What's New in Decommissioning of Nuclear Facilities

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Recent and Upcoming Meetings and Activities

The NRC consolidated its decommissioning guidance in a three volume NUREG-1757 series, which was originally issued in 2003.  NUREG-1757, Volume 2 was recently revised (Revision 2) and issued for public comment in December 2020.  Over 200 comments in 9 comment letters were received on the draft document.  The NRC has addressed most of the comments and plans to issue a final NUREG-1757, Volume 2, Rev. 2 in the summer of 2022.  NUREG-1757, Volume 1 is also in the process of being revised (Revision 3) and is expected to be issued in fall 2022.  Other decommissioning guidance document revisions that were recently issued include:  NUREG-1507, Rev. 1, “Minimum Detectable Concentrations with Typical Radiation Survey for Instruments for Various Contaminants and Field Conditions”, and NUREG-1700, Rev. 2, “Standard Review Plan for Evaluating Nuclear Power Reactor License Termination Plans”.  MARSSIM Rev. 2, draft for public comment, (NUREG-1575, Rev. 2) was also issued for public comment.  The public comment period was recently reopened on December 28, 2021, for 45 days (see 86 FR 73757).

Some comments received on NUREG-1757, Volume 2, Rev. 2 were more difficult to address (comments on subsurface surveys and discrete radioactive particles) and are expected to result in significant changes to the guidance document.  Therefore, the NRC plans to take additional time to address those comments and provide opportunities for interested stakeholders to weigh in on the revised guidance prior to incorporation of the guidance in the next revision to NUREG-1757, Volume 2. The interim guidance development section below provides additional information on the need for additional guidance in the areas of subsurface surveys and discrete radioactive particles, as well as historical and more recent information pertinent to the guidance that is being considered in finalizing the draft interim guidance.  The following table lists upcoming meetings and activities to keep interested stakeholders informed of NRC progress on guidance development as well as provide information on opportunities for public participation in the guidance development process.

 

Meeting/Activity Date/Timeframe Link/Meeting Notice/Notes
RIC Virtual 2022

(Reactor Decommissioning Session)

March 8-10, 2022 Session W14, Reactor Decommissioning: Planning for Tomorrow. The W14 virtual session will focus on initiatives to improve the overall reactor decommissioning program and make it more efficient and effective. Presenters will highlight the overall program status, key accomplishments in the decommissioning program, resource initiatives to enhance the program, and implementation of “Be RiskSMART” initiatives.  Session W14 will be held on Wednesday, March 9 at 1:00 pm.  Additional details will be posted on the RIC 2022 web site prior to the conference.
2nd Annual Subsurface Investigations Workshop May 11, 2022 NRC contractors will be presenting information on the technical basis for interim guidance on subsurface surveys and associated dose modeling.  Proposed tools in Visual Sample Plan will also discussed.
The draft technical report will be issued prior to the workshop to facilitate discussion at the meeting.  Industry and other interested stakeholders will participate in discussions regarding the proposed methodologies.
Public Meeting on Discrete Radioactive Particles (DRP) Summer 2022  
Issuance of Final SC&A Subsurface Technical Letter Report Summer 2022  
Final NUREG-1757, Volume 2, Rev. 2 Summer 2022 The public comment period ended in April 2021.  Over 200 comments in 9 comment letters were received on the draft document. The final report is coming soon.
Issuance of NUREG-1757, Volume 1, Rev. 3, Draft for Public Comment Fall 2022  

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Interim Guidance Development

Because the NRC’s Consolidated Decommissioning Guidance is only updated every few years, interim guidance can be used between guidance revisions to communicate methods to demonstrate compliance with radiological criteria for license termination related to important topics of interest to NRC licensees.  Two areas for which the NRC is currently developing interim guidance include:  (i) subsurface investigations and (ii) discrete radioactive particles.  The NRC staff is issuing interim guidance for these two topics to allow members of the public to participate in the guidance development process.  Opportunities for public engagement in the guidance development process are listed in the Recent and Upcoming Meetings and Activities section.  Historical and recent information related to subsurface and discrete radioactive particle surveys are listed in the sections below to provide context for the issue.  Staff will consider the complete record on these topics in developing interim guidance which will ultimately be folded into the next revision of NUREG-1757.

