ML20199B534

Forwards Technical Basis for Elimination of Postulated Pipe Ruptures in High Energy Piping.Exemption for Treatment of Pipe Breaks on Encl List of Piping requested.WCAP-11043 Withheld (Ref 10CFR2.790)

ML20199B534
Person / Time
Site:	South Texas
Issue date:	06/10/1986
From:	Goldberg J HOUSTON LIGHTING & POWER CO.
To:	Harold Denton NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV), Office of Nuclear Reactor Regulation
Shared Package
ML19292F429	List: ML20199B534 ML20199B541 ST-HL-AE-1681, Nonproprietary South Texas Project Leak-Before-Break Screening Criteria for High Energy Auxiliary Piping Sys
References
CON-#286-563 OL, ST-HL-AE-1681, NUDOCS 8606170168
Download: ML20199B534 (14)

Text

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l June 10, 1986 l ST-HL-AE-1681 File No.: G9.10 l l

Mr. Harold Denton, Director Office of Nuclear Reactor Regulation Region IV Nuclear Regulatory Commission Washington, DC 20555 South Texas Project Units 1 & 2 Docket Nos. STN 50-498, STN 50 499 Alternative Pipe Break Criteria For Auxiliary and Balance of Plant Piping

Reference:

1) Letter from J. H. Goldberg (HIAP) to H. R. Denton (NRC) dated September 28, 1983 (ST HL-AE-1010)

2) Letter from J.11. Goldberg (HL&P) to H. R. Denton (NRC) dated July 17, 1984 (ST-ilL-AE-1096)

3) Letter from J.11. Goldberg (HL&P) to 11. R. Denton (NRC) dated August 19, 1985 (ST-HL-AE-1326)

4) Letter from J.11. Goldberg (llL&P) to H. R. Denton (NRC)

March 12, 1986 (ST-HL-AE-1617)

5) Letter from T. M. Novak (NRC) to J. J. Carey (DLC) dated March 3, 1986

Dear Mr. Denton:

n The purpose of this transmittal is to provide a technical basis for og elimination of postulated pipe ruptures in high energy piping, the associated w o n. dynamic effects, and the required hardware to mitigate these dynamic effects.

$@ Our program takes advantage of state of the art leak before break (LBB) jg technology and advanced engineering methods in pipe stress analysis to provide appropriate pipe break protection.

(D x N! This program is consistent with the NRC Staff Piping Review Committee's Q

g recommendations in NUREG 1061, Volume 3, and those programs which formed the bases for schedular exemptions authorized for numerous plants for reactor oct coolant system main loop piping (References 1 through 4 have been provided by jh HL&P). Ill4P considers the application of the leak before break technology to be a more effective and reasonable approach to ensure adequate pipe break protection than the installation of pipe restraints nd jet shields.

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3 ST-HL-AE-1681 h n @ng & h Cmpany Fila No.: G9.10 Page 2 This program will be applied to STP Unit 2 only.

HL&P intends to use the leak-before-break technology on the 16 lines listed in Table 1 of Attachment A to this letter. All of these break locations are located inside the containment building.

The enclosed technical bases, Attachments A through F, are provided in support of our program for eliminating from consideration postulated circumferential and longitudinal pipe breaks and their associated dynamic effects. Elimination of these postulated breaks would have the following effects on STP designs o Eliminate the need to install associated pipe break restraints and jet impingement shields, o Eliminate the need to consider associated dynamic effects and loading conditions including jet impingement loads, subcompartment pressurization, blowdown loads in the lines, attached piping and adjacent components, and component supports.

This program will not affect the followings o Emergency Core Cooling System (ECCS) design bases o Containment design bases o Equipment qualification design bases o Engineered Safety Features System response o Design margin of RCS heavy component supports The alternative pipe break criteria presented in Attachment A through F are provided as specific acceptance criteria for auxiliary and balance of plant piping r>ystems for STP Unit 2. These attachments address the NRC questions raised relative to Reference 5 (Beaver Valley, Unit 2) as they may relate to the South Texas Project program. These criteria provide the technical bases for an exemption under 10CFR50.12(a). Accordingly, HL&P hereby applies for an exemption under 10CFR50.12(a) for the treatment of pipe breaks on the piping listed in Attachment A for STP Unit 2 given that they meet all acceptance criteria relative to leak-before-break analysis. Special circumstances exist in that the state-of-the art in fracture mechanics now provides analytical means to achieve the underlying purpose of GDC-4 without requirements to install pipe whip restraints or jet impingement shields.

