[Federal Register Volume 80, Number 173 (Tuesday, September 8, 2015)]
[Rules and Regulations]
[Pages 53691-53694]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-22053]



 ========================================================================
 Rules and Regulations
                                                 Federal Register
 ________________________________________________________________________
 
 This section of the FEDERAL REGISTER contains regulatory documents 
 having general applicability and legal effect, most of which are keyed 
 to and codified in the Code of Federal Regulations, which is published 
 under 50 titles pursuant to 44 U.S.C. 1510.
 
 The Code of Federal Regulations is sold by the Superintendent of Documents. 
 Prices of new books are listed in the first FEDERAL REGISTER issue of each 
 week.
 
 ========================================================================
 

  Federal Register / Vol. 80, No. 173 / Tuesday, September 8, 2015 / 
Rules and Regulations  

[[Page 53691]]



NUCLEAR REGULATORY COMMISSION

10 CFR Part 72

[NRC-2015-0067]
RIN 3150-AJ58


List of Approved Spent Fuel Storage Casks: Holtec International 
HI-STORM UMAX Canister Storage System, Certificate of Compliance No. 
1040, Amendment No. 1

AGENCY: Nuclear Regulatory Commission.

ACTION: Direct final rule; confirmation of effective date.

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

SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is confirming the 
effective date of September 8, 2015, for the direct final rule that was 
published in the Federal Register on June 23, 2015. This direct final 
rule amended the NRC's spent fuel storage regulations by revising the 
Holtec International, Inc. (Holtec), HI-STORM (Holtec International 
Storage Module) Underground Maximum Capacity (UMAX) Canister Storage 
System listing within the ``List of approved spent fuel storage casks'' 
to add Amendment No. 1 to Certificate of Compliance (CoC) No. 1040. 
Amendment No. 1 provides a seismically enhanced version of the HI-STORM 
UMAX Canister Storage System, identified as the ``Most Severe 
Earthquake (MSE)'' version that could be used in areas with higher 
seismic demands than those analyzed previously. Amendment No. 1 also 
includes minor physical design changes to help ensure structural 
integrity of the amended system. These are the addition of a hold-down 
system to the closure lid; replacing the fill material in the 
interstitial spaces between the cavity enclosure containers (CECs) 
surrounding the casks with 3000 psi concrete; strengthening the multi-
purpose canister (MPC) guides, and engineering the guides' nominal gap 
with the MPC to be tighter than the original HI-STORM UMAX Canister 
Storage System design.

DATES: Effective date: The effective date of September 8, 2015, for the 
direct final rule published June 23, 2015 (80 FR 35829), is confirmed.

ADDRESSES: Please refer to Docket ID NRC-2015-0067 when contacting the 
NRC about the availability of information for this action. You may 
obtain publicly-available information related to this action by any of 
the following methods:
     Federal Rulemaking Web site: Go to http://www.regulations.gov and search for Docket ID NRC-2015-0067. Address 
questions about NRC dockets to Carol Gallagher; telephone: 301-415-
3463; email: [email protected]. For technical questions, contact 
the individual listed in the FOR FURTHER INFORMATION CONTACT section of 
this document.
     NRC's Agencywide Documents Access and Management System 
(ADAMS): You may obtain publicly-available documents online in the 
ADAMS Public Documents collection at http://www.nrc.gov/reading-rm/adams.html. To begin the search, select ``ADAMS Public Documents'' and 
then select ``Begin Web-based ADAMS Search.'' For problems with ADAMS, 
please contact the NRC's Public Document Room (PDR) reference staff at 
1-800-397-4209, 301-415-4737, or by email to [email protected].
     NRC's PDR: You may examine and purchase copies of public 
documents at the NRC's PDR, Room O-1F21, One White Flint North, 11555 
Rockville Pike, Rockville, Maryland 20852.

FOR FURTHER INFORMATION CONTACT: Solomon Sahle, Office of Nuclear 
Material Safety and Safeguards, U.S. Nuclear Regulatory Commission, 
Washington, DC 20555-0001; telephone: 301-415-3781; email: 
[email protected].

