ML20028C124

Responds to 820414 Request for Addl Info Re Inservice Insp Program Items 8 & 10.Justification for Relief Requests Discussed

ML20028C124
Person / Time
Site:	FitzPatrick
Issue date:	12/29/1982
From:	Bayne J POWER AUTHORITY OF THE STATE OF NEW YORK (NEW YORK
To:	Vassallo D Office of Nuclear Reactor Regulation
References
NUDOCS 8301070082
Download: ML20028C124 (10)

Text

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POWER AUTHORITY OF THE STATE OF NEW YORK 10 CoLUMous CIRCLE NEW YORK. N. Y.10019 (2128 397 6200 LEROY S CLAIR TRUSTEES orestavene orrecas dOHNS.DYSON r ese 7 m"x ur wa ese e nomans re a rsv a

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December 29, 1982 ,oSE o$co ,,o ,

JPN-82-93 *;;*",',';; "'*:,,,

RICH A RD M. FLYNN a nsesum a n ROBE RT 3. MILLONZ8 STEPHEN L. B AUM sameon voc e enassomar

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J AMES L. LAROCC A Director of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Attention: Mr. Domenic B. Vassallo, Chief Operating Reactors Branch No. 2 Division of Licensing

Subject:

James A. FitzPatrick Nuclear Power Plant Docket No. 50-333 Inservice Inspection Program Request for Additional Information

References:

1) P.J. Early (PASNY) to T.A. Ippolito (USNRC) dated September 10, 1979 regarding Inservice Inspection Program - Inservice Examination of Welds and Supports (JPN-79-57)

2) D.B. Vassallo (USNRC) to L.W. Sinclair (PASNY) dated April 14, 1982 - same subject

3) J.P. Bayne (PASNY) to D.B. Vassallo (USNRC) dated June 21, 1982 - same subject (JPN-82-52)

4) J.P. Bayne (PASNY) to D.B. Vassallo (USNRC) dated September 28, 1982 - same subject (JPN-82-52)

Dear Sir:

The Power Authority submitted, via Reference 1, Inservice Inspection Program relief requests for our FitzPatrick nuclear power facility. As a result of your initial review, you requested additional information on these relief requests via Reference 2. We found it necessary, for the reasons in Reference 3, to reschedule the submittal for that additional information. A partial response (excluding responses to Items 8 and 10) was transmitted to you via Reference 4.

8301070082 821229 IL PDR ADOCK 05000333 O PDR

Attached to this letter is our response to Items 8 and 10.

We are proceeding on the basis that relief will be granted upon identification of those specific components not inspected at the end of the ten year inspection interval.

If you have any questions, please contact Mr. J.A. Gray, Jr. of my staff.

Very truly yours,

k. h J.P. Bayne gf 1 Executive Vice President Nuclear Generation cc: Mr. J. Linville Resident Inspector U.S. Nuclear Regulatory Commission P.O. Box 136 Lycoming, N.y. 13093 Mr. G. Freund c/o S.A.I.

P.O. Box 696 Icaho Falls, Idaho 83402

Attachmant to JPN-82-93 Power Authority of the State of Nsw York James A. FitzPatrick Nuclear Power Plant 1

RESPONSE TO APRIL 14, 1982 REQUEST FOR ADDITIONAL INFORMATION - INSERVICE INSPECTION PROGRAM These responses are keyed to the enclosure of the April 14, 1982 letter, D.B. Vassallo (USNRC) to L.W. Sinclair regarding the James A. FitzPatrick Inservice Inspection Program.

Item II.8 <

Ultrasonic examination can be performed on pipe with 0.500 inch

} wall thickness and occassionally on 0.375 inch thick pipe under I certain conditions. Ultrasonic testing of this range of pipe wall thickness often results in limited scans and inspection from only one side of the weld because of joint geometry. These problems are more severe for pipe-to-valve, pipe-to-elbow and pipe-to-fitting

• welds (tees, crosses, sweepolets etc.) Internal reflections resulting from internal joint geometry make interpretation of ultrasonic test results difficult.

Class 1 Piping A 1977 baseline inspection was conducted on Class 1 pipe with wall thickness less than 0.500 inch. The results of this ultrasonic inspection are summarized in Table 2. During this baseline inspection 74 percent of the welds inspected received only limited inspection due to geometry. Fifteen percent of the welds had to be

reinspected because of difficulty interpreting the initial results.

Ultrasonic examination of welds in piping with less than 0.500 inch  :

thick walls results in incomplete weld inspection and increased personnel radiation exposure for reexamination.

