ML20079S078

Technical Evaluation Rept;Evaluation of Util Response to Suppl 1 to NRC Bulletin 90-01:Hatch-1/-2

ML20079S078
Person / Time
Site:	Hatch
Issue date:	09/26/1994
From:	Meyer L, Udy A EG&G IDAHO, INC., IDAHO NATIONAL ENGINEERING & ENVIRONMENTAL LABORATORY
To:	NRC
Shared Package
ML20079S081	List: ML20079S078
References
CON-FIN-L-1695 EGG-DNSP-11489, IEB-90-001, IEB-90-1, TAC-M85395, TAC-M85396, NUDOCS 9410040241
Download: ML20079S078 (18)

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EGG-DNSP-ll489 TECHNICAL EVALUATION REPORT Evaluation of Utility Response to Supplement I to NRC Bulletin 90-01: Hatch-1/-2 Docket Nos. 50-321 and 50-366 LeRoy C. Meyer Alan C. Udy Published September 1994 EG&G Idaho, Inc.

Idaho National Engineering Laboratory Idaho Falls, Idaho 83415 Prepared for the U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Under DOE Contract No. DE-AC07-761D01570 FIN No. L1695, Task No. 11a i l

TAC Nos. M85395 and M85396 l

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SUMMARY

This report documents the EG&G Idaho, Inc., review of the Georgia Power Company submittals that respond to Supplement 1 to NRC Bulletin 90-01 for the Edwin I. Hatch Nuclear Plant. This NRC Bulletin provides information on the loss of fill-oil in certain pressere and differential pressure transmitters manufactured by Rosemount, Inc. This report fi;;ds the licensee complies to the requested actions and the reporting requirements of the Supplement.

FIN No. Ll695, Task No. 11a B&R No. 320 19-1E-05-0 Docket No. 50-321 and 50-366 TAC Nos. M85395 and M85396 ii

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l 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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1 CONTENTS ii I

SUMMARY

PREFACE .............................................................. iii

1. INTRODUCTION .................................................... 1

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 ;

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4. CONCLUSIONS .. ................................................. 12

5. REFERENCES .................................................... - 13 iv

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Evaluation of Utility Response to Sucolement 1 to NRC Bulletin 90-01: Hatch-1/-2

1. INTRODUCTION The NRC issued Bulletin 90-01 on March 9, 1990 (Reference 1). That Bulletin discussed certain Rosemount pressure and differential pressure 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 l l

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 f1P -oil, the transmitter would not have the long term accuracy, time response, and reliability needed for its intended 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. Thus, this potential failure mechanism raised concern for the reliability of reactor protection systems (RPS), engineered safety features (ESF) actuation systems, and anticipated transient without scram (ATWS) mitigating systems. To achieve j high functional reliability, there must be a low probability of component failure while operating, with any failures readily detectable.

Supplement 1 to NRC Bulletin 90-01 (Reference 2) was issued on l 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

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respond to the NRC. The Reauested Actions in Supplement I to NRC Bulletin 90-01 supersede the original NRC Bulletin 90-01 Reauested 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, Reauested Actions or taking exception to those actions.

2. Addressing the actions committed to in the above statement,  :

I provide:

a. a list of the specific actions, including any justifications, to be taken to complete the commitment,

b. a schedule for completion, and

c. after completion, a statement confirming the actions committed to are complete.

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3. A statement identifying the NRC Bulletin 90-01, Supplement 1, Reauestadl:tions not taken, along with an evaluation providing the basis for exemption.

In implementing the replacement option of the NRC Reauested Actions, plant shutdown exclusively for replacing the transmitters is not required.

This allowance infers that replacements can be scheduled. With replacement in a timely manner, enhanced surveillance monitoring for interim operation is not required.