SUPPLEMENTARY INFORMATION:

I. Discussion

    On June 23, 2015 (80 FR 35829), the NRC published a direct final 
rule amending its regulations in Sec.  72.214 of Title 10 of the Code 
of Federal Regulations (10 CFR) by revising the Holtec HI-STORM UMAX 
Canister Storage System listing within the ``List of approved spent 
fuel storage casks'' to add Amendment No. 1 to CoC No. 1040. Amendment 
No. 1 provides a seismically enhanced version of the HI-STORM UMAX 
Canister Storage System, identified as the ``Most Severe Earthquake 
(MSE)'' version that could be used in areas with higher seismic demands 
than those analyzed previously. Amendment No. 1 also includes minor 
physical design changes to help ensure structural integrity of the 
amended system. These are the addition of a hold-down system to the 
closure lid; replacing the fill material in the interstitial spaces 
between the CECs surrounding the casks with 3000 psi concrete; 
strengthening the MPC guides, and engineering the guides' nominal gap 
with the MPC to be tighter than the original HI-STORM UMAX Canister 
Storage System design.

II. Public Comments on the Companion Proposed Rule

    In the direct final rule, the NRC stated that if no significant 
adverse comments were received, the direct final rule would become 
effective on September 8, 2015. The NRC received 10 comment submittals 
on the companion proposed rule (80 FR 35872). Electronic copies of 
these comments can be obtained from the Federal Rulemaking Web site, 
http://www.regulations.gov, by searching for Docket ID NRC-2015-0067. 
The comments are also available in ADAMS under Accession Nos. 
ML15210A145, ML15210A150, ML15210A151, ML15210A155, ML15210A169, 
ML15210A164, ML15210A166, ML15210A177, ML15210A181, and ML15210A184. 
For the reasons discussed in more detail in Section III, ``Public 
Comment Analysis,'' of this document, none of the comments received are 
considered significant adverse comments as defined in NUREG/BR-0053, 
Revision 6, ``United States Nuclear Regulatory Commission Regulations 
Handbook'' (ADAMS Accession No. ML052720461).

III. Public Comment Analysis

    The NRC received 10 comment submittals on the proposed rule, many 
raising multiple and overlapping issues. As explained in the June 23, 
2015, direct final rule (80 FR 35829), the NRC would withdraw the 
direct final rule only if it received a ``significant adverse 
comment.'' This is a comment where the

[[Page 53692]]

commenter explains why the rule would be inappropriate, including 
challenges to the rule's underlying premise or approach, or would be 
ineffective or unacceptable without a change. A comment is adverse and 
significant if:
    (1) The comment opposes the rule and provides a reason sufficient 
to require a substantive response in a notice-and-comment process. For 
example, a substantive response is required when:
    (a) The comment causes the NRC staff to reevaluate (or reconsider) 
its position or conduct additional analysis;
    (b) The comment raises an issue serious enough to warrant a 
substantive response to clarify or complete the record; or
    (c) The comment raises a relevant issue that was not previously 
addressed or considered by the NRC staff.
    (2) The comment proposes a change or an addition to the rule, and 
it is apparent that the rule would be ineffective or unacceptable 
without incorporation of the change or addition.
    (3) The comment causes the NRC staff to make a change (other than 
editorial) to the rule, CoC, or Technical Specifications (TSs).
    The NRC determined that none of the comments submitted on this 
direct final rule met any of these criteria. The comments either were 
already addressed by the NRC staff's safety evaluation report (SER) 
(ADAMS Accession No. ML15070A149), or were beyond the scope of this 
rulemaking. The NRC has not made any changes to the direct final rule 
as a result of the public comments. However, the NRC is taking this 
opportunity to respond to some of the comments in an effort to clarify 
information about the 10 CFR part 72 CoC rulemaking process.
    For rulemakings amending or revising a CoC, the scope of the 
rulemaking is limited to the specific changes requested by the 
applicant in the request for the amendment or amendment revision. 
Therefore, comments about the system or spent fuel storage in general 
that are not applicable to the changes requested by the applicant are 
outside the scope of this rulemaking. Comments about details of the 
particular system that is the subject of the rulemaking, but that are 
not being addressed by the specific changes requested, have already 
been resolved in prior rulemakings. Persons who have questions or 
concerns about prior rulemakings and the resulting final rules may 
consider the NRC's process for petitions for rulemaking under 10 CFR 
2.802. Additionally, safety concerns about any NRC-regulated activity 
may be reported to the NRC in accordance with the guidance posted on 
the NRC's Web site at http://www.nrc.gov/about-nrc/regulatory/allegations/safety-concern.html. This Web page provides information on 
how to notify the NRC of emergency or non-emergency issues.
    The NRC identified the following issues raised in the comments, and 
the NRC's responses to these issues follow.

