ML23192A534
| 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: |
| 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 Kailua, HI 96734 Email: hagerpmil@gmail.com ML23167A354 Mr. Rod McCullum Nuclear Energy Institute, 1201 F Street, NW, Suite 1100, Washington, DC 20004 Telephone: (202) 739-082 Email: rxm@nei.org ML23181A029 Mr. John Macdonald, ISFSI Manager Yankee Atomic Electric Company 49 Yankee Road, Rowe, MA 01367 Telephone: (413) 424-5261, extension 304 Email: sday@3yankees.com ML23181A030 Mr. Rob Desmarais, ISFSI Manager Connecticut Yankee Atomic Power Company Haddam Neck Plant Independent Spent Fuel Storage Installation 362 Injun Hollow Rd, East Hampton, CT 06424-3099 Telephone: (860) 267-6426, extension 306 Email: sday@3yankees.com ML23181A031 Mr. Dan Laing, ISFSI Manager Maine Yankee Atomic Power Company Maine Yankee Independent Spent Fuel Storage Installation 21 Old Ferry Road, Wiscasset, ME 04578 Telephone: (207) 882-1303 Email: sday@3yankees.com ML23181A032 Ms. Kimberly Manzione Holtec Technology Campus One Holtec Blvd, Camden, NJ 08104 Telephone: (856) 797-0900 Email: k.manzione@holtec.com ML23188A012 T. Forland Ameren MissouriCallaway Plant Email: tforland@Ameren.com ML23186A020
Response to Public Comments on Draft Regulatory Guide (DG)-3057 2
NRC ID # Commenter Comment Number Text of Comment NRC Resolution 1
Peter Hager General comment The infostructure of our solid waste incinerations units and small municipal waste units 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.
The subject and content of this comment do not pertain to DG-3057. No changes were made to the final regulatory guide in response to the comment.
2 Rod McCullum (Comments 1-4 from cover letter)
Comment 1 On Page 2 of the Regulatory Analysis, in the Second Paragraph under Alternative 1, NRC states that Many licensees are currently using administrative controls in contradiction to their design bases to meet regulatory requirements under the enforcement discretion provided by EGM
[Enforcement Guidance Memorandum] 22-01. This is a broad generalization and should be removed. Industry believes it has consistently been in compliance with the The NRC staff agrees in part with this comment.
The NRC staff has identified multiple instances of noncompliance regarding the use of administrative controls in lieu of engineering analysis in contradiction to the licensees design bases to meet regulatory requirements. This is evident as multiple instances of enforcement discretion have been issued under the provisions of EGM 22-01, Enforcement Discretion for Noncompliance of Tornado Hazards Protection Requirements at Independent Spent Fuel Storage Installations.
Three instances of past precedent were identified by the commenter (comment ID number 3) regarding the use of administrative controls in lieu of engineering analysis.
This includes two consolidated interim storage facilities
Response to Public Comments on Draft Regulatory Guide (DG)-3057 3
requirements in its respective DSS [dry storage system]
FSARs [final safety analysis statements] and 10 CFR 72.212(b)(6). We believe that this disagreement stems from a lack of clarity regarding the use of administrative controls in accordance with the design bases. Incorporation of our attached comments will resolve this uncertainty.
that have not been constructed and a certificate of compliance (CoC) that has recently been issued.
To reduce the broad generalization and subjectivity of the language in the regulatory analysis, the staff revised the sentence to remove the term many. No changes were made to the final regulatory guide as no similar statements were made in it.
3 Rod McCullum Comment 2 In a public meeting held on 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 See responses to comment ID numbers 7 through 13.
Response to Public Comments on Draft Regulatory Guide (DG)-3057 4
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 McCullum Comment 3 We remain confident that DG-3057 can be finalized in a way that will restore regulatory stability and predictability to DSS ODHAs [outdoor dry storage system handling activities] and improve efficiency. We look forward to finalization of RG 3.77 in the 4th quarter of 2023 so that the needed regulatory improvements, and any corresponding actions on the part of licensees, can be implemented prior to the expiration of EGM 22-01 in April 2024. Because a number of licensees plan loading The NRC staff agrees with the comment.
