L-2012-417, Flooding Walkdown Report FPL061-PR-001, Rev 0, in Response to the 50.54(f) Information Request Regarding Near-Term Task Force Recommendation 2.3: Flooding

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Flooding Walkdown Report FPL061-PR-001, Rev 0, in Response to the 50.54(f) Information Request Regarding Near-Term Task Force Recommendation 2.3: Flooding
ML12340A411
Person / Time
Site: Turkey Point  NextEra Energy icon.png
Issue date: 11/20/2012
From: Raines N
Enercon Services
To:
Florida Power & Light Co, Office of Nuclear Reactor Regulation
References
L-2012-417 FPL061-PR-001, Rev 0
Download: ML12340A411 (24)
v • d • e


Text

Turkey Point Nuclear Plant L-2012-417 Docket Nos. 50-250 and 50-251 Enclosure Enclosure Flooding Walkdown Report FPL061-PR-001, Rev. 0 In Response to the 50.54(f) Information Request Regarding Near-Term Task Force Recommendation 2.3: Flooding for the Turkey Point Units 3 & 4 24 page

FLOODING WALKDOWN REPORT FPL061-PR-001, Rev. 0 IN RESPONSE TO THE 50.54(f) INFORMATION REQUEST REGARDING NEAR-TERM TASK FORCE RECOMMENDATION 2.3:

FLOODING for the Turkey Point Units 3 & 4 9760 SW 3 4 4 th Street Florida City, FL 33035 Presented to:

Florida Power & Light Company 700 Universe Boulevard Juno Beach, FL 33408 Prepared by:

ENERCON Services, Inc.

500 Townpark Lane, Suite 275 Kennesaw, GA 30144-5509 November 15, 2012 Printed Name/Title Affiliation Signature Date Preparer: Nathan Raines / Engineer ENERCON It15/11 Reviewer: Craig Ramsey / Sr. Engineer ENERCON 11/(5-1.)

Atwood Browning /

Approver: Principal Engineer ENERCON Gary Priolo /

Lead Engineer, Site Lead: Flooding Walkdowns FPL Site Sponsor:

Sergio Chaviano /

Special Projects Manager, Site Fukushima Lead FPL 41LN~// /6' Ii

NTTF Recommendation 2.3 (Walkdowns): Flooding Florida Power & Light Company - Turkey Point Units 3 & 4 November 15, 2012 FPL06I-PR-001, Revision 0 Contents

1. EX EC U TIVE SU M M AR Y .................................................................................................................. 3
2. PU RPO S E ............................................................................................................................................ 4
a. B ackground ....................................................................................................................................... 4
b. S ite D escription ................................................................................................................................. 4
3. M ET HO D O L O G Y ............................................................................................................................... 5
4. REQUESTED INFORMATION ...................................................................................................... 5
a. Requested Information Item 2(a) - Design Basis Flood Hazards ................................................ 5
b. Requested Information Item 2(b) - CLB Protection and Mitigation Features .............................. 6
c. Requested Information Item 2(c) - Flood Warning Systems ........................................................ 7
d. Requested Information Item 2(d) - Flood Protection System/Barrier Effectiveness ................... 8
e. Requested Information Item 2(e) - Implementation of Walkdown Process .............................. 10
f. Requested Information Item 2(f) - Findings and Corrective Actions Taken/Planned .................... 11
g. Requested Information Item 2(g) - Cliff-Edge Effects and Available Physical Margin ....... 16
h. Requested Information Item 2(h) - Planned/Newly-Installed Flood Protection Enhancements .... 17
5. CO N C L U SIO N S ................................................................................................................................. 18
6. RE FERE N C ES ................................................................................................................................... 20 A TT A C H M EN TS ............................................................................................................................... 21 Page 2 of 23

NTTF Recommendation 2.3 (Walkdowns): Flooding Florida Power & Light Company - Turkey Point Units 3 & 4 November 15, 2012 FPL06I-PR-001, Revision 0

1. EXECUTIVE

SUMMARY

This report was developed to provide information requested by the United States Nuclear Regulatory Commission (NRC) pursuant to Title 10 of the Code of Federal Regulations, Section 50.54 (f) on March 12, 2012 for Turkey Point Units 3 & 4. In response to the NRC request, walkdowns and assessments were performed to verify that plant features credited in the current licensing basis (CLB) for protection and mitigation from external flood events are available, functional, and properly maintained. The scope of work included verification that permanent structures, systems, components (SSCs), portable flood mitigation equipment, and the procedures needed to install and or operate them during a flood are acceptable and capable of performing their design function as credited in the current licensing basis.

Walkdowns were performed in accordance with NEI 12-07 (Rev. 0-A), "Guidelines for Performing Verification of Plant Flood Protection Features", dated May, 2012 [Ref. 1]. This document was endorsed by the NRC on May 31, 2012. Turkey Point Units 3 & 4 configuration and procedures were compared to the flood protection features credited in the current licensing basis documents [Ref. 7] for external flooding events. Site-specific features credited for protection and mitigation against external flooding events were identified and evaluated. A summary of the Turkey Point CLB, flood protection features, and the results of the inspections is provided below.

Current Licensing Basis

  • The predicted maximum flood stage resulting from the maximum probable hurricane has been calculated to be +18.3 feet above mean low water (MLW) [Ref. 7]. The probable maximum hurricane (PMH) is the only design basis external flood condition considered for Turkey Point Units 3 & 4.

Flood Protection Features

  • Grade level of the plant structures at Turkey Point Units 3 & 4 is +18 feet above MLW.

External flood protection has been provided to +20 feet above MLW to the north, south, and west of the facility by a continuous barrier consisting of building exterior walls, flood walls, a flood embankment, and stop logs for the door openings. External flood protection has been provided to

+22 feet above MLW to the east of the facility. Elevation +20 feet and +22 feet is required to provide protection for maximum wave run-up [Ref. 7]. This continuous barrier creates a continuous flood protection perimeter around equipment vital to safety.

  • The intake cooling water (ICW) pump motor bases are located at +22.5 feet MLW, and are therefore protected by their elevation [Ref. 7].

For PMH conditions, drain plugs are installed to prevent flooding within the flood protected areas due to backflow from the storm surge through the drainage system. Temporary dewatering pumps are installed to remove any rainwater accumulation in these areas while the drains are plugged.

  • Hurricane preparation actions taken by plant staff that are credited for flood protection include:

installation of portable dewatering pumps, drain plugs, stop logs, and small sandbag dikes.

