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{{#Wiki_filter:,^BRES^*****UNITED | {{#Wiki_filter:,^BRES^*****UNITED STATES NUCLEAR REGULATORY COMMISSION REGION IV 1600 E LAMAR BLVD ARLINGTON, TX 76011-4511 April 9, 2015 EA-14-228 Mr. Michael R. Chisum Site Vice President Entergy Operations, Inc. | ||
17265 River Road Killona, LA 70057-0751 | |||
==SUBJECT:== | ==SUBJECT:== | ||
PUBLIC MEETING SUMMARY - REGULATORY CONFERENCE | PUBLIC MEETING SUMMARY - REGULATORY CONFERENCE WITH ENTERGY OPERATIONS, INC. FOR WATERFORD STEAM ELECTRIC STATION, UNIT 3 | ||
==Dear Mr. Chisum:== | ==Dear Mr. Chisum:== | ||
This refers to the Category 1 meeting conducted on April 7, 2015, in Arlington, Texas. | |||
This refers to the Category 1 meeting conducted on April 7, 2015, in Arlington, Texas. The purpose of this meeting was to allow representatives of Entergy Operations, Inc., the licensee for Waterford Steam Electric Station, Unit 3, to meet with U.S. Nuclear Regulatory Commission (NRC) personnel to discuss their position with regard to the preliminary Greater-than-Green finding and associated apparent violation. The apparent violation of Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Appendix B, Criterion XVI, "Corrective Action," was associated with through-wall corrosion of vent piping for the emergency diesel generator fuel oil day tanks. The holes En these vent pipes could allow water to enter the day tanks and contaminate the diesel fuel oil, challenging the operability and functionality of both safety-related emergency diesel generators. The apparent violation is discussed in NRC Inspection Report 05000382/2014007, dated January 22, 2015 (ADAMS Accession No. ML15022A637). | |||
During the meeting, Entergy Operations, Inc., representatives provided an assessment of the significance of the finding, their root cause evaluation and corrective actions, and the results of tests they conducted on the effects of water contamination of the diesel fuel oil. A member of the public asked questions about why it took the NRC so long to identify the issue, the effect a clogged roof drain would have, and the probability of a loss of offsite power event. The Region IV Regional Administrator responded to these questions. | |||
A list of attendees and a copy of the presentation handouts are enclosed. | |||
In accordance with Title 10 of the Coofe of Federal Regulations (10 CFR) 2.390, "Public Inspections, Exemptions, Requests for Withholding," a copy of this letter, its enclosure, and your response (if any) will be available electronically for public inspection in the NRC's Public Document Room or from the Publicly Available Records (PARS) component of the NRC's Agencywide Documents Access and Management System (ADAMS). ADAMS is accessible M. Chisum from the NRC Web site at httD://www.nrc.aov/readina-rm/adams.html (the Public Electronic Reading Room). | |||
Sincerely, IRfiJThomas R. Farnholtz, Chief Engineering Branch 1 Division of Reactor Safety Docket No. 50-382 License No. NPF-38 | |||
==Enclosures:== | ==Enclosures:== | ||
: 1. List of | : 1. List of Attendees | ||
: 2. Entergy Presentation Handouts ec w/encl: | |||
Electronic Distribution | |||
ML15099A563 13 SUNSI Review By: JLDi B Non-Sensitive D Sensitive 13 Publicly Available D Non-Publicly Available Keyword:RGN-002OFFICESRI:DRS/EB1 SPAOC:DRS/EB1 NAME! JDixonVDricksTFarnholtz SIGNATURE l /RA/ | |||
/RA//RA/DATE4/8/20154/8/20154/8/2015 Letter to Michael R. Chisum from Thomas R. Farnholtz, dated April 9,2015 | |||
==SUBJECT:== | ==SUBJECT:== | ||
PUBLIC MEETING SUMMARY - REGULATORY CONFERENCE | PUBLIC MEETING SUMMARY - REGULATORY CONFERENCE WITH ENTERGY OPERATIONS, iNC. FORWATERFORD STEAM ELECTRIC STATION, UNIT 3 DESTRIBUTION: | ||
^RRES%,***^SIGN-IN | Regionai Administrator (Marc.Dapas@nrc.gov) | ||
.^ ^^SIGN-IN | Deputy Regional Administrator (Kriss.Kennedy@nrc.gov) | ||
ENCLOSURE | DRP Director (Troy.Pruett@nrc.gov) | ||
'"^ | Acting DRP Deputy Director (Thomas. Farnholtz@nrc.gov) | ||
As-Foundnter'm | DRS Director (Anton.Vegef@nrc.gov) | ||
Impact on | DRS Deputy Director (Jeff.CIark@nrc.gov) | ||
^\^\\\^\\\\\\\\\>X\^\\\Y^.\\\\\\\^\\\N\\\\\<\\NS?^u^^i?oS^-J >:CQ\s\\v;.xs\\\<\\\\<\\\<\\\\\\\'^^^1g5g^.\\^\\\N\\\\\\\\\V^\\\\\\\\^\\\ | Senior Resident inspector (Frances.Ramirez@nrc.gov) | ||
~'sfEnte^ | Resident Inspector (Chris.Speer@nrc.gov) | ||
Roof | WAT Administrative Assistant (Linda.Dufrene@nrc.gov) | ||
Roof Ponding Test | Branch Chief, DRP/D (Michael.Hay@nrc.gov) | ||
Water Tolerance | Senior Project Engineer, DRP/E (Bob.Hagar@nrc.gov) | ||
