ML20129E034

Requests Addl Info Re Porous Concrete sub-foundation at Unit 3

ML20129E034
Person / Time
Site:	FitzPatrick
Issue date:	10/22/1996
From:	Cotton K NRC (Affiliation Not Assigned)
To:	William Cahill POWER AUTHORITY OF THE STATE OF NEW YORK (NEW YORK
References
NUDOCS 9610250246
Download: ML20129E034 (4)

Text

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• Mr. Williaa J.-Cahill, Jr. October 22, 1996 ,

i Chief Nuclear _0fficer 4

,Pcwsr Authority of the' State of 4 New York 123 Main Street White Plains, NY 10601 i '

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION CONCERNING POROUS CONCRETE j SUB-FOUNDATION i

Dear Mr. Cahill:

4 j The NRC has been evaluating the reported eros' ion of cement from under the containment foundation basemat at Millstone 3. The Millstone Unit 3 i containment foundation'basemat is supported on rock; however, between the rock surface and the underside of the structural concrete basemat there are several l layers of material, one of which is _ a 9-inch thick porous concrete layer i consisting of coarse stone' aggregates and high alumina cement. Six-inch '

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diameter porous concrete pipes are installed in this porous concrete layer to i collect and drain ground water which may seep down along the periphery of the  ;

containment wall. The collected water drains into two sumps inside the  !

e Engineered Safety Features Building. Cement slurry has been observed in these l 4

sumps. Based on our review of the information provided to us so far, there in l

} no immediate safety concern because the amount of cement estimated to have possibly eroded since the plant was built in 1975 is only a small fraction of 1

the total cement weight of the porous concrete, and because no adverse i consequences of the cement erosion are either predicted or have been observed

! at Millstone 3. With regards to any generic implication of this issue on i

other containment foundations with similar design, the staff has identified additional plants for which it requires more detailed information, including

FitzPatrick.

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! Enclosed is a request for additional information. Please provide your j response within 14 days from receipt of this letter.

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Sincerely,

/S/

l i Karen R. Cotton, Acting Project Manager Project Directorate I-1 kk $$$ oko0$$33 Division of Reactor Projects - I/II p PDR Office of Nuclear Reactor Regulation

! 4 i Docket No. 50-333 l j

Enclosure:

As stated l i

DISTRIBUTION:

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{ 250071 g i

] DOCUMENT NAME: G:\FITZ\BASEMAT.KC i To receive a copy of this document, indicate in the box: "C" - Copy without i

attachment / enclosure "E" - Copy with attachment / enclosure "N" - No copy j OFFICE PM:PDI-1 j ,lE LA:PDI-1 @ l PD:PDI-1 . l l l NAME KCotton/rst' {AL SLittl # S8elwe //717 i DATE 10/AJM 10/ 2//% 10/ w / % 10/ /% 10/ /%

Official Record Copy 4

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, p 4 UNITED STATES

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' NUCLEAR REGULATORY COMMISSION f WASHINGTON, D.C,2006H001 g , / October 22, 1996 Mr. William J. Cahill, Jr.  !

Chief Nuclear Officer Power Authority of the State of i New York 123 Main Street l j White Plains, NY 10601 l

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION CONCERNING POROUS CONCRETE i

SUB-FOUNDATION 4

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Dear Mr. Cahill:

The NRC has been evaluating the reported erosion of cement from under the containment foundation basemat at Millstone 3. The Millstone Unit 3 containment foundation basemat is supported on rock; however, between the rock

' surface and the underside of the structural concrete basemat there are several layers of material, one of which is a 9-inch thick porous concrete layer consisting of coarse stone aggregates and high alumina cement. Six-inch diameterporousconcretepipesareinstalledinthisporousconcretelaierto collect and drain ground water which may seep down along the periphery of the containment wall. The collected water drains into two sumps inside the i

Engineered Safety Features Building. Cement slurry has been observed in these  ;

sumps. Based on our review of the information provided to us so far, there is i no immediate safety concerr because the amount of cement estimated to have l

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possibly eroded since the L ant was built in 1975 is only a small fraction of  ;

the total cement weight of the porous concrete, and because no adverse  !

consequences of the cement crosion are either predicted or have been observed at Millstone 3. With regards to any generic implication of this issue on 4

other containment foundations with similar design, the staff has identified additional plants for which it requires more detailed information, including FitzPatrick, i

! Enclosed is a request for additional information. Please provide your response within 14 days from receipt of this letter.

Sincerely, 44L &

Karen R. Cotton, Acting Project Manager Project Directorate I-1 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation Docket No. 50-333

Enclosure:

As stated N

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William J. Cahill, Jr. James A. FitzPatrick Nuclear Power Authority of the State Power Plant of New York cc:

j Mr. Gerald C. Goldstein Regional Administrator, Region I

Assistant General Counsel U.S. Nuclear Regulatory Commission Power Authority of the State 475 Allendale Road of New York King of Prussia, PA 19406

. 1633 Broadway i New York, NY 10019 Mr. F. William Valentino, President New York State Energy, Research, Resident Inspector's Office and Development Authority U. S. Nuclear Regulatory Commission 2 Rockefeller Plaza j P.O. Box 136 Albany, NY 12223-1253 Lycoming, NY 13093 Mr. Richard L. Patch, Director Mr. Harry P. Salmon, Jr. Quality Assurance Resident Manager Power Authority of the State i James A. FitzPatrick Nuclear of New York

Power Plant 123 Main Street P.O. Box 41 White Plains, NY 10601 Lycoming, NY 13093 Mr. Gerard Goering Ms. Charlene D. Faison 28112 Bayview Drive 4

Director NurJear Licensing Red Wing, MN 55066

! Power Author'.ty of the State of New York Mr. James Gagliardo 123 Main Street Safety Review Committee White Plains, NY 10601 708 Castlewood Avenue Arlington, TX 76012 Town of Scriba Mr. Arthur Zaremba, Licensing Route 8, Box 382 Manager Oswego, NY 13126 James A. FitzPatrick Nuclear Power Plant Mr. Robert G. Schoenberger, P.O. Box 41 Vice President Lycoming, NY 13093 and Chief Operating Officer Power Authority of the State of New York 123 Main Street White Plains, NY 10601 Charles Donaldson, Esquire Assistant Attorney General New York Depirtment of Law 120 Broadway New York, NY 10271

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i RE0 VEST FOR ADDITIONAL INFORMATION i CEMENT EROSION UNDER CONTAINMENT FOUNDATION  !

l Your plant appears to have a porous concrete layer below the containment basemat. l

1. Have you found slurry in the drainage from this layer?

2. Has there been any settlement of the containment basemat?

3. Have you noticed any unusual conditions which may be related to the porous concrete sub-foundation layer?

4. Are you monitoring anything related to the drainage from the porous concrete sub-foundation layer (s) below the containment basemat?

5. Is calcium aluminate (high alumina) cement used as a constituent in the porous concrete mix?

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1 Enclosure

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