ML20006D255
| ML20006D255 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 01/30/1990 |
| From: | Fitzpatrick E GENERAL PUBLIC UTILITIES CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-89-13, NUDOCS 9002120295 | |
| Download: ML20006D255 (5) | |
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- OPU Nuclear Corporation d, Nuclear;
- ia'g;see Forked River,New Jersey 087310388 609 971 4000 Writer's Direct Dial Number
J anuary 30 _1990 U.S. Nuclear Regulatory Commission Attentions Document Control Desk p
' Washington, DC 20555 Gentlemen Subjects oyster Creek Nuclear Generating Station
- Docket No. 50-219 Generic Letter 89-13 Response Attached is GPU Nuclear's response to Generic Letter 89-13 concerning the oyster Creek Service Water System. The attachment summarizes the NRC recommended actions followed by GPU Nuclear's response to each action.
If you have any questions regarding the submittal, please contact Kathy Barnes, oyster Creek Licensing _ Engineer at (609)971-4390.
Very truly yours,
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-E. E. Fitz trick-Vice President and Director oyster Creek EEF dmd docs \\barnes\\gl89-13 Attachment
_cc Mr.' William T. Russell, Administrator Sworn to and Subscribed before Region'I U.S.: Nuclear Regulatory Commission me this d
day
'475 Allendale Road v
King of Prussia, PA 19406 of 4
, 1990.
Mr. Alex W. Dromerick, Project Manager US Nuclear Regulatory Commission Washington, DC 20555 a ho M.
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NRC Resident Inspector DIANA M. DeBLASIO oyster Creek Nuclear Generating Station f
9002120295,900130 PDR ADOCK 05000219 j$
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P PDC dj GPU Nuclear Corporation is a subsidiary of the General Public Utilities Corporation 4
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ATTACHMENT NRC Recommended Action In-
> - "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 problems as a result of biofouling."
GPUN Response
. The affected open cycle service water system, per the criteria of GL 89-13, consists of the Emergency Service Water (ESW) system.
Enclosure l'(Items A-D) to GL 89-13 provided a recommended program for responding.
to Recommended Action 1.
The fo.llowing provides GPUN's program in response to each of those items.
Enclosure I.
Item'A An inspection program for the intake structure at Oyster Creek was implemented during the past two refueling outages. During the 11R outage, the north intake. structure was dowatered, cleaned and repaired as necessary.
The south intake was done during the 12R outage.
The inspection was performed primarily to examine structural integrity of the intake structure components and to make repairs as necessary.
GPUN does not believe that dewatering and inspecting the externals of the intake structure would be beneficial to ensuring reliability of the oyster-Creek ESW system, and has implemented an effective alternative course of action.. As outlined in response to Recommended Action III below, a-surveillance and inspection program are in place that provide early indication of biofouling and flow degradation. As indicated by these surveillance and inspection results, corrective actione are taken as necessary to ensure sufficient system-flow.
Enclosure I.
Item B The ESW system is currently chlorinated to prevent biofouling to the extent allowed by NJ State permits. There is a portion of piping, approximately 50-100 ft., that is not chlorinated. A modification would be required that would relocate the chlorination injection point to include this portion of pipe, and therefore, provide chlorination of a greater percentage of the ESW piping. _.This modification is presently being evaluated as an improvement to
.our existing chlorination system, and if it is determined to be necessary, will be scheduled in accordance with the integrated schedule.
Enclosure I.
Item C l
The ESW system is currently tested at full flow once per month.
The system has few mechanical interfaces with other systems (Chlorination, Service Water, and containment spray), there are no infrequently used loops, and the redundant pumps are tested at the same frequency as the primary pumps.
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Enclosure I, Item D
.This-requirement is not applicable to oyster Creek as the cooling water source is not freshwater.
.GPUN considers Oyster Creek to be in compliance with the recommended Action I.
NRC Recommended Action II:
" conduct m' test program to-verify the heat transfer capability of all safety
.related heat exchangers-cooled by service water..."
GPUN. Responses currently, GPUN does not have a' program for performance testing of the containment Spray Heat exchangers.
