Virginia Electric and Power Company; Surry Power Station Units 1 and 2; Independent Spent Fuel Storage Installation; Exemption, 24539-24541 [2012-9802]
Download as PDF
Federal Register / Vol. 77, No. 79 / Tuesday, April 24, 2012 / Notices
accordance with the NRC E-filing rule,
which the NRC promulgated in August
2007 (72 FR 49,139).
Issued at Rockville, Maryland, this 18th
day of April 2012.
E. Roy Hawkens,
Chief Administrative Judge, Atomic Safety
and Licensing Board Panel.
[FR Doc. 2012–9801 Filed 4–23–12; 8:45 am]
BILLING CODE 7590–01–P
NUCLEAR REGULATORY
COMMISSION
[Docket Nos.: 50–280, 50–281, 72–55, 72–
1030; NRC–2012–0085]
Virginia Electric and Power Company;
Surry Power Station Units 1 and 2;
Independent Spent Fuel Storage
Installation; Exemption
mstockstill on DSK4VPTVN1PROD with NOTICES
1.0 Background
Virginia Electric and Power Company
(Dominion or licensee) is the holder of
Facility Operating License Nos. DRP–32
and DRP–37, which authorize operation
of the Surry Power Station Units 1 and
2 in Surry County, Virginia, pursuant to
Title 10 of the Code of Federal
Regulations (10 CFR), part 50. The
licenses provide, among other things,
that the facility is subject to all rules,
regulations, and orders of the U.S.
Nuclear Regulatory Commission (NRC
or the Commission) now or hereafter in
effect.
Pursuant to 10 CFR part 72, Subpart
K, a general license is 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
power reactors under 10 CFR part 50.
Dominion is authorized to operate a
nuclear power reactor under 10 CFR
part 50, and holds a 10 CFR part 72
general license for storage of spent fuel
at the Surry Power Station ISFSI. Under
the terms of its general license,
Dominion loaded spent fuel using the
Transnuclear, Inc, (TN) NUHOMS® HD
Storage System (HD–32PTH) dry cask
storage system (Certificate of
Compliance (CoC) No. 1030,
Amendment No. 0) at the Surry Power
Station ISFSI.
2.0 Request/Action
The TN NUHOMS® HD dry cask
storage system is designed for zone
loading based on decay heat. CoC No.
1030 specifies requirements, conditions,
and operating limits of the dry shielded
canisters (DSCs) in Appendix A of the
Technical Specifications (TS). The TS
restrict the decay heat in lower Zone 1a
locations to ≤1.05 kW and the upper
VerDate Mar<15>2010
17:40 Apr 23, 2012
Jkt 226001
Zone 1b locations to ≤0.8 kW. The
licensee inadvertently reversed the
upper and lower zones while preparing
the dry shielded canister (DSC) loading
maps. This resulted in five fuel
assemblies being loaded into four DSCs
with decay heat greater than the limits
specified in the CoC. The four DSCs are
designated with serial numbers DOM–
32PTH–001–C, –002–C, –003–C, and
–009–C.
In a letter dated July 21, 2011, as
supplemented September 28, 2011
(Agencywide Documents Access and
Management System (ADAMS)
Accession Nos. ML11208B629 and
ML11286A115, respectively), Dominion
requested a one-time exemption from
the following requirements to allow
storage of the four DSCs, with serial
numbers DOM–32PTH–001–C, –002–C,
–003–C, and –009–C, in their current,
as-loaded, condition at the Surry Power
Station ISFSI:
• 10 CFR 72.212(b)(3), which states
the general licensee must ‘‘[e]nsure that
each cask used by the general licensee
conforms to the terms, conditions, and
specifications of a CoC or an amended
CoC listed in § 72.214.’’
• The portion of 10 CFR
72.212(b)(11), which states that ‘‘[t]he
licensee shall comply with the terms,
conditions, and specifications of the
CoC * * *’’
3.0 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.
