Information Notice 1992-17, NRC Inspections of Programs Being Developed at Nuclear Power Plants in Response to Generic Letter 89-10: Difference between revisions
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{{#Wiki_filter:UNITED STATES | {{#Wiki_filter:UNITED STATES | ||
COMMISSION | NUCLEAR REGULATORY COMMISSION | ||
OFFICE OF NUCLEAR REACTOR REGULATION | |||
NOTICE 92-17: NRC INSPECTIONS | WASHINGTON, D.C. 20555 February 26, 1992 NRC INFORMATION NOTICE 92-17: NRC INSPECTIONS OF PROGRAMS BEING DEVELOPED | ||
AT NUCLEAR POWER PLANTS IN RESPONSE TO | |||
GENERIC LETTER 89-10 | |||
==Addressees== | ==Addressees== | ||
All holders of operating | All holders of operating licenses or construction permits for nuclear power | ||
licenses or construction | |||
reactors. | |||
==Purpose== | ==Purpose== | ||
The U.S. Nuclear Regulatory | The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice | ||
Commission (NRC) is issuing this information | |||
notice | |||
to alert addressees to the general conclusions derived from the NRC inspections | |||
of the programs being developed at nuclear power plants in response to | |||
Generic Letter (GL) 89-10, "Safety-Related Motor-Operated Valve Testing and | |||
that | Surveillance." It is expected that recipients will review the information for | ||
applicability to their facilities and consider actions, as appropriate, to | |||
avoid similar problems. However, suggestions contained in this information | |||
notice are not NRC requirements; therefore, no specific action or written | |||
response is required. | |||
Background | |||
In GL 89-10 (June 28, 1989), the NRC staff requested that holders of nuclear | |||
power plant operating licenses and construction permits ensure the capability | |||
of motor-operated valves (MOVs) in safety-related systems by reviewing MOV | |||
design bases, verifying MOV switch settings initially and periodically, testing | |||
evaluations | MOYs under design basis conditions where practicable, improving evaluations of | ||
MOV failures and necessary corrective action, and determining trends of MOV | |||
problems. The NRC staff requested that licensees complete the GL 89-10 program | |||
by the end of the third refueling outage or 5 years from the issuance of the | |||
generic letter, whichever is later. On June 13, 1990, the NRC staff issued | |||
Supplement 1 to GL 89-10 to provide detailed information on the results of | |||
public workshops held to discuss the generic letter. On August 3, 1990, the | |||
NRC staff issued Supplement 2 to GL 89-10 to allow licensees additional time to | |||
review and to incorporate the information provided in Supplement 1 into their | |||
programs in response to the generic letter. Upon reviewing the results of | |||
NRC-sponsored MOV tests, the NRC staff issued Supplement 3 to GL 89-10 on | |||
October 25, 1990, which requested licensees of boiling water reactor (BWR) | |||
nuclear plants to take action in advance of the GL 89-10 schedule to resolve | |||
concerns about the capability of MOYs used for containment isolation in the | |||
steam supply line of the high pressure coolant injection and reactor core | |||
isolation cooling systems, in the supply line of the reactor water cleanup | |||
system, and in other systems directly connected to the 'reactor vessel. In | |||
4 ek219371 t= v dsO]- qWog Xe | |||
IN 92-17 February 26, 1992 Supplement 4 to GL 89-10, the NRC staff indicated that BWR licensees need not | |||
address inadvertent MOY operation in their GL 89-10 programs. The NRC staff is | |||
the | considering whether or not similar actions should be taken regarding the need | ||
for licensees of pressurized-water reactor (PWR) nuclear plants to address the | |||
inadvertent operation of MOVs in their programs to respond to GL 89-10. | |||
==Description of Circumstances== | |||
The NRC staff has conducted inspections at more than 30 nuclear power plant | |||
of | sites of programs being developed by, licensees in response to GL 89-10. The | ||
of | reports of those inspections are available in the NRC Public Document Room. In | ||
performing the inspections, the NRC staff has followed Temporary Instruction | |||
(TI) 2515/109 of January 14, 1991, Inspection Requirements for | |||
and | Generic Letter 89-10, Safety-Related Motor-Operated Valve Testing and Sur- veillance.' Part 1 of TI 2515/109 provides guidance for reviewing the program | ||
being established.by theLlicensee. in response to GL 89-10, and.Part 2 provides | |||
guidance for reviewing program implementation. The NRC has focused these | |||
inspections on reviewing the GL 89-10 programs (Part 1 of TI 2515/109). The | |||
staff is issuing this information notice to provide the more significant | |||
notice to provide the more significant | |||
results of those NRC inspections. | results of those NRC inspections. | ||
In GL 89-10, the NRC staff requested | In GL 89-10, the NRC staff requested that licensees prepare descriptions of | ||
their programs established in response to GL 89-10 within 1 year after the | |||
generic letter was issued or by the first refueling outage after | |||
December 28, 1989, whichever was later. The NRC staff's response to | |||
in | Question 44 in Supplement 1 to GL 89-10 provided guidance on information | ||
expected in the program descriptions. The NRC inspectors found-some licensees | |||
to have program descriptions that are thorough while other licensees did not. | |||
1 to | Attachment 1 Is a discussion of the inspection findings pertaining to the | ||
recommendations of GL 89-10. | |||
===Related Generic Communications=== | |||
In addition to NRC Generic Letter 89-10, "Safety-Related Motor-Operated Valve | |||
Testing and Surveillance," and its supplements, the NRC has addressed.this and | |||
related topics in NRC Information Notices.89-88, "Recent NRC-Sponsored Testing | |||
of Motor-Operated Valves;" 90-40,."Results of NRC-Sponsored Testing of | |||
Motor-Operated Valves;" 90-72, "Testing of Parallel Disc Gate Valves in | |||
Europe;" and 91-61, "Preliminary Results of Validation Testing of Motor- Operated Valve Diagnostic Equipment.". | |||
IN 92X17 February 26, 1992 This information notice requires no specific action or written response. If | |||
you have any questions about the Information in this notice, please contact the | |||
technical contact listed below or the appropriate Office of Nuclear Reactor | |||
Regulation (NRR) project manager. | |||
arIes E. Ross D rec o | |||
Division of Operational Events Assessment | |||
Office of Nuclear Reactor Regulation | Office of Nuclear Reactor Regulation | ||
Technical | Technical contact: Thomas G. Scarbrough, NRR | ||
(301) 504-2794 Attachments: | |||
1. Inspection | 1. Inspection Findings Pertaining to the Recommendations Contained In | ||
Generic Letter 89-10 | |||
2. List of Recently Issued NRC Information Notices | |||
Attachment 1 IN 92-17 February 26, 1992 INSPECTION FINDINGS PERTAINING | |||
TO THE RECOMMENDATIONS CONTAINED IN GENERIC LETTER 89-10 | |||
===Administration=== | |||
Some licensees have not ensured adequate management oversight and direction for | |||
the motor-operated valve (MOY) program. One licensee had contracted an | |||
internal audit that revealed problems with the MOY program similar to those | |||
found subsequently during the NRC inspection, but the licensee had not taken | |||
action to correct the deficiencies. The safety significance of the MOV program | |||
and the extensive resources needed to develop and implement the program make it | |||
imperative that licensee's management closely monitor its staff's activities. | |||
Scope | |||
In issuirng Generic Letter (GL) 89-10, the NRC staff intended that the scope | |||
include all safety-related MOVs and other MOVs in safety-related systems. In | |||
Supplement 1 to GL 89-10, the NRC staff limited the scope of GL 89-10 to | |||
safety-related MOYs and other MOVs that are position-changeable in safety- related piping systems, as well as safety-related MOVs that might be in | |||
nonsafety-related piping systems. The NRC staff's response to Questions 3-13 in Supplement 1 to GL 89-10 provided further guidance on the scope of GL 89-10. | |||
For example, in the NRC staff's response to Question 4 in Supplement 1, the | |||
staff defined "position-changeable" as any MOV in a safety-related piping | |||
system that is not blocked from inadvertent operation from the control room. | |||
