ML23192A534

DG-3057 (RG 3.77 Rev 0) Responses to Public Comments

ML23192A534
Person / Time
Issue date:	09/21/2023
From:	Jeremy Tapp NRC/NMSS/DFM/IOB
To:
Harriet Karagiannis 301-437-2799
Shared Package
ML23192A530	List: ML23192A532 ML23192A534
References
RG-3.077, Rev 0 DG-3057
Download: ML23192A534 (27)

Text

Response to Public Comments on Draft Regulatory Guide DG-3057, Weather-Related Administrative Controls at Independent Spent Fuel Storage Installations Proposed New Regulatory Guide 3.77 On June 5, 2023, the U.S. Nuclear Regulatory Commission (NRC) published a notice in Volume 88 of the Federal Register (FR)

(88 FR 36514) announcing the availability for public comment of Draft Regulatory Guide (DG)-3057, Weather-Related Administrative Controls at Independent Spent Fuel Storage Installations, for proposed new Regulatory Guide (RG) 3.77. The public comment period ended on July 5, 2023. The NRC received comments from the individuals and organizations listed below. The comment documents are available in the NRCs Agencywide Documents Access and Management System at the accession numbers given.

Mr. Peter Hager Mr. Rod McCullum Mr. John Macdonald, ISFSI Manager Kailua, HI 96734 Nuclear Energy Institute, Yankee Atomic Electric Company Email: hagerpmil@gmail.com 1201 F Street, NW, Suite 1100, 49 Yankee Road, Rowe, MA 01367 ML23167A354 Washington, DC 20004 Telephone: (413) 424-5261, extension Telephone: (202) 739-082 304 Email: rxm@nei.org Email: sday@3yankees.com ML23181A029 ML23181A030 Mr. Rob Desmarais, ISFSI Manager Mr. Dan Laing, ISFSI Manager Ms. Kimberly Manzione Connecticut Yankee Atomic Power Maine Yankee Atomic Power Company Holtec Technology Campus Company Maine Yankee Independent Spent Fuel One Holtec Blvd, Camden, NJ 08104 Haddam Neck Plant Independent Spent Storage Installation Telephone: (856) 797-0900 Fuel Storage Installation 21 Old Ferry Road, Wiscasset, ME Email: k.manzione@holtec.com 362 Injun Hollow Rd, East Hampton, CT 04578 ML23188A012 06424-3099 Telephone: (207) 882-1303 Telephone: (860) 267-6426, extension 306 Email: sday@3yankees.com Email: sday@3yankees.com ML23181A032 ML23181A031 T. Forland Ameren MissouriCallaway Plant Email: tforland@Ameren.com ML23186A020

Response to Public Comments on Draft Regulatory Guide (DG)-3057 NRC Comment Commenter Text of Comment NRC Resolution ID # Number 1 Peter Hager General comment The infostructure of our solid The subject and content of this comment do not pertain to waste incinerations units and DG-3057. No changes were made to the final regulatory small municipal waste units guide in response to the comment.

need to [be] versatile in the sense that support the amount of waste going in and they allow the plants to better combat the emissions produced from them.

Environmental protection, administrative practice and procedure, Air pollution control, Hazardous substances, Intergovernmental relations should all be reviewed in order to effectively reduce the emissions.

2 Rod Comment 1 On Page 2 of the Regulatory The NRC staff agrees in part with this comment.

McCullum Analysis, in the Second (Comments Paragraph under Alternative 1, The NRC staff has identified multiple instances of 1-4 from NRC states that Many noncompliance regarding the use of administrative cover letter) licensees are currently using controls in lieu of engineering analysis in contradiction to administrative controls in the licensees design bases to meet regulatory contradiction to their design requirements. This is evident as multiple instances of bases to meet regulatory enforcement discretion have been issued under the requirements under the provisions of EGM 22-01, Enforcement Discretion for enforcement discretion Noncompliance of Tornado Hazards Protection provided by EGM Requirements at Independent Spent Fuel Storage

[Enforcement Guidance Installations.

Memorandum] 22-01. This is a broad generalization and Three instances of past precedent were identified by the should be removed. Industry commenter (comment ID number 3) regarding the use of believes it has consistently administrative controls in lieu of engineering analysis.

been in compliance with the This includes two consolidated interim storage facilities 2

Response to Public Comments on Draft Regulatory Guide (DG)-3057 requirements in its respective that have not been constructed and a certificate of DSS [dry storage system] compliance (CoC) that has recently been issued.

FSARs [final safety analysis statements] and 10 CFR To reduce the broad generalization and subjectivity of the 72.212(b)(6). We believe that language in the regulatory analysis, the staff revised the this disagreement stems from sentence to remove the term many. No changes were a lack of clarity regarding the made to the final regulatory guide as no similar use of administrative controls statements were made in it.

in accordance with the design bases. Incorporation of our attached comments will resolve this uncertainty.