Authorized by Law
This exemption would allow the
licensee to continue to store four DSCs
(loaded with spent nuclear fuel
assemblies having decay heat exceeding
the limits required by CoC No. 1030,
Amendment No. 0, at the time of
loading) in their as-loaded configuration
at the Surry Power Station ISFSI. The
provisions in 10 CFR part 72 from
which Dominion is requesting an
exemption, require the licensee to
comply with the terms, conditions, and
specifications of the CoC for the
approved cask model that it uses.
The Commission issued 10 CFR 72.7
under the authority granted to it under
Section 133 of the Nuclear Waste Policy
Act of 1982, as amended, 42 U.S.C.
10153. Section 72.7 allows the NRC to
grant exemptions from the requirements
PO 00000
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Fmt 4703
Sfmt 4703
24539
of 10 CFR part 72. Granting the
licensee’s proposed exemption provides
adequate protection to public health and
safety, and the environment. 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 provisions in 10 CFR 72.212(a)
specifically state that the general
licensee is limited to spent fuel that the
general licensee is authorized to possess
at the site under the specific license for
the site. Sections 72.212(b)(3) and
72.212(b)(11) require the general
licensee to store spent fuel in cask
models approved under the provisions
of 10 CFR part 72 (which are listed in
10 CFR 72.214) and require general
licensees to comply with the terms and
conditions of the CoC for the approved
cask model that is used. The requested
exemption would allow the licensee to
continue to store four DSCs (loaded
with spent nuclear fuel assemblies
having decay heat exceeding the limits
required by CoC No. 1030, Amendment
No. 0 at the time of loading) in their asloaded configuration at the Surry Power
Station ISFSI.
Currently, the five affected fuel
assemblies have been in storage for a
minimum of 2.5 years and have decayed
to meet the required decay heat limits
of the CoC. The licensee submitted TN
Calculation No. 10494–174, which
performed a bounding thermal analysis
using ANSYS finite element software to
evaluate the misloading events. The
ANSYS analysis consists of a halfsymmetric, three-dimensional model of
a 32PTH DSC with a number of
conservative assumptions. First, the
modeled fuel assembly loading pattern
is based on the configuration that
resulted in the maximum fuel cladding
temperature presented in the UFSAR
analysis dated October 2, 2009, with the
exception that the two fuel assemblies
in Zone 1b were set to 860 W. The
licensee states this configuration bounds
the design zone limits as listed in TS,
Section 2.1, which are based on each
Zone 1b fuel assemblies being 800 W. It
also bounds the as-loaded
configurations, where one or both fuel
assemblies in Zone 1b exceeded a decay
heat of 800 W, up to a value of 806 W.
The remaining DSC fuel assembly decay
heats were within the design basis.
Therefore, since the as-loaded
configuration had a total DSC decay
heat of 33.31 kW, the licensee states the
model conservatively assumes a total
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mstockstill on DSK4VPTVN1PROD with NOTICES
24540
Federal Register / Vol. 77, No. 79 / Tuesday, April 24, 2012 / Notices
DSC decay heat of 34.92 kW. Secondly,
the licensee applies a storage condition
ambient temperature of 115 °F, which is
above the maximum normal storage
ambient temperature of 100 °F. The NRC
staff finds the assumed 115 °F boundary
condition provides a reasonably
conservative ambient temperature
choice, considering that summer
temperatures often are greater than 90 °F
and can reach 100 °F (per weather
almanac, www.NOAA.gov). The NRC
staff further finds that applying a higher
ambient temperature boundary
condition also mitigates the thermal
effects of other ambient weather
conditions, such as wind direction
relative to the DSC’s inlet and outlet
openings.
Using the conservative assumptions
stated above, the TN Calculation No.
