ML100900384
ML100900384 | |
Person / Time | |
---|---|
Site: | McGuire, Mcguire |
Issue date: | 03/31/2010 |
From: | Bartley J NRC/RGN-II/DRP/RPB1 |
To: | Repko R Duke Energy Carolinas, Duke Power Co |
References | |
IR-10-007 | |
Download: ML100900384 (24) | |
See also: IR 05000369/2010007
Text
UNITED STATES
NUCLEAR REGULATORY COMMISSION
REGION II
SAM NUNN ATLANTA FEDERAL CENTER
61 FORSYTH STREET, SW, SUITE 23T85
ATLANTA, GEORGIA 30303-8931
March 31, 2010
Mr. Regis T. Repko
Vice President
Duke Power Company, LLC
d/b/a Duke Energy Carolinas, LLC
McGuire Nuclear Station
MG01VP/12700 Hagers Ferry Road
Huntersville, NC 28078
SUBJECT: MCGUIRE NUCLEAR STATION - NRC SUPPLEMENTAL INSPECTION
REPORT 05000369/2010007 AND 05000370/2010007
Dear Mr. Repko:
On March 9, 2010, the U.S. Nuclear Regulatory Commission (NRC) completed a supplemental
inspection pursuant to Inspection Procedure 95001, Inspection for One or Two White Inputs in
a Strategic Performance Area, at your McGuire Nuclear Station, Units 1 and 2. The enclosed
inspection report documents the inspection results, which were discussed at the exit meeting on
March 9, 2010, with Mr. Steven D. Capps and other members of your staff.
As required by the NRC Reactor Oversight Process Action Matrix, this supplemental inspection
was performed because a finding of low to moderate safety significance (White) was identified
in the third quarter of 2008 for failure to correct a significant condition adverse to quality related
to macro-fouling of the nuclear service water (RN) system strainers. This finding was
documented previously in NRC Inspection Report 05000369,370/2008009 and resulted in
Violation (VIO) 05000369,370/2008009-01, Failure to Take Adequate Corrective Action for
Implementation of Safety-Related RN Strainer Backwash. The NRC was informed of your
readiness for the inspection on January 11, 2010.
The objectives of this supplemental inspection were to provide assurance that: (1) the root
causes and the contributing causes for the risk-significant issues were understood; (2) the
extent of condition and extent of cause of the issues were identified; and (3) corrective actions
were or will be sufficient to address and preclude repetition of the root and contributing causes.
This inspection examined activities conducted under your license as they related to safety and
compliance with the Commission's rules and regulations, and with the conditions of your
license. The inspector reviewed the root cause determination report, selected procedures and
records, and interviewed personnel.
DEC 2
The inspector determined that your staff, in general, performed an adequate evaluation of the
White finding. Your staffs evaluation determined that the root cause of the issue was changing
the configuration of the plant without a total understanding of the design and licensing bases for
the RN system strainers during accident conditions, which resulted in the inability to conduct
manual strainer backwashes during certain plant conditions.
Your staff also identified that this lack of understanding of design and licensing bases was not
limited to the RN strainers, but to the RN system in general and has taken corrective actions to
ensure the system design basis documents accurately reflect current licensing bases. The
inspector determined that the corrective actions taken and planned will restore the RN strainer
to full compliance with the licensing basis. In addition, the inspector found that corrective
actions taken or planned appear reasonable and will correct the causes that led to the non-
compliance and prevent recurrence. However, the inspector had several observations
regarding specific aspects of the root cause evaluation and corrective actions that warranted
additional consideration by your staff. These observations were discussed with your staff at the
exit meeting and are included in the report.
Based on the results of this supplemental inspection, no findings of significance were identified.
In accordance with the Code of Federal Regulations 10 CFR 2.390 of the NRCs Rules of
Practice, a copy of this letter, its enclosure, and your response (if any) will be available
electronically for public inspection in the NRC Public Document Room or from the Publicly
Available Records (PARS) component of the NRCs document system (ADAMS). ADAMS is
accessible from the NRC Website at http://www.nrc.gov/reading-rm/adams.html (the Public
Electronic Reading Room).
Sincerely,
/RA/
Jonathan H. Bartley, Chief
Reactor Projects Branch 1
Division of Reactor Projects
Docket Nos.: 50-369, 50-370
Enclosure: NRC Integrated Inspection Report 05000369/2010007 and 05000370/2010007
w/Attachment - Supplemental Information
cc w/encl: (See page 3)
