[Federal Register Volume 79, Number 250 (Wednesday, December 31, 2014)]
[Notices]
[Pages 78912-78915]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2014-30718]


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NUCLEAR REGULATORY COMMISSION

[Docket Nos. 50-313, 50-368, 72-13, and 72-1014; NRC-2014-0270]


Independent Spent Fuel Storage Installation, Entergy Operations, 
Inc.; Arkansas Nuclear One, Units 1 and 2

AGENCY: Nuclear Regulatory Commission.

ACTION: Exemption; issuance.

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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is issuing an 
exemption in response to an October 2, 2014, request from Entergy 
Operations, Inc., (Entergy or licensee) from the requirement to comply 
with the terms, conditions, and specifications in Section 2.1 of 
Appendix B of the Technical Specifications for certificate of 
compliance (CoC) No. 1014, Amendment No. 5.

DATES: Notice of issuance of exemption given on December 31, 2014.

ADDRESSES: Please refer to Docket ID NRC-2014-0270 when contacting the 
NRC about the availability of information regarding this document. You 
may obtain publicly-available information related to this document 
using any of the following methods:
     Federal Rulemaking Web site: Go to http://www.regulations.gov and search for Docket ID NRC-2014-0270. Address 
questions about NRC dockets to Carol Gallagher; telephone: 301-287-
3422; 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]. The 
ADAMS accession number for each document referenced in this document 
(if that document is available in ADAMS) is provided the first time 
that a document is referenced.
     NRC's PDR: You may examine and purchase copies of public 
documents at the NRC's PDR, Room O1-F21, One White Flint North, 11555 
Rockville Pike, Rockville, Maryland 20852.

FOR FURTHER INFORMATION CONTACT: Chris Allen, Office of Nuclear 
Material Safety and Safeguards, telephone: 301-287-9225, email: 
[email protected]; U.S. Nuclear Regulatory Commission, Washington, 
DC 20555.

SUPPLEMENTARY INFORMATION:

I. Background

    Entergy is the holder of Facility Operating License Nos. DRP-51 and 
NPF-6, which authorize operation of ANO, Units 1 and 2, in 
Russellville, Arkansas, pursuant to part 50 of title 10 of the Code of 
Federal Regulations (10 CFR). The licenses provide, among other things, 
that the facility is subject to all rules, regulations, and orders of 
the NRC now or hereafter in effect.
    Under subpart K of 10 CFR part 72, a general license has been 
issued for the storage of spent fuel in an independent spent fuel 
storage installation (ISFSI) at power reactor sites to persons 
authorized to possess or operate nuclear

[[Page 78913]]

power reactors under 10 CFR part 50. Entergy is licensed to operate a 
nuclear power reactor under 10 CFR part 50, and authorized under the 10 
CFR part 72 general license to store spent fuel at the ANO ISFSI. Under 
the terms of the general license, Entergy stores spent fuel using the 
Holtec International (Holtec) HI-STORM 100 System CoC No.1014 at ANO.

II. Request/Action

    While performing drying operations on a loaded Holtec HI-STORM 100 
Model 24 Multi-Purpose Canister (MPC-24), serial number MPC-24-060, 
Entergy detected Krypton-85 (Kr-85) gas. Kr-85 gas is a fission product 
gas and its presence may indicate fuel rods with greater than pinhole 
leaks or hairline cracks. Section 2.1 of Appendix B of the Technical 
Specifications for the HI-STORM 100 CoC No. 1014 specifies that only 
intact fuel assemblies, which is defined as fuel assemblies without 
known or suspected cladding defects greater than pinhole leaks or 
hairline cracks and which can be handled by normal means, are 
authorized for loading into an MPC-24 canister. Entergy stated that 
although all fuel assemblies loaded into MPC-24-060 were tested 
subsequent to their final operating cycle using standard, accepted 
methods (i.e., in-mast sipping and ultrasonic testing), and were 
visually inspected for indications of rod damage, assembly damage, or 
other potential issues before being loaded into the canister, a fuel 
assembly with a defect greater than a pinhole leak or hairline crack 
may have been loaded into MPC-24-060.
    By letter dated October 2, 2014, as supplemented October 14 and 
November 7, 2014 (ADAMS Accession Nos. ML14279A246, ML14289A239, and 
ML14311A121, respectively), Entergy requested an exemption from the 
following requirements to allow storage of MPC-24-060 in its current, 
as-loaded, condition at the ANO ISFSI:
     10 CFR 72.212(a)(2), which limits the storage of spent 
fuel to casks approved in subpart K of 10 CFR part 72.
     10 CFR 72.212(b)(11), which states, in part, that the 
``licensee shall comply with the terms, conditions, and specifications 
of the CoC . . .''

