ML22339A035

NEI Response to Clarified Request for Supplemental Information Included with Nrc’S Acceptance of NEI 22-02, Guidelines for Weather-Related Administrative Controls for Short Duration Outdoor Dry Cask Storage Operations - Dated September 12,

ML22339A035
Person / Time
Site:	Nuclear Energy Institute, 99902028
Issue date:	11/04/2022
From:	Mccullum R Nuclear Energy Institute
To:	Janice Nguyen Office of Nuclear Reactor Regulation, Document Control Desk
References
Download: ML22339A035 (1)

Text

ROD MCCULLUM Sr. Director, Decommissioning and Used Fuel 1201 F Street, NW, Suite 1100 Washington, DC 20004 P: 202.739.8082 rxm@nei.org nei.org November 4, 2022 Mr. John-Chau Nguyen Division of Fuel Management Office of Nuclear Material Safety and Safeguards U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

Subject:

NEI Response to Clarified Request for Supplemental Information included with NRCs Acceptance of NEI 22-02, Guidelines for Weather-Related Administrative Controls for Short Duration Outdoor Dry Cask Storage Operations - dated September 12, 2022 (ML22216A117)

Project Number: 689

Dear Mr. Nguyen:

The purpose of this letter is to submit the Nuclear Energy Institutes (NEI)0F1 response to NRCs clarified request for supplemental information (RSI) pertaining to a guidance document submitted by NEI, on behalf of its members, titled NEI 22-02, Guidelines for Weather-Related Administrative Controls for Short Duration Outdoor Dry Cask Storage Operations. Attached to this letter is Revision 2 to NEI 22-02, which responds to the clarified RSIs by adding a clear definition of safe condition and forecast and revising the document to assure that this definition is consistently applied throughout the guidance. We believe that this improved clarity and consistency will enable effective site-specific implementation of the guidance over the wide range of operational and weather conditions that may exist across industry dry storage facilities. NRC endorsement of Revision 2 to NEI 22-02 will provide regulatory certainty and predictability for the industry to apply appropriate administrative controls during short duration outdoor dry cask storage operations.

It is our understanding that the NRC staffs ongoing review of NEI 22-02 is covered by the partial fee waiver granted by the Chief Financial Officer (CFO) in her September 29, 2022, letter to NEI.1F2 In that letter, the CFO partially granted NEIs fee waiver request for the NRCs initial review of the activities required to supplement NEI 22-02 prior to docketing. We believe that Revision 2 of NEI 22-02 supports the docketing and review of 1 The Nuclear Energy Institute (NEI) is responsible for establishing unified policy on behalf of its members relating to matters affecting the nuclear energy industry, including the regulatory aspects of generic operational and technical issues. NEIs members include entities licensed to operate commercial nuclear power plants in the United States, nuclear plant designers, major architect and engineering firms, fuel cycle facilities, nuclear materials licensees, and other organizations involved in the nuclear energy industry.

2 Letter to R. McCullum (NEI) from C.K. Johnson (NRC), September 29, 2022 (ML22244A217).

Mr. John-Chau Nguyen November 4, 2022 Page 2 NEI 22-02 for endorsement by the NRC. Further, we believe that the staffs endorsement review of NEI 22-02 would meet the criteria for a fee exemption under 10 CFR 170.11(a)(1)(ii) and 10 CFR 170.11(d).

Please contact me or Mark Richter of my staff (mar@nei.org) with any comments or questions on the content of this letter.

Sincerely, Rod McCullum Attachments c:

Mr. John Lubinski, NRC/NMSS Mr. Shana Helton, NRC/NMSS/DFM Ms. Linda Howell, NRC/NMSS/DFM NRC Document Control Desk

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nei.org NEI 22-02, Rev 2 GUIDELINES FOR WEATHER-RELATED ADMINISTRATIVE CONTROLS FOR SHORT DURATION OUTDOOR DRY CASK STORAGE OPERATIONS Prepared by the Nuclear Energy Institute November 2022 Revision 2

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nei.org Revision Table Revision Description of Changes Date Modified Responsible Person 1