_ X SUNSI REVIEW COMPLETE JHB
OFFICE RII:DRP RII:DRP RII:DRP
SIGNATURE KJK /RA/ JBB /RA/ JHB /RA/
NAME KKorth JBrady JBartley
DATE 03/31/2010 03/31/2010 03/31/2010
E-MAIL COPY? YES NO YES NO YES NO YES NO YES NO YES NO YES NO
DEC 3
cc w/encl: Dhiaa M. Jamil
Steven D. Capps Group Executive and Chief Nuclear Officer
Station Manager Duke Energy Carolinas, LLC
Duke Energy Carolinas, LLC Electronic Mail Distribution
Electronic Mail Distribution
Scotty L. Bradshaw
Training Manager
Duke Energy Carolinas, LLC
Electronic Mail Distribution
Kenneth L. Ashe
Regulatory Compliance Manager
Duke Energy Carolinas, LLC
Electronic Mail Distribution
R. L. Gill, Jr.
Manager
Nuclear Regulatory Issues & Industry Affairs
Duke Energy Carolinas, LLC
Electronic Mail Distribution
Lisa F. Vaughn
Associate General Counsel
Duke Energy Corporation
526 South Church Street-EC07H
Charlotte, NC 28202
Kathryn B. Nolan
Senior Counsel
Duke Energy Corporation
526 South Church Street-EC07H
Charlotte, NC 28202
David A. Repka
Winston Strawn LLP
Electronic Mail Distribution
County Manager of Mecklenburg County
720 East Fourth Street
Charlotte, NC 28202
W. Lee Cox, III
Section Chief
Radiation Protection Section
N.C. Department of Environmental
Commerce & Natural Resources
Electronic Mail Distribution
DEC 4
Letter to Regis T. Repko from Jonathan H. Bartley dated March 31, 2010
SUBJECT: MCGUIRE NUCLEAR STATION - NRC SUPPLEMENTAL INSPECTION REPORT
05000369/2010007 AND 05000370/2010007
Distribution w/encl:
C. Evans, RII
L. Slack, RII
OE Mail
RIDSNRRDIRS
PUBLIC
RidsNrrPMMcGuire Resource
U.S. NUCLEAR REGULATORY COMMISSION
REGION II
Docket Nos.: 50-369, 50-370
Report Nos.: 05000369/2010007, 05000370/2010007
Licensee: Duke Energy Carolinas, LLC
Facility: McGuire Nuclear Station, Units 1 and 2
Location: Huntersville, NC 28078
Dates: March 1, 2010, through March 9, 2010
Inspectors: K. Korth, Resident Inspector Browns Ferry Nuclear Plant
Approved by: Jonathan H. Bartley, Chief
Reactor Projects Branch 1
Division of Reactor Projects
Enclosure
SUMMARY OF FINDINGS
IR 05000369/2010007, 05000370/2010007; 03/01/2010 - 03/09/2010; McGuire Nuclear Station,
Units 1 and 2; Supplemental Inspection IP 95001 in response to a White inspection finding for
failure to correct a significant condition adverse to quality related to macro-fouling of the nuclear
service water (RN) system strainers.
This inspection was conducted by a resident inspector. No findings of significance were
identified. The NRCs program for overseeing the safe operation of commercial nuclear power
reactors is described in NUREG-1649, Reactor Oversight Process, Revision 4, dated
December 2006.
Cornerstone: Mitigating Systems
This supplemental inspection was performed in accordance with Inspection Procedure (IP) 95001, Inspection for One or Two White Inputs in a Strategic Performance Area, to assess the
licensee's evaluation associated with a White inspection finding involving with the inability to
perform manual backwash on the Nuclear Service Water (RN) strainers identified in August of
2007. The NRC staff previously characterized this issue as having low to moderate safety
significance (White) as documented in NRC IR 05000369,370/2008009.
During this supplemental inspection, the inspector determined that, in general, the licensee
performed an adequate evaluation of the White finding. The licensees evaluation determined
that the root cause of the issue was changing the configuration of the plant without a total
understanding of the design. The RN strainer backwash system had been modified to replace
RN strainer backwash outlet manual valves with air-operated valves that could not be manually
over-ridden. This root cause, along with four other contributing causes, led to operation of the
system from 2000/2001 to 2007 without having the capability to manually backwash the
strainers following a loss of instrument air (VI). The licensee also identified that this lack of
understanding of design and licensing bases was not limited to the RN strainers, but to the RN
system in general and has taken corrective actions to ensure the system design basis
documents accurately reflect current licensing bases. The inspector determined that the
corrective actions taken and planned will restore the RN strainer to full compliance with the
licensing basis. In addition, the inspector found that corrective actions taken or planned appear
reasonable and will correct the causes that led to the non-compliance and prevent recurrence.
However, the inspector had the following observations regarding specific aspects of the root
cause evaluation (RCE) and corrective actions that warranted additional consideration by the
licensee. The RCE did not fully document the organizational and programmatic weaknesses
that led to the condition, or the reasons that multiple opportunities were missed for earlier
discovery (section 02.02.b). The licensee did not revise the RCE when new information was
discovered or when additional reviews of the RCE were conducted (section 02.02.b).
Weakness of the original extent of condition and extent of cause evaluations resulted in delays
in conducting a thorough review, some aspects of which were still in progress at the time of the
inspection (section 02.02.d). The RCE did not specifically consider the safety culture
components of Inspection Manual Chapter 0305 (section 02.02.e). The root cause and
contributing causes were not well linked to the associated corrective actions (section 02.03.a).
The quantitative and qualitative measures of success for determining the effectiveness of the
Enclosure
3
corrective actions to preclude repetition were not well established (section 02.03.d). Based on
the results of the inspection, the licensee initiated PIP M-10-1516 to evaluate the quality of root
cause evaluations.
Given the licensees acceptable performance in addressing the non-compliance of the RN
strainer with its licensing bases, the White finding associated with this issue is being closed and
will only be considered in assessing plant performance until the end of this quarter in
accordance with the guidance in IMC 0305, Operating Reactor Assessment Program. Since
many of the corrective actions have not been completed, the implementation and effectiveness
of the licensees corrective actions will be reviewed during future inspections.
Enclosure
REPORT DETAILS
4. OTHER ACTIVITIES
4OA4 Supplemental Inspection
.01 Inspection Scope
The NRC staff performed this supplemental inspection in accordance with IP 95001 to
assess the licensees evaluation of a White finding which affected the Mitigating
Systems cornerstone in the Reactor Safety strategic performance area. The inspection
objectives were to:
- provide assurance that the root and contributing causes of risk-significant issues were
understood;
- provide assurance that the extent of condition and extent of cause of risk-significant
issues were identified; and
- provide assurance that the licensees corrective actions for risk-significant issues
were or will be sufficient to address the root and contributing causes and to preclude
repetition.
The licensee entered the Regulatory Response Column of the NRCs Action Matrix in
the third quarter of 2008 as a result of one inspection finding of low to moderate safety
significance (White). The finding was associated with the failure to take adequate
corrective actions related to implementation of a safety-related RN strainer backwash
system. On August 6, 2007, the "A" Train of the RN system was declared inoperable
when the licensee discovered that manually backwashing RN strainers was not always
possible during design basis accidents. In 2000 on Unit 2 and in 2001 on Unit 1, a
modification had been implemented to replace strainer backwash outlet manual valves
with air-operated valves that could not be manually over-ridden. The Station Instrument
Air (VI) system was non-safety-related and could not be relied upon to manually
backwash the RN strainers during or following design basis accidents. The finding was
characterized as having low to moderate safety significance (White) based on the results
of a Phase 3 risk analysis performed by a region-based senior reactor analyst (SRA), as
discussed in NRC Inspection Report (IR) 05000369,370/2008009.
