ML25346A044
| ML25346A044 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 12/30/2025 |
| From: | Richard Guzman Plant Licensing Branch 1 |
| To: | Casulli E Susquehanna |
| References | |
| EPID L-2025-LLA-0020 | |
| Download: ML25346A044 (0) | |
Text
December 30, 2025 Mr. Mark Jones Site Vice President Susquehanna Nuclear, LLC 769 Salem Boulevard NUCSB3 Berwick, PA 18603-0467
SUBJECT:
SUSQUEHANNA STEAM ELECTRIC STATION, UNITS 1 AND 2 -
SUMMARY
OF REGULATORY AUDIT IN SUPPORT OF LICENSE AMENDMENT REQUEST TO REVISE TECHNICAL SPECIFICATIONS FOR REACTOR VESSEL WATER LEVEL 3 AND LEVEL 8 ALLOWABLE VALUES (EPID L-2025-LLA-0020)
Dear Mr. Jones:
By letter PLA-8144 dated January 29, 2025,1 Susquehanna Nuclear, LLC (the licensee) submitted a license amendment request (LAR) for Susquehanna Steam Electric Station, Units 1 and 2.2 The licensee proposed changes to revise the reactor vessel water level - low, level 3 allowable values for the reactor protection system, emergency core cooling system, reactor pressure vessel water inventory control, and primary containment isolation instrumentation technical specifications (TS). The amendment also revises the reactor vessel water level - high, level 8 allowable value for the emergency core cooling system and reactor core isolation cooling system instrumentation TS.
The U.S. Nuclear Regulatory Commission (NRC) staff conducted a virtual audit to support its review of the LAR. The NRC staff audited various licensee documents and detailed responses provided by licensee staff. The NRC staff issued its audit plan on June 25, 2025.3 of this audit summary lists the individuals that took part in or attended the audit. lists the NRC staffs audit requests and questions.
The NRC staff conducted the audit using an internet-based portal provided by the licensee.
Using the licensees portal, the NRC staff reviewed documents (e.g., calculations and reports) related to the LAR but not available on the Susquehanna dockets. During the audit, NRC staff had additional questions, which were sent via email to the licensee and made an official agency record. 4 1 Agencywide Documents Access and Management system (ADAMS) Accession No. ML25029A032 2 Renewed Facility Operating License Nos. NPF-14 and NPF-22, respectively 3 ADAMS Accession No. ML25162A064 4 ADAMS Accession No. ML25224A060
After the audit discussions, the licensee supplemented its LAR on September 10, 2025.5 The NRC staff has reviewed the supplement, and no additional information is needed to complete its review of the licensees request.
The audit was completed by July 25, 2025. There were no open items resulting from the audit.
If you have any questions, please contact me at (301) 415-0489 or by email to Thomas.Buffone@nrc.gov.
Sincerely,
/RA/
Richard Guzman, Senior Project Manager Plant Licensing Branch I Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-387 and 50-388
Enclosures:
- 1. List of Audit Participants
- 2. List of Audit Questions and Audited Documents cc: Listserv 5 PLA 8189, ADAMS Accession No. ML25253A240
List of Audit Participants U.S. Nuclear Regulatory Commission and Contract Staff Licensee Staff Audrey Klett (NRR1/DORL2/LPL13)
Derek Smith (Susquehanna4)
Thomas Buffone (NRR/DORL/LPL1)
Fredrick OBrien (NRR/DEX5/EICB6)
David Nold (NRR/DSS7/SCPB8)
Angelo Stubbs (NRR/DSS/SCPB)
Jo Abrosini (NRR/DSS/SNSB9)
Thomas Scarbrough, (NRR/DEX/EMIB10)
Tarico Sweat (NRR/DSS/STSB11) 1 Office of Nuclear Reactor Regulation 2 Division of Operating Reactor Licensing 3 Plant Licensing Branch 1 4 Susquehanna Nuclear, LLC 5 Division of Engineering and External Hazards 6 Instrumentation and Controls Branch 7 Division of Safety Systems 8 Containment and Plant Systems Branch 9 Nuclear Systems Performance Branch 10 Mechanical Engineering and Inservice Testing Branch 11 Technical Specifications Branch
List of Audit Questions and Documents Reviewed The U.S. Nuclear Regulatory Commission (NRC) staff requested the following information during its audit to support its review of the license amendment request (LAR) (ADAMS Accession No. ML25029A032) for the Susquehanna Steam Electric Station (Susquehanna, or SSES), Units 1 and 2.
- 1. Provide licensee calculations supporting the technical specifications (TS)
Reactor Vessel Water Level (RVWL) - Low, Level 3 & High, Level 8 new allowable values (AV), as proposed in Section 3 of Attachment 1 to the license amendment request (LAR), for the following instrument functions: Reactor Protection System (RPS)
[TS Table 3.3.1.1-1, Function 4], Emergency Core Cooling System (ECCS)
[Table 3.3.5.1.-1, Functions 3.c, 4.d and 5.d], Reactor Pressure Vessel (RPV) Water Inventory Control [TS Table 3.3.5.2-1, Function 3.a], Primary Containment Isolation [TS Table 3.3.6.1-1, Functions 2.a, 6.b, and 7.a], and Reactor Core Isolation Cooling System
[TS Table 3.3.5.3-1, Function 2]. The calculations should include: (1) The uncertainties associated with these functions, (2) the expected drift between surveillances, (3) and the as-found and as-left tolerance acceptance values to be applied during TS surveillances.
