ML20077J989

Inservice Insp Program, Technical Evaluation Rept

ML20077J989
Person / Time
Site:	Nine Mile Point
Issue date:	09/17/1982
From:	SCIENCE APPLICATIONS INTERNATIONAL CORP. (FORMERLY
To:	NRC
Shared Package
ML17054A137	List: ML20077J989
References
CON-NRC-03-82-096, CON-NRC-3-82-96 SAI-186-028-11, SAI-186-28-11, NUDOCS 8209200354
Download: ML20077J989 (30)

Text

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SAI Repcrt No. 186-028-11 i

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^ ,E NINE MILE POINT UNIT 1

,k INSERVICE INSPECTION PROGRAft 1

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TECHNICAL EVALUATION REPORT

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[- Submitted to:

U.S. Nuclear Regulatory Commission Contract No. 03-82-096 Science Applications, Inc.

McLean, Virginia 22102 I'

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CONTENTS INTRODUCTION . . . . . . . . . . . . . . . . . . . . ........... 1 I. CLASS 1 COMP 0NENTS . . . . . . . . . . . . . . . . . . . . . . . . . 4 A. Reactor Vessel . . . . . . . . . . . . . . . . . . . . . . , , 4

1. Requests for Relief I and 2, Appendix E; Pressure Retaining Welds, Categories B-A and B-B, Items Bl.1 and Bl.2 . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2. Request for Relief 4, Appendix E; Class 1 Bolting, Category B-G-1, Item Bl.8 .................. 8

3. Request for Relief 9, Appendix E; Interior Attachments to Reactor Vessels , Category B-N-2, Ite:- Bl .16 . . . . . . . 10 B. Pressurizer (Dces not apply to BWRs)

C. Heat Exchangers and Steam Generators (No relief requests)

D. Piping Pressure Boundary . . . . . . . . . . . . ........ 12

1. Request for Relief 6, Appendix E; Support Members for Piping, Valves and Pumpt, Category B-K-1, Items B4.9, B5.4 and B6.4 ................. 12 E. Pump Pres s u re Bounda ry . . . . . . . . . . . . . . . . . . . . . 15

1. Request for Relief 6, Appendix E; Support Members for Piping, Valves and Pumps, Category B-K-1, Item B5.4 ......................... 15

2. Request for Relief 7, Appendix E; Internal Surfaces of Pumps, Category B-L-2, Item B5.7 ............ 15 F. Valve Pressure Boundary .................... 18

1. Request for Relief 6, Appendix E; Support Members for Piping, Valves and Pumps, Category B-K-1, Item B6.4 . . . 18

2. Request for Relief 8, Appendix E; Internal Surfaces of Val ves ,' Category B-M-2, Item B6.7 . . . . . . . . . . . . 18 II. CLASS 2 COMPONENTS . . . . . . . . . . . . . . . . . . . . . . . . . 22

A. Pressure Vessels . . . . . . . . . . . . . . . . . . . . . . . . 22

1. Request for Relief 10, Appendix E; Pressure Retaining Nozzle Welds in Vessels, Category C-B, Item C1.2 . . . . . . 22 B. Piping . . . . . . . . . . . . . . . . . . ........... 24

1. Request for Relief 11, Appendix E; Support Members for Piping, Valves and Pumps, Category C-E-1, Items C2.5, C3.3 and C4.3 .................... 24 4l J Science Applications.Inc.

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TECHNICAL EVALUATION REPORT NINE MILE POINT UNIT 1 INSED.VICE INSPECTION PROGRAM INTRODUCTION The revision to 10 CFR 50.55a, published in February 1976, required that Inservice Inspection (ISI) Programs be updated to meet the requirements (to the extent practical) of the Edition ar.d Addenda of Section XI of the taerican Society of Mechanical Engineers Boiler and Pressure Vessel Code

• incorporated in the Regulation by reference in paragraph (b). This updating of the programs was required to be done every 40 months to reflect the new requirements of the later editions of Section XI.

As specified in the February 1976 revision, for plants with Operating Licenses issued prior to March 1, 1976, the regulations became effective after September 1,1976, at the start of the next regular 40-month inspection period.

The initial inservice examinations conducted during the first 40-month period were to comply with the requirements in editions of Section XI and addenda in effect no more than six months prior to the date of start of facility commercial operation.

The Regulation recognized that the requirements of the later editions and addenda of the Section XI might not be practical to implement at facilities be-cause of limitations of design, geometry, and materials of construction of components and systems. It therefore permitted determinations of impractical examination or testing requirements to be evaluated. Relief from these require-ments could be granted provided health and. safety of the public were not endan-gered giving due consideration to the burden place on the licensee if the requirements were imposed. This report provides evaluations of the various requests for relief by the licensee, Niagara Mohawk Power Corporation (NMPC),

l of Nine Mile Point Unit 1. It deals only with inservice examinations of com-ponents and with system pressure tests. Inservice tests of pumps and valves (IST programs) are being evaluated separately.

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• Hereinafter referred to asSection XI or Code.

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The revisior, to 10 CFR 50.55a, effective November 1,1979, mocified the time interval for updating ISI programs and incorporated by reference a later edition and addenda of Section XI. The updating intervals were extended from 40 months to 120 months to be consistent with intervals as defined in Section XI.

