4-13-2017 | APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2018 Reported lessons learned are incorporated into the licensing process and fed back to industry.
Send comments regarding burden estimate to the FOIA, Privacy and Information Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by e-mail to Infocollects.Resource@nrc.gov, and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202, (3150-0104), Office of Management and Budget, Washington, DC 20503. If a means used to impose an information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection. |
---|
Similar Documents at Hatch |
---|
Category:Letter
MONTHYEARNL-24-0337, Interim 10 CFR 21.21(a)(2) Report Regarding Operation Technology, Inc., ETAP Software Error in Transient Stability Program2024-09-0909 September 2024 Interim 10 CFR 21.21(a)(2) Report Regarding Operation Technology, Inc., ETAP Software Error in Transient Stability Program ML24249A1362024-09-0404 September 2024 EN 57304 - Westinghouse Electric Company, LLC, Final Report - No Embedded Files. Notification of the Potential Existence of Defects Pursuant to 10 CFR Part 21 NL-24-0334, 0 to the Updated Final Safety Analysis Report, Technical Specifications Bases Changes, Technical Requirements Manual Changes, License Renewal 10 CFR 54 .37(b) Changes, 10 CFR 50.59 Summary Report & Revised Nrc2024-09-0303 September 2024 0 to the Updated Final Safety Analysis Report, Technical Specifications Bases Changes, Technical Requirements Manual Changes, License Renewal 10 CFR 54 .37(b) Changes, 10 CFR 50.59 Summary Report & Revised Nrc IR 05000321/20240052024-08-26026 August 2024 Updated Inspection Plan for Edwin I. Hatch Nuclear Plant, Units 1 and 2 - Report 05000321/2024005 and 05000366/2024005 NL-24-0313, Application to Revise Technical Specifications Surveillance Requirements to Increase Safety/Relief Valves Setpoint Response to Request for Additional Information2024-08-23023 August 2024 Application to Revise Technical Specifications Surveillance Requirements to Increase Safety/Relief Valves Setpoint Response to Request for Additional Information IR 05000321/20240022024-08-0808 August 2024 Edwin I Hatch Nuclear Plants, Units 1 and 2 – Integrated Inspection Report 05000321-2024002 and 05000366-2024002 NL-24-0276, Post-Audit Supplement to License Amendment Request to Revise Renewed Facility Operating Licenses to Adopt an Alternative Seismic Method for Categorization of Structures, Systems, and Components2024-07-26026 July 2024 Post-Audit Supplement to License Amendment Request to Revise Renewed Facility Operating Licenses to Adopt an Alternative Seismic Method for Categorization of Structures, Systems, and Components NL-24-0290, Response to Request for Additional Information Related to Request for Specific Exemption2024-07-26026 July 2024 Response to Request for Additional Information Related to Request for Specific Exemption NL-24-0261, 10 CFR 50.46 ECCS Evaluation Model Annual Report for 20232024-07-19019 July 2024 10 CFR 50.46 ECCS Evaluation Model Annual Report for 2023 ML24198A1252024-07-16016 July 2024 Edwin I Hatch Nuclear Plant Units 1 - 2 Notification of Conduct of Title 10 of the Code of Federal Regulations 50 NL-24-0260, Inservice Inspection Program Owner’S Activity Report (OAR-1) for Refueling Outage 1R312024-07-0909 July 2024 Inservice Inspection Program Owner’S Activity Report (OAR-1) for Refueling Outage 1R31 NL-24-0143, Proposed Alternative to Use ASME Code Case