ML23226A075
| ML23226A075 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 08/14/2023 |
| From: | Michael Mahoney NRC/NRR/DORL/LPL2-2 |
| To: | Mack J Florida Power & Light Co |
| References | |
| L-2022-LLR-0128 | |
| Download: ML23226A075 (6) | |
Text
From:
Michael Mahoney Sent:
Monday, August 14, 2023 9:15 AM To:
Mack, Jarrett
Subject:
Turkey Point Nuclear Generating Unit Nos. 3 and 4 - Request for Additional Information - RCP LAR (L-2022-LLA-0128)
Attachments:
RAIs - Turkey Point RCP Seal LAR - 1st Round 2nd Set.pdf Hi Jarrett, By application dated August 26, 2022 (ADAMS Accession No. ML22243A161) as supplemented by letter dated July 27, 2023 (ML23208A191), Florida Power and Light Company (FPL, the licensee) submitted a license amendment request (LAR) for the Turkey Point Nuclear Generating Station, Units 3 and 4 (Turkey Point). The proposed LAR will revise the operating license, paragraph 3.D, Fire Protection, for fire protection program changes that may be made without prior U.S. Nuclear Regulatory Commission (NRC) approval. The change is to support replacement of the currently installed reactor coolant pump (RCP) seals with the Framatome RCP hydrostatic seal package equipped with the Passive Shutdown Seal (PSDS).
The U.S. Nuclear Regulatory Commission (NRC) staff is reviewing your submittal and has identified areas where additional information is needed to complete its review.
As discussed, response to the attached RAIs is requested no later than 30 business days from todays date.
The NRC staff considers that timely responses to RAIs help ensure sufficient time is available for staff review and contribute toward the NRCs goal of efficient and effective use of staff resources. If circumstances result in the need to revise the requested response date, please contact me.
Once this email is added to ADAMS, I will provide the accession number.
Thanks Mike Mahoney Project Manager, LPL2-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Desk: (301)-415-3867 Mobile: (301)-250-0450 Email: Michael.Mahoney@nrc.gov
Hearing Identifier:
NRR_DRMA Email Number:
2197 Mail Envelope Properties (SA1PR09MB94861B7474E13B59E1668625E517A)
Subject:
Turkey Point Nuclear Generating Unit Nos. 3 and 4 - Request for Additional Information - RCP LAR (L-2022-LLA-0128)
Sent Date:
8/14/2023 9:14:55 AM Received Date:
8/14/2023 9:14:57 AM From:
Michael Mahoney Created By:
Michael.Mahoney@nrc.gov Recipients:
"Mack, Jarrett" <Jarrett.Mack@fpl.com>
Tracking Status: None Post Office:
SA1PR09MB9486.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 1635 8/14/2023 9:14:57 AM RAIs - Turkey Point RCP Seal LAR - 1st Round 2nd Set.pdf 106200 Options Priority:
Normal Return Notification:
No Reply Requested:
No Sensitivity:
Normal Expiration Date:
REQUEST FOR ADDITIONAL INFORMATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION REGARDING LICENSE AMENDMENT REQUEST TO REVISE THE FIRE PROTECTION PROGRAM IN SUPPORT OF REACTOR COOLANT PUMP SEAL REPLACEMENT PROJECT FLORIDA POWER AND LIGHT COMPANY TURKEY POINT NUCLEAR GENERATING STATION, UNITS 3 AND 4 FLORIDA POWER AND LIGHT COMPANY DOCKET NOS. 50-250 AND 50-251 EPID NO. L-2022-LLA-0128
Background
By application dated August 26, 2022 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML22243A161), Florida Power and Light Company (FPL, the licensee) submitted a license amendment request (LAR) for the Turkey Point Nuclear Generating Station, Units 3 and 4 (Turkey Point).
The proposed LAR will revise the operating license, paragraph 3.D, Fire Protection, for fire protection program changes that may be made without prior U.S. Nuclear Regulatory Commission (NRC) approval. The change is to support replacement of the currently installed reactor coolant pump (RCP) seals with the Framatome RCP hydrostatic seal package equipped with the Passive Shutdown Seal (PSDS). The following are requests for additional information (RAIs) from staff in the Division of Engineering and External Hazards, Mechanical Engineering Branch and Division of Reactor Oversight, Human Factors.
NRC Staff Requests for Additional Information (RAIs)
- 11.
The LAR submittal dated August 26, 2022, in Attachment 1, provides proprietary information regarding the replacement RCP seals at Turkey Point. Please describe the RCP seal design changes and their improvement over the current Turkey Point RCP seals.
Additionally, the LAR 276 attachment does not provide a discussion of the seal actuation time. Seal action time is affected by the PSDS actuation temperature, initial seal leakoff flow rate, operator actions to cool and depressurize the plant, and other factors. Please discuss in detail how the seal actuation time was determined. Also, make the following information available for staff audit:
2 11a.
Reactor Coolant System (RCS) temperature and pressure response for the loss of seal cooling event.
