IR 05000374/2023010

NRC Inspection Report 05000374/2023010

ML23284A181
Person / Time
Site:	LaSalle
Issue date:	10/11/2023
From:	Nestor Feliz-Adorno NRC/RGN-III/DORS/ERPB
To:	Rhoades D Constellation Energy Generation, Constellation Nuclear
References
IR 2023010
Download: ML23284A181 (1)

Text

SUBJECT:

LASALLE COUNTY STATION, UNIT 2 - NRC INSPECTION REPORT 05000374/2023010

Dear David P. Rhoades:

On September 20, 2023, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at LaSalle County Station, Unit 2, and discussed the results of this inspection with John Van Fleet and other members of your staff. The results of this inspection are documented in the enclosed report.

No findings or violations of more than minor significance were identified during this inspection.

This letter, its enclosure, and your response (if any) will be made available for public inspection and copying at http://www.nrc.gov/reading-rm/adams.html and at the NRC Public Document Room in accordance with Title 10 of the Code of Federal Regulations 2.390, Public Inspections, Exemptions, Requests for Withholding.

Sincerely, Néstor J. Féliz Adorno, Chief Engineering and Reactor Projects Branch Division of Operating Reactor Safety Docket No. 05000374 License No. NPF-18

Enclosure:

As stated

Inspection Report

Docket Number: 05000374

License Number: NPF-18

Report Number: 05000374/2023010

Licensee: Constellation Nuclear

Facility: LaSalle County Station, Unit 2

Location: Marseilles, IL

Inspection Dates: September 11, 2023 to September 20, 2023

Inspectors: M. Domke, Reactor Inspector

Approved By: Néstor J. Féliz Adorno, Chief Engineering and Reactor Projects Branch Division of Operating Reactor Safety

Enclosure

SUMMARY

The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting a NRC inspection at LaSalle County Station, Unit 2, in accordance with the Reactor Oversight Process. The Reactor Oversight Process is the NRCs program for overseeing the safe operation of commercial nuclear power reactors. Refer to https://www.nrc.gov/reactors/operating/oversight.html for more information.

List of Findings and Violations

No findings or violations of more than minor significance were identified.

Additional Tracking Items

None.

INSPECTION SCOPES

Inspections were conducted using the appropriate portions of the inspection procedures (IPs) in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards.

OTHER ACTIVITIES

- TEMPORARY INSTRUCTIONS, INFREQUENT AND ABNORMAL

===71003 - Post-Approval Site Inspection for License Renewal

The NRC conducted this Phase 2 Post-Approval Site Inspection for License Renewal in accordance with the License Renewal Inspection Program (LRIP) for LaSalle, Unit 2. The inspection took place prior to the Unit 2 period of extended operation (PEO) which begins December 16, 2023. Per Inspection Manual Chapter 2516, the LRIP is the process used by the NRC staff to verify adequacy of aging management programs (AMP), Time Limited Aging Analyses (TLAA), and other activities associated with an applicants request to renew an operating license of a commercial nuclear power plant beyond the initial licensing period under 10 CFR part 54, Requirements for the Renewal of Operating Licenses for Nuclear Power Plants.

The NRC completed its Phase 2 Post-Approval Site Inspection for License Renewal for Unit 1 on February 22, 2023. During this prior inspection, the inspectors reviewed at least 70 percent of regulatory commitments, along with their associated AMPs and TLAAs (ML22073A100).

During this Unit 2 inspection, the inspector focused on Unit 2 commitments, such as the examination of ASME class 1 small-bore piping and ASME IWE Containment Liner. The inspector also conducted samples for other programs that impact both units. As described in inspection procedure (IP) 71003, subsequent Phase 2 inspections at multi-unit sites may not require the same level of effort as the initial Unit's Phase 2 inspection.

Post-Approval Site Inspection for License Renewal===

(1) Commitment Item 17: Fire Water System

(2) Commitment Item 21: One-Time Inspection

(3) Commitment Item 22: Selective Leaching

(4) Commitment Item 28: Buried and Underground Piping

(5) Commitment Item 29: ASME Section XI, Subsection IWE

(6) Commitment Item 48: Unit 2 Inspection of ASME Code Class 1 Small-Bore Piping Program

INSPECTION RESULTS

Observation: Unit 2 Cable Spreading Room Pre-action Fire Sprinkler Obstruction 71003 Evaluation Lacked Supporting Information The licensee did not provide a description of the source of the obstruction in sprinkler nozzle 4-5 and lacked a sufficient basis for their conclusion that asserted the absence of age-related degradation.

Updated Safety Analysis Report (USAR) Fire Water AMP enhancement no. 3, states Perform internal visual inspections of sprinkler and deluge system piping to identify internal corrosion and obstructions to flow. If the presence of sufficient foreign organic or inorganic material to obstruct pipe or sprinklers is detected during pipe inspections, the material is removed and its source is determined and corrected where possible. Follow up volumetric examinations will be performed if internal visual inspections detect age-related degradation in excess of what would be expected accounting for design, previous inspection experience, and inspection interval.

Additionally, USAR Fire Water AMP enhancement no. 4 states Perform obstruction evaluations when degraded conditions are identified through visual inspections, flow testing, or volumetric examinations. The obstruction evaluations will include an extent of condition determination, need for increased inspections, and follow up examinations if internal visual inspections detect age-related degradation in excess of what would be expected accounting for design, previous inspection experience, and inspection interval.

On September 4, 2020, during pre-action fire sprinkler testing in the Unit 2 cable spreading room, blockage at nozzle 4-5 was identified. In accordance with procedure LOS-FP-R6, step E.2.16.1, and license renewal commitment AR 01603204-17, the system engineer was contacted for evaluation. However, inspectors noted that the conclusions drawn from this assessment were not supported.

