|
---|
Category:SAFETY EVALUATION REPORT--LICENSING & RELATED ISSUES
MONTHYEARML20210D8951999-07-23023 July 1999 Safety Evaluation Accepting First 10-yr Interval Inservice Insp Plan Requests for Relief ISI-018 - ISI-020 ML20195J8951999-06-17017 June 1999 Safety Evaluation Granting Relief for Listed ISI Parts for Current Interval,Per 10CFR50.55a(g)(5)(iii) ML20207E8631999-06-0303 June 1999 Safety Evaluation Accepting Licensee 990114 Submittal of one-time Request for Relief from ASME B&PV Code IST Requirements for Pressure Safety Valves at Plant,Unit 3 ML20205A6331999-03-25025 March 1999 SER Accepting Request to Use Mechanical Nozzle Seal Assemblies as an Alternative Repair Method,Per 10CFR50.55a(a)(3)(i) for Reactor Coolant Sys Applications at Plant,Unit 3 ML20203H8591999-02-17017 February 1999 Safety Evaluation Accepting Licensee Second Ten Year ISI Program & Associated Relief Requests for Plant,Unit 3 ML20199H6261999-01-21021 January 1999 Safety Evaluation Accepting Classification of Instrument Air Tubing & Components for Safety Related Valve Top Works.Staff Recommends That EOI Revise Licensing Basis to Permit Incorporation of Change ML20196F4911998-12-0101 December 1998 SER Accepting Request for Relief ISI2-09 for Waterford Steam Electric Station,Unit 3 & Arkansas Nuclear One,Unit 2 ML20195C4841998-11-0606 November 1998 SER Accepting QA Program Change to Consolidate Four Existing QA Programs for Arkansas Nuclear One,Grand Gulf Nuclear Station,River Bend Station & Waterford 3 Steam Electric Station Into Single QA Program ML20237C5661998-08-17017 August 1998 Safety Evaluation Accepting Licensee Request for Exemption from Section Iii.O of Appendix R to 10CFR50 ML20236S9031998-07-22022 July 1998 SER Accepting Rev 19 to Quality Assurance Program for Waterford Steam Electric Station,Unit 3 ML20217P8281998-04-0707 April 1998 Safety Evaluation Accepting Relief Authorization for Alternative to Requirements of ASME Section Xi,Subarticle IWA-5250 Bolting Exam for Plants,Per 10CFR50.55a(a)(3)(i) ML20203E9371997-12-0909 December 1997 Safety Evaluation Granting Relief Request,Per 10CFR50.55a(g) (I) ML20199H3711997-11-19019 November 1997 SER Accepting Approving Request Relief from Requirements of Section XI, Rule for Inservice Insp of NPP Components, of ASME for Current or New 10-year Inservice Insp Interval IAW 50.55(a)(3)(i) of 10CFR50 ML20216E9921997-09-0404 September 1997 Safety Evaluation Accepting 970623 Request for Relief Re Authorization for Use of ASME Code Case N-416-1 & N-532,ISI Program for Listed Plants ML20141H8411997-07-30030 July 1997 Safety Evaluation Accepting Use of Code Case N-508-1 for All Four Plants for Rotation of Serviced Snubbers & Pressure Relief Valves for Purpose of Testing in Lieu of ASME Code ML20141F3881997-06-30030 June 1997 Safety Evaluation Authorizing Licensee Request for Extension of First ISI Interval to 970924 ML20148H1271997-06-0505 June 1997 Supplemental Safety Evaluation Re Conformance to Reg Guide 1.97,Entergy Operations,Inc,Waterford Steam Electric Station Unit 3 ML20149M4221996-12-12012 December 1996 Safety Evaluation Supporting Update Insvc Insp Programs to 1992 & Portions of 1993 ASME Boiler & Pressure Vessel Code, Sect XI for Licenses DPR-51,NPF-6,NPF-38,NPF-29 & NPF-47. Technical Ltr Rept Encl ML20107F5611996-04-17017 April 1996 Safety Evaluation Providing Guidance on Submitting plant- Specific Info W/Respect to IST Program Alternatives Request ML20058A3661993-11-17017 November 1993 Safety Evaluation Allowing Accumulator Level & Pressure Monitoring Instrumentation to Be Relaxed from Category 2 to Category 3 & Allowing Commercial Grade Instruments to Be Used,In Ref to GL 82-33 & Reg Guide 1.97 ML20059J1721993-11-0808 November 1993 Safety Evaluation Accepting First 10-yr Interval ISI Program Through Rev 