III. Discussion

    Pursuant to 10 CFR 72.7, the Commission may, upon application by 
any interested person or upon its own initiative, grant exemptions from 
the requirements of the regulations of 10 CFR part 72 as it determines 
are authorized by law and will not endanger life or property or the 
common defense and security and are otherwise in the public interest. 
In addition to the requirements from which Entergy requested exemption, 
the NRC determined exemption from the following requirements would be 
necessary to authorize Entergy's proposal:
     10 CFR 72.212(b)(3), which requires that each cask used by 
the general licensee conforms to the terms, conditions, and 
specifications of a CoC listed in Sec.  72.214.
     10 CFR 72.212(b)(5)(i), which requires written evaluations 
be performed before use that a loaded cask will conform to the terms, 
conditions, and specifications of a CoC listed in Sec.  72.214.
     10 CFR 72.214, which lists the casks approved for storage 
of spent fuel under conditions specified in their CoCs.

Authorized by Law

    This exemption would allow the licensee to store MPC-24-060 (loaded 
with spent nuclear fuel assemblies which are not authorized per Section 
2.1 of Appendix B of the Technical Specifications for CoC No. 1014, 
Amendment No. 5) in its as-loaded configuration at the ANO ISFSI. The 
provisions in 10 CFR part 72 from which Entergy requested an exemption, 
as well as the provisions considered by the NRC, require the licensee 
to comply with the terms, conditions, and specifications of the CoC for 
the approved cask model that it uses.
    Section 72.7 allows the NRC to grant exemptions from the 
requirements of 10 CFR part 72. Issuance of this exemption is 
consistent with the Atomic Energy Act of 1954, as amended, and not 
otherwise inconsistent with NRC regulations or other applicable laws. 
As explained below, the proposed exemption will not endanger life or 
property, or the common defense and security, and is otherwise in the 
public interest. Therefore, the exemption is authorized by law.

Will Not Endanger Life or Property or the Common Defense and Security

    The requested exemption would allow the licensee to store MPC-24-
060 (loaded with spent nuclear fuel assemblies which are not authorized 
per Section 2.1 of Appendix B of the Technical Specifications for CoC 
No. 1014, Amendment No. 5) in its as-loaded configuration at the ANO 
ISFSI.
    In support of its exemption request, the licensee submitted Holtec 
Report HI-2146265, ``Justification for ANO Exemption Request for 
Loading of Damaged Fuel in MPC-24,'' Rev. 0 (ADAMS Accession No. 
ML14279A246). Holtec stated that the most likely source of the Kr-85 
gas was a single breached rod in one fuel assembly and that it is 
unlikely that the cladding defects would allow fuel pellets to be 
released into the canister cavity. Nevertheless, as discussed further 
below, Holtec assumed in its thermal, criticality, and shielding 
analyses that multiple breached fuel rods had been loaded into MPC-24-
060 and that fuel pellets had been released into the canister cavity. 
Based upon the fact that only trace amounts of Kr-85 gas were detected 
after the initial alarm annunciation, NRC staff concludes that these 
are conservative assumptions and therefore finds them acceptable.
    The Holtec report asserted that, since the damaged fuel rods do not 
contact either the HI-STORM overpack or the HI-TRAC transfer cask, they 
will have no impact on the structural performance of either the HI-
STORM overpack or the HI-TRAC transfer cask. Also, the normal, off-
normal, and accident condition pressures and temperatures specified in 
Tables 2.2.1 and 2.2.3 of Revision 7 of the HI-STORM Final Safety 
Analysis Report (FSAR) are not exceeded as a result of the damaged fuel 
rods (ADAMS Accession No. ML110250163). Furthermore, the report stated 
that the stresses in the overpack and the transfer cask due to normal 
and off-normal handling events remain as calculated in the HI-STORM 
FSAR since the dead weight of the loaded casks and their centers of 
gravity are unaffected by the damaged fuel rods. In addition, the 
impact decelerations experienced by the cask as a result of either a 
handling accident or a hypothetical tip-over event are not increased, 
and the stability of the cask under design basis natural phenomena 
events (i.e., tornado winds, earthquake, etc.) continues to be assured. 
The staff reviewed the structural evaluation provided by the applicant 
and the basis of its conclusions. Based on its review of the 
representations, determinations, and information provided by the 
applicant in the above mentioned Holtec report, the NRC staff concludes 
continued storage of one or more fuel assemblies with fuel rods having 
greater than a pinhole leak, not placed in a damaged fuel container, 
and loaded into a HI-STORM 100 MPC-24 will have no impact on the 
ability of the HI-STORM overpack, HI-TRAC transfer cask, or the MPC to 
withstand pressure loads due to tornado winds, floods, or explosions. 
The NRC staff also concludes that there is a reasonable assurance that 
the

