ML18005A775
| ML18005A775 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 02/03/1989 |
| From: | Mcduffie M CAROLINA POWER & LIGHT CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| GL-88-14, NLS-89-022, NLS-89-22, NUDOCS 8902100345 | |
| Download: ML18005A775 (8) | |
Text
REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS) 4 ACCESSION NBR:8902100345 DOC.DATE: 89/02/03 NOTARIZED: YES FACIL:50-400 Shearon Harris Nuclear Power Plant, Unit 1, Carolina AUTH.NAME AUTHOR AFFILIATION MCDUFFIE,M.A.
Carolina Power
& Light Co.
RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)
SUBJECT:
Forwards response to Generic LTr 88-14, "Instrument Air Supply Sys Problems Affecting SAfety-Related...."
I DISTRIBUTION CODE: A001D COPIES RECEIVED:LTR ENCL SIZE TITLE: OR Submittal:
General Distribution NOTES:Application for permit renewal filed.
DOCKET I 05000400 S
05000400 RECIPIENT ID CODE/NAME PD2-1 LA BECKER,D INTERNAL: ACRS NRR/DEST/ADS 7E NRR/DEST/ESB 8D 1
NRR/DEST/RSB 8E NRR/DOEA/TSB 11 OGC/HDS1 RES/DSIR/EIB EXTERNAL LPDR NSIC COPIES LTTR ENCL 1
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1 RECIPIENT ID CODE/NAME PD2-1 PD ARM/DAF/LFMB NRR/DEST/CEB 8H NRR/DEST/MTB 9H NRR/DEST/S ICB NUJ3+CS~BS CT G FILE 0
NRC PDR COPIES LTTR ENCL 2
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NOTE 'l0 ALL 'KIDS" RZCIPZERIS:
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TOTAL NUMBER OF COPIES REQUIRED:
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M. A. McDUFFIE Senior vice President Nuclear Generation
~L Carolina Power 8 Ught Company P. O. Box1551 ~ Raielgh, N.C.27602 FEB 0 3 1989 SERIAL:
United States Nuclear Regulatory Commission ATTENTION:
Document Control Desk Washington, DC 20555 SHEARON HARRIS NUCLEAR POWER PLANT DOCKET NO. 50-400/LICENSE NO.
RESPONSE
TO NRC GENERIC LETTER 88-14 INSTRUMENT AIR SUPPLY SYSTEM PROBLEMS-AFFECTING SAFETY>>RELATED EQUIPMENT Gentlemen:
Carolina Power 8 Light Company (CPAL) hereby responds to requests in NRC Generic Letter 88-14 for the Shearon Harris Nuclear Power Plant (SHNPP).
This generic letter requested that CPAL review NUREG-1275, Volume 2, and perform a design and operations verification of the instrument air system.
The verification efforts that have been performed in accordance with the NRC Generic Letter 88-14 are addressed in the attachment to this letter.
Notwithstanding the favorable conclusions that were documented in the respective verifications, CP8L has' project underway to enhance previously identified areas for improvement in the instrument air system.
In particular, instrument and service air usage exceeds the original design estimates and would routinely require use of three of the four installed air compressors to maintain system pressure.
A temporary air compressor was added prior to fuel load as an interim measure to provide additional capacity and confidence in system reliability for planned and unplanned compressor outages.
Presently, additional air dryer capacity is also planned to provide additional redundancy and capacity.
In addition, while instrument air is not assumed to function in design basis accidents, it is very desirable to restore instrument air following a loss of off-site power.
While one compressor can be manually loaded onto each safety-related
- bus, the capacity of a single or two compressors may not be sufficient for the instrument air system to be functional.
Potential improvements to these areas are currently being studied.
In summary, the current configuration of the instrument air system at SHNPP supports the proper functioning of safety-related components supplied with instrument air; however, the areas for improvement discussed above will be prioritized and resolved based on their impact on overall plant reliability.
pool i90 i0034S eS020S PDR ADOCK 05000400 P
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'ocument Control Desk NLS-'89-022 / Page 2
Should you have any questions regarding the information contained herein, please contact Mr. John Eads at (919) 836-8165.
Yours very truly, Qd >~
M. A. McDuffie MAMIJCPlcrs (188CRS)
Attachment cc'.
Mr. R. A. Becker Mr. W. H. Bradford Mr. M. L. Ernst M. A. McDuffie, having been first duly sworn, did depose and say that the information contained herein is true and correct to the best of his information, knowledge and belief; and the sources of his information are officers, employees, contractors, and agents of Carolina Power
& Light Company.
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NRC GENERIC LETTER 88-'4 Carolina Power
& Light Company (CP&L) has been following the efforts by the nuclear industry and the NRC to identify concerns with the design, operations, maintenance, and training of personnel with respect to instrument air systems.
CP&L has initiated a program to assure that the SHNPP Instrument Air (IA) System will meet the intent of its design and that the safety-related portions of the system will function as required.
This'ncludes verification that the safety-related components will perform their intended safety-related function in the event of a loss of instrument air.
NRC GENERIC LETTER 88-14, ITEM 1 "Verification by test that actual instrument air quality is consistent with the manufacturer's recommendations for individual components served."
RESPONSE
A review of air quality sample results demonstrated that air quality in the IA System is consistent with the requirements of the individual components serviced.
The manufacturer's recommendations for air quality for the components associated with the safety-related pneumatically operated valves and operators were identified.