The NRC staff recognizes and agrees that the period between the public release date of the final regulatory guide and the expiration of EGM 22-01 should be appropriate to ensure that needed regulatory improvements, and any corresponding actions on the part of licensees, can be implemented before the expiration of EGM 22-01 in April 2024. The NRC staff will evaluate the extension of EGM 22-01 as appropriate.
No changes were made to the final regulatory guide in response to the comment.
Response to Public Comments on Draft Regulatory Guide (DG)-3057 5
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 McCullum Comment 4 We also request that NRC inspection procedures associated with RG 3.77 be updated and shared with the industry to enhance the licensees understanding of NRC expectations and to ensure regulatory compliance.
The NRC staff agrees with the comment.
During the next routine review of independent spent fuel storage installation (ISFSI) inspection procedures, the staff plans to revise the appropriate inspection procedures to enhance the guidance for reviewing licensee/CoC holder compliance with Title 10 of the Code of Federal 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 McCullum Item 2 Exception:
Lastly, the guidance only applies to a DSS when the DSSs confinement boundary has been established as required by its licensing basis.
The guidance addresses all outdoor DCS [dry cask storage] activities. The state of the canister and cask at any time while outdoors is a site-specific issue each licensee should consider in implementing the guidance, including in rare short-duration situations where the confinement boundary has not yet been established. Since there are situations in which the confinement boundary has not yet been established during which ODHAs must be protected by the use of administrative controls, this The NRC staff agrees with the comment.
This guidance should be applicable in all situations, including those rare situations in which site-specific conditions do not allow for the confinement boundary to be established before the DSS leaves the reactor facility for a short duration. The NRC oversight program allows for the evaluation of these situations to ensure all regulatory requirements are met.
In response to the comment, the staff removed the following sentence from the exception in item 2, section C of DG-3057 from the final RG 3.77, as recommended:
Lastly, the guidance only applies to a DSS when the DSSs confinement boundary has been established as required by its licensing basis.
Response to Public Comments on Draft Regulatory Guide (DG)-3057 6
guidance should not be limited to apply only in cases where the confinement boundary is established.
NEI Recommended ResolutionDelete the sentence.
7 Rod McCullum Comments 7 through 13 are taken from one comment regarding Item 3Clarification, Item 4 Clarification, and Item 5 Clarification:
Industry concerns regarding the regulatory uncertainty likely to be created by the combined effect of these three clarifications The combined effect of Clarifications 3, 4, and 5 is to greatly expand the definition of safe condition and forecast to include a wide range of conditions that would exceed an SSCs [structure, system, or components] design criteria.
This significantly, in turn, expands the scope of the guidance.
The NRC staff agrees that the clarifications in items 3, 4, and 5 of DG-3057 expand the definition of safe condition and forecast beyond that included in NEI 22-02 Revision 2, but such expansion of the definition is necessary to ensure that an SSC is not placed in a configuration that would exceed the SSCs design criteria. As described in the final RG 3.77, 10 CFR 72.122(b) requires that SSCs important to safety (ITS) be designed to accommodate the effects of, and to be compatible with, site characteristics and environmental conditions associated with normal operation, maintenance, and testing of the ISFSI or MRS [monitored retrievable storage] and to withstand postulated accidents (emphasis added).
Similarly, 10 CFR 72.236(l) states that SSCs ITS must be evaluated, by appropriate tests or by other means acceptable to the NRC, to demonstrate that they will reasonably maintain confinement of radioactive material 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
Response to Public Comments on Draft Regulatory Guide (DG)-3057 7
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 McCullum Item 3 Clarification, Item 4 Clarification, and Item 5 Clarification:
Industry concerns regarding the regulatory uncertainty likely to be created by the combined effect of these three clarifications This clarification has been written as an overly prescriptive task which will be difficult, if not impossible, to complete.