3 Rod Comment 2 In a public meeting held on See responses to comment ID numbers 7 through 13.

McCullum June 13, the NRC staff explained the interconnected nature of Clarifications #3, #4, and #5. We agree that these clarifications have a combined effect, and we are very concerned that this effect could undermine the regulatory certainty that the completed Regulatory Guide would otherwise provide. These three clarifications expand the scope of the guidance in a way that will introduce new uncertainties going forward and deviate from established licensing precedent (footnote 2Interim Storage Partners license SNM-2515, issued September 13, 2021; Holtec license SNM-2516, issued May 9, 2023, and Orano-TN EOS CoC Amendment 3, to become effective July 17, 2023). The added language is both 3

Response to Public Comments on Draft Regulatory Guide (DG)-3057 prescriptive (calling for licensees to perform substantial additional analyses of system performance during a wide range of weather events) and vague (using undefined terms like appropriate error margin).

This expansion in scope goes beyond both what was intended when the DSSs were licensed and the focus on severe weather events (tornadoes, in particular) in related inspections that provided the impetus for this issue. Our detailed comments elaborate on this concern and recommend that these 3 clarifications be deleted.

4 Rod Comment 3 We remain confident that DG- The NRC staff agrees with the comment.

McCullum 3057 can be finalized in a way that will restore regulatory The NRC staff recognizes and agrees that the period stability and predictability to between the public release date of the final regulatory DSS ODHAs [outdoor dry guide and the expiration of EGM 22-01 should be storage system handling appropriate to ensure that needed regulatory activities] and improve improvements, and any corresponding actions on the part efficiency. We look forward to of licensees, can be implemented before the expiration of finalization of RG 3.77 in the EGM 22-01 in April 2024. The NRC staff will evaluate the 4th quarter of 2023 so that the extension of EGM 22-01 as appropriate.

needed regulatory improvements, and any No changes were made to the final regulatory guide in corresponding actions on the response to the comment.

part of licensees, can be implemented prior to the expiration of EGM 22-01 in April 2024. Because a number of licensees plan loading 4

Response to Public Comments on Draft Regulatory Guide (DG)-3057 campaigns in 2024 that could be affected by this guidance, NRC should consider allowing an implementation period for RG 3.77 and, if necessary, extending the date of EGM 22-01 until the end of that period.

5 Rod Comment 4 We also request that NRC The NRC staff agrees with the comment.

McCullum inspection procedures associated with RG 3.77 be During the next routine review of independent spent fuel updated and shared with the storage installation (ISFSI) inspection procedures, the industry to enhance the staff plans to revise the appropriate inspection procedures licensees understanding of to enhance the guidance for reviewing licensee/CoC NRC expectations and to holder compliance with Title 10 of the Code of Federal ensure regulatory compliance. Regulations (10 CFR) 72.122 or 10 CFR 72.236 accordingly, as it relates to issuance and use of RG 3.77.

No changes were made to the final regulatory guide in response to the comment.

6 Rod Item 2 The guidance addresses all The NRC staff agrees with the comment.

McCullum Exception: outdoor DCS [dry cask Lastly, the storage] activities. The state of This guidance should be applicable in all situations, guidance only the canister and cask at any including those rare situations in which site-specific applies to a DSS time while outdoors is a site- conditions do not allow for the confinement boundary to when the DSSs specific issue each licensee be established before the DSS leaves the reactor facility confinement should consider in for a short duration. The NRC oversight program allows boundary has implementing the guidance, for the evaluation of these situations to ensure all been established including in rare short-duration regulatory requirements are met.

as required by its situations where the licensing basis. confinement boundary has not In response to the comment, the staff removed the yet been established. Since following sentence from the exception in item 2, section C there are situations in which of DG-3057 from the final RG 3.77, as recommended:

the confinement boundary has not yet been established during Lastly, the guidance only applies to a DSS when which ODHAs must be the DSSs confinement boundary has been protected by the use of established as required by its licensing basis.

administrative controls, this 5

Response to Public Comments on Draft Regulatory Guide (DG)-3057 guidance should not be limited to apply only in cases where the confinement boundary is established.

NEI Recommended ResolutionDelete the sentence.

7 Rod Comments 7 The combined effect of The NRC staff agrees that the clarifications in items 3, 4, McCullum through 13 are Clarifications 3, 4, and 5 is to and 5 of DG-3057 expand the definition of safe condition taken from one greatly expand the definition of and forecast beyond that included in NEI 22-02 Revision comment safe condition and forecast to 2, but such expansion of the definition is necessary to regarding Item include a wide range of ensure that an SSC is not placed in a configuration that 3Clarification, conditions that would exceed would exceed the SSCs design criteria. As described in Item 4 an SSCs [structure, system, or the final RG 3.77, 10 CFR 72.122(b) requires that SSCs Clarification, and components] design criteria. important to safety (ITS) be designed to accommodate Item 5 This significantly, in turn, the effects of, and to be compatible with, site Clarification: expands the scope of the characteristics and environmental conditions associated Industry concerns guidance. with normal operation, maintenance, and testing of regarding the the ISFSI or MRS [monitored retrievable storage] and regulatory to withstand postulated accidents (emphasis added).