For plants with Operating Licenses issued prior to March 1,1976, the pre-visions of the November 1,1979, revision are effective af ter September 1,1976, at the start of the next one-third of the 120-month interval. During the one-third of an interval and throughout the remainder of the interval, inservice examinations shall comply with the latest edition and adoenda of Section XI, incorporated by reference in the Regulation, on the date 12 months prior to the start of that one-third of an interval. For Nine Mile Point Unit 1, the ISI program and the relief requests evaluated in this report should cover the entire current 120-month inspection interval (December 1979 December 1989)*. This orogram was based upon the 1974 Edition of Section XI of the ASME Boiler and Pressure Code, with Addenda through the Summer of 1975.

The November 1979 revision of the Regulation also provides that ISI programs may meet the requirements of subsequent code editions and addenda, incorporated by reference in paragraph (b) and subject to Nuclear Regulatory Commission (NRC) approval. Portions of such editions or addenda may be used provided that all related requirements of the respective editions or addenda are met. These in-stances are addressed on a case-by-case basis in the body of this report.

Finally,Section XI of the Code provides for certain components and systems  ;.

to be exempted from its requirements. In some instances, these exemptions are f not acceptable to NRC or are only acceptable with restrictions. As appropriate,  !

these instances are also discussed in this report. l References (1) to (7) listed at the end of this report pertain to previous information transmittals on ISI between the licensee and the Comission. By .

letters of April 26 and November 22,1976,(1,3) the Comission provided general f ISI guidance to all licensees. Submittals in response to that guidance were  !

made by the licensee on June 4,1976,(2) and December 9,1976.(4) The ISI pro-gram was submitted by the licensee on May 2, 1980.( ) By letter of April 14, 1982(6) the Commission requested additional information to complete the review As of August 26, 1982, the licensee has not acknowledged that this is j wwi.cw. 6 6. a p.c o . . vi . . 6 6 .s a = w . . J science Apphcations, Lnc.

of the ISI program. This information was furnished by tne licensee on July 30, 1982.I7) i From these submittals, a total of 9 requests (a.' far relief from Code j requirements, (b) for upuating to a later Code, and (cf for exemptions not

', necessarily acceptable to the Commission were identified. The requests are

[ evaluated in the following sections of this report.

? In addition, other relief requests criginally made by the licensee (5) were withdrawn by Reference 7. These were: Full Penetration Welds, Category B-D; Feedwater Check Valve Bolting, Category B-G-1; Reactor Pressure Vessel Support Skirt, Category B-H; and Pressure Retaining Welds in Piping, Pumos and Valves in Systems Which Circulate Reactor Coolant, Category C-F.

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1. CLASS 1 COMPONENTS A. Reactor Vessel

1. Reouests for Relief I and 2, Appendix E:(5) Dressure Retainine Welds, Categories B-A and B-B, Items Bl.1 and 81.2 Code Reouirement Catecory B-A (In Reactor Vessel Beltline Region):

Volumetric examination of the shell, longitudinal and cir-cumferential welds shall be performed and sh611 cover at least 10% of the length of each longitudinal weld, and 5% of the lengtn of each circumferential weld, with the minimum length of weld examined equal to one wall thickness. The examination may be performed at or near the end of each inspection interval.

Catecory B-B (In Vessels):

Volumetric examinations shall be performed during each in-spection interval and shall cover at least 10% of the length of each longitudinal shell weld and meridional head weld and 5% of the length of each circumferential shell weld and head weld. The examination may be performed at or near the end of each inspec-tion interval.

Code Relief Reouest Relief is requested from the volumetric examination of the following reactor pressure vessel welds:

Category B-A : All pressure retaining welds in the reactor vessel beltline region.

Category B-B: All pressure retaining welds in the reactor vessel shell other than in the beltline region, and all merid-l ional and circumferential welds in

.i the bottom head.

i i Proposed Alternative Examination

I For those Category B-A and B-B welds for which code relief i is requested, remote visual examination from the vessel inside

{ diameter will be performed on the accessible weld length. Dr.e-l third of the accessible weld length will be examined each in-spection interval.

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Licensee's Basis for Recuestino Relief These welds are not accessible due to plant design and high radiation levels.

Category B-A Welds:

Accessibility for inspection of welds in the core beltline region (Category B-A) was not provided for in the original plant design. Inspection from outside the vessel is prevented due to the vessel's permanent mirror insulation (which is mounted to the vessel) and close proximity of the sacrificial shield wall. There is approximately 7 inches of clearance between the insulation and the shield wall which is insufficient tc' allow direct access of personnel. Even if the non-replaceable ihsulation were removed from the reactor vessel, only 4 inches of additional clearance would be afforded, which is still insufficient for personnel access.

Cateoory B-B Welds:

,rcessibility for inspection of the longitudinal and cir-cumfero tial welds in the vessel shell (Category B-B) area was not prov:ded for in the original plant design. Inspection of some welds from outside the vessel is prevented due to the vessel's permanent mirror insulation (mounted to the vessel). Inspection of the other welds is prevented due to the vessel's permanent mirror insulation and close proximity of the sacrificial shield wall.

There is approximately 7 inches of clearance between the insula-tion and wall which is insufficient to allow direct access of per-sonnel. Even if the insulation were removed, only 4 inches of additional clearance would be afforded, which is still insufficient for personnel access.

