[Federal Register Volume 71, Number 18 (Friday, January 27, 2006)]
[Notices]
[Pages 4614-4622]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-1035]
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NUCLEAR REGULATORY COMMISSION
[Docket No. 50-271]
Entergy Nuclear Vermont Yankee, LLC and Entergy Nuclear
Operations, Inc., Vermont Yankee Nuclear Power Station; Final
Environmental Assessment and Finding of No Significant Impact Related
to the Proposed License Amendment To Increase the Maximum Reactor Power
Level
AGENCY: U.S. Nuclear Regulatory Commission (NRC or the Commission).
SUMMARY: The NRC has prepared a final Environmental Assessment as its
evaluation of a request by Entergy Nuclear Vermont Yankee, LLC and
Entergy Nuclear Operations, Inc. (Entergy or the licensee) for a
license amendment to increase the maximum thermal power at Vermont
Yankee Nuclear Power Station (VYNPS) from 1593 megawatts-thermal (MWt)
to 1912 MWt. This represents a power increase of approximately 20
percent for VYNPS. As stated in the NRC staff's position paper dated
February 8, 1996, on the Boiling-Water Reactor Extended Power Uprate
(EPU) Program, the NRC staff will prepare an environmental impact
statement if it believes a power uprate will have a significant impact
on the human environment. The NRC staff did not identify any
significant impact from the information provided in the licensee's EPU
application for VYNPS or the NRC staff's independent review; therefore,
the NRC staff is documenting its environmental review in an
environmental assessment. The final environmental assessment and
finding of no significant impact is being published in the Federal
Register.
The NRC published a draft environmental assessment and finding of
no significant impact on the proposed action for public comment in the
Federal Register on November 9, 2005 (70 FR 68106). Two sets of
comments were received as discussed below.
The licensee provided three comments in a letter dated December 8,
2005 (Agencywide Documents Access and Management System (ADAMS)
Accession No. ML053500122). The first comment clarified operation of
the three modes of operation of the circulating water system. Based on
this comment, the NRC revised the description of the system in the
``Plant Site and Environs'' and ``Water Use Impacts'' sections of the
final environmental assessment. The second comment clarified that
transmission lines are owned and operated by different transmission
operators, rather than Entergy as was indicated in the draft
environmental assessment. Based on this comment, the NRC revised the
``Transmission Facility Impacts'' section of the final environmental
assessment. The third comment provided information regarding
replacement of 21 of the 22 cooling tower fan motors with higher
horsepower motors. Since Entergy indicated that the conclusions in the
draft environmental assessment regarding cooling tower operation
(including noise) were correctly stated, no changes were made based on
this comment.
Mr. David L. Deen of the Connecticut River Watershed Council (CRWC)
provided three comments in an e-mail dated December 9, 2005 (ADAMS
Accession No. ML053500124). The first comment raised concerns that the
current National Pollutant Discharge Elimination System (NPDES) permit
for VYNPS places no upper bound on the temperature of the river at
which the licensee must stop adding waste heat through its cooling
tower discharge and that a draft amendment to this permit fails to
address this shortcoming. The CRWC proposed that Entergy should not
raise the ambient water temperature beyond 85 [deg]F at any point
within the
[[Page 4615]]
Connecticut River. This comment exceeds the scope of the NRC's review
of the proposed EPU amendment. The purpose of the NRC's environmental
assessment is to evaluate the potential impact of the proposed action
(i.e., the change due to the proposed EPU). As discussed in the NRC's
draft environmental assessment, Entergy has requested that the State of
Vermont issue an amendment to the current NPDES permit which would
allow a one-degree increase in the thermal discharge limits, for
certain river water temperature ranges. Entergy stated that the NPDES
permit amendment is not necessary for the proposed EPU and the licensee
will comply with the current NPDES permit thermal discharge limits if
the permit amendment is not granted. The current NPDES permit
represents the upper bound on the current impact on the river water
temperatures in the vicinity of the discharge. The NRC's draft
environmental assessment found that any discharge impacts for the
proposed action will be the same as the current impacts from plant
operation and, as such, the NRC concluded that there will be no
significant impact on the Connecticut River from VYNPS discharge due to
the EPU. The CRWC comment pertains to concerns regarding lack of an
upper bound temperature limit in the NPDES permit. The ``upper bound''
referenced in the NRC's draft environmental assessment refers to an
upper bound on the impact of the proposed EPU. Since the CRWC comment
focuses on issues regarding the NPDES permit and does not provide any
information regarding the impact of the proposed EPU, no changes were
made to the final environmental assessment based on this comment.
The second comment from the CRWC stated that if the NPDES permit
thermal discharge limits are increased, there would be harm to specific
aquatic species (i.e., American shad, Atlantic salmon, spottail shiner,
smallmouth bass, yellow perch, walleye, largemouth bass, fallfish,
white sucker, and white perch). Similar to the first comment, since the
CRWC comment focuses on issues regarding the proposed amendment to the
NPDES permit and does not provide any information regarding the impact
of the proposed EPU, no changes were made to the final environmental
assessment based on this comment.
The third comment from the CRWC questioned the NRC's draft
environmental assessment statement that there are no threatened and
endangered aquatic species in the Connecticut River. The CRWC stated
that the dwarf wedge mussel was listed as endangered under the
Endangered Species Act in 1990, and that in 1993, the U.S. Fish and
Wildlife Service approved a recovery plan to attempt to reestablish
populations of the dwarf wedge mussel throughout its historical range
including the Connecticut River. The CRWC stated that reestablishing
the population in or near VYNPS would require the presence of one of
its host species, the tessellated darter. The CRWC stated that although
the nearest population of the wedge mussel is relatively far north of
VYNPS, since the species is endangered and depends on the tessellated
darter for its survival, the tessellated darter should be included in
the threatened and endangered species review for the proposed EPU.
According to the U.S. Fish and Wildlife Service's 1993 recovery
plan, the dwarf wedge mussel (Alasmidonta heterodon) is an endangered
species located in the Connecticut River system. To assess the impact
of the proposed action, the aquatic species evaluated in the draft
environmental assessment were those in the vicinity of the VYNPS intake
and discharge structures. The dwarf wedge mussel is not located in
Windham County, Vermont and, therefore, was not included in the draft
environmental assessment. The dwarf wedge mussel larvae attach to a
host species for survival. One host species for the dwarf wedge mussel
is the tessellated darter (Etheostoma olmstedi), which is also found in
the Connecticut River system. The tessellated darter is not threatened
or endangered and, therefore, was not included in the draft
environmental assessment for the VYNPS EPU.
