05000382/LER-2022-001-02, Non-Compliance with Technical Specifications Due to Incorrect Procedural Guidance for Radiation Monitors
| ML23053A354 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 02/22/2023 |
| From: | Milster L Entergy Operations |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| W3F 1-2023-0015 LER 2022-001-02 | |
| Download: ML23053A354 (1) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 3822022001R02 - NRC Website | |
text
S) entergy W3F 1-2023-0015 February 22, 2023 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Leia Milster Manager Regulatory Assurance 504-739-6250 10 CFR 50.73
Subject:
Licensee Event Report Supplement 50-382/2022-001-02, Non-Compliance with Technical Specifications Due to Incorrect Procedural Guidance for Radiation Monitors Waterford Steam Electric Station, Unit 3 NRC Docket No. 50-382 Renewed Facility Operating License No. NPF-38 Entergy Operations, Inc. (Entergy) submits the enclosed Licensee Event Report (LER) supplement 50-382/2022-001-02 for Waterford Steam Electric Station, Unit 3. The event is reportable in accordance with 1 O CFR 50. 73(a)(2)(i)(B), any operation or condition which was prohibited by the plant's Technical Specifications.
The LER, as supplemented, describes non-compliances with TS 3.3.3.1 due to incorrect procedure revisions resulting in inadequate calibration methods applied to the Condenser Wide Range Gas Monitor (WRGM), Plant Stack WRGM, Fuel Handling Building WRGM, Main Steam Line B radiation detector, and Component Cooling Water Liquid Radiation Monitors.
This letter contains no new commitments.
Should you have any questions concerning this issue, please contact Leia Milster, Manager, Regulatory Assurance, at 504-739-6250.
Respectfully, Leia Milster LEM/ahv Entergy Operations, Inc., 17265 River Road, Killona, LA 70057
W3F1-2023-0015 Page 2 of 2 Enclosure: Licensee Event Report 50-382/2022-001-02 cc:
NRC Region IV Regional Administrator NRC Senior Resident Inspector - Waterford Steam Electric Station, Unit 3 NRC Project Manager - Waterford Steam Electric Station, Unit 3 Louisiana Department of Environmental Quality
Enclosure W3F1-2023-0015 Licensee Event Report 50-382/2022-001-02
Abstract
On January 18, 2022, while operating in Mode 1, at 100% power, Waterford 3 Steam Electric Station Unit 3 (WF3) discovered that the engineering conversion factors (ECF) used in three gaseous radiation monitors were incorrect.
This resulted in the Condenser Wide Range Gas Monitor (WRGM), Plant Stack WRGM, and Fuel Handling Building WRGM being inoperable. WF3 Technical Specification (TS) 3.3.3.1, Action b pursuant TS Table 3.3-6 Action 27, require the minimum number of Effluent Accident Monitor channels to be operable in Modes 1, 2, 3, and 4. TS 3.3.3.1, Action b, and TS Table 3.3-6, Action 27, required that the radiation monitors be restored to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, or initiate the preplanned alternate method of monitoring the appropriate parameter(s). The WRGMs exceeded the allowed outage time.
The ECFs were not revised when the original detectors were replaced, which caused incorrect count-rates to be used in the detector calibrations. Additionally, some detectors' ECFs were calculated based on the detector's response to Cobalt-60 instead of Cesium-137 which existed since plant startup. The correct ECFs were determined, and the radiation monitors were recalibrated using the corrected ECFs. This supplement includes an update to the Extent of Condition (EOC) activities.
PLANT STATUS
- 2. DOCKET NUMBER
- 3. LERNUMBER 00382 YEAR SEQUENTIAL NUMBER 2022 001 REV NO.
02 On January 18, 2022, at 1018 Central Time, Waterford Steam Electric Station, Unit 3 (WF3) was operating at 100%
power in Mode 1. There were no other structures, systems, or components that were inoperable at the time that contributed to the event.