L1/NRC/ab

7 ST-HL-AE-1681 Houston Ughtiag & hmer Company Fils No.: G9.10 Page 3 This exemption would eliminate the need to install the associated pipe whip restraints and jet impingement shields and to eliminate the need to design for the dynamic effects associated with thess breaks. These dynamic effects are specifically defined as the effects of missiles, pipe whipping, subcompartment pressurization, and fluid jets. Approval of this request would (1) eliminate the need to postulate longitudinal and circumferential pipe breaks in the listed piping in Attachment A, and (2) eliminate the requirement to analyze and design for the following dynamic effects of these breaks: jet impingement, blowdown loads, pipe whip, reactor cavity pressurization, subcompartment pressurization transients, and load combination assumptions.

. This exemption request does not affect the containment pressure boundary, the emergency core cooling system, or environmental qualification design bases.

Pursuant to 10CFR50.12(a), HL&P believes the requested exemption "will not endanger life or property or the common defense and security and is otherwise in the public interest."

A schedule to provide information to the NRC of significant analysis completion dates is included as part of Attachment A. We look forward to meeting with NRR staff to discuss this program further.

4 As Attachment C contains information proprietary to Westinghouse Electric

Corporation, it is supported by an affidavit signed by Westinghouse, the owner of the information. The affidavit sets forth the basis on which the information may be withheld from public disclosure by the Commission and i addresses with specificity the considerations listed in paragraph (b)(4) of Section 2.7980 of the Commission's regulations.

Accordingly, it is respectfully requested that the information which is proprietary to Westinghouse be withheld from public disclosure in accordance with 10CFR Section 2.790 of the Commission's regulations. Correspondence with respect to the proprietary aspects of the Application for Withholding or the 1 supporting Westinghouse affidavit should reference CAW-86-004 and should be addressed to R. A. Wiesmann, Manager, Regulatory & Legislative Affairs, i

Westinghouse Electric Corporation, Post Office Box 355, Pittsburgh,

! Pennsylvania 15230.

Very truly yours.

i J. H. Goldberg Group Vice President, Nuclear i JNB/ABP/yd Attachments:

L1/NRC/ab

. ST-HL-AE-1681 flouston Lightmg & Power Company File No.: C9.10 Page 4 Attachment A Technical Description for Application of Leak Before Break to High Energy Auxiliary System Piping for South Texas Project Attachment B Division of Responsibilities of LBB on South Texas Project Auxiliary Lines Attachment C* South Texas Project Leak Before Break Screening Criteria for High Energy Auxiliary Piping Systems (WCAP-11043)

Attachment D Provisions for Minimizing Stress Corrosion Cra: king in high Energy Lines (WCAP-11044)

Attachment E Provisions for Minimizing the Effects of Thermal and Vibration,-

Induced Piping Fatigue Attachment F Provisions for Minimizing Wat.er/ Steam Hammer Effects

• Westinghouse Authorization Letter (CAW 86-004), Proprietary Information Notice, and accompanying affidavit.

WCIP-11043 Westinghouse Proprietary Class 2 WCAP-11044 Westinghouse Proprietary Class 3 '

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l L1/NRC/ab

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UNITED STATES OF AMERICA NUCLEAR REGUIATORY COMMISSION In the Matter 5 5

Houston Lighting & Power 5 Docket No. 50-499 Company, et al., 5 5

South Texas Project 5 Unit 2 AFFIDAVIT J. H. Goldberg, being duly sworn, deposes and says: that he is Group Vice President, Nuclear of HOUSTON LIGHTING & POWER COMPANY, Project Manager of the South Texas Project and an Applicant herein; that the foregoing request for exemption from the requirements of 10CFR50, Appendix A, General Design Criteria 4 pursuant to 10CFR50.12 to permit elimination of postulated circumferential and longitudinal breaks in the Auxiliary and Balance of plant piping identified herein and the associated dynamic effects from consideration in the structural design basis of the South Texas Project has been prepared under his supervision and direction; that he knows the contents thereof; an that to the best of his knowledge and belief said request and the facts contained therein are true and correct.