In Supplement 4 to GL 89-10, the NRC staff indicated that licensees for boiling | |||
water reactor (BWR) plants need not address inadvertent MOV operation in their | |||
GL 89-10 programs. The NRC staff is considering whether or not similar actions | |||
the | should be taken regarding the need for the licensees of pressurized-water | ||
reactor (PWR) plants to address inadvertent MOV operation in their programs to | |||
respond to GL 89-10. | |||
The NRC inspectors found most licensees to be establishing the scope of their | |||
GL 89-10 programs consistent with the recommendations of the generic letter. | |||
MOVs | However, some licensees needed to improve the documentation of their justifi- cation for excluding particular MOVs from the GL 89-10 program. | ||
Design-Basis Reviews | |||
In recommended action "a" of GL 89-10, the NRC staff requested the licensees to | |||
review and document the design basis for operating each MOV within the generic | |||
letter program to determine the maximum differential pressure and flow (and | |||
other factors) expected for both normal operations and abnormal conditions. | |||
The NRC staff's response to Questions 14 to 18 and 36 in Supplement 1 to | |||
GL 89-10 provides guidance on performing design-basis reviews under GL 89-10. | |||
Many licensees are appropriately reviewing plant documentation such as the | |||
final safety analysis report and the technical specifications as part of their | |||
design-basis reviews. However, some licensees had failed to identify | |||
worst-case conditions for various design-basis scenarios. Some licensees have | |||
's.- Attachment 1 IN 92-17 February 26, 1992 assumed nominal reactor pressure for differential pressure across MOVs in lines | |||
directly connected to the reactor vessel without evaluating whether this | |||
differential pressure bounds the worst-case MOV design-basis differential | |||
pressure. At certain facilities, the licensee found errors in the previous | |||
design basis determinations for many MOVs that would have affected the cap- ability of the MOVs to perform their safety function if called upon under | |||
design-basis conditions. | |||
Some licensees focused on differential pressure and had not adequately ad- dressed other design-basis parameters such as flow, fluid temperature, ambient | |||
temperature, and the effects of seismic and dynamic events. Although differen- tial pressure is the primary design-basis parameter used to predict the thrust | |||
the | requirements in the industry's equations, the other design-basis parameters are | ||
needed to ensure that the test results demonstrate that the MOV would operate | |||
under design-basis conditions. Some licensees have not ensured that generic | |||
studies of design-basis differential pressure apply to specific plants. | |||
===MOY Sizing and Switch Settings=== | |||
In recommended action "b" of GL 89-10, the NRC staff requested licensees to | |||
review and revise, as necessary, the methods for selecting and setting all MOV | |||
to | switches. The NRC staff's response to Questions 19-21 in Supplement 1 to | ||
GL 89-10 provides guidance on selecting and setting MOV switches. | |||
The recommendations of GL 89-10 for selecting and setting MOV switches apply to | |||
switches for torque, torque bypass, limit, and thermal overload. The licensees | |||
are using various methods to determine the proper size of MOVs and their | |||
appropriate torque switch settings. Some licensees have increased the valve | |||
factors assumed in the industry's equations used to predict the thrust required | |||
to operate the valves to reflect experience throughout the industry and at | |||
their specific plant. However, other licensees continue to use old guidance | |||
from valve vendors and manufacturers in estimating the thrust requirements that | |||
may be found inadequate during design-basis tests. | |||
The NRC inspectors found that licensees for various facilities had not done the | |||
following when establishing methods to size MOVs and set their switches: | |||
(1) Provide justification for assumptions regarding stem friction coefficients | |||
the | and changes in stem friction over the lubrication interval | ||
pressure and flow | (2) Consider effects that can reduce the thrust delivered by the motor opera- tor under high differential pressure and flow conditions in relation to | ||
the thrust delivered under no-load conditions | |||
(3) Consider the effects of ambient temperature on motor output and thermal | |||
overload sizing | |||
(4) Demonstrate applicability of industry's databases in predicting thrust | |||
requirements | |||
(5) Consider inertia in establishing the maximum settings for torque switches | |||
Attachment 1 IN 92-17 February 26, 1992 (6) Demonstrate applicability of contractors' studies of actuator capability | |||
(7) Demonstrate applicability of generic motor curves for specific motors | |||
(8) Provide justification for removing conservatisms (such as the application | |||
factor) from the industry's standard sizing calculations | |||
factor) from the industry's | |||
standard sizing calculations | |||
(9) Consider torque switch repeatability | (9) Consider torque switch repeatability | ||
(10) Consider uncertainties | (10) Consider uncertainties regarding the accuracy of MOV diagnostic equipment. | ||
regarding | |||
the accuracy of MOV diagnostic | |||
equipment. | |||
Some licensees have had problems in performing MOV sizing and switch setting | |||
from different | calculations because of (1) incorrect spring packs installed in MOVs, | ||
(2) incorrect MOV data on the motor or actuator nameplates and in the procure- ment documents from the vendor, and (3) spring packs with different performance | |||
manufacturers, but with the same part number. | characteristics from different manufacturers, but with the same part number. | ||
that the MOV sizing and switch setting activities | One licensee determined that the MOV sizing and switch setting activities to | ||
establish motor operator capability had not adequately addressed the effect of | |||
those activities on other MOY safety functions. These activities had hindered | |||
the ability of the clutch of certain MOYs to be released to enable the MOV to | |||
be manually operated in the event of an evacuation of the control room. | |||
the | Many licensees are updating their degraded voltage studies to ensure that the | ||
worst-case minimum voltage available at the motor has been determined for each | |||
MOV. Some licensees had not ensured that their assumptions of minimum voltage | |||
available at the MOYs were consistent with their licensing commitments in | |||
safety analyses. Some licensees did not justify the assumptions for the | |||
starting point for the degraded voltage calculations, current used to calculate | |||
cable losses, losses caused by the resistance of thermal overload devices in | |||
the circuit, or the effects on MOV stroke time under degraded voltage condi- tions. Of particular significance, the inspectors found one licensee to be | |||
for | assuming an excessively small locked-rotor power factor (0.2) in the motor for | ||
use in the calculation of voltage drop from the motor control center to the | |||
of | MOV. The licensee's selection of this power factor was based on guidance in an | ||
Institute of Electrical and Electronics Engineers' standard that was not | |||
applicable to the size of motors typically used to operate valves in nuclear | |||
power plants. The assumption of an excessively small power factor causes an | |||
in | underestimation of the cable voltage drop and may result in the overestimation | ||
of MOV capability under design-basis conditions. | |||
Licensees are improving their documentation of current and required MOV switch | |||
settings, but some weaknesses remain. For example, one licensee had simplified | |||
its control over changes to torque switch settings to expedite the process but, In so doing, caused the concern that the quality assurance department may not | |||
participate adequately in accepting those changes. Some of the weakness in | |||
documenting torque switch settings appears to result from the difficulty in | |||
reading the switches. Some licensees have raised torque switch settings for | |||
MOVs above the manufacturer's maximum specified value without performing an | |||
of | adequate safety analysis in accordance with the requirements of 10 CFR 50.59. | ||
