ML20034G456

Forwards Response to Requested Actions Delineated in NRC Bulletin 90-001,Suppl 1, Loss of Fill-Oil in Transmitters Mfg by Rosemount. Total of 114 Transmitters,Within Scope of Bulletin,Installed at Facilities

ML20034G456
Person / Time
Site:	LaSalle
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 9303090540
Download: ML20034G456 (11)

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Downers Grove, lilinois 60515 March 5, 1993 Dr. Thomas E. Murley, Director Office of Nuclear Reactor Regulation J.S. Nuclear Regulatory Commission Washington, DC 20555 Attention:

Document Control Desk

Subject:

Response to NRC Bulletin 90-01 Supplement 1, dated December 22, 1992.

LaSalle County Station Units 1 and 2, (NRC Dockets 50-373 and 50-374)

Reference:

NRC Bulletin 90-01 Supplement 1. " Loss of Fill Oil in Transmitters Manufactured by Rosemount," dated December 22, 1992.

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Dear Dr. Murley:

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The purpose of this letter is to provide the LaSalle County Station response to the requested actions of Bulletin 90-01, Supplement 1. The details of the LaSalle response are contained in Attachment I and a-tabular summary is provided in Attachment 2. Attachment 3 contains the necessary justification to extend the enhanced surveillance frequency to a refueling outage for certain j

affected transmitters.

LaSalle has a total of one hundred fourteen (114) transmitters within the scope of the referenced Bulletin. Based on transmitter maturity, operating pressure and Bulletin categorization, LaSalle Station has twenty-five (25) transmitters which require justification to maintain a refueling outage erhanced surveillance frequency.

Consistent with the Bulletin's reporting requirements, LaSalle Station has reviewed the requested actions and agrees to comply with the applicable actions.

Specifically, LaSalle will:

maintain an enhanced surveillance program, at a refueling CJtage frequency, for t

the thirty-four (34), Category 1 d transmitters until they reach maturity-and maintain the refueling outage enhanced surveillance for the twenty five (25)

Category 1.c transmitters until they reach maturity.

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Dr. Murley March 5, 1993 i

Hith NRC approval of LaSalle's Category 1.c monitoring program and justifications, LaSalle will fully comply with the recommended actions of the Supplement.

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 CECO 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.

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Sincerely.

David J. Chrzanowski j

Generic Issues Administrator Nuclear Regulatory Services Attachments:

! - Response to NRCB 90-01 S1 Actions

- Tabular Summary of Transmitter Status l - Justification for Extended Surveillance l

Frequency cc: Regional Administrator-RIII R. Stransky, LaSalle Project Manager-NRR/PDIII-2 D. Hills, Senior Resident Inspector (LaSalle) l t

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- ZNLD/2524/2

g LaSalle Station Response to NRCB 90-01 51 Requested Actions Re_questeLAc1Lon; 1.

Review Plant records and identify any Rost.ount 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).

LaSalle has completed this review and has determined that a total of one hundred fourteen (114) affected 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 pressure greater than 1500 psi and that are installed in reactor protection trip systems, ESF actuation systems or ATHS systems.

Action for those transmitters that have not met the Rosemount psi-month threshold criterion should be expedited.

LaSalle 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.

LaSalle does not have any transmitters in this category.

b.

Replace, or monitor for the life of the transmitter on a quarterly basis using an enhanced surveillance monitoring program, any transmitters 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.

i LaSalle does not have any transmitters in this category.

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4 LaSalle Station Response to NRCB 90-01 S1 Requested /.ctions 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.

LaSalle does not have any transmitters in this category.

c.

T.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 less than or equal to 1500 psi, that are installed in reactor protection trip systems, ESF actuation systems or ATHS systems.

LaSalle has a total of seventeen (17) transmitters in this category. contains a justification to extend the enhanced survelliance to a refueling outage frequency. Also, LaSalle is attempting to develop a on-line monthly surveillance to satisfy this requirement.

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.

LaSalle has a total of eight (8) transmitters in this category. The justification for 2xtending the surveillance to a refueling outage frequency for these transmitters is described in Attachment 3.

c.