[[Page 78914]]

overpack and transfer cask's structural performance will meet the 
requirements of 10 CFR part 72.
    In Chapter 5 of Revision 7 to the HI-STORM FSAR, Holtec stated that 
storage of damaged fuel assemblies is identical from a shielding 
perspective to storage of intact fuel assemblies (ADAMS Accession No. 
ML082401632). Dose rate measurements performed by Entergy which show 
that the dose rates for MPC-24-060 are below the limits specified in 
the CoC support the results presented in the Holtec FSAR. The shielding 
analyses performed for accident conditions in Chapter 5 of Revision 7 
to the HI-STORM FSAR simulated four collapsed, damaged fuel assemblies 
located on the periphery of an MPC-24. Since there are approximately 
208 fuel rods in a fuel assembly, this equates to approximately 832 
collapsed fuel rods. The results of these analyses showed that external 
dose rates at the bottom of the canister increased by less than 27% and 
dose rates at higher locations decreased. Since the number of damaged 
fuel rods assumed in the Holtec report is much less than that described 
in the FSAR analysis, the applicant stated that the effect on dose for 
MPC-24-060 loaded with fuel assemblies having defects greater than 
pinhole leaks and hairline cracks would be expected to be less than 
that described in the FSAR. Similarly, according to the Holtec report 
the postulated relocation of the fuel from a small number of rods would 
have a negligible effect on the dose contribution at the site boundary. 
Additionally, Chapters 7 and 11 of Revision 7 to the HI-STORM FSAR 
shows that leakage is not credible under normal, off-normal, and 
accident conditions (ADAMS Accession No. ML082401621 and ML082401626 
respectively). The NRC staff reviewed Revision 7 to the HI-STORM 100 
FSAR and information provided by the applicant and found that analysis 
acceptable to demonstrate the dose rates for MPC-24-060. Based on its 
review, the NRC staff finds that storage of fuel assemblies having 
greater than pinhole leaks and hairline cracks in the HI-STORM 100 MPC-
24 Storage System will meet the dose rate and exposure limit 
requirements in 10 CFR part 20 and 10 CFR part 72.
    Holtec assumed one fuel pin per assembly is damaged in each of the 
24 assemblies loaded into MPC-24-060. The criticality evaluation 
indicated the potential relocation of fuel pellets from damaged fuel 
rods in the MPC has a negligible effect on the reactivity of the 
system, and the maximum reactivity remains well below 0.95. During 
storage operations, the MPC is internally dry, resulting in a low 
reactivity and large reactivity margins. For unloading operations, 
where the MPC is flooded, confirmatory calculations for possible 
relocation of fuel both within and outside of an assembly confirmed 
that the effect of fuel relocation on the reactivity of the system is 
small even if the MPC is flooded with unborated water. The NRC staff 
has reviewed the criticality evaluation and the basis of the 
conclusions reached by Holtec in support of Entergy's exemption 
request. Based on its review of the representations, determinations, 
and information provided, the NRC staff finds that the as-loaded 
potentially damaged fuel will not impact the criticality performance of 
the HI-STORM 100 MPC-24 Storage System, and therefore, as loaded, MPC-
24-060 will meet the criticality safety requirements of 10 CFR part 72.
    The staff also finds that there is no impact on the ability of the 
fuel to be retrieved from the canister for the following reasons. A 
complete break of a fuel rod on the periphery of a fuel assembly could 
affect retrievability; however, this condition was not identified by 
the visual inspections performed during loading. Also, the amount of 
gas released is not indicative of a complete break of a fuel rod. 
