[Federal Register Volume 63, Number 17 (Tuesday, January 27, 1998)]
[Notices]
[Pages 3929-3932]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-1903]
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NUCLEAR REGULATORY COMMISSION
[Docket No. 50-263]
Draft Environmental Assessment; Relating to a Proposed License
Amendment To Increase the Maximum Rated Thermal Power Level at the
Monticello Nuclear Generating Plant
AGENCY: Nuclear Regulatory Commission.
ACTION: Notice of opportunity for public comment.
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SUMMARY: The Nuclear Regulatory Commission has prepared a draft
environmental assessment related to the Northern States Power Company's
(NSP's) request for a license amendment to increase the maximum rated
thermal power level from 1670 megawatts-thermal (MWt) to 1775 MWt. As
stated in the NRC staff's position paper on the Boiling-Water Reactor
Extended Power Uprate Program dated February 8, 1996, the staff has the
option of preparing an environmental impact statement if it believes a
significant impact results from the power uprate. The staff did not
identify a significant impact related to the NSP's request and,
therefore, the NRC staff documented its
[[Page 3930]]
environmental review in an environmental assessment (EA). In accordance
with the February 8, 1996, staff position paper, the draft EA and
finding of no significant impact is being published in the Federal
Register for a 30-day comment period.
DATES: Comment period expires February 26, 1998. Comments received
after this date will be considered if it is practical to do so, but the
Commission is able to assure consideration only for comments received
on or before this date.
ADDRESSES: Submit written comments to Chief, Rules Review and
Directives Branch, U.S. Nuclear Regulatory Commission, Mail Stop T-6D-
69, Washington, DC 20555-0001. Written comments may also be delivered
to 11545 Rockville Pike, Rockville, Maryland, from 7:30 am to 4:15 pm,
Federal Workdays. Copies of written comments received may be examined
at the NRC Public Document Room, 2120 L Street, N.W. (Lower Level),
Washington, DC.
FOR FURTHER INFORMATION CONTACT: Tae Kim, Office of Nuclear Reactor
Regulation, Mail Stop O-13D18, U.S. Nuclear Regulatory Commission,
Washington, DC 20555-0001, telephone (301) 415-1392.
SUPPLEMENTARY INFORMATION: The U.S. Nuclear Regulatory Commission (the
Commission) is considering issuance of an amendment to Facility
Operating License No. DPR-22, issued to Northern States Power Company,
for operation of the Monticello Nuclear Generating Plant located in
Wright County, Minnesota. The Commission's draft environmental
assessment and finding of no significant impact related to the subject
license amendment is provided below:
Environmental Assessment
1.0 Introduction
1.1 Description of Proposed Action
By letter dated July 26, 1996, as revised December 4, 1997,
Northern States Power Company (NSP) requested an amendment to License
No. DPR-22 for the Monticello Nuclear Generating Plant (MNGP) that
would increase the maximum power level from 1670 megawatts-thermal
(MWt) to 1775 MWt. This change is approximately 6.3 percent above the
current maximum license power level and is considered an extended power
uprate.
1.2 Need for the Proposed Action
NSP has projected the need for additional generation resources
through a comparison of needs to available resources. NSP has projected
a shortfall of generating capacity in the future. The proposed action
would provide increased reactor power, thus adding an additional 26 MW
of reliable electrical energy generating capacity without major
hardware modifications to the plant. Hardware changes are not needed
because of improvements in technology, performance, and design. These
improvements have resulted in a significant increase in the difference
between the calculated safety analysis results and licensing limits
established by the original license.
2.0 Environmental Impacts
The issuance of the operating license for MNGP stated that any
activity authorized by the license is encompassed by the overall action
evaluated in the Final Environmental Statement (FES), which was issued
in November 1972. The license for MNGP allowed a maximum reactor power
level of 1670 MWt. NSP submitted an environmental evaluation supporting
the proposed power uprate action and provided a summary of its
conclusions concerning both the radiological and nonradiological
environmental impacts of the proposed action. The evaluations performed
by the licensee concluded that the environmental impacts of power
uprate are well bounded or encompassed by previously evaluated
environmental impacts and criteria established by the staff in the FES.