Inspection Results o The walkdowns did not identify any conditions that would have compromised the protection of safety related equipment in the event of a probable maximum hurricane. However, the following types of deficiencies were identified:

Page 3 of 23

NTTF Recommendation 2.3 (Walkdowns): Flooding Florida Power & Light Company - Turkey Point Units 3 & 4 November 15, 2012 FPL061-PR-001, Revision 0 o Missing or degraded conduit seals in the electrical ductbanks associated with the Unit 4 Emergency Diesel Generator (EDG) Building.

o Some electrical manholes were found with approximate one inch diameter holes and other small openings in the covers. Water that enters through the openings would collect in the manholes and could eventually travel through conduits in the ductbank system that are not sealed. Some of the ductbanks provide a pathway for floodwater to potentially infiltrate from outside the flood protected barrier to inside the flood protected barrier.

o Some of the drain plugs used to prevent backflow from the drainage system during a PMH were found to be degraded.

o Degraded flood barrier walls (e.g., cracks, small unsealed penetrations, corrosion, holes) o The quantity of fuel oil required for temporary dewatering pumps to be operable for the duration of the PMH is not specified.

The deficiencies identified have been evaluated to ensure that there are no operability or functionality concerns. These issues will be brought into full compliance in a timely fashion in accordance with the guidance provided in Regulatory Information Summary (RIS) 2005-20.

Using reasonable simulation, staffing levels were verified to be adequate and the flooding protection procedure could be implemented as written for performance of these activities prior to storm arrival.

2. PURPOSE
a. Background In response to the nuclear fuel damage at the Fukushima-Dai-ichi power plant due to the March 11, 2011 earthquake and subsequent tsunami, the United States Nuclear Regulatory Commission (NRC) established the Near Term Task Force (NTTF) to conduct a systematic review of NRC processes and regulations, and to make recommendations to the Commission to clarify and strengthen the regulatory framework for protection against natural phenomena. On March 12, 2012, the NRC issued a request for information pursuant to Title 10 of the Code of FederalRegulations, Section 50.54 (f) (10 CFR 50.54(f) or 50.54(f)) [Ref. 2].

In Enclosure 4 of this document, the NRC requested that licensees 'perform flood protection walkdowns using an NRC-endorsed walkdown methodology to identify and address plant-specific degraded, nonconforming, or unanalyzed conditions and cliff-edge effects through the corrective action program and verify the adequacy of monitoring and maintenance procedures'. The flooding walkdowns have been completed and the results are described in this report.

b. Site Description Turkey Point Units 3 & 4 are on the shore of Biscayne Bay, about 25 miles south of Miami, Florida. The area surrounding the site is flat and slopes very gently to the west from sea level at the shoreline of Biscayne Bay to an elevation of about 10 feet above mean sea level (MSL) at a point some 8 to 10 miles inland. The Miami area has experienced winds of hurricane force periodically. During storms, the plant may be subjected to flood tides of varying heights. The two nuclear units have been constructed on compacted limerock fill to elevation +1 8 feet MLW.

Page 4 of 23

NTTF Recommendation 2.3 (Walkdowns): Flooding Florida Power & Light Company - Turkey Point Units 3 & 4 November 15, 2012 FPL06 I-PR-001, Revision 0

3. METHODOLOGY The walkdowns were performed in accordance with NEI 12-07 (Rev. 0-A), "Guidelines, for Performing Verification of Plant Flood Protection Features", dated May, 2012 [Ref. 1]. This document was endorsed by the NRC on May 31, 2012.
4. REQUESTED INFORMATION The information requested in Reference 2, Enclosure 4, under paragraph 2 of the 'Requested Information' section, is provided below. The contents of each item were developed in accordance with Reference 1, Appendix D.
a. Requested Information Item 2(a) - Design Basis Flood Hazards Describe the design basis flood hazard level(s) for all flood-causing mechanisms, including groundwater ingress.

Appendix 5G of the Updated Final Safety Analysis Report (UFSAR) [Ref. 7] describes the design basis and flood protection features provided at Turkey Point Units 3 & 4 for protection against the effects of an external flood.

The flood criteria considered by the Army Corps of Engineers is for a hurricane flood tide associated with a 100 year hurricane. Hurricane flood tide is the only design basis external flood condition considered for Turkey Point Units 3 & 4. The Turkey Point design bases for flooding do not include a 100 year rainstorm concurrent with a hurricane. However, anticipated rainfall associated with the hurricane is considered. No other sources of external flooding were considered in the Turkey Point CLB (i.e. dam breaks, tsunami, local intense precipitation, etc) but are being evaluated as part of the request for information associated with NTTF recommendation 2.1.

The calculation methodology used to determine the maximum flood stage postulates the maximum probable hurricane hover at the most critical position in proximity to the site long enough to establish steady state conditions. The predicted maximum flood stage resulting from the maximum probable hurricane has been calculated to be +18.3 feet above MLW. Site grade is at +18 feet above MLW.

An assessment was performed to quantify the amount of rainfall that could be experienced during a design basis hurricane. The assessment concluded that the Turkey Point site could potentially experience approximately 3.8 inches of rainfall during a 30 minute duration storm.

Model tests were done at the University of California to obtain information on possible flooding of the cooling pumps on the intake structure as a result of waves occurring with a water stage of +18.3 feet above MLW. These model tests provide the basis for raising the ICW pump motors and providing a 4'-0" splash wall at the intake structure.

Groundwater ingress is not explicitly mentioned in any design basis documents, but all areas inside of the protected flood wall below grade are credited as being dry. Therefore, all below grade exterior walls and floors were inspected for signs of groundwater ingress [Ref. 6, Attachment 2].

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NTTF Recommendation 2.3 (Walkdowns): Flooding Florida Power & Light Company - Turkey Point Units 3 & 4 November 15, 2012 FPL061-PR-001, Revision 0

b. Requested Information Item 2(b) - CLB Protection and Mitigation Features Describe protection and mitigation features that are considered in the licensing basis evaluation to protect against external ingress of water into SSCs important to safety.

The two nuclear units have been constructed on compacted lime rock fill to elevation +18 feet MLW.

Based on the conclusions derived from the analysis and model testing performed at the University of California, the following flood protection provisions were taken:

  • A 4 foot high concrete splash wall is provided at the seaward extremity (east side) of the intake structure deck. The splash wall provides flood protection from waves to +20 feet above MLW.

The 4 foot high splash wall is placed on the outer edge of the front lip (east side) of the intake structure to hold wave action and water levels to a minimum at the ICW motors.

" In addition to building a 4 foot splash wall, the intake cooling water pump motor bases were raised to +22.5 feet MLW. Their elevation, combined with the protection provided by the splash wall, provide adequate flood protection for the ICW pumps. The ICW pumps are the only equipment vital to safety located outside of the flood protection barrier perimeter.

