IR 05000458/2024040
| ML24074A476 | |
| Person / Time | |
|---|---|
| Site: | River Bend  |
| Issue date: | 03/15/2024 |
| From: | Mark Haire NRC/RGN-IV/DRSS |
| To: | Hansett P Entergy Operations |
| References | |
| IR 2024040 | |
| Download: ML24074A476 (1) | |
Text
March 15, 2024
SUBJECT:
RIVER BEND STATION - 95001 SUPPLEMENTAL INSPECTION REPORT 05000458/2024040 AND FOLLOW-UP ASSESSMENT
Dear Phil Hansett:
On February 1, 2024, the U.S. Nuclear Regulatory Commission (NRC) completed a supplemental inspection using Inspection Procedure 95001, Supplemental Inspection Response to Action Matrix Column 2 (Regulatory Response) Inputs at the River Bend Station (River Bend).
The enclosed inspection report documents the inspection results which were discussed with Phil Hansett, Site Vice President, and other members of your staff during a virtual meeting on February 1, 2024. The NRC performed this inspection to review your stations actions in response to one White violation in the emergency preparedness cornerstone area. On October 5, 2023, you informed the NRC that your station was ready for the supplemental inspection.
The NRC determined that your staffs evaluation identified the cause of the White violation.
Specifically, the root cause evaluations for the White violation, as well as a common cause root cause evaluation, identified the root causes. These root causes identified detector engineering conversion factors were not correctly transferred when installed or when detectors were replaced. Also included was a radiation monitor database configuration control process that lacked measures to ensure that the associated system data, calculations, and documentation was complete, accurate, and up to date. Corrective actions to preclude repetition are discussed in detail in the enclosed inspection report.
Overall, the NRC determined that River Bends problem identification, causal analyses, and corrective actions sufficiently addressed the performance issues that led to the White violation.
All inspection objectives, as described in Inspection Procedure 95001, were met, and this inspection is, therefore, closed. With the closure of this White violation, and as a result of our continuous review of plant performance, the NRC has updated its assessment of River Bend.
This assessment supplements, but does not supersede, the end-of-cycle letter issued on March 1, 2023. Based on successful completion of the supplemental inspection, and issuance of this inspection report, River Bend has transitioned to the licensee response column of the NRC Action Matrix (Column 1) as of the date of the exit meeting for this inspection on February 1, 2024. In accordance with 10 CFR 2.390 of the NRCs Agency Rules of Practice and Procedure, a copy of this letter, its enclosure, and your response, if you choose to provide one, will be made available electronically for public inspection in the NRC Public Document Room and from the NRCs ADAMS, accessible from the NRC website at http://www.nrc.gov/reading-rm/adams.html.
Sincerely, Mark Haire, Chief, Response Coordination Branch Docket No. 05000458 License No. NPF-47
Enclosure:
Supplemental Inspection Report 2024040
Inspection Report
Docket Number:
05000458
License Number:
Report Number:
Enterprise Identifier:
I-2024-040-0000
Licensee:
Entergy Operations, Inc.
Facility:
River Bend Station
Location:
Killona, LA
Inspection Dates:
January 15, 2024, to February 1, 2024
Inspectors:
B. Baca, Health Physicist
H. Strittmatter, Resident Inspector, Comanche Peak
Approved By:
Mark Haire, Chief
Response Coordination Branch
Division of Radiological Safety & Security
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an inspection procedure 95001 supplemental inspection at the River Bend Station, in accordance with the Reactor Oversight Process. The Reactor Oversight Process is the NRCs program for overseeing the safe operation of commercial nuclear power reactors. Refer to https://www.nrc.gov/reactors/operating/oversight.html for more information.
List of Findings and Violations
No findings or violations of more than minor significance were identified.
Additional Tracking Items
Type Issue Number Title Report Section Status NOV 05000458/2023092-01 Failure to Maintain Accurate EAL Thresholds and Dose Assessment Methods EA-23-071 95001 Closed
INSPECTION SCOPES
Inspections were conducted using the appropriate portions of the inspection procedures (IPs)in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html.
Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards.
OTHER ACTIVITIES
95001 - Supplemental Inspection Response to Action Matrix Column 2 (Regulatory Response)
Inputs The inspectors reviewed and selectively challenged aspects of the licensees problem identification, causal analysis, and corrective actions in response to a White finding in the Emergency Preparedness cornerstone. The NRC communicated to the licensee of their entry into Reactor Oversight Process Action Matrix Column 2, Regulatory Response Column, in the cover letter of NRC Inspection Report 05000458/2023091, dated July 20, 2023 (Agencywide Document and Management System (ADAMS) Accession Number ML23187A639). In addition, in NRC Inspection Report 05000458/2023092, dated August 15, 2023 (ML23201A132), the licensee was informed they remained in the Reactor Oversight Process Action Matrix Column 2, Regulatory Response Column. The finding is summarized below:
The licensee failed to follow and maintain the effectiveness of an emergency plan in accordance with 10 CFR 50.54(q)(2). Specifically, the licensee failed to maintain a standard emergency classification scheme as required by 10 CFR 50.47(b)(4) because radiation monitoring system (RMS) monitors RMS-RE125 (Main Plant Exhaust Primary),
RMS-RE126 (Main Plant Exhaust Secondary), RMS-RE5A (Fuel Building Ventilation Primary), RMS-RE6A (Radwaste Building Vent Primary), and RMS-RE107 (Liquid Radwaste Effluent) had errors causing them to read lower values than they should causing emergency action levels (EAL) up to the General Emergency level to be ineffective. In addition, the licensee failed to use adequate methods, systems, and equipment for assessing and monitoring actual and potential offsite consequences of a radiological emergency as required by 10 CFR 50.47(b)(9), because those same errors, excluding RMS-RE107 since it is not used for dose assessment, would result in inaccurate dose assessments for a radiological release through the main plant exhaust, fuel building, and radwaste building paths.
