ML20100N865

Amended Final Deficiency Rept,Item 116 Re Potential Design Deficiency Allowing Freezing of Buried Piping Sys.Walls Will Be Installed & Temp Monitored.Pipes Will Not Be Rerouted

ML20100N865
Person / Time
Site:	Fermi
Issue date:	11/30/1984
From:	Jens W DETROIT EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
116, EF2-70220, NUDOCS 8412130521
Download: ML20100N865 (2)

Text

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Coyne H. Jens V

. , ' Vb) Ruhm Nuclear Oper:.t:ons DNehtWt 6400 North Dune Hghway

% Q y . g y 7 4aies November 30, 1984 EF2-70220 Mr. James G. Keppler Regional Administrator Region III U. S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137

Dear Mr. Keppler ,

References (1) Fermi 2 NRC Docket No. 50-341 (2) Letter, D. A. Wells to J. G. Keppler, February 29, 1984, QA-84-326 (3) Letter, W. H. Jens to J. G. Keppler, August 23, 19 84, EF2-69 69 8.

Subject:

Amended Report of 10CFR50.55(e), Item 116

" Potential Design Deficiency Allowing Freezing of Buried Piping Systems" This letter amends Reference 3, Detroit Edison's final report of 10CFR50.55(e), Item 116, " Potential Design Deficiency Allowing Freezing of Buried Piping Systems". As stated in Reference 3, sections of the fire protection supply lines to the Residual Heat Removal Complex could be subjected to freezing temperatures. The concrete walls in which these pipes are embedded do not provide sufficient protection during severe cold weather. Detroit Edison stated that design efforts were in progress to reroute these pipes to provide protection from cold weather.

During the design process, it was determined that adequate protection from freezing could be provided by adding insula-tion to the outside of the wall in which the pipes are embedded. Therefore, insulation will be added, and the affected pipes will not be rerouted.

D A 0

/

Mr. James G. Keppler November 30, 1984 EF2-70220

, Page 2 To verify the effectiveness of this solution, instrumenta-tion will be installed to allow monitoring of the tempera-ture between the outside wall and the new insulation. The inside wall is exposed to the RHR reservoir and the air space above the reservoir and below the Emergency Diesel Generator Room. The reservoir, which was frozen when the affected pipes were frozen, is normally maintained at a temperature greater than 43 0F. The air space temperature will also be monitored. The data collected during the 1984/1985 Winter will be used to validate calculation assumptions and determine if the added insulation will be sufficient during an abnormally severe winter, i

During the 1984/1985 Winter, while the effectiveness of the insulation is being evaluated, a continuous flow at a rate sufficient to prevent freezing will be maintained in both of the affected pipes.

If you have any questions concerning this matter, please contact Mr. Lewis Bregni, (313) 586-5083.

Sincerely, cc Mr. P. M. Byron Mr. R. C. DeYoung Mr. R. C. Knop USNRC Document Control Desk Washington, D.C. 20555

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