A summary of the nonradiological and radiological effects on the
environment that may result from the proposed amendment is provided
below.
2.1 Nonradiological Impacts
2.1.1 Land use. Power uprate does not modify land use at the site.
No new facilities, access roads, parking facilities, laydown areas, or
onsite transmission and distribution equipment, including power line
right of way, are needed to support the uprate or operation after
uprate. No change to above or below ground storage tanks would occur as
a result of power uprate and the uprate does not affect land with
historical or archeological sites.
Based on the operating history at the MNGP, the effects of drift,
icing, and fog have been negligible. The frequency of fog and drift
were provided by the licensee at the time of original licensing and the
impacts of that frequency of drift and fog are bounded by the
evaluation contained in the FES. The FES assumed cooling tower
operation of 7 months, with the total fogging time estimated at 45
hours per year. If the cooling tower fogging rate is assumed to
increase proportional to the proposed power increase, the amount of
fogging due to power uprate could increase by approximately 6.3 percent
above the normal summer operating period of 4 months. Additionally, the
licensee determined that power uprate may involve an extra week of
cooling tower operation. Taking into account the additional fogging
rate and the additional cooling tower operation, the conditions at
power uprate are still bounded by the FES.
The increase in power level would cause a current and magnetic
field increase on the onsite transmission line between the main
generator and the plant substation. The line is located entirely within
the fenced, licensee-controlled boundary of the plant, and it is not
expected that members of the public or wildlife would be affected.
Exposure from magnetic fields from the offsite transmission system is
not expected to increase significantly.
2.1.2 Water Use. Power uprate does not involve a significant
increase in water use at MNGP. Both ground and surface water
appropriation limits are established by the Minnesota Department of
Natural Resources. Operating history shows that over the last 5 years
MNGP has used less than 13 million gallons of ground water per year.
The annual limit established in the permit for groundwater use is 15
million gallons. Power uprate is not expected to change the groundwater
usage and, therefore, operation within the allowable limit would
continue. Under the surface water appropriation limit, MNGP may
withdraw a maximum of 645 cubic feet per second (cfs) from the
Mississippi River. There are special restrictions when the river flow
is particularly high or low; however, power uprate is not expected to
change the surface water requirements of the plant and, therefore,
current appropriation limits would be maintained.
Power uprate would result in an increase in the evaporation rate of
the cooling towers resulting in an increase in evaporative losses from
the river. Assuming the evaporation rate of the cooling towers
increases linearly in proportion to the power increase, the evaporation
rate would increase to 4400 acre-ft/yr [acre-foot per year]. The value
assumed in the FES was 5000 acre-ft/yr evaporative losses; therefore,
the FES is still bounding.
Discharges to the water are governed by the National Pollutant
Discharge Elimination System (NPDES) permit, issued by the State of
Minnesota. Temperature and effluent limits at certain points are
established in the permits. As a result of power uprate, a slight
increase in circulating water
[[Page 3931]]
discharge temperature is projected to occur. This is due to an increase
in heat rejected by the condenser due to the increased power levels and
increased steam flow. A conservative estimate by the licensee predicts
a maximum 1.7 deg.F [degrees Fahrenheit] increase in the temperature
of the water entering the discharge canal. This increase would not
result in exceeding the limits delineated in the FES or the limits
established by the State in the permit. Additionally, temperature
monitoring is continuous and this maximum temperature increase would
occur only at certain times of the year with certain river flows. In
the past, when MNGP has approached the limit designated in the NPDES
permit, NSP has reduced power at the plant to maintain compliance; this
will continue in the future. The slight increase in temperature does
not require any changes to permit requirements and would not result in
any significant impacts to the environment that are different from
those previously identified or change the previous Clean Water Act
Section 316(a) demonstration concerning thermal plume in the
Mississippi River.
Power uprate would not introduce any new contaminants or pollutants
and would not significantly increase the amount of potential
contaminants previously allowed by the State. NSP will continue to
adhere to effluent limitation and monitoring requirements as part of
compliance with the NPDES permit. As a result of the additional week of
cooling tower operation, a slight increase in normal bromine and sodium
hypochlorite injection may be required; however, the effluent
concentrations would continue to be well below the NPDES permit limits.
