ML25206A280
| ML25206A280 | |
| Person / Time | |
|---|---|
| Issue date: | 07/25/2025 |
| From: | Harvey J Office of Nuclear Reactor Regulation |
| To: | Michael Wentzel Office of Nuclear Reactor Regulation |
| References | |
| EPID N-2024-ADV-0004 | |
| Download: ML25206A280 (1) | |
Text
July 25, 2025 MEMORANDUM TO:
Michael Wentzel, Chief Advanced Reactor Projects Branch Division of Advanced Reactors and Non-power Production and Utilization Facilities Office of Nuclear Reactor Regulation FROM:
Jackie Harvey, Senior Project Manager /RA/
Advanced Reactor Projects Branch Division of Advanced Reactors and Non-power Production and Utilization Facilities Office of Nuclear Reactor Regulation
SUBJECT:
SUMMARY
OF THE JUNE 23, 2025, OBSERVATION MEETING WITH THE NUCLEAR ENERGY INSTITUTE TO DISCUSS NEI 24-05, REVISION 0, AN APPROACH FOR RISK-INFORMED PERFORMANCE-BASED EMERGENCY PLANNING (EPID NO.
N-2024-ADV-0004)
Meeting Information:
Participant: The Nuclear Energy Institute (NEI)
Public Meeting Notice Agencywide Documents Access and Management System (ADAMS)
Accession No.: ML25174A002 NEI Presentation Slides ADAMS Accession No.: ML25175A055 Meeting Attendees: See the enclosure for a list of meeting attendees.
CONTACT:
Jackie Harvey, NRR/DANU 301-415-7534
Meeting Summary:
The U.S. Nuclear Regulatory Commission (NRC) staff conducted the meeting in accordance with NRC Management Directive 3.5, Attendance at NRC Staff-Sponsored Meetings (ADAMS Accession No. ML21180A271). Prior to the meeting, NRC staff provided NEI a list of questions and clarifications regarding NEI 24-05 (ADAMS Accession No. ML25168A016). During the meeting, NEI representatives provided responses to these comments in the form of a presentation, followed by discussion of each comment. The NEI responses to the NRC staffs questions can be found in ML25175A055, several of which include NEI providing revised text to NEI 24-05. The additional points of discussion during the meeting included:
NEI responded to multiple comments from NRC staff regarding the preliminary licensing basis event screening step of emergency planning zone (EPZ) determination. NEI clarified that because NEI 24-05 is intended to be technologically inclusive, the guidance would not be overly prescriptive.
o NRC staff asked if the basis for the 2.5 mrem dose will be captured, to which NEI responded yes, they are planning on including a reference for the basis.
o NRC staff asked if it is intended for an applicants design specific screening performed in this section to be included in their application. NEI responded yes, and that it would be on the user to justify the site-specific information and analysis and this clarification would be added to NEI 24-05.
NEI responded to an NRC staff question requesting clarity on how screening would be performed for the time available for the implementation of protective measures for personnel within the site boundary.
o NRC staff questioned the idea that prompt protective measures are not applicable within the site boundary and discussed a yellow finding for Columbia Generating Station for prompt protective measures for members of the public who were within the site boundary.
o NEI discussed that the timing of taking protective measures onsite was not considered in NEI 24-05 for the EPZ sizing determination, and that if the dose assessment exceeds the established criteria within the site boundary, then the EPZ defaults to a site boundary.
o NRC staff asked if this was captured in NEI 24-05. NEI responded in the affirmative that it was captured in figure 4.10 and that NEI 24-05 would be updated to provide greater clarity.
NEI provided a justification for not including prompt protective measures in section 4.4.2 of NEI 24-05 as identified by NRC staff.
o NEI stated that there are only three possible outcomes of the methodology: no EPZ, an EPZ at the site boundary, and an EPZ beyond the site boundary.