5,except Where Relief Denied ML20127D1361993-01-11011 January 1993 Safety Evaluation Re IST Program Request for Relief.Util Proposal Complies W/Requirements of Later Edition of ASME Code.Approval to Use Applicable Portion of Later Edition Acceptable ML20247F2571989-09-0808 September 1989 SER Accepting Licensee Submittal in Compliance W/Atws Rule, 10CFR50.62, Requirements for Reduction of Risk from ATWS Events for Light-Water Cooled Nuclear Power Plants ML20246M6701989-08-29029 August 1989 Safety Evaluation Supporting Amend 56 to License NPF-38 ML20244D9781989-06-13013 June 1989 Supplemental Safety Evaluation Supporting Util Dcrdr Program That Satisfies Requirements of Suppl 1 to NUREG-0737 ML20244C8151989-06-0606 June 1989 Safety Evaluation Supporting Util First Interval Inservice Insp Program ML20244C8121989-06-0606 June 1989 Safety Evaluation Accepting Relief from Performing Inservice Insp Program Re Volumetric Exam on Inside Radius Section of Main Steam & Feedwater Nozzles ML20247J9431989-05-24024 May 1989 SER Accepting Util Response to Generic Ltr 83-28, Reactor Trip Sys Reliability ML20235B6381989-02-0707 February 1989 Safety Evaluation Re Inservice Testing Program & Requests for Relief from ASME Code,Section Xi.Program for Pumps & Valves & Request for Relief Acceptable.Relief Requests May Not Be Implemented W/O Prior NRC Approval ML20154R7301988-09-28028 September 1988 Safety Evaluation Supporting Util 840206 Response to Generic Ltr 83-28,Item 4.5.1, Reactor Trip Sys Reliability (Sys Functional Testing) ML20154N7071988-09-22022 September 1988 Safety Evaluation Accepting Util Responses to Generic Ltr 83-28,Items 3.1.1,3.1.2,3.2.1 & 3.2.2 Re post-maint Test Program for safety-related Components ML20207F3391988-08-0909 August 1988 Safety Evaluation Supporting Proposed Rev to Tech Spec Bases B 3/4.7.6, Control Room Air Conditioning Sys ML20151M5281988-07-21021 July 1988 Safety Evaluation Re Control Sys Single Failure Study ML20155D6231988-05-27027 May 1988 Safety Evaluation Supporting Conditional Approval of Fracture Mechanics Analysis of Reactor Vessel Flaw Indications in Hot Leg Nozzle to Shell Weld for Util ML20154A9631988-05-0505 May 1988 Safety Evaluation Accepting Util 880303 Request for Partial Exemption from 10CFR50,App J, Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors. Util May Continue Type a Testing When Excessive Leakage Identified ML20151B5691988-03-30030 March 1988 SER Accepting Util Proposal Re Item 2.2.1 of Generic Ltr 83-28 Concerning Equipment Classification Programs for All safety-related Components ML20237D7811987-12-21021 December 1987 Safety Evaluation Supporting Util Proposal Re Boraflex Surveillance Program in Spent Fuel Storage Racks ML20236X6491987-12-0101 December 1987 Safety Evaluation Accepting 871006 Request for Reduced Duration Integrated Leak Rate Test at Facility,Based on Methodology in BN-TOP-1,Rev 1, Testing Criteria for Integrated Leak Rate Testing of Primary Containment.. ML20236U1821987-11-24024 November 1987 Safety Evaluation Supporting Util 870724 Evaluation Demonstrating That Adequate Shoulder Gap Will Be Provided in Cycle 3 & Subsequent Cycles ML20236F7651987-10-27027 October 1987 Safety Evaluation Supporting Util 870626 & 0701 Surveillance Program & Results of Confirmatory Analyses Program.Util Satisfactorily Completed Confirmatory Analyses Program Demonstrating Adequacy of Basemat.Bnl Evaluation Rept Encl ML20236C0001987-10-20020 October 1987 Safety Evaluation Re Generic Ltr 83-28,Items 4.1,4.2.1 & 4.2.2 Concerning Preventive Maint Program for Reactor Trip Breakers/Maint & Trending.Licensee Position on Items Acceptable ML20237G7881987-08-20020 August 1987 Safety Evaluation Accepting Util 870731 Proposed Change to Bases Section of Tech Specs,Reflecting Commitment to 1982 Rev of ASTM