ML20072T915
| ML20072T915 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 08/31/1994 |
| From: | Udy A EG&G IDAHO, INC., IDAHO NATIONAL ENGINEERING & ENVIRONMENTAL LABORATORY |
| To: | NRC |
| Shared Package | |
| ML20072T921 | List: |
| References | |
| CON-FIN-L-1695 EGG-DNSP-11449, IEB-90-001, IEB-90-1, NUDOCS 9409160037 | |
| Download: ML20072T915 (18) | |
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EGG-DNSP-11449 l
TECHNICAL EVALUATION REPORT Evaluation of Utility Response to Supplement I to NRC Bulletin 90-01:
Sequoyah-1/-2 Docket Nos. 50-327 and 50-328 Alan C. Udy Published August 1994 EG&G Idaho, Inc.
Idaho National Engineering Laboratory Idaho Falls, Idaho 83415 l
Prepared for the U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Under DOE Contract No. DE-AC07-76ID01570 FIN No. L1695, Task No. 11 TAC Nos. M85442 and M85443
.je" (T409/h37 x4
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SUMMARY
This report documents the.EG&G Idaho, Inc., review of the Tennessee Valley Authority submittals that respond to Supplement 1 to NRC Bulletin _90-01 for Unit Nos. I and 2 of the Sequoyah Nuclear Plant. This NRC Bulletin provides information on the loss of fill-oil in certain pressure and
'I differential pressure transmitters manufactured by Rosemount, Inc. This report finds the licensee complies with the requested actions and reporting requirements of the Supplement.
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FIN No. L1695, Task No. 11 B&R No. 320-19-15-05-0 Docket Nos. 50-327 and 50-328 TAC Nos. M85442 and M85443 11
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t PREFACE This report is supplied as part of the " Technical Assistance in Support of the Instrumentation and Controls Systems Branch."
It is being conducted for the U.S. Nuclear Regulatory Commission, Office of Nuclear Reactor Regulation, Division of Reactor Controls and Human Factors, by EG&G Idaho, Inc., DOE /NRC Support Programs Unit.
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4 CONTENTS
SUMMARY
ii PREFACE..............................................................
iii 1.
INTRODUCTION....................................................
I 2.
NRC SPECIFIED REQUESTED ACTIONS.................................
4 3.
EVALUATION......................................................
7 3.1 Evaluation of Licensee Response to Reporting Requirements.
7 3.2 Evaluation of Licensee Response to Requested' Actions......
8 4.
CONCLUSIONS.....................................................
12 5.
REFERENCES......................................................
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1 Evaluation of Utility Resoonse to Suoolement I to i
j NRC Bulletin 90-01:
Seouovah-1/-2 l
1.
INTRODUCTION The NRC issued Bulletin 90-01 on March 9, 1990 (Reference 1)
Bulletin discussed certain Rosemount pressure and differential pressu That transmitter models identified by the manufacturer as prone to fill oil leakage.
The bulletin requested licensees to identify whether these transmitters were or may later be installed in safety-related systems Actions were detailed for licensee implementation for certain identified transmitters installed in a safety-related system.
These same actions apply to those identified transmitters presently held in inventory for later installation in a safety-related system.
With the gradual leakage of fill-oil, the transmitter would not have long term accuracy, time response, and reliability needed for its inte safety function.
Further, this condition could go undetected over a long period.
Redundant instrument channels are subject to the same degradation mechanism.
This increases the potential for a common mode failure.
this potential failure mechanism raised concern for the reliability of r
- Thus, protection systems (RPS), engineered safety features (ESF) actuation s eactor and anticipated transient without scram (ATWS) mitigating systems.
high functional reliability, there must be a low probability of componen To achieve failure while operating, with any failures readily detectable.
Supplement 1 to NRC Bulletin 90-01 (Reference 2) was issued on December 22, 1992.
The Supplement informed licensees of NRC staff activities regarding the subject transmitters, and noted continuing reports of transmitter failures.