  • External flood protection has been provided to +20 feet above MLW to the north, south, and west of the facility by a continuous barrier consisting of building exterior walls, flood walls, a flood embankment, and stop logs for the door openings. External flood protection has been provided to

+22 feet above MLW to the east of the facility. With the exception of the ICW pumps located at the intake structure, this continuous barrier creates a flood protection perimeter surrounding all systems, structures, and components vital to safety. Building walls include the Turbine Building, Radwaste Building, Auxiliary Building, Emergency Diesel Generator Buildings, and Containment Structures. The flood walls are concrete masonry units (CMU) walls. The CMU walls are constructed between buildings that are not immediately adjacent to one another in order to form the continuous barrier. Elevation +20 feet and +22 feet is required to provide protection for maximum wave run-up. The licensing and design basis documents do not indicate an exact elevation to which waves are expected to reach. These documents imply that the maximum wave run-up is less than the elevation of protection provided.

  • Conduits associated with the Unit 4 Emergency Diesel. Generator Building installation that cross beneath the Unit 4 Emergency Diesel Generator Building flood barrier and the main plant flood barrier are provided with water seals. Seals are provided at the last manhole prior to crossing the flood protection boundary.

Various portions of the hurricane season readiness procedure outline the actions to be taken prior to the start of hurricane season (June through November) and 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> prior to the projected arrival of tropical storm force winds (39 mph). Reliable information on approaching severe weather disturbances is available from the National Oceanic and Atmospheric Administration (NOAA) and the National Weather Service (NWS). All actions taken for flood protection and mitigation are performed prior to hurricane arrival as part of the hurricane season readiness procedure. Therefore, these actions will not be impeded by the design basis hurricane. Depending on the storm intensity, some actions in the hurricane season readiness procedure are not required. For PMH conditions, actions taken by plant staff that are credited for flood protection include:

o Installation of portable dewatering pumps, electric generators with fuel supplies, and associated suction and discharge hoses in various plant areas.

  • Installation of mechanical and inflatable plugs in plant drainage system drains.

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NTTF Recommendation 2.3 (Walkdowns): Flooding Florida Power & Light Company - Turkey Point Units 3 & 4 November 15, 2012 FPL06 I-PR-001, Revision 0

  • Installation of stop logs at door openings on plant flood protection walls.

o Filling sandbags and building sandbag dikes at specified plant doors, drains, and manhole covers.

The above installations and preparations are begun 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> prior to storm arrival. These installations must be completed by the time the storm arrives. Discussion of manpower required to achieve successful installation of these temporary features can be found in Section 4.d, Flood Protection Systemr/Barrier Effectiveness.

The CLB does not specifically identify the design basis flood duration. The calculation methodology used to determine the maximum flood stage postulates the maximum probable hurricane hovers at the most critical position in proximity to the site long enough to establish steady state conditions.

The Turkey Point design bases for flooding do not include a 100 year rainstorm concurrent with a hurricane. However, anticipated rainfall associated with the hurricane is considered. During PMH conditions, drain plugs are installed to prevent flooding within the flood protected areas due to backflow from the storm surge. Flooding from rain water inside the flood protected barrier is prevented by installing temporary dewatering pumps.

Credited flood protection features at Turkey Point are independent of plant modes of operation.

Therefore, changing plant modes does not affect credited flood protection features and actions.

Notes regardingflood protection licensing and design documents discrepancies Appendix 5G of the UFSAR states "A 4 foot high concrete wall is provided at the seaward extremity (east side) of the intake structure deck. The wall provides flood protection to +20 feet above MLW."

Similarly, the design basis document for external flooding criteria discusses this same structure and states the "Intake structure flood wall shall extend up to the +22.0-foot MLW elevation."

The concrete wall provided at the east side of the intake structure has been verified to be 4'-0" tall, as indicated in all plant documentation. The intake structure platform elevation is 16'-0". Therefore, the wall provides protection to +20 feet above MLW, consistent with Appendix 5G of the UFSAR.

Supplement No. 13 to Application for Licenses [Ref. 9] discusses the model testing used for the intake structure hurricane flood protection design. A review of Supplement No. 13 verified that the flood wall height is intended to be 4'-0". Therefore, the acceptance criteria used for the intake structure splash wall was to verify the flood wall height of 4'-0". This discrepancy between elevation +20 feet as indicated in the UFSAR and elevation +22 feet as indicated in the design basis document has been entered into the CAP.

c. Requested Information Item 2(c) - Flood Warning Systems Describe any warning systems to detect the presence of water in rooms important to safety.

Turkey Point Units 3 and 4 do not depend upon water level alarms for flood warnings of external floods.

Water level alarms are credited for internal flooding as described in Appendix 5F of the UFSAR [Ref. 7].

No credit is taken for external flooding.

See Section 4.d for discussion on additional existing SSC's that are not part of the external flooding CLB but could be used to mitigate an external flood.

Page 7 of 23

NTTF Recommendation 2.3 (Walkdowns): Flooding Florida Power & Light Company - Turkey Point Units 3 & 4 November 15, 2012 FPL06 I-PR-001, Revision 0

d. Requested Information Item 2(d) - Flood Protection System/Barrier Effectiveness Discuss the effectiveness of flood protection systems and exterior, incorporated, and temporary flood barriers. Discuss how these systems and barriers were evaluated using the acceptance criteria developed as part of Requested Information Item l.h [in Enclosure 4 of the March 12, 2012, 50.54(f) letter]

In accordance with NET 12-07, the following general criteria were used as acceptance criteria for flood protection features:

" Flood protection configuration was in accordance with as-built drawings, as-built installation records, inspection records, vendor documents, etc.

" Visual inspection was utilized to identify any material degradation.

  • Instructions contained within the implementation procedures can be implemented as written and within the allowed time considering the warning time available for the applicable flood hazard and expected conditions during the event.
  • When applicable, preventative maintenance (PM) or periodic inspections were in place, within their required periodicity, and of adequate scope.

" There were no unresolved adverse PM or periodic inspection implementation results.

  • No topography changes, including security barrier installations, adversely affected the site drainage plan.
  • All below grade exterior walls and floors were inspected for signs of groundwater ingress.

All observations not immediately judged as acceptable by the criteria above were entered into the Turkey Point Corrective Action Program (CAP) where an evaluation of the observation was made.

The predicted maximum flood stage resulting from the maximum probable hurricane has been calculated to be 18.3 feet above MLW. The ICW pumps are protected by their elevation of +22.5 feet and the 4'-0" splash wall located at the east extremity of the intake structure. This ICW pump motor height was verified by field measurements and is adequate for flood protection. The splash wall height was verified by field measurements and is adequate for flood protection.

Components vital to safety are flood protected to +22 feet above MLW to the east of the facility and +20 feet to the north, south, and west by a continuous barrier consisting of building exterior walls and stop logs. Wall condition, penetrations, and seals in the flood barrier were inspected and no conditions that would compromise the protection of safety related equipment were identified. The Unit 3 and Unit 4 Containment buildings were not able to be entered for inspection of the below grade walls. External inspection of the containment structures was performed and no flooding related findings were observed.

