ML19354E536

Responds to Generic Ltr 89-13, Svc Water Sys Problems Affecting Safety-Related Equipment & Informs That Util Intends to Review Existing Programs for safety-related Svc Water Sys to Ensure Intent of Generic Ltr Recommendations

ML19354E536
Person / Time
Site:	Vogtle
Issue date:	01/25/1990
From:	Hairston W GEORGIA POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
0192, 192, ELV-01212, ELV-1212, GL-89-13, NUDOCS 9001310338
Download: ML19354E536 (8)

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Georgia Pm.cr Commmy .

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• Stephore 404 M% 3195 Ma hrg; Adtheu 40 inemez Center Mwar Post OVe Box 1P95 0,mungnam Atatuma 35?Of hephone 205 sC3 %81 January 25, 1990

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$nNN$m ELV-01212 l num onmens 0192 Docket Nos. 50-424 50-425 4 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555 Gentlemen:

V0GTLE ELECTRIC GENERATING PLANT RESPONSE TO GENERIC LETTER 89-13 SERVICE WATER SYSTEM PROBLEMS AFFECTING SAFETY-RELATED E0VIPMENT Generic Letter 89-13, " Service Water System Problems Affecting Safety-Related Equipment", was issued on July 18, 1989 to all holders of operating licenses or construction permits for nuclear power. plants. The generic letter requires  ;

licensees to ensure that the service water systems are in compliance with t General Design Criteria (GDC) 44, " Cooling Water; GDC 45, " Inspection of Cooling Water System"; and GDC 46, "Tcsting of Cooling Water System" in 10 CFR 50,-  ;

Appendix A. Licensees are required to advise the NRC whether programs-have been.  !

established to implement Recommendations I-V of this Generic Letter or that an '

equally effective alternative course of action has been established.- The licensees response to this requirement for information shall be made to the NRC within 180 days of receipt of this Generic letter and each licensee and  ;

applicant shall confirm to the NRC that all recommended actions or their '

justified alternatives have been implemented within 30 days after implementation.

In response, at the Vogtle Electric Generating Plant (VEGP), Georgia Power .

l Company intends to review existing programs for the safety-related service water i systems to ensure the intent of the Generic Letter recommendations is met. If 1 the existing programs do not adequately address the Generic Letter, existing j programs will be revised or new programs will be established. The programs j

.shall be established prior to unit startup following the Fall 1990 refueling j outage for VEGP - Unit 2 and Fall 1991 refueling outage for VEGP. - Unit 1. A  ;

response indicating that all initial tests or activities have been completed and ^j that programs have been established will be submitted within 30 days.of the J final implementation. Enclosure'1 presents a brief summary of the various i service water systems at VEGP. Enclosure 2 provides.a discussion of each of the initial recommended actions along with GPC's response.

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Geolgia Powei U. S. Nuclear Regulatory Commission ELV-01212 Pace Two Mr. W. G. Hairston, 111 states that he is a Senior Vice President of Georgia Power Company and is authorized to execute this oath on behalf of Georgia Power Company and that, to the best of his knowledge and belief, the facts set forth in this letter and enclosures are true.

GEORGIA POWER, COMPANY

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/ t^W. G. Hairston, Ill 7

Sworn to and subscribed before me this 25Uof d a vi m, , - , 1990.

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Enclosures:

1. Description of Service Water Systems

2. Service Water System Problems Affecting Safety-Related Equipment xt: Georaia Power Comnany Mr. C. K. McCoy Mr. G. Bockhold, Jr.

Mr. P. D. Rushton Mr. R. M. Odom NORMS U. S. Nuclear Reaulatory Commission Mr. S. D. Ebneter, Regional Administrator Mr. J. B. Hopkins, Licensing Project Manager, NRR Mr. J. F. Rogge, Senior Resident Inspector, Vogtle

l ENCLOSURE 1 V0GTLE ELECTRIC GENERATING PLANT DESCRIPTION OF COOLING WATER SYSTEMS Safety-Related Service Water Systems The nuclear service cooling water (NSCW) system, which is essentially a closed system, pr ovides cooling water for the containment coolers, the essential chilled water chiller condensers, various engineered safety feature (ESF) pump and motor coolers, the standby diesel generator jacket water coolers, the piping penetration area coolers, the reactor cavity cooling coil, and the component cooling water (CCW) and auxiliary component cooling water (ACCW) heat exchangers. The NSCW system transfers the heat removed from these systems to the ultimate heat sink (VHS), which is the NSCW cooling tower basin. Makeup for each NSCW tower basin is normally provided by a connection with the plant makeup water wells.

The component cooling water (CCW) system, which is a closed system, provides cooling for the spent fuel pool during all plant operating modes and for the residual heat removal (RHR) system during normal shutdown and emergency conditions. The CCW system also serves as an intermediate system or barrier between the reactor coolant system and the nuclear service cooling water (NSCW) system, which is open to the atmosphere.

