ML20071J302
| ML20071J302 | |
| Person / Time | |
|---|---|
| Site: | Midland |
| Issue date: | 05/20/1983 |
| From: | Jackie Cook CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, 22207, 82-12-3, 82-123, NUDOCS 8305260218 | |
| Download: ML20071J302 (5) | |
Text
.
Consumers power James W Cook A
0 0
Vice President - Projects, Enginee,ing and Construction General offices: 1945 West Parnall Road. Jackson, MI 49201 * (517) 788 0453 May 20, 1983 82-12 #3 Mr J G Keppler, Regional Administrator US Nuclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn, IL 60137 MIDLAND NUCLEAR C0 GENERATION PLANT DOCKET NOS 50-329 AND 50-330 SHEAR LUG DESIGN FOR EMBEDS FILE:
0.4.9.68 SERIAL: 22207
Reference:
J W Cook letter to J G Keppler, Same Subject
- 1) Serial 19106, dated December 3, 1982
- 2) Serial 20721, dated March 1, 1983 This letter, as were the referenced letters, is an interim 50.55(e) report regarding the design of embedments in concrete that use shear lugs located in tension zones. The attachment to this letter provides a description of the investigat" n and the corrective actions being taken with regard to this subject.
Another report, either interim or final, will be sent on or before November 22, 1983.
m W. M JWC/WRB/cd
Attachment:
(1) MCAR-63, Interim Report 3, dated May 3, 1983 CC: Document Control Desk, NRC Washington, DC RJCook, NRC Resident Inspector Midland Nuclear Plant 8305260218 830520 PDR ADOCK 05000329 S
PDR OC0583-0017A-MP01 gyg3 g 3 E27
I i
l 2
82-12 #3 Serial 22207 CC: CBechhoefer, ASLB Panel FPCowan, ASLB Panel JHarbour ASLB Panel AS&L Appeal Panel MMCherry, Esq MSinclair BStamiris CRStephens, USNRC WDPaton, Esq. USNRC FJKelley, Esq, Attorney General SHFreeman, Esq, Asst Attornel General WHMarshall CJMerritt, Esq, TNK8J INPO Records Center t
l l
(
l i
l h
OC0583-0017A-MP01 i
I
(
t.
l Atta hment 1 1i3942 Bechtel Associates Professional Corporation Ii4066
SUBJECT:
MCAR 63 (Issued 11/10/82)
Design of Steel Embedmonts That Use Shear Lugs Located in Tension Zones INTERIM REPORT 3 DATE:
May 3, 1983 PROJECT:
Consumers Power Company Midland Plant Units 1 and 2 Bechtel Job 7220 Introduction This report addresses a concern with the design of steel embedmonts in concrete that use shear lugs located in tension zones.
Backaround 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 accousmodate shear loads and tension bars to accommodate tension loads. Other than ACI 349, Appendix B, no known design code or industry standard issued before ACI 349, Appendix B, restricts the design of embedmonts using shear lugs.
For embedmonts within the scope of this NCAR, the Midland Final Safety Analysis Report, Section 3.8, is cousaitted 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 embedmont design.
Investiaative Action An evaluation to determine which of the embedments identified have shear lugs located in tension zones has been essentially completed for the existing loads.
To determine if the embedments installed in the Midland plant are capable of performing their safety function, a testing program is I
being prepared at the University of Michigan. The purpose of the testing program is to determine the effectivity of shear lugs k
located in tension zones. The investigative action is expected to be completed in approximately 6 months.
0348u
- -,.- _ - _ _ _ _ _, _ n _,w,
-.my_.-,,.e-?,-,~~
li3942 Bechtel Associates ProfessionalCorporation Ii4066 HCAR 63 INTERIM REPORT 2 Page 2 Probable Ceuse The apparent root cause is that before issuance of ACI 349, Appendix B, this possible behavior of shear lugs in tension zones was not recognized by codes or industry standards, t
Corrective Action To enable new designs and modifications to existing designs to be completed, an interim embedment design criterion is being developed for use before completion of the testing program. After completic.n of investigative actions, the embedment criterion will be finalized for all design and evaluation. However, no final corrective action has been established at this time.
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 it may not be capable of performing its required safety function.
Reportability This concern is considered potentially reportable in accordance with Title 10 of the Code of Federal Regulations, Part 50.55(e).
1 i
l i
l l
0348u
~ - mam m m ~ ~ m * ~ ~" "' " ~ ~ ~ ~
-~nma
li3942 Bechtel Associates Professional Corporation Ii4066
,c,,g3 INTERIM REPORT 2 Page 3 Submitted p
S.L. Sobkowski g4 Civil / Structural Group Supervisor Mkb Approved by:
E.M. Hughes
\\h Project Engineer l
concurrence by:
141 T.E.J%fson l
Civil Discipline Chief I
Concurrence by:
E.H. Smith
~
Engineering Manager Concurrence by:
M.A. Dietrich Project Quality Assurance Engineer i
l 0348u
~~_-----..-..-,n,n_.n...e--.2.--~~~.
..