EVENT DESCRIPTION
On January 18, 2022, during an engineering review, it was discovered that the engineering conversion factors used in three gaseous radiation monitors [IL] were incorrect. This resulted in the Plant Stack [VL] Wide Range Gas Monitor (WRGM) (PRMIRE0110), the Fuel Handling Building (FHB) [ND] WRGM (PRMIRE3032), and the Condenser [SG]
WRGM (PRMIRE0002) being inoperable. Waterford Technical Specification (TS) 3.3.3.1 requires the minimum number of Effluent Accident Monitor channels shown in TS Table 3.3-6 to be operable in Modes 1, 2, 3, and 4. TS 3.3.3.1, Action b, pursuant TS Table 3.3-6 Action 27, require that, with the number of operable channels less that required by the minimum channels operable requirement, either restore the inoperable channel(s) to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, or initiate the preplanned alternate method of monitoring the appropriate parameter(s), and if the monitor is not restored to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> after the failure, a special report is required to be submitted in accordance with TS 6.9.2 within 14 days after the failure outlining the actions taken, the cause of the inoperability and the plans and schedule for restoring the system to operable status.
The engineering conversion factors used in the three WRGMs were not revised when the original detectors for these monitors were replaced (PRMIRE0110 high range in 2005; PRMIRE3032 mid-range in 2008; PRMIRE0002 mid and high range in 2011). In addition, the incorrect count-rate was used to calibrate the PRMIRE0110 high range detector since 2005; the PRMIRE3032 mid-range detector since 2008; and the PRMIRE0002 mid-range and high-range detectors since 2011. This caused these radiation monitors to be inoperable during the period following their respective detector replacements until the correct conversion factors were applied and the detectors were calibrated on February 4, 2022. This period exceeds the allowed outage time required by Action 27 of TS Table 3.3-6.
Special Report SR-22-001-00 (ML22032A066) was issued on February 1, 2022, and Special Report SR-22-002-00 I
(ML22039A278) was issued on February 8, 2022, after discovery, as required by Action 27 of TS Table 3.3-6.
The radioactive gaseous effluent instrumentation is provided to monitor and control, as applicable, the releases of radioactive materials in gaseous effluents during actual or potential releases of gaseous effluents. The alarm/trip setpoints for these instruments shall be calculated and adjusted in accordance with the methodology and parameters in the Offsite Dose Calculation Manual (ODCM) to ensure that the alarm/trip will occur prior to exceeding the limits of 10 CFR Part 20.
The Condenser WRGM monitors condenser vacuum pump [Pl discharge continuously to detect steam generator tube leakage and to quantify release rate.
The Plant Stack WRGM monitors air being released from the plant stack to measure the radiation being released to the environment during both normal and accident conditions.
The FHB WRGM monitors air which is released from the FHB emergency exhausts during accident conditions.
This event is being reported under 10 CFR 50.73(a)(2)(i)(B) which requires submittal of a Licensee Event Report within 60 days after the discovery for any operation or condition that was prohibited by the plant's technical specifications. Page 2 of 5 (01-10-2023) u_s_ NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB: NO. 3150-0104 EXPIRES: 12/31/2023 LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET (See NUREG-1022, R.3 for instruction and guidance for completing this form https://www.nrc.govlreading-rm/doc-collections/nuregs/staff/sr1022/r3D 1-FACILITY NAME 181 050 Waterford Steam Electric Station, Unit 3 052 EXTENT OF CONDITION EstimalBd
- 2. DOCKET NUMBER
- 3. LERNUMBER 00382 YEAR SEQUENTIAL NUMBER 2022 001 REV NO.