>s:' | Project Engineer, DRP/D (Brian.Parks@nrc.gov) | ||
Water Tolerance | Project Engineer, DRP/D (Jan.Tice@nrc.gov) | ||
Water Tolerance | Public Affairs Officer (Victor.Dricks@nrc.gov) | ||
Water Intrusion Rate | Public Affairs Officer (Lara.Uselding@nrc.gov) | ||
( _ _ IEntergySAFETY | Project Manager (Michael.0renak@nrc.gov) | ||
* Rainfall Probabi ity CoinddentACDF | Branch Chief, DRS/TSB (Geoffrey.Miller@nrc.gov) | ||
* RR * (CCDPpo-CCDP^iine)5.1 E-03/yr | RITS Coordinator (Marisa.Herrera@nrc.gov) | ||
* 9.5E-04 * (2.92E 5.28E-04) = 1.16E-08/yr Non-CoincidentACDF | ACES (R4Enforcement.Resource@nrc.gov) | ||
Regional Counsel (Karla.Fuller@nrc.gov) | |||
Congressional Affairs Officer (Jenny.Weil@nrc.gov) | |||
Technical Support Assistant (Loretta.Williams@nrc.gov) | |||
RIV Congressional Affairs Officer (Angel.Moreno@nrc.gov) | |||
RIV/ETA: OEDO (Michael.Waters@nrc.gov) | |||
ROPreports | |||
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ENCLOSURE 2 ENTERGY PRESENTATION HANDOUTS | |||
'"^Entefgy WATERFORD 3 REGULATORY CONFERENCE Through-Wall Corrosion on Emergency Diesel Generator A and B Day Tank Vents Apri 7,2015 Entei^gyOP EN NG REMARKS Michael Chisum Site Vice President Waterford 3 Waterford 3 Representatives Ran Gilmore Brian Lanka Manager, Systems and Components Engineering Director, Engineering Jessica Walker PRA Consultant, Jensen Hughes Marvin Chase Director, Regulatory & Performance Improvement Agenda. Overview of Performance Deficiency | |||
. Causes and Corrective Actions nQ©Inputs to the Risk Calculation Safety Significance Calculation Conclusion f:s:'Entergy OVERVIEW OF PERFORMANCE DEFICIENCY Ran Gilmore Manager, Systems and Components Engineering Waterford 3 Performance Deficiency Failure to identify and correct through-wall corrosion on the A and BEmergency Diesel Generator Fuel Oil Day Tank Vent I'nes. | |||
As-Foundnter'm repair HoleLocated at Roofon Missile Shield Side i^ | |||
Impact on Plant Not to Scale | |||
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~'sfEnte^gy CAUSES AND CORRECTIVE ACTIONS Ran Gilmore Manager, Systems and Components Engi eering Waterford 3 Day Tank Vent Line Evaluation Resu ts Direct Cause | |||
. Failure of the pipe coating al owed accelerated, local, general corrosion to occur. | |||
Key Cause 0 Failure mechanism ofthrough-wall corrosion combined with postulated precipitation events at the site could challenge EDG safety functions. | |||
a Corrective Actions Replace Temporary Repair with a Permanent Design Change. Immediate Walkdown of Roofs for Similar Configuration | |||
- Reassess impact of Non-Safety Components on EDG(s) | |||
. Emergency Diesel Generator Comprehensive hlealth Assessment General Corrosion Evaluation Results | |||
. Direct Cause | |||
. Normalization of external corrosion on plant equipment by station personnel. | |||
3 Key Cause Inadequate programmatic guidance to ensure consistent identification and correction of coating degradation and external corrosion 0 Corrective Actions 0 Create an External Corrosion standard and program capable of identifying, prioritizing, monitoring, applying resources and repairing degradation of plant equipment related to external corrosion. | |||
6 Utilizing an External Corrosion Team m ^ MEntergyINPUTS TO THE R SK CALCULATION Ran Gi more Manager, Systems and Components Eng Waterford 3 Key Inputs 0©Water Intrusion Rate | |||
. Hole Size and Location 0 Analytic Estimate 0 Roof Test Water Tolerance of EDG | |||
. Test Approach e Test Results Determination of hlole Size Fuel Oil Day Tank B (East Vent) | |||
Not to Scale Determination of Hole Size Fuel Oi Day Tank A (West Vent) | |||
Not to Scale Water Intrusion Analysis Vent BRequired Ponding Depth: A Vent Not to Scale Water Intrusion Analysis 454035305 252015105Day Tank Accumulations 567Rain Rate (In/hr) | |||
- -West ("A") Tank | |||
.East ("B") Tank T9T10-r11t12 Roof Test Purpose9 Validate Analytical Model of Roof Drainage0 Assess Ponding Depth and Boundaries 0 Assess Debris Behavior Roof Test Results° Water Did Not Reach Fuel Oil Day Tank A Vent Line in 20 GPM (5 in/hr) | |||
Test0 Drain Resistance is Less Than Calculated Water Line Near "A" Vent y^s^"\ | |||
Roof Test As-found Debris Location Results- Found debris did not transport when placed n as-found location. | |||
e Manually placed next to drain to evaluate effects Debris Next to Drain Debris in As-found Location | |||
-.^^ | |||
Roof Ponding Test Results sI454035302520151050Day Tank Accumulations Roof Ponding Result-r1.r-^-^u^^zT6T7T8T9T10T11112Rain Rate (in/hr) | |||
