Bulletin 90-01: Supplement 1, Loss of Fill-oil in Transmitters Manufactured by Rosemount
OMB No.: 3150-0011
NRCB 90-01, Supplement 1
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION
WASHINGTON, D.C. 20555
December 22, 1992
NRC BULLETIN NO. 90-01, SUPPLEMENT 1: LOSS OF FILL-OIL IN TRANSMITTERS
MANUFACTURED BY ROSEMOUNT
Addressees
All holders of operating licenses or construction permits for nuclear power
reactors
Purpose
The U.S. Nuclear Regulatory Commission (NRC) is issuing this bulletin
supplement to inform addressees of activities taken by the NRC staff and the
industry in evaluating Rosemount transmitters and to request licensees to take
actions to resolve this issue. This supplement updates information provided
in Bulletin 90-01, "Loss of Fill-Oil in Transmitters Manufactured by
Rosemount." It is requested that recipients review the information for
applicability to their facilities and modify, as appropriate, their actions
and enhanced surveillance programs as described in this bulletin supplement.
Description of Circumstances
On April 21, 1989, the NRC issued Information Notice (IN) 89-42, "Failure of
Rosemount Models 1153 and 1154 Transmitters," to alert the industry to a
series of reported failures of Models 1153 and 1154 pressure and differential
pressure transmitters manufactured by the Rosemount Inc. (Rosemount).
Rosemount investigated the cause of the failures and confirmed that the
failure mode was a gradual loss of fill-oil from the sealed sensing module of
the transmitter. On March 9, 1990, the NRC issued Bulletin 90-01, in which it
requested that licensees promptly identify and take appropriate corrective
actions for Model 1153 Series B, Model 1153 Series D, and Model 1154
transmitters manufactured by Rosemount that may be or have the potential for
leaking fill-oil. During the summer and fall of 1990, the Nuclear Management
and Resources Council (NUMARC) surveyed the industry to gather data on all
installed Rosemount Model 1153 and 1154 transmitters and safety-related Model
1151 and 1152 transmitters at commercial nuclear facilities. NUMARC also
requested data on all suspected or confirmed failures of Rosemount
transmitters attributed to a loss of fill-oil from these same facilities.
9212170002.
NRCB 90-01, Supplement 1
December 22, 1992
Page 2 of 14
Discussion
The staff has reviewed the Rosemount transmitter loss of fill-oil issue by
analyzing data gathered from (1) licensee event reports, (2) the licensee's
responses to NRC Bulletin 90-01, (3) technical information provided by
Rosemount, (4) site visits, (5) NUMARC report 91-02, "Summary Report of NUMARC
Activities to Address Oil Loss in Rosemount Transmitters," (Reference 5) and
(6) numerous meetings with representatives from the industry, NUMARC, and
Rosemount. The NRC became concerned about this complex technical issue
because the failure could occur and remain undetected while the transmitter
was in service and could be a common mode failure. The manufacturer indicated
that these failures resulted from a failure of a glass-to-metal seal inside
the sensor which allowed fill fluid to leak out of the sensor at a very slow
rate. When this condition occurs, the transmitter performance gradually
deteriorates and may lead to failure. The loss of fill-oil failures has not
been traced to a specific time of manufacture, manufacturing lots, or process
conditions for transmitters manufactured before July 11, 1989. The manufac-
turer performed extensive analyses to thoroughly understand and quantify the
symptoms of the failure and to develop diagnostic guidelines for detecting a
loss of fill fluid. While performing these analyses and reviewing historical
data on the failed transmitters, the manufacturer found that the issue
involved a number of interacting factors. These factors are discussed in
references (1) through (5). These factors include the range code of the
transmitter, the ability of various evaluation methods to detect the
characteristics of a loss of fill fluid, the operating pressure of the
transmitter, and the amount of time that the transmitter had been in service.
Rosemount attributed many of the failures resulting in a loss of fill-oil to
the use of stainless steel "O" rings and the increased stresses on the sensor
module that result. The manufacturer made improvements to the manufacturing
process and the post-production screening for transmitters and sensors
produced after July 11, 1989. These improvements included making process
changes to reduce stresses on the sensor modules and pressure testing the
sensors to identify any incipient failures caused by leaking fill fluid. By
making these improvements, the manufacturer corrected to a large extent the
problem of sensor fill-oil loss, since only one failure attributed to a loss
of fill-oil has been found in transmitters manufactured after that date.
