ML17354B169
| ML17354B169 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 11/04/1998 |
| From: | Jabbour K NRC (Affiliation Not Assigned) |
| To: | Plunkett T FLORIDA POWER & LIGHT CO. |
| Shared Package | |
| ML17354B171 | List: |
| References | |
| REF-GTECI-A-46, REF-GTECI-SC, TASK-A-46, TASK-OR GL-88-20, TAC-M83687, TAC-M83688, NUDOCS 9811100097 | |
| Download: ML17354B169 (32) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 2055&0001 tbveib.r 4, 1998
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Mr. T. F. Plunkett President - Nuclear Division, Florida Power and Light Company P.O. Box 14000 Juno Beach, Florida 33408-0420
SUBJECT:
GENERIC LETTER 88-20, SUPPLEMENT 4, "INDIVIDUALPLANT EXAMINATIONFOR EXTERNALEVENTS FOR SEVERE ACCIDENT VULNERABILITIES"- TURKEYPOINT NUCLEAR PLANT, UNITS 3 AND4 (TAC NOS. M83687 AND M83688)
On June 28, 1991, the U.S. Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 88-20, Supplement 4, requesting all licensees to perform individual plant examinations of external events (IPEEE) to identify plant-specific vulnerabilities to severe accidents and to report the results to the NRC together with any licensee-determined improvements and corrective actions.
In a letter dated June 25, 1991, Florida Power and Light Company (FPL) submitted its individual plant examination (IPE) to the NRC. The IPE contained the IPEEE fire and hurricane analyses.
On April 30, 1993, FPL submitted a seismic analysis to resolve unresolved safety issue (USI) A-46. This analysis was also used to address the seismic aspects of IPEEE.
In a letter dated June 24, 1994, FPL submitted the rest of its IPEEE to the NRC.
The staff contracted with Energy Research, lnc., to conduct a completeness and reasonableness (step 1) review of your IPEEE submittal and its associated documentation.
On the basis of the review performed by the contractor and reviewed by an IPEEE senior review board (SRB), the staff concluded that the aspects of seismic; fires; and high winds, floods, transportation and other external events were adequately addressed.
The SRB is comprised of the NRC's Offices of Nuclear Regulatory Research (RES) and Nuclear Reactor Regulation staff, and RES consultants (Sandia National Laboratories) with probabilistic risk assessment expertise for external events.
Details of the staffs and contractor's findings are presented in the Technical Evaluation Report attached to the Staff Evaluation (SE) (enclosed).
FPL conducted a seismic walkdown in order to evaluate component anchorage capability and potential spatial interactions.
FPL has used the Electric Power Research Institute (EPRI)'s fire-induced vulnerability evaluation methodology and performed an extensive walkdown of the plant.
FPL estimated that the contributions to core damage frequency (CDF) from other external events (e.g., external floods and high winds) are insignificant at the Turkey Point site.
FPL estimated that the CDF due to internal events is about 1.0x10~/ry, including internal flooding.
FPL developed the following criteria for vulnerability identification and treatment:
(1) ifthe probabilistic risk assessment (PRA) development effort identifies plant features outside the current design/operating basis, the identification of such features would be reported (in accordance with 10 CFR 50.72 and 50.73) and FPL would immediately commence efforts to take corrective action, or (2) ifthe PRA development effort identified a plant feature that contributed to a significant fraction of the CDF, strategies to correct the feature would be identified and reported
'along with FPL's schedule for completion.
FPL did not identify any potential severe accident vulnerabilities related to seismic, fire, or other external events.
However, a number of plant-specific improvements were implemented at Turkey Point.
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Mr. T. F. Plunkett On the basis of the reasonableness review, the staff concludes that FPL's IPEEE process is capable of identifying the most likely severe accidents and severe accident vulnerabilities and, therefore, the Turkey Point IPEEE has met the intent of Supplement 4 to Generic Letter 88-20.
