IR 05000397/2023092

NRC Inspection Report 05000397/2023092 and Preliminary White Finding

ML23139A121
Person / Time
Site:	Columbia
Issue date:	06/01/2023
From:	Geoffrey Miller, Aida Rivera-Varona NRC Region 4
To:	Schuetz R Energy Northwest
Kramer J
References
EA-23-054 IR 2023092
Download: ML23139A121 (12)

Text

June 1, 2023

SUBJECT:

COLUMBIA GENERATING STATION - NRC INSPECTION REPORT 05000397/2023092 AND PRELIMINARY WHITE FINDING

Dear Robert Schuetz:

This letter refers to the inspection conducted from March 9 to April 11, 2023, by the U.S. Nuclear Regulatory Commission (NRC). The purpose of the inspection was to evaluate the additional information obtained by the NRC after the March 1, 2022, Regulatory Conference with Energy Northwest concerning the May 28, 2021, contamination uptake event at the Columbia Generating Station. On May 30, 2023, a final exit briefing was conducted with you and other members of your staff. The results of the inspection are documented in the enclosed report.

The enclosed report discusses a finding of low to moderate safety significance (preliminary White) and an apparent violation of Title 10 of the Code of Federal Regulations (10 CFR) 20.1204(a) which is being considered for escalated enforcement action in accordance with the NRC Enforcement Policy, which can be found at http://www.nrc.gov/about-nrc/regulatory/enforcement/enforce-pol.html. As described in the enclosed report, following the contamination event that occurred on May 28, 2021, your staff failed to take suitable and timely combination of measurements to determine compliance with occupational dose equivalent limits. The finding was assessed based on the best available information, using the applicable significance determination process (SDP). The final resolution of this finding will be conveyed in separate correspondence.

In accordance with NRC Inspection Manual Chapter 0609, we intend to complete our evaluation using the best available information and issue our final significance determination and enforcement decision, in writing, within 90 days from the date of this letter. The SDP encourages an open dialogue between your staff and the NRC; however, the dialogue should not impact the timeliness of our final determination.

Before we make a final decision on this matter, we are providing you with an opportunity to either (1) attend a Regulatory Conference where you can present to the NRC your perspective on the facts and assumptions the NRC used to arrive at the finding and assess its significance, or (2) submit your position on the finding to us in writing. If you request a Regulatory Conference, it should be held within 40 days of the receipt of this letter, and we encourage you to submit supporting documentation at least one week prior to the conference in an effort to make the conference more efficient and effective. The focus of the Regulatory Conference is to discuss the significance of the finding and not necessarily the root cause(s) or corrective action(s) associated with the finding. If a Regulatory Conference is held, it will be open for public observation. If you decide to submit only a written response, such submittal should be sent to us within 40 days of the receipt of this letter.

If you choose to send a written response, it should be clearly marked as a Response to Apparent Violation in NRC Inspection Report 05000397/2023092; EA-23-054 and should include for the apparent violation: (1) the reason for the apparent violation or, if contested, the basis for disputing the apparent violation; (2) the corrective steps that have been taken and the results achieved; (3) the corrective steps that will be taken; and (4) the date when full compliance will be achieved. Your response may reference or include previously docketed correspondence if the correspondence adequately addresses the required response. To the extent possible, your response should not include any personal privacy or proprietary information so that it can be made available to the public without redaction.

Additionally, your written response should be sent to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, DC 20555-0001, with a copy to the Director, Division of Radiological Safety and Security, U.S. Nuclear Regulatory Commission, Region IV, 1600 East Lamar Blvd., Arlington, Texas 760114511, and the NRC Resident Inspector at the Columbia Generating Station, and emailed to R4Enforcement@nrc.gov, within 40 days of the date of this letter. If an adequate response is not received within the time specified or an extension of time has not been granted by the NRC, the NRC will proceed with its enforcement decision or schedule a Regulatory Conference.

