ML20080C137
| ML20080C137 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 12/06/1994 |
| From: | Marsh W SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9412070324 | |
| Download: ML20080C137 (4) | |
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Southem Califomia Edison Company 23 PARKER STREET tRVINE CALIFORNIA 92718 WALT ER C. MARSH December 6, 1994 - F,<me MANACel Ft OF NUCLI AR F9Et3ULATORY AF F AeRS (714)454-4403 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555 Gentlemen:
Subject:
Docket Nos. 50-361 and 50-362 ASME Section XI Repair and Replacement Program Use of Code Case N-416-1 San Onofre Nuclear Generating Station Units 2 and 3
References:
- 1) ASME Code Case N-416-1, " Alternate Pressure Test Requirement for Welded Repairs or Installation of Replacement Items by Welding, Class 1, 2, and 3 Section XI, Division 1."
- 2) Letter from Mohan C. Thadani (NRC) to Mr. J. P. O'Hanlon (VEPCO) dated October 14, 1994;
Subject:
Surry Power Station, Units 1 and 2, Requesting Approval of Code Case N-416-1 as an Alternative to the Required Hydrostatic Pressure Test (TAC Nos. M89884 and M89885)
- 3) Letter from Mr. J. P. O'Hanlon (VEPC0) to the Document Control Desk (NRC) dated June 22, 1994;
Subject:
Virginia Electric and Power Company, Surry Power Station Units 1 and 2, Inservice Inspection Program, ASME Code Case N-416-1 Southern California Edison (Edison) requests that the NRC approve the use of ASME Code Case N-416-1 (Reference 1) at San Onofre Units 2 and 3. Approval of Code Case N-416-1, with the additional surface examinations described below, is requested for use beginning with the Unit 2 Cycle 8 refueling outage and ending when Code Case N-416-1 is incorporated in Regulatory Guide 1.147. Code Case N-416-1 will allow an alternative pressure test in lieu of the hydrostatic pressure test required following welded repairs or installation of replacement items by welding.
San Onofre Units 2 and 3 are in the second ten-year Inservice Inspection (ISI) interval, and the current ISI program is based on the 1989 Edition of the ASME Code with no Addenda. ASME Code,Section XI, Repair and Replacement activities are planned for the scheduled refueling outages in 1995. Some of these activities involve welded repairs; therefore, hydrostatic pressure tests i
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I Document Control Desk j " [2-5 are required by Section IWA-4000 of the ASME Code. Specific examples currently planned are 1) replacing a section of 18 inch feedwater piping to each steam generator (Unit 2 only), 2) installirj a 3 inch gate valve in the chemical and volume control system (which ties into the shutdown cooling system), 3) replacing two 3 inch check valves in the component cooling water system, and 4) replacing a valve in tne high pressure safety injection system (Unit 3 only). Additional repairs or replacements requiring welding may be identified during the outage.
Edison would prefer to perform system leakage tests as allowed by ASME Code Case N-416-1, which was approved by the ASME Code Committee on February 15, 1994. However, this Code Case has not yet been endorsed by the NRC in Regulatory Guide 1.147, " Inservice Inspection Code Case Acceptability ASME Section XI Division 1" due to the recent approval by the ASME.
Therefore, Edison requests NRC approval to use Code Case N-416-1 at San Onofre Units 2 and 3 pursuant to 10 CFR 50.55a(a)(3)(ii). In addition, Edison will perform additional surface examinations on the root (pass) layer of all welds on the pressure retaining boundary of Class 3 components when the surface examination method is used in accordance with ASME Section III. This request is consistent with the NRC approval (Reference 2) granted to a similar request by Virginia Electric and Power Company (Reference 3).
Also, Code Case N-416-1 requires the use of Methods and Acceptance Criteria of the applicable Subsection of Section III. Edison will also impose the examination requirements imposed by the 1992 Edition of Section III. For example, in the case of ASME Section III, Class 3 joints, the additional Non-Destructive Examination (NDE) proposed above will be imposed on joints greater than 2" Nominal Pipe Size (NPS) in accordance with the 1992 Edition of the ASME Section III Code, rather than 4" NPS which would be required by the San Onofre Units 2 and 3 original construction Code (ASME Section III,1974 Edition, with addenda through the Summer of 1974).
The hydrostatic pressure tests currently scheduled to be performed at Units 2 and 3 during the Cycle 8 refueling outages will have significant costs for labor, without considering the potential effect on the critical path schedule.
(There is a hydrostatic pressure test scheduled in each outage that is within two hours of the critical path.)
