ML20212D750

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Responds to Undated Memo to Commissioner Asselstine Assessing Fracture Toughness of Containment Pressure Boundary.Concerns Adequately Addressed & Piping Acceptable for Svc
ML20212D750
Person / Time
Site: Millstone, Hope Creek, 05000000
Issue date: 12/24/1986
From: Harold Denton
Office of Nuclear Reactor Regulation
To: Halapatz J
AFFILIATION NOT ASSIGNED
Shared Package
ML20209D299 List:
References
NUDOCS 8701050009
Download: ML20212D750 (5)
v • d • e


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+ A (o' .g UNITED STATES 8 g NUCLEAR REGULATORY COMMISSION O N8 WASHINGTON, D. C. 20655

%.] DEC 2 41986 Docket No.: 50-423 Mr. Joe Halapatz j 3162 Northgate Drive '

Apt. #2014 Irving, Texas 75062

Dear Mr. Halapatz:

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In your memorandum (undated) to Commissioner Asselstine, you assessed the fracture toughness of the Millstone Unit 3 Containment Pressure Boundary. You concluded that the Millstone 3 20-inch schedule 100 feedwater piping fabricated by Cameron to ASME Code SA 106 GR.B requirements and the Millstone 3 feedwater isolation valve bodies and bonnets fabricated to ASME Code SA 216 GR.WCB '

requirements were unacceptable for service. Your conclusion is based on an evaluation of the materials' fracture toughness and service temperatures.

In your memorandum you assigned a nil ductility transition (NDT) temperature of 77*F to the SA 106 GR.B material and a NDT temperature of 57*F to the SA 216 GR.WCB material. The lowest service temperature for each component was estimated as 74*F. Based on its NDT temperature, the feedwater piping could operate at the most 3*F (77*F-74*F) below its NDT temperature. Based on its NDT temperature, the feedwater isolation valve bodies and bonnets could operate as low as 17*F (74*F-57 F) above its NDT temperature. Your concern appears to be that these components could operate at temperatures slightly above or below their NDT temperatures and as a result would not have sufficient fracture toughness to prevent fracture.

The feedwater piping and the isolation valve bodies and bonnets were reviewed and determined to meet General Design Criterion (GDC) 51. This GDC states, in part, that the reactor containment boundary shall be designed with sufficient margin to assure that under operating, maintenance, testing, and postulated accident conditions (1) its ferritic materials behave in a nonbrittle manner and (2) the probability of rapidly propagating fracture is minimized. The staff's review requirements for satisfying GDC-51 are contained in Standard Review Plan (SRP) 6.2.7, " Fracture Prevention of Containment Pressure Boundary." This SRP indicates that the fracture toughness of the materials of the components of the containment pressure boundary shall be reviewed in accordance with the fracture toughness criteria for Class 2 components identified in the Summer 1977 Addenda of Section III of the ASME Code. For Class 2 components, the fracture toughness criteria in the Summer 1977 Addenda of Section III of the ASME Code permit three approaches. Fracture resistance may be demonstrated by Charpy V-notch testing at or below the Lowest Service Temperature; the materials may be evaluated to the NDT temperature requirements of Table NC-2311(a)-1 of the ASME Code; or the materials may be evaluated using the fracture mechanics methods contained in Appendix G of the ASME Code. The 8701050009 861224 PDR ADOCK 05000423 p PDR

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Mr. Joe Halapatz materials in the feedwater piping and the isolation valve bodies and bonnets were evaluated using the fracture mechanics methods described in Appendix G of the ASME Code. This evaluation is contained in Attachment 1 to the W. V. Johnston memorandum dated September 16, 1985. The W. V. Johnston memorandum is contained in Attachment A to your letter.

The fracture mechanics analyses performed by Northeast Utilities (the licensee) use a 26.78 ksi (in.)gconservative

. The fracture reference mechanicsstress intensity analyses value normal, considered of upset, test, emergency, and faulted conditions and satisfy the margins in Appendix G of the ASME Code. The reference stress intensity value provides a lower bound that addresses your concerns, since it is applicable to ferritic materials at temperatures 180*F below their NDT temperature. Since the reference stress intensity value used in the fracture mechanics analyses corresponds to a fracture toughness value for these materials significantly below their service temperature and NDT temperatures, the analyses demonstrate that the materials have sufficient fracture resistance at the service temperature. By meeting the safety margins recommended in Appendix G of the ASME Code, the licensee's fracture mechanics analyses have demonstrated that the feedwater materials in the Millstone 3 Containment Pressure Boundary will behave in a nonbrittle manner, the probability of rapidly propagating fracture will be minimized and the requirements of GDC-51 are satisfied.

Based on the above discussion and referenced staff evaluations, we believe your concerns have been adequately addressed and that the Millstone 3 piping is acceptable for service.

O da k t eten a q ,,

)Mard H. VoUmar Harold R. Denton, Director Office of Nuclear Reactor Regulation DISTRIBUTION:

Docket File CPaul NRC/PDR DMossburg Local PDR PAEB Reading File, 316 1 EDO #2348 CERossi l EDO Reading File RL8allard VStello ESullivan RVollmer/HDenton BJElliot TMurley PBaker TNovak PA:PD#5 p

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DATEil2/18/86 E12/19/86 512/22/86 512/22/86 312/23 /86 il2/?l /86 il2ht /86 0FFICIAL RECORD COPY / /

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Mr. Joe Halapatz 7-

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materials in the feedwater piping and the isolation valve bodies and bonnets j were evaluated using the fracture mechanics methods described in Appendix G of the ASME Code. This evaluation is contained in Attachment 1 to the W. V. Johnston memorandum dated September 16, 1985. The W. V. J6hnston memorandum is contained in Attachment A to your letter. /