NEI provided a response to a question posed by NRC staff on how the potential consideration of a non-uniform EPZ based on meteorological phenomena would be included in the determination of a EPZ when actual meteorological conditions during an event are unknown. NRC staff had additionally asked if there are examples of meteorological and site conditions that would always reduce the dose in certain directions such that it may lead to consideration of non-uniform EPZs.
o NEI agreed with NRC staff that a situation in which meteorological conditions would reduce the dose in certain directions is unlikely to occur and stated that NEI 24-05 would be revised to provide clarity.
NEI answered a question from NRC staff on how close section 5.3 is intended to get an applicant to an approved Emergency Action Level (EAL) scheme.
o NRC staff asked if this section could be described as initial guidance for the creation of an EAL scheme, but not necessarily something that would drive standardization or consistency between applicants.
o NEI responded that an applicant could use the information in this section as a starting point but emphasized that each applicant would need to use this information to develop their own schemes dependent on their technology.
NEI provided a response to an NRC staff question on how this guidance would address a situation where an event greater than 1 rem over 96 hrs is known but the accident progression time slow enough to allow ad hoc protective actions.
o NRC staff clarified that this question was intended to address offsite scenarios, to which NEI responded that in that case, it is important for the applicant to document what those ad hoc protective measures might be.
o NRC staff asked if they thought a situation like that would result in a general emergency on an EAL scheme. NEI responded that they had originally considered this question in the onsite application and would need to think on this issue further.
NEI responded to a question provided by NRC staff on if section 5.3.5, Staffing and Operations, is intended to be enough guidance for an applicant to determine appropriate their staffing levels.
o NRC staff provided an observation that it did not seem obvious how the amount of guidance within NEI 24-05 is going to be enough to cover the entire breadth of technologies from microreactors with potentially minimal staffing to a larger facility with a greater security footprint. NRC staff asked if this section is similar to the EAL section in which guidance was only meant to be a starting point. NEI stated that yes, this was also the intent of this section.
NEI addressed a comment from NRC staff requesting clarification on the use of the terms mean meteorology and mean results.
o NRC staff emphasized that NEI should be cognizant of terms used in the guidance and ensure they mean the same to all users of the guidance. NEI stated that they would revise NEI 24-05 to clarify the intent of the discussion while allowing consideration of a range of potential methodologies and margins to criteria.
NRC staff provided a general comment that the document should be clear on any differences in the methodology when used to support construction permit (CP) applications vs. operating license or combined license applications.
o NRC staff agreed that there is a range of potential design finalities but stated that the applicant would still need to provide a preliminary EPZ size for a CP. Staff further highlighted the importance of documentation of this consideration to support applications. NEI stated potentially considering additional text in the guidance to clarify difference in methodology.
NRC staff provided recommended information that NEI 24-05 should include for documentation of EPZ size determination, such as including determination of the spectrum of events, consequence analyses, protective measure evaluation, and final determination of the Plume Exposure Pathway (PEP) EPZ, and compliance with the regulatory criteria.
o NRC staff asked if NEI is not planning to include this information in a Safety Analysis Report, then how are they ensuring any changes that impact the emergency plan are captured. NEI responded that they are currently working on a process as part of the Technology Inclusive Management of Safety Case (TIMaSC) project. Similar to the method in Regulatory Guidance (RG) 1.219, if any changes occur, there will be a defined process for evaluating the effect of any changes to the emergency plan. NEI will update text in NEI 24-05 to point to TIMaSC.
A member of the public expressed concern regarding the approach in NEI 24-05 for identifying security events. The individual stated that a fundamental issue is that a design basis attack may result in a scenario that is screened out in accident space based on frequency.
A member of the public also expressed concern that the EPZ size determination does not consider a separate consideration for a childs thyroid dose. The individual asked NRC staff if an event resulting in exceeding a childs thyroid dose limit were to be exceeded, would that require a prompt protective measure (administering potassium iodine).
o NRC staff responded that EPZ size determination is not specific to the pathway for exposure, but includes 1 rem total effective dose equivalent over 96 hrs as a criterion for determining EPZ size. The member of the public stated that the second criterion [for an EPZ in draft §53.1109(g)(2)(i)(B)] is necessity for prompt protective measures.
o NRC staff requested clarification on if their question was do you think it would be possible that a child 5 rem thyroid would be reached before a 1 rem total effective dose equivalent?.
o The member of the public discussed that the second criterion could be invoked for a get out of jail free card, if an Environmental Protection Agency (EPA)
Protective Action Guides (PAGs) for provision of potassium iodide based on child thyroid dose could be exceeded. This approach does not consider the EPA PAG on child thyroid dose, even though the EPA PAGs are routinely cited for meeting this rule.
o NRC staff thanked the individual for the comment and stated it will take the comment into consideration for the review.