As a result of identifying this non-conformance, the licensee made some plant
modifications, including a modification to allow operation of the RN strainer backwash
outlet valves without reliance on VI, and took other measures to compensate for this
condition until full compliance with the design and licensing bases can be restored
through additional planned modifications. The licensee conducted a root cause
evaluation (RCE), as documented in Problem Investigation Process report (PIP) M-07-
4313, to identify weaknesses that existed in various organizations which allowed for a
risk-significant finding and to determine the organizational attributes that resulted in the
White finding. Subsequently, a number of events and additional reviews impacted the
corrective actions associated with the original RCE. During the February 13, 2008,
Enclosure
5
meeting of the Nuclear Safety Review Board (NSRB), the board challenged the depth of
the original extent of condition and extent of cause evaluations (PIP M-08-1574).
Testing of the backwash system on May 27, 2008, to evaluate a potential piping
modification revealed the system had inadequate pressure to provide RN strainer
backwash flow to the normal discharge path to the Condenser Circulating Water (RC)
system and that at high RN flow rates, a negative pressure was created in the strainers
making backwash discharge flow to the ground water (WZ) sump unavailable (PIP M-08-
3371). On April 27, 2009, during testing of the RN system at high flow rates, the
strainers became clogged with corrosion products from the suction piping which was a
new macro-fouling source not previously identified (PIP M-09-2216). All of these events
and reviews resulted in changes to or additions of corrective actions to the original RCE.
The licensee staff informed the NRC staff on January 11, 2010, that they were ready for
the supplemental inspection. From January 25, 2010, to February 4, 2010, in
preparation for this inspection, the licensee conducted an in-depth readiness review of
the original RCE report using the inspection attributes of IP 95001. As a result of that
self-critical readiness assessment, the licensee issued several additional PIPs and
added additional corrective actions to the original PIP M-07-4313.
The inspector reviewed the RCE associated with PIP M-07-4313, along with several
other evaluations that were conducted in support of or that impacted the corrective
actions for the root cause determination. The inspector reviewed the licensees extent of
condition and extent of cause evaluations to ensure they were sufficient in breadth. The
inspector reviewed the corrective actions that were taken or planned to address the
identified causes. The inspector also held discussions with licensee personnel to ensure
that the root and contributing causes, as well as the contribution of safety culture
components, were understood and that corrective actions taken or planned were
appropriate to address the causes and preclude repetition.
.02 Evaluation of the Inspection Requirements
02.01 Problem Identification
a. IP 95001 requires that the inspection staff determine that the licensees evaluation of the
issue documents who identified the issue (i.e., licensee-identified, self-revealing, or
NRC-identified) and the conditions under which the issue was identified.
The inspector determined that the event evaluations were sufficiently detailed to identify
who and under what conditions the issue was identified. The issue was identified on
August 6, 2007, by the licensee during the investigation of an abnormally high number of
RN strainer automatic backwashes (PIP M-07-4177).
b. IP 95001 requires that the inspection staff determine that the licensees evaluation of the
issue documents how long the issue existed and prior opportunities for identification.
The licensees root cause documented that the condition had existed since the
implementation of a modification that replaced the RN strainer backwash outlet manual
valves with air-operated valves on Unit 2 in 2000 (MM-8444) and on Unit 1 in 2001 (MM-
Enclosure
6
11224). However, subsequent testing in May 2008 revealed that there was no strainer
backwash discharge flow when aligned to the RC system and that strainer discharge
flow to the WZ sump was not possible at high RN flow rates (PIP M-08-3371). Based on
this information, the operability determination was revised, as were the interim and long
term actions to correct the condition. This additional time where backwash was
unavailable did not impact the NRCs significance determination of the condition since
no credit for strainer backwash was given and the duration used in the evaluation was
over a one year period.
The licensees root cause documented multiple missed opportunities to identify the
issue. Opportunities to recognize that manual backwash relied on non-safety related VI,
which could be unavailable following an accident, included the evaluation of the need to
upgrade the system to meet safety related requirements (PIP M-02-2427), design and
implementation of the modification that upgraded the system to meet safety related
requirements (MGMM-14403), evaluation of a variance to the modification to add the
ability to manually operate the strainer backwash outlet valves using an air supply
bypass valve, and revisions to the procedures to manually backwash the strainers.
The inspector determined that the licensees evaluation was adequate with respect to
identifying how long the issue existed and prior opportunities for identification.
c. IP 95001 requires that the inspection staff determine that the licensees evaluation of the
issue documents the plant-specific risk consequence, as applicable, and compliance
concerns associated with the issue.
The NRC determined this issue was a White finding, as documented in NRC IR
05000369,370/2008009. The root cause evaluation did not qualitatively assess the
increased risk associated with this condition, but the LER submitted by the licensee
(LER 05000369/2007-004) stated that based on a preliminary PRA evaluation, the
conditional core damage probability (CCDP) associated with this condition was greater
than 1E-6. At the Regulatory Conference held at the Region II offices on September 18,
2008, the licensee presented the results of their revised evaluation of CCDP as
approximately 4.7 E-7. However, the licensee did not contest the violation or its
categorization as having low to moderate safety significance.
The root cause evaluation appropriately documented the condition as a non-compliance
with their licensing bases and took appropriate compensatory actions, including plant
and procedural modifications to allow manual backwash without instrument air. Full
compliance will be restored when all corrective actions associated with this issue are
completed.
The inspector concluded that the licensee appropriately documented the risk
consequences and compliance concerns associated with the issue.
d. Findings
No findings of significance were identified.
Enclosure
7
02.02 Root Cause, Extent-of-Condition, and Extent-of-Cause Evaluation
a. IP 95001 requires that the inspection staff determine that the licensee evaluated the
issue using a systematic methodology to identify the root and contributing causes.
The licensee used the following systematic methods to complete PIP M-07-4313
problem evaluation:
- data gathering through interviews and document review;
- timeline construction;
- events and causal factor charting; and
- barrier analysis.
The inspector determined that the licensee evaluated the issue using a systematic
methodology to identify root and contributing causes.
b. IP 95001 requires that the inspection staff determine that the licensees RCE was
conducted to a level of detail commensurate with the significance of the issue.