E 185 Re Reactor Vessel Surveillance Program Required by 10CFR50,App H.Rev to Page B 3/4 4-7 Encl ML20249C8131987-07-21021 July 1987 Safety Evaluation Supporting Amend 20 to License NPF-38 ML20215E9781986-12-10010 December 1986 Safety Evaluation Supporting Addl Delay in Implementing Charcoal Filter Deluge Sys Mods Since Fire Protection Capability Provided ML20215B1881986-12-0808 December 1986 Safety Evaluation Re Util 860902 Submittal of CEN-335(c)-P, Waterford Unit 3,Cycle 2,Shoulder Gap Evaluation Rept, in Response to License Condition 2.c.7.Shoulder Gaps in All Fuel Acceptable Through Cycle 2 ML20211A2311986-05-29029 May 1986 Safety Evaluation Supporting Util 860123 & 0220 Responses to 10CFR50.61 Re Pressurized Thermal Shock Rule.Submittal of Reevaluation of Rt(Pts) & Comparison W/Predicted Value in Future pressure-temp Submittals Required ML20198C5541986-05-15015 May 1986 Safety Evaluation Accepting Util Response to Items 3.1.3 & 3.2.3 of Generic Ltr 83-28 Requiring Licensee Review of Existing Tech Specs for post-maint Testing Requirements That May Degrade Safety.Items Closed ML20197E3651986-05-0606 May 1986 Safety Evaluation Supporting Util Large Break LOCA ECCS Analysis ML20203Q0931986-04-22022 April 1986 Safety Evaluation Supporting Util 850613 & 860311 Responses Re Confirmatory Tests of Auxiliary Pressurizer Spray Sys. Design Satisfies Requirements of BTP Rsb 5-1 W/Single Failure of Charging Loop Isolation Value ML20137Z1641985-12-0202 December 1985 Safety Evaluation Supporting Release of Shift Advisors from Advisory Duties 1999-07-23
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML20217F2891999-10-13013 October 1999 Drill 99-08 Emergency Preparedness Exercise on 991013 ML20217G7211999-09-30030 September 1999 Monthly Operating Repts for Sept 1999 for Waterford 3 Ses. with ML20211Q2141999-08-31031 August 1999 Monthly Operating Rept for Aug 1999 for Waterord 3 Ses.With ML20210Q6361999-07-31031 July 1999 Corrected Monthly Operating Rept for July 1999 for Waterford 3 ML20210S0581999-07-31031 July 1999 Monthly Operating Rept for July 1999 for Waterford 3.With ML20210D8951999-07-23023 July 1999 Safety Evaluation Accepting First 10-yr Interval Inservice Insp Plan Requests for Relief ISI-018 - ISI-020 ML20209H3781999-06-30030 June 1999 Monthly Operating Rept for June 1999 for Waterford 3 Ses. with ML20195J8951999-06-17017 June 1999 Safety Evaluation Granting Relief for Listed ISI Parts for Current Interval,Per 10CFR50.55a(g)(5)(iii) ML20207E8631999-06-0303 June 1999 Safety Evaluation Accepting Licensee 990114 Submittal of one-time Request for Relief from ASME B&PV Code IST Requirements for Pressure Safety Valves at Plant,Unit 3 ML20195K3391999-05-31031 May 1999 Monthly Operating Rept for May 1999 for Waterford 3 Ses.With ML20195C3041999-05-28028 May 1999 Annual Rept on Abb CE ECCS Performance Evaluation Models ML20206S7401999-04-30030 April 1999 Monthly Operating Rept for Apr 1999 for Waterford 3.With ML20205T2621999-04-22022 April 1999 LER 99-S02-00:on 990216,contract Employee Inappropriately Granted Unescorted Access to Plant Protected Area.Caused by Personnel Error.Security Personnel Performed Review of Work & Work Area That Individual Was Involved with ML20205N9671999-03-31031 March 1999 Monthly Operating Rept for Mar 1999 for Waterford 3 Ses.With ML20205E8531999-03-30030 March 1999 Corrected Pages COLR 3/4 1-4 & COLR 3/4 2-6 to Rev 1, Cycle 10, Colr ML20205A6331999-03-25025 March 1999 SER Accepting Request to Use Mechanical Nozzle Seal Assemblies as an Alternative Repair Method,Per 10CFR50.55a(a)(3)(i) for Reactor Coolant Sys Applications at Plant,Unit 3 ML20204H1401999-03-23023 March 1999 Rev 1 to Engineering Rept C-NOME-ER-0120, Design Evaluation of Various Applications at Waterford Unit 3 ML20204H1231999-03-22022 March 