Examination from the vessel outside diameter of the merid-ional and circumferential welds in the lower vessel head is pre-vented by the insulation configuration and Control Rod Drive housings.

Evaluation

! Imposition of the Code requirements would necessitate removing portions of the concrete biological shield and the permanently installed insulation to perform the required exam-ination of the welds listed from the vessel exterior. The only

! examinations that the licensee can perform from the internal of i the reactor pressure vessel are visual examinations of those accessible welds. The vessel internals preclude examination of certain internal areas, i.e., the core shroud and the core P plate preclude examination of the lower head circumferential

and meridional welds and other welds in the lower part of the

', vessel.

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, T y reactor pressure vessel was the sub.iect of a special i

stut ic/* coaducted by tne Nuclear Regulatory Cox.issier,

); as pir; cf tne staff's regulatory activities to evalu-ate and update information on the integrity of the reactor

,F vesse' to ensure that the integrity of the vessel is maintainec

] at a high level throughout its service life. The study concluded that Nine Mile Point reactor vessel includes sufficient margin 7 of design conservatism that, in combination with the very con-

'l servative limits established for operation, provides adequate

assurance for safe continued operation. The reactor vessel was designed to Sections I and VIII of the ASME Boiler Pressure i! Vessel Code. However, the requirements of these Codes were j supplemented by the requirements of Nuclear Code Cases and pur-g chase specifications so that the design and materi H acceptance

! inspections were essentially in accordance with the rules of the

.l ASME Code,Section III. Primary stresses in the vessel core 7 I region are low approximately 3/4 of those permitted by tne ASME l Code,Section III. The reactor vessel is presently monitored for radiation damage in the beltline region by a surveillance program

, in accordance with ASTM-E185-73 to the axtent po:sible and there-for conforms to the intent of 10 CFR 50, Appendix H.

This examination requirement is impractical due to the exist-ing design that precludes access to the welds. In addition, high

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radiation fields are present that severely restrict access to ~

! the reactor pressure vessel. The only welds accessible for the Code-required examinations are those in the closure head. To maintain the extent of examination, an alternative inservice in-spection program would be required. The examination of the accessible Category B-B welds in the closure head could be a

increased to achieve an examination sample equivalent to the

. Category B-A and B-B welds for which relief was requested. The closure head welds (Category B-B) are subjected to different I stresses than the welds in the body of the reactor pressure  !

vessel (Categories B-A and B-B). But an examination of an increased amount of closure head welds is about the only mean-ingful alternative examination that could substitute for examining the welds in the reactor pressure vessel body. In addition, visual examinations from the inside of the vessel

should be performed during each inspection interval on 100% of l those welds that are accessible; the licensee has proposed examination of only one-third of the accessible weld length f

during each inspection interval. Also, visual inspections of

! the areas beneath the reactor pressure vessel could be per-formed during system leakage and hydrostatic tests. All these

. examinations should furnish sufficient infonnation to evaluate

' the continued structural' reliability of the welds in the reactor pressure vessel.

Conclusions and Recommendations Based on the above evaluation, it is concluded that for the welds discussed above, the Code requirements are impracti- '

cal. It is further concluded that the alternative examinations discussed above will provide necessary added assurance of I structural reliability. Therefore, the following is recomended:

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Relief should be granted from the volumetric examinations of the identified welds with the following provisions:

(a) The examinations of the accessible Category B-B welds are increased to achieve, to the extent pos- .

sible, an examination sample eouivalent to the  !

, Category B-A and B-B welds for which relief is requested.

i c (b) Visual examinations of 100% of the accessible Category B-A and B-B welds are performed from the inside of the reactor presspre vessel.

i (c) Visual inspection of the areas beneath the reactor i pressure vessel is conducted for evidence of leakage during system hydrostatic tests when performed as  !

required by IWB-5000.

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References References 5, 6 and 8.

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2. Recuest for Relief 4, Accendix E;(5) Class 1 Boltina, Category B-G-1, item Bl.8 l Code Recuirement l

l Volumetric'and surface examinations shall be made on reactor vessel closure studs and nuts, 2-in, and larger in diameter, when removed, The areas shall include bolts, studs, nets, bushings, washers, and threads in base material and flange liga. tents between threadeo stud holes. -

The examinations performed during eacn inspection inter-val shall cover 100L of the bolts, studs, nuts, bushings, and l threads in base material and flange ligaments between threaced i

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stud holes.

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Code Relief Reauest t

Licensee requests relief from the surface examination of the reactor vessel closure head studs and nuts.

Procosed Alternative Examination Visual examination will be performed as an alternative to the code-required surface examination for which relief is re-quested.

Licensee's Basis for Requesting Relief The reactor vessel closure head studs and nuts have been Parkerized (corrosion treatment) which renders surface examina-tion results invalid.

Evaluation I

[ Parkerizing is similar to anodizing. A thin film is de-t posited upon the surface of the reactor vessel closure studs i and nuts for corrosion protection. This film would interfere l with surface testing of the studs and nuts and render the j examination results invalid. Thus, the requirement to perform i

i a surface examination of the reactor pressure vessel studs and nuts f

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is i practical. Since the film is thin, Parkerizing does net tctally interfere with ultrasonic examination of the studs and nuts; hence, volumetric examination of the reactor vessel ci:sure stuos and nuts will be performed as required by the Code. The licensee proposes to perform a visual examinatien '

ir. lieu of the surface examination. The volumetric and visual '

examinations should provide sufficient information to evaluate ,

the structural integrity of the studs and nuts.