-J-West ("A") Tank Water Tolerance Testing G Waterford EDG Characteristics to Maintain in Test System | |||
- Delivery of water to engine 0 Engine combustion conditions | |||
° Engine loading during a LOOP e Approach 0 Full Scale Testing at Sumner Municipal Light Plant (SMLP) in Sumner. IA 0 12 cylinder Cooper-Bessemer KSV Engine similar to the 16 cylinder Cooper-Bessemer KSV engines at Waterford 9 Duplicate Waterford fuel delivery skid at Sumner Water Tolerance Testing | |||
: 1. Delivery of Water to the Engine Duplicate Waterford Fuel Supply System. | |||
Maintain fuel (and water) flow rates through system the same as at Waterford by: (1) scaling the load profile, and (2) providing takeoff from header to simulate "missing" four cylinders. | |||
: 2. Engine Combustion Conditions Use similar Cooper-Bessemer KSV Engine with same bore, stroke, cylinder liners, pistons, and similar cylinder heads. | |||
Load SMLP engine at a conservatively greater power per cylinder per cycle (to maintain consistent fuel flow rate). | |||
Fuel Injection System with similar characteristics. | |||
(Waterford: Bendix FDX-22, SMLP: Bendix FDX-22G) | |||
: 3. Engine Loading Use Load Bank to simulate Waterford LOOP load profile (scaled to 12 cylinders). | |||
SMLP governor is slower than the Waterford governor, which results in a conservative measure of the impact on EDG frequency. | |||
Water Tolerance Testing Tower with Day Tank New Fuel Header 4 Cylinder Take-Off | |||
-\^^.-r^fwind Straii lers | |||
.4 Water Tolerance Testing Conduct of Test | |||
. "Trickle" Test (Loss of Offsite Power with Rain Event) | |||
. Diesel Started and Loaded to Maximum Peak LOOP Load Scaled to the SMLP Engine 9 Water Introduced into Day Tank at Specified Flow Rate | |||
° "Slug" Test (Loss of Offsite Power after Rain Event) | |||
" Diesel in Standby Specified Water Volume Added to Day Tank and Settled into Low Point of Piping | |||
- Diesel Started and Loaded with LOOP Load Profile Scaled to SMLP Engine | |||
>s:'Entergy TEST RESULTS Brian Lanka Director, Engineering Waterford 3 Water Tolerance Testing Cases Base Line 0 No water test Sug. 1 Gallon | |||
. 5 Gallon with 24 hour endurance run | |||
- 7 Gallon (5.4 in/hr) | |||
Trickle. 2.7 GPH Trickle 0 21 GPH Trickle with 24 hour endurance run | |||
. 40 GPH Trickle (11 in/hr) | |||
Water Tolerance Testing AS-BUILT WATERFORD FUEL AND WATER TEST MECHANICAL SYSTEM MPR DwuimntWo. OQe.10e2.140M75-REVISKlN 6->>27<a)1S nFS^-^ff^-Qs^^^^^^^imsTiwwutsimwssiiaiaimiw fMiwnfwvnwisi. | |||
ENS'ffittBAWTmUMCTfflS wnanEW^nm^wapni | |||
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^SSSSSlSS^^^WcS'W" FUEtlWOCOaiBNfWto' FigUrtl. Test System Schemafic ig Water Tolerance Test Video | |||
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Water Tolerance Testing Test Type Water VoIume/Flow Engine Fuel Rack PositionGenerator Output Frequency Trickle2.7 GPH for 1 hour No detectable effect No detectable effect Trickle221 GPH for 1 hour Up to 2 mm increase1 No detectable effect Trickle40 GPH for 1 hour Up to 3 mm increase1 No detectable effect Slug1 GallonNo detectable effect No detectable effect Slug25 GallonUp to 3 mm increase1 | |||
<1 Hz decrease1 Slug7 GallonUp to 10 mm increase1 1 Hz decrease during a minor load step1 2 Hz decrease during a major load step1 | |||
: 1. Compared with the response in the baseline test. | |||
: 2. A 24-hour endurance test was performed immediately afterthis test. | |||
Water Intrusion Rate Determination 45403530^25I.20IS1050Day Tank Accumulations I 40 GPH Trickle Roof Ponding Result-T1567Rain Rate (In/hr) | |||
^West("A")Tank 112 | |||
( _ _ IEntergySAFETY SIGNIFICANCE CALCULATION Jessica Walker, PRA Consultant Jensen hlughes Risk Analysis Risk = Frequency of the Event* Consequences Initiating Event Frequency Rainfall Rate Probability LOOP Frequency Likelihood of High Rainfall Coincident with LOOP Consequences Conditional Core Damage Probabilities | |||
. Coincident | |||
. Non-Coincident Rainfall Rate National Weather Service Data for Waterford 3 Plant0 Provides average recurrence interval in years to achieve hour ong rainfall in inches Used to determine probability of specific rainfa I rates AverageRecurrence Interval(years)10 25 50 100 200 500 1,000 Inches of Rainfall in 1.89 2.21 2.77 3.27 3.98 4.57 5.18 5.83 6.72 7.43 One HourExample: 2 percent (1/50) of the time the highest rainfall rate during the year is approximately 4.6 in/hr nitiating Event Frequency Rainfall Rate Took the average recurrence interval and assumed a direct probabi ity of rain 0 Conservatively used the annual recurrence as the probability | |||