uncertainty likely Similarly, 10 CFR 72.236(l) states that SSCs ITS must to be created by be evaluated, by appropriate tests or by other means the combined acceptable to the NRC, to demonstrate that they will effect of these reasonably maintain confinement of radioactive material three clarifications under normal, off-normal, and credible accident conditions (emphasis added). Accordingly, 10 CFR 72.122 and 10 CFR 72.236 also include requirements for normal and off-normal conditions. Without modification of the definition of safe condition and forecast, the guidance would not be applicable for licensees to use with the emphasized portion of the regulatory requirements when implementing administrative controls because the definition in Nuclear Energy Institute (NEI) 22-02, Revision 2, Guidelines for Weather-Related Administrative Controls for Short Duration Outdoor Dry Cask Storage Operations, issued November 2022, only references accident conditions. Expansion of the definition thus also allows for the use of this guidance as 6

Response to Public Comments on Draft Regulatory Guide (DG)-3057 one method of demonstrating compliance with the emphasized portion of the regulatory requirements.

No changes were made to the final regulatory guide in response to the comment.

8 Rod Item 3 This clarification has been The NRC staff agrees, in part, with this comment. While McCullum Clarification, written as an overly the NRC staff disagrees that the guidance is overly Item 4 prescriptive task which will be prescriptive, difficult, or impossible to complete, based Clarification, and difficult, if not impossible, to upon the comment provided and further consideration, the Item 5 complete. staff believes that the language in the guidance related to Clarification: this comment may be too specific given the wide scope Industry concerns of potential SSCs to be evaluated and site-specific regarding the environmental conditions. The staff believes that the CoC regulatory holders or licensees design control program provides an uncertainty likely adequate process to determine a safe condition and to be created by forecast based upon the NRCs clarification of the the combined definition. Accordingly, the staff have removed the effect of these clarification in item 5, section C of DG-3057 from the final three clarifications RG 3.77.

9 Rod Item 3 It could cause licensees to The staff agrees, in part, with this comment. While the McCullum Clarification, chase information about things NRC staff disagrees that the language could cause Item 4 such as projected barometric licensees to chase information about things such as Clarification, and pressures and monitoring barometric pressure, in the final regulatory guide, the staff Item 5 weather below the threshold of clarified the definition of safe condition and forecast as Clarification: severe weather. follows:

Industry concerns regarding the A safe condition and forecast is considered to regulatory be the absence of (1) forecasted weather for uncertainty likely wind speeds (gusts or sustained) that could to be created by exceed an SSCs ITS design criteria and (2) a the combined hazardous weather outlook indicating a risk of effect of these severe storms that could generate at the site, three clarifications for example, tornado winds, missiles, or pressure differentials, or hurricane winds or missiles, that could exceed an SSCs ITS design criteria, for the expected duration of the ODHA.

7

Response to Public Comments on Draft Regulatory Guide (DG)-3057 The definition identifies that wind speeds (gusts or sustained) that are used in determining wind loading or equipment operability limits should be reviewed for forecasted weather that could exceed an SSCs ITS design criteria, but it does not include barometric pressure as a criterion to be evaluated for determining a safe condition and forecast.

Further, the staffs revised definition implies that tornado pressure differentials are covered by the acceptance criteria associated with a hazardous weather outlook.

Therefore, barometric pressure differentials are not identified as a characteristic that specifically needs to be assessed.

10 Rod Item 3 Additional monitoring of things The NRC staff disagrees with this comment and notes McCullum Clarification, below the threshold or below that monitoring of these conditions is required to ensure Item 4 other bounding conditions compliance with the regulations. The staff has specifically Clarification, and would be an unnecessary identified wind speed (gusts and sustained winds) as Item 5 burden that would divert specific parameters that should be evaluated for normal Clarification: resources away from more and off-normal conditions. The NWS provides a 48-hour Industry concerns safety significant tasks. This hourly forecast graph for wind speed, including gusts that regarding the could then cause licensees to may be used by the licensees. Checking this forecast regulatory have to go beyond the NWS should take a minimal amount of time (under 5 minutes) uncertainty likely [National Weather Service] before the start of operation.

to be created by severe weather alert system as the combined a resource. No changes were made to the final regulatory guide in effect of these response to the comment.

three clarifications 11 Rod Item 3 This will subsequently trigger The NRC staff disagrees with this comment. The staff McCullum Clarification, extensive design reviews recognizes that licensees or CoC holders may need to Item 4 based on this inevitably perform evaluations to determine a safe condition and Clarification, and uncertain population of forecast for some SSCs ITS. However, as highlighted in Item 5 information. A significant level the regulatory analysis for the first alternative, instead of Clarification: of effort will be required to using administrative controls, absent established and 8

Response to Public Comments on Draft Regulatory Guide (DG)-3057 Industry concerns conduct these reviews. Again, specifically licensed alternatives, the SSCs are required regarding the this will place an inordinate to demonstrate through engineering analyses that they regulatory focus on items of little to no are capable of withstanding effects such as weather-uncertainty likely safety significance and further related wind and tornado natural phenomena without to be created by divert resources from more impairing their capability to perform their intended design the combined safety significant tasks. Most functions. Such analyses, as well as the potential need to effect of these significantly, these design modify SSCs ITS to demonstrate compliance with three clarifications reviews would be of little to no 10 CFR 72.122(b) and 10 CFR 72.236(l) through use towards meeting the engineering analysis, requires a more significant level of intended purpose of this effort, with minor safety benefit. Therefore, the NRC guidance. believes that the level of evaluation required to use administrative controls in accordance with the regulatory guide is appropriate.