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Ccnclusions and Recommendations  ;

Based on the above evaluation, it is concluded that for the pressure-retaining bolting examination discussed above, the c:de requirements are impractical. It is further concluced inat the alternative examination discussed above will orovide necessary added assurance of structural reliability. Therefore,

the following is recommended

Relief should be granted from the surface examination of the reactor vessel closure head studs and nuts provided that t e propcsed visual examinations are performed.

I References References 5, 6 and 7. - -- - - - -- - - - - - - - - - - - --'

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3. Reamest for Relief L k ren::, E: -' Interice 4 :a: mer::

to Reactor Vessels. Catecorv E-N-2  ::e- 51.16 Code Re::uirement ,

Visual examinations shall be perforred during each in-spection interval and shall include 100% of tne visually acces-Sible attachment welds and visually accessible surfaces of the core-support structure. This examination may be perforned at  !

or near the end of the inspection interval.

l The areas shall include attachments and core-support structures welded to the vessel wall of the direct cyc!e boiling water type.

Code Relief Request Licensee requests relief from the visual examination of the liquid poison sparger attachments to the reactor pressure vessel.

Procosed Altarnative Examination None.

Licensee's Basis for Reouestino Relief  !

The liquid poison spargers are not accessible for visual inspection durirg normal refueling outages.

Evaluation The original request for relief, item 9 of Appendix E(5) ,

categorized the liquid poison sparger attachments as B-N-1.

In Reference 7, the licensee recategorized these as B-N-2, and stated that no code relief is required since these attachments are not accessible for examination by removal of components during a normal refueling outage, as stated in the Code. It is true that for Category B-N-1 components the examination re-quirements depend upon accessibility during normal refueling outages. However, the Code does not include such a dependency clause for Category B-N-2 components.  ;

The liquid poison spargers are welded to the Reactor Pressure Vessel wall for support. The Code requires that these welds be examined visually once an interval to provide additional assurance that the Standby Liquid Control System

, will perform as designed, when needed. No justification has l been presented to show that the Code requirements are

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Conclusions and Recomendations i Based on the above evaluation, the Code requirements i have not been shown to be impractical. Therefore it is recomended that this relief request be denied. If, at the end of the interval the licensee has not been able to perform the Code required examinations, he should submit a code l relief request at that time. That code relief reauest should l

include specific details justifyinn why the required examir.ations cannot be performed.

I References References 5, 6 and 7.

i B. Pressurizer Does not apply to BWRs.

C. Heat Exchangers and Steam Generators No relief requests.  !

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D. Piping Pressure Boundary

1. Recuest for Relie' 6, Apoendix E;(5) Succort Members for Pipino, Valves and Pu1ps, Cateoory B-K-1, Items B4.9, B5.4 and B6.4 '

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Code Requirement The volumetric examination performed during each in-spection interval shall cover 25% of the integrally welded supports. The areas shall include the inte.grally welded ex-ternal support attachnents. This includes the welds to the pressure-retaining boundary and the base metal beneath the weld zone and along the support attachment member for a dis-tance of two support thicknesses.

Code Relief Request Relief is requested from the volumetric examination of all  !

integrally welded external support attachments for piping, '

valves and pumps, i

1 Prooosed Alternative Examination I Integrally welded support attachments will be liquid  !

penetrant examined in place of ultrasonic examinations. A visual examination will be recommended if the surface condi-tions can not be made compatible with proper surface penetrent examination prerequirements.

Licensee's Basis for Requestino Relief  !

l Category B-K-1 supports at Nine Mile Point Unit I are in the configuration shown in Figure IWB-2500-15 (1977 Code).

i However, these welds are fillet welds rather than full penetra- i tion and cannot be volumetrically examined as required. ,

I Liquid penetrant examination has been performed on a l

l number of the welds. Since the weld surface was never pre-pared for surface examination, but left in the "as-welded" condition, surface examinations show a large number of irrel- l evant indications. These indications are of such an extent i l

that they would mask any relevant indications. Periodically, l as allowed by operational and radiation exposure considerations, some of these welds have been prepared for surface examination.

Those welds that have been prepared will receive a surface  !

examination. The welds not prepared will receive a visual l (VT-1, 1977 Code) examination. Additionally, all welds not '

prepared will receive a surface examination for infonnation ,

only. This examination will be documented but the results  !

will not be used to accept or reject the subject weld.

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l Evaluation Because of the weld design, i.e., fillet welds, ultrasonic examination required by th3 Code is impractical.

Substitution of surface for volumetric examination would be acceptable as is evidenced by the changes in the later editions of the Cooe for Category B-K-1 components, which permit surface examination of Class 1 integrally welded support attachments for piping, pumps and valves. However, there is no basis for per-mitting substitution of visual for volume ~tric examination of Class 1 integrally welded support attachments. Consequently, visual examination would not be an acceptable alternative examination.

j The licenses should be pemitted to update to the 1977 Edition

. of Section XI, through Summer 1978 Addenda, for Category B-K-1 com-ponerts.

i Surface examination would be performed on all integrally welded support attachment welds where volumetric examination is not applicable. Should it not be possible to perform surface examina-tions on some welds, the licensee could submit code relief requests for those particular welds at that time. The justification for these code relief requests should contain engineering data that demonstrate that adequate safety factors are contained in the I

design of each weld joint so that there are no questions relative to the safety of those welds for which code relief is requested.

