ML20203J089

Forwards Second Request for Addl Info Re 981109 Request for leak-before-break Approval for Plant,Unit 2 Surge Line. Staff Agreed to Provide Info by 990301

ML20203J089
Person / Time
Site:	Millstone
Issue date:	02/04/1999
From:	Stephen Dembek NRC (Affiliation Not Assigned)
To:	Bowling M, Loftus P NORTHEAST NUCLEAR ENERGY CO.
References
TAC-MA4126, NUDOCS 9902230277
Download: ML20203J089 (6)

Text

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February 4,1999 Mr. Martin L Bowling, Jr.

Recovery Officer - Technical Services Northeast Nuclear Energy Company c/o Ms. Patricia A. Loftus Director-Regulatory Affairs P.O. Box 128 Waterford, CT 06385

SUBJECT:

SECOND REQUEST FOR ADDITIONAL INFORMATION REGARDING SUBMITTAL REQUESTING LEAK-BEFORE-BREAK APPROVAL - MILLSTONE NUCLEAR POWER STATION, UNIT NO. 2 (TAC NO. MA4126)

Dear Mr. Bowling:

i By letter dated November 9,1998, Northeast Nuclear Energy Company submitted a request for leak-before-break approval for the Millstone Unit 2 surge line. This approval was requested in response to Licenset.s Event Report 98-005-01 and was suNnitted to address concems about the dynamic effects of pipe rupture in accordance with tne provisions of General Design i

Criteria 4 of Title 10 of the Code of Federal Regulations Part 50, Appendix A. In order to i

complete the staff's review of this issue, additional information, as specified in the enclosure, is required. This is the second request for additional information on this issue, the first was i

related mainly to materials engineering issues. This one primarily concems mechanical engineering issues.

In a January 28,1999, phone call, Mike Ehredt of your staff agreed to provide this information by March 1,-1999. ' Should a situation occur that would prevent you from meeting this due date, please contact me at (301) 415-1455.

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PDR ADOCK 05000336 Project Directorate 1-2 P

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Docket No. 50-336 l

Enclosure:

As stated cc w/ encl 5 See next page DISTRIBUTION Docket File SDembek

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CM February 4, 1999 Mr. Martin L. Bowling, Jr.

Recovery Officer - Technical Servicee Northeast Nuclear Energy Company c/o Ms. Patric!r A. Loftus Director-Regu,atory Affcirs -

P.O. Box 128 Waterford, CT 06385

SUBJECT:

SECOND REQUEST FOR ADDITIONAL INFORMATION REGARDING SUBMITTAL REQUESTING LEAK BEFORE BREAK APPROVAL-MILLSTONE NUCLEAR POWER STATION, UNIT NO. 2 (TAC NO. MA4126)

Dear Mr. Bowling:

By letter dated November 9,1998, Northeast Nuclear Energy Company submitted a request for leak before-break approval for the Millstone Unit 2 surge line. This approval was requested in response t; Licensee Event Report 98-005-01 and was submitted to address concerns about the dynamic effects of pipe rupture in accordance with the provisions of General Des:gn Criteria 4 of Title 10 of the Code of Federal Regulations Part 50, Appendix A. In order to complete the staff's review of this issue, additionalinformation, as specified in the encbsure, is required. This is the second reouest for additionalinformation on this issue, the first was j

related mainly to materials engineering issues. This one primarily concerns mechanical engirnering issues.

In a January 28,1999, phor.e call, Mike Ehredt of your staff agreed to provide this information by March 1,1999. 0;iOJld a situation occur that Would prevent you from meeting this due date, please contact me at (301) 415-1455.

Sincerely, Stephen Dembek, Project Manager Project Directorate 1-2 Division of Reactor Projects - 1/11 Office of Nuclear Reactor Regulation Docket No. 50-336

Enclosure:

As stated cc w/ encl: See next page

.. _ +

Millston) Nucle:r Power Station Unit 2 cc:

Ms. L. M. Cuoco Emest C. Hadley, Esquire Senior Nuclear Counsel 1040 B Main Street Northeast Utilities Service Company P.O. Box 54g P. O. Box 270 West Wareham, MA 02576 Hartford, CT 06141-0270 Mr. R. P. Nocci Edward L Wilds, Jr., Ph.D.

Vice President-Nuclear Oversight Director, Division of Radiaten and Regulatory Affairs Department of Environmental Protection Northeast Nuclear Energy Company -

79 Elm Street P. O. Box 128 Hartford, CT 06106-5127 Waterford, CT 06385 Regional Administrator, Region 1 Mr. J. T. Carlin U.S. Nuclear Regulatory Commission Vice President-Human Services

'475 Allendale Road.

Northeast Utilities Service Company King of Prussia, PA 19406 P. O. Box 128 Waterford, CT 06385 i-First Selectmen Town of Waterford Mr. Allan Johanson, Assistant Director l

15 Rope Feny Road Office of Policy and Management i

Waterford, CT 06385 Policy Development and Planning i

Division Mr. Wayne D. Lanning, Director 450 Capitol Avenue-MS# 52ERN Millstone inspections P. N Box 341441 Office of the Regional Administrator Hz. Jcrd, CT 06134-1441 I

475 Allendale Road King of Prussia, PA 19406-1415 Mr. M. H. Brothers Vice President - Millstone Operations Charles Brinkman, Manager Northeast Nuclear Energy Company l

Washington Nuclear Operations P.O. Box 128 ABB Combustion Engineering Waterford, CT 06385 12300 Twinbrook Pkwy, Suite 330

]

Rockville, MD 20852 Mr. J. A. Price Director-Unit 2 OperatMns Senior Resident inspector Northeast Nuclear Energy Company i