As a part of the IPEEE, USI A-45, "Shutdown Decay Heat Removal Requirements," and generic safety issue (GSI)-57, "Effects of Fire Protection System Actuation of Safety-Related Equipment,"
GSI-103, "Design for Probable Maximum Precipitation (PMP)," GSI-131, "Potential Seismic Interaction Involving the Movable In-Core Flux Mapping System Used in Westinghouse Plants,"
and the Sandia Fire Risk Scoping Study (FRSS) issues were specifically identified in Supplement 4 to GL 88-20 and its associated guidance in NUREG-1407, as needing to be addressed in the IPEEE. The specific information associated with each issue is identified and discussed in the attached SE.
Based on the staff's and contractors'eviews of the information contained in the submittal, the staff believes that FPL's process is capable of identifying potential vulnerabilities, associated with USI A-45, GSI-103, GSI-131, and three FRSS issues.
On the basis that no vulnerabilities associated with the external events aspects of these issues were, identified at Turkey Point, the staff considers that these safety issues have been satisfactorily resolved for Turkey Point.
However, GSI-57 and two FRSS issues, which are identified in the'attached SE, were not explicitly or completely addressed in the submittal. The need for any additional assessment or actions related to the resolution of GSI-57 and these individual FRSS issues for Turkey Point will be addressed by the NRC staff separately from the IPEEE program.
In addition, FPL's IPEEE submittal contains some specific information that addresses the external event aspects of certain generic safety issues not identified in GL 88-20, Supplement 4, or NUREG-1407. These are GSI-147, "Fire-Induced Alternate Shutdown/Control Room Panel Interactions," GSI-148, "Smoke Control and Manual Fire-Fighting Effectiveness," GSI-156, "Systematic Evaluation Program (SEP)," and GSI-172, "Multiple System Responses Program (MSRP). The specific information associated with each of these issues is identified and discussed in the attached SE.
Based on the staff's and contractors'eviews of the information contained in the submittal, the staff believes that FPL's process is capable of identifying potential vulnerabilities associated with GSI-147, GSI-156, and five MSRP issues.
On the basis that no vulnerabilities, associated with the external events aspects of these issues, were identified at Turkey Point, the staff considers that these safety issues have been satisfactorily resolved.
However, GSI-148 and three MSRP issues, which are identified in the attached SE, were not explicitly or completely addressed in the submittal. The need for any additional assessment or actions related to the resolution of GSI-148 and these individual MSRP issues for Turkey Point will be addressed by the NRC staff separately from the IPEEE program.
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Mr. T. F. Plunkett Ifyou have any questions regarding this matter, please contact me at (301) 415-1496.
Sincerely, Kahtan N. Jabbour, Senior Project Manager Project Directorate II-3 Division of Reactor Projects - I/II Office of Nuclear Reactor Projects Docket Nos. 50-250 and 50-251
Enclosure:
Staff Evaluation Report cc w/encl: See next page
Nov8Bber 4, 1998 Mr. T. F. Plunkett Ifyou have any questions regarding this matter, please contact me at (301) 415-1496.
Sincerely, Original signed by:
Kahtan N. Jabbour, Senior Project Manager Project Directorate II-3 Division of Reactor Projects - I/II Office of Nuclear Reactor Projects Docket Nos. 50-250 and 50-251
Enclosure:
Staff Evaluation Report cc w/encl: See next page DISTRIBUTION:
Q)ocOOe~F'IeU PUBLIC PDII-3 r/f J. Zwolinski (A)
F. Hebdon B. Clayton K. Jabbour OGC ACRS L. Plisco, Rll E. Chow, RES A. Rubin, RES C. Woods, RES D. Coe DOCUMENT NAME: G:ETURKENIPEEE.SE To receive a copy of this docwent, indicate in the box:
"C" = Copy without attachment/enclosure eEa
= Copy with attachment/enclosure "H" ~ Ho co OFFICE PD I I -3/PH PD I I-3/LA PD I I-3/D HAHE KJabbour:cw BCla ton /
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Noveter 4, 1998 Mr. T. F. Plunkett Ifyou have any questions regarding this matter, please contact me at (301) 415-1496.