Additionally, Internal Leak Rate Tests are periodically performed on both containment structures. It is reasonable to expect that the containment structures can perform their credited flood protection functions.

By use of reasonable simulation, it is concluded that all stop logs can be installed within the credited flood warning time and the staffing levels are adequate. The stoplogs were walked down to verify that they are properly staged, in good working condition, and accessible. Documentation for annual inspection and installation of stop logs was reviewed and found to be adequate. All stoplogs are expected to be available to perform their intended flood protection function under design basis conditions.

Plugging of storm drains during PMH conditions prevent flood water from backing up through floor drain pipes. The capability to install the plugs within the available time was verified using the reasonable simulation process. A representative sample of drain plugs was installed, the time spent and staffing level required for the effort was documented, and the results extrapolated to determine the time and staffing levels required to complete all drain plug installations. The results of the simulation determined that Page 8 of 23

NTTF Recommendation 2.3 (Walkdowns): Flooding Florida Power & Light Company - Turkey Point Units 3 & 4 November 15, 2012 FPL061-PR-001, Revision 0 current staffing levels are adequate to complete the drain plug installations within the credited flood warning time. The drain locations were walked down to verify that the installation points are accessible and drain plugs can be installed as described in the hurricane season readiness procedure. The drain plugs were verified to be properly staged in the correct storage location of the Central Receiving Facility (CRF).

The hurricane season readiness procedure has contingency for building of sandbag dikes at floor drains that cannot be plugged. The ability to implement this contingency was also verified as part of the simulation process.

Supplemental portable dewatering pumps installed during PMH events provide adequate assurance that the effect of rainwater accumulation inside the flood protected area is minimized. By use of reasonable simulation, one temporary pump was installed. The time spent and staffing level required for the effort was documented and the results extrapolated to determine the time and staffing levels required to complete all temporary pump installations. The results of the simulation determined that current staffing levels are adequate to complete all temporary pump installations within the credited flood warning time.

All areas identified for temporary pump installation were walked down to confirm the areas were accessible and that the pumps could be installed as described in the hurricane season readiness procedure.

The pumps, generators, and accessories were verified to be properly staged in the correct storage location of the Central Receiving Facility (CRF). These features are expected to be available to perform their intended flood protection function under design basis conditions.

Provisions are made for the filling of 3500 sandbags per the hurricane season readiness procedure. Based on field observations, it is not estimated that 3500 sandbags are required to provide plant flood protection.

However, for the purposes of manpower estimation, 3500 is a conservative requirement. Using reasonable simulation, a sample number of sandbags were filled and a sandbag dike was constructed at the Radwaste Building north door. The time spent and staffing level required for the effort was documented and the results extrapolated to determine the time and staffing levels required to complete all sandbag installations. The results of the simulation determined that current staffing levels are adequate to fill and place 3500 sandbags. This feature is expected to be available to perform its intended flood protection function under design basis conditions.

The reliance on station staff to execute required flood protection features indicated above has been reviewed. The aggregate effect of these actions have been evaluated and concluded that all actions can be completed as required.

As indicated in Section 4.b, the actions taken for flood protection and mitigation discussed above are performed prior to hurricane arrival as part of the hurricane season readiness procedure. Therefore, these actions will not be impeded by the design basis hurricane.

Topographical changes were reviewed to consider water flow on site and evaluate for their effect on flooding. The design basis flood at Turkey Point is for a hurricane flood stage. Site topography surrounding the flood protected area is not used for flood mitigation. Therefore, there is no potential for increased flood levels due to altered site drainage characteristics.

Additional SSC's andproceduresnot part of the externalflooding CLB that could be used for mitigation:

The Residual Heat Removal (RHR) pump rooms contain flood protection features that are not credited for external flooding. The RHR pumps are located below grade elevation in the Auxiliary Building. These pump rooms could be subject to flooding should an external flood barrier fail. The pump rooms contain sump level alarms, which are powered from a vital source and annunciate in the control room to notify the operator of an abnormal condition in the room. In addition, each pump room is equipped with a permanent surnp and automatic pumping system. The pump motors and valves are positioned at least 30 Page 9 of 23

NTTF Recommendation 2.3 (Walkdowns): Flooding Florida Power & Light Company - Turkey Point Units 3 & 4 November 15, 2012 FPL061-PR-001, Revision 0 inches above the floor. Water entering the rooms would be pumped out or an alarm would be received when the water reaches undesired levels.

Additional flood protection measures not credited in the CLB include the structures monitoring program, which provides guidance for conducting a structural condition monitoring program to meet the requirements of 10 CFR 50.65, the Maintenance Rule. The program provides a systematic approach for evaluation of plant systems/structures which will provide reasonable assurance that those structures are capable of fulfilling their intended 10 CFR 50.65 function. The program consists of a review of the condition of plant structures via periodic inspections, routine walkdowns, surveillance tests, and ongoing review of the effect of the condition of plant structures on significant plant equipment. The program consists of defining and performing periodic structural evaluation which will ensure the timely identification, assessment and repair of degraded structural elements. Items which require aging management include buildings, structures, and miscellaneous items such as flood protection seals and stop logs. Concrete structures are inspected for cracking, spalling, erosion, corrosion of reinforcing bars, settlement, deformation, leaching, discoloration, groundwater leakage, rust stains, exposed rebars, rust bleeding and other surface irregularities. Flood barriers and flood seals for structures determined to be within the scope of the Maintenance Rule are examined. Maintaining the structures monitoring program provides reasonable assurance that those structures that fall under the program will be able to perform their intended function.

e. Requested Information Item 2(e) - Implementation of Walkdown Process Present information related to the implementation of the walkdown process (e.g., details of selection of the walkdown team and procedures,) using the documentation template discussed in Requested Information item l.i, including actions taken in response to the peer review.

Consistent with Section 5.3 of NEI 12-07, walkdown teams consisted of at least two trained individuals with a complementary set of skills. The walkdown team consisted of two civil/structural engineers and two mechanical engineers. Each walkdown was performed by two members of the walkdown team. Both civil engineers performing walkdown inspections hold a master of science in civil engineering and have previous experience and familiarity with Turkey Point from support provided to previous plant design modifications. Both mechanical engineers either have previous experience at Turkey Point or other relevant experience applicable to the walkdown inspections.

Per Section 5.3 of NEI 12-07, personnel selected to perform walkdown inspection activities were experienced and knowledgeable of the site current licensing basis. Personnel were experienced or trained to perform visual inspections of structures, systems and components (SSC) and met the knowledge requirements of Appendix C of NEI 12-07.

