Draft Notes from Site Visit at Duke Energy's Catawba Nuclear Station on October 19 , 200 9

EPA conducted a site visit at Duke Energy ’s Catawba Nuclear Station ( Catawba ) located in
York

, S C on Mond ay, October 19 , 2009 to learn about the operations at the pla nt and the wastewaters generated at the plant . Table 1, located at the end of this memorandum, identifies the site visit participants. The presentation that the Catawba personnel gave during the site visit is provided as Attachment 1 to this memorandum. A n overall water balance diagram for the plant i s included within Attachment 1.

This memorandum describes the information collected during the site visit and the pre

- site visit phone call, which was held on October 1 3 , 2009.

Plant Overview

**•** The Catawba pl ant is located on a 500

- acre site next to Lake Wylie

. Lake Wylie has a total surface area of 13,443 acres with 325 miles of shoreline. The plant intake from the lake is approximately 110 MGD

.

**•** Catawba operates two identical nuclear

- fueled electric generati ng units

. Information on the two nuclear units is summarized in the table below.

Unit Installation

Date Gross Capacity

(MW) Reactor Type Fuel

1 1985 1,129 Westinghouse
Pressurized water

reactor (PWR) Uranium dioxide

2 1986 1,129 Westinghouse PWR Uraniu m dioxidePage 2

**•** Units 1 and 2 are both fueled by uranium dioxide. Both reactors are refueled approximately every 18 months. Units 1 and 2 are refueled on staggered intervals

, refuel ing one unit approximately every 9 months so that only one unit is non

operati onal at a time.

**•** Catawba stated that the next refueling cycle is scheduled to begin in late November 2009 and takes approximately 30 days to complete. During refueling outages, the plant may have as many as 1,800 contractors on site.

**•** Catawba stated that the analog equipment in the control room of Unit 1 will be upgraded to a digital control system during the upcoming refueling outage . The digital control system will be the first of its kind in the United States. Catawba plans to upgrade Unit 2 to a digit al system in Fall 2010.

**•** Each unit has a separate spent fuel pool and fuel storage area.

**•** Catawba has 1,270 employees. The plant t ypically has an additional 450

- 500
contractors on site.

Nuclear Service Water (NSW) and Low

- Pressure Service Water (LPSW) S ystems

**•** Catawba stated that there are two service water systems at the plant, both of which use water from Lake Wylie. The l ow

- pressure service water (LPSW)
system is the primary water system that is used t o provide cooling for the steam turbine cycle. Th e nuclear service water (NSW) system provides cooling to nuclear safety components and heat exchangers

. [QUESTION FOR CATAWBA: Please confirm that the NSW is primarily used as a back

- up system . Is the NSW used to as cooling water for processes that the L PSW system does not cool? ]

The NSW system is not a backup system. The NSW system typically pulls off Lake Wylie and the NSW pond is a backup water source to the lake. The NSW system is always in service providing cooling to the nuclear safety componen ts in the plant. The LPSW system provides cooling water to the non

- nuclear safety related components in the plant.

**•** As an added safety measure, the NSW system has the capability of withdrawing intake water from either Lake Wylie or the plant’s standby nu clear service water pond (SNSWP) . The SNSWP is maintained by the plant and the plant uses water from Lake Wylie to keep the pond at an acceptable level in case of emergencies. Therefore, if the water level in Lake Wylie was too low for the plant to withd raw water, then the plan t would use the water reserve in the SNSWP . Catawba stated that they have never had to use the SNSWP water as a result of an emergency involving the loss of Lake Wylie . However, th e intake pumps are tested periodically

. The plant has an outfall for the transfer of water from the SNSWP to Lake Wylie in case the SNSWP becomes to full, which is Outfall 006. [QUESTION FOR CATAWBA: What is the volume of the SNSWP? ]
18.8 Million GallonsPage 3

**•** Catawba operates cooling towers to recirculate the steam turbine cooling water in
the Recirculating Cooling Water (RC) system. Catawba operates six cooling towers, three for each unit. The blowdown from the cooling towers flows almost continuously at approximately 5,000 gpm via i ntern al Outfall 005, whi ch
combines with other waste streams into Outfall 001 and is discharge d to Lake Wylie

.