Sincerely, Original signed by:
Kahtan N. Jabbour, Senior Project Manager Project Directorate II-3 Division of Reactor Projects - I/II Office of Nuclear Reactor Projects Docket Nos. 50-250 and 50-251
Enclosure:
Staff Evaluation Report cc w/encl: See next page DISTRIBUTION:
"Docket File PUBLIC PDII-3 r/f J. Zwolinski (A)
F. Hebdon B. Clayton K. Jabbour OGC ACRS L. Plisco, Rll E. Chow, RES A. Rubin, RES C. Woods, RES D. Coe DOCUMENT NA'ME: G:LTURKENIPEEE.SE To receive a copy of this docunent, indicate in the box:
>>C>> >> Copy without attachment/enclosure
>>E>> >> Copy with attachment/enclosure
>>H>> = Ho co OFFICE.
PDII-3/PH PD I I-3/LA PD I 1-3/D NAME KJabbour:cw J
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FHebdon DATE 11/
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/98 11/ 4 /98 OFFICIAL RECORD COPY
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Mr. T. F. Plunkett Florida Power and Light Company TURKEYPOINT PLANT CC:
M. S. Ross, Attorney Florida Power 8 Light Company P.O. Box 14000 Juno Beach, FL 33408-0420 Mr. Robert J. Hovey, Site Vice President Turkey Point Nuclear Plant Florida Power and Light Company 9760 SW. 344th Street Florida City, FL 33035 County Manager Metropolitan Dade County 111 NW 1 Street, 29th Floor Miami, Florida 33128 Senior Resident Inspector Turkey Point Nuclear Generating Station U.S. Nuclear Regulatory Commission P.O. Box 1448 Homestead, Florida 33090 Mr. WilliamA. Passetti, Chief Department of Health Bureau of Radiation Control 2020 Capital Circle, SE, Bin ¹C21 Tallahassee, Florida 32399-1741 Mr. Joe Myers, Director Division of Emergency Preparedness Department of Community Affairs 2740 Center view Drive Tallahassee, Florida 32399-2100 Regional Administrator, Region II U.S. Nuclear Regulatory Commission 61 Forsyth. Street, SW., Suite 23T85 Atlanta, GA 30303-3415 Attorney General Department of Legal Affairs The Capitol Tallahassee, Florida 32304 Plant Manager
~Turkey Point Nuclear Plant Florida Power and Light Company 9760 SW. 344th Street Florida City, FL 33035 Mr. Gary E. Hollinger Licensing Manager Turkey Point Nuclear Plant 9760 SW. 344th Street Florida City, FL 33035 Mr. Leonard D. Wert U.S. Nuclear Regulatory Commission 61 Forsyth Street, SW., Suite 23T85 Atlanta, GA 30303-3415 Mr. John Gianfrancesco Manager, Administrative Support and Special Projects Florida Power 8 Light Company P. O. Box 14000 Juno Beach, Florida 33408-0420 Mr. Rajiv S. Kundalkar Vice President - Nuclear Engineering Florida Power 8 Light Company P. O. Box 14000 Juno Beach, Florida 33408-0420
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STAFF EVALUATIONREPORT OF INDIVIDUALPLANT EXAMINATIONOF EXTERNALEVENTS (IPEEE) SUBMITTAL ON TURKEYPOINT NUCLEAR POWER STATION UNITS 3 AND 4
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STAFF EVALUATIONREPORT OF INDIVIDUALPLANTEXAMINATIONOF EXTERNALEVENTS (IPEEE) SUBMITTAL ON TURKEYPOINT NUCLEAR POWER STATION UNITS 3 AND4 I.
INTRODUCTION On June 28, 1991, the NRC issued Generic Letter 88-20, Supplement 4 (with NUREG-1407, Procedural and Submittal Guidance) requesting all licensees to perform individual plant examinations of external events (IPEEE) to identify plant-specific vuinerabilities to severe accidents and to report the results to the Commission together with any licensee-determined improvements and corrective actions.
In a letter dated June 25, 1991, the licensee, Florida Power and Light Company (FPL), submitted its individual plant examination (IPE) to the NRC, containing the IPEEE fire and hurricane analyses.
On April30, 1993, the licensee submitted a seismic analysis by Stevenson and Associates to resolve Unsolved Safety Issue (USI) A<6 (Generic Letter (GL) 87-02, "Verification of Seismic Adequacy of Mechanical and Electrical Equipment in Operating Reactors" ). This analysis was also used to address the seismic aspects of the IPEEE.