[For PWRsf 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 installed in reactor protection trip systems. ESF actuation systems, or ATHS systems.

The PWR requirements are not applicable to LaSalle County Station.

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Attrchment 1 LaSalle Station Response to NRCB 90-01 S1 Requested Actions d.

Replace, or monitor at least once every refueling cycle, but not exceeding 24 months, using an enhanced surveillance monitoring program ur il 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.

LaSalle has thirty-four (34) transmitters in this category.

LaSalle has, since issuance of the original Bulletin 90-01, maintained an enhanced surveillance program for these transmitters. This program will continue with a refueling outage surveillance frequency.

e.

At licensee discretion, exclude from the enhanced surveillance program any transmitters that have a normal operating 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 l

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.

LaSalle has ten (10) transmitters in this category. LaSalle has, since issuance of the original Bulletin 90-01, maintained an enhanced surveillance program for these transmitters. This program will continue with a refueling outage surveillance frequency thereby maintaining confidence that transmitter failures can be detected.

f.

At licensee discretion, exclude from the enhanced surveillance program any transmitters that have a normai 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.

LaSalle has a total of forty-five (45) transmitters in this category.

LaSalle has, since issuance of the original Bulletin 90-01, maintained an enhanced surveillance program for these transmitters.

This program will continue with a refueling outage surveillance frequency thereby maintaining confidence that transmitter failures can be detected.

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.

LaSalle has an enhanced surveillance program that monitors, with required accuracy, the parameters indicative of a loss of fill oil condition.

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Summary of Transmitter Status for LaSalle Station Buttetin Transmitter Frequency of Discussion /Coments Category Pressure /Fmetion Maturity Enhanced Survel11as e 1.a Not Mature, LaSalle does not have any transmitters in Normal Operating Pressure

< 60,000 N/A this category

>1500 psi and transmitter psi

• months is installed in RPS,ESF or ATWS systems

Mature, LaSalle does not have any transmitters in

> 60,000 N/A this category psi

• months 1.b Not Mature, LaSalle does not have any transmitters in Normal Operating Pressure

< 60,000 N/A this category

>1500 psi. Transmitter is psi

• months safety related but is nod installed in RPS, ESF or

Nature, LaSalle does not have any transmitters in ATWS systems

> 60,000 N/A this category psi

• months 1.c Operating pressure from Not Mature, Modthl9 LaSai lF haF17 hansmitiersVtM Fiategory (BWR) 500 to 1500 psi and

< 60,000 transmitter is in RPS, ESF psi

• months Refueijrid LASaikhislS[tferdEf ttd(jkjhKc:aieg@p i

or ATWS systems Outage

Nature, N/A LaSalle does not have any transmitters in

> 60,000 this category psi

• months l

1 1.c Operating pressure from Not Mature, Not applicable to LaSalle I

(PWR) 500 to 1500 psi and

< 60,000 N/A transmitter is in RPS, ESF psi

• months or AtWS systems

Mature, Not applicable to LaSalle

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> 60,000 N/A osi* months 1.d Operating pressure from Not Mature,

%Ung bSaue!ns)MammlMelrs%yVeayg6rp 500 to 1500 psi and

< 60,000 transmitter is npLt in RPS, psi

• months f,

ESF or ATWS systems but is

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safety related 1.e Operating pressure from

nature, flempt LaSalle^nas] O H ansmitt' ( Jnithis';d M p i

e 500 to 1500 psi

> 60,000 psi

• months 1.f Operating pressure less N/A Ekespt

[aSa} t e3as 35[t rarsmi t t @in[thi s[ssieg6py than or couat to 500 psi 2

LaSalle has an enhanced surveillance monitoring program that provides measurement data with an accuracy range consistent for determining degradation caused by loss of fill oil.

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Justification for Refueling Outage Surveillance' Frequencies for

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i 1/2B21-N402A,B,C,D Reactor Vessel Low Low Low (Level 1) and Low Low (Level 2) Water Level MSIV Isolation.

