IR 05000335/2017012
ML17263A055 | |
Person / Time | |
---|---|
Site: | Saint Lucie ![]() |
Issue date: | 09/20/2017 |
From: | Ladonna Suggs NRC/RGN-II/DRP/RPB3 |
To: | Nazar M Florida Power & Light Co |
References | |
IR 2017012 | |
Download: ML17263A055 (13) | |
Text
UNITED STATES tember 20, 2017
SUBJECT:
ST. LUCIE PLANT - NRC SUPPLEMENTAL INSPECTION REPORT 05000335/2017012 AND ASSESSMENT FOLLOWUP LETTER
Dear Mr. Nazar:
On August 24, 2017, the U.S. Nuclear Regulatory Commission (NRC) completed a supplemental inspection using Inspection Procedure (IP) 95001, Supplemental Inspection Response to Action Matrix Column 2 Inputs. The NRC inspection team discussed the results of this inspection and the implementation of your corrective actions with Mr. Dan DeBoer and other members of your staff. The results of this inspection are documented in the enclosed report.
The NRC performed this inspection to review your stations actions in response to a White finding in the initiating events cornerstone which was documented and finalized in NRC Inspection Reports 05000335/2016012 (Agencywide Documents Access and Management System (ADAMS) Package No. ML17179A497) and 05000335/2017011 (ADAMS Accession No. ML17108A232), respectively. On June 29, 2017, your staff informed the NRC that your station was ready for the supplemental inspection.
The NRC determined that your staffs evaluation identified the primary root cause of the White finding was licensee procedure, ADM-08.12, Maintenance Configuration Control, did not require sufficient detail to be included in the work instructions to modify synchronization selector switch SS-888. The corrective action to preclude repetition was to revise the governing procedure to: 1) require the use of a lifted lead sheet in work instructions where wiring de-terminations or re-terminations are performed; and 2) require an independent verification that the as-left configuration exactly matches the post modification as-designed configuration.
After reviewing Saint Lucie Plant, Unit 1, performance in addressing the White finding subject of IP 95001, Supplemental Inspection Response to Action Matrix Column 2 Inputs, the NRC concluded that your actions met the objectives of IP 95001. Therefore, in accordance with the guidance in Inspection Manual Chapter 0305, Operating Reactor Assessment Program, the white finding will only be considered in assessing plant performance for a total of four quarters. As a result, the NRC determined the performance at Saint Lucie Plant, Unit 1, to be in the Licensee Response Column of the Reactor Oversight Process Action Matrix as of October 1, 2017.
The NRC inspectors did not identify any finding or violation of more than minor significance.
This letter, its enclosure, and your response (if any) will be made available for public inspection and copying at http://www.nrc.gov/reading-rm/adams.html and at the NRC Public Document Room in accordance with 10 CFR 2.390, Public Inspections, Exemptions, Requests for Withholding.
Sincerely,
/RA/
LaDonna B. Suggs, Chief Reactor Projects Branch 3 Division of Reactor Projects Docket No.: 50-335 License No.: DPR-67
Enclosure:
IR 05000335/2017012 w/Attachment: Supplemental Information
REGION II==
Docket Nos: 50-335 License Nos: DPR-67 Report Nos: 05000335/2017012 Licensee: Florida Power & Light Company (FPL)
Facility: St. Lucie Plant, Unit 1 Location: 6501 South Ocean Drive Jensen Beach, FL 34957 Dates: August 21, 2017 to August 24, 2017 Inspectors: D. Jackson, Project Engineer N. Hobbs, Project Engineer Approved by: LaDonna B. Suggs, Chief Reactor Projects Branch 3 Division of Reactor Projects Enclosure
SUMMARY
Inspection Report (IR) 05000335/2017012; 08/21/2017 - 08/24/2017; St. Lucie Plant, Unit 1;
Supplemental Inspection - Inspection Procedure (IP) 95001 Two regional inspectors performed this inspection. The NRCs program for overseeing the safe operation of commercial nuclear power reactors is described in NUREG-1649, Reactor Oversight Process, Revision 6.