In a letter dated June 24, 1994, the licensee submitted the rest of its IPEEE to the NRC.
The staff contracted with Energy Research, Inc. (ERI) to conduct a Step 1 review of the licensee's IPEEE submittal and its associated documentation in March 1995 and sent a request for additional information (RAI) to the licensee in October 1995. The licensee responded to the RAI in December 1995.
Based on the results of the review, the staff concluded that the aspects of seismic; fires; and high winds, floods, transportation and other external events were adequately addressed.
Staff and contractor review findings are summarized in the evaluation section below. Details of the contractor's findings are presented in the technical evaluation report attached to this staff evaluation report.
tn accordance with Supplement 4 to GL 88-20, the licensee has provided information on Fire Risk Scoping Study (FRSS) issues, generic safety issue (GSI)-57, "Effects of Fire Protection System Actuation of Safety-Related Equipment," GSI-131, "Potential Seismic Interaction Involving the Movable In-Core Flux Mapping System Used In Westinghouse Plants," GSI-103, "Design for Probable Maximum Precipitation (PMP)," and Unresolved Safety Issue (USI) AA5, "Shutdown Decay Heat Removal Requirements" which were explicitly requested in Supplement 4 to GL 88-20 and its associated guidance in NUREG-1407. The licensee did not propose to resolve any additional USIs or GSls as part of the Turkey Point IPEEE.
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EVALUATION h
The Turkey Point Nuclear Plant is a two-unit, Westinghouse 3-loop pressurized-water reactor (PWR) located about 25 miles south of Miami, Florida. The plant was designed to a seismic acceleration level of 0.15g PGA (peak ground acceleration) anchored to a Housner spectral shape.
With respect to the seismic IPEEE, Turkey Point is assigned to the reduced-scope seismic review category in NUREG-1407.
However, the licensee used a site-specific seismic program associated with USI AA6 (GL 87-02, "Verification of Seismic Adequacy of Mechanical and Electrical Equipment in Operating Reactors" ) to address the seismic aspects of the IPEEE.
For fire events, the licensee has used the Electric Power Research Institute's (EPRI) fire-induced vulnerability evaluation (FIVE) methodology and performed an extensive walkdown of the plant. For the analyses of other external events, the licensee used the progressive screening procedure as described in NUREG-1407.
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Core Dama e Fre uenc CDF Estimate The licensee did not provide a CDF estimate related to seismic events.
Instead, the licensee used a walkdown that focused on component anchorage capability and the potential for adverse seismic-induced spatial interactions.
Regarding the fire analysis, the licensee estimated that the CDF for control room fires is about 1.9x10~/reactor-year (RY), and there are several fire zones resulting in CDFs above 10~/RY. The licensee also estimated that the contributions to CDF from high wind, flood, and other external events (HFO) are insignificant at Turkey Point. The CDF due to internal events is about 1.0x10~/RY, including internal flooding.'ominant Contributors Based on the plant-specific seismic adequacy evaluation forTurkey Point, the licensee identified 35 components as seismic outliers which were mostly related to anchorage/support concerns.
The licensee has proposed or implemented relevant plant improvements or resolution procedures to address the identified outliers.
In addition, the seismic review team documented some cases of poor seismic "housekeeping" during seismic walkdowns. Afteran NRC site audit conducted on the USI A-46 review process, the licensee has agreed to address additional issues related to: an anchorage concern, corrosion concerns requiring maintenance, a concern with interaction of station batteries, and the need for a strict housekeeping program.
The licensee's submittal reports the results of high confidence of low probability of failure (HCLPF) calculations that were performed for a number of large storage tanks.
Even after implementation of safety upgrades, the reported HCLPF capacities for the condensate storage tanks (CSTs) and refueling water storage tanks (RWSTs) were found to fall below the level of the design basis earthquake (DBE) for Turkey Point. Subsequently, the licensee re-evaluated the capacities of CSTs and RWSTs, and reported that they. meet the seismic design basis of 0.15g PGA.
The staff notes that there are several minor weaknesses in the licensee's seismic submittal.