N-752, Risk-Informed Categorization and Treatment for Repair/ Replacement Activities in2024-06-27027 June 2024 Proposed Alternative to Use ASME Code Case N-752, Risk-Informed Categorization and Treatment for Repair/ Replacement Activities in NL-24-0239, Response to Apparent Violation in NRC Inspection Report 05000321, 366/2024090: EA-23-1392024-06-17017 June 2024 Response to Apparent Violation in NRC Inspection Report 05000321, 366/2024090: EA-23-139 ML24163A0532024-06-14014 June 2024 Audit Plan - Alternative Seismic Method LAR NL-24-0148, Report of Changes to Emergency Plan and Summary of 50.54(q) Analysis2024-06-0404 June 2024 Report of Changes to Emergency Plan and Summary of 50.54(q) Analysis ML24149A0492024-06-0404 June 2024 SNC Fleet - Regulatory Audit in Support of Review of the License Amendment Request to Revise TS 1.1, Use and Application Definitions, and Add New Technical Specification 5.5.21 and 5.5.17, Online Monitoring Program, NL-24-0202, SNC Response to Regulatory Issue Summary 2024-01: Preparation and Scheduling of Operator Licensing Examinations2024-05-24024 May 2024 SNC Response to Regulatory Issue Summary 2024-01: Preparation and Scheduling of Operator Licensing Examinations IR 05000321/20240902024-05-15015 May 2024 NRC Inspection Report 05000321-2024090 and 05000366-2024090, Investigation Report 2-2023-003; and Apparent Violation NL-24-0191, Annual Radiological Environmental Operating Reports for 20232024-05-10010 May 2024 Annual Radiological Environmental Operating Reports for 2023 NL-24-0195, Response to Request for Additional Information Regarding License Amendment Request to Revise Technical Specifications to Adopt Risk Informed Completion Times for Residual Heat Removal Service Water.2024-05-0707 May 2024 Response to Request for Additional Information Regarding License Amendment Request to Revise Technical Specifications to Adopt Risk Informed Completion Times for Residual Heat Removal Service Water. NL-24-0064, Units 1 & 2 and Hatch Nuclear Plant - Units 1 & 2 License Amendment Request to Revise Technical Specification 1.1 and Add Online Monitoring Program to Technical Specification 5.52024-05-0303 May 2024 Units 1 & 2 and Hatch Nuclear Plant - Units 1 & 2 License Amendment Request to Revise Technical Specification 1.1 and Add Online Monitoring Program to Technical Specification 5.5 IR 05000032/20240112024-04-25025 April 2024 Notification of Edwin I. Hatch Nuclear Plant - Comprehensive Engineering Team Inspection (CETI) Baseline Inspection Report 0500032/2024011 and 05000366/2024011 NL-24-0165, Annual Non-Radiological Environmental Operating Reports and Annual Radioactive Effluent Release Reports for 20232024-04-25025 April 2024 Annual Non-Radiological Environmental Operating Reports and Annual Radioactive Effluent Release Reports for 2023 IR 05000321/20240012024-04-22022 April 2024 Plants, Units 1 & 2 - Integrated Inspection Report 05000321/2024001 and 05000366/2024001 NL-24-0026, Application to Revise Technical Specifications Surveillance Requirements to Increase Safety/Relief Valves Setpoint2024-04-19019 April 2024 Application to Revise Technical Specifications Surveillance Requirements to Increase Safety/Relief Valves Setpoint NL-24-0115, Response to Request for Additional Information Exemption Requests for Physical.2024-04-0404 April 2024 Response to Request for Additional Information Exemption Requests for Physical. NL-24-0116, Nuclear Property Insurance Coverage as of April 1, 2024 