ML18153A563
| ML18153A563 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 12/19/1995 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML18153A562 | List: |
| References | |
| NUDOCS 9512280150 | |
| Download: ML18153A563 (12) | |
Text
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NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 2055~1
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO THE SECOND TEN-YEAR INTERVAL INSERVICE INSPECTION PROGRAM PLAN REQUESTS FOR RELIEF NOS. SR-22 THROUGH SR-26 VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION, UNIT NO. 2 DOCKET NO. 50-281 I. 0*
INTRODUCTION The Technical Specifications for the Surry Power Station, Unit 2, state that the inservice inspection of the American Society of Mechanical Engineers (ASME) Code Cl ass 1, 2, and 3 comp.onents sha 11 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).
10 CFR 50.55a{a)(3) states that alternatives to the requirements of paragraph
{g) may be used, when authorized by the NRC, if (i) the proposed alternatives -
would provide an acceptable level of quality and safety or (ii) compliance with the specified requirements would result in hardship or unusual difficulties 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 c.onducted during the first ten-year interval and subsequent intervals comply wtth the requirements in the latest edition and addenda of Section XI of the ASME Code incorporated by reference in 10 CFR 50.SSa(b) twelve months prior to the s_t~rt_oUhe_l2D".'"month_ interval, subject to the.limitations and
- ---:modifications listed therein~
The applicable edition of Section XI of the ASME Code for the Surry Power Station, Unit 2 second IO-year inservice ip~e_ctio_!'.!._(1~J)__jnt_erv~l*-;_~:t11~.J~~Q_Jgjti911-.:throug~_ Winter 1980 Addenda...
7 -~-~fie components (including supports) may meet.*the requirements set forth in subsequent editions and addenda of the ASME Code incorporated by reference in
(
i I
10 CFR 50.55a{b) subject to the limitations and modifications listed therein and subject to Commis~ion approval.
9512280150 951219 ~--~---------,
PDR ADOCK 05000281
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p PDR ENCLOSURE 1
- Pursuant to 10 CFR 50.SSa(g)(S), 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, pursuant to 10 CFR 50.55a(g)(6)(i), the Commission may grant relief and may impose alternative 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 req~irements were imposed.
In a letter dated April 28, 1995, Virginia Electric and Power Company submitted to the NRC its second ten-year interval inservice inspection program plan, Requests for Relief Nos. SR-22 through SR-26 for the Surry Power Station, Unit 2.
2.0 EVALUATION AND CONCLUSIONS The staff, with technical assistance from its contractor, the Idaho National Engineering Laboratory (INEL), has evaluated the information provided by the licensee in support of its second ten~year interval inservice inspection program plan, Requests for Relief Nos. SR-22 through SR-26 for the Surry Power Station, Unit 2.
Based on the information submitted, the staff adopts the contractor's conclusions and recommendations presented in the Technical Letter Report.
The staff concludes that the Code requirement is impractical, and would be a burden on the licensee if imposed.
In addition, the proposed alternative testing will provide a reasonable assurance of operational readiness of the subject systems in Requests for Relief Nos. SR-22 through SR-26.
Therefore, relief is granted for Requests for Relief Nos. SR-22 through SR-26 pursuant to 10 CFR 50.55a(g)(6)(i).
Principal Contributor: T. Mclellan Date:
December 19, 1995
1.0 INTRODUCTION
TECHNICAL LETTER REPORT SECOND TEN-YEAR INTERVAL ISI RELIEF REQUESTS SR-22 THROUGH SR-26 VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION, UNIT 2 DOCKET NUMBER:
50-281 In a letter dated April 28, 1995., the licensee, Virginia Electric and Power Company, submitted Relief Requests SR-22 through SR-26 for the Second Ten-Year Inservice Inspection *(ISI) Interval at Surry Power Station, Unit 2. This interval ended during the 1995 Surry Unit 2 refueling outage.
The Idaho National Engineering Laboratory (INEL) staff has evaluated the subject requests for relief in the following section.