Under the purview of the USI A<6 program, the licensee only examined shutdown equipment during earthquakes; however, the IPEEE program also includes an examination of piping and structures in addition to the shutdown equipment.
The licensee only selected one success path, namely, the loss of offsite power scenario, whereas NUREG-1407 recommends two success paths (one pertaining to a small break loss of coolant accident (LOCA))for a reduced-scope plant. The staff believes that the impact of these weaknesses appears to be minimal because the seismic risk at Turkey Point is perceived to be low.
An extensive walkdown of the plant was conducted using EPRI's fire-induced vulnerability evaluation (FIVE) methodology to support the analysis.
Based on the screening results, the licensee identified six fire risk-significant areas, which include the control room, cable spreading room, the intake cooling water structures, and control rod equipment rooms. This screening was based on either: (a) a lack of safe shutdown equipment in a given area; or (b) an estimated fire-induced CDF of fess than 10~/RY for a given area.
The licensee noted that the two most fire-risk significant areas are the control room and the cable spreading room. The licensee identified the following operator recovery actions for the unscreened fire areas, for example, operate valve hand-.wheels in case of a fire in the reactor control rod equipment room, or cross-tie the component cooling water (CCW) system, or connect a hose to the service water system for the charging pump oil cooler in order to establish reactor coolant pump (RCP) seal integrity in case of loss of intake cooling water (ICW).
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With respect to the HFO events, the licensee identified that the dominant HFO contributor to risk was a storm surge overtopping the plant flood walls. As a result, the licensee enhanced the "Natural Emergencies" Emergency Plant Implementation Procedure (EPIP) No. 20106 and used itfor preparing and mitigating the effects of Hurricane Andrew. Regarding the effects of intense rainfall on roof loads, the submittal notes that the control building can withstand water accumulation up to 6 inches; above the level of 6 inches water spills over the sides of the roof.
Increases in rainfall intensity would only result in a more rapid accumulation ofwater on the roof. The submittal also mentions that the roofs of other buildings at the plant would not accumulate water.
Containment Performance The licensee has not conducted an IPEEE containment performance seismic walkdown for Turkey Point. Since Turkey Point is a reduced-scope plant, and its containment is designed for the safe shutdown earthquake (SSE), it is unlikely that a seismic event would have a significant impact on the containment performance at Turkey Point. The staff concludes that not conducting a seismic waikdown is a weakness in the licensee's IPEEE; however, the staff does not believe that the licensee missed any significant containment seismic vulnerabilities at Turkey Point.
With respect to assessing the impact of fires on containment performance, the licensee identified four fire zones which might impact containment performance.
However, these fire zones were screened out in'the application of Phase II of the FIVE methodology which is acceptable to the staff.
Generic Safet Issues As a part of the IPEEE, a set of generic and unresolved safety issues (USI A45, GSI-57, GSI-103, GSI-131, and the Sandia Fire Risk Scoping Study (FRSS) issues) were speciflicaliy identified in Supplement 4 to GL 88-20 and its associated guidance in NUREG-1407 as needing to be addressed in the IPEEE. The staffs evaluation ofthese issues is provided below.
1.
USI A<5, "Shutdown Decay Heat Removal (DHR) Requirements" The licensee selected a success path needed to accomplish one method of decay heat removal following a fire or a seismic event. The staff finds that the licensee's USI A45 evaluation is consistent with the guidance provided in Section 6.3.3.1 of NUREG-1407, and therefore the staff considers this issue resolved.
2.
GSI-57, "Effects of Fire Protection System Actuation on Safety-Related Equipment" The licensee noted that for fire protection systems protecting safety-related equipment, seismic considerations and requirements were addressed in the plant change/modification packages associated with fire suppression system installation. Essentially, the II/I criteria (namely, falling objects due to failure of Class II (non-safety) systems in a seismic event impacting the Class I (safety) systems) were applied to fire protection systems whose failure could affect the operation of safety-related systems.
However, the staff finds a weakness in the licensee's GSI-57 evaluation.
The staff notes that the effects of seismic-induced actuation of fire protection system on safety-related equipment were not addressed.
It is not clear whether the licensee has conducted a seismic/fire walkdown to
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assess such effects.