Class 1 pipe with walls less than 0.375 inch thick present greater problems for ultrasonic inspection. Limited scans due to geometry and ultrasonic signal reflections make distinguishing between reflections and actual flaws difficult. Only limited

! confidence can be placed in weld inspections conducted under these circumstances. Therefore, surface examination provides an equivalent level of reliability for assuring the structural

, integrity of pipe less than 0.375 inch thick.

The added personnel radiation exposure associated with the inspection of 0.375 to 0.500 inch thick Class 1 pipe is justified because of it's importance in maintaining reactor coolant boundary integrity.

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C1cas 2 Piping Tharo are 71 Class 2 walds in piping with wall thicknasses bstwson 0.375 and 0.500 inch for which relief is raquanted. The results of the ultraconic examination of Claco 1 piping (Table 1)

! show that a significant amount of additional time must be spent, during the examination and evaluation, to obtain accurate results.

This additional inspection time, (50 to 100 percent longer than inspections without reflectors) results in a comparable increase in personnel radiation exposure. Extrapolating from the results of the 1977 baseline inspection, a large portion of these welds would not be examinable from both sides and/or from 100 percent of the circumference. No baseline inspections were conducted for Class 2 welds since volumetric examination was not required by the codes in effect during construction and preservice examination.

Additionally, extensive weld preparation would be required prior to ultrasonic examination of any of these welds. The cost to prepare these welds and adjacent surfaces for ultrasonic examination would be substantial. The extensive labor and radiation exposure required to prepare the welds, perform a baseline inspection, and perform the necessary inspections would not be justified by with a comparable increase in safety. ,

Considering the less critical role of this piping in regard to j plant safety, surface examination of Class 2 welds in piping less

{ than 0.500 inch thick provides a reliable and appropriate means of ensuring pipe integrity.

Item II.10 i

1) Relief request R4 is based on two premises:

i a) The geometry of most branch connection weld joints

prohibits meaningful ultrasonic examination. Specifically, l

any partial penetration weld, any full penetration weld (that is not a butt weld), and any weld joint covered by a reinforcing ring pad or saddle, cannot be volumetrically examined by ultrasonic testing (UT).

i Only certain sweepolet branch connection geometries permit any sort of volumetric (UT) examination. Examination results often require additional evaluation or reexamination which increases personnel radiation exposure and labor costs.

b) The stresses on a branch connection weld due to branch pipe bending moments are higher on the outside surfaces than on the inside. Considering only the effects of stress, failure is likely to occur first at the outside surface.

Therdfore, surface examinations provide a reliable means of early detection of service-induced cracking.

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j 2. Relief rcqunst R4 applies to Class 1 piping branchas

- greator thnn 6 inch nominal pipo size. Specifically, this relief request partains to Class 1 walds in the Racctor

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• Water Racirculation and Ranidual Hnct Ramoval (Codo Category B-J) Systems, a) Recirculation System The welds for which relief is requested are stainless l steel and are sweepolet-to-ring header welds connecting the riser to the ring-header. These are 12

' inch to'22 inch connections. These welds are numbered:

Loop A Loop B 22-02-2-5 22-02-2-62 22-02-2-11 22-02-2-68 22-02-2-16 22-02-2-73 22-02-2-21 22-02-2-79 Figures 1 and 2 illustrate typical geometry of these welds. Figure 1 shows the relative roughness of the weld crown and the variable contour of the sweepolet.

The weld crowns have not been ground flush because

! preservice examinations were not required when this piping was installed. The contour, surface conditions, and internal geometry of these branch connections prevent ultrasonic examination from the l sweepolet side of the weld. Additionally, results of

' ultrasonic examinations conducted from the ringheader side of the weld are difficult to interpret due to various weld joint geometry problems resulting from weld joint preparation and fitup. These welds will be

performed to the extent practicable depending on individual weld and fitting geometry inspected in accordance with the requirements of the effective ASME code in terms of frequency and extent of examination.

Surface examination methods will meet the requirements of the code recognized relief.

These sweepolet welds are required by NUREG-0313 Rev. 1 to be examined on an augmented basis. To meet the requirements of NUREG-0313 Rev. 1, the specialized (non-code) ultrasonic examination method, will be used to detect flaws in the inner one third of the wall.

These non-code inspections supplement code inspections to detect intergranular stress corrosion cracking (IGSCC).

Ultrasonic examinations will be performed on an augmented basis (as per NUREG-0313, Rev. 1) and will be done to the extent possible considering weld / joint geometry. Since stresses are generally higher on the outside surface for branch connections, IGSCC in sweepolet welds will as likely be discovered by surface as by volumetric examination.

