ML20052D184
| ML20052D184 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 03/23/1982 |
| From: | Lentine F COMMONWEALTH EDISON CO. |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.F.2, TASK-TM 3696N, NUDOCS 8205060344 | |
| Download: ML20052D184 (2) | |
Text
j'^X Commonwealth Edison M
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) one Fast Hitional Ptara. chicago. lihnois
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l Addr:ss Reply to: Post Othce Box 767 g
Chicago, Ithnois 60690 O
March 23, 1982 v
Mr. Darrell G.
Eisenhut, Director Division o f Licensing U.S.
Nuclear Regulatory Commission e
Washington, DC 20555 g
p, s
Subject:
Zion Station Unit 2 F
g 51982i' j0 NUREG 0737 Item II.F.2
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.a s Reactor Vessel Level o
- a Indicating System (RVLIS)
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NRC Docke t No. 50-304
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- sg References (a)
Decembe r 15, 1981, lette r from E. Swartz to D.
G. Eisenhut.
(b):
July 30, 1981, letter from L. DelGeorge to D. G.
Eisenhut.
Dear Mr. Eisenhut:
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This is to confirm our understanding a f the agreement reached in telephone conversations with Messrs. D. A. Wigginton and S.
A. Va rga o f your o f fice on March 12 and March 15, 1982, respectively, regarding the status o f RVLIS at Zion Station.
Tha t agreement permitted startup of Unit 2 with RVLIS out o f service.
The basis for that agreement is as follows.
As you know, NUREG 0737 item II.F.2 requires a "preimplementation review" o f RVLIS "before use as a basis for operator decisions."
The NRC has not yet completed that review.
Nevertheless, by mutual agreement between Commonwealth Edison and the NRC staff, RVLIS was made operational on Unit 2 in the Fall, 1980, and on Unit 1 in Spring, 1981, in order to gain experience in how the device responds, and to f acilitate testing, calibration and operator training.
Since that time, valuable experience has been obtained regarding the performance of RVLIS in an nperating plant.
The Unit 2 RVLIS was taken out of service at the last re fueling outage in November, 1981, due to a high pressure fitting leak at the reactor vessel head.
This leak allowed borated reactor coolant water to get into and damage the control rod drive mechanisms, resulting in a ten day extension of the outage.
As a result o f this occurrence, we have undertaken a review o f the design of the high pressure RVLIS connections with the objective o f identi-fying improvements that can oe made to reduce the susceptibility of 9,
the sytem to leaks and to facilitate disconnection o f the system for O
3 82050603g4 4
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j D.
G.
Eisenhut March 23, 1982
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refueling operations.
Modifications under consideration include the installation o f a protective structure over the existing swagelock fitting and high pressure tubing, and replacement o f the swagelock fitting with another type o f high pressure connection.
It is Commonwealth Edison's position that the RVLIS should remain out o f service until these improvements can be made.
Our schedule for implementation of these improvements on Unit 2 is as follows.
Design o f the proposed modifications is expected to be completed about April 19, 1982.
It would be our intention, then, to install these modifications at the next refueling outage, presently scheduled for Spring, 1983.
Ho we ve r,
should a unit outage occur that requires a cold shutdown and reactor coolant system depressurization of sufficient duration to complete the installation, the modifications would be installed at that time.
Based on preliminary design information, it is estimated that a period of five days would be sufficient to complete the installa-tion.
A number o f additional modifications are being considered for improvement o f the system's reliability, serviceability, and environmental qualification.
However, as stated previously in
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reference (b), none of these additional modifications will be made until the NRC has completed its review of RVLIS.
j Please address questions regarding this matter to this office.
Very truly yours, F.
G.
Lentine Nuclear Licensing Adminstrator 1m cc:
Zion Resident Inspector 3696N I
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