On September 13, 2023, the inspectors reviewed the obstruction evaluation, which asserted the absence of age-related degradation "in excess of" expectations, with no need for follow-up volumetric examinations. The evaluation did not describe the obstruction and did not identify its source in the nozzle 4-5 sprinkler branch, as specified in the commitment.

Also, the evaluation concluded there was no age-related degradation because only one out of eleven sprinkler branch lines was affected by the obstruction. However, using just one impacted sprinkler among any number as a basis is inconsistent with the test acceptance criteria. Interviews revealed that the system engineer did not observe the test, and there was no information forthcoming from the individuals who conducted the test. Interviews with licensee personnel also affirmed that the issue report documenting the obstruction yielded minimal information regarding its cause or source.

The inspectors concluded that the absence of specific details about the obstruction in nozzle 4-5 undermined the evaluation conclusions. Despite deficiencies in the evaluation, there is a reasonable assurance that the Unit 2 cable spreading room pre-action sprinkler system can fulfill its intended function. The obstruction evaluation in issue report IR 04367410 was an isolated instance with the obstruction cleared through flushing, and no other fire protection obstruction evaluations were brought to the attention of inspectors.

Not determining the obstruction's source can lead to overlooking biologically influenced corrosion. The lack of qualification for obstruction-related degradation introduces subjectivity and the potential for overlooking necessary further action, such as volumetric examinations, for ensuring the pre-action system's functionality throughout the extended operation period.

The licensee captured this observation in issue report IR 04703313, which intends to improve the evaluation process by developing a list of information for consideration during obstruction evaluations. According to the licensee, this list will ensure proper information is obtained at the time of the obstruction event and should improve the ability of evaluation personnel to determine necessary follow up actions.

EXIT MEETINGS AND DEBRIEFS

The inspectors verified no proprietary information was retained or documented in this report.

• On September 20, 2023, the inspectors presented the NRC inspection results to John Van Fleet, and other members of the licensee staff.

DOCUMENTS REVIEWED

Inspection Type Designation Description or Title Revision or

Procedure Date

71003 Corrective Action 04350050 Fire Protection Leak During Performance of LOS-FP-R6 06/12/2020

Documents 04367410 U2 Cable Spreading Room FP System Blockage at Nozzle 4-5 09/04/2020

04431105 LR-UT Inspection on 0WW28A-2" 06/23/2021

04431106 LR-UT Inspection on 0WW30A-2" 06/23/2021

04440284 Documentation of Selective Leaching Based on Powerlabs 08/12/2021

04440286 Documentation of Selective Leaching Based on Powerlabs 08/12/2021

04452213 Extent of Condition Assessment for One-Time Inspection AMP10/11/2021

04522696 Buried Pipe -2022 gPIMS Examination Results 09/15/2022

Corrective Action AR 04703313 NRC ID Improvement Suggested for FW Obstruction 09/18/2023

Documents Evaluation

Resulting from

Inspection

Miscellaneous PMCR 00092160 Service Request 04/15/2020

NDE Reports AH1543-PIMS Re-Inspection Various Piping Lines 06/20/2022

41060080

AH1548-Long Range Guided Wave Ultrasonic Pipe Screening Results 06/21/2022

410762266

LAS-48146 License Renewal Socket Weld Inspections, ASME Code 06/29/2023

Class 1 Small-Bore Piping Program

Procedures ER-AA-330-012 ASME Code Class 1 Small-Bore Piping Aging Management 6

Program

ER-AA-700-301 License Renewal One-Time Inspection Program 1

LA-AMPBD-SLI Selection Leaching Inspection Sample Basis Document 0

LOP-FP-03 Viking Automatic Deluge Valve Actuation and Reset 30

LOS-FP-R6 Preaction Spray Systems Functional Test 17

Work Orders 01579781-05 Technical Report AM4103-535476-R 03/26/2014

01849461-01 CM Provide Support for UT Exam of DW Liner 03/11/2019

01924992 LR -Exterior Prot. Re-Coat Degraded -WS Inlet Pipe/Valve 07/10/2017

01925023-02 LR -Exterior Prot. Re-Coat Degraded -D WS Inlet Pipe/Valve07/10/2017

01925025 LR -Exterior Prot. Re-Coat Degraded -E WS Inlet Pipe/Valve07/10/2017

01934305-01 MM (LROT)/2MS04B Steam Relief Tail Pipe Support NDE 02/23/2019

Inspection Type Designation Description or Title Revision or

Procedure Date

(Prep)

04665916-01 Coating Surface Preparation and Application Report 08/15/2020

04665916-02 MM (LR) Excavate and Inspect Pipe 0FP08A-6" 09/20/2020

04828202-01 LRA OP LOS-FP-R6 U0 Cable Tray Over Lab Sprinkler 06/13/2020

Section E.5

05018308-01 CMO (LR) Perform Cathodic Protection Effectiveness Review 02/21/2021

05108476 Service Water Inlet to VA Compressor Valve Failure 05/24/2021

05109393 Unable to Perform WO 01942056-01 Due to Poor Isolation 05/20/2021

05109396 Replace 0WS041 Isolation Valve 08/12/2021

05125267 CMO (LR) Perform Cathodic Protection Effectiveness Review 01/24/2022

05134421-01 CM (LR) Provide Support for UT Exam of DW Liner 02/11/2023

05165205 Replace the 0WW30A-2"" and Drain Valve 06/19/2023

219788 L2R19 LR-License Renewal One-Time U-2 Class 1/A Socket 03/08/2023

Welds

228543-01 CMO (LR) Perform Cathodic Protection Effectiveness Review 01/04/2023

7