1999 Rev 1 to Design Rept C-PENG-DR-006, Addendum to Cenc Rept 1444 Analytical Rept for Waterford Unit 3 Piping ML20204H2451999-03-22022 March 1999 Rev 2 to C-NOME-SP-0067, Design Specification for Mechanical Nozzle Seal Assembly (Mnsa) Waterford Unit 3 ML20204F0791999-03-17017 March 1999 Rev 1 to Waterford 3 COLR for Cycle 10 ML20207M9231999-03-12012 March 1999 Amended Part 21 Rept Re Cooper-Bessemer Ksv EDG Power Piston Failure.Total of 198 or More Pistons Have Been Measured at Seven Different Sites.All Potentially Defective Pistons Have Been Removed from Svc Based on Encl Results ML20207F3491999-03-0505 March 1999 LER 99-S01-00:on 990203,contraband Was Discovered in Plant Protected Area.Bottle Was Determined to Have Been There Since Original Plant Construction.Bottle Was Removed & Security Personnel Performed Search of Area.With ML20204B5141999-02-28028 February 1999 Monthly Operating Rept for Feb 1999 for Waterford 3.With ML20203H8591999-02-17017 February 1999 Safety Evaluation Accepting Licensee Second Ten Year ISI Program & Associated Relief Requests for Plant,Unit 3 ML20199H6261999-01-21021 January 1999 Safety Evaluation Accepting Classification of Instrument Air Tubing & Components for Safety Related Valve Top Works.Staff Recommends That EOI Revise Licensing Basis to Permit Incorporation of Change ML20199C9101998-12-31031 December 1998 Monthly Operating Rept for Dec 1998 for Waterford 3.With ML20196F4911998-12-0101 December 1998 SER Accepting Request for Relief ISI2-09 for Waterford Steam Electric Station,Unit 3 & Arkansas Nuclear One,Unit 2 ML20206N4131998-11-30030 November 1998 Monthly Operating Rept for Nov 1998 for Waterford 3.With ML20195C4841998-11-0606 November 1998 SER Accepting QA Program Change to Consolidate Four Existing QA Programs for Arkansas Nuclear One,Grand Gulf Nuclear Station,River Bend Station & Waterford 3 Steam Electric Station Into Single QA Program ML20195E5161998-10-31031 October 1998 Monthly Operating Rept for Oct 1998 for Waterford 3.With ML20155C1351998-10-26026 October 1998 Rev B to Entergy QA Program Manual ML20154K0801998-09-30030 September 1998 Monthly Operating Rept for Sept 1998 for Waterford 3 Ses. with ML20151W8331998-08-31031 August 1998 Monthly Operating Rept for Aug 1998 for Waterford,Unit 3. with ML20237B6831998-08-17017 August 1998 LER 98-S01-00:on 980723,discovered That Waterford 3 Physical Security Plan,Safeguards Document Was Not Under Positive Control of Authorized Person at All Times.Caused by Human Error/Inappropriate Action.Counseled Employee Involved ML20237C5661998-08-17017 August 1998 Safety Evaluation Accepting Licensee Request for Exemption from Section Iii.O of Appendix R to 10CFR50 ML18066A2771998-08-13013 August 1998 Part 21 Rept Re Deficiency in CE Current Screening Methodology for Determining Limiting Fuel Assembly for Detailed PWR thermal-hydraulic Sa.Evaluations Were Performed for Affected Plants to Determine Effect of Deficiency ML20237B5261998-07-31031 July 1998 Monthly Operating Rept for July 1998 for Waterford 3 ML20236S9031998-07-22022 July 1998 SER Accepting Rev 19 to Quality Assurance Program for Waterford Steam Electric Station,Unit 3 ML20198H3911998-07-14014 July 1998 Non-proprietary Rev 5 to HI-961586, Thermal-Hydraulic Analysis of Waterford-3 Spent Fuel Pool ML20236N4181998-06-30030 June 1998 Monthly Operating Rept for June 1998 for Waterford,Unit 3 ML20248E7781998-06-0101 June 1998 Annual Rept on Abb CE ECCS Performance Evaluation Models ML20249A4711998-05-31031 May 1998 Monthly Operating Rept for May 1998 for Waterford 3 Ses ML20196A4051998-05-31031 May 1998 Rept of Facility Changes,Tests & Experiments,Per 10CFR50.59 for 970601-980531. with ML20198H4681998-05-20020 May 1998 Non-proprietary Rev 1 to HI-981942, Independent Review of Waterford Unit 3 Spent