Otherwise, there is no basis for determining the safety of those particular welds, since they cannot be adequately examined.

The 1977 Edition, Sumer 1978 Addend of Section XI h s taen referenced in 10 CFR 50.55a and inservice examinations may meet the requirements of this edition in lieu of those from previous editions with the following provisions:

(a) Commission approval is required to update to the more recent edition (pursuant to 10 CFR 50.55a(g)(4)(iv));

(b) When applying the 1977 Edition, all the addenda through Summer 1978 Addenda must be used; (c) Any requirement of the more recent edition which is related to the one(s) under consideration must also be met. .

Updating to the 1977 Edition, Sumer 1978 Addenda, for 1

i Category B-K-1 components permits surface examination of integ-rally welded support attachments for piping, pumps and valves l

where volumetric examination of such welds is not applicable.

l Conclusions and Recommendations I

Based on the above evaluation, relief from the Code require-

! ments should not be granted. Instead, pursuant to 10 CFR 50.55a (g)(4)(iv), approval should be granted to update to the requirements of the 1977 Edition, Sumer 1978 Addenda, for Category B-K-1 items.

This approval would permit surface examination of Class 1 rally I

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weldec support attachments for piping, pumps anc valves wnere volumetric examination of such welcs is not applicable. {

Where surface examination of Class 1 integrally welded support attachments fcr piping, ? umps and valves is not possible, the licensee should submit specific code relief requests for those welds that cannot be examined as required by the Code.

Tnese code relief requests should contain sufficient engineer-ing data as justification to demonstrate the degree of safety involved in not examining the welds.

References References 5, 6 and 7 l

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i E. Pum; Pressure Boundary

1. Reauest for Relief 6, Appendix E;(5) Suecort Members for Piping, Valves and Pumos, Category B-K-1, Item B5.4 The request for relief from volumetric examination of integrally welded external support attachments for pumps (I.D.1 of this report) applies here. Therefore, the following is recommended:

Pursuant to 10 CFR 50.55a(g)(4)(iv), approval should be granted to update to the requirements of the 1977 Edition, Summer 1978 Addenda, for Category B-K-1 items. This approval would permit surface examination of Class 1 integrally welded support attachments for pumps where volumetric examination of such welds is not applicable.

Where surface examination of Class 1 integrally welded support attachments for pumps is not possible, the licensee should submit specific code relief requests for those welds that cannot be examined as required by the Code. These code relief requests should contain sufficient engineering data as justification to demonstrate the degree of safety involved in not examining the welos.

Recuest for Relief 7, Appendix E;(5)- ~IdernaT SuWacE bf- -~~~~~ ~

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Pumos, Category B-L-2, Item B5.7 Code Recuirement Pump internal pressure boundary surfaces shall be visually examined.

One pump in each of the group of pumps performing similar functions in the system shall be examined during each inspection interval. The examinations may be performed at or near the cad of the inspection interval.

Code Relief Reouest Relief is requested from the visual examination of the internal surfaces of the reactor recirculation pump at the pressure boundary.

Proocsed Alternative Examination If a reactor recirculation pump requires disassembly, a visual examination will be performed on the pump casing. Only one pump casing will be examined as required by the ASME Code.

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E. Pump Pressure Boundary

1. Reouest for Relief 6, Appendix E;(5) Support Members for Piping, Valves and Pumps, Category B-K-1, Item B5.4 The request for relief from volumetric examination of integrally welded external support attachments for pumps (I.D.1 of this report) applies here. Therefore, the following is recommended:

Pursuant to 10 CFR 50.55a(g)(4)(iv), approval should be granted to update to the requirements of the 1977 Edition, Summer 1978 Addenda, for Category B-K-1 items. This approval would permit surface exainination of Class 1 integrally welded support attachments for pumps where volumetric examination of such welds is not applicable.

Where surface examination of Class 1 integrally welded support attachments for pumps is not possible, the licensee should submit specific code relief requests for those welds that cannot be examined as required by the Code. These code relief requests should contain sufficient engineering data as justification to demonstrate the degree of safety involved in not examining thc welds.

I 2. Reouest for Relief 7, Appendix E;(5) Internal Surfaces of .

Pumos, Category B-L-2, Item B5.7 Code Recuirement Pump internal pressure boundary surfaces shall be visually examined.

One pump in each of the group of pumps performing similar functions in the system shall be examined during each inspection interval. The examinations may be performed at or near the end of the inspection interval.

Code Relief Reouest Relief is requested from the visual examination of the internal surfaces of the reactor recirculation pump at the pressure boundary.

Proposed Alternative Examination _

If a reactor recirculation pump reouires disassembly, a visual examination will be performed on the pump casing. Only e e pump casing will be examined as required by the ASME Code.

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I Licensee's Basis for Recuestino Relief In absence of required maintenance, disassembly of a re-circulation pump solely to perform a visual examination of internal surfaces is impractical. This would represent un-necessary exposure of employees to high radiation and con-tamination areas and excessive expense.