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The fracture mechanics analyses performed by the Northeast ytilities (the  !

l licensee) use a conservative reference stress intensity value of I 26.78 ksi (in.)g The fracture mechanics analyses considered normal, upset, l

! test, emergency, and faulted conditions and satisfy the/ margins in Appendix G l of the ASME Code. The reference stress intensity valy'e provides a lower bound that addresses your concerns, since it is applicable /to ferritic materials at '

temperatures 180 F below their NDT temperature. Since the reference stress intensity value used in the fracture mechanics ana'lvses corresponds to a fracture touahness value for these materials sicifificantly below their service temperature and NDT temperatures, the analyses 'emonstrate that the materials have sufficient fracture resistance at the se ice temperature. Ry meeting the safety margins recommended in Appendix G of e ASME Coda, the licensee's fracture mechanics analyses have demonstra d that the feedwater materials in the Millstone 3 Containment Pressure Roun ry will behave in a nonbrittle manner, the probability of rapidly propagating fracture will be minimized and the reouirements of GDC-51 are satisfie '.

Rased on the above discussion and referenced staff evaluations, we believe your cencerns have been adequatelv atfdressed and that the Millstone 3 piping is acceptable for service.

/

/ Harold R. Denton, Director

/ Office of Nuclear Reactor Reoulation i

DISTRTRilTION:

Docket File ' CPaul NRC/PDR DMossburo Local PDR PAEB Reading File, 316 ED0 #2348 / CERossi EDOReadingFile/ RLBallard VStello / ESullivan )  !

RVollmer/HDenton RJElliot TMurley PRaker TNovak U

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NAME :RElliot:,is :ESullivan :R Ral d .. o si :T. Novak :R. Vollmer :H.R. Denton

_____:___.C_______:____________:__. __________:____________:____________:____________:___________

DATE:12/18/86 :17/@/86 :12/ 'l}/86 :1?/ D /86 :1.?/ /86 :1?/ /86 :12/ /86 0FFICIAL RECORD COPY

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Mr. Joe Halapatz \

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may be demonstrated by Charpy V_ notch testing at or below the Lowest Service Temperature; the. materials may be evaluated to the NDT temperature requirements of Table NC-2311(ai-1 of the ASME Code; or the materials may be evaluated using

~,. the fracture mechanics nethods contained in Appendix G of the ASME Code. The materials in the feedwater piping and the isolation valve bodies and bonnets were evaluated using the fracture mechanics methods described in Appendix G of the ASME Code. This\ evaluation is contained in Attachment 1 to the W. V.

Johnston memorandum dated September 16, 1985. The W. V. Johnston memorandum is contained in Attachment A to your letter.

The fracture mechanics analyses performed by the Northeast Utilities (the licenseel use a conservative reference stress intensity value of 26.78 ksi (in.)g The fracture mechanics analyses considered normal, upset, test, emergency, and faulted conditions and satisfy the margins in Appendix G of the ASME Code. The reference stress intensity value provides a lower bound for your concerns, since it,is applicable to ferritic materials at temperatures 180*F below their NDT temperature. Since the reference stress intensity value used in the fracture mechanics analyses corresponds to a fracture toughness value for these materials significantly below their service temperature and NDT temperatures, the analyses will ensure that the materials have sufficient fracture resistance at the serv. ice temperature. By meeting the safety margins recommended in Appendix G of the ASME Code, the licensee's fracture mechanics analyses have demonstrated that the feedwater materials in the Millstone 3 Containment Pressure Boundary will behave in a nonbrittle manner, the probability of rapidly propagating fracture will be minimized and the requirements of GDC-51 are satisfied.

Based on the above discussion and referenced staff evaluations, we believe your concerns have been adeouately addressed and that the Millstone 3 piping is acceptable for service.

Harold R. Denton, Director Office'of Nuclear Peactor Regulation s

DISTRIBUTION:

Docket File CPaul NRC/PDR DMossburg s Local PDR PAEB Reading File, 316 \

ED0 #2348 ED0 Reading File CERossi RLBallard

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VStello ESullivan RVollmer/HDenton RJElliot TMurley PRaker TNovak 0FC :PAEB p p :PAEB :PAER :A/D:DPLA :DD:0PLA :DD:0NRR :D:0NRR

_ _ _ _ _ : _ _ _ _ _ _cC__ _ : _ _ _ _ _p_K.__:-___________:____________:____________:____________:___________

NAME :BElliot:js :ESullivan :R. Pallard :C.E. Rossi :T. Novak :R. Vollmer :H.R. Penton DATE :12//f/86 :12/lt/86 :12/ /86 :12/ /86 :12/ /86 :12/ /86 :12/ /86 0FFICIAL RECORD COPY

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FROM: DUE: J2712/86 EDO CONTROL: 002348 DOC DT: 11/12/86 JOE HALAPATZ FINAL REPLY:

(REFERRED BY MEMO JOHN AUSTIN TO REHM, 11/25/86 TO:

COMM. ASSELSTINE FOR SIGNATURE OF: ** GREEN ** SECY NO:

DENTON .

5, DESC: ROUTING: /

SAFETY CONCERNS RELATED TO MILLSTONE UNIT 3 MllRLEY CONTAINMENT PRESSURE BOUNDARY DATE: 11/26/86 ASSIGNED TO: NRR CONTACT: DENTON SPECIAL INSTRUCTIONS OR REMARKS:

J NRR RECEIVED: 11/28/86 ACTION: Y;19th;-inbVAKf7 NRR ROUTING: DEN'lON/VOLLMER PPAS MOSSBURG/'IOMS

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