A member of the public asked that for the language of the emergency classification levels relating to degradation, how is it intended to measure of quantify that degradation, related to Table 5.1 in NEI 24-05.
o NEI responded that the safety function and involvement with licensing basis events could give understanding to what level of degradation would be involved.
Once it is known what structures, systems, and components are impacting safety, the applicant must then determine what level of degradation would result in those levels.
No regulatory decisions were made as a result of this meeting.
Enclosure:
List of Meeting Attendees cc: Advanced Reactor Updates via GovDelivery
SUBJECT:
SUMMARY
OF THE JUNE 23, OBSERVATION MEETING WITH THE NUCLEAR ENERGY INSTITUTE TO DISCUSS NEI 24-05, REVISION 0, AN APPROACH FOR RISK-INFORMED PERFORMANCE-BASED EMERGENCY PLANNING (EPID NO. N-2024-ADV-0004). DATED: JULY 25, 2025 DISTRIBUTION:
PUBLIC RidsNrrDanuUarp Resource RidsNrrDanuUtb1 Resource RidsNrrDanuUtb2 Resource MWentzel, NRR TTate, NRR CRosales-Cooper, NSIR MHart, NRR KBucholtz, NRR ESchrader, NSIR TSmith, NSIR CMurray, NSIR JHarvey, NRR KMcElwee, NRR ADAMS Accession Number: ML25206A280 NRR-001 OFFICE NRR/DANU/UARP/PM NRR/DANU/UARP/BC NRR/DANU/UARP/PM NAME JHarvey MWentzel JHarvey DATE 7/16/2025 7/16/2025 7/25/2025 OFFICIAL RECORD COPY
Enclosure LIST OF MEETING ATTENDEES FOR THE JUNE 23, OBSERVATION MEETING WITH THE NUCLEAR ENERGY INSTITUTE TO DISCUSS NEI 24-05, REVISION 0, AN APPROACH FOR RISK-INFORMED PERFORMANCE-BASED EMERGENCY PLANNING Name Organization Jackie Harvey U.S. Nuclear Regulatory Commission (NRC)
Michael Wentzel NRC Kristin McElwee NRC Eric Schrader NRC Cindy Rosales-Cooper NRC Charles Murray NRC Michelle Hart NRC Kristy Bucholtz NRC Dave Grabaskas ANL Jon Facemire NEI David Young NEI Stanley Gardocki NRC Bridget Curran NRC Kelli Voelsing NEI Gina Taylor Public Monica Ray Public Lindsay Vance TerraPower Keyleigh Wahrmund Public Martin J Phalen Public Jin L Public Owen Scott TVA David Daigle TVA James Robert Thornton TVA Jana Bergman Public Robert Kahler Public Matthew Osborne TerraPower Addison Hall Public Sari Alkhatib Public Amir Afzali Public Robert Sandford Public Cindy Williams Public Dennis Henneke Public Nathan DeKett GE Venova Ingrid Nordby Deep Fission John Richards Public David Hinds Public Dennis Henneke Public Deepayan Home GE Vernova Michael Norwood GE Vernova Ted Amundson Public Edwin Lyman Public SB Public
2 Name Organization PJ Steel Public Jill Monahan Public Partha Chandran Public Jose Pires Public Orjowen Hamdouni Public Nikola Popov Public Antonios Zoulis Public Kaci Studer Public Harley Hutchins Public David Hindera GE Vernova Tanya Hockett Public Nils-Erik Kramer Public Elfrida Connell Public Robert Harrsch Public Jeremiah Doyle Public