Respond to NRC request for supplemental information 6/17/22 M. Richter 2

Respond to NRC clarified request for supplemental information 11/10/22 M. Richter

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nei.org Acknowledgements NEI 22-02 was developed by the Nuclear Energy Institute. NEI acknowledges and appreciates the contributions of NEI members and other organizations in providing input, reviewing and commenting on the document. Completion of NEI 22-02 would not have been possible without the support and commitment of the contributors noted below:

NEI Lead: Mark Richter George Carver, NAC International Clay Channel, Southern Nuclear Brian Gutherman, Gutherman Technical Services Karl Harris, Wolf Creek Nuclear Operating Co.

Kenn Hunter, Constellation Generation Matt Keene, Duke Energy Kimberly Manzione, Holtec International Rod McCullum, Nuclear Energy Institute Glenn Schwartz, PSEG Nuclear Doug Yates, TN Americas Notice Neither NEI, nor any of its employees, members, supporting organizations, contractors, or consultants make any warranty, expressed or implied, or assume any legal responsibility for the accuracy or completeness of, or assume any liability for damages resulting from any use of, any information apparatus, methods, or process disclosed in this report or that such may not infringe privately owned rights.

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nei.org Foreword This document provides guidance for licensees of Independent Spent Fuel Storage Installations (ISFSIs) to use for developing weather-related administrative controls applicable to short duration, outdoor dry cask storage (DCS) operations. This guidance does not apply to normal storage operations at the ISFSI.

The purpose of the administrative controls to which this guidance applies is to provide reasonable assurance that a safe condition and forecast is present and is likely to remain during such operations.

This document also provides guidance for administrative controls to address actions to be taken in response to changes in weather forecasts that may occur during short duration outdoor DCS operations.

This guidance provides a shared understanding of the principles guiding the development of appropriate measures that can be implemented by licensees to address the potential for severe weather during a DCS campaign. 10 CFR 72 CoC holders may use this guidance to develop the generic considerations for administrative controls to be used with their particular dry storage system (DSS) technologies. The document also provides resources and implementation guidance to help licensees develop the details of appropriate site-specific administrative controls that cannot be generically specified due to site-specific configurations or conditions.

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nei.org Table of Contents Introduction..................................................................................................................................... 1 Scope of the Guidance..................................................................................................................... 2 2.1 Short Duration Outdoor DCS Activities............................................................................... 2 2.2 Licensing Basis and Administrative Controls...................................................................... 3 Guidance.......................................................................................................................................... 4 3.1 Resources............................................................................................................................ 5 3.2 Use of Safe Condition and Forecast to Guide Decision-making......................................... 5 3.3 Implementation.................................................................................................................. 6 3.4 Generic Implementation Guidance for CoC Holders.......................................................... 7 3.5 Specific Implementation Guidance for General Licensees................................................. 7 References....................................................................................................................................... 9

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nei.org 1 INTRODUCTION This document was prepared in response to NRC questions pertaining to spent nuclear fuel (SNF) dry storage system (DSS) and related auxiliary equipment designs for natural phenomena events0F1. Of particular interest is the potential occurrence of a tornado during dry cask storage (DCS) operations occurring outdoors between the time the loaded SNF cask1F2 is exposed to outdoor conditions and before it is in its storage location at the Independent Spent Fuel Storage Installation (ISFSI).

The activities of interest are short-duration DCS operations that are necessary to transfer the SNF to the ISFSI. These activities are performed outdoors and in equipment configurations for which deterministic tornado wind/missile analyses have not been performed. The types and durations of these activities, and the equipment involved, are defined by the combination of the DSS design and site-specific facility configuration and procedures. Section 2.1 defines and provides examples of short duration outdoor DCS operations. Section 3 provides implementation guidance.