Fuel Pool Cfd Model ML20247A3891998-05-0101 May 1998 SG Eddy Current Examination (8th Refueling Outage) ML20247F6761998-04-30030 April 1998 Monthly Operating Rept for Apr 1998 for Waterford,Unit 3.W/ ML20217M8951998-04-30030 April 1998 QA Program Manual ML20217P8281998-04-0707 April 1998 Safety Evaluation Accepting Relief Authorization for Alternative to Requirements of ASME Section Xi,Subarticle IWA-5250 Bolting Exam for Plants,Per 10CFR50.55a(a)(3)(i) ML20216B1751998-03-31031 March 1998 Monthly Operating Rept for Mar 1998 for Waterford 3 Ses ML20217M1411998-03-0303 March 1998 Rev 2 of Waterford 3 Cycle 9 Colr 1999-09-30
[Table view] |
Text
-
. ~ ' .-
//3W 1
l Supplement to the ' Safety Evaluation Report I Hydrologic Engineering Section '
s t-- ..
Waterford Steam Electric Stationi Unit 3 Docket Number 50-382
- 2. SITE CHARACTERISTICS 2.4 Fydrataoic Enoineerina' 2.4.2 Flood Potential 2.4.2.3 Local Intense Precipitation Waterford 3 has wet and dry cooling towers which are open at the top.
There are two open cooling tower areas A and B. Local intense precipitation which fatts directly over the e open areas plus' runoff from .
adjacent roofs will accumulate and pond on the floors of the dry cooling
' '~'
tower areas. A combination of floor drains and a network of drainage piping will convey this water to two sumps where a set of duplex pumps in each sum'p will remove water from the cooling tower areas.
\ .
Design Basis Rainfall Event:
l In Section 2.4.2.3 of the Safety Evaluation Reports the staff concluded t
that the applic' ant's analysis of potential flooding in cooling tower l
L areas A and B did not meet the design criteria suggested in Regulatory j Guides 1.59 and 1.102 nor the requirements of GDC-2 because certain i
safety-related transformers and motor control centers located in the cooling tower areas could be flooded during a design basis rainfall -
event. The staff stated that safety related components in cooling tower 8505300232 850301 PDR FDIA PDR
[ QAR DE84-A-56 l
, - - - . . , - , , , - - . - - , ., - - , . , . - , _ - . - . ~ , . . - - , - . -, --
} .
-2 '
areas A and B should be flood protected to d.2 feet and 3.6 feet respectively.
Thestaffalsostatedthatlower'floodprEtectiohdepthswouldbeacceptable if additional or larger pumps were used to reduce ponding levels or if the j applicant could provide assurances that roof drains would not become clogged. The applicant subsequently presented an evaluation of the potential
. for blockage of roof drains. This evaluation showed that clogging of roof drains would be highly unlikely. However, as described belows the appl.icant conservatively assumed that 33 percent of the roof drains would be clogged during a design basis rainfall event. Based on the information presented by the applicant, the staff agrees that it is highly unlikely that all of the roof drains would become clogged. The' Staff further agrees that a 33 percent blockage of roof drains is a conservative assumption.
In Amendment 21 to the FSAR, the applicant presented a revised analysis ,
of potential flooding in cooling tower areas A and B. In this analysis roof drains were assumed to be 33 percent blocked. The applicant also assumed that one of the sump pumps in each cooling tower . area would be inoperable during a probable maximum precipitation (PMP) event. Amendment 21 also stated that the sump pumps in the cooling tower areas each have a i
i capacity of 325 gallons per minute (gpm). Initiallyr the FSAR had shown l
L these pumps as having a capacity of 140 gpm. This revised analysis by the -
l-applicant resulted in Lower ponding levels in the cooling tcwer areas.
t l These Levels however were not low enough to prevent flooding of the motor i
i control centers which are located on the floors of the dry cooling towers.