The licensees RCE included an extensive timeline of events, as well as an event and
causal factors (E&CF) chart as discussed in the previous section. Using a
multidisciplinary team, the licensee identified a single root cause as changing the plant
configuration (i.e., manual valves on the RN strainer backwash outlet were replaced with
air-operated valves) without a total understanding of the design and licensing bases. In
addition, the RCE identified four contributing causes (CC) stemming from inappropriate
actions identified on the E&CF chart.
CC1: Design study conducted in 1990 to evaluate the RN strainer design bases
(MGDS-224) missed the UFSAR requirement for manual backwash following a
LOCA.
CC2: Modifications made in 1993-1994 that downgraded the strainer backwash function
to non-safety related (MGMM-3794) were completed without a 10 CFR 50.59
evaluation as an editorial minor modification.
CC3: An assessment completed in 1993 (SITA-93-01) on the operational readiness and
functionality of the RN system found issues with the system design including the
need for safety related instrumentation for strainer backwash initiation, but the PIP
that was generated had no evaluation and no corrective actions.
CC4: The corrective actions from PIP M-02-2427 generated in 2002 for engineering to
evaluate the safety classification of the RN strainers based on past strainer fouling
events, did not correct the condition. The resulting modification that upgraded the
strainer to safety related requirements (MMGM-14403) did not consider the ability
to manually backwash the strainers following a loss of VI.
Enclosure
8
The RCE did not fully document the organizational and programmatic weaknesses that
led to the condition, nor the reasons that multiple opportunities were missed for earlier
discovery. For example, the reason(s) why there was not a clear understanding of the
design bases of the system or why the design change/50.59 process failed to identify the
USFAR requirement for manual backwash were not fully explored. This was identified
by the licensee during their 95001 readiness review (M-SAG-SA-10-11) and PIP M-10-
1208 was initiated to evaluate the reasons why the design bases were not fully
understood. It concluded that the licensee did not know the UFSAR was the Current
Licensing Basis (CLB) source at the time of the modification and that the Design and
Licensing ownership had moved from the General Office to the site in the 1992 to 1996
timeframe.
Contributing to the apparent lack of detailed documentation of the causes of the event
was that the licensee did not revise the RCE when new information was discovered (M-
08-3371 and M-09-2261) or when additional review of the RCE was conducted. The
inspector identified that Nuclear System Directive (NSD) 212, Cause Analysis, indicated
that in the event further information becomes available that potentially affects the results
of a root cause evaluation, the root cause should be reevaluated to determine if a
revision was required. The operability determination was revised and numerous
corrective actions were added or revised, however the evaluation portion of the PIP was
not changed. This resulted in cases where the critical thinking on why a corrective
action was added was not documented and made the linkage between the root and
contributing causes and the associated CAs to address the causes difficult. Additionally,
the original RCE did not identify that the failure to conduct testing to ensure that the
backwash system functioned as designed was a contributor to this event. This was
identified in the corrective actions for PIP M-08-3371, but the original RCE was never
updated.
However, the inspector determined that the organizational and programmatic
weaknesses that caused this event, even if not specifically documented in the RCE,
were ultimately addressed in the corrective actions for this PIP and in other related PIPs.
For example, the corrective actions addressed weaknesses in the design bases
documentation (e.g., DBD and UFSAR), in the design change process, in the 50.59
process and in the knowledge and skills of engineering personnel and 10 CFR 50.59
qualified evaluators and screeners. Based on the results of the inspection, the licensee
initiated PIP M-10-1516 to evaluate the quality of root cause evaluations, including
determining the reasons PIP M-07-4313 did not apply the why staircase sufficiently to
determine what process weaknesses needed to be corrected and the reasons the RCE
was not revised when additional information was uncovered.
c. IP 95001 requires that the inspection staff determine that the licensees RCE include a
consideration of prior occurrences of the problem and knowledge of prior operating
experience.
The licensees RCE included a review of both internal and external operating experience
(OE). A search of the McGuire PIP database was conducted for previous events
assigned cause codes of F1b (Unplanned entry into TS LCO) and J1e (Risks and
Consequences associated with change not adequately reviewed). No previous events
Enclosure
9
were identified. However, these specific cause codes were not assigned to the root or
contributing causes for this evaluation. This was identified by the licensee in their IP
95001 readiness review (M-SAG-SA-10-11) and a subsequent search using the
appropriate codes did not identify any prior occurrences. Based on the licensees
evaluation and conclusions, the inspector determined that the licensees RCE included a
consideration of prior occurrences of the problem and knowledge of prior OE.
d. IP 95001 requires that the inspection staff determine that the licensees RCE addresses
the extent of condition and the extent of cause of the issue.
To address the extent of condition issue, the licensees RCE contained a review of air-
operated valves (AOVs) that receive safety signals that may need to be repositioned
from their safety position following an accident. Based on recommendations from the
McGuire NSRB meeting on February 13, 2008, additional corrective actions were added
to expand the scope of the AOVs that were reviewed and to include instrumentation that
is required post-accident that relied on instrument air (VI). No additional valves were
found that required VI post-accident and some procedure changes were made to identify
alternate indications that could be used for instrumentation that would be unavailable
following a loss of VI. During the IP 95001 readiness review a deficiency was identified
with the extent of condition. The team found that the extent of condition corrective
actions (CAs) should address motive forces other than air (e.g., power-operated
components) and other systems containing safety related/non-safety related interfaces
should be sampled and evaluated to ensure no similar issues with other safety related
systems exist (PIP M-10-1210). At the time of the inspection, the extent of condition
review of safety/non-safety system interactions was still in progress.
To address the extent of cause the RCE reviewed other areas where engineering may
not have a clear understanding of design bases prior to changing plant configuration.