The staff has reviewed licensee individual responses to NRC Bulletin 90-01 and
concluded that the actions taken as a result of the bulletin helped to improve
the safety of operating reactors by reducing the susceptibility to Rosemount
transmitter failures due to a loss of fill-oil. This was accomplished mainly
by prompting licensees to remove Rosemount transmitters that were installed in
the reactor protection systems (RPS) or engineered safety feature (ESF)
actuation systems that the manufacturer found to have a high failure fraction
resulting from a susceptibility to a loss of fill-oil (i.e., suspect lot
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NRCB 90-01, Supplement 1
December 22, 1992
Page 3 of 14
transmitters). The licensee also was to evaluate against appropriate
operability acceptance criteria those transmitters that were suspected of
exhibiting symptoms of a loss of fill-oil when reviewing the plant's
historical records on the calibration of these transmitters. The licensees
established enhanced surveillance programs by considering various diagnostic
procedures for detecting transmitter fill-oil leakage. These diagnostic
procedures included trending calibration data, trending operational data,
reviewing transmitter performance for sluggish transient response, and
conducting process noise analysis.
However, the staff raised a number of concerns upon reviewing the licensee
responses. These included the following:
1. The responses from two licensees indicated that they did not intend to
replace suspect lot transmitters installed in RPS or ESF actuation
systems. These responses were reviewed with the licensees concerned,
and the staff determined that based on the available monitoring program
or the specific applications and available backup indications, the
licensee actions were acceptable.
2. Using pressure times time-in-service criteria provided in the Rosemount
Technical Bulletin No. 4 (Reference 4) as a means to identify which
transmitters should be included in the enhanced surveillance program.
In evaluating the industry survey data, the staff has since confirmed a
relationship, as had been previously found by Rosemount and NUMARC,
between operating pressure, time-in-service and failure rate, and that
these parameters were acceptable for identifying which transmitters
should be included in an enhanced surveillance program.
3. Eliminating low pressure application (below 250 psi) transmitters from
the enhanced surveillance program because the low oil pressure was not
sufficient to cause oil loss. The staff has since confirmed a
relationship between operating pressure and transmitter failure. A high
operating pressure was the most dominant factor leading to a loss of
fill-oil. Transmitters in low pressure applications had low failure
rates due to a loss of fill-oil.
4. The difference between the number of transmitters manufactured by
Rosemount and the total number of transmitters (those installed and
those in the suspect lots) found from the responses of all licensees,
and the reasons for this difference. The staff has since found the
NUMARC report evaluation and the associated database sufficiently
account for the difference between the number of transmitters
manufactured by Rosemount and the total number of transmitters (those
installed and those in the suspect lots) identified from the responses
of all licensees to the original Bulletin 90-01.
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NRCB 90-01, Supplement 1
December 22, 1992
Page 4 of 14
5. The adequacy of licensee enhanced surveillance programs to detect failed
transmitters. The staff has since completed a review of the NUMARC
transmitter data and specific modified and additional requested actions
regarding enhanced surveillance programs are contained within this
supplement.
During the licensee response period to Bulletin 90-01, NUMARC surveyed all
utilities to collect data on all installed Rosemount Model 1153 and 1154
transmitters, and on Rosemount Model 1151 and 1152 transmitters installed in
safety-related systems. NUMARC conducted the survey to address the staff
concerns (2) through (4) above, the closure of enhanced surveillance
monitoring activities, and to address concerns regarding the loss of fill-oil
in the Rosemount Model 1151, 1152, and 1153 Series A transmitters.
The staff reviewed the data collected by NUMARC to (1) verify NUMARC
conclusions, (2) evaluate surveillance issues regarding licensee responses in
implementing the enhanced surveillance program requested by the staff in the
bulletin, and (3) determine if other insights could be drawn from this data.
The Brookhaven National Laboratory (BNL) assisted the staff in evaluating the
data by assessing the failure rates for various types of transmitters by
operating pressure, time-in-service, and suspect or nonsuspect lot
classification. BNL provided the staff with the report, "Evaluation of
Surveillance and Technical Issues Regarding Rosemount Pressure Transmitter
Loss of Fill-Oil Failures," December 20, 1991 (Reference 6). The staff
evaluated the effect of the various failure rates to address the staff
concerns (2), (3), and (5) discussed above. In addition, the staff considered
the effects of the various failure rates on the potential for anticipated
transients without scram (ATWS). The staff concluded that estimated
unavailabilities and the associated impact on ATWS frequency could be very
sensitive to changes in the transmitter failure rate.