The NRC requested licensee action to resolve the issue.
The Supplement also updated the information contained in the original bulletin.
The licensee was requested to review the information and determine if it was applicable at their facility.
Further, the licensee was requested to modify their actions and enhanced surveillance monitoring programs to conform with the direction given.
Finally, the licensee was instructed to 1
respond to the NRC.
The Reouested Actions in Supplement I to NRC Bulletin 90-01 supersede the original NRC Bulletin 90-01 Recuested Actions.
In responding to Supplement I to NRC Bulletin 90-01, the licensee is directed to address three items.
1.
A statement either committing the licensee to take the NRC Bulletin 90-01, Supplement 1, Reouested Actions or taking exception to those actions.
2.
Addressing the actions committed to in the above statement, provide:
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a.
a list of specific actions, including any justifications, to be taken to complete the commitment, b.
a schedule for completion, and after completion, a statement confirming the actions c.
committed to are complete.
3.
A statement identifying the NRC Bulletin 90-01, Supplement 1,
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Reouested Actions not taken, along with an evaluation providing the basis for exemption.
In implementing the replacement option of the NRC Reouested Actions, plant shutdown exclusively for replacing the transmitters is not required.
This allowance infers that replacements can be scheduled. With replacement in i
a timely manner, enhanced surveillance monitoring for interim operation is not required.
The Tennessee Valley Authority, the licensee for Unit Nos. I and 2 of the Sequoyah Nuclear Plant, responded to Supplement I of NRC Bulletin 90-01 with a letter dated March 4, 1993 (Reference 3). The licensee provided additional information in submittals dated March 15, 1994 (Reference 4), and July 8, 1994 (Reference 5). This technical evaluation report evaluates the completeness of those submittals.
It also determines whether proposed 2
surveillance methods are adequate to determine fill-oil loss-caused degradation of the transmitter.
Finally, this report addresses the interval l
of surveillance proposed by the licensee for any transmitters included in the enhanced surveillance monitoring program.
l Many Rosemount transmitter failures have been attributed to the use of stainless steel "0"-rings between the sensing module and the process flanges.
Rosemount improved the manufacturing process for transmitters manufactured after July 11, 1989. Those improvements included a limit of the torque applied to the flange bolts.
This limits the stress caused in the sensing module by the "0"-ring.
Post-production screening, including pressure testing of the sensing module for this potential latent defect, was also implemented at that time.
Therefore, as described in Supplement 1 of NRC Bulletin 90-01, those Rosemount transmitters manufactured after July 11, 1989, are not subject j
to this review.
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2.
NRC SPECIFIED REQUESTED ACTIONS The NRC staff specified the following Reauested Actions of licensees of operating reactors.
1.
Review plant records and identify the following Rosemount transmitters (if manufactured before July 11,1989) that either are used in or may be used in either safety-related or ATWS mitigating systems.
Rosemount Model 1153, Series B Rosemount Model 1153, Series 0 Rosemount Model 1154 Following identification, the licensee is to establish the following:
For those identified transmitters having a normal operating a.
pressure greater than 1500 psi, and are installed as part of reactor protection trip systems, ESF actuation systems, or ATWS mitigating systems, either replace the transmitter in an expedited manner, or monitor monthly, for the life of the transmitter, using an enhanced surveillance program.
If the identified transmitter exceeds the 60,000 psi-month or the 130,000 psi-month criterion (depending on the range code of the transmitter) established by Rosemount, enhanced surveillance on a refueling (not exceeding 24 months) basis is acceptable.
Under this option, justification must be based on the service record and the specific safety function of the transmitter.
That justification can be based on high functional reliability provided by redundancy or diversity.
b.
For those identified transmitters having a normal operating pressure greater than 1500 psi, and are installed as part of a safety-related system other than reactor protection trip systems, ESF actuation, or ATWS mitigating systems, either replace the transmitter or monitor qua'rterly, for the life of the transmitter, using an enhanced surveillance program.
