Acceptability of Probabilistic Risk Assessment Results for Non-Light Water Reactor Risk-Informed Activities, 62894-62896 [2022-22536]

Download as PDF 62894 Federal Register / Vol. 87, No. 199 / Monday, October 17, 2022 / Notices Activity for Which Permit is Requested: Waste Management. The applicant seeks an Antarctic Conservation Act permit for waste management activities associated with coastal camping and the operation of a remotely piloted aircraft system (RPAS) in the Antarctic Peninsula region. The applicant seeks permission for no more than 40 campers and expedition staff to camp overnight at select locations for a maximum of 10 hours ashore. Camping would be away from vegetated sites and at least 150m from wildlife concentrations or lakes, protected areas, historical sites, and scientific stations. Tents would be pitched on snow, ice, or bare smooth rock, at least 20m from the high-water line. No food, other than emergency rations, would be brought onshore and all wastes, including human waste, would be collected and returned to the ship for proper disposal. For remotely piloted aircraft systems (RPAS) operation, the applicant proposes to operate small, batteryoperated RPAS consisting, in part, of a quadcopter equipped with cameras to collect commercial and educational footage of the Antarctic. The quadcopter would not be flown over concentrations of birds or mammals, or over Antarctic Specially Protected Areas or Historic Sites and Monuments. The RPAS would only be operated by pilots with extensive experience, who are preapproved by the Expedition Leader. Location: Port Lockroy, Damoy Point/ Dorian Bay, Paradise Bay, Neko Harbor, Danco Island and Cuverville and the vicinity of the Errera Channel, Neumeyer Channel, Petermann Island, South of the Lemaire Channel, South Shetland Islands, Antarctic Peninsula area. Dates of Permitted Activities: October 22, 2022–March 30, 2023. Erika N. Davis, Program Specialist, Office of Polar Programs. [FR Doc. 2022–22451 Filed 10–14–22; 8:45 am] BILLING CODE 7555–01–P NUCLEAR REGULATORY COMMISSION Sunshine Act Meetings Weeks of October 17, 24, 31, November 7, 14, 21, 2022. The schedule for Commission meetings is subject to change on short notice. The NRC Commission Meeting Schedule can be found on the internet at: https:// www.nrc.gov/public-involve/publicmeetings/schedule.html. lotter on DSK11XQN23PROD with NOTICES1 TIME AND DATE: 17:35 Oct 14, 2022 Week of November 14, 2022—Tentative There are no meetings scheduled for the week of November 14, 2022. Week of October 17, 2022 [NRC–2022–0052] There are no meetings scheduled for the week of October 17, 2022. Week of October 24, 2022—Tentative There are no meetings scheduled for the week of October 24, 2022. Week of October 31, 2022—Tentative There are no meetings scheduled for the week of October 31, 2022. Week of November 7, 2022—Tentative Tuesday, November 8, 2022 9:00 a.m. Briefing on Regulatory Approaches for Fusion Energy Devices (Public Meeting) (Contact: Samantha Lav: 301–415–3487) Additional Information: The meeting will be held in the Commissioners’ Conference Room, 11555 Rockville Pike, Rockville, Maryland. The public is invited to attend the Commission’s meeting in person or watch live via webcast at the Web address—https:// video.nrc.gov/. Thursday, November 10, 2022 [NRC–2022–0001] VerDate Sep<11>2014 The NRC provides reasonable accommodation to individuals with disabilities where appropriate. If you need a reasonable accommodation to participate in these public meetings or need this meeting notice or the transcript or other information from the public meetings in another format (e.g., braille, large print), please notify Anne Silk, NRC Disability Program Specialist, at 301–287–0745, by videophone at 240–428–3217, or by email at Anne.Silk@nrc.gov. Determinations on requests for reasonable accommodation will be made on a case-by-case basis. STATUS: Public. Members of the public may request to receive the information in these notices electronically. If you would like to be added to the distribution, please contact the Nuclear Regulatory Commission, Office of the Secretary, Washington, DC 20555, at 301–415–1969, or by email at Wendy.Moore@nrc.gov or Tyesha.Bush@ nrc.gov. MATTERS TO BE CONSIDERED: PLACE: Jkt 259001 10:00 a.m. Briefing on NRC International Activities (Public Meeting) (Contact: Jen Holzman, 301– 287–9090) Additional Information: The meeting will be held in the Commissioners’ Conference Room, 11555 Rockville Pike, Rockville, Maryland. The public is invited to attend the Commission’s meeting in person or watch live via webcast at the Web address—https:// video.nrc.gov/. PO 00000 Frm 00113 Fmt 4703 Sfmt 4703 Week of November 21, 2022—Tentative There are no meetings scheduled for the week of November 21, 2022. CONTACT PERSON FOR MORE INFORMATION: For more information or to verify the status of meetings, contact Wesley Held at 301–287–3591 or via email at Wesley.Held@nrc.gov. The NRC is holding the meetings under the authority of the Government in the Sunshine Act, 5 U.S.C. 552b. Dated: October 13, 2022. For the Nuclear Regulatory Commission. Monika G. Coflin, Technical Coordinator, Office of the Secretary. [FR Doc. 2022–22594 Filed 10–13–22; 11:15 am] BILLING CODE 7590–01–P NUCLEAR REGULATORY COMMISSION Acceptability of Probabilistic Risk Assessment Results for Non-Light Water Reactor Risk-Informed Activities Nuclear Regulatory Commission. ACTION: Regulatory guide for trial use; response to comments. AGENCY: The U.S. Nuclear Regulatory Commission (NRC) is addressing comments received after issuing for public comment on the trial use of the new regulatory guide (RG) 1.247, ‘‘Acceptability of Probabilistic Risk Assessment Results for Non-Light Water Reactor Risk-Informed Activities.’’ The NRC will not make any changes to the RG as a result of these comments. DATES: The public comment period for RG 1.247 ended on May 23, 2022. ADDRESSES: Please refer to Docket ID NRC–2022–0052 when contacting the NRC about the availability of information regarding this document. You may obtain publicly available information related to this document using any of the following methods: • Federal Rulemaking Website: Go to https://www.regulations.gov and search for Docket ID NRC–2022–0052. Address questions about Docket IDs in Regulations.gov to Stacy Schumann; telephone: 301–415–0624; email: Stacy.Schumann@nrc.gov. For technical questions, contact the individuals listed in the FOR FURTHER INFORMATION CONTACT section of this document. • NRC’s Agencywide Documents Access and Management System SUMMARY: E:\FR\FM\17OCN1.SGM 17OCN1 Federal Register / Vol. 87, No. 199 / Monday, October 17, 2022 / Notices (ADAMS): You may obtain publicly available documents online in the ADAMS Public Documents collection at https://www.nrc.gov/reading-rm/ adams.html. To begin the search, select ‘‘Begin Web-based ADAMS Search.’’ For problems with ADAMS, please contact the NRC’s Public Document Room (PDR) reference staff at 1–800–397–4209, 301– 415–4737, or by email to PDR.Resource@nrc.gov. The ADAMS accession number for each document referenced (if it is available in ADAMS) is provided the first time that it is mentioned in this document. • NRC’s PDR: You may examine and purchase copies of public documents, by appointment, at the NRC’s PDR, Room P1 B35, One White Flint North, 11555 Rockville Pike, Rockville, Maryland 20852. To make an appointment to visit the PDR, please send an email to PDR.Resource@nrc.gov or call 1–800–397–4209 or 301–415– 4737, between 8:00 a.m. and 4:00 p.m. Eastern Time (ET), Monday through Friday, except Federal holidays. RG 1.247 for trial use and the regulatory analysis may be found in ADAMS under Accession Nos. ML21235A008 and ML21235A010, respectively. Regulatory guides are not copyrighted, and NRC approval is not required to reproduce them. FOR FURTHER INFORMATION CONTACT: Michelle Gonzalez, telephone: 301–415– 5661, email: Michelle.Gonzalez@ nrc.gov, Anders Gilbertson, telephone: 301–415–1541, email: Anders.Gilbertson@nrc.gov, or Harriet Karagiannis, telephone: 301–415–2493, email: Harriet.Karagiannis@nrc.gov. These individuals are staff in the Office of Nuclear Regulatory Research at the U.S. Nuclear Regulatory Commission, Washington, DC 20555–0001. SUPPLEMENTARY INFORMATION: lotter on DSK11XQN23PROD with NOTICES1 I. Background The NRC has issued for trial use this new RG titled, ‘‘Acceptability of Probabilistic Risk Assessment Results for Non-Light Water Reactor RiskInformed Activities,’’ and it is designated as trial use RG 1.247. It describes one acceptable approach for determining whether a design-specific or plant-specific probabilistic risk assessment (PRA) used to support an application is sufficient to provide confidence in the results, such that the PRA can be used in regulatory decisionmaking for non-light water reactors (NLWRs) for implementing the requirements in part 50 and 52 of title 10 of the Code of Federal Regulations (10 CFR). In addition, this trial use RG VerDate Sep<11>2014 17:35 Oct 14, 2022 Jkt 259001 is intended to be consistent with the NRC’s PRA Policy Statement and reflects and endorses, with staff exceptions, national consensus PRA standards provided by standards development organizations and guidance provided by nuclear industry organizations. As a trial use RG, this issuance allows early use prior to general implementation, and the guidance may be revised based on experience obtained by the NRC from the implementation of the trial use RG. The staff is planning to conduct a public meeting by the end of calendar year 2022 to obtain stakeholder feedback on the development of a draft guide, which will be issued at the conclusion of the trial use period, and subsequent final publication of RG 1.247. The NRC will also provide an additional opportunity for formal public comment on the planned draft RG, with feedback considered prior to final RG publication. II. Public Comments This trial use RG was not published for public comment as a draft RG. Trial use RG 1.247 was issued for a 60-day, post-promulgation public comment in the Federal Register on March 24, 2022 (87 FR 16770). Pursuant to 10 CFR 2.804(e), the NRC must publish in the Federal Register an evaluation of any significant comments and describe any revisions made as a result of the comments and