- To further reduce ponding levels in the cooling tower arease the applicant ,
f
?
. . -3 .
proposed to allow water to flow into and pond in the Fuel Handling -
Building. Openings wiLL have to"6e provided betsien the cooling tower areas and the Fuel Handling Building. The applicant has determined that three 4-inch diameter openings have to be installed in the sills beneath exit doors located on each side of the Fuel Handling Building. Howevere to allow for some clogging o.f pipess.3 total of eight 4-inch diameter pipes wiLL be installed. The applicant has estimated that by al' Lowing f
water to pond in the Fuel Handling Buildings a maximum of 1.6 feet of water wiLL pond in the cooling tower areas and in the Fuel Handling Building. Themaximumheighttowhichwate[canpondinthecooling tower areas before flooding of essential poFtions of the transformers occurs is 3.0 feet. For the motor control centers it is 1.71 feet.
~
The staff has reviewed the material presented by the applicant and has' performed' independent analysis. The staff therefore concludes thate with the eight 4-inch diameter opening installed as indicated by the applicants water depths in the cooling tower areas will remain below 1.6 feet following a PMP event and wiLL thus not affect _the safe operation
. of Wate,rford 3. -
i Combination of Events:
l l
Regulatory Guide 1.59 suggests that a sufficient number of combinations
. of flood causing events be tested or discussed to assure that the highest flood level has been determined. An alternative combination which should be considered is an operating basis earthquake (OBE)r -
e D
E
- Yy
~4 e
which fails the sump pumps, coincident with a rainfall event less
-s._. - m ._ .A severe than the PMP. This combination is considered appropriate since the pumps are not seismically qualified, and thu.s.cannot be shown to be operable following a seismic event. The staff therefore requested that .the applicant provide an analysis of the effects of a.
Standard Project Storm (SPS assumi'n g all four sump pumps in the cooling tower areas are inoperable.
r- ,
\ .
MThe applicant has described the sump pumps as designed to seismic Category 1 requirements but not classified as seismic Category 1 (FSAR Table 3.2-1). ,
l' '
l.
- 3/The SPS is a storm used for design of flood control structures by the U.S. Army Corps of Engineers. Rainf all resulting from a SPS is generally equal to about 40 to 60 percent of the PMP.
1 i
l .
m 4
i
j
-5. .
The applicant's analysis of this comb'ination of events showed that
.w. a* %m .
there would be some flooding of motor control centers about 7 hour8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br />.s after ponding in the cooling towers began. The applicant stated that reactiyation of even one of the sump pumps would, at an increasingly rapid rater reduce the total accumulated water level. ' There was no
- discussion or description of how the sump pumps would be reactivated
~
nor how Long it would take to do so. Th'us the staf f was unable to conclude that a rainfall event coincident with an OBE would not result in flooding of motor control centers and transformers in the cooling tower areas.
~
In analyzing the PMPs both the applicant and the staff determined that
' ~ '
ponded v'ater in the cooling tower areas would peak at about the 5th or 6th hour. After this, levels would decrease because.the capacit'y of the sump pumps would exceed the amount of water coming in.
Thus consideration of a 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> PMP as a design basis event was adequate.
I For the coincident SPS and OBE events howevers storm duration is a much more critical parameter because the sump pumps are assumed to be
~
inoperabler allowing water to accumulate for the entire duration of the storm.
l In Section 2.4.2.3 of the SERr a 48-hour PMP is estimated to be 43.5 .
' inches. The 48 hour5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> SPS rainfall would be about 21.8 inches assuming that the SPS is equal to 50 percent of the PMP. Since ponding depth in 4
e
- # i the cooling tower areas is dependent on the duration of the rainfall
.u. -w .
event, the staff considered a SPS of 96 hours0.00111 days <br />0.0267 hours <br />1.587302e-4 weeks <br />3.6528e-5 months <br /> dur'ation. This eve'nt would produce a total rainfall of about 23 inches ,and would result in a ponding depth of about 1.9 feet in the cooling tower areas assuming that all four sump pumps are inoperable.- Since this is higher than.
the maximum allowable' ponding depth of 1.71 feets the applicant har-proposed to provide a portable pump with a pumping capacity of 100 gallons per minute (gpm) and sufficient head to pump over the cooling tower wall. This pump will be stored on pallets placed away from any non-seismic category I eqdipment which coul fall and gamage the pump.