DSS designs and operations are determined to be safe by NRC review and approval of the specific ISFSI license or DSS Certificate of Compliance (CoC) as described in the supporting NRC Safety Evaluation Report (SER). Safe storage of the SNF also depends on licensees using the DSS as described in the approved licensing basis and implementing site-specific administrative controls, as appropriate. This guidance introduces the term safe condition and forecast to define the conditions necessary to proceed with, or continue, short-duration outdoor DCS operations. Safe condition and forecast is defined as follows for the purposes of this guidance2F3:

A safe condition and forecast is considered to be the absence of: tornado and severe thunderstorm watches, tornado and severe thunderstorm warnings, and hazardous weather outlook indicating a moderate or high risk of severe thunderstorms for the current date (Day 1).

Requiring a safe condition and forecast during short-duration outdoor DCS operations has not historically been addressed in the ISFSI or DSS FSAR, or the NRCs SER. Instead, most licensees rely on administrative controls to assure that these operations only take place during times that a safe condition and forecast exists. The multitude of equipment types and configurations that could be possible across the dozens of ISFSI sites in the United States make it infeasible to address every conceivable circumstance at every site.

This document will benefit ISFSI licensees and the NRC by aligning the expectations for a safe condition and forecast during short duration outdoor DCS operations. This guidance provides the principles underpinning the site-specific measures that should be implemented by licensees to address the need for a safe condition and forecast during certain required outdoor operations conducted as part of a DCS campaign. 10 CFR 723F4 CoC holders may use this guidance to develop the generic considerations for administrative controls to be used with their particular DSS technologies. The guidance also provides resources and implementation guidance to help licensees develop appropriate and consistent site-specific administrative controls that cannot be generically specified, because they depend on site-specific factors such as specific weather forecasting resources that may vary by geographic location, 1 Nguyen, John-Chau to Rod McCullum dated September 12, 2022, (Reference 1) 2 As used in this document. cask means a fuel-loaded bare fuel cask, canister inside a transfer cask, or canister inside a storage cask.

3 NRC SNM-2515, Appendix A, Sections 1.1 and 5.4, Amendment 1 (Reference 2) 4 10 CFR Part 72 (Reference 3)

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nei.org 2 details of the loading campaign that vary by design of the system used, etc. The topics of interest include:

Forecast resources that should be consulted prior to initiating short duration outdoor DCS operations and during such operations, Forecast conditions under which short duration outdoor DCS operations may be conducted at time when a safe condition and forecast exists.

This guidance provides a common set of practices acceptable to industry and the NRC for developing the appropriate site-specific procedures or instructions to be implemented at each site. This guidance does not supersede any requirements in an ISFSI specific license, a DSS CoC, or the associated FSARs. The licensing basis as described in those documents always governs.

Administrative controls also play a role in guiding licensee actions with respect to DSS operations, particularly with respect to natural phenomena. This guidance provides a shared understanding of the principles guiding the implementation of appropriate administrative control measures that can be implemented by licensees to address the potential for severe weather during a DCS campaign. The document also provides resources and implementation guidance to help licensees develop the details of appropriate site-specific administrative controls that cannot be generically specified due to site-specific configurations or conditions.

SCOPE OF THE GUIDANCE This section summarizes what is meant by short duration outdoor DCS activities and the use of administrative controls by ISFSI licensees during those activities.

2.1 Short Duration Outdoor DCS Activities This guidance is applicable to short-duration DCS operations conducted outdoors that are necessary at many sites to accomplish moving SNF from wet to dry storage. These activities occur between when the cask loaded with SNF leaves the indoor plant facility and when it is in its storage location at the ISFSI. 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.

The specific types of these activities and ancillary equipment involved vary by DSS design and site facility infrastructure. For these reasons, neither a complete list of all activities and equipment nor a single bounding duration for these activities can be defined. Each licensee must individually determine what, if any, short duration outdoor DCS activities are conducted at its site and the time frames involved.

The overall goal of licensees conducting DCS operations is to move the cask to the ISFSI as expeditiously as possible considering safety, personnel dose, and time in an appropriate balance. Short duration outdoor DCS activities are performed continuously. That is, they continue until completed, i.e., have reached the point where the cask is at the ISFSI in its storage location in its analyzed storage configuration. During these activities, there are also periods where the DSS is in an analyzed condition temporarily (e.g., cask resting on the ground) to allow for shift changes, equipment adjustments, and other operational needs. Importantly, short duration outdoor DCS activities are used to transition from

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nei.org 3 one analyzed configuration to another and are performed pursuant to utilities written procedures or instructions. These activities are conducted under the active control of DCS personnel from start to finish by the work crew and its supervision.