The licensee staff informed the NRC by letter, dated October 5, 2023, of their readiness for this supplemental inspection (ML23278A239). The licensee performed a root cause evaluation (RCE) in preparation for the inspection to identify the process and organizational weaknesses that resulted in the White finding. The RCE reviewed was condition report (CR)
CR-RBS-2023-4055, Root
Cause:
Radiation detectors related to Equipment Important to Emergency Response (EITER) and Technical Specification (TS) Out of Calibration, Revision-2.
As part of the evaluation, the licensee also assessed their safety culture to identify any contribution to the root or contributing causes. The licensee provided the inspectors a copy of their RCE on December 21, 2023, along with other supporting evaluations and documentation by January 5, 2024. Subsequently, the NRC performed the onsite portion of this supplemental inspection during the week of January 15-19, 2024.
The objectives of this supplemental inspection were to:
1. Ensure that the root and contributing causes of significant individual and collective
white performance issues are understood.
2. Ensure that the extent-of-condition and extent-of-cause of individual and collective
white performance issues are identified.
3. Ensure that completed corrective actions to address and preclude repetition of white
performance issues are timely and effective.
4. Ensure that planned corrective actions to preclude repetition direct timely and
effective actions to address and preclude repetition of significant individual and collective performance issues.
The inspectors reviewed the licensees RCE and other corrective action program evaluations conducted in support of, or as a result of, the RCE. The inspectors reviewed corrective actions (CAs) that the licensee had taken to address the identified causes. The inspectors also held discussions, conducted field walkdowns reviewing subject radiation monitoring equipment and systems, and conducted interviews with the licensees personnel to determine if the root and contributing causes, and the contribution of safety culture components, were understood, as well as whether completed or planned CAs were adequate to address the causes and prevent recurrence.
INSPECTION RESULTS
Objective 1: Ensure that the root and contributing causes of significant individual and collective white performance issues are understood.
The inspectors reviewed the root cause evaluation the licensee conducted for the failure to maintain accurate EAL thresholds and dose assessment methods as documented in NRC Inspection Report 05000458/2023092. The inspectors review consisted of an evaluation the following:
- the licensee's identification of the issues,
- when and how long the issues existed,
- prior opportunities for identification,
- documentation of significant plant-specific consequences and compliance concerns,
- use of systematic methodology to identify causes with a sufficient level of supporting detail,
- consideration of prior occurrences,
- identification of extent-of-condition and extent-of-cause, and
- identification of any potential programmatic weaknesses in performance.
NRC Assessment: The team concluded that this objective was met.
The inspectors determined that the licensee had multiple opportunities to identify and address the conditions that led to the White finding, prior to their recent licensee identification. The root and common cause evaluations adequately assessed and addressed prior opportunities to identify the issues. The licensee appropriately understood the risk and compliance aspects of the White finding.
a.
Identification. The issues resulting in the White finding were identified by the licensee. The situations leading to their identification were described within the Event Summary of RCE CR-RBS-2023-4055:
On March 18, 2023, CR-RBS-2023-02765 was initiated and documented an extent of condition review of the following CRs: Waterford 3s CR-WF3-2022-03999 and CR-WF3-2022-00284 and RBSs CR-RBS-2022-05800. Investigation into these CRs revealed an initial set of five improperly calibrated and non-functional EITER radiation monitors that had detectors previously replaced without the associated engineering conversion factor (ECF) being updated in RMS. Each detector has its own ECFs used to accurately convert measured (raw) activity count rate to either a radiation concentration or a dose rate value in engineering units for display in the RMS. These five radiation monitors (RMS-RE125, RMS-RE126, RMS-RE5A, RMS-RE6A, and RMS-RE107) would not have displayed accurate (+/-10%) radioactive release information and as such, if an actual release had occurred, the licensee would have developed inaccurate dose assessments and potentially inaccurate protective action recommendations issued.
These conditions were considered self-revealing based on the extent of condition document reviews and validated through discussions between the vendor and the RMS engineer.
The NRC issued Inspection Report 2023092 on Augus15, 2023, documenting a final performance deficiency significance determination of a White (low to moderate safety significance) for the five inaccurate radiation monitors, because of their impact on the Emergency Planning Cornerstone.
Furthermore, Nuclear Independent Oversight generated CR-RBS-2023-07174 to document a problem identified during the 2023 Combined Chemistry, Effluents and Environmental Monitoring Audit, QA-2/6-2023-RBS-1. This condition report was generated on September 14, 2023, and was assigned to the chemistry department to perform an investigation validating data from these release points was accurate when using the activity rates on the detectors affected by the incorrect conversion factors.
b.
Exposure Time. The issues had the following exposure times as documented in RCE CR RBS-2023-4055:
- In 1986, the maintenance control procedures (MCPs) and surveillance test procedures (STPs) in effect had no detector replacement methodology. The ECF was not updated when a detector was installed or replaced.