Please contact Gregory Warnick at 817-200-1249 within 10 days from the issuance of this letter to notify the NRC of your intentions. If we have not heard from you within 10 days, we will continue with our significance determination and enforcement decision.

If you decline to request a Regulatory Conference or to submit a written response, you relinquish your right to appeal the final SDP determination, in that by not doing either, you fail to meet the appeal requirements stated in the Prerequisite and Limitation sections of Attachment 2 of NRC Inspection Manual Chapter 0609.

Because we have not made a final determination in this matter, a Notice of Violation is not being issued at this time. In addition, please be advised that the number and characterization of the apparent violations described in the enclosed inspection report may change as a result of our further review.

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 Agencywide Documents Access and Management System (ADAMS), accessible from the NRC website at http://www.nrc.gov/reading-rm/adams.html. If you have any questions concerning this matter, please contact Gregory Warnick of my staff at 817-200-1249.

Sincerely, Rivera-Varona, Aida signing on behalf of Miller, Geoffrey on 06/01/23 Geoffrey B. Miller, Director (Acting)

Division of Radiological Safety & Security Docket No. 05000397 License No. NPF-21

Enclosure:

As stated

Inspection Report

Docket Number: 05000397 License Number: NPF-21 Report Number: 05000397/2023092 Enterprise Identifier: I-2023-092-0000 Licensee: Energy Northwest Facility: Columbia Generating Station Location: Richland, Washington Inspection Dates: March 09 to April 11, 2023 Inspectors: D. Antonangeli, Health Physicist N. Greene, Senior Health Physicist Approved By: Gregory G. Warnick, Chief Decommissioning, ISFSI & Operating Reactors Branch Division of Radiological Safety & Security Enclosure

SUMMARY

The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting a NRC inspection at Columbia Generating 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

Failure to Adequately Determine Internal Dose of Pipefitters Cornerstone Significance Cross-Cutting Report Aspect Section Occupational Preliminary White [H.1] - 71153 Radiation Safety AV 05000397/2023092-01 Resources Open EA-23-054 The inspectors identified a finding of low to moderate safety significance (preliminary White)and an apparent violation of 10 CFR 20.1204(a). Specifically, the licensee failed to take suitable and timely combination of measurements, including radioactive material in air in work areas, and urine and fecal samples to properly evaluate alpha emitters in the body contributing to the accrued internal dose. These failures resulted in the inability of the licensee to properly assess the dose accrued by the pipefitters following the reactor water cleanup contamination event on May 28, 2021.

Additional Tracking Items

None.

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 - BASELINE

71153 - Follow Up of Events and Notices of Enforcement Discretion Event Follow-up (IP section 03.01)

(1) The NRC held a Regulatory Conference on March 1, 2022, with Energy Northwest personnel to address concerns and violations from a contamination uptake event that occurred at the Columbia Generating Station on May 28, 2021. The violations were preliminarily determined as low to moderate safety significance (preliminary White).

At the conference, additional information was provided which warranted additional review by the NRC. During the subsequent review of information provided regarding the uptake event, NRC inspectors identified a performance deficiency associated with the licensees dose assessment of the event and an associated apparent violation of Title 10 of the Code of Federal Regulations (10 CFR) 20.1204(a).

INSPECTION RESULTS

Failure to Adequately Determine Internal Dose of Pipefitters Cornerstone Significance Cross-Cutting Report Aspect Section Occupational Preliminary White [H.1] - 71153 Radiation Safety AV 05000397/2023092-01 Resources Open EA-23-054 The inspectors identified a finding of low to moderate safety significance (preliminary White)and an apparent violation of 10 CFR 20.1204(a). Specifically, the licensee failed to take suitable and timely combination of measurements, including radioactive material in air in work areas, and urine and fecal samples to properly evaluate alpha emitters in the body contributing to the accrued internal dose. These failures resulted in the inability of the licensee to properly assess the dose accrued by the pipefitters following the reactor water cleanup (RWCU)contamination event on May 28, 2021.

