ML20236Q316

Safety Evaluation Accepting Licensee Proposed Alternative to ASME Code Requirements PTP-3-01 & PTP-3-02

ML20236Q316
Person / Time
Site:	Point Beach
Issue date:	07/10/1998
From:	NRC (Affiliation Not Assigned)
To:
Shared Package
ML20236Q315	List: ML20236Q313 ML20236Q316
References
NUDOCS 9807200167
Download: ML20236Q316 (6)

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i UNITED STATES g-NUCLEAR REGULATORY COMMIS810N o,

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t SAFETY EVALUATION BY THE OFFICE OF NUCI I:AR REACTOR REGULATION REVIEW OF PROPOSED ALTERNATIVES TO THE ASME CODE FOR INSERVICE PRESSURE TESTING WISCONSIN ELECTRIC POWER COMPANY POINT BEACH NUCI I:AR PLANT. UNITS 1 AND 2 mri 50-301

1.0 INTRODUCTION

The Technical Specifications for the Point Beach Nuclear Power Plant, Units 1 and 2, state that the inservice inspection (ISI) of the American Society of Mechanical Engineers (ASME) Code Class 1,2, and 3 components shall be performed in accordance with Section XI of the ASME Boiler and Pressure Vessel Code and applicable addenda as required by 10 CFR 50.55a(g),

except where specific written relief has been granted by the Commission pursuant to 10 CFR 50.55a(g)(6)(i). Section 50.55a(a)(3) of 10 CFR states that attematives to the requirements of paragraph (c) may be used when authorized by the NRC if (i) the proposed altamatives would provide an acceptable level of quality and safety, or (ii) compliance with the specified requirements would result in hardship or unusual difficulty without a compensating increase in the ' level of quality and safety.

Pursuant to 10 CFR 50.55a(g)(4), ASME Code Class 1,2, and 3 components (including supports) shall meet the requirements, except the design and access provisions and the preservice examination requirements, set forth in the ASME Code,Section XI, " Rules for Inservice inspection of Nuclear Power Plant Components," to the extent practical within the limitations of design, geometry, and materials of construction of the components. The regulations require that inservice examination of components and system pressure tests conducted during the first 10-year interval and subsequent intervals comply with the requirements in the latest edition and addenda of Section XI of the ASME Code incorporated by reference in 10 CFR 50.55a(b) 12 months prior to the start of the 120-month interval, subject to the limitations and modifications listed therein. The applicable ASME Code,Section XI, for the Point Beach Nuclear Power Plant third 10-year ISI interval is the 1986 Edition, no addenda.

l The components (including supports) may meet the requirements set forth in subsequent editions and addenda of the ASME Code incorporated by reference in 10 CFR 50.55a(b) l subject to the limitations and modifications listed therein and subject to Commission approval.

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' Pursuant to 10 CFR 50.55a(g)(5), if the licensee determines that conformance with an

. examination requirement of Section XI of the ASME Code is not practical for its facility, information shall be submitted to the Commission in support of that determination and a request made for relief from the ASME Code requirement.' After evaluation of the determination, ENCLOSURE

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L l~~ l pursuant to 10 CFR 50.55a(g)(6)(i), the Commission may grant relief and may impose attemative requirements that are determined to be authorized by law, will not endanger life, property, or the common defense and security, and are otherwise in the public interest, giving due consideration to the burden upon the licensee that could result if the requirements were imposed Pursuant to 10 CFR 50.55a(s)(3)(i), proposed attematives to the requirements of paragraphs (c), (d), (e), (f), (g), and (h) of 10 CFR 50.55a may be used when authorized by the Director of the Office of Nuclear Reactor Regulation and the applicant can demonstrate that the proposed altematives would provide an acceptable level of quality and safety.

By letters dated December 16,1997, and June 17 and July 2,1998, Wisconsin Electric (WE or the licensee) Power Company requested relief for pressure testing containment penetration piping and components associated with non-ASME classed systems for Units 1 and 2.

The staff has reviewed and evaluated the licensee's request and supporting information on the proposed attemative to the Code requirements for Point Beach Unit 2, pursuant to the provisions of 10 CFR 50.55a(a)(3)(i).

2.0 DISCUSSION OF REllEF REQUEST PTP-3-02 2.1 Comoonent Description Pressure testing of containment penetration piping - Request for approval to use Code Case N-522

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l The following penetrations will be tested using Code Case N-522:

l Penetration Line Number Desenption l

1CPP-V1 U1C pipe penetration purge e' haust x

1CPP-V2 U1C pipe penetration purge supply i

l 1CPP-X1.