These requirements were compared with the actual measurements taken in the IA System and the Diesel Generator Air Starting System.
The moisture and oil content and the particles measured in the system were found to be acceptable.
It should also be noted that CP&L has installed in-line filters upstream of safety-related
- valves, and in components being supplied control air from the Diesel Generator Starting Air System to help assure the cleanliness of the air.
SHNPP has committed in the Safety Evaluation Report (Supplement 2
0 1
Section 9.3.1) for a dewpoint of -25 F in the IA System, which exceeds the individual component requirements addressed above (Reference Correspondence SER NLS-85-113 dated April 15, 1985).
A review of the recent air samples and the results of recent blowdowns to remove potential moisture indicated dewpoints in the range of 0 F rather than -25 F.
Although the air was not as dry as it should have been, a review of plant operating and maintenance records indicates no reason to suspect excessive moisture content in the IA System during this period of time.
Carolina Power
& Light Company is aggressively pursuing improvements to the IA System to bring the dewpoint measurement into compliance with our commitments.
Specifically, additional air dryer capacity and more efficient desiccant materials in existing air dryers are planned.
In the case of the Diesel Generator Starting Air System, moisture content is acceptable for operation of the critical components in the control system.
Actual measured dewpoint in the tanks is above desirable levels due to moisture collecting in low points in the air dryer towers.
A modification to provide a drain at the low point is being pursued to enhance air quality in the receivers.
The receivers have drain taps that are periodically blown down to remove collected moisture.
No problems have been identified for any components in the system due to moisture content.
(188CRS)
NRC GENERIC LETTER 88-14, ITEM 2 "Verification that maintenance practices, emergency procedures, and training are adequate to ensure that safety-related equipment will function as intended on loss of instrument air."
RESPONSE
CP&L has reviewed the manufacturer's recommendation for maintenance to be performed on the safety-related components served by the instrument air system and has compared them with the Preventive Maintenance (PM) Program at the SHNPP.
Although some minor deviations were noted, the PM Program was found to be adequate for ensuring that the equipment will function as intended.
CP&L has also reviewed the emergency procedures and training given to SHNPP personnel and found them to be adequate to address a postulated loss of instrument air and to ensure that safety-related equipment will function as intended.
NRC GENERIC LETTER 88-14, ITEM 3 "Verification that the design of the entire instrument air system including air or other pneumatic accumulators is in accordance with its intended function, including verification by test that air-operated safety-related components will perform as expected in accordance with all design basis
- events, including a loss of the normal instrument air system.
This design verification should include an analysis of current air-operated component failure positions to verify that they are correct for assuring required safety functions."
RESPONSE-CP&L has conducted a review of the Instrument Air System to verify that the design is in accordance with its intended safety function.
The following tasks were included in this review'.
l.
Identification of safety-related components
- that, upon loss of normal instrument air, must fail in a position which accomplishes that component's safety-related function and verification of correct fail positions.
2.
Identification of safety-related components that must perform safety-related functions after an assumed loss of instrument air.
These components are those required to have a safety-related supply of air in the form of stored air in an accumulator and/or from a safety-related air/nitrogen supply.
The capacity of the accumulators must be sufficient to allow the component to perform its safety-related function and to account for assumed leakage throughout the duration of the loss of instrument air event.
(188CRS)
3.
Review and verification of the interfaces between the safety-related and nonsafety-related parts of the Instrument Air System to assure, that upon the loss of normal instrument air, pressure is maintained in the safety-related part of the system, i.e., pressure in accumulators, etc.
This verification assures that the safety-related supply of air is directed to the appropriate components and is not lost from the system.
CP&L has conducted a test program during SHNPP start-up/preoperational testing to demonstrate that the air-operated safety-related components would perform their safety-related function upon an assumed loss of normal instrument air as expected.
This testing was completed in the fall of 1984.
These tests demonstrated the following.'.
The safety-related component would fail to its required position in order to fulfillits safety-related function.
2.
The safety-related component would be able to accomplish its safety-related function with the stored air in its associated, accumulator.
Only two valves, which provide vacuum relief capability to the containment, must operate to the non-fail-safe position to accomplish a safety-related function.
Carolina Power
& Light Company includes in its in-service inspection requirement periodic disassembly and inspection of the check valves separating the safety-related air accumulators and tubing from the nonsafety-related portions of the IA System, to ensure the accumulator remains pressurized following loss of instrument air.
In order to ensure integrity of the accumulator and its associated
- tubing, SHNPP intends to incorporate a pressure drop test into the post-maintenance testing requirements following any disassembly of the check valves.
NRC GENERIC LETTER 88-14, UNNUMBERED ITEM "In addition to the above, each licensee/applicant should provide a discussion of their program for maintaining proper instrument air quality."
RESPONSE
Carolina Power
& Light Company has established a preventive maintenance program at SHNPP to maintain proper air quality in the SHNPP IA and Diesel Generator Starting Air Systems.
The program includes: periodic sampling of the air quality in the instrument air system, including evaluation of the sample results by the system engineer; the proper maintenance of the instrument ai r compressors dryers and filters which are covered by plant preventive and corrective maintenance procedures',
and the training of personnel in operations and maintenance on the importance of maintaining good air quality in the Instrument Air System.
The training programs include both classroom and simulator instruction for licensed operators and candidates for a license, classroom training for maintenance personnel, and briefings t'o operations and maintenance personnel on industry events.
(188CRS)