The NRC staff performed this supplemental inspection in accordance with IP 95001,
Supplemental Inspection Response to Action Matrix Column 2 Inputs, to assess the licensees evaluation associated with the failure to maintain configuration control of the Unit 1 main generator inadvertent energization lockout relay circuitry, which resulted in a reactor trip and loss of offsite power on August 21, 2016. The NRC staff previously characterized this issue as having low to moderate safety significance (White), as documented and finalized in NRC IRs 05000335/2016012 and 05000335/2017011, respectively. During this supplemental inspection, the inspectors determined that the licensee performed a comprehensive evaluation of the self-revealed issue, which occurred during plant startup. The licensee identified the root cause of the issue to be licensee procedure, ADM-08.12, Maintenance Configuration Control, did not require sufficient detail to be included in the work instructions to modify synchronization selector switch SS-888. The corrective action to preclude repetition was to revise the governing procedure to 1) require the use of a lifted lead sheet in work instructions where wiring de-terminations or re-terminations are performed, and 2) require an independent verification that the as-left configuration exactly matches the post modification as-designed configuration.
Given the licensees acceptable performance in addressing the issue, the white finding associated with this issue will only be considered in assessing plant performance for a total of four quarters in accordance with the guidance in Inspection Manual Chapter (IMC) 0305,
Operating Reactor Assessment Program. Inspectors will review the licensees implementation of corrective actions during a future inspection.
Findings No findings of significance were identified.
REPORT DETAILS
OTHER ACTIVITIES
Cornerstone: Initiating Events
4OA3 Follow-up of Events and Notices of Enforcement Discretion
.1 (Closed) Licensee Event Report (LER) 05000335/2016-003-01; 05000335/2016-003-02,
Generator Lockout Relay Actuation During Power Ascension Results in Reactor Trip
a. Inspection Scope
On August 21, 2016, during a Unit 1 restart following a maintenance outage, at 38 percent power, the main generator inadvertent energization lockout relay unexpectedly actuated which caused the main generator to trip, resulting in an automatic reactor trip. The relay actuation prevented the automatic transfer of station auxiliaries to the startup transformers and resulted in a loss of offsite power, although offsite power remained available at the switchyard. Other than the generator lockout, all systems functioned as designed, and the plant stabilized in Mode 3. The licensee declared a Notice of Unusual Event (NOUE) based on the lockout relay preventing the automatic transfer to available startup transformer power. The NOUE was terminated approximately one hour later, following restoration of forced cooling within the reactor coolant system. The original LER, 2016-003-00, was closed in IR 05000335/2016012.
The licensee made two revisions to the LER to reflect the final root cause evaluation (RCE). Specifically, the revised root cause and contributing causes, corrective actions to preclude repetition (CAPR), and safety significance, were updated. The inspectors reviewed the updated LERs to verify accuracy with the final RCE, including appropriateness of corrective actions. Documents reviewed are listed in the Attachment.
b. Findings
A self-revealing White finding was previously documented in IR 05000335/2017011. No additional findings or violations were identified during the review of these LERs. These LERs are closed.
4OA4 Supplemental Inspection
.1 Inspection Scope
The NRC staff performed this supplemental inspection in accordance with IP 95001 to assess the licensees evaluation of a White finding, which affected the initiating events cornerstone in the reactor safety strategic performance area. The inspection objectives were to ensure the:
- root cause and contributing causes of the significant issue were understood;
- extent of condition and extent of cause of the significant issue were identified;
- corrective actions taken to address and preclude repetition of the significant issue were or will be prompt and effective; and
- corrective plans direct prompt actions to effectively address and preclude repetition of the significant performance issue.