10494–174 analysis presented by the
licensee indicates a maximum cladding
temperature of 689 °F for the as-loaded
DSC with the reversed heat load zoning
for storage conditions. This is 5 °F
higher than the previously calculated
cladding temperature found in Table 4–
2 of the UFSAR. The temperatures of
other DSC components increased by less
than 5 °F. The temperature increases
due to the misloaded fuel assemblies are
essentially unchanged for transfer
conditions. By applying an additional 5
°F to the previously calculated
temperature for transfer conditions
listed in Table 4–1 of the UFSAR, the
licensee estimates that the maximum
fuel cladding temperature for the asloaded DSC with the reversed heat load
zoning for transfer conditions to be 724
°F. As a result, the licensee concluded
that the maximum cladding
temperatures for both normal storage
and transfer conditions were below the
752 °F maximum allowable cladding
temperature limit noted in the UFSAR
analysis. The NRC staff has reviewed
the analysis presented by Dominion and
finds the thermal effect of the misloaded
fuel assemblies to be minimal, and that
the thermal margins were sufficient to
mitigate the effects of the misloaded fuel
assemblies so as to provide adequate
heat removal capabilities when the DSC
fuel assembly arrangement was not
within the design basis. This thermal
evaluation provides reasonable
assurance that the TN NUHOMS® HD
Storage System (HD–32PTH) loaded
with fuel assemblies exceeding the
decay heat limits allowed by the CoC
will allow for continued safe storage of
the spent fuel.
The licensee also discusses structural
and pressure considerations due to the
increased decay heat of the Zone 1b fuel
assemblies. The licensee concludes that
the increased decay heat did not have
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17:40 Apr 23, 2012
Jkt 226001
an effect on the structural evaluation
since the DSC fuel compartment and
basket rails are at temperatures below
those considered in the design basis
analysis. The submitted analysis finds
that the 5 °F higher temperature, due to
the larger as-loaded decay heat, would
result in a DSC pressure increase of 0.1
psig. The resulting 6 psig and 6.5 psig
DSC pressures for the normal storage
and transfer conditions were less than
the 15 psig design basis pressure. The
NRC staff has reviewed the analysis
submitted in the exemption request and
finds that there were no structural
implications on the cask system
resulting from the misloaded fuel
assemblies.
The licensee verified the design basis
shielding analysis remained bounding
for the as-loaded DSCs. The licensee
concluded the design basis shielding
analysis assumes a DSC loading of 32
assemblies all having source terms
applicable to assemblies generating 1.5
kW of decay heat and therefore bounds
the as-loaded DSCs. The NRC staff has
reviewed the design basis shielding
analysis and concludes that the design
remains bounding for the as-loaded
DSCs and the radiation protection
system of the NUHOMS® HD–32PTH
dry cask storage system remains in
compliance with 10 CFR part 72.
The NRC staff has reviewed
Dominion’s exemption request and
finds that the five fuel assemblies
loaded into four DSCs with decay heat
greater than specified in the CoC do not
affect the heat removal capabilities, the
structural integrity, or the radiation
protection system of the cask systems.
Therefore, the NRC staff concludes that
the exemption to allow the licensee to
store the four DSCs in their as-loaded
configuration does not pose an
increased risk to public health and
safety or the common defense or
security.
Otherwise in the Public Interest
The information Dominion submitted
with its exemption request and the TN
analysis documented in TN Calculation
No. 10494–174 demonstrate that the asloaded DSCs are not compromised due
to the misloaded fuel assemblies.
Dominion has also considered an
alternative action to correct the
condition by reloading the affected
DSCs to be in compliance with CoC No.
1030. This would involve retrieving
each of the DSCs from their Horizontal
Storage Modules (HSM), unloading the
spent fuel assemblies from the DSC,
performing inspections of various DSC
components, reloading the spent fuel
assemblies into the used DSC or a new
DSC (if there was damage noted on the
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Frm 00086
Fmt 4703
Sfmt 4703
used DSC) in accordance with CoC No.
1030, performing the DSC closing
procedures, and transferring the DSC
back to the ISFSI for re-insertion into
the HSM.