In evaluating this issue, the staff confirmed a relationship, as had been
previously found by Rosemount and NUMARC, between operating pressure, time-in-
service, and the suspect and nonsuspect lot classifications in identifying
where the transmitters would most likely fail. A high operating pressure was
the most dominant factor leading to a loss of fill-oil.
Second among these factors was time-in-service, with those transmitters having
been in service for less than 60,000 psi-months exhibiting higher failure
rates than transmitters that had been in service for more than 60,000 psi-
months. Attachment 1 represents the staff estimates of Rosemount transmitter
failure rates based on pressure application and the time in service derived
from the NUMARC survey data.
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NRCB 90-01, Supplement 1
December 22, 1992
Page 5 of 14
Third among these factors was the classification of the lot as suspect or
nonsuspect. All suspect lots as defined by Rosemount contained at least one
confirmed failure and possibly more, depending on the size of the lot.
However, many confirmed or suspected failures caused by a loss of fill-oil
were identified in nonsuspect lots. If all other factors were assumed equal,
suspect lots had higher failure rates than nonsuspect lots. When pressure
application or time-in-service was considered, classification by suspect or
nonsuspect lot was of lesser importance.
Throughout this evaluation period, the staff found several noteworthy items
including the following:
1. The manufacturer continues to confirm that transmitters are failing
because of a loss of fill-oil.
When the NRC issued Bulletin 90-01, the manufacturer confirmed that
approximately 90 transmitters had failed because of a loss of fill-oil.
By taking the actions requested in the bulletin, the licensees would
have removed from service both those groups of transmitters identified
as suspect transmitters and those transmitters suspected of oil loss
based on historical calibration data. Since that time, Rosemount has
confirmed approximately 50 additional transmitters as having failed
because of a loss of fill-oil. While the number of failures resulting
from a loss of fill-oil has decreased recently, this condition continues
to cause transmitters to fail. However, only one failure attributed to
a loss of fill-oil has been found in transmitters manufactured after
July 11, 1989.
2. The manufacturer continues to classify more transmitters as being
suspect lots.
In December 1989, Rosemount issued the initial list of suspect lot
transmitters which included approximately 1075 transmitters. Since that
time, the manufacturer has updated this list with four addenda
(references 1 through 4), with the most recently issued addendum adding
approximately 215 transmitters in December 1991. The current number of
transmitters found in the suspect lots is approximately 1700. The staff
now concludes that the suspect lot classification is of lesser
importance than operating pressure and time-in-service.
3. At nuclear facilities, Model 1151 and Model 1152 transmitters have
failed because of a loss of fill-oil.
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NRCB 90-01, Supplement 1
December 22, 1992
Page 6 of 14
The fact that these transmitters failed indicates that the failures are
not limited to transmitters with stainless steel "O" rings. However, the
number of Model 1151 and Model 1152 transmitters which have been
confirmed to have failed due to loss of fill-oil is very small for their
considerable operating experience.
4. In November 1991, Rosemount informed the NRC that it was recalling
approximately 1300 Model 1151 transmitters based on a Rosemount
engineering analysis which indicated that these transmitters are
susceptible to a loss of fill-oil.
Rosemount indicated that it had shipped only a few of these transmitters
to nuclear facilities and that none had been reported as having failed
because of a loss of fill-oil. The staff reviewed information on these
transmitters and concluded that Rosemount has addressed the issue
adequately by making a recall. Rosemount is also improving the post-
production screening test of Model 1151 transmitters.