- 2. 0 EVALUATION The Code of record for the Surry Power Station, Unit 2, Second Ten-Year ISi Interval is the American Society of Mechanical Engineers Boiler and Pressure Vessel Code,Section XI, 1980 Edition with the Winter 1980 Addenda.
The information provided by the licensee in support of the requests for relief has been evaluated and the basis for disposition is documented.below.
A.
Request for Relief SR-22, Examination Category B-K-1, Item 810.10, Class 1 Integrally Welded Piping Attachments Code Requirement:. Tab)e _IWB-?500-1, Examination Category.B-K.;.1 1
. ~
Item No~ Bl0.10 r~quires 100%Vo.1umetric or sUr.tace examinatio~s as.
applicable, of welded attachments as defined in Figures IWB-13, -14, and -1~. These requirements apply when the base material design thickness is 5/8 in. and greater. Examination is required of the ENCLOSURE 2
- welded attachments to piping that is requi~ed to be examined by Examination Category 8-J and of the welded attachments to pumps and valves integral to such piping.
licensee's Code Relief Request:
The licensee requested relief from the essentially 100% examination coverage required by Table IWB-2500-1, Examination Category 8-K-l, Note 2 for the following welded attachment components:
Component ID H-006 H-007 line#
Drawing#
12"-SI-247-1502 11548-WMKS-122Al 12"-SI-245-1502 11548-WMKS-122Ll Licensee's Basis for Requesting Relief (as stated):
uT.he components listed above has(sjcJ been e*~amined to the extent practical as required by the Code.
Due to the interferences from pipe support structures and location of the supports at the point where the pipe passes through the floor, a reduction in covera~e of the surface examinations of 50% was necessary.
Figure SR-22-1 is provided detailing the limitations experienced.
The figure is similar for both support structures. Alternative components could not be substituted for examination due to the mandatory selection requirem~nts of the Code."
Licensee's Proposed Alternative (as stated):
- 1t is proposed that the examinat,on already completed at the reduced coverage be counted as meeting the Code requirements~"
flli.yation:
The -Code requires*a 100% *surface examination of the
- subject -welded attachments*.
However, based on review of tlie drawings provided by the licensee, it is evident that the design of the supports and location of the welded attachments make the surface
- Not included with this evaluationi
.:. 3 -
examination impractical to perform to the extent required by the Code.
To perform the Code-required surface examination of the entire length of the weld, the supports and welded attachments would require design modification to allow access for examination.
Imposition of this requirement would cause a considerable burden on the licensee.
Based on examination of other welded attachments and the 50% of the Code-required examination that was performed on the subject welded attachments, it is concluded that degradation, if present, would have been detected.
As a result, reasonable assurance of structural integrity has been confirmed. Therefore, it is recommended that relief be granted pursuant to 10 CFR 50.55a(g){6){i).
B.
Request for Relief SR-23, Examination Category 8-D, Item B3.150, Class 1 Regenerative Heat Exchanger Nozzle-to-Vessel Weld Code Requirement:
Table IWB-2500-1, Examination Category 8-D, Item No. 83.150 requires 100% volumetric examination of the applicable volumes shown in Figures IWB-2500-7{a) through {d) for nozzle-to-vessel welds in Class 1 heat exchangers.
Relief from this requirement was granted previously* with the provision that a surface examination of the subject nozzle-to-vessel weld was to be performed in place of the Code-required volumetric examination.
Licensee's ~ode Relief Request:
The licensee requested relief from examina_tion-cover_ag~ requirements for '.T°able IWB--2500-L Examination
- Category a.:.K-1, *Item No.-' 83.150~ aricf-from the prov*isions of Relief
- Relief Request SR-018, granted in Safety Evaluation Report issued on April 14, 1994.
- Request SR-18, alternative surface examination for the following nozzle-to-vessel weld:
Component ID Draw;nq 1-11 11548-WMKS-CH-E-3 Licensee's Basis for Requesting Relief (as stated):
- The component listed above has been examined to the extent practical as required by relief request SR-018 of the Inservice Inspection Program for the Unit 2 Second Interval.