Specifically, a corrective action was created to review the design basis document (DBD)
for the entire RN system and the Design Basis Accident DBD to ensure they adequately
reflect the current licensing basis. In addition, engineering personnel and 10 CFR 50.59
qualified personnel were trained on this event and on the use of licensing basis
documents during the design change process. During the IP 95001 readiness review a
deficiency was identified with the extent of cause. The team found that the extent of
cause CAs should be expanded to include the 10 CFR 50.59 process (program
changes, effectiveness reviews and examples) and the Engineering
Change/Engineering Change Approval process (program changes, effectiveness
reviews and examples) to ensure current processes would prevent similar events (PIP
M-10-1211). This PIP determined that recent 10 CFR 50.59 process changes provide
confidence in the current processes such that a similar failure of the program, as
documented under PIP M-07-4313, would not occur. Likewise, the current modification
process related toward editorial changes process provides sufficient barriers to prevent
design and implementation of a non-editorial modification under the editorial process. In
addition, PIP M-10-1240 was initiated to perform detailed design bases impact reviews
for historical modifications, which were deemed to have potentially similar attributes to
the historical modification which improperly downgraded RN strainer safety
classification. At the time of the inspection, this review was still in progress.
Enclosure
10
As stated earlier, the original RCE did not identify that the failure to conduct testing to
ensure that the backwash system functioned as designed was a contributor to this event.
However, this was identified following the discovery that backwash to the RC system
was not possible and that backwash to the WZ sump could not be performed at high RN
flow rates (PIP M-08-3371). Subsequently an extent of cause was conducted that
sampled several other safety systems to ensure that all safety functions have been
adequately functionally tested and/or monitored (PIP M-08-4602).
The inspector concluded that the licensee has ultimately addressed the extent of
condition and the extent of cause of the issue. However, weakness of the original extent
of condition and extent of cause evaluations resulted in delays in conducting a thorough
review, some aspects of which were still in progress at the time of the inspection.
e. IP 95001 requires that the inspection staff determine that the licensees root cause
evaluation, extent of condition, and extent of cause appropriately considered the safety
culture components as described in IMC 0305.
As part of the RCE, the licensee did not specifically consider the safety culture
components of IMC 0305, but did reference some safety culture components in their
cause determination. Specifically, CC3 was assigned a cause code of previous industry
or in-house operating experience was not effectively used to prevent problems (safety
culture component of operating experience) and CC4 was assigned a cause code of
corrective actions from previously identified problems or previous event causes were
not adequate to prevent recurrence (safety culture component of problem identification
and resolution). The failure to consider safety culture components in the RCE was
recognized by the IP 95001 readiness review team (M-SAG-SA-10-11). A corrective
action was created in PIP M-07-4313 to conduct an assessment of the safety culture
components and a corrective action to PIP M-10-1205 was created for the Safety
Assurance/Performance Improvement (SA/PI) Manager to review the current processes
and McGuire site understanding of requirements for considering safety culture
components. The safety culture component evaluation that was conducted as a result of
the readiness review team recommendation concluded that there were no aspects of the
RCE that would indicate that the organizations or individuals involved exhibited behavior
indicative of a weakness in safety culture, even though the cause codes assigned to two
of the contributing causes directly relate to safety culture components. This further
demonstrated the lack of specific guidance on considering safety culture components
during root cause evaluations.
Based on the results of the inspection, the licensee initiated PIP M-10-1516 to evaluate
the quality of root cause evaluations, including addressing the lack of guidance on
considering safety culture components during root cause evaluations.
f. Findings
No findings of significance were identified.
Enclosure
11
02.03 Corrective Actions
a. IP 95001 requires that the inspection staff determine that: (1) the licensee specified
appropriate corrective actions for each root and/or contributing cause; or (2) an
evaluation that states no actions are necessary is adequate.
The root cause and contributing causes 1 and 2 were linked to corrective actions.
However contributing causes 3 and 4 were not linked to specific corrective actions. This
was identified in the IP 95001 readiness review and PIP M-10-1214 was initiated to
correct this oversight.
The inspector reviewed the corrective actions taken for PIP M-07-4313 and determined
that, although not well linked, adequate corrective actions have been or will be taken to
address the causes of this condition.
b. IP 95001 requires that the inspection staff determine that the licensee prioritized
corrective actions with consideration of risk significance and regulatory compliance.
The licensee took immediate corrective actions to compensate for the inability to
manually backwash the RN strainers following a loss of instrument air by modifying the
strainer backwash outlet valves to provide a manual means to open the valves without
relying on VI. These compensatory actions and associated operability determination
were later modified following the discovery that backwash flow path to the RC system
was unavailable and that a negative pressure was created in the strainer during high RN
flow rates (PIP M-08-3717). This led to procedure changes that provided guidance on
aligning strainer backwash flow, if needed, to the WZ sump only and to throttle RN flow
to the Component Cooling Water (KC) heat exchangers if strainer pressure was
inadequate for sump discharge. These compensatory actions and the associated
operability determination were modified again following the discovery of additional
macro-fouling sources (PIP M-09-2216). On November 6, 2009, the NRC requested the
licensee provide an explanation addressing what compensatory or other measures were
in place to assure the operability of the RN system in case strainer macro-fouling does
occur until full compliance is restored. In their response dated December 7, 2009, the
licensee stated that a dedicated operator was stationed to perform time-critical actions to
initiate backwash supply flow to the strainers on a loss of instrument air and listed
several modifications and procedural changes that have been made. The response only
addressed macro-fouling from soft debris that could be crushed in the strainer and
passed through the system and did not reference the procedure to align backwash outlet
flow to the WZ sump or the potential need to throttle RN flow to the KC heat exchangers
to achieve adequate strainer pressure for backwash operation. The licensee committed
to supplement their December 7, 2009 response by April 12, 2010, to more completely
describe their interim compensatory measures, including those that would mitigate all
design basis type macro-fouling mechanisms that could impact the RN system during
design basis events.
These events also impacted the corrective actions needed to restore the system to full
compliance. The licensee determined that the preferred approach to restore compliance
would be to implement a series of modifications including installation of safety related
Enclosure
12
strainer backwash discharge pumps to provide the motive force to direct backwash flow
to the RN return header. In a letter dated October 1, 2009, the licensee changed their
original commitment of submitting a license amendment to resolve the NOV, to
completing these modifications by December 2012. On November 6, 2009, the NRC
requested the licensee provide a discussion on why the proposed completion date
represented the first available opportunity to restore compliance. In their response dated
December 7, 2009, the licensee provided the justification for the proposed durations for
modification implementation. The inspector reviewed the reasons provided for the
projected completion dates for the modifications and found them to be reasonable given
the magnitude of the modifications.
