ML20004D479
| ML20004D479 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 05/26/1981 |
| From: | Carey J DUQUESNE LIGHT CO. |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| IEB-81-03, IEB-81-3, NUDOCS 8106090446 | |
| Download: ML20004D479 (7) | |
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Rt.; s May 26, 1981 United States Nuclear Regulatory Commission Office of Inspection and Enforcementg Atta: Boyce H. Grier, Regional Director Region I 631 Park Avenue King of Prussia, Pennsylvania 19406
Reference:
Beaver Valley Power Station, Unic No. 1 Docket No. 50-334, License No. DPR-66 IE Bulletin 81-03 Gentlemen:
We have completed our review of IE Bulletin 81-03, " Flow Blockage of Cooling Water to Safety System Components by QRSICULA SP. (Asiatic Clam) and MYTILUS SP. (Mussel) and a report containing the details of our evalua-tica is attached. The Duquesne Light Annual Ecological Report indidates the presence of Corbicula sp. during previous years, however, no clams have been reported in the quarterly surveys for 1979 and 1980.
The last reported sa=ple taken on Septe=ber 23, 1980 indicated no cla=s present in the local environment.
The Mvt11us sp. problem is not applicable to 3eaver Valley since the Mvtilus sp. is a salt water species.
Since clam shells had been fcund during past inspections, an investi-gation was perfor=ed to confirm the absence of class or clas debris in potentially affected fire protection and safety related systems at Beaver l
Valley Power Station.
l The following systems and components were within the scope of this l
inves tigation:
1 i
1)
Intake Structure Bays 2)
Recirculation Spray Heat Exchangers 3)
Reactor Plant Component Cooling Water Heat Exchangers 4)
River Water In-line Strainers 5)
Charging Pump Coolers l
6)
Control Room Ventilation System River Water Cooling Coils and l
Air Conditioning Condenser g
l 7)
Emergency Diesel Generator Coolers 8)
Fire Protection System k(
1 8106090 N 9
3eaver Valley Power Station, Unit No.1 Docket No. 50-334, License No. DPR-66 IE Bulletin 81-03 Page 2 A visual inspection was conducted on components of the potentially affected systems whenever it was possible. Where a visual inspection was not practicable, Operational Surveillance Test (OST) results were evaluated and it was concluded that no flow blockage had occurred.
Af ter visually inspecting or operationally testing a representative sample of components within the scope of this inspection, we have determined that clams are not causing a degradation of cooling systems at Beaver Valley Power Statica, Unit No. 1.
In addition to present prevention and detection methods, visual inspections for clams have been added to existing procedures to aid in detecting any future increase in clam infestation of cooling systems.
The prevention and detection methods used presently and planned for the future should provide adequate indication of potential problems involving flow block-age or degradation due to clam debris.
Our estimate of the manpower expended in conducting the review and preparing this response is 50 manhours.
The additional manpower required for procedure revision was 2 manhours.
If you have any questions concerning this response, p'.0ase contact my office.
Very truly yours,
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Carey
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Attachment Vice President, Nuclear cc:
D. A. Beckman, Resident Inspector United States Nuclear Regulatory Commission Beaver Valley Power Station Shippingport, PA 15077 United States Nuclear Regulatory Commission c/o Document Management Branch Washington, DC 20555 United States Nuclear Regulatory Concission 1
Director, Office of Inspection and Enrorcement Washington, DC 20555
CCMMONWEALTH OF PENNSYLVANIA)
SS:
COUNTY OF BEAVER On thi " 2 82/
day of M A.u
- f/, before me
_/
/44-~ a Notary Pur#i"c in and for said Commonwealth argCounty, personally appeadd J. J. Carey, who being duly sworn, deposed, and said that (1) he is Vice President of Duquesne Light, (2) he is duly authorized to execute and file the foregoing Submittal on behalf of said Company, and (3) the statements set forth in the Submittal are true and correct to the best of his knowledge, information and belief.
JAA r swg a JUDITH 0. ANTHCNY, Notary Puclic Shippingsort Serough, leaver Co., Pa.
My Carntnission Egires Dec. 12, 1983 l
DUQUESNE LIGHT COMPANY Nuclear Operations Depart =ent Beaver Valley Power Station, Unit No. 1 Report Flow 31ockage of Cooling Water to Safety System Ccmponents by COR3ICULA SP. at the 3eaver Valley Power Station Prepared in Response to NRC IE 3cliecin 31-03 Prepared by:
bkh J. S. Patterson Reviewed by:
R."T. Zabowski
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Attachment Response to IE Bulletin No. 81-03 of the Nuclear Regulatorv Commission-Flow Blockage of Cooling Water To Safety System Components by Corbicula at the Beaver Vallev Power Station The Duquesne Light Annual Ecological Report indicated that corbicula densities had increased greatly from 1975 through 1976, but declined in number from 1977 through 1978.
During the year 1979, no clams were collected in the quarterly surveys. The lase sample taken on September 23, 1980 also indicated no clams were present in the local environment.
These samples were taken by three replicate ponar grab samples at mid-river and both river banks.
Shells, however, had been found in the main condenser inlet water boxes and chilled water condensers during past inspections.
Therefore, a thorough investigation was performed to confirm the absence of clams in the fire pro-tection and safety related systems at the 3eaver Valley Pcwer Station.
