Document ID: EPA-HQ-OW-2008-0667-0015
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2009-11-05T05:00Z

Site Visit Report

	Surry Nuclear Power Station

5570 Hog Island Road

Surry, VA 23883 

January 28, 2008

Background and Objectives

The Environmental Protection Agency (EPA) is in the process of
developing 316(b) cooling water intake structure requirements that
reflect the best technology available (BTA) for minimizing adverse
environmental impact for all existing power plants and manufacturing
facilities. As part of this process, EPA staff is visiting electric
generators and manufacturers to better understand the cooling water
intake structure (CWIS) technologies in use at facilities, including the
site-specific characteristics of each facility and how these affect the
selection and performance of CWIS technologies.  EPA is also visiting
facilities to better understand cooling water use and specific issues or
technologies that can affect 316(b) compliance.  Surry Nuclear Power
Station (Surry) was selected for a site visit due to its use of Ristroph
screens, its large intake flows, and its proximity to the Washington,
D.C. area and other site visit locations.

Facility Description

The Surry Power Station (SPS) is a nuclear power station located on the
James River on Hog Island in Surry County, Virginia.  The site is owned
and operated by Dominion Power.  It has two generating units that were
originally licensed in 1972 and 1973.  Dominion has obtained license
renewals for the generating units through 2032/2033.   The facility
employs approximately 1000 people and is located on approximately 850
acres.  

It operates under NPDES Permit number VA0004090.  The current permit was
renewed in January 2007 and expires on January 21, 2012.

Electricity Generation and Transmission

SPS has two 1700 MW nuclear power generating base-load units with a
total annual energy generation of approximately 12,930,000 MWh.  Both
units operate 100% of the time (CUR = 100%) for 465 days in a row. 
Every 18 months, the plant has a scheduled outage that typically ranges
from 25-35 days.  SPS alternates which unit is down during the scheduled
outage. The switchyard is also owned and operated by Dominion.

Cooling Water Intake Structure

SPS uses a once-through cooling water system with a shoreline intake at
the end of a ½ mile long intake canal; the facility also has a
discharge canal 2 miles in length.  SPS refers to the intake structure
at the shoreline as the low level intake and the intake structure at the
end of the canal as the high level intake structure.  Cooling water is
withdrawn from the James river through a common low level intake
structure which is oriented parallel to the river with an intake
velocity of 0.8 – 1.2 ft/sec.  The intake orientation is downstream
rather than upstream for purposes of oyster bed protection. The total
design cooling water intake flow is 2,535 MGD.  The river at the low
level intake structure is about 3.7 miles wide and has water depths
ranging from 21 ft to 90 feet in the main channel.  The non-tidal flow
of the James River fluctuates with a high monthly average flow of 39,778
cfs and a low monthly average of 857 cfs.  Water levels at the Surry
CWIS are affected by the tides with a mean low tide water level of EI.
1.0 ft and a high tide level of EI.1.1 ft.  In addition, the salinity of
the James River can vary from summer to winter with the former being
18,000ppm and the latter being near zero.

A trash rack extends across each of the eight intake bays to prevent
debris from entering the intakes.  The trash racks are 18ft wide.  To
increase survival of impinged fish, SPS operates 8 Ristroph screens
located approximately 17 feet downstream of each trash rack.  SPS
originally installed the Ristroph screens in 1975/1976 after trying
diffusers, bubble screens, lights, and sound with little overall
success.  In SPS experience, these technologies are generally not
effective in turbid waters with the saltline movement experienced by the
facility. Mr. Ristroph worked for the plant at the time and designed the
modified screens for this facility.  He subsequently patented them.  The
stainless steel screens are 15 feet wide, extend approximately 15 feet
below the water, and are operated continuously.  They have 3/8 inch
fish-friendly mesh with fiberglass screen baskets on the front (2 inch
deep by 5.5 inches wide). Sprockets are subject to heavy wear, and are
also stainless steel in construction.  While the screens may be operated
at two speeds (5 and 10 ft/sec), SPS has always operated them at 5
ft/sec.  In the event of spring surge of fish, the screens could be
operated at the higher speed. Each screen panel (47 screens) takes
approximately 8.6 minutes to make one rotation at this speed.  The
screens also have a low pressure spray system (24 spray nozzles inside
and 48 spray nozzles outside) to remove any collected fish from the
buckets and convey them to a trough which then conveys them back to the
river approximately 1000 feet downstream of the intake structure and 500
feet from the shore.   

