ML20004D414

Forwards Response to IE Bulletin 81-03, Flow Blockage of Cooling Water to Safety Sys Components by Corbicula Sp (Asiatic Clam) & Mytilus Sp (Mussel). Mytilus Sp Is Salt Water Organism & Cannot Inhabit Freshwater Mo River

ML20004D414
Person / Time
Site:	Fort Calhoun
Issue date:	05/22/1981
From:	William Jones OMAHA PUBLIC POWER DISTRICT
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
TASK-3.A.1.2, TASK-TM IEB-81-03, IEB-81-3, TAC-45959, NUDOCS 8106090366
Download: ML20004D414 (5)

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'h Omaha Public Power District 1623 MARNEY 1 OMAMA, NESRASMA 66102 s TELEPHONE 536.AOOO AREA CODE A02 May 22, 1981 Mr. K. V. Seyfrit, Director U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement Region IV 611 Ryan Plaza Drive, Suite 1000 Arlington. Texas 76011

Reference:

Docket No. 50-285

Dear Mr. Seyfrit:

Omaha Public Power District has evaluated the concerns detailed in IE Bulletin No. 81-03, dated April 9,1981, regarding flow blockage of cooling water to safety system ccmponents by asiatic clams and mussels. The result of the District's evaluation is attached in response to the bulletin.

Sin erely, W. C. Jones k Division Manager Production Operations WCJ/KJM/TLP/1p Attachment

'C, pc: Office of Inspection and Enforcement, Washington, D. C.

I LeBoeuf, Lamb, Leiby, and MacRae

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In the Matter

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Docket No. 50-285 OMAHA PUBLIC POWER DISTRICT

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AFFIDAVIT

...being duly sworn, hereby deposes and says that he is the Section Manager-0perations of Omaha Public Power District; that he is duly authorized to sign and file with the Nuclear Regulatory Commission the attached response to IE Bulletin No. 81-03; that he is familiar with the content thereof; and that the matters set forth therein are true and correct to the best of his knowledge, information, and belief.

R. L. Andrews Section Manager Production Operations STATE OF NEBRASKA

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Subscribed and sworn to before me, a Notary Public in and for the State of Nebraska, on this

_ day of May, 1981.

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Nntary Public I

l LT.ausson we cama. em w as, sas My Commission expires

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OMAHA PUBLIC POWER DISTRICT Fort Calhoun Station Unit No. 1 Response to IE Bulletin No. 81-03 ACTIONS TO BE TAKEN BY LICENSE 1 Item No. 1 Determine whether Corbicula Sp. or Mytilus Sp. is present in the vicinity of the station (local environment) in either the source or receiving water body.

If the results of current field monitoring programs provide reasonable evidence that neither of these species is presert in the local environment, no further action is necessary except for Items 4 and 5 ln this section for holders of operating licenses.

Rescanse Fort Calhoun Station has been operating for the past seven and one-half years. The extensive environmental monitoring program carried out during this period did not show presence of any asiatic clam shalls. Also, regular inspection of the components that use river water has been conducted during each of the past five refueling outages.

These inspections did not show the presence of any clam shells in the condenser or the raw water heat exchangers.

A literature and field investigation effort was conducted to determine if the Corbicula Sp. or the Mytilus Sp. is present in the vicinity of the Fort Calhoun Station.

The Mytilus Sp.

is a salt water organism and, therefore, cannot innaoit the freshwater Missouri River. The results of a literature research effort into the presence or absence of the Corbicula Sp. near the Fort Calhoun Station indicates that there nave been none reported. This information was verified by field sampling efforts conducted in response to this bulletin upstream and downstream of the Fort Calhoun Station.

Items No. 2 and 3 Not Applicable.

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Item No. 4 Describe methods either in use or planned (including imple-mentation date) for preventing and detecting future flow blockage or degradation due to clams or mussels or shell debris.

Include the following information in this description:

a.

Evaluation of the potential for intrusion of the organisms intu these systems due to low water level and high velocities in the intake structure expected during worst case conditions.

b.

Evaluation of effectiveness of p'revention and detection methods used in the past or present or planned for future use.

Response

It is believed that continued surveillance and inspection of the com-ponents that use river water during the refueling outage will be adequate for detecting asiatic clams at the Fort Caihoun Station.

The District also has additional non-nuclear units along the Missouri River. The condenser of these units are also inspected at regular intervals.

Fouling of the condenser at these facilities, due to Coroicula Sp. has not been detected in the past.

Should asiatic clams be detected at Fort Calhoun or any of the other units operated by the District, appropriate measures for detecting flow

• blockage or degradation will be implernented.

The worst case of low -Iver level occurs during the winter months.

During this period, river water temperature at the Fort Calhoun Station is < 45'F, and the circulating water discharge temperatuare is < 55'F. At these temperatures, the Corbicula Sp. will not spawn.

Therefore, it is highly unlikely that the asiatic clams will pose any problems for the cooling system at the Fort Calhoun Station.

Item No. 5 Describe the actions taken in Items 1 through 3 above and include the following informa!. ion:

l a.

Applicable portions of the environmental monitoring l

program including last sample date and results.

b.

Components and systems affected.

c.

Extent of fouling if any existed.

d.

Hcw and when fouling was discovered.

e.

Corrective and preventive actions.

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Response

An environmental sampling program was conducted after receiving IE Bulletin 81-03 to determine the presence of asiatic clars.s at Fort Calhoun Station. This program consis:od of taking grab samples-of the Missouri River upstream and downstream of the Fort Calhoun Station. The results of this program showed absence of asiatic clams in the vicinity of the Fort Calhoun Station.

At present, ngr.c of the components and systems are affected and no fouling G1 the system exists.

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