As noted above, the proposed EPU does not require an increase in
discharge temperature limits. Further, following implementation of the
EPU, the flow rate of water being withdrawn from the Connecticut River
through the intake structure would not increase, and there would not be
a configuration change to the intake structure to support the EPU.
Therefore, the EPU would not change existing impacts on the tessellated
darter. In addition, according to Ecological Studies of the Connecticut
River--Vernon, Vermont--Report 32, dated May 2003, the quantity of
tessellated darters impinged on the VYNPS traveling screens is small
compared to other impinged species. Impingement from the VYNPS intake
does not significantly impact the tessellated darter population. The
inter-governmental Environmental Advisory Committee (comprised of
certain Vermont, New Hampshire, Massachusetts, and federal agencies)
established limits for impingement of American shad (Alosa sapidissima)
and Atlantic salmon (Salmo salar), and because VYNPS has not approached
the impingement limits set for these species, the Vermont Agency of
Natural Resources (ANR) concluded that the impingement of other species
at VYNPS meets applicable laws. Entrainment of all aquatic species was
monitored for over a decade beginning in 1972 and determined to be
insignificant by the Environmental Advisory Committee. Entrainment was
subsequently removed from the VYNPS NPDES permit. Therefore, the staff
concludes that there would be no significant impact from impingement or
entrainment to the tessellated darter or the dwarf wedge mussel
associated with the proposed action.
Environmental Assessment
Plant Site and Environs
The EPU will apply to the facilities at the site of VYNPS located
on the west shore of the Connecticut River in the town of Vernon,
Vermont. Vernon is approximately four miles north of the Massachusetts
state line. Vernon is located in Windham County.
The VYNPS site is located on Vernon Pond on the Connecticut River,
about two-thirds of a mile upstream of the Vernon Hydroelectric Dam, at
Connecticut River mile 138.3. Vernon Pond is the portion of the
Connecticut River above Vernon Hydroelectric Dam. The site is
surrounded by the Connecticut River on the east, by farm and pasture
land mixed with wooded areas on the north and south, and by the town of
Vernon on the west. The elevation of the VYNPS site is approximately 76
meters (250 feet) above mean sea level.
Northeast of the site, the Pisgah Mountain range rises to 457
meters (1500 feet). To the west and northwest of the site, mountains
and hills rise to 549 meters (1800 feet). Approximately 13 kilometers
(km) (8 miles (mi)) southeast of the site are Warwick State Forest and
Northfield State Forest. Colrain State Forest is approximately 29 km
(18 mi) southwest of Vernon. Green Mountain National Forest is located
approximately 48 km (30 mi) west of Vernon.
VYNPS is a single-unit boiling-water reactor designed by General
Electric, with a maximum reactor core power level output of 1593 MWt.
Plant cooling is provided by either an open-cycle system, a closed-
cycle cooling system, or a hybrid-cycle system. The mode of operation
is selected to limit the heat discharged to the Connecticut River. The
closed-cycle cooling system is
[[Page 4616]]
equipped with a cooling tower that dissipates heat primarily to the
atmosphere. After passing through the condenser, circulating water
rejects waste heat to the atmosphere utilizing the cooling tower.
Remaining waste heat is discharged in the form of blowdown from the
circulating water system into the Connecticut River. In the open-cycle
mode, no water passes through the cooling towers. Water is removed from
the Connecticut River for cooling and discharged back to the
Connecticut River downstream of the intake structure. In the hybrid-
cycle mode, all of the circulating water flow is cycled through the
cooling towers, but only a portion is discharged to the river while the
remainder is recycled.
Identification of the Proposed Action
By letter dated September 10, 2003, Entergy proposed an amendment
to the operating license for VYNPS to increase the maximum thermal
power level by approximately 20 percent, from 1593 MWt to 1912 MWt. The
change is considered an EPU because it would raise the reactor core
power level more than 7 percent above the original licensed maximum
power level. This amendment would allow the heat output of the reactor
to increase, which would increase the flow of steam to the turbine.
This would result in the increase in production of electricity and the
amount of waste heat delivered to the condenser, and an increase in the
temperature of the water being discharged into the Connecticut River.
This is the first request by Entergy for a power uprate at VYNPS; no
other power uprates have previously been requested or granted for this
site.
The Need for the Proposed Action
Entergy estimates that the EPU will result in an additional 100 to
110 megawatts-electric being generated. This additional electricity
generation can power approximately 110,000 extra homes, reducing the
need to obtain electricity from other sources. The EPU would not cause
the environmental impacts that would occur if construction of a new
power generation facility were sought to meet the region's electricity
needs.
Environmental Impacts of the Proposed Action
At the time of issuance of the operating license for VYNPS, the NRC
staff noted that any activity authorized by the license would be
encompassed by the overall action evaluated in the Final Environmental
Statement (FES) for the operation of VYNPS, which was issued in July
1972. This environmental assessment summarizes the radiological and
non-radiological impacts on the environment that may result from the
currently proposed action.
Non-Radiological Impacts
Land Use Impacts
The potential impacts associated with land use for the proposed
action include impacts from construction and plant modifications. The
impacts from construction due to the proposed EPU are minimal. No
expansion of roads, parking lots, equipment storage or laydown areas,
or transmission line rights-of-way is anticipated to support the
proposed action. The only new construction required to support the EPU
is the installation of temporary office space using modular units. This
resulted in minor soil disturbance due to trenching, setting foundation
columns, hook-up of water, sewer, telephone, and electricity.
In addition, a few modifications to plant equipment will take place
to support the EPU. The most significant modifications include
replacement of the high-pressure turbine steam path, rewinding the main
generator, replacement of four high-pressure heaters, and replacement
of the main transformer. The plant modifications will not result in any
changes in land use and historic and archeological resources should not
be affected by the proposed EPU. The proposed EPU would not modify land
use at the site significantly over that described in the FES.