Saint Lucie Plant, Unit 1, entered the Regulatory Response column of the NRCs Action Matrix in the fourth quarter of 2016 as a result of one inspection finding of low to moderate safety significance (White), in the initiating events cornerstone. The self-revealing finding was associated with failure to maintain configuration control of the Unit 1 main generator inadvertent energization lockout relay circuitry, which resulted in a reactor trip and loss of offsite power on August 21, 2016. The finding was characterized as having White safety significance based on the results of a detailed risk analysis performed by a region-based senior reactor analyst, as discussed in NRC IRs 05000335/2016012 and 05000335/2017011.
The licensee staff informed the NRC staff on June 29, 2017, that they were ready for the supplemental inspection. In preparation for the inspection, the licensee performed RCE 2151217, Revision 2, to evaluate organizational and programmatic weaknesses related to the event that resulted in the White finding.
The inspectors reviewed the licensees RCE in addition to other evaluations conducted in support of the RCE. The inspectors reviewed corrective actions that were taken or planned to address the identified causes. The inspectors also held discussions with licensee personnel to ensure that the root and contributing causes and the contribution of safety culture components were understood and corrective actions taken or planned were appropriate to address the causes and preclude repetition.
.2 Evaluation of the Inspection Requirements
02.01 Problem Identification a. IP 95001 required that the inspection staff determine that the licensees evaluation of the issue documents who identified the issue (i.e., licensee-identified, self-revealing, or NRC-identified) and the conditions under which the issue was identified.
The event occurred on August 21, 2016, during a plant startup. The finding associated with the event was self-revealing; evident after the main generator trip and subsequent reactor trip, which resulted in a plant-centered loss of offsite power. The inspectors verified that this information was documented in the licensees RCE.
b. IP 95001 required that the inspection staff determine that the licensees evaluation of the issue documents how long the issue existed and prior opportunities for identification.
The licensees RCE documented that the unintended removal of a jumper cable (wire)during maintenance on automatic synchronizer circuitry during October 2013 was the direct cause of the event on August 21, 2016. The licensee determined that the event could have been avoided if proper configuration control was used during the October 2013 modification. Additionally, the licensee determined there was an opportunity for identification of the error, if a final 100 percent wiring configuration verification was performed after the work was completed. The inspectors determined that the licensees evaluation was adequate with respect to identifying how long the issue existed and prior opportunities for identification.
c. IP 95001 required that the inspection staff determine that the licensees evaluation documents the plant-specific risk consequences, as applicable, and compliance concerns associated with the issue.
The NRC determined this issue was a White finding, as documented in IR 05000335/2017011, and the licensees RCE also documented that the finding associated with this issue had white safety significance. In addition, RCE 2151217 documented the consequences of the issue, which included the following:
- spurious generator lockout;
- turbine and reactor trip from 38 percent power;
- automatic transfer of station auxiliaries to startup transformer prevented due to generator lockout;
- plant-centered loss of offsite power;
- loss of reactor coolant pumps and main feedwater pumps; and
- declaration of a NOUE.
The licensee also documented aspects of their probabilistic risk analysis that were performed for the event, as well as the mitigation and recovery actions that were needed due to the unavailability of safety-significant equipment during the event. The inspectors determined that the licensee appropriately considered and documented the risk consequences and compliance concerns associated with the issue.
d. Findings
No findings were identified.
02.02 Root Cause, Extent of Condition, and Extent of Cause Evaluation a. IP 95001 required that the inspection staff determine that the licensee evaluated the issue using a systematic methodology to identify the root and contributing causes.
The licensee used the following systematic methods to complete RCE 2151217:
- data gathering through interviews and document review;
- timeline construction;
- events and causal factors chart;
- cause and effect diagram;
- causal factor test matrix; and
- why staircase analyses.
The inspectors determined that the licensee evaluated the issue using systematic methodologies to identify root and contributing causes.
b. IP 95001 required that the inspection staff determine that the licensees RCE was conducted to a level of detail commensurate with the significance of the issue.
The licensees RCE included a timeline of events and several methodologies as listed in the previous section. The licensees RCE documented the root cause of the issue to be the maintenance configuration control procedure (ADM-08.12) did not require sufficient detail to be included in the work instructions to modify synchronization switch SS-888.