(1) Potential Supersonic Shear Earthquakes and Site Specific Seismic 
Standards

    Several commenters raised concerns regarding the ability of this 
CoC system to withstand seismic events, particularly if the system were 
to be used at specific sites with known seismic activity, such as San 
Onofre Nuclear Generating Station (SONGS). These commenters stated that 
Holtec casks have not been tested for newly discovered potential 
Supersonic Shear Earthquakes, which might result in a rupture after 
Supersonic Shear Earthquake Events. According to the comments, cask 
venting can be blocked after a tsunami leading to cask failure.

NRC Response

    These comments are outside the scope of this rulemaking because 
they are not specific to the amendment at issue in the rule, but 
instead raise concerns with the general 10 CFR part 72 requirements and 
process for certification of the CoC systems. This rule adds Amendment 
No. 1 to the HI-STORM UMAX Canister Storage System, CoC No. 1040. 
Applicants submitting CoC's for approval are required to document a 
design bases for their CoC or amendment CoC, which includes seismic 
parameters. Under 10 CFR 72.212(b)(6), general licensees (power 
reactors seeking to use those CoC systems at their specific sites) are 
required to conduct a review of the CoC's Final Safety Analysis Report 
(FSAR) and the related NRC SER prior to use of the general license to 
ensure that the reactor site parameters, including analyses of 
earthquake intensity, are enveloped by the cask design bases considered 
in these reports. This rulemaking makes no determination regarding the 
acceptability of this amended system for use at any specific site. Nor 
does this rule seek to change the existing generic nature of CoC 
approvals or the technical qualifications outlined for CoC approval, as 
currently envisioned in 10 CFR part 72. Commenters with concerns 
regarding the existing 10 CFR part 72 regulations for technical review 
and approval of CoC systems could consider filing a petition for 
rulemaking under 10 CFR 2.802.

(2) Wind Effect on Underground Cask Maximum Heat Load

    Commenters stated that according to NUREG-2174 ``Impact of 
Variation in Environmental Conditions on the Thermal Performance of Dry 
Storage Casks'' (ADAMS Accession No. ML15054A207), low-speed wind 
conditions increased the peak cladding temperature on underground 
systems, and asked whether this was considered in the development of 
the heat load limits of the HI-STORM UMAX Canister Storage System.

NRC Response

    The comment is outside the scope of this rulemaking because it is 
not specific to the amendment at issue in the rule. The NRC evaluated 
and approved the HI-STORM UMAX Canister Storage System heat loads in 
the initial CoC certification, and this is provided in its SER (ADAMS 
Accession No. ML15093A510). The Amendment No. 1 application requested 
no thermal changes that required NRC evaluation.

(3) MPC Seismic Evaluation

    A commenter stated that the thin stainless steel MPC canisters are 
subject to pitting and corrosion (particularly from marine environments 
like chloride-induced stress corrosion cracking). According to the 
comment, since cracks may initiate during the initial licensing period 
in these canisters, cracking canisters should be included in the 
seismic analysis for MPC's stored while in the HI-STORM UMAX Canister 
Storage System since it would be of more concern in high risk seismic 
areas as proposed for this UMAX Amendment.