Therefore, the staff concludes that the environmental land use impacts
of the proposed EPU are bounded by the impacts previously evaluated in
the FES.
Cooling Tower Impacts
The potential impacts associated with increased cooling tower
operation for the proposed action include aesthetic impacts due to the
increased moisture content of the air. VYNPS has cooling towers that
are currently used to reduce the heat output to the environment. The
cooling towers are not currently used during the ``winter period'' of
October 15 through May 15, but following the EPU, the cooling towers
may be required for this period in order to meet the water discharge
thermal limits set forth in the NPDES permit. The operation of the
cooling towers during the ``winter period'' will result in a visible
plume. However, heat rejection rates during this period are less than
during the ``summer period'' of May 16 to October 14, so the visible
plume size will not be larger than during the remainder of the year.
The cooling tower plume dimensions during the ``summer period'' will
increase following the EPU. The dimensions will increase by
approximately 100 meters in length, 20 to 30 meters in width, and up to
50 meters in height. The increase in plume dimensions during the
``summer period'' and the presence of a plume during the ``winter
period'' will not cause a significant aesthetic impact because similar
plumes have been present in the area of VYNPS since 1972, and
industrial plumes are a common feature to the Connecticut River Valley.
No significant fogging or icing due to cooling tower operation is
predicted for the EPU. The Seasonal/Annual Cooling Tower Impact Program
evaluation determined that there is no predicted ground-level fogging
or icing during the year. The evaluation was performed for NPDES
``summer period'' and ``winter period'' thermal discharge limits.
No significant increase in noise is anticipated for cooling tower
operation following the EPU. A study performed on the VYNPS cooling
tower resulted in sound increases of less than one decibel for the
increased cooling tower operation.
The aesthetic impacts associated with increased cooling tower
operation for the proposed action will not change significantly over
the aesthetic impacts associated with current cooling tower operation.
Plume dimensions will increase, but will remain consistent with the
current aesthetic impacts in the VYNPS environment. No significant
fogging or icing is predicted, and no significant increase in noise
level is predicted for the increased cooling tower operation.
Therefore, the staff concludes that there are no significant aesthetic
or atmospheric impacts associated with increased cooling tower
operation for the proposed action.
Transmission Facility Impacts
The potential impacts associated with transmission facilities for
the proposed action could include changes in transmission line corridor
right-of-way maintenance and electric shock hazards due to increased
current. The proposed EPU would not require any physical modifications
to the transmission lines. Transmission line right-of-way maintenance
practices, including the management of vegetation growth, would not
change. There will be no change to operating voltage or transmission
line rights-of-way. Transmission line clearances will remain unchanged.
Modifications to onsite transmission equipment are necessary to support
the EPU, including
[[Page 4617]]
installation of capacitor banks to maintain system voltage
requirements.
The National Electric Safety Code (NESC) provides design criteria
that limit hazards from steady-state currents. The transmission lines
currently meet the applicable shock prevention provisions of the NESC.
There will be an increase in current passing through the transmission
lines associated with the increased power level of the proposed EPU.
The increased electrical current passing through the transmission lines
will cause an increase in electromagnetic field strength in the
transmission line corridors. The licensee provided an evaluation of the
transmission line loadings based on the approximately 20-percent power
uprate which concluded that there will be no significant increase in
the risk of shock under the transmission lines. Based on this
information, the staff concludes that adequate protection will be
provided against hazards from electric shock even with the slight
increase in current attributable to the EPU.
The impacts associated with transmission facilities for the
proposed action will not change significantly over the impacts
associated with current plant operation. There are no physical
modifications to the transmission lines, transmission line right-of-way
maintenance practices will not change, there are no changes to
transmission line rights-of-way or vertical clearances, and electric
current passing through the transmission lines will increase only
slightly. Therefore, the staff concludes that there are no significant
impacts associated with transmission facilities for the proposed
action.
Water Use Impacts
Potential water use impacts from the proposed action include
hydrological alterations to the Connecticut River and changes to plant
water supply. VYNPS uses cooling water from Vernon Pond on the
Connecticut River, and discharges heated water back to the Connecticut
River. Vernon Pond is the portion of the Connecticut River above Vernon
Hydroelectric Dam. VYNPS can be operated in one of three modes: The
open-cycle mode, the closed-cycle mode, or the hybrid-cycle mode. Each
of the modes is discussed previously under ``Plant Site and Environs.''
The NPDES permit limits the amount of heat discharged to the
Connecticut River from the operation of VYNPS. The thermal limit set in
the NPDES permit will not change with the EPU. In order to comply with
the NPDES thermal limit following the EPU, Entergy plans to operate the
cooling towers more often to dissipate heat to the atmosphere rather
than the river.
Due to the large flow rate of the Connecticut River, heated water
discharged to the Connecticut River will begin to mix immediately with
the river water and cool. A hydrological-biological study of Vernon
Pond conducted in 1974-1977 included a thermal study. This study
concluded that during periods of low flow in the Connecticut River, the
thermal plume from the VYNPS discharge extends outward into the river
channel before being swept downstream. During periods of high flow in
the Connecticut River, the strong river currents shear the thermal
plume and force the plume to flow along the Vermont shore. Due to these
flow patterns in the Connecticut River and the thermal limits set in
the NPDES permit, the EPU should not cause hydrological alterations to
the Connecticut River.
The EPU would not involve any configuration change to the intake
structure. The pump capacity will not change, so that there will not be
an increase in the rate of withdrawal of water from the Connecticut
River. There would be a slight increase in the amount of Connecticut
River water consumed as a result of the EPU under all cooling modes of
operation due to increased evaporative losses. During the NPDES summer
period (May 16 to October 14), the increased water consumption will be
less than 0.1% of the average monthly river flow. During the NPDES
winter period (October 15 to May 15), the increased water consumption
will be less than 0.2% of the average monthly river flow. Therefore,
the increased loss is insignificant relative to the flow in the
Connecticut River. On this basis, the staff concludes that there is no
significant impact to the hydrological pattern on the Connecticut
River, and there is no significant impact due to water consumption as a
result of the proposed action.