Expanded damage of breached rod(s) during storage could make handling 
of the fuel at a later time more difficult than if it was repackaged at 
the current time. However, the only degradation mechanism which could 
further damage the fuel is oxidation of exposed fuel pellets. Oxidized 
fuel pellets would exert stress on the cladding, potentially causing 
further damage and release of fuel pellets. Since the MPC has been seal 
welded shut and an inert atmosphere of helium has been introduced into 
the cavity, unless there is a breach of containment letting air into 
the canister, oxidation of the pellets will not occur. Consequently, 
the cladding will not be damaged further and fuel pellets will not be 
released. Therefore, NRC staff finds that storage of fuel assemblies 
having greater than pinhole leaks and hairline cracks in the HI-STORM 
100 MPC-24 Storage System will meet the retrievability requirements of 
10 CFR part 72.
    As part of its thermal assessment of storage of the damaged fuel in 
a HI-STORM 100 MPC-24, Holtec stated that the damaged fuel rods in the 
canister would be well below 1% of the total number of fuel rods 
(approximately 50 fuel rods). Holtec evaluated the effect of damaged 
fuel on the different heat transfer mechanisms while the canister is in 
the storage configuration. Holtec stated that the damaged rods would 
remain in their correct physical positions within the fuel assembly and 
that the fuel assembly geometry is unchanged. Therefore, both the 
conduction heat transfer mechanism and the radiation heat transfer 
mechanism would not be impacted. Holtec also stated that the resistance 
to movement of helium within the fuel assemblies (i.e., the hydraulic 
resistance that is also dependent on the fuel geometry) is unaffected. 
Consequently, the natural convection heat transfer mechanism, which is 
dependent upon the hydraulic resistance, would not be impacted. Even 
though Holtec believes the fuel rods are intact, Holtec evaluated the 
impact on the natural convection heat transfer mechanism within the 
canister from either fuel pellets or pieces of fuel cladding becoming 
dislodged from the damaged fuel rods. Holtec stated that, if a fuel 
pellet or piece of fuel cladding were to block one of the rod-to-rod 
interstitial spaces, the impact on the natural convection heat transfer 
would be very small because each interstitial space is connected to 
four adjacent rod-to-rod interstitial spaces. Therefore, helium could 
easily flow around any blocked rod-to-rod interstitial space. Holtec 
also stated that, if a fuel pellet or piece of fuel cladding were to 
fall completely out of the fuel assembly and into the bottom region of 
the fuel basket, the impact on the natural convection heat transfer 
mechanism due to helium circulation would be similarly negligible 
because openings in the bottom region of the fuel basket are sized 
sufficiently large enough to allow the movement of helium within the 
canister.
    The NRC staff reviewed Holtec's evaluation on the impact of damaged 
spent fuel on the MPC-24 thermal performance discussed above and 
determined that it demonstrated that the presence of damaged fuel (to 
the extent described in the technical justification) would not affect 
the heat transfer characteristics (i.e., conduction heat transfer, 
radiation heat transfer, and natural convection heat transfer by helium 
circulation). Since the impact on the thermal performance is small and 
because the total cask heat load is relatively low as compared to the 
design basis heat load, the staff concludes that neither temperature 
nor pressure limits in the FSAR would be exceeded. Also, the licensee 
characterized all the spent fuel assemblies loaded in MPC-24-060 as low 
burnup fuel, which is permitted to reach higher temperatures in storage 
than fuel of other burnup levels. The