The NRC staff agrees, in part, with this comment. While the NRC staff disagrees that the guidance is overly prescriptive, difficult, or impossible to complete, based upon the comment provided and further consideration, the staff believes that the language in the guidance related to this comment may be too specific given the wide scope of potential SSCs to be evaluated and site-specific environmental conditions. The staff believes that the CoC holders or licensees design control program provides an adequate process to determine a safe condition and forecast based upon the NRCs clarification of the definition. Accordingly, the staff have removed the clarification in item 5, section C of DG-3057 from the final RG 3.77.
9 Rod McCullum Item 3 Clarification, Item 4 Clarification, and Item 5 Clarification:
Industry concerns regarding the regulatory uncertainty likely to be created by the combined effect of these three clarifications It could cause licensees to chase information about things such as projected barometric pressures and monitoring weather below the threshold of severe weather.
The staff agrees, in part, with this comment. While the NRC staff disagrees that the language could cause licensees to chase information about things such as barometric pressure, in the final regulatory guide, the staff clarified the definition of safe condition and forecast as follows:
A safe condition and forecast is considered to be the absence of (1) forecasted weather for wind speeds (gusts or sustained) that could exceed an SSCs ITS design criteria and (2) a hazardous weather outlook indicating a risk of severe storms that could generate at the site, 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.
Response to Public Comments on Draft Regulatory Guide (DG)-3057 8
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 McCullum Item 3 Clarification, Item 4 Clarification, and Item 5 Clarification:
Industry concerns regarding the regulatory uncertainty likely to be created by the combined effect of these three clarifications Additional monitoring of things below the threshold or below other bounding conditions would be an unnecessary burden that would divert resources away from more safety significant tasks. This could then cause licensees to have to go beyond the NWS
[National Weather Service]
severe weather alert system as a resource.
The NRC staff disagrees with this comment and notes that monitoring of these conditions is required to ensure compliance with the regulations. The staff has specifically identified wind speed (gusts and sustained winds) as specific parameters that should be evaluated for normal and off-normal conditions. The NWS provides a 48-hour hourly forecast graph for wind speed, including gusts that may be used by the licensees. Checking this forecast should take a minimal amount of time (under 5 minutes) before the start of operation.
No changes were made to the final regulatory guide in response to the comment.
11 Rod McCullum Item 3 Clarification, Item 4 Clarification, and Item 5 Clarification:
This will subsequently trigger extensive design reviews based on this inevitably uncertain population of information. A significant level of effort will be required to The NRC staff disagrees with this comment. The staff recognizes that licensees or CoC holders may need to perform evaluations to determine a safe condition and forecast for some SSCs ITS. However, as highlighted in the regulatory analysis for the first alternative, instead of using administrative controls, absent established and
Response to Public Comments on Draft Regulatory Guide (DG)-3057 9
Industry concerns regarding the regulatory uncertainty likely to be created by the combined effect of these three clarifications conduct these reviews. Again, this will place an inordinate focus on items of little to no safety significance and further divert resources from more safety significant tasks. Most significantly, these design reviews would be of little to no use towards meeting the intended purpose of this guidance.
specifically licensed alternatives, the SSCs are required to demonstrate through engineering analyses that they are capable of withstanding effects such as weather-related wind and tornado natural phenomena without impairing their capability to perform their intended design functions. Such analyses, as well as the potential need to modify SSCs ITS to demonstrate compliance with 10 CFR 72.122(b) and 10 CFR 72.236(l) through engineering analysis, requires a more significant level of effort, with minor safety benefit. Therefore, the NRC 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 McCullum Item 3 Clarification, Item 4 Clarification, and Item 5 Clarification:
Industry concerns regarding the regulatory uncertainty likely to be created by the combined effect of these three clarifications This is because ensuring weather conditions and forecast would not exceed design criteria does not address the time when these cask systems would be in unanalyzed outdoor configurations, i.e., when the limiting criteria are unknown, for example, a storage cask being carried by a transporter (that may be NITS [not important to safety]), or a 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 The NRC staff agrees that the purpose of the guidance is to avoid operation during severe weather; however, the staff reiterates that unless the licensee or CoC holder evaluates what level of normal, off-normal, or accident conditions exceed the design basis of the SSC, the definition of severe weather cannot be correctly established.
