U-601384, Responds to Generic Ltr 88-14, Instrument Air Supply Sys Problems Affecting Safety-Related Equipment, Requesting Review of NUREG-1275,Vol 2.Util Considers Program for Monitoring Air Quality Adequate
| ML20244B127 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 04/06/1989 |
| From: | Hall D ILLINOIS POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| RTR-NUREG-1275 DPH-0188-89, DPH-188-89, GL-88-14, U-601384, NUDOCS 8904190016 | |
| Download: ML20244B127 (6) | |
Text
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til.INDIS POWER COMPANY IP CLINTON POWEA STAT 40N, P.O. box 678. CLINTON, ILLINOIS 61727
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April 6, 1989-1 w
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. Docket No. 50-461-Document Control Desk Nuclear Regulatory Commission Washington,;D.C.
20555
Subject:
Clinton Power Station s
Instrument Air Supply System Problems Affecting
. Safety-Related Equipment (Generic Letter 88-14)-
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Dear Sir:
Julis letter is in response to Generic Letter 88-14 which requested a review of NUREG 1275, Volume 2 "O Experience Feedback Report - Air' System Problems," perating and performance of a' design and operations verification of the instrument air system.
Illinois Power Company'(IP) completed-the' requested review and verification,'and the:
results are provided in the attachment to this letter.-
Based on the results, IP concludes that overall,1Clinton
~ Power Station'(CPS).has an adequate program in place for monitoring air quality.
Although the air monitoring ~ program
'is adequate and-capable of identifying-system problems,'IP recognizes the need'to improve instrument air quality in the areas of moisture con-at and particulate size.
By making minor procedure revisions, reworking the air dryers, upgrading the priority of maintenance work, utilizing
-training programs and completing existing modifications, the instrument air system will'be enhi.nced and air quality will be improved.
Sincerely yours, s
8904190016$00061 PDR ADOCK PNV D. P. Hall P
Vice President DPH/pgc attachment cc:
NRC Resident Office NRC Region III, Regional Administrator f
NRC Clinton Licensing Project Manager Illinois Department of Nuclear Safety
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Attachment STATE 0F ILLIN0IS COUNTY OF-DEWITT l'GNALD P. HALL, being first duly sworn, deposes and says:
I am Vice' President of Illinois Power. Company.
The information
'provided'in the Attachment to this letter dated April (o, 1989,.
Subject:
Clinton Power Station Instrument Air Supply Tjstem l
Problems Affecting Safety-Related Equipment (Generic Letter F
88-14), was prepared under my supervision and direction.
.I know the' contents thereof, and to the best of my knowledge and belief the facts-contained therein are true and correct.
i Donald P.
Hall
)
Dated:
April I, 1989
)
J Subscribed and sworn to before me this M' /
day of April 1969 i
Notary Public My Commission Expires:
1 C
'0FilCIAL SEAL" ll Linda S. French b
f Notary Public, State of Illinois j My Commission Expires 9/1/92 1
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Attachment-
' Summary of Generic Letter 88-14 Verification-Items for Clinton Power Station Item I:'
Verification by test that actual instrument air
. quality is consistent with the manufacturer's recommendations for individual components served.
Response
At Clinton, instrument air quality'is monitored and maintained through performance of test. procedures.
Due to air. compressor design, the test procedures use dewpoint and particulate size as the only two criteria for measuring air quality.- A dewpoint of -40 degrees Fahrenheit and a particle size of 5 microns were determined to be the most limiting vendor values for, these two criteria.
A review of the CPS test procedures found that CPS currently tests for a deg oint of -40 degrees Fahrenheit and a particle size of 3 microns.
This review determined that the inspection criteria and air sampling methods utilized in the CPS test procedures were adecuate to assure that test results provide an accurate incication of internal' system conditions.
Although the program for monitoring air quality is adequate, the program for maintaining air quality consistent with the manufacturer's recommendations needs to be improved.
A review of past. test results indicates that system air quality has frequently not-met the manufacturer's specifications and that dryer performance has been erratic.
The apparent root cause for instrument air system problems is excessive time between the discovery and repair of instrument air system problems and a lack of cleanliness guidelines during preventive maintenance activities.
Corrective Actions taken to address the root cause include:
assigning instrument air dryer problems a higher priority to decrease the amount of time between discovery and repair and adding procedure steps to certain preventive maintenance activities to specifically invoke the cleanliness control' procedure, CPS No. 1019.02, System Cleanliness.
The approximate implementation date for these actions was December i
1988.
