ML20151C750
| ML20151C750 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 07/13/1988 |
| From: | Tucker H DUKE POWER CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| NUDOCS 8807220160 | |
| Download: ML20151C750 (5) | |
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DUKE POWER GOMPANY _
' P.O. BOX 33189 -
CHARLOTrE. N.O. 98949 HAL H. TUCKER rus arssown -
exa parainert
. (704) GTMMI umsan enoncernon July 13, 1988 7
U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C. 20555
Subject:
RII/PKV/MSL Catawba Nuclear Station Docket Noa. 50-413 and 50-414 IE Report 50-413 -414/88-14 Reply to Notice of Violation
Dear Sir:
Please find attached a reply to the Notice of Violation for Violations 413,414/88-14, A and B, which was transmitted by Dr. J. Nelson Grace's letter of June 13, 1988.
Very truly yours,
/h Hal B. Tucker PGL/42/sbn Attachments xc:
Dr. J. Nelson Grace, Regional Administrator U. S. Nuclear Regulatory Commission j
Pegion II 101 Marietta Street, NW, Suite 2900 l
Atlanta, Georgia 30323 Mr. P. K. Van Doorn NRC Resident Inspector Catawba Nuclear Station
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o Duka Power Company Reply to Notice of Violation (A) 413,414/88-14
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10 CFR Part 50, Appendix B, Criterion XI, requires that a test program be established to assure that all te? ting required to damonstrate that structures, systems, and components will perform satisfactorily in service is identified and performed in accordance with written tests procedures which-incorporate the requirements and acceptance limits contained in applicable design documents. The tent program shall include, as appropriate, proof tests prior to installation, pre-operational tests, and operational tests during nuclear power plant operation, of structures, systems, and components. Test results shall be documented and evaluated to assure that test requirements have been satisfied.
Contrary to the above, as of March 9, 1988, the test program implemented by the licensee to assure the operability of the auxiliary feedwater system (AFS) was inadequate in that it did not provide an adequate method to detect the growth of asiatic clams in the inactive portions of the Nuclear Service Water system and, as such, did not detect the growth of such clams, which resulted in the clogging of AFS Train 'A' discharge control valves 2CA-56 ad 2CA-60 with clam shells after the motor-driven AFS pump 2A suction realigned to the nuclear _ervice water assured source.
(1) Admission or Denial of Violation:
Duke Power Company admits the violation.
(2) Reasons for Violation:
A test program was in place to detect the growth of asiatic clams in the inactive portions of the Nuclear Service Water (RN) system.
Periodic testing had been proceeding since initial operation of the plant in response to Bulletin 81-03.
This testing included:
Flow balancing of the RN system to verify adequate flow to o
appropriate equipment.
Testing of essential heat exchangers served by the RN system to 3
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ensure adequate flow and heat transfer capability.
Cleaning and inspection of heat exchangers or piping if testing o
dictated, with emphasis on examination for unusual fouling or presence of clams, Radiographing (RT) sections of dead leg RN piping where clam o
growth could be a problem.
Prior to March 9, 1988 this testing and inspection program revealed very minor clam infestation in raw water systems at Catawba.
Clams were rarely found in the RN system.
However, clams were growing in stagnant areas of RN q
piping that were not being inspected. This allowed these clams to grow to maturity and degrade Auxiliary Feedwater (CA) flow to the steam generators i
when the suction for the CA motor-driven pump 2A swapped from normal condensate sources to the RN system.
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u' Violation Response 88-14 Page Two.
(3) Corrective Actions'Taken and Results-Achieved:
- The testing and inspection program for the identifying clam infestation has been expanded.
This will ensure all areas, of the essential Nuclear Servic9-Water (RN) system that are susceptible-to clam infestation, will remain-clear of flow blockage that can: result from clam infestation. The testing and inspection expansion includes periodic flushing of systems when RN serves as the. essential backup water. supply and is normally stagnant. Also, when flushing of the stagnant piping is in progress, collection of. water samples is made. The water is analyzed to determine the offectiveness of the system flushing.' The results of this expanded testing program have shown no further degraded systems as a result of clam infestation.
(4) Corrective Actions to be Taken to Avoid Further Violations:
The expanded testing program outlined in paragraph (3) above should allow Catawba to avoid further violations.
(5) Date of Full Compliance:
r Duke Power Company is now in full compliance.
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e Duke Power Company Reply to Notice of Violation (B) 413,414/88-14 Catawba Nuclear Station Technical Specification 3.7.1.2 requires that three independent steam generator auxiliary feedwater pumps and associated flow paths be operable with:
o Two motor-driven auxiliary feedwater pumps, each capable of being powered from separate emergency busses, and o
One steam turbine-driven auxiliary feedwater pump capable of being powered from an operable steam supply system when the unit is in modes 1, 2, or 3.
With one auxiliary feedwater pump inoperable, it is required to be restored to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or the unit be in at least hot standby within the next six hours and in bot shutdown within the following six hours.
Contrary to the above, on March 9, 1988, with Unit 2 in mode 1 and operating at 20 percent power, three independent steam generator auxiliary feedwater pumps and associated flow paths were not operable during an actual turbine trip /feedwater isolation transient and resulting auxiliary feedwater system (CA) initiation.
(1) Admission or Denial of Violation:
i Duke Power Company admits the violation.
(2) Reasons for Violation:
Asiatic clam larvae from Lake Wylie entered the Nuclear Service Water (RN) j system, settled in stagnant areas of piping and grew to maturity. When the suction for the Auxiliary Feedwater (CA) system motor-driven pump 2A swapped from normal condensate sources to the RN system, clam shells lodged in the control valves for pump 2A and degraded the flow to 'A' and 'B' steam generators from CA motor-driven pump 2A.
(3) Corrective Actions Taken and Results Achieved:
l All areas of the essential Nuclear Service Water (RN) system that are susceptible to clam infestation, have been flushed, inspected or both. This flushing or inspection included the RN to Auxiliary Feedwater (CA) piping, the RN to Containment Valve Injection Water (NW) piping, the RN to Component Cooling (KC) piping and the RN makeup to the spent fuel pool piping. This flushing or inspection was done on both units.
The control valves from the CA motor-driven pump 2A to A and B steam generators were disassembled and cleaned. The Unit 2 CA system was flow balanced to ensure operability. The results of the flushing and inspection have ensured the operability of the Auxiliary Feedwater system and all other essential systems served by the RN system. A safety analysis of the degraded CA system flow was performed.
This analysis showed this incident to have no effect on the safety of the plant.
Violetion Raponro 88-14 Page Two (4) Corrective Actions to be Taken to Avoid Further Violations:
The actions outlined in paragraph (3) above should allow Catawba to avoid further violations.
(5) Date of Full Compliance:
Duke Power Company is now in full compliance.
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