The corrective action to prevent recurrence for the root cause was to revise the DBD for
the RN system. This action was appropriately prioritized and has been completed.
Based upon the appropriate prioritization of the DBD revision and the review of the
implementation schedule for the modifications needed to restore full compliance of the
system, the inspector determined that the corrective actions were prioritized with
consideration of the risk significance and regulatory compliance.
c. IP 95001 requires that the inspection staff determine that the licensee established a
schedule for implementing and completing the corrective actions.
The inspector determined that all of the corrective actions listed in the RCE have been
either scheduled or completed and that the schedule was consistent with the licensees
commitments made to resolve the violation as clarified in their December 7, 2009
response for additional information.
d. IP 95001 requires that the inspection staff determine that the licensee developed
quantitative and qualitative measures of success for determining the effectiveness of the
corrective actions to preclude repetition.
As documented in PIP M-07-4313, the licensee established measures for determining
the effectiveness of the corrective actions. These measures included the following:
- Conduct an independent review of the RN DBD to ensure that it clearly provides
design and licensing bases of the RN Strainer and meets the actual design; and
- Perform an effective review six to nine months following completion of the
modifications to RN strainer backwash system using the effectiveness review
template.
The licensees corrective action program only requires effectiveness reviews to be
conducted on corrective actions to prevent recurrence (CAPR) and does not provide
explicit guidance on how to conduct the reviews. The licensee uses a template posted
on their performance improvement website as guidance for these reviews. It consists of
a series of five questions: 1) Have the CAPR(s) been properly implemented; 2) Were
CAPR(s) implemented per the latest approved schedule; 3) Have the CAPR(s) been
challenged adequately; 4) Were the CAPR(s) successful in preventing recurrence; and
5) Have the CAPR(s) prevented the same or similar events?
Enclosure
13
The independent review of the revised DBD merely verifies that the action was
completed adequately and does not evaluate whether the revision prevented recurrence
of improper design changes. The effectiveness of the modifications to restore
compliance will be demonstrated during the post-modification testing. The action was
initiated to correct the condition, not to prevent recurrence for the causes of the event.
Since no other actions were designated as CAPRs, no additional reviews of
effectiveness to prevent recurrence are required by the CAP process. This was
recognized by the IP 95001 readiness review team (M-SAG-SA-10-11). A corrective
action on PIP M-10-1205 was created for the SA/PI Manager to review the current
processes and McGuire site understanding of requirements for evaluating CAPR
effectiveness.
e. IP 95001 requires that the inspection staff determine that the licensees planned or taken
corrective actions adequately address a Notice of Violation (NOV) that was the basis for
the supplemental inspection, if applicable.
The NRC issued the NOV to the licensee on October 27, 2008. The licensee provided
the NRC a written response to the NOV on November 25, 2008. The licensees
response described: 1) the reasons for the violation; 2) corrective steps which have
been taken and the results achieved; 3) corrective steps which will be taken to avoid
further violations; and 4) the date when full compliance will be achieved. However, the
licensee revised their commitments contained in the response to the NOV in a letter
dated October 1, 2009. The licensee had originally planned to submit a license
amendment to request that the NRC accept the non-conforming condition as is, however
following a detailed review the licensee determined a preferred approach would be to
implement plant changes to bring the system into full compliance. These changes will
be implemented in three phases. Phase 1 will add an assured air supply to the strainer
backwash inlet valves. Phase 2 will improve the piping layout from the strainer
backwash outlets to the WZ sump to reduce head loss when conducting backwash
operation to the sump. Phase 3 will install safety related strainer backwash discharge
pumps to provide the motive force to discharge backwash effluent to the RN return
header and will remove the air-operated strainer backwash outlet valves.
During this inspection, the inspector reviewed the preliminary designs for these
modifications and associated calculations. The inspector determined that when Phase 1
and 3 are completed the system will be restored to full compliance and that the
licensees planned and taken corrective actions addressed the NOV. However, the
inspector was unable to determine if the Phase 2 modification would be acceptable due
to incomplete design and associated calculations; and the potential reliance on throttling
RN flow to achieve the necessary strainer pressure for backwash operations to the WZ
sump. Since these corrective actions have not been completed, the implementation and
effectiveness of the licensees corrective actions will be reviewed during future
inspections.
f. Findings
No findings of significance were identified.
Enclosure
14
4OA6 Exit Meeting
On March 9, 2010, the inspector presented the results of the supplemental inspection to
Mr. Steven D. Capps and other members of licensee management and staff. The
inspector confirmed that no proprietary information was provided or examined during the
inspection.
