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05000289/FIN-2018003-02Minor Violation2018Q3This violation of minor significance was identified by the licensee and has been entered the licensee corrective action program and is being treated as a minor violation, consistent with the NRC Enforcement Policy. During TMIs 2015 refueling outage (T1R21) NRC and the licensee identified issues regarding reactor building pre-staging of materials were documented in NRC inspection report 05-289/2017008 (ADAMS Accession Number ML17191A697). Exelon evaluated and documented corrective actions in ACE report 2578255 which included an action to conduct an effectiveness review of those corrective actions. On October 18, 2017, after refueling outage T1R22, Exelon completed this effectiveness review. Exelon concluded that the implemented corrective actions were ineffective based on an adverse trend of licensee-identified reactor building pre-staging issues during the T1R22 refueling outage preparations. Exelon documented the results of the effectiveness review under assignment 21 of ACE 2578255 and the adverse trend in issue report 4051608. Primarily, direct oversight by Exelon staff during all phases of pre-staging, as approved by the management review committee, was not implemented and resulted in improper storage of materials in the reactor building during pre-staging activities. The improper storage was identified by Exelon during end-of-day walkdowns, from September 11 thru September 14, 2017, and documented in the corrective action program. All other corrective actions from ACE 2578255 were properly implemented. Screening: Exelons failure to implement the approved corrective actions is a performance deficiency. The inspector evaluated the significance in accordance with IMC 0612, Appendix B, Issue Screening. The inspector determined that this issue was of minor safety significance because non-compliant material configurations in the reactor building were corrected before being left unattended at the end of shift and that the corrective actions determined by ACE 2578255, except for direct Exelon supervision during pre-staging activities, were adequately implemented. Enforcement: Exelon identified this violation and documented the issue in report assignments 2578255-21 and 4051608-02. Exelon has initiated actions to include direct Exelon supervision to the current pre-staging corrective actions (AR 4051608-03) and will conduct an effectiveness review of pre-staging activities after the next outage (AR 2578255-22). This failure to comply with 10 CFR Part 50 Appendix B Criterion XVI constitutes a minor violation that is not subject to enforcement action in accordance with the NRCs Enforcement Policy.
05000289/FIN-2018003-011A Emergency Diesel Generator Lube Oil Leak Inadequate Corrective Actions2018Q3A self-revealed Green non-cited violation of 10 CFR Part 50, Appendix B, Criterion XVI, Corrective Action, was identified for failure to develop and implement adequate corrective actions to ensure the availability and reliability of the 1A emergency diesel generator.
05000289/FIN-2018410-01Security2018Q3
05000289/FIN-2018012-01Failure to Establish Appropriate Corrective ActionsAssociated with a Degraded Non-Safety Related Piping System.2018Q2The NRC identified a Green finding when Exelon failed to establish appropriate corrective actions for a non-safety related system in the vicinity of safety-related equipment from 2010 to 2018. Specifically, failure to fix non-safety related piping resulted in its failure and water intrusion into the ESAS cabinets. This resulted in an event that required extensive clean up and detailed inspection of several Emergency Safeguards Actuation System (ESAS) cabinets due to water intrusion from the non-safety related system.
05000289/FIN-2018001-03Licensee-Identified Violation2018Q1This violation of very low safety significancewas identified by the licensee and has been entered into the licensee corrective action program and is being treated as a Non-Cited Violation, consistent with Section2.3.2 of the Enforcement Policy.Violation: 10 CFR 50.63(c)(2) states, in part, that the alternate ac power source will constitute acceptable capability to withstand station blackout provided an analysis is performed which demonstrates that the plant has this capability from onset of the station blackout until the alternate ac source and required shutdown equipment are started and lined up to operate. The time required for startup and alignment of the alternate ac power source and this equipment shall be demonstrated by test. If the alternate ac source can be demonstrated by test to be available to power the shutdown buses within 10 minutes of the onset of station blackout, then no coping analysis is required. The Three Mile Island Unit 1 Station Blackout Evaluation Report 990-1879 identifies the station blackout (SBO) diesel generator as the alternate ac power source for the unit. Contrary to the above, from January 11, 2018, to January 12, 2018, the Three Mile Island Unit 1 alternate ac power source did not constitute acceptable capability to withstand station blackout. Specifically, during this timeframe, the SBO diesel generator was rendered unavailable due to fire service valve FS-V-225 being closed with no dedicated operator to reopen the valve. The time required for startup and alignment of the SBO diesel generator in this configuration had not been demonstrated by test to be available to power the shutdown buses within 10 minutes of the onset of station blackout.Significance/Severity Level: The inspectors evaluated this finding using IMC 0609.04, Initial Characterization of Findings, and IMC 0609, Appendix A, Exhibit 2, Mitigating Systems Screening Questions. The inspectors determined that the finding required a detailed risk evaluation due it representing an actual loss of function of one non-Technical Specification train of equipment designated as high safety-significance for more than 24 hours. A Region I senior reactor analyst completed the detailed risk evaluation and estimated the increase in core damage frequency (CDF) associated with this performance deficiency to be 7E-8/yr or of very low safety significance (Green). The senior reactor analyst used the Systems Analysis Programs for Hands-On Evaluation (SAPHIRE) Revision 8.1.6, Standardized Plant Analysis Risk (SPAR) Model, Version 8.54, for evaluating the increase in risk. The analyst performed the assessment by failing the station blackout diesel generator for an exposure period of 30 hours due to its assumed unavailability. The dominant core damage sequence involved a steam line break in the turbine building (SLBTB) with a failure to isolate the steam line break, a loss of reactor coolant pump (RCP) seal cooling, failure of rapid secondary depressurization, failure of the RCP seal stage 2 integrity and failure of the High Pressure Injection mitigating function. In accordance with IMC 0609, Appendix H, Containment Integrity Significance Determination Process, Figure 5.1, the increase in core damage frequency per year was below 1E-7/yr and therefore the Large Early Release Frequency (LERF) contribution was determined not to have an effect on the very low safety significance determination.Corrective Action Reference(s): CR 04093302
05000289/FIN-2018001-02Enforcement Action (EA)-18-038: Primary Containment Declared Inoperable Due to Both Airlock Doors Open Simultaneously2018Q1On September 5, 2017, Three Mile Island Unit 1 was operating at 100% power and preparing for a scheduled maintenance and refueling outage. During a planned entry through the primary containment personnel airlock of the equipment hatch, the inner and outer doors were open simultaneously for less than one minute due to a failure of the interlock mechanism. The breach was immediately recognized by the operator and the inner door of the equipment hatch airlock was closed. Exelon determined the opening of both airlock doors constituted a violation of Technical Specification 3.6.12, Personnel or emergency air locks. The event was reported under 10 CFR 50.73(a)(2)(ii)(A) due to a principal safety barrier being seriously degraded, 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, and 10 CFR 50.73(a)(2)(i)(B) as a condition prohibited by Technical Specification.Corrective Actions: Corrective actions included repairing the affected portion of the interlock mechanism and retesting its operation. An extent of condition was performed on the containment personnel hatch doors resulting in no similar issues. Corrective Action Reference(s): Issue report 04049166 Violation: Three Mile Island Technical Specification 3.6.12, Personnel or emergency air locks, states at least one door in each of the personnel or emergency air locks shall be closed and sealed during personnel passage through these air locks.Contrary to the above, on September 5, 2017, at least one door of a Three Mile Island Unit 1 personnel or emergency air lock was not closed and sealed during personnel passage through the air lock. Specifically, as the result of a failure of the interlock mechanism, the inner and outer equipment hatch emergency air lock doors were simultaneously opened for less than one minute. Severity/Significance: For violations warranting enforcement discretion, Inspection Manual Chapter 0612 does not require a detailed risk evaluation, however, safety significance characterization is appropriate. The NRC Enforcement Policy, Section 2.2.1 states, in part, that, whenever possible, the NRC uses risk information in assessing the safety significance of violations. The inspectors determined that finding was of very low safety significance (Green).Basis for Discretion: The inspectors determined that both containment hatch doors opening simultaneously was not within Exelons ability to foresee and prevent. As a result, no performance deficiency was identified. The inspectors assessment considered previous surveillances performed on the equipment hatch doors and interlock mechanisms. The inspectors reviewed all recent surveillances performed on the equipment and personnel inner and outer doors for timeliness and any abnormal results. No abnormalities were discovered and all surveillances were completed within periodicity. The NRC determined that it was not reasonable for Exelon to have been able to foresee and prevent this violation of NRC requirements, and as such, no performance deficiency existed. Therefore, the NRC has decided to exercise enforcement discretion in accordance with Sections 2.2.4 and 3.10 of the NRC Enforcement Policy and refrain from issuing enforcement action for the violation of technical specifications (EA-18-038). Further, because Exelons actions did not contribute to this violation, it will not be considered in the assessment process or the NRC Action Matrix. Inspectors elected to inspect the cause evaluation and corrective action determination related the issue described in LER 2017-003 as a selected annual sample. Exelon evaluated the condition and determined the cause of the event to be the failure of the outer door pawl to engage, providing a false indication that the outer door was closed prior to opening the inner door. The inspectors placed additional inspection focus to evaluate additional maintenance activities on the containment door mechanism, prior to outage activities where the door is cycled on a frequent basis with many new operators on site. Existing procedures and maintenance activities do not specify any subcomponent replacements until there is a failure or indication of damage. In addition to performing repairs to the outer door pawl, Exelon reviewed the current preventative maintenance activities for scheduling adequacy with the focus on high usage periods, evaluating additional maintenance activities that would include preventative subcomponent replacements, and reviewing industry operational experience for similar failures and corrective actions prior to the next refueling outage. Exelon documented the inspectors observation in issue report 04049166.