Due to interferences from a support clamp the reduction in coverage of the surface examination was 14.6%.
Figure SR-23-1* is provided detailing the limitations experienced.
Alternative components could not -be substituted for examination due to the mandatory selection requirements of the Cod~."
Licensee's Proposed Alternative (As stated):
- it is proposed that the examina~ion already completed at the reduced coverage be counted as meeting the Code requirements."
Evaluation: The previously granted relief request (SR-018) permitted a surface examination to be substituted for the Code-required volumetric examination but did not address any limitations to the proposed surface examination of the subject nozzle-to-vessel weld.
However, based on review of the drawing prQvided by the licensee, it is evident that the location of the support clamp makes the surface examination impractical to perform to the extent required ~Y the Code and Relief ~equest SR-018.
To perform the required surface
- *-----*"' -. -:--:-*:.-**-**-:---exarnina:tiorr uf-the**entire-~lengttT"1>f~the \\'.teld,. the support would
- ,... - **----*.---- -i
~iq~ire desi~~ m6dific~tion to allow access for examinati6n.
Imposition of this requirement would cause a considerable burden on the licensee.
Based on the examination coverage of other nozzle-to-
- Not included with this evaluation.
'., vessel welds and the 85.4% of the required examination that was performed on the subject nozzle-to-vess~l weld, it is concluded that degradation, if present, would have been detected.
As a result, reasonable assurance of structural integrity has been confirmed.
Therefore, it is recommended that relief be granted pursuant to 10 CFR 50.55a(g)(6)(i).
C.
Request for Relief SR-24, Examination Category C-A, Item Cl.20, Class 1 Seal Injection Filter Pressure Vessel Head Circumferential Weld Code Requirement: Table IWC-2500-1, Examination Category C-A, Item No. Cl.20, Note 1 requires that essentially 100% of the selected welded length of the head-to-shell weld selected be volumetrically examined.
In the case of multiple vessels of similar design, size, and service (such as steam generators, heat exchangers) the required examinations may be limited to one vessel or distributed among the vessels.
Licensee's Code Relief Request:
The licensee requested relief from performing the 100% volumetric examination required by Table IWC-2soo.:.1, Examination Category C-A, Item No. Cl.20, for the following Seal Injection Filter vessel weld:
-- _________.:_ ___ -Component ID Drawing#
1-01 0
- 11548~WMKS~tH~FL-4A/B
-*- -- --*--,c--.- ------ *--- *---
Ll cen see' s Basis for*Requesting Relief (a"s stated):*
- The component listed above has been examined to the extent practical as required by the Code.
Due to interferences from three permanent support legs the reduction in coverage of the ultrasonic
- examination was 35% (12" out of 34 11 ). Figure SR-24-1* is provided detailing the limitations experienced. Alternative components could not be substituted for examination due to the mandatory selection requirements of the Code."
Licensee's Proposed Alternative (as stated):
- 1t is proposed that the examination already completed at the reduced coverage be counted as meeting the Code requirements."
Evaluation: The Code requires a 100% volumetric examination of the subject vessel weld.
However, based on review of the drawing provided by the licensee, it is concluded that the location of the support legs interferes with ultrasonic scanning and makes the volumetric examination impractical to perform to the extent required by the Code.
To perform the required volumetric examination of the entire length of the weld, the support legs would require design modification to allow access for examination.
Imposition o-f this requirement would cause a considerable burden on the licensee.
Based on the examination of other vessel welds and the 65% of the required examination that was performed on the subject vessel weld, it is concluded that degradation, if present, would have been detected.
- As a result, reasonable assurance of structural integrity has been attained. Therefore, it is recommended that relief be granted pursuant to 10 CFR 50.55a(g)(6)(i).
. ~--.__ --~~
- Not included with this evaluation.
- D.
Request for Relief SR-25, Examination Category 8-J, Item 89.11, Class 1 Piping Weld 1-09 Code Requirement: Table IWB-2500-1, Examination Category B-J, Item No. 89.11, Note 3 requires 100% volumetric examination of selected Class 1 piping welds.