The internal pressure boundary surfaces of the recircula-tion pumps are not normally accessible during operation or re-fueling / maintenance outages. Access requires the disassembly of the pump and removal of the impeller involving approximately six man-days.

The radiation levels in the general area of the pumps are approximately 100 mr-1.5R/hr; the pumps on contact are approxi-mately 220 mr-1.5 R/hr. The estimated man-rem exposure for the disassembly, inspection, reassembly of one pump is broken down as follows:

Disassembly -

0.85 man-rem (based on actual motor removal)

Inspection -

0.5 man-rem (estimated)

Reassembly -

1.5 man-rem (estimated)

Total 2.85 man-rem / pump The manufacturer does not recommend regular maintenance on the pumps. The pump technical manual indicates that if the pump is running normally, allow the pump to continue in operation.

The benefit received from this major effort is minimal considering employee exposure, potential damage to safety-related equipment, and cost in dollars.

Evaluation The visual examination is to determine whether unanticipated severe cracking or erosion of the casing is occurring. However, previous experience during examinations of pumps at other plants '

has not shown any significant degradation of casings.

The disassembly of the reactor recirculation pumps the degree necessary to examine the internal pressure retain'ng surfaces is a major effort, involving large personnel exposure and the generation of large amounts of radioactive waste. In view of the effort required to disassemble a pump, the information returned from visual examination of its internal surfaces would be marginal.

l The licensee has committed to the concept of visual examination if a pump is disassembled for maintenance. Mean-while, pressure'and flow are monitored during pump operation to assess performance.

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el b.

O The visual examination of tne internal pressure boundary may be perfomed at or near the end of the 10-year inspection interval. Therefore, relief from examination requirements is not necessary until then because the licensee will be in com-pliance with the Regulation up to that time. The Code committee and the Electric Power Research Institute (EPRI) are undertaking a program to assemble and evaluate results of visual examinations of internal pump surfaces. Within the next two years, this pro-gram should provide a more definitive basis for the Code committee and HRC for upholding or modifying this Code requirement. Since so many licensees consider this requirement impractical and an undue burden, it is reasonable to postpone a . decision to grant relief until that orogram is completed. The licensee cou.id submit a new relief request at that time.

Visual exa .ination of the externals of the pump casings could be conducted for leakage when pressure tests are performed as required by IUB-5000.

Conclusions and Recommendations ,

Based on the above evaluation, it is concluded that for the visual examination discussed above, a more definitive tech-nical basis is needed. Therefore, the following is recommended:

(a) Relief should not be granted at this time from the visual examination of the internai surfaces of the reactor recirculation pump at the pressure boundary.

(b) The licensee's proposal to perfom a visual examina-tion whenever the surfaces are made accessible because a pump is disassembled for maintenance purposes should be accepted.

(c) Visual examination of the externals of the pump casings should be conducted for leakage when pressure tests are performed as required by IWB-5000.

References References 5, 6 and 7.

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F. Va've Pressure Bouncary

1. Recuest for Relief 6, Appendix E:(5) Succort Members for Picing, Valves and Pumos, Category B-K-1, Item B6.4 The request for relief from volumetric examination of integrally welded external support attachments for valves (I.D.1 of this report) applies here. Therefore, the followirg is recommended:

Pursuant to 10 CFR 50.55a(g)(4)(iv), approval should be granted to update to tne requirements of the 1977 Edition, Summer 1978 Addenda, for Category B-K-1 items. This approval would permit surface examination of Class 1 integrally welded -

support attachments for valves where volumetric examination of such welds is not applicable.

Wnere surface examination of Class 1 integrally welded support attachments for valves is not possible, the licensee should submit specific code relief requests for those welds that cannot be examined as required by the Code. These code relief requests should contain sufficient engineering data as justification to demonstrate the degree of safety involved in not examining the welds.

2. Request for Relief 8, Appendix E;(5) Internal Surfaces of Valves. Category B-M-2, Item B6.7 Code Recuirement l Visual examination of the internal pressure boundary surfaces, on valves exceeding 4-in. nominal pipe size.

One valve in each group of valves of the same con-structional design, e.g., globe, gate, or check valve, manufacturing method and manufacturer that performs similar functions in the system shall be examined during each in-spection interval.

The examinations may be performed at or near the end of the inspection interval.

Code Relief Recuest l

Relief is requested from the visual examination of the

. internal surfaces at the pressure boundary of the recircula-tion suction and discharge valves.

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l Proposed Alternative Examination The internal pressure boundary surfaces of one re-circulation suction or discharge valve will be examined, should valve maintenance be required and radiation exposure levels permit.

Visual (VT-2, 1977 Code) examinations of the valves are performed in conjunction with the system pressure tests (IWA-5000) and are conducted in accordance with the require-ments for Category B-P.

Ultrasonic thickness testing was performed prior to im-plementation of our ASME Section XI In-servi'ce Inspection Program, and is being considered as an alternate metnod.

Licensee's Basis for Requestina Relief During routine maintenance, visual examinations of valve body internal ' pressure beundary surfaces are performed and documented under existing plant administrative procedures. ,

It is estimated that the exposure to personnel to dis-assemble, examine, and reassemble each recirculation valve would be eight man-rem per valve. To inspect the recirculation valves requires unloading the core and draining the vessel before the valves can be disassembled.