02 An Extent of Condition (EOC) review resulted in LER 2022-003-00 and LER 2022-004-00, which documents events involving Containment High Range A and B radiation monitors out of calibration due to inadequate procedural guidance. The corrective actions associated with the Containment High Range monitors were to revise procedural guidance with area radiation monitor calibration source reference values. This revision included Ml-003-389 "Main Steam Line Radiation Monitor Channel Calibration ARMIR5500A or ARMIR5500B" and contained no specific guidance for detector replacement versus detector transfers. The guidance was updated through non-technical processes and was based upon the assumption that the detectors are obtained pre-calibrated and do not require recalibration.
On October 13, 2022, Main Steam Line B radiation monitor (ARMIRE5500B) failed. ARMIRE5500B is used to detect and indicate dose levels following an accident. If the condenser WRGM is unavailable or the condenser is isolated, ARMIRE5500B would be one of the primary radiation monitor used for accessing dose. WF3 purchased a replacement RD-12, General Atomics part number 03602039-002 Geiger-Mueller (GM) tube assembly, detector from another site. WF3 technicians installed the replacement monitor per the newly revised procedure, using Ml-003-389.
The procedure revision did not specify acceptance criteria and subsequent functional testing was not performed.
During the performance of the work order, count rates were noted to be low, but the procedure did not specify an acceptance criteria. On October 20, 2022, WF3 declared ARMIRE5500B operable.
On October 31, 2022, a Radiation Monitor System (RMS) subject matter expert (SME) was brought in to support additional EOC evaluation actions. The SME reviewed the work order associated with ARMIRE5500B replacement and identified that the count rate was low. It was confirmed on November 3, 2022, that the detector was out of tolerance and unable to perform its specified function since replacement on October 20, 2022. This resulted in ARMIRE5500B exceeding TS 3.3.3.1, Action b, pursuant TS Table 3.3-6, Action 27, and is reportable per 10 CFR 50.73(a)(2)(i)(B) for any operation or condition that was prohibited by the plant's technical specifications.
ARMIRE5500B was replaced with a compatible detector, calibrated, and returned to service on November 10, 2022.
On November 16, 2022, the RMS engineer discovered the ECFs in the Component Cooling Water (CCW) Radiation Monitors (PRMIRE5700/PRMIRE7050A/PRMIRE7050B) were based on the detectors' response to Cobalt-60 (Co-60) instead of Cesium-137 (Cs-137). The CCW Radiation Monitor's function is to provide indication within the two component cooling loops whenever the activity reaches or exceed a pre-established level. The use of Co-60 resulted in the sensitivity of the detector to be approximately 46% lower than Cs-137. It was confirmed on December 8, 2022, that the process monitors had been inoperable for this condition since initial plant start up and exceeded TS 3.3.3.1, Action b, pursuant TS Table 3.3-6, Action 27, and is reportable in accordance with 10 CFR 50.73(a)(2)(i)(B) for any operation or condition that was prohibited by the plant's technical specifications. CCW Radiation Monitors were returned to service on November 17, 2022.
On December 15, 2022, during performance of mid-range detector validation of the Plant Stack radiation monitor (PRMIRE0110) using the multi-channel analyzer, it was discovered that the mid-range detector values were not in acceptable range when exposed to sources. On January 30, 2023, a past operability evaluation determined that the detector was out of tolerance and unable to perform its specified function since November 11, 1987. This resulted in PRMIRE0110 exceeding TS 3.3.3.1 and is reportable per 10 CFR 50.73(a)(2)(i)(B) for any operation or condition that was prohibited by the plant's technical specifications. Adjustments were made to the PRMIRE0110 mid-range detector and returned to service on December 15, 2022. While the plant stack WRGM mid-range channel is used for EAL classification, during a loss of coolant accident, emergency classification would likely be based on Fission Product Barrier losses since those EALs would be met prior to the same Emergency Classification EAL threshold associated with the Plant Stack WRGM. The basis for this determination is the defense-in-depth concept which Page 3 of 5 (01-10-2023)
U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB: NO. 3150-0104 EXPIRES: 12/31/2023 LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET (See NUREG-1022, R.3 for instruction and guidance for completing this form https://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr102'2Jr3D
- 1. FACILITY NAME 181 050 Waterford Steam Electric Station, Unit 3 D 052 Estima1ed
- 2. DOCKET NUMBER
- 3. LERNUMBER 00382 YEAR SEQUENTIAL NUMBER 2022 001 REV NO.