In accordance with the recommendation, GPUN is evaluating E
the feasibility of monitoring heat exchanger performance, based on accuracies of
.available instrumentation and adequate temperature differential.
If it is
-determined to be feasible, a monitoring program, as outlined below, will be in effect prior to startup from the 13R outage.
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Additional instrumentation will be installed to measure Heat Exchanger tube side inlet and outlet temperatures, and heat oxchanger shell side 1:
inist-temperature.
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A test procedure will be developed with appropriate acceptance-criteria, or with a method for craculating acceptable performance based on the data.
-obtained.
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An initial test frequency will be established. Testing of the heat exchangers will only be possible when-there is sufficient;tomperature differential between the intake canal and the torus water, sucia as in the fall, months.
Performance testing may not be possible immediately after
.the-tube cleaning due to insufficient. temperature differential, but'will be scheduled at~the first opportunity.
If such a monitoring program is not feasible, GPUN will implement an alternative
. action such as that suggested in Enclosure 2 to GL 89-13.
The alternative actions would include visual inspections, when possible, and trending of surveillance data to ensure cleanliness of the heat exchangers.
Based on this discussion, GPUN will provide a description of our monitoring program in future correspondence related to GL 89-13.
NRC Recommended Action III:
" 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."
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l'CPUN Response Differential pressure across the heat exchangers is monitored during the monthly system surveillance test. Maintenance, which includes tube cleaning and inspection, is performed when the differential pressure reaches predetermined
. limits. The monthly surveillance tests also provide an indication of the degree of fouling in the ESW pump discharge piping. The effect of this fouling on pump flow is monitored and cleaning is scheduled as appropriate _to maintain system capabilities.
The majority of the ESW piping has an internal protective coating. GPUN has established a program which roquires ultrasonic test measurements to be performed on the uncoated portions of the piping each refueling outage. The results are evaluated to determine corrosion in the piping.
The results of the evaluation are used to identify requisite corrective actions, as appropriate. During the 11R and 12R outages, portions of the ESW piping were monitored by UT measurements and video camera.
Both surveillance methods revealed that the pipe wall thickness remains equal to, or greater than, the minimum required thickness.
The video
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camera revealed no coating degradation in the observed line areas.
In accordance with ASME Section XI requirements, GPUN will perform a pressure test of the underground portion of the ESW piping that cannot be visually inspected.
This test will be performed prior to startup from the 13R outage.
MPC Recommended Action IV:
" Confirm that the service water system will perform it's intended function in accordance with the licensing basis of the plant..."
GPUN Response During August and September 1989, the NRC conducted _a Safety System Functional Inspection (SSFI) of the Oyster Creek ESW and Containment Spray Systems.
As documented.in NRC Inspection Report 89-80, the overall conclusion was that these systems would perform their intended functions during a design basis event. The weakneoses that were identified have been addressed in GPUN correspondence dated November 27, 1989 and January 23, 1990.
The SSFI team noted that the Containment Spray and ESW pump operability flow limits were not consistent with the flowrates assumed in containment performance analyses. Additionally, previous containment analyses assumed a maximum intake l
canal temperature of 85'F, which had recently been exceeded. During December, l
1989, GPUN issued Technical Data Report (TDR) 993 which resolved these issues.
Your letter of December 20, 1989 provided concurrence that these issues have been resolved. Therefore, GPUN considers Oyster Creek to be in compliance with Recommended Action IV.
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b EBQ,,, 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 eystem will function as intended and that operators of this equipment will ',4rform ef fectively.... "
GPUN Response GPUN procedures are reviewed at least every two years and are revised as required, which provides reasonable assurance that procedures are adequate and reflect plant configuration. In addition, these procedures were reviewed during the recent SSFI and found to be acceptable.
The oyster Creek training department maintains lesson plans for training operators on plant systems.
Lesson plans are reviewed and revised as necessary to reflect changes in system configuration and operation.
GPUN concludes that our current procedure review and training programs provide assurance that the safety related equipment cooled by service water systems will-perform their intended functions, and that operators of this equipment will perform effectively.
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