All team members that performed the visual inspections were trained to and knowledgeable of the below information:

  • NANTEL lesson on Generic Flood Protection Walkdowns

" Specific Turkey Point licensing basis training material

" NTTF recommendation 2.3-Flooding and the NRC letter dated March 12, 2012 o NEI 12-07, Revision 0-A ENERCON personnel were supported by site and craft personnel during the walkdown who were not required to meet the above requirements. These personnel were used because of their familiarity with plant SSC's and protective measures. Generally, these personnel met the knowledge requirements but did Page 10 of 23

NTTF Recommendation 2.3 (Walkdowns): Flooding Florida Power & Light Company - Turkey Point Units 3 & 4 November 15, 2012 FPL061-PR-001, Revision 0 not undergo the required training. A pre-job brief was performed prior to conducting the walkdowns using plant human performance procedures and was tailored to the walkdown task. Each walkdown performed a specified inspection to assess the capability of the item to perform its required function. All walkdown results were documented in accordance with the recommendations of Section 7 of NEI 12-07 and using the walkdown record form template in Appendix B of NEI 12-07.

f. Requested Information Item 2(f) - Findings and Corrective Actions Taken/Planned Results of the walkdown including key findings and identified degraded, non-conforming, or unanalyzed conditions. Include a detailed description of the actions taken or planned to address these conditions using the guidance in Regulatory Issues Summary 2005-20, Rev. 1, Revision to NRC Inspection Manual Part 9900 Technical Guidance, "Operability Conditions Adverse to Quality or Safety," including entering the condition in the corrective action program.

All key findings discovered during the duration of the walkdown inspections were recorded and entered into the CAP to be dispositioned. Findings determined to be deficiencies as defined in the NEI 12-07 guidance document are summarized below:

Description of Deficiency Feature Turkey Point Disposition Status Category Localized areas of spalling, Incorporated The amount of ground water Being tracked delamination, bulging, and Passive intrusion is expected to be limited under cracking of the concrete walls and and existing sump pumps corrective flooring were found primarily on provided for internal flood action the below grade walls and floors of mitigation would be used to program the Auxiliary Building, Turbine mitigate potential water intrusion Building, and Radwaste Building. into these areas. Additional These could lead to intrusion of measures will be incorporated ground water if not corrected. into existing procedures to provide dewatering pumps as required for increased margin and redundancy. Note that a majority of these conditions had been previously identified under the structures monitoring program.

Assessments of those conditions determined that the overall integrity of the structures has not been compromised. Repair options for the identified deficiencies are being evaluated.

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NTTF Recommendation 2.3 (Walkdowns): Flooding Florida Power & Light Company - Turkey Point Units 3 & 4 November 15, 2012 FPL06I-PR-001, Revision 0 A number of manholes associated Incorporated The manhole covers are fitted Being tracked with the Unit 4 Emergency Diesel Passive with sealing material and under Generator Building installation call essential equipment in the Unit 4 corrective for the conduits in the ductbanks Emergency Diesel Generator action that cross beneath the Unit 4 Building is located above the program Emergency Diesel Generator flood plain. Thus, only a limited Building flood barrier and the main amount of water would be plant flood barrier to be internally expected to reach the conduits sealed as required by the design and the equipment is protected by document. Inspection of these elevation as well. The conduits manholes found that a limited without seals will be sealed.

number of the conduit seals were missing. 4 Electrical manholes were found Incorporated It is expected that a limited Being tracked with approximate one inch Passive amount of water would pass under diameter holes and other small through the small number of corrective openings in the covers. Water that holes identified on the manholes. action enters through the openings would Water that enters through the program collect in the manholes and could holes would not have sufficient eventually travel through conduits head to travel the long distance in the ductbank system that are not and torturous path through the sealed. Some of the ductbanks cable-filled conduits in significant provide a pathway for floodwater quantities. Additionally, there are to potentially infiltrate from temporary dewatering pumps outside the flood protected barrier provided within the flood to inside the flood protected protected area to address barrier. incidental quantities of water that get through the barriers. To address the vulnerability, the holes in the manhole covers will be plugged. Efforts are being undertaken to seal the entire manhole system to preclude any water intrusion from passing through underground conduits altogether.

Conduit and other pipe Incorporated The amount of water intrusion is Being tracked penetrations were identified with Passive expected to be limited in the under degraded internal and external Electrical Penetration Room and corrective seals in the Electrical Penetration lower levels of the Auxiliary action Rooms, Condenser Pits, and the Building. Temporary dewatering program lower levels of the Auxiliary pumps provided for external flood Building. The penetrations were mitigation would be used to often accompanied by water stains mitigate potential water intrusion or corrosion. into the areas of the Auxiliary Building. Repair options are being evaluated to address the identified vulnerabilities.

Page 12 of 23

NTTF Recommendation 2.3 (Walkdowns): Flooding Florida Power & Light Company - Turkey Point Units 3 & 4 November 15, 2012 FPL061-PR-001, Revision 0 Stoplog SL-2 was measured to be Temporary Stoplog SL-2 currently provides Being tracked 24 inchestall. This matches the Passive protection to +20 feet which is under details shown on the design 1.7 feet above the maximum corrective drawing. However, stoplog SL-2 is flood stage. Flood protection to action located on the east wall of the +22 feet is required for wave run program Radwaste Building which is up from the east. The Access &

protected to +22 feet MLW. Dress Facility located to the east Therefore, stoplog SL-2 should of Stoplog SL-2 provides some have a height of 48 inches. level of protection from wave run-up to the east but was not included in the initial license. To be consistent with the UFSAR, the feature will be modified to provide protection up to an elevation of +22 above MLW.

Some inflatable drain plugs Temporary Contingency for sandbagging Being tracked credited for plugging of the storm Passive inaccessible drains is provided, under drain pipes were in a degraded This is not a concern based on corrective condition and could not hold air. time available to implement action sandbag dike installations. A program preventative maintenance procedure for inspection of the drain plugs is being developed.

Several through holes were Incorporated These holes are above the Being tracked discovered on the Unit 3 condenser Passive maximum flood stage elevation, under pit perimeter flood protection It is not expected that a large corrective barrier. The presence of these volume would enter into the action holes creates a path for flood water condenser pit due to wave run-up. program to by-pass the flood barrier. In addition, temporary dewatering pumps are provided in these areas by procedure. The holes will be sealed.

Two 3" diameter penetrations were Incorporated The penetrations are above the Being tracked found at the exterior wall of the Passive maximum flood stage. Thus, under an Unit 4 Spent Fuel Pool (SFP) heat wave run-up is the only concern. Engineering exchanger room that are not As such, little water intrusion Change properly sealed. These two would be expected due to wave package penetrations were found with run-up. These penetrations are foreign material exclusion (FME) being controlled as part of an covers. The exterior walls of the ongoing construction effort and Unit 4 SFP heat exchanger room will be sealed upon completion.

are credited as an external flood protection barrier. The elevation of the penetrations is lower than

+22 feet as described in the UFSAR for flood protection from the east.