their evaluation. The public comment period ended on May 23, 2022, and comments were received from two organizations (Nuclear Energy Institute (NEI) and Xenergy). NEI and X-energy submitted separate comments on the staff endorsement of items HLR–HR–E and HR–E4 from the American Society of Mechanical Engineers (ASME) and American Nuclear Society (ANS) NLWR PRA standard. The staff considers these comments significant to the extent they warrant a response to clarify the record. While the staff is not responding in this notice to the other comments submitted in response to the opportunity to comment the NRC published at 87 FR 16770, the staff will consider those comments in preparing a draft of RG 1.247 for comment or in considering the experience obtained through trial use of RG 1.247. For items HLR–HR–E and HR–E4, the staff takes exceptions to the ASME and ANS NLWR PRA standard regarding the treatment of errors of commission (EOCs) in a PRA. The exceptions provide for consideration of EOCs that result in adverse safety impacts for Compatibility Category I, (CC–I). CC–I defines the minimum capability needed PO 00000 Frm 00114 Fmt 4703 Sfmt 4703 62895 for a PRA element. In contrast, Compatibility Category II (CC–II) defines the minimum capability needed to meet current good practice standards for each PRA element. The comments indicate that these exceptions are not consistent with the current PRA state of practice, which does not call for broad consideration of EOCs for PRAs for LWRs as per the NRC endorsement of HR–E4 in the trial use RG. Thus, the comment contends that broadly considering EOCs goes above and beyond the requirement for the current operating fleet. Although no changes were made to the trial use RG based on these comments, the staff provides a brief discussion on these significant comments. Specifically, the comment recommends that this exception to HR– E4 and the HLR–HR–E be removed from the trial use RG or only be applicable for CC–II of HR–E4, the latter of which would represent good practice as opposed to a minimum capability. Another comment notes that the trial use RG 1.247 includes additional language on the scope of such considerations; however, the comment states that this added language does not maintain consistency with the LWR PRA standard. The comment supports retaining consistency with the LWR PRA standard in the trial use RG 1.247, which would call for removal of this added exception regarding consideration of EOCs in the NLWR PRA standard. The staff is keeping the exceptions related to EOCs in this trial use RG, which is based on the following consideration. The development efforts for the ASME/ANS NLWR PRA standard relied substantially on the development efforts for the next edition of the ASME/ANS Level 1/large early release frequency (LERF) LWR PRA standard and, in many cases, the NLWR PRA standard adopted the same or similar requirements as the next edition of the Level 1/LERF LWR PRA standard. However, the Level 1/LERF LWR PRA standard state of practice relies on significant LWR operating experience that facilitates a consensus to generally exclude EOCs from LWR PRAs, but no similar body of operating experience underlies the NLWR PRA standard. Because there is limited operating experience regarding EOCs for NLWRs and the scope of the ASME/ANS NLWR PRA standard is broader than the scope of the ASME/ANS Level 1/LERF LWR PRA standard, EOCs may play a more important role in NLWR PRA than for LWR PRA and, therefore, NLWR PRA developers will need to demonstrate that EOCs are not an issue before E:\FR\FM\17OCN1.SGM 17OCN1 62896 Federal Register / Vol. 87, No. 199 / Monday, October 17, 2022 / Notices lotter on DSK11XQN23PROD with NOTICES1 eliminating them from consideration. However, the staff also notes that such identification of EOCs is generally expected to apply to a PRA developed for the operational phase of a plant’s lifecycle. This is based on the premise that there is expected to be a general lack of available, relevant information that would allow meaningful identification of EOCs in preoperational stages of a plant’s lifecycle. Related staff guidance on the treatment of such EOCs during pre-operational phases of a plant’s lifecycle is currently under development. A comment states that EOCs are already captured in FHR–A1 at CC–II for fires where operating experience supports consideration of spurious signals. Therefore, the comment notes that the RG 1.247 position on HR–E4 requiring EOCs at CC–I is not internally consistent with the trial use RG position on FHR–A1 requiring EOCs only at CC– II. The comment also states that, for non-fire hazards, spurious signals should occur with low frequency and would require significant operator error due to the redundancy of information available to the operator. The staff notes that, while the consideration of spurious signals as a potential cause of an EOC is important and spurious signals may occur due to fire damage, such spurious signals are not the only reason an EOC may occur. NUREG–1880, ‘‘ATHEANA User’s Guide,’’ (ADAMS Accession No. ML072130359) recommends searching for potential EOCs and the contexts that