The staff has added detail to the clarification in item 4 of the final regulatory guide to describe and provide an example of the expectations of how to determine a safe condition and forecast.
Response to Public Comments on Draft Regulatory Guide (DG)-3057 10 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 McCullum Item 3 Clarification, Item 4 Clarification, and Item 5 Clarification:
Industry concerns regarding the regulatory uncertainty likely to be created by the combined effect of these three clarifications In accordance with 10 CFR 72.212(b)(6), licensees must comply with operating limits associated with normal and off normal conditions established in the cask FSAR. It should be noted that NRC did not ask for the prescriptive design reviews called for in this clarification when staff approved the FSARs. To essentially require them now in operationally focused guidance would constitute a backfit. Before issuing these clarifications, NRC must thoroughly weigh the potential resources required against the safety benefits that would be gained.
The NRC staff disagrees with this comment.
The regulation in 10 CFR 72.212(b)(6) states that the general licensee must review the safety analysis report referenced in the CoC or amended CoC and the related NRC safety evaluation report before using the general license, to determine whether or not the reactor site parameters, including analyses of earthquake intensity and tornado missiles, are enveloped by the cask design bases considered in these reports. The results of this review must be documented in the evaluation made in 10 CFR 72.212(b)(5).
The staff reiterates that NUREG-2215, Standard Review Plan for Spent Fuel Dry Storage Systems and Facilities Final Report, issued April 2020, contains the current licensing guidance for weather-related protection contained within DSS FSARs.
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
Response to Public Comments on Draft Regulatory Guide (DG)-3057 11 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.
Response to Public Comments on Draft Regulatory Guide (DG)-3057 12 14 Rod McCullum Item 5 Clarification: In this determination, forecast conditions should provide a conservative threshold, including an appropriate error margin, to ensure that SSCs ITS are not subjected to any load combinations beyond those analyzed.
It is not clear what is meant by an appropriate error margin in the context of the paragraph.
NEI Recommended Resolution:
Although we are recommending that Clarification 5 be deleted, we are making this comment to highlight the regulatory uncertainty that would be introduced by the open-ended expansion of the scope of this guidance.
The NRC staff agrees with the comment.
The staff recognizes that the evaluation performed to identify a safe condition and forecast will, in nature, include conservative engineering evaluation practices.
Therefore, including additional margin with the acceptance criteria for a safe condition and forecast is redundant and unnecessary.
With the removal of the clarification in item 5, section C of the DG-3057 from the final RG 3.77 based on comment ID number 8, this comment is resolved.
15 Rod McCullum Item 5 Clarification:
From the load conditions, the qualitative or quantitative criteria that define/outline a safe condition and forecast should be determined.
These criteria will form the acceptance criteria of the procedure establishing administrative control.
AND The terms qualitative or quantitative and quantitative and qualitative are used interchangeably. This is confusing and inconsistent with the regulatory and licensing precedent upon which the definition of safe condition and forecast is based.
NEI Recommended Resolution:
Although we are recommending in the comment above that Clarification 5 be deleted, we make this comment to emphasize the importance of maintaining the established licensing precedent. The term quantitative or qualitative acceptance criteria is based on 10 CFR 72.150. This term has The NRC staff agrees with the comment.
With the removal of the clarification in item 5, section C of the DG-3057 from the final RG 3.77 based on comment ID number 8, this comment is resolved.