Licensee's Code Relief Request:
The licensee requested relief from examination coverage requirements of the Code for the following circumferential piping weld:
Component ID Line Drawing 1-09 31 11-RC-308-2501R 11548-WMKS-RC-10-l Licensee's Basis for Requesting Relief (as stated):
uThe component listed above has been examined to the extent practical as required by the Code.
Due to the geometry of the weld crown the reduction in coverage of the volumetric examinations are detailed in Table SR-25-1*.
Figure SR-25-1* is provided detailing the limitations experienced. Substituting with another weld of the same size would not necessarily improve the examination coverage since similar geometric conditions are expected."
Licensee's Proposed Alternative (as stated):
Mit is proposed that the examination already completed at the reduced coverage be counted as meeting the Code requirements."
Evaluation:. The Code *requires a 100% volumetric ex-amlna.tion of tl1e subject* piping weld~. f~owever, based on review of the tijble and drawing provided by the *ncenseti, it is concluded that the geometry and material of the elbow (cast stainless steel) makes the volumetric examination impractical to perform to the extent required
- Not included with this evaluation.
- . by the Code.
To perform the required volumetric examination of the entire length of the weld, the piping would require design modification to sufficiently improve the geometry and material to provide for a complete examination.
Imposition of this requirement would cause a considerable burden on the licensee. Based on examination of other piping: welds and on the 50% to 83% coverage with multiple angle ultrasonic scans and the 100% surface examination that were performed on the subject piping weld, it is concluded that degradation, if present, would have been detected.
As a result, reasonable assurance of structural integrity has been attained. Therefore, it is recommended that relief be granted pursuant to 10 CFR 50.55a{g){6){i).
E.
Request for Relief SR-26, Examination Category C-G, Item CG.10, Class 2 Outside Recirculation Spray Pump Casing Weld Code Requirement:. Table IWC-2500-1, Examination Category C-G, Item No. C6.10 requires a 100% surface examination of the casing welds in all pumps in each piping run selected under examination Category C~
F.
In the case of multiple pumps or valves of similar design, function, and service in a system, the examination of only one pump and one valve among each group of multiple pumps and valves is required.
_ Licensee's Code Relief~guest: The licensee ~equested relief from the Code examination coverage r~quirements for* the folltiwfog p*ump_
.. *c*asing ~eld:
9 -
Drawing Component ID 2-05 11548-WMKS-RS-P-2A Licensee's Basis for Requesting Relief (as stated}:
- The component listed above*has been examined to the extent practical as required by the Code.
Due to interferences from a pump casing support the reduction in coverage of the surface examination was 25%.
Figure SR-26-1* is provided detailing the limitations experi,enced.
No other alternative is available for substitution since the *B" pump has the same limitation."
Licensee's Proposed Alternative {as stated):
- it is proposed that the examination already completed at the reduced coverage be counted as meeting the Code requirements."
Evaluation:
The Code requires a 100% surface examination of the subject pump casing weld.
However, based on review of the drawing provided by the licensee, it is concluded that the design of the pump and support makes the surface examination impractical to perform to the extent required by the Code.
To perform the required surface examination of the entire length of the weld, the pump and support would require design modifications to provide access for complete examination.
Imposition of this requirement would cause a considerable burden on the 1icense~.
Based on the examination of other pump casing welds and. the 75% coverage surface examination of t~e subject pump casing weld, it is concluded that degradation, if pres~nt~ wotlld have be~n detect_ed.
As a result, reasonable assuran'ce of. structural'.:integrity. has been provided. '.:rherefore' it is recommended that relief be granted pursuant to 10 CFR 50.55a{g}{6}{i}.
- Not included with this evaluation.
3.0 CONCLUSION
The INEL staff has revi~wed the licensee's requests for relief and determined that the Code examination coverage requirements are impractical for the Surry Power Station, Unit 2. Therefore, it is recommended that relief be granted pursuant to 10 CFR 50.55a(g}(6}(i}
for Relief Requests SR-22 through SR-26.
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