The licensee estimates this alternative
action of loading and unloading
operations would increase personnel
exposures by 250 mRem per affected
DSC. In addition, the licensee also states
the alternative to the proposed action
would generate radioactive
contaminated material and waste during
loading and unloading operations and
disposal of the used DSCs (if the DSCs
were damaged during the unloading
process). The licensee estimates the
alternative to the proposed action would
cost an estimated $300,000 for
unloading and reloading operations of
each affected DSC and also necessitate
additional fuel handling operations. If
the DSC was damaged during
unloading, the licensee estimates an
additional $1,000,000 for purchase of a
new DSC and $200,000 for disposal of
the used DSC.
The exemption, by allowing the four
affected DSCs to remain in their asloaded condition, is consistent with
NRC’s mission to protect public health
and safety. Approving the DSCs to
remain in their as-loaded condition
results in less of an opportunity for a
release of radioactive material than the
alternative to the proposed action.
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 a request for a one-time
exemption from the requirements of 10
CFR 72.212(b)(3) and the portion of
72.212(b)(11), which requires
compliance with the terms, conditions,
and specifications of a CoC, but only to
the extent necessary to allow Dominion
to store the four DSCs in the current asloaded configuration at the Surry Power
Station 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
E:\FR\FM\24APN1.SGM
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Federal Register / Vol. 77, No. 79 / Tuesday, April 24, 2012 / Notices
the proposed action. In addition the
proposed action only affects the
requirements associated with the fuel
assemblies already loaded into the casks
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 are documented in
the Federal Register (77 FR 20440,
dated April 4, 2012).
4.0 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 Dominion a one-time
exemption from the requirements in 10
CFR 72.212(b)(3) and from the portion
of 10 CFR 72.212(b)(11) that states the
licensee shall comply with the terms,
conditions, and specifications of the
CoC for the TN NUHOMS® HD dry cask
storage system with DSCs serial
numbers DOM–32PTH–001–C, –002–C,
–003–C, and –009–C, at the Surry Power
Station ISFSI.
This exemption is effective upon
issuance.
For the Nuclear Regulatory Commission.
Dated: Dated at Rockville, Maryland, this
12th day of April 2012.
Doug Weaver,
Deputy Director, Division of Spent Fuel
Storage and Transportation, Office of Nuclear
Material Safety and Safeguards.
[FR Doc. 2012–9802 Filed 4–23–12; 8:45 am]
BILLING CODE 7590–01–P
NUCLEAR REGULATORY
COMMISSION
[Docket Nos. 50–338, 50–339, 72–56, and
72–1030; NRC–2012–0084]
Virginia Electric and Power Company,
North Anna Power Station Units 1 and
2, Independent Spent Fuel Storage
Installation; Exemption
mstockstill on DSK4VPTVN1PROD with NOTICES
1.0
Background
Virginia Electric and Power Company
(Dominion, the licensee) is the holder of
Facility Operating License Nos. NPF–4
and NPF–7, which authorize operation
of the North Anna Power Station Units
1 and 2 in Louisa County, Virginia,
pursuant to Title 10 of the Code of
Federal Regulations (10 CFR), part 50.
The licenses provide, among other
things, that the facility is subject to all
rules, regulations, and orders of the U.S.
Nuclear Regulatory Commission (NRC
VerDate Mar<15>2010
17:40 Apr 23, 2012
Jkt 226001
or the Commission) now or hereafter in
effect.
Pursuant to 10 CFR part 72, Subpart
K, a general license is 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
power reactors under 10 CFR part 50.
Dominion is authorized to operate a
nuclear power reactor under 10 CFR
part 50, and holds a 10 CFR part 72
general license for storage of spent fuel
at the North Anna Power Station ISFSI.
Under the terms of its general license,
Dominion loaded spent fuel using the
Transnuclear, Inc., (TN) NUHOMS® HD
Storage System (HD–32PTH) dry cask
storage system (Certificate of
Compliance (CoC) No. 1030,
Amendment No. 0) at the North Anna
Power Station ISFSI.