If the identified transmitter exceeds the 60,000 psi-month or the 130,000 psi-month criterion (depending on the range code of the transmitter) established by Rosemount, enhanced surveillance on a rafueling (not exceeding 24 months) basis is acceptable.
Under this option, justification must be based on the service record and the specific safety function of the transmitter.
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justification can be based on high functional reliability provided by redundancy or diversity.
c.
For boiling water reactors (BWR)--
For those identified transmitters having a normal operating pressure greater than 500 psi and less than or equal to 1500 psi, and are installed as part of reactor protection trip systems, ESF actuation systems, or ATWS mitigating systems, either replace the transmitter, or monitor monthly with an enhanced surveillance monitoring program, until the transmitter reaches the designated (by Rosemount) psi-month criterion (60,000 psi-month or 130,000 psi-month, depending on the transmitter range code).
For transmitters that provide signals to the RPS or ATWS trips for high pressure or low water level, the enhanced surveillance must be monthly.
For other transmitters in this classification, enhanced surveillance on a refueling (not exceeding 24 months) basis is acceptable.
Under this option, justificaticn must be based on the service record and the specific safety function of the transmitter.
That justification can be based on high functional reliability provided by redundancy or diversity.
For pressurized water reactors (PWR)--
For those identified transmitters having a normal operating pressure greater than 500 psi and less than or equal to 1500 psi, and are installed as part of reactor protection trip systems, ESF actuation systems, or ATWS mitigating systems, either replace the transmitter, or monitor with an enhanced surveillance monitoring program, until the transmitter reaches the designated (by Rosemount) psi-month criterion (60,000 psi-month or 130,000 psi-month, depending on the transmitter range code) on a refueling (not exceeding 24 months) basis.
d.
For those identified transmitters having a normal operating pressure greater than 500 psi and less than or equal to 1500 psi, and are installed as part of a safety-related system other than reactor protection trip systems, ESF actuation, or ATWS mitigating systems, either replace the transmitter or monitor with an enhanced surveillance monitoring program, until the transmitter reaches the designated (by Rosemount) psi-month criterion (60,000 psi-month or 130,000 psi-month, depending on the transmitter range code) on a refueling (not exceeding 24 months) basis.
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e.
Those transmitters having a normal operating pressure greater than 500 psi and less than or equal to 1500 psi, and have accumulated sufficient psi-month operating history to exceed the criterion established by Rosemount, may be excluded from the enhanced surveillance monitoring program at the discretion of the licensee.
However, the licensee should retain a high level of confidence that a high level of reliability is maintained and that transmitter failure due to loss of fill-oil is detectable.
f.
Those transmitters having a normal operating pressure less than or equal to 500 psi may be excluded from the enhanced surveillance monitoring program at the discretion of the licensee.
- However, the licensee should retain a high level of confidence ~ that a high level of reliability is maintained and that transmitter failure due to loss of fill-oil is detectable.
2.
Evaluate the enhanced surveillance monitoring program.
The evaluation is to ensure the measurement data has an accuracy commensurate with the accur::y needed to compare the data to the manufacturers drift data criteria.
It.is this comparison that determines the degradation threshold for loss of fill-oil failures of the subject transmitters.
The Supplement also states the NRC may conduct audits or inspections in the future to verify compliance with the established requirements.
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3.
EVALUATION The licensee responded to Supplement 1 of NRC Bulletin 90-01 on March 4, 1993.
The licensee augmented that information on March 15, 1994, and July 8, 1994.
The responses were compared to the Bulletin Reoortino Reauirements and Reauested Actions as described below.
In Reference 3, the licensee reports having nine Rosemount transmitters that are subject to the Reauested Actions of the Supplement.
Reference 4 reports that one of those transmitters was replaced with a transmitter manufactured after July 11, 1989.