-'- Attachment 1 IN 92-17 February 26, 1992 Design-Basis Differential Pressure and Flow Testing | |||
of | In recommended action "c" of GL 89-10, the NRC staff requested | ||
test MOVs within the generic letter program in situ under licensees to | |||
and | differential pressure and flow conditions. The NRC staff their design-basis | ||
methods to be used to demonstrate the capability of the allows alternate | |||
MOV if testing in situ | |||
under those conditions is not practicable. The NRC staff | |||
licensees follow a two-stage approach for a situation in suggested that the | |||
testing in situ is not practicable and the licensees couldwhich design-basis | |||
not justify an | |||
of MOV capability | alternate method of demonstrating MOV capability. In performing | ||
approach, a licensee would evaluate the capability of the the two-stage | |||
data available and then would obtain applicable test data MOV using the best | |||
of the generic letter. The NRC staff's response to Questionswithin the schedule | |||
Supplement 1 to GL 89-10 provides guidance on design-basis 22-32 and 37 in | |||
two-stage approach. testing and the | |||
Many licensees have committed to test MOVs within the scope | |||
program under design-basis conditions, where practicable. of their GL 89-10 | |||
Some | |||
indicated that most MOVs can be tested at or near design-basis licensees have | |||
Other licensees (primarily those of BWR plants) estimate conditions. | |||
that a much smaller | |||
percentage of MOVs can be tested at or near design-basis | |||
conditions. These | |||
licensees have not thoroughly evaluated the dbility to conduct | |||
design-basis or maximum achievable conditions. MOV tests under | |||
Licensees who have begun differential pressure and flow testing | |||
MOYs to require more thrust to operate than predicted by have found some | |||
dard equation with typical valve factors (such as 0.3 for the industry's stan- flexible wedge gate | |||
valves) assumed in the pdst. For example, the Alabama Power | |||
licensee of the Joseph M. Farley Nuclear Plant, found less Company, the | |||
than half of the | |||
55 flexible wedge gate valves tested under differential pressure | |||
conditions to have their thrust requirements bounded by the and flow | |||
equation with a 0.3 valve factor. The industry's test results industry's standard | |||
conclusions of NRC-sponsored MOV research that the industry's confirm the | |||
determining the size of MOYs and setting their torque switches past methods of | |||
for some MOVs. were inadequate | |||
The NRC staff has found weaknesses in the licensees' procedures | |||
the differential pressure and flow tests, the acceptance criteriafor conducting | |||
to | in evaluating the capability of the MOV to perform its safety for the tests | ||
design-basis conditions, and the process for incorporating function under | |||
into the methodology used by the licensee in predicting MOY the test results | |||
The NRC | thrust require- ments. The NRC regulations and the plant's technical specifications | ||
establish requirements for licensees' actions and reporting (TS) | |||
equipment is determined to be, or has been, unable to perform when safety-related | |||
of | functions. Some licensees did not appear aware of their its safety | ||
MOV operability following testing performed under their obligations to address | |||
response to GL 89-10. For example, some licensees have notprograms established in | |||
results of MOV tests to verify the capability of the tested been evaluating the | |||
their safety functions under design-basis conditions and MOYs to perform | |||
adequacy of their methodology to size and set other MOYs. to evaluate the | |||
appeared to discard test data as suspect without careful Some licensees | |||
evaluation. The NRC | |||
Attachment 1 IN 92-17 February 26, 1992 staff has also found a lack of coordination among licensees in disseminating | |||
and using MOV test data. For example, some licensees are not considering tests | |||
conducted by other licensees which might reflect on the adequacy of their | |||
assumptions in predicting thrust requirements. | |||
For MOVs that cannot be tested under design-basis differential pressure and | |||
flow conditions, the NRC inspectors have found that some licensees are not | |||
following their commitments to the two-stage approach (discussed in | |||
Supplement 1 to GL 89-10) to test those MOVs at the maximum differential | |||
test | pressure and flow achievable. If the test pressure and flow are near to the | ||
design-basis conditions, the licensee may be able to Justify extrapolating from | |||
the test results to demonstrate the capability of the MOY to perform its safety | |||
function under design-basis conditions. Where the MOV cannot be tested near | |||
design-basis conditions, the licensee can use the results of the test at | |||
maximum achievable conditions to help confirm valve factor assumptions in its | |||
sizing and switch setting methodology and to set the MOV using the best avail- able data. The licensee may also find TS actions and reporting requirements | |||
and to set the MOV using the best avail-able data. The licensee may also find TS actions and reporting | |||
requirements | |||
that take effect as a result of tests of MOVs at less than full design-basis | that take effect as a result of tests of MOVs at less than full design-basis | ||
differential | differential pressure and flow conditions if those tests reveal that the MOYs | ||
could not perform their safety functions under design-basis conditions. | |||
if | Testing MOVs at maximum achievable conditions is especially helpful in estab- lishing a plant-specific database if the licensee estimates that only a small | ||
percentage of 14OVs can be tested at or near design-basis conditions. | |||
Some licensees who, in their initial response to GL 89-10, committed to imple- ment the recommendations of GL 89-10 to test MOYs where practicable have | |||
indicated an interest in grouping certain MOVs to reduce the amount of testing | |||
(although testing of those MOVs would be practicable). Item 1. of GL 89-10 | |||
states that licensees shall submit any changes to scheduled commitments, and | |||
that revised schedules or alternative actions may be implemented without NRC | |||
approval with justification retained on site. | |||
In their initial responses to GL 89-10, some licensees stated that they would | |||
that | attempt to group MOVs to limit the extent of design-basis testing. The prelim- inary results of design-basis tests at several plants (for example, Catawba, Farley, Oconee and Surry) Indicated that apparently identical MOYs performed | ||
significantly different uider high differential pressure and flow conditions. | |||
This could cause difficulty in grouping MOVs in such a manner that a small | |||
sample of MOV tests can be used to demonstrate that all MOVs can perform their | |||
safety functions under design-basis conditions. | |||
to | The motor operators for most gate valves are set to close on torque to provide | ||
adequate leakage control. Licensees are attempting to develop a method to | |||
ensure that MOVs closed using the limit switch meet the requisite leakage | |||
an | limitations in safety analyses without causing an MOV overstress condition. | ||
===Periodic Verification of MOV Capability=== | |||
In recommended action 'Id"of GL 89-10, the NRC staff requested that licensees | |||
prepare or revise procedures to ensure that adequate MOV switch settings are | |||
Attachment 1 IN 92-17 February 26, 1992 determined and maintained throughout the life of the plant. | |||
of GL 89-10, the NRC staff recommended that the surveillance In paragraph "ij | |||
on (1) the safety importance and (2) the maintenance and interval be based | |||
the MOV, but that the interval not exceed 5 years or 3 performance history of | |||
refueling outages, whichever is later. Further, the staff stated that the | |||
outages, whichever | |||
is later. Further, the staff stated that the | |||
capability | capability | ||
should be verified if the MOV Is replaced, modified, or overhauled of the MOY | |||
to | that the existing test results do not represent the MOV. to an extent | ||
response to Questions 33-35 and 38 in Supplement 1 to GL The NRC staff's | |||
89-10 provides | |||
guidance on periodically verifying MOY switches and performing | |||
