ML20004B171
| ML20004B171 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 05/15/1981 |
| From: | Conway W VERMONT YANKEE NUCLEAR POWER CORP. |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| FVY-81-78, IEB-81-03, IEB-81-3, NUDOCS 8105270329 | |
| Download: ML20004B171 (3) | |
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VER>10NT YAN KEE NUCLEAR POWER CORPORATION SEVENYY SEVEN GROVE STREET 2.C.2.ll RUT 1.AND. VERMONT 05701 yyy 31_73 MEPLY TO:
ENGINEERING OFFICE 1671 WORCESTER ROAD FRAMINGH AM, M ASSACHUSETTS 017o1 7ELaPHONE G17 472 8100 May 15, 1981
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0 United States Nuclear Regulatory Commission Office of Inspection and Enforcement
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.$ _.; N Attention:
Mr. Boyca H. Grier, Director j j m,
References:
(a) License No. DPR-28 (Docket No. 50-271)
(b) Letter, USNRC to VYNPC, dated April 10, 1981, IE Bulletin 81-03
Dear Sir:
Subject:
Response to IE Bulletin 81 Flow Blockage of Cooling ifater to Safety System Components by COR3ICULA SP. (Asiatic Clam) and MYTILUS SP. (Mussel)
The following information is provided in response to the app 11-cable items of Reference (b) above concerning the potential for flow blockage of cooling water to safety system components.
INSPECTION / SAMPLING Continuing benthic fauna sampling and analyses since August 1967 has shown that the " Asiatic Clam," Corbicula sp., does not oscur in the Connecticut River near the Vermont Yankee Nuclear Power Station. Annual plant inspections of the cooling water systems, including condenser water boxes and condenser tubes, has shown no Corbicula sp. life stages to oe present. The mussel Mvtilus sp. is a marine taxon and cannot exist in a fresh-water environment as is found at the Vermont Yankee site.
Information on the Vermont Yankee benthic fauna monitoring program has been reported in an annual series of, to date, ten ecologi:a1 studies and environmental ranitoring reports titled
" Ecological Studies of the Connecticut River, Vernon, Vermont,"
Reportu I-X inclusive, covering the periods 1967-1972 (preoper-ational) and 1972 to 1980 (operational). A further comprehensive
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l VERMCNT YANKEE NUCLEAR PCWER CORPORATICP United States Nuclear Regulatory Commission May 15,1981 Page 2 environmental assessment report, including benthic fauna infor-marion, is contained in the "316 Demonstration" reported dated March 1978. All of these reports have been previously submitted to the Commission.
The most recent benthic sampling waa conducted on April 16, 1981, and May 5, 1981, consisting of 45 hauls with a 9" Ekman dredge in the vicinity of the intake structure. This sampling produced one juvenile Unionid clam. We have previously charac-terized the Connecticut River in the vicinity of Vermont Yankee as poor habitat in general for mollusks and bivalves in partic-ular. Currently, benthic fauna monitoring is required and con-ducted monthly from May to November at four river stations by our NPDES permit.
Such monitoring would pick up Corbicula if it should migrate into our study area. To date, the genus has not been reported in the New England states.
PROGRAMS IN PLACE FOR DETECTION AND PREVENTION OF FLOW BLOCKAGE A.
Detection 1.
Ongoing river benthic sampling and entrainment moni-toring at intake structure (NPDES permit requirement).
2.
In-plant annual inspection of condenser water boxes and approximately one-third of condenser tubes (plant procedure).
3.
Ongoing in-plant surveillance for adequate water flow in cooling systems (plant procedure).
B.
Proposed Method of refouling if Blockage From Corbicula Should Occur 1.
Heat treatment of affected systems at temperatures and durations high enough to cause mortality of Corbicula life stages (120-170*F).
The following information is submitted in response to your re-quest for estimates of manpower expended in the research and subse-quent performance of actions associated with this bulletin.
Manpower Recuirements Hours Bulletin Response 10 Man-Hours Corrective Actions Not Applicable i
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- o VERMONT YANKEE NUCLEAR POWEM CORPORATICP United States Nuclear Regulatory Commission May 15, 1981 Page 3 We trust the above supplied information is satisf'accory; however, should you desire additional information, please contact us.
Very truly yours, VERMONT YANKEE NUCLEAR POWER CORPORATION W
William F. Conw President and Chief Operating Officer RJW/jh STATE OF VERMONT)
)ss WINDHAM COUNTY )
Then personally appeared before me, William F. Conway, who, being duly sworn, did state that he is President and Chief Operating Officer of Vermont Yankee Nuclear Power Corporation, that he is duly authorized to execute and file the foregoing reqtiest in thc name and on the behalf of Vermont Yankee Nuclear Power Corporation, and that the statements therein are true to the best of.his knowledge and selief.
OffEb, 0.
Q) A YA J JudigA. Harris Notary Public My Commission Expires February 10, 1983
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