IR 05000346/1986011

Insp Rept 50-346/86-11 on 860227-28.No Violation or Deviation Noted.Major Areas Inspected:Licensee Action on IE Bulletin 80-11, Masonry Wall Designs

ML20141N909
Person / Time
Site:	Davis Besse
Issue date:	03/12/1986
From:	Muffett J, Norton J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
Shared Package
ML20141N904	List: IR 05000346/1986011
References
50-346-86-11, IEB-80-11, NUDOCS 8603180271
Download: ML20141N909 (3)

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'U.S. NUCLEAR REGULATORY COMMISSION

REGION III

Report No. 50-346/86011(DRS)

Docket No. 50-346 License No. NPF-3 Licensee: Toledo Edison Company Edison Plaza, 300 Madison Avenue Toledo, _0H - 43652 -

~ Facility Name: Davis-Besse 1 Inspection At: Oak Harbor, OH

' Inspection Conducted: February 21 and 28, 1986

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. Inspector: C.J F. Norton 3-tz M Date Approved By:

hd J. W. Muffett, h f A/i2[86 Plant Systems Section Date Inspection Sumary Inspection on February 27 and 28 1986 Repor_t No. 50-346/86011DRSJ)

Areas Inspecteif:~Ul'ceIIsTe Tc'tTo,n~iinl]E BulTetin BDMT Masonry] Wall Desig Kesults: No violations or deviations were identified during this inspection,

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8603180271 860"J1M PDR ADOCK 05000346 G PDR l- .

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DETAILS 1. Persons Contacted Toledo Edison Company

• C, Mekbel, Civil / Structural Engineering Supervisor U.S. Nuclear Regulatory Commission D. Kosloff, Resident Inspector

• Denete: thsse who attended the exit meeting on February 28, 1986.

2. Action'on Inspection Findings (Closed) Open Item 50-346/8011-BB: IE Bulletin 80-11 " Masonry Wall Design." A review of relevant information on plant masonry walls revealed that IE Bulletin 80-11 requirements have been fully implemented at Davis-Bess . Licensee Action on IE Bulletin 80-11 IE Bulletin 80-11 required licensees to identify plant masonry walls and their intended functions. Licensees were also required to present reevaluation criteria for the masonry walls with the analyses to justify those criteri If modifications were proposed, the methods and schedules for the modifications were to be presente In response to IE Bulletin 80-11, Toledo Edison Company provided the NRC with documents describing the status of masonry walls at Davis-Besse. The information in these documents was reviewed, and

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a request for additional information was sent to the licensee on March 8, 198 The licensee responded concerning this issue in letters-to the NRC on June 16 and July 14, 1982. As the result of a meeting between Toledo Edison and members of the NRC staff on May-27, 1982, and a combined technical meeting and site visit held June 21-23, 1983, additional questions were sent to the licensee to which it responded with letters on June 23, 1982, (Roy to DeAgazio),

and August,1982 (Harris and Hamid Report, " Applicability of Energy Balance Technique to Reinforced Masonry Walls"). There are 169 safety-related masonry walls at Davis-Bess The functions of these walls include fire and flood barriers, radiation shielding, and negative pressure boundaries. Also, the walls support minor platforms, piping, conduit, and instrumentation. None of the walls were designed to act as shear wall The masonry walls are typically hollow unit construction, laid in stacked bond, single or double wythe, (two blocks in thickness)

partially or fully grouted, and are vertically reinforced.

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.o .,- The licensee employed the working stress method to qualify 66 of the walls. This method is acceptable for this type of walls. The licensee relied on the energy balance technique to qualify 75 of the safety-related masonry walls to resist cut-of-plane forces. The NRC staff position on the use of the energy balance (or any other nonlinear analysis) technique is that the method is not acceptable without further confirmation by an appropriate test program. The licensee subsequently reanalyzed the 75 walls by the linear elastic working stress method. Several conservatisms had been incorporated in the energy balance analyses. The 75 walls were reanalyzed by the working stress method after reduction factors were applied to some of the conservatisms in the method. The applied reduction factors resulted in qualification of the 75 walls, The licensee conunitted to modify 28 safety-related walls on which overstressing was indicated under full loading conditions. The

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modifications included additional external steel bracing and the reinforcing of boundary connections with bolted angles. All modifications have been complete During an inspection performed in October,1985 (Inspection Report No. 50-346/85032(DRS)), approximately one-half of the 28 walls were individually examined by the Region III inspector. This was accomplished in the company of the Senior Assistant Civil / Structural Engineer and the Facility Modification Engineer. Detailed individual review was accomplished to assure that construction modifications were in accordance with design. Structural design drawings, and contractor' procedures and QA/QC documentation relative to the construction were also reviewed and found to be appropriat No discrepancies were discerned between design drawings and construction, therefore the walls inspected are acceptabl Based on the above findings, IE Bulletin 80-11 requirements have been fully implemented at Davis-Besse. There is reasonable assurance ' hat all of the 169 safety-related masonry walls will withstand 6 specified design loading conditions without impairment of wall integrity or the performance of the required safety function . Exit Meeting The inspector met with the licensee representative (denoted under Persons Contacted) at the conclusion of the inspection on February 28, 1986. The inspector sunnarized the purpose and findings as reported herein. The inspector also discussed the likely infortnational content of the inspector's report with regard to documents or processes reviewed by the inspector during the inspection. The licensee did not identify any such documents / processes as proprietar _- .-.

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