and Licensee Guarantees of Payment of Deferred.2024-03-29029 March 2024 Nuclear Property Insurance Coverage as of April 1, 2024 and Licensee Guarantees of Payment of Deferred. NL-24-0062, Report of Changes to Emergency Plan and Summary of 50.54(q) Analysis2024-03-12012 March 2024 Report of Changes to Emergency Plan and Summary of 50.54(q) Analysis NL-24-0089, Correction of Technical Specification Omission2024-03-0909 March 2024 Correction of Technical Specification Omission ML24069A0012024-03-0909 March 2024 – Correction of Amendment No. 266 Regarding License Amendment Request Regarding Relocation of Specific Surveillance Frequencies to a Licensee-Controlled Program (TSTF-425, Revision 3) ML24047A0362024-03-0404 March 2024 Response to Hatch and Vogtle FOF Dates Change Request (2025) NL-24-0061, Cycle 32 Core Operating Limits Report Version 12024-03-0101 March 2024 Cycle 32 Core Operating Limits Report Version 1 IR 05000321/20230062024-02-28028 February 2024 Annual Assessment Letter Edwin I. Hatch Nuclear Plant Units 1 and 2 - Nrc Inspection Report 05000321/2023006 and 05000366/2023006 NL-24-0067, 10 CFR 72.48(d)(2) Biennial Report2024-02-26026 February 2024 10 CFR 72.48(d)(2) Biennial Report NL-24-0051, License Amendment Request to Revise Renewed Facility Operating Licenses to Adopt an Alternative Seismic Method for Categorization of Structures, Systems, and Components2024-02-20020 February 2024 License Amendment Request to Revise Renewed Facility Operating Licenses to Adopt an Alternative Seismic Method for Categorization of Structures, Systems, and Components NL-24-0042, Response to Request for Additional Information Exemption Requests for Physical Barriers2024-02-13013 February 2024 Response to Request for Additional Information Exemption Requests for Physical Barriers NL-24-0033, Response to Question for Withholding Information from Public Disclosure Exemption Requests for Physical Barriers2024-02-0505 February 2024 Response to Question for Withholding Information from Public Disclosure Exemption Requests for Physical Barriers IR 05000321/20230042024-01-31031 January 2024 Integrated Inspection Report 05000321/2023004 and 05000366/2023004 NL-24-0014, Revised Response to Request for Additional Information Regarding License Amendment Request to Relax the Required Number of Fully Tensioned Reactor Pressure Vessel Head Closure Studs in Technical.2024-01-30030 January 2024 Revised Response to Request for Additional Information Regarding License Amendment Request to Relax the Required Number of Fully Tensioned Reactor Pressure Vessel Head Closure Studs in Technical. ML24012A0652024-01-30030 January 2024 Exemption from Select Requirements of 10 CFR Part 73 (Security Notifications, Reports, and Recordkeeping and Suspicious Activity Reporting) IR 05000321/20233012024-01-17017 January 2024 NRC Operator License Examination Report 05000321/2023301 and 05000366/2023301 ML23341A2042024-01-12012 January 2024 Request for Additional Information Exemption Requests for Physical Barriers (EPID L-2023-LLE-0018 & L-2023-LLE-0021) ML23345A1312024-01-0303 January 2024 Withholding Letter - SNC Fleet - Physical Barriers Exemption (L-2023-LLE-0018 and L-2023-LLE-0021) NL-23-0889, Units 1 and 2 - License Amendment Request to Revise Technical Specifications to Adopt Risk Informed Completion Times for Residual Heat Removal Service Water (RHRSW) and Plant Service Water (Psw) Systems2023-12-0606 December 2023 Units 1 and 2 - License