Specifically, ADM-08.12 lacked requirements to adequately document and verify the lifting and landing of wires manipulated, and did not require that the as-left configuration exactly match the post modification as-designed configuration, of the component. The licensee determined that the contributing causes included; 1) inadequate oversight of work performed by the supplemental workers, and 2) no means to verify the disabled status of the inadvertent energization lockout before manually placing the main generator in service. Based on the documented work performed for this root cause evaluation, the inspectors concluded that the root cause evaluation was conducted to a level of detail commensurate with the significance of the problem.
c. IP 95001 required that the inspection staff determine that the licensees RCE included a consideration of prior occurrences of the issue and knowledge of operating experience (OE).
The licensees RCE included an evaluation of internal and external OE. The licensee also considered previous occurrences. As a result of the review, the licensee determined this issue did not meet the definition of a repeat event. Based upon the considerations described in the analysis, the inspectors concluded that the analysis appropriately considered prior occurrences of the issue and knowledge of prior operating experience.
d. IP 95001 required that the inspection staff determine that the licensees RCE addressed the extent of condition and extent of cause of the issue.
The licensees evaluation considered the extent of condition associated with the issue of the missing jumper wire in the synchronization selector switch SS-888. The RCE documented the results of the same object, same defect, same object, similar defect, and similar object, similar defect, evaluations. The licensee concluded that no additional follow-up actions were warranted resulting from the extent of condition review.
The RCE also considered the extent of cause associated with the root cause and contributing causes. The licensee reviewed other configuration control related procedures to ensure sufficient detail was contained for the configuration control of wiring. The licensee documented several corrective actions resulting from the review of the root cause, which included modifications to ADM-08.12 and ADM-0010432, Control of Plant Work Orders. The licensee also documented corrective actions associated with contributing cause 1 (CC1), which included steps to ensure stronger supervisor oversight for vendor and contractor activities. The RCE also documented corrective actions associated with contributing cause 2 (CC2), which included procedure revisions to verify the disabled status of the inadvertent energization lockout, prior to manual generator operation. The inspectors concluded that the licensees RCE adequately addressed the extent of condition and extent of cause of the issue.
e. IP 95001 required that the inspection staff determine that the licensees root cause, extent of condition, and extent of cause evaluations appropriately considered the safety culture components as described in IMC 0310, Aspects within the Cross-Cutting Areas.
The licensee performed a nuclear safety culture (NSC) review and associated the root cause and contributing causes with weaknesses in the following safety culture aspects:
Resources (H.1), Work Management (H.5), Avoid Complacency (H.12), Consistent Process (H.13), and Conservative Bias (H.14). The licensee also identified associations with the following attributes to a lesser degree: Field Presence (H.2), Change Management (H.3), Design Margins (H.6), Trending (P.4), Job Ownership (X.7), and Benchmarking (X.8). The licensee considered each of these aspects in detail in the contexts of both IMC 0310 and NUREG 2165, Safety Culture Common Language. The licensee determined that no additional corrective actions were warranted because of the NSC review and that none of the aspects were indicative of a higher-level safety culture issue. The inspectors determined that the RCE included an appropriate consideration of whether a weakness in any safety culture component was a root cause or significant contributing cause of the issue.
f. Findings
No findings were identified.
02.03 Corrective Actions a. IP 95001 required that the inspection staff determine that the licensee specified appropriate corrective actions for each root and/or contributing cause, or adequately evaluated that no actions were necessary.
The inspectors determined that the licensee specified appropriate corrective actions for each root and contributing cause. The licensees RCE concluded that the corrective action to preclude repetition include a revision to ADM-08.12, Maintenance Configuration Control, to provide adequate instructions for the control of permanent configuration changes. The corrective action identified the specific changes required to revise the procedure appropriately. The corrective actions for CC1 associated with supervisor oversight for vendor and contractor activities had been implemented though other previous corrective actions. However, the licensee verified the actions were also appropriate for this issue. The corrective actions for CC2 included procedure revisions to verify the disabled status of the inadvertent energization lockout, prior to manual generator operation. The inspectors determined that the corrective actions specified were appropriate for the root and contributing causes.
b. IP 95001 required that the inspection staff determine that the licensee prioritized corrective actions with consideration of risk significance and regulatory compliance.
