ML19289D762

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Deficiency Rept on RHR Heat Exchanger Relief Valve.Current Design Does Not Conform to ASME Stds.Larger Relief Valves Will Be Installed
ML19289D762
Person / Time
Site: Fermi DTE Energy icon.png
Issue date: 03/02/1979
From: Fahrner W
DETROIT EDISON CO.
To: James Keppler
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
EF2-44360, NUDOCS 7903140367
Download: ML19289D762 (1)


Text

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March 2, 1979 EF2-44360 Mr. James G. Keppler Directorate of Regulatory Operations United States Nuclear Regulatory Commission Region III, 799 Roosevelt Road Glen Ellyn, Illinois 60137

Reference:

10 CFR 50.55(e) Potential Deficiency Report Telephone conversation of February 5, 1979 to NRC Region III

Subject:

10 CFR 50.55(e) Deficiency Report on RHR Heat Exchanger Relief Valve

Dear Mr. Keppler:

Pursuant to the provisions of 10 CFR 50.55(e)(3) this report is being filed as an official response to our initial 10 CFR 50.55(e) telephone conversation with your Mr. D. Hayes on Monday, February 5, 1979.

We have completed our evaluation of the deficiency in sizing of the relief valves (F055A and B) on RHR heat exchangers when used in the steam condensing mode. The current design, with steam talieving capacity of 21,000 lbs/hr at 450 psig, does not conform to the criteria and bases of ASME Boiler and Pressure Vessel Code,Section III, NC-7000. Larger relief valves and associated piping will be instal-led to fully meet the code requirements using the following design criteria:

e The total rate relieving capacity of the relief valve shall be sufficient to prevent a rise in pressure of more than 110% above the design pressure of the RilR heat exchanger.

e Under the steam condensing mode of RHR heat c:cchanger , the pressure control valves F051A or B shall be considered fully open and the discharge from the heat exchanger shall be considered blocked by closed valve F003A or B.

Sincerely,

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%.u W. J. Fahrner e Project Manager WJF: ghn HitD:vr . Enrico Fermi Unit 2 O cc: Mr. E. Volgenau, Director United States Regulatory Commission 1 Office of Inspec* ion and enforcement I Division of I.eactor I...,pection Programs Ji D. C. 2e555 b-

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