The Georgia Power Company, the licensee for Unit Nos. I and 2 of the Edwin I. Hatch Nuclear Plant, responded to Supplement 1 of NRC Bulletin 90 Gi i 1

with a letter dated February 17, 1993 (Reference 3). The licensee provided )

additional information on July 25, 1994 (Reference 4). This technical evaluation report evaluates the completeness of those submittals. It also determines whe+her proposed surveillance methods are adequate to determine 2 4 4

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fill-oil loss-caused degradation of the transmitter. Finally, this report addresses the interval of surveillance proposed by the licensee for any transmitters included in the enhanced surveillance monitoring program.

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 inc',uded 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 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 D (

• - Rosemount Model 1154 Following identification, the licensee is to establish the following:

a. For those identified transmitters having a normal operating 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 quarterly, 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 4

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1 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, justificatior must be based or 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 tne 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 ,

accuracy needed to compare the data to the manufacturers drift data It is this comparison that determines the deuradation cri c aria.

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 i

The licensee responded to Supplement 1 of NRC Bulletin 90-01 on February 17, 1993. The licensee provided additional information on July 25, 1994.

Those responses were compared to the Bulletin Reportina Reauirements and Reauested Actions as described below. The licensee reports having six Rosemount transmitters that are subject to the Reauested Actions of the Supplement. Other Rosemount transmitters ar. Outside the scope of the Supplement due to replacement, refurbishment, or use in non-safety applications.

3.1 Evaluation of Licensee Rescense to Reportina Reauirements The licensee states they have taken the Reauested Actions detailed in Supplement 1 of 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 accomplish the Reauested Actions in Reference 3. The Hatch Nuclear Plant units are BWRs.

The submittal identifies where the licensee action deviates from the requirements of the Supplement. The licensee provides evaluation and justification supporting the position that the deviation is acceptable. No transmitters at the Hatch Nuclear Plant operate at greater than 1500 psi. The licensee noted, in Reference 3, that they replaced Rosemount transmitters used in safety-related applications if the transmitter did not exceed its psi-month maturity threshold, except for six transmitters in Unit No. 1. The licensee scheduled five of these transmitters for replacement during the Spring 1993 refueling outage. The remaining transmitter was about two psi-months below the maturity threshold criterion. Consequently, the licensee did not develop an enhanced surveillance monitoring program. The licensee states that the short duration of such a program would not provide meaningful results.

Reference 4 confirms the replacement of the five Unit No. I transmitters with transmitters manufactured after July 11, 1989, or with transmitters refurbished with sensor modules manufactured after July 11, 1999.

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4 The licensee submittal conforms with the Reportina Reauirements of Supplement 1 of NRC Bulletin 90-01.

3.2 Evaluation of Licensee Resoonse 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 identified a total of 6 transmitters in Unit No. I that are in the scope of this review. Unit No. 2 has no Rosemount transmitters subject to the Supplement Reauested Actions.

The licensee response is discussed in the following sections. f 3.2.1 Licensee Response to Reauested Action 1.a The licensee states there are no Rosemount transmitters from this transmitter classification at the Hatch 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 Hatch Nuclear Plant.

3.2.3 Licensee Response to Rer, casted Action 1.c The licensee states they replaced Unit No. 1 Rosemount transmitters in this transmitter classification with transmitters refurbished with a sensor module manufactured after July 11, 1989, or with transmitters manufactured after July 11, 1989, or the transmitter exceeds its psi-month maturity threshold. One transmitter, IB21-N090F, was about two psi-months from reaching its maturity threshold when the licensee responded to the Supplement 8

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in Reference 3. That transmitter remained in service. A review of prior.

calibration data performed by the licensee showed the transmitter does not exhibit symptoms indicative of a loss of fill-oil. Due to the short time frame remaining until achieving the psi-month maturity threshold, the licensee did not start an enhanced surveillance monitoring program for this transmitter.

The licensee states that Rosemount transmitters in this transmitter classification in Unit No. 2 with less than the appropriate psi-month maturity threshold, were replaced with a transmitter refurbished with a sensor module manufactured after July 11, 1989, or replaced with a transmitter manufactured after July 11, 1989. Unit No. 2 requires no further actions.