U1C pipe penetration supply to RE-211 and RE-212 l

1CPP-X2 U1C pipe penetration retum from RE-211 and RE-212 1CPP-09 U1C pipe penetration reactor coolant drain tank (RCDT) drain 1CPP-12C U1C pipe penetration waste gas vent header 1CPP-14B U1C pipe penetration containment pressure transmitter 1CPP-25C U1C pipe penetration post-accident containment ventilation system (PACVS) supply 1CPP-28D U1C pipe penetration deadweight tester 1CPP-31A U1C pipe penetration containment pressure transmitter 1CPP-318 U1C pipe penetration PACVS sample 1CPP-31C U1C pipe penetration PACVS exhaust 1CPP-32A U1C pipe penetration containment pressure transmitter 1CPP-33A U1C pipe penetration instrument air (IA) supply to containment 1CPP-33B U1C pipe penetration IA supply to containment 1CPP-34D U1C pipe penetration gas analyzer from RCDT 1CPP-52 U1C pipe penetration -

heating steam to containment 1CPP-53 U1C pipe penetration condensate retum from heaters 1CPP-71 U1C pipe penetration sump A to primary auxi!iary building (PAB) sump

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2CPP-V1 U2C pipe penetration purge exhaust 2CPP-V2 U2C pipe penetration purge supply 2CPP-X1 U2C pipe penetration supply to RE-211 and RE-212 2CPP-X2 U2C pipe penetration retum from RE-211 and RE-212 2CPP-09 U2C pipe penetration reactor coolant drain tank (RCDT) drain 2CPP-12C U2C pipe penetration waste gas vent header 2CPP-14B U2C pipe penetration containment pressure transmitter 2CPP-28D U2C pipe penetration deadweight tester 2CPP-42C U2C pipe penetration post-accident containment ventilation system (PACVS) supply 2CPP-31A U2C pipe penetration containment pressure transmitter 2CPP-31B U2C pipe penetration PACVS sample 2CPP-31C U2C pipe penetration PACVS exhaust 2CPP-32A U2C pipe penetration containment pressure transmitter 2CPP-33A U2C pipe penetration IA supply to containment 2CPP-338 U2C pipe penetration IA supply to containment 2CPP-34D U2C pipe penetration gas analyzer from RCDT 2CPP-52 U2C pipe penetration heating steam to containment 2CPP-53 U2C pipe penetration condensate retum from heaters 2CPP-71 U2C pipe penetration sump A to primary auxiliary building (PAB) sump 2.2 Code Class ASME Section XI, Class 2 2.3 ASME Examination Requirements. ASME Section XI.1986 Edition. no addenda ASME Section XI, Table IWC-2500-1 Code Examination Category, C-H; Item Number C7.10 through C7.80 Paragraph IWA-5211 TEST DESCRIPTION The pressure-retaining components within each system boundary shall be subject to the following system pressure tests under which conditions visual examination VT-2 is performed in accordance with IWA-5240 to detect leakage.

Paragraph IWC-5210 TEST (a)

The pressure-retaining components within each system boundary shall be subjected to the following system pressure tests and visually examnined by the method specified in table IWC-2500-1, Examination category C-H:

(1) a system pressure test shall be conducted during a system functional test of those [lWA 5211(b)] systems (or components) not required to operr.te during normal plant

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operations but for which periodic system (or components) functional tests are performed to meet the Owner's requirements; (2) a system pressure test conducted during a system inservice test [lWA 5211(c)] for those systems required to operate during normal plant operations; and (3) a system hydrostatic pressure test [lWA-5211(d)] for each system or portions of systems and for repaired or replaced components, or altered portions of systems.

(b)

The system pressure tests and visual examinations shall be conducted in accords;.,e with IWA-500 and this Article. - The contained fluid in the system shall serve as the pressurizing medium, except that in steam systems either water or air may be used. Where air is used, the test procedure shall permit the detection of through-wallieskages in components of the system tested.

2.4 Basis for Rehef (As stated) i i

This request for relief is submitted under the provisions of 10 CFR 50.55a(a)(3). The proposed attemative to test those portions of piping systems penetrating containment in accordance with the requirements of ASME Code Case N-522 will provide an acceptable level of safety to ensure that both intemal and extemal system leakage is maintained at levels less than [that] required by the Point Beach Nuclear Plant Technical Specifications.