Because of the apparent weakness in the submittal, the staff can not conclude that GSI-57 is fullyresolved.
3.
GSI-103, "Design for Probable Maximum Precipitation" The licensee has assessed GSI-103 and concluded that the new Probable Maximum Precipitation (PMP) criteria willnot have any impact on Turkey Point. The staff finds that the licensee's GSI-103 evaluation is consistent with the guidance provided in Section 6.2.2.3 of NUREG-1407, and therefore the staff considers this issue resolved.
4.
GSI-131, "Potential Seismic Interaction Involving the Movable In-Core Flux Mapping System Used in Westinghouse Plants" The licensee stated that lateral restraint was added to the movable support assembly of the flux mapping system in 1989 in order to prevent any loss of reactor coolant boundary due to a design-basis earthquake (DBE) at Turkey Point. The staff finds that the licensee's Gl-131 evaluation and improvement are consistent with the guidance provided in Section 6.2.2.1 of NUREG-1407, and therefore the staff considers this issue resolved.
5.
Fire Risk Scoping Study Issues The licensee's IPEEE submittal and other associated documentation were reviewed for information directly addressing the following external events-related FRSS issues: fire-induced alternate shutdown/control room panel interaction (Section 3.7.4 Item 6 of IPE);
seismic-fire interactions (Section 3.7;4 Item 2 of IPE); and adequacy of fire barriers (Section 3.7.4 Item 3 of IPE) ~
Based on the results of the IPEEE submittal review, the staff considers that the licensee's process is capable of identifying potential vulnerabilities associated with these FRSS issues.
However, the staff identified weaknesses in the licensee's submittal regarding the following two FRSS issues:.
(i)
Regarding the effects of fire protection system actuation on safety-related equipment, the licensee did not provide any discussion of potential adverse effects on plant equipment by spurious suppression system actuation.
This issue is clo'sely related to GSI-57 discussed above.
(ii)
Regarding the issue of smoke control and manual fire-fighting effectiveness, the staff noted that manual fire fighting was not credited in the analysis.
Therefore, manual fire-fighting effectiveness is not addressed in the submittal. This issue is the same as GSI-148 discussed below.
Because of these apparent weaknesses, the staff can not conclude that the above two FRSS issues were fullyresolved.
In addition to those safety issues discussed above that were explicitly requested in Supplement 4 to GL 88-20, four generic safety issues were not specifically identified as issues to be resolved under the IPEEE program; thus, they were not explicitly discussed in Supplement 4 to GL 88-20 and NUREG-1407.
However, subsequent to the issuance of the generic letter, the NRC evaluated the scope and the specifi information requested in the generic letter and the associated IPEEE guidance, and concluded that the plant-specific analyses being requested in the IPEEE program could also be used, through a satisfactory IPEEE submittal review, to
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resolve the external event aspects of these four safety issues.
The following discussions summarize the staff's evaluation of these safety issues at Turkey Point.
GSI-147, "Fire-Induced A'Itemate Shutdown/Control Room Panel Interactions" The licensee's response to the staffs RAI contains information addressing this issue. The licensee has considered the occurrence of LOCAs, toss of offsite power, RCP seal failure, inadvertent opening of a power operated relief valve (PORV), and failure ofthe ICW and CCW systems, from a fire-induced event. The licensee noted that the circuits for the alternate shutdown panel are isolated from the circuits whose routing passes through or terminates in the control room. Therefore, the staff considers that the licensee's process is capable of identifying potential vulnerabilities associated with this issue.
On the basis that no vulnerability associated with this issue was identified in the IPEEE submittal, the staff considers this issue resolved.
GSI-148, "Smoke Control and Manual Fire-Fighting Effectiveness" The staff noted that manual fire-fighting was not credited in the analysis.
Therefore, manual fire-fighting effectiveness is not addressed in the submittal. The staff considers this issue not resolved.