completing maintenance. tests after | |||
The recommendation of GL 89-10 for verifying periodically | |||
switch settings includes torque, torque bypass, limit, and the adequacy of MOV | |||
Many licensees have stdted that they will attempt to use thermal overloads. | |||
tests of MOVs with | |||
diagnostic equipment under zero differential pressure and | |||
(static conditions) to demonstrate the adequacy of torque flow conditions | |||
the continued capability of MOYs to perform their safety switch settings and | |||
design-basis conditions. However, to date, none of those functions under | |||
licensees have pro- vided justification for applying the results of tests conducted | |||
conditions to demonstrate design-basis capability. These under static | |||
licensees appear to | |||
be waiting on yet to be developed generic justification for | |||
differential pressure and flow testing. static or low | |||
to | At least one licensee indicated an intent to clean and lubricate | ||
before performing periodic verification testing. This would the valve stem | |||
with demonstrating that the MOV had been set adequately be inconsistent | |||
performing its function at the end of the test interval. and was capable of | |||
In GL 89-10, the NRC staff stated that testing at design-basis | |||
not be repeated unless the MOV is replaced, modified, or conditions need | |||
that the | extent that the licensee considers that the existing test overhauled to the | ||
representative of the MOV in its modified configuration. results are not | |||
Many | |||
improving their methods to demonstrate that the MOVs are capable licensees are | |||
following | their safety functions under design-basis conditions following of performing | ||
maintenance. | maintenance. | ||
MOV Failures, Corrective | MOV Failures, Corrective Actions, and Trending | ||
In recommended action "h" of GL 89-10, the NRC staff requested | |||
action | analyze or justify each MOV failure and corrective action. that licensees | ||
that | requested that the documentation include the results and The staff also | ||
history | |||
as-found deteriorated condition, malfunction, test, inspection, of each | |||
repair, or alteration. The staff noted that the licensee analysis, report all documentation in accordance with the plant's must retain and | |||
staff also suggested that the material be examined every requirements. The | |||
2 years or after each | |||
refueling outage after the program is Implemented as part | |||
of the monitoring and | |||
feedback effort to establish trends of MOV operability. | |||
provide the basis on which the licensee can revise the These trends could | |||
testing frequency | |||
established to verify periodically that the MOV has adequate | |||
NRC staff indicated that the system should be well-structured capability. The | |||
capture, and share history datd on individual components. and should track, response to Questions 39 and 40 in Supplement 1 to GL 89-10 The NRC staff's | |||
on identifying trends of MOV problems. provides guidance | |||
to | Attachment 1 IN 92-17 February 26, 1992 The NRC inspectors have found some licensees to have weaknesses in evaluating | ||
MOV failures and deficiencies (such as the operability effects of spring pack | |||
relaxation). Some licensees have not been thorough in performing root cause | |||
analyses of MOY problems. Most licensees are attempting to improve their | |||
methods for identifying trends in MOY problems. | |||
Schedule | |||
In GL 89-10, the NRC staff requested that, by June 28, 1994, or by the third | |||
refueling outage after December 28, 1989, whichever is later, licensees com- plete all design-basis reviews, analyses, verifications, tests, and inspections | |||
that were initiated in order to satisfy the actions recommended in the generic | |||
letter. The NRC staff's response to Question 41 in Supplement 1 to GL 89-10 | |||
provides guidance on the schedule for implementing these actions specified in | |||
GL 89-10. | |||
Some licensees have not made adequate progress for resolving the MOV issue for | |||
their facilities within the recommended schedule of GL 89-10. The findings of | |||
to | licensees as they begin to initiate their programs in response to GL 89-10 and | ||
the results of the NRC inspections of GL 89-10 programs reinforce the impor- tance of promptly resolving this safety-significant issue. The NRC staff has | |||
accepted limited extensions of the GL 89-10 schedule for particular licensees | |||
who have provided Justification. | |||
I emnt2 February 26. 1992 Pap 1 of I | |||
LIST OF RECEITLY ISSUED | |||
NRCIIIFORITION NOTICES | |||
Information Date of | |||
notice No.. Subject Issuance Issued to | |||
92-16 Loss of Flow from the 02/25192 All holders of OLs or CPs | |||
Residual Heat Removal for nuclear power reactors. | |||
Pump during Refueling | |||
Cavity Dr"indown | |||
92-15 Failure of Primary System 02/24/92 All holders of OLs or CPs | |||
Compression Fitting for nuclear power reactors. | |||
92-14 Uranium Oxide Fires at Fuel 02/21/92 All fuel cycle and uranium | |||
Cycle Facilities fuel research and development | |||
licensees. | |||
92-02. RelapS/Hod3 Computer Code 02/19/92 All holders of OLs or CPs | |||
Supp. I Error Associated with the for nuclear power reactors. | |||
of | Conservation of Energy | ||
Equation | |||
92-13 Inadequate Control Over 02/18/92 All holders of OLs or CPs | |||
Vehicular Traffic at' for nuclear power reactors. | |||
Nuclear Power Plant Sites | |||
92-12 Effects of Cable Leakage 02/10/92. All holders of OLs or CPs | |||
Currents on Instrument for nuclear power reactors. | |||
Settings and Indications | |||
92-11 Soll and hater Contamina- 02/05/92 All uranium fuel fabrica- tion at Fuel Cycle Facil- tion and conversion facil- ities ities. | |||
92- | 92-10 8rachytherapy Incidents 01/31/92 AlI luclear Regulatory Com- Involving Irdium-192 Wire - mission (NRC) licensees | ||
Used i Endobronchisl authorized to use | |||
Treatments iridium-192 for brachy- therapyi manufacturers and | |||
distributors of iridiu-I92 wire for use in brachy- therapy. | |||
OL | |||
* Operating License | |||
CP | |||
* Construction Permit | |||
UNITED STATES | |||
NUCLEAR REGULATORY COMMISSION POSTAGE FEES PAID | |||
WASHINGTON, D.C. 20555 UMNO | |||
nIEM No. 0J | |||
OFFICIAL BUSINESS | |||
PENALTY FOR PRIVATE USE, $300 | |||
IN 92-17 February 26, 1992 This information notice requires no specific action or written response. If | |||
you have any questions about the information in this notice, please contact the | |||
technical contact listed below or the appropriate Office of Nuclear Reactor | |||
Regulation (NRR) project manager. | |||
Charles E. Rossi, Director | |||
Division of Operational Events Assessment | |||
Office of Nuclear Reactor Regulation | Office of Nuclear Reactor Regulation | ||
Technical | Technical contact: Thomas G. Scarbrough, NRR | ||
contact: Thomas G. Scarbrough, NRR | |||
to the Recommendations | (301) 504-2794 Attachments: | ||
1. Inspection Findings Pertaining to the Recommendations Contained In | |||
Generic Letter 89-10 | |||
2. List of Recently Issued NRC Information Notices | |||
Document Name: GL 89-10 INSPECTION RESULTS IN | |||
*SEE PREVIOUS CONCURRENCES | |||
*C/OGCB:DOEA:NRR | |||
CHBerlinger | CHBerlinger | ||
02/11/92 | 02/11/92 | ||
*OGCB:DOEA:NRR *EMEB:DET:NRR *C/EMEB:DET:NRR*D/DET:NRR '*RPB:ADM | |||
RJKiessel TGScarbrough JANorberg JERlchardson TechEd | |||
01/14/92 01/09/92 01/13/92 01/29/92 01/14/92 | |||
IN 92-XX | |||
notice requires no specific action or written response. | February xx, 1992 This information notice requires no specific action or written response. If | ||
you have any questions about the information in this notice, please contact the | |||
technical contact listed below or the appropriate Office of Nuclear Reactor | |||
Regulation (NRR) project manager. | |||
Charles E. Rossi, Director | |||
Division of Operational Events Assessment | |||
Office of Nuclear Reactor Regulation | Office of Nuclear Reactor Regulation | ||
Technical | Technical contact: Thomas G. Scarbrough, NRR | ||
contact: Thomas G. Scarbrough, NRR | |||
(301) 504-2794 Attachments: | |||
1. Inspection Findings Pertaining to the Recommendations Contained In | |||
Generic Letter 89-10 | |||
2. Inspection Findings Pertaining to Other MOY Areas | |||
3. List of Recently Issued NRC Information Notices | |||
