ML17131A067
| ML17131A067 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 05/11/2017 |
| From: | Kennedy K Region 4 Administrator |
| To: | Heflin A Wolf Creek |
| References | |
| EA-16-273 | |
| Download: ML17131A067 (9) | |
See also: IR 05000482/2016003
Text
EA-16-273 UNITED STATES NUCLEAR REGULATORY
COMMISSION
REGIO N IV 1600 E LAMAR BL VO ARLINGTON. TX 76011-4511
May 11 , 2017 Adam C. Hefl in , Pres ident and Chief Executive
Officer Wolf Creek Nuclear Operating
Corporation
P.O. Box411 Burlington , KS 66839 SUBJECT: WOLF CREEK GENERATING
STATION -NRC INSPECTION
REPORT 5000482/2016003
AND RESPONSE TO DISPUTED NON-CITED
V IOLATION Dear Mr. Heflin: On November 8, 2016 , the U.S. Nuclear Regulatory
Commission (NRC) issued the subject inspection
report and non-cited
violation
(NCV) of Technical
Specification
5.4.1.a , " Procedures
," associated
with the failure to develop and specify preventive
maintenance
activities
that considered
vendor recommendations
and operating
experience
to ensure safety-related
equipment
remains capable of performing
its safety functions (Agencywide
Documents
Access and Management
System (ADA MS) Accession
ML 163148839). On December 8, 2016 , you provided a response (A DAMS Accession
ML 16350A 100) in which you contested
described
in the inspection
report. On December 19 , 2016 , the NRC acknowledged
receipt of this letter (ADAMS Accession
ML 163548181) and informed you that we would evaluate your response and provide you the results of our evaluation.
We conducted
a detailed review of your response and the applicable
regulatory
requirements , in accordance
with Part I , Section 2.2.7 , of the NRC Enforcement
Manua l. The NRC staff who performed
the rev i ew were not involv ed with the original inspection
effort. After careful consideration
of the basis for your denial of the NCV , we have concluded
that the inspection
report adequately
describes
the violation
and characterization
of the finding; however , clarification
regarding
the basis for the NCV is provided in the enclosure
to this l etter. As a result, the NRC is upholding
the NCV contained
in the inspection
report.
A. Heflin 2 The results of the NRC's evaluation
of your reply to the NCV are contained
in the enclosure
to this letter. In accordance
with Title 10 of the Code of Federal Regulations
(10 CFR) 2.390 , " Public inspections. exemptions. requests for withholding
," a copy of this letter and i ts enclosure
will be made available
electronically
for public inspection
in the NRC's ADAMS , accessible
from the NRC Web site at http://www.nrc.gov/r ead i nq-rm/adams
.html. Docket No. 50-482 License No. NPF-42 Enclosure:
NRC E valuation
of Licensee Response to Non-Cited
Violation
cc: Electronic
Distribution
Sincerely ,
NRC EVALUATION
OF LICENSEE RESPONSE TO NON-CITED
VIOLATION
Restatement
of the Non-Cited
Violation
Technical
Specification
5.4.1.a , " Procedures
," requ i res , in part , that procedures
s h all be established , implemented , and maintained
covering the app li cab l e procedures
recommended
i n Append ix A to Regu l atory Gu i de 1.33 , Rev i sion 2. Sect i on 9.b of Append ix A to Regulatory
Gu i de 1.33 , Revision 2 , requ i res that prevent i ve maintenance
sched ul es be developed
to specify i nspect i ons of equipment
and inspection
or replacement
of parts that have a spec i fic lifetime.
The licensee establ i shed Procedure
AP 168-003 , " Planning and Scheduling
P r eventive Ma i n t enance." wh i ch prov i des direction
for implementing
the preventive
maintenance
program to meet the Regulatory
Guide 1.33 requ i rement. Section 6.2 of Procedure
AP 168-003 requires, i n part , that preventive
ma i ntenance activities
be developed
by considering
vendor recommendations
and operating
experience.
Contrary to the above , unt il October 16 , 2016 , the l i censee d i d not ensure that p r eventive maintenance
act i vit i es were developed
by consider i ng vendor r ecommendat
i ons and operat i ng expe r ience. Specifically , the l i censee d i d not ensure that adequate prevent i ve maintenance
activities
were developed
for the NB0215 186/M lockout relay by cons i der i ng vendor recommendat
i ons to tr i p the relay electrically
during any scheduled
outage of the equipment
and operating
experience
documented
in Performance
Improvement
Request 2003-2708
and Condition
Report 54212. As a resu l t , the NB0215 186/M lockout re l ay failed on or before August 2 , 2016 , and the safety-related
4160V NB02 bus was susceptible
to locking out as a result of an overcurrent
condition.