The staff concern throughout the evaluation of this issue is the need to
determine whether or not the Rosemount transmitter meets current criteria as a
reliable component for which failures can be readily detected. The NRC issued
General Design Criterion (GDC) 21, "Protection System Reliability and
Testability" in Appendix A to Part 50 of Title 10 of the
Code of Federal Regulations (10 CFR 50) to require the protection system to be
designed with high functional reliability and with a capability to permit
periodic testing of its functioning when the reactor is in operation. The NRC
established this requirement to ensure that the licensee can readily detect
failures of subcomponents and subsystems within the protection system and can
readily detect loss of the required protection system redundancy when it
occurs. In 10 CFR 50.55a(h), the NRC requires that protection systems meet
the Institute of Electrical and Electronics Engineers Standard, "Criteria for
Protection Systems for Nuclear Power Generating Stations" (IEEE-279). In
IEEE-279, the Standard states that means shall be provided for checking, with
a high degree of confidence, the operational availability of each system input
sensor during reactor operation. To achieve a high functional reliability, a
transmitter must have a low probability of failure while it is operating.
Furthermore, failures should be readily detectable, commensurate with the
safety function, while the transmitter is in operation. Upon reviewing the
analyses, evaluations, and historical data on the loss of fill-oil, the staff
concludes that actions requested by the previous bulletin are insufficient to
ensure compliance with the regulations requiring that the transmitters achieve
the desired high functional reliability.
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NRCB 90-01, Supplement 1
December 22, 1992
Page 7 of 14
The staff concludes the following:
1. The following Rosemount transmitters are not achieving high functional
reliability: Model 1153 Series B, Model 1153 Series D, and Model 1154
transmitters manufactured before July 11, 1989, that are currently used
in either safety-related systems or systems installed in accordance with
10 CFR 50.62 (the ATWS rule), and that:
a. have a normal operating pressure greater than 1500 psi, or
b. have a normal operating pressure greater than 500 psi and less than
or equal to 1500 psi that have not reached the appropriate psi-month
threshold recommended by Rosemount (60,000 psi-months or 130,000
psi-months depending on the range code of the transmitter).
Since these transmitters are not achieving high functional reliability,
the transmitters should be replaced or use of an enhanced surveillance
program should be implemented. Details are provided in Requested
Actions below. The availability of access points to the instrument
loops and the potential for inadvertent actuation should be considered
in any decision to implement the enhanced surveillance program option
rather than replace transmitters. Plant shutdown solely for the
purposes of implementing the replacement option of transmitters
identified in the Requested Actions is not intended.
2. The following Rosemount transmitters are achieving a high functional
reliability: Model 1153 Series B, Model 1153 Series D, and Model 1154
transmitters manufactured before July 11, 1989, that are currently used
in either safety-related systems or systems installed in accordance with
10 CFR 50.62 (the ATWS rule), and that:
a. have a normal operating pressure less than or equal to 500 psi, or
b. 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 recommended by Rosemount (60,000 psi-months or 130,000
psi-months depending on the range code of the transmitter).
These transmitters may remain in service and may be excluded from any
enhanced surveillance program provided that a high degree of confidence
is maintained for detecting degradation of these transmitters caused by
a loss of fill-oil and a high degree of reliability is maintained for
the function consistent with its safety significance.
3. As a minimum, enhanced surveillance monitoring programs should provide
measurement data with an accuracy range consistent with that needed for
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NRCB 90-01, Supplement 1
December 22, 1992
Page 8 of 14
comparison with manufacturer drift data criteria for determining
degradation caused by a loss of fill-oil. To achieve the desired
accuracy, the licensee can determine the trending of zero drift and span
drift from the calibration data for most Rosemount transmitter range
codes. Other methods may include measuring the output of a transmitter
that is in service using a calibrated instrument and comparing the
results with redundant channels.
4. The appropriate enhanced surveillance test interval for each of the
transmitters in the program should consider the specific safety
function(s), available diversity, and other factors. In determining the
test interval for those transmitters which are to be monitored by an
enhanced surveillance program, the licensee may find that the normal
calibration interval may not be sufficient to provide a high degree of
confidence for detecting degradation caused by a loss of fill-oil.
5. Replacing a Rosemount transmitter with one manufactured after July 11,
1989, means installing a transmitter which has been refurbished with a
sensor module manufactured after July 11, 1989 (sensor module number
greater than 2182605), or installing a transmitter manufactured after
July 11, 1989 (a transmitter having a serial number greater than
500000).
6. The performance experience and identified failures do not indicate that
additional licensee action is warranted to address the issue of a loss
of fill-oil for Rosemount Model 1151, 1152, and 1153 (Series A)
transmitters. The number of Model 1151 and Model 1152 transmitters
which have been confirmed to have failed due to a loss of fill-oil is
very small given their operating experience, and therefore is
sufficiently low to be of minimum concern.