Document Name: GL 89-10 INSPECTION RESULTS IN | |||
*SEE PREVIOUS CONCURRENCES | |||
D/DOEA:NRR *C/OGCB:DOEA:NR11! - | |||
CERossi CHBerlinger -0 | |||
02/ /92 01/31/92 A | |||
*OGCB:DOEA:NRR *EMEB:DET:NRR *C/EMEB:DET:NRR*D/DET:NRR *RPB:ADM | |||
RJKiessel TGScarbrough JANorberg JERichardson TechEd | |||
01/14/92 01/09/92 01/13/92 01/29/92 01/14/92 | |||
IN 92-XX | |||
notice requires no specific action or written response. | January xx, 1992 This information notice requires no specific action or written response. If | ||
you have any questions about the information in this notice, please contact the | |||
technical contact listed below or the appropriate Office of Nuclear Reactor | |||
Regulation (NRR) project manager. | |||
Charles E. Rossi, Director | |||
Division of Operational Events Assessment | |||
Office of Nuclear Reactor Regulation | Office of Nuclear Reactor Regulation | ||
Technical | Technical contact: Thomas G. Scarbrough, NRR | ||
contact: Thomas G. Scarbrough, NRR | |||
to the Recommendations | (301) 504-2794 Attachments: | ||
1. Inspection Findings Pertaining to the Recommendations Contained In | |||
Generic Letter 89-10 | |||
2. Inspection Findings Pertaining to Other MOV Areas | |||
3. List of Recently Issued NRC Information Notices | |||
Document Name: GL 89-10 INSPECTION RESULTS IN | |||
to | *SEE PREVIOUS CONCURRENCES ---- -'11/ | ||
D/DOEA:NRR C/OGCB:DOEA:N Zg; | |||
CERossi HBerlinger to | |||
01/ /92 / 0lL1/92 | |||
*OGCB:DOEA:NRR *EMEB:DET:NRR *C/EMEB:DET:NRR D/DE tAJg*RPF.ADM | |||
RJKiessel TGScarbrough JANorberg JER i d d q TechEd | |||
01/14/92 01/09/92 01/13/92 Ad 01// 01/14/92 | |||
Charles E. Rossi, Director | |||
Division of Operational Events Assessment | |||
Office of Nuclear Reactor Regulation | Office of Nuclear Reactor Regulation | ||
Technical | Technical contact: Thomas G. Scarbrough, NRR | ||
contact: Thomas G. Scarbrough, NRR | |||
Contained | (301) 504-2794 Attachments: | ||
1. Inspection Findings Pertaining to the Recommendations Contained In | |||
Generic Letter 89-10 | |||
2. Inspection Findings Pertaining to Other MOV Areas | |||
3. List of Recently Issued NRC Information Notices | |||
Document Name: GL 89-10 INSPECTION RESULTS IN | |||
D/DOEA:NRR C/OGCB:DOEA:NRR | |||
CERossi CHBerlinger | |||
Ol/ /92 01/ /92 OGCB:DOEA:NRR EMEB:DET:NRR C/EMEB:DET:NRR D/DET: NRR RPB:ADM | |||
01/ /92 | RJKiessel TGScarbrough JANorberg JERichardson TechEd 1Miain 91 | ||
01/ /92 01/ /92 01/ /92 01/ /92 01/jq/92 | |||
Charles E. Rossi, Director | |||
Division of Operational Events Assessment | |||
Office of Nuclear Reactor Regulation | Office of Nuclear Reactor Regulation | ||
Technical | Technical contact: Thomas G. Scarbrough, NRR | ||
contact: Thomas G. Scarbrough, NRR | |||
(301) 504-2794 Attachments: | |||
1. Inspection Findings Pertaining to the Recommendations Contained In | |||
Generic Letter 89-10 | |||
2. Inspection Findings Pertaining to Other MOV Areas | |||
3. List of Recently Issued NRC Information Notices | |||
Document Name: GL 89-10 INSPECTION RESULTS IN | |||
D/DOEA:NRR C/OGCB:DOEA:NRR | |||
CERossi CHBerlinger | |||
01/ /92 01/ /92 OGCB:DOEA:NRR EMEB:DET:NRR C/EMEB:DET:NRR D/DET:NRR RPB:ADM | |||
01/ /92 C/EMEB:DET:NRR | |||
JANorberg 01/ /92}} | RJKiessel L TGScarbrough JANorberg JERicharoson TechEd JIMahl97 | ||
01/fl/ 92 01/ /92 01/ /92 01/ /92 01//q/92}} | |||
{{Information notice-Nav}} | {{Information notice-Nav}} |
Latest revision as of 03:20, 24 November 2019
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION
WASHINGTON, D.C. 20555 February 26, 1992 NRC INFORMATION NOTICE 92-17: NRC INSPECTIONS OF PROGRAMS BEING DEVELOPED
AT NUCLEAR POWER PLANTS IN RESPONSE TO
GENERIC LETTER 89-10
Addressees
All holders of operating licenses or construction permits for nuclear power
reactors.
Purpose
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice
to alert addressees to the general conclusions derived from the NRC inspections
of the programs being developed at nuclear power plants in response to
Generic Letter (GL) 89-10, "Safety-Related Motor-Operated Valve Testing and
Surveillance." It is expected that recipients will review the information for
applicability to their facilities and consider actions, as appropriate, to
avoid similar problems. However, suggestions contained in this information
notice are not NRC requirements; therefore, no specific action or written
response is required.
Background
In GL 89-10 (June 28, 1989), the NRC staff requested that holders of nuclear
power plant operating licenses and construction permits ensure the capability
of motor-operated valves (MOVs) in safety-related systems by reviewing MOV
design bases, verifying MOV switch settings initially and periodically, testing
MOYs under design basis conditions where practicable, improving evaluations of
MOV failures and necessary corrective action, and determining trends of MOV
problems. The NRC staff requested that licensees complete the GL 89-10 program
by the end of the third refueling outage or 5 years from the issuance of the
generic letter, whichever is later. On June 13, 1990, the NRC staff issued
Supplement 1 to GL 89-10 to provide detailed information on the results of
public workshops held to discuss the generic letter. On August 3, 1990, the
NRC staff issued Supplement 2 to GL 89-10 to allow licensees additional time to
review and to incorporate the information provided in Supplement 1 into their
programs in response to the generic letter. Upon reviewing the results of
NRC-sponsored MOV tests, the NRC staff issued Supplement 3 to GL 89-10 on
October 25, 1990, which requested licensees of boiling water reactor (BWR)
nuclear plants to take action in advance of the GL 89-10 schedule to resolve
concerns about the capability of MOYs used for containment isolation in the
steam supply line of the high pressure coolant injection and reactor core
isolation cooling systems, in the supply line of the reactor water cleanup
system, and in other systems directly connected to the 'reactor vessel. In
4 ek219371 t= v dsO]- qWog Xe
IN 92-17 February 26, 1992 Supplement 4 to GL 89-10, the NRC staff indicated that BWR licensees need not
address inadvertent MOY operation in their GL 89-10 programs. The NRC staff is
considering whether or not similar actions should be taken regarding the need
for licensees of pressurized-water reactor (PWR) nuclear plants to address the
inadvertent operation of MOVs in their programs to respond to GL 89-10.
Description of Circumstances
The NRC staff has conducted inspections at more than 30 nuclear power plant
sites of programs being developed by, licensees in response to GL 89-10. The
reports of those inspections are available in the NRC Public Document Room. In
performing the inspections, the NRC staff has followed Temporary Instruction
(TI) 2515/109 of January 14, 1991, Inspection Requirements for
Generic Letter 89-10, Safety-Related Motor-Operated Valve Testing and Sur- veillance.' Part 1 of TI 2515/109 provides guidance for reviewing the program
being established.by theLlicensee. in response to GL 89-10, and.Part 2 provides
guidance for reviewing program implementation. The NRC has focused these
inspections on reviewing the GL 89-10 programs (Part 1 of TI 2515/109). The
staff is issuing this information notice to provide the more significant
results of those NRC inspections.
In GL 89-10, the NRC staff requested that licensees prepare descriptions of
their programs established in response to GL 89-10 within 1 year after the
generic letter was issued or by the first refueling outage after
December 28, 1989, whichever was later. The NRC staff's response to
Question 44 in Supplement 1 to GL 89-10 provided guidance on information
expected in the program descriptions. The NRC inspectors found-some licensees
to have program descriptions that are thorough while other licensees did not.
Attachment 1 Is a discussion of the inspection findings pertaining to the
recommendations of GL 89-10.
Related Generic Communications
In addition to NRC Generic Letter 89-10, "Safety-Related Motor-Operated Valve
Testing and Surveillance," and its supplements, the NRC has addressed.this and
related topics in NRC Information Notices.89-88, "Recent NRC-Sponsored Testing
of Motor-Operated Valves;" 90-40,."Results of NRC-Sponsored Testing of
Motor-Operated Valves;" 90-72, "Testing of Parallel Disc Gate Valves in
Europe;" and 91-61, "Preliminary Results of Validation Testing of Motor- Operated Valve Diagnostic Equipment.".