Nonsafetv-Related Service Water Systems The auxiliary component cooling water (ACCW) system transfers heat from reactor auxiliary components to the nuclear service cooling water (NSCW) system. The ACCW system forms an intermediate system or barrier between components which could possibly release radioactivity and the NSCW which is open to the atmosphere. The ACCW system is not essential for safe plant shutdown (not safety-related) under accident conditions but is necessary for normal startup, power operations, and normal cooldown (without an accident).

The turbine plant closed cooling water (TPCCW) system provides chemically treated, deminera'ized water for the removal of heat from nonsafety-related heat exchangers in the turbine building and to reject the heat to the turbine plant cooling water systam.

The turbine plant cooling water (TPCW) system supplies cooling water to remove heat from nonsafety-related heat exchangers in the turbine building and non-safety related heat exchangers in the auxiliary building.

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ENCLOSURE 2 V0GTLE ELECTRIC GENERATING PLANT GENERIC LETTER 89-13 SERVICE WATER SYSTEM PROBLEMS AFFECTING SAFETY-RELATED E0VIPMENT Recommended Action i "For open-cycle service water systems, implement and maintain an ongoing program of surveillance and control techniques to significantly reduce the incidence of flow blockage as a result of biofouling...."

Resnonse to Recommended Action 1 A closed-cycle system is defined in the generic letter as "... a part of the service water system that is not subject to significant sources-of contamination, one in which the water chemistry is controlled, and one .in which heat is not directly rejected to a heat sink." As discussed below, the Nuclear Service Cooling Water (NSCW) system at the Vogtle Electric Generating Plant (VEGP) is essentially a closed system.

As noted in Enclosure 1, makeup water to 'the nuclear service cooling water )

system is provided from wells. The use of well water significantly reduces the j possibility of biological fouling. ~

A review of chemical treatment records and plant procedures has also been performed. The review indicates that the NSCW system has had proper chemistry- 1 control since the system was initially placed in use. Additionally, chemistry procedures exist for the nuclear service cooling water system and other systems 1 which ensure that there is an ongoing program of surveillance and control i techniques to significantly reduce the incidence of flow blockage as_ a result of biofouling.

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Most nuclear power stations discharge safety-related cooling water directly to a j river or pond; thus the outlet piping is subject to biofouling. _At VEGP, the NSCW system cooling water towers are used to reject heat from the NSCW system. 1 Thus, there is no chance of an outlet pipe experiencing flow blockage problems .!

as a result of biofouling. Even though heat is directly rejected to-heat sink 4 open to the atmosphere, the' NSCW system is essentialy a closed-cycle system.

Recommended Action II }

" Conduct a test program to verify the heat transfer capability of all safety-related heat exchangers cooled by service water. The total test program ,

should consist of an initial test and a periodic retest program. Both the t initial test program and the periodic retest program should include heat' -i exchangers connected to or cooled by one or more open-cycle systems as defined above. Operating experience and studies indicate that closed-cycle service . I water systems, such as component cooling water systems, have the potential for significant fouling as a consequence of aging-related in-leakage and erosion _or corrosion. The need for testing closed-cycle system heat exchangers has not  ;

been considered necessary because of the assumed high quality of existing '

chemistry control programs.

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ENCLOSURE 2 V0GTLE ELECTRIC GENERATING PLANT GENERIC LETTER 89-13 SERVICE WATER SYSTEM PROBLEMS AFFECTING SAFETY-RELATED E0VIPMENT If the adequacy of these chemistry control programs cannot be confirmed over the '

total operating history of the plant or if during the conduct of _the total testing program any unexplained downward trend in heat exchanger performance is identified that cannot be remedied by maintenance of an open-cycle system, it may be necessary to selectively extend the test program and the routine inspection and maintenance program addressed in Action III, below, to the attached closed-cycle systems.

A program acceptable to the NRC for heat exchanger testing is described in

" Program for Testing Heat Transfer Capability" (Enclosure 2). It should be noted that Enclosure 2 is provided as guidance for an acceptable program. An equally effective program to ensure satisfaction of the heat removal '

requirements of the service water system would also be acceptable...." q Response to Recommended Action II As previously discussed, GPC considers the NSCW system at VEGP .to be a closed-cycle system. VEGP intends to develop and implement either a test program or a regular maintenance program to verify acceptable operation of safety-related heat exchangers cooled by the NSCW system. If applicable, the test program will utilize, to a large extent, the guidance provided by the EPRI interim report of July 1989 entitled, " Heat Exchanger Testing and Analysis '

Guidelines for Service Water Systems."

Test results (with extropolation as necessary)- will be used to calculate significant performance parameters and compare them to design values. The parameters will also be trended to monitor heat exchanger performance on a continuing basis. Significant deviations will be identified and-corrected if-possible. The component will be restored to the original performance basis or an assurance will be provided that it can still adequately perform its intended l

design functions. Since the NSCW system is essentially a closed system, the results of testing and regular inspection programs at the next-outage will be

utilized for determining the appropriate frequency. for future testing or scheduled maintenance to provide assurance that the equipment will perform the intended safety functions. Additionally, since the NSCW system is not considered to be an open system, the final testing -frequency may exceed the-recommended frequency of 5 years, i

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I ENCLOSURE 2- j V0GTLE ELECTRIC GENERATING PLANT-GENERIC LETTER 89-13 j SERVICE WATER SYSTEM PROBLEMS AFFECTING SAFETY-RELATED E0VIPMENT. ,

VEGP has also determined that the CCW system for each unit has received proper ,

chemistry control since the systems were initially placed.in operation at both  !

units. VEGP intends to perform tests on the CCW heat exchangers and the results of the test program is expected to be used for scheduling additional tests or regular maintenance. However,. regular maintenance may be implemented at extended intervals since this is a closed system and proper chemistry controls have been in existence.