The industry has established that hydrostatic pressure tests add marginal (if any) vaha to the total engineering product. This was the basis of the ASME approval of Ccde Case N-416 and N-416-1. During the refueling outages there are many activities that must be coordinated. Edison has concluded that compliance with the Code hydrostatic testing requirements for welded repairs or replacements of Code Class 1, 2, and 3 components would result in hardships without a compensating increase in the level of quality and safety.
The references are enclosed for your convenience. Because some repairs and replacements will be made early in the outage, and because equipment and systems cannot be considered operable and returned to service until the ASME Code requirements are satisfied, NRC approval to use Code Case N-416-1 is
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. Document Control Desk f [3- -
a".w" requested by the outage start date, February 11, 1995. Please let me know if you have any questions.
Very truly yours, hh0 t(At Enclosures cc: L. J. Callan, Regional Administrator, NRC Region IV A. B. Beach, Director, Division of Reactor Projects, Region IV K. E. Perkins, Jr., Director, Walnut Creek Field Office, NRC Region IV J. A. Sloan, NRC Senior Resident Inspector, San Onofre Units 2 & 3 M. B. Fields, NRC Project Manager, San Onofre Units 2 and 3
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REFERENCE 1 CASE :
N-416
, CASES OF ASME BOILER AND PRESSURE VESSEL CODE 9
Approval Date: December 5,1984 See Numeric Index for expiration and any restfirmation dates.
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Case N 416 4210 in earlier Code editions) for repair or replacement Alternative Rules for Hydrostatic Testing of Repair of Class 2 piping that cannot te isolated by existing or Replacement of Class 2 Piping' ,
valves or that requires securing safety or relief valves . '
Section XI, Divislan 1 for isolation may be deferred until the next regularly
- scheduled system hydrostatic tests (IWC-5000), pro- ,
Inquiry: For Section XI, Division 1, repair or re- vided both of the following conditions are met,
- '.imme ately upon return to seMee, placement of Class 2 piping that cannot be isolated by existing valves or that requires securing safety or relief a visual examination (VT 2) for leakage shall be con-valves for isolation, may the system hydrostatic test ducted Mg a system functiond test or dudng a required by IWA-4400 (IWA-4210 in earlier Code edi- system inservice test in the repaired or replaced portion tions) be deferred until the next regularly scheduled f the piping system.
system hydrostatic test (IWC-5000) for that system? (b) The repair or replacement welds shall be ex.
. ammed in accordance with IWA-4000 and IWA 1000 using volumetric examination methods (IWA-2230)
Reply It is the opinion of the Committee'that the for full penetration welds or surface examination system hydrostatic test required by IWA-4400 (IWA- methods (IWA 2220) for partial penetration welds.
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. UNITED STATES J. ..
- j. NUCLEAR REGULATORY COMMISSION WAeMfMGT@ld, e.0. m g **,,+ / October 14, 1994 Mr. J. P. O'Hanlon -
p"q Senior Vice President Nuclear Virginia Electric and Power Company kl 'r l 5000 Dominion Blvd.
Glen Allen, Virginia 23060 '
SUBJECT:
SURRY POWER STATION, UNITS 1 AND 2. REQUESTING APPROVAL OF CODE CASE N-416-1 A5 AN ALTERNATIVE TO THE REQUIRED HYDROSTATIC PRESSUR (TAC NOS. M89884 AND M89885)
Dear Mr. O'Hanlon:
We have completed our review of your submittal dated June 22, 1994, which ,
requested approval to use ASME Code Ca$e N-416-1 in lieu of performing the Code-required hydrostatic pressure test for welded repairs or installation of replacement items by welding. Use of code Case N-416-1 is authorized pursuant to 10 CFR 50.55a(a) performed on the roo(3)(ii) provided that additional surface examinations are t (pass) layer of.hutt and socket welds on the pressure retaining boundary of Class 3 components when the surface examination method is used in accordance with Section III. Use'of Code Case N-416-1 is authorized until such time as this Ccd6 case is published in a future revision of Regulatory Guide 1.247. At that time if you intend to continue to implement this Code case, you are required to follow all provisions in Code case N-436-1, with limitations issued in Regulatory Guide 1.147, if any. The staff's evaluation and conclusions are continued in the attached Safety Evaluation.
This cc:rpletes our efforts on this issue and we are, therefore, closing out '
Tac Nos. M89884 and N69885.
Mohan C. Thadani, Acting Director .