No changes were made to the final regulatory guide in response to the comment.

12 Rod Item 3 This is because ensuring The NRC staff agrees that the purpose of the guidance is McCullum Clarification, weather conditions and to avoid operation during severe weather; however, the Item 4 forecast would not exceed staff reiterates that unless the licensee or CoC holder Clarification, and design criteria does not evaluates what level of normal, off-normal, or accident Item 5 address the time when these conditions exceed the design basis of the SSC, the Clarification: cask systems would be in definition of severe weather cannot be correctly Industry concerns unanalyzed outdoor established.

regarding the configurations, i.e., when the regulatory limiting criteria are unknown, The staff has added detail to the clarification in item 4 of uncertainty likely for example, a storage cask the final regulatory guide to describe and provide an to be created by being carried by a transporter example of the expectations of how to determine a safe the combined (that may be NITS [not condition and forecast.

effect of these important to safety]), or a three clarifications storage cask without its lid. It is unclear how design criteria based on a prescribed configuration for a cask system can be extrapolated to an unanalyzed configuration to determine the triggers for weather conditions and outlooks. The purpose of the 9

Response to Public Comments on Draft Regulatory Guide (DG)-3057 guidance is to avoid operations during severe weather, not to confirm and re-evaluate every design basis parameter that could be affected by any kind of weather. The search to do this would inevitably become open-ended and, absent any limiting principle, the extent to which it will have been completed would be subject to differing interpretations between and amongst licensees and NRC inspectors.

13 Rod Item 3 In accordance with 10 CFR The NRC staff disagrees with this comment.

McCullum Clarification, 72.212(b)(6), licensees must Item 4 comply with operating limits The regulation in 10 CFR 72.212(b)(6) states that the Clarification, and associated with normal and off general licensee must review the safety analysis report Item 5 normal conditions established referenced in the CoC or amended CoC and the related Clarification: in the cask FSAR. It should be NRC safety evaluation report before using the general Industry concerns noted that NRC did not ask for license, to determine whether or not the reactor site regarding the the prescriptive design reviews parameters, including analyses of earthquake intensity regulatory called for in this clarification and tornado missiles, are enveloped by the cask design uncertainty likely when staff approved the bases considered in these reports. The results of this to be created by FSARs. To essentially require review must be documented in the evaluation made in the combined them now in operationally 10 CFR 72.212(b)(5).

effect of these focused guidance would three clarifications constitute a backfit. Before The staff reiterates that NUREG-2215, Standard Review issuing these clarifications, Plan for Spent Fuel Dry Storage Systems and Facilities NRC must thoroughly weigh Final Report, issued April 2020, contains the current the potential resources licensing guidance for weather-related protection required against the safety contained within DSS FSARs.

benefits that would be gained.

NUREG-2215 Section 4.5.3.3.3, states the following:

The NRC does not accept the presumption that there will be sufficient warning of tornadoes so that operations, such as transfer between the 10

Response to Public Comments on Draft Regulatory Guide (DG)-3057 fuel transfer facility and storage site, may never be exposed to tornado effects Ensure that the SAR shows that the cask system will continue to perform its intended safety functions (i.e., criticality, radioactive material release, heat removal, radiation exposure, and retrievability).

Based upon the discussion above, in prior instances, the staff reviewed evaluations that demonstrated, by engineering analysis, that SSCs ITS would continue to perform their intended safety functions during the maximum credible accident loads (i.e., simultaneous tornado missile, pressure, and wind).

Based upon this evaluation performed in the FSAR, applicants were able to demonstrate that the SSCs would be able to withstand a tornado accident, which in most scenarios bounds all normal, off-normal, and accident environmental conditions. Therefore, normal, and off-normal winds did not need to be analyzed in the FSAR in terms of the ability of the SSC to withstand structural environmental loading.

However, when a licensee uses administrative controls for ODHAs, the licensee is no longer reliant upon the bounding accident analysis evaluation to ensure compliance with 10 CFR 72.212(b)(6), which in turn was generally relied upon to demonstrate compliance with 10 CFR 72.122. Accordingly, the licensee must ensure compliance with 10 CFR 72.122 for the entire scope of the regulatory requirements, including normal and off-normal environmental conditions.

No changes were made to the final regulatory guide in response to the comment.

11

Response to Public Comments on Draft Regulatory Guide (DG)-3057 14 Rod Item 5 It is not clear what is meant by The NRC staff agrees with the comment.

McCullum Clarification: In an appropriate error margin in this determination, the context of the paragraph. The staff recognizes that the evaluation performed to forecast conditions NEI Recommended identify a safe condition and forecast will, in nature, should provide a Resolution: include conservative engineering evaluation practices.

conservative Although we are Therefore, including additional margin with the threshold, recommending that acceptance criteria for a safe condition and forecast is including an Clarification 5 be deleted, we redundant and unnecessary.

appropriate error are making this comment to margin, to ensure highlight the regulatory With the removal of the clarification in item 5, section C of that SSCs ITS are uncertainty that would be the DG-3057 from the final RG 3.77 based on comment not subjected to introduced by the open-ended ID number 8, this comment is resolved.

any load expansion of the scope of this combinations guidance.

beyond those analyzed.

