ML20072U413
| ML20072U413 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 03/21/1983 |
| From: | Tucker H DUKE POWER CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| REF-SSINS-6820 IEB-81-03, IEB-81-3, NUDOCS 8304110304 | |
| Download: ML20072U413 (3) | |
Text
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d March 21, 1983 Mr. James P. O'Reilly, Regional Administrator U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30303 Subj ect: Oconee Nuclear Station IE Bulletin 81-03 Asiatic Clams and Mussels
Dear Sir:
Attached is Duke Power Company's response to a Request for Additional Information concerning IE Bulletin No. 81-03, Flow Blockage of Cooling Water to Safety Components by Corbicula sp. (Asiatic Clam) and Mytilus sp. (Mussel), which was transmitted in a January 24, 1983 letter from Mr. E. L. Jordan.
I declare under penalty of perjury that the statements set forth herein are true and correct to the best of my knowledge, executed on March 21, 1983.
Very truly yours, d
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Hal B. Tucker PFG/php Attachment cc: Director Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission Washington, D. C. 20555 8304110304 830321 PDR ADDCK 05000269 (T)
PDR Yll
e Duke Power Company Oconee Nuclear Station Request for Additional Information Re: IE Bulletin 81-03 To close out IE Bulletin No. 81 Flow Blockage of Cooling Water to Safety Components by Corbicula Sp. (Asiatic Clam) and Mytilus.Sp. (Mussel), the following additional information on the methods used to monitor for clam infestation is provided. The numbered items below are in direct reference to the requests in IE Bulletin 81-03.
2.
Inspecting two condenser water boxes, a cooler, and a heat exchanger does not form the " representative sample" requested in the bulletin. Perform more inspections in all three units and report the results. Particular attention should be paid to the High Pressure Service Water Syster.
Response
A procedure, CP/0/B/4002/12, was approved on September 22, 1981 to monitor clam infestation in Oconee Nuclear Station's service water systems. Quarterly, the Condenser Cooling Water (CCW) System (Condensate Coolers and Recirculating Cooling Water (RCW) Heat Exchangers), the Low Pressure Service Water (LPSW)
System (the strainers on the LPSW system pumps), and the High Pressure Service Water (HPSW) System (the HPSW pump strainers and the fire protection system) are sampled for evidence of clams. Additionally, during clam spawning season, samples are collected from the LPSW system and a microscopic check for clam veligers is conducted. Station personnel have been made aware that any evidence of clam infestation found during maintenance work shall be reported to the Environmental Section. The Performance Section maintains information on flow rates through the Low Pressure Injection and Decay Heat Coolers and monitors temperature data on other safety-related components. Any degradation in flow or rises in temperatures will be noted and the cause will be determined. If the source is clams, the preventive measures discussed in the Oconee response l
to IE Bulletin 81-03 will be evaluated.
4.b.
As there is a potential for fouling of safety systems, provide description of the formal monitoring program designed for early detection of infesta-tion and prevention.
Response
l See item 2 above. Flow rates are monitored on the LPI and Decay Heat Coolers are monitored by the Oconee Performance Section. The fire protection system is part of the quarterly clam monitoring program. Four fire hose stations in the Turbine Building and six fire hydrants on the station grounds are flushed through a strainer and the effluent is inspected for evidence of clams. Keowee Hydro Station is used as a back-up power source for Oconee and is included in l
the clam monitoring program. Evidence of clams has been found in the Keowee Service water system and a modification has been initiated to chlorinate the i
fire protection system.
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- 5.a.
Provide last sampling date and results.
b.
See item 2 above.
Response
5.a.
Last quarterly inspection was conducted on December 20, 1982. One piece of clam shell was found in the Unit 1 Condensate Cooler. Several shell fragments were found in the Keowee Hydro Station fire hydrant.
5.b.
There was no evidence of clam infestation in either the HPSW pump strainers or the Oconee fire protection system. At this time, although some evidence of clams has been found in the CCW and the LPSW systems at Oconee, the degree of infestation is believed to be low and no corrective action is anticipated at this time.