7. The NUMARC report evaluation and the associated database sufficiently
account for the difference between the number of transmitters
manufactured by Rosemount and the total number of transmitters (those
installed and those in the suspect lots) found from the responses of all
licensees to the original Bulletin 90-01. The NUMARC survey data
provided the staff a "snapshot" of the installed population of Rosemount
transmitters subject to the bulletin, including application by function,
time-in-service, and operating pressure.
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NRCB 90-01, Supplement 1
December 22, 1992
Page 9 of 14
Requested Actions
Operating Reactors
The NRC requests that all holders of operating licenses for nuclear power
reactors take the following actions:
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 ATWS rule), and
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 ATWS systems. Action for those
transmitters that have not met the Rosemount psi-month threshold
criterion should be expedited. 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. The justification should show
that a sufficiently high level of reliability for the function is
provided by the redundancy or diversity of applicable
instrumentation and control systems, commensurate with the
importance of the function, when considered in conjunction with the
overall performance of the reactor protection trip system, ESF
actuation systems, or ATWS system. Provide to the NRC a copy of the
licensee justification to extend the enhanced surveillance program
beyond the monthly test interval for transmitters that have reached
the appropriate psi-month threshold criterion recommended by
Rosemount.
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 ATWS systems. 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
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NRCB 90-01, Supplement 1
December 22, 1992
Page 10 of 14
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. Provide to the NRC a copy of the
licensee justification to extend the enhanced surveillance program
beyond the quarterly test interval for transmitters that have
reached the appropriate psi-month threshold criterion recommended by
Rosemount.
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 less than or equal to 1500 psi, that are installed in
reactor protection trip systems, ESF actuation systems or ATWS
systems. On a case-by-case basis except for transmitters that
initiate reactor protection or ATWS 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 justification should show that a sufficiently high level of
reliability for the function is provided by the redundancy or
diversity of applicable instrumentation and control systems,
commensurate with the importance of the function, when considered in
conjunction with the overall performance of the reactor protection
trip system, ESF actuation systems, or ATWS system. Provide to the
NRC a copy of the licensee justification to extend the enhanced
surveillance program beyond the monthly test interval.
[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 installed in reactor protection trip
systems, ESF actuation systems, or ATWS systems.
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 ATWS systems.
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NRCB 90-01, Supplement 1
December 22, 1992
Page 11 of 14
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 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.
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.
Summary tables are included as Attachment 2 to aid in understanding the
above actions requested in this Bulletin Supplement compared with those
in Bulletin 90-01.
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.
The actions described in this supplement supersede the actions requested in
the original bulletin. Compliance with applicable Commission requirements may
be the subject of NRC audits or inspections in the future.
Construction Permit Holders
All holders of construction permits are requested to complete Items 1 and 2 of
Requested Actions for Operating Reactors before the date scheduled for loading
fuel.
The actions described in this supplement supersede the actions requested in
the original bulletin. Compliance with applicable Commission requirements may
be the subject of NRC audits or inspections in the future.
Reporting Requirements
Operating Reactors
Provide within 60 days after receipt of this bulletin, a response that
includes the following:
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NRCB 90-01, Supplement 1
December 22, 1992
Page 12 of 14
1. A statement whether the licensee will take the actions requested above.
2. With regard to the actions requested above that the licensee is taking:
a. A list of the specific actions that the licensee will complete to
meet Item 1 of Requested Actions for Operating Reactors provided in
this supplement, including justifications as appropriate.
b. The schedule for completing licensee actions to meet Item 1 of
Requested Actions provided in this supplement.
c. When completed, a statement confirming that Items 1 and 2 of
Requested Actions for Operating Reactors provided in this supplement
have been completed.
3. A statement identifying those actions requested by the NRC that the
licensee is not taking and an evaluation which provides the bases for
not taking the requested actions.
Construction Permit Holders
Before the date scheduled for loading fuel, all holders of construction
permits are required to provide a response that confirms that the Requested
Action for Construction Permit Holders has been completed.