Millstone Nuclear Power Station P.O. Box 128

~ lo U.S. Nuclear Regulatory Commission Waterford, CT 06385 i

c P.O. Box 513 Niantic, CT 06357 Mr. L. Olivier Senior Vice President and Chief C

- Mr. F. C. Rothen Nuclear Officer-Millstone Vice President - Nuclear Wonc. services Northeast Nuclear Energy Company Northeast Utilities Service Company P.O. Box 128 P. O. Box 128 Waterford,CT 06385 Waterford, CT 06385

1 Millstone Nuclear Power Station L-

- Unit 2 I

cc:

l Citizens Regulatory Commission Ms. Nancy Burton ATTN: Ms. Susan Perry Luxton 147 Cross Highway 180 Great Neck Road Redding Ridge, CT 00870 Waterford, CT 06385 Deborah Katz, President

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Citizens Awareness Network P. O. Box 83 Shelbume Falls, MA 03170 Ms. Tony Concannon Co-Chair Nuclear Energy Advisory Council Room 4100 Legislative Office Building Capitol Avenue Hartford, CT 06106 Mr. Evan W. Woollacott i

Co-Chair Nuclear Energy Advisory Council I

128 Terry's Plain Road Simsbury, CT 06070 Little Harbor Consultants, Inc.

Millstone -ITPOP Project Office P. O. Box 0630 Niantic, CT 06357-0630 Attomey Nicholas J. Scobbo, Jr.

Ferriter, Scobbo, Caruso, Rodophele, PC 1 Beacon Street,11th Floor Boston, MA 02108 Mr. D. B. Amerine Vice President - Engineering Services Northeast Nuclear Energy Company P. O. Box 128 Waterford,CT 06385 Mr. D. A. Smdh Manager-Regulatory Affairs Nostheast Nuclear Energy Company P. O. Box 128 i

Waterford, CT 06385

l i

N REQUEST FOR ADDITIONAL INFORMATION MILLSTONE NUCLEAR POWER STATION. UNIT NO. 2 DOCKET NO, 50-336

1. General Design Criterion (GDC) 4 permits the exclusion of dynamic effects associated with I

postulated pipe ruptures in nuclear power units, from the design basis when analyses reviewed and approved by the Commission demonstrate that the probability of fluid system piping rupture is extremely low under conditions consistent with the design basis for the piping. In 52 FR 41291, the Commission indicated that the concept of Leak-Before-Break (LBB)is applicable only to high quality piping. The Commission further indicated that LBB is applicable to systems where failure mechanisms such as fatigue are not significant contributors to the potential for pipe rupture. The staff has interpreted the Commission direction to mean that the piping has a low fatigue usage. Given that current fatigue data has shown that the pressurized water reactor (PWR) environment can have a significant impact on the fatigue life of stainless steel components (

Reference:

NRC letter to NEl dated September 2,1998, providing Argonne National Laboratory assessment of fatigue j

data), provide an assessment of the influence of the PWR water environmental effects on the ASME Section 111 fatigue analysis of the surge line.

2. Provide justification why thermal cycling due to turt>ulent penetration wiil not affect the fatigue crack propagation calculations of the welds closest to the hot leg (welds 2 through 7 in Figure B-1.)

1 Appendix A

3. Provide justification for basing Equation 20 in Appendix A on true stress-true strain values of the material. State, or provide a reference, that the stresses and strains in the equations on which the elastic-plastic fracture mechanics analysis in Section 6 and Appendix D is based are true stress-true strain quantities, and the analysis uses a true stress-true strain curve.

4. In Appendix A, Equations 19 and 20 are taken from the paper (shown as Reference 19) by Cofie, N. G., et. al., " Stress-Strain Parameters in Elastic-Plastic Fracture Mechanics",

presented at the 10th SMIRT Intemational Conference, August 14-18,1989. This paper was not published in the Proceedings of the Conference. Please provide a copy of this paper.

5. The thermal stratification moments used in the fatigue calculations described in CEN-387-P, Rev.1-P-A, were based on maximum stratified flow conditions. This was accepted by the staff in its safety evaluation report dated July 14,1993, and included in the report. In Appendix B, the thermal stratification moments are based on a linear top-to-bottom temperature distribution. Provide justification why these moments were determined on this basis, instead of the maximum stratified flow condition, as stated in CEN-387-P, Rev.1-P-A.

ENCLOSURE

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s 2-Section 6.0 and Appendix D

6. Provide the detailed analysis of the maximum throughwall thermal stresses, showing all relevant input parameters for both the temperature and the stress distributions, for the

. thermal stratification loading condition.

7. The calculation of the global moments and local stresses due to thermal stratification were based on a linear top-to-bottom temperature gradient. In Combustion Engineering Owners Group (CEOG) report CEN-387-P, Rev.1 P-A, dated May 1994, the thermal stratification moments used in the ASME Section ill fatigue calculations were based on maximum stratified flow conditions. This was accepted by the staff in its safety evaluation report dated July 14,1993, and included in the CEOG report. The staff considers maximum t

stratified flow conditions also applicable to the LBB calculations. Provide a reevaluation of all relevant quantities to the LBB appilcation based on maximum stratified flow conditions.

Section D.5

8. Provide the model for calculating the additional local stresses at the nozzle-to-safe-end welds due to bimetallic stress effects.

9. State the purpose for curve fitting the axial stress distribution with a cubic polynomial.

10. Provide an explanation for why the axial stress distribution in Figure D-5 for ferritic steelis apoarently the mirror image of the axial stress distribution in Figure D-6 for austenitic steel, both at 550 'F.

11. In Figure D-6, the axial stress determined from the curve fit underestimates the axial stress calculated from the stress analysis at the outer surface by about 15% Provide a discussion of the significance of this underestimation in the fatigue crack growth analysis.

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