[Federal Register Volume 68, Number 27 (Monday, February 10, 2003)]
[Notices]
[Pages 6784-6786]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-3234]
-----------------------------------------------------------------------
NUCLEAR REGULATORY COMMISSION
[Docket 72-30]
Maine Yankee Atomic Power Company, Independent Spent Fuel Storage
Installation; Issuance of Environmental Assessment and Finding of No
Significant Impact for a Proposed Exemption
The U.S. Nuclear Regulatory Commission (NRC or Commission) is
considering issuance of an exemption to Maine Yankee Atomic Power
Company (MYAPC or licensee), pursuant to 10 CFR 72.7, from specific
provisions of 10 CFR 72.212(a)(2), 72.212(b)(2)(i), 72.212(b)(7), and
72.214. The licensee is planning to use the NAC-UMS Storage System to
store spent nuclear fuel from the decommissioning reactor. The
requested exemption would allow MYAPC to deviate from requirements of
the NAC-UMS Certificate of Compliance 1015 (CoC or
Certificate), Appendix A, Limiting Condition for Operation (LCO) Items
3.1.1.1, 3.1.1.2, 3.1.4.1, and 3.1.4.2. Specifically, the exemption
would allow MYAPC to increase: (1) Vacuum drying time limits based on
canister heat load; (2) vacuum drying time limits after 24 hours of in-
pool or forced air cooling; (3) time duration limit from completion of
canister helium backfill through completion of canister transfer to the
concrete cask; and (4) time duration limit from completion of in-pool
or forced air cooling through completion of the canister transfer to
the concrete cask.
By letter dated January 15, 2002, the designer of the NAC-UMS
system, NAC International, requested an amendment to CoC 1015,
that seeks, among several other changes, to increase the vacuum drying
time limits. That request was supplemented on November 27, 2002. The
information provided in the amendment request, as supplemented, is
relevant to the exemption request by MYAPC and provides the safety
basis for the time limits increase.
Environmental Assessment (EA)
Identification of Proposed Action
By letter dated November 7, 2002, as supplemented on December 19,
2002, MYAPC requested an exemption from the requirements of 10 CFR
72.212(a)(2), 72.212(b)(2)(i), 72.212(b)(7), and 10 CFR 72.214 to
deviate from the requirements in CoC No. 1015, Appendix A, LCO Items
3.1.1.1, 3.1.1.2, 3.1.4.1, and 3.1.4.2. MYAPC has informed the NRC of
its plans to store spent nuclear fuel under the general licensing
provisions of 10 CFR part 72. The licensee has begun loading spent fuel
into the NAC-UMS Storage System at an Independent Spent Fuel Storage
Installation (ISFSI) located at the Maine Yankee Atomic Power Station
in Wiscasset, Maine.
The current requirements in CoC No. 1015, Appendix A, LCO Items
3.1.1.1, 3.1.1.2, 3.1.4.1, and 3.1.4.2 establish time limits for vacuum
drying operations as follows:
(1) LCO 3.1.1.1 limits the vacuum drying time for the fuel canister
based on heat load per canister to the following:
(a) 34 hours for heat loads less than or equal to 8 kilowatts (kW).
(b) 30 hours for heat loads greater than 8 kW and less than or
equal to 11 kW.
(c) 23 hours for heat loads greater than 11 kW and less than or
equal to 14 kW.
(d) 19 hours for heat loads greater than 14 kW and less than or
equal to 17.6 kW.
[[Page 6785]]
(2) LCO 3.1.1.2 limits canister vacuum drying time after the end of
24 hours of in-pool or of forced air cooling to the following:
(a) 14 hours for heat loads less than or equal to 14 kW.
(b) 10 hours for heat loads greater than 14 kW and less than or
equal to 20 kW.
(3) LCO 3.1.4.1 limits the time duration from completion of
backfilling the canister with helium through completion of canister
transfer to the concrete cask to 48 hours for canister heat loads
greater than 14 kW and less than or equal to 17.6 kW.
(4) LCO 3.1.4.2 limits the time duration from completion of in-pool
or forced air cooling through completion of canister transfer to the
concrete cask to 20 hours for canister heat loads greater than 14 kW
and less than or equal to 17.6 kW.
By exempting MYAPC from 10 CFR 72.212(a)(2), 72.212(b)(2)(i),
72.212(b)(7), and 10 CFR 72.214 for this request, MYAPC will be
authorized to change the above mentioned time limits as follows:
(1) For LCO 3.1.1.1, the time limits per canister will be increased
as follows:
(a) 103 hours for heat loads less than or equal to 8 kW.
(b) 52 hours for heat loads greater than 8 kW and less than or
equal to 11 kW.
(c) 40 hours for heat loads greater than 11 kW and less than or
equal to 14 kW.
(d) 33 hours for heat loads greater than 14 kW and less than or
equal to 17.6 kW.
(2) For LCO 3.1.1.2, the time limits per canister will be increased
as follows:
(a) 78 hours for heat loads less than or equal to 8 kW.
(b) 27 hours for heat loads greater than 8 kW and less than or
equal to 11 kW.
(c) 16 hours for heat loads greater than 11 kW and less than or
equal to 14 kW.
(d) 9 hours for heat loads greater than 14 kW and less than or
equal to 17.6 kW.
(3) For LCO 3.1.4.1, the time limit for canister heat loads less
than or equal to 17.6 kW, will be increased to 600 hours.