15 Rod Item 5 The terms qualitative or The NRC staff agrees with the comment.

McCullum Clarification: quantitative and quantitative From the load and qualitative are used With the removal of the clarification in item 5, section C of conditions, the interchangeably. This is the DG-3057 from the final RG 3.77 based on comment qualitative or confusing and inconsistent with ID number 8, this comment is resolved.

quantitative the regulatory and licensing criteria that precedent upon which the define/outline a definition of safe condition and safe condition and forecast is based.

forecast should NEI Recommended be determined. Resolution:

These criteria will Although we are form the recommending in the comment acceptance above that Clarification 5 be criteria of the deleted, we make this procedure comment to emphasize the establishing importance of maintaining the administrative established licensing control. precedent. The term quantitative or qualitative AND acceptance criteria is based on 10 CFR 72.150. This term has 12

Response to Public Comments on Draft Regulatory Guide (DG)-3057 Based upon the been used in the definition of licensees review safe condition and forecast described above, that NRC approved in the licensee Reference. To avoid any should determine possible misunderstanding, quantitative and NRC should consistently use qualitative quantitative or qualitative acceptance acceptance criteria, to be criteria. consistent with the regulation.

The definition in NEI 22-02 is verbatim the same as the referenced precedents.

16 Rod Item 6 The NRCs clarification to the The NRC staff agrees with the comment.

McCullum Clarification: statement adds and forecast, Licensees should but it also deletes for the site The staff agrees that hazardous weather outlook and use the NWSs and retains that can be forecast information should be reviewed specifically for hazardous justified as providing This is the ISFSI site.

weather outlook an important distinction (that) and forecast industry needs. If a licensee The staff has revised the clarification in item 5 of the final information unless sees a severe weather alert in RG 3.77.

another resource the region, but it does not for the site is include the site, they need the available that flexibility to make a site-provides appropriate decision to move equivalent forward. In addition, the closest information in NWS station to an ISFSI site terms of timeliness may not represent the weather and accuracy. at the site as accurately as other sources. The NWS often provides a forecast based on data from the closest airport, which may not be near the site.

NEI Recommended Resolution:

We suggest a simpler clarification that recognizes licensees may also use forecasts that are more 13

Response to Public Comments on Draft Regulatory Guide (DG)-3057 representative of local conditions if such forecasts can be shown to provide equivalent (or better) weather information for the site than NWS.

17 Rod Item 7 Industry believes that The NRC staff agrees with the comment.

McCullum Clarification: The benchmarking or dry runs is licensee should too restrictive. These activities The staff believes that relevant operating experience determine the are largely site-specific when should be part of the clarification and has revised it in the expected duration plant locations and facilities are final RG 3.77.

of short duration layered on the generic outdoor activities operations described in the by either DSS FSAR. The most accurate benchmarking or estimate of ODHA durations is dry runs. The site operating experience.

ODHA duration NEI Recommended should be Resolution: Add site periodically operating experience to assessed based benchmarking or dry runs.

upon operating experience.

18 Rod Item 8 The premise of this exception The NRC staff agrees in part with the comment.

McCullum Exception: is that malfunctions and severe Licensees should weather would occur at the The staff agrees that for the application of this guidance, have procedures same time. For the purposes of equipment malfunctions that simply cause a delay to to ensure the DSS this guidance, malfunctions of ODHAs can be defined as off-normal events.

can be placed into handling equipment and other an analyzed delays can be construed as As referenced by the commentor, NUREG-2215, section condition in the off-normal events. Off-normal 3.5.2.4, states the following:

event of a events occurring at the same malfunction or time as design basis natural Off-normal conditions and events are presumed to delay phenomena events would not occur in combination with normal conditions that be considered in the design of are not mutually exclusive. Nonetheless, the SAR is systems or require analysis of not required to analyze nor must the DSS or DSF the condition as stated in be designed for the simultaneous occurrence of NUREG-2215, Section 3.5.2.4, independent off-normal conditions or events, External Conditions as design-basis accidents, or design-basis natural 14

Response to Public Comments on Draft Regulatory Guide (DG)-3057 follows: Off-normal conditions phenomena. Conditions involving a latent and events are presumed to equipment or instrument failure or malfunction (that occur in combination with is, one that occurs and remains undetected) should normal conditions that are not be presumed to exist concurrently with other off-mutually exclusive. normal or design-basis accident conditions and Nonetheless, it is not required events. Typical latent malfunctions include a that the SAR analyze, or the misreading instrument that is not detected as part system be designed for, the of routine procedures, an undetected ventilation simultaneous occurrence of blockage, or undetected damage from an earlier independent off-normal design-basis off-normal or accident event or conditions or events, design- condition if no provisions exist for detection, basis accidents, or design- recovery, or remediation of such conditions.

basis natural phenomena.