Project Directorate 11-2 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation Docket Nos. 50-280 and 50-261 cc: See next page i
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- 3 Md j NUCLEAR REGULATORY COMMISSION WAeMOTo 4. o.C. Intes.eem SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGU ON ASME CODj? CASE N-416-1
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y!RGINIA ELECTRIC & p0WER COMPANY SURRY POWER STATION. UNITS 1 AND 2 DOCKETS N05.:_JiO-280 AND 50-281_
1.0 JNTRODUCTION The Technical Specifications for Surry m.2r Station, Units 1 and 2, state that the inservice inspection and testig 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 30 CFR written relief has 50.55a(g)(6)(i , been granted by the Commission pursuant to
- requirements of paragr)aph (g) may be used, when authorized b (i) the proposed alternatives would provide an acceptable level of' quality and safety or (ii) compliance with the specified requirements would result in hardship of quality or unusual and safety.difficulties without a compensating increase in the level 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 3nspection of Nuclear Power Plant Compenents," to the extent practical within the limitations of design, geometry, and materials of construction of the components.
recuire that inservice examination of ccmponents and system pressure testsThe regula with the requirements in the latest elition and addenca of ASME Code incorporated by reference ir 10 CFR 50.55a(c) on the date twelve months prior to the start cf the ICO-manth interval, subject to the limitations and modifications listed therein. The applicable edition of Section XI of the ASME Code for the Surcy Power Station, Units 1 and 2, seco 10-year Winter 1980inservice Addenda. inspection (151) Intenal is the 1980 Edition, through The components (including supports) may meet the require'nents set forth in subsequent edicions and addenda of the A5ME Code incorporated by reference in 10 CFR 50.5!ia(b) subject to the limitations and modifications listed therein anc subject to Commission approval.
By letter dated June 22, 1994 requested approval for the implamentatior cf the alternative rules of ASME Section XI Coce Case N-416-1 dated February 15, 1994, entitled " Alternative Pressure Test Requirement for Weldeo Repairs or InstaHation of Replacement
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2 Items by Welding Class 1, 2. and 3,Section XI, Division 1,a pursuant to 10 CFR 50.55a(a)(3) to be applied to the Inservice Inspection (151) program for Surry. Power Station, Units 1 and 2.
2.0 EVALUATION f.CDF 31"A- MSA N-418-1 AL"ERNAT?VE PRES!UP1 TEST RE1UIRENikT FOR WELDED AR DIV S ..AMION 10N 1 OF REPUitEMEN" ITEMS BY WELDING c_ASE 1. 2.-and 3 - SEC" ION Comeonent Identification o ASME Class 2, 2, and 3 eiping Systems 'l ASME Code Sectien XI second Interval Requ_irements The 1980 Edition through Winter 1980 Ad:lenda,Section XI, IWA-4700(a) requires that a system hydrostatic test be perfomed in accordance with IWA-5000 after repairs by welding on the pressure retaining boundary.
Licenson's Basis for Raouest "In past situations we have found it necessary to defer hydrostatic tests or ask relief from post ASME 5ection XI byorostatic tests following repair or reolacement activities. This was due to various reasons of impracticality in testing, ranging from boundary valve isolation problems to incorporation of steam generators within the hyorossatic test boundary. These situations are typically unexpected and are usually only identified during the actual inservice inspection. As a consequence, some of these situations have necessitated immediate communication' wit 1 the NRC to avoid exceeding limiting conditions of operation or startup delays.
"Use of hydrostatic test deferrals, which are presently illowed in the current Ccde Case N-416 for Class 2 c aponents, (is) not a satisfactory solution.
because the test must eventucily be perfomed, and it is the performance of the test itself that is considered burdensome. Deferred hydrostatic testing i I'
requirernents should be Eisessed considering that the 10-year hydrostatic test is no longer required with the NRC endorsement of code case N-498, Alternate i
Rules Section forXI,10-year Hydrostatic Division 1. pressure Testing for Class 1 and 2 Systems
" Code Case N-416-2 provides increased testing flexibility to the Owner, which should considerably reduce, if not eliminate reitef request requirements ,
associated with post welded repair /replacemen,t hydrostatic testing. This is I accomplished determined while by the ASME maintaining Code." an acceptasle level of safety and quality as Pronosed Alternative Examination 4
The licensee proposes to apply Code Case N-416-1 as alternative rules for welded and 3 piping. repairs or installation of replacenent items by welding in Class 1, 2
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Evaluation /Conclusient In lieu of hydrostatic pressure testing for welded repairs or installation or replacement items by welding, Code Case H-416-1 requires a visual examination (VT-2) he performed in con.iunction with a system leakage testing using the 1992 Edition of Section XI, in accordan:e with paragraph IWA-5000, at nominal operating pressure and temperature. This Code case also specifies that non i
destructive examination (NDE) of the welds be performed in accordance with the applicable Subsection of the 1992 Edition of Section III.