02 mitigates the release of radioactive fission products to the environment through the use of physical barriers (Fuel Clad, Reactor Coolant System & Containment).
This completes the extent of condition investigation involving the incorrect ECFs and multi-channel analyzer for WRGMs.
SAFETY ASSESSMENT
The actual consequences were that the condenser WRGM mid and high-range detectors, the plant stack WRGM mid and high-range detector, and FHB WRGM mid-range detector were incorrectly calibrated, resulting in these channels being incapable of performing their TS 3.3.3.1 functions. The actual consequence to AMIRE55008 reading low was that the monitor would have had impacts on dose assessment in the event of an emergency. There were no actual consequences to general safety of the public, nuclear safety, industrial safety, and radiological safety for this event.
The potential consequence to general safety of the public, nuclear safety, industrial safety, and radiological safety of this event if the other radiation detectors monitoring similar release points (plant stack Particulate Iodine Gas [PIG]
A and B; FHB PIG A and B; steam generator steam line Nitrogen-16 [N-16] detectors) were removed, is the inability to enter applicable emergency action levels when those criteria are met. The safety significance of an inability to enter an emergency action level and take appropriate action vary depending on the emergency action level severity.
The safety significance of this event is determined to be low. The basis for this determination is that multiple, alternative monitoring methods exist to monitor the site release points enabling WF3 to accurately classify radiological events.
There is an impact on the station's dose assessment capability due to the ARMIRE55008 calibration issue. In scenarios where the Main Condenser is isolated rendering the Condenser WRGM unavailable (Main Steam Isolation Valves are closed), the Main Steam Line radiation monitors would then be used as the primary monitors for dose assessment. In those instances, any dose assessment completed using the Main Steam Line radiation monitor B (ARMIRE5500B) would have been lower than actual.
The incorrect CCW Radiation Monitors' ECFs resulted in the potential of in-leakage from radioactive systems to be inaccurately monitored within the CCW system. The incorrect ECF resulted in the CCW Radiation Monitors reading approximately 46% lower than required. The CCW is a closed-loop system and there were no actual consequences to general safety of the public, nuclear safety, industrial safety, and radiological safety for this event.
EVENT CAUSE(S)
The engineering conversion factor for WRGM mid/high range detector types is specific to each detector. Review of historical documents confirmed that the mid and high range engineering conversion factors associated with the original detectors were still being used for the channels listed above after detector replacements. These values were not revised when the original detectors were replaced (PRMIRE0110 high range - 2005; PRMIRE3032 mid-range -
2008; PRMIRE0002 mid and high range in 2011) due to a lack of procedural guidance. The RMS users' group was unaware of this requirement until the vendor stressed this requirement in 2009.
An adjustment factor must be applied to the calibration count-rate when a WRGM mid/high range detector is replaced. This guidance did not exist in 2005 and 2008. Procedural guidance did exist in 2011, however the form used to perform this calculation is missing a field for the last step. Review of work records revealed that maintenance personnel noticed this deficiency in 2013 during PRMIRE3032 high range detector replacement and added a calibration count-rate adjustment factor field to that work package, which was used to calibrate PRMIRE3032.
Therefore, the PRMIRE3032 high range is considered calibrated and capable of achieving its alarm set-point.