Response to Public Comments on Draft Regulatory Guide (DG)-3057 13 Based upon the licensees review described above, the licensee should determine quantitative and qualitative acceptance criteria.
been used in the definition of safe condition and forecast that NRC approved in Reference. To avoid any possible misunderstanding, NRC should consistently use quantitative or qualitative acceptance criteria, to be consistent with the regulation.
The definition in NEI 22-02 is verbatim the same as the referenced precedents.
16 Rod McCullum Item 6 Clarification:
Licensees should use the NWSs hazardous weather outlook and forecast information unless another resource for the site is available that provides equivalent information in terms of timeliness and accuracy.
The NRCs clarification to the statement adds and forecast, but it also deletes for the site and retains that can be justified as providing This is an important distinction (that) industry needs. If a licensee sees a severe weather alert in the region, but it does not include the site, they need the flexibility to make a site-appropriate decision to move forward. In addition, the closest NWS station to an ISFSI site may not represent the weather 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 The NRC staff agrees with the comment.
The staff agrees that hazardous weather outlook and forecast information should be reviewed specifically for the ISFSI site.
The staff has revised the clarification in item 5 of the final RG 3.77.
Response to Public Comments on Draft Regulatory Guide (DG)-3057 14 representative of local conditions if such forecasts can be shown to provide equivalent (or better) weather information for the site than NWS.
17 Rod McCullum Item 7 Clarification: The licensee should determine the expected duration of short duration outdoor activities by either benchmarking or dry runs. The ODHA duration should be periodically assessed based upon operating experience.
Industry believes that benchmarking or dry runs is too restrictive. These activities are largely site-specific when plant locations and facilities are layered on the generic operations described in the DSS FSAR. The most accurate estimate of ODHA durations is site operating experience.
NEI Recommended Resolution: Add site operating experience to benchmarking or dry runs.
The NRC staff agrees with the comment.
The staff believes that relevant operating experience should be part of the clarification and has revised it in the final RG 3.77.
18 Rod McCullum Item 8 Exception:
Licensees should have procedures to ensure the DSS can be placed into an analyzed condition in the event of a malfunction or delay The premise of this exception is that malfunctions and severe weather would occur at the same time. For the purposes of this guidance, malfunctions of handling equipment and other delays can be construed as off-normal events. Off-normal events occurring at the same time as design basis natural phenomena events would not be considered in the design of systems or require analysis of the condition as stated in NUREG-2215, Section 3.5.2.4, External Conditions as The NRC staff agrees in part with the comment.
The staff agrees that for the application of this guidance, equipment malfunctions that simply cause a delay to ODHAs can be defined as off-normal events.
As referenced by the commentor, NUREG-2215, section 3.5.2.4, states the following:
Off-normal conditions and events are presumed to occur in combination with normal conditions that are not mutually exclusive. Nonetheless, the SAR is not required to analyze nor must the DSS or DSF be designed for the simultaneous occurrence of independent off-normal conditions or events, design-basis accidents, or design-basis natural
Response to Public Comments on Draft Regulatory Guide (DG)-3057 15 follows: Off-normal conditions and events are presumed to occur in combination with normal conditions that are not mutually exclusive.
Nonetheless, it is not required that the SAR analyze, or the system be designed for, the simultaneous occurrence of independent off-normal conditions or events, design-basis accidents, or design-basis natural phenomena.
Conditions involving a latent equipment or instrument failure or malfunction (that is, one that occurs and remains undetected) should be presumed to exist concurrently with other off-normal or design-basis conditions and events.
Typical latent malfunctions include a misreading instrument that is not detected as part of routine procedures, an undetected ventilation blockage, or undetected damage from an earlier design-basis event or condition if no provisions exist for detection, recovery, or remediation of such conditions. As ODHAs are inherently performed while personnel are in attendance, any equipment malfunction would be immediately detected, and would not fall phenomena. Conditions involving a latent equipment or instrument failure or malfunction (that is, one that occurs and remains undetected) should be presumed to exist concurrently with other off-normal or design-basis accident conditions and events. Typical latent malfunctions include a misreading instrument that is not detected as part of routine procedures, an undetected ventilation blockage, or undetected damage from an earlier design-basis off-normal or accident event or condition if no provisions exist for detection, recovery, or remediation of such conditions.