Recommended Action Ill

" Ensure by establishing a routine inspection and maintenance program for open-cycle service water system piping and components that corrosion, erosion, ,

protective coating failure, silting, and-biofouling cannot degrade the performance of the safety-related systems supplied by service water . The maintenance program should have at least the following purposes: ..

A. To remove excessive accumulations of biofouling agents,' corrosion products, and silt; B. To repair defective protective coatings and corroded-service water system piping and components that could adversely affect performance of their intended safety functions.

This program should be established before plant startup following the fi'rst a refueling outage beginning 9 months after the date of this letter. A description of the program and the results of these maintenance inspections should be documented. All revelant documentation -should be retained in appropriate plant records."

Response To Recommended Action 111 l The existing maintenance programs will be reviewed to ensure that the i appropriate components in the NSCW-and other systems are being inspected.

Heat exchangers and other components are visually inspected at established

intervals to ensure the proper cleanliness level is being maintained and that no.

pitting, cracks, leaks or other damage exists, Components will be added, if necessary, to existing plant checklists. The l existing plant programs ensure any identified deficiency as a result of-the l- above, is corrected. Results of testing and/or inspection programs may be used to modify subsequent test and inspection frequencies.

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ENCLOSURE 2 (CONTINUED)

GENERIC LETTER 89-13 SERVICE WATER SYSTEM PROBLEMS AFFECTING SAFETY-RELATED E0VIPMENT-Recommended Action-IV

" Confirm that the service water system will perform its intended function in accordance with the licensing basis for the plant. Reconstruction of the design basis of the system is not intended. This confirmation should include a review of the ability to perform required safety functions in the event of failure of a single active component. To ensure that the as-built system is in accordance

with the appropriate licensing basis documentations, this confirmation should-include recent (within the past 2-years) system walkdown inspections...."

Resnonse to Recommended Action IV The initial Plant Vogtle design confirmed that the service water system.will perform its intended design function in accordance with the licensing design basis. After completion of the preoperational testing, a system walkdown was ,

conducted by Engineering Startup and Operations personnel prior to placing the  !

system in continuous operation. These walkdowns were completed in 1986 for Unit 'j l 1 and 1988 for Unit 2. One of the objectives of this walkdown was to i demonstrate and document (in the turnover package) that the'as-built condition was in accordance with appropriate licensing. basis documents. Minor deviations' were identified, tracked and corrected.to bring the system configuration in l conformance with the licensing documentation, j After preoperational testing and system turnover, plant management assumed the responsibility for controlling, approving and implementing- plant modifications.

FSAR Section 17.2.3 " Design Change Control" ensures that design changes. made to l

VEGP are accomplished in a planned manner and controlled in accordance with I written, approved procedures. Safety evaluation processes for design changes-ensure that changes to FSAR or Technical Specifications are reviewed and-evaluated. Licensing document changes are processed using appropriate plant p ocedures. This enables Plant Management to maintain system configuration control. Finally, because this is a relatively new plant, a re-review of these processes is not needed at this time. q Recommended Action V

" Confirm that maintenance practices, operating and emergency procedures, and training that involves the service water system are adequate to ensure that-safety-related > equipment cooled by the service water system will function as J intended and that operators of this equipment will perform effectively. This f confirmation should included recent reviews of practices, procedures, and 1 training modules...."  !

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i ENCLOSURE 2 (CONTINUED)

V0GTLE ELECTRIC GENERATING PLANT- I GENERIC LETTER 89-13 SERVICE WATER SYSTEM PROBLEMS AFFECTIN(L SAFETY-RELATED E0UIPMENT-Response To Recommended Action V VEGP has reviewed maintenance practices, operating and emergency procedures for ,

the past 2 years for service water systems. Administrative controls for review and revision of all plant procedures are performed by Procedure 00051-C

" Procedure Review and Approval". Procedures are required to be reviewed'no later than 60 days prior to the second anniversary of the latest approval date of a procedure. The respective departments review their procedures based on past experience.

4 Additionally, VEGP has established training programs based on a systematic approach to training (SAT) process to develop accredited programs. The recently~ p developed training programs using the SAT process ensures that the training.will ,

be commensurate with the importance of th'e operation of the safety-related- r equipment cooled by the service water systems.

Based on these actions Georgia Power Company believes that the overall work .

controls system (practices, procedures and training) are adequate to ensure that

• safety-related equipment cooled by the service water systems will function as intended and that equipment operators will perform effectively.

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