Independent Spent Fuel Storage Installation, Department of Energy; Fort St. Vrain, 40354-40357 [2016-14673]

Agencies

• NUCLEAR REGULATORY COMMISSION

[Federal Register Volume 81, Number 119 (Tuesday, June 21, 2016)]
[Notices]
[Pages 40354-40357]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-14673]


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NUCLEAR REGULATORY COMMISSION

[Docket No. 72-09; NRC-2015-0150]


Independent Spent Fuel Storage Installation, Department of 
Energy; Fort St. Vrain

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 a request submitted by the Department of 
Energy (DOE or the licensee) on April 27, 2016, from NRC's requirement 
to comply with the terms, conditions, and specifications concerning 
testing and surveillance in Special Nuclear Material License No. SNM-
2504 for the Fort St. Vrain independent spent fuel storage installation 
(ISFSI). The exemption request seeks the extension of the time to 
perform an O-ring leakage rate test required by Technical Specification 
(TS) 3.3.1 of Appendix A of Special Nuclear Material License No. SNM-
2504 and to perform an aging management surveillance described in the 
Fort St. Vrain (FSV) Final Safety Analysis Report (FSAR). The DOE 
requests the dates for performance of the testing and surveillance 
requirements be extended until December 2016. The NRC previously 
granted DOE an exemption (80 FR 33299 dated, June 11, 2015) extending 
the completion date for these actions until June 2016.

DATES: The exemption is effective on June 21, 2016.

ADDRESSES: Please refer to Docket ID NRC-2015-0150 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 https://www.regulations.gov and search for Docket ID NRC-2015-0150. Address 
questions about NRC dockets to Carol Gallagher; telephone: 301-415-
3463; email: Carol.Gallagher@nrc.gov. 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 https://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 pdr.resource@nrc.gov. The 
ADAMS accession number for each document referenced (if it is available 
in ADAMS) is provided the first time that it is mentioned in this 
document.
     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: Bernard White, Office of Nuclear 
Material Safety and Safeguards, U.S. Nuclear Regulatory Commission, 
Washington, DC 20555-0001; telephone: 301-415-6577; email: 
Bernard.White@nrc.gov.

I. Background

    The DOE is the holder of Special Nuclear Material License No. SNM-

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2504 which authorizes receipt, possession, storage, transfer, and use 
of irradiated fuel elements from the decommissioned FSV Nuclear 
Generating Station in Platteville, Colorado, under part 72 of title 10 
of the Code of Federal Regulations (10 CFR).

II. Request/Action

    In a letter dated, April 27, 2016, the DOE requested an exemption 
to delay performance of both the fuel storage container O-ring leakage 
rate test requirement and the FSAR aging management surveillance of 
fuel storage containers by six months, until December 31, 2016 (ADAMS 
Accession No. ML16120A410). Technical Specification 3.1.1 in Appendix A 
of License No. SNM-2504 stipulates that, the fuel storage container 
seal leakage rate for shall not exceed 1 x 10-\3\ reference 
cubic centimeters per second (ref-cm\3\/s). Surveillance Requirement 
(SR) 3.3.1.1 requires that one fuel storage container from each vault 
to be leakage rate tested every five years to confirm that the seal 
leakage rate is not exceeded. DOE performed the last leakage rate test 
in June 2010 and the next leakage rate test is scheduled to be 
completed in June 2016.
    Fort St.Vrain implemented its aging management program as part of 
license renewal in 2011. Condition 9 of SNM-2504 states, in relevant 
part, that authorized use of the material at the FSV ISFSI shall be 
``in accordance with statements, representations, and the conditions of 
the Technical Specifications and Safety Analysis Report.'' Condition 11 
of SNM-2504 directs the licensee to operate the facility in accordance 
with the Technical Specifications in Appendix A. In Chapter 9 of the 
FSV FSAR the licensee committed to assess six fuel storage containers 
for potential hydrogen buildup by the end of June 2015. This date was 
extended until June 2016, with NRC's grant of an exemption. The 
hydrogen sampling schedule was established to parallel the fuel storage 
container seal leakage rate testing schedule.

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 10 CFR part 72 when 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. The DOE requested an 
exemption from both 10 CFR 72.44(c)(1) and 10 CFR 72.44(c)(3). Section 
72.44(c)(1) requires, in part, compliance with functional and 
operational limits to protect the integrity of waste containers and to 
guard against the uncontrolled release of radioactive material. Section 
72.44(c)(3) requires compliance with surveillance requirement in 
Limiting Condition of Operation (LCO) 3.3.1 which the licensee will use 
show that the ISFSI has not exceeded the fuel storage container or 
storage well seal leakage rate. For these reasons, the staff also 
grants DOE an exemption from the requirements of 10 CFR 72.44(c)(1) and 
10 CFR 72.44(c)(3).
    As is explained in following paragraphs, the proposed exemption is 
lawful, will not endanger life or property, or the common defense and 
security, and is otherwise in the public interest.