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NTTF Recommendation 2.3 (Walkdowns): Flooding Florida Power & Light Company - Turkey Point Units 3 & 4 November 15, 2012 FPL061-PR-001, Revision 0 There is a small gap between the Incorporated The gap is above the maximum Being tracked north end of the Radwaste Passive flood stage. It is not expected under Building pipe chase and the that a large volume would enter corrective Auxiliary Building. No seal exists through the gap due to wave run- action at this gap. This gap provides a up. Temporary dewatering pumps program direct path for floodwater to provided for external flood infiltrate into the Radwaste protection would be able to Building and Auxiliary Building accommodate any intermittent which are credited flood protection water intrusion due to wave run-barrier walls. up. To address the deficiency, the gap will be sealed in the short-term.

Open conduits pass beneath the Incorporated The conduits are cable-filled and Being tracked flood barrier from the discharge Passive some are partially sealed or under canal to the Unit 3 and Unit 4 covered by a steel box which corrective condenser pits. The elevation of would limit any water intrusion, action these conduits is low enough such It is expected that the amount of program that under design basis flood water that would enter into the conditions, these conduits would condenser pits would not be of be completely submerged sufficient quantity to overcome providing a direct flood path into the volume of the condenser pits the condensate pits which are part and temporary dewatering pumps of the flood protected area so as to adversely impact any boundary. safety related equipment.

Some drain locations were Temporary There are only two mislabeled Being tracked incorrectly marked on the drawing Passive drain locations on the under in the drain plug installation implementation drawing. The corrective procedure. Some discrepancies drains were on the drawing, just action were found between the drawing not shown in the correct location, program and list of drain plugs in the However, the table describing installation procedure. As such, the each drain plug location correctly procedure could not be indicates the area in which the implemented as written, drains are located. It is expected that this would have been identified during the installation process and a resolution provided to plug the drains. The drawing is being revised to show the correct locations.

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NTTF Recommendation 2.3 (Walkdowns): Flooding Florida Power & Light Company - Turkey Point Units 3 & 4 November 15, 2012 FPL061-PR-001, Revision 0 No quantity of fuel oil is specified Temporary The dewatering pumps are Being tracked for the dewatering pumps to be Active provided to remove rain water under operable for the duration of the friom the flood protection area corrective PMH. when the drain plugs are installed. action These pumps are designed for a program 100 year storm with a runoff that would be less than 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> in duration. Each of the pumps has been properly sized for the design flow rates and is powered by generators with enough fuel to last the duration of the predicted runoff associated with the 100 year storm.

The deficiencies identified in the table above have been evaluated to ensure that there are no operability or functionality concerns. These issues will be brought into full compliance in a timely fashion in accordance with the guidance provided in Regulatory Information Summary 2005-20.

Inaccessible areas are areas of the plant that cannot reasonably be inspected due to significant personnel safety hazard, very high radiation areas, major equipment disassembly, or no reasonable means of access.

Below is summary of the inaccessible areas at Turkey Point:

Inaccessible Feature Description Basis for Acceptance The spent resin storage tank at the 2'-0" elevation The only available method for inspection of the of the Auxiliary Building was partially inaccessible room housing the resin tank is by inserting a for inspection. camera on a pole into the room through an approximate 6" diameter hole. Using this method, the southeast corner of the room was inspected and no signs of water intrusion were apparent. The spent resin storage tank is located at the lowest level of the Auxiliary Building, and as such, groundwater intrusion is the only concern. The current absence of water provides reasonable assurance that the below grade walls are in good condition and will prevent water ingress during a design basis flooding event. Additionally, no safety related equipment is located in this room.

The floor and bottom 4 feet of the walls of the The Waste Hold-up Tank room is located at the Waste Hold-up Tank room at the 2'-0" elevation of lowest level of the Auxiliary Building, and as such, the Auxiliary Building could not be inspected due groundwater intrusion is the only concern. There to being covered by a protective coating. were no signs of water intrusion beneath the coating. No bubbling of the coating was observed.

The absence of water provides reasonable assurance that the below grade walls are in good condition and will prevent water ingress during a design basis flooding event. Additionally, no safety related equipment is located in this room.

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NTTF Recommendation 2.3 (Walkdowns): Flooding Florida Power & Light Company - Turkey Point Units 3 & 4 November 15, 2012 FPL061-PR-001, Revision 0 The sump pit in the Unit 4 electrical penetration The portions of the area that could be observed room (Fire Zone 027) could not be closely appeared to be dry. There were no other signs of inspected due to obstructions by conduits and cable water ingress on the walls. The absence of water in trays. Similarly, some of the south wall could not this room provides reasonable assurance that the be inspected, below grade walls are in good condition and will prevent water ingress during a design basis flooding event.

The sump pits at the Radwaste Building pipe chase, These areas are designed for water in the vicinity to Unit 3 condenser pit, Unit 4 condenser pit, and Fire accumulate in the sump pits. The material Zone 005 could not be inspected due to the pits condition of the walls and floors surrounding the being filled with water. sump pits is acceptable and able to perform their flood protection function. It is expected that the walls of the sump pits are in similar condition and also able to perform their flood protection function.

Additionally, if the wall condition were not acceptable, the leak paths due to groundwater would have manifested and overcome the capacity of the pits. Therefore, an inspection is not required.

The walls surrounding and floors beneath the Unit The material condition of the walls and floors of 3 and Unit 4 condensers could not be inspected, the surrounding areas of the condenser pit are Inspection of these walls and floors would require acceptable and therefore are expected to be able to major equipment (condensers) disassembly. perform their flood protection function. It is expected that the walls and floor surrounding the condensers are in similar condition and also able to perform their flood protection function.

Areas that are normally not accessible for direct visual inspection are classified as "Restricted Access".

The Unit 3 and Unit 4 Containment buildings were not able to be entered for inspection of the below grade walls. As discussed in section 4.d, external inspection of the containment structures was performed and no flooding related findings were observed. Additionally, Internal Leak Rate Tests are periodically performed on both containment structures to demonstrate that they are air tight and therefore water tight.

It is reasonable to expect that the containment structures can perform their credited flood protection functions.

g. Requested Information Item 2(g) - Cliff-Edge Effects and Available Physical Margin Document any cliff-edge effects identified and the associated basis. Indicate those that were entered into the corrective action program. Also include a detailed description of the actions taken or planned to address these effects.

In accordance with NEI 12-07 Section 7 and Appendix B, Available Physical Margins have been collected and documented in the Walkdown Record form. The guidance provided in FAQ-006 [Ref. 5, ] was also followed. This information will be used in the flood hazard reevaluations performed in response to Item 2.1: Flooding in the 50.54(f) letter [Ref. 2]. There were no cliff-edge effects identified to this point. Any cliff-edge effects identified as part of the flooding hazard reevaluations will be reported separately.