Description:

On May 28, 2021, while performing weld preparations on highly contaminated RWCU heat exchanger system piping, an airborne radioactivity event occurred that caused 22 positive intakes of radioactive materials, including significant uptakes of radioactive material by two pipefitters.

The weld preparation work was conducted under Radiation Work Permit (RWP) 30004732, R25 RX RWCU HX RM - INSTALL NEW HX & PIPING, which had already been successfully completed on pipe cut #4 during the dayshift on May 28, 2021. This event occurred during the next scheduled job, on pipe cut #3, with the nightshift crew. The nightshift personnel failed to follow multiple requirements of RWP 30004732 relative to stop work conditions and the associated ALARA work plan. With failures in following the work plans and briefing instructions, the work crew relied on skill of the craft, as stated in the licensees Investigation Template. The NRC documented the specific aspects regarding the nightshift crew failures in Inspection Report 05000397/2021-090.

The two pipefitters were conducting weld preparation inside a glove bag without the high efficiency particulate air (HEPA) vacuum running. They flapped the inside of the pipe with a flapping wheel (grinding), which forced the dried contamination on the pipe surfaces to become airborne within the glove bag and due to the HEPA vacuum being off the airborne radioactivity levels were not reduced. Nor were air samples effectively taken in the breathing zone of the workers to determine airborne conditions. When the glove bag was removed after completion of the flapping of the pipe, the airborne radionuclides were then accessible to the pipefitters, they were exposed internally via inhalation and/or ingestion pathways which resulted in individual internal uptakes of greater than 700 millirem committed effective dose equivalent (CEDE).

As the pipefitters left the RWCU heat exchanger room, they were frisked by radiation protection (RP) staff and the instrument readings went off-scale high. They were then escorted to the personnel contamination monitors (PCMs) and alarmed the PCMs indicating there was radioactive material present on or possibly in the worker. After multiple showers and scans on the alarming PCMs, the licensee confirmed the pipefitters had internal uptakes. Therefore, the pipefitters were sent to initiate the whole-body count (WBC) process. The initial WBCs confirmed that the pipefitters were highly contaminated with positive uptakes of predominantly cobalt-58 and colbalt-60 radionuclides.

As the licensee staff identified these uptakes had occurred, they began to evaluate the internal dose of each pipefitter. However, in the documentation reviewed by NRC staff, the staff determined that the licensees dose assessment program that was in place at the time was not suitable to fully address the spectrum of possible internal radionuclides, and not all the procedural instructions to implement their process were met. Moreover, the NRC asserts that the procedures related to dose assessment did not provide clear direction on which steps are required to be taken, resulting in the licensees failure to complete needed steps and fully implement a successful dose assessment process without compromise.

Procedure PPM 11.2.4.5, Whole Body Counts and Daily Checks Using the Renaissance Fastscan, revision 16, section 5.4 contains guidelines that provide for appropriate actions to take in response to positive WBCs. Step 5.4.3 designates Action Level 3 for 0.1 annual limit on intake (ALI) to 0.25 ALI or 500 mrem CEDE to 1.25 rem CEDE, which was appropriate for the level determined by the WBCs. Step 5.4.3.c requires that Radiological Support reviews air sampling data and other exposure and survey data to determine consistency with bioassay results. Step 5.4.3.d requires Radiological Support to evaluate use of alternate bioassay methods to confirm internal dose measurements. Based on the information provided, the NRC determined that the licensee failed to conduct this step or to conduct this step adequately.

Within the pipe smear data results and bioassay measurements, there were statistically significant positive counts of plutonium-239 and plutonium-240 (Pu-239/240) located on the pipe that the pipefitters were flapping on and positive Pu-239/240 counts within the urinalysis data for one pipefitter. This information was not used to properly assess dose to the workers for the possibility of exposure from alpha emitters. Additionally, the licensee only conducted one 24-hour urinalysis sample for each pipefitter and did not continue follow-up urinalysis samples or evaluate other bioassay methods, such as fecal in vitro analysis, to properly assess the internal dose from alpha emitting radionuclides, such as Pu-239/240. Air samples, pipe smears, or excreta from the worker would provide information for dose assessment for the possibility of exposure from alpha emitters. The licensee did not gather air samples and focused on the body counts and did not use any of the other data available to them to ensure dose was assessed properly.