05000289/FIN-2018001-01Enforcement Action (EA)-EA-18-029: Multiple Examples of Nonconforming to Design for Tornado Missile Protection2018Q1Resulting from a systematic review of plant design and licensing basis Exelon determined four nonconforming conditions where components that could be depended upon to safely shutdown the reactor were not adequately protected from tornado missiles. These conditions include diesel fuel oil and day tank vents, borated water supplies, and once through steam generator pressure control isolation valves.Corrective Action(s): In accordance with the guidance in Regulatory Issues Summary 2015-06 Tornado Missile Protection (ML15020A419) and EGM 15-002, Revision 1, Enforcement Discretion for Tornado Generated Missile Protection Non-Compliance, (ML16355A286) the licensee implemented compensatory measures to maintain the equipment in a degraded but operable condition. These actions include verifying that procedures, training,and equipment are in place to take appropriate action in the event of a tornado watch or warning and establishing a heightened level of awareness and preparedness to tornado missile vulnerabilities. To restore full compliance, the licensee intends to evaluate the vulnerabilities utilizing approved methodologies and submitting a license amendment request per the timeline in Enforcement Guidance Memorandum 15-002, Revision 1.Corrective Action Reference(s):Issue Reports04081290, 04085589, 04085596, 04085607Enforcement:Violation: 10 CFR 50, Appendix B, Criterion III, Design Control, requires, in part, that measures shall be established to assure that the applicable regulatory requirements and the design basis for SSCs are correctly translated into specifications, drawing, procedures, and instructions. Contrary to the above, from April 19, 1974, until December 6, 2018, Exelon failed to correctly translate the design basis for protection against tornado-generated missiles into their specifications and procedures. Specifically, Exelon did not adequately protect TMI Unit 1 diesel fuel oil and day tank vents, borated water supplies, and once through steam generatorpressure control isolation valves from tornado generated missiles.Severity/Significance: For violations warranting enforcement discretion, Inspection Manual Chapter 0612 does not require a detailed risk evaluation, however, safety significance characterization is appropriate. The NRC Enforcement Policy, Section 2.2.1 states, in part, that, whenever possible, the NRC uses risk information in assessing the safety significance of violations. Accordingly, the NRC concluded that this issue is of low risk significance based on a generic and bounding risk evaluations performed in support of the resolution of tornado-generated missile non-compliances.Basis for Discretion: Because this violation was identified during the discretion period covered by EGM 15-002, Revision 1, and because Exelon has implemented compensatory measures, the NRC is exercising enforcement discretion, is not issuing enforcement action, and is allowing continued reactor operation.
05000289/FIN-2017004-01Failure to correct degraded control rod connections2017Q4The inspectors documented a self-revealing finding involving the failure to follow LS-AA-125, Corrective Action Program, Revision 14. Specifically, the licensee failed to take appropriate corrective actions to correct degraded control rod drive mechanism cable connections identified during a 2010 stuck rod event. This resulted in a rod drop event on October 10, 2017, that caused a turbine runback to 55 percent and required a plant shutdown to repair. As an immediate corrective action, the licensee replaced the Bendix 7-pin electrical connector for the control rod drive mechanism (CRDM) and performed extent of condition visual and resistance checks on the other CRDM cables. The issue was entered into their corrective action program (CAP) as issue report (IR) 04061160.The performance deficiency is more-than-minor because it was associated with the equipment performance attribute of the Initiating Events cornerstone and adversely affected the objective to limit the likelihood of events that upset plant stability and challenge critical safety functions during power operations. Specifically, a transient resulting from a dropped rod challenged the critical safety function of reactivity control. The inspectors determined that this finding was of very low safety significance (Green) since it did not cause both a reactor trip and the loss of mitigation equipment relied upon to transition the plant to a stable shutdown condition. This finding has a cross-cutting aspect in the area of Problem Identification and Resolution, Evaluation, because despite indications of degradation during inspections in 2013 and 2015, the site failed to ensure that a resolution addressed the cause commensurate with its safety significance (P.2).
05000289/FIN-2017003-01Licensee-Identified Violation2017Q3The following violation of very low safety significance (Green) was identified by Exelon and is a violation of NRC requirements, which meets the criteria of the NRC Enforcement Policy for being dispositioned as a non-cited violation.Technical specification 4.1.4, Operational Safety Review, requires each remote shutdown system function shown in Table 3.5-4 shall be demonstrated operable by the performance of the following check, test, and calibration. The technical specification surveillance requirement 4.1.4.b states that the licensee shall verify each required control circuit and transfer switch is capable of performing the intended function in accordance with the licensees surveillance frequency control program, in this caseevery refueling interval. Contrary to SR 4.1.4.b, from January, 1987, until September 2017, Exelon did not verify that each required control circuit on the Unit 1 remote shutdown panel was capable of performing the intended function. Specifically, Exelon did not test four of the required six relays for the B EDG either by operation of the components or by performance of a continuity check. Exelons corrective action included entering this issue into the CAP as issue reports 4020064 and 4047426, developing a remote shutdown system testing procedure for the B EDG system, and the completion of a risk evaluation as required by surveillance requirement 4.0.2. The inspectors determined that the finding was more than minor because it is associated with the equipment performance attribute of the Mitigating Systems cornerstone and affected the cornerstone objective to ensure the reliability of systems that respond to initiating events to prevent undesirable consequences. It is of very low safety significance (Green) in accordance with NRC IMC 0609, Appendix F, Fire Protection Significance Determination Process, since the missed surveillance did not impact the ability to reach safe shutdown.
05000289/FIN-2017403-03Security2017Q3
05000289/FIN-2017403-01Security2017Q3
05000289/FIN-2017403-02Security2017Q3
05000289/FIN-2017008-01Failure to Correct Deficiency in Implementing Controls for Pre-Staging Material in the Reactor Building2017Q1Green. The inspectors identified a finding of very low safety significance involving a non- cited violation (NCV) of 10 CFR 50, Appendix B, Criterion XVI, "Corrective Action Program," because Exelon did not effectively correct a condition adverse to quality regarding the implementation of controls for pre-staging of materials in the reactor building. Specifically, Exelon did not effectively implement corrective actions regarding the control of pre-staging materials in the reactor building during power operations, which resulted in unsecured prohibited material in a location that had the potential, during a large break loss of coolant accident (LOCA), to be transported to and impact the emergency core cooling system (ECCS) sump. Exelon documented this finding in issue reports 2608560 and 2578255. Corrective actions include Exelon to establish a focus team, led by the maintenance manager, to ensure pre-outage loading of the reactor building is conducted in accordance with requirements and directly supervised by Exelon personnel. The performance deficiency is rnore than minor because, if left uncorrected, it has the potential to lead to a more significant safety concern. Specifically, without proper controls implemented, materials may be pre-staged in the reactor building in a quantity or configuration that may render the ECCS sump inoperable. The inspectors evaluated the finding against the Mitigating System Cornerstone using Manual Chapter 0609, Attachment 4, "Initial Characterization of Findings," and Appendix A, "The Significance Determination Process for Findings At-Power," Exhibit 2, and determined this finding to be of very low safety significance (Green). The finding has a cross-cutting aspect in the area of Human Performance, Field Presence, because Exelon senior managers did not ensure the oversight of work activities by supplemental personnel (H.2).
05000289/FIN-2017008-02Licensee-Identified Violation2017Q1The following licensee-identified violation of NRC requirements was determined to be of very low safety significance and meets the NRC Enforcement Policy criteria for being dispositioned as a Non-Cited Violation. Technical Specifications 6.8., "Procedures and Programs," requires, in part, that written procedures be established, implemented, and maintained covering the applicable procedures recommended in Appendix 'A' of Regulatory Guide 1.33, Revision 2, 1978. Regulatory Guide 1.33, Revision 2, "Quality Assurance Program Requirements," Appendix A, requires administrative procedures for access to containment. Exelon Administrative Procedure 1015, Revision 7, "Equipment Storage Inside Class I Building," requires that no equipment shall be stored, placed, or staged inside a Class I Building without an approved Equipment Storage Data Sheet (ESDS). It further states, in part, that within the reactor building materials such as plastic sheeting must be fastened/secured in such a way as to prevent them from being washed into the reactor building sump post-LOCA. Contrary to the above, between October 27, 2015, and October 28, 2015, Exelon did not properly implement a procedure related to the staging of equipment in preparation for a Three Mile Island, Unit 1 refueling outage. Specifically, on October 28, 2015, Exelon performed a reactor building loading walkdown to review the equipment staged for the upcoming outage. During the walkdown, Exelon noted that several items staged in the reactor building were not in accordance with TMI Procedure AP 1 015. Items inappropriately stored included loose plastic, light stands, light bulbs, a Knaack locker box, and bolt cutters. Exelon immediately removed the prohibited items from the reactor building and documented the condition in IR 2575255. The finding is more than minor because it was associated with the availability and reliability attribute of the Mitigating Systems cornerstone and affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, the loose plastic had the potential to adversely impact the ECCS by compromising the recirculation suction flow path due to blockage of the suction strainer. The inspectors evaluated the finding using Inspection Manual Chapter 0609, Attachment 4, "Initial Characterization of Findings," and Appendix A, "The Significance Determination Process for Findings At- Power," Exhibit 2, and determined this finding screened as very low safety significance (Green) because, based on inspector review of a technical debris evaluation (ACIT 4 2578255-08) by Exelon, the finding did not represent an actual loss of function of a system.