ATTACHMENT: SUPPLEMENTAL INFORMATION
Enclosure
SUPPLEMENTAL INFORMATION
KEY POINTS OF CONTACT
Licensee Personnel
R. Abbott, Regulatory Compliance Engineer
K. Ashe, Regulatory Compliance Manager
D. Brewer, Safety Assurance Manager
M. Broome, Electrical and I&C Engineer
S. Capps, Station Manager
K. Crane, Regulatory Compliance Engineer
C. Curry, Engineering Manager
R. Harris, Modifications Engineer
G. Holbrooks, Project Management
S. Heuertz, Performance Improvement Team
S. Karriker, Balance of Plant Engineering Supervisor
G. Kent, Duke Energy Regulatory Compliance Engineer
M. Leisure, Regulatory Compliance Engineer
W. Leggette, Nuclear Operations Support
J. Nolin, Mechanical and Civil Engineering Manager
R. Pacetti, Performance Improvement Team Manager
T. Pederson, RN System Engineer
R. Repko, Site Vice President
F. Twogood, Engineering Consultant
R. Weathers, RN System Engineer
M. Weiner, Nuclear Operations Support
NRC Personnel
J. Brady, Senior Resident Inspector - McGuire
J. Bartley, Chief, Reactor Projects Branch 1
ITEMS OPENED, CLOSED AND DISCUSSED
Closed
05000369,370/2008009-01 VIO Failure to Take Adequate Corrective Action
for Implementation of Safety-Related RN
Strainer Backwash (Section 4OA4)
LIST OF DOCUMENTS REVIEWED
Procedures
AP/1/A/5500/22, Loss of VI Abnormal Procedure, Rev. 28
AP/2/A/5500/22, Loss of VI Abnormal Procedure, Rev. 25
OP/1/A/6400/006, Nuclear Service Water System, Rev. 180
OP/2/A/6400/006, Nuclear Service Water System, Rev. 136
OP/1/A/6100/010 M, Annunciator Response for Panel 1 AD-12, Rev. 47
Attachment
2
OP/2/A/6100/010 M, Annunciator Response for Panel 2 AD-12, Rev. 31
RP/0/A/5700/006, Natural Disaster, Rev. 22
EDM-601, Engineering Change, Rev. 10
NSD 201, Reporting Requirements, Rev. 21
NSD 202, Reportability, Rev. 21
NSD 203, Operability/Functionality, Rev. 21
NSD 208, Problem Investigation Process (PIP), Rev. 31
NSD 209, 10CFR 50.59 Process, Rev. 14
NSD-212, Cause Analysis, Rev. 16
NSD-228, Applicability Determination, Rev. 5
NSD-301, Engineering Change Process, Rev. 34
M-89-0290, Design Engineering Evaluate Safety Classification of RN Strainers
M-93-0297, Viability of RN Strainers
M-00-3122, RN strainer backwash valve modification MGMM8444 does not incorporate
adequate provisions for Operations to perform manual strainer backwash
M-02-2427, Re-evaluation of RN Strainer Filtration Function (Safety or Non-Safety Related)
M-07-4177, 1B and 2B RN strainer experienced numerous Hi D/P backwashes
M-07-4313, Inability to manually backwash RN strainers during post-accident conditions
M-07-5978, Evaluate Compliance with Design Basis for RN Strainer Backwash System Utilizing
Non-Safety Related Equipment
M-08-1574, McGuire NSRB Meeting Minutes from February 13, 2008
M-08-3371, RN Strainer Backwash Return Flow Direction is from RC (Lake) to the Strainer
Instead of from the Strainer to RC (Lake)
M-08-3668, Assess Functionality of Groundwater Level Monitoring System Based on RN
Strainer Backwash Flow to WZ Sump
M-08-4602, Engineering Management Discussion on Extent of Condition M-08-3371 Problem
Evaluation
M-08-4911, NRC Issuance of a Preliminary Greater then Green Finding
M-08-7507, NRC Issuance of Violation (VIO) 08-09-01
M-09-2216, 2A RN Strainer Fouled During High RN Flow Testing per TT Procedure
M-09-2341, During Loss of Instrument Air (VI) Events, RN A Train Pump Flow May Self-Limit
Based on Suction Pressure Limits When Aligned to the SNSWP
M-10-1145, engineering Review of SITA 93-01 Audit
M-10-1205, Assessment M-SAG-SA-10-11: NRC IP 95001 Supplemental Inspection Readiness
Review - RN System White Finding.
M-10-1208, Assessment M-SAG-SA-10-11 Deficiency #1 (M-07-4313 Root Cause Evaluation
lacks development)
M-10-1209, Assessment M-SAG-SA-10-11 Deficiency #2 (No evaluation was performed to
reconcile the difference between the M-07-4313 Root Cause and the NRC NOV EA-08-220)
M-10-1210, Assessment M-SAG-SA-10-11 Deficiency #3 (M-07-4313 Root Cause Extent of
Condition evaluation and corrective actions are fragmented and inadequate)
M-10-1211, Assessment M-SAG-SA-10-11 Deficiency #4 (M-07-4313 Extent of Cause
evaluation corrective actions are inadequate and not all-encompassing)
Attachment
3
M-10-1212, Assessment M-SAG-SA-10-11 Deficiency #5 (M-07-4313 Root Cause is not
adequately addressed by the CAPRs)
M-10-1214, Assessment M-SAG-SA-10-11 Deficiency #6 (There are no CAs for M-07-4313
Root Cause Evaluation Contributing Cause 3 (CC-3) or Contributing Cause 4 (CC-4))
M-10-1217, Assessment M-SAG-SA-10-11 Deficiency #7 (several situations noted in PIP M-07-
4313 wherein the individual performing the corrective action and the approver were the
same person)
M-10-1240, Perform Detailed Design Bases Impact Review for Historical Modifications Similar
to Modification to Downgrade RN Strainer Safety Classification
Miscellaneous
MCS-1465.00-00-0004, Design Basis Specification for Loss of VI, Rev. 1
MCS-1465.00-00-0005, Design Basis Specification for Design Events, Rev. 4
MCS-1574.RN-00-0001, Design Basis Specification for Nuclear Service Water (RN) System,
Rev. 28
MCS-1581.WZ-00-0001, Design Basis Specification for the WZ System, Rev. 9
MGDS-224, McGuire Design Study to Document the Design Basis for the RN Pump Strainer,
7/11/1990
M-SAG-SA-10-11, NRC IP 95001 Supplemental Inspection Readiness Review-RN System
White Finding
SITA-93-01, operational readiness and functionality of McGuires Nuclear Service Water (RN)
System