The code-required examination would be performed if valve maintenance is required for one of the recirculation suction or discharge valves. Also, visual examinations of the valves are performed for evidence of leakage in con-junction with the system pressure tests (IWA-5000) and these are conducted in accordance with the requirements for Category B-P.

Evaluation The disassembly of large valves to the degree necessary to inspect the internal pressure retaining surfaces (bodies) is a major effort involving large personnel exposures.

The licensee has committed to the concept of visual exam-ination if the valve is disassembled for maintenance. The visual examination specified is to determine whether unantici-pated severe degradation of the casing is occurring due to phenomena such as erosion or corrosion.

The visual examination of the internal pressure boundary may be performed at or near the end of the 10-year inspection interval. Therefore, relief from examination requirements is not 4ll

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necessary until then because the licensee will be in compliance witn the regulation up to that time. Since so many licensees censider this requirement impractical and an undue burden, it is reasonable to postpone a decision to grant relief until near the end of the inspection interval, when additicnal relevant information from this unit and from the industry in general will be available.

The licensee could submit a new rel-ief' request at that time for eacn valve classification for which a valve has not been dis-assembled and examined in each unit. Submitting such relief requests as soon as possible after the next-to-last scheduled outage of the inspection interval and at least six months before the scheduled start of the last outage would minimi::e delays and outage time.

In the ever. that a code required valve is not disassembled for maintenance during the interval, the licensee is considering performing ultrasonic wall thickness measurements. Such measure-cents, using the minimum wall thickness requirements of Section III of the ASME Code as the acceptance standard and done to para-graph T-560,Section V, 1977 Edition, Winter 1978 Addenda, are potentially an acceptable alternative examination. However, detailed procedures, establishing such parameters as frequency and location of measurements, would have to be developed. If the licensee is seriously considering UT thickness measurements "

for future inspection intervals, he would be well advised tomake -

baseline measurements at representative locations on any valve opened for maintenance to supplement any taken during the testing program mentioned above.

For those inspection periods when valve maintenance does not occur, visual examinations are performed when the system pressure tests (IWA-5000) are conducted in accordance with the requ.irements for Category B-P.

Conclusions and Recommendations Based on the above evaluation, it is concluded that for the valves discussed above, there is not presently enough justification for declaring the code requirements impractical.

Therefore, the following is recommended:

(a) Relief should not be granter; at this time from visual examination of the 'nternal pressure boundary surfaces on the recirculation suction and discharge valves.

(b) The licensee's proposal to perform the code-required examinations whenever one of the valves is opened

.because of maintenance should be accepted.

science wcanons, inc.

i (c) During other inspection periods, the licensee should continue to perform visual examinations when the system pressure tests (IWA-5000) are conducted in accordance with the requirements for Category B-P.

(d) The licensee should submit specific relief requests as the end of the inspection interval approaches for each valve classification for which a valve has not  ;

been disassembled and examined.

(e) When the licensee is properly prepared to perform UT  !

thickness measurements of the valve bodies, and so requests, permission should be granted to do so.

References References 5, 6 and 7.

E science Apphcations,Inc. -

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11. CLASS 2 COMP 0NEC S A. Pressure Vessels 1.

Recuest for Relief 10 Aopendix E:(5) Pressure Retaininn Nozzle Welds in Vessels. Catecory C-8, Item C1.2 Code Reauirenent Volumetric examination of 100L of the nozzle-to-vessel attachment welds shall be performed.

One inlet and one outlet nozzle from the three shutdown coolinc heat exchangers shall be examined over the life of the plant (four inspection intervals).

Code Relief Reauest Relief is requested from the volumetric examination of the shutdown cooling heat exchanger inlet / outlet nozzle welds.

The welds include inlet and outlet nozzle attachment welds on heat exchangers #11, #12, and #13, welds HX-38-111N-W, HX-38-110VT-W, HX-38-121N-W, HX-38-120UT-W, HX-38-13IN-W and HX-38-130UT-W.

Proposed Alternative Examination A liquid penetrant examin6t;on has been substituted fcr the required volumetric method.

Licensee's Basis for Recuestina Relief The shutdown cooling heat exchangers (ill, #12, =13) inlet and outlet nozzles are fillet welded to the pressure vessel. Fillet welds cannot be ultrasonically tested and provide meaningful examination data.

Evaluation Two 8-inch nozzles are recessed into the heat exchanger head on the tube side and welded to the head by fillet welds.

The welds that are required to be examined are 3/4-inch fillet welds which cannot be adequately inspected by a volumetric ex-amination as required by the Code. The licensee proposes to perform a surface examination on the fillet welds that are completely accessible. Weld cracking would be detected by the surface examination.

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, . . o Visual examinations of the welds during periodic hydro-static testing would provide additional assurance that an adequate level of safety will be maintained.

Conclusions and Recommendations Based on the above evaluation, it is concluded that for the welds discussed above, the code requirements are impracti-cal. '

It is further concluded that the alternative examination discusseo above will provide necessary added assurance of structural reliability. Therefore, the following is recommended:

Relief should be granted from performing volumetric examina-welds, the tion of shutdown provided that:cooling heat exchanger inlet / outlet nozzle (a) The proposed alternative surface examination is performed.