- On May 15, 1996, both MCP and STP revisions removed the multichannel analyzer calibration testing/verification method.
- In 2009, the General Atomics radiation monitor system users group discussion revealed that the sites replacement of radiation detector (RD) RD-72 detector setup rules were considered skill of the craft (a mindset and not a documented process) which was lost as experienced individuals transition from the maintenance organization. Most of the audience did not know that, unlike scintillation detectors, ECFs must be updated during RD-72 detector replacement.
- On March 11, 2009, replacement radiation detector RMS-RE126 was installed during work order (WO) WO-51034129. Later it was identified the ECF was not updated when the detector was installed/replaced.
- On May 18, 2022, Waterford 3 initiated CR to document an NRC finding due to their failure to maintain configuration control of several radiation monitors which adversely impacted the health and safety of the public.
- On August 29, 2022, Waterford 3 developed a CA to determine the applicability of RD-72 detector calibration causes to the site. In response, system engineers responded and stated the licensee was vulnerable; however, no follow-up actions were generated, or CR written to document the vulnerability. The CA was subsequently closed by the system supervisor with no further actions.
- On October 6, 2022, a system engineer generated CR-RBS-2022-05800 to document the licensee was susceptible to the same calibration causes for the RD-72 detectors (cadmium telluride solid state mid and high range detectors), specifically the inability to utilize a multi-channel analyzer (MCA) resulting in the calibrations of RMS-RE5A and RMS-RE6A detectors being inadequate.
- On March 18, 2023, the licensee identified the radiation monitors MCPs and STPs did not provide correct installation guidance when a detector was replaced.
c.
Identification Opportunities. The licensee had multiple prior opportunities to identify the conditions leading to the White finding, including operating experience (e.g., General Atomics radiation monitor system users group discussion, industry and regulatory notices),previous detector failures, response to previous regulatory issues with calibration and maintenance practices, and system reviews. The licensees RCE sufficiently addressed these prior opportunities to identify these conditions, as discussed below.
d. Risk and Compliance. With emergency preparedness issues being evaluated from a deterministic perspective, no formal risk analysis was performed for the White finding.
However, using the existing criteria, the identified issues had a violation of White significance issued in the respective inspection report.
The licensee evaluated the risk and consequences as part of the RCE. The licensee identified the effluent and EITER radiation monitors were out of calibration, resulting in these channels being incapable of performing their technical requirements manual (TRM)
TRM 3.3.11.3 function to monitor radioactive liquid and gaseous effluent. The radiation monitors included the mid-and high-range wide range gas monitors (WRGM) as well as the gas and particulate monitors for the primary and secondary main plant exhaust; fuel building ventilation exhaust; and radwaste building ventilation exhaust. In addition, these monitors are used as part of the licensees EAL scheme and are used in radiological dose projection modeling for emergency response purposes, except for RE-107. While the actual consequence for impacting effluent monitoring and release was determined to be within regulatory limits, the calibration errors resulted in an EAL impact to the site area emergency (mid) and general emergency (high) declarations and an inaccurate dose assessment lower than the radiological conditions. The described consequences and risk insights were consistent with the NRC assessment.
In addition, work orders were generated and scoped into the refueling outage RF22 to correct the initial conditions prior to plant startup. Radiation monitor detectors, specifically the effluent, EITER, and TS monitors that impact plant startup, were addressed prior to startup. Actions were taken to verify/validate other radiation detectors which were identified to have incorrect parameters and were documented in respective condition reports to track resolution.
e.
Methodology. The RCE for the White finding employed multiple causal analysis methods to identify root and contributing causes. The primary analysis techniques were the event & causal factor chart and barrier analysis. Other techniques (comparative timeline, organizational and programmatic screening, and performance analysis) provided input to these primary technique. The analytical techniques were supported by document reviews, interviews, operating experience searches, internal reviews, and independent reviews. The evaluation was performed by a cross-functional team with internal and external team members with broad plant experience.
The team determined the causes of the event by consolidating the information, perspectives, and insights.
The inspectors reviewed each of the documented method results for the RCE and determined that the different methods provided a detailed, reliable, and scrutable evaluation. Also, the inspectors determined these analyses were performed with sufficient rigor and depth to identify the root and contributing causes.
f.
Level of Detail. The inspectors determined that the causal analysis was of sufficient detail and depth commensurate with the significance and complexity of the issues and regulatory requirements. The licensee provided sufficient detail in the timeline review and event and causal factor chart to determine root causes of deficient development and revision to radiation monitor procedures and work instruction technical reviews, and deficient configuration controls to prevent human performance errors in the development of radiation detector digital parameters and the transfer of parameters into the RMS RM-80/RM-11 databases. A missed opportunity related to a 2019 NRC non-cited violation for failure to calibrate monitors per procedure was identified and that the extent of condition should have looked for additional calibration deficiencies. A second missed opportunity was identified when biannual assessments of emergency preparedness and radiation protection did not recognize deficiencies in the calibration program and procedure guidance. The barrier analysis confirmed inappropriate procedures and procedure changes and missed opportunities to identify the procedure and process deficiencies. The inspectors reviewed associated referenced documents to ensure the information supported an adequate analysis.
g.
Operating Experience. For the evaluation performed, the licensee conducted reviews of internal (assessments, audits, and prior NRC findings) and external operating experience, such as industry and regulatory notices, users group conference discussions, and similar NRC findings. The licensee reviewed the occurrences for same or similar performance issues where knowledge gained would improve the evaluation.
h.
