ML20203A540

Advises That Subj to Listed Insp Requirement,Applicant Criteria on Chloride Content for Category I Concrete Structures Acceptable.Insps Should Be Conducted Every Yr to Establish Listed Changes to Structures

ML20203A540
Person / Time
Site:	Braidwood
Issue date:	04/09/1986
From:	Noonan V Office of Nuclear Reactor Regulation
To:	Farrar D COMMONWEALTH EDISON CO.
References
NUDOCS 8604160437
Download: ML20203A540 (4)

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k p, UNITED STATES NUCLEAR REGULATORY COMMISSION O j WASHINGTON, D. C. 20555

%.....# Apg t 896 Docket Nos.: 50-456 .

and 50-457 Mr. Dennis L. Farrar Director of Nuclear licensing Commonwealth Edison Company P.O. Box 767 Chicago, Il 60690

SUBJECT:

cpl 0 RIDE CONTENT FOR THE CATEGORY I CONCRETE STRUCTURES AT BRAIDWOOD STATION, UNITS I and 2 During the FSAR review for Braidwood Station, a question was raised concerning the chloride content and frequency of testing of concrete for compressive strength for the Category I concrete structures. The applicant provided a response to the staff concern in FSAR Question 421.19 (Amendment 36). The staff subsequently provided a safety evaluation report concerning this issue.

Subject to the inspection requirement described below, the staff found the applicant's criteria on chloride content for the Category I concrete structures acceptable based on the following facts: (1) the average compressive strength of the concrete was determined to be well above the design strength (5265 psi vs. 3500 psi), (2) the total average chloride content in water, cement and admixtures for the concrete at the site is much lower than the threshold level that would result in corrosion of I the reinforcing steel with the concrete (0.025% vs. 0.15%) and, (3) the l chloride content of the cement paste portion of the concrete used in the l prestressed containment structures is slightly higher than the amount considered acceptable by the ASME/ACI design code (170 ppm vs. 150 ppm). However, the reinforcing steel tendons are sheltered by greased  ;

protective ducts. l To monitor long term effects of potentially excessive chloride content, the staff requires that an inspection program be established by the applicant to provide periodic visual inspections of parts of the Category I, structures affected by the chlorides (especially portions of the concrete structures and the tendons galleries which are below grade). We recommend inspections be conducted every year in order to establish (1) accumulation of chloride deposits, (2) discoloratfdh of concrete (possibly rust by deteriorating reinforcing steel), (3) cracks, and (4) changes from previous observations. The areas of inspection should be established by the applicant and approved by the staff.

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, M4 3g-4 Mr. Dennis L. Farrar For further clarification, please contact Ms. J. A. Stevens, the licensing Project Manager at (301) 492-7702.

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i Mr. William Kortier Ms. l.orraine Creek Atomic Power Distribution Route 1, Box 182 Westinghouse Electric Corporation Manteno Illinois 60950 Post Office Box 355 4 Pittsburgh, Pennsylvania 15230 Douglass W. Cassel,Esq.

109 N. Dearborn Street Joseph Gallo, Esq. Chicago, Illinois 60602 Isham, Lincoln & Beale 1150 Connecticut Ave., N. W. Elena Z. Kezelis, Esq.

Suite 110 Isham, licoln & Beale Washington, D.C. 20036 Three First National Plaza Suite 5200

C. Allen Bock, Esq. Chicago, Illinois Post Offices Box 342 Urbana, Illinois 61801 Mr. Charles D. Jones, Director 4

Illinois Emergency Services j Thomas J. Gordon, Esq. and Disaster Agency l Waaler, Evans, & Gordon 110 East Adams 2503 S. Neil Springfield, Illinois 62706 Champaign, Illinois 4

Ms. Bridget little Rorem George L. Edgar Appleseed Coordinator Newman & Poltzinger, P.C.

117 North I.inden Street 1615 L Street, N. W.

Essex, Illinois 60935 Washington, D. C. 20036 Mr. Edward R. Crass Nuclear Safeguards and I.icensing Division Sargent & l. undy Engineers 55 East Manroe Street

! Chicago, illinois 60603 U. S. Nuclear Regulatory Commission Resident Inspectors Office RR#1, Box 79 Braceville, Illinois 60407 _.

Regional Administrator, Region III U. S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137

Art' 9 M Mr. Dennis L. Farrar For further clarification, please contact Ms. J.A. Stevens, the licensing Project Manager at (301) 492-7702.

Vincent S. Noonan, Director PWR Project Directorate No. 5 Division of PWR't.icensing-A cc: See next page Distribution:

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