Authorized by Law

    This exemption delays until December 2016, the licensee's 
performance of (1) a fuel storage container O-ring leakage rate test 
required by TS 3.3.1 of Appendix A of Special Nuclear Material License 
No. SNM-2504 and (2) an FSAR aging management surveillance to inspect 
six fuel storage containers for hydrogen buildup. Condition 9 of SNM-
2504 states, in relevant part, that authorized use of the material at 
the FSV's ISFSI shall be ``in accordance with statements, 
representations, and the conditions of the Technical Specifications and 
Safety Analysis Report.'' Condition 11 of SNM-2504 also directs the 
licensee to operate the facility in accordance with the Technical 
Specifications in Appendix A.
    The provisions in 10 CFR 72.44(c)(1) and (3) require the licensee 
to follow the technical specifications and the functional and 
operational limits for the facility. The testing and inspection 
requirements from which DOE requested exemption are detailed in the 
Special Nuclear Material License No. SNM-2504, the FSAR, and FSV's 
technical specifications and must be complied with pursuant to 10 CFR 
part 72. Section 72.7 allows the NRC to grant specific 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. 
Therefore, the exemption is authorized by law.

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

    In granting the March 19, 2015 exemption request, the NRC staff 
determined that it would not endanger life or property, or the common 
defense and security. The current exemption extends the deadline for 
performance of the testing and surveillance requirements until December 
2016. The staff evaluated whether the additional six month extension 
provided by this exemption would change its earlier finding; the staff 
finds that the current exemption does not endanger life or property, or 
the common defense and security for the reasons discussed below.
Potential Corrosion
    Fort St. Vrain's ISFSI Aging Management Program described in 
Section 9.8 of FSV's ISFSI FSAR identifies a commitment to test one 
fuel storage container in each vault for hydrogen buildup. The test is 
designed to identify corrosion in the interior of the fuel storage 
containers. In its FSAR the licensee committed to complete testing for 
hydrogen buildup on the same schedule as the leak test, which required 
the test to be completed no later than June 2015. In its March 2015 
exemption request, FSV concluded that hydrogen buildup had not occurred 
in fuel storage containers in its ISFSI. The NRC extended the 
completion date for the sampling for actual hydrogen buildup until to 
June 2016. Fort St. Vrain's conclusions were supported by the following 
observations:
    1. The fuel was stored in dry helium prior to placement in the fuel 
storage containers.
    2. General corrosion, as opposed to galvanic corrosion, was the 
only corrosion mechanism of concern for the canister.
    3. The expected corrosion reactions would not generate significant 
quantities of hydrogen, because any water inside the fuel storage 
container is expected to have neutral pH (i.e., not acidic).

Therefore, FSV concluded there were no safety implications associated 
with delaying the hydrogen test for one year. The licensee presented 
the same conclusions and observations in support of its April 2016 
request to extend the testing date.
    The staff conducted its own evaluation of the data supporting FSV's 
March 2015 and April 2016 requests and found no safety implications 
associated with delaying the hydrogen test until December 2016. The 
staff made specific determinations concerning the safety of granting 
the exemption, including that the maximum hydrogen volume fraction is 7 
percent inside the fuel storage container. Therefore, a fire or 
explosion of hydrogen at this level is very unlikely

[[Page 40356]]