These transmitters feed a single failure proof logic scheme to isolate various primary containment valves, including the MSIV's in the event of a low water level. Therefore the failure of one transmitter will not preclude l

a trip.

Presently, calibration of the transmitters are performed during refuel and the calibration data is used as part of an enhanced monitoring program. Calibrations are. not presently performed with the unit at power due to the potential for inadvertent actuation. LThe consequences of an

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inadvertent actuation would be a containment isolation signal being supplied to various components including the MSIV's.

Closure of MSIV's would cause a i

Reactor Scram and pressurization transient if the unit was at rated j

conditions. Testing which is performed at power includes monthly functional testing of each transmitter's trip unit (s) and shiftly channel checks, which-l compare indication to redundant channels of the same parameter. While

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neither functional testing or channel checks are used as input to an

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enhanced monitoring program, this information is used qualitatively to i

determine if degradation is present.

i In Unit 1, 2 of the 4 installed transmitters are new transmitters or sensing j

modules and thus do not require enhanced monitoring. The other transmitters installed in Unit I and all 4 transmitters instaIIed in Unit 2 have been in service for a ninimum of 4.5 years and have had at least 4 calibrations. At this time, the trending of calibration data performed on an 18 month j

frequency has resulted in no reason to believe the transmitter is subject to i

oil loss at this time.

I Based on the installed redundancy, potential for inadvertent actuation, and

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the acceptable performance history, the present monitoring is sufficient to determine degradation due to loss of oil. No additional actions will be I

taken on these transmitters. This monitoring provides a high degree of confidence that oil loss will be diagnosed and corrected.

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1/2B21-N400A,B,C,D Reactor Water Low, Low (Level 2) ATWS/ Reactor Recirc Pump Trip (RPT) and Alternate Rod Insertion (ARI)

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. These transmitters are part of the trip logic for ATWS/RPT and alternate Rod Insertion (ARI) on low Reactor Water Level or Reactor High Pressure. These transmitters feed one of two redundant tripping schemes, each of which f

utilizes a one out of two twice logic of reactor level and pressure signals i

to trip.

Therefore, failure of one level transmitter would not preclude any safety function. Presently calibration of the level transmitters is performed at each refuel and the calibration data used as part of an enhanced monitoring program.

Calibrations are not currently performed with j

the unit at power due to the potential for inadvertent actuation. The consequences of an inadvertent actuation would be a Reactor Scram and trip of Reactor Recirculation Pumps. The pressure transmitters which also provide an input into the ATWS/RPT and ARI tripping scheme are calibrated quarterly. Therefore, sufficient redundancy exists such that the failure of one level transmitter would not cause a failure of the system to trip in the

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event of an ACTUAL event (ATWS).

Additional testing which is performed at l

power includes monthly functional testing of each transmitter's trip unit i

and shiftly channel checks, which compare indication to redundant channels of the same parameter. While neither functional testing or channel checks are used as input to an enhanced monitoring program, this information is l

used qualitatively to determine if degradation is present.

In both Units 1 and 2, 2 out of the 4 installed transmitters are new transmittern or sensing modules and thus do not require enhanced monitoring. The other transmitters installed in both units have been a minimum of 4.5 years in service and have at least-4 calibrations.

Enhanced

- i monitoring is being performed as described above and currently the f

transmitters do not show signs of oil loss.

i Based on the installed redundancy, potential for inadvertent actuation and.

the acceptable past performance history, enhanced monitoring of these

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transmitters will continue as is being performed at the present time.

This monitoring provides a high degree of confidence that oil loss will be l

diagnosed and corrected.

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1/2B21-N401A,B,C,D Reactor Vessel Hi Pressure ATWS/ Reactor Recirc Pump Trip (RPT) and Alternate Rod Insertion (ARI)

These transmitters are part of the trip logic for ATWS/RPT and Alternate Rod Insertion (ARI) on low Reactor Water Level or Reactor High Pressure. These transmitters feed one of two redundant tripping schemes, ecch of which utilizes a one out of two twice logic of reactor level and pressure signals to trip. Therefore, failure of one pressure transmitter would not preclude j

any safety function. Presently calibration of each_of the 4 pressure transmitters is performed quarterly and the calibration data used as part of l

an enhanced monitoring program. Additional testing includes a monthly l

functional test of each transmitters trip unit and shiftly channel checks, l

which compare indication to redundant channels of the same parameter. While neither functional testing or channel checks are used as input to an l

enhanced monitoring program, this information is used qualitatively to determine if degradation is present.