Amendment Request to Revise Technical Specifications to Adopt Risk Informed Completion Times for Residual Heat Removal Service Water (RHRSW) and Plant Service Water (Psw) Systems NL-23-0879, Request for Exemption from Security Event Notification Implementation2023-11-29029 November 2023 Request for Exemption from Security Event Notification Implementation IR 05000321/20234022023-11-29029 November 2023 Security Baseline Inspection Report 05000321/2023402, 05000366/2023402, and 07200036/2023401 NL-23-0841, Update to Notice of Intent to Pursue Subsequent License Renewal2023-11-20020 November 2023 Update to Notice of Intent to Pursue Subsequent License Renewal IR 05000321/20230112023-11-17017 November 2023 Biennial Problem Identification and Resolution Inspection Report 050003212023011 and 050003662023011 ML23324A4472023-11-14014 November 2023 302 Exam Approval Letter 2024-09-09
[Table view] Category:Licensee Event Report (LER)
MONTHYEARNL-20-0230, Edwin I. Hatch Nuclear Plant, Unit 2, Primary Containment Penetration Exceeded Maximum Allowable Primary Containment Leakage Rate (La)2020-03-0202 March 2020 Edwin I. Hatch Nuclear Plant, Unit 2, Primary Containment Penetration Exceeded Maximum Allowable Primary Containment Leakage Rate (La) 05000366/LER-2020-0012020-03-0202 March 2020 LER 2020-001-00 for Edwin I. Hatch Nuclear Plant, Unit 2, Primary Containment Penetration Exceeded Maximum Allowable Primary Containment Leakage Rate (La) 05000321/LER-2017-0042017-08-24024 August 2017 Tornado Missile Vulnerabilities Result in Condition Prohibited by Technical Specifications, LER 17-004-00 for Edwin I. Hatch Regarding Safety Relief Valves' as Found Settings Resulted in Not Meeting Tech Spec Surveillance Criteria 05000366/LER-2017-0022017-04-13013 April 2017 Emergency Diesel Generator Start Due to Inadvertent Electrical Bus De-Energization, LER 17-002-00 for Edwin I. Hatch, Unit 2, Regarding Emergency Diesel Generator Start Due to Inadvertent Electrical Bus De-Energization 05000366/LER-2017-0032017-04-13013 April 2017 LER 17-003-00 for Edwin I. Hatch, Unit 2, Regarding Primary Containment Isolation Penetration Exceeded Overall Allowable Technical Specification Leakage Limits 05000321/LER-2017-0022017-04-0707 April 2017 High Pressure Coolant Injection System Declared Inoperable Due to Degraded Inverter, LER 17-002-00 for Edwin I. Hatch, Unit 1, Regarding High Pressure Coolant Injection System Declared Inoperable Due to Degraded Inverter 05000366/LER-2016-0042017-01-0303 January 2017 Condition Prohibited by Technical Specifications Due to Inoperable PCIV, LER 16-004-00 for Edwin I. Hatch Nuclear Plant, Unit 2, Regarding Condition Prohibited by Technical Specifications Due to Inoperable PCIV 05000366/LER-2016-0022016-07-13013 July 2016 Group I Isolation Received During Turbine Testing, LER 16-002-00 for Edwin I. Hatch, Unit 2, Regarding Group 1 Isolation Received During Turbine Testing 05000366/LER-2016-0012016-06-0808 June 2016 2C EDG Fuel Oil Relief Valve Leakage Caused Train Inoperability, LER 16-001-00 for E.I. Hatch, Unit 2, Regarding 2C EDG Fuel Oil Relief Valve Leakage Caused Train Inoperability 05000321/LER-2016-0042016-05-26026 May 2016 Safety Relief Valves As Found Settings Resulted in Not Meeting Tech Spec Surveillance Criteria, LER 16-004-00 for Edwin I. Hatch Nuclear Plant Unit 1 RE: Safety Relief Valves as Found Settings Resulted in Not Meeting Tech Spec Surveillance Criteria 05000321/LER-2016-0032016-04-14014 