could cause them. However, while the staff maintains that other sources of EOCs should be considered for identification in CC–I of FHR–A1, the staff did not intend for new, undesired operator actions that could result from spurious indications from fire-induced failure of a single instrument to be identified to meet CC–I of FHR–A1. The staff would therefore not call for such identification as part of meeting the trial use RG. The staff notes that while the comment characterizes the staff positions as ‘‘requirements,’’ no regulatory guide establishes requirements. Rather, the exceptions and clarifications in a regulatory guide are guidance to an applicant stating elements of an acceptable method for complying with NRC regulations. Dated: October 12, 2022. For the Nuclear Regulatory Commission. Meraj Rahimi, Chief, Regulatory Guide and Programs Management Branch, Division of Engineering, Office of Nuclear Regulatory Research. [FR Doc. 2022–22536 Filed 10–14–22; 8:45 am] BILLING CODE 7590–01–P VerDate Sep<11>2014 17:35 Oct 14, 2022 Jkt 259001 POSTAL REGULATORY COMMISSION [Docket Nos. MC2023–13 and CP2023–12] New Postal Products Postal Regulatory Commission. Notice. AGENCY: ACTION: The Commission is noticing a recent Postal Service filing for the Commission’s consideration concerning a negotiated service agreement. This notice informs the public of the filing, invites public comment, and takes other administrative steps. DATES: Comments are due: October 19, 2022. ADDRESSES: Submit comments electronically via the Commission’s Filing Online system at https:// www.prc.gov. Those who cannot submit comments electronically should contact the person identified in the FOR FURTHER INFORMATION CONTACT section by telephone for advice on filing alternatives. SUMMARY: FOR FURTHER INFORMATION CONTACT: David A. Trissell, General Counsel, at 202–789–6820. SUPPLEMENTARY INFORMATION: Table of Contents I. Introduction II. Docketed Proceeding(s) I. Introduction The Commission gives notice that the Postal Service filed request(s) for the Commission to consider matters related to negotiated service agreement(s). The request(s) may propose the addition or removal of a negotiated service agreement from the market dominant or the competitive product list, or the modification of an existing product currently appearing on the market dominant or the competitive product list. Section II identifies the docket number(s) associated with each Postal Service request, the title of each Postal Service request, the request’s acceptance date, and the authority cited by the Postal Service for each request. For each request, the Commission appoints an officer of the Commission to represent the interests of the general public in the proceeding, pursuant to 39 U.S.C. 505 (Public Representative). Section II also establishes comment deadline(s) pertaining to each request. The public portions of the Postal Service’s request(s) can be accessed via the Commission’s website (https:// www.prc.gov). Non-public portions of the Postal Service’s request(s), if any, can be accessed through compliance PO 00000 Frm 00115 Fmt 4703 Sfmt 4703 with the requirements of 39 CFR 3011.301.1 The Commission invites comments on whether the Postal Service’s request(s) in the captioned docket(s) are consistent with the policies of title 39. For request(s) that the Postal Service states concern market dominant product(s), applicable statutory and regulatory requirements include 39 U.S.C. 3622, 39 U.S.C. 3642, 39 CFR part 3030, and 39 CFR part 3040, subpart B. For request(s) that the Postal Service states concern competitive product(s), applicable statutory and regulatory requirements include 39 U.S.C. 3632, 39 U.S.C. 3633, 39 U.S.C. 3642, 39 CFR part 3035, and 39 CFR part 3040, subpart B. Comment deadline(s) for each request appear in section II. II. Docketed Proceeding(s) 1. Docket No(s).: MC2023–13 and CP2023–12; Filing Title: USPS Request to Add Priority Mail Express, Priority Mail, First-Class Package Service & Parcel Select Contract 65 to Competitive Product List and Notice of Filing Materials Under Seal; Filing Acceptance Date: October 11, 2022; Filing Authority: 39 U.S.C. 3642, 39 CFR 3040.130 through 3040.135, and 39 CFR 3035.105; Public Representative: Kenneth R. Moeller; Comments Due: October 19, 2022. This Notice will be published in the Federal Register. Erica A. Barker, Secretary. [FR Doc. 2022–22489 Filed 10–14–22; 8:45 am] BILLING CODE 7710–FW–P POSTAL REGULATORY COMMISSION [Docket No. R2023–1; Order No. 6296] Market Dominant Price Adjustment Postal Regulatory Commission. Notice. AGENCY: ACTION: The Commission is recognizing a recently filed Postal Service notice of inflation-based rate adjustments affecting market dominant domestic and international products and services, along with proposed classification changes. This notice informs the public of the filing, invites public comment, and takes other administrative steps. DATES: Comments are due: November 7, 2022. SUMMARY: 1 See Docket No. RM2018–3, Order Adopting Final Rules Relating to Non-Public Information, June 27, 2018, Attachment A at 19–22 (Order No. 4679). E:\FR\FM\17OCN1.SGM 17OCN1

