ML20034G468
| ML20034G468 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 03/05/1993 |
| From: | Chrzanowski D COMMONWEALTH EDISON CO. |
| To: | Murley T NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), Office of Nuclear Reactor Regulation |
| References | |
| IEB-90-001, IEB-90-1, NUDOCS 9303090558 | |
| Download: ML20034G468 (7) | |
Text
(~'\\ L Comm:nmalth Edisin
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/ z /.1400 Opus Place kV Downers Grove, Illinois 60515 C -
March 5, 1993 Dr. Thomas E. Murley, Director i
Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555 Attention:
Document Control Desk
Subject:
Response to PRC Bulletin 90-01 Supplement 1, dated December 22, L992.
Byron Units 1 and 2, (NRC Dockets 50-454 and 50-455)
Reference:
NRC Bulletin 90-01 Supplement 1
" Loss of Fill 011 in Transinitters Manufactured by Rosemount," dated December 22, 1992.
Dear Dr. Murley:
The purpose of this letter is to provide the Byron Station response to the requested actions of Bulletin 90-01 Supplement 1. The details of the Byron response are contained in Attachment 1 and a tr' ular summary is provided in.
Byron has a total of forty-two (42) transmitters within the scope of the referenced Bu11 Rin; however, no enhanced monitoring more frequent than once per refueling cycle will be required. This determination is based on transmitter maturity, operating pressure and Bulletin categorization.
Consiste c with the Bulletin's requirements, Byron Station agrees to comply with all applicable actions. Specifically, Byron will maintain an enhanced surveillance program, at a refueling outage frequcncy, for the two (2) transmitters in Bulletin category 1.d.
In addition, Byron Station will continue trending cumulative zero drift for the remaining forty (40) installed Rosemount transmitters on a refueling outage frequency. Although this trending is not required by the Bulletin, this enhanced surveillance program will provide additional confidence that fallare of these transmitters, caused by a lo:: of fill-oil, will be detected.
The enhanced surveillance program will be continued until all suspect transmitters have been replaced through normal maintenance and attrition.
These actions meet or exceed the recommendations of the Supplement anf no additional actions or justifications are required.
0D0011 9303090558 930305
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ZNLD/2522/1-PDR ADDCK 05000454
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r March 5, 1993-Dr. Murley
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To the best of my knowledge and belief, the statements contained.in this document are true and. correct. In some respects'these statements are not based-on my personal Knowledge, but on information furnished by other Commonwealth Edison employees,' contractor employees, and/or consultants. Such information has.-
been reviewed in accordance with company practice, and I believe it to be reliable.
If there are any questions or comments, please contact me.
+
Sincerely, David J. Chrzanowski-Generic Issues Administrator Nuclear Regulatory Services Attachments: - Response to NRCB 90-01 S1 Actions
, - Tabular Summary of Transmitter Status cc:
Regional Administrator-RIII 1
J. Hickman, Byron Project Manager-NRR/PDIII H. Peterson, Senior Resident Inspector (Byron) cm;af/f County g_ ?r,,g v,,}
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Byron Station Response to NRCB 90-01 S1 Requested Actions Requested _Acilons 1.
Review Plant records and identify any Rosemount Model 1153 Series B, Model 1153 Series D, and model 1154 transmitters manufactured before July 11, 1989, that are used or may be used in the future in either safety-related systems or systems installed in accordance with 10 CFR 50.62 (the ATHS rule), and i
Byron Station has completed this review and has determined that a total f<orty-two (42) Rosemount transmitters are installed in the described systems.
a.
Expeditiously replace, or monitor for the life of the transmitter on a monthly basis using an enhanced surveillance monitoring program, any transmitters that have a normal operating p qssure greater than 1500 psi and that are installed in reactor protectior, trip systems,
~F actuation systems or ATHS systems.
Action for those transmitters that have not met the Rosemount psi-month threshold criterion should be expedited.
Byron Station does not have any transmitters in this category.
At their discretion, licensees may monitor using an enhanced surveillance program at least once every refueling cycle, but not exceeding 24 months, transmitters in this category if the appropriate psi-month threshold criterion recommended by Rosemount has been reached, and the monitoring interval is justified based upon transmitter performance in service and its specific safety function.
Byron Station does not have any transmitters in this category.
b.
Replace, or monitor for the life of the transmitter on a que-terly basis using an enhanced surveillance monitoring program, any trants Itters that have a normal operating pressure greater than 1500 psi and that are used in safety-related applications but are not installed in reactor protection trip systems, ESF actuation systems, or ATHS systems.
Byron Station does not have any transmitters in this category.
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ZNLD/2522/3
Byron Station Response to NRCB 90-01 51 Requested Actions At their discretion, licensees may monitor using an enhanced surveillance program at least once every refueling cycle, but not exceeding 24 months, transmitters in this category if the appropriate psi-month threshold criterion recommended by Rosemount has been reached, and the monitoring interval is justified based upon transmitter performance in service and its specific function.
Byron Station does not have any transmitters in this category.
c.
[For BWRs) Replace, or monitor on a monthly basis using an enhanced surveillance monitoring program, until the transmitter reaches the appropriate psi-month threshold criterion ' recommended by Rosemount, any transmitters that have a normal operating pressure greater than 500 psi and 1ess than or equal to 1500 psi, that are installed in reactor protection trip systems, ESF actuation systems or ATHS systems.
The BWR requirements are not applicable to Byron Station.
On a case-by-case basis except for transmitters that initiate reactor protection or ATHS trips for high pressure or low water level, licensees may monitor using an enhanced surveillance program at least once every refueling cycle, but not exceeding 24 months, if sufficient justification is provided based upon transmitter performance in service and its specific safety function The BWR requirements are not applicable to Byron Station.
c.