Discharge Impacts
Potential impacts to the Connecticut River from the VYNPS discharge
could include increased turbidity, scouring, erosion, and
sedimentation. These discharge-related impacts apply to open-cycle flow
due to the large volume of water discharged to the river. However,
since the EPU will not result in any significant change in the amount
of water withdrawn from the Connecticut River during open-cycle
operation there will be no significant change in the discharge volume
or velocity; therefore, there will be no changes in turbidity,
scouring, erosion, or sedimentation related to the EPU.
Surface water and wastewater discharges at VYNPS are regulated by
the State of Vermont via a NPDES permit (NPDES No. VT0000264). The
NPDES permit is periodically reviewed and renewed by the Vermont ANR,
Department of Environmental Conservation in Waterbury, Vermont. The EPU
would cause an increase in the temperature of the water discharged to
the Connecticut River, but the temperature of the water discharged will
remain within thermal limits specified in the NPDES permit. The
blowdown from the increased usage of the cooling towers would also be
discharged to the Connecticut River. There is no significant additional
impact to the Connecticut River expected from the increased operation
of the cooling towers because cooling tower blowdown will increase only
slightly due to minor increased usage of the cooling towers.
Entergy is requesting an amendment to the NPDES permit to allow a
one-degree increase in the thermal discharge limit, for certain river
water temperature ranges, for the ``summer period'' as shown in Table
1.
Table 1.--Proposed Summer NPDES Permit Change
----------------------------------------------------------------------------------------------------------------
Existing delta- Proposed delta-
Upstream river temperature temperature increase temperature increase
limit limit
----------------------------------------------------------------------------------------------------------------
Above 78 [deg]F................................................... 2 [deg]F 2 [deg]F
Greater than 63 [deg]F, Less than or equal to 78 [deg]F........... 2 [deg]F 3 [deg]F
Greater than 59 [deg]F, Less than or equal to 63 [deg]F........... 3 [deg]F 4 [deg]F
Greater than or equal to 55 [deg]F, Less than or equal to 59 4 [deg]F 5 [deg]F
[deg]F...........................................................
Below 55 [deg]F................................................... 5 [deg]F 5 [deg]F
----------------------------------------------------------------------------------------------------------------
[[Page 4618]]
The NPDES permit amendment is not necessary for the EPU, and VYNPS
will continue to operate under the current thermal discharge limits
(under either the current NRC license or the EPU) if the NPDES permit
amendment is not granted.
VYNPS has been operating within the current NPDES limits;
therefore, these thermal limits represent an upper bound of the current
impact on the river water temperatures in the vicinity of the
discharge. The proposed one-degree increase in the current NPDES
thermal discharge limit similarly represents the expected upper bound
of the impact on the river water temperatures during the EPU. VYNPS
will comply with the current thermal limits in the NPDES permit
following the EPU if the NPDES permit amendment request is not granted,
and any discharge impacts for the proposed action will be the same as
the current impacts from plant operation. Therefore, the staff
concludes that there will be no significant impact on the Connecticut
River from VYNPS discharge for the proposed action.
Chemicals and concentrations released from VYNPS into the
Connecticut River are regulated by the State of Vermont through the
NPDES permit. VYNPS will continue to operate within the current NPDES
permit limits following the power uprate.
Since there will be no significant increase in the VYNPS staffing
levels during operations as a result of the power uprate, there will
also be no increase in sanitary waste.
Impacts on Aquatic Biota
The potential impacts to aquatic biota from the proposed action
include impingement, entrainment, thermal discharge effects, and
impacts due to transmission line right-of-way maintenance. The VYNPS
has intake and discharge structures on the Connecticut River. The
aquatic species evaluated in this environmental assessment are those in
the vicinity of the intake and discharge structures.
VYNPS does entrain and impinge aquatic species. Entrainment and
impingement of aquatic species are covered in the NPDES permit under
Section 316(b) of the Clean Water Act. Entrainment was monitored for
over a decade beginning in 1972, and determined to be insignificant by
the inter-governmental Environmental Advisory Committee. The
Environmental Advisory Committee is made up of Vermont Department of
Environmental Conservation, Vermont Department of Fish and Wildlife,
New Hampshire Fish and Game Department, New Hampshire Department of
Environmental Services, Massachusetts Office of Watershed Management,
Massachusetts Division of Fisheries and Wildlife, and the Coordinator
of the Connecticut River Anadromous Fish restoration program of the
U.S. Fish and Wildlife Service. The Vermont ANR concluded that no
further entrainment sampling was required following historical studies
conducted during the same time period, and dropped entrainment from the
NPDES permit. Entrainment is no longer monitored at VYNPS. The ANR
determined that entrainment sampling should be replaced with
alternative biological monitoring of species in the Connecticut River.
Therefore, since the 1980's, the licensee has conducted extensive
monitoring as required by the ANR to determine if there are any
potential impacts to aquatic species in the VYNPS intake and discharge
areas. These procedures are not expected to change following the EPU.
Impingement is monitored annually and is considered low. Ecological
studies of the Connecticut River--Vernon, Vermont--Report 32, dated May
2003, describes how Entergy meets the requirements of the NPDES permit
through impingement sampling. During 2002, 27 species of fish were
collected, and all fish species collected were typical of the
Connecticut River drainage. The Environmental Advisory Committee has
established limits for impingement of American shad and Atlantic
salmon, and VYNPS has never approached the impingement limits set for
these species. Since VYNPS has never approached the impingement limits
set for American shad and Atlantic salmon, the ANR has concluded that
impingement of other species at VYNPS meets applicable laws. The flow
rate of water being withdrawn from the Connecticut River through the
intake structure will not increase following the EPU, and there will
not be any configuration change to the intake structure to support the
EPU. Therefore, no increase in the impingement of fish or shellfish, or
in the entrainment of planktonic organisms would be expected following
the EPU.
On July 9, 2004, the Environmental Protection Agency (EPA)
published a final rule in the Federal Register (69 FR 41575) addressing
cooling water intake structures at existing power plants whose flow
levels exceed a minimum threshold value of 50 million gallons per day.
