ML19310A933
| ML19310A933 | |
| Person / Time | |
|---|---|
| Site: | Fort Saint Vrain  |
| Issue date: | 05/29/1980 |
| From: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Millen C PUBLIC SERVICE CO. OF COLORADO |
| References | |
| NUDOCS 8007010044 | |
| Download: ML19310A933 (1) | |
Text
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a STATE May 29, 1980 Dockst No. 50-267 Public Service Company of Colorado ATTN: Mr. C. K. Millen Senior Vice President P. O. Box 840 Denver, Colorado 80201 Gentlemen:
This IE Information Notice is forwarded for information.
No written response to this Information Not Lee is required.
If you have any questions related to this matter, please contact this office.
Sincerely, 0,.L9.h u
v Karl V. Seyfri, Director
Enclosures:
1.
IE Information Notice No. 80-23 2.
List of Recently Issued IE Information Notices cc:
D. W. Warembourg, Nuclear Production Manager Fort St. Vrain Nuclear Station
'P. O. Box 368 Platteville, Colorado 80651 L. Brey, Manager, Quality Assurance f
8007010 g4/
UNITED STATES.
SSINS No.:
6835 NUCLEAR REGULATORY COMMISSION Accession No.:
0FFICE OF INSPECTION AND ENFORCEMENT
-8005050061 WASHINGTON, D. C.
20555
'N Ld' I
IE Information Notice No.
-23 Date: May 29, 1980 Page 1 of 1 LOSS OF SUCTION TO EMERGENCY FEEDWATER PUMPS l
Description of Circumstances:
)
On April 7, 1980, Arkansas Nuclear One, Unit 2, suffered a loss of offsite power due to tornado damage to 500 kV transmission towers.
The unit tripped from 98%
power; the diesel generators started and supplied vital loads; natural circula-tion in the reactor coolant system was established; and the emergency feedwater l
(EFW) pumps supplied feedwater to the steam generators.
The suction of the EFW pumps was' aligned to the Condensate Storage Tanks (CST) and to the Startup and Blowdown Demineralizer effluent in parallel. Approxi-mately 15 minutes after the unit tripped, both EFW pumps loct suction.
Prompt 1
operator action was taken to isolate the EFW pump suction from the Startup and Blowdown Demineralizer and to vent the EFW pumps. EFW flow was re-established j
within one minute.
4
)
Investigation revealed that the EFW pump suction loss was caused by flashing in the main feedwater train forcing hot water through the Startup and Blowdown j
Demineralizers to the EFW p 'p suction where it flashed to steam.
The steam caused cavitation of the EFW pumps, and the pressure in the EFW suction header orevented flow from the CST.
The licensee has submitted Licensee Event Report No. 50-369/80-18/03L-0, dated May 5, 1980, describing this event. Action to prevent recurrence included revising the EFW system operating procedure and the Plant Startup Procedure to require thutting the EFW suction valve from the Startup and Blowdown Demineralizers during plant startup at about 5% full power after i
the steam generator feedwater source has been shifted to a main feedwater pump.
In addition, the EFW suction valve from the Startup and Blowdown i
Demineralizers will be verified closed once per shift during Mode 1 operation.
i This IE Information Notice is provided as an early notification of a possibly significant matter that is still under review by the NRC staff.
It is expected that recipients will review the information for possible applicability to their facilities.
No specific action or response is requested at this i
time.
If NRC evaluations so indicate, further licensee actions may be requested or required.
No written response to this IE Information Notice is required.
If you have any questions regarding this matter, 'please contact the Director of the appropriate NRC Regional Office.
i
IE Information Notice No. 80-23 May 29, 1980 LISTING OF RECENTLY ISSUED IE INFORMATION NOTICES Information Subject Date Issued To Notice No.
Issued 80-17 Potential Hazards Associated 5/5/80 All radiography With Interchangable Parts Licenses On Radiographic Equipment 80-18 Possible Weapons Smuggling 5/5/80 All power reactor Pouch facilities with an Operating License (OL), fuel fabrication and processing facilities and Materials Priority I licensees (processors and distributors) 80-19 NIOSH Recall of Ricircu-5/6/80 All holders of a lating-Mode (Closed Circuit) power reactor Operating Self-Contained Breathing License (OL), Research Apparatus (Rebreathers)
Reactor License, Fuel Cycle Facility License and Priority I Material License 80-20 Loss of Decay Heat Removal 5/8/80 All light water reactor Capability at Davis-Besse facilities holding 1
Unit 1 While in a Refueling power reactor Operating Mode Licenses (OLs) or Construction Permits (cps) 80-21 Anchorage and Support of 5/16/80 All power reactor Safety-Related Electrical facilities with an Equipment Operating License (OL) or Construction Permit (CP) l 80-22 Breakdown In Contamination 5/28/80 All power reactor Control Programs Operating Licenses (OLs) and near term Construction Permits (cps)
Enclosure
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