B16403, Forwards Root Cause Analysis & Residual Strength Assessment, Porous Concrete Matls Properties Evaluation & Containment Structure Seismic Assessment in Response to Rai,

Forwards Root Cause Analysis & Residual Strength Assessment, Porous Concrete Matls Properties Evaluation & Containment Structure Seismic Assessment in Response to Rai,

ML20138E627
Person / Time
Site:	Millstone
Issue date:	04/30/1997
From:	Brothers M NORTHEAST NUCLEAR ENERGY CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20138E631	List: B16403, Forwards Root Cause Analysis & Residual Strength Assessment, Porous Concrete Matls Properties Evaluation & Containment Structure Seismic Assessment in Response to Rai, ML20138E639 ML20138E647
References
B16403, NUDOCS 9705050068
Download: ML20138E627 (5)

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o Northeast ""P" '"Y "d - ( """" T'* **d"'d "f ""3"T' Nuclear Energy nautone Nuarar ro.er staiion Northca.it Nudear Energy Onnpany P.O. Hoa 128 Waterford, Ur 0638T,-0128 (860) 447 1791 l'as (860) 444 4277

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ne Nordient Utdities Systnn APR 30 1997 l l

Docket No. 50-423 )

B16403 i l

U.S. Nuclear Regulatory Commission '

Attention: Document Control Desk Washirtgton, DC 20555 i

Millstone Nuclear Power Station Unit 3  !

Response to Request for Additional information on Erosion d Cement frora the Underivina Porous Concrete Drainaac System. Millstc orinit No. 3

?n a letter dated April 11, 1997, the NRC Staff requested addit:onal information  !

regrading the erosion of cement from ths underlying porous concrete drainage system at Millstone Unit No. 3. The Staff requested copies of the following reports: the root 4

cause analysis and residual strength assessment, the porous concrete materials properties evaluation, and the containment structure seismic assessment.

We are providing these reports in Attachment 2 to this letter. The root cause analysis and residual strength assessment are contained in the attached CTL report dated i April 11,1997. The porous concrete materials propenies evaluation is contained in Section 4 of the attached gel report dated March 14, 1997, and the containment  !

structure seismic assessment is contained in Section 3 of the same report. Our commitments associated with this letter are provided in Attachment 1.

Should you have any questions or require additional information please contact Mr. James M. Peschel at (860) 437-5840.

Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY

[

NH NO M. H. Brothers 1 Vice President - Millstone Unit No. 3 ()/

Attachments cc: See Page 2 9705050068 970430 PDR ADOCK 05000423 P PDQ

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. U.S. Nuclear Regulctory Commission B16403\Page 2 oc: H. J. Miller, Region l Administrator W. D. Travers, PhD, Director, Special Projects Office J. W. Andersen, NRC Project Manager, Millstone Unit No. 3 4

A C. Corne, Senior Resident inspector, Millstone Unit No. 3 4

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A Docket No. 50 423 B16403 Attachment 1 Millstone Nuclear Power Station Unit 3 Response to Request for Additional information on Erosion of Coment from the Underlying Porous Concrete Drainage System NNECO's Commitments i

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April 1997 l

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U.S. Nuclear Regulttory Commission i

B16403%ttachment 1\Page 1 Enclosure List of Regulatory Commitments The following table identifies those actions committed to by NNECO in this document. <

Any other actions discussed in the submittal represent intended or planned actions by NNECO. They are described to the NRC for the NRC's information and are not regulatory commitments. Please notify the Manager - Nuclear Licensing at the

! Millstone Nuclear Power Station Unit No. 3 of any questions regarding this document or any associated regulatory commitments.

a l Commitment Committed Date or

Outage i None N/A i

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Docket No. 50-423 B16403 i

Attachment 2 Millstone Nuclear Power Station Unit 3 Response to Request for Additional Information on Erosion of Cement front the Underlying Porous Concrete Drainage System Underivino Porous Concrete Evaluations and Assessments April 1997