The licensee entered this condition
into their corrective
act i on program as Condition
Reports 106164 , 108440 , and 108548. The licensee replaced the relay armature assembly and retested the relay satisfactorily. Add i tional correct i ve actions to add r ess the preventive
ma i ntenance activities
are expected as a resu l t of Condition
Reports 108440 and 1 08548. Th i s violation
is be i ng treated as a non-cited
vio l at i on consiste n t with Section 2.3.2 of the Enfo r cement Policy: NCV 05000482/2016003-01 , " Fa i lure to Adequately
Adjust Test i ng and Prevent i ve Maintenance
for Safety-Related
Lockou t Relays." Summary of Licensee Response The Wo l f Creek Nuclear Operating
Corporat i on (Wolf Creek o r li censee) contested
t he non-cited
violation
as described
above in a letter dated December 8 , 2016. The letter p r ovided the l i censee's basis for denying the non-c i ted violation. Wo l f Creek contends that the performance
deficiency
described
in the non-cited
violation
is not valid because Wo l f Creek staff d i d comply with the requirements
of Procedure
AP 168-003 when they determ i ned that no change to the 6-year preventive
maintenance
frequency
was required. Wolf Creek provided a r esponse i n writing and p r ovided additiona l informat i on when requested
dur i ng the NRC eva l uat i on of Wolf Creek's response.
A summary of Wolf Creek's documentation
of their assessment
of each of the procedure
criteria is d i scussed below: 1. Wolf Creek Vendor Recommendations
Performance
Improvement
Request 2003-2708
evaluated
industry operating
experience (OE) 16724 , " General Electric Type HEA Lockout Relay Test Internal." Wolf Creek took into considerat
i on the h i story of the relays , the applicat i on , the low failure rate , the environment
Enclosure
in which the relays operate , and vendor recommendations , and determined
that the vendor recommendation
was very conservative
with the requirement
to perform annual testing. The station that issued OE 16724 had an informal discussion
with General Electric (GE) regarding
sluggish behavior of Type HEA relays tested on a 3-5 year interval.
There are no records of any official GE publication
that makes reference
to " sluggish operation" in Type HEA relays. General Electric issued two prior service advice letters (SAL) related to Type HEA relays. Service Advice Letter 165.1 issued in 1981 , which addressed
the potential
for malformed
torsion springs in certain relays; and SAL 175.1 i ssued in 1983, which addressed
the potential
for mis-operation
of relays manufactured
within a specific time period. Wolf Creek indicated
both SALs resulted in inspections
of all safety-related
GE Type HEA lockout relays with no issues. Wolf Creek concluded
that no evidence existed that GE officially
indicated
these relays exhibit sluggish behavior based on testing frequency.
2. Equipment
History Wolf Creek reviewed the preventive
maintenance
history of GE Type HEA relays in service at the Wolf Creek Generating
Station. Wolf Creek stated that since January 1 , 2000, only 1 out of 119 tests would have resulted in a failure of a safety-related GE Type HEA relay to actuate , and this very low failure rate supports the current preventive
maintenance
frequency.
Wolf Creek also stated that for the NB0215 186/M lockout relay specifically, which failed on August 2 , 2016, the preventive
maintenance
was performed
s i x times prior to this failure starting on November 15, 1988 , with the last successful
test on August 10 , 2009. Therefore , there were five performances
over 21 years in which the relay actuated at or below the acceptance
criteria of 87. 5 Vdc. 3. Regulatory
and Code Requirements
Wolf Creek identified
that no regulatory
or code requirements
specify a preventive
maintenance
frequency
for these types of protective
devices. 4. Operating
Experience
Wolf Creek identified
that OE 16724 , issued on June 11, 2003, indicated
that the failure of the relay to actuate at another station was caused by excessive
time between preventive
maintenance. The preventive
maintenance
frequency
of the relay discussed
in this OE was 4 years. Wolf Creek reiterated
that the discussion
between GE and the station that issued the OE regarding
the performance
of preventive
maintenance
every 3-5 years for relays that exhibit "sluggish" behavior , was an informal communication. Thus , no official documentation
from GE which described
this behavior as being caused by inadequate
preventive
maintenance
frequencies
existed. 2
Wolf Creek reiterated
that personnel
determined
a 6-year preventive
maintenance
frequency
coinciding
with breaker maintenance
was appropriate
based on the low number of failures of the relays at Wolf Creek Generating
Station and the fact that these relays operated in air conditioned
environments.