Extent of Condition and
Cause.
RCE CR-RBS-2023-4055:
Root Cause 1: Development and revisions to radiation monitor procedures and work instruction technical reviews did not include critical steps for detector replacement to ensure that radiation digital parameters were documented, updated, and maintained such that detectors were left in a configuration that ensured full alert and alarm ranges could be achieved.
Supporting Information:
- Maintenance instructions did not have guidance when replacing a detector, specifically updating the engineering conversion factor. Radiation detector replacements did not have configuration controls sufficient to maintain the conversion factors up to date. Specifically, the interfaces between MCPs and STPs with the licensees procedure PEP-0028, Digital Radiation Monitoring System (DRMS) RM-80 Database Management, did not have documented configuration controls to maintain the conversion factors up to date.
- Multiple RMS detectors were found during extent of condition reviews that did not have the correct conversion factor. This meant the full alert and alarm range capabilities were affected moving the detectors into an out of acceptance criteria when replaced.
- The root cause analysis identified the inappropriate calibration of the RD-72 using inputs from current personnel (maintenance instrument and control (I&C)and maintenance training). Procedure guidance was inadequate to perform a correct calibration. The calibration task was considered the skill of the craft and not adequately documented.
The root cause was validated by the multiple instances where detectors were replaced without keeping the documentation up-to-date and accurate and without performing a correct calibration for the RD-72 detectors.
Root Cause 2: Configuration controls were inadequate to prevent human performance errors in the development of radiation detector digital parameters and the transfer of parameters into the RMS RM-80/RM-11 databases at the initial setup and configuration of the radiation detectors RM-80/RM-11 data. This led to the inaccurate calibration of the radiation detectors.
Supporting information:
- Multiple radiation detectors were identified where the ECF was incorrect when compared to the computed ECF based on the vendor supplied documentation to parameters installed in RM-80/RM-11 databases with no history of detector transfer or replacement.
- Radiation detectors were identified where the ECF was incorrect in the RM-80 when compared to the vendor supplied ECF at the time of installation with no history of detector transfer or replacement (i.e., RMS RE-112).
Contributing Cause 1: Verification methods for count rates on WRGM detectors did not ensure full alert and alarm ranges were adequate causing the detectors to be out of acceptance criteria and undetected when replaced or calibrated.
Supporting Information:
- The RD-72 high voltage power supply is not adjustable; thus, an MCA was required when adjusting the detectors region of interest for the calibration source (Cs-137) of a newly installed RD-72 detector. The MCA was used to obtain a count-rate for a specific isotope as well as background count-rate measurements. The station has an MCA in possession; however, there were no methods or procedural guidance to successfully use the MCA in monitor calibrations.
- Vendor resources, with the appropriate equipment, performed the verification and validation of detector setups. Vendor resources were utilized during the initial assessment of this issue under CR-RBS-2023-2765 to validate the adequate setup when the issue was identified.
Contributing Cause 2: Maintenance I&C and engineering managers and supervisors did not ensure industry best practices, and evaluation and incorporation of internal and external operating experience were integrated into the RMS program and processes.
Supporting Information:
- The 2009 owners group information was not incorporated into the station practices.
- Original equipment manufacturer data was available to the station but was not used or adhered to for industry practices of calibration validation and verification.
Contributing Cause 3: Self-assessments of the RMS were ineffective at identifying program deficiencies for maintaining and updating radiation monitor critical information.
Examples Include:
- Bi-annual radiation protection self-assessments (ex. LO-RLO-2020-00018)performed for compliance-based evaluations did not identify capability concerns with radiation monitoring systems. The licensee identified additional objectives or separate assessments were required to ensure proper assessment of processes, controlled documentation, use of internal/external operating experience, and proper execution of configuration controls and calibrations.
- The Emergency Plan Program performed a bi-annual self-assessment for compliance-based inspections that did not identify capability concerns with radiation monitoring systems.
Supporting Information:
- Long standing issues were not identified through periodic RMS program assessments.
- The licensee does not have resources for in-depth RMS technical assessment.
Participation from Entergy Fleet subject matter experts or outside vendor technical specialists were needed to help identify the deficiencies.
- NRC Information Notice 2013-13, Deficiencies with Effluent Radiation Monitoring System Instrumentation, revision 1, was not utilized to identify or further evaluate the monitors during program assessments. A condition report or reference was not identified related to this notice.
This cause was validated by longstanding issues which went unrecognized through monitoring and assessment activities.
In addition, the licensee performed a safety culture assessment to determine if any of the identified root or contributing causes correlated to a weakness in the application of healthy nuclear safety culture traits.
Root Cause 3: During the development and revision to radiation monitor procedures and work instruction technical reviews, critical steps for detector replacement were not included to ensure radiation digital parameters were documented, updated, and maintained such that detectors were left in a configuration that ensured full alert and alarm ranges were achieved.
- H.1 / NLA1.d: Resources - Leaders ensure that personnel, equipment, procedures, and other resources are available and adequate to support nuclear safety. The root cause was identified as a legacy issue and not representative of current performance. Maintenance instructions existed since original installation which allowed for installation or replacement of monitors without clear guidance for calculation, update, and verification that the conversion factor was recorded.
- H.3 / NLA5.c: Change Management - Leaders use a systematic process for evaluating and implementing change so that nuclear safety remains the overriding priority. The root cause was identified as a legacy issue and not representative of current performance. Maintenance instructions existed since original installation which allowed for installation or replacement of monitors without clear guidance for calculation, update, and verification that the conversion factor was recorded.
