ML22067A185

Enc 3 - Energy Northwest Presentation

ML22067A185
Person / Time
Site:	Columbia
Issue date:	03/01/2022
From:	Energy Northwest
To:	NRC Region 4
Greene N
Shared Package
ML22067A190	List: ML22067A183 ML22067A184 ML22067A185 ML22067A186
References
EA-21-170
Download: ML22067A185 (28)

Text

NRC Regulatory Conference - March 1, 2022 1

Columbia Generating Station Reactor Water Cleanup Uptake Event Regulatory Conference March 1, 2022

NRC Regulatory Conference - March 1, 2022 2

Introduction and Agenda Introduction and Agenda Desirée Wolfgramm, Regulatory Affairs Manager Management Overview Dave Brown, Site Vice President Event Description Tony Hedges, Chemistry/Radiological Services Manager Root Cause and Corrective Actions Sam Nappi, Assistant Chemistry/Radiological Services Manager Significance Determination Desirée Wolfgramm, Regulatory Affairs Manager Closing Comments Grover Hettel, Vice President Nuclear Generation / Chief Nuclear Officer

NRC Regulatory Conference - March 1, 2022 3

Management Overview Dave Brown Site Vice President

NRC Regulatory Conference - March 1, 2022 4

NRC Regulatory Conference - March 1, 2022 5

Event Description Tony Hedges Chemistry/Radiological Services Manager

NRC Regulatory Conference - March 1, 2022 6

Reactor Water Cleanup Heat Exchanger Replacement Major activities of the project:

Preparing system for replacement of components Performing destructive chemical decontamination of heat exchangers and piping Removal of old components from the room Installing new components and welding new pipe to system piping The planning and staffing aspects:

Dedicated Radiation Protection (RP) Technician with planning qualifications Planning incorporated elevated and high-risk aspects of the project Planning addressed Locked High Radiation Area (LHRA) controls, contamination and airborne controls Dedicated staffing to the project for each shift included a RP Supervisor and RP Lead Technician

NRC Regulatory Conference - March 1, 2022 7

RP Preplanning for Weld Preparations Remote dose and dose rate monitoring Visual monitoring by camera

- Portable video cameras, placed by RP, monitored at remote monitoring station (RMS)

Supervisory oversight - required per procedure 11.2.7.3

- PROVIDE direct oversight during activities that have a potential for unplanned exposures, such as:

• Work involving Dose Significant Activities as defined by this procedure

• Diving operations into pools, tanks, or cavities

• Radiography

• Access to plant components that contain or may contain highly radioactive materials

NRC Regulatory Conference - March 1, 2022 8

Cut Location #3 - As seen through cameras at Remote Monitoring Station Pre-Work Activities May 27 - Nightshift - glove bag task preview at the mock-up with pipefitters, RP Lead Tech, and RP Tech #3 Mock-up not effectively used for practice Decision to use smaller glove bag Pipefitters controlled installation and removal of glove bag May 28 - Dayshift - Successful weld prep on Cut #4 using larger glove bag under RP control Mock-up used for practice Used larger glove bag RP controlled installation and removal of glove bag

NRC Regulatory Conference - March 1, 2022 9

• May 28 - Nightshift

- Project Team Pre-job Brief and LHRA Brief

- RP Job Coverage Tech changeout from RP Tech #1 to RP Tech #2

- Glove bag was removed contrary to briefed steps

- Pipe was wiped inside and out after glove bag removal

- Actions performed after glove bag removal were observed by RP Lead Tech and RP Supervisor via cameras at RMS

- RP Lead Tech directed RP Tech #1 to stop work

- RPT #1 directed pipefitters to cover pipe and exit

- Bag installed over pipe, then removed and foreign material exclusion (FME) cover installed, leaving jobsite in a safe condition Uptake Event

NRC Regulatory Conference - March 1, 2022 10 Briefed Steps Removed pipe plug in plastic bag Wetting a FME plug inside of a glove bag Installing the glove bag onto the cut location Attaching a HEPA vacuum to the glove bag to control any contaminants disturbed during the work Turning the HEPA vacuum on Installing the wetted FME plug into the pipe through the glove bag Cleaning the inside of the pipe using a flapping wheel inside of the glove bag Wetting down the inside of the pipe and wiping down the surfaces with the glove bag still in place Removing the FME plug through the glove bag Removing the glove bag from the cut location Installing FME cover Removed pipe plug in plastic bag Wetting a FME plug inside of a glove bag Installing the glove bag onto the cut location Attaching a HEPA vacuum to the glove bag to control any contaminants disturbed during the work Turning the HEPA vacuum on Turning the HEPA vacuum off Installing the wetted FME plug into the pipe through the glove bag Cleaning the inside of the pipe using a flapping wheel inside of the glove bag Removing the FME plug through the glove bag Removing the glove bag from the cut location Wetting down the inside of the pipe and wiping down the surfaces with the glove bag removed Installation of plastic bag, removal of bag and replaced with FME cover Performed Steps