April 2016 Reactor Coolant System Piping Has Unacceptable Weld Indication Discovered During Refueling Outage, LER 16-003-00 for E.I. Hatch, Unit 1, Regarding Reactor Coolant System Piping Has Unacceptable Weld Indication Discovered During Refueling Outage 05000321/LER-2016-0022016-04-11011 April 2016 Performance of Operations With the Potential to Drain the Reactor Vessel (OPDRV) Without Secondary Containment, LER 16-002-00 for E.I Hatch, Unit 1, Regarding Performance of Operations With the Potential to Drain the Reactor Vessel (OPDRV) Without Secondary Containment 05000321/LER-2016-0012016-04-0808 April 2016 Performance of Fuel Movement with Inoperable Rod Position Indication System in Violation of Technical Specifications, LER 16-001-00 for Edwin I. Hatch, Unit 1, Regarding Performance of Fuel Movement With Inoperable Rod Position Indication System in Violation of Technical Specifications NL-08-1906, LER 08-S01-00, for Edwin I. Hatch, Failure to Report Arrest Results in Inappropriate Access to Protected and Vital Areas2008-12-19019 December 2008 LER 08-S01-00, for Edwin I. Hatch, Failure to Report Arrest Results in Inappropriate Access to Protected and Vital Areas ML1019404552008-05-0808 May 2008 Southern Nuclear Plant E. I. Hatch - Actions for Potential Groundwater Contamination Events NL-06-2726, LER 06-S01-00 for Edwin I. Hatch Nuclear Plant, Re Contract Employee Failure to Self-Disclose Material Information for Unescorted Access2006-12-0505 December 2006 LER 06-S01-00 for Edwin I. Hatch Nuclear Plant, Re Contract Employee Failure to Self-Disclose Material Information for Unescorted Access ML17252B4401976-04-15015 April 1976 LER 76-026-00 for Hatch, Unit 1 Regarding an Occurrence of Open Links in Panel H11-P601 Defeating the Starting of All RHR Pumps After They Had Been Stopped 2020-03-02
[Table view] |
Primary Containment Isolation Penetration Exceeded Overall Allowable Technical Specification Leakage Limits 8. OTHER FACILITIES INVOLVED 5. EVENT DATE 6. LER NUMBER 7. REPORT DATE
FACILITY NAME DOCKET NUMBER REV
MONTH YEAR DAY YEAR MONTH DAY YEAR
DOCKET NUMBER FACILITY NAME
02 19 2017 2017 - 003 - 00 4 13 2017 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR 10 CFR : (Check all that apply) q 20.2203(a)(3)(i) 0 50.73(a)(2)(viii)(A) q 20.2201(b) 50.73(a)(2)(ii)(A) 0 20.2201(d) 0 50.73(a)(2)(viii)(B) 0 20.2203(a)(3)(ii) 0 50.73(a)(2)(ii)(B) 0 20.2203(a)(1) 0 50.73(a)(2)(ix)(A) 0 20.2203(a)(4) 0 50.73(a)(2)(iii) 0 20.2203(a)(2)(i) 0 50.73(a)(2)( 0 50.36(c)(1)(i)(A) 0 50 73(a)(2)(iv)(A) 0 20.2203(a)(2)(ii) 0 73.71(a)(4) 0 50.36(c)(1)(ii)(A) 0 50.73(a)(2)(v)(A) 0 20.2203(a)(2)(iii) 0 73.71(a)(5) 0 50.36(c)(2) 0 50.73(a)(2)(v)(B) 0 20.2203(a)(2)(iv) 0 73.77(a)(1) 0 50.46(a)(3)(ii) 50.73(a)(2)(v)(C) 0 20.2203(a)(2)(v) q 73.77(a)(2)(i) 0 50.73(a)(2)(i)(A) 0 50.73(a)(2)(v)(D) 0 20.2203(a)(2)(vi) 0 73.77(a)(2)(ii) 0 50.73(a)(2)(i)(B) 0 50.73(a)(2)(vii) 0 50.73(a)(2)(i)(C) 0 OTHER Specify in Abstract below or in NRC Form 366A TELEPHONE NUMBER (Include Area Code) ICENSEE CONTACT Edwin I. Hatch / Jimmy Collins - Licensing Supervisor 912-537-2342
13. COMPLETE ONE UNE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT
1 MANU- REPORTABLE COMPONENT CAUSE SYSTEM COMPONENT FACTURER TO EPIX
REPORTABLE
MANU-
FACTURER CAUSE SYSTEM
4 X BB ISV F130 Y
15. EXPECTED
SUBMISSION
DATE
DAY YEAR MONTH
outboard drywell ventilation penetration isolation valve 2T48F320 (EIIS Code: ISV) failed local leak rate testing (LLRT).
