ML19318C271
| ML19318C271 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 05/29/1980 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Kay J YANKEE ATOMIC ELECTRIC CO. |
| References | |
| NUDOCS 8007010288 | |
| Download: ML19318C271 (1) | |
Text
1 UNITEO STATES mec,30 o
NUCLEAR REGULATORY COMMISSION g
R RE*lON I 3
j s31 PARK AVENUE e4 g
KING OF PRUSSI A. PENN5Yt.VANI A 19406 Docket No. 50-29 Yankee Atomic Electric Company ATTN:
Mr. James A. Kay Senior Engineer - Licensing 25 Research Drive Westborough, Massachusetts 01581 Gentlemen:
The enclosed IE Information Notice No. 80-23, " Loss of Suction To Emergency Feedwater Pumps", is forwarded to you for information.
No written response is required.
If you desire additional information regarding this matter, please contact this office.
Sincerely, ht o e H. Grier i
' rector
Enclosures:
1.
IE Information Notice No. 80-23 2.
List of Recently Issued IE Information Notices CONTACT:
E. G. Greenman (215-337-5267) cc w/encls:
H. Autio, Plant Superintendent J. E. Tribble, President l
r
O' ENCLOSURE 1 UNITED STATES SSINS No.:
6835 NUCLEAR REGULATORY COMMISSION Accession No.:
OFFICE OF INSPECTION AND ENFORCEMENT 8005050061 WASHINGTON, D. C.
20555 IE Information Notice Nof 80-23 Date:
May 29, 1980 Page lof 1 LOSS OF SUCTION TO EMERGENCY FEEDWATER PUMPS 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 (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 lost suction.
Prompt 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 within one minute.
Investigation revealed that the EFW pump suction loss was caused by flashing in the main feedwater train forcing lot water through the Startup and Blowdown Demineralizers to the EFW pump suction where it flashed to steam.
The steam caused cavitation of the EFW pumps, and the pressure in the EFW suction header prevented flow from the CST.
The licensee has submitted Licensee Event Report No. 50-368/80-18/03L-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 shutting the EFW suction valve from the Startup and Blowdown Demineralizers during plant startup at about 5% full power after the steam generator feedwater source has been shifted to a main feedwater pump.
In addition, the EFW suction valve from the Startup and Blowdown Demineralizers will be verified closed once per shift during Mode 1 operation.
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 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.
ENCLOSURE 2 IE Information Notice No. 80-23 Date:
May 29, 1980 Page 1 of 1 RECENTLY ISSUED IE INFORMATION NOTICES Information Subject Date Issued to Notice No.
Issued 80-15 Axial (Longitudinal) 4/21/80 All Power Reactor Facil-Oriented Cracking in ities with an Operating P' ing License (OL) or Construc-tion Permit (CP) 80-16 Shaft Seal Packing 5/5/80 All Power Reactor Facil-Causes Binding in Main ities with an OL or CP Steam Swing Check and Isolation Valves 80-17 Potential Hazards 5/5/80 All Radiographic Licensees Associated With Interchangeable Parts On Radiographic Equipment 80-18 Possible Weapons 5/5/80 All Power Reactor Faci-Smuggling Pouch lities with an OL, Fuel Fabrication and Processing Facilities and Materials Priority I Licensees 80-19 NIOSH Recall of Recir-5/6/80 All Power Reactors with an culation-Mode (Closed-OL,ilities and Priority I Research Reactors, Fuel Circuit) Self-Contained Fac Breathing Ap aratus Material Licensees (Rebreathers 80-20 Loss of Decay Heat Re-5/8/80 All Power Reactor Faci-moval Capability at lities with an OL or CP Davis-Besse Unit 1 While in Refueling Mode 1
80-21 Anchorage and Support 5/16/80 All Power Reactor Faci-of Safety-Related lities with an OL or CP Electrical Equipment 80-22 Breakdown in Contamin-5/28/80 All Power Reactor Facili-ation Control Systems ties with an OL l