Accordingly, as the commentor suggests and as highlighted in NUREG-2215, section 3.5.2.4, the analysis of simultaneous occurrences of independent off-normal conditions or events, design-basis accidents, or design-basis natural phenomena is not required, and therefore an equipment malfunction coincident with a tornado or hurricane is not required to be assessed.
However, as referenced in NUREG-2215, off-normal conditions and events are presumed to occur in combination with normal conditions that are not mutually exclusive. Accordingly, an equipment malfunction coincident with normal winds may occur and therefore is credible.
Section 3.5 of NEI 22-02, Revision 2, appropriately identifies that malfunctions and delays should be handled through the licensees corrective action program. It separately identifies that the procedures or instructions should specify compensatory actions to be taken as part of the administrative controls if the weather forecast changes during short-duration outdoor activities. Such compensatory actions should be clear, detailed, and specifically tied to the location and configuration of the DSS and associated equipment to avoid delays and
Response to Public Comments on Draft Regulatory Guide (DG)-3057 16 into the category of latent as described in NUREG-225, Section 3.5.2.4 above.
Because probability of the tornado event is small to begin with, postulating a concurrent equipment malfunction can be considered not credible.
Requiring procedures to respond to a malfunction of equipment in the context of a concurrent tornado is unreasonable and could actually be detrimental to safety. Malfunctions are addressed in a controlled, deliberate, and timely manner commensurate with safety significance. Layering weather-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 confusion during implementation, and compensatory actions should be taken without delay in a controlled, deliberate manner considering the concomitant need to provide for personnel safety. Once the DSS is in an analyzed configuration, it may remain in that configuration for the time necessary for the weather to clear and DCS operations to resume safely. The need for additional qualified personnel to implement the compensatory actions should be considered and the necessary training provided.
Therefore, the staff believes that NEI 22-02, Revision 2, contains the appropriate level of guidance through corrective action and compensatory actions to respond to equipment malfunctions and delays.
In response to the comment, the staff has removed the item 8 exception from section C of DG-3057 in the final RG 3.77.
Response to Public Comments on Draft Regulatory Guide (DG)-3057 17 situation can be promptly evaluated for safety significance with respect to contingency actions and/or returning the condition to an analyzed condition.
19 John Macdonald/
Rob Desmarais/
Dan Laing Comment 1 Overall, the draft Regulatory Guide DG-3057 provides a prescriptive methodology for managing the performance of Outdoor Dry Cask Storage Operations. Over numerous years, licensees have successfully applied administrative controls to minimize the risks associated with the performance of Outdoor Dry Cask Storage Operations. A risk-informed and performance-based approach should be adopted without introducing a new significant level of effort.
The NRC staff agrees in part with this comment.
The staff notes that the previous use of administrative controls to minimize the risks associated with the performance of outdoor DCS operations does not necessarily mean that these administrative controls ensured compliance with NRC regulations in lieu of minimizing risks as a means of prudent defense in depth.
The NRC defines risk-informed, performance-based regulation as follows:
A risk-informed, performance-based regulation is an approach in which risk insights, engineering analysis and judgment (including the principle of defense-in-depth and the incorporation of safety 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
Response to Public Comments on Draft Regulatory Guide (DG)-3057 18 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 Macdonald/
Rob Desmarais/
Dan Laing Comment 2 Clarification #5 effectively requires a design review to determine what weather conditions are analyzed in 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 See responses to comment ID numbers 8, 12, and 14.
Response to Public Comments on Draft Regulatory Guide (DG)-3057 19 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 Macdonald/
Rob Desmarais/
Dan Laing Comment 3 Although Clarification #6 allows for justification to use an equivalent weather service to the national weather service (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 See response to comment ID number 16.