	A circulating water pump is located downstream of each screen.  The 8
circulating non-variable speed water pumps (210,000 gpm each) convey the
water to the intake canal.  Water then flows down the approximately 1.7
miles long and 32 feet wide trapezoidal shaped intake canal into a
secondary screenhouse at the plant.  This screenhouse has conventional
traveling water screens.  Biocides (sodium bromide and sodium
hypochlorite) are used at the high level intakes for 2 hours/day.  SPS
also has the capability to shut off a portion of the system to
deoxygenate the water. Water is then conveyed by gravity to the rest of
the station and to the condensers.  

The facility does much of the maintenance of the Ristoph screens on
site.  They have a team of 6-8 employees that operate and maintain the
intake structure, screens, etc. as part of their responsibilities.  SPS
rotates out approximately 4 screens per year for maintenance (i.e., each
screen operates continuously for 24 months).  They inspect, clean, and
repair screens as necessary and lubricate and/or replace chains and/or
baskets.  SPS estimated that it costs them approximately $40,000-$50,000
for a total rebuild of a screen.  SPS performs maintenance from October
to March so that all 8 screens are in operation during the spring and
summer.  

Water is discharged from the plant through the discharge canal and back
to the James River.  The delta T is approximately 13 degrees F.

Impingement and Entrainment Information

SPS performed impingement studies in the mid 1970s.  They collected two
samples per day, five days a week for four years.  They also collected
24 hour composite samples once per month.  The data shows 94% survival
for all species combined.  SPS published these results in the American
Fisheries Society (AFS) Journal.  These efficacy studies include pre and
post- Ristroph screen data.  Prior to the Ristroph screens, the facility
had fine mesh traveling screens (not modified) and trash racks at the
high level intake structure.  More recently, the Virginia Institute of
Marine Science (VIMS) performed an impingement and entrainment study for
SPS.  Bay anchovies and naked gobies represented the majority of the
impinged species.  SPS has not yet analyzed the data for entrainment
efficacy.  SPS believes its data collected in the 1970s to still be
representative.  The only difference between the 1970s study and the
more recent study is that shellfish were included in the more recent
study.  SPS also noted that the fish population in the river has
remained largely unchanged.    

The plant was confident it could meet the impingement requirements of
the now-suspended 2004 316(b) Phase II rulemaking.  Because the rule was
remanded, the facility has not put much thought or study into how they
would have achieved the entrainment requirements.

Cooling Tower Feasibility

Facility representatives noted that the plant’s containment domes are
excavated 6 feet into the ground and that its condensers are
underground.  Facility representatives added that the partially
excavated nuclear domes keep the facility out of the skyline from the
nearby Jamestown area.  They also indicated that water chemistry would
be complicated due to variable salt levels.  Finally, they raised
Nuclear Regulatory Commission (NRC) permitting concerns.  The plant
indicated it would review its permit application and respond to EPA with
more information on cooling tower feasibility, as applicable.

Attachments

Attachment A		List of Attendees

Attachment B		Aerial Photos

Attachment C		Site Visit Photos

Attachment A--List of Attendees

Mike Holland, Dominion Generation, Surry Power Station

Barry A. Arber, Dominion Generation, Surry Power Station

Bill Bolin, Dominion Generation, Richmond, VA

Ronal Birckhead, Dominion Generation, Surry Power Station

Paul Shriner, EPA

Jan Matuszko, EPA

Josh Hall, EPA

Erik Helm, EPA

Attachment B—Aerial Photos

Please see DCN 10-6516A accompanying this document.

Attachment C—Site Visit Photos

Please see DCNs 10-6516B-HH accompanying this document.

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