The rule is Phase II in EPA's development of Section 316(b) regulations
that establish national requirements applicable to the location,
design, construction, and capacity of cooling water intake structures
at existing facilities that exceed the threshold value for water
withdrawals. The national requirements, which are implemented through
NPDES permits, minimize the adverse environmental impacts associated
with the continued use of the intake systems. Licensees are required to
demonstrate compliance with the Phase II performance standards at the
time of renewal of their NPDES permit. Licensees may be required, as
part of the NPDES renewal, to alter the intake structure, redesign the
cooling system, modify station operation, or take other mitigative
measures as a result of this regulation. The new performance standards
are designed to reduce significantly impingement and entrainment losses
due to plant operation. Any site-specific mitigation would result in
less impact due to continued plant operation.
The NPDES permit limits the amount of heat discharged to the
Connecticut River from the operation of VYNPS. An analysis conducted in
accordance with the NPDES permit on fish and aquatic species in 2002
concluded that there is no significant negative relationship between
these species and the thermal discharge. Actually, a larger community
of aquatic species was found to colonize near the VYNPS discharge. The
thermal limits specified in the NPDES permit will not change with the
EPU. Because Entergy will continue to meet the thermal discharge limit
set by the NPDES permit following the EPU, there should be no
additional thermal discharge effects on aquatic species for the
proposed action.
As discussed in the transmission facility impacts section of this
environmental assessment, transmission line right-of-way maintenance
practices will not change for the proposed action. Therefore, the staff
concludes that there are no significant impacts to aquatic biota
associated with transmission line right-of-way maintenance for the
proposed action.
In conclusion, there will be no increase in the impacts of
entrainment or impingement because there will be no increase in the
flow rate of water being withdrawn from the Connecticut River, and the
amount of heat discharged to the Connecticut River will remain within
the thermal limit specified by the NPDES permit following the EPU.
There are no changes in transmission line right-of-way maintenance
associated with the proposed action. Therefore, the staff concludes
that there are no significant impacts to aquatic biota for the proposed
action.
[[Page 4619]]
Impacts on Terrestrial Biota
The potential impacts to terrestrial biota from the proposed action
include impacts due to construction activities and transmission line
right-of-way maintenance. As discussed in the transmission facility
impacts section of this environmental assessment, transmission line
right-of-way maintenance practices will not change for the proposed
action. Similarly, as discussed above, apart from the construction of
temporary office space using modular units, construction activities due
to the EPU will not disturb land on the VYNPS site. Therefore, the
staff concludes that there are no significant impacts to terrestrial
plant or animal species associated with construction activities or
transmission line right-of-way maintenance for the proposed action.
Impacts on Threatened and Endangered Species
Potential impacts to threatened and endangered species from the
proposed action include the impacts assessed in the aquatic and
terrestrial biota sections of this environmental assessment. These
impacts include impingement, entrainment, thermal discharge effects,
and impacts due to transmission line right-of-way maintenance for
aquatic species, and impacts due to transmission line right-of-way
maintenance for terrestrial species.
There are three species listed as threatened or endangered under
the Federal Endangered Species Act within Windham County, Vermont.
These are the Bald Eagle (Haliaeetus leucocephalus), Indiana Bat
(Myotis sodalis), and Northeastern Bulrush (Scirpus ancistrochaetus).
There are no records of any of these species on the VYNPS site.
However, no formal surveys have been conducted by Entergy or the State
of Vermont on the VYNPS site. Critical habitat has been designated for
the Indiana Bat (M. sodalis), but not in the State of Vermont. Critical
habitat has not been designated for the Bald Eagle (H. leucocephalus)
or the Northeastern Bulrush (S. ancistrochaetus). There is a Bald Eagle
(H. leucocephalus) nest downstream of the VYNPS site, on Stebbins
Island in New Hampshire, and Bald Eagles (H. leucocephalus) have been
observed flying over the VYNPS site. However, the Bald Eagle (H.
leucocephalus) should not be impacted by the EPU because there are no
Bald Eagles (H. leucocephalus) on the site and the NPDES permit
includes provisions for protection of the Bald Eagle (H. leucocephalus)
habitat.
Ecological Studies of the Connecticut River--Vernon, Vermont--
Report 32, dated May 2003, describes how Entergy meets the requirements
of the NPDES permit through impingement sampling. An analysis of this
report determined that no Federally-listed threatened or endangered
species were collected.
The Vermont Nongame and Natural Heritage Program, associated with
the Vermont ANR, reviewed the EPU project and found no undue adverse
impact to nongame resources or natural areas from the proposed action.
There are no Federally-listed threatened and endangered species
recorded on the VYNPS site, and there is no critical habitat in the
state of Vermont for the three listed species in Windham County.
Therefore, the staff concludes that there is no effect to threatened
and endangered species associated with the proposed action.
Social and Economic Impacts
Potential social and economic impacts due to the proposed action
include changes in tax revenue for Windham County and changes in the
size of the workforce at VYNPS. The NRC staff has reviewed the
information provided by the licensee regarding socioeconomic impacts.
Entergy is a major employer in the community with approximately 670
full-time employees and contractors. Entergy is also a major
contributor to the local tax base, but does not remit tax revenues
directly to Windham County. Entergy personnel indirectly contribute to
the tax base by paying sales and property taxes, state income taxes,
and hotel and meal taxes which are paid by Entergy contractors while
working at VYNPS. VYNPS pays a State Education Tax which is based on
the level of generation of electrical power. The additional electrical
power generated from the EPU will result in a proportional increase in
taxes. The Tax Stabilization Contract, entered into by the Town of
Vernon, Vermont and the owners of VYNPS, determines Entergy's
contribution to the remaining local tax base. The contract specifies a
Total Listed Value to be used for assessing Municipal Services property
tax through 2010. The Total Listed Value applies to all real and
personal property owned on April 1, 2000, and acquired thereafter,
which is used in connection with the generation of electrical power
through the nuclear fission process.
The proposed EPU would not significantly affect the size of the
VYNPS labor force and would not have a material effect upon the labor
force required for future outages after all stages of the modifications
needed to support the EPU are complete. Entergy completed all major
modifications in the Spring 2004 refueling outage, which required
approximately 425 additional workers. Normally, less than 700
additional personnel are required for refueling outages; the Spring
2004 refueling outage required approximately 1125 additional personnel.