and does not present a significant safety issue. The staff's 
calculation of the hydrogen volume fraction was a time independent 
calculation to determine the maximum hydrogen concentration assuming 
the possible reactants, oxygen and water, were fully consumed. A delay 
in performing the hydrogen test for six additional months will increase 
the container storage period from 25 years to 25.5 years without the 
performance of a hydrogen test. However, the staff finds that the 
extension will not increase the probability of either a hydrogen 
ignition event during storage or failure of the fuel storage container 
integrity due to corrosion, and therefore, fuel storage container 
safety is not reduced.
    The NRC staff concludes that hydrogen ignition events associated 
with handling fuel storage containers are very unlikely to occur 
because the Modular Vault Dry Store building where the fuel storage 
canisters are located contains no volatile materials or gases. A full 
discussion of this issue is found in FSV's SAR 3 (see ADAMS Accession 
No. ML102380351). The Component Operational Testing procedures in the 
Aging Management Program, which must be implemented after license 
renewal, are described in FSV's SAR (see ADAMS Accession No. 
ML103640385). These procedures eliminate hydrogen ignition sources by 
sampling and analyzing the air inside containers for the presence of 
hydrogen and purging hydrogen before moving or removing lids from 
containers holding spent fuel.
Leakage Rate
    Limiting Condition of Operation 3.3.1 in Appendix A of License No. 
SNM-2504 states that the fuel storage containers seal leakage rate 
shall not exceed 1 x 10-\3\ ref-cm\3\/s. Surveillance 
Requirement 3.3.1.1 stipulates that one fuel storage container from 
each vault be subject to a leakage rate test every 5 years. The basis 
for SR 3.3.1.1 is that performance of a leakage rate test of at least 
six fuel storage containers every 5 years provides reasonable assurance 
of continued integrity. The original leakage rate test at FSV was 
performed in 1991 after the loading of canisters; subsequent leakage 
rate tests were performed on one fuel storage container from each vault 
in years 1996, 2001, 2005, and 2010. The results of all FSV's leakage 
rate tests have never exceeded the maximum rate of 1 x 
10-\3\ ref- cm\3\/s.
    As part of its April 2016 exemption request, DOE evaluated whether 
the exemption is consistent with the confinement barrier requirements 
described in FSV's FSAR at 3.3.2.1 and in SR 3.3.1.1. The DOE 
classified the failure of the redundant metal O-ring seals in a fuel 
storage cylinder as a low probability event. In addition, Section 
8.2.15 of the FSV FSAR identifies no credible failure mechanisms for 
the fuel storage container O-rings. The DOE calculated that in June 
2017, the average and maximum O-ring seal leakage rates for fuel 
storage containers are expected to be 3.75 x 10-\4\ and 6.76 
x 10-\4\ ref-cm\3\/s, respectively. These conservative 
calculations are presented in Engineering Design File-10727, Estimation 
of 2017 Leak Rates of Fort St. Vrain Fuel Storage Containers (ADAMS 
Accession No. ML15104A064). Both the average and maximum seal leakage 
rate values are below the maximum leakage rate of 1 x 10-\3\ 
ref-cm\3\/s, permitted by TS 3.3.1. The DOE identified O-ring failure 
as a potential failure mode that could result in leakage in excess of 1 
x 10-\3\ ref-c cm\3\/s, although DOE did not provide 
specific details of potential O-ring failure mechanisms.
    The NRC staff's evaluation notes that typical failure modes for O-
ring seals include:
    1. Corrosion of the O-ring,
    2. corrosion of the O-ring flange sealing surface (area in contact 
with the O-ring), and
    3. creep or relaxation of the O-ring.
    The DOE's March 2015 exemption request, as supplemented on June 1, 
2015 (ADAMS Accession No. ML15153A280), describes the O-rings as silver 
plated alloy X-750 in the work-hardened condition. The O-rings are 
installed with a grease/lubricant to facilitate sealing and prevent 
damage to the O-rings during lid installation and compression of the O-
rings. The presence of grease, the construction materials used, and the 
limited amount of water in the vicinity of the O-rings reduce the 
likelihood of corrosion of the O-rings and the O-ring seal area on the 
fuel storage containers.
    The NRC staff reviewed the testing methods and the test pressures 
generated by previous leakage rate tests. In addition, the staff 
evaluated the correlations between leakage rate and pressure drop for 
the O-ring seals. These estimated O-ring seal leakage rates were 
reported in EDF-10727. The NRC staff determined that the data and 
correlations that DOE used accurately predict the June 2017 fuel 
storage container O-ring seal leakage rates. The staff confirmed that 
DOE's average and maximum 2017 leakage rate estimates of 3.75 x 
10-\4\ and 6.76 x 10-\4\ ref-cm\3\/s are both 
acceptable and below the maximum limit of 1 x 10-\3\ ref-
cm\3\/s in LCO 3.3.1.
    The NRC staff also reviewed Section 8.2.15 of FSV's FSAR and DOE's 
analyses of the consequences associated with a radiological release 
from a fuel storage container. The staff confirmed that even if the 
leakage rate of 1 x 10-\3\ ref-cm\3\/s were grossly 
exceeded, the consequences would be minimal. For example,
    1. The radiological consequences at the controlled area boundary 
would be within the requirements of 10 CFR 72.106.
    2. A radiological release with a leakage rate greater than 1 x 
10-\3\ ref-cm\3\/s that passes beyond the redundant O-ring 
seals would be bounded by the maximum credible accident described in 
the FSV's FSAR at 8.2.15.
    3. Furthermore, the failure of the redundant metallic seals (loss 
of confinement) is considered a low probability event during the entire 
storage period.
    Based on the findings discussed in this section, the NRC staff 
concludes that granting the DOE's exemption will not endanger public 
health and safety or the common defense and security. Delaying the fuel 
storage container O-ring leakage rate test required by TS 3.1.1 and the 
aging management monitoring of six fuel storage containers for hydrogen 
buildup until December 2016, will not increase the likelihood of a seal 
leak occurring. Therefore, the extension permitted by the current 
exemption does not change the licensing basis of the ISFSI design and 
it does not alter the staff's conclusion in June 2015, that the fuel 
storage container design and lid seals are acceptable.