On June 19 , 2012 , Wolf Creek received an industry experience
notification
pertaining
to GE Type HEA rel ays , and initiated
Condition
Report 54212. Wolf Creek indicated
that there were two recommendations
in the notification
did not apply to Wolf Creek Generating
Station; and (2) review the subset of lockout relays that are not normally actuated each cycle , or within the preventive
maintenance
frequency
in accordance
with Relay Industry Guidance AP-913. Relays that can be tested on-line should be tested as soon as practical.
Wolf Creek determined
that no changes to the preventive
maintenance
activities
for the safety-related
GE Type HEA relays were necessary. Wolf Creek reiterated
the very low failure rate previously
discussed
would indic ate that a 6-year preventive
maintenance
frequency
was sufficient.
5. Predictive
Ma intenance
Req uirements
Wolf Creek indicated
that there were no predictive
maintenance
recommendations
for these types of protection
devices. 6. Component
Funct ional Importance
Wolf Creek stated that Performance
Improvement
Request 2003-2708
evaluated
the functional
importance
of the safety-related
GE Type HEA relays, and that the failure of one of these devices might allow a safety-related
piece of equipment
to be further damaged or cause the bus to trip if the condition
was severe enough. Wolf Creek reiterated
that preventive
maintenance
test results since January 1 , 2000 , showed only one test result out of 119 had a fa ilure to actuate. Therefore , Wolf Creek stated that the preventive
maintenance
frequency
was adequate for the functional
importance
of these components. W olf Cre e k's C on clus i on The above information
demonstrates
that Wolf Creek complied with Procedure
AP 168-003 by considering
vendor recommendations
and industry operating
experience
in developing
preventive
maintenance
activities
for the NB0215 186/M GE Type HEA lockout relays. In addition , Wolf Creek asserted that it had considered
equipment
history and station operating
experience
and that when all of the criteria is evaluated; including
service conditions
and low failure rate , the adequacy of the current preventive
maintenance
practices
is supported. Wolf Creek also stated that had the NB0215 Type HEA 86 relay been tested more frequently , no evidence existed that a failure of this relay to actuate would have been prevented. Finally, Wolf Creek stated that the non-cited
violation
over-emphasized
the consideration
of vendor recommendations
and did not provide appropriate
credit for all of the information, including
equipment
history , service operating
conditions , and station specific operating
experience.
Wolf Creek denied the performance
deficiency
as described
by the inspectors , and therefore , denied that there was a valid basis for the non-cited
violation. 3
NRC E va luat ion The NRC acknowledged
that Wolf Creek did review the operating
experience
in 2003 under Performance
Improvement
Request 2003-2708
and Condition
Report 54212. The NRC also evaluated
Wolf Creek's review of individual
preventive
maintenance
attributes
to determine
if Wolf Creek should have reasonably
concluded
that the preventive
maintenance
periodicity
would require revision to a shorter frequency. The NRC assessment
of Wolf Creek's response to each of the attr ibut es of a preventive
maintenance
designation
i s provided below: 1. Vendor Recommendations
The NRC reviewed the vendor recommendation
for testing of the Type HEA relays during any scheduled
outage and preferably
at yearly intervals.
The NRC also reviewed the Electric Power Research Inst it ute (EPRI) guidance related to funct io nal testing of these types of relays. (Electric Power Research Inst it ute recommends
a funct i ona l test interval of between 18 months and 2 years depending
on the fuel cycle.) La stly , the NRC evaluated
a sampling of industry OE involving
failure of these types of re l ays and assoc i ated causes. The NRC noted that two aspects were commonly identified
with these i ndustry failures: mechanical
binding and age-related
degradation. Several OE documents
ident ified a contributing
factor of relay inactivity
of the relay over long periods of time. As part of th is review , the NRC asked Wolf Creek if it had performed
an age-related
analysis of the recent relay failure or if it had conducted
a failure mode ana l yses on the relay to determine
the cause of the failure. Wolf Creek responded
that neither an age-related
ana l ysis nor relay failure mode analysis were performed
following
the August 2 , 2016 , safety-related
relay failure. Wolf Creek also stated that a replacement
preventive
maintenance
frequency
had not been evaluated. Wolf Creek indicated
that the environment
in which the Type HEA relay is located was a factor discussed
in their procedural
guidance in determining
the preventive
maintenance
frequency. The NRC noted that the same procedural
guidance also discussed
att ributes such as the age of the inst alled equipment , the qualified
life of the equipment , and equipment
idled in a standby mode for a long period. These attributes
are not discussed
in prev i ous or more recent Wolf Creek assessments
of the prevent ive maintenance
frequency
of these relays. The NRC determined
that the basis of the relay be i ng operated in an a ir conditioned
environment
was not un i que to Wolf Creek and would not , in and of itself , provide a basis for extending
or maintaining
a prevent i ve ma i ntenance frequency
of 6 years. Of the industry OE reviewed by the NRC , none identified
the relay environment
as causing or contributing
to the relay failure. In the 2003 OE analysis , Wolf Creek asserted that it would continue to monitor the system for adverse trends , and that future preventive
maintenance
intervals
would be adjusted according
to information
received from the preventive
maintenance
performance.