° Probability of having a rainfall rate of 4.57 in/hr is 0.02 (1/50) | |||
Fina Probability Values interpolated from available data to provide rainfall rates that correspond with testing | |||
>> 5.4in/hr=7.1E-03 | |||
. 11 in/hr = 9.5E-04* | |||
*Note: Data past 8 in/hr has greater uncertainty 9.5E-04 (8 in/hr value) utilized Initiating Event Frequency LOOP Frequency Coincident - Severe Weather Related LOOP | |||
. 12 separate severe weather induced LOOP events at U.S. | |||
nuclear plants from 1986 through 2012 | |||
. Dividing by total critical reactor years during this period (2,332.6 rcry) | |||
. Weather induced at power LOOP Frequency of 5.1 E-03/yr Non-Coincident - LOOP not caused by weather | |||
. Utilized the WFSAt-Power model 0 Removed the Severe Weather events | |||
" LOOP Frequency of 2.1 E-02/yr Initiating Event Frequency Rainfall and LOOP | |||
. Historical weather induced LOOP events | |||
. Lightning strikes 8 High winds (e.g. tornado and hurricane) e No mention of significant rainfall | |||
' Review of rainfall data for these events | |||
. Rainfall not a direct cause of Loss of Offsite Power Severe Weather assumed to cause both the LOOP and the extreme ra'nfall Initiating Frequency | |||
. Severe Weather LOOP | |||
* Rainfall Probabi ity CoinddentACDF Calculatio Initiating Event Frequency | |||
° Severe Weather LOOP Frequency 9 Utilized Severe Weather Offsite Recovery Factors 0 Coincident Rainfall Rate Probability Consequences Successful 40 GPH trickle test. Assumed reduced reliability of diesels- Utilized WF3 Internal Event PRA Model | |||
. CCDPpo = 2.92E-03 | |||
- CCDP^eline = 5.28E-04 ACDF = LOOP | |||
* RR * (CCDPpo-CCDP^iine) 5.1 E-03/yr | |||
* 9.5E-04 * (2.92E 5.28E-04) = 1.16E-08/yr Non-CoincidentACDF Calculation Initiating Event Frequency 0 LOOP Frequency without Severe Weather | |||
- Rainfall Rate Probability | |||
. Exposure time of 0.019 year8 Based on EDG surveillance testing frequency Consequences Successful 7 gallon slug test. Assumed failed diesels at > | |||
5.4 in/hr rainfall Utilized WF3 Internal Event PRA Model | |||
. CCDFpD=1.19E-03/yr | |||
. CCDF^eiine = 4.39E-06/yr ACDF = (RR) * (exp) * (CCDFpo-CCDF^eiine) | |||
ACDF = (7 1E-03) * (0.019) * (1.19E-03/yr - 4.39E-06/yr) | |||
ACDF = 1.62E-07/yr Combined ACDF Results | |||
° Coincident LOOPACDF = 1.16E-08/vr | |||
. Non-Coincident LOOPACDF = 1.62E-07/vr | |||
" Total ACDF = 1.73E-07/vr Q LERF calculations performed in similar manner as CDF calculations Total ALERF = 1.77E-09/vr Coincident LOOP CDF Sensitivity Frequency 0 Lower Bound Case R 5th percentile for severe weather LOOP frequency 0 5th percentile for probability of rainfall rate | |||
- Total ACDF = 2.41 E-08/vr 0 Nominal Case 0 Nominal severe weather LOOP frequency 0 Nominal probability of rainfal rate | |||
- Total ACDF = 1 .73E-07/vr 0 Upper Bound Case 0 95th percentile for severe weather LOOP frequency 0 95th percentile for probability of rainfall rate | |||
< Total ACDF = 5.81 E-07/vr Non - Coincident LOOP CDF Sensitivity Rainfall Rate Lower Bound Case | |||
. Rainfall rate of 6.4 in/hr ffl Total ACDF = 7.96E-08/vr Nominal Case 0 Rainfall rate of 5.4 in/hr | |||
. Total ACDF == 1.73E-07/vr Upper Bound Case 8 Rainfall rate of 4.4 in/hr Total ACDF = 4.72E-07/vr PRA Specific Conservatisms | |||
. Coincident Case | |||
. Diesels showed successful operation during 40 GPH trickle test | |||
. Analysis assumes run failure ofdiesels increased by a factor of 10 above 8 in/hr rainfall | |||
. Analysis utilizes 8 in/hr rainfall although 40 GPH is closer to 11 in/hr | |||
. Assumed that a LOOP at Waterford occurs coincident with the highest rainfall event of the year | |||
. Non-Coincident Case | |||
. Diesel showed successfu operation during 7 gallon slug test | |||
. Analysis failed both diesels for rainfall rates above 5.4 in/hr | |||
- No credit assumed in PRAfor restart ofdiesels Ente^yCONCLUSION Marvin Chase Director, Regu atory and Performance mprovement Waterford 3 Sum naryCompleted Extensive Water Tolerance Testing of Diesel Generator | |||
° Trickle Tests B S ug Tests In ALL Cases Diesel Demonstrated Continued Capability to Perform its Safety Function Summary. Established Station Rainfall Rate 0 Determined Roof Ponding Depths | |||
. Determined Water Intrusion Rates via Day Tank Vent Determined LOOP Coincident with Rainfall Frequency from NRC Data | |||
" PRA Results Organizational Learnings Conclusion | |||