The written reports required above with respect to both operating reactors and
plants under construction shall be addressed to the U.S. Nuclear Regulatory
Commission, ATTN: Document Control Desk, Washington, D.C. 20555, and shall be
submitted under oath or affirmation pursuant to the provisions of
Section 182a, Atomic Energy Act of 1954, as amended and 10 CFR 50.54(f). A
copy shall also be submitted to the appropriate Regional Administrator.
Because the information sought above is to verify licensee compliance with
10 CFR 50.55a(h) and GDC 21, which are part of the current licensing basis for
all plants, justification for this information request need not be prepared by
the Commission pursuant to 10 CFR 50.54(f).
Backfit Discussion
The NRC is requesting that the addressees take the actions described herein to
ensure that they promptly detect transmitter failures caused by a loss of
fill-oil. A loss of fill-oil may result in a transmitter not performing its
intended safety function.
The actions requested in this bulletin supplement represent new positions of
the staff and thus, this request is considered a backfit in accordance with .
NRCB 90-01, Supplement 1
December 22, 1992
Page 13 of 14
the NRC's procedures. The staff is imposing this backfit to bring facilities
into compliance with existing requirements and did not perform a full backfit
analysis. However, the staff performed an evaluation of the type discussed in
10 CFR 50.109(a)(6) including a statement of the objectives of and reasons for
the actions requested and the basis for invoking the compliance exemption. It
will be made available in the Public Document Room with the minutes of the
228th meeting of the Committee to Review Generic Requirements. The staff
disposition of comments received on the proposal for this Supplement 1 to
Bulletin 90-01, which was published in the Federal Register on April 7, 1992
will also be made available with those minutes.
This request is covered by Office of Management and Budget Clearance Number
3150-0011 which expires June 30, 1994. The estimated average number of burden
hours is 2 person-hours for each transmitter for each licensee. This includes
the time needed to assess the requested actions, review plant records, analyze
the data obtained from plant records, evaluate the existing enhanced
surveillance program, and prepare the required response. This does not
include the time needed to revise the enhanced surveillance programs or to
replace transmitters. Send comments regarding this burden estimate or any
other aspect of this collection of information, including suggestions for
reducing this burden, to the Information and Records Management Branch,
Division of Information Support Services, Office of Information Resources
Management, U.S. Nuclear Regulatory Commission, Washington, D.C. 20555; and to
Ronald Minsk, (3150-0011), Office of Management and Budget, Washington, D.C.
20503.
Although no specific request or requirement is intended, the following
information would be helpful to the NRC in evaluating the cost of complying
with this bulletin supplement:
(1) the licensee staff time and costs to perform requested inspections,
evaluations, modifications, and associated testing
(2) the licensee staff time and costs to complete the requested reports and
documentation
(3) the additional short-term costs incurred as a result of performing the
requested actions such as the costs of additional corrective actions or
costs of down time
(4) an estimate of the additional long-term costs which will be incurred in
the future as a result of implementing commitments such as the estimated
cost of conducting future surveillances or increased maintenance
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NRCB 90-01, Supplement 1
December 22, 1992
Page 14 of 14
If you have any questions about the information in this supplement, please
contact the technical contact listed below or the appropriate Office of
Nuclear Reactor Regulation (NRR) project manager.
ORIGINAL SIGNED BY
James G. Partlow
Associate Director for Projects
Office of Nuclear Reactor Regulation
Technical contact: Paul Loeser, NRR
(301) 504-2825
Lead Project Manager: Ngoc Le, NRR
(301) 504-1458
Attachments:
1. Figure 1, Rosemount Transmitter Failure Rates
2. Comparison of Requested Actions
3. List of Recently issued NRC Bulletins
References:
1. Rosemount Technical Bulletin No. 1, May 10, 1989
2. Rosemount Technical Bulletin No. 2, July 12, 1989
3. Rosemount Technical Bulletin No. 3, October 23, 1989
4. Rosemount Technical Bulletin No. 4, December 22, 1989
5. NUMARC Report 91-02, "Summary of NUMARC Activities to Address Oil Loss in
Rosemount Transmitters," April 1991.
6. BNL Report, "Evaluation of Surveillance and Technical Issues Regarding
Rosemount Pressure Transmitter Loss of Fill-Oil Failures," December 20,
1991..