05000289/FIN-2016004-01Licensee-Identified Violation2016Q4Technical specification 3.2.12.1, "LTOP Protection", requires when the reactor vessel head is installed and indicated reactor coolant system temperature is 313F, high pressure injection pump breakers shall not be racked in unless injection valves (MU-V16A/B/C/D and MU-V217) are closed with their associated breakers open and that pressurizer level is maintained 100 inches, or restore pressurizer level to 100 inches within 1 hour. Contrary to technical specification 3.2.12.1, during reactor coolant system filling with the vessel head installed and temperature < 313F, high pressure injection pump breakers were racked in while pressurizer level was >100 inches for greater than 1 hour. The condition existed for 2 hours and 49 minutes until recognized by the operating crew when questioned by a senior reactor operator trainee, at which time the crew took immediate actions to reduce pressurizer level <100 inches within 1 hour. Additional corrective actions included crew remediation, additional main control room supervisory oversight, and procedure changes. Exelon entered this issue into the corrective action program as issue report 3949713. The inspectors determined that the finding was of very low safety significance (Green) in accordance with NRC IMC 0609, Appendix G, Shutdown Operations, Attachment 1, Exhibit 4, since the finding did not represent an inadvertent safety injection and did not render the power-operated relief valve (LTOP Protection) unavailable or degraded.
05000289/FIN-2016003-01Emergency Diesel Generator Internal Flooding Risk Not Evaluated2016Q3The inspectors identified an NCV of Title 10 Code of Federal Regulations (CFR) 50, Appendix B, Criterion III, Design Control, in that Exelon did not ensure the availability of the emergency diesel generator (EDG) following a seismic event. The inspectors reviewed the TMI licensing basis for internal flooding, associated evaluations and conditions reports, and walked down safety-related structures system and components (SSCs). During this review the inspectors determined that non-seismic piping failures in the EDG room were not properly evaluated. Specifically, the inspectors determined that pressurized fire water pipes in both EDG rooms were not classified as safety-related or seismically qualified. The inspectors reviewed Exelons evaluation of the potential failure of the pipe, as assumed in the TMI design and licensing basis, and determined that operator actions were credited to mitigate the pipe failure in order to prevent water from affecting the operation of the EDGs. The inspectors determined that these operator actions could not be performed prior to water from the pipe break impacting the operation of the EDGs. Following identification of the issue, Exelon entered this issue into their corrective action program and performed an analysis on the structural loading on the fire water piping during a safe shutdown earthquake and concluded that the piping would not break during the design basis event and, therefore, the EDGs remained operable. The inspectors reviewed the analysis and found it reasonable. The inspectors determined the failure to adequately evaluate the effects of a pipe failure in the EDG room in accordance with the design and licensing basis was a performance deficiency. The performance deficiency is considered more than minor because it is associated with the Protection Against External Factors attribute of the Mitigating Systems cornerstone and adversely affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences (i.e., core damage). Additionally, the performance deficiency is considered more than minor in accordance with Manual Chapter 0612, Appendix E - Question 3K, in that there was a reasonable doubt of operability for the EDGs requiring engineering calculations and analysis to resolve. In accordance with IMC 0609.04, Initial Characterization of Findings, and Exhibit 2 of IMC 0609, Appendix A, The Significance Determination Process for Findings At-Power, the inspectors determined the finding to be of very low safety significance (Green) because the finding was determined to be a design or qualification deficiency that did not result in an inoperability. No cross-cutting attribute is assigned to this finding because the performance deficiency was not indicative of Exelons current performance. Specifically, this issue was last identified and reviewed by Exelon in issue report 1201424 in 2010.
05000289/FIN-2016007-01Licensee-Identified Violation2016Q1Title 10 CFR 50.55a (g)(4), In-service Inspection Requirements, requires in part, that throughout the service life of a boiling or pressurized water-cooled nuclear power facility, components (including supports) that are classified as ASME Code Class 1, must meet the requirements, except design and access provisions, and preservice examination requirements set forth in Section XI of editions and addenda of the ASME Boiler Pressure and Vessel Code (BPVC) that become effective subsequent to editions specified in paragraphs (g)(2) and (g)(3) of this Section, and that are incorporated by reference in paragraph (b) of this Section, to the extent practical within the limitations of design, geometry, and materials of construction of the components. Section XI of the ASME BPVC, 2001 Edition with 2003 Addenda, Table IWF-2500-1, Examination Category F-A Supports, requires VT-3 examination of 100 percent of the ASME Class 1 supports, other than piping supports, every ISI Interval (examination item F1.40), as modified by Notes 1, 2, 3 and 5 of Table IWF-2500-1. Contrary to this requirement, from initial plant operation until November 14, 2015, (when Exelon staff completed the initial required VT-3 examination), Exelon failed to perform the required VT-3 examination of ASME Class 1 supports, other than piping supports, (i.e. seismic support plates and associated load path components) on the TMI control rod drive mechanism assemblies. Exelon staff entered the issue into their corrective action program as IR 01678190. The inspectors evaluated this finding using IMC 0609.04, Initial Characterization of Findings, IMC 0609, Appendix A, Exhibit 2, Mitigating Systems Screening Questions, and IMC 0609, Appendix A, Exhibit 3, Barrier Integrity Screening Questions. The finding is more than minor because it is associated with the protection against external factors attribute of the mitigating systems cornerstone and adversely affects the objective to ensure availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. The inspectors determined that the finding was of very low safety significance (Green) because the finding did not involve the loss or degradation of equipment or function specifically designed to mitigate a seismic initiating event and was not associated with pressurized thermal shock of the reactor coolant system boundary.
05000289/FIN-2016001-01Deficient Design Control of ECCS Level Transmitter Instrument Line Heat Trace Causes Freezing and Inoperability2016Q1A self-revealing NCV of Title 10 of the Code of Federal Regulations (CFR), Part 50, Appendix B, Criterion III, Design Control, was identified for failure to establish and implement adequate design control measures to assure that the borated water storage tank (BWST) was capable of performing its design function to mitigate a design basis loss of coolant accident (LOCA) event. Specifically, Exelon made a modification to the BWST level indicator safety grade heat trace circuit that placed the circuit in an unapproved electrical configuration, which failed to prevent instrument line freezing during cold weather periods, contrary to its safety-function to maintain BWST level indication operable in cold weather. This adversely impacted the availability of a BWST level indication necessary for operators to reliably perform a critical design basis manual action. Exelon documented these issues in issue reports 2609417 and 2611119. Immediate corrective actions included replacement of the affected heat trace and completion of a compatible modification to its electrical configuration. This performance deficiency was more than minor because it was associated with the design control attributes of the Mitigating Systems cornerstone and adversely affected the cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Additionally, the finding was similar to example 2.f in Appendix E of IMC 0612, in that failure to properly maintain cold weather protection equipment for the BWST level transmitters resulted in DH-LT-809 becoming inoperable. The finding was of very low safety significance (Green) because it did not affect design or qualification, did not represent a loss of system function, did not cause at least one train of BWST level instrumentation to be inoperable for greater than its Technical Specification limiting condition of operation (LCO) allowed outage time, and did not involve external event mitigation systems. The finding had a cross-cutting aspect in the area of Human Performance, Procedure Adherence, because station personnel did not follow the heat trace procedure, which did not allow the two types of heat trace to be spliced together.
05000289/FIN-2016001-02Licensee-Identified Violation2016Q1On February 6, 2016, while making preparations to perform procedure 1303-11.45, PORV Setpoint Check, a senior operator identified that the assigned risk for this planned maintenance activity was inaccurate. Specifically, the risk for the maintenance activity was Yellow, not Green, as originally determined. The reason for the inaccurate risk was due to not previously recognizing the pressurizers block valve (RC-RV-2) would be rendered inoperable during the maintenance activity. This condition could result in failure to operate the pressurizers power operated relief valve. The failure to accurately assess the risk of the power operated relief valve setpoint check was a performance deficiency that was within the licensees ability to identify and correct. The inspectors noted that this maintenance activity had an inaccurate risk assessment for at least the past three years. This performance deficiency was a violation 10 CFR Part 50.65(a)(4), which requires, in part, the licensee to assess and manage the increase in risk that may result from the proposed maintenance activity. Contrary to the above, Exelon failed to accurately assess the risk for the power operated relief valve setpoint check over the past three years. The issue was more than minor because it was associated with the configuration control attribute of the initiating systems cornerstone and it adversely affected the cornerstone objective of limiting the likelihood of events that upset plant stability and challenge critical safety functions during shutdown as well as power operations. The inspectors determined that the finding was of very low safety significance (Green), based on IMC 0609, Appendix K, Maintenance Risk Assessment and Risk Management Significance Determination Process, screening criteria. The finding screened to Green because the incremental core damage probability of failing to operate RC-RV-2 is less than 1.00 10-6 per year during the short period which the valve is rendered inoperable during each performance of this maintenance activity. Exelon has entered this issue into its corrective action program (issue report 2622859) and revised the risk assigned to this maintenance activity. Because this finding is of very low safety significance and had been entered into Exelons corrective action program, this violation is being treated as a Green, licensee-identified NCV, consistent with section 2.3.2 of the NRCs Enforcement Policy.