Accordingly, as the commentor suggests and as Conditions involving a latent highlighted in NUREG-2215, section 3.5.2.4, the analysis equipment or instrument failure of simultaneous occurrences of independent off-normal or malfunction (that is, one that conditions or events, design-basis accidents, or design-occurs and remains basis natural phenomena is not required, and therefore undetected) should be an equipment malfunction coincident with a tornado or presumed to exist concurrently hurricane is not required to be assessed.

with other off-normal or design-basis conditions and events. However, as referenced in NUREG-2215, off-normal Typical latent malfunctions conditions and events are presumed to occur in include a misreading combination with normal conditions that are not mutually instrument that is not detected exclusive. Accordingly, an equipment malfunction as part of routine procedures, coincident with normal winds may occur and therefore is an undetected ventilation credible.

blockage, or undetected damage from an earlier design- Section 3.5 of NEI 22-02, Revision 2, appropriately basis event or condition if no identifies that malfunctions and delays should be handled provisions exist for detection, through the licensees corrective action program. It recovery, or remediation of separately identifies that the procedures or instructions such conditions. As ODHAs should specify compensatory actions to be taken as part are inherently performed while of the administrative controls if the weather forecast personnel are in attendance, changes during short-duration outdoor activities. Such any equipment malfunction compensatory actions should be clear, detailed, and would be immediately specifically tied to the location and configuration of the detected, and would not fall DSS and associated equipment to avoid delays and 15

Response to Public Comments on Draft Regulatory Guide (DG)-3057 into the category of latent as confusion during implementation, and compensatory described in NUREG-225, actions should be taken without delay in a controlled, Section 3.5.2.4 above. deliberate manner considering the concomitant need to Because probability of the provide for personnel safety. Once the DSS is in an tornado event is small to begin analyzed configuration, it may remain in that configuration with, postulating a concurrent for the time necessary for the weather to clear and DCS equipment malfunction can be operations to resume safely. The need for additional considered not credible. qualified personnel to implement the compensatory Requiring procedures to actions should be considered and the necessary training respond to a malfunction of provided.

equipment in the context of a concurrent tornado is Therefore, the staff believes that NEI 22-02, Revision 2, unreasonable and could contains the appropriate level of guidance through actually be detrimental to corrective action and compensatory actions to respond to safety. Malfunctions are equipment malfunctions and delays.

addressed in a controlled, deliberate, and timely manner In response to the comment, the staff has removed the commensurate with safety item 8 exception from section C of DG-3057 in the final significance. Layering weather- RG 3.77.

related time pressure atop the normal manner in which the corrective action program is implemented adds unnecessary pressure and increases the likelihood of errors.

NEI Recommended Resolution:

Revise this exception as a clarification to consider addressing malfunctions and unexpected delays in a more generic way in which equipment malfunctions during ODHAs that leave the DSS in an unanalyzed condition are entered into the corrective action program so that the 16

Response to Public Comments on Draft Regulatory Guide (DG)-3057 situation can be promptly evaluated for safety significance with respect to contingency actions and/or returning the condition to an analyzed condition.

19 John Comment 1 Overall, the draft Regulatory The NRC staff agrees in part with this comment.

Macdonald/ Guide DG-3057 provides a Rob prescriptive methodology for The staff notes that the previous use of administrative Desmarais/ managing the performance of controls to minimize the risks associated with the Dan Laing Outdoor Dry Cask Storage performance of outdoor DCS operations does not Operations. Over numerous necessarily mean that these administrative controls years, licensees have ensured compliance with NRC regulations in lieu of successfully applied minimizing risks as a means of prudent defense in depth.

administrative controls to minimize the risks associated The NRC defines risk-informed, performance-based with the performance of regulation as follows:

Outdoor Dry Cask Storage Operations. A risk-informed A risk-informed, performance-based regulation is and performance-based an approach in which risk insights, engineering approach should be adopted analysis and judgment (including the principle of without introducing a new defense-in-depth and the incorporation of safety significant level of effort. margins), and performance history are used, to (1) focus attention on the most important activities, (2) establish objective criteria for evaluating performance, (3) develop measurable or calculable parameters for monitoring system and licensee performance, (4) provide flexibility to determine how to meet the established performance criteria in a way that will encourage and reward improved outcomes, and (5) focus on the results as the primary basis for regulatory decision-making.

This guidance provides that formally documented administrative controls, in certain limited situations, can form an appropriate basis for demonstrating compliance with 10 CFR 72.122(b) and 10 CFR 72.236(l) in lieu of 17

Response to Public Comments on Draft Regulatory Guide (DG)-3057 engineered analysis, and constitute a risk-informed, performance-based approach to meeting regulatory requirements. As a part of its determination, the staff recognizes that licensees may need to develop measurable or calculable parameters for monitoring the weather to ensure the administrative controls are effective. The NRC staff believes that if these parameters are not developed, the administrative controls are ineffective. The NRC staff believes that the level of effort associated with determining these parameters is in alignment with the risk of the activity and is significantly less than performing additional analysis or modifications to SSCs ITS to demonstrate compliance with 10 CFR 72.122(b) and 10 CFR 72.236(l) through engineering analysis.