Wolf Cre ek then concluded
that no changes were required to the 6-year preventive
maintenance
testing interval.
The NRC noted that four performances
of the relay preventive
maintenance
tests documented
relay actuation
above the test allowance
of 87.5 Vdc but less than the maximum allowed by the licensee of 95 Vdc. The licensee did not consider these tests to be failures , and therefore , d id not generate condition
r eports to evaluate the condition. In 4
the absence of condition
reports to evaluate test results that were out of tolerance. it was not clear how or if Wolf Creek monitored
these relays for adverse trends to determine
if preventive
maintenance
intervals
needed to be adjusted.
In addition , the NRC requested
the basis for the original preventive
maintenance
selection
of 6 years, which occurred prior to February 2 , 2000. Wolf Creek could not locate the original basis for the selection
of a 6-year preventive
maintenance
interval , but it did indicate that prior preventive
maintenance
frequency
was something
less than 6 years. In the absence of a basis for the 6-year preventive
maintenance
interval, the NRC determined
that the OE analysis by Wolf Creek in 2003 was insufficient
to conclude a 6-year preventive
maintenance
interval was appropriate.
In addition , the NRC's review of more recent (June 19 , 2012) industry OE on age-related
and mechanical
binding issues with this
type of relay indicates
that a 6-year preventive
maintenance
periodicity (and in this event approximately
7 years passed between tests when a 1 year grace period was included by Wolf Creek) results in an undue period of time for a degraded or degrading
condition
to exist in a safety-related
system prior to its identification.
The NRC determined
by Wolf Creek were first issued in 1981 and 1983 and involved manufacturing
defects identified
at that time. The NRC determined
that the Wolf Creek conclusion
that these SALs had been previously
analyzed and did not impact Wolf Creek did not have any relevance
to the determination
that a 6-year preventive
maintenance
test frequency
was appropriate. Wolf Creek acknowledged
that the relay preventive
maintenance
frequency
was not evaluated
as part of Condition
Report 54212 , which in June 2012 , evaluated
industry experience
related to GE Type HEA relays. 2. Equipment
History The NRC asked Wolf Creek if it had performed
a relay failure rate analysis at the time of the 2003 OE assessment
or during the Condition
Report 54212 review. Wolf Creek indicated
that a failure rate analysis was not performed , though they had determined
three instances
of potential
failures were the result of sluggish operation.
The NRC considered
sluggish relay behavior to be indicative
of relay degradation
and that Wolf Creek should have evaluated
the adverse relay operation.
The NRC noted that preventive
maintenance
activities
and tests of safety-related
components
are intended, in part, to ensure that related components
are capable of performing
their safety function(s)
and to identify degrading
performance
prior to failure. Wolf Creek Procedure
AP 168-003 defined preventive
maintenance
as "maintenance
activities
designed and scheduled
to ensure function , improve availability, and minimize the effects of aging on systems , structures , and components." This definition
was consistent
with the NRC understanding
of the purpose of preventive
maintenance
activit i es. The NRC determined
that a preventive
maintenance
frequency
of once every 6 years, and the licensee's acceptance
of a failure once every six times a component
is tested , is not consistent
with the preventive
maintenance
expectation
that preventative
maintenance
frequencies (and acceptable
failure rates) be commensurate
with the risk and safety significance
of the affected components.