IN 92X17 February 26, 1992 This information notice requires no specific action or written response. If
you have any questions about the Information in this notice, please contact the
technical contact listed below or the appropriate Office of Nuclear Reactor
Regulation (NRR) project manager.
arIes E. Ross D rec o
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical contact: Thomas G. Scarbrough, NRR
(301) 504-2794 Attachments:
1. Inspection Findings Pertaining to the Recommendations Contained In
2. List of Recently Issued NRC Information Notices
Attachment 1 IN 92-17 February 26, 1992 INSPECTION FINDINGS PERTAINING
TO THE RECOMMENDATIONS CONTAINED IN GENERIC LETTER 89-10
Administration
Some licensees have not ensured adequate management oversight and direction for
the motor-operated valve (MOY) program. One licensee had contracted an
internal audit that revealed problems with the MOY program similar to those
found subsequently during the NRC inspection, but the licensee had not taken
action to correct the deficiencies. The safety significance of the MOV program
and the extensive resources needed to develop and implement the program make it
imperative that licensee's management closely monitor its staff's activities.
Scope
In issuirng Generic Letter (GL) 89-10, the NRC staff intended that the scope
include all safety-related MOVs and other MOVs in safety-related systems. In
Supplement 1 to GL 89-10, the NRC staff limited the scope of GL 89-10 to
safety-related MOYs and other MOVs that are position-changeable in safety- related piping systems, as well as safety-related MOVs that might be in
nonsafety-related piping systems. The NRC staff's response to Questions 3-13 in Supplement 1 to GL 89-10 provided further guidance on the scope of GL 89-10.
For example, in the NRC staff's response to Question 4 in Supplement 1, the
staff defined "position-changeable" as any MOV in a safety-related piping
system that is not blocked from inadvertent operation from the control room.
In Supplement 4 to GL 89-10, the NRC staff indicated that licensees for boiling
water reactor (BWR) plants need not address inadvertent MOV operation in their
GL 89-10 programs. The NRC staff is considering whether or not similar actions
should be taken regarding the need for the licensees of pressurized-water
reactor (PWR) plants to address inadvertent MOV operation in their programs to
respond to GL 89-10.
The NRC inspectors found most licensees to be establishing the scope of their
GL 89-10 programs consistent with the recommendations of the generic letter.
However, some licensees needed to improve the documentation of their justifi- cation for excluding particular MOVs from the GL 89-10 program.
Design-Basis Reviews
In recommended action "a" of GL 89-10, the NRC staff requested the licensees to
review and document the design basis for operating each MOV within the generic
letter program to determine the maximum differential pressure and flow (and
other factors) expected for both normal operations and abnormal conditions.
The NRC staff's response to Questions 14 to 18 and 36 in Supplement 1 to
GL 89-10 provides guidance on performing design-basis reviews under GL 89-10.
Many licensees are appropriately reviewing plant documentation such as the
final safety analysis report and the technical specifications as part of their
design-basis reviews. However, some licensees had failed to identify
worst-case conditions for various design-basis scenarios. Some licensees have
's.- Attachment 1 IN 92-17 February 26, 1992 assumed nominal reactor pressure for differential pressure across MOVs in lines
directly connected to the reactor vessel without evaluating whether this
differential pressure bounds the worst-case MOV design-basis differential
pressure. At certain facilities, the licensee found errors in the previous
design basis determinations for many MOVs that would have affected the cap- ability of the MOVs to perform their safety function if called upon under
design-basis conditions.
Some licensees focused on differential pressure and had not adequately ad- dressed other design-basis parameters such as flow, fluid temperature, ambient
temperature, and the effects of seismic and dynamic events. Although differen- tial pressure is the primary design-basis parameter used to predict the thrust
requirements in the industry's equations, the other design-basis parameters are
needed to ensure that the test results demonstrate that the MOV would operate
under design-basis conditions. Some licensees have not ensured that generic
studies of design-basis differential pressure apply to specific plants.
MOY Sizing and Switch Settings
In recommended action "b" of GL 89-10, the NRC staff requested licensees to
review and revise, as necessary, the methods for selecting and setting all MOV
switches. The NRC staff's response to Questions 19-21 in Supplement 1 to
GL 89-10 provides guidance on selecting and setting MOV switches.
The recommendations of GL 89-10 for selecting and setting MOV switches apply to
switches for torque, torque bypass, limit, and thermal overload. The licensees
are using various methods to determine the proper size of MOVs and their
appropriate torque switch settings. Some licensees have increased the valve
factors assumed in the industry's equations used to predict the thrust required
to operate the valves to reflect experience throughout the industry and at
their specific plant. However, other licensees continue to use old guidance
from valve vendors and manufacturers in estimating the thrust requirements that
may be found inadequate during design-basis tests.
The NRC inspectors found that licensees for various facilities had not done the
following when establishing methods to size MOVs and set their switches:
(1) Provide justification for assumptions regarding stem friction coefficients
and changes in stem friction over the lubrication interval
(2) Consider effects that can reduce the thrust delivered by the motor opera- tor under high differential pressure and flow conditions in relation to
the thrust delivered under no-load conditions
(3) Consider the effects of ambient temperature on motor output and thermal
overload sizing
(4) Demonstrate applicability of industry's databases in predicting thrust
requirements
(5) Consider inertia in establishing the maximum settings for torque switches
Attachment 1 IN 92-17 February 26, 1992 (6) Demonstrate applicability of contractors' studies of actuator capability
(7) Demonstrate applicability of generic motor curves for specific motors
(8) Provide justification for removing conservatisms (such as the application
factor) from the industry's standard sizing calculations
(9) Consider torque switch repeatability
(10) Consider uncertainties regarding the accuracy of MOV diagnostic equipment.
Some licensees have had problems in performing MOV sizing and switch setting
calculations because of (1) incorrect spring packs installed in MOVs,
(2) incorrect MOV data on the motor or actuator nameplates and in the procure- ment documents from the vendor, and (3) spring packs with different performance
characteristics from different manufacturers, but with the same part number.
One licensee determined that the MOV sizing and switch setting activities to
establish motor operator capability had not adequately addressed the effect of
those activities on other MOY safety functions. These activities had hindered
the ability of the clutch of certain MOYs to be released to enable the MOV to
be manually operated in the event of an evacuation of the control room.
Many licensees are updating their degraded voltage studies to ensure that the
worst-case minimum voltage available at the motor has been determined for each
MOV. Some licensees had not ensured that their assumptions of minimum voltage
available at the MOYs were consistent with their licensing commitments in
safety analyses. Some licensees did not justify the assumptions for the
starting point for the degraded voltage calculations, current used to calculate
cable losses, losses caused by the resistance of thermal overload devices in
the circuit, or the effects on MOV stroke time under degraded voltage condi- tions. Of particular significance, the inspectors found one licensee to be
assuming an excessively small locked-rotor power factor (0.2) in the motor for
use in the calculation of voltage drop from the motor control center to the
MOV. The licensee's selection of this power factor was based on guidance in an
Institute of Electrical and Electronics Engineers' standard that was not
applicable to the size of motors typically used to operate valves in nuclear
power plants. The assumption of an excessively small power factor causes an
underestimation of the cable voltage drop and may result in the overestimation
of MOV capability under design-basis conditions.
Licensees are improving their documentation of current and required MOV switch
settings, but some weaknesses remain. For example, one licensee had simplified
its control over changes to torque switch settings to expedite the process but, In so doing, caused the concern that the quality assurance department may not
participate adequately in accepting those changes. Some of the weakness in
documenting torque switch settings appears to result from the difficulty in
reading the switches. Some licensees have raised torque switch settings for
MOVs above the manufacturer's maximum specified value without performing an
adequate safety analysis in accordance with the requirements of 10 CFR 50.59.