Alternatively, the licensee may provide a full setpoint uncertainty calculation.
- 2. Provide documentation showing that (1) the analytical limits for L3 and L8 correspond with the analytical limit values stated in the amendment request and (2) those analytical limits are the values utilized in the safety analysis. The calculations mentioned in Section 3.1 of Attachment 1 to the LAR should provide (1) above, and either the reload safety analyses (Updated Final Safety Analysis Report (UFSAR) references 15C.1.2-1, 15D.1.2-1, or equivalent) or the input documents provided to the vendor to support reload safety analysis generation should be able to provide (2) above since the information is not readily available in the UFSAR.
- 3. TS Table 3.3.5.1-1 (Function 3.c) and Table 3.3.5.3-1 (Function 2) state that L8 RVWL trips are also relied upon to trip the feedwater pumps and main turbine in the event of a feedwater controller failure to maximum demand (UFSAR Section 15.1.2, TS 3.3.2.2).
The TS and TS Bases indicate different numbers of instrumentation channels for the TS 3.3.5.1 and TS 3.3.5.3 L8 trips versus the TS 3.3.2.2 L8 trips; however, the TS Bases and UFSAR do not appear to contain sufficient detail to confirm or deny that those trip channels utilize different level instruments, reference legs, and/or variable legs. Provide documentation to confirm the feedwater pump and main turbine trips are unaffected by this proposed change.
Upon NRC staff reviewing documents provided by the licensee, the following questions were asked:
- 1. Document EC-080-1012, Revisions 3 U1 L3 and L8, Section 4, part c, states [Full scale is the factory set range of switch calibration, equivalent to the indicator range =0 - 60 water level. This would calculate to be 0.025*60 = 0.15]. It is mentioned in part c that the Switch Repeatability has an accuracy 0.25 percent full scale; however, the noted calculation is set for a Switch Repeatability of 2.5 percent which would not match with the resulting calculation of 0.15. Does the Switch Repeatability have an accuracy of 0.25 percent or 2.5 percent full scale?
- 5. For Document EC-080-1012, Revisions 3 U1 L3 and L8, Section 6 describes the Process Measurement Accuracy (PMA). Part A in Section 6 states [PMA is defined in GE NEDC-31336 section 3.3.5]; however, the full paragraph stated in Section 6,part A matches the paragraph for Process Element Accuracy (PEA) in GE NEDC-31336 Section 3.3.5, Part 1, while Part 2 closely matches the definition for PMA. It is also noted in Document EC-080-1012 that the full paragraph stated in Section 7 for PEA matches the paragraph for PMA in GE NEDC-31336, Section 3.3.5, Part 2,while Part 1 closely matches the definition for PEA. The NRC staff requests the licensee to verify the reference callouts and confirm whether this affects the assumptions and uncertainties towards the results established by these definitions.
- 6. The NRC staff has the same requests (from Document EC-080-1012, Revision 3 U1L3 and L8) for Document EC-080-1008, Revision 3 U1 L3 and L8.
- 7. The NRC staff requests the licensee to explain why it uses the drift data from a Unit 2 transmitter for the Unit 1 determinations (e.g., are the units have differing environmental conditions)? How much would process setpoints associated with individual units change if the calculations used a drift data set associated with a transmitter in that designated unit?
The NRC staff reviewed, in a sampling manner, the following documents:
EC-080-1008, Reactor Water Level 3 and 8 Allowable Values, TRM Setpoint and Process Setpoint of LS-B21-1N024A/B/C/D, Revision 3, dated 01/21/2025 EC-080-1012, Reactor Water Level 3 and 8 Allowable Values, TRM Setpoint and Process Setpoint of LS-B21-2N024A/B/C/D, Revision 3, dated 01/21/2025
SUBJECT:
SUSQUEHANNA STEAM ELECTRIC STATION, UNITS 1 AND 2 -
SUMMARY
OF REGULATORY AUDIT IN SUPPORT OF LICENSE AMENDMENT REQUEST TO REVISE TECHNICAL SPECIFICATIONS FOR REACTOR VESSEL WATER LEVEL 3 AND LEVEL 8 ALLOWABLE VALUES (EPID L-2025-LLA-0020) DATED DECEMBER 30, 2025 DISTRIBUTION:
PUBLIC PM File Copy RidsNrrLAKEntz Resource RidsNrrPMSusquehanna Resource RidsRgn1MailCenter Resource RidsACRS_MailCTR Resource RidsNrrDorlLpl1 Resource RidsNrrDexEicb Resource RidsNrrDexEmib Resource RidsNrrDssSfnb Resource RidsNrrDssSnsb Resource RidsNrrDssStsb Resource AKlett, NRR FOBrien, NRR DNold, NRR AStubbs, NRR JAmbrosini, NRR TScarbrough, NRR TSweat, NRR ADAMS Package Accession No.: ML25346A044
- via eConcurrence NRR-106 OFFICE NRR/DORL/LPL1/PM NRR/DORL/LPL1/PM NRR/DORL/LPL1/LA NAME TBuffone RGuzman KEntz DATE 12/18/2025 12/15/2025 12/18/2025 OFFICE NRR/DSS/SNSB/BC NRR/DEX/EICB/BC (A)
NRR/DORL/LPL1/BC (A)
NAME NDifrancesco SDarbali UShoop (MMarshall for)
DATE 12/18/2025 12/18/2025 12/29/2025 OFFICE NRR/DORL/LPL1/PM NAME RGuzman DATE 12/30/2025 OFFICIAL RECORD COPY