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b) Rscidual Hsat Ramoval System The wold for which relief in cought is a 6 inch caddle to 20 inch piping. Thin joint connecto the 6 inch Reactor Water Cleanup return to the RHR system. The weld number is 20-10-141.

The geometry of a saddle, compared to the sweepolet in 2a, is even more extreme with regards to volumetric examination (UT). As previously stated, the stresses on this joint are higher on the outer surface.

Therefore, in light of an extremely prohibitive geometry and the higher stresses on the outer surface, surface examination only will be performed to meet ASME code requirements. If practical, the specialized ultrasonic testing methods for IGSCC will be employed to meet the requirements of NUREG-0313, Rev 1. If such ultrasonic testing proves impractical or not meaningful, surface examinations will be performed to meet the f requency per NUREG-0313, Rev. 1.

3. Relief request R4 also applies to Class 2 (Code Categories C-F and C-G of the 1974 Edition, Summer 1975 Addenda of the ASME Code) branch connections of any size. Table 1 lists these welds. With the exception of the two 4 inch branches of 10 by 20 inch tees in the RHR system and the 10 by 10 inch branch connection in the HPCI system, all other connections are small diameter service water connections.

The geometry of such small diameter branches prevents volumetric examination. This fact is recognized in later (1977 and 1980) editions of the ASME code which require only surface examination.

The RHR 4 inch branch connections are carbon steel 4 inch schedule 40 saddles to 20 by 20 by 20 inch carbon steel tees (weld nos. 20-10-448, 10-10-549). Their geometry effectively prevents volumetric examination by UT and, as discussed above, higher stresses occur on the outer surface. Surface examination will likely detect the

presence of any service induced flaws.

l The HPCI 10 by 10 inch branch connection (weld No.

10-23-675) is an open butt welded joint between two 10 inch schedule 80 carbon steel pipes. The meaningful and

! accurate interpretation of volumetric examination (UT) results for such a branch connection, while feasible, is difficult. The higher stresses on the outer surfaces of these branch connections make examination by surface methods likely to reveal service-induced flaws. The cost of UT in terms of additional personnel radiation exposure and labor will not contribute significantly to increased safety.

Conclucion

.Surfcco excminations of brcnch wolds is more relichle in dstceting servico-induced ficwn, and results in lower psreonnel radiation exposure. The reliability of surface examinations is recognized industry-wide, as evidenced by later editions (1977 and 1980) of the code, which require only surface examination of all Class 2 branch connections.

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. Table 1 Claec 2 Branch Walda for Ralief Raquent R4 Code Category Branch Size and Function Weld No.

Residual Heat Removal System C-G 4" branch to 20" Tee 20-10-442 0.75" service water (SW) conn to 20" x 8" reducer 20-10-44T 2"x6" SW conn 6-10-437 0.75"x8" SW conn 8-10-472 1.25"x16" SW conn 16-10-45@

1.5"x16" SW conn 16-10-457 1.5"x8" SW conn 8-10-502 4" branch to 20" Tee 20-10-54%

.75"x20" SW conn at above weld 20-10-553 1"x16" SW conn 16-10-555

, 1.5"x16" SW conn 16-10-55%

1"x8" SW conn 8-10-537 1.25"x8" SW conn 8-10-546 0.75" SW conn to 20"x8" reducer 8-10-548R 3"x6" SW conn 6-10-581 0.75"x6" SW conn 6-10-592 Reactor Core Isolation Cooling System C-F 0.75"x8" SW conn

• 8-13-100 0.75"x8" SW conn

• 8-13-100 0.75"x8" SW conn

• 8-13-100s High Pressure Coolant Injection System C-F 2"x10" SW conn 10-23-67 10"x10" Branch conn 10-23-67 2"x10" SW conn 10-23-68 0.75"x10" SW conn 10-23-70 i 1"x10" SW conn 10-23-70 O.75"x10" SW conn 10-23-70 1"x10" SW conn 10-23-70 0.75"x10" SW conn 10-23-70:

• 8 inch piping with a wall thickness of 0.322" (as per relief request Rl) requires surface examination of the circumferential and longitudinal piping welds.

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Figure 1

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, Riser Pipe to Sweepolet Neld

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- i pnA{ ..._J Sweepolet to Ring Header Weld Photograph of Sweepolet area at Riser N-2J, Reactor Water Recirculation System l

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a Figure 2 MsW N

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n NT: 'u Typical of welds #

22-02-2-5 22-02-2-62 id' ,r 22-02-2-11 22-02-2-68 22-02-2-16 22-02-2-73 4" NOMINAL 22-02-2-21 22-02-2-79

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Reactor Water Recirculation System 22" Ring header to 12" Riser branch connection