-'- Attachment 1 IN 92-17 February 26, 1992 Design-Basis Differential Pressure and Flow Testing
In recommended action "c" of GL 89-10, the NRC staff requested
test MOVs within the generic letter program in situ under licensees to
differential pressure and flow conditions. The NRC staff their design-basis
methods to be used to demonstrate the capability of the allows alternate
MOV if testing in situ
under those conditions is not practicable. The NRC staff
licensees follow a two-stage approach for a situation in suggested that the
testing in situ is not practicable and the licensees couldwhich design-basis
not justify an
alternate method of demonstrating MOV capability. In performing
approach, a licensee would evaluate the capability of the the two-stage
data available and then would obtain applicable test data MOV using the best
of the generic letter. The NRC staff's response to Questionswithin the schedule
Supplement 1 to GL 89-10 provides guidance on design-basis 22-32 and 37 in
two-stage approach. testing and the
Many licensees have committed to test MOVs within the scope
program under design-basis conditions, where practicable. of their GL 89-10
Some
indicated that most MOVs can be tested at or near design-basis licensees have
Other licensees (primarily those of BWR plants) estimate conditions.
that a much smaller
percentage of MOVs can be tested at or near design-basis
conditions. These
licensees have not thoroughly evaluated the dbility to conduct
design-basis or maximum achievable conditions. MOV tests under
Licensees who have begun differential pressure and flow testing
MOYs to require more thrust to operate than predicted by have found some
dard equation with typical valve factors (such as 0.3 for the industry's stan- flexible wedge gate
valves) assumed in the pdst. For example, the Alabama Power
licensee of the Joseph M. Farley Nuclear Plant, found less Company, the
than half of the
55 flexible wedge gate valves tested under differential pressure
conditions to have their thrust requirements bounded by the and flow
equation with a 0.3 valve factor. The industry's test results industry's standard
conclusions of NRC-sponsored MOV research that the industry's confirm the
determining the size of MOYs and setting their torque switches past methods of
for some MOVs. were inadequate
The NRC staff has found weaknesses in the licensees' procedures
the differential pressure and flow tests, the acceptance criteriafor conducting
in evaluating the capability of the MOV to perform its safety for the tests
design-basis conditions, and the process for incorporating function under
into the methodology used by the licensee in predicting MOY the test results
thrust require- ments. The NRC regulations and the plant's technical specifications
establish requirements for licensees' actions and reporting (TS)
equipment is determined to be, or has been, unable to perform when safety-related
functions. Some licensees did not appear aware of their its safety
MOV operability following testing performed under their obligations to address
response to GL 89-10. For example, some licensees have notprograms established in
results of MOV tests to verify the capability of the tested been evaluating the
their safety functions under design-basis conditions and MOYs to perform
adequacy of their methodology to size and set other MOYs. to evaluate the
appeared to discard test data as suspect without careful Some licensees
evaluation. The NRC
Attachment 1 IN 92-17 February 26, 1992 staff has also found a lack of coordination among licensees in disseminating
and using MOV test data. For example, some licensees are not considering tests
conducted by other licensees which might reflect on the adequacy of their
assumptions in predicting thrust requirements.
For MOVs that cannot be tested under design-basis differential pressure and
flow conditions, the NRC inspectors have found that some licensees are not
following their commitments to the two-stage approach (discussed in
Supplement 1 to GL 89-10) to test those MOVs at the maximum differential
pressure and flow achievable. If the test pressure and flow are near to the
design-basis conditions, the licensee may be able to Justify extrapolating from
the test results to demonstrate the capability of the MOY to perform its safety
function under design-basis conditions. Where the MOV cannot be tested near
design-basis conditions, the licensee can use the results of the test at
maximum achievable conditions to help confirm valve factor assumptions in its
sizing and switch setting methodology and to set the MOV using the best avail- able data. The licensee may also find TS actions and reporting requirements
that take effect as a result of tests of MOVs at less than full design-basis
differential pressure and flow conditions if those tests reveal that the MOYs
could not perform their safety functions under design-basis conditions.
Testing MOVs at maximum achievable conditions is especially helpful in estab- lishing a plant-specific database if the licensee estimates that only a small
percentage of 14OVs can be tested at or near design-basis conditions.
Some licensees who, in their initial response to GL 89-10, committed to imple- ment the recommendations of GL 89-10 to test MOYs where practicable have
indicated an interest in grouping certain MOVs to reduce the amount of testing
(although testing of those MOVs would be practicable). Item 1. of GL 89-10
states that licensees shall submit any changes to scheduled commitments, and
that revised schedules or alternative actions may be implemented without NRC
approval with justification retained on site.
In their initial responses to GL 89-10, some licensees stated that they would
attempt to group MOVs to limit the extent of design-basis testing. The prelim- inary results of design-basis tests at several plants (for example, Catawba, Farley, Oconee and Surry) Indicated that apparently identical MOYs performed
significantly different uider high differential pressure and flow conditions.
This could cause difficulty in grouping MOVs in such a manner that a small
sample of MOV tests can be used to demonstrate that all MOVs can perform their
safety functions under design-basis conditions.
The motor operators for most gate valves are set to close on torque to provide
adequate leakage control. Licensees are attempting to develop a method to
ensure that MOVs closed using the limit switch meet the requisite leakage
limitations in safety analyses without causing an MOV overstress condition.
Periodic Verification of MOV Capability
In recommended action 'Id"of GL 89-10, the NRC staff requested that licensees
prepare or revise procedures to ensure that adequate MOV switch settings are
Attachment 1 IN 92-17 February 26, 1992 determined and maintained throughout the life of the plant.
of GL 89-10, the NRC staff recommended that the surveillance In paragraph "ij
on (1) the safety importance and (2) the maintenance and interval be based
the MOV, but that the interval not exceed 5 years or 3 performance history of
refueling outages, whichever is later. Further, the staff stated that the
capability
should be verified if the MOV Is replaced, modified, or overhauled of the MOY
that the existing test results do not represent the MOV. to an extent
response to Questions 33-35 and 38 in Supplement 1 to GL The NRC staff's
89-10 provides
guidance on periodically verifying MOY switches and performing
completing maintenance. tests after
The recommendation of GL 89-10 for verifying periodically
switch settings includes torque, torque bypass, limit, and the adequacy of MOV
Many licensees have stdted that they will attempt to use thermal overloads.
tests of MOVs with
diagnostic equipment under zero differential pressure and
(static conditions) to demonstrate the adequacy of torque flow conditions
the continued capability of MOYs to perform their safety switch settings and
design-basis conditions. However, to date, none of those functions under
licensees have pro- vided justification for applying the results of tests conducted
conditions to demonstrate design-basis capability. These under static
licensees appear to
be waiting on yet to be developed generic justification for
differential pressure and flow testing. static or low
At least one licensee indicated an intent to clean and lubricate
before performing periodic verification testing. This would the valve stem
with demonstrating that the MOV had been set adequately be inconsistent
performing its function at the end of the test interval. and was capable of
In GL 89-10, the NRC staff stated that testing at design-basis
not be repeated unless the MOV is replaced, modified, or conditions need
extent that the licensee considers that the existing test overhauled to the
representative of the MOV in its modified configuration. results are not
Many
improving their methods to demonstrate that the MOVs are capable licensees are
their safety functions under design-basis conditions following of performing
maintenance.
MOV Failures, Corrective Actions, and Trending
In recommended action "h" of GL 89-10, the NRC staff requested
analyze or justify each MOV failure and corrective action. that licensees
requested that the documentation include the results and The staff also
history
as-found deteriorated condition, malfunction, test, inspection, of each
repair, or alteration. The staff noted that the licensee analysis, report all documentation in accordance with the plant's must retain and
staff also suggested that the material be examined every requirements. The
2 years or after each
refueling outage after the program is Implemented as part
of the monitoring and
feedback effort to establish trends of MOV operability.
provide the basis on which the licensee can revise the These trends could
testing frequency
established to verify periodically that the MOV has adequate
NRC staff indicated that the system should be well-structured capability. The
capture, and share history datd on individual components. and should track, response to Questions 39 and 40 in Supplement 1 to GL 89-10 The NRC staff's
on identifying trends of MOV problems. provides guidance
Attachment 1 IN 92-17 February 26, 1992 The NRC inspectors have found some licensees to have weaknesses in evaluating
MOV failures and deficiencies (such as the operability effects of spring pack
relaxation). Some licensees have not been thorough in performing root cause
analyses of MOY problems. Most licensees are attempting to improve their
methods for identifying trends in MOY problems.