Because short duration outdoor DCS activities require coordination with other plant activities and personnel, there is site-wide awareness, including main control room and shift management personnel.

Furthermore, as part of their normal duties, shift operations personnel are aware of changes to the weather forecast and site procedures or instructions are in place to respond based on the circumstances of the forecast change and the activities ongoing at the time. The response includes making appropriate notifications and announcements to site personnel and ensuring appropriate actions for any ongoing outdoor activity, including DCS activities, are implemented.

Some examples of common short-duration outdoor activities are listed below. Others may exist that are unique to a particular site.

Movement of cask with a motorized crawler, truck and trailer, air pads, rail carts, self-propelled modular transporter, or similar conveyance, Use of an outdoor facility to perform the transfer of the canister from the transfer cask to the storage cask, Removal of the transfer cask lid, insertion of the canister into the horizontal storage module (HSM), retraction of the transfer trailer with the HSM door uninstalled, and installation of the HSM door, Installation of a vertical storage cask lid after the canister has been downloaded from the transfer cask into the storage cask, and Use of a crane or other lifting device to lift or move the cask outside the plant facility or to support transfer of the canister from the transfer cask to the vertical storage cask or HSM.

ISFSI licensees responsible for the safety of the SNF have an obligation to determine if additional controls may be prudent for their particular sites. In doing so, ISFSI licensees use the best available and appropriate methods to provide reasonable assurance of adequate protection of public health and safety. This includes the use of administrative controls.

2.2 Licensing Basis and Administrative Controls Dry storage systems (vertical and horizontal) and transfer casks are designed and analyzed for tornado winds and tornado missiles in accordance with 10 CFR 72.122(b). The DSS designer (i.e., CoC holder) determines the design criteria for the design and supporting analyses, including maximum wind speed and tornado missile size and mass using applicable regulatory guidance. Importantly, the DSSs and transfer casks are assumed to be fully configured for the related safety analyses. That is, lid installed and fully bolted in place. The location of the cask (on ground or situated on a transfer vehicle) may also be specified in the FSAR.

Certain short duration outdoor DCS operations and the ancillary equipment involved often are either not addressed in ISFSI or DSS FSAR at all or are addressed at a high level to allow the operational flexibility individual licensees need. That is, the licensing basis in the FSAR often does not define in detail

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nei.org 4 all scenarios where an SSC may be subject to tornado winds or tornado missiles. Portable lifting devices such as boom cranes and cask transport vehicles (whether classified as important to safety or not) may not be designed or analyzed for high winds and/or tornado missiles because they are used intermittently and for short periods of time to lift and move the loaded cask and these devices are not operated during times when a safe condition and forecast is not present4F5.

Present day weather forecasting capability and technology in the United States is sufficiently sophisticated and accurate to enable ISFSI licensees to reliably determine with high confidence whether a safe condition and forecast will exist during the windows of time required to conduct the various required short duration outdoor DCS activities at their sites. A prediction of a safe condition and forecast for that window provides the basis for the licensee to consider tornadoes as non-credible events during that time. Thus, use of the administrative controls to prohibit commencement of the movement of casks outdoors if a safe condition and forecast is not in place gives the utility reasonable assurance of adequate protection without having conducted tornado missile analyses addressing all configurations that may exist during these short-term windows.

ISFSI licensees also recognize that routine DCS operations conducted outdoors sometimes involve DSS components in an unanalyzed configuration for short time segments. These operations do not require detailed tornado missile analysis due to the low risk associated with them, the extremely low probability of them being disrupted by severe weather during these short time periods, and the further risk reduction provided by administrative controls. This also provides needed operational flexibility and avoids the significant burden that analyzing each and every operational configuration would impose.

Thus, for short duration outdoor DCS activities and component configurations where the licensing basis is silent, it is prudent for ISFSI licensees to have appropriate site-specific administrative controls in place to address the potential for severe weather.