11b.
The model of PSDS installed at the plant.
11c.
Qualification test data for the applicable PSDS model. The test data should include relevant seal temperatures, pressures, and flow rates sufficient for the staff to confirm that the seal will actuate in the assumed timeframe.
11d.
The PRA appears to include failure modes for the Framatome seals different from those assumed for the N9000 seal. In particular, seal leakoff line isolation is assumed to result in a rapid failure of the seal plus actuation of the safety seal before the RCPs are tripped. The LAR attachment discusses changes to the seal leakoff system to reduce the impact of the event. Discuss other plant modifications that were needed to install the Framatome seals with PSDS.
- 12.
In LAR section 3.1.5, Operator Action, the licensee states that the current required time for the operator to trip the RCPs following a LOSC event was established as 20 minutes to protect the RCP seals from damage. The licensee proposed that for the replacement Framatome RCP seals, the available operator time to trip RCPs is 16 minutes during a LOSC event. The change in the RCP trip time on a LOSC event would affect the Human Error Probability values, which are inputs to the Fire probabilistic risk assessment model. In LAR section 2.1, the licensee states that the current operator action time of 20 minutes was previously approved by the NRC (Reference 5 of the LAR, ML19064A903).
The associated NRC safety evaluation report (SER) indicated that the approval was based, in part, on the data of the RCP trip time in LOSC conditions applicable to the Flowserve RCP seals, which are similar to the current RCP seals at Turkey Point.
Specifically, The SER (page 10) quoted the following licensees statement as part of the basis for approval: the licensee further stated that the time available to trip the RCPs following a loss of seal cooling is 20 minutes, whereas the time available assumed in the Flowserve topical report (TR) is 60 minutes, and that assuming a shorter time for operators to recognize the need and trip the RCPs results in increases in the calculated failure probability, which in turn increases the calculated core damage frequency (CDF) and LERF values, and is conservative.
Provide a discussion to justify that the reduction in time to trip the RCPs during a LOSC from 20 minutes to 16 minutes, to be implemented for the replacement Framatome RCP seals, is acceptable for protecting the RCP seals from damage at TP.
12a.
NUREG-1764 section 4.2 provides criteria regarding the conduct of task analysis, including analyses regarding how personnel will both know when action is necessary and that it is performed correctly. However, the LAR does not provide any discussion of the results of any task analysis for the proposed change.
Please provide a description of any task analysis conducted for operator actions affected by the proposed change, including whether the results of any such analysis was that operator tasks would remain unchanged.
3 12b.
NUREG-1764 section 4.2 provides criteria regarding staffing, including analyses of effects of the changes in human actions upon the number, qualifications, and staffing levels of operations personnel. However, the LAR does not provide any discussion of the results of any staffing-related analysis for the proposed change.
Please provide a description of any staffing-related analysis conducted in support of the proposed change, including whether the results of any such analysis was that operator staffing levels would remain unchanged.
12c.
NUREG-1764 section 4.3 provides criteria regarding modifications to human-system interfaces (HSIs) as they relate to changes in operator task requirements. However, the LAR does not provide any discussion of modifications to HSIs.
Please provide a description of any modifications to HSIs (e.g., indications and controls located in the main control room) that will be made in conjunction with the proposed change, including whether no modifications to HSIs will occur in conjunction with the proposed change.
12d.
NUREG-1764 section 4.3 provides criteria regarding modifications to operator training as it relates to operator task requirements. However, the LAR does not describe the operator training that will be conducted for the manual operator actions affected by the proposed change.
Please provide a description of the operator training that is conducted for the manual operator actions that are discussed in the LAR, as well as whether any modifications to the operator training program will occur in conjunction with the proposed change.
12e.
NUREG-1764 section 4.4 provides criteria regarding the availability and accessibility of all required components. However, the LAR does not discuss whether the availability and accessibility of those indications and controls needed to support operator actions will be affected by the proposed change.
Please provide a description of any effects on the availability and accessibility of required indications and controls that will occur in conjunction with the proposed change, including whether no such components will be affected.
12f.
NUREG-1764 section 4.4 provides criteria regarding walkthrough activities conducted for human actions to determine that procedures are accurate and usable, that the training program appropriately addressed the changes, and that the human actions can be completed within the required time. In Section 3.1.5 of the LAR, FPL stated the following:
The change in RCP seal design reduces the time available to verify the RCPs are tripped in the event of a complete loss of RCP seal cooling to 16 minutes.
Please provide a description of the results of the full validation of the new time critical operator action for verification of RCP cooling. As part of this, please include details regarding the following:
Measures included to create realistic scenario conditions.
Any issues identified with procedural completeness, technical accuracy, and usability.
Any training program issues identified.
4 Whether the credited operator actions could be completed within the allowed time and whether adequate margin exists between the time required and time allowed.
Whether any complicating factors that might be expected to affect the crews' ability to perform the credited operator actions were included.
How many complete crews of operators participated in the walkthrough scenarios.