NRC Response

    The comment is outside the scope of this rulemaking because it is 
not specific to the amendment at issue in the rule. The NRC has 
evaluated the design of the HI-STORM UMAX Canister Storage System and 
has determined that the design is robust, and contains a number of 
layers of acceptable confinement systems in compliance with 10 CFR part 
72 requirements. Furthermore, the NRC has evaluated the susceptibility 
to and effects of stress corrosion cracking and other corrosion 
mechanisms on safety significant systems for spent nuclear fuel (SNF) 
dry cask storage (DCS) systems during an initial certification period. 
The NRC staff has determined that the HI-STORM UMAX Canister Storage 
System, when used within the requirements of the proposed CoC, will 
safely store SNF and prevent radiation releases and exposure consistent 
with

[[Page 53693]]

regulatory requirements, including seismic requirements. This 
evaluation is documented in the NRC staff's SERs (ADAMS Accession Nos. 
ML15070A149 and ML14202A031).

(4) Transfer Cask

    Commenters ask if the transfer casks were approved for storage of 
an MPC in case of a failed MPC.

NRC Response

    To the extent that this comment raises a concern with the 
availability of a transfer cask, it raises an issue that was addressed 
in the NRC's evaluation of this amendment and fails to cite any 
specific information that would alter the NRC's conclusions. In this 
case, the transfer cask utilized in the HI-STORM UMAX Canister Storage 
System is described in the HI-STORM Flood/Wind (F/W) Multipurpose 
Canister (MPC) Storage System FSAR (ADAMS Accession No. ML15177A336). 
The HI-STORM UMAX transfer cask is authorized to transfer intact MPC's 
in accordance with the CoC No. 1040 TSs.

(5) Failed Canister Remediation

    A commenter asked if there is a plan to remediate a failed 
canister.

NRC Response

    The comment is outside the scope of this rulemaking because it is 
not specific to the amendment at issue in the rule, but instead raises 
a concern with the general 10 CFR part 72 requirement and process for 
certification of the CoC systems. Implementing corrective actions in 
the event of a failed MPC is the responsibility of the general licensee 
and those corrective actions are not incorporated into CoC No. 1040.

(6) MPC Thickness

    Commenters questioned the maximum MPC thickness allowed in this 
amendment, noting that although the FSAR indicated 0.5'' as the maximum 
thickness, Holtec has proposed using a thickness of 0.625 at San Onofre 
(SONGS). The commenters raised concerns regarding the implications of 
such a change outside of a license amendment where it could be properly 
evaluated to determine if the change in limiting parameters will affect 
seismic, thermal, weight, dimensions and other critical analyses.

NRC Response

    The comment is outside the scope of this rulemaking because it is 
not specific to the amendment at issue in the rule, but instead raises 
concerns with the general 10 CFR part 72 requirements and process for 
certification of the CoC systems. The nominal MPC thickness for the 
canisters certified under CoC No. 1040, Amendment No. 1 is 0.5''. The 
NRC has no knowledge of a Holtec proposal to increase the thickness of 
an MPC to 0.625''. If presented with an amendment request to do so, the 
NRC will evaluate it in accordance with 10 CFR part 72 requirements.

(7) Definition of ``Long-term''

    Commenters requested the NRC require a definition of ``long-term'' 
in the FSAR.

NRC Response

    The comment is outside the scope of this rulemaking because it is 
not specific to the amendment at issue in the rule, but instead raises 
general concerns regarding terminology. The definitions required by the 
NRC to support the evaluation and approval of CoC No. 1040, Amendment 
No. 1, are provided in Appendix A of the CoC, Technical Specifications 
for the HI-STORM UMAX Canister Storage System. ``Long-term'' is a 
general descriptive term that is not required to support any regulatory 
or technical evaluation, and thus is not required to be more formally 
defined.

(8) Definition of Underground

    Commenters requested the NRC define the term ``underground'' as 
used in this system. The comments raised concerns that a structure that 
is only partially underground, but covered on the side with an 
``earthen berm,'' could still be considered ``underground'' for 
compliance with this CoC.