For licensees operating ISFSIs under a Part 72 general license, this guidance recommends that the CoC holders include in the DSS FSARs the generic considerations for developing administrative controls that apply to the DSS technology designs they own related to natural phenomena, where it is not currently addressed. Upon receipt of the approved DSS FSAR change from the CoC holder, a general licensee should review and implement the generic change, as applicable to its site. Guidance for how each of these entities should develop their respective considerations and detailed procedures or instructions is provided in Section 3.4.

GUIDANCE This section describes the resources and principles for licensees to review existing administrative controls and develop or revise DCS-related administrative controls, as necessary to address this guidance. There are both proactive and reactive elements to such administrative controls involving:

Actively checking to confirm a safe condition and forecast before and during short term outdoor DCS operations, and Reacting to alerts regarding the loss of a safe condition and forecast received outside of the active checks (e.g., notification from the control room).

5 In cases where the lifting device is designed in accordance with ASME NOG-1, Section 4134(c) specifically states that the crane will not be operational, but be secured during tornado winds. This implies the ability to predict tornado winds. (Reference 4)

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nei.org 5 3.1 Resources In the United States, the National Weather Service (NWS) is an agency under the National Oceanic and Atmospheric Administration (NOAA), within the Department of Commerce. The NWS manages a hazardous weather outlook program and severe weather alert system that should be used as the resource for confirming a safe condition and forecast before and during short duration outdoor DCS operations. Licensees should use the NWSs hazardous weather outlook information unless another resource for the site is already used or can be justified as providing equivalent information in terms of timeliness and accuracy.

NWS weather forecasting is highly accurate and reliable in the near-term windows of time associated with planning short duration outdoor DCS activities. The NWSs hazardous weather outlook program includes three classifications of severe weather alerts: watch, warning, and advisory. The NWS defines over 40 weather watches, warnings, and advisories.5F6 Those that apply to this guidance to be used to confirm a safe condition and forecast are listed in Section 3.3.

The NWS Active Alerts web page6F7 has several useful links to determine if a safe condition and forecast is in effect for the site for the upcoming time periods of interest, including:

Warnings by State Latest Warnings Thunderstorm/Tornado Outlook Hurricanes Licensees should also use available on-site meteorological data and can also use one of several mobile phone and internet-based applications (e.g., the Weather Channel) to augment the NWS forecast resources and allow receipt of notifications in real time for the site area to confirm a safe condition and forecast. However, mobile phone applications should be considered defense-in-depth and not a replacement for written procedures or instructions.

3.2 Use of Safe Condition and Forecast to Guide Decision-making The overarching principle for this guidance is: short duration outdoor DCS activities are to be avoided if certain watches or warnings are in effect or expected for the geographic area that includes the site. A safe condition and forecast is considered to be the absence of tornado and severe thunderstorm watches, tornado and severe thunderstorm warnings, and hazardous weather outlook indicating a moderate or high risk of severe thunderstorms for the current date (Day 1)7F8. Other NWS advisories should also be considered as reasons to avoid certain DCS operations by ISFSI licensees, case-specifically, based on the particular circumstances of the advisory, as discussed further below.

Avoiding short duration outdoor DCS operations means not conducting these activities until a safe condition and forecast can be established for the site and for the expected duration of the activities. If a 6 Watch/Warning/Advisory Definitions (weather.gov) [Reference 5]

7 Active Alerts (weather.gov/alerts) [Reference 6]

8 See NRC special nuclear materials license SNM-2515, Appendix A, Sections 1.1 and 5.4, Amendment 1. [Reference 2]

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nei.org 6 safe condition and forecast cannot be confirmed before and during short duration outdoor DCS activities, the intent of ISFSI licensee response actions is fundamentally the same - to ensure the cask is placed in an analyzed configuration. Such actions should reflect the specific circumstances and timing of the potential change to the weather forecast as well as the current status of the short duration outdoor DCS operation. Response actions may involve any of the following, depending on the severity and timing of the pending weather situation:

Keeping the cask in a suitable structure, Returning the cask to a suitable structure, Completing the placement of the fully configured cask in its storage location at the ISFSI, Placing the cask in an analyzed configuration at or near its then-current location, or Other action deemed appropriate by the licensee.

