ML20023D411
| ML20023D411 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 05/03/1983 |
| From: | Garrity J Maine Yankee |
| To: | Allan J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| 0930L, 930L, JHG-83-84, MN-83-78, NUDOCS 8305200467 | |
| Download: ML20023D411 (2) | |
Text
T LN MAME %]HAllHEE Aleml0P0lilER00MPARS*
,uaugr,j,$gy"g
>WN (207) 623-3521
_-Q May 3, 1983 MN-83-78 JHG-83-84 Region I United States Nuclear Regulatory Commission Office of Inspection and Enforcement 631 Park Avenue King of Prussia, Pennsylvania 19406 A
Attention: Mr. James M. Allen, Deputy Administrator
Reference:
(a) License No. DPR-36 (Docket No. 50-309)
Subject:
Containment Weight of Air Monitoring System
Dear Sir:
Maine Yankee Atomic Power Company hereby submits the following report in accordance with Technical Specification 3.11.D.1.
On Friday, April 8 at 1600, while at steady-state full power operation, fluctuations on the order of 1400-500 lbm were observed in the real time computer-calculated " containment weight of air" parameter used to monitor and trend containment leaktightness. These fluctuations were determined to have started not more than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> earlier.
1 Hand calculations of containment weight of air were initiated. These calculations indicate the weight of air fluctuation is not real.
An investigation showed that the output of the Exactel Servo-Manometer, which provides containment pressure input to the computer calculation, was fluctuating. The cause of the fluctuation was believed to be a recirculation i
fan failure in the Exactel.
l l
On April 15, 1983, the NRC resident inspector was notified that the containment weight of air monitoring system was out of service and was informed of plans to restore system operability.
l l
Since discovery of the recirculation fan failure on April 10, 1983, operations personnel performed manual containment weight of air calculations twice per shift. The calculations utilized the same equations and parameters as the on-line computer program, except for the substitution of containment narrow range manometer reading for the Exactel pressure input.
8305200467 830503 PDR ADOCK 05000309 q
/r S
PDR D
0930L - SEN t
F-
]
a MAINE YANKEE ATOMIC POWER COMPANY
/
United States Nuclear Regulatory Commission May 3, 1983 Attent. ion: Mr. James M. Allen, Deputy Administrator Page Two MN-83-78 A new air recirculation fan was received and installed on April 23, 1983.
This corrected the fluctuation, however, calibration was necessary prior to returning the Exactel to service.
Calibration of the Exactel was completed on April 29, 1983 and it returned to service on May 2, 1983. Hand calculations continued, however, until operations personnel could verify the accuracy of the Exactel output.
We trust that this information is satisfactory.
If you have any further questions, please contact us.
Very truly yours, MAINE YANKEE ATOMIC POWER COWANY Wl
'lf g
dk NWw John H. Garrity, Senic r Director Nuclear Engineering ard Licensing JHG:pjp cc: Mr. Robert A. Clark Mr. Paul A. Swetland 0930L - SEN