The 10 CFR 1989 Edition of Sections XI and III are the latest editions referenced i 50.55a. The staff has compared the system pressure test requirements of the 1992 Edition of Section XI to the requirements of IWA-5000 of the 1989 Edition of Section XI. In summary, the 1992 Edition imposes a more uniform set of system pressure test requirements for Code Class 1, 2, and 3 systems.
The terminology associated with the system pressure test requirments for all three Code classes has been clarified and streamlined. The test frequency and The hold times for these tests has either remained unchanged The corrective actions with respect to removal of bolts from leaking bolted connections has been relaxed in the 1992 Edition, but use of this change has been accepted by the staff in previous Safety Evaluations. The post-welded repair NDE requirements of the 1992 Edition of Section !!! remain the same as the requirements of the 1989 Edition of 3ection III. Therefore, the~ staff finds this aspect of Code Case N-416-1 to be acceptable.
Hardships are generally encountered with the performance of hydrostatic testing performed in accordance with the Code. For example, since hydrostatic test pressure would be higher than nomini.1 operating pressure, hydrostatic pressure testing frequently requires sigrificant effort to set up and perform.
The need to use special equipment, such as temporary attachment of test pumps be on critical path.and gages, and the need for individual valve lineups can ca Piping components are designed for a number of loadings that would be postulated to occur under the various modes of plant operation. Hydrostatic testing only subjects the piping components to a small increase in pressure over the design pressure and, therefore, does not present a significant challenge to pressure boundary integrity. Accordingly, hydrostatic pressure testing is primarily regarded as a means ;o enhance leakage detection during the examination of components under pressure, rather than solely as a measure to determine the structural integrity of the components.
The industry indicates that experience har demonstrated that leaks are not being discovered preexisting as a result flaw through wall. of hydrostatic test pressures propagating a j
being found when the system is at normal operating pressure.They This is largelyindicate that due to the fact that hydrotatic pressure testing is required only upon installation and then once every 10-year inspection interval, while system leakage tests at nominal operating pressures are conducted a minimum of once l
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4 each refueling for Class 2 andoutage for Class 1 systems and each 40-senth inspection period 3 systems.
walkdowns by plant operators which may be conducted as often as onc Following the performance of welding, the code requires volumetric examination of repairs or replacements in Code class 1 and I, but only requires a surface 1 ersmination of the final weld pass in Code Class 3 piping components. There I
, are no ongoing NOE requirements for Code Class 3 components except for visual examination the for leaks tests.
periodic pressure in conjunction with the 10-year hydrostatic tests and Considering the NDE performed on code Class 1 and t' systems and considering that the hydrostatic pressure tests rartily result in pressure boundary leaks that would not cccur during system leakage tests, the staff believes that increased assurance of the integrity of Class 1 and 2 welds is not comeensurate with the burden of performing hydrostatic testing. However, considering the nature of NDE requirements for Code Class 3 components, the -
staff does not believe that eliminating the hydrostatic pressure testing and only performing system pressure testing is an acceptable alternative to ,
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hydrostatic testing unless additional surface examinations are performed on ;
the root pass layer of butt and socket wilds en the pressure retaining ,
boundary of Class 3 components when the surface examinasion method is used in '
accordance with Section III. '
With this provision applied to Code Class 3 components, the staff concludes that compliance with the Code hydrostatic testing requirements for welded repairs or replacements of Code Class 1 2, and 3 components would result in hardships without a compensating increas,e in the level of quality and safety.
Accordingly the licensee's proposed alternative to use Code Case N-415-1 is authorized for Surry Power Station, Units 1 and 2, pursuant to 10CFR50.55a(a)(3 (ii 1 on the root pass)laye)r of butt and socket wolds on the pressu boundary of Class 3 components when the surftce examination method is used in accordance with Section III. Use of Code Case N-416-1, with provision as noted above, is authorized until such tini as tPe Coce Care is published in a future revision of Regulatory Guide 1.147 At that time, if the licensee i intends to continue to implement this Coda case, the licensee is to follow all j provisions 1.147, if any. in Code Case N-416-1, with limitations issued in Regulatory Guide J Principal Contributor: T. McLellan .
Date: Oetcher 14 1994 I
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REFERENCE 3 Niaxi s 1::. :: i u si a vis l'ows:a remi Ass
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June 22, 1994 L
United States Nuclear Regulatory Commission Serial No. i 94-320 Attention: Document Control Desk SPS/ETS i
Washington, D. C. 20555 ]
Docket Nos. 50 280 50 281 Ucense Nos. DPR-32 DPA-37 Gentlemen, !