05000289/FIN-2015004-01Failure to Trend Vibration Data for Safety Related River Water Pump2015Q4The inspectors identified a finding of very low safety significance involving an NCV of 10 Code of Federal Regulations (CFR) 50, Appendix B Criterion XVI, Corrective Action Program, because Exelon did not identify and correct a condition adverse to quality on the B nuclear river water pump (NR-P-1B). Specifically, Exelon did not properly evaluate an adverse vibration trend on NR-P-1B, which resulted in exceeding its in-service test (IST) required action level and declared inoperable on October 10, 2015. Exelon entered the condition into their corrective action program (CAP) as issue report 2568763 and emergently replaced the pump, engaged the vendor for short and long term design and material changes to correct the vibration, and created process and peer check corrective actions to ensure all vibration data is reviewed timely and trends are addressed commensurate with their safety significance. The performance deficiency is more than minor because it was associated with the equipment performance attribute of the Mitigating Systems cornerstone and adversely affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, the elevated vibrations reduced the reliability and capability of NR-P-1B to perform its safety function. The inspectors evaluated the finding using IMC 0609, Attachment 4, Initial Characterization of Findings, and Appendix A, The Significance Determination Process for Findings At-Power, Exhibit 2, and determined this finding to be of very low safety significance (Green) because the degraded condition was not a design deficiency that affected system operability; did not represent an actual loss of function of a system; did not represent an actual loss of function of a single train or two separate trains for greater than its technical specification (TS) allowed outage time and did not represent an actual loss of function of one or more non-technical specification trains of equipment designated as high safety significant. The finding has a cross-cutting aspect in the area of Problem Identification and Resolution, Evaluation, because the station did not thoroughly evaluate the elevated vibration data such that the issue was addressed before NR-P-1B became inoperable (P.2).
05000289/FIN-2015003-01Internal Flooding Licensing Basis Commitment Not Met2015Q3The inspectors identified a finding because Exelon failed to meet a commitment made during original licensing to mitigate an internal flooding event. Specifically, Exelon committed to making changes to the fire water supply system to mitigate the impact of a pipe rupture in the auxiliary building. The inspectors identified that the commitment actions were not completed and no changes to the commitment were identified. The inspectors determined that the failure to perform the modifications to the fire service system, as committed to the NRC in a letter dated November 10, 1972, was a performance deficiency that was reasonably within its ability to foresee and correct. Exelon documented the issue in issue report 2544387, performed an immediate operability evaluation, and developed corrective actions to restore compliance with the commitment. The inspectors determined that the performance deficiency is associated with the Mitigating Systems cornerstone attribute of protection against external factors (internal flood hazard) and is more than minor because it adversely affected the cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, the performance deficiency adversely impacted the operators ability to detect and mitigate a fire service system pipe rupture in the safety related auxiliary building. The inspectors utilized IMC 0609, Appendix A, The Significance Determination Process for Findings At-Power, to determine the significance of the performance deficiency. The inspectors determined the finding to be of very low safety significance (Green) because the finding is not a design or qualification deficiency, does not represent a loss of system safety function or loss of a single train for greater than its allowed technical specification time, does not result in the loss of a high safety-significant maintenance rule train and does not involve the loss of function to mitigate internal flooding events. The finding is not assigned a cross-cutting aspect because the performance deficiency occurred during original plant construction and is not indicative of current plant performance.
05000289/FIN-2015002-01Failure to Maintain Turbine Bypass Valve Simulator Modeling2015Q2A self-revealing NCV of 10 CFR Part 55.46(c), Plant-Referenced Simulators, was identified for Exelons failure to ensure that the plant-referenced simulator demonstrated expected plant response to normal, transient, and accident conditions to which the simulator has been designed to respond. Specifically, Exelon failed to ensure simulator modeling of once through steam generator (OTSG) turbine bypass valve (TBV) operation was consistent with the actual plant which introduced negative operator training and challenged orderly unit shutdown on May 7, 2015. The licensee documented their corrective actions for this issue in TMI issue reports (IR) 02496279 and 2497542, which included software changes to the simulator to reflect actual system design, crew remediation, and procedure changes. The performance deficiency is more than minor because it is associated with the human performance attribute of the Initiating Events cornerstone and affected the cornerstone objective of limiting the likelihood of events that upset plant stability and challenge critical safety functions during shutdown as well as power operations. Specifically, the simulator difference introduced negative operator training and, as a result, challenged orderly shutdown of the unit on May 7, 2015. The inspectors evaluated the finding in accordance with NRC Manual Chapter 0609, Significance Determination Process, and the corresponding Appendix I, Licensed Operator Requalification Significance Determination Process. The finding was determined to have very low safety significance (Green) because the impact on operator performance was not during a reportable event. This finding has no cross-cutting aspect assigned because the cause was not representative of current licensee performance. Specifically, the difference in TBV modeling existed since initial simulator certification on June 28, 1990.
05000289/FIN-2015001-01Licensee-Identified Violation2015Q1LER 05000289/2014-001-00 describes an unanalyzed condition in which Exelon identified DC motor control circuits were unfused. Specifically, Exelon did not provide overcurrent protection for wiring associated with 250VDC full-voltage control circuits for four non-safety emergency bearing oil pumps in the turbine building to prevent wires from overheating due to fire-induced faults and excessive currents flowing through the cable. With enough current flowing through the cable, the potential exists that the overloaded motor control wiring could damage adjacent control circuit wiring for both instrument air compressors (IA-P-1A/B), which are needed to achieve and maintain post-fire safe shutdown for a fire in the cable spreading room. This condition could result in a loss of the associated safe shutdown components or a secondary fire in another fire area. The failure to protect safe shutdown cables from the effect of postulated fires was a performance deficiency. This performance deficiency was a violation of TMI Operating License Condition 2.C.(4), which requires, in part, post-fire safe shutdown cables remain free of the effects of fire-induced cable faults during postulated fires. Contrary to the above, Exelon identified they failed to meet this requirement and the condition existed since initial construction. The issue was more than minor because it was associated with the protection against external events (fire) attribute of the mitigating systems cornerstone and it adversely affected the cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. The inspectors determined that the finding was of very low safety significance (Green), based on IMC 0609, Appendix F, Fire Protection Significance Determination Process, Phase 2 screening criteria. The finding screened to Green based upon task number 2.3.5, and because no credible fire ignition source was determined to adversely affect the motor control circuits of concern as determined. Additionally, a fire area of concern (cable spreading area) is an alternate shutdown fire area protected by detection and an automatic suppression system. The cables in the other fire area of concern (turbine building) are Institute of Electrical and Electronics Engineers 383 (thermoset) construction with steel armor and tied to station ground which decreases the likelihood of inter-cable and intra-cable interactions. Because this finding is of very low safety significance and had been entered into Exelons corrective action program (IRs 1651702, 1658837, 1658842), this violation is being treated as a Green, licensee-identified NCV consistent with the NRCs Enforcement Policy.
05000289/FIN-2015007-02Untimely Identification and Correction of Degraded BWST Level Transmitter Cold Weather Protection Equipment2015Q1The NRC identified an NCV of Title 10 of the Code of Federal Regulations (10 CFR), Part 50, Appendix B, Criterion XVI, Corrective Action, for failure to promptly identify and correct degraded borated water storage tank (BWST) level transmitter instrument line cold weather protection equipment. Specifically, station personnel performed periodic maintenance and testing activities to verify the adequacy of cold weather protection for the BWST level transmitters prior to the onset of cold weather, but did not identify existing uninsulated sections of the instrument lines or degraded heat trace circuit continuity. Consequently, on February 15, 2015, the sensing line for BWST level transmitter DH-LT-808 froze which challenged the operators capability to successfully perform a critical design basis manual action. Namely, swapover from the injection to recirculation phase of ECCS operation following a LOCA. Immediate actions included entering the applicable technical specification (TS) limiting condition of operation (LCO), thawing the frozen instrument line, restoring DH-LT-808 to service, and exiting the TS LCO. Exelon entered the cold weather protection issue into their corrective action program as issue reports (IR) 2445164, 2451342, 02452858, and 02454925. This finding was more than minor because it was associated with the equipment and human performance attributes of the Mitigating Systems cornerstone and adversely affected the cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. The team determined that the finding was of very low safety significance because it did not affect design or qualification, did not represent a loss of system, did not cause at least one train of BWST level instrumentation to be inoperable for greater than its TS LCO allowed outage time, and did not involve external event mitigation systems. The team assigned a cross-cutting aspect in the area of Human Performance, Procedure Adherence (aspect H.8), because station personnel did not follow processes, procedures, and work instructions when performing maintenance and operational activities that should have identified degraded BWST level instrument cold weather protection equipment associated with missing insulation and loss of heat trace circuit continuity.
05000289/FIN-2015007-01Deficient Design Control for Verifying Reactor Building Fan Assembly Capability to Perform Design Basis Function2015Q1The NRC identified an NCV of Title 10 of the CFR, Part 50, Appendix B, Criterion III, Design Control, for failure to establish and implement adequate design control measures to assure that the reactor building (RB) fan assemblies were capable of performing their design function to mitigate a design basis loss of coolant accident (LOCA) event. Specifically, testing and design calculations used a non-conservative RB ventilation system alignment to determine the brake horsepower of the RB fan motors during a LOCA. As a result, engineers had not evaluated the capability of the RB fan motors to operate above their nameplate full load rating to perform their intended safety function. Additionally, RB fan motor electrical overload protection analyses were incorrect. Immediate corrective actions included interim calculations which demonstrated that the RB fan assemblies would remain capable of performing their safety functions and that the emergency diesel generators were capable of supplying the additional electrical load requirements. Exelon entered the issues into their corrective action program as IRs 2458932, 2458929, and 2451855. This finding was more than minor because it was associated with the design control attribute of the Barrier Integrity cornerstone and adversely affected the cornerstone objective of ensuring the operational capability of the containment barrier to protect the public from radionuclide releases caused by accidents or events. Additionally, the finding was similar to example 3.j in Appendix E of IMC 0612, in that the engineering calculation error resulted in a condition where there was reasonable doubt of the operability of the RB fan assemblies to perform their safety function during a design basis LOCA. The team determined the finding was of very low safety significance because it: did not affect the reactor coolant system (RCS) boundary; did not affect the radiological barrier function of the control room, auxiliary building, or spent fuel pool systems or boundaries; and did not represent an actual open pathway in containment or involve a reduction in the function of hydrogen igniters. This finding was not assigned a cross-cutting aspect because the underlying cause was not indicative of current performance in that the non-conservative calculation error occurred in 1993.