2.0 Request/Action
The TN NUHOMS® HD dry cask
storage system is designed for zone
loading based on decay heat. CoC 1030
specifies requirements, conditions, and
operating limits of the dry shielded
canisters (DSCs) in Appendix A of the
Technical Specifications (TS). The TS
restrict the decay heat in lower Zone 1a
locations to <1.05 kW and the upper
Zone 1b locations to ≤0.8 kW. The
licensee inadvertently reversed the
upper and lower zones while preparing
the DSC loading maps. This resulted in
twelve fuel assemblies being loaded into
seven DSCs with decay heat greater than
the limits specified in the CoC. The
seven DSCs are designated with serial
numbers DOM–32PTH–004–C, –005–C,
–007–C, –010–C, –013–C, –019–C and
GBC–32PTH–011–C.
In a letter dated July 21, 2011, as
supplemented September 28, 2011
(Agencywide Documents Access and
Management System (ADAMS)
Accession Nos. ML11208C453 and
ML11286A143, respectively), Dominion
requested a one-time exemption from
the following requirements to allow
storage of the seven DSCs, with serial
numbers DOM–32PTH–004–C, –005–C,
–007–C, –010–C, –013–C, –019–C and
GBC–32PTH–011–C, in their current, asloaded, condition at the North Anna
Power Station ISFSI:
• 10 CFR 72.212(b)(3), which states
the general licensee must ‘‘[e]nsure that
each cask used by the general licensee
conforms to the terms, conditions, and
specifications of a CoC or an amended
CoC listed in § 72.214.’’
• The portion of 10 CFR
72.212(b)(11), which states that ‘‘[t]he
licensee shall comply with the terms,
conditions, and specifications of the
CoC * * *’’
PO 00000
Frm 00087
Fmt 4703
Sfmt 4703
3.0
24541
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.
Authorized by Law
This exemption would allow the
licensee to continue to store seven DSCs
(loaded with spent nuclear fuel
assemblies having decay heat exceeding
the limits required by CoC No. 1030,
Amendment No. 0, at the time of
loading) in their as-loaded configuration
at the North Anna Power Station ISFSI.
The provisions in 10 CFR Part 72 from
which Dominion is requesting an
exemption, require the licensee to
comply with the terms, conditions, and
specifications of the CoC for the
approved cask model that it uses.
The Commission issued 10 CFR 72.7
under the authority granted to it under
Section 133 of the Nuclear Waste Policy
Act of 1982, as amended, 42 U.S.C.
10153. Section 72.7 allows the NRC to
grant exemptions from the requirements
of 10 CFR part 72. Granting the
licensee’s proposed exemption provides
adequate protection to public health and
safety, and the environment. 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 provisions in 10 CFR 72.212(a)
specifically state that the general
licensee is limited to spent fuel that the
general licensee is authorized to possess
at the site under the specific license for
the site. Sections 72.212(b)(3) and
72.212(b)(11) require the general
licensee to store spent fuel in cask
models approved under the provisions
of 10 CFR part 72 (which are listed in
10 CFR 72.214) and require general
licensees to comply with the terms and
conditions of the CoC for the approved
cask model that is used. The requested
exemption would allow the licensee to
continue to store seven DSCs (loaded
with spent nuclear fuel assemblies
having decay heat exceeding the limits
required by CoC No. 1030, Amendment
No. 0 at the time of loading) in their asloaded configuration at the North Anna
Power Station ISFSI.
E:\FR\FM\24APN1.SGM
24APN1
Agencies
[Federal Register Volume 77, Number 79 (Tuesday, April 24, 2012)]
[Notices]
[Pages 24539-24541]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-9802]
-----------------------------------------------------------------------
NUCLEAR REGULATORY COMMISSION
[Docket Nos.: 50-280, 50-281, 72-55, 72-1030; NRC-2012-0085]
Virginia Electric and Power Company; Surry Power Station Units 1
and 2; Independent Spent Fuel Storage Installation; Exemption
1.0 Background
Virginia Electric and Power Company (Dominion or licensee) is the
holder of Facility Operating License Nos. DRP-32 and DRP-37, which
authorize operation of the Surry Power Station Units 1 and 2 in Surry
County, Virginia, pursuant to Title 10 of the Code of Federal
Regulations (10 CFR), part 50. The licenses provide, among other
things, that the facility is subject to all rules, regulations, and
orders of the U.S. Nuclear Regulatory Commission (NRC or the
Commission) now or hereafter in effect.