Therefore, that transmitter is no longer subject to the requirements of the Supplement. All the subject transmitters are Model 1153, Series D, transmitters installed in either the auxiliary feedwater system or the core spray system.
Other Rosemount transmitters are outside the scope of the Supplement due to replacement, refurbishment, or use in non-safety applications.
3.1 Evaluation of Licensee Response to Reportino Reauirements The licensee states they intend to take appropriate actions in response to the Reauested Actions of Supplement 1 to NRC Bulletin 90-01.
Included with that statement is clarification, interpretation, and the limits placed on that commitment.
The licensee described the specific actions taken to implement the Reauested Actions.
References 4 and 5 elaborate on those actions.
The licensee reported no new actions in response to the Reauested Actions.
This implies that existing programs satisfy the Reauested Actions.
The licensee provides evaluation and justification supporting the position that no changes to their enhanced surveillance monitoring program, established in response to NRC Bulletin 90-01, are necessary.
The licensee, as described in Reference 4, has a calibration data trending program that complies with the Supplement.
The licensee submittals conform to the Reoortino Reauirements of Supplement 1 of NRC Bulletin 90-01.
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3.2 Evaluation of Licensee Response to Reauested Actions Supplement 1 of NRC Bulletin 90-01 requested licensee action to resolve the issue of fill-oil leakage in Rosemount transmitters.
This Technical Evaluation Report summarizes the Reauested Actions and the associated transmitter criteria in Section 2.
The licensee, as of March 15, 1994, has eight transmitters in the scope of this review.
The licensee has only Rosemount model 1153, series D, transmitters installed at the Sequoyah Nuclear Plant that are within the scope of the Supplement. Three participate in the enhanced surveill.ince monitoring program. The following sections discuss the licensee response to the Supplement.
3.2.1 Licensee Response to Reauested Action 1.a The licensee states there are no Rosemount transmitters from this transmitter classification at the Sequoyah Nuclear Plant.
3.2.2 Licensee Resoonse to Reauested Action 1.b The licensee states there are no Rosemount transmitters from this transmitter classification at the Sequoyah Nuclear Plant.
3.2.3 Licensee Response to Reauested Action 1.c The licensee states there are no Rosemount transmitters from this transmitter classification at the Sequoyah Nuclear Plant.
3.2.4 Licensee Resoonse to Reauested Action 1.d The licensee states, in Reference 3, that there are four Rosemount transmitters from this transmitter classification at the Sequoyah Nuclear 8
Plant. These four transmitters (1-FT-3-142, 2-FT-3-142, 1-FT-3-147, and 1-FT-3-155) monitor flow in the auxiliary feedwater system.
In Reference 4, the licensee documents that transmitter 1-FT-3-155 was replaced with a Rosemount transmitter manufactured after July 11, 1989.
Thus, transmitter 1-FT-3-155 is no longer subject to the Supplement requirements. These transmitters are not subject to operating pressure during normal reactor operation.
Exposure to operating pressure occurs during plant startup and shutdown operations, unanticipated unit trips and safety injections, and system testing. The licensee includes transmitters 1-FT-3-142, 2-FT-3-142, and 1-FT-3-147 in their enhanced surveillance monitoring program. That program trends the transmitter drift over the life of the transmitter. The transmitters will remain in the drift trending program until replaced. Transmitter calibration data provides the drift data. Calibrations take place during refueling outages.
We find the licensee actions for this transmitter classification acceptable.
3.2.5 Licensee Response to Reauested Action 1.e The licensee states there is one Rosemount transmitter from this transmitter classification at the Sequoyah Nuclear Plant.
Transmitter 1-FT 163 monitors flow in the Unit I auxiliary feedwater system. This transmitter is, however, exposed to pressure during normal reactor operation. Thus, it has a working history exceeding the psi-month maturity threshold established by Rosemount and endorsed by the NRC.
At the discretion of the licensee, this transmitter is not in the enhanced surveillance monitoring program. This is permitted by the Supplement.