The following systems and components were within the scope of this investigation:
1)
Intake Structure Bays 2)
Recirculation Spray Heat Exchangers 3)
Reactor Plant Component Cooling Water Heat Exchangers 4)
River Water In-line Strainers (RW-452 and -453) 5)
Charging Pu=p Coolers s
6)
Control Room Ventilation System River Water Cooling Coils and Air Conditioning Condenser 7)
Emergency Diesel Generator Coolers 8)
Fire Protection System A visual inspection was conducted on components of these potentially affected systems whenever it was possible.
For components such as recircu-lation spray heat exchangers, where a visual inspection was not practicable, Operational Surveillance Test (OST) results were used to give conclusive evidence that flow blockage had not occurred. Results of the inspection are given below.
1.
Intake Structure 3ays a.
Method of Inspection:
OST 1.30.10, " Quarterly Silt check" b.
Extent of Fouling: No clam shells seen.
J c.
Inspected:
1/23/81 by diver.
d.
Pre entive Action:
Test is perforned four times a year to check and 4_.M aate debris frem the bays of the intake structure. Also, revisions lave been made to the test procedure to visuall'f inspect for clams.
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2.
Recirculation Spray Heat Exchangers 1A, 13, 1C and 1D a.
Method of Inspection: BVT 1.1-2.30.1 and
.2, " River Water Pump Head Capacity Curve Test" b.
Extent of Fouling: By directing water through the A and 3 river water headers, which supply the recirculation spray heat exchangers, acceptable flows of greater than 8000 gpm through the "A" header (lA and 1C heat exchangers) and "3" header (13 and 1D heat exchangers) were obtained (8000 gpm design flow).
c.
Inspected: Heat exchangers lA and 1C were tested on 12/19/80.
Heat exchangers 13 and ID were tested on 9/25/80.
d.
Preventive Action:
These tests were performed following pump modifications, however, OST 1.30.2 and
.3, "RP River Water Pump 1A and 13 Tests," which directs flow through the heat exchangers, are performed monthly.
3.
Reactor Plant Component Cooling Water Heat Exchangers CC-E-1A, 13 and 1C a.
Method of Inspection: Visual Inspection d
b.
Extent of Fouling:
Fouling consisted mostly of silt and sud, however, a total of about 30 clam shells approx 1=ately 0.5 in.
in diameter were removed.
c.
Inspected:
Each heat exchanger was opened and cleaned catching all solid debris in 55 gal. drums. The dates of the cleaning were 4/16/81, 4/22/81 and 5/4/81 (5'R 810846, 810847 and 310848).
d.
Preventive Action: 3ecause the plant nor= ally operates with a mn hum of two heat exchangers, the spare can be cleaned when performance is hindered by fouling.
4.
River Water System In-line Strainers RW-452 and -453 a.
Method of Inspection: Visual Inspection b.
Extent of Fouling:
No clam shells found.
c.
Inspected:
Each strainer is removed and cleaned daily.
d.
Preventive Action:
3ecause the strainers prevent fouling in the charging pu=p oil coolers and control room air conditioner condensers, the strainer baskets are removed and cleaned daily, paying particular attention for shells.
5.
Charging Pump Coolers a.
Method of Inspection: Visual Inspection b.
Extent of Fouling: No clam shells found. -
c.
Inspected: The oil and gear coolers of charging pump LA were cleaned on 4/11/81. A visual inspection was performed prior to clenning in which no clan shells were seen.
d.
Preventive Action: 3ecause the six coolers are downstream of the river water strainers, it see=s very imlikely that clam shells could cause clogging.
6.
E=ergency Diesel Generator Coolers a.
Method of Inspection: Visual Inspection b.
Extent of Fouling: No clams were found.
c.
Inspected:
NSQC provided surveillance during the cleaning of each diesel generator cooler.
Cooler EE-E-1A cleaned 4/28/80; cooler EE-E-13 cleaned 7/14/80. No clam shells were found.
d.
Preventive Action: Maintenance surveillance inspections are performed every 13 =onths to insure perfor=ance will not be hindered by fouling (MSF 36.23).
7.
Fire Protection System a.
Method of Inspection:
CST 1.33.3, " Fire Protaction System Drain Test," OST 1.33.4, " Fire Protection System Hydrant Test, and OST 1.33.6, " Fire Protection Systes Annual Test."
b.
Eitent of Fouling: No class were found 'in any of the fire protection systa=s.
c.
Inspected:
All systems were tested for an acceptable water supply.
Also, all strainers were flushed or changed if necessary.
(Drain Test OST 1.33.3 last perfor=ed 4/6/81; Hydrant Test OST 1.33.4 last perfor=ed 4/10/81; Annual Test CST 1.33.6 last perfor=ed 5/23/81.
l d.
Preventive Action:
These tests are perfor=ed either =onthly or L
annually to assure proper operation of the systa=s.
- Also, revisions have been made to procedure OST 1.33.6 to visus 11y I
inspect for class while perfor=ing the test.
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After visually and operationally examining a representative sat.p'7 M ccmponents within the scope of the inspection; it has been deter =ined that class l
are not a current proble= at the Beaver Valley Pcwer Station. Furthermore, the prevention and detection =ethods used presently and planned for the future should be adequate to avoid flow blockage or degradation due to clam debris.
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