Previously on February 7, 2017 at 1427 EST, the inboard drywell ventilation penetration isolation valve 2T48F319 had also failed LLRT. Therefore, due to both primary containment isolation valves (PCIVs) in this penetration flow path exceeding the maximum allowable leakage rate (La), this event represents a failure of the associated penetration (2T23X26) to maintain primary containment integrity per Technical Specifications (TS).
Actions were taken to repair both of the PCIVs and on February 21, 2017, the valves were successfully retested. During the next scheduled Unit 2 refueling outage, the 2T48F320 isolation valve will be completely rebuilt. Also a corrective maintenance rebuild procedure will be developed for Fisher Series 9200 butterfly valves.
Reported lessons learned are incorporated into the licensing process and fed back to industry Send comments regarding burden estimate to the FOIA, Privacy and Information Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by e-mail to Infocollects.Resource@nrc.gov, and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202, (3150-0104), Office of Management and Budget, Washington, DC 20503. If a (See NUREG-1022, R.3 for instruction and guidance for completing this form means used to impose an information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
CONTINUATION SHEET
http://www.nrc.00v/readino-nn/doc-collections/nureps/staff/sr1022/r3/) 05000-366
Event Description
On February 19, 2017 at 2323 EST, with Unit 2 at 0 percent rated thermal power due to a refueling outage, the Unit 2 outboard drywell ventilation penetration isolation valve 2T48F320 (EIIS Code: ISV) failed local leak rate testing (LLRT). Previously on February 7, 2017 at 1427 EST, the inboard drywell ventilation penetration isolation valve 2T48F319 had also failed LLRT. Therefore, due to both primary containment isolation valves (PCIVs) in this penetration flow path exceeding the maximum allowable leakage rate (La), this event represents a failure of the associated penetration (2T23X26) to maintain primary containment integrity per Technical Specifications (TS).
The as-found results of the LLRT rendered penetration 2T23X26 inoperable. Actions were made to repair both of the PCIVs and on February 21, 2017, the valves were successfully retested. Observed leakage rates were determined to be acceptable.
Failed Components Information:
Master Parts List Number 2T48F319 and 2T48F320 Manufacturer: Fisher Controls Co.
Model Number. Model 9220 Type: Isolation Valves Event Cause Analysis The cause of the both the 2T48F319 and 2T48F320 PCIVs exceeding their acceptable maximum allowable leakage limits was attributed to inadequate conditions related to the disc sealing ring that was found on both valves. Specifically for the 2T48F320 isolation valve, it was revealed that the set screws that are used to hold in place the retaining plate for the disc sealing ring were all loose. This allowed the ring to loosen over time, creating a gap between the valve disc and the ring.
Safety Assessment This event is reportable per 10 CFR 50.73(a)(2)(ii)(A) due to an event or condition that resulted in the condition of the nuclear power plant, including its principle safety barriers, being seriously degraded. This event is also reportable per 10 CFR 50.73(a)(2)(v)(C) as an event or condition that could have prevented the fulfillment of the safety function of structures or systems that are needed to control the release of radioactive material due to the failure of the penetration flow path to meet its maximum allowable leakage rate.
The function of the PCIVs, in combination with other accident mitigation systems, is to limit fission product release during and following postulated Design Basis Accidents (DBAs) to within limits. Primary containment isolation ensures that the release of radioactive material to the environment will be consistent with the assumptions used in the analyses for a DBA. Operability requirements for the PCIVs help ensure that an adequate primary containment boundary is maintained during and after an accident by minimizing potential paths to the environment. This provides assurance that the primary containment function as assumed in safety analyses is maintained. Two barriers in series are provided for each penetration such that no single credible failure or malfunction of an active component can result in a loss of isolation or leakage that exceeds limits assumed in the safety analyses.
`NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2018 LICENSEE EVENT REPORT(LER) Reported lessons learned are incorporated into the licensing process and fed back to industry.