Recognizing that the applicable piping penetration systems are designated extensions of the containment, the overall piping systems are non-safety related or classed ASME. The only basis for classification is to provide for containment isolation. Since ASME Section XI pressure testing only provides for extemal system leakage and provides indication of system integrity the importance of containment isolation is also to restrict inter-system leakage to the outside environment. To perform the redundant and less restrictive tests of ASME Section XI would not provide for any commensurate increase in safety.

2.5 Altemative Examination (As stated)

ASME Section XI pressure testing of containment penetration piping and components solely designated Class 2 for the purposes of the containment system where the balance of the system is outside the scope of ASME will be pressure tested in accordance with the provisions of ASME Section XI, Code Case N-522. As directed j

by the provisions of the Code Case, pressure testing will be conducted in accordance l

with the requirements of 10 CFR [Part] 50, Appendix J. If subsequent to the approval i

of this request for relief the NRC adopts Code Case N-522 in NRC Regulatory Guide 1.147 and the Commission provides additional guidance or impose [s] specific restriction, Point Beach Nuclear Plant will adopt the provisions of Regulatory l

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5-Guide 1.147,' Inservice inspection Code Case Acceptability, ASME Section XI, Division 1," following its revision. Testing and any required examinations will be performed by certified personnelin accordance with approved plant procedures.

3.0 EVALUATION I

The system leakage test required by the Code in Examination Category C-H provides periodic verification of the leak-tight integrity of Class 2 piping syr,tems or segments once every 40 months. The pipe segments from non-Code class systems that penetrate containment are designed and examined as Class 2 piping for the sole purpose of maintaining the integrity of containment. The Appendix J pressure testing proposed by the licensee as an attemative to the VT-2 method of testing provides periodic verification by test, of the leak-tight integrity of the primary reactor containment, and of systems and components that penetrate containment. The test provides assurance that the containment pressure boundary is being maintained at an acceptable level while monitoring for deterioration of seals, valves, and piping.

The containment penetration piping along with the containment isolation valves (CIVs), are part of containment pressure boundary and are classified as Class 2. Hence, the containment isolation valves along with the connecting pipe segments must withstand the calculated peak containment intemal pressure related to the design-basis loss-of-coolant accident as specified in the Technical Specifications. Since Code Case N-522 has not specified the test pressure for containment penetration piping. the staff has determined that the pressure testing must be conducted at the peak calculated containment pressure for design-basis accident. In the acceptance criteria for the Appendix J test, the combined leakage from all penetrations and valves must be below a permissible limit, whereas the ASME Section XI Code does not allow any pressure boundary leakage during pressure testing and requires in paragraph IWC-5210(b) that when air is used as a testing medium, the test procedure must include methods for detection and location of through-wallleaks in system components. Since most Appendix J tests are conducted using air as test medium, the staff has determined that the licensee's proposed citemative of conducting the Appendix J test at peak calculated containment pressure with the provision to detect and locate pressure boundary leak would provide an acceptable level of quality and safety as that of the ASME Code,Section XI,1986 Edition for pressure testing of containment penetration piping.

4.0 CONCLUSION

The staff has evaluated the information provided by the licent ce in support of its Code relief request to use Code Case N-522 as an attemative to pressuru testing of Class 2 components at containment penetrations in the licensee's Relief Request PTP-3-02 for the third 10-year inspection interval of Point Beach Nuclear Plant Units 1 and 2. The staff concludes that implementation of Code Case N-522, subject to requirements that the test be conducted at peak calculated containment pressure and the test procedure include methods for detection and location of through-wall leakage in CIVs and pipe segments between the CIVs, would provide an acceptable level of quality and safety. The use of Code Case N-522 is for Point Beach during the third inspection interval unt,i'euch time as the Code Case is approved by reference in Regulatory Guide 1.147. At that time, if the licensee intends to continue to implement this Code Case, the licensee shrl! follow all provisions in Code Case N-522 with limitations issued in Regulatory Guide 1.147, if any. The staff, therefore, concludes that the

.' licensee's proposed attemative is authorized by law and the proposed alternatives will provide an acceptable level of quality and safety.

' Principal Contributors: P. Patniak L. Gundrum Date:

July 10,1998 l

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