Pursuant to 10 CFR part 72, Subpart K, a general license is 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 power reactors under 10 CFR part 50.
Dominion is authorized to operate a nuclear power reactor under 10 CFR
part 50, and holds a 10 CFR part 72 general license for storage of
spent fuel at the Surry Power Station ISFSI. Under the terms of its
general license, Dominion loaded spent fuel using the Transnuclear,
Inc, (TN) NUHOMS[supreg] HD Storage System (HD-32PTH) dry cask storage
system (Certificate of Compliance (CoC) No. 1030, Amendment No. 0) at
the Surry Power Station ISFSI.
2.0 Request/Action
The TN NUHOMS[supreg] HD dry cask storage system is designed for
zone loading based on decay heat. CoC No. 1030 specifies requirements,
conditions, and operating limits of the dry shielded canisters (DSCs)
in Appendix A of the Technical Specifications (TS). The TS restrict the
decay heat in lower Zone 1a locations to <=1.05 kW and the upper Zone
1b locations to <=0.8 kW. The licensee inadvertently reversed the upper
and lower zones while preparing the dry shielded canister (DSC) loading
maps. This resulted in five fuel assemblies being loaded into four DSCs
with decay heat greater than the limits specified in the CoC. The four
DSCs are designated with serial numbers DOM-32PTH-001-C, -002-C, -003-
C, and -009-C.
In a letter dated July 21, 2011, as supplemented September 28, 2011
(Agencywide Documents Access and Management System (ADAMS) Accession
Nos. ML11208B629 and ML11286A115, respectively), Dominion requested a
one-time exemption from the following requirements to allow storage of
the four DSCs, with serial numbers DOM-32PTH-001-C, -002-C, -003-C, and
-009-C, in their current, as-loaded, condition at the Surry Power
Station ISFSI:
10 CFR 72.212(b)(3), which states the general licensee
must ``[e]nsure that each cask used by the general licensee conforms to
the terms, conditions, and specifications of a CoC or an amended CoC
listed in Sec. 72.214.''
The portion of 10 CFR 72.212(b)(11), which states that
``[t]he licensee shall comply with the terms, conditions, and
specifications of the CoC * * *''
3.0 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.
Authorized by Law
This exemption would allow the licensee to continue to store four
DSCs (loaded with spent nuclear fuel assemblies having decay heat
exceeding the limits required by CoC No. 1030, Amendment No. 0, at the
time of loading) in their as-loaded configuration at the Surry Power
Station ISFSI. The provisions in 10 CFR part 72 from which Dominion is
requesting an exemption, require the licensee to comply with the terms,
conditions, and specifications of the CoC for the approved cask model
that it uses.
The Commission issued 10 CFR 72.7 under the authority granted to it
under Section 133 of the Nuclear Waste Policy Act of 1982, as amended,
42 U.S.C. 10153. Section 72.7 allows the NRC to grant exemptions from
the requirements of 10 CFR part 72. Granting the licensee's proposed
exemption provides adequate protection to public health and safety, and
the environment. 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 provisions in 10 CFR 72.212(a) specifically state that the
general licensee is limited to spent fuel that the general licensee is
authorized to possess at the site under the specific license for the
site. Sections 72.212(b)(3) and 72.212(b)(11) require the general
licensee to store spent fuel in cask models approved under the
provisions of 10 CFR part 72 (which are listed in 10 CFR 72.214) and
require general licensees to comply with the terms and conditions of
the CoC for the approved cask model that is used. The requested
exemption would allow the licensee to continue to store four DSCs
(loaded with spent nuclear fuel assemblies having decay heat exceeding
the limits required by CoC No. 1030, Amendment No. 0 at the time of
loading) in their as-loaded configuration at the Surry Power Station
ISFSI.