(4) For LCO 3.1.4.2, the time limit for canister heat loads less
than or equal to 17.6 kW, will be increased to 600 hours.
The proposed action before the Commission is whether to grant this
exemption under the provisions of 10 CFR 72.7. The NRC staff has
reviewed the exemption request and determined that the increased LCO
time limits for vacuum drying operations are consistent with the safety
analyses previously reviewed for the NAC-UMS system, and would have no
impact on the design basis and would not be inimical to public health
and safety.
Need for the Proposed Action
At the time of the exemption request, MYAPC had loaded
approximately seven casks. During these cask loadings, MYAPC discovered
that the existing NAC-UMS Technical Specification (TS) limits for
vacuum drying and subsequent cool down required the licensee to
repeatedly enter into the required actions of the TS. Since successful
vacuum drying could not be accomplished within the TS limits, MYAPC was
required to take the LCO remedial actions. Specifically, the licensee
was required to perform in-pool or forced-air cooling of the canister
for a 24 hour period if the canister could not be vacuum dried within
the prescribed times. The TS further limits subsequent drying times
after this cool-down period.
Consequently, the licensee found it difficult to achieve sufficient
vacuum drying on the second drying attempt, thus requiring another
cool-down period. The repeated entries into vacuum drying and cool-down
periods added to the processing time and to the occupational exposures.
The licensee estimated that processing times for each canister was
increased by a minimum of 60 hours.
The licensee calculated that the reduction in radiological exposure
to the operators, fuel handlers, and security personnel involved in
handling, preparing and transferring the canisters would be
approximately 5 rem during the remainder of the spent fuel loading
campaign. This reduction is a significant percentage of the overall
station dose for the entire decommissioning project. The expected
savings of 5 rem represents nearly 8% of the 2002 total station dose
and will likely represent an even greater percentage of the 2003
station dose.
Environmental Impacts of the Proposed Action
The licensee requested the exemption to increase current vacuum
drying time limits specified in CoC No. 1015. The NRC staff performed a
safety evaluation of the proposed exemption. Staff reviewed the
analysis provided in the NAC-UMS amendment application addressing spent
fuel cladding integrity and thermal performance of canisters for
increased vacuum drying times. The safety evaluation performed by the
staff concludes that the NRC has reasonable assurance that increasing
the vacuum drying time limits has no impact on off-site doses, results
in a dose savings to workers, and meets the requirements of 10 CFR
72.104, 10 CFR 72.106 and 10 CFR 20.1301, and is therefore acceptable.
Therefore, the environmental impact of increasing vacuum drying
time limits is no greater than the environmental impact already
assessed in the initial rulemaking for the NAC-UMS storage system (65
FR 62581, dated October 19, 2000).
The proposed action will not increase the probability or
consequences of the analyzed accidents, no changes are being made to
the types of effluents that may be released offsite, and there is no
increase in occupational or public radiation exposure. Therefore, there
are no significant radiological environmental impacts associated with
the proposed action. Therefore, the staff has determined that there is
no reduction in the ability of the NAC-UMS system to perform its safety
function, nor significant environmental impacts, as a result of
increasing vacuum drying time limits.
Alternative to the Proposed Action
Since there is no significant environment impact associated with
the proposed action, alternatives with equal or greater environmental
impact are not evaluated. The alternative to the proposed action would
be to deny approval of the exemption. Denial of the exemption request
will have the same environmental impact, but would likely result in a
dose increase to workers involved in cask loading activities.
Agencies and Persons Consulted
This exemption request was discussed with Ms. Paula Craighead,
State Nuclear Safety Advisor for the State of Maine, on January 28,
2003. Ms. Craighead sent an e-mail to NRC on January 31, 2003,
identifying the State's concerns with the exemption request. The safety
concerns raised by Ms. Craighead were addressed by NRC staff in the
evaluation of the exemption request and did not provide a basis to deny
the exemption request.
Finding of No Significant Impact
The environmental impacts of the proposed action have been reviewed
in accordance with the requirements set forth in 10 CFR part 51. Based
upon the foregoing EA, the Commission finds that the proposed action of
granting the exemption from 10 CFR 72.212(a)(2), 72.212(b)(2)(i),
72.212 (b)(7), and 10 CFR 72.214 and allowing MYAPC to increase the
vacuum drying time limits for loading spent fuel in the NAC-UMS storage
system will not significantly impact the quality of the human
environment. Accordingly, the Commission has determined that an
[[Page 6786]]
environmental impact statement for the proposed exemption is not
warranted.
The request for exemption was docketed under 10 CFR Part 72, Docket
72-30. For further details with respect to this action, see the
exemption request dated November 7, 2002. The NRC maintains an
Agencywide Documents Access and Management System (ADAMS), which
provides text and image files of NRC's public documents. These
documents may be accessed through the NRC's Public Electronic Reading
Room on the Internet at http://www.nrc.gov/reading-rm/adams.html. If
you do not have access to ADAMS or if there are problems in accessing
the documents located in ADAMS, contact the NRC Public Document Room
Reference staff at 1-800-397-4209, 301-415-4737, or by e-mail to
[email protected].
Dated at Rockville, Maryland, this 31st day of January, 2003.
For the Nuclear Regulatory Commission.
Stephen C. O'Connor,
Sr. Project Manager, Spent Fuel Project Office, Office of Nuclear
Material Safety and Safeguards.
[FR Doc. 03-3234 Filed 2-7-03; 8:45 am]
BILLING CODE 7590-01-P