05000289/FIN-2014004-01Inadequate Evacuation Time Estimate Submittals2014Q3The inspectors identified an NCV of Title 10 of the Code of Federal Regulations (10 CFR) 50.54(q)(2), 10 CFR 50.47(b)(10), and 10 CFR 50, Appendix E, Section IV.4, for failing to maintain the effectiveness of the Three Mile Island Nuclear Station (TMI) emergency plan as a result of failing to provide the station evacuation time estimate (ETE) to the responsible offsite response organizations (OROs) by the required date. Upon identification, Exelon entered this issue into its corrective action program (CAP) as issue reports (IRs) 1525923 and 1578649. Exelon submitted a third ETE for TMI on April 4, 2014, and the NRCs review of that ETE is documented in section 1EP4 of this report. The finding is more than minor because it is associated with the Emergency Preparedness cornerstone attribute of procedure quality and adversely affected the cornerstone objective of ensuring that the licensee is capable of implementing adequate measures to protect the health and safety of the public in the event of a radiological emergency. The ETE is an input into the development of protective action strategies prior to an accident and to the protective action recommendation decision making process during an accident. Inadequate ETEs had the potential to reduce the effectiveness of public protective actions implemented by the OROs. The finding is determined to be of very low safety significance (Green) because it is a failure to comply with a non-risk significant portion of 10 CFR 50.47(b)(10). The cause of the finding is related to cross-cutting aspect of Human Performance, Documentation, because Exelon did not appropriately create and maintain complete, accurate and, up-to date documentation (H.7).
05000289/FIN-2014003-02UFSAR Max Hypothetical Dose Not Updated, Consistent with Current Plant Conditions2014Q2The inspectors identified a Severity Level lV (SL-lV) NCV of 10 CFR 50.71(e), Maintenance of Records, Making of Reports, because TMI personnel did not update the Updated Final Safety Analysis Report (UFSAR) with information consistent with plant conditions. Specifically, TMI personnel did not remove reference to or correct information in UFSAR Section 14.2.2.3.4.a, Environmental Analysis of Loss of Coolant Accidents - Consequences of LOCA Radioactive Releases to the Environment, to reflect current plant conditions with regard to maximum hypothetical accident doses at the main control room, exclusion area boundary, or low population zone. Exelon documented this in issue report 1662515 to address the UFSAR discrepancy. This issue was determined to be within the traditional enforcement process because it had the potential to impede or impact the NRC's ability to perform its regulatory functions. Specifically, the issue was determined to have a material impact on licensed activities and was considered more than minor using section 7.3.D of the NRC Enforcement Manual. Using example d.3 of section 6.1 of the NRC Enforcement Policy, the inspectors determined that the violation was a SL-IV violation because the erroneous information was not used to make an unacceptable change to the facility or procedure. In accordance with inspection manual chapter 0612, section 07.03c, this traditional enforcement violation was not assigned a cross-cutting aspect.
05000289/FIN-2014009-01Inadequate Corrective Actions for a Condition Adverse to Quality that Caused the Failure of Two Primary Containment Isolation Valves2014Q2The inspectors identified a finding of very low safety significance involving an NCV of Title 10 of the Code of Federal Regulations (10 CFR) 50, Appendix B, Criterion XVI, Corrective Action, because Exelon did not take adequate corrective actions to address a condition adverse to quality that caused the failure of two primary containment isolation valves. Specifically, the corrective actions implemented after the failure of CA-V-13 in 2010 and WDL-V- 303 in 2013 did not ensure that the deficient basic work practices that resulted in the valve failures were corrected. Exelon documented this issue in the corrective action program as issue report (IR) 1664529 and took prompt actions to validate the operability of valves with similar actuators that had been worked since refueling outage T1R19. In addition, Exelon is performing a cause evaluation to fully understand the causes of the issue and implement actions to correct the condition adverse to quality prior to the next valve maintenance window. The finding is associated with the Barrier Integrity cornerstone and is more than minor because if left uncorrected it could lead to a more significant safety concern. Specifically, the uncorrected deficient basic work practices could result in additional primary containment isolation valve failures. In accordance with IMC 0609.04, Initial Characterization of Findings, and Exhibit 3 of IMC 0609, Appendix A, The Significance Determination Process for Findings At-Power, issued June 19, 2012, the inspectors determined that the finding was of very low safety significance (Green) because it does not represent an actual open pathway in the containment and did not impact the hydrogen igniters. The finding has a cross-cutting aspect of evaluation in the problem identification and resolution area because Exelon did not thoroughly evaluate the condition to ensure that corrective actions addressed the cause. Specifically, Exelon identified that deficient basic work practices during valve actuator reassembly were the probable cause of the WDL-V-303 failure in 2013 and had been previously identified as the cause of the CA-V-13 failure in 2010, but Exelon did not evaluate the effectiveness of the corrective actions completed after the CA-V-13 failure or the need for additional corrective actions to address the probable cause.
05000289/FIN-2014003-01Risk Mitigation Actions Not Performed for Excavation of Nuclear River System Cable Conduits2014Q2The inspectors identified a finding of very low safety significance (Green) involving a non-cited violation (NCV) of 10 CFR Part 50.65(a)(4), Requirements for monitoring the effectiveness of maintenance at nuclear power plants, because Exelon did not implement risk management actions (RMAs) to manage risk associated with the nuclear service river pump B (NR-P-1B) during excavation for fire service piping replacement. Specifically, the excavation exposed a cable conduit duct bank containing safety-related cables for nuclear service river valve 1B (NR-V-1B) without having adequate RMAs in place to ensure NR-V- 1B cabling would remain protected from a tornado generated missiles. Exelon entered the condition into their corrective action program as IR 1670876 and took immediate corrective actions to modify the work instructions to include RMAs for soil restoration over the conduit duct bank in the event of a tornado. The performance deficiency is more than minor because it is associated with the Protection Against External Factors attribute of the Mitigating Systems cornerstone, and adversely affected the cornerstones objective to ensure the availability and capability of systems that respond to initiating events to prevent undesirable consequences. The inspectors evaluated the findings using IMC 0609.04, Initial Characterization of Findings. The finding involved the licensees management of risk in accordance with 10 CFR 50.65(a)(4) therefore, the inspectors evaluated the significance using IMC 0609, Appendix K, Maintenance Risk Assessment and Risk Management Significance Determination Process. The inspectors determine that this performance deficiency was of very low safety significance (Green) because the finding was associated with RMAs only and the incremental core damage probability (IDCP) was not >1E-6. This finding has a cross-cutting aspect in the area of Human Performance, Work Management; because Exelon did not manage risk associated with the underground piping replacement project and did not effectively communicate job activities between work groups to ensure the RMAs would be implemented as required.
05000289/FIN-2014405-01Licensee-Identified Violation2014Q2
05000289/FIN-2014002-01Failure to Perform a 10 CFR 50.59 Evaluation for the BWST Seismic Qualifications2014Q1The inspectors identified a Severity Level IV (SL-IV), Non-Cited Violation of 10 CFR 50.59, Changes, Tests, and Experiments, and an associated finding of very low safety significance (Green) for Exelons failure to perform a 50.59 evaluation review to determine whether a license amendment was required to align the borated water storage tank (BWST) to non-seismic piping. Specifically, Exelon staffs 50.59 screening accepted the alignment of the seismically qualified BWST to a non-seismically qualified clean-up system. The inspectors determined the alignment would involve a change to the BWST that adversely affects its Updated Final Safety Analysis Report chapter 5.1.1, Classes of Structures and Systems for Seismic Design, described design function of being seismically qualified. Additionally, the inspectors determined that following the 50.59 review Exelon placed the line-up in service. The inspectors determined these two actions were performance deficiencies that were reasonably within Exelons ability to foresee and prevent. Furthermore, the 50.59 screening credited unapproved operator manual actions to ensure functionality of the BWST. Exelon documented this as issue report 1631468 and implemented interim corrective actions to isolate the BWST from the clean-up system until a permanent resolution is determined and implemented. The inspectors determined the 50.59 violation regarding the failure to perform an evaluation was more than minor because the inspectors could not reasonably determine that the alignment would not have ultimately required NRC prior approval, because the BWST alignment was not in accordance with the current licensing basis and the evaluation credited the use of unapproved operator manual actions. The inspectors also determined that the performance deficiency of accepting and aligning the adverse clean-up line-up, challenging the BWST seismic qualification, was more than minor because it adversely affected the Mitigating Systems cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. The inspectors evaluated the finding using IMC 0609, Attachment 4, Initial Characterization of Findings, and Appendix A, The Significance Determination Process for Findings At-Power, and determined that this finding required a detailed risk evaluation. The detailed evaluation was performed which determined that the performance deficiency was a finding of very low safety significance (Green). Additionally, In accordance with Section 6.1.d.2 of the NRC Enforcement Policy, the 50.59 violation is categorized as a Severity Level IV. This finding has a cross-cutting aspect in the area of Problem Identification and Resolution, Operating Experience, in that the station did not effectively evaluate and internalize relevant external operating experience (Information Notice (IN) 2012-01) regarding connections between safety-related seismic and non-seismic qualified piping and components.
