ML19338G581
| ML19338G581 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 10/23/1980 |
| From: | Reed C COMMONWEALTH EDISON CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8010310280 | |
| Download: ML19338G581 (2) | |
Text
f^'N Commonwealth Edison
/
) One First Natiorni Pina Chicrgo, Illinois
- ^ J Address Reply to: Post Office Box 767
\\
/ Chicago, Illinois 60690 October 23, 1980 Mr. Harold R.
Denton, Director Of fice of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555
Subject:
Zion Station Units 1 and 2 Additional Information on Steam Generator J-Tube Installation NRC Docket Nos. 50-295 and 50-304 References (a):
June 20, 1979, letter from Cordell Reed to A. Schwencer.
(b):
October 1, 1980, letter from K. L.
Graesser to J. G. Keppler.
Dear Mr. Denton:
In Reference (a), Commonwealth Edison Company confirmed its commitment that J-tubes would be installed in all the Zion Station steam generators at a rate of one steam generator per refueling outage.
To date, Commonwealth Edison has installed J-tubes on IC, 2C, and 2D steam ca erators with 10 planned for the next Unit 1 refueling outage uled to commence in Janua 1981.
Refereice 2 contained Special Report 50-)J4/80-02 on the Zion Unit 2 water hammer event of September 4, 1980.
As concluded in this report, the water hammer event was the same as previous events and with the installation of J-tubes the likelihood of such an event will be greatly reduced.
In addition, procedure changes were made to first reduce, after unit trips, the auxiliary feedwater flow to those steam generators not equipped with J-tubes.
By specifying the order of throttling, the procedure change should limit auxiliary feedwater flow transients in steam generators without J-tubes and thus also reduce the likelihood of future water hammer events, j
Af ter the water hammer event of September 4,
- 1980, Commonwealth Edison reassessed its schedule for J-tube installation.
Noting that TMI modifications have the higher priority and contingent upon qualified manpower availability, Commonwealth Edison will make every ef fort to install J-tubes on 1D and 1A steam generators during the next Unit I refueling outage.
The last steam generator, 1B, will be modified during the Spring 1982 refueling outage.
Also contingent upon manpower requirements, a similar effort will be made to complete the Unit 2 modifications during the 1981 refueling outage, i.e.,
steam generators 2A and 28.
8 010 810,2PO
[
Please address any questions that you might have concerning this matter to this of fice.
One (1) signed original and thirty-nine (39) copies of this letter are provided for your use.
Very truly yours, I
i-c..-
C. Reed Vice President cc:
Resident Office - Zion
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