Agencies

[Federal Register Volume 87, Number 199 (Monday, October 17, 2022)]
[Notices]
[Pages 62894-62896]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-22536]


-----------------------------------------------------------------------

NUCLEAR REGULATORY COMMISSION

[NRC-2022-0052]


Acceptability of Probabilistic Risk Assessment Results for Non-
Light Water Reactor Risk-Informed Activities

AGENCY: Nuclear Regulatory Commission.

ACTION: Regulatory guide for trial use; response to comments.

-----------------------------------------------------------------------

SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is addressing 
comments received after issuing for public comment on the trial use of 
the new regulatory guide (RG) 1.247, ``Acceptability of Probabilistic 
Risk Assessment Results for Non-Light Water Reactor Risk-Informed 
Activities.'' The NRC will not make any changes to the RG as a result 
of these comments.

DATES: The public comment period for RG 1.247 ended on May 23, 2022.

ADDRESSES: Please refer to Docket ID NRC-2022-0052 when contacting the 
NRC about the availability of information regarding this document. You 
may obtain publicly available information related to this document 
using any of the following methods:
     Federal Rulemaking Website: Go to https://www.regulations.gov and search for Docket ID NRC-2022-0052. Address 
questions about Docket IDs in Regulations.gov to Stacy Schumann; 
telephone: 301-415-0624; email: [email protected]. For technical 
questions, contact the individuals listed in the FOR FURTHER 
INFORMATION CONTACT section of this document.
     NRC's Agencywide Documents Access and Management System

[[Page 62895]]