No changes were made to the final regulatory guide in response to the comment.

20 John Comment 2 Clarification #5 effectively See responses to comment ID numbers 8, 12, and 14.

Macdonald/ requires a design review to Rob determine what weather Desmarais/ conditions are analyzed in Dan Laing order to then determine what weather conditions are unanalyzed, to then determine qualitative or quantitative criteria that define/outline a safe condition and forecast. A significant level of effort would be required to meet the prescriptive requirements of this clarification. If the concern is that activities/equipment/

personnel used to support the operation need to be considered, then this clarification could be simplified to specify that review. This 18

Response to Public Comments on Draft Regulatory Guide (DG)-3057 clarification has been written to be an overly prescriptive task which can be re-written to require that the given project has considered all supporting work and has applied stop work criteria for the limitations specific to those activities/

equipment/personnel.

In addition, how would a licensee properly apply the appropriate error margin? Did the NRC intend for this to permit licensees to take credit for using cranes with extra capacity and setting wind speed thresholds that are less than the specified limits by the crane manufacturer or industry standards? This term is vague and subject to interpretation and the sentence that contains this term should be deleted.

The sentence that precedes it provides enough additional guidance to licensees.

21 John Comment 3 Although Clarification #6 allows See response to comment ID number 16.

Macdonald/ for justification to use an Rob equivalent weather service to Desmarais/ the national weather service Dan Laing (NWS), the NRC should recognize that the closest NWS to a site may not represent the weather at the site. In these cases, the user would enter the sites zip-code and the NWS usually provides 19

Response to Public Comments on Draft Regulatory Guide (DG)-3057 a forecast based on data from the closest airport, not from NWS data. Does the utilization of this data provided through the NWS meet the intent of the NRCs clarification?

22 John Comment 4 Exception #8 is too open See response to comment ID number 18.

Macdonald/ ended and could be subject to Rob differing opinions on how well a Desmarais/ site has addressed Dan Laing contingencies. What a licensee develops as a sufficient contingency policy for a site may not seem sufficient to an inspector/auditor.

Consideration should also be given to Independent Spent Fuel Storage Installation (ISFSI) only sites that do not have access to plant equipment like single failure proof cranes. Aging management inspections performed to date have proved to have sufficient contingencies. Examples that have been used in typical planning activities include; using mobile cranes with double the capacity for the heaviest lift and documented in the crane certifications; using single failure proof rigging; identifying sources for a suitable backup crane with an acceptable response time to the site; maintaining redundant torque wrenches on site for 20

Response to Public Comments on Draft Regulatory Guide (DG)-3057 torquing requirements; obtaining tooling to address stuck bolts; utilizing personnel with multiple qualifications to address personnel absences; limiting load lift height when removing/reinstalling components over casks; requiring load transit paths that avoid other casks and safety related hardware; and obtaining multiple spare parts for inspection robots and cameras.

Typically, malfunctions and delays are addressed in technical support documents.

As a result of these considerations, limitations are included in the work order controlling the work that include contingency steps for malfunctions and delays. All such events would also be documented in the sites corrective action program. This is standard practice for licensees using existing programs and processes which already occur without reliance on the NEI guidance or the NRC exception. We think the NEI guidance adequately highlights the consideration to licensees engaged in these activities.

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Response to Public Comments on Draft Regulatory Guide (DG)-3057 23 Kimberly Comment 1 Clarification 5 in DG-3057 The NRC staff agrees with the comment.

Manzione includes a statement that For SSCs ITS that are determined The staff agrees with the interpretation provided by the to be fully analyzed by commentor regarding the intent of the clarification in engineering analysis item 5 of DG-3057. However, as discussed in the administrative controls may be response to comment ID number 8, the NRC has implemented removed this clarification from section C of the final RG Holtec suggests that some 3.77.

additional clarity be added to this statement to say that, For No changes were made to the final regulatory guide in SSCs ITS that are determined response to the comment.

to be fully analyzed by engineering analysis or bounded by another existing analysis administrative controls may be implemented In many operational sequences, similar equipment is used, and one bounding analysis may exist to cover a number of steps. The suggested clarification will make it clear that this approach remains acceptable.

24 Kimberly Comment 2 Clarification 5 discusses the The NRC staff agrees with the comment.

Manzione need to demonstrate the analyzed wind speed that is The staff agrees that the original licensing basis may appropriate for short-term continue to be followed in lieu of the final RG. However, operations, and gives an the staff recognizes that, in certain instances, as example of a crane wind speed explained in the RG, if the original licensing basis is acceptance criterion. modified to follow the regulatory guide, additional While Holtec agrees with the evaluation to meet the regulatory guide may be NEI comments that this necessary.

clarification should be deleted, in the event that it is not, the In response to the comment, the staff added a discussion clarification should recognize to the clarification in item 4 of section C of the final the current licensing basis of RG 3.77.

22

Response to Public Comments on Draft Regulatory Guide (DG)-3057 some systems. Some systems include design of handling equipment to codes with significant safety factors.