Root Cause 4: Configuration controls were inadequate to prevent human performance errors in the development of radiation detector digital parameters and the transfer of parameters into the radiation monitoring RM-80/RM-11 systems at initial setup and configuration of the radiation detector RM-80/RM-11 data leading to inaccurate calibration of the radiation detectors.
- H.1 / NLA1.d: Resources - Leaders ensure that personnel, equipment, procedures, and other resources are available and adequate to support nuclear safety. The root cause was identified as a legacy issue and not representative of current performance. Maintenance instructions existed since original installation which allowed for installation or replacement of monitors without clear guidance for calculation, update, and verification that the conversion factor was recorded.
- H.3 / NLA5.c: Change Management - Leaders use a systematic process for evaluating and implementing change so that nuclear safety remains the overriding priority. The root cause was identified as a legacy issue and not representative of current performance. Maintenance instructions existed since original installation which allowed for installation or replacement of monitors without clear guidance for calculation, update, and verification that the conversion factor was recorded.
Contributing Cause 1: Verification methods for count rates on WRGM detectors did not ensure full alert and alarm ranges were adequate causing the detectors to be out of acceptance criteria and undetected when replaced or calibrated.
- H.1 / NLA1.d: Resources - Leaders ensure that personnel, equipment, procedures, and other resources are available and adequate to support nuclear safety. The contributing cause was identified as a legacy issue and not representative of current performance. Maintenance instructions were revised in 1996 which removed what was believed to be excess guidance and allowed use of a scalar device in lieu of the MCA for validation of correct detector setup and calibration. The removal of this information was not recognized as required for future RD-72 replacement tasks or to be needed for troubleshooting detector problems. This issue was determined to be a human performance error when performing the technical reviews of the procedure revision.
Contributing Cause 2: Maintenance I&C and engineering managers and supervisors did not ensure industry best practices, and evaluation and incorporation of internal and external operating experience were integrated into the RMS program and processes.
- P.5/NCL1.b: Operating Experience - The organization systematically and effectively collects, evaluates, and implements relevant internal and external operating experience in a timely manner. There were multiple opportunities to learn from industry best practices and evaluate and incorporate internal and external operating experience into the RMS program and processes.
Contributing Cause 3: Self-assessments of the RMS were ineffective to identify program deficiencies for maintaining and updating radiation monitor critical information.
- P.6/NCL2.a: Self-Assessment - The organization routinely conducts self-critical and objective assessments of its programs and practices. Long standing issues have not been identified through periodic RMS program assessments.
The inspectors utilized NUREG-2165, Safety Culture Common Language, March 2014, and Inspection Manual Chapter 0310, Aspects Within the Cross-Cutting Areas, dated February 25, 2019, which described the essential traits and attributes of a healthy nuclear safety culture. The inspectors reviewed the licensees assessment and confirmed CAs included a safety culture review. The inspectors determined the human performance safety culture aspects were not representative of current performance issues. The inspectors reviewed the licensees determination of two problem identification and resolution aspects (i.e., systematic and effective evaluation of operating experience and performing critical and objective assessments) and confirmed the two-licensee identified safety culture aspects were applicable to current operational performance. There were multiple opportunities to identify program and process deficiencies as related to correct calibration of the sites radiation monitors.
i.
Common
Cause.
A common cause analysis is performed for two white inputs in the same cornerstone. The associated two white inputs were in different cornerstones:
mitigating systems as documented in Inspection Report 05000458/2023090 (ML23187A639) and emergency preparedness as documented in Inspection Report 05000458/2023092 (ML23201A132).
Objective 2: Ensure that the extent-of-condition and extent-of-cause of individual and collective white performance issues are identified.
Under this objective, the inspectors independently evaluated the licensees RCE, associated CAs, procedures (emergency procedures, emergency action level declaration charts), work orders (monitor calibrations), technical specifications, offsite dose calculation manual (ODCM),and updated safety analysis report to assess the licensee's extent-of-condition and extent-of-cause.
NRC Assessment: The team concluded that this objective was met with one general weakness identified.
The inspectors identified a general weakness with the licensees extent of condition evaluation/assessment. The inspectors determined that the extent of condition described by the root cause evaluation was adequate and commensurate with the safety significance of the White performance issue. The licensee intended to verify that every radiation monitor used for dose assessment or Emergency Action Level (EAL) classification had the correct monitor and channel items (engineering conversion factors, calibration factors) in the local RM-80 database and RM-11 database. This would ensure that the licensee would identify every instance of a radiation monitor not having the correct engineering conversion factors (ECFs) and be able to evaluate all possible root causes. If a radiation monitor was found to have incorrect values stored in RM-80 or RM-11 then a condition report would be written, and the station would evaluate the impact on their ability to classify EALs or perform technically adequate dose projections. All radiation monitors used for EAL classification or dose assessment would be listed in the sites EPP-2-503, Equipment Important to Emergency Response (EITER)procedure, revision 7. However, the inspectors noted a general weakness in that there were three radiation monitors used for EAL classification that did not appear in the EITER procedure and werent treated and evaluated by RCE as EITER area radiation monitors: RMS-RE212 (high pressure core spray), RMS-RE216 (low pressure core spray equipment room), and RMS-RE218 (low pressure core spray penetration). The inspectors questioned why these radiation monitors werent being evaluated as EITER in the RCE. The licensee was able to show that two of the three had been evaluated appropriately in the RCE and only RMS-RE212 was not evaluated. The licensee discovered that the three radiation monitors had been inadvertently removed from the EITER procedure starting with revision 5 of EPP-2-503 effective October 29, 2020. Monitors RMS-RE216 and RMS-RE218 were verified with the correct ECFs by the licensee in April 2023 during the extent of condition; however, the RMS-RE212 was verified during the inspection as a result of inspector questioning. It, too, was verified to have the correct ECF.