DATED: This /#}/s day of Tun G , 1986. f Signed: . , # A J. H. Gol'dberg V Group Vice President, Nuclear STATE OF TEXAS COUNTY OF HARRIS Subscribed and sworn to before me, a Notary Public in and for Harris County, Texas, this /c day of June, 1986.

t ut $1 )

Nota Public in 'and for he Stat f Texas My commission expires:

>/n/n L1/NRC/ab

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flouston Lighting & Power Company ST-HL-AE-1681 File No.: C9.10 Page 5 cc:

(*)Hugh L. Thompson, Jr. , Director Brian E. Berwick, Esquire Division of PWR Licensing - A Assistant Attorney Ceneral for Office of Nuclear Reactor Regulation the State of Texas U.S. Nuclear Regulatory Commission P.O. Box 12548, Capitol Station Washington, DC 20555 Austin, TX 78711 Robert D. Martin Lanny A. Sinkin Regional Administrator, Region IV Christic Institute Nuclear Regulatory Commission 1324 North Capitol Street 611 Ryan Plaza Drive, Suite 1000 Washington, D.C. 20002 Arlington, TX 76011 Oreste R. Pirfo, Esquire

(*)N. Prasad Kadambi, Project Manager Hearing Attorney U.S. Nuclear Regulatory Commission Office of the Executive Legal Director 7920 Norfolk Avenue U.S. Nuclear Regulatory Commission Bethesda, MD 20814 Washington, DC 20555 Claude E. Johnson Charles Eechhoefer, Esquire Senior Resident Inspector /STP Chairman, Atomic Safety &

c/o U.S. Nuclear Regulatory Licensing Board Commission U.S. Nuclear Regulatory Commission P.O. Box 910 Washington, DC 20555 Bay City, TX 77414 Dr. James C. Lamb, III M.D. Schwarz, Jr. , Esquire 313 Woodhaven Road Baker & Botts Chapel Hill, NC 27514 One Shell Plaza Houston, TX 77002 Judge Frederick J. Shon Atomic Safety and Licensing Board J.R. Newman, Esquire U.S. Nuclear Regulatory Commission Newman & Holtzinger, P.C. Washington, DC 20555 1615 L Street, N.W.

Washington, DC 20036 Citizens for Equitable Utilities, Inc, c/o Ms. Peggy Buchorn Director, Office of Inspection Route 1, Box 1684 and Enforcement Brazoria, TX 77422 U.S. Nuclear Regulatory Commission Washington, DC 20555 Docketing & Service Section Office of the Secretary T.V. Shockley/R.L. Range U.S. Nuclear Regulatory Commission Central Power & Light Company Washington, DC 20555 P.O. Box 2121 (3 Copies)

Corpus Christi, TX 78403 Advisory Committee on Reactor Safeguards H.L. Peterson/C. Pokorny U.S. Nuclear Regulatory Commission City of Austin 1717 H Street P.O. Box 1088 Washington, DC 20555 Austin, TX 78767 J.B. Poston/A. vonRosenberg City Public Service Board P.O. Box 1771 San Antonio, TX 78296

• Includes Attachment C. All others without Attachment C.

L1/NRC/ab Revised 5/22/86

7 Attachment A ST-HL-AE- 1681 PFN: G9.10 Page 1 of 5 TECHNICAL DESCRIPTION FOR APPLICATION OF LEAK BEFORE BREAK TO HIGH ENERGY AUXILIARY SYSTEM PIPING FOR SOUTH TEXAS PROJECT A. INTRODUCTION The purpose of this effort is to provide a technical basis for elimi-nation of postulated pipe ruptures, the associated dynamic effects, and the required hardware for the mitigation of these dynamic effects. This will be accomplished through application of the state of the art leak-before-break (LBB) technology by using a screening process developed to minimize the total effort. Latest technology developed in piping stress analysis may also be used as required to evaluate piping loads that are the basis of the fracture mechanics analysis.

B. METHODOLOGY The program involves the application of fracture mechanics technology, leak-before-break concept, a three stage screening criteria, and the reassessment of conservatism based on current ASME Codes and other technological developments. These technologies will be applied to high energy piping systems identified in Table 1. The implementation of this~

methodology to enhance the success of the program is dependent on a close interface relationship between all the parties involved for their respon-sibilities as defined in Attachment B. A brief description of each of the three key technical segments are described in the following sections.

The planned schedule for implementation of the program is provided in Table 2.

B.1 SCREENING CRITERIA Objective The objective of developing the screening criteria is to minimize the implementation effort and to avoid any unnecessary conservatism in the application of LBB approach. The screening criteria, based on general industrial and specific Westinghouse technology (Attachment C), provides the basis for a request to the NRC for approval of the LBB initiative.