Those system FSARs specifically indicate that further wind analyses of equipment designed to those codes is not necessary. Therefore, this DG should acknowledge that users should stay within their current licensing basis, and not expand to new analyses not required in the original licensing basis.

25 Kimberly Comment 3 Clarification 7 states that See response to comment ID number 17.

Manzione licensees should determine the duration of activities by benchmarking or dry runs.

Holtec suggests that this statement be revised to include licensees own operating experience, since many sites have been loading casks for decades. The statement could be revised to say, by site operating experience, benchmarking, or dry runs.

26 Kimberly Comment 4 Clarification 8 states that See response to comment ID number 18.

Manzione licensees should have specific procedures directing actions in the event of a combination of a malfunction at the same time as an adverse weather event.

The need to require a combination of malfunction and 23

Response to Public Comments on Draft Regulatory Guide (DG)-3057 a low probability weather event is a new expectation that has not been previously required in any licensing application.

Holtec has previously licensed systems that do combine accidents with other scenarios, but those accidents were significantly long term (30 days) and not the low probability, low duration occurrence of a severe weather event. Holtec suggests that this clarification be removed, as the current wording in the NEI guidance clearly states that the licensee should develop case-specific measures and involve the sites corrective action program as needed.

27 T. Forland Comment 1 Based on the 6-13-2023 public See response to comment ID number 18.

meeting, licensees will not be required to anticipate and have specific procedures addressing all causes for delays and all SSC failure modes. In general, a high-level procedure that utilizes the stations Corrective Action Program (CAP), makes required notifications, and triggers prompt repairs would be acceptable. The exception to this would be if OE, benchmarking, or dry runs show that: a given failure or delay has a high probability of occurrence, the failure/delay 24

Response to Public Comments on Draft Regulatory Guide (DG)-3057 could occur during an unanalyzed condition, and restoration to an analyzed condition would take significant time (>24 hours).

In these cases, there should be specific contingencies (procedures and equipment) to promptly restore the system to an analyzed condition. If this is the intended meaning of the guidance, clarifying text should be added to indicate this.

28 T. Forland Comment 2 It is understood that See response to comment ID number 18.

contingency equipment, if required as discussed above, would need to be readily available and its usage to have been demonstrated in a dry run or by other means acceptable to the NRC.

If this is the intended meaning of the guidance, clarifying text should be added to indicate this.

29 T. Forland Comment 3 Based on the 6-13-2023 public The NRC staff agrees in part with the comment.

meeting, the duration for a "safe condition and forecast" The NRC staff disagrees that additional clarification is should be based on the necessary. Section 2.1 of NEI 22-02, Revision 2, states environmental design criteria that, In these locations and at several interim locations for equipment that would be between the two, the DSS either is in an analyzed used while in an unanalyzed configuration for tornado missiles or can be placed in condition during an outdoor dry such a configuration without delay, but in controlled, storage system (DSS) handling deliberate manner, if necessary.

activity (ODHA). If this is an 25

Response to Public Comments on Draft Regulatory Guide (DG)-3057 accurate interpretation, The staff believes that NEI 22-02, Revision 2 provides clarifying text should be added adequate guidance regarding the duration of the ODHA, to indicate this. which is defined as the time beginning when the DSS leaves the indoor reactor facility and ending when it is in its storage location at the ISFSI, which includes any unanalyzed conditions during ODHAs.

No changes were made to the final regulatory guide in response to the comment.

30 T. Forland Comment 4 Will the unanalyzed conditions Section 3.4 of NEI 22-02, Revision 2, states the following:

typically occurring during ODHAs that have not been The generic guidance should, at a minimum, generically evaluated, be define the analyzed configurations relative to required documentation in the tornado wind and missile design. Further, this storage system FSAR (i.e., the guidance should direct licensees to develop the chapter 9 description of administrative controls for confirming a safe generic loading procedures)? condition and forecast before commencing outdoor Would this description be DCS activities and for implementing compensatory expected to include recovery measures should those conditions be lost, during steps, contingency equipment such activities. CoC holders should also assist needed, and estimated licensees in developing procedures and durations? instructions to the extent necessary to ensure a reasonable level of consistency across licensees.

Additionally, section 3.5 states that the general licensee should establish procedures or instructions that include

[t]he type of activity, configuration, and equipment being used in short-duration outdoor DCS activities and [t]he definition of analyzed configuration as determined by the CoC holder.

Accordingly, the unanalyzed conditions typically occurring during ODHAs that have not been generically evaluated will not be required documentation in the storage system FSAR. However, it is expected that they will be documented in licensee procedures and the 10 CFR 72.212 report.

26

Response to Public Comments on Draft Regulatory Guide (DG)-3057 No changes were made to the final regulatory guide in response to the comment.

31 T. Forland Comment 5 Some licensees have loading See response to comment ID number 4.

campaigns scheduled in early 2024 (after or during the current expiration date for EGM 22-01). The EGM expiration date should be extended to allow adequate time for resolution of public comments, approval, and issuance of the final Regulatory Guide, updating of cask vendors FSARs, and utility implementation activities.

It is suggested the EGM expiration date be extended at least 6 months beyond the date of issuance of the finalized Regulatory Guide.

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