. The station conclusion is that the PRA results support a determination that the failure to identify and correct through-wa I corrosion on the A and B EDG Fuel Oil Day Tank Vent lines is of a very low safety significance EntergyCLOSING COMMEN S Michael Chisum Site Vice President Waterford 3 Letter to Michael R. Chisum from Thomas R. Farnholtz, dated April 9,2015 | |||
==SUBJECT:== | ==SUBJECT:== | ||
PUBLIC MEETING SUMMARY - REGULATORY CONFERENCE | PUBLIC MEETING SUMMARY - REGULATORY CONFERENCE WITH ENTERGY OPERATIONS, INC. FOR WATERFORD STEAM ELECTRIC STATION, UNET 3 DISTRIBUTiON: | ||
Regional Administrator (Marc.Dapas@nrc.gov) | |||
Deputy Regional Administrator (Kriss.Kennedy@nrc.gov) | |||
DRP Director (Troy.Pruett@nrc.gov) | |||
Acting DRP Deputy Director (Thomas.Farnholtz@nrc.gov) | |||
DRS Director (Anton.Vegel@nrc.gov) | |||
DRS Deputy Director (Jeff.Clark@nrc.gov) | |||
Senior Resident Inspector (Frances.Ramirez@nrc.gov) | |||
Resident Inspector (Chris.Speer@nrc.gov) | |||
WAT Administrative Assistant (Linda.Dufrene@nrc.gov) | |||
Branch Chief, DRP/D (Michael.Hay@nrc.gov) | |||
Senior Project Engineer, DRP/E (Bob.Hagar@nrc.gov) | |||
Project Engineer, DRP/D (Brian.Parks@nrc.gov) | |||
Project Engineer, DRP/D (Jan.Tice@nrc.gov) | |||
Public Affairs Officer (Victor.Dricks@nrc.gov) | |||
Public Affairs Officer (Lara.Uselding@nrc.gov) | |||
Project Manager (Michael.0renak@nrc.gov) | |||
Branch Chief, DRS/TSB (Geoffrey.Miller@nrc.gov) | |||
RITS Coordinator (Marisa.Herrera@nrc.gov) | |||
ACES (R4Enforcement.Resource@nrc.gov) | |||
Regional Counsel (Karla.Fuller@nrc.gov) | |||
Congressional Affairs Officer (Jenny.Weil@nrc.gov) | |||
Technical Support Assistant (Loretta.Williams@nrc.gov) | |||
RiV Congressional Affairs Officer (Angel.Moreno@nrc.gov) | |||
RIV/ETA: OEDO (Michael.Waters@nrc.gov) | |||
ROPreports}} |
Revision as of 03:03, 1 July 2018
ML15099A563 | |
Person / Time | |
---|---|
Site: | Waterford ![]() |
Issue date: | 04/09/2015 |
From: | Thomas Farnholtz NRC Region 4 |
To: | Chisum M R Entergy Operations |
References | |
EA-14-228 | |
Download: ML15099A563 (57) | |
Text
,^BRES^*****UNITED STATES NUCLEAR REGULATORY COMMISSION REGION IV 1600 E LAMAR BLVD ARLINGTON, TX 76011-4511 April 9, 2015 EA-14-228 Mr. Michael R. Chisum Site Vice President Entergy Operations, Inc.
17265 River Road Killona, LA 70057-0751
SUBJECT:
PUBLIC MEETING SUMMARY - REGULATORY CONFERENCE WITH ENTERGY OPERATIONS, INC. FOR WATERFORD STEAM ELECTRIC STATION, UNIT 3
Dear Mr. Chisum:
This refers to the Category 1 meeting conducted on April 7, 2015, in Arlington, Texas. The purpose of this meeting was to allow representatives of Entergy Operations, Inc., the licensee for Waterford Steam Electric Station, Unit 3, to meet with U.S. Nuclear Regulatory Commission (NRC) personnel to discuss their position with regard to the preliminary Greater-than-Green finding and associated apparent violation. The apparent violation of Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Appendix B, Criterion XVI, "Corrective Action," was associated with through-wall corrosion of vent piping for the emergency diesel generator fuel oil day tanks. The holes En these vent pipes could allow water to enter the day tanks and contaminate the diesel fuel oil, challenging the operability and functionality of both safety-related emergency diesel generators. The apparent violation is discussed in NRC Inspection Report 05000382/2014007, dated January 22, 2015 (ADAMS Accession No. ML15022A637).
During the meeting, Entergy Operations, Inc., representatives provided an assessment of the significance of the finding, their root cause evaluation and corrective actions, and the results of tests they conducted on the effects of water contamination of the diesel fuel oil. A member of the public asked questions about why it took the NRC so long to identify the issue, the effect a clogged roof drain would have, and the probability of a loss of offsite power event. The Region IV Regional Administrator responded to these questions.
A list of attendees and a copy of the presentation handouts are enclosed.
In accordance with Title 10 of the Coofe of Federal Regulations (10 CFR) 2.390, "Public Inspections, Exemptions, Requests for Withholding," a copy of this letter, its enclosure, and your response (if any) will be available electronically for public inspection in the NRC's Public Document Room or from the Publicly Available Records (PARS) component of the NRC's Agencywide Documents Access and Management System (ADAMS). ADAMS is accessible M. Chisum from the NRC Web site at httD://www.nrc.aov/readina-rm/adams.html (the Public Electronic Reading Room).