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NTTF Recommendation 2.3 (Walkdowns): Flooding Florida Power & Light Company - Turkey Point Units 3 & 4 November 15, 2012 FPL061-PR-001, Revision 0

h. Requested Information Item 2(h) - Planned/Newly-Installed Flood Protection Enhancements Describe any other planned or newly installed flood protection systems or flood mitigation measures including flood barriers that further enhance the flood protection. Identify results and any subsequent actions taken in response to the peer review.

The main plant external flood protection drawing currently shows the Unit 3 and 4 Cask Handling Facility walls as credited flood barriers. Stoplogs have been provided at the door openings of these areas as an additional flood protection measure.

During the walkdowns it was observed that the design drawings associated with the Unit 4 Emergency Diesel Generator Building installation called for conduit seals in the last manhole prior to passing beneath the Unit 4 Emergency Diesel Generator Building flood barrier and the main plant flood barrier. Manholes meeting this criteria not associated with the Unit 4 Emergency Diesel Generator Building installation do not have conduit seals installed. This condition is consistent with the design drawings, but constitutes an open pathway beneath the flood barrier if leakage into the manholes from openings in the covers or other breaches were to exist. Additional sealing of manholes located outside of the flood protection perimeter are being pursued to gain additional defense-in-depth for this feature. There are no other planned flood protection enhancements or flood mitigation measures at the Turkey Point plant.

There were no changes to the walkdown process or methodology as described in Section 7. No changes were made to the form used in Appendix B of NEI 12-07.

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NTTF Recommendation 2.3 (Walkdowns): Flooding Florida Power & Light Company - Turkey Point Units 3 & 4 November 15, 2012 FPL061 -PR..0O, Revision 0

5. CONCLUSIONS Walkdowns were performed in accordance with NEI 12-07 (Rev. 0-A), "Guidelines for Performing Verification of Plant Flood Protection Features", dated May, 2012 [Ref. I]. This document was endorsed by the NRC on May 31, 2012. Turkey Point Units 3 & 4 configuration and procedures were compared to the flood protection features credited in the current licensing basis documents [Ref. 7] for external flooding events. Site-specific features credited for protection and mitigation against external flooding events were identified and evaluated. The results of the inspections are summarized below.

Reasonable Simulations The capability to execute credited flood protection procedures within the available time was verified using the reasonable simulation process. Staffing levels were verified to be adequate and the flood protection procedure could be implemented as written for performance of these activities prior to storm arrival.

Inspection Deficiencies The flooding walkdowns verified that permanent structures, systems, components (SSCs), portable flood mitigation equipment, and the procedures needed to install and or operate them during a flood are acceptable and capable of performing their design function as credited in the current licensing basis with these exceptions:

" A number of manholes associated with the Unit 4 Emergency Diesel Generator Building installation call for the conduits in the ductbanks that cross beneath the Unit 4 Emergency Diesel Generator Building flood barrier and the main plant flood barrier to be internally sealed as required by the design document. Inspection of these manholes found that some of the conduit seals were missing.

  • Electrical manholes were found with approximate one inch diameter holes in the cover. The conduits inside the manholes pass beneath the flood barrier, providing a pathway for water that would enter the manhole to potentially infiltrate inside the flood protected area.
  • Some of the drain plugs used to prevent backflow from the drainage system during a PMH were found to be degraded.

" Degraded flood barrier walls (e.g., cracks, small unsealed penetrations, corrosion, holes) were found.

" Stoplog SL-2 was found to be 24" in height instead of the required 48".

  • The quantity of fuel oil required for temporary dewatering pumps to be operable for the duration of the PMH is not specified.

Corrective Actions The following corrective actions were taken in response to the above identified deficiencies:

o The conduits in the manholes will be sealed as described in the design documents.

o Efforts are being undertaken to seal the entire manhole system.

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NTTF Recommendation 2.3 (Walkdowns): Flooding Florida Power & Light Company - Turkey Point Units 3 & 4 November 15, 2012 FPL061-PR-001, Revision 0

" Drain plugs will be replaced and a periodic inspection to assess the material condition of the storm drain system plugs will be created.

  • Degraded portions of the flood barrier and underground structures will be repaired.

" To be consistent with the UFSAR, Stoplog SL-2 will be modified to a height of 48".

" An exact quantity of fuel will be determined to ensure that the dewatering pumps can function for the duration of the PMH. Procedure revision may be required depending on the quantity determined.

Newly installed and planned flood protection enhancements

  • Currently the Unit 3 and 4 Cask Handling Facility walls are credited flood barriers. Newly installed stoplogs have been provided at the door openings as additional flood protection in these areas.
  • Additional sealing of manholes located outside of the flood protection perimeter are being pursued. There are no other planned flood protection enhancements or flood mitigation measures at the Turkey Point plant.

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NTTF Recommendation 2.3 (Walkdowns): Flooding Florida Power & Light Company - Turkey Point Units 3 & 4 November 15, 2012 FPL061-PR-001, Revision 0

6. REFERENCES
1. Nuclear Energy Institute (NEI), Report 12-07 [Rev 0-A]. Guidelinesfor Performing Verification Walkdowns of Plant Flood Protection Features. May 2012 [NRC endorsed May 31, 2012; updated and re-issued June 18, 2012].
2. U.S. Nuclear Regulatory Commission. Letter to Licensees. Requestfor Information Pursuant to Title 10 of the Code of FederalRegulations 50.54()g Regarding Recommendations 2.1, 2.3, and 9.3 of the Near Term Task Force Review of Insights from the Fukushima Dai-ichi Accident.

March 12, 2012.

3. U.S. Nuclear Regulatory Commission. Recommendations for Enhancing Reactor Safety in the 21st Century, The Near Term Task Force Review of Insights from the Fukushima Dai-ichi Accident. July 12, 2011.
4. U.S. Nuclear Regulatory Commission. OperabilityDeterminations & FunctionalityAssessments for Resolution of Degraded or Nonconforming Conditions Adverse to Quality or Safety. NRC Inspection Manual. Part 9900: Technical Guidance. Regulatory Issues Summary 2005-20, Revisions 1. September 26, 2005.
5. FAQ-006, Inquiry Form-NRC Submittal, Revision 3, Applicable Features for Quantifying APM, September 13, 2012.
6. FAQ-007, Inquiry Form-NRC Submittal, Revision 0, Inspection of Exterior Walls, August 1, 2012.
7. Turkey Point Units 3 & 4 Updated Final Safety Analysis Report, Rev. 16, Chapter 5, Structures.
8. Turkey Point Units 3 & 4 Updated Final Safety Analysis Report, Rev. 16, Chapter 2, Site and Environment.
9. Supplement No. 13 to application for licenses of the Turkey Point PSAR, December 11, 1967, Turkey Point Units 3 and 4 Hurricane Flood Protection Criteria Additional Information.