3. Regulatory
and Code Requirements
Wolf Creek identified
that there are no regulatory
or code requirements
associated
with specifying
a preventive
maintenance
frequency
for these types of devices. The NRC did not 5
identify any regulatory
or code requirements
specific to the preventive
maintenance
frequency
of these relays. 4. Operating
Experience
The NRC determined
that Wolf Creek addressed
the OE discussion
with GE as "anecdotal
," and in the absence of " official" documentation
from GE regarding
sluggish behavior , Wolf Creek discounted
the OE assessment
and concluded
the Wolf Creek 6-year preventive
maintenance
frequency
was sufficient.
The NRC asked Wolf Creek whom it had contacted
at GE at the time of this evaluation. Wolf Creek indicated
the evaluator
could not recall who at GE was contacted. Wolf Creek had prev iously asserted that in their discuss i on with GE , GE stated that no official documentation
of " sluggish operation" was generated
by GE. The NRC determined
that dismissing
the OE discussion
with GE as informal and relying on the lack of " official" documentation
from GE was a missed opportunity
by Wolf Creek to revisit the 6-year periodicity
of the relay preventive
maintenance
testing. In light of the 2003 and 2012 OE , this was an opportunity
for Wolf Creek to invest ig ate the preventive
maintenance
test frequencies
that had been establ i shed w it hin the ind ustry to determine
if the licensee was an outlier or consistent
with current i ndustry pract i ce. There i s no discussion
in the Wolf Creek OE event report evaluations
or their response to the non-cited
violation
that explores an industry perspective
to support this conclusion , part i cular l y given the similarity
of this type of relay applicat i on , environment , and safety significance
at other nuclear utilities. 5. Predictive
Maintenance
Requirements
Wolf Creek stated that there are no predictive
maintenance
recommendat
io ns for these types of protection
dev i ces. The NRC did not identify any predict iv e maintenance
recommendations
for these types of relays. As previously
discussed
in the Vendor Recommendations
section , the NRC identified
only preventive
maintenance
frequency
recommendations
from EPRI for functional
testing of these relays when they are not in-service (every 18-24 months). 6. Component
Functional
Importance
The NRC agreed that the function of the component
as described
by Wo l f Creek and the potential
safety impact from the relay failure was accurate. However , the NRC's evaluat ion of these c i rcumstances
does not support Wolf Creek's conc lu sion that the preventive
maintenance
frequency
is adequate for the im portance of the i dent ified function. NRC C o n c l usi o n The NRC considered
the following
information
in determining
that sufficient
information
existed for Wolf Creek to conclude that additional
engagement
of the vendor and industry peers should have been performed: * 2003 OE and Condit ion Report 54212 * Difference
between Wolf Creek prevent i ve maintenance
test frequency
of once every 6 years , in comparison
to the vendor recommendation
6
- Preventive
maintenance
test frequency
of once every 4 years that resulted in a relay failure at another facility * Sufficient
industry operating
experience
on th e type of relay failures existed in 2012 The NRC Information
Notice 2012-06 , " Ineffective
Use of Vendor Technical
Recommendations," issued on April 24 , 2012 , states , in part , that " the NRC staff's review of recent operating
experience
involving
in effect ive use of vendor technical
recommendations
indicated
that many of these events potentially
allow latent failures to exist undetected
and become an underlying
cause of risk-significant
initiating
events. The NRC review of this event concluded
that lengthy preventive
maintenance
test intervals
can result in degraded or degrading
conditions
going undetec ted for long periods of time resulting
in incre ased safety-related
component
vulnerability
and risk." In addit ion , the NRC concluded
that the current position maintained
by Wolf Creek that no further evaluation
of the preventive
maintenance
test frequency
is warranted , even though a failure has occurred , does not sufficiently
estab lish whether any performance
trends exist for these components
at Wo l f Creek, particularly
as they age. The lack of a failure analysis of the August 2016 relay failure and the lack of any age-related
component
analysis or rep l acement preventive
maintenance
frequency
based on service life precludes
Wolf Creek from establishing
confidence
that future safety-relat ed relay failures will be minimized
and/or detected.
Based on the result of the review , the NRC concluded
that the non-cited
violation
of Technical
Specification
5.4.1.a for the licensee's failure to ensure that adequate prevent i ve maintenance
activities
were developed
for the NB0215 186/M lockout relay , as documented
in NRC Inspection
Report 05000482/2016003 , is valid. In addition , this NRC's review reinforces
the characterization
in the inspection
report that this i s indicative
of current licensee performance
and , absent any rev i sion to the current preventative
maintenance
frequency , could result in future unexpected
relay failure(s).
7