NRC Response

    The comments regarding the need to define the term ``underground'' 
as used in the HI-STORM UMAX Canister Storage System are outside the 
scope of this rulemaking because they are not specific to the amendment 
at issue in the rule, but instead raise concerns with the general 10 
CFR part 72 requirements and process for certification of CoC systems. 
In this instance, Holtec has provided and analyzed specific structure 
placement parameters, and the NRC has evaluated these parameters that 
bound the placement of such a system in the ground. Pursuant to the 
regulatory requirements in 10 CFR 72.212(b), any general licensee that 
seeks to use this system must determine that the design and 
construction of the system, structures, and components are bounded by 
the conditions of the CoC by analyzing the generic parameters provided 
and analyzed in the FSAR and SER to ensure that its site specific 
parameters are enveloped by the cask design bases established in these 
reports. The NRC is aware of the SONGS proposed configuration submitted 
to the California Coastal Commission and is closely monitoring this 
issue. The NRC will continue to ensure that the facility constructed at 
SONGS meets the requirements of the CoC and TS of the specific DCS 
system selected by Southern California Edison.

(9) Heat Load Charts

    One commenter stated that the FSAR indicates that changes to 
storage cell kW heat loads were made and requested that the NRC 
determine if this was evaluated in the amendment request. The comment 
also requested clarification on the placement configuration of SNF 
assemblies in the MPC, as well as the rationale for the heat load 
configuration.

NRC Response

    This comment is outside the scope of this rulemaking because it is 
not specific to the amendment at issue in the rule, but instead raises 
concerns with the general 10 CFR part 72 requirements and process for 
certification of CoC systems. The comment is addressing revision bars 
that are incorporated into the HI-STORM UMAX Canister Storage System 
FSAR, Revision 2 (ADAMS Accession No. ML14202A031). The tables 
referenced in the comment were revised due to changes made during the 
original HI-STORM UMAX Canister Storage System evaluation; 10 CFR 
72.248(a)(1) requires that an updated FSAR reflecting any changes made 
during the NRC review process be submitted within 90 days after an 
approval of the cask design. The loading patterns were evaluated and 
approved by the NRC staff in its initial SER (ADAMS Accession No. 
ML15093A510). The Amendment No. 1 application required no further 
changes to these tables requiring NRC evaluation.

(10) MPC Inspection

    A commenter requested that the NRC clarify that the MPC leak test 
inspection, that is used to verify the integrity of the confinement 
boundary, is performed before the MPC is loaded with fuel.

NRC Response

    This comment is outside the scope of this rulemaking because it is 
not specific to the amendment at issue in the rule, but instead raises 
concerns with the general 10 CFR part 72 requirements and process for 
certification of CoC systems. The HI-

[[Page 53694]]

STORM F/W MPC Canister System FSAR clearly identifies the purpose of 
the MPC leak detection requirement as a post fabrication certification 
test that is only required to be performed one time.

(11) Assumption of No Fuel Cladding Degradation After Dry Storage Is 
Not Substantiated

    Some commenters raised an issue with Holtec's claim that there is 
no credible mechanism for gross fuel cladding degradation of fuel 
classified as undamaged during storage in the HI-STORM UMAX Canister 
Storage System.

NRC Response

    These comments are outside the scope of this rulemaking because 
they are not specific to the amendment at issue in the rule. Instead, 
these comments raise issues that would be addressed during any renewal 
application review. The NRC has determined that fuel cladding 
degradation is not an issue during the initial 20-year certification 
period, but instead, is an issue that would have to be addressed if a 
CoC holder requested renewal of the CoC for a period beyond the initial 
20 years. If a renewal application is filed, NRC regulations require 
that the application include programs to manage the effects of aging, 
including necessary monitoring and inspection programs. Those programs 
would have to be reviewed and determined acceptable by the NRC before 
any CoC renewal is approved.