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NTTF Recommendation 2.3 (Walkdowns): Flooding Florida Power & Light Company - Turkey Point Units 3 & 4 November 15, 2012 FPL061-PR-001, Revision 0 Attachment 1. FAQ-006 - Applicable Features for Quantifying APM A. TOPIC: Applicable Features for Quantifying APM Source document: NEI 12-07 Section:3.13 & 5.8 B. DESCRIPTION:

Sections 3.13 and 5.8 provide a definition, description, and examples for Available Physical Margin (APM). In Section 3.13, APM is defined as "the difference between licensing basis flood height and the flood height at which water could affect an SSC important to safety". This inquiry is intended to clarify the latter part of this definition, considering that that some features will not have a clearly defined exceedance height.

D. RESOLUTION: (Include additional pages if necessary. Total pages: 2 Inquiry number: 006 Priority:H Sections 3.13 and 5.8 provide a definition, description, and examples for Available Physical Margin (APM). In Section 3.13, APM is defined as "the difference between licensing basis flood height and the flood height at which water could affect an SSC important to safety". The latter (underlined) part of the definition can be interpreted as the height at which the flood protection capability of a feature is exceeded. For some features, the exceedance height can be clearly defined (e.g. flood walls, levees, dikes, cofferdams, flood gates, the elevation of unsealed penetrations or other openings, etc.). For other features (e.g. seal, plug, or water-tight door pressure ratings, pump flow rates, etc.), the exceedance height cannot be clearly defined without performing an engineering analysis that is beyond the scope of the flooding walkdowns. As a result, it is appropriate to record APM as a simple measurement of height difference, however additional considerations apply.

There is a concern that recording a large APM on the Walkdown Record Form could be misleading if the APM is interpreted as margin that is available for additional flood protection without further evaluation.

For example, for a flood protection wall that is 10-ft high and the CLB water height is 9.5-ft., it is reasonable to state that the APM is 6-inches for the wall. However, if the previous wall is now 20-ft high and CLB water height is still 9.5-ft, it cannot be stated that the wall's APM is 10.5-ft based on engineering judgment alone. In order to verify a large APM that is not already defined in the existing design documents, an analysis would have to be performed to evaluate the effect of the additional flood height on wall loads and pressure retention capability for any associated penetration seals. As a result, the manner in which an APM should be recorded on the Walkdown Record form depends upon whether the APM is considered large (an interpretation of what constitutes a "large" APM is at the discretion of the utility).

The following guidance applies.

For walkdowns that have not yet been performed and/or documented:

Recording APMs on the Walkdown Record Sheet as a difference in height is a reasonable statement of the available margin based on engineering judgment unless the APM is large. For Page 21 of 23

NTTF Recommendation 2.3 (Walkdowns): Flooding Florida Power & Light Company - Turkey Point Units 3 & 4 November 15, 2012 FPL061-PR-00 l, Revision 0 large APMs , three options are available: (1) record a smaller, but defensible, APM value based on engineering judgment with a corresponding note in the "comments" section; (2) record no value for the APM with a corresponding note in the "comments" section that an engineering analysis is necessary to determine the maximum APM the wall can withstand before a functional failure; or (3) reference the existing FSAR section or design document that supports the APM.

Note that this notation should be made in the response to Q1l, Q23, or Q27 of the Walkdown Record Form, as applicable.

For walkdowns that have been completed:

Recognizing that it is not resource effective to revise completed paperwork, it is not necessary to change the way the APM was recorded in completed portions of the Walkdown Record Form.

In these cases, APMs that have been recorded as simple measurements of height differences are acceptable as long as the APM determination process did not result in overlooking some potential small margins, as defined by the site per Section 5.8 of NEI 12-07.

For Walkdown Reports:

Indicate in the walkdown report if any APM information was recorded before the large APM approach described in this FAQ was developed.

Notes:

1. Typically, the CLB for the site will indicate what the probable maximum flood level is and the level to which the SSC important to safety is protected. If the recorded APM exceeds the difference between these two values and the margin is to be credited for additional flood protection, the margin must be justified by one of the following methods:
a. Documented application of reasonable and independently verified engineering judgment
b. Performance of new engineering analysis
c. Reference to an existing document or analysis that supports the higher protection level Revision: 4 Date: 9/13/12 E. NRC Review:

Not Necessary Necessary X Explanation:

F. Industry Approval:

Documentation Method: Sept 13, 2012 meeting Date:

G. NRC Acceptance:

Interpretation X Agency Position Documentation Method: Sept 13, 2012 meeting Date:

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NTTF Recommendation 2.3 (Walkdowns): Flooding Florida Power & Light Company - Turkey Point Units 3 & 4 November 15, 2012 FPL061-PR-001, Revision 0 Attachment 2. FAQ-007 - Inspection of Exterior Walls A. TOPIC: Inspection of exterior walls Source document: NEI 12-07 Section:5.5.2 B. DESCRIPTION:

We have a wet site where the SSCs are licensed to flood and the core is protected using mitigating actions. Some of the buildings have safety-related equipment below grade and below groundwater levels. The building's concrete walls keep groundwater from entering the structure but there is no mention of the walls being credited flood or groundwater protection features in the CLB. If the walls and any associated penetration seals are not credited in the CLB as providing protection (against surface water or groundwater flooding), do they need to be included in the walkdown scope?

On the other hand, if the walls and associated seals are performing a flood protection function, specifically for groundwater ingress, even though the CLB for flooding is silent on it, should a visual observation of the walls be performed?

C. Initiator:

Name: J Bellini Phone: (610) 877-6022 Date: 7/31/12 E-Mail: ioe.bellini@amec.com D. RESOLUTION: (Include additional pages if necessary. Total pages: 1 Inquiry number: 007 Priority:H Any exterior wall (above or below grade) protecting space credited as dry in the CLB from groundwater or surface water flooding should be included in the walkdown scope, even if the exterior walls are not explicitly mentioned in the CLB. The inspection of the walls should also note degrading or nonconforming conditions for associated penetrations, seals, etc., although the penetrations/seals themselves do not need to be listed as separate features, with separate walkdown record forms, unless individually credited in the CLB. The inspection applies to portions of the walls below design basis flood and/or groundwater levels.

Note that Available Physical Margin should be obtained to the lowest unsealed, unqualified and or inspected sealed penetration above the design basis water level.

Revision: 0 Date: 8/1/2012 E. NRC Review:

Not Necessary X Necessary_

Explanation:

F. Industry Approval:

Documentation Method: Date:

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