GSI-156, "Systematic Evaluation Program (SEP)"
The licensee's IPEEE submittal and other associated documentation were reviewed for information directly addressing the following external events-related SEP issues:
settlement of foundations and buried equipment (Section 2.2 of the Stevenson report which was produced by Stevenson Associates for the licensee);
seismic design of structures, systems, and components (Sections 2.5, 3, and 4 of the Stevenson report); site hydrology and ability to withstand floods (Section 3.8 of IPE); industrial hazards (Sections 5.3.4.2 and 5.3.4.3 of IPEEE); tornado missiles (Section 5.1 of IPEEE); severe weather effects on structures (Sections 5.1 and 5.2 of IPEEE and Section 3.8 of IPE); design codes, criteria, and load combinations (Sections 2.5, and 3.1 to 3.5 ofthe Stevenson report, Sections 5.1.5 of IPEEE, and Section 3.8 of IPE); and shutdown systems and
'lectrical instrumentation and control features (Section 3.9 of IPE). Based on the results of the IPEEE submittal review, the staff considers that the licensee's process is capable of identifying potential vulnerabilities associated with this issue.
On the basis that no potential vulnerability associated with this issue was identified in the IPEEE submittal, the staff considered the IPEEE-related aspects of this issue resolved.
In addition, the issue of dam integrity and site flooding is considered resolved because there are no dams near the site.
4.
GSI-172, 'Multiple System Responses Program (MSRP)
The licensee's IPEEE submittal and associated documentation were reviewed for information directly addressing the following external events-related MSRP issues: effects of fire protection system actuation on safety-related equipment (Section 3.7.4 of IPE);
seismically induced spatial and functional interactions (Section 4.7 of the Stevenson report); seismic-fire interactions (Section 3.7.4 of IPE); non-safety-related control system/safety-related system dependencies (Section 4.7 of the Stevenson report); and effects of flooding and/or moisture intrusion on non-safety related and safety-related
equipment (Sections 3.7 and 3.8 of IPE). Based on the fact that no vulnerabilities were identified, the staff considers these MSRP issues resolved.
In addition, the staff considers that the following MSRP issues resolved for the reasons given below:
(i)
In accordance with Table 7.17.2 of NUREG-1407, for reduced-scope plants (i.e.,
sites where the seismic hazard is low), the NRC recommendations for relay chatter review is the same as the Nuclear Management and Resources Council (NUMARC) recommendations, namely, performing an A-46 review, and not performing additional review for IPEEE relays.
Since Turkey Point is a reduced-scope plant and has performed an AC6 review, no additional review of relay chatter is needed for Turkey Point.
(ii)
In accordance with Section 3.2.4.5 of NUREG-1407, reduced-scope plants should use the SSE ground response spectra in their seismic margins methodology.
Therefore, evaluation of an earthquake greater than the SSE did not need to be addressed for Turkey Point, which is a reduced-scope plant.
(iii)
Regarding the effects of hydrogen line ruptures, it appears that the licensee used the FIVE walkdown verification checklist to identify any flammable liquid or gas storage vessels or piping. Even though the effects of hydrogen line ruptures were not explicitly discussed, the licensee evaluated a hydrogen trailer as a potential source.
During our review, the staff was unable to find any specific reference to all or part of the following three MSRP issues:
(i)
Regarding the IPEEE-related aspects of common cause failures associated with human errors, human errors occuring as part of recovery actions during certain fire scenarios were addressed in the submittal; however, the licensee provided a very limited discussion of operator recovery actions following a seismic event.
(ii)
The issue of seismically induced flooding was not addressed in the submittal ~
(iii)
Regarding the issue of seismically induced fire suppression system actuations, the licensee did not discuss its assessment of seismic-induced multiple fire suppression system actuations which may in turn cause failures of redundant trains of safety related systems.
This issue is part of GSI-57 discussed previously in this SER.
Based on the overall results of the staffs IPEEE submittal review, with the possible exception of the three MSRP issues discussed above, the staff considers that the licensee's process is capable of identifying potential vulnerabilities associated with GSI-172. The need for any additional assessment or actions related to the resolution of these three MSRP issues for Turkey Point willbe addressed by the NRC staff separately from the IPEEE program..
. For the MSRP issues that were addressed, on the basis that no potential vulnerabilities associated with these issues were identified in the IPEEE submittal, the staff considers the IPEEE-related aspects of these issues to be resolved.
