NUREG-0661, Safety Evaluation Re Util 840831 Submittal of Addendum to Plant Unique Analysis Rept on Mark I Containment Mod Program.Safety/Relief Valve Load Cases C3.2 & C3.3 Adequately Addressed & Resolved

Safety Evaluation Re Util 840831 Submittal of Addendum to Plant Unique Analysis Rept on Mark I Containment Mod Program.Safety/Relief Valve Load Cases C3.2 & C3.3 Adequately Addressed & Resolved

ML20215M104
Person / Time
Site:	Brunswick
Issue date:	05/07/1987
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20215M075	List: NUREG-0661, Safety Evaluation Re Util 840831 Submittal of Addendum to Plant Unique Analysis Rept on Mark I Containment Mod Program.Safety/Relief Valve Load Cases C3.2 & C3.3 Adequately Addressed & Resolved
References
RTR-NUREG-0661, RTR-NUREG-661 NUDOCS 8705130090
Download: ML20215M104 (2)

Text

_.

UNITED STATES

(,/ 'g NUCLEAR REGULATORY COMMISSION r, sy WASHINGTON. D. C. 20555

'e SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION CAROLINA POWER AND LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT UNITS 1 AND 2 MARK I CONTAINMENT PROGRAM

1.0 INTRODUCTION

By letter dated August 31, 1984, the Carolina Power and Light Company (CP&L) submitted an addendum to the Brunswick Plant Unique Analysis Report (PUAR) on the Mark I Containment Modification Program. This addendum detailed the analytical approach taken to resolve the safety /

relief valve (SRV) second lift loading concerns at Brunswick. It showed that the SRV discharge lines and supports, the torus internal structures, and the torus shell, as modified by the Mark I Containment Program, are acceptable under SRV load cases C3.2 and C3.3. The methodology employed in the analysis is the same as that reviewed and approved by NRC in NUREG-0661.

2.0 EVALUATION The original PUAC proposed to eliminate SRV load cases C3.2 and C3.3 by lowering the MSIV isolation water level trip and modifying the SRV logic.

However, due to the cceplexity and corresponding difficulty of instal-lation, testing and maintenance of the modifications, CP&L instead per-formed analyses to prove that the Mark I Containment Modifications on SRV discharge lines and their supports, internal structures, and torus shell will offer adequate resistance to the second SRV lift loads con-current with a LOCA.

The primary concern of load case C3.2 is the potentially large high frequency loading on the containment, while the primary concern of load case C3.3 is the potentially large water clearing thrust loads on the SRV discharge piping. This is reflected on the torus shell pressure and SRV air bubble induced drag loads calculated for load case C3.2, and SRV discharge line thrust loads calculated for load case C3.3. Appropriate SRV lines were selected so that most significant loadings would be considered.

3.0 CONCLUSION

Since results obtained from using approved analytical techniques show that subsequent SRV actuations concurrent with a LOCA will not overstress the SRY piping and their supports, the torus internal structures or the torus shell, the staff concludes that SRV load cases C3.2 and C3.3 have been adequately addressed and resolved.

Principal Contributor: H. Shaw Dated:

8705130090 870507 4 DR ADOCK 0500

/Mr.E.E.Utley .

Brunswick Steam Electric Plant

-c -Carolina Power & Light Company Units 1 and 2 cci Mr. P. W. Howe Mr. C. R. Dietz Vice President Plant General Manager-

. Brunswick Nuclear Project Brunswick Nuclear Project

-Box 10429 '

Box 10429 Southport, North Carolina -28461 Southport, North Carolina 28461 Thomas A.- Baxter, Esquire Mr. H. A. Cole Shaw, Pittman, Potts & Trowbridge Special Deputy Attorney ~ General

~2300 N Street, N. W. State of North Carolina Washington, D. C. 20037 Post Office Box 629 Raleigh, North Carolina -27602 Mr. D. E. Hollar Associate General Counsel Mr. Robert P. Gruber Carolina Power & Light Company Executive Director Post Office Box 1551 Public Staff - NCUC Raleigh, North Carolina 27602 Port Office Box 29520 Mr. Christopher Chappell, Chairman Board of Commissioners Post Office Box 249 Bolivia, North Carolina 28422 Mrs. Chrys Baggett

State Clearinghouse Budget and Management 116 West Jones Street Raleigh, North Carolina 27603 Resident Inspector U.'S. Nuclear Regulatory Commission Star Route 1 Post Office Box 208 Southport, North Carolina 28461 Regional Administrator, Region II U. S. Nuclear Regulatory Consission 101 Marietta Street, Suite 2900 Atlanta, Georgia 30303 Mr. Dayne H. Brown, Chief Radiation Protection Branch Division of Facility Services N. C. Department of Human Resources 701 Barbour Drive

-Raleigh, North Carolina 27603-2008

_ _ _ - - - _ - - _ _ _ _ - - - - - - - _ - - - - - - - - - - ---__J