ML19312A096
| ML19312A096 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 11/13/2019 |
| From: | Dennis Galvin Plant Licensing Branch IV |
| To: | Gerry Powell South Texas |
| Galvin D, NRR/DORL/LPLIV, 415-6256 | |
| References | |
| EPID L-2019-LLR-0096 | |
| Download: ML19312A096 (5) | |
Text
November 13, 2019 Mr. G. T. Powell President and CEO STP Nuclear Operating Company South Texas Project P.O. Box 289 Wadsworth, TX 77483
SUBJECT:
SOUTH TEXAS PROJECT, UNITS 1 AND 2 - SUPPLEMENTAL INFORMATION NEEDED FOR ACCEPTANCE OF REQUESTED LICENSING ACTION RE: PROPOSED ALTERNATIVE TO ASME CODE REQUIREMENTS FOR THE REPAIR OF ESSENTIAL COOLING WATER SYSTEM CLASS 3 BURIED PIPING (EPID: L 2019-LLR-0096)
Dear Mr. Powell:
By letter dated September 26, 2019 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML19274C393), STP Nuclear Operating Company (STPNOC, the licensee) submitted a proposed alternative to the requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code) at South Texas Project Units 1 and 2. The proposed alternative to ASME Code,Section XI, IWA-4000, applies a carbon fiber reinforced polymer system for the internal repair of buried essential cooling water piping.
The purpose of this letter is to provide the results of the U.S. Nuclear Regulatory Commission (NRC) staffs acceptance review of this of this proposed alternative request. The acceptance review was performed to determine if there is sufficient technical information in scope and depth to allow the NRC staff to complete its detailed technical review. The acceptance review is also intended to identify whether the application has any readily apparent information insufficiencies in its characterization of the regulatory requirements or the licensing basis of the plant.
Pursuant to Sections 50.55a(z)(1) and 50.55a(z)(2) of Title 10 of the Code of Federal Regulations (10 CFR), the applicant shall demonstrate that the proposed alternatives would provide an acceptable level of quality and safety, or that compliance with the specified requirements of Section 50.55a would result in hardship or unusual difficulty without a compensating increase in the level of quality or safety.
The NRC staff has reviewed your application and concluded that the information delineated in the enclosure to this letter is necessary to enable the staff to make an independent assessment regarding the acceptability of the proposed alternative in terms of regulatory requirements and the protection of public health and safety and the environment.
In order to make the application complete, the NRC staff requests that STPNOC supplement the application to address the information requested in the enclosure by November 27, 2019. This will enable the NRC staff to begin its detailed technical review. If the information responsive to the NRC staffs request is not received by the above date, the application will not be accepted
for review pursuant to 10 CFR 2.101, and the NRC will cease its review activities associated with the application. If the application is subsequently accepted for review, you will be advised of any further information needed to support the staffs detailed technical review by separate correspondence.
The information requested and associated timeframe in this letter were discussed with Drew Richards of your staff on November 7, 2019.
If you have any questions, please contact me at 301-415-6256 or via e-mail at Dennis.Galvin@nrc.gov.
Sincerely,
/RA/
Dennis J. Galvin, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-498 and 50-499
Enclosure:
Supplemental Information Needed cc: Listserv
- by email OFFICE NRR/DORL/LPL4/PM NRR/DORL/LPL4/LA NRR/DEX/EMIB/BC*
NAME DGalvin PBlechman SBailey DATE 11/12/19 11/12/19 10/15/2019 OFFICE NRR/DORL/LPL4/BC*
NRR/DORL/LPL4/PM NAME JDixon-Herrity DGalvin DATE 11/13/19 11/13/19
Enclosure SUPPLEMENTAL INFORMATION NEEDED PROPOSED ALTERNATIVE TO ASME SECTION XI REQUIREMENTS FOR REPAIR/REPLACEMENT OF ESSENTIAL COOLING WATER CLASS 3 BURIED PIPING IN ACCORDANCE WITH 10 CFR 50.55a(z)(1)
STP NUCLEAR OPERATING COMPANY SOUTH TEXAS PROJECT UNITS 1 AND 2 DOCKET NOS. 50-498 AND 50-499 By letter dated September 26, 2019 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML19274C393), STP Nuclear Operating Company (STPNOC, the licensee) submitted a proposed alternative to the requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code) at South Texas Project, Units 1 and 2. The proposed alternative to ASME Code,Section XI, IWA-4000, applies a carbon fiber reinforced polymer (CFRP) system for the internal repair of buried essential cooling water (ECW) piping.
The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the application and has determined that the following additional information is necessary for the staff to make an independent assessment regarding the acceptability of the proposed alternative:
- 1.
ASME Code,Section XI, IWA-4221 (b) requires repair/replacement piping to meet the original Construction Code requirements for the ECW piping. However, the applicable Construction Code for South Texas Project does not provide the requirements for the design, fabrication, installation, examination and testing of CFRP in buried piping.
The application identifies 12 separate lines to use CFRP (three supply lines each for Units 1 and 2, and three return lines each for Units 1 and 2). Specific analyses or technical evaluations demonstrating structural integrity for these 12 separate lines using CFRP are missing in the submittal. Attachment C in Enclosure 5 of the application provides only a sample calculation. Thus, critical technical analysis information required for the NRC to draw a safety conclusion is missing.
- a.
Provide a summary of design inputs to include loads, pressures, temperatures, geometrical inputs, length of repair, CFRP layers, thicknesses, bonding length used for the analysis and evaluations of these 12 lines.
- b.
Provide a summary of the results of all analyses and evaluations to include circumferential design analysis, buckling evaluations, longitudinal design analysis, bond integrity at terminations for the applicable load combinations, corresponding allowable limits, and margins for all 12 of the repairs using CFRP.
- c.
Provide the missing details for Sections E/S-7, H/S-10, and G/S-9 in the piping layout drawings in Enclosure 2, Attachments B1, B2, and B3.
- d.
Provide an evaluation of the terminations of the repairs considering the effects from both sides (repair side and the other or non-repaired side). Also, describe whether any of the repair terminations interface with piping not buried such as piping in valve pits, piping in buildings, or any other continuations.
- e.
Provide or include in the evaluations the effect of dissimilar thermal expansion of the repaired aluminum-bronze pipe and the CFRP material on the terminations.
- f., Figure 2a, provides a typical design summary sheet for the piping repair. Figure 2a, Column 3, specifies the approximate length of piping repaired with CFRP but the listed value is TBD. Clarify the reference to TBD or provide the associated value.
- g., Item 1)c), refers to an Enclosure B. The application does not include an Enclosure B. Clarify the reference to Enclosure B or provide Enclosure B.
- 2.
The application includes an analysis methodology change from the ASME Code. ASME Codes and Standards for piping analysis are discussed in Title 10 of the Code of Federal Regulations Section 50.55a. Piping analysis for safety-related Class 3 piping in ASME Subsection ND does not utilize the load and resistance factor design (LRFD) method.
The application describes using the LRFD methodology for buried aluminum-bronze buried piping in soil.
- a.
Provide a discussion of the analysis method used in the original design for ASME safety-related Class 3 ECW piping and any variances between the ASME ND allowable stress methodology and the LRFD methodology.
- b.
Provide a summary of the results of the piping analysis for one limiting case.