ML20069G583
| ML20069G583 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 03/22/1983 |
| From: | Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | Deyoung R, Jordan E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| References | |
| REF-SSINS-6820 IEB-81-03, IEB-81-3, NUDOCS 8303280056 | |
| Download: ML20069G583 (3) | |
Text
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VIRGINIA ELECTRIC AND PowEn COMPANY RrcuxoNn,VINGINIA 23261 W. L. StuwAart Vaca Panasoust N u es.... o,.. mon.
March 22, 1983 Mr. Richard C. DeYoung, Director Serial No. 051 Office of Inspection and Enforcement N0/RMT:acm Attn:
Mr. Edward L. Jordan, Director Docket Nos. 50-338 Division of Engineering and 50-339 Quality Assurance License Nos. NPF-4 U. S. Nuclear Regulatory Commission NPF-7 Washington, D. C. 20555 Gentlemen:
Subject:
IE Bulletin 81 Flow Blockage of Cooling Water to Safety Components by Corbicula SP.(Asiatic Clam) and Mytilus SP.(Mussel)
We have received your letter concerning the subject bulletin and the attached request for additional information.
The enclosure to this letter provides responses to the specific areas referenced.
To facilitate your review, the numbering is the same as that used in the IE Bulletin and your letter.
Very truly yours, f
~
gy W. L. Stewart Attachment cc:
Mr. James P. O'Reilly Regional Administrator Region II 8303200056 0
Attachment Serial No. 051 Page 1 NORTH ANNA UNITS 1 AND 2 RESPONSE TO IEB 81-03 ADDITIONAL INFORMATION Upon notification of the potential for clogging of plant water systems by 2.
Corbicula shells or shell debris, the following sites were visually inspected.
May 5, 1981 - The Unit 1 and Unit 2 fire system piping strainers.
A.
No evidence of Corbicula shells or shell debris.
Results:
B.
May 15, 1981 - Circulating Water Intake Structure (Unit 2).
Results: No evidence of Corbicula shells or shell debris.
C.
May 15, 1981 - Service Water Reservoir (Units 1 and 2).
Results: No evidence of Corbicula shells in dredge sample, however, Corbicula have been observed by divers while inspecting the reservoir spray piping.
In addition to the above, more recent inspections of Service Water and Bearing Cooling Water System supply piping to various components were conducted to determine the extent of iron bacteria infestation.
The following components and piping were visually examined with no evidence of the Corbicula shells or shell debris.
Service Water pump (1-SW-P-1B) discharge line (20"-WS-7-151-03)
A.
B.
Air conditioning condenser (1-HV-E-4B)
Peretration cooling coil Service Water header piping (3" 0. D.)
C.
D.
Various Service Water piping (3" 0. D. and under)
E.
Recirculation Spray Heat Exchanger (1-RS-E-1A)
Component Cooling Heat Exchanger (1-CC-E-1A)
F.
16" 0. D. Service Water supply piping to Recirculation Spray Heat G.
7 Exchangers Bearing Cooling piping to Steam Generator Feed pump seals and oil H.
coolers.
i 3.
A periodic test was generated and approved November 16, 1982 which is currently employed to monitor the performance of various Service Water supplied equipment.
Although Corbicula have not been found in potentially affected safety related piping systems, this procedure could The identify a possible flow restriction caused by Corbicula intrusion.
following component and associated parameters are monitored.
Attacharnt Serial No. 051 Paga 2 Charging Pump (HHSI) lube oil cooler outlet temperatures A.
B.
Service Water header discharge flow C.
Air conditioning condenser flows and temperatures D.
Pipe penetration cooling coil temperatures t
E.
Service Water header temperatures Delta T and Delta P F.
Component Cooling Heat Exchangers Service Water supply flow to Charging Pump (HHSI)
G.
Visual inspection of the Service Water reservoir spray nozzles H.
periodic monitoring program implemented September 1, 1981 involved 4.
The adding steps to existing periodic tests on systems that could be contaminated with Corbicula.
These new steps require an potentially inspection for Corbicula and/or shell debris if and when the particular In addition, a Maintenance Department system is opened for maintenance.
Procedure was generated to provide for inspections of Administrative plant water systems opened for maintenance in order to observe corrosion.
and/or the presence of Corbicula.
These inspections are performed by a qualified Chemistry Technician.
To date, no evidence of Corbicula infestation has been noted.
5.
b.
See items 2 and 3 above See items 2 and 3 above c.
d.
See items 2 and 3 above See item 4.b above e.
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