The licensees corrective action to preclude repetition was to revise procedure ADM-08.12, to provide instructions for the control of permanent configuration changes.
The procedure was revised in a timely manner and was available for review during this inspection. Additionally, the corrective actions associated with each contributing cause were complete and also available for review. The inspectors concluded that the corrective actions had been prioritized with consideration to risk significance and regulatory compliance.
c. IP 95001 required that the inspection staff determine that the licensee established a schedule for implementing and completing the corrective actions.
The inspectors determined that the licensee adequately established a schedule for implementing and completing the corrective actions. The corrective actions that were associated with the root cause and contributing causes were completed in a timely manner.
d. IP 95001 required that the inspection staff determine that the licensee developed quantitative and/or qualitative measures of success for determining the effectiveness of the corrective actions to preclude repetition.
As documented in RCE 2151217, the licensee established measures for determining the effectiveness of the corrective actions. These measures included the following:
- interim effectiveness review to review electrical work packages developed;
- review of electrical work packages, both developed and completed; and
- perform observations of supplemental workforce electrical crew.
The licensee staff entered these corrective action items into their corrective action program to ensure the effectiveness reviews and enhanced monitoring are performed.
The inspectors determined that quantitative and qualitative measures of success had been developed for determining the effectiveness of the corrective actions to preclude repetition.
e. IP 95001 required that the inspection staff determine that the licensees planned or taken corrective actions adequately address a Notice of Violation (NOV) that was the basis for the supplemental inspection, if applicable.
The NRC staff did not issue an NOV to the licensee because the performance deficiency was not a violation of regulatory requirements; therefore, this inspection requirement was not applicable.
f. Findings
No findings were identified.
02.04 Evaluation of IMC 0305 Criteria for Treatment of Old Design Issues The licensee did not request credit for self-identification of an old design issue; therefore, the issue was not evaluated against the IMC 0305 criteria for treatment of an old design issue.
4OA6 Meetings
.1 Exit Meeting Summary
On August 24, 2017, the inspectors presented the inspection results to Mr. Dan DeBoer, Site Director, and other members of the staff. The inspectors confirmed that no proprietary information was retained or documented in the inspection report.
.2 Regulatory Performance Meeting
On August 24, 2017, as part of the exit meeting associated with the 95001 inspection, the NRC met with the licensee to discuss their performance in accordance with Section 10.02.b.4 of IMC 0305. During this meeting, the NRC and licensee discussed the issues related to the White finding that resulted in Saint Lucie Plant, Unit 1, being placed in the Regulatory Response Column of the NRC Action Matrix. This discussion included the causes, corrective actions, and other planned licensee actions.
ATTACHMENT:
SUPPLEMENTAL INFORMATION
KEY POINTS OF CONTACT
Licensee Personnel
- A. Dong, Maintenance Manager
- R. Sciscente, Licensing
- M. Snyder, Licensing Manager
- D. Whitwell, Root Cause Evaluator
NRC Personnel
- L. Suggs, Chief, Branch 3, Division of Reactor Projects
- T. Morrissey, Senior Resident Inspector
- S. Roberts, Resident Inspector
LIST OF ITEMS
OPENED AND CLOSED
Closed
- 05000335/2016-003-01 LER Generator Lockout Relay Actuation During Power Ascension Results in Reactor Trip (Section 4OA3)
- 05000335/2016-003-02 LER Generator Lockout Relay Actuation During Power Ascension Results in Reactor Trip (Section 4OA3)
- 05000335/2016012-01 FIN Failure to Maintain Component Configuration Control Resulted in a Complicated Reactor Trip (Section 4OA4)