(ADAMS): You may obtain publicly available documents online in the 
ADAMS Public Documents collection at https://www.nrc.gov/reading-rm/adams.html. To begin the search, select ``Begin Web-based ADAMS 
Search.'' For problems with ADAMS, please contact the NRC's Public 
Document Room (PDR) reference staff at 1-800-397-4209, 301-415-4737, or 
by email to [email protected]. The ADAMS accession number for each 
document referenced (if it is available in ADAMS) is provided the first 
time that it is mentioned in this document.
     NRC's PDR: You may examine and purchase copies of public 
documents, by appointment, at the NRC's PDR, Room P1 B35, One White 
Flint North, 11555 Rockville Pike, Rockville, Maryland 20852. To make 
an appointment to visit the PDR, please send an email to 
[email protected] or call 1-800-397-4209 or 301-415-4737, between 
8:00 a.m. and 4:00 p.m. Eastern Time (ET), Monday through Friday, 
except Federal holidays.
    RG 1.247 for trial use and the regulatory analysis may be found in 
ADAMS under Accession Nos. ML21235A008 and ML21235A010, respectively.
    Regulatory guides are not copyrighted, and NRC approval is not 
required to reproduce them.

FOR FURTHER INFORMATION CONTACT: Michelle Gonzalez, telephone: 301-415-
5661, email: [email protected], Anders Gilbertson, telephone: 
301-415-1541, email: [email protected], or Harriet Karagiannis, 
telephone: 301-415-2493, email: [email protected]. These 
individuals are staff in the Office of Nuclear Regulatory Research at 
the U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001.

SUPPLEMENTARY INFORMATION:

I. Background

    The NRC has issued for trial use this new RG titled, 
``Acceptability of Probabilistic Risk Assessment Results for Non-Light 
Water Reactor Risk-Informed Activities,'' and it is designated as trial 
use RG 1.247. It describes one acceptable approach for determining 
whether a design-specific or plant-specific probabilistic risk 
assessment (PRA) used to support an application is sufficient to 
provide confidence in the results, such that the PRA can be used in 
regulatory decision-making for non-light water reactors (NLWRs) for 
implementing the requirements in part 50 and 52 of title 10 of the Code 
of Federal Regulations (10 CFR). In addition, this trial use RG is 
intended to be consistent with the NRC's PRA Policy Statement and 
reflects and endorses, with staff exceptions, national consensus PRA 
standards provided by standards development organizations and guidance 
provided by nuclear industry organizations. As a trial use RG, this 
issuance allows early use prior to general implementation, and the 
guidance may be revised based on experience obtained by the NRC from 
the implementation of the trial use RG.
    The staff is planning to conduct a public meeting by the end of 
calendar year 2022 to obtain stakeholder feedback on the development of 
a draft guide, which will be issued at the conclusion of the trial use 
period, and subsequent final publication of RG 1.247. The NRC will also 
provide an additional opportunity for formal public comment on the 
planned draft RG, with feedback considered prior to final RG 
publication.