05000289/FIN-2014002-03Failure to Restore Station Blackout Diesel Generator Cooling Water Lineup following Maintenance and Testing Activities2014Q1A self-revealing non-cited violation (NCV) of 10 CFR 50.63, Loss of All Alternating Current Power, was identified for Exelons failure to properly restore the station blackout (SBO) diesel generator system following maintenance and testing activities, rendering the SBO diesel generator unable to be available in 10 minutes of and cope for 4 hours after a postulated SBO event. Specifically, during the restoration from SBO switchgear maintenance during the previous Fall 2013 refueling outage, operators failed to remove a blocking device (gag) from the SBO diesel generator fire service water cooling isolation valve (FS-V-646) as part of its restoration to an automatic, standby configuration. As a result the SBO diesel generator was not in the configuration required by 10 CFR 50.63 (c)(2), which describes acceptable capability standards for alternate AC power systems. Exelon entered this issue into their corrective action program as IR 1608625. Exelon restored the valve configuration and revised affected and related procedures. The inspectors determined this performance deficiency in that Exelon failed to remove the blocking devise from FS-V-646 prior to restoring the SBO diesel to service was more than minor because it is associated with the mitigating systems affecting the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, in the event of a station blackout, the SBO diesel generator was not able to be started and operated from the control room with no local operations required to allow the prompt restoration of electrical power to at least one vital bus as assumed in the TMI SBO analysis. The inspectors evaluated the finding using IMC 0609, Attachment 4, Initial Characterization of Findings, and Appendix A, The Significance Determination Process for Findings At-Power, and determined that this finding required a detailed risk evaluation because, with FS-V-646 gagged, the SBO diesel was not capable of performing its safety function. The detailed risk evaluation determined the finding to be of very low safety significance (Green). This finding has a cross-cutting aspect in the area of Human Performance, Documentation, because Exelons procedure for restoration from the maintenance and testing (OP-TM-731- 510, Rev. 5) was not adequate to specify actions to return the cooling water isolation valve (FS-V-646) to its normal automatic condition (H.7).
05000289/FIN-2014002-02Loss of Air Intake Tunnel Sump Pump Function due to Inadequate Work Execution2014Q1The inspectors identified a finding of very low safety significant (Green) for Exelons failure to follow work order instructions in accordance with MA-AA-716-011, Work Execution and Close Out, during planned maintenance activities on the air intake tunnel (AIT) deluge sump pump (SD-P-7). Specifically, in May 2013, a maintenance worker applied epoxy to the sump pumps float switch contrary to work order instructions. Inspectors identified that the float switch was fixed in the OFF position, rendering the pump unavailable, during a system walkdown in March 2014. Exelon documented this as issue report 1628577 and performed prompt corrective actions to remove the epoxy coating from the float switch. In addition, corrective actions were performed to replace the float ball that likely was submerged and filled with water as a result of the float switch being stuck. Exelon successfully postmaintenance tested the float switch and pump on March 6, 2014, and returned it to service. The inspectors determined the performance deficiency associated with this finding involved Exelons failure to follow work order instructions in accordance with MA-AA-716-011, Work Execution and Close Out, during planned maintenance activities on SD-P-7 was more than minor because it was associated with mitigating systems cornerstone adversely affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, in May 2013, a technician applied epoxy to SD-P-7s float switch, contrary to work order instructions, rendering the pump non-functional. The inspectors evaluated the finding using IMC 0609, Attachment 4, Initial Characterization of Findings, and Appendix A, The Significance Determination Process for Findings At-Power, Exhibit 4, External Events Screening Questions, and determined, based on operator response to an air intake tunnel deluge alarm, this finding to be of very low safety significance (Green). This finding has a cross-cutting aspect in the area of Human Performance because the worker did not follow work order instructions and incorrectly applied epoxy to the SD-P-7 float switch assembly, rendering the pump non-functional and unavailable (H.8).
05000289/FIN-2013005-01Improper Storage of Material in Reactor Building2013Q4The inspectors identified a Green non-cited violation of Technical Specification 6.8.1 for Exelons failure to implement procedure requirements governing storage of equipment in Class 1 structures. Specifically, Exelon stored unsecured material, one (1) roll of plastic sheeting and three (3) plastic sheets, in the Reactor Building (RB) during power operations, contrary to Exelon Procedure 1015, Equipment Storage Inside Class 1 Buildings. This resulted in unsecured material in a location that had the potential, during a large break loss of coolant accident, to be transported to and adversely impact the performance of the emergency core cooling system (ECCS) suction sump. Exelon documented the issue in their corrective action program under issue report (IR) 1577437 and took immediate corrective actions to remove the unsecured plastic from the RB. This finding is more than minor because it is associated with the availability and reliability attribute of the Mitigating Systems cornerstone and affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, the unsecured plastic had the potential to impact the reliability and availability of the ECCS recirculation suction flow path, due to the potential increased debris loading. The inspectors evaluated the finding using Inspection Manual Chapter 0609, Attachment 4, Initial Characterization of Findings, and Appendix A, The Significance Determination Process for Findings At-Power, Exhibit 2, and determined this finding is very low safety significance (Green) because the degraded condition is a design deficiency that affects system operability, but did not represent an actual loss of function of a system; did not represent an actual loss of function of a single train or two separate trains for greater than its technical specification allowed outage time and did not represent an actual loss of function of one or more non-technical specification trains of equipment designated as high safety significant. The finding has a cross-cutting aspect in the area of Problem Identification and Resolution, Corrective Action Program, because Exelon did not take adequate corrective actions to address the cause of improperly staged material in the RB (IR 1577100), resulting in a subsequent recurrence of improper staging of additional material in the RB identified by the inspectors (IR 1577437).
05000289/FIN-2013005-03Licensee-Identified Violation2013Q4TMI License Condition 2.C.(4) and the Fire Hazards Analysis Report (FHAR) require administrative breaker position restrictions for Appendix R valves needed for safe shutdown, including reactor coolant pump #1 seal bypass valve (MU-V-38). TMI procedure AP-1038 is the implementing procedure for License Condition 2.C.(4) and the FHAR. On November 28, 2013, the licensee identified the breaker for MU-V-38 to be in the ON position contrary to the required OFF position. It was determined that the breaker was in the incorrect position for six (6) days of the seven (7) days allowed by the AP-1038 time clock. In that, compensatory measures and a risk assessment were not in place for this out-of-position breaker, in the event of a postulated fire and fire-induced spurious operation of MU-V-38, and the inspectors determined the issue was more than minor. The cause of the mispositioned breaker was determined by Exelon to be auxiliary operator distraction from multiple work activities and failure to restore the breaker to its expected position following post-maintenance testing during the fall refueling outage. Exelon entered this issue into their CAP as IR 1591314 and promptly positioned the breaker to the correct OFF position, including validation of the position of the remaining Appendix R breakers. The inspectors determined that the finding was of very low safety significance (Green) in accordance with IMC 0609, Appendix F, Fire Protection Significance Determination Process, based upon this Fire Prevention and Administrative Controls issue having a low degradation category.
05000289/FIN-2013005-02Failure to Perform Leak Rate Testing on Containment Boundary Piping2013Q4The inspectors identified a Green non-cited violation of 10 CFR 50, Appendix J, Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors, for Exelons failure to establish an adequate program that leak tested components penetrating the primary containment pressure boundary. Specifically, Exelon failed to implement leak rate testing of the reactor building (RB) normal closed loop cooling piping to verify piping integrity to support its containment isolation function. As a result, on November 10, 2013, engineering personnel identified an inoperable containment isolation boundary due to a degraded RB closed cooling piping condition. Exelon documented this issue in issue report (IR) 1598590 and took corrective actions to revise the Appendix J test program and address the missed leak rate surveillance test. This finding is more than minor because it is associated with the Barrier Performance attribute of the Barrier Integrity cornerstone and affected the cornerstone objective to provide reasonable assurance that physical barriers, as designed, protect the public from radionuclide releases caused by accidents or events. Specifically, Exelon failed to perform leak rate testing of the RB normal closed loop cooling piping and failed to identify the degraded piping condition that impacted the containment isolation function. In accordance with IMC 0609.04, Initial Characterization of Findings, and Exhibit 3 of IMC 0609, Appendix A, The Significance Determination Process for Findings At-Power, issued June 19, 2012, the inspectors determined that the finding did not represent an actual open pathway in the physical integrity of the reactor containment isolation system nor did it involve an actual reduction in function of hydrogen recombiners for the reactor containment therefore, the finding was of very low safety significance (Green). The finding was not assigned a crosscutting aspect because the most significant causal factor of the finding was the failure to implement leak rate testing since 1991 and was not indicative of current plant performance.