Plant Safe Features Potential Vulnerabilities and Im rovements The licensee reported the following safety features. at the plant:
1.
Several systems potentially'important to risk are either shared or can be cross-tied.
For example, high head safety injection (HHSI), AFW, heating ventilation and air conditioning
~ (HVAC), and electric power (AC and DC) are shared between the units. Component cooling water and instrument air can be cross-tied.
2.
There are various ways to remove decay heat.
For example, main feedwater, AFW, standby steam generator feedwater pumps, feed and bleed, and condensate pumps can be used for secondary heat removal.
3.
Turkey Point has four safety-related emergency diesel generators (EDGs). A station blackout cross-tie allows a unit's safety-related bus to be fed from an EDG from the opposite unit through the D bus.
One safety-related EDG has the capacity to bring both units to the hot standby condition.
The license developed the following criteria for vulnerability identification and treatment: (1) if the PRA development effort identifies plant features outside the current design/operating basis, the identification of such features would be reported (in accordance with 10 CFR 50.72 and 50.73) and FPL would immediately commence efforts to take corrective action, or (2) ifthe PRA development effort identified a plant feature that contributed to a significant fraction of the CDF, strategies to correct the feature would be identified and reported along with FPL's schedule for completion. The licensee did not identify any potential severe accident vulnerabilities related to seismic, fire, or HFO events.
FPL's seismic adequacy evaluation study has identified 35 outliers (primarily relating to weak anchorage),
and has proposed relevant modifications to enhance safety. The.NRC has already reviewed these outiiers and modifications for Turkey Point as part of the resolution of USI A<6.
In response to the NRC's USI A-46 review, FPL agreed to resolve additional concerns related to: an anchorage problem, a maintenance issue pertaining to corrosion, a seismic interaction potential, and seismic housekeeping procedures.
With respect to HFO events, the licensee developed the following plant improvements:
1.
Modifications were performed to refurbish the existing flood walls and stop logs.
2.
The Unit 3 EDG fuel oil transfer pump elevation was raised to reduce its vulnerability to hurricane surge.
3.
The plant EPIP 20106 ("Natural Emergencies" ) was revised to better prepare operators to weather a storm.
4.
As a result of the damage of Hurricane Andrew to Turkey Point in August 1992, the stacks of Units 1 and 2 (fossil units) have been upgraded to a design wind load of 225 miles per hour (MPH). Other modifications and procedure enhancements were made as a result of lessons learned from Hurricane Andrew.
The licensee did not identify any fire improvements based on the findings of its IPEEE fire analysis.
4
III.
CONCLUSIONS On the basis of the above findings, the staff notes that the IPEEE results are reasonable given the Turkey Point design; operation, and history. The staff concludes that the licensee's IPEEE process is capable of identifying the most likelysevere accidents and severe accident vulnerabilities, and therefore, that the Turkey Point IPEEE ha's met the intent of Supplement 4 to Generic Letter 88-20 and the resolution of specific generic safety issues discussed in this SER.
As indicated in Section II of this SER, there are two issues under the Fire Risk Scoping Study, three issues under the Multiple System Response Program (MSRP/GSI-172), and GSI-148 that the licensee did not appear to address in its submittal.
In addition, GSI-57 is addressed in part, but is not fullyresolved.
The need for any additional assessment or actions related to the resolution of these issues for Turkey Point willbe addressed by the NRC staff separately from the IPEEE program.
It should be noted, that the staff focused its review primarily on the licensee's ability to examine Turkey Point for severe accident vulnerabilities. Although certain aspects of the IPEEE were explored in more detail than others, the review was not intended to validate the accuracy of the licensee's detailed findings (or quantification estimates) that underlie or stemmed from the examination.
Therefore, this SER does not constitute NRC approval or endorsement of any IPEEE material for purposes other than those associated with meeting the intent of Supplement 4 to GL 88-20 and the resolution of specific generic safety issues discussed in this SER.
1 f
Attachment TURKEY POINT NUCLEAR PLANT UNITS 3 AND 4 INDIVIDUALPLANT EXAMINATIONOF EXTERNAL EVENTS (1PEEE}
TECHNICALEVALUATIONREPORj
c.
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