**•** Catawba stated that they add sodium hypochlorite and/or Stabrex biocides to NSW systems and at the SNSWP intake structure. Sodium hypochlorite is added
at the LPSW in take structure.

**•** Catawba adds s odium hypochlorite and/or S tabrex to the NSW system up to four hours p er day, three to four days per week. Sodium Hypochlorite is added to the LPSW system up to 4 hours per day, 2 days per week. The sodium hypochlorite
and /or Stabrex prevent bio fouling and sludge formation on heat exchanger
surfaces. [QUESTION FOR CATAWBA: Is polyacrylic acid also used for biofouling control?]

Polyacrylic acid is not used for biofouling control. It is used to control solids deposition. Biocides and the dispersant are used together to prevent/reduce fouling of piping and Heat exchangers

**•** Catawba adds a dispersant to the NSW system at the SNSWP intake structure. The dispersant increases the efficiency of the biocides. [QUESTION FOR

CATA WBA: What is th e frequency and duration of biocide addition for the NSW system?]

Biocide could be added to the NSW system up to 4 hours per day for up to 4 days per week depending on the amount of biofouling. Dispersant is added continually

.

**•** Catawba stated that hydrazine or carbohydrazide are used to lay

- up Secondary components during refueling outages. This practice prevent s corrosion in the
steam generator tubes due to their ability to act as oxygen scavengers. Catawba uses carbohydrazide due to th e toxicity of hydrazine. Catawba uses sodium hypochlorite to break down the hydrazine or carbohydrazine when wet layup chemicals are drained to conventional waste systems . [ QUESTION FOR

CATAWBA: Does the plant add sodium hypochlori t e at Outfall 002 or el sewhere within the plant ? ]

Sodium hypochlorite is added upstream of Outfall 002 for hydrazine control and /or for algae control in the conventional wastewater ponds. This wastewater is then discharged through Outfall 002 when it is verified that the w astewater is in specifications.

**•** The plant adds sodium bisulfite at Outfall 001 to dechlorinate the water before discharging into Lake Wylie. Catawba operates two sodium bisul fi te pump trains

, one of which is a back up system

. Catawba has oxidation reducti on potentialPage 4

probe s that are used to determine the amount of s odium bisul fi te needed . Catawba stated that the required contact time for the dechlorination reaction is 30 minutes.

**•** Catawba stated that during biocide addition to the cooling towers (RC syste m)

, the plant isolates the blowdown from the cooling towers (i.e., they do not discharge cooling tower blowdown until the chlorine has dissipated ).

Nuclear Unit Operations and Wastewaters

**•** The energy from fission of uranium dioxide fuel heats the prima ry reactor cooling system. The primary cooling system is pressurized to ensure that the coolant in the primary loop does not boil. Pressure, temperature

, and flow rate are adjusted
to enable the efficient transfer of heat from the reactor to the coolant. T he primary cooling system then transfers heat to the secondary system which generates steam. The steam is used to generate electricity and then Catawba uses water from Lake Wylie to condense the steam via RC (reticulating Cooling system)

.

**•** Boron is a neutr on moderator and is used in the primary cooling system to
maintain the desired rate of fission within the reactors. As the uranium fuel starts slowly losing its reactivity, the plant begins diluting some of the boron from the system because less is needed to control the reaction. [ QUESTION FOR

CATAWBA: What is the source of boron (e.g. boric acid)? What is the concentration of boron in the primary cooling system at the beginning of the fuel cycle? Please describe how the boron is purged from the system? Which wastewaters generated at the plant contain boron? How are these wastewaters
treated? ]

The source of boron is boric acid.