Application of these criteria will allow the elimination of the breaks, the associated dynamic effects and the elimination of the need for whip restraints and jet shields; when required, subsequent detailed analysis will demonstrate LBB for those lines selected.

Screening Criteria Parameters The screening process for selecting cases for detailed fracture mechanics evaluation is based on the review and evaluation for pipe failure mecha-nisms, leak detection capability, crack stability and fatigue crack growth. The key areas of screening are highlighted below:

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m Attachment A ST-HL-AE-1681 PFN: G9.10 Page 2 of 5 Review of Potential Pipe Failure Mechanisms

- Fatigue

- Water Hammer

- Corrosion Leakage Detection Visual outside containment (only one location to require review)

Reg. Guide 1.45 systems inside containment Augmented in-service inspection inside containment, if required Crack Stability

- Material strength and toughness Limit moment approach

- Maximum longitudinal stress approach Fatigue Crack Growth Transient descriptions

- Transient loadings (including flow stratification review)

From an analytical point of view, the screening criteria is dependent on the limit moment approach and the maximum longitudinal stress approach to be incorporated into a criteria document. These approaches, applied in sequence, will limit the cases requiring detailed investigation and assure the successful implementation of using the available industrial and Westinghouse specific technology to minimize the effort with no sacrifice of safety. ,

B.2 FRACTURE MECHANICS ANALYSIS The implementation of screening criteria will provide information on the material strength and the severity of mechanical and thermal loadings.

The application of fracture mechanics technology to implement the LBB concept can be categorized into three separate levels based on the required effort of implementation as described below.

1. Hand Calculations Without Finite Element Analysis This method applies to those cases where the combination of material strengths and all applicable loadings for a specific pipe size group meet the most conservative screening criteria requirements. 1he l application of hand calculation with simple formula minimizes the required effort for an expeditious completion of these cases.

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m Attachment A ST-HL-AE- 1681 PFN: G9.10 Page 3 of 5

2. Partial Finite Element Analysis This method applies to those cases where the combination of material strengths and all applicable loadings for a specific pipe size group meet the medium level requirements of the screen criteria. For these cases, available analytical results will be used and finite element analysis will be performed only on an as needed basis. The deterni-nation of where this method is to be applied is dependent on the results of the screening process and previous knowledge of the LBB application to the auxiliary system piping. The adoption of limited finite element analysis, where applicable, will reduce the effort and time significantly for this program.

3. Detailed Fracture Mechanics Analysis Using Finite Element Analysis Methods This method applies to cases where the combination of material strengths and all applicable loadings for a specific pipe size group meets the lowest level of the screening criteria. For these cases, finite element analysis must be applied to both the crack stability analysis and leakage calculations to demonstrate the applicability of LBB.

4. Material Testing Material properties are being reviewed for the actual plant piping.

To date the following testing is planned. Based upon the complete material data review, additional testing may be added to the programs as determined to be required.

a) 30" Main Steam Line (SA 155 KCF70 Class 1)

The following tests will be completed for both base metal and weld metal samples.

• Obtain 3 J-R curves at 550 F

• Obtain 1 J-R curve at RT

• Obtain 3 stress-strain curves at 550 F

• Obtain I stress-strain curve at RT l b) 8" SI line (SA-312 TP 304L)

The following test will be completed on base metal.

• Obtain 3 J-R curves at 550 F

• Obtain 1 J-R curve at RT

• Obtain 3 stress-stain curves at 550 F

• Obtain 1 stress-strain curve at RT txt\abp L-

Attachment A ST-HL-AE- 1681 PFN: G9.10 Page 4 of 5 B.3 METHODS TO REASSESS CONSERVATISM The purpose of this LBB application program is to eliminate postulated pipe breaks and with them the hardware that would be needed to mitigate dynamic effects of the postulated pipe ruptures. If necessary, reassess-ment in conservatisms associated with conventional stress analysis will help the elimination of these breaks by either enhancing the probability of success for fracture mechanics analysis or qualifying more locations for elimination as arbitrary intermediate breaks. Only proven methodolo-gy will be used in this process. The technology to be applied is either recommended by the NRC piping review committee, summarized in NUREG-1061 reports, or existing in previous licensing precedents or technical reports endorsed by the U.S. NRC.

C BASE SCOPE The scope for the schedular exemption to eliminate postulated pipe ruptures, the associated dynamic effects and the required hardware for the mitigation of these dynamic effects is summarized in Table 1.