Currently, the five affected fuel assemblies have been in storage
for a minimum of 2.5 years and have decayed to meet the required decay
heat limits of the CoC. The licensee submitted TN Calculation No.
10494-174, which performed a bounding thermal analysis using ANSYS
finite element software to evaluate the misloading events. The ANSYS
analysis consists of a half-symmetric, three-dimensional model of a
32PTH DSC with a number of conservative assumptions. First, the modeled
fuel assembly loading pattern is based on the configuration that
resulted in the maximum fuel cladding temperature presented in the
UFSAR analysis dated October 2, 2009, with the exception that the two
fuel assemblies in Zone 1b were set to 860 W. The licensee states this
configuration bounds the design zone limits as listed in TS, Section
2.1, which are based on each Zone 1b fuel assemblies being 800 W. It
also bounds the as-loaded configurations, where one or both fuel
assemblies in Zone 1b exceeded a decay heat of 800 W, up to a value of
806 W. The remaining DSC fuel assembly decay heats were within the
design basis. Therefore, since the as-loaded configuration had a total
DSC decay heat of 33.31 kW, the licensee states the model
conservatively assumes a total
[[Page 24540]]
DSC decay heat of 34.92 kW. Secondly, the licensee applies a storage
condition ambient temperature of 115 [deg]F, which is above the maximum
normal storage ambient temperature of 100 [deg]F. The NRC staff finds
the assumed 115 [deg]F boundary condition provides a reasonably
conservative ambient temperature choice, considering that summer
temperatures often are greater than 90 [deg]F and can reach 100 [deg]F
(per weather almanac, www.NOAA.gov). The NRC staff further finds that
applying a higher ambient temperature boundary condition also mitigates
the thermal effects of other ambient weather conditions, such as wind
direction relative to the DSC's inlet and outlet openings.
Using the conservative assumptions stated above, the TN Calculation
No. 10494-174 analysis presented by the licensee indicates a maximum
cladding temperature of 689 [deg]F for the as-loaded DSC with the
reversed heat load zoning for storage conditions. This is 5 [deg]F
higher than the previously calculated cladding temperature found in
Table 4-2 of the UFSAR. The temperatures of other DSC components
increased by less than 5 [deg]F. The temperature increases due to the
misloaded fuel assemblies are essentially unchanged for transfer
conditions. By applying an additional 5 [deg]F to the previously
calculated temperature for transfer conditions listed in Table 4-1 of
the UFSAR, the licensee estimates that the maximum fuel cladding
temperature for the as-loaded DSC with the reversed heat load zoning
for transfer conditions to be 724 [deg]F. As a result, the licensee
concluded that the maximum cladding temperatures for both normal
storage and transfer conditions were below the 752 [deg]F maximum
allowable cladding temperature limit noted in the UFSAR analysis. The
NRC staff has reviewed the analysis presented by Dominion and finds the
thermal effect of the misloaded fuel assemblies to be minimal, and that
the thermal margins were sufficient to mitigate the effects of the
misloaded fuel assemblies so as to provide adequate heat removal
capabilities when the DSC fuel assembly arrangement was not within the
design basis. This thermal evaluation provides reasonable assurance
that the TN NUHOMS[supreg] HD Storage System (HD-32PTH) loaded with
fuel assemblies exceeding the decay heat limits allowed by the CoC will
allow for continued safe storage of the spent fuel.
The licensee also discusses structural and pressure considerations
due to the increased decay heat of the Zone 1b fuel assemblies. The
licensee concludes that the increased decay heat did not have an effect
on the structural evaluation since the DSC fuel compartment and basket
rails are at temperatures below those considered in the design basis
analysis. The submitted analysis finds that the 5 [deg]F higher
temperature, due to the larger as-loaded decay heat, would result in a
DSC pressure increase of 0.1 psig. The resulting 6 psig and 6.5 psig
DSC pressures for the normal storage and transfer conditions were less
than the 15 psig design basis pressure. The NRC staff has reviewed the
analysis submitted in the exemption request and finds that there were
no structural implications on the cask system resulting from the
misloaded fuel assemblies.