Procedure PPM 11.2.4.6, In Vitro Bioassay Sampling and Analysis, revision 3, describes the established protocol for performing in vitro bioassay sampling and analysis. Step 5.1 determines the type of sample required and the sample collection period. Step 5.1.1. states 8.1 provides guidelines for the type of sample needed for various radionuclides.

8.1 recommends both urine and feces samples are collected for indications of Pu-239/240 radionuclides (alpha emitters). Step 5.1.3 states, fecal sampling should continue for the first three to five days following the intake; and step 5.1.4 states, continue excreta collection until the elimination rates are well-established.

Licensee procedure HPI-5.9, Evaluation of In-Vivo Bioassay Results Following a Potential Intake, revision 15, step 5.1.4 states that, Excreta collection, if applicable, should be continued until the elimination rates are well-established. Refer to PPM 11.2.4.6 for in vitro sampling and analysis. Step 5.8.1 of this procedure states, in part, that If gamma emitting fission products are detected by in vivo measurements, the presence of hard-to-detect nuclides should be considered. If fission products are detected by in vivo bioassay at levels exceeding Derived Action Level 2 (0.02 ALI), in vitro samples (fecal and/or urine) should be collected for initial screening.

Contrary to procedure PPM 11.2.4.6 and procedure HPI-5.9, the licensee only took one urine sample for each pipefitter within the first 24 to 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> following the uptakes. A single urine sample is insufficient for effective in vitro bioassay because multiple samples are typically required to correctly determine the elimination rates and apply the methodologies used to conduct dosimetry of in vitro samples. Additionally, fecal samples were never taken. The in vitro sample type is important because it enables the identification of the radionuclides that were taken up, and it helps determine the exposure pathway. If alpha emitters are suspected in an internal exposure event, then in vitro samples are typically specified because alpha radiation is not detectable through whole body counting. In conclusion, not only did the licensee fail to implement the most appropriate sampling methods to detect the level of hard-to-detect radionuclides from the intake, including alpha emitters, but they did not take any additional samples to suitably establish trends and elimination rates of these radionuclides.

The potential exposure source, including at least one alpha emitter of Pu-239/240, was not properly addressed or evaluated by the licensee. Specifically, the internal dose assessment data for the workers show the presence of an alpha emitter based on the following: the RWCU pipe smear had positive alpha counts for Pu-239/240, the air sampler within the RWCU heat exchanger room had indications of Pu-239/240 (no air sampling was completed in the breathing zone of the workers), and one of the pipefitters had a positive count for Pu-239/240 within their urine sample. This became evident during subsequent review of the information provided to the NRC.

Based on NRCs assessment of these failures and review of the provided data, the ability to fully evaluate the internal dose was compromised in that inadequate procedures resulted in program failures that could have resulted in the licensees failure to account for more than 100 millirem of unassigned dose to at least one of the pipefitters from alpha emitters. In support of this conclusion, the internal dose assessment performed by the licensees vendor stated, Additional 24-hour fecal samples would have been needed to determine how much of the initial intake cleared through ingestion because the initial intake data performed by the vendor was not matching the licensees WBC data, as provided. In information provided to the NRC through interviews, the licensee noted that the procedures related to internal dose assessment, PPM 11.2.4.5, PPM 11.2.4.6, and HPI-5.9, did not have the details needed to conduct this level of assessments.

