ML18036B128
| ML18036B128 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 12/23/1992 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML18036B127 | List: |
| References | |
| 50-260-92-41, GL-88-14, NUDOCS 9301200099 | |
| Download: ML18036B128 (1) | |
Text
ENCLOSURE 1
NOTICE OF DEVIATION Tennessee Valley Authority Browns Ferry 2
Docket No. 50-260 License No.
DPR-52 The following deviation was identified during a Nuclear Regulatory Commission (NRC) inspection conducted on November 14 - December 16, 1992.
In reply to Generic Letter 88-14, Instrument Air Supply System Problems Affecting Safety-Related Equipment, TVA committed to revise Technical Instruction (TI)-34, Monthly Control Air System Dryer Dewpoint Test And Purge Control, prior to Unit 2 restart to verify that adequate margin between the ambient air temperature and dew point range at air dryer outlets is maintained.
Contrary to the above, TI-34 was not revised to verify adequate margin is maintained between the ambient air temperature and dew point range for all components supplied by the drywell control air system.
In addition, the system dew point is not maintained to the requirements recommended by the vendors of all the components supplied.
The vendor requirements for the main steam isolation valves for dew point is -40 degrees Fahrenheit (F).
TI-34 only verifies dew point to 30 degrees Fahrenheit.
The following examples indicate that the system repeatedly fails to reach even this setpoint:
1.
February 21, 1992, the 2B drywell control air dryer could only achieve a dewpoint of 37.2 degrees F.
2.
March 12, 1992, the 2A drywell control air dryer could only achieve a dewpoint of 40.8 degrees F.
3.
April 13, 1992, the 2B drywell control air dryer could only achieve a dewpoint of 39 degrees F.
4.
April 16, 1992 the 2B drywell control air dryer could only achieve a dewpoint of 38 degrees F.
This deviation is applicable to Unit 2.
Please provide to the U.S. Nuclear Regulatory Commission, ATTN:
Document Control
- Desk, Washington, DC 20555, with a copy to the Regional Administrator, Region II, and a copy to the NRC Resident Inspector, Browns Ferry, in writing within 30 days of the date of this Notice, the reasons for the deviation, the corrective steps which have been taken and the results
- achieved, the corrective steps which will be taken to avoid further deviations, and the date when your corrective action will be completed.
Where good cause is shown, consideration will be given to extending the response time.
Dated at Atlanta, GA thisQp4ay of December, 1992 9301200099 921223 PDR ADOCK 05000259 8