3.3 Implementation Licensees should create administrative controls to implement this guidance in the form of new or revised DCS procedures or instructions if existing procedures or instructions do not sufficiently address applicable aspects of this guidance. Such procedures or instructions should be consistent with plant protocols and input from the DSS designer, as necessary, for compensatory actions. Furthermore, existing protocols for plant-wide actions required in the event a severe weather alert is declared for the site should be reviewed and revised, if necessary, to appropriately consider DCS activities in progress at the time. This provides a two-way set of administrative controls for the affected activities.

The procedures or instructions should require a check for any active weather conditions that would be contrary to a safe condition and forecast before outdoor DCS activities commence. The expectation is that unless the weather forecast is acceptable for the entire duration of short-duration outdoor activities, such activities will not commence. Even though near-term weather forecasts are highly reliable, the procedures or instructions should also include checking the future radar projections for the plant site. Outdoor activities should be prohibited if a licensee independently determines that severe weather is likely at any time over the expected duration of the outdoor activity. Lastly, the responsible personnel should also decide if an advisory (as opposed to one of the watches or warnings listed above) or other weather forecast information (e.g., temperature, wind, etc.) should prohibit such operations based on the particular circumstances of that advisory or other forecast information.

Depending on the expected duration of the DCS activity, the procedures or instructions should include additional checks of the weather forecast one or more times during the activity. Licensees should decide if, and how frequently, additional weather forecast checks should be performed and include that frequency in procedures or instructions. These formal forecast checks should be recorded and maintained with the documentation for the DCS campaign. Licensees may also wish to consider, as a defense-in-depth measure, having designated DCS personnel download an application to a mobile device that will provide immediate notification of the loss of a safe condition and forecast affecting the site in real time.

Lastly, the procedures or instructions for implementing the administrative controls should include guidance at a level of detail sufficient for specific actions to be taken if the weather forecast changes.

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nei.org 7 Such information could come from a planned check of the forecast, notification from the plant control room, an alert from a mobile device application, or other source. Information not verified to have come from the NWS or other source approved by the site and specified in procedures/instructions should be validated. Sections 3.4 and 3.5 provide additional details for CoC holders and general licensees to implement this guidance. Specifically licensed ISFSI sites and sites operating ISFSIs under both a specific and a general license should combine these details in an appropriate manner to develop the administrative controls for those sites.

3.4 Generic Implementation Guidance for CoC Holders Once this guidance is endorsed by the NRC, CoC holder actions to implement it will not require NRC approval in the form of an ISFSI license or DSS CoC amendment. CoC holders should develop a change to the DSS FSAR Operations chapter, reviewed under the provisions of 10 CFR 72.48, that addresses this guidance. This guidance may be considered an NRC-approved approach to developing weather-related administrative controls. This approach to administrative controls is not a method of evaluation (MOE) as defined in NEI 12-04 because it does not meet the MOE definition. Rather, revisions to the administrative controls would be reviewed as a modification to the method of performing or controlling a design function. If the 10 CFR 72.48 screening process determines the revision to the administrative controls is a change, (i.e., has an adverse effect) a 10 CFR 72.48 evaluation would be performed.

The DSS FSAR change should apply this guidance to the DSS designs described in that FSAR and provide the appropriate instructions to general licensees using the DSS design so that general licensees may develop site-specific implementing procedures or instructions. Deviations from this guidance by the CoC holder should be identified, justified, and specifically considered in the 10 CFR 72.48 review of the FSAR change. 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.

3.5 Specific Implementation Guidance for General Licensees General licensees should use the DSS FSAR information developed by the CoC holder described above to create site-specific, detailed implementing procedures or instructions. The procedures or instructions should be briefly summarized in the sites 10 CFR 72.212 Report section required by 10 CFR 72.212(b)(6) with appropriate references to the CoC holders guidance and the procedures or instructions. The procedures or instructions should include the following:

a. The type of activity, configuration, and equipment being used in short-duration outdoor DCS activities.

b. The location and estimated duration of each short-duration outdoor activity when the SNF cask and associated equipment are in an unanalyzed configuration.

c. Site-specific characteristics that could affect the times frames for short-duration outdoor DCS activities.