Send comments regarding burden estimate to the FOIA, Privacy and Information Collections
CONTINUATION SHEET
Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by e-mail to Infocollects.Resource@nrc.gov, and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202, (3150-0104), Office of Management and Budget, Washington, DC 20503. If a (See NUREG-1022, R.3 for instruction and guidance for completing this form means used to impose an information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
Edwin I. Hatch Nuclear Plant Unit 2 05000-366 NUMBER NO.
A calculation was performed to determine the impact of drywell ventilation penetration 2T23X26 leakage exceeding La on post-LOCA doses, where La is the maximum allowable primary containment leakage rate per TS 5.5.12. The calculation evaluated doses to the main control room (MCR), the technical support center (TSC), the exclusion area boundary (EAB), and the low population zone (LPZ). The results of the calculation show that with an assumed containment leakage rate of 3 times La, and an assumed MSIV leakage of twice the as-found leakage rate, doses to the MCR, TSC, EAB and LPZ were all within the regulatory limits. The actual as-found overall leakage rate of primary containment was determined to be 2.3 times La, 23 percent less than the assumed value.
Therefore, based on the aforementioned calculation results, the potential safety consequences of exceeding the maximum allowable TS primary containment leakage rate by a factor of 2.3 are very low due to radiation doses in the MCR, TSC, EAB and LPZ all being within regulatory limits. Radiation doses would not have exceeded federal limits during a design basis event.
Corrective Actions
The ring assemblies on both the 2T48F319 and 2T48F320 valves were replaced and the set screws were adjusted. The valves were successfully retested with an observed acceptable leakage rate. During the next scheduled Unit 2 refueling outage, the 2T48F320 isolation valve will be completely rebuilt Also a corrective maintenance rebuild procedure will be developed specifically for Fisher Series 9200 butterfly valves.
Previous Similar Events
On April 16, 2011, during the Hatch Nuclear Plant 2R21 refueling outage, a local leak rate test (LLRT) was performed on torus purge supply primary containment isolation valve (PCIV) 2T48-F324 which is associated with primary containment penetration 2T23-X205. At that time, plant engineers and technicians were performing an LLRT for penetration 2T23-X205 when it was discovered that both PCIVs (2T48-F309 and 2T48-F324) had failed their LLRTs for this penetration. This resulted in the penetration leakage exceeding the overall allowable leakage (La) requirements by the Technical Specifications (TS) for primary containment.
Although the event documented above is similar, the corrective actions taken did not prevent the 2T48F319 or 2T48F320 valves from failing their LLRT.
htto://www.nrc.novireadine-rm/doc-collectionsinureps/staff/sr1022/1-30
|
---|
|
|
| | Reporting criterion |
---|
05000366/LER-2017-001 | 1 OF 3 | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications | 05000366/LER-2017-002 | Emergency Diesel Generator Start Due to Inadvertent Electrical Bus De-Energization LER 17-002-00 for Edwin I. Hatch, Unit 2, Regarding Emergency Diesel Generator Start Due to Inadvertent Electrical Bus De-Energization | 10 CFR 50.73(a)(2)(iv)(A), System Actuation | 05000321/LER-2017-002 | High Pressure Coolant Injection System Declared Inoperable Due to Degraded Inverter LER 17-002-00 for Edwin I. Hatch, Unit 1, Regarding High Pressure Coolant Injection System Declared Inoperable Due to Degraded Inverter | 10 CFR 50.73(a)(2)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | 05000366/LER-2017-003 | LER 17-003-00 for Edwin I. Hatch, Unit 2, Regarding Primary Containment Isolation Penetration Exceeded Overall Allowable Technical Specification Leakage Limits | 10 CFR 50.73(a)(2)(v)(C), Loss of Safety Function - Release of Radioactive Material 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded | 05000321/LER-2017-004 | Tornado Missile Vulnerabilities Result in Condition Prohibited by Technical Specifications LER 17-004-00 for Edwin I. Hatch Regarding Safety Relief Valves' as Found Settings Resulted in Not Meeting Tech Spec Surveillance Criteria | 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
|