ML20081A757

Interim Deficiency Rept Re Nonconservative Design of Embedments in Concrete Using Shear Lugs Located in Tension Zones.Next Rept Expected by 840601

ML20081A757
Person / Time
Site:	Midland
Issue date:	02/24/1984
From:	Jackie Cook CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
28015, 82-12-#5, NUDOCS 8403060269
Download: ML20081A757 (6)

Text

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consumem Power company t""',,",,L.,,,o.,,,,,.,

and Constructson General offices: 1945 West Pernell Road, Jackson, MI 49201 e (517) 7880453

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February 24, 1984 82-12 #5

[PrJry,lPAL STAFF T/Ii5. M pppp Mr J G Keppler, Regional Administrator US Nuclear Regulat,'ry Commission JE Region III Deri

)pf.y 799 Roosevelt Road l.

RaA Glen Ellyn, IL 60137

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'4 L' gr HIDLAND ENERGY CENTER

's F'l l o TOu' DOCKET NOS 50-329 AND 50-330 SHEAR LU'; DESIGN FOR EMBEDS FILE:

0.4.9.63 SERIAL:

28015

Reference:

J W Cook letters to J G Keppler, Same Subject

1) Serial 19106, dated December 3, 1982

2) Serial 20721, dated March 1,1983

3) Serial 22207, dated May 20, 1983

4) Serial 26603, dated November 22, 1983 This letter, as were the referenceci letters, is an interim 50.55(e) report regarding the design of the embedments in concrete that use shear lugs located in tension zones. The attachment to this letter provides a description of the investigation and the corrective actions being taken with regard to this subject.

Another report, either interim or final, will be sent on or before June 1, 1984.

JWC/WRB/rlm

Attachment:

(1) MCAR-63, Interim Repo.t 5, dated February 3, 1984 8403060269 840223 PDR ADOCK 05 S

kMk OC0284-0028A-MP01 y

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2 82-12 #5 SERIAL:

28015 CC: Document Control Desk NRC Washington, DC RJCook, NRC Resident Inspector Midland Nuclear Plant DSHood, USNRC Office of NRR INPO Records Center OC0284-0028A-MP01

i-3 82-12 ft SERIAL:

28015 OM/0L SERVICE LIST Mr Frank J Kelley Atomic Safety & Licensing Attorney General of the Appeal Board State of Michigan U S Nuclear Regulatory Commission Ms Carole Steinberg, Esq Washington, DC 20555 Assistant Attorney General Environmental Protection Division Mr C R Stephens (3) 720 Law Building Chief, Docketing & Services Lansing, M1 48913 U S Nuclear Regulatory Commission Office of the Secretary Washington, DC 20555 Mr Myron M Cherry, Esq Suite 3700 Ms Mary Sinclair Three First National Plaza 5711 Summerset Street Chicago, IL 60602 Midland, MI 48640 Mr Wendell H Marshall Mr William D Patoa., Esq RFD 10 Counsel for the NRC Staff Midland, MI 48640 U S Nuclear Regulatory Commission Washington, DC 20555 Mr Charles Bechhoefer, Esq Atomic Safety & Licensing Atomic Safety & Licensing Board Panel Board Panel U S Nuclear Regulatory Commission U S Nuclear Regulatory Commission Washington, DC 20555 Washington, DC 20555 Dr Frederick P Cowan Ms Barbara Stamiris 6152 N Verde Trail 5795 North River Road Apt B-125 Rt 3 Boca Raton, FL 33433 '

Freeland, MI 48623 Mr Fred C Williams Mr Jerry Harbour Isham, Lincoln & Beale Atomic Safety & Licensing 1120 Connecticut Ave, NW, Suite 325 Board Panel Washington, DC 20036 U S Nuclear Regulatory Commission Washington, DC 20555 Mr Jamea E Brunner, Esq Mr M I Miller, Esq Consumers Power Company Isham, Lincoln & Beale 212 West Michigan Avenue Three First National Plaza Jackson, M1 49201 52nd Floor Chicago, IL 60602 Mr D F Judd Mr John Demeester, Esq Babcock & Wilcox Dow Chemical Building

.P0 Box 1260 Michigan Division

_Lynchburg, VA 24505 Midland, MI 48640 Mr Steve Cadler, Esq Ms Lynne Bernebei 2120 Carter Avenue Government Accountability Project St Paul, MN 55108 1901 Q Street, NW Washington, DC 20009 September 6, 1983 OC0284-0028A-MP01

s Serial 28015 8

Bechtel Associates ProfessionalCorporation I42084-777 easi e,senno.e, es,.sy Ann Arbcr, Michigan l

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.: P.O. Box 10u0, Ann Arbor, Michigan 48106

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SUBJECT:

MCAR 63 (Issued 11/10/82)

Design of Steel Embedmonts That Use Shear Lugs Located in Tension Zones INTERIM REPORT 5 DATE:

February 3, 1984 PROJECT:

Consumers Power Company Midland Plant Units 1 and 2 Bechtel Job 7220 Introduction This report addresses a concern with the design of steel embedments in concrete that use shear lugs located in tension zones.

Background

The American Concrete Institute (ACI) 349 Code, Appendix B, issued August 1979, specifies that shear lugs in embedment designs shall be considered effective only in compression zones. Midland embedment designs completed and installed before this date considered shear lugs to accomanodate shear loads and tensiosa bars to accossmodate tension loads. Other than ACI 349, Appendix B, no known design code or industry standard restricts the design of embedments using shear lugs outside the compression zone.

For embedmonts within the scope of this MCAR, the Midland Final Safety Analysis Report Section 3.8, is comunitted to design reinforced concrete according to ACI 318-63 and 318-71, and structural steel according to the AISC 1969 edition; however, these codes do not specifically address all aspects of embeinent design.

Investinative Action An evaluation to determine which of the embedmonts identified have shear lugs located in tension zones has been completed for the existing loads.

To determine if the embedmonts installed in the Midland plant are capable of performing their safety function, a testing program was completed at the University of Michigan to determine the effectiveness of shear lugs located in tension zones. Bechtel's evaluation of the test results is expected to be complete by February 29, 1984.

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'l42186 1420*84 Bechtel Associates Professional Corporation NCAR 63 INTERIM REPORT 5 Page 2 Analysis of Safety Implications The concern is that shear lugs located in tension zones may not be fully effective and that this may result in a nonconservative design. The design may be nonconservative to the extent that the 1

embedmont may not be capable of performing its required safety function.

Probable cause The apparent root cause is that before issuance of ACI 349, Appendie B, the possible behavior of shear lugs in tension zones was not recognized by codes or industry standards.

Corrective Action To enable new designs and modifications to existing designs to be completed, an interim embedment design criterion was developed and is presently being used. 'After evaluating the invastigative actions, the embedment design criterion will-be finalized, and other corrective actions will be determined.

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Bechtel Associates Professional Corporation 42004 i

mu 63 142186 INTERIM REPORT 5 Page 3 l

Rorortsbility i

This concern is considered potentially reportable in accordance with Title 10 of the Code of Federal Regulations, Part 50.55(c) and was reported to the NRC by Consumers Power company on November 5, 1982.

9-J Submitted b :

M,.

E.B. Poser

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Project Engineering Manager Approved by:

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b; g T.E. Johnson Civil Chief Engineer

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Approved by:

E.H. Smith Engineering Manager Concurrenco by:

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.fe r M. A. Dietrief Project Quality Assurance Engineer PVR/MPA/jsh*

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