It is anticipated that these two actions will enhance the program for maintaining air quality and in turn will improve air quality significantly.
l Two additional long term actions will be taken to further improve air quality.
First, in accordance with a Nuclear Station Engineering Department action plan developed in October of 1988, all three air dryers will be reworked shortly after the current refueling outage to improve their performance.
The rework will consist Page 1 of 4
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Attachment'
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of' replacing each dryer's desiccant, checking and
. repairing all dryer skid valves, andLcalibrating and repairing. dryer instrumentation.
Second, Field Alteration IAF007, which resulted from a review of the instrument air system performed by Stone and Webster, is scheduled to be implemented in late 1989.
This.
Field Alteration will add automatic drain traps to both sides of the Instrument Air dryeriprefilters and sample-valves to both sides of the dryer afterfilters.
The drain traps will replace the' existing time operated solenoid drain valves and will help to alleviate moisture accumulation.
The sample valves will allow intermittent testing of individual dryer air quality.
These changes should improve the quality of air and make it consistent with manufacturer's recommendations.
Item II:
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
The preventive maintenance activities (PMs) for all the, safety-related instrument air supplied equipment were reviewed for adequacy.
This review indicated that a PM task had been initiated, approved, and scheduled for all equipment that required a PM task.
With the exception of a few PMs being deficient in the area of system cleanliness guidelines, the PMs were found to be sufficient in detail and instruction.
The PMs for the instrument air system are being performed as scheduled.
Only three of the one-hundred and twenty-one PMs are-behind schedule.
These three PMs are expected to be completed within the twenty-five percent extension grace period.
The instructor guides for Operations and Maintenance training were also reviewed for completeness and accuracy.
No major deficiencies were identified.
Both Operations and Maintenance training procedures describe the instrument / service air system configuration and basic component operation.
Operations training identifies critical setpoints as well as the automatic and necessary manual actions.
In addition, the system operating procedure, annunciator procedure, and emergency procedure were reviewed and were verified to accurately diagnose and direct corrective action within the capability of the system.
While maintenance personnel were trained on the maintenance procedures, it was determined that maintenance personnel were not required to attend training on the instrument air system.
To provide maintenance. personnel with a more thorough understanding of the instrument air system, appropriate maintenance personnel will be trained on Page 2 of 4
'Attachmsntf the' instrument air system.- This training will be completed by June-15, 1989.
The adequacy.of the. system PMs, the Operations and Maintenance' training program, and the emergency / operating procedures should ensure that safety-related equipment functions as. intended-upon loss of instrument air.
Item III:
Verification that the~ design of theLentire 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
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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
At Clinton, all loss of air testing required by Generic Letter 88-14 was performed in 1986 via preoperational testing procedures PTP-IA/SA-02 and PTP-MS-01 The preoperational testing at CPS exceeded the requirements of the generic letter by testing for a' gradual loss of air as well as for required fast-loss of air.
A design review of all air operated safety-related components was also performed to assure that the failure position for the required safety function was correct.
No design discrepancies were found.
Item IV:
Each licensee / applicant should provide a discussion of their program for maintaining proper instrument air quality.
Response
The program for maintaining proper instrument air quality at CPS is extensive and detailed.
It consists of four procedures which are used to gather information about air quality.
Two of the four procedures (NSED R.0, " Equipment Failure Maintenance Work Request Trending and' Evaluation Program" and' CPS No. 1016.01,
" Condition Reports") identify frequent maintenance problems and Field discrepancies and provide engineering with information regarding hardware / equipment problems.
The remaining two procedures (CPS No. 1820.00 " Instrument Air Quality" and 6804.01, " Collection and Determination of Instrument Air Particles") describe the method of monitoring actual air quality through sampling.
Directions for the use of system blowdowns and visual inspections are also provided.
Together, these four procedures examine the immediate physical characteristics of the system and long-term problems and trends.
In addition to the four procedures, condition reports are used to define and disposition Page 3 of 4
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system problems by utilizing modifications, maintenance y
work requests, or action plans to complete. analysis'and 1
corrective' actions-.
'As.a' result of the air' quality: monitoring / program,-the-
-late 1987. prove air quality'at CPS.was identified in'.
need to im p
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.At.that' time, IP contracted'with Stone-and L
Webstersto' perform a' review ofLthefcapability:and-reliability of the instrument ~ air system.
The Stone and Webster-review resulted in the development of Field Alteration IAF007.. The Field Alttration, as well as the other actions' discussed in the response to Item 4I, should result in improved air quality..
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