Procedure Ml-003-389, Revision 309 added a new Section 6.4 titled "Detector Transfer Calibration" which does not perform a calibration. By only performing this section and not Section 6.5, the performer is not directed to validate the Page 4 of 5 (01-10-2023)
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LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET (See NUREG-1022, R.3 for instruction and guidance for completing this form https://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1022/r3D
- 1. FACILITY NAME 181 050 Waterford Steam Electric Station, Unit 3 052 Estimated burden per response to comply with this mandatory collection request 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />. Reported lessons learned a-e incorporated into the licensing process and fed back to industry. Send comments regarding burden estimate to the FOIA, Library, and Information Collection Branch (T-6 A10M), U.S.
Nuclear Regulatory Commission, Washington, DC 20555-0001, or by e-mail to lnfacallects.Resaurce@nrc.gov, and the 0MB reviewer at 0MB Office of Information and Regulatory Affairs, (3150-0104), Attn: Desk Officer for the Nuclear Regulatory Commission, 725 17th Shet NW, Washington, DC 20503; e-mail: oira submission@omb.eop.gov. The NRC may not conductor sponsor, and a person is not required to respond to, a collection of information unless the document requesting or requi"ing the collection displays a currently valid 0MB contol number.
- 2. DOCKET NUMBER
- 3. LER NUMBER 00382 YEAR SEQUENTIAL NUMBER 2022 001 REV NO, 02 acceptance criteria within the body of the procedure. The consensus of those interviewed was that only Section 6.4 "Detector Transfer Calibration" needed to be performed when a new detector was installed as setting the baseline for future calibrations. The revision was performed using an editorial correction process and did not reference an approved technical document which resulted in a procedure that was inadequate to declare a transferred radiation detector operable and contained technically inaccurate information.
During the extent of condition, the CCW liquid radiation monitors were discovered to have the incorrect ECFs. These ECFs reflect a detector sensitivity based on the liquid detectors' response to Co-60. The sensitivity is approximately 46% lower than detectors whose sensitivity is based on Cs-137. The cause of the event was determined to be inadequate historical procedure revisions.
CORRECTIVE ACTIONS
The correct engineering factors were determined, and the radiation monitors were recalibrated using the corrected engineering factors. Waterford implemented the following additional corrective actions for the WRGM event in January 2022.
Revised the Ml-005-906 (Radiation Monitoring System Desk Guide) to have sufficient guidance to correctly perform a cadmium telluride solid state radiation detector (RD-72) replacement and sensitivity adjustment instruction Revised procedures to include steps to refer to Ml-005-906 for calibration instructions when the replacement of a RD-72 radiation detector is required AMIRE55008 was replaced, calibrated, and returned to service. The correct technical justification via EC 93617 was created. Waterford implemented the following additional corrective actions.
Revised Ml-003-389 with technical guidance.
Identified the procedures revised as EOC actions that included the incorrect "Detector Transfer Calibration" section and revised with technical guidance.
Adjustments were made on December 15, 2022, to the PRMIRE0110 mid-range channel and as left values were within the acceptance criteria.
CCW liquid radiation monitors ECFs were revised, and the monitors were returned to service. Procedural revisions were made to liquid radiation monitor calibration procedures associated with RD-53 detectors to ensure the ECF value that is used is based on Cs-137.
PREVIOUS SIMILAR EVENTS
LER 2022-003-00 reported a non-compliance with TS 3.3.3.1, Action b, TS Table 3.3-6 Action 27, due to the calibration procedure for the Containment High Range radiation monitors containing incorrect procedural guidance to account for the keep alive source decay when the original Log Pico-ammeter and ADC circuit board was replaced.
LER 2022-004-00, "Operation Prohibited by Technical Specifications Due to Inadequate Radiation Monitor Calibration Procedures," was a direct result of the extent of condition reviews and activities conducted as part of the corrective actions for LER 2022-001-00 and LER 2022-003-00. LER 2022-006-00 reported during engineering reviews, it was discovered that the Plant Stack and FHB WRGM monitors were recalibrated during maintenance to the previous, incorrect engineering conversion factor(s) due to a human performance error with the RMS control room database. Page 5 of 5