In both Unit 2, 2 out of the-4 installed pressure transmitters are new transmitters or sensing modules and thus do not require enhanced-monitoring. The other transmitters ir.Jtalled in both units have a minimum l

of 4.5 years in service and have at least 10 calibrations. Enhanced monitoring is currently being performed and the transmitters are presently I

within manufacturers drift criteria.

t Based on the insta13ed redundancy, and the quarterly calibrations and f

monitoring, no further actions will be taken for these transmitters. This monitoring provides a high degree of confidence that oil loss will be diagnosed and corrected.

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1/2B21-N403A,B,C,D Reactor Vessel Water Level Low (Level 3) RPS Scram i

These transmitters are part of the RPS trip logic on Reactor Low Water

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Level. There are two redundant RPS divisions each requiring a signal from l

one of two level transmitters to trip. Additionally, RPS is fed by signals l

from several other plant parameters. Therefore, sufficient redundancy l

exists such that the failure of one transmitter would not cause a failure of i

the respective RPS division to trip. Calibrations are performed on these transmitters.at each refuel with drift data trended as part of an enhanced monitoring program.

Currently calibrations are not performed on these i'

transmitters with the unit at power due to the potential for inadvertent actuation and resulting reactor scram. Additional testing which is l

performed includes monthly functional checks of the trip unit and shiftly channel checks which compare' indication to redundant channels of the same l

parameter. While data from the channel checks or functional tests is not used for enhanced monitoring, this information is used qualitatively to

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' determine if degradation is present.

All transmitters with the exception of one transmitter in Unit 1 are in the

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category which requires enhanced monitoring on a monthly frequency.

i However, all of these transmitters have been in service for a minimum of 3 t

years and have been calibrated a minimum of 3 times. Drift data taken at I

the time of calibration is being used for enhanced monitoring in accordance with manufacturers acceptance criteria. No transmitters show signs of l

degradation at this time.

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Based on the diversity of installed instrumentation, and the potential for

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and consequences of inadvertent actuation, the present frequency of monitoring will be used to determine degradation. This monitoring provides a high degree of confidence that oil loss will be diagnosed and corrected.

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i 1/2E31-N503 Reactor Water Cleanup System Inlet Flow This transmitter.provides an input into the Primary Containment Isolation on j

Reactor Water Cleanup System Differential Flow.

The sum of system return

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and blowdown flows, obtained from other transmitters, is subtracted form this transmitter's signal to obtain' differential flow. While a single set of transmitters services-both divisions of primary containment isolation logic, redundancy is provided by the fact that an increase in inlet flow due to a pipe break downstream of that sensing element would also show up as a decrease in return flow in the system. Additionally, a diverse trip is l

provided by RWCU area temperature sensors. Therefore, the failure of one transmitter would not prevent an isolation of the RWCU system.

i Transmitter calibration is performed each refuel. outage and zero drift data is trended as part of an enhanced monitoring program. Additionally, a monthly functional test of the tr?nsmitter and associated electronics is performed. Since this functional te6*. includes the transmitter, any gross degradation of transmitter response vot.'d be noted.

The transmitters for both Units 1 and ? have been installed for at least 4

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1/2 years, have accumulated a minimum o ' 41,500 psi-months and have been r

calibrated at least 4 times.

Based on c 'ibration data utilized in the enhanced monitoring program to date, these transmitters show no signs of degradation at this time.

Based on the diversity of installed instrumentation, these transmitters will continue to be calibrated at each refuel outage.

The results of these f

calibrations will be used as part of the enhanced monitoring program. This 7

monitoring provides a high degree of confidence that oil loss will be diagnosed and corrected.

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