(12) Vertical Ventilated Module Needs Substantiation for Expected 
Lifespan

    Commenters questioned Holtec's claims of a design life of 60 years, 
a service life of 100 years and a licensed life of 40 years. Since no 
substantiation was provided for these claims, the commenters requested 
the claims be removed from the FSAR.

NRC Response

    This issue is outside of the scope of this rulemaking because the 
term of a certificate is determined in the original certification, not 
in amendments to that certification. This rulemaking seeks to add 
Amendment No. 1 to CoC No. 1040. In this case, the UMAX CoC was 
approved on March 6, 2015 (80 FR 12073), for an initial 20-year term. 
This 20-year term will also apply to Amendment No. 1. Use of this 
system beyond the expiration date of 20 years would require an 
evaluation of a renewal application for this CoC which would be 
addressed in a subsequent rulemaking process.

(13) Concrete Inspection and Inspection Limitations

    Some commenters questioned whether the HI-STORM UMAX Canister 
Storage System design provided a safe and accessible method to perform 
inspections within the license period given that high seismic risk 
areas are more likely to cause cracking or other structural changes, 
and indicated that such an evaluation should be part of the NRC's 
review process.

NRC Response

    This comment is outside the scope of this rulemaking because it is 
not specific to the amendment at issue in the rule, but instead raises 
concerns with the general 10 CFR part 72 requirements and process for 
certification of CoC systems. The NRC has determined that concrete 
degradation is not an issue requiring inspection during the initial 20-
year certification period, but instead, is an issue that would have to 
be addressed if a CoC holder requested renewal of the CoC for a period 
beyond the initial 20 years. If a renewal application is filed, NRC 
regulations require that the application include programs to manage the 
effects of aging, including necessary monitoring and inspection 
programs. Those programs would have to be reviewed and determined 
acceptable by the NRC before any CoC renewal is approved.

(14) High Burnup Fuel

    Commenters also raised questions regarding the long-term 
acceptability of the extended storage of high burnup fuel (HBF).

NRC Response

    To the extent these comments raise issues about the storage of HBF 
in the CoC for the first 20 years, these comments are outside the scope 
of this rulemaking. The NRC has evaluated the acceptability of storage 
of HBF for the initial 20-year certification term for the HI-STORM UMAX 
Canister Storage System during its review of the initial certificate. 
As documented in the NRC staff's SER under Docket ID NRC-2014-0120, the 
NRC staff has determined that the use of the HI-STORM UMAX Canister 
Storage System, including storage of HBF, will be conducted in 
compliance with the applicable regulations of 10 CFR part 72, and the 
CoC should be approved for the initial 20-year term. This amendment 
does not impact the analysis conducted by the NRC staff during the 
initial certification of this system.
    Additionally, to the extent these comments raise concerns regarding 
the storage of HBF beyond the initial term of 20 years, the comments 
are also outside the scope of this rulemaking. A request to store HBF 
beyond the initial 20 years provided in the certification of this 
system will require the applicant to submit a license renewal 
application with the inclusion of Aging Management Programs addressing 
HBF. In that regard, a demonstration project is being planned by the 
U.S. Department of Energy to provide confirmatory data on the 
performance of HBF in DCS. The NRC plans to evaluate the data obtained 
from the project to confirm the accuracy of current models that are 
relied upon for authorizing the storage of HBF for extended storage 
periods beyond the initial 20-year certification term.
    The NRC staff has concluded that the comments received on the 
companion proposed rule for the Holtec HI-STORM UMAX Canister Storage 
System, CoC No. 1040, Amendment No. 1, are not significant adverse 
comments as defined in NUREG/BR-0053, Revision 6, ``United States 
Nuclear Regulatory Commission Regulations Handbook.'' Therefore, this 
rule will become effective as scheduled.

    Dated at Rockville, Maryland, this 1st day of September, 2015.

    For the Nuclear Regulatory Commission.
Cindy Bladey,
Chief, Rules, Announcements, and Directives Branch, Division of 
Administrative Services, Office of Administration.
[FR Doc. 2015-22053 Filed 9-4-15; 8:45 am]
 BILLING CODE 7590-01-P