Failing to maintain a comprehensive list of radiation monitors used for EAL classification in the EITER procedure, as required by the EITER procedure, was a performance deficiency. The inspectors questioned if RMS-RE212, RMS-RE216, or RMS-RE218 were taken out of service due to preventative or corrective maintenance during the timeframe that they were not in the EITER procedure. They had been taken out of service during the time period for preventative maintenance only, but the compensatory measures that would have been required were still in place due to operations impact assessments. Furthermore, the preventative maintenance procedure and frequency was not different than what was required by the EITER procedure.
They were never out of service for reasons other than preventative maintenance. Therefore, the performance deficiency did not adversely impact the emergency preparedness cornerstone and was minor. This was captured in the licensees corrective action program as CR-RBS-2024-00392.
Because a radiation monitor used for EAL classification, specifically RMS-RE212, was not evaluated in the extent of condition, the inspectors determined that the extent of condition, in practice, was initially inadequate. However, because the missed radiation monitor was verified to have the correct ECF during the inspection period, there was no actual adverse impact on the extent of condition or RCE as a whole. Therefore, this was a general weakness or omission and not a significant weakness.
Extent of Condition and
Cause.
Initially, the licensee scoped into the assessment all EITER and TS required radiation monitors where the ECFs or other important information provided by the vendor could result in inaccurate displayed RMS information. This included originally installed RMS equipment and monitors where a detector was transferred or replaced. The probability and consequence was considered high resulting in a high risk for a repeat condition. The review identified issues that could impact RMS accuracy in 22 of 25 EITER and TS radiation monitors, therefore, additional reviews were warranted, and the assessment ultimately included all EITER, TS, TRM, ODCM, and updated safety analysis report monitors and their associated ECFs. When the additional reviews indicated an EITER detector, which had not been transferred or replaced (initial installation), had an incorrect ECF and calibration methodology, all installed radiation monitors were scoped in. Approximately 106 radiation monitors were reviewed, regardless of detector type. The licensee included in the extent of condition related pressure and flow transmitters which could impact a monitors readings or results.
The inspectors also confirmed all monitors in question did not exceed their routine calibration periodicity or frequency of calibration during this assessment.
Objective 3: Ensure that completed corrective actions to address and preclude repetition of white performance issues are timely and effective.
Under this objective, the inspectors assessed the appropriateness and timeliness of the licensee's CAs.
NRC Assessment: The team concluded that this objective was met.
The inspectors determined the licensee implemented or planned appropriate and timely CAs to preclude repetition. The licensee also identified appropriate effectiveness reviews for these actions. With respect to evaluating the licensees response to the White notice of violation, the licensee demonstrated actions addressing the reasons for the violation, taken or planned for CAs with achievable results, and addressed restoration of full compliance, as applicable. The inspectors identified no significant weaknesses for this objective:
a. Completed Corrective Actions to Prevent Recurrence
- (1) CR-RBS-2023-4055 CA-37 CAPR: Revised the procedure revision process to include revising review checklists to ensure consideration is made for functionality impacts, independent verification and validation of technical adequacy when revisions to methodology occurs. Technical reviews were to be cross disciplined and required engineering participate at a minimum.
The inspectors reviewed the applicable procedure revisions and references to the CAPR and other applicable documents (vendor manual, purchase order documentation, etc.) in the revisions. The inspectors interviewed radiation protection, chemistry, emergency preparedness, maintenance, and licensing staff to understand stakeholder roles and responsibilities to ensure appropriate technical input was considered during CAPR procedure revisions and future procedure revisions.
- (2) CR-RBS-2023-4055 CA-80 CAPR: Developed and implemented new MCPs and STPs using the methodology developed in CA-78 (below) for replacement/transfer and calibration of each type of radiation detector affected. A separate procedure was developed and implemented which included a transfer calibration worksheet, steps for the correct detector replacement calibration methodology, and verification steps by system engineering and maintenance when radiation monitors were replaced. Guidance included required vendor documentation, the engineering conversion factor, steps for replacing a detector, and other channel and monitor items.