NRC Regulatory Conference - March 1, 2022 11 Root Cause Clarifications

• Information discovered during the root cause investigation provides clarity on the sequence of events and circumstances of the night of May 28, 2021

• The following 5 slides provides this additional information

NRC Regulatory Conference - March 1, 2022 12 Inspection Report The ALARA Work Plan included specific instructions such as using powered air purifying respirators (PAPRs) on highly contaminated components there were inadequate surveys used to support down-posting the RWCU HX area from a high contamination area to a contamination area Root Cause Clarifications Additional Information from Root Cause Evaluation for ALARA Planning and Pre-Job Surveys The ALARA Work Plan was inclusive of the entire RWCU Project which did consist of work in PAPRs, which included removal of old components from the room, the RWP was specific to the job of the uptake event Surveys 20210527-23 & 20210529-6, supported down-posting the RWCU HX area to a contamination area

NRC Regulatory Conference - March 1, 2022 13 Inspection Report Contrary to the RWP requirements for continuous job coverage, RP Tech #1 left the workers unattended RP Tech #2 was not a part of the required formal briefing for this job Root Cause Clarifications Additional Information from Root Cause Evaluation for Local Job Coverage Continuous coverage was not required. Dose rates were 450-550 mR/hr during the work at the jobsite location RP Tech #2 was at LHRA brief the day of the uptake event but not the task preview

NRC Regulatory Conference - March 1, 2022 14 Inspection Report the lead RP tech, who is an RP Supervisor but was not assigned to provide continuous coverage The RP tech (not credited as job coverage) was at the remote monitoring station with a view of the glove bag activity the RP tech viewed the grinding activity at the right point in time on the correct monitor and camera the RP tech had enough background information and/or experience to recognize the abnormal situation Root Cause Clarifications Additional Information from Root Cause Evaluation for Direct Oversight at Remote Monitoring Station There were three people at the RMS, RP Tech #3, RP Lead Tech, and RP Supervisor In accordance with PPM 11.2.7.3 Step 3.4.1.b the RP Supervisor was providing direct oversight from the RMS The RP Supervisor and RP Lead Tech both recognized that steps were being performed out of the briefed sequence The RP Lead Tech was a part of the task preview at the mock-up, and RP Supervisor and RP Lead Tech were in the brief the day of the uptake event

NRC Regulatory Conference - March 1, 2022 15 Inspection Report the additional time needed to clean up the area, gather tools, and leave the job in a safe work condition is a reasonable scenario with minor alterations could have led to overexposure Root Cause Clarifications Additional Information from Root Cause Evaluation for Job Completion The pipefitters documented work complete. All briefed steps were completed, some out of order. All tools were contained in the glove bag. The pipe was covered by the FME cover when the pipefitters left the platform, leaving the job in a safe condition.

NRC Regulatory Conference - March 1, 2022 16 Inspection Report Airborne radioactive material was released from the glove bag and dispersed into the RWCU HX room Based on the inspectors derived air concentration (DAC) estimate, the pipefitters could have reasonably received greater than 5 rem if they had remained in the work area for an additional five minutes. These estimates were confirmed by the results of the licensees Calculation 21-02.

Root Cause Clarifications Additional Information from Root Cause Evaluation for Dose Assessment Opportunities for airborne contamination include glove bag removal, wiping pipe inside and out, and installation and removal of plastic bag Based upon further investigation, there were multiple opportunities for airborne contamination which invalidates the assumption in the calculation that the entire dose was received in one puff release

NRC Regulatory Conference - March 1, 2022 17 Root Cause and Corrective Actions Sam Nappi Assistant Chemistry/Radiological Services Manager

NRC Regulatory Conference - March 1, 2022 18 Results of Causal Evaluations

• Direct Cause:

- Improper setup, use (without HEPA vacuum), and removal of a glove bag (engineering control) while performing pipe preparation activities.

• Root Cause:

- The Radiological Risk for the work was evaluated by staff presupposing the successful use of engineering controls to mitigate radiological hazards and didnt evaluate or recognize the overall risk associated with the work being performed or potential consequences of engineering control failure or incorrect use.

