permit.
Facility:
JPM A3 is approval of a Waste Gas Release. Exam question 23 deals with a Liquid release. No overlap.
o NRC: JPM Task Standards should clearly indicate how the critical steps were identified. For instance, generally stating do something in accordance with a procedure is not adequate as it can be construed that any verifiable action steps done when performing that procedure would be critical.
Facility:
Task Standards were changed to clearly link them to Critical Steps.
Written Exam Outline/Audit Exam Outline o NRC: SRO NRC written question 16 associated with Tier 2/Group 2 system 015 Nuclear Instrumentation and Tier 3 SRO NRC question 22 are both linked to K/A 2.2.36. One will have to be changed to minimize overlap.
Facility:
Request a new KA for Q22, will generate a new question to address this concern.