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nei.org 8

d. The use of operating experience from previous short-duration outdoor DCS activities.

e. The definition of analyzed configuration as determined by the CoC holder.

f.

The time frames required to move the cask to an analyzed configuration.

g. The site structures available to temporarily place the cask should a safe condition and forecast be lost during short-duration outdoor DCS activities.

The procedures or instructions implementing the administrative controls should be developed with compensatory actions based on CoC holder input. The procedures or instructions should include a clear definition of roles and responsibilities and lines of communication (i.e., within the DCS work crew and between the DCS shift supervision and the plant control room). Compensatory actions to be taken as part of the administrative controls if the weather forecast changes during short-duration outdoor activities should be specified in the procedures or instructions. Such compensatory actions should be clear, detailed, and specifically tied to the location and configuration of the SNF cask and associated equipment to avoid delays and confusion during implementation. Deviations from the CoC holder generic instructions in the DSS FSAR require review pursuant to 10 CFR 72.48 as a potential change to a method of performing or controlling a design function.

Implementing procedures or instructions should contain specific steps to document the satisfactory execution of the weather forecast check before and, if required, periodic checks during the outdoor activity. DCS shift supervisory personnel should be involved in determining the satisfactory execution of the weather forecast check(s).

Compensatory actions should be taken without delay, in a controlled, deliberate manner considering the concomitant need to provide for personnel safety. Once the SNF cask is in an analyzed configuration, it may remain in that configuration for the time necessary for the weather to clear and DCS operations to safely resume. The need for additional qualified personnel to implement the compensatory actions should be considered, along with providing the necessary training.

Malfunctions and unexpected delays during short-duration outdoor activities can and do occur.

However, they are infrequent and the likelihood of a malfunction or delay occurring at the same time as the unexpected loss of a safe condition and forecast is so low, it should be considered non-credible.

Such malfunctions and delays are outside the scope of this guidance and should be handled on a case-specific basis and within the sites corrective action program, at the licensees discretion.

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nei.org 9 REFERENCES

1. Nguyen, John-Chau to Rod McCullum, Acceptance of Request for Review and Endorsement of NEI 22 Guidelines for Weather-Related Administrative Controls for Short Duration Outdoor Dry Cask Storage Operations (CAC NO. A33009, EPID: L-2022-NFO-0008), dated September 12, 2022. ML22216A117

2. NRC Special Nuclear Materials License SNM-2515, Interim Storage Partners WCS Consolidated Interim Storage Facility, including Appendix A, Technical Specifications. ML21188A096

3. Title 10, Code of Federal Regulations (10 CFR), Part 72, Licensing Requirements for the Independent Storage of Spent Nuclear Fuel, High-Level Radioactive Waste, and Reactor-Related Greater than Class C Waste, U.S. Nuclear Regulatory Commission.

4. Rules for Construction of Overhead and Gantry Cranes (Top Running Bridge, Multiple Girder),

NOG-1-2020, American Society of Mechanical Engineers, 2020.

5. National Weather Service, Glossary, https://w1.weather.gov/glossary/

6. National Weather Service, Active Alerts, https://www.weather.gov/alerts Although not cited in this guidance, the following documents are closely related to its use and are recommended for additional information.

NRC Enforcement Guidance Memorandum 22-001, Enforcement Discretion for Noncompliance of Tornado Hazards Protection Requirements at Independent Spent Fuel Storage Installations, April 15, 2022.

NUREG-2215, Standard Review Plan for Spent Fuel Dry Storage Systems and Facilities, U.S.

Nuclear Regulatory Commission.

NRC Regulatory Guide 1.76, Design Basis Tornado and Tornado Missiles for Nuclear Power Plants, Revision 1, U.S. Nuclear Regulatory Commission.