ML100900384

IR 05000369-10-007, 05000370-10-007, on 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 Qu

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

License Nos.: NPF-9, NPF-17

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

License Nos.: NPF-9, NPF-17

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

PIPs

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

Sump

EC 101549, Improved Piping Layout for Manual Strainer Backwash from 1B RN Strainer to WZ

Sump

EC 101548, Improved Piping Layout for Manual Strainer Backwash from 2A RN Strainer to WZ

Sump

EC 101550, Improved Piping Layout for Manual Strainer Backwash from 2B RN Strainer to WZ

Sump

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