ML20004F581
| ML20004F581 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 05/22/1981 |
| From: | Crouse R TOLEDO EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 1-202, IEB-81-03, IEB-81-3, NUDOCS 8106190148 | |
| Download: ML20004F581 (5) | |
Text
Dwyg Docket No. 50-346 s
License No. NPF-3 TDtE00 6erial No. 1-202 EDISON May 22, 1981 n,:m:p cac se 0,*.;" '
~ ww Mr. James C. Keppler, Regional Director Region III United States Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137
Dear Mr. Keppler:
IE Bulletin No. 81-03, dated April 10, 1981, (Log No. 1-493), requested that we investigate the possibility that the Asiatic Clam, Corbicula, might be found in the source or receiving waters of the Davis-Besse Nuclear Power Station, Unit I, and, if found, what measures would be taken to mini-mize flow blockage to nuclear safety related equipment.
Attached is Toledo Edison's response to IE Bulletin No. 81-03.
The response items arc numbered consistently with those in the Bulletin.
Very truly yours,
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9 THE TCLEDO EDISON COMPANY E0tSON PLAZA 300 MADfSON AVETWE TDLEDO, OHIO 43652 WM 2,6. SiH
f Docket No. 50-346 License No. NFF-3 i
Serial No. 1-202 May 22, 1981 ATTACIDfENT Item 1
" Determine whether Corbicula or Mytilis is present in the vicinity of the station in either the source or receiving water body".
Response
Mytilis is a salt water clam, and Lake Erie does not provide a suitable habitat for its existence. Therefore, this clam is not an actual nor a potential problem at Davis-Besse.
However, Corbicula is a fresh water clam that has recently been found in Lake Erie - the source and receiving water for Davis-Besse. Late last fall and again this spring, on May 14, 1981, field investigators from Detroit Edison discovered substantial numbers of Corbicula at the mouth of f.he overflow canal at the coal-fired Monroe Power Plant, located on the western shore of Lake Erie. The density of clams was about 15 indi-viduals per square foot.
Item 2
"... Determine whether fire protection or safety related systems that directly circulate water from the station source or receiving water body are fculed by clams or... debris consisting of their shells. An acceptable method of confirming the absence of organisms or shell debris consists of opening and visually examining a representative sample of components in potentially affected safety systems and a sample of locations in potentially affected fire protection systems. The sample shall have included a dis-tribution of components with supply and return piping of various diameters which exist in potentially affected systems. This inspection shall have been conducted since the last clam... spawning season or within the nine month period preceding the date of this bulletin."
Response
Within the past six months, routine maintenance was performed on all raw water syecess and no clams or shell debris were found in the piping. In l
addition, the condenser and circulating water canal were inspected last summer and no evidence of c1 Lams was seen in either loration. On May 13, 1981, a diver went down into Intake Bay No.1 at Davis-Besse to check for clam i-shells. No shells Of any kind were found in either the bottom of the bay or on the concrete sides.
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.,,e Docket No. 50-346 License No. NFF-3
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Serial No. 1-202 May 22,1981 Page 2 - Attachment Response to Item 2 - continued Furthermore, inspections at Toledo Edison's coal-fired Bay Shore Generating Station indicate that no shell debris was found in the water box or tubes of a candenser that was cleanad in March,1981 during a unit outage. If Toledo Edison were to develop a problem with Corbicula, Bay Shore would probably be affected first because its much larger thermal plume could support a substantial colony of Corbicula.
At the present time, the absence of clams and shell debris at the Davis-Besse Station has been confirmed by these inspections.
Item 3 "If clams...were f.sund in potentially affected systems or their absence was not confirmed by action in Item 2 above, measure the flow rates through individual components in potentially affected systems to confirm adequate flow rates...".
Response
s x
No clams were found, therefore, Iten. 3 is not cpgl'. cable to the Davis-Besse Nuclear Power Station, Unit I.
Item 4
" Describe methods whether in use or planned (including implementation date) for preventing and detecting future flow blockage or degradation due to class...or shall debris. Include the following information in th!.s descrip-tion:
o a.
Evaluation of the potential for intrusion of the organisms into I
these systems due to low water level and high velocities in the j
intake structure expected during worst case conditions.
l I
b.
Evaluation of effectiveness of prevention and detection methods used in the past or present or planned for future use."
Response
An annual piping inspection program will be conducted beginning in the fall.
These inspections of the service water system, fire protection system, and l
the et cooling water system piping will be conducted in sccordance with a Treventive Maintenance Work Order.
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tocket 1to. 50-346 License No. NPF-3 Serial No. 1-202 May 22, 1981 Page 3 - Attachment Response to Item 4 - continued However, Davis-Besse withdraws water from a lake, not a river, and due to subsequent absence of low water levels and high velocities in the intake structure, we anticipate minimal potential for intrusion of clams into these systems.
The prevention and detection methods will be determined to be effective if, during the annual inspections, there is no indication of significant flow blockage due to clams or shell debris to any plant system.
Item 5
" Describe the actions taken in Items 1 through 3 above and include the following information:
a.
Applicable portion of the environmental monitoring program, including last sample date and results.
b.
Components and systems affected.
c.
Extent of flouling, if any existed.
d.
How and when fouling was discovered.
e.
Corrective and preventive actions."
Essponse i
a.
A review of the pre-operational and operational benthos monitoring reports indicates that no Corbicula were found in any of the samples taken from 1973 to November 20, 1980. These bottom sediment samples were taken from
. Lake Erie in the vicinity of Locust Point, near Davis-Besse.
l b.
No components or systems have been affected.
c.
no fouling has been detected.
i d
No fouling h/s been detected.
e.
Preventive and corrective actions will consist of preparing Preventive Maintenance Work Orders in which piping in the fire protection system, service water system,'and component cooling water system will be in-spected for clams and ahell debris sa an manual basis during the fall of the year after the peak breeding period for Corbicula has passed.
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V-I ATCHIC ENERGY ACT OF 1954 SECTION 182 t
SUBMITTAL IN RESPONSE FOR THE DAVIS-BESSE NUCLEAR POWER STATION UNIT 1 FACILITY OPERATINC LICENSE NPF-3 o
This response is submitted in conformance with Atomic Energy Act of 1954, Section 182, relating to IE Bulletin No. 81-03, Flow Blockage of Cooling Water to Safety System Components by Corbicula Sp. (Asiatic Clam) and Mytilus Sp. (Hussel).
By:
Nuclear Services Director For:
R. P. Crouse Vice President, Nuclear
[ / ~S r day of May,1981, Sworn to and subscribed before me this By 4/
C N%aryPublic/
UND.A L COSTELL Notary Puti.: - Sta:e et ONo My Comm:ss. n Ex; es Feo. 9,1982 em