ML20070S132

Responds to Request for Addl Info Re IE Bulletin 81-03, Flow Blockage of Cooling Water to Safety Sys Components for Corbicula Sp (Asiatic Clam) & Mytilus Sp (Mussel). All Svc Water & Component Cooling HX Inspected & Cleaned Quarterly

ML20070S132
Person / Time
Site:	Calvert Cliffs
Issue date:	01/27/1983
From:	Lundvall A BALTIMORE GAS & ELECTRIC CO.
To:	Jordan E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
References
REF-SSINS-6820 IEB-81-03, IEB-81-3, NUDOCS 8302040265
Download: ML20070S132 (2)

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BALTIMORE GAS AND ELECTRIC CHARLES CENTER. P.O. BOX 1475. BALTIMORE, MARYLAND 21203 ARTHUR E LUNDVALL,.JR.

Vict PRESIDENT SUPPLv January 27,1983 U. S. Nuclear Regulatory Commission Docket Nos.

50-317 Office of Inspections and Enforcement 50-318 Washington, D.C. 20555 License Nos.

DPR-53 DPR-69 ATTENTION: Mr. E. L. Jordan, Director Gentlemen:

This is in response to your request for more information regarding IE Bulletin 81-03,

" Flow Blockage of Cooling Water to Safety System Components for CORBICULA SP.

(Asiatic Clam) and MYTILUS SP. (Mussel)". The applicable items are addressed below.

4a.

If Corbicula sp. or Mytilus sp. were pasent in the Chesapeake Bay water used for cooling safety systems at Calvert Cliffs there would be an intrusion potential.

Our plant employs a system of trash rakes and traveling screens to protect pumps and heat exchangers from damage. These screens are too coarse to prevent the entrance of Asiatic Clam or Mussellarve.

As stated in our May 7,1981 reply on this subject, neither Corbicula sp. or Mytilus sp. are found in the molluscan species lists in submerged substrate studies or benthic studies in the vicinity of Calvert Cliffs Nuclear Power Plant.

The estuarine salinity regime (8 - 15 o/oo) at Calvert Cliffs is inappropriate for these species, (e.g., too saline for Corbicula sp., and too brackish for Mytilus sp.).

Because these species do not exist in our area, intrusion is not a problem.

4b.

Calvert Cliffs currently uses hypochlorite injected into the salt water pumps discharge to minimize biofouling. Alternative biocides are being considered for future use. The composition of the tubes in our service water and component cooling heat exchangers (90% Copper /10% Nickel) discourages fouling.

In addition, heat exchanger temperatures are monitored to ensure proper performance.

Our present practices require all service water and component cooling heat exchangers be opened, inspected, and mechanically cleaned quarterly.

Our experience has shown this schedule ensures maximum heat exchanger performance and minimizes tube degradation.

8302040265 830127 PDR ADOCK 05000317 C

PDR

Mr. E. L., u dan January 27,1983 Page 2 Should you have any further questions regarding this matter, we would like to discuss them with you.

Very truly yours,

= AnW t

A. E. Lundvall, Jr.

Vice President - Supply AEL/3RS/sjb STATE OF MARYLAND :

TO WIT:

CITY OF BALTIMORE :

Authur E. Lundvall, Jr., being duly sworn states that he is Vice President of the Baltimore Gas and Electric Company, a corporation of the State of Maryland; that he provides the foregoing response for the purposes therein set forth; that the statements and that made are true and correct to the best of his knowledge,information, and belief;7 he was authorized to provide the response on behalf of said Corporation.

WITNESS my Hand and Notarial Seal:

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A._IL, N'otary Public l

My Commission Expires o[ti

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cc:

3. A. Biddison, Esquire l

G. F. Trowbridge, Esquire l

D. H. Jaff e, NRC R. E. Architzel, NRC E. L. Bauereis, BG&E

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