However, the Supplement requires the licensee to maintain a high degree of confidence that transmitters in this transmitter glassification remain highly reliable.
The licensee states that steps in calibration procedures initiate a management review of a transmitter if its as-found calibration data is outside 9
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4 the normal drift tolerance. The procedures are said to describe the loss of fill-oil concern. With these two actions taken, the licensee states they maintain a high degree of confidence in the reliability of the transmitter's function, consistent with its safety significance.
3.2.6 Licensee Response to Reouested Action 1.f The licensee states there are four Rosemount transmitters from this transmitter classification at the Sequoyah Nuclear Plant.
These transmitters (1-FT-72-13, 2-FT-72-13,1-FT-72-34, and 2-FT-72-34) monitor the flow in the core spray system at the two units. The licensee states the normal operating pressures is less than 500 psi for these transmitters.
Surveillance tests (quarterly) and operability tests (during refueling outages) are the only exposures to these pressures.
At the discretion of the licensee, these four transmitters are not in the enhanced surveillance monitoring program.
This is permitted by the Supplement.
However, the Supplement requires the licensee to maintain a high degree of confidence that these transmitters remain highly reliable.
The licensee states that steps in calibration procedures initiate a management review of a transmitter if its as-found calibration data is outside the normal drift tolerance.
The procedures are said to describe the loss of fill-oil concern.
With these two actions taken, the licensee states they i
maintain a high degree of confidence in the reliability of the transmitter's function, consistent with its safety significance.
i 3.2.7 Enhanced Surveillance Monitorino Prooram The licensee described their enhanced surveillance monitoring program in' Reference 4.
The program consists af trending the calibration data of each-suspect transmitter. Calibrations are performed each refueling outage.
The The data September 1985 calibration data provides a baseline for comparison.
is plotted as the total accumulated drift.
Each of the five calibration 10 i
points (4 mA, 8 mA, 12 mA, 16 mA, and 20 mA) is plotted with adjustment removed from the raw data.
Thus the plotted data is the absolute magnitude of the transmitter drift.
Continued drift from the baseline data during successive calibrations establishes the transmitter is not acceptable for continued operation.
The licensee explained how their drift data criteria was developed.
The licensee criteria was shown more conservative than the drift criteria given in Rosemount Technical Bulletin No. 4.
The enhanced surveillance monitoring program described by the licensee is acceptable.
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4.
CONCLUSIONS Based on our review of the licensee submittal, we find that the licensee has completed the reporting requirements of Supplement 1 of NRC Bulletin 90-01.
Further, the licensee's description of existing programs conforms to the requested actions of Supplement 1 to NRC Bulletin 90-01.
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REFERENCES 1.
NRC Bulletin No. 90-01:
" Loss of Fill-oil in Transmitters Manufactured by Rosemount," March 9, 1990, OMB No. 3150-0011.
2.
NRC Bulletin No. 90-01, Supplement 1:
" Loss of Fill-oil in Transmitters Manufactured by Rosemount," December 22, 1992, DMB No. 3150-0011.
i 3.
Letter, Tennessee Valley Authority (R. A. Fenech) to NRC, "NRC Bulletin 90-01, Supplement 1 -- Loss of Fill-0il in Transmitters Manufactured by Rosemount," March 4, 1993.
4.
Letter, Tennessee Valley Authority (K. Powers) to NRC, "NRC Bulletin 90-01, Supplement 1 - Loss of Fill-Oil in Transmitters Manufactured by Rosemount, Verbal Request for Additional Information (TAC Nos. 85442 and 85443)," March 15, 1994.
5.
Letter, Tennessee Valley Authority (K. Powers) to NRC, "NRC Bulletin 90-01, Supplement 1 - Loss of Fill-Oil in Transmitters i
Manufactured by Rosemount, Verbal Request for Additional Information (TAC Nos. 85442 and 85443)," July 8, 1994.
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