Additional modifications needed to support the EPU were completed
during the Fall 2005 refueling outage. The remaining modifications were
less significant than those implemented during the Spring 2004
refueling outage and required less than 100 additional workers to
supplement typical refueling outage staffing levels.
It is expected that the proposed EPU will increase the economic
viability of VYNPS and lower the probability of early plant retirement.
With the increased likelihood that VYNPS will remain operational at
least through the end of the current license term, local employment
opportunities will remain available. Early plant retirement would be
expected to have a negative impact on the local economy and the
community as a whole by reducing tax revenues and limiting local
employment opportunities, although these effects could be mitigated by
decommissioning activities in the short term.
The Vermont Public Service Board has determined that the EPU will
not greatly interfere with the development of the region and will have
a minimal impact outside the immediate area of VYNPS. Entergy has not
identified any negative socioeconomic impacts associated with the EPU.
Therefore, the staff concludes that there are no significant social or
economic impacts associated with the proposed action.
Summary
The proposed EPU would not result in a significant change in non-
radiological impacts in the areas of land use, water use, waste
discharges, cooling tower operation, terrestrial and aquatic biota,
transmission facility operation, or social and economic factors. No
other non-radiological impacts were identified or would be expected.
Table 2 summarizes the non-radiological environmental impacts of the
proposed EPU at VYNPS.
[[Page 4620]]
Table 2.--Summary of Non-Radiological Environmental Impacts
------------------------------------------------------------------------
------------------------------------------------------------------------
Land Use.......................... No significant land use
modifications; installed temporary
office space to support EPU.
Cooling Tower..................... No significant aesthetic impact,
slightly larger plume size; no
significant increase in noise; no
significant fogging or icing.
Transmission Facilities........... No physical modifications to
transmission lines; lines meet
shock safety requirements; no
changes to right-of-ways; small
increase in electrical current
would cause small increase in
electromagnetic field around
transmission lines.
Water Use......................... No configuration change to intake
structure; no increased rate of
withdrawal; slight increase in
water consumption due to increased
evaporation; no water use
conflicts.
Discharge......................... Increase in water temperature
discharged to Connecticut River;
will meet thermal discharge limits
in current NPDES permit following
EPU; no change in chemical or
sanitary waste discharges.
Aquatic Biota..................... No additional impact expected on
aquatic biota.
Terrestrial Biota................. Vermont Nongame and Natural Heritage
Program found no adverse impact
from EPU; no additional impact on
terrestrial plant or animal
species.
Threatened and Endangered Species. Three Federally-listed species in
Windham County; EPU will have no
effect on species.
Social and Economic............... No significant change in size of
VYNPS labor force required for
plant operation or future refueling
outages; increased production of
tax revenues.
------------------------------------------------------------------------
Radiological Impacts
Radioactive Waste Stream Impacts
VYNPS uses waste treatment systems designed to collect, process,
and dispose of gaseous, liquid, and solid wastes that might contain
radioactive material in a safe and controlled manner such that
discharges are in accordance with the requirements of Title 10 of the
Code of Federal Regulations (10 CFR) Part 20, ``Standards for
Protection Against Radiation'', and 10 CFR Part 50, ``Domestic
Licensing of Production and Utilization Facilities'', Appendix I. These
radioactive waste streams are discussed in the FES. The proposed EPU
would not result in changes in the operation or design of equipment in
the gaseous, liquid, or solid waste systems.
Gaseous Radioactive Waste and Offsite Doses
During normal operation, the gaseous effluent treatment systems
process and control the release of gaseous radioactive effluents to the
environment, including small quantities of noble gases, halogens,
tritium, and particulate material. The gaseous waste management systems
include the offgas system and various building ventilation systems.
Entergy estimates that gaseous radioactive effluents will increase
following the EPU but will remain within regulatory limits. In the past
three years, the peak dose from gaseous effluents at VYNPS was less
than 1 millirem (mrem) per year. The increase in gaseous effluents
following the EPU is not expected to be more than 20 percent of the
current gaseous effluent release, consistent with the EPU. If there
were a 20 percent increase from the peak dose of less than 1 mrem per
year, the projected dose would still remain well below the dose design
objectives of Appendix I to 10 CFR Part 50. Therefore, the increase in
offsite dose due to gaseous effluent release following the EPU would
not be significant.
Liquid Radioactive Waste and Offsite Doses
During normal operation, the liquid effluent treatment systems
process and control the release of liquid radioactive effluents to the
environment, such that the doses to individuals offsite are maintained
within the limits of 10 CFR Part 20 and 10 CFR Part 50, Appendix I. The
liquid radioactive waste systems are designed to process the waste and
then recycle it within the plant as condensate, reprocess it through
the radioactive waste system for further purification, or discharge it
to the environment as liquid radioactive waste effluent in accordance
with State and Federal regulations. Entergy estimates that the volume
of liquid radioactive waste generated would increase by 1.2 percent of
the current total, following the EPU. This is an increase in the volume
of liquid radioactive waste that will require processing, and not an
increase in liquid radioactive effluent. The increased volume of liquid
radioactive waste is due to the increased frequency of reactor water
cleanup filter demineralizer and condensate demineralizer backwashes.
The demineralizer backwashes will increase due to an increase in
conductivity of the reactor water cleanup system and an increase in
feedwater flow following the EPU. Entergy indicated that the percentage
increase in liquid radioactive waste generated due to the EPU is within
the designed system total volume capacity. There is a very small
increase in the volume of liquid radioactive waste generated due to the
EPU, but no liquid radioactive waste discharges are expected.
Therefore, there would not be a significant environmental impact from
the additional volume of liquid radioactive waste generated following
the EPU.
Solid Radioactive Wastes
The solid radioactive waste system collects, processes, packages,
and temporarily stores radioactive dry and wet solid wastes prior to
shipment offsite and permanent disposal. The largest volume of solid
radioactive waste at VYNPS is low-level radioactive waste; sources of
this include spent ion exchanger resins, filter sludges, air filters,
and miscellaneous papers and rags. In 2001, which represents a year of
peak solid waste generation, Entergy generated 37 cubic meters (1291
cubic feet) of solid waste. The proposed EPU is expected to increase
the amount of reactor water cleanup and condensate demineralizer resins
due to increased flow rates for the steam, feedwater, and condensate
systems. This is the only expected waste increase. Entergy estimates
that the volume of this solid waste could increase by as much as 17.8
percent over the volume of solid waste generated in 2001. Even with
such an increase, the expected volume of low-level radioactive waste
would be well below the value in the FES.