Sincerely, IRfiJThomas R. Farnholtz, Chief Engineering Branch 1 Division of Reactor Safety Docket No. 50-382 License No. NPF-38
Enclosures:
- 1. List of Attendees
- 2. Entergy Presentation Handouts ec w/encl:
Electronic Distribution
ML15099A563 13 SUNSI Review By: JLDi B Non-Sensitive D Sensitive 13 Publicly Available D Non-Publicly Available Keyword:RGN-002OFFICESRI:DRS/EB1 SPAOC:DRS/EB1 NAME! JDixonVDricksTFarnholtz SIGNATURE l /RA/
/RA//RA/DATE4/8/20154/8/20154/8/2015 Letter to Michael R. Chisum from Thomas R. Farnholtz, dated April 9,2015
SUBJECT:
PUBLIC MEETING SUMMARY - REGULATORY CONFERENCE WITH ENTERGY OPERATIONS, iNC. FORWATERFORD STEAM ELECTRIC STATION, UNIT 3 DESTRIBUTION:
Regionai Administrator (Marc.Dapas@nrc.gov)
Deputy Regional Administrator (Kriss.Kennedy@nrc.gov)
DRP Director (Troy.Pruett@nrc.gov)
Acting DRP Deputy Director (Thomas. Farnholtz@nrc.gov)
DRS Director (Anton.Vegef@nrc.gov)
DRS Deputy Director (Jeff.CIark@nrc.gov)
Senior Resident inspector (Frances.Ramirez@nrc.gov)
Resident Inspector (Chris.Speer@nrc.gov)
WAT Administrative Assistant (Linda.Dufrene@nrc.gov)
Branch Chief, DRP/D (Michael.Hay@nrc.gov)
Senior Project Engineer, DRP/E (Bob.Hagar@nrc.gov)
Project Engineer, DRP/D (Brian.Parks@nrc.gov)
Project Engineer, DRP/D (Jan.Tice@nrc.gov)
Public Affairs Officer (Victor.Dricks@nrc.gov)
Public Affairs Officer (Lara.Uselding@nrc.gov)
Project Manager (Michael.0renak@nrc.gov)
Branch Chief, DRS/TSB (Geoffrey.Miller@nrc.gov)
RITS Coordinator (Marisa.Herrera@nrc.gov)
ACES (R4Enforcement.Resource@nrc.gov)
Regional Counsel (Karla.Fuller@nrc.gov)
Congressional Affairs Officer (Jenny.Weil@nrc.gov)
Technical Support Assistant (Loretta.Williams@nrc.gov)
RIV Congressional Affairs Officer (Angel.Moreno@nrc.gov)
RIV/ETA: OEDO (Michael.Waters@nrc.gov)
ROPreports
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ENCLOSURE 2 ENTERGY PRESENTATION HANDOUTS
'"^Entefgy WATERFORD 3 REGULATORY CONFERENCE Through-Wall Corrosion on Emergency Diesel Generator A and B Day Tank Vents Apri 7,2015 Entei^gyOP EN NG REMARKS Michael Chisum Site Vice President Waterford 3 Waterford 3 Representatives Ran Gilmore Brian Lanka Manager, Systems and Components Engineering Director, Engineering Jessica Walker PRA Consultant, Jensen Hughes Marvin Chase Director, Regulatory & Performance Improvement Agenda. Overview of Performance Deficiency
. Causes and Corrective Actions nQ©Inputs to the Risk Calculation Safety Significance Calculation Conclusion f:s:'Entergy OVERVIEW OF PERFORMANCE DEFICIENCY Ran Gilmore Manager, Systems and Components Engineering Waterford 3 Performance Deficiency Failure to identify and correct through-wall corrosion on the A and BEmergency Diesel Generator Fuel Oil Day Tank Vent I'nes.
As-Foundnter'm repair HoleLocated at Roofon Missile Shield Side i^
Impact on Plant Not to Scale
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~'sfEnte^gy CAUSES AND CORRECTIVE ACTIONS Ran Gilmore Manager, Systems and Components Engi eering Waterford 3 Day Tank Vent Line Evaluation Resu ts Direct Cause
. Failure of the pipe coating al owed accelerated, local, general corrosion to occur.
Key Cause 0 Failure mechanism ofthrough-wall corrosion combined with postulated precipitation events at the site could challenge EDG safety functions.
a Corrective Actions Replace Temporary Repair with a Permanent Design Change. Immediate Walkdown of Roofs for Similar Configuration
- Reassess impact of Non-Safety Components on EDG(s)
. Emergency Diesel Generator Comprehensive hlealth Assessment General Corrosion Evaluation Results
. Direct Cause
. Normalization of external corrosion on plant equipment by station personnel.
3 Key Cause Inadequate programmatic guidance to ensure consistent identification and correction of coating degradation and external corrosion 0 Corrective Actions 0 Create an External Corrosion standard and program capable of identifying, prioritizing, monitoring, applying resources and repairing degradation of plant equipment related to external corrosion.
6 Utilizing an External Corrosion Team m ^ MEntergyINPUTS TO THE R SK CALCULATION Ran Gi more Manager, Systems and Components Eng Waterford 3 Key Inputs 0©Water Intrusion Rate
. Hole Size and Location 0 Analytic Estimate 0 Roof Test Water Tolerance of EDG
. Test Approach e Test Results Determination of hlole Size Fuel Oil Day Tank B (East Vent)
Not to Scale Determination of Hole Size Fuel Oi Day Tank A (West Vent)
Not to Scale Water Intrusion Analysis Vent BRequired Ponding Depth: A Vent Not to Scale Water Intrusion Analysis 454035305 252015105Day Tank Accumulations 567Rain Rate (In/hr)
- -West ("A") Tank
.East ("B") Tank T9T10-r11t12 Roof Test Purpose9 Validate Analytical Model of Roof Drainage0 Assess Ponding Depth and Boundaries 0 Assess Debris Behavior Roof Test Results° Water Did Not Reach Fuel Oil Day Tank A Vent Line in 20 GPM (5 in/hr)
Test0 Drain Resistance is Less Than Calculated Water Line Near "A" Vent y^s^"\
Roof Test As-found Debris Location Results- Found debris did not transport when placed n as-found location.
e Manually placed next to drain to evaluate effects Debris Next to Drain Debris in As-found Location
-.^^
Roof Ponding Test Results sI454035302520151050Day Tank Accumulations Roof Ponding Result-r1.r-^-^u^^zT6T7T8T9T10T11112Rain Rate (in/hr)
-J-West ("A") Tank Water Tolerance Testing G Waterford EDG Characteristics to Maintain in Test System
- Delivery of water to engine 0 Engine combustion conditions
° Engine loading during a LOOP e Approach 0 Full Scale Testing at Sumner Municipal Light Plant (SMLP) in Sumner. IA 0 12 cylinder Cooper-Bessemer KSV Engine similar to the 16 cylinder Cooper-Bessemer KSV engines at Waterford 9 Duplicate Waterford fuel delivery skid at Sumner Water Tolerance Testing
- 1. Delivery of Water to the Engine Duplicate Waterford Fuel Supply System.