[[Page 78915]]

HI-STORM 100 system is rated also to store high burnup fuel. As a 
result, MPC-24-060 has a large thermal margin. Therefore, based on the 
NRC staff's review of Holtec's evaluation and technical justification, 
the staff concludes that MPC-24-060 (loaded with the contents described 
in the ANO exemption request letter) inside the HI-STORM 100 system 
will meet the 10 CFR part 72 thermal requirements.
    Based on its review, the NRC staff has reasonable assurance that 
Entergy's exemption request for an MPC loaded with fuel assemblies 
classified as having defects greater than pinhole leaks and hairline 
cracks will meet the thermal, structural, criticality, retrievability 
and radiation protection requirements of 10 CFR part 72 and the offsite 
dose limits of 10 CFR part 20. Therefore, the NRC staff concludes that 
the exemption to allow the licensee to store MPC-24-060 in its as-
loaded configuration will not endanger life or property or the common 
defense and security.

Otherwise in the Public Interest

    The information Entergy submitted with its exemption request, and 
the Holtec analyses documented in Holtec Report No. HI-2146265, 
``Justification for ANO Exemption Request for Loading of Damaged Fuel 
in MPC-24,'' Rev. 0, demonstrates that the as-loaded MPC is not 
compromised due to the misloaded fuel (ADAMS Accession No. 
ML14279A246). If the NRC did not grant this exemption, Entergy would 
need to take action to correct the condition by reloading the affected 
MPC to be in compliance with CoC No. 1014, Amendment No. 5. This would 
involve unloading the spent fuel assemblies from the MPC, performing 
inspections of various MPC components, loading different spent fuel 
assemblies into the used MPC or a new MPC (if there was damage noted on 
the used MPC) in accordance with CoC No. 1014, Amendment No. 5 and 
performing the MPC closing procedures.
    The licensee estimates that unloading and reloading the MPC would 
increase personnel exposures by 600 mRem. In addition, the licensee 
states that unloading and reloading would generate radioactive 
contaminated material and waste not only during unloading and reloading 
operations, but also from disposal of the used MPC (if the MPC were 
damaged during the unloading process). The licensee estimates this 
action would cost an estimated $300,000 for unloading and reloading 
operations. If the MPC was damaged during unloading, the licensee 
estimates an additional $750,000 for purchase of a new MPC and $200,000 
for disposal of the used MPC. The licensee also states additional 
opportunities for design basis accidents, such as a fuel handling 
accident, would be introduced if the MPC were unloaded and reloaded.
    Because the corrective action would result in increased radiation 
exposure to personnel and provides increased opportunities for fuel 
handling accidents which could result in radioactive material releases 
to the environment, granting the exemption, and allowing MPC-24-060 to 
remain in its as-loaded condition, is consistent with the NRC's mission 
to protect public health and safety. Therefore, the exemption is in the 
public interest.

Environmental Consideration

    The NRC staff also considered in the review of this exemption 
request whether there would be any significant environmental impacts 
associated with the exemption. For this proposed action, the NRC staff 
performed an environmental assessment pursuant to 10 CFR 51.30. The 
proposed action is the approval of an exemption from the requirements 
of 10 CFR 72.212(a)(2), 10 CFR 72.212(b)(3), 10 CFR 72.212(b)(5)(i), 
and the portion of 72.212(b)(11) that requires compliance with the 
terms, conditions, and specifications of a CoC, and 10 CFR 72.214, but 
only to the extent necessary to allow Entergy to store MPC-24-060 in 
its current as-loaded configuration at the ANO ISFSI.
    The NRC staff performed an environmental assessment and determined 
that the proposed action will not significantly impact the quality of 
the human environment. The NRC staff concludes that there are no 
changes being made in the types or amounts of any radiological 
effluents that may be released offsite, and there is no significant 
increase in occupational or public radiation exposure as a result of 
the proposed action. In addition, the proposed action only affects the 
requirements associated with the fuel assemblies already loaded into 
the canister and does not affect non-radiological plant effluents, or 
any other aspects of the environment. The Environmental Assessment and 
the Finding of No Significant Impact were published in the Federal 
Register on December 19, 2014 (79 FR 75843).

IV. Conclusion

    Based on the foregoing considerations, the NRC has determined 
pursuant to 10 CFR 72.7, that the exemption is authorized by law, will 
not endanger life or property or the common defense and security, and 
is otherwise in the public interest. Therefore, the NRC grants Entergy 
a one-time exemption from the requirements in 10 CFR 72.212(a)(2), 10 
CFR 72.212(b)(3), 10 CFR 72.212(b)(5)(i), and the portion of 10 CFR 
72.212(b)(11) that requires compliance with the terms, conditions, and 
specifications of a CoC, and 10 CFR 72.214 for storage of HI-STORM 100 
MPC-24-060 at the ANO ISFSI.
    This exemption is effective upon issuance.

    Dated at Rockville, Maryland, this 19th day of December 2014.

    For the Nuclear Regulatory Commission.
Mark Lombard,
Director, Division of Spent Fuel Management, Office of Nuclear Material 
Safety and Safeguards.
[FR Doc. 2014-30718 Filed 12-30-14; 8:45 am]
BILLING CODE 7590-01-P