VIRGINIA ELECTRIC AND POWER COMPANY !
SURRY POWER STATION UNITS 1 AND 2 I
INSERVICE INSPECTION PROGRAM ASME CODE CASE H-416-1 !
ASME Code Case N-416-1 (attached), -Alternative Pressure Test Requirement for Welded Repairs or installation of Replacement hems by Welding, Class 1,2, and 3 Section XI Division 1. was approved by the ASME Code on February 15, 1994 However, this Code Case has not yet been endorsed in Regulatory Guide 1.147 inserv>ce Inspection Code Oase Acceptability ASME Section XI Division 1," due to its recent approval by ASME. Therefore, pursuant to 10 CFR 50.55a(a)(3), it is requested that Code Case N 416-1 be approved for uso during the Surry Units 1 and 2 third 10-year ;ntervals in lieu of the previous!y submitted relief request.
By letter dated July 16,1993 (Serial No.93-420), Relief Request 9 of the third interval ISI Program for Surry Unit 1 was submitted to the NRC for approval. This request addresses post weld repair and replacement testing requirements, which are similar to the requiremen'= delineated in Code Case N 4161. Since the ASME Code now
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addresses post weld repair and replacement hydrostatic testing requirements through Code Case N-416-1, Relief Request 9 of the Unit 1 ISI Program is no longer necessary and is hereby withdrawn.
In past situations we have found it necessary to defer hydrostatic tests or ask relief from pcst ASME Section XI hydrostatic tests fo!!owing repair or replacement activities.
This was due to vanous reasons of impracticality in testing, ranging from boundary vatve isolation problems to incorporation of the steam generators within the hydrostatic test boundary.
These situations are typically unexpected and are usually only identifie j dunng the actual inservice inspection. As a cor' sequence, some of these situatio1s have necessitated immediate communication with the NRC to avoid '
excee6ng limiting conditions of operation or startup delays.
Use of hydrostatic test deferrals, which are presently allowed in the current Code Case N-416 for Class 2 componer:ts, are not a satisfactory solution because the test must oventually be performed, and it is the performance of the test itself that is considered
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burdansome.
Deferred hydrostatic testing requiremerits should be assessed
.considering endorsement of Code that the ; Case N-498, A!!ernative Rules 'or 10 Testing for Class 1 and 2 SystemsSection XI, Division 1.
Code Case N 416-1 provides increased testing floxibility to the Owner, which should considerably welded repair /reduce, if not eliminate, relief requ6st requirements associated with post replacement hydrostatic testing. This is accomplished while maintaining an acceptable level of safety and quality as determined by the ASME Code Unit 2 is currently scheduled to start its refueling outago in January of 1995. The Unit I refuehng outage is currently scheduled to start in September of 1995. If permanent approval for use of Code Case N 416-1 cannot be obtained in the time period remaining prior to tne refueling culages, it is requested that Surry be granted interim approval to use Code Case N 4161 for the next refueling outages.
If you have any questions, please contact us.
Very truly yours.
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James P O'Hanlon Senior Vice President Nuclear Attachment r U.S. Nuclear Regulatory Commission Region il ^
101 Marietta Street, N.W.
Atlanta, Georgia 30323 Mr. Morris Branch NRC Senior Resident inspector Surry Power Stat.'on )
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.- 1 CASE
'. I N-416-1 CASES OF ASME BOILER AND PRESSURE VESSEL CODE Approval Date: February 15,1994 See Homeric index for expiration and any teattirmation dates Case N-416-1 Alkrnative Presstre Test Requhrmmt for Wefded placement items by wc! ding system leakage test may be used prov;ded the following requirements are met.
rs or Iristal!Mion of Replacemmt hems by W iding, Class I, 2 and 3 (a) NDE shall be performed in accordance with the Section XI, Division I methods and acceptance critoia of the applicable Sub-section of the 1992 Edition of Secdon 111.
(h) Prior to or immediately upon return to service, a visual examinadon (VT 2) shall be performedin con-juncdon with a system leakage test, using the 1992 Edi-Innairy: What alternative pressure test may be per- tion of Secdon XI. in accordance with para. IWA-5000 formed in lieu of the hydrustatic pressure test required at nominal operating pressure and temperature.
by para. IWA4(XX) for wc!ded repairs or irntallation of replacement items by welding? (c) Use of this Case shall be documented on an NIS.
2 Form.
Reply It is the opinion of the Committee that in lieu if the previous version of this case were used to defer of perfomiing the hydmstatic pressure test req! ired by a Class 2 hydmstade test, the deferred test may be elim-para. IWA.4tXX) for welded repairs or installation of re. insted when the requirements of this revision are met.
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