3.2.4 Licensee Response to Reauested Action 1.d The licensee states they replaced Units Nos. I and 2 Rosemount transmitters in this transmitter classification or the transmitter exceeds its psi-month maturity threshold, with the exception of one Unit No. I transmitter. This transmitter, 1821-N027, provides wide.-range reactor _

pressure vessel water level indication and does not have a trip-function. The licensee replaced this transmitter during the Spring 1993 refueling outage, as i reported in Reference 4. The licensee did not develop an interim enhanced surveillance program for the transmitter; as discussed in response to Supplement Reauested Action 1.c.

3.2.5 Licensee Response to Reauested Action 1.e I The licensee states they will exclude transmitters in this transmitter classification from an enhanced surveillance monitoring program. These-transmitters have reached the appropriate psi-month maturity threshold recommended by Rosemount and endorsed by the NRC. The Supplement permits this action.

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The Supplement requires the licensee to maintain a high degree of confidence that these transmitters remain highly reliable. The licensee added three factors to calibration and surveillance procedures to assure this capability.

1. Verify the transmitter response is not sluggish.

2. Confirm as-found calibration data does not show zero or span drift.

3. Verify the ability of the transmitter to operate over the entire calibrated range.

These steps enable the licensee to identify fill-oil loss in transmitters during routine calibrations. Therefore, the licensee actions for this transmitter classification are acceptable.

3.2.6 Licensee Response to Reauested Action 1.f The licensee states they will exclude enhanced surveillance for transmitters with a normal operating pressure less than or equal to 500 psi.

The Supplement requires the licensee to maintain a high degree of confidence that these transmitters remain highly reliable. The licensee added three factors to calibration and surveillance procedures to assure this capability.

1. Verify the transmitter response is not sluggish.

2. Confirm as-found calibration data does not show zero or span drift.

3. Verify the ability of the transmitter to operate over the entire calibrated range.

These steps enable the licensee to identify fill-oil loss in transmitters during routine calibrations. Therefore, the licensee actions for this transmitter classification are acceptable.

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3.2.7 Enhanced Surveillance Monitorina Proaram The licensee states that, consistent with Supplement 1 to NRC Bulletin 90-01, an enhanced surveillance monitoring program is not needed for  !

transmitters that have been replaced, refurbished, or transmitters in i transmitter classification 1.e or 1.f. We note that Hatch Nuclear Plant has 'I no transmitters in transmitter classification 1.a or 1.b. For five of the six  !

Unit No. I transmitters in transmitter class;fication 1.c and 1.d in exception to the Supplement provisions, the licensee response provides justification for  !

not developing an interim enhanced surveillance monitoring program before replacing the transmitters. The remaining transmitters in transmitter j classifications 1.c and 1.d (including the transmitter in transmitter  !

classification 1.c that had not ac.hieved maturity) now exceed their psi-month maturity threshold and are included in transmitter classification 1.e.

Transmitter classifications 1.e and 1.f allow licensee discretion for exclusion from an enhanced surveillance monitoring program. The licensee took this elective, and addresses maintaining confidence in transmitter reliability. Consequently, the Hatch Nuclear Plant does not require an enhanced surveillance monitoring program.

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4. CONCLUSIONS Based on our review, we find the licensee has completed the reporting requirements of Supplement 1 of NRC Bulletin 90-01. Further, the licensee conforms to the requested actions of Supplement I to NRC Bulletin 90-01.

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5. REFERENCES

1. NRC Bulletin No. 90-01: "

Loss of Fill-oil in Transmitters Manufactured by Rosemount," Harch 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, OMB No. 3150-0011.

3. Letter, Georgia Power Company (J. T. Beckham, Jr.) to NRC, "NRC Bulletin 90-01, Supplement 1, Loss of Fill-oil in Transmitters Manufactured by Rosemount," February 17, 1993, HL-3123.

4. Letter, Georgia Power , Company (J. T. Beckham, Jr.) to NRC, "NP.C Bulletin 90-01, Supplement 1, Loss of Fill-oil in Transmitters Manufactured by Rosemount," July 25, 1994, HL-4646.

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