The proposed EPU would also result in a greater percentage of fuel
assemblies being removed from the reactor core and replaced with new
fuel assemblies during each refueling outage. Entergy expects the
number of fuel assemblies consumed each cycle to increase by 28 percent
following the EPU for the remaining term of the license. The additional
amount of fuel assemblies consumed will result in greater storage of
spent fuel at VYNPS. Entergy estimates that VYNPS can operate to the
Fall 2008 refueling outage before exhausting its full-core discharge
capability and reaching the capacity of the spent fuel pool, if the
plant does not implement the proposed EPU.
[[Page 4621]]
Assuming the proposed EPU is implemented, Entergy estimates that VYNPS
would exhaust its full core discharge capability one cycle earlier
(i.e., by the Spring 2007 refueling outage). Regardless of the EPU,
Entergy plans to utilize dry cask storage at VYNPS in the near future
(pending Vermont Public Service Board approval), to permit continued
operations for the full term of the current license. Dry cask storage
at VYNPS will be necessary regardless of the EPU, subject to State
approval separate from the EPU application, and would not involve a
significant increase in the total number of spent fuel assemblies
requiring storage over the term of the current license. Accordingly,
the NRC staff concludes that there will be no significant environmental
impact resulting from storage of the additional fuel assemblies.
In-Plant Radiation Doses
The proposed EPU would result in the production of more radioactive
material and higher radiation dose rates in some areas at VYNPS. For
most areas, radiation doses are unchanged due to the ample margin in
the radiation shielding design. Area dose rates inside shielded
cubicles can increase as much as 20 percent. However, these areas are
not normally occupied during plant operation. Entergy estimates that
there will be higher radiation levels in and around the turbine, due to
increased steam flow and velocity following the EPU, which will lead to
shorter travel times to the turbine and less time for radioactive decay
in transit. Therefore, Entergy estimates that the overall increase in
radiation level could be as high as 26 percent in those areas with
higher steam flow.
The VYNPS FES does not contain an estimate for annual collective
occupational radiation dose. The collective occupational dose at VYNPS
in 2001 and 2002 was 142 person-rem and 150 person-rem, respectively.
The potentially higher dose rates due to the EPU are not expected to
increase the annual collective occupational dose by more than 20
percent. Therefore, the annual average collective occupational dose
after the EPU is implemented may increase by approximately 30 person-
rem.
Individual worker exposure is maintained within acceptable limits
by the VYNPS ``as low as reasonably achievable'' (ALARA) program which
controls access to radiation areas. Procedural controls compensate for
increased radiation levels to ensure that worker exposure remains ALARA
and that the normal operation radiation zones are labeled and
controlled for access in accordance with the requirements of 10 CFR
Part 20 related to allowable worker exposure and access control.
Accordingly, occupational doses after the EPU is implemented will
remain within acceptable levels and will not result in a significant
environmental or radiological dose impact.
Direct Radiation Doses Offsite
Direct radiation emitted skyward from radionuclides (mainly
nitrogen-16) in the main steam system components in the turbine
building is scattered back to ground level by molecules in the air and
provides another offsite public dose pathway (skyshine) from an
operating boiling-water reactor. The licensee routinely monitors whole
body dose rate offsite using high purity germanium detectors,
pressurized ion chambers, and thermoluminescent dosimeters. Based on
measurements of radiation, the highest direct radiation dose offsite
was found at the west side boundary. Entergy estimates that
approximately 90 percent of the direct radiation dose at the west side
boundary is due to skyshine. The highest annual dose at the west side
boundary is 13.4 mrem from skyshine. Following the EPU, skyshine is
expected to increase by 26 percent due to the expected increase in the
nitrogen-16 source in the turbine building. Assuming a 26-percent
increase in direct radiation dose offsite due to skyshine following the
EPU, the direct radiation dose offsite at the site boundary would be
16.9 mrem from skyshine. The total maximum direct radiation dose
offsite at the site boundary would be 18.6 mrem (16.9 mrem from
nitrogen-16 skyshine plus 1.7 mrem from miscellaneous radwaste stored
on site).
The annual whole body dose equivalent to a member of the public
beyond the site boundary is limited to 25 mrem (0.25 mSv) by 40 CFR
Part 190. The projected maximum direct radiation dose offsite at VYNPS
is within this limit. The licensee will continue to perform surveys as
the EPU is implemented to ensure continued compliance with 40 CFR Part
190. Therefore, the impact of the EPU on direct radiation dose offsite
would not be significant.
Postulated Accident Doses
As a result of implementation of the proposed EPU, there is an
increase in the source term used in the evaluation of some of the
postulated accidents in the FES. The inventory of radionuclides in the
reactor core is dependent upon power level; therefore, the core
inventory of radionuclides could increase by as much as 20 percent. The
concentration of radionuclides in the reactor coolant may also increase
by as much as 20 percent; however, this concentration is limited by the
VYNPS Technical Specifications. This coolant concentration is part of
the source term considered in some of the postulated accident analyses.
Some of the radioactive waste streams and storage systems evaluated for
postulated accidents may contain slightly higher quantities of
radionuclides than is present under current operations. For those
postulated accidents where the source term has increased, the
calculated potential radiation dose to individuals at the site boundary
(the exclusion area) and in the low population zone would be increased
over values presented in the FES, but would be within the doses
calculated by the licensee and approved by the NRC staff in a separate
license amendment dated March 29, 2005, as discussed below.
In support of the EPU, the licensee submitted a separate license
amendment request which proposed a full-scope implementation of an
alternative source term (AST) methodology pursuant to 10 CFR 50.67. The
licensee performed the radiological analyses that support the AST
amendment assuming a reactor power of 1950 MWt which is approximately
102 percent of the proposed EPU power level of 1912 MWt. The NRC
approved the AST amendment request on March 29, 2005. As discussed in
the safety evaluation for the AST amendment, the NRC staff concluded
that the doses, for postulated design-basis accidents under EPU
conditions, would meet the acceptance criteria of 10 CFR 50.67 and the
guidance in Regulatory Guide 1.183. Therefore, the NRC staff concludes
that any increased environmental impact under EPU conditions, in terms
of potential increased radiological doses from postulated accidents,
would not be significant.