05000289/FIN-2013404-01Security2013Q2
05000289/FIN-2013404-02Security2013Q2
05000289/FIN-2013002-01Failure to Maintain Combustible Loading Near the B CST within Fhar Limits2013Q1The inspectors identified a Green non-cited violation (NCV) of license condition DPR-50 section 2.C.(4), Fire Protection, for Exelons failure to maintain transient combustible loading within fire loading limits near the B condensate storage tank (CST). Specifically, on January 9, the inspectors identified a Portable On-Demand storage (POD) container staged within 50 feet of the B CST. The POD and its contents contained transient combustible materials in excess of the allowed fire loading in accordance with the fire hazards analysis report (FHAR). Exelon promptly removed the POD container and restored transient combustible loading within allowable limits. Exelon entered this issue into their corrective action program under issue report (IR) 1461029. Corrective actions included additional postings around the safety-related above-ground tanks, site-wide notifications and the performance of a root cause evaluation to address recent station fire protection issues. This performance deficiency is more than minor because it is associated with the Protection Against External Factors (Fire) attribute and adversely affected the Mitigating Systems cornerstone objective to ensure availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. In addition, it was determined to be more than minor since it is similar to more than minor example 4.k of IMC 0612, Power Reactor Inspection Reports, Appendix E because the fire loading was not within the FHAR limits. In accordance with IMC 0609.04, Phase 1 Initial Screen and Characterization of Findings, the inspectors determined the finding affected the administrative controls for transient combustible materials. Therefore, the inspectors conducted a phase 1 SDP screening using IMC 0609, Appendix F, Fire Protection Significance Determination Process, and the inspectors determined that the finding affected the category of Fire Prevention and Administrative Controls in that combustible material was not being properly controlled, the finding had a low degradation rating, and the finding was of very low safety significance (Green). This finding has a cross-cutting aspect in the area of Problem Identification and Resolution, Corrective Action Program, because Exelon failed to thoroughly evaluate and take appropriate corrective actions for similar transient combustible loading issues such that the cause and extent of condition were fully addressed.
05000289/FIN-2012005-02Failure to Identify and Correct Licensing Basis Flood Barrier and Support Equipment Deficiencies in Intake Screen and Pump House2012Q4The inspectors identified a non-cited violation (NCV) of 10 CFR 50, Appendix B, Criterion XVI, Corrective Actions, in that Exelon failed to identify and correct conditions adverse to quality regarding the licensing basis external flood barrier integrity. Specifically, Exelon failed to identify and correct 13 unsealed penetrations through the Intake Screen and Pump House (ISPH) flood barrier and multiple deficiencies that challenged the fulfillment of ISPH support equipment capability to maintain the integrity of the licensing basis flood barrier. The deficiencies were entered into the corrective action program and permanent corrective actions were taken to seal the penetrations to restore the external flood barrier integrity and restoration of the support equipment capability for flood protection. The finding was more than minor because it is associated with the protection against external factors attribute of the mitigating systems cornerstone to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, Exelon did not identify and correct 13 unsealed penetrations in a licensing basis external flood barrier and its associated support equipment deficiencies such that the barrier is fully capable of maintaining the ISPH free of flood water. The inspectors evaluated the finding in accordance with IMC 0609, Appendix A, Exhibit 2 Mitigating Systems Screening Questions and Exhibit 4 External Events Screening Questions and determined that a detailed risk evaluation was required based upon the assumed complete failure of the flood barrier would degrade two trains of Decay Heat Removal. A detailed risk evaluation modeled in SAPHIRE 8 using the TMI SPAR model version 8.18 determined the finding to be of very low safety significance (Green). This finding has a cross-cutting aspect in the area of Problem Identification and Resolution, Corrective Action Program, because Exelon failed to identify the unsealed penetrations through the flood barrier and multiple deficiencies in supporting equipment in a timely manner commensurate with its safety significance.
05000289/FIN-2012005-01Adequacy of Seismic Gap Flood Seal2012Q4The inspectors identified a non-cited violation (NCV) of General Design Criterion 2, Performance Standards, because Exelon had not established measures to ensure that the seismic gap flood seal was adequate to remain watertight during a probable maximum flood (PMF) event, as required by the TMI design. Specifically, the design requirement for the seismic gap seal specified that it was to be watertight. However, the installed seal configuration had measurable leakage when tested. The inspectors determined that the failure to construct, maintain, and inspect the seismic gap flood seal consistent with its design (e.g., watertight) was a performance deficiency within Exelon\'s ability to foresee and prevent. Exelon entered this issue into their corrective action program, took appropriate interim corrective actions, and completed permanent modifications to restore the watertight function of the seismic gap barrier. This finding was more than minor because it was similar to the more than minor example 3.j in Inspection Manual Chapter (IMC) 0612 Appendix E, Examples of Minor Issues, in that the seal\'s as-built and maintained configuration resulted in a condition where there was reasonable doubt regarding the functionality of the seismic gap seal to remain watertight during a PMF event. Also, this finding was associated with the protection against external factors attribute of the Mitigating Systems Cornerstone and adversely affected the cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. In accordance with IMC 0609, Appendix G, Shutdown Operations Significance Determination Process, the inspectors performed a bounding risk evaluation using an unavailability period of greater than one year for the watertight seal, and determined this finding was of very low safety significance (Green). This finding has a cross-cutting aspect, as described in IMC 0310, in the area of Human Performance, Decision Making, because Exelon failed to verify the validity of underlying assumptions or continued functionality of the seismic gap flood seal following an external flood re-analysis which revised the design basis PMF conditions.
05000289/FIN-2012005-03Failure to Identify and Correct Missing Electrical Conduit Flood Seals in the Air Intake Tunnel2012Q4The inspectors identified an apparent violation (AV) of 10 CFR 50, Appendix B, Criterion XVI, Corrective Actions, was identified during the TI-187 flooding walkdowns for Exelons failure to identify and correct an external flood barrier deficiency. Specifically, Exelon failed to identify and correct, during external flood barrier walkdowns, that electrical cable conduits were not flood sealed in the Air Intake Tunnel (AIT), as designed, to maintain the integrity of the external flood barrier. The deficiency was entered into Exelons corrective action process and permanent corrective actions were taken to seal the electrical conduits and restore the external flood barrier integrity. The finding was determined to be more than minor because it is associated with the protection against external factors attribute of the mitigating systems cornerstone to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, Exelon failed, during multiple focused walkdowns, to identify the degraded external flood barrier in the Crouse-Hinds couplings in the AIT that challenged the external flood barrier operability. The significance of the degraded external flood barrier is to be determined and cannot accurately be calculated until additional testing and analysis of the as-found configuration is complete. Specifically, Exelon is performing additional testing on the capability of as-found foam fire sealant material, present in the conduits at the AIT/Aux Building interface, to mitigate flood water entry into the safety-related structures. These results will be an input into the licensees flood mitigation aggregate impact review. This finding has a cross-cutting aspect in the area of Problem Identification and Resolution, Corrective Action Program, because Exelon failed to review the external flood barrier with a low threshold for identifying issues which resulted in the failure to identify the unsealed electrical conduits in the AIT in a timely manner commensurate with its safety significance.
05000289/FIN-2012012-01Failure to provide complete and accurate decommissioning status reports2012Q4During an NRC investigation completed on November 22, 2011, and a supplemental investigation completed on October 10, 2012, a violation of NRC requirements was identified. In accordance with the NRC Enforcement Policy, the violation is listed below: 10 CFR 50.75(a) establishes requirements for indicating to the NRC how a licensee will provide reasonable assurance that funds will be available for the decommissioning process and states that for power reactor licensees, reasonable assurance consists of a series of steps as provided in paragraphs (b), (c), (e), and (f) of 10 CFR 50.75. 10 CFR 50.75(f)(2) states, in part, that power reactor licensees shall report at least every 2 years on the status of its decommissioning funding for each reactor or part of a reactor that it owns; and, that the information in this report must include, at a minimum, the amount of decommissioning funds estimated to be required pursuant to 10 CFR 50.75(b) and (c). 10 CFR 50.75(b)(1) states, in part, that for a holder of an operating license under 10 CFR Part 50, financial assurance for decommissioning shall be provided in an amount which may be more, but not less, than the amount stated in the table in paragraph (c)(1) adjusted using a rate at least equal to that stated in paragraph (c)(2). 10 CFR 50.75(c)(1) states the minimum amount required to demonstrate reasonable assurance of funds for decommissioning by reactor type and power level. 10 CFR 50.75(c)(2) requires, in part, that an adjustment factor be applied, which is based on escalation factors for labor and energy, and waste burial. 10 CFR 50.9(a) states, in part, that information provided to the Commission by a licensee shall be complete and accurate in all material respects. Contrary to the above, on March 31, 2005, March 31, 2006, March 31, 2007, and March 31,2009, Exelon Generation Company, LLC (Exelon) provided information on the status of its decommissioning funding that was not complete and accurate in all material respects, when it submitted the decommissioning funding status (DFS) reports pursuant to 10 CFR 50.75. Specifically, the March 31, 2005, March 31, 2007, March 31, 2006, and March 31, 2009, DFS reports stated that the decommissioning funds estimated to be required for each of the reactors, as listed in the report, were determined in accordance with 10 CFR 50.75(b) and the applicable formulas of 10 CFR 50.75(c). However, in multiple instances, the amount reported was a discounted value that was less than the minimum required amount specified by 10 CFR 50.75(b) and (c). This is a Severity Level IV violation.