Schedule
In GL 89-10, the NRC staff requested that, by June 28, 1994, or by the third
refueling outage after December 28, 1989, whichever is later, licensees com- plete all design-basis reviews, analyses, verifications, tests, and inspections
that were initiated in order to satisfy the actions recommended in the generic
letter. The NRC staff's response to Question 41 in Supplement 1 to GL 89-10
provides guidance on the schedule for implementing these actions specified in
Some licensees have not made adequate progress for resolving the MOV issue for
their facilities within the recommended schedule of GL 89-10. The findings of
licensees as they begin to initiate their programs in response to GL 89-10 and
the results of the NRC inspections of GL 89-10 programs reinforce the impor- tance of promptly resolving this safety-significant issue. The NRC staff has
accepted limited extensions of the GL 89-10 schedule for particular licensees
who have provided Justification.
I emnt2 February 26. 1992 Pap 1 of I
LIST OF RECEITLY ISSUED
NRCIIIFORITION NOTICES
Information Date of
notice No.. Subject Issuance Issued to
92-16 Loss of Flow from the 02/25192 All holders of OLs or CPs
Residual Heat Removal for nuclear power reactors.
Pump during Refueling
Cavity Dr"indown
92-15 Failure of Primary System 02/24/92 All holders of OLs or CPs
Compression Fitting for nuclear power reactors.
92-14 Uranium Oxide Fires at Fuel 02/21/92 All fuel cycle and uranium
Cycle Facilities fuel research and development
licensees.
92-02. RelapS/Hod3 Computer Code 02/19/92 All holders of OLs or CPs
Supp. I Error Associated with the for nuclear power reactors.
Conservation of Energy
Equation
92-13 Inadequate Control Over 02/18/92 All holders of OLs or CPs
Vehicular Traffic at' for nuclear power reactors.
Nuclear Power Plant Sites
92-12 Effects of Cable Leakage 02/10/92. All holders of OLs or CPs
Currents on Instrument for nuclear power reactors.
Settings and Indications
92-11 Soll and hater Contamina- 02/05/92 All uranium fuel fabrica- tion at Fuel Cycle Facil- tion and conversion facil- ities ities.
92-10 8rachytherapy Incidents 01/31/92 AlI luclear Regulatory Com- Involving Irdium-192 Wire - mission (NRC) licensees
Used i Endobronchisl authorized to use
Treatments iridium-192 for brachy- therapyi manufacturers and
distributors of iridiu-I92 wire for use in brachy- therapy.
- Operating License
- Construction Permit
UNITED STATES
NUCLEAR REGULATORY COMMISSION POSTAGE FEES PAID
WASHINGTON, D.C. 20555 UMNO
nIEM No. 0J
OFFICIAL BUSINESS
PENALTY FOR PRIVATE USE, $300
IN 92-17 February 26, 1992 This information notice requires no specific action or written response. If
you have any questions about the information in this notice, please contact the
technical contact listed below or the appropriate Office of Nuclear Reactor
Regulation (NRR) project manager.
Charles E. Rossi, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical contact: Thomas G. Scarbrough, NRR
(301) 504-2794 Attachments:
1. Inspection Findings Pertaining to the Recommendations Contained In
2. List of Recently Issued NRC Information Notices
Document Name: GL 89-10 INSPECTION RESULTS IN
- SEE PREVIOUS CONCURRENCES
- C/OGCB:DOEA:NRR
CHBerlinger
02/11/92
- OGCB:DOEA:NRR *EMEB:DET:NRR *C/EMEB:DET:NRR*D/DET:NRR '*RPB:ADM
RJKiessel TGScarbrough JANorberg JERlchardson TechEd
01/14/92 01/09/92 01/13/92 01/29/92 01/14/92
IN 92-XX
February xx, 1992 This information notice requires no specific action or written response. If
you have any questions about the information in this notice, please contact the
technical contact listed below or the appropriate Office of Nuclear Reactor
Regulation (NRR) project manager.
Charles E. Rossi, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical contact: Thomas G. Scarbrough, NRR
(301) 504-2794 Attachments:
1. Inspection Findings Pertaining to the Recommendations Contained In
2. Inspection Findings Pertaining to Other MOY Areas
3. List of Recently Issued NRC Information Notices
Document Name: GL 89-10 INSPECTION RESULTS IN
- SEE PREVIOUS CONCURRENCES
D/DOEA:NRR *C/OGCB:DOEA:NR11! -
CERossi CHBerlinger -0
02/ /92 01/31/92 A
- OGCB:DOEA:NRR *EMEB:DET:NRR *C/EMEB:DET:NRR*D/DET:NRR *RPB:ADM
RJKiessel TGScarbrough JANorberg JERichardson TechEd
01/14/92 01/09/92 01/13/92 01/29/92 01/14/92
IN 92-XX
January xx, 1992 This information notice requires no specific action or written response. If
you have any questions about the information in this notice, please contact the
technical contact listed below or the appropriate Office of Nuclear Reactor
Regulation (NRR) project manager.
Charles E. Rossi, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical contact: Thomas G. Scarbrough, NRR
(301) 504-2794 Attachments:
1. Inspection Findings Pertaining to the Recommendations Contained In
2. Inspection Findings Pertaining to Other MOV Areas
3. List of Recently Issued NRC Information Notices
Document Name: GL 89-10 INSPECTION RESULTS IN
- SEE PREVIOUS CONCURRENCES ---- -'11/
D/DOEA:NRR C/OGCB:DOEA:N Zg;
CERossi HBerlinger to
01/ /92 / 0lL1/92
- OGCB:DOEA:NRR *EMEB:DET:NRR *C/EMEB:DET:NRR D/DE tAJg*RPF.ADM
RJKiessel TGScarbrough JANorberg JER i d d q TechEd
01/14/92 01/09/92 01/13/92 Ad 01// 01/14/92
Charles E. Rossi, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical contact: Thomas G. Scarbrough, NRR
(301) 504-2794 Attachments:
1. Inspection Findings Pertaining to the Recommendations Contained In
2. Inspection Findings Pertaining to Other MOV Areas
3. List of Recently Issued NRC Information Notices
Document Name: GL 89-10 INSPECTION RESULTS IN
D/DOEA:NRR C/OGCB:DOEA:NRR
CERossi CHBerlinger
Ol/ /92 01/ /92 OGCB:DOEA:NRR EMEB:DET:NRR C/EMEB:DET:NRR D/DET: NRR RPB:ADM
RJKiessel TGScarbrough JANorberg JERichardson TechEd 1Miain 91
01/ /92 01/ /92 01/ /92 01/ /92 01/jq/92
Charles E. Rossi, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical contact: Thomas G. Scarbrough, NRR
(301) 504-2794 Attachments:
1. Inspection Findings Pertaining to the Recommendations Contained In
2. Inspection Findings Pertaining to Other MOV Areas
3. List of Recently Issued NRC Information Notices
Document Name: GL 89-10 INSPECTION RESULTS IN
D/DOEA:NRR C/OGCB:DOEA:NRR
CERossi CHBerlinger
01/ /92 01/ /92 OGCB:DOEA:NRR EMEB:DET:NRR C/EMEB:DET:NRR D/DET:NRR RPB:ADM
RJKiessel L TGScarbrough JANorberg JERicharoson TechEd JIMahl97
01/fl/ 92 01/ /92 01/ /92 01/ /92 01//q/92