Otherwise in the Public Interest

    In the March 2016 exemption application, the DOE sought a delay of 
the fuel storage container O-ring leakage rate test and FSAR aging 
management surveillance for one year. The DOE explained that the 
extension would allow it to prioritize activities at the FSV site and 
reduce the administrative burden on the licensee and the NRC staff to 
perform the June 2016 test. The staff finds these statements are still 
valid and support a six-month extension, therefore issuance of the 
proposed exemption is otherwise in the public interest.

Environmental Consideration

    The NRC staff evaluated whether significant environmental impacts 
are associated with the issuance of the requested exemption. The NRC 
staff determined that the proposed action fits a category of actions 
that does not require an environmental assessment or

[[Page 40357]]

environmental impact statement. The exemption meets the categorical 
exclusion criteria of 10 CFR 51.22(c)(25)(i)-(vi).
    Granting an exemption from the requirements of 10 CFR 72.44(c)(1) 
and 10 CFR 72.44(c)(3) will extend the time for DOE to conduct the 
inspection and surveillance of the fuel storage container O-ring 
leakage rate test required by TS 3.3.1 and the FSAR aging management 
surveillance of fuel storage containers for hydrogen buildup required 
by license Condition No. 9. A categorical exclusion for inspection and 
surveillance requirements is provided under 10 CFR 51.22(c)(25)(vi)(C), 
when the criteria in 10 CFR 51.22(c)(25)(i)-(v) are also satisfied. In 
its review of the exemption request, the NRC staff determined that, 
under 10 CFR 51.22(c)(25) granting the exemption: (i) Does not involve 
a significant hazards consideration because it does not reduce a margin 
of safety, create a new or different kind of accident not previously 
evaluated, or significantly increase the probability or consequences of 
an unevaluated accident; (ii) would not significantly change the types 
or amounts of effluents that may be released offsite because the 
exemption does not change or produce additional avenues of effluent 
release; (iii) would not significantly increase occupational or public 
radiation exposure, individually or cumulatively, because the exemption 
does not introduce new or increased radiological hazards; (iv) would 
not result in significant construction impacts because the exemption 
does not involve construction or other ground disturbing activities, or 
change the footprint of the existing ISFSI; and (v) would not increase 
the potential for or the consequences of radiological accidents. For 
example, a gross leak from a fuel storage container or excessive 
hydrogen buildup in a fuel storage container is unlikely because the 
exemption does not reduce the ability of the container to confine 
radioactive material or create new accident precursors at FSV's ISFSI. 
Accordingly, this exemption meets the eligibility criteria for 
categorical exclusion in 10 CFR 51.22(c)(25). There are no significant 
radiological environmental impacts associated with the proposed action.

IV. Conclusions

    Accordingly, the NRC has determined that, pursuant to 10 CFR 72.7, 
this 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 hereby grants DOE an exemption from the 
regulations at 10 CFR 72.44(c)(1) and 10 CFR 72.44(c)(3) to permit a 
delay by six months of the monitoring and surveillance scheduled for 
June 2016. The exemption extends the date for completion of the O-ring 
leakage rate test under SR 3.3.1.1 for one fuel storage container from 
each vault and the FSAR aging management inspection of FSCs for 
hydrogen until December 31, 2016. This exemption is effective as of 
June 21, 2016.

    Dated at Rockville, Maryland, this 15th day of June, 2016.

    For the Nuclear Regulatory Commission.
John McKirgan,
Chief, Spent Fuel Licensing Branch, Division of Spent Fuel Management, 
Office of Nuclear Material Safety and Safeguards.
[FR Doc. 2016-14673 Filed 6-20-16; 8:45 am]
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