(b) Visual examination of the welds for leakage is performed during periodic hydrostatic testing in accordance with IWC-5000.

References References 5, 6, and 7.

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B. Diping ,

1. Recuest for Relief 11, Appendix E;(5) Suoport Members for Piping, Valves and Pumos, Catecory C-E-1, items C2.5, C3.3,  :

and C4.3 Code Reauirement Surface examination shall be perfomed of the external support attachments, including the welds to the pressure-retaining boundary and the base metal beneath the weld zone, and along the support attachment member for a distance of l two' support thicknesses.

l Code Relief Recuest i

Relief is requested from the surface examination of all J Group B integrally welded external support attachments.

i Procosed Alternative Examination I

All welds which have been prepared- for surface ~ examinar-- --

tion will be examined as required. Those welds which have not been prepared for surface examination will receive a visual (VT-1, 1977 Code) examination. Additionally, all welds not prepared will receive a surface examination for information only.

Licensee's Basis for Requesting Relief Relief is requested because these attachment welds were left in the "as-welded" condition during construction. After welding, these welds were never ground to provide a surface that could be dye penetrant tested. Surface limitations show a large number of irrelevant indications. These indications are of such an extent that they would mask any relevant in-dications. Periodically, as allowed by operational and radiation exposure considerations, some welds have been pre-pared for surf ace examination. Those welds not prepared will receive a visual examination. Additionally, all welds not prepared will receive a surface examination for information j only. This examination is documented but the results will not be used to accept or reject the subject weld.  ;

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Evaluation There is no basis for permitting substitution of visual for surface examination of Class 2 integrally wcidec support attachments for piping, pumps and valves. Consequently, visual examination would not be an acceptable alternative examination.

Surface examination should be performed on all integrally welded support attachment welds. Should it not be possible to perform surface examinations on some welds, the licensee should submit code relief requests for those particular welds at that time. The justification for these code relief requests should contain engineering data which demonstrate that adequate safety factors are contained in the design of each weld joint so that I there are no questions relative to the safety of those welds for which code relief is requested. Otherwise there is no basis for determining the safety of those particular welds, as they cannot be adequately examined.

Conclusions and Recomendations  ;

Based on the above evaluation, it is concluded that for the welds discussed above, the Code requirements have not been shown to be impractical. Hence, it is recomended that this code relief request be denied, i i

Where surface examination of Class 2 integrally welded l support attachments for piping, pumps and valves is not possible, licensee should submit specific code relief requests for those  ;

welds that cannot be examined as required by the Code. These .

code relief requests should contain sufficient engineering data as justification to demonstrate the degree of safety involved in not examining the welds.

References References 5, 6 and 7.

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C. Pum:s

1. Recuest for Relief 11. Accendix E. Support MemDers for Pum:s, b Category C-E-1, Item C3.3 The request for relief from surface examination of integrally welded external support attachments for piping, valves and pumos -

(II.B.1 of this report) applies here. Therefore, it is recommended that relief not be granted from the surface examination of integ-rally welded external support attachments for pumps.

Where surface examination of Class 2 integrally welded support attachments for pumps is not possible. The licensee should submit specific code relief requests for those welds that cannot be examined as required by the Code. These code relief requests should contain sufficient engineering data as  ;

justification to demonstrate the degree of safety involved in not examining the welds. I_

D. Valves

1. Recuest for Relief 11, Appendix E;(5) Succort Members for Valves, '

Category C-E-1, Item C4.3 The request for relief from surface examination of integrally welded external support attachments for piping, valves and pumps (II.B.1 of this report) applies here. Therefore, it is recommended that relief not be granted from the surface examination of integ-rally welded external support attachments for valves.

Where surface examination of Class 2 integrally welded support attachments for valves is not possible, the licensee should submit specific code relief requests for those welds that cannot be examined as required by the Code. These code relief requests should contain sufficient engineering data as justification to demonstrate the degree of safety involved in not examining the welds.

'III. CLASS 3 COMPONENTS No relief requests.

IV. PRESSURE TESTS No relief requests.

V. GENERAL No relief requests.

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REFERENCES I. G. Lear (NRC) to G. K. Rhode (NMPC), Nine Mile Point, Docket No. 50-220, April 26, 1976.

2. G. K. Rhode (NMPC) to G. Lear (NRC), Nine Mile Point Unit 1, Docket No. 50-220, DPR-63, June 4, 1976.

3. G. Lear (NRC) to G. K. Rhode (NMPC), Nine Mile Point Nuclear Station Unit No. 1, Docket No. 50-220, November 22, 1976.

e- G. K. Rhode (NMPC) to G. Lear (NRC), Nine Mile Point Unit 1, Docket No. 50-220, DPR-63, December 9, 1976. p i:

5. D. P. Dise (NMPC) to T. A. Ippolito (NRC), Nine Mile Point Unit 1, Docket No. 50-220, DPR-63, May 2, 1980. }

6. D. B. Vassallo (NRC) to D. P. Dise (NMPC), April 14, 1982. l

7. T; E. Lempges (NMPC) to D. B. Vassallo (NRC), Nine Mile Point Unit 1, Docket No. 50-220, DPR-63, July 30,1982.

8. Evaluation of the Integrity of Vessels, NUREG 0081, June 1976. i l

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