II. Public Comments

    This trial use RG was not published for public comment as a draft 
RG. Trial use RG 1.247 was issued for a 60-day, post-promulgation 
public comment in the Federal Register on March 24, 2022 (87 FR 16770). 
Pursuant to 10 CFR 2.804(e), the NRC must publish in the Federal 
Register an evaluation of any significant comments and describe any 
revisions made as a result of the comments and their evaluation.
    The public comment period ended on May 23, 2022, and comments were 
received from two organizations (Nuclear Energy Institute (NEI) and X-
energy). NEI and X-energy submitted separate comments on the staff 
endorsement of items HLR-HR-E and HR-E4 from the American Society of 
Mechanical Engineers (ASME) and American Nuclear Society (ANS) NLWR PRA 
standard. The staff considers these comments significant to the extent 
they warrant a response to clarify the record. While the staff is not 
responding in this notice to the other comments submitted in response 
to the opportunity to comment the NRC published at 87 FR 16770, the 
staff will consider those comments in preparing a draft of RG 1.247 for 
comment or in considering the experience obtained through trial use of 
RG 1.247.
    For items HLR-HR-E and HR-E4, the staff takes exceptions to the 
ASME and ANS NLWR PRA standard regarding the treatment of errors of 
commission (EOCs) in a PRA. The exceptions provide for consideration of 
EOCs that result in adverse safety impacts for Compatibility Category 
I, (CC-I). CC-I defines the minimum capability needed for a PRA 
element. In contrast, Compatibility Category II (CC-II) defines the 
minimum capability needed to meet current good practice standards for 
each PRA element. The comments indicate that these exceptions are not 
consistent with the current PRA state of practice, which does not call 
for broad consideration of EOCs for PRAs for LWRs as per the NRC 
endorsement of HR-E4 in the trial use RG. Thus, the comment contends 
that broadly considering EOCs goes above and beyond the requirement for 
the current operating fleet. Although no changes were made to the trial 
use RG based on these comments, the staff provides a brief discussion 
on these significant comments.
    Specifically, the comment recommends that this exception to HR-E4 
and the HLR-HR-E be removed from the trial use RG or only be applicable 
for CC-II of HR-E4, the latter of which would represent good practice 
as opposed to a minimum capability. Another comment notes that the 
trial use RG 1.247 includes additional language on the scope of such 
considerations; however, the comment states that this added language 
does not maintain consistency with the LWR PRA standard. The comment 
supports retaining consistency with the LWR PRA standard in the trial 
use RG 1.247, which would call for removal of this added exception 
regarding consideration of EOCs in the NLWR PRA standard.
    The staff is keeping the exceptions related to EOCs in this trial 
use RG, which is based on the following consideration. The development 
efforts for the ASME/ANS NLWR PRA standard relied substantially on the 
development efforts for the next edition of the ASME/ANS Level 1/large 
early release frequency (LERF) LWR PRA standard and, in many cases, the 
NLWR PRA standard adopted the same or similar requirements as the next 
edition of the Level 1/LERF LWR PRA standard. However, the Level 1/LERF 
LWR PRA standard state of practice relies on significant LWR operating 
experience that facilitates a consensus to generally exclude EOCs from 
LWR PRAs, but no similar body of operating experience underlies the 
NLWR PRA standard.
    Because there is limited operating experience regarding EOCs for 
NLWRs and the scope of the ASME/ANS NLWR PRA standard is broader than 
the scope of the ASME/ANS Level 1/LERF LWR PRA standard, EOCs may play 
a more important role in NLWR PRA than for LWR PRA and, therefore, NLWR 
PRA developers will need to demonstrate that EOCs are not an issue 
before

[[Page 62896]]

eliminating them from consideration. However, the staff also notes that 
such identification of EOCs is generally expected to apply to a PRA 
developed for the operational phase of a plant's lifecycle. This is 
based on the premise that there is expected to be a general lack of 
available, relevant information that would allow meaningful 
identification of EOCs in pre-operational stages of a plant's 
lifecycle. Related staff guidance on the treatment of such EOCs during 
pre-operational phases of a plant's lifecycle is currently under 
development.
    A comment states that EOCs are already captured in FHR-A1 at CC-II 
for fires where operating experience supports consideration of spurious 
signals. Therefore, the comment notes that the RG 1.247 position on HR-
E4 requiring EOCs at CC-I is not internally consistent with the trial 
use RG position on FHR-A1 requiring EOCs only at CC-II. The comment 
also states that, for non-fire hazards, spurious signals should occur 
with low frequency and would require significant operator error due to 
the redundancy of information available to the operator.
    The staff notes that, while the consideration of spurious signals 
as a potential cause of an EOC is important and spurious signals may 
occur due to fire damage, such spurious signals are not the only reason 
an EOC may occur. NUREG-1880, ``ATHEANA User's Guide,'' (ADAMS 
Accession No. ML072130359) recommends searching for potential EOCs and 
the contexts that could cause them. However, while the staff maintains 
that other sources of EOCs should be considered for identification in 
CC-I of FHR-A1, the staff did not intend for new, undesired operator 
actions that could result from spurious indications from fire-induced 
failure of a single instrument to be identified to meet CC-I of FHR-A1. 
The staff would therefore not call for such identification as part of 
meeting the trial use RG. The staff notes that while the comment 
characterizes the staff positions as ``requirements,'' no regulatory 
guide establishes requirements. Rather, the exceptions and 
clarifications in a regulatory guide are guidance to an applicant 
stating elements of an acceptable method for complying with NRC 
regulations.

    Dated: October 12, 2022.

    For the Nuclear Regulatory Commission.
Meraj Rahimi,
Chief, Regulatory Guide and Programs Management Branch, Division of 
Engineering, Office of Nuclear Regulatory Research.
[FR Doc. 2022-22536 Filed 10-14-22; 8:45 am]
BILLING CODE 7590-01-P
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