Licensee Event Report (LER) 05000369/2007-004-00, Procedure Deficiency identified for
Performing a Manual Backwash of Nuclear Service Water (RN) Strainers due to Reliance on
Non-Safety Instrument Air
UFSAR Section 9.2.2, Nuclear Service Water System and Ultimate Heat Sink
TS 3.7.7, Nuclear Service Water System (NSWS), Amendment Nos. 184/166, & Bases B3.7.7,
Rev. 0
A/R 00302781, 10CFR50.59 Screen for Modifications to Add Safety Related Air Supply to the
RN Strainer Backwash Inlet valves
A/R 00302920, 10CFR50.59 Screen for Modifications to Reroute the Backwash Effluent Line to
the Auxiliary Building Groundwater Sump (WZ)
A/R 00302925, 10CFR50.59 Screen for Modifications to Incorporate New Pressure Transmitters
and New Backwash Discharge Pumps
A/R 00302927, 10CFR50.59 Evaluation for Modifications to Incorporate New Pressure
Transmitters and New Backwash Discharge Pumps
A/R 00303967, 10CFR50.59 Screen for Modifications to Incorporate New Pressure
Transmitters and New Backwash Discharge Pumps
A/R 00303869, 10CFR50.59 Evaluation for Modifications to Incorporate New Pressure
Transmitters and New Backwash Discharge Pumps
A/R 00304335, 10CFR50.59 Screen for OP/1(2)/A/6400/006, Nuclear Service Water Revisions
202/158
A/R 00304336, 10CFR50.59 Screen for OP/1(2)/A/6400/006, Nuclear Service Water Revisions
203/159
OMP 12-1, Dedicated RN Strainer Backwash Operator is Required, Rev. 2 dated 5/6/2009
SOMP 01-13, Designated RN Back-Flush Operator for Loss of VI, Rev. 1 dated 6/22/2009
Attachment
4
Modifications
MGMM-3794, Editorial Minor Modification to Allow Downgrade of the function of the RN
Strainers, 8/12/1993
MGMM-8444, Install New ITT Diaphragm valves at Outlet of RN Strainers on Unit 2, 4/18/2001
MGMM-11224, Install New ITT Diaphragm valves at Outlet of RN Strainers on Unit 1, 9/7/2001
MGMM-14403, Reclassify RN Strainers as QA-1 due to Recent Macro-Fouling Events,
8/11/2003
MD101360, Temporary Modification to Install Ball Thrust Bearing on 1RN0022A and Mechanical
Gag on 1RN0023, 8/8/2007
MD101361, Temporary Modification to Install Ball Thrust Bearing on 1RN0026B and Mechanical
Gag on 1RN0027, 8/8/2007
MD201362, Temporary Modification to Install Ball Thrust Bearing on 2RN0022A and Mechanical
Gag on 2RN0023, 8/8/2007
MD201363, Temporary Modification to Install Ball Thrust Bearing on 2RN0026A and Mechanical
Gag on 2RN0027, 8/8/2007
MD102035, Permanently Install Ball Thrust Bearing on 1RN0022A/26B and Remove
Mechanical Gag on 1RN0023/27, 11/5/2008
MD202037, Permanently Install Ball Thrust Bearing on 1RN0022A/26B and Remove
Mechanical Gag on 1RN0023/27, 11/5/2008
MD501561 - LLI macrofouling barrier
MD101813 - RN Strainer 1A Backwash Instrumentation
MD101624 - RN Strainer 1B Backwash Instrumentation
MD201814 - RN Strainer 2A Backwash Instrumentation
MD201629 - RN Strainer 2B Backwash Instrumentation
EC 101543, Installation of an Assured Air Supply for 1-RN-21A
EC 101545, Installation of an Assured Air Supply for 1-RN-25B
EC 101544, Installation of an Assured Air Supply for 2-RN-21A
EC 101546, Installation of an Assured Air Supply for 2-RN-25B
EC 101547, Improved Piping Layout for Manual Strainer Backwash from 1A RN Strainer to WZ
EC 101549, Improved Piping Layout for Manual Strainer Backwash from 1B RN Strainer to WZ
EC 101548, Improved Piping Layout for Manual Strainer Backwash from 2A RN Strainer to WZ
EC 101550, Improved Piping Layout for Manual Strainer Backwash from 2B RN Strainer to WZ
EC 102477, Installation of RN Strainer Backwash Discharge Pump for 1A RN Strainer
EC 102478, Installation of RN Strainer Backwash Discharge Pump for 1B RN Strainer
EC 102479, Installation of RN Strainer Backwash Discharge Pump for 2A RN Strainer
EC 102482, Installation of RN Strainer Backwash Discharge Pump for 2B RN Strainer
ECR 2081, Provide Remote Throttling Capability to Unit 1 KC HX Supply Isolation Valves
ECR 2087, Provide Remote Throttling Capability to Unit 2 KC HX Supply Isolation Valves
Attachment
5
Calculations
MCC-1223.24-00-00P1, Mechanical/ Civil Design Inputs for Assured Air Supply for Strainer
Backwash Valves, Rev. 0
MCC-1223.24-00-00P2, Mechanical/ Civil Design Inputs for Piping Layoout for Manual Strainer
Backwash, Rev. 0
MCC-1223.24-00-00P3, Mechanical/ Civil Design Inputs for RN Strainer Backwash Discharge
Pumps, Rev. 0
MCC-1223.24-00-0096, RN System Flow Balance Acceptance Criteria Calculation, Rev. 4
MCC-1223.24-00-0100, FMEA of RN Strainer Modifications MD101813, MD101624,
MD201814, and MD201629, Rev. 1
MCC-1223.24-00-0102, RN Pump NPSH Calculation, Rev. 3
MCC-1223.24-00-0103, RN Strainer Macrofouling Source Calculation, Rev. 3
MCC-1223.24-00-0107, FMEA of RN Strainer Backwash Discharge Modifications, Rev. 3
MCC-1223.31-00-0010, Groundwater Drainage System Flow Analysis, Rev. 3
MCC-1331.16-00-0410, Electrical Discipline Design Inputs for EC 101543, EC 101544, EC 101545, EC 101546, Rev. 0
MCC-1331.16-00-0411, Electrical Discipline Design Inputs for EC 102477, EC 102478, EC 102479, EC 102482, Rev. 1
PIPs generated as a result of this inspection
PIP M-10-1429, NRC Inspector Questioned Basis and Conclusion of the Applicability
Determination for Procedure Change That Allowed Throttling of KC Flow
PIP M-10-1430, NRC Inspector Questioned Classification of Strainer Backwash as a Functional
Failure
PIP M-10-1448, NRC 95001 Supplemental Inspection Items to be Resolved
PIP M-10-1516, Evaluate the Quality of Root Cause Evaluations and Associated Process
Guidance Based on NRC 95001 Supplemental Inspection Results
Attachment