NRC Regulatory Conference - March 1, 2022 19 Completed Corrective Actions

• Immediate Corrective Actions:

- Stopped work

- Assigned additional resources

- Performed coaching to the RP supervision and Leads

- Ensured the remaining cuts were completed appropriately

• Actions Taken Since the Uptake Event

- Revised the radiological risk screening form for high contamination work

- Revised the Radiation Work Permit (RWP) procedure and Contamination Control Containment Devices procedure

- Developed a new procedure for RP outage preparation

NRC Regulatory Conference - March 1, 2022 20 Corrective Actions

• Additional Actions to Be Taken:

- Revising the radiological risk assessment procedure

- Provide training to individuals on how to assess radiological risk when elimination or mitigation actions are prescribed

- Revising the TEDE/ALARA evaluation process

- Require RWP revisions to be screened for changes in risk classification

- Establishing clear roles and responsibilities for glove bag use in HPI-12.90

- Formally perform culpability assessments per station procedures for the individuals involved

NRC Regulatory Conference - March 1, 2022 21 Significance Determination Desirée Wolfgramm Regulatory Affairs Manager

NRC Regulatory Conference - March 1, 2022 22 Performance Deficiency and Apparent Violations Performance Deficiency Energy Northwest agrees with the Performance Deficiency Apparent Violation #1 Energy Northwest agrees with Apparent Violation #1 but suggest some wording changes to reflect the issue. The engineering control was not planned for with enough specificity in accordance with station procedures, specifically HPI-12.90, to ensure proper control for installation and removal to prevent airborne contamination Apparent Violation #2 Energy Northwest disagrees with Apparent Violation #2. The dose rates in the area at the time of the uptake event were less than those requiring continuous coverage Apparent Violation #3 Energy Northwest disagrees with Apparent Violation #3. Adequate dose surveys were completed in the field by RP Technicians during the work activity

NRC Regulatory Conference - March 1, 2022 23 Inspection Report Significance Determination Finding Identified ALARA Planning or Work Controls?

Was It An Over-exposure?

Was there A Substantial Potential?

Was the Ability to Assess Dose Compromised

?

SDE/DRP Exposure?

Was it a Whole Body Exposure in a VHRA?

Green White No No No No No Yes No Assessed under the NRC's Reactor Oversight Process (ROP) Occupational Radiation Safety Significance Determination Process (SDP) Inspection Manual Chapter (IMC) 0609 Appendix C:

NRC Regulatory Conference - March 1, 2022 24 Substantial Potential for Overexposure IMC 0609 Appendix C II.C Substantial Potential for Overexposure An event presents a substantial potential when it was fortuitous that the resulting exposure did not exceed the limits of 10 CFR 20. The concern is not the significance of the resulting, or potential, exposure, but whether the licensee provided adequate controls over the situation, as required, to ensure the Part 20 dose limits are not exceeded. No credit is given for luck.

Required Controls per ALARA Plan and/or Station Procedures:

- Engineered Control - Glove bag

- Job coverage - RPT #2

- Direct Oversight - RP Supervisor at RMS

- Tele-dosimetry - RPT #3 at RMS

NRC Regulatory Conference - March 1, 2022 25 Substantial Potential for Overexposure (cont.)

IMC 0609 Appendix C II.C Substantial Potential for Overexposure (continued)

When assessing whether a finding constitutes a substantial potential for overexposure, consider if it is possible to construct a reasonable scenario in which a minor alteration of circumstances (as they actually happened) would have resulted in a violation of the Part 20 limits. The following circumstances should be considered: timing, source strength, distance, and shielding.

"Fortuitous" circumstances as described in the Inspection Report, but through the root cause investigation were found to be pre-planned in the ALARA Plan and/or station procedures:

- RP tech (not credited as job coverage) was at the remote monitoring station with a view of the glove bag activity

- The RP tech viewed the grinding activity at the right point in time on the correct monitor and camera

- The RP tech had enough background information and/or experience to recognize the abnormal situation

- The RP tech only had a "40 foot/30 second" walking path to the entrance of the RWCU HX room from the remote monitoring station

NRC Regulatory Conference - March 1, 2022 26 Alteration of Circumstances From Inspection Report If the lead RP tech had not intervened, the additional time needed to clean up the area, gather tools, and leave the job in a safe work condition is a reasonable scenario with minor alterations [that] could have led to overexposure.

Additional Clarification from further investigation:

- Calculation 21-002 assumptions are invalid

- Pipefitters completed work and left jobsite in a safe condition

NRC Regulatory Conference - March 1, 2022 27 Significance Determination Assessed with additional information discovered through the root cause under the NRC's ROP Occupational Radiation Safety SDP IMC 0609 Appendix C:

Finding Identified ALARA Planning or Work Controls?

Was It An Over-exposure?

Was there A Substantial Potential?

Was the Ability to Assess Dose Compromised

?

SDE/DRP Exposure?

Was it a Whole Body Exposure in a VHRA?

Green White No No No No No Yes No

NRC Regulatory Conference - March 1, 2022 28 Closing Comments Grover Hettel Vice President Nuclear Generation /

Chief Nuclear Officer