Maintain fuel (and water) flow rates through system the same as at Waterford by: (1) scaling the load profile, and (2) providing takeoff from header to simulate "missing" four cylinders.
- 2. Engine Combustion Conditions Use similar Cooper-Bessemer KSV Engine with same bore, stroke, cylinder liners, pistons, and similar cylinder heads.
Load SMLP engine at a conservatively greater power per cylinder per cycle (to maintain consistent fuel flow rate).
Fuel Injection System with similar characteristics.
(Waterford: Bendix FDX-22, SMLP: Bendix FDX-22G)
- 3. Engine Loading Use Load Bank to simulate Waterford LOOP load profile (scaled to 12 cylinders).
SMLP governor is slower than the Waterford governor, which results in a conservative measure of the impact on EDG frequency.
Water Tolerance Testing Tower with Day Tank New Fuel Header 4 Cylinder Take-Off
-\^^.-r^fwind Straii lers
.4 Water Tolerance Testing Conduct of Test
. "Trickle" Test (Loss of Offsite Power with Rain Event)
. Diesel Started and Loaded to Maximum Peak LOOP Load Scaled to the SMLP Engine 9 Water Introduced into Day Tank at Specified Flow Rate
° "Slug" Test (Loss of Offsite Power after Rain Event)
" Diesel in Standby Specified Water Volume Added to Day Tank and Settled into Low Point of Piping
- Diesel Started and Loaded with LOOP Load Profile Scaled to SMLP Engine
>s:'Entergy TEST RESULTS Brian Lanka Director, Engineering Waterford 3 Water Tolerance Testing Cases Base Line 0 No water test Sug. 1 Gallon
. 5 Gallon with 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> endurance run
- 7 Gallon (5.4 in/hr)
Trickle. 2.7 GPH Trickle 0 21 GPH Trickle with 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> endurance run
. 40 GPH Trickle (11 in/hr)
Water Tolerance Testing AS-BUILT WATERFORD FUEL AND WATER TEST MECHANICAL SYSTEM MPR DwuimntWo. OQe.10e2.140M75-REVISKlN 6->>27<a)1S nFS^-^ff^-Qs^^^^^^^imsTiwwutsimwssiiaiaimiw fMiwnfwvnwisi.
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Water Tolerance Testing Test Type Water VoIume/Flow Engine Fuel Rack PositionGenerator Output Frequency Trickle2.7 GPH for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> No detectable effect No detectable effect Trickle221 GPH for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Up to 2 mm increase1 No detectable effect Trickle40 GPH for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Up to 3 mm increase1 No detectable effect Slug1 GallonNo detectable effect No detectable effect Slug25 GallonUp to 3 mm increase1
<1 Hz decrease1 Slug7 GallonUp to 10 mm increase1 1 Hz decrease during a minor load step1 2 Hz decrease during a major load step1
- 1. Compared with the response in the baseline test.
- 2. A 24-hour endurance test was performed immediately afterthis test.
Water Intrusion Rate Determination 45403530^25I.20IS1050Day Tank Accumulations I 40 GPH Trickle Roof Ponding Result-T1567Rain Rate (In/hr)
^West("A")Tank 112
( _ _ IEntergySAFETY SIGNIFICANCE CALCULATION Jessica Walker, PRA Consultant Jensen hlughes Risk Analysis Risk = Frequency of the Event* Consequences Initiating Event Frequency Rainfall Rate Probability LOOP Frequency Likelihood of High Rainfall Coincident with LOOP Consequences Conditional Core Damage Probabilities
. Coincident
. Non-Coincident Rainfall Rate National Weather Service Data for Waterford 3 Plant0 Provides average recurrence interval in years to achieve hour ong rainfall in inches Used to determine probability of specific rainfa I rates AverageRecurrence Interval(years)10 25 50 100 200 500 1,000 Inches of Rainfall in 1.89 2.21 2.77 3.27 3.98 4.57 5.18 5.83 6.72 7.43 One HourExample: 2 percent (1/50) of the time the highest rainfall rate during the year is approximately 4.6 in/hr nitiating Event Frequency Rainfall Rate Took the average recurrence interval and assumed a direct probabi ity of rain 0 Conservatively used the annual recurrence as the probability
° Probability of having a rainfall rate of 4.57 in/hr is 0.02 (1/50)
Fina Probability Values interpolated from available data to provide rainfall rates that correspond with testing
>> 5.4in/hr=7.1E-03
. 11 in/hr = 9.5E-04*
- Note: Data past 8 in/hr has greater uncertainty 9.5E-04 (8 in/hr value) utilized Initiating Event Frequency LOOP Frequency Coincident - Severe Weather Related LOOP
. 12 separate severe weather induced LOOP events at U.S.