Corrective Action Reference: AR 00446059

Performance Assessment:

Performance Deficiency: The licensee failed to take suitable and timely measurements of concentrations of:

(1) radioactive material in air in work areas;

(2) quantities of radionuclides in the body;

(3) quantities of radionuclides excreted from the body; or

(4) combinations of these measurements. These measurements resulted in the compromise of the licensees ability to adequately assess the internal dose of the two pipefitters. Specifically, the licensee failed to use a combination of measurements, based on steps noted in their dose assessment procedures, PPM 11.2.4.5, PPM 11.2.4.6, and HPI-5.9 to adequately assess the internal dose.

The licensee only took one 24-hour urine sample from each pipefitter, day 2 post the uptake event, and did not continue these in vitro assessments to establish elimination rates, nor did they take radioactive material in air in work area, evaluate the WBC and survey assessments to determine that fecal sampling was needed to appropriately measure hard-to-detect radionuclides, including alpha emitters.

Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Program and Process attribute of the Occupational Radiation Safety cornerstone and adversely affected the cornerstone objective to ensure the adequate protection of the worker health and safety from exposure to radiation from radioactive material during routine civilian nuclear reactor operation.

Significance: The inspectors assessed the significance of the finding using Inspection Manual Chapter (IMC) 0609 Appendix C, Occupational Radiation Safety Significance Determination Process. Using IMC 0609, Appendix C, the violation was preliminarily determined to be of low to moderate safety significance (preliminary White) because:

(1) it was not a finding associated with ALARA Planning or Work Controls,

(2) it was not an overexposure,

(3) there was no substantial potential for overexposure from the performance deficiency in this case, but there was a substantial potential with the uptake event, based on the failures in radiological controls as documented in the final significance determination of NRC Inspection Report 05000397/2023-090, and

(4) the ability to assess dose was compromised.

Cross-Cutting Aspect: H.1 - Resources: leaders ensure that personnel, equipment, procedures, and other resources are available and adequate to support nuclear safety.

Specifically, the licensee did not have adequate procedures, equipment, or personnel available to address the level of contamination and internal dose assessment needed to prevent a compromise to their ability to properly assess dose to the pipefitters post the uptake event.

Enforcement:

Violation: 10 CFR 20.1204(a) requires, in part, that the licensee shall, when required under 10 CFR 20.1502, take suitable and timely measurements of:

(1) concentrations of radioactive materials in air in work areas; or

(2) quantities of radionuclides in the body; or

(3) quantities of radionuclides excreted from the body; or

(4) combinations of these measurements, to determine compliance with occupational dose equivalent limits.

Contrary to the above, on May 28, 2021, when required under 10 CFR 20.1502, the licensee failed to take suitable and timely combination of measurements to determine compliance with occupational dose equivalent limits. Specifically, the licensee failed to take suitable and timely measurements of concentrations of radioactive materials in air in work areas, urine and fecal samples, as well as properly evaluate alpha emitters in the body contributing to the accrued internal dose. These failures resulted in an inability for the licensee to properly assess the dose accrued by the pipefitters.

Enforcement Action: This violation is being treated as an apparent violation pending a final significance (enforcement) determination.

EXIT MEETINGS AND DEBRIEFS

The inspectors verified no proprietary information was retained or documented in this report.

On May 30, 2023, the inspectors presented the preliminary White significance exit inspection results and the apparent violation to Mr. Robert Schuetz, Chief Executive Officer, and other members of the licensee staff.

DOCUMENTS REVIEWED

Inspection Type Designation Description or Title Revision or

Procedure Date

71153 Miscellaneous Intake and Internal Dose Evaluation for worker #1 07/01/2021

71153 Intake and Internal Dose Evaluation for worker #2 07/01/2021

Energy Northwest Independent Internal Dose Assessment 1

20829 Root Cause Evaluation: Reactor Water Clean Up (RWCU) 02/25/2022

Heat Exchanger Pipe Weld Contamination Event

Procedures HPI-5.9 Evaluation of In-Vivo Bioassay Results Following a Potential 15

71153 Intake

PPM 11.2.4.5 Whole Body Counts and Daily Checks Using the Renaissance 16

Fastscan

PPM 11.2.4.6 In Vitro Bioassay Sampling and Analysis 3

8