InadditionithepumpwiLLbeincludedin'ifesurvhittancetesting program which will include a demonstration at least once per refueling that the pump will circulate water. As part of the station's emergency proceduress a provision wiLL be included for emplacing >the portable pump within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> of a seismic event if the installed pumps fail.
\
, The staff has determined that a 100 gpm pump capable of Lifting water 75 feet vertically is adequate to prevent flooding of safety related ;
l equipment in the cooling tower areas during a combined SPS-0BE event provided the pump is placed in operation within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
t
]
Conclusion:
l The staff now concludes that with respect to potential flooding of the '
i
~
cooling tower arease the station meets the requirements of GDC-2 and the criteria of Regulatory Guides 1.59 and 1.102. .
l
,. Tad 45 if.-l8 4 Y W W M N N' M # N 1
I Wet and dry cooling towers at Waterford 3 are open at the top and could be affected by local intense precipitation which falls directly over the cooling towers and by runoff from adjacent roofs: Theie are two open cooling towers areas, A and B. These areas have. floor drains that flow into a sump for each area. Each sum of 280 gal / min.p is drained by two sump pumps which have a combined capacity Th.e pumps remove ponded water from the cooling tower areas to the exterior plant drainage system.
A rooftop draina'ge system has also been designed to. prevent roof ponding of water for rainfall rates up to 6 in./hr. More intense rainfall will either pond below roof parapets or overflow. Part of this overflow will enter the open cooling tower areas. - --
The applicant performed an analysis of' the effects of a 6-hr duration PHP on the open cooling tower areas and adjacent roofs. In this analysis the rooftop drainage system was assumed to be functioning and all sump pumps, w,hich are described as seismically designed were assume'd to be pumping water from each cooling tower area at a maximum ra,te of 280 gal / min. The computed ponding depths were 1.35 ft in cooling tower area A and 1.70 ft in cooling tower area B.
The applicant stated that all safety related equipment would be located above these ponding levels. ,.- ,
At the request of NRC, the applicant provided drawings and descriptions of safety-related components that are located in the coolin These consist of transformers and motor control centers (MCCs)gmounted tower areas.
on the floors of the dry cooling towers. Although these components will be partially inundated by water, the a3plicant has stated that the transformers are watertight for approximately tie lower 3 ft and the MCC's can withstand ponded water up to 1.75 ft without harmful effects. Thus the applicant's analysis shows that water levels in Cooling Tower Area B, assuming that roof drains and sump pumps function as. design, will be wi' thin 0.05 ft (5/8 in.) of flood'ag the MCC's
,and affecting the operability of the dry cooling towers. The margin in Cooling Tower Area A as calculhted by the applicant, is 0.4 ft (4.8 in.). These margins could easily be exceeded should the roof. drains become partially clogged or not function at their design c pacity or if a sump pump does not switch on when needed or does not operate at full capacity. Based on this, the staff concludes that the app.licant,'s analysis'and design are not conservative and that the flood protection for the cooling tower areas does not meet the design criteria suggested in Regulatory Guides 1.59 and 1.102 nor the requirements of GDC 2. -
The staff performed an independent analysis of potential flooding of these
- cooling tower areas, assuming that one sump pump in each area is inoperable and that the roof drainage system is clogged with debris during the PHP. This
' analysis resulted in a ponding depth of 4.2 ft in Cooling Tower Area A and 3.6 ft in Cooling Tower Area B. These ponding depths would inundate the transformers and MCC's in the cooling tower areas and affect the safety of the .
plant. The staff wi11' require that all safety-related components in the cooling towers area be flood protected to these depths. Lower flood levels may be acceptable if t.he applicant can provide adequate assurances that the roof drains will not becom.e clogged during a design basis event. Additional or larger
' capacity pumps may also be used to reduce calculated ponding level. NRC will need to review the applicant's proposal prior to issuance of an operating license. The results of review will be provided in a supplement to this report.
. potA N 5r,P/
- ~
l E/B.h
. ..