ML20073T174

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Requests That 830418 Proposed Amend to Tech Specs to Revise Setpoint for Upper Head Injection Accumulator Automatic Isolation Be Changed to Incorporate Revised Setpoint Calculation
ML20073T174
Person / Time
Site: Mcguire, McGuire  Duke Energy icon.png
Issue date: 05/04/1983
From: Tucker H
DUKE POWER CO.
To: Adensam E, Harold Denton
Office of Nuclear Reactor Regulation
Shared Package
ML20073T175 List:
References
TAC-51383, TAC-51384, NUDOCS 8305100383
Download: ML20073T174 (2)


Text

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Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Attention: 18. E. G. Adensam, Chief Licensing Branch No. 4 Re: McGuire Nuclear Station Docket Nos. 50-369, 50-370

Dear Mr. Denton:

Our letter of April 18, 1983 contained proposed amendments to McGuire Units 1 and 2 Technical Specifications to revise the setpoint for Upper Head Injection (UHI) accumulator automatic isolation. We have since discovered a problem with the calculation of the setpoint tolerance. Thus, we request that the proposed amendment be changed to incorporate a setpoint tolerance of 13.3 inches instead of 14.5 inches as originally requested. Attached is a revised page 3/4 5-4 of the Technical Specifications showing the proposed change.

The problem with the calculation mentioned above concerned the conversion factor used in determining the setpoint tolerance which is equivalent to the level switch repeatability of 166.4 ft.3 shown in Attachment 3 of our previous submittal. This conversion factor is determined based upon the dimensions of the accumulator tank to relate volume (ft.3) to level (inches). This relationship varies with tank level, because the tank sides are not vertical. The correct conversion factor was determined by finding the volume at two different levels and relating the change in volume to the change in level. The two different levels were chosen approxi-mately one inch above and below the nominal level setpoint of 73.7 inches. Pre-viously the conversion factor was determined using levels significantly farther from the nominal level setpoint resulting in a non-representative conversion factor. Please note that the problem with the previous calculation only affects the determination of the setpoint tolerance and does not affect the uncertainty analysis shown in Attachment 3 of our previous submittal.

The reason for this change to our previous submittal has been discussed with the NRC staff, and we apologize for any inconvenience caused by this change. Please advise, if there are further questions.

Very truly yours, l A"2- D Hal B. Tucker d REH:jfw 8305100383 830504 PDR ADOCV 05000369 p PDR

r Harold R. Denton ,

May 4, 1983 Page 2 cc: Mr. James P. O'Reilly, Regional Administrator U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, Suite 2900 Atlanta, Georgia 30303 Mr. W. T. Orders NRC Resident Inspector McGuire Nuclear Station