The concentration of boron in the primary cooling system at the beginning of the fuel cycle varies from about 1600 to 1800 ppm depending on core design. The concentration at the end of the fuel cycle is less than 50 ppm.

Water is added to reactor coolant to maintain the desired temperature. The boron is diluted and the system volume is maintained by draining the reactor co olant to the recycle hold up tanks. Where approximately 80% is reclaimed using an evaporator. The remaining 20% is drained to the liquid waste system to control

on

- site inventory of tritium.

Wastewaters from Outfall 004 contain boron. These wastewater s are treated using demineralizers and filters.

**•** Catawba’s reactor cooling system and radiological liquid waste processing system are designed to minimize the release of radioactive liquids to unrestricted parts of the plant.

**•** The liquid radiological wa stes generated at Catawba include wastewaters from
drains from the contained nuclear reactor area including reactor cooling systemPage 5

equipment drains, floor drains, decontamination drains, and laundry and shower facility drains

. Radioactive liquid waste is s egregated. The bulk of the reactor coolant drainage is reclaimed and used as makeup to the Reactor Coolant system. The remaining radiological wastewaters a re transferred to storage tanks in the auxiliary building and waste monitor tank building, adjacent to the reactor
containment area. This radioactive liquid waste system processes the water through demineralizers and filters.

**•** Catawba monitors the radioactivity of the wastes stored in the waste collection
tanks

. Catawba then processes the liquid radiol ogical wastes through
demineralizers and filters to the release tanks. The tanks are then sampled and verified in specification for release. [QUESTION FOR CATAWBA: Does the plant treat all the radiological wastes through the demineralizers and/or filters? Does the plant perform any chemical treatments on the liquid radiological wastes? If so, what chemicals and amounts are used? ]

Radioactive liquid waste is segregated. The bulk of the reactor coolant drainage is reclaimed and used as makeup to the reac tor coolant system. The remaining radiological wastes are processed through demineralizers and/or filters. Periodically 1

- 2 liters of hydrogen peroxide per 5,000 gallons of wastewater are added to the liquid radiological waste system.

**•** The treated liquid radiological wastes are then discharged via internal Outfall 004 to Outfall 001, which discharges to Lake Wylie. The l iquid radiological waste s generated at the plant are discharged in batches

. Catawba performs calculations to
determine the amount of was te which can be released to the discharge canal according to NRC regulations. Catawba stated that because they discharge into a

cove , they need to limit the amount of wastes discharged at one time because of
limited dilution due to discharging into a cove

.

**•** Catawba stated that they typically discharge a batch of liquid radiological wastes twice a week; however, it is more frequent during outages because they are draining a lot of the equipment. [QUESTION FOR CATAWBA : How does the frequency of the discha rge vary from the beginning of the fuel cycle to the end of the fuel cycle? What are typical volumes discharged? ]

During innage periods Catawba typically has one discharge of approximately 20,000 gallon per week. During an outage Catawba has 2

- 3 discha rges of approximately 5,000 gallons per week in addition to the 20,000 gallon per week discharge.

Metal Cleaning Wastes

**•** Catawba has perform ed two metal cleaning operations on the let

- down piping of
its reactor coolant system. Catawba use d nit ric acid an d EDTA to perform the cleaning. This cleaning was last performed in May 2008 and September 2007, and each occurrence generated approximately 500 gallons of was tewater, which were treated by a portable demineralizer. These cleaning are not normalPage 6

activiti es

. [ QUESTION FOR CATAWBA: Please confirm the information is correct.]

**•** Catawba performed a one time metal cleaning operation on the Nuclear Service water side of the NS heat exchanger. Catawba used phosphoric acid to reduce fouling in the heat exchanger s

. This cleaning operation was last performed in 2000 or 2001 and generated approximately 14,000 gallons of wastewater . T h e waste that did not contain radioactivity was discharged through the conventional waste system in small batches to ensure all paramete rs remained in spec. A second portion of the waste was drained to radwaste system due to a leaking fitting on the pump skid. This waste was treated and transported to a vendor for processing

**•** The spent resins from the demineralizer are monitored for rad ioactivity and
treated as non

- hazardous waste. The Demineralizers were only used on the cleaning if the letdown piping not the heat exchangers cleaning using Phosphoric
acid.