Subsurface Investigations

Many complex materials and decommissioning sites undergoing decommissioning have significant levels of residual radioactivity in subsurface soils and groundwater.  The Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) addresses radiological surveys for surface residual radioactivity; however, federal guidance does not currently address characterization and radiological surveys for the subsurface.  Subsurface soils are more difficult to access, and traditional scanning techniques are ineffective at measuring residual radioactivity at depth.  Given challenges and limitations with subsurface surveys, methods to leverage existing data and optimize subsurface survey design will be proposed.  Potential tools currently available to assist with remedial and final status survey decisions will be described.  Additionally, the NRC has contracted out with Pacific Northwest National Laboratory to scope out additional tools for implementation in Visual Sample Plan to assist with subsurface survey design and data analysis to support decommissioning decision-making. The following table provides historical and more recent information related to the topic that will be considered in developing the draft interim guidance.

Document No./Title Date Notes
NUREG/CR-7021, "A Subsurface Decision Model for Supporting Environmental Compliance" January 2012 Preliminary technical basis for design of subsurface surveys using the Spatial Analysis Decision Assistance (SADA) code.
NUREG-1757, Volume 2, Rev. 2, "Consolidated Decommissioning Guidance, Characterization, Survey, and Determination of Radiological Criteria: Draft Report for Comment" December 2020 The draft for public comment was issued in December 2020.  New subsurface survey and dose modeling guidance was included in Appendix G and J.
NUREG-1757, Volume 2, Rev. 2 Public Meeting
Presentation Slides (ML21057A335)
Public Meeting Notice (ML21057A335)
March 2021 A public meeting was held on March 15, 2021, to discuss updates to Volume 2 of NUREG-1757, as well as listen to comments on the draft document. The March 15, 2021, meeting summary and transcript can be found here:
ML21102A144.
2021 Subsurface Soils Workshop
Research Information Letter 2021-12 
Subsurface Soil Surveys Public Workshop - DAY 1
Subsurface Soil Surveys Public Workshop - DAY 2
 
July 14-15, 2021 The NRC held a workshop in July 2021 that was attended by over 160 participants.  Topics included use of geostatistical methods for complex reactor and material decommissioning; dose modeling and elevated area considerations for subsurface soils; and challenges associated with surveys of open excavations. Additional information can be found here: ML21208A206.
Technical Letter Report on characterizing and evaluating subsurface residual radioactivity (authored by NRC contractor: SC&A Inc.) Draft Expected March/April 2022 Technical basis document.

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Discrete Radioactive Particles

Interim guidance is also being developed related to radiological survey considerations for detection of discrete radioactive particles (DRPs), as well as methods to evaluate the potential dose or risk associated with exposure to DRPs.  Lack of control of DRPs has been an issue for some decommissioning sites seeking unrestricted release.  DRPs may be anticipated as part of decontamination and decommissioning activities, although some activities have higher potential of DRP generation compared to others.  Guidance is available for isolation and ventilation procedures adequate for operations with the potential for DRP generation.  Licensees should be cognizant of potential activities that could generate DRPs and have a program in place to control DRP to avoid issues with assessing the presence and risk significance of DRPs at the time of license termination.  The NRC staff are in the process of collecting existing guidance which will be considered in developing consolidated draft interim guidance on this topic.  Workshops are planned for late 2022 to discuss the draft interim guidance.  Interim guidance is expected to be finalized in the 2023 timeframe.

Lessons Learned

Lessons learned can be found at ML20052C815, "Lessons learned and Questions and Answers to Clarify Decommissioning and License Termination Guidance and Plans". Most of these lessons learned were folded into the current revisions to NUREG-1757, Volumes 1 and 2. Future lessons learned will be captured in this section to provide a basis for future guidance development.

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Page Last Reviewed/Updated Tuesday, January 18, 2022