[For PWRs] Replace, or monitor at least once every refueling cycle, but not exceeding 24 months, using an enhanced surveillance program until the transmitter reaches the appropriate psi-month threshold criterion recommended by Rosemount, any transmitters that have a normal operating pressure greater than 500 psi and less than or equal to 1500 psi and that are instailGd in reactor protection trip systems, ESF actuation systems, or ATt.S systems.
Byron Station does not have any transmitters, mature or non-mature, in this category.
l 1
ZNLD/2522/4
Attachnent 1 Byron Station Response to NRCB 90-01 51 Requested Actions d.
Replace, or monitor at least once every refueling cycle, but not exceeding 24 months, using an enhanced surveillance monitoring program until the transmitter reaches the appropriate psi-month threshold criterion recommended by Rosemount, any transmitters used in safety-related systems that have a normal operating pressure greater than 500 psi and less than or equal to 1500 psi, and that are not installed in reactor protection trip systems, ESF actuation systems, or ATHS systems.
Byron has two (2) transmitters in this category.
e.
At licensee discretion, exclude from the enhanced surveillance program any transmitters that have a normal operatiq9 pressure greater than 500 psi and less than or equal to 1500 psi that have reached the appropriate psi-month threshold criterion recommended by Rosemount (60,000 psi-months or 130,000 psi-months depending on the range code of the transmitter).
A high degree of confidence should be maintained for detecting failure of these transmitters caused by a loss of fill-oil and a high degree of reliability should be maintained for the function consistent with its safety significance.
Byron has six (6) transmitters in this category.
f.
At licensee discretion, exclude from the enhanced surveillance program any transmitters that have a normal operating pressure less than or equal to 500 psi.
A high degree of confidence should be maintained for detecting failure of these transmitters caused by a loss of fill-oil and a high degree of reliability should be maintained for the function consistent with its safety significance.
Byron has thirty-four (34) transmitters in this category. Sixteen (16) of these transmitters provide the control signal to the AF throttle valves and AF flow indication to the Main Control Board (MCB). The pressure these transmitters are exposed to the vast majority of the time is 15-30 psig which comes from the head pressure of the Condensate Storage Tank (CST).
Every month the AF pumps are run during a surveillance test for approximately I hour.
During the surveillance these flow transmitters are exposed to a systen pressure of approximately 2000 psi. At present these transmitters are calibrated every 18 months and the results are trended for cumulative zero drift.
Byron ronsiders that Bulletin Action 1.f is the appropriate category for these transmitters. The main consideration is that the primary risk factor contributing to the loss of fill-oil condition (high pressure) does not apply to these transmitters.
In Rosemount Technical Bulletin No. 4, Rosemount evaluated various risk factors and determined that " Transmitters normally not pressurized (stand by service) are at acceptable low failure rates due to limited time in service". Rosemounts classification of " stand by service" is applicable to these AF transmitters and by their review are not susceptible to high failure rates.
ZNLD/2522/5
Byron Station Response to NRCB 90-01 S1 Requested Actions 2.
Evaluate the enhanced surveillance. monitoring program to ensure that the program provides measurement data with an accuracy range consistent with that needed for comparison with manufacturer drift data criteria for determining degradation caused by a loss of fill-oil.
Byron Station has an enhanced surveillance program that monitors, with required accuracy, the parameters indicative of a loss of fill oil condition.
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ZNLD/2522/6-i i
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Summary of Transmitter Status for Byron Station Duttetin Transmitter frequency of Discussion /Consnents Category Pressure / Function MC urity Enhanced Surveillance 1.a Not Mature, Byron does not have any transmitters in this Normat operating Pressure
< 60,000 N/A category
>1500 psi and transmitter palamonths is installed in RPS,ESF or ATWS systems
- Mature, Byron does ;.ot have any transmitters in this
> 60,000 N/A cate pry a
psi
- months h
1.b Not Mature, Byron does not have any transmitters in this Normal Operating Pressure
< 60,000 N/A category
>1500 psi. Transmitter is y l* months safety related but is Ird installed in RPS, ESF or
- Mature, Byron does not have any transmitters in this ATWS systems
> 60,000 N/A category psl* months 1.c Operating pressure from Not Mature, N/A Not applicable to Byron (BWP) 500 to 1500 psi and
< 60,000 transmitter is in RPS, ESF psi
- months N/A Not applicable to Byron or ATWS systems
- Nature, N/A Not applicable to Byron
> 60,000 psi
- months 1.c Operating pressure from Not Mature, Byron does net have any transmitters in this (PWR) 500 to 1500 psi and
< 60,000 N/A category transmitter is in RPS, ESF psi
- months or ATWS systems
- stature, Byron does not have any transmitters in this
> 60,000 N/A category psl* months 1.d Operating pressure from Not Mature, Refueling B yrosjas(2 yansmi t ters[/}g th@ cat epary 500 to 1500 psi and
< 60,000 outage transmitter is no_t in RPS, psi
- Mature, benpj Byfon.has' 6}trarsmitte{i Itijhl(ciaffg6ry 500 to 1500 psi
> 60,000 psi
- months
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1 1.f Operating pressure less N/A herrpt Byronhas34 transmitters]n[this[capgory than or equal to 500 psi
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2 Byron Station has an enhanced surveillance monitoring program that provides measurement data with an accuracy range consistent for determining degradation caused by loss of ffit all.
1 Sixteen of these 34 transmitters are Auxiliary Feed System transmitters that normally operate at <100 psi. Per the Rosemount Technical Bulletin these transmitters are considered " Standby" and are exempt from enhanced surveillance.