Response to Public Comments on Draft Regulatory Guide (DG)-3057 20 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 Macdonald/
Rob Desmarais/
Dan Laing Comment 4 Exception #8 is too open ended and could be subject to differing opinions on how well a site has addressed 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 See response to comment ID number 18.
Response to Public Comments on Draft Regulatory Guide (DG)-3057 21 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.
Response to Public Comments on Draft Regulatory Guide (DG)-3057 22 23 Kimberly Manzione Comment 1 Clarification 5 in DG-3057 includes a statement that For SSCs ITS that are determined to be fully analyzed by engineering analysis administrative controls may be implemented Holtec suggests that some additional clarity be added to this statement to say that, For SSCs ITS that are determined 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.
The NRC staff agrees with the comment.
The staff agrees with the interpretation provided by the commentor regarding the intent of the clarification in item 5 of DG-3057. However, as discussed in the response to comment ID number 8, the NRC has removed this clarification from section C of the final RG 3.77.
No changes were made to the final regulatory guide in response to the comment.
24 Kimberly Manzione Comment 2 Clarification 5 discusses the need to demonstrate the analyzed wind speed that is appropriate for short-term operations, and gives an example of a crane wind speed acceptance criterion.
While Holtec agrees with the NEI comments that this clarification should be deleted, in the event that it is not, the clarification should recognize the current licensing basis of The NRC staff agrees with the comment.
The staff agrees that the original licensing basis may continue to be followed in lieu of the final RG. However, the staff recognizes that, in certain instances, as explained in the RG, if the original licensing basis is modified to follow the regulatory guide, additional evaluation to meet the regulatory guide may be necessary.
In response to the comment, the staff added a discussion to the clarification in item 4 of section C of the final RG 3.77.
Response to Public Comments on Draft Regulatory Guide (DG)-3057 23 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 Manzione Comment 3 Clarification 7 states that 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.
See response to comment ID number 17.
26 Kimberly Manzione Comment 4 Clarification 8 states that 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 See response to comment ID number 18.
Response to Public Comments on Draft Regulatory Guide (DG)-3057 24 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 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 See response to comment ID number 18.
Response to Public Comments on Draft Regulatory Guide (DG)-3057 25 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 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.
See response to comment ID number 18.
29 T. Forland Comment 3 Based on the 6-13-2023 public meeting, the duration for a "safe condition and forecast" should be based on the environmental design criteria for equipment that would be used while in an unanalyzed condition during an outdoor dry storage system (DSS) handling activity (ODHA). If this is an The NRC staff agrees in part with the comment.
The NRC staff disagrees that additional clarification is necessary. Section 2.1 of NEI 22-02, Revision 2, states that, In these locations and at several interim locations between the two, the DSS either is in an analyzed configuration for tornado missiles or can be placed in such a configuration without delay, but in controlled, deliberate manner, if necessary.
Response to Public Comments on Draft Regulatory Guide (DG)-3057 26 accurate interpretation, clarifying text should be added to indicate this.
The staff believes that NEI 22-02, Revision 2 provides adequate guidance regarding the duration of the ODHA, 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 typically occurring during ODHAs that have not been generically evaluated, be required documentation in the storage system FSAR (i.e., the chapter 9 description of generic loading procedures)?
Would this description be expected to include recovery steps, contingency equipment needed, and estimated durations?
Section 3.4 of NEI 22-02, Revision 2, states the following:
The generic guidance should, at a minimum, define the analyzed configurations relative to tornado wind and missile design. Further, this guidance should direct licensees to develop the administrative controls for confirming a safe condition and forecast before commencing outdoor DCS activities and for implementing compensatory measures should those conditions be lost, during such activities. CoC holders should also assist licensees in developing procedures and 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.
Response to Public Comments on Draft Regulatory Guide (DG)-3057 27 No changes were made to the final regulatory guide in response to the comment.
31 T. Forland Comment 5 Some licensees have loading 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.
See response to comment ID number 4.