Continuous flowrate monitoring at designated points will continue.
Over the years of operation, a number of modifications to the
intake structure have been implemented to reduce cold shock,
impingement, and entrainment of organisms and fish. Because the
discharge canal inlet temperature is expected to increase 1.7 deg.F at
power uprate, the overall discharge canal temperature is not
significantly increased; therefore, the temperature decrease during
cold shock is not significantly changed.
Additionally, impingement and entrainment mortality of drift
organisms is not increased above what was previously evaluated by the
staff.
2.1.3 Other impacts. No significant increases or changes to the
noise generated by MNGP are expected as a result of power uprate;
therefore, the FES remains bounding. A small number of endangered and
threatened species exist within the licensee-controlled area at MNGP.
Using information from the Minnesota Department of Natural Resources,
the licensee performed a biological assessment of the impact of power
uprate on these species. The assessment did not identify any impacts.
Power uprate would not result in any significant changes to land use or
water use, or result in any significant changes to the quantity or
quality of effluents; therefore, no effects on the endangered or
threatened species or on their habitat are expected as a result of
power uprate.
The proposed power uprate would not change the method of generating
electricity nor the method of handling any influent from the
environment or nonradiological effluents to the environment. Therefore,
no changes or different types of nonradiological environmental impacts
are expected.
2.2 Radiological Impacts
MNGP has a number of radioactive waste systems designed to collect,
process, and dispose of solid, liquid, and gaseous radioactive waste.
No changes to these systems are required for power uprate conditions.
The licensee considered the effect of the higher power level on solid
radioactive wastes, liquid radioactive wastes, gaseous radioactive
wastes, and radiation levels.
As a result of power uprate, a slight increase in solid waste from
the reactor water cleanup (RWCU) system demineralizers and condensate
demineralizers would occur. This is due to more frequent filter
backwashes. Additional RWCU filter backwashes would result in less than
1 cubic meter of additional resin waste per year; condensate
demineralizer filter backwashes are estimated to result in an
additional 4 cubic meters of resin waste per year. Therefore, the
projected increase in spent resin volume is less than 6 cubic meters
per year, which would bring the total generation rate to approximately
55 cubic meters per year.
In addition to the solid process waste, there are solid reactor
system wastes generated from the plant. These include irradiated fuel
assemblies and control blades. Due to extended burnup and the higher
enrichments, the number of irradiated fuel assemblies is not expected
to significantly increase the volume of waste; however, the activity of
the waste generated from spent control blades and incore ion changers
may increase slightly. This is due to the higher flux conditions
expected under power uprate. Improvements in technology and longer fuel
cycles are expected to offset this slight increase. The increase in
waste would be insufficient to impact the amount of waste generated at
the site. Further, the licensee believes ongoing efforts at MNGP to
reduce radioactive wastes will balance the slight increase in waste
that would be generated as a result of power uprate.
The FES and Technical Specifications allow MNGP to discharge a
limited amount of liquid radioactive waste. The FES concluded that,
based on the allowed amounts, no adverse environmental impact would
result from release of the allowable radioactive waste. However, since
1972, an administrative limit of zero radioactive liquid release has
been imposed by NSP. MNGP expects to keep the zero release
administrative limit and remain well within the bounds of the FES.
A slight increase in input to the liquid radioactive waste system
is expected due to the increase in backwash frequency of the RWCU and
condensate demineralizer system. However, the liquid radioactive waste
input will be recycled instead of discharged and will not result in a
significant increase in volume of liquid radioactive waste. Other
sources of liquid radioactive waste such as valve packings, pump seal
flows, drain waste, etc., are not expected to change or increase as a
result of power uprate. Based on the above, it does not appear that
power uprate will cause an increase in liquid radioactive waste above
the presently allowed limits and will not affect compliance with the
limits of 10 CFR Part 20 or Appendix I of 10 CFR Part 50.
Gaseous radioactive waste effluents consist of two pathways:
reactor building ventilation system and offgas system pathway.