The new procedures and revisions included the following:
- MCP-4201, Low Range Area Monitor Calibration,
- MCP-4203, DRMS High Range Area Monitor Calibration,
- MCP-4204, DRMS Gas Radiation Monitor Calibration,
- MCP-4205, DRMS Liquid Radiation Monitor Calibration,
- MCP-IC-511-001, Area Monitor Detector Replacement,
- MCP-IC-511-002, High Range Area Monitor Detector Replacement,
- MCP-IC-511-003, Particulate, Gas and Low Range WRGM Radiation Monitor Detector Replacement,
- MCP-IC-511-004, Liquid, Mid and High Range WRGM Radiation Monitor Detector Replacement,
- MCP-IC-511-005, DRMS Monitor Channel Background Determination,
- STP-511-4205, SCIS/RMS Fuel Building Ventilation Exhaust Radiation High Channel Calibration RMS-RE5A,
- STP-511-4206, SCIS/RMS Fuel Building Ventilation Exhaust Radiation High Channel Calibration RMS-RE5B,
- STP-511-4209, RMS Control Room Fresh Air System Radiation Monitor Local Intake Channel Calibration RMSRE13A,
- STP-511-4210, RMS Control Room Fresh Air System Radiation Monitor Local Intake Channel Calibration RMSRE13B,
- STP-511-4211, RMS Control Room Fresh Air System Radiation Monitor Remote Intake Channel Calibration RMS-RE14A,
- STP-511-4212, RMS Control Room Fresh Air System Radiation Monitor Remote Intake Channel Calibration RMS-RE14B,
- STP-511-4216, RMS Radwaste Building Ventilation Exhaust Duct Noble Gas Activity Monitor Channel Calibration RMSRE6A,
- STP-511-4217, RMS Radwaste Building Ventilation Exhaust Duct Noble Gas Activity Monitor Channel Calibration RMSRE6B,
- STP-511-4248, RMS Reactor Coolant System Leakage Drywell Atmosphere Radioactivity Channel Calibration RMS-RE112,
- STP-511-4249, RMS Primary Containment Area Radiation Monitor Channel Calibration RMS-RE16A,
- STP-511-4250, RMS Primary Containment Area Radiation Monitor Channel Calibration RMS-RE16B,
- STP-511-4280, RMS Liquid Radwaste Effluent Line Radiation Monitor Channel Calibration RMS-RE107,
- STP-511-4290, RMS Primary Drywell Area Radiation Monitor Channel Calibration RMS-RE20B.
The inspectors reviewed the applicable new and revised MCP and STP procedures and the incorporated references to the CAPR and other applicable documentation (vendor manual, purchase order documentation, etc.) to ensure appropriate CAs were taken. The inspectors interviewed radiation protection, chemistry, emergency preparedness, maintenance, and licensing staff to understand stakeholder roles and responsibilities to ensure appropriate technical input was considered during CAPR procedure revisions and future procedure revisions.
b. Other Completed Corrective Actions
- (1) CR-RBS-2023-4055 CA-9 and CA-11: For TS, TRM, ODCM, and other regulatory required radiation monitors,
- (1) documented the as-found settings, reference values, reference date, and detector serial numbers and
- (2) compared the calibration data for the last and current results to ensure accuracy.
The inspectors confirmed 14 of the 17 radiation monitors that were determined to be deficient were issued a work order to bring the monitors into compliance: 00593314, 00593315, 00593316, 00593317, 00593318, 00593319, 00593320, 00593321, 00593322, 00593323. The licensee completed the actions by December 31, 2023.
- (2) CR-RBS-2023-4055 CA-40: Performed an assessment of all equipment listed in EN-EP-202, Equipment Important to Emergency Response, revision 4, covered by other actions in this CR and ensure items which use database entries, software parameters, conversion factors, set points, or constants which can be changed that can affect the capability of the equipment to respond accurately have configuration controls.
The inspectors identified a weakness in the extent of condition regarding the EITER monitors as listed in EN-RP-202 whereby three monitors were removed from the list and one monitor was not evaluated per this CA during the assessment (CR-RBS-2024-00392).
- (3) CR-RBS-2023-4055 CA-55: Revised the radiation protection program self-assessment template to implement periodic reviews of radiation detector documentation to ensure documentation and parameters were being maintained up to date when radiation detectors were replaced, transferred, or calibrated. The licensee completed associated actions by October 31, 2023.
The inspectors discussed the cross-discipline assessment of maintenance I&C and engineering activities associated with radiation monitor calibration going forward. While a general objective for the assessment was known, specific objectives were not captured to ensure an effective self-assessment. The licensee wrote CR-RBS-2024-00582.
- (4) CR-RBS-2023-4055 CA-78: Developed RMS methodology for replacement, transfer, and calibration for each type of radiation detector. The methodology included required vendor documentation, guidance on replacing a detector and use of the engineering conversion factor, and other channel and monitor items. The methodology included transfer calibration datasheets, steps for the correct detector replacement calibration methodology when replacing each type of radiation detector (i.e., RD-52/61, RD-59/56, and RD-72), and verification steps by system engineering and maintenance when radiation detectors are replaced. The methodology was documented in an engineering change.
The inspectors included the methodology during the review of the new and revised procedures to ensure sufficient guidance was provided for obtaining, documenting, and archiving the detector data, and transfer of data to ensure a successful calibration and RM80/RM10 database update.
- (5) CR-RBS-2023-4450 CA-79: Performed a workshop to review methodology for replacement, transfer, and calibration with engineering and maintenance personnel involved with RMS activities - 100percent of personnel involved received the workshop.
The inspectors reviewed the workshop attendees list and workshop training documents such as applicable revised procedures, the meeting minutes from the RMS Methodology Workshop for the calibration of transfer and replacement detectors dated October 25, 2023, and vendor MCA training.
- (6) CR-RBS-2023-06955: verify area radiation monitor calibration data and conversion factors for the following monitors in the field: RMS-RE193 (fuel bldg. operating floor), RMS-RE214 (residual heat exchanger equipment room B), RMS-RE215 (residual heat removal equipment room C), RMS-RE219 (reactor core isolation cooling system equipment room),
RMS-RE140 (refueling floor near north entrance), RMS-RE141 (refueling floor near south entrance), RMS-RE170 (main control room), RMS-RE192 (fuel building refueling platform),
RMS-RE213 (residual heat removal Equipment Room A), and RMS-RE217 (high pressure core spray penetration area).