The licensee verified the design basis shielding analysis remained
bounding for the as-loaded DSCs. The licensee concluded the design
basis shielding analysis assumes a DSC loading of 32 assemblies all
having source terms applicable to assemblies generating 1.5 kW of decay
heat and therefore bounds the as-loaded DSCs. The NRC staff has
reviewed the design basis shielding analysis and concludes that the
design remains bounding for the as-loaded DSCs and the radiation
protection system of the NUHOMS[supreg] HD-32PTH dry cask storage
system remains in compliance with 10 CFR part 72.
The NRC staff has reviewed Dominion's exemption request and finds
that the five fuel assemblies loaded into four DSCs with decay heat
greater than specified in the CoC do not affect the heat removal
capabilities, the structural integrity, or the radiation protection
system of the cask systems. Therefore, the NRC staff concludes that the
exemption to allow the licensee to store the four DSCs in their as-
loaded configuration does not pose an increased risk to public health
and safety or the common defense or security.
Otherwise in the Public Interest
The information Dominion submitted with its exemption request and
the TN analysis documented in TN Calculation No. 10494-174 demonstrate
that the as-loaded DSCs are not compromised due to the misloaded fuel
assemblies. Dominion has also considered an alternative action to
correct the condition by reloading the affected DSCs to be in
compliance with CoC No. 1030. This would involve retrieving each of the
DSCs from their Horizontal Storage Modules (HSM), unloading the spent
fuel assemblies from the DSC, performing inspections of various DSC
components, reloading the spent fuel assemblies into the used DSC or a
new DSC (if there was damage noted on the used DSC) in accordance with
CoC No. 1030, performing the DSC closing procedures, and transferring
the DSC back to the ISFSI for re-insertion into the HSM.
The licensee estimates this alternative action of loading and
unloading operations would increase personnel exposures by 250 mRem per
affected DSC. In addition, the licensee also states the alternative to
the proposed action would generate radioactive contaminated material
and waste during loading and unloading operations and disposal of the
used DSCs (if the DSCs were damaged during the unloading process). The
licensee estimates the alternative to the proposed action would cost an
estimated $300,000 for unloading and reloading operations of each
affected DSC and also necessitate additional fuel handling operations.
If the DSC was damaged during unloading, the licensee estimates an
additional $1,000,000 for purchase of a new DSC and $200,000 for
disposal of the used DSC.
The exemption, by allowing the four affected DSCs to remain in
their as-loaded condition, is consistent with NRC's mission to protect
public health and safety. Approving the DSCs to remain in their as-
loaded condition results in less of an opportunity for a release of
radioactive material than the alternative to the proposed action.
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 a request for a one-time exemption
from the requirements of 10 CFR 72.212(b)(3) and the portion of
72.212(b)(11), which requires compliance with the terms, conditions,
and specifications of a CoC, but only to the extent necessary to allow
Dominion to store the four DSCs in the current as-loaded configuration
at the Surry Power Station 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
[[Page 24541]]
the proposed action. In addition the proposed action only affects the
requirements associated with the fuel assemblies already loaded into
the casks 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 are documented in the Federal Register
(77 FR 20440, dated April 4, 2012).
4.0 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 Dominion
a one-time exemption from the requirements in 10 CFR 72.212(b)(3) and
from the portion of 10 CFR 72.212(b)(11) that states the licensee shall
comply with the terms, conditions, and specifications of the CoC for
the TN NUHOMS[supreg] HD dry cask storage system with DSCs serial
numbers DOM-32PTH-001-C, -002-C, -003-C, and -009-C, at the Surry Power
Station ISFSI.
This exemption is effective upon issuance.
For the Nuclear Regulatory Commission.
Dated: Dated at Rockville, Maryland, this 12th day of April
2012.
Doug Weaver,
Deputy Director, Division of Spent Fuel Storage and Transportation,
Office of Nuclear Material Safety and Safeguards.
[FR Doc. 2012-9802 Filed 4-23-12; 8:45 am]
BILLING CODE 7590-01-P