Fuel Cycle and Transportation Impacts
The environmental impacts of the fuel cycle and transportation of
fuels and wastes are described in Tables S-3 and S-4 of 10 CFR 51.51
and 10 CFR 51.52, respectively. An additional NRC generic Environmental
Assessment (53 FR 30355, dated August 11, 1988, as corrected by 53 FR
32322, dated August 24, 1988) evaluated the applicability of Tables S-3
and S-4 to higher burnup cycle and concluded that there is no
significant change in environmental impact from the parameters
evaluated in Tables S-3 and S-4 for fuel cycles with
[[Page 4622]]
uranium enrichments up to 5 weight percent Uranium-235 and burnups less
than 60,000 megawatt (thermal) days per metric ton of Uranium-235 (MWd/
MTU). Entergy has concluded that the fuel enrichment at VYNPS will
increase to approximately 4.6 weight percent Uranium-235 as a result of
the EPU. Entergy states that the expected core average exposure for the
EPU is 35,000 MWd/MTU and the maximum bundle exposure is 58,000 MWd/
MTU. The fuel enrichment for the EPU will not exceed 5 weight percent
Uranium-235, and the rod average discharge burnup will not exceed
60,000 MWd/MTU. Therefore, the environmental impacts of the EPU will
remain bounded by the impacts in Tables S-3 and S-4 and are not
significant.
Summary
The proposed EPU would not result in a significant increase in
occupational or public radiation exposure, would not significantly
increase the potential doses from postulated accidents, and would not
result in significant additional fuel cycle environmental impacts.
Accordingly, the Commission concludes that there are no significant
radiological environmental impacts associated with the proposed action.
Table 3 summarizes the radiological environmental impacts of the
proposed EPU at VYNPS.
Table 3.--Summary of Radiological Environmental Impacts
------------------------------------------------------------------------
------------------------------------------------------------------------
Gaseous Effluents and Doses....... Up to 20% increase in dose due to
gaseous effluents; doses to
individuals offsite will remain
within NRC limits.
Liquid Effluents and Doses........ Volume of liquid effluent generated
expected to increase by 1.2%;
slight increase in the amount of
radioactive material in liquid
effluent; no discharge of liquid
effluent expected, no increase in
dose to public.
Solid Radioactive Waste........... Volume of solid waste expected to
increase by 17.8% due to
demineralizer resins; within FES
estimate; increase in amount of
spent fuel assemblies to be stored
onsite.
In-plant Dose..................... Occupational dose could increase by
20% overall; will remain within
acceptable limits under the VYNPS
ALARA program.
Direct Radiation Dose............. Up to 26% increase in dose rate
offsite due to skyshine; expected
annual dose continues to meet NRC/
EPA limits.
Postulated Accidents.............. Licensee using Alternative Source
Term; doses are within NRC limits.
Fuel Cycle and Transportation..... Increase in bundle average
enrichment and burnup; impacts
stated in Tables S-3 and S-4 in 10
CFR Part 51 are bounding.
------------------------------------------------------------------------
Alternatives to Proposed Action
As an alternative to the proposed action, the NRC staff considered
denial of the proposed EPU (i.e., the ``no-action'' alternative).
Denial of the application would result in no change in the current
environmental impacts. However, if the EPU were not approved, other
agencies and electric power organizations may be required to pursue
other means of providing electric generation capacity to offset future
demand. Such alternatives could include construction of fossil fuel or
other generating capacity, or purchase of power from generating
facilities outside the service area; such alternatives, however, would
likely result in environmental impacts comparable to or greater than
those involved in the EPU. For example, fossil fuel plants routinely
emit atmospheric pollutants, causing impacts in air quality that are
larger than if VYNPS were to provide the same amount of electric
generation. Construction and operation of a fossil fuel plant also
creates impacts in land use and waste management.
Alternative Use of Resources
This action does not involve the use of any resources not
previously considered in the 1972 FES for operation of the VYNPS.
Agencies and Persons Consulted
In accordance with its stated policy, on September 2, 2005, the NRC
staff consulted with the Vermont State official, William K. Sherman, of
the Department of Public Service, regarding the environmental impact of
the proposed action. The State official had no comments.
Finding of No Significant Impact
On the basis of the environmental assessment, the Commission
concludes that the proposed action will not have a significant effect
on the quality of the human environment. Accordingly, the Commission
has determined not to prepare an environmental impact statement for the
proposed action.
For further details with respect to the proposed action, see the
licensee's application dated September 10, 2003, as supplemented on
October 1, and October 28 (2 letters), 2003; January 31 (2 letters),
March 4, May 19, July 2, July 27, July 30, August 12, August 25,
September 14, September 15, September 23, September 30 (2 letters),
October 5, October 7 (2 letters), December 8, and December 9, 2004;
February 24, March 10, March 24, March 31, April 5, April 22, June 2,
August 1, August 4, September 10, September 14, September 18, September
28, October 17, October 21 (2 letters), October 26, and October 29,
November 2, November 22, and December 2, 2005; and January 10, 2006.
Documents may be examined, and/or copied for a fee, at the NRC's Public
Document Room (PDR), located at One White Flint North, 11555 Rockville
Pike (first floor), Rockville, Maryland. Publicly available records
will be accessible electronically from the ADAMS Public Electronic
Reading Room on the NRC Web site, http://www.nrc.gov/reading-rm/adams.html. Persons who do not have access to ADAMS or who encounter
problems in accessing the documents located in ADAMS should contact the
NRC PDR Reference staff at 1-800-397-4209, or 301-415-4737, or send an
e-mail to [email protected].
Dated at Rockville, Maryland, this 20th day of January 2006.
For the Nuclear Regulatory Commission.
Richard B. Ennis,
Senior Project Manager, Plant Licensing Branch I-2, Division of
Operating Reactor Licensing, Office of Nuclear Reactor Regulation.
[FR Doc. E6-1035 Filed 1-26-06; 8:45 am]
BILLING CODE 7590-01-P