ML20010A475

Interim Deficiency Rept Re Shear Reinforcement at Major Containment Penetrations.Review & Confirmation of Design Adequacy of All Major Penetrations Will Continue.Next Rept Expected by 811214

ML20010A475
Person / Time
Site:	Midland
Issue date:	07/31/1981
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, 12066, 81-05-#2, 81-5-#2, 81-5-2, NUDOCS 8108110460
Download: ML20010A475 (4)

Text

r ,

/N18/50M(+

O consumers Power James W Cook Vice President - Projects, Engineering and Ce nstruction General Offices: 1945 West Parnalt Fload, Jackson, MI 49201 * (517) 788-0453 t-05 #2 July 31,1981 p IiOff Q

s

,i Mr J G Keppler, Regional Director Office of Inspection & Enforcement  !

k g1 0 gB1F N jl US Nuclear Regulatory Commission

( El Region III 9# .%

799 Roosevelt Road g j Glen Ellyn, IL 60137 i-

% E-MIDLAND PROJECT -

DOCKET NOS 50-329 AND 50-330 SHEAR REINFORCEMENT AT MAJOR CONTAINMENT PENETRATIONS FILE: 0.4.9 53 SERIAL: 12066

Reference:

J W Cook letter to J G Keppler, Same Subject, Serial 11993, dated May 15, 1981 This letter, as is the referenced letter, is an interim 50 55(e) report concerning the adequacy of shear reinforcements at major contairs t penetrations.

Attachment 1 provides a description of the corrective actions beiag taken to correct the condition.

Another report, either interim or final, will be sent on or before December 14, 1981.

I M ' ( .. _

WRE/lr Attachment (1): MCAR 51, Interim Report 2, " Shear Reinforcement at Containment Building Major Penetrations," dated July 17, 1981 $6N CC: Director of Office of Inspection & Enforcement Att Mr Victor Stello, USHRC (15) l\

Director, Office of bhnagement Information & Program Control, USNRC (1)

RJUook, USNRC Resident Inspector Midland Nuclear Plant (1) 8108110460 810731' PDR ADOCK 05000329 s PDR AUG 5 . 19 81

Serial 12066 2 81-05 #2 CC: CBechhoefer, ASLB Panel RSDecker, ASLB Panel FPCowan, ASLB Panel AS&L Appeal Panel MMCherry, Esq MSinclair BStamiris CRStephens, USNRC WDPaton, Esq, USNRC FJKelly, Esq, Attorney General SHFreeman, Esq, Asst Attorney General Wh7arshall GJMerritt ,1sq, TUK&J

.c . . -

Attachment 1 036860 Bechtel Associates Professional Corporation serial 12066 81-05 #2

SUBJECT:

MCAR 51 (issued 4/21/81)

Shear Reinforcement at Containment Building Major Pene-trations INTERIM REPORT 2 Date: July 17, 1981 PROJECT: Consumers Power Company Midland Plant Units 1 and 2 Bechtel Job 7220 '

Introduction The discrepancies discussed in this report concern the amount of radial shear reinforcement provided around the containment building major penetrations.

Backg round While examining drawings for the containment shell, it was determined that there is less radial shear tie reinforcement around the equipment hatch, personnel lock, and the emergency airlock penetrations than in other projects of similar design. The design for these areas was com-pleted in November 1973, the drawings for the equipment hatch were issued for construction in July 1974, and the containment walls for Units 1 and 2 were constructed in 1976 and 1977.

Investigative Action The equipment hatch and personnel lock calculations have been reviewed, including the finite element model for the equipment hatch. Radial shear stresses at a vertical and a horizontal section around the equipment t.atch were calculated for the corresponding governing load

! combination:

(1.05D + F + 1.5P + TA )

where D = dead load F = prestressing load P = accident pressura load TA = thermal loads based on a temperature corresponding to accident pressure

o

~.  :.

. Bechtel Associates Professional Corporation MCAR 51 Interim Report 2 036660 July 17, 1981 Page 2 These shear stresses were found to meet the acceptance criteria.

Because some of the modeling assumptions and input parameters made in the original analysis can be questicaed, an independent analysis and design check of the equipment hatch, personnel lock, and other major penetrations are being made to confirm the findings of the calculation review.

Corrective Action Based upon the results of the ongoing analysis, the need for design modifications, if any, will be established. Review and confirmation of the design adequacy of all .najor penetrations will continue and findings from this ef fort will be presented in the next interim report.

In the course of this review, discrepancies in Section 3.8.1.5.1.3 of the FSAR were noted and will be amended. In addition, any other changes deemed nececsary as a result of this review will be made.

Safety Implications If the results of the ongoing analysis indicate a deficiency in the design, this deficiency could possibly adversely affect the safety of the Midlad plant.

Reportability This condition was reported to the NRC by Consumers Power Company as "potentially reportable" under 10 CFR 50 55(e) on April 17, 1981.

Submitted by h D((

Approved by: M-  % L.H.( upT14 Concurrence by: ,

SS/ LED /bjm

- _,r- - - , ,