05000289/FIN-2012403-02Security2012Q3
05000289/FIN-2012403-01Security2012Q3
05000289/FIN-2012004-02Remote Shutdown Relay 69X1RR Contact Failure2012Q3On December 22, 2011, the reactor building emergency cooling water pump discharge valve B (RR-V-1B) failed to open during performance of an engineered safeguards actuation system (ESAS) quarterly surveillance test. TMI declared RR-V-1B inoperable and entered a 72 hour limited condition for operation (LCO) in accordance with technical specification (TS) 3.3.2. TMI performed troubleshooting and determined that the remote shutdown (RSD) transfer selector switch relay (69X1RR), which is in series with the ESAS signal, exhibited intermittent contact make-up. The function of the RSD selector switch and associated relay (69X1RR) is to transfer control of RR-V-1B from the main control room to the RSD panel. The relay (69X1RR) was found in the open-state thus, inhibiting the ESAS actuation signal. The selector switch relay was cycled until proper contact make-up was achieved. TMI applied administrative controls to ensure the transfer switch relay (69X1RR) contact closed properly if the RSD transfer switch was manipulated prior to the relay replacement. RR-V-1B was successfully tested and declared operable on December 22, 2011. The relay transfer switch was replaced and tested satisfactorily on January 6, 2012. The last successful RSD functional test of RR-V-1B had been completed on November 10, 2011 during refueling outage T1R19. TMI concluded that the relay (69X1RR) had most likely not fully re-closed at the completion of the test. Thus, TMI determined that RR-V-1B was inoperable from November 10, 2011 through December 22, 2011. This issue constituted two violations of NRC requirements. Namely, a) the licensee made the reactor critical on November 24, 2011 (while starting up from T1R19), without all engineered safeguards valves associated with the reactor building emergency cooling system being operable as required by TS 3.3.1; and, b) and that RR-V-1B was inoperable for more than 72 hours, and the unit wsa no paced in a hot shutdown condition within 6 hours, as required by TS 3.3.2. However, the NRC concluded that it was not reasonably within the licensees ability to foresee and correct the relay failure that caused these violations. Specifically, the failure analysis of the relay identified that an unforeseen manufacturing defect caused the failure and that the relay exhibited no visual abnormalities or indications to the licensee that a defect existed prior to its failure. In addition, the NRC identified that no significant plant or industry operating experience existed on this style relay that would have alerted the licensee to this potential issue. Therefore, the NRC did not identify any performance deficiency associated with the violations. Inspection Manual Chapter (IMC) 0612, Appendix B, Issue Screening, directs disposition of this issue in accordance with the Enforcement Policy because there was no performance deficiency associated with the violations. The inspectors used the enforcement policy, Section 6.1, Reactor Operations, to evaluate the significance of this violation. The inspectors concluded that the violation is more than minor and best characterized as Severity Level IV (very low safety significance) because it is similar to Enforcement Policy Section 6.1, example d.1. Additionally, the inspectors assessed the risk associated with the issue by using IMC 0609, Appendix A, SDP For Findings at Power. The inspectors screened the issue, and evaluated it using Exhibit 3 of IMC 0609, Appendix A. Evaluating the criteria under the Barrier Integrity cornerstone, the finding did not represent an actual open pathway in the physical integrity of the containment and did not involve a reduction in function of hydrogen igniters in the reactor containment. Based on these reviews, the issue would screen as very low safety significance (Green). Because it was not reasonable for TMI to have been able to foresee and prevent the relay failure, the NRC determined no performance deficiency existed. Thus, the NRC has decided to exercise enforcement discretion in accordance with Section 3.5 of the NRC Enforcement Policy and refrain from issuing enforcement action for the violation (EA-12-164). Further, because the licensees action and/or inaction did not contribute to this violation, it will not be considered in the assessment process or the NRCs Action Matrix. This LER is closed.
05000289/FIN-2012004-01Failure to Maintain Combustible Loading in the Bwst Tunnel within Fhar Limits2012Q3The inspectors identified a Green non-cited violation (NCV) of license condition DPR- 50, section 2.C.(4), Fire Protection, for Exelon storing transient combustibles in excess of the fire loading allowed near the borated water storage tank (BWST). Specifically, on July 11, the inspectors identified eight bags of trash/transient combustible materials stored within 50 feet of the BWST which is in excess of the allowed fire loading in accordance with the Fire Hazards Analysis Report (FHAR) and transient combustible control program. The inspectors determined that the failure to maintain combustible loading in the BWST tunnel within the FHAR limits was a performance deficiency that was within Exelons ability to foresee and correct. Exelon promptly removed the improperly stored transient combustibles and entered the performance deficiency into their corrective action program as issue report 1388097. Corrective actions were implemented to alert technicians of the restrictions on transient combustible materials near the BWST. This finding was determined to be more than minor since it is similar to more than minor example 4.k of Inspection Manual Chapter (IMC) 0612, Power Reactor Inspection Reports, Appendix E, because the fire loading was not within the FHAR limits. In accordance with Inspection Manual Chapter (IMC) 0609.04, Phase 1 Initial Screen and Characterization of Findings, the inspectors determined the finding affected the administrative controls for transient combustible materials. Additionally, the inspectors determined that this issue was more than minor because it affected the protection against external events attribute of the mitigating systems cornerstone objective of ensuring the availability, reliability and capability of systems that respond to initiating events to prevent undesirable consequences. The inspectors conducted a phase 1 SDP screening using IMC 0609, Appendix F, Fire Protection Significance Determination Process, and the inspectors determined that the finding affected the category of Fire Prevention and Administrative Controls in that combustible material was not being properly controlled, the finding had a low degradation rating, and the finding was of very low safety significance (Green). This finding has a cross-cutting aspect in the area of Human Performance, Resources, because Exelon failed to appropriately ensure interdepartmental coordination during the work activities such that the transient combustibles were promptly removed from the BWST tunnel.
05000289/FIN-2012008-01Inadeguate Corrective Actions Associated with Esas Relay Failure2012Q2The inspectors identified a finding of very low safety significance (Green) involving a non-cited violation (NCV) of 10 CFR 50, Appendix B, Criterion XVI, Corrective Action, for Exelons failure to implement prompt corrective actions following the identification of a degraded engineered safeguards actuation system (ESAS) emergency diesel generator (EDG) block load relay. Specifically, Exelon staff did not perform a relay replacement in a timely manner to correct a condition adverse to quality commensurate with its safety significance. This resulted in an EDG block load relay failing a subsequent surveillance test on April 24, 2012. Exelon staff entered this issue into their corrective action program as issue report (IR) 1368183 and replaced the relay on May 31, 2012. This finding is more than minor because it was associated with the equipment performance attribute of the Mitigating Systems cornerstone and adversely affected the cornerstone objective of ensuring the reliability and capability of systems that respond to initiating events to prevent undesirable consequences. In accordance with IMC 0609.04, Phase Initial Screen and Characterization of Findings, the inspectors conducted a Phase 1 SDP screening and determined that the finding was of very low safety significance (Green) because the finding was not a design or qualification deficiency, did not represent a loss of system safety function, and did not screen as potentially risk significant due to external initiating events. Specifically, Exelon staffs past operability evaluation affirmed the relay would have performed its safety function given the degraded relay condition that existed. This finding had a cross-cutting aspect in the area of problem identification and resolution in that Exelon staff actions were not timely in addressing an adverse trend associated with a degraded ESAS block load relay.
05000289/FIN-2012007-05Licensee-Identified Violation2012Q110 CFR Part 50, Appendix B, Criterion lll, Design Control, requires in part, that design control measures provide for verifying or checking the adequacy of design, Contrary to this, design control measures had not ensured and verified that connected Class 1E loads are not damaged or become unavailable for a design basis event concurrent with a degraded voltage condition between the 4kV degraded voltage dropout setting and the loss-of-voltage setting, prior to and following transfer to the EDG onsite source. Exelon had previously identified in early 2009, within AR 838100, that actions were required to review their design at TMI with respect to the selection and sizing of TOLs which were not bypassed on an accident signal. This included proposed actions to review the long time trip of protective relays and the impact of extended duration of locked rotor current on potential motor damage from additional heating. Additionally, Exelon identified in December 2011 within AR 1276061, the need to review the design to verify the allowable degraded voltage relay (DVR) time duration would not result in failure of safety-related systems or components. The finding was of very low safety significance (Green) because the finding did not represent the loss of a system salety function, an actual loss of safety function of a single train for greater than the TS allowed outage time, or screen as potentially risk significant due to a seismic, flooding, or severe weather initiating event. Exelon initiated AR 1347885 to ensure all aspects of the design issue will be resolved based on additional comments from the inspection team.
05000289/FIN-2012007-02Inadequate TOL Sizing Evaluation for Jogging/Throttling Valves2012Q1The team identified a finding of very low safety significance (Green) involving a non-cited violation of 10 CFR Part 50, Appendix B, Criterion lll, Design Control, because Exelon had not verified the adequacy of the design regarding motor operated valve (MOV) thermal overload relay (TOL) sizing. Specifically, Exelon had not verified that TOL relays on safety-related low pressure injection (LPl) MOV circuits for the LPI injection valves, DH-V-4A(B), were properly sized to support the design function of repetitive jogging and throttling of the MOVs in response to design basis accidents. Exelon entered the issue into their corrective action program to evaluate the condition that the existing design analysis did not address TOL sizing for jogging MOVs. Exelon performed an initial review for operability of the LPI injection valves and included an extent-of-condition review for other engineered safeguards (ES) MOVs that are operated in a jogging mode to ensure the MOVs would not inadvertently trip under reasonable assumptions. The performance deficiency was determined to be more than minor because it was associated with the design control attribute of the Mitigating Systems Cornerstone and adversely affected the cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. The team evaluated the finding in accordance with IMC 0609, Significance Determination Process, Attachment 4, Phase 1 - Initial Screening and Characterization of Findings, The finding was determined to be of very low safety significance because it was a design deficiency confirmed not to result in a loss of operability. This finding was not assigned a cross-cutting aspect because it was a historical design issue not indicative of current performance.
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