The CA was closed to work order 593317 to verify each detectors information and was completed by October 19, 2023.
- (7) CR-RBS-2023-07174: Performed an investigation validating data from all release points was accurate when using the activity rates on the detectors affected by the incorrect conversion factors.
The inspectors reviewed the licensees actions and documentation for this CA. The inspectors determined the effluent sampling methods used to perform effluent dose calculations were independent of the monitor readings (actual effluent streams were sampled), thus associated effluent dose reporting did not require adjustment.
Objective 4: Ensure that planned corrective actions to preclude repetition direct timely and effective actions to address and preclude repetition of significant individual and collective performance issues.
Under this objective, the inspectors assessed the appropriateness and timeliness of the licensee's planned CAs.
NRC Assessment: The inspectors concluded that this objective was met.
The inspectors reviewed the licensees RCE and corrective action program documentation to ensure the CAs were described in sufficient detail to ensure RCE actions would be adequately completed.
a.
Planned Corrective Actions to Prevent Recurrence. The licensee completed the CAPRs as generated in the RCE and no additional CAPRs were identified as planned for future completion.
b.
Other Planned Corrective Actions
- (1) CR-RBS-2023-4328 (to include 2023-3265 and 2023-4421): Repair out of service RMS-RE125 under work orders 00595669 and 00590099. The initial RCE ECF and calibration conditions were addressed.
- (2) CR-RBS-2023-4450 CA-16: Review a sample of similar EITER equipment, that are not radiation monitors but are still used for dose assessment, which would require calibration to within acceptable ranges, e.g. meteorological instruments.
- (3) CR-RBS-2023-09209: Repair out of service RMS-RE6B under work order 54095043.
The initial RCE ECF and calibration conditions were addressed.
- (4) CR-RBS-2024-00038: Repair out of service RMS-RE16A under work order 54098645.
The initial RCE ECF and calibration conditions were addressed.
- (5) CR-RBS-2024-00560: Repair alarm function for RMS-RE5A. The initial RCE ECF and calibration conditions were addressed.
Conclusion Overall, the inspectors determined that the licensees problem identification, causal analyses, and CAs sufficiently addressed the performance issues that led to the White finding. All inspection objectives, as described in Inspection Procedure 95001, were met. Scheduled corrective action items will be inspected as part of the ongoing NRC baseline inspection program. Therefore, this inspection is closed.
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
On February 1, 2024, the inspectors presented the 95001 supplemental inspection results to Phil Hansett, Site Vice President, and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
CR-RBS-2023-
06953, 07235
Corrective
Action
Documents
CR-RBS-2024-
00392
Corrective
Action
Documents
Resulting from
Inspection
CR-RBS-2024-
00637, 00560, 00480, 00425,
00403, 00402, 00360, 00359,
00357, 00358
River Bend Station 95001 Root
Cause Evaluation Story Board
01/10/2024
Pre-Inspection Assessment
Worksheet for IP 95001
Radiation Monitors Calibration
09/12/203
Miscellaneous
EIP-2-001
Classification of Emergencies
EIP-2-002
Classification Actions
EIP-2-024
Offsite Dose Calculations
Equipment Important to
Emergency Response (EITER)
Emergency Planning
Assessment of Offsite
Emergency Response
Capability Following a Natural
Disaster
Emergency Classifications
Corrective Action Program
Assessments
Causal Analysis Process
Causal Analysis Process
EPP-2-503
River Bend Station Equipment
Important to Emergency
Response (EITER)
EPP-2-503
River Bend Station Equipment
Important to Emergency
Response (EITER)
EPP-2-503
River Bend Station Equipment
Important to Emergency
Response
PEP-0028
DRMS RM-80 Data Base
Management
PEP-0028
DRMS RM-80 Data Base
Management
95001
Procedures
PEP-0028
DRMS RM-80 Database
Change Request (typical) for
09/25/2023
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
RMS-RE16B Primary
Containment - PAM B
PEP-0028
DRMS RM-80 Database
Change Request (typical) for
RMS-RE193 Fuel Bldg.
Operating Floor
09/25/2023
PEP-0028
DRMS RM-80 Database
Change Request (typical) for
RMS-RE219 RCIC Equipment
Room
09/27/2023
PEP-0028
DRMS RM-80 Database
Change Request (typical) for
RMS-RE126 Main Control
Room Local Intake Monitor
04/02/2023
PEP-0028
DRMS RM-80 Database
Change Request (typical) for
RMS-RE125 Main Stack
Monitor
09/29/2023
PEP-0028
DRMS RM-80 Database
Change Request (typical) for
RMS-RE140 Refueling Floor
Near North Entrance
11/08/2023
PEP-0028
DRMS RM-80 Database
Change Request (typical) for
RMS-RE213 RHR Equipment
Room 'A' Area
09/13/2023
Protective
Action
Recommendati
on Guidelines
EIP-2-007
WO- 00593102, 00593103,
00593321, 00593104,
00593317, 00593324,
00593324, 54025438,
54048049, 54048053,
54048060, 54048061,
54048062, 54048063,
54048065, 54048066,
54048067, 54048068,
54054283, 54054284
Work Orders
Determine Engineering
Conversion Factors for RMS-
RE218