Operational experience at MNGP shows a 4-year average release of 688
Ci/yr [curie per year] noble gas and 0.22 Ci/yr iodine and particulate
release. The FES assumed release rates of 110,376 Ci/yr for noble gases
and 0.75 Ci/yr for iodine and particulate releases. Assuming power
uprate increases the offgas release rate linearly in proportion to the
core thermal power increase, the increase in offgas stack release would
be well below that assumed in the FES. Assuming the radioactivity of
the reactor coolant system increases in a linear fashion proportional
to the power increase, the reactor building release rate is well below
that assumed in the FES. Based on the above, power uprate has an
insignificant effect on the present production and activity of gaseous
effluents released through the reactor building ventilation system and
the offgas system pathways and the dose from effluent releases is well
within the bounds of Appendix I to 10 CFR Part 50
[[Page 3932]]
and 10 CFR Part 20. The changes in core flux profile would result in
increased consequences of a fuel defect for a bundle in a non-leak
location; however, this continues to be bounded by the consequences for
the peak bundle and those limits are not changed.
Power uprate does not introduce any new or different radiological
release pathways and does not increase the probability of an operator
error or equipment malfunction that would result in a radiological
release.
Tables S-3 and S-4 of 10 CFR 51.51 and 10 CFR 51.52, respectively,
outline the environmental effects of uranium fuel cycle activities and
fuel and radioactive waste transportation. The environmental evaluation
supporting Table S-3 assumed a reference reactor with a specific
capacity factor that results in an adjusted daily electricity
production during a reference year. An average burnup and enrichment
are also assumed. MNGP will not exceed the assumption of the reference
reactor year, but will exceed the average burnup and fuel enrichment
criteria as a result of power uprate. The environmental impacts of the
higher burnup and enrichment values were documented in NUREG/CR-5009,
``Assessment of the Use of Extended Burnup Fuels in Light Water Power
Reactors,'' and discussed in the Environmental Assessment and Finding
of No Significant Impact, which was published in the Federal Register
on February 29, 1988 (53 FR 6040). The staff concluded that no
significant adverse effects will be generated by increasing the burnup
levels as long as the maximum rod average burnup level of any fuel rod
is no greater than 60 Gwd/MtU [gigawatt-days per metric ton of
uranium]. The staff also stated that the environmental impacts
summarized in Tables S-3 and S-4 for a burnup level of 33 Gwd/MtU are
conservative and bound the corresponding impacts for burnup levels up
to 60 Gwd/MtU and uranium-235 enrichments up to 5 weight percent. Based
on the above, there are no adverse radiological or non-radiological
impacts associated with the use of extended fuel burnup and/or
increased enrichment and, therefore, power uprate will not
significantly affect the quality of the human environment.
3.0 Alternatives
As an alternative to the proposed action, the staff considered
denial of the proposed action. Denial of the proposed action would
result in no change in current environmental impacts of plant operation
but would restrict operation to the currently licensed power level. The
environmental impact of the proposed action and the alternative action
are similar.
4.0 Alternative Use of Resources
This action does not involve the use of any resources not
previously considered in the Final Environmental Statement for the
MNGP.
5.0 Basis and Conclusions for Not Preparing an Environmental Impact
Statement
The staff has reviewed the proposed power uprate for the MNGP
relative to the requirements set forth in 10 CFR Part 51. Based upon
the environmental assessment, the staff has concluded that there are no
significant radiological or nonradiological impacts associated with the
proposed action and that the proposed license amendment will not have a
significant effect on the quality of the human environment. Therefore,
the Commission has determined pursuant to 10 CFR 51.31 not to prepare
an environmental impact statement for the proposed amendment but to
prepare this draft finding of no significant impact.
For further details with respect to the proposed action, see the
licensee's letter dated July 26, 1996, as revised by letter dated
December 4, 1997, which are available for public inspection at the
Commission's Public Document Room, The Gelman Building, 2120 L Street,
NW., Washington, DC, and at the local public document room located at
the Minneapolis Public Library, Technology and Science Department, 300
Nicollet Mall, Minneapolis, Minnesota 55401.
Dated at Rockville, Maryland, this 21st day of January 1998.
Cynthia A. Carpenter,
Acting Director, Project Directorate III-1, Division of Reactor
Projects--III/IV, Office of Nuclear Reactor Regulation.
[FR Doc. 98-1903 Filed 1-26-98; 8:45 am]
BILLING CODE 7590-01-P
