ML20071C299
| ML20071C299 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 02/11/1983 |
| From: | Tucker H DUKE POWER CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| REF-SSINS-6820, REF-SSINS-SSINS-6 TAC-57444, TAC-57445, NUDOCS 8303010650 | |
| Download: ML20071C299 (3) | |
Text
s Duxn POWER GOMPANY P.O. Box 33180 011ARLOTTE, N.C. 28242 HALH. TUCKER Ten.ernoxe vu:a reunionst (704) 373-4331 wars. nam reontcreon February 11, 1983~
Mr. James P. O'Reilly,' Regional Administrator U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, Suite 3100 m
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W Atlanta, Georgia 30303 m
Attention:
Mr. Andy Cunningham S
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.u b Re: RII:ELJ Cu
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McGuire Nuclear Station
.d Docket Nos. 50-369 and 50-370 u:
v, IE Bulletin 81-03 (Additional Infonnation)
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Dear Mr. O'Reilly:
Please find attached Duke Power Conpany's response to IE Bulletin 81-03.
This bulletin concerns flow blochage of cooling water to safety co:2 pore _nt s by Corbicula sp. (Asiatic Clams) and Mytilus sp. (Mussel). This is being submitted as additional information as requested oy Mr. Edward L. Jordan, NFC/0!E, in his letter dated December 14, 1982.
I declare under penalty of perjury that the statements set fortit herein are true and correct to the best of my knowledge.
j Very truly yours,
..y G g,d
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Hal B. Tucker WHM/php Attachment cc: Director Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Mr. W. T. Orders Senior Resident Inspector McGuire Nuclear Station l
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l 8303010650 830211 PDR ADOCK 05000369 O
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Duke Power Company-McGuire Nuclear Station-Response to IE Bulletin 81-03 (Additional Information) 2.) McGuire Nuclear-Sthtion has confirmed the absence of clams and shell-
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debris in'the Nuclear Service Water System (RN) and the Fire Protection System (RF) by visual inspections during routine maintenance activities
.and high~ velocity flushes. As described in Section-3, a representative-
! sample of components in the RN system will be monitored onfa regular basis to assure proper-operation. Results of the high velocity flushL tests on the RF system are also provided in Section-3.. These activities will assure-that no system degradation is occurring-due to clams. Station
- personnel are aware of the intrusion potential of clams.and continue to visually inspect for class during normal maintenance activities. Neither the RN or RF systems _have ever been fouled by clams or shell debris.
3.) McGuire Nuclear Station will monitor two heat exchangers in-the RN system on a quarterly basis. This monitoring will consist of setting a reproducible flow and recording the inlet and outlet pressures.. The differential pressure will be compered over time to determine if fouling.
is occurring. The heat exchangers to be monitored are Containment Spray-
' Heat Exchanger lA (18" piping) and the Air Handling Unit for Residual
. Heat Removal Pump Motor lA (2" piping). This performance test is to be-
- implemented by: April 1,1983, assuming; that flow instrumentation' will be calibrated by this time. ~If significant fouling is detected on these heat.
exchangers,.other heat exchangers in the RN system will be inspected.
i A high velocity flush of the RF system is performed annually-to detect any flow blockage which may occur. The initial high velocity flush showed evidence of clams in the system. Subsequent high velocity flushes have shown a reduction-of clams in the system. No clams were detected j
during the most recent high velocity flush conducted in October 1982.
6 4a.) The potential for intrusion of clams into the RN and RF systems during low water level conditions in Lake Norman is no greater than during 2 '
normal water level' conditions. A sufficient volume of water is provided during low water level conditions to preclude a significant increase in the velocity of inlet water to the pump suctions.
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-Under worst case conditions, the standby nuclear service water pond is maintained at full' level (as required by the Technical Specifications) and is available-for use. Therefore, high velocities for this source are not s' problem.
4b.) Although no clams are present in the RN system at this time, the, performance
. test as stated in Section 3 will be implemented to determine any system degradation' caused by clams. Station personnel will also continue to monitor this system for evidence of clams during normal maintenance activities. A high velocity flush of the RF system is performed annually to detect any flow blockage which may be occurring, f
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~2-In order to prevent clams from entering-the RN' system, the intake pumps are filtered.with a 3/16 inch mesh strainer. If necessary the RN system design allows for high velocity flush and backflushing also.
To prevent clams from entering the RF system, the system is flushed with chlorinated water. Chlorine is fed,into the Jockey Pumps to maintain a residual concentration of 1-3 ppm' chlorine. The chlorine-level is monitored weekly to verify this concentration. Also, duplex strainers are located on the suction of the Jockey Pumps to prevent adult clams.from entering the system.
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5b.) The following safety related components in the'RN system are potentially.
affected by Corbicula:
Component Cooling System (KC) heat Exchanger Containment Spray System (NS) Heat Exchanger Nuclear Service Water System (RN) Pump Motor Heat Exchanger Component Cooling System (KC) Pump Motor Heat Exchanger Auxiliary Feedwater System (CA) Pump Motor Heat Exchanger Safety-Injection System (NI) Pump Motor Heat Exchanger Chemical & Volume Control. System (NV) Pump Motor Heat Exchanger Safety Injection System (NI) Pump 011 Heat Exchanger Chemical & Volume Control System (NV) Pump Cil Heat Exchanger.
Control Area Ventilation System (VC) Chiller Heat Exchanger Diesel Generator Engine Cooling Water System (KD) Heat Exchanger Air handling units for the Residual Heat Remeval Pump Motors (ND),
Containment Spray Pump Motors (NS), and Spent Fuel Cooling Pump Motors (KF)
The RF system has no components such as heat exchangers that could be affected by clams.
Sc.) Although there has been evidence of clams in the RN and RF systems in the past, no fouling has been observed.
5d.) Corbicula sp..(clams) were first discovered at McGuire Nuclear Station during preoperational testing of the RF system in August of 1978. Although there has been evidence of clams in the RN and RF systems in the past, no fouling has been observed.
Se.) Because McGuire Nuclear Station has never. experienced any flow blockage due to clams, no corrective actions have been deemed necessary. Preventive actions takca to eliminate clams in the RN and RF systems are described in Section 4b.