nuclear plants from 1986 through 2012
. Dividing by total critical reactor years during this period (2,332.6 rcry)
. Weather induced at power LOOP Frequency of 5.1 E-03/yr Non-Coincident - LOOP not caused by weather
. Utilized the WFSAt-Power model 0 Removed the Severe Weather events
" LOOP Frequency of 2.1 E-02/yr Initiating Event Frequency Rainfall and LOOP
. Historical weather induced LOOP events
. Lightning strikes 8 High winds (e.g. tornado and hurricane) e No mention of significant rainfall
' Review of rainfall data for these events
. Rainfall not a direct cause of Loss of Offsite Power Severe Weather assumed to cause both the LOOP and the extreme ra'nfall Initiating Frequency
. Severe Weather LOOP
- Rainfall Probabi ity CoinddentACDF Calculatio Initiating Event Frequency
° Severe Weather LOOP Frequency 9 Utilized Severe Weather Offsite Recovery Factors 0 Coincident Rainfall Rate Probability Consequences Successful 40 GPH trickle test. Assumed reduced reliability of diesels- Utilized WF3 Internal Event PRA Model
. CCDPpo = 2.92E-03
- CCDP^eline = 5.28E-04 ACDF = LOOP
- RR * (CCDPpo-CCDP^iine) 5.1 E-03/yr
- 9.5E-04 * (2.92E 5.28E-04) = 1.16E-08/yr Non-CoincidentACDF Calculation Initiating Event Frequency 0 LOOP Frequency without Severe Weather
- Rainfall Rate Probability
. Exposure time of 0.019 year8 Based on EDG surveillance testing frequency Consequences Successful 7 gallon slug test. Assumed failed diesels at >
5.4 in/hr rainfall Utilized WF3 Internal Event PRA Model
. CCDFpD=1.19E-03/yr
. CCDF^eiine = 4.39E-06/yr ACDF = (RR) * (exp) * (CCDFpo-CCDF^eiine)
ACDF = (7 1E-03) * (0.019) * (1.19E-03/yr - 4.39E-06/yr)
ACDF = 1.62E-07/yr Combined ACDF Results
° Coincident LOOPACDF = 1.16E-08/vr
. Non-Coincident LOOPACDF = 1.62E-07/vr
" Total ACDF = 1.73E-07/vr Q LERF calculations performed in similar manner as CDF calculations Total ALERF = 1.77E-09/vr Coincident LOOP CDF Sensitivity Frequency 0 Lower Bound Case R 5th percentile for severe weather LOOP frequency 0 5th percentile for probability of rainfall rate
- Total ACDF = 2.41 E-08/vr 0 Nominal Case 0 Nominal severe weather LOOP frequency 0 Nominal probability of rainfal rate
- Total ACDF = 1 .73E-07/vr 0 Upper Bound Case 0 95th percentile for severe weather LOOP frequency 0 95th percentile for probability of rainfall rate
< Total ACDF = 5.81 E-07/vr Non - Coincident LOOP CDF Sensitivity Rainfall Rate Lower Bound Case
. Rainfall rate of 6.4 in/hr ffl Total ACDF = 7.96E-08/vr Nominal Case 0 Rainfall rate of 5.4 in/hr
. Total ACDF == 1.73E-07/vr Upper Bound Case 8 Rainfall rate of 4.4 in/hr Total ACDF = 4.72E-07/vr PRA Specific Conservatisms
. Coincident Case
. Diesels showed successful operation during 40 GPH trickle test
. Analysis assumes run failure ofdiesels increased by a factor of 10 above 8 in/hr rainfall
. Analysis utilizes 8 in/hr rainfall although 40 GPH is closer to 11 in/hr
. Assumed that a LOOP at Waterford occurs coincident with the highest rainfall event of the year
. Non-Coincident Case
. Diesel showed successfu operation during 7 gallon slug test
. Analysis failed both diesels for rainfall rates above 5.4 in/hr
- No credit assumed in PRAfor restart ofdiesels Ente^yCONCLUSION Marvin Chase Director, Regu atory and Performance mprovement Waterford 3 Sum naryCompleted Extensive Water Tolerance Testing of Diesel Generator
° Trickle Tests B S ug Tests In ALL Cases Diesel Demonstrated Continued Capability to Perform its Safety Function Summary. Established Station Rainfall Rate 0 Determined Roof Ponding Depths
. Determined Water Intrusion Rates via Day Tank Vent Determined LOOP Coincident with Rainfall Frequency from NRC Data
" PRA Results Organizational Learnings Conclusion
. The station conclusion is that the PRA results support a determination that the failure to identify and correct through-wa I corrosion on the A and B EDG Fuel Oil Day Tank Vent lines is of a very low safety significance EntergyCLOSING COMMEN S Michael Chisum Site Vice President Waterford 3 Letter to Michael R. Chisum from Thomas R. Farnholtz, dated April 9,2015
SUBJECT:
PUBLIC MEETING SUMMARY - REGULATORY CONFERENCE WITH ENTERGY OPERATIONS, INC. FOR WATERFORD STEAM ELECTRIC STATION, UNET 3 DISTRIBUTiON:
Regional Administrator (Marc.Dapas@nrc.gov)
Deputy Regional Administrator (Kriss.Kennedy@nrc.gov)
DRP Director (Troy.Pruett@nrc.gov)
Acting DRP Deputy Director (Thomas.Farnholtz@nrc.gov)
DRS Director (Anton.Vegel@nrc.gov)
DRS Deputy Director (Jeff.Clark@nrc.gov)
Senior Resident Inspector (Frances.Ramirez@nrc.gov)
Resident Inspector (Chris.Speer@nrc.gov)
WAT Administrative Assistant (Linda.Dufrene@nrc.gov)
Branch Chief, DRP/D (Michael.Hay@nrc.gov)
Senior Project Engineer, DRP/E (Bob.Hagar@nrc.gov)
Project Engineer, DRP/D (Brian.Parks@nrc.gov)
Project Engineer, DRP/D (Jan.Tice@nrc.gov)
Public Affairs Officer (Victor.Dricks@nrc.gov)
Public Affairs Officer (Lara.Uselding@nrc.gov)
Project Manager (Michael.0renak@nrc.gov)
Branch Chief, DRS/TSB (Geoffrey.Miller@nrc.gov)
RITS Coordinator (Marisa.Herrera@nrc.gov)
ACES (R4Enforcement.Resource@nrc.gov)
Regional Counsel (Karla.Fuller@nrc.gov)
Congressional Affairs Officer (Jenny.Weil@nrc.gov)
Technical Support Assistant (Loretta.Williams@nrc.gov)
RiV Congressional Affairs Officer (Angel.Moreno@nrc.gov)
RIV/ETA: OEDO (Michael.Waters@nrc.gov)
ROPreports