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Attachment A ST-HL-AE-1681 ]

PFN: G9.10 Page 5 of 5 l l

Table 1 l l

List of High Energy Lines  :

for LBB on South Texas Proiect Auxiliary Lines Stainless Steel Material Pioina Material Tvoe 12" RHR Lines and/or Accumulator SA312, TP304, 304L, 316 or Injection Lines 316L and SA376, TP304, 316 10"/8" Branches off Accumulator SA312, TP304, 304L, 316 or Injection Lines 316L and SA376, TP304, 316 8" SI lines off RC Hot Legs SA312, TP304, 304L, 316 or 316L and SA376, TP304, 316 4" Pressurizer Spray Lines from the SA312, TP304, 304L, 316 or Loop Connections to the Spray Valves 316L and SA376, TP304, 316 4" Charging, Alternate Charging, and SA312, TP304, 304L, 316 or Letdown Lines 316L and SA376, TP304, 316 3"/6" Auxiliary Spray, Loop Drain, and - SA312, TP304, 304L, 316 or Excess Letdown Lines 316L and SA376, TP304, 316 Carbon Steel Material 30" Main Steam Lines SA155 GR KCF-70 Class 1 16"/18" Main Feedwater Lines SA333 GR6 SMLS 8"- Auxiliary Feedwater Lines SA106 GRB SMLS 4" Feed Bypass Lines SA106 GRB SMLS 3"/4"/ Steam Generator Blowdown Lines SA335-P22 SMLS 6"

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Attachment A ST-HL-AE-1681 PFN: G9.10 Page Sa of 5 Table 2 Schedule for Implementation of LBB on South Texas Pro.iect Auxiliary lines HL&P to meet with NRC to discuss screening June, 1986 criteria in Attachment C.

NRC concurrence with STP methodology and screening July, 1986 criteria for program implementation.

HL&P complete detailed results of screening criteria August, 1986 for all lines, available to discuss with NRC during a technical meeting.

HL&P complete detailed fracture mechanics analysis for October, 1986 main steam line and submit to NRC.

HL&P establish a detailed program to ensure leak December, 1986 detection capability at the plant. This will be accomplished by means of current standard leak detection systems plus standard plant instrumentation such as pressure readings, water levels, make-up flows, etc.

Technical specifications and operating instructions will be reviewed to ensure appropriate warnings and instructions are in place to ensure any significant leakage will be detected and handled properly.

HL&P complete remaining detailed fracture mechanics January, 1987 analysis for all lines and have on file for NRC review.

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Attachment B ST-HL-AE-PFN: G9.10 Page 1 of 1 Division of Responsibility of LBB on South Texas Pro.iect Auxiliary lines Lead Supporting e

J_t_em Group Group

1. Preparation of licensing documents and HL&P W/B and submittals and coordination of meetings with NRC

2. Development of Screening Criteria W HL&P/B

3. Identification of existing break B W location loads and other piping data per prescribed form

4. Implementation of Screening Criteria W B to all high energy line cases (see Attachment A, Table 1)

5. Perform Safety Balance calculations B W

6. Fracture Mechanics Analysis Scheduling B Grouping and analysis W

7. Assessment of conservatisms of conventional HL&P B/W piping analysis (Code Cases 411 & 397, stress indices, etc.)

8. Piping reanalysis B W Notes:

HL&P - Houston Lighting & Power Co.

B - Bechtel Energy Corporation W - Westinghouse Electric Corporation

Attachment C ST-HL-AE -1681 PFN: G9.10 SOUTH TEXAS PROJECT LEAK-BEFORE-BREAK SCREENING CRITERIA FOR HIGH ENERGY AUXILIARY PIPING SYSTEMS This attachment presents the screening criteria for the application of leak-before-break to high energy piping systems in South Texas Project.

The purpose of this effort is to apply the state-of-the-art technology in leak-before-break through a screening process developed to minimize the downstream effort and to obtain an insight in ascertaining the possibility of successful demonstration of leak-before-break. Successfully passing the screening criteria establishes technical justification to eliminate the dynamic effects of postulated breaks. The screening criteria are provided in the following enclosures:

Enclosure 1: WCAP #11043 - South Texas Project Leak-Before-Break Screening Criteria for High Energy Auxiliary Piping Systems (Proprietary Class 2)

Enclosure 2: WCAP #11044 - Souch Texas Project Leak-Before-Break Screening Criteria for High Energy Auxiliary Piping Systems (Proprietary Class 3)

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