Attachment 2
NRCB 90-01, Supplement 1
December 22, 1992
Page 1 of 3
COMPARISON OF REQUESTED ACTIONS
High Pressure Supplement to Bulletin 90-01 Original Bulletin 90-01
Non-Mature \Replace or monitor with an \Replace suspect lot
RPS/ESF/ATWS \enhanced surveillance program \transmitters
\on a monthly basis. \Monitor remainder in an
\ \enhanced surveillance
\ \program
Non-Mature \Replace or monitor with an \Monitor with an
Non-RPS/Non- \enhanced surveillance program \enhanced surveillance
ESF/Non-ATWS \on a quarterly basis. \program
Mature \Replace or monitor with an \Replace suspect lot
RPS/ESF/ATWS \enhanced surveillance program \transmitters
\on a monthly basis. (24 month \Monitor remainder in an
\basis with adequate \enhanced surveillance
\justification.) \program
Mature \Replace or monitor with an \Monitor with an
Non-RPS/Non- \enhanced surveillance program \enhanced surveillance
ESF/Non-ATWS \on a quarterly basis. (24 month\program
\basis with adequate
\justification.)
NOTE: Non-Mature refers to a transmitter that has not reached the appropriate
psi-month threshold recommended by Rosemount (60,000 psi-months or 130,000
psi-months depending on the range code of the transmitter). Mature refers to
a transmitter that has met the Rosemount psi-month threshold criterion.
.
Attachment 2
NRCB 90-01, Supplement 1
December 22, 1992
Page 2 of 3
COMPARISON OF REQUESTED ACTIONS
Medium Pressure Supplement to Bulletin 90-01 Original Bulletin 90-01
Non-Mature \(BWR) Replace or monitor with \Replace suspect lot
RPS/ESF/ATWS \an enhanced surveillance \transmitters
\program on a monthly basis.(24 \Monitor remainder in an
\month basis with adequate \enhanced surveillance
\justification, except for \program
\transmitters that initiate RPS \
\or ATWS trips for high pressure\
\or low water level.) \
\ \
\(PWR) Replace or monitor with \
\an enhanced surveillance \
\program at intervals no greater\
\than 24 months. \
Non-Mature \Replace or monitor with an \Monitor with an
Non-RPS/Non- \enhanced surveillance program \enhanced surveillance
ESF/Non-ATWS \at intervals no greater than \program
\24 months. \
Mature \Enhanced surveillance program \Replace suspect lot
RPS/ESF/ATWS \discretionary. Maintain \transmitters
\ability to detect failures \Monitor remainder in an
\ \enhanced surveillance
\ \program
Mature \Enhanced surveillance program \Monitor with an
Non-RPS/Non- \discretionary. Maintain \enhanced surveillance
ESF/Non-ATWS \ability to detect failures \program
NOTE: Non-Mature refers to a transmitter that has not reached the appropriate
psi-month threshold recommended by Rosemount (60,000 psi-months or 130,000
psi-months depending on the range code of the transmitter). Mature refers to
a transmitter that has met the Rosemount psi-month threshold criterion.
.
Attachment 2
NRCB 90-01, Supplement 1
December 22, 1992
Page 3 of 3
COMPARISON OF REQUESTED ACTIONS
Low Pressure Supplement to Bulletin 90-01 Original Bulletin 90-01
Non-Mature \Enhanced surveillance program \Replace suspect lot
RPS/ESF/ATWS \discretionary. Maintain \transmitters
\ability to detect failures \Monitor remainder in an
\ \enhanced surveillance
\ \program
Non-Mature \Enhanced surveillance program \Monitor with an
Non-RPS/Non- \discretionary. Maintain \enhanced surveillance
ESF/Non-ATWS \ability to detect failures \program
Mature \Enhanced surveillance program \Replace suspect lot
RPS/ESF/ATWS \discretionary. Maintain \transmitters
\ability to detect failures \Monitor remainder in an
\ \enhanced surveillance
\ \program
Mature \Enhanced surveillance program \Monitor with an
Non-RPS/Non- \discretionary. Maintain \enhanced surveillance
ESF/Non-ATWS \ability to detect failures \program
NOTE: Non-Mature refers to a transmitter that has not reached the appropriate
psi-month threshold recommended by Rosemount (60,000 psi-months or 130,000
psi-months depending on the range code of the transmitter). Mature refers to
a transmitter that has met the Rosemount psi-month threshold criterion.
.
Page Last Reviewed/Updated Tuesday, March 09, 2021