**•** Some of t he wastewaters generated by metal cleaning were discharged in small
ba tches from Outfall 002 (conventional wastewater treatment plant effluent) or Outfall 004. The effect of discharging in batches is that the plant can dilute the metal cleaning wastewater and not exceed its permit limits. (Phosphoric Acid cleaning of Heat ex changer)

**•** Catawba does not perform metal cleaning operations on the turbines.

Other Plant Wastewaters and Treatment Systems

**•** Outfall 001 is the largest flow outfall at the plant and discharges once

- through cooling water, nuclear service water, cooling to wer blowdown (via internal Outfall 005), and liquid radiological wastes (via internal Outfall 004) to Lake Wylie. There are no dilution specifications for O utfall 001.

**•** Catawba operates a conventional wastewater treatment system to treat the

wastewaters co llected in sumps at the plant that are not located within the nuclear
containment area.

**•** The conventional wastewater treatment system consists of two ponds, each 5 million gallons in volume. The ponds alternate between discharging and receiving

wastewa ter. Catawba stated that the plant switches between the ponds every one to two weeks. Catawba stated that it takes approximately three and a half days to drain one of the ponds and the flow rate from the pond is approximately 1,500

gpm.

**•** The convention al wastewater treatment system batch discharges to Lake Wylie via Outfall 002. Catawba can add sodium hydroxide or sulfuric acid to adjust the pH in the ponds. Sodium hydroxide may also be used to control algal growth in the ponds.Page 7

**•** Catawba stated that O utfall 002 has “ monitor and report ” requirements for a number of pollutants, including cadmium, zinc, hydrazine, an d pentachlorophenol

. Catawba stated that the plant is required to monitor for cadmium even though the plant has never detected cadmium in the effluent.

D uring Catawba’s permit application Form 2C data collection requirement, they reported cadmium as less than the detection limit. However, the detection limit
was not less than the concentration necessary to avoid to the requirements for
monitor i ng and report ing cadmium as determined by the permit writer

. [QUESTION S FOR CATAWBA: What is the detection limit of cadmium for the method used by the plant? What was the concentration required by the permit writer?]

The detection limit used by the plan t for cadmium i s 0. 1 ug/L. Per the rational for the current permit there was only one data point to consider in the evaluation and an insufficiently sensitive PQL. Therefore, additional data is being obtained to perform a reasonable potential evaluation.

**•** Catawba operates two final hold

- up basins adjacent to the two conventional wastewater treatment ponds. Catawba stated that stormwater runoff from the plant’s three yard sumps are typically transferred to the hold

- up basins. Catawba
monitors the effluent from the ponds for pH and radiological activity (curies). The discharge of the hold

- up basins is combined with the discharge from the
conventional wastewater treatment ponds and discharge d via Outfall 002. Catawba stated that the plant only discharges fr om the hold

- up ponds when the plant is also discharging from the conventional wastewater treatment ponds.

**•** Catawba performs whole effluent toxicity (WET) tests on Outfalls 001 and 002 quarterly and must meet discharge limitations on Ceriodaphnia dubia sur vival from these outfalls as required by the plant’s permit. In the summer of 2008,
Catawba ha d a failure in its WET test for Outfall 002. Catawba stated that the issue didn’t occur in September of 2008, but they failed another WET test in the
summer of 2 009. At the time

, Catawba believed that blue

- green algae growth in
the hold

- up ponds is likely responsible for these difficulties. Prior to th ese recent
failures , Catawba had not experienced a toxicity failure for 10

- 15 years.

**•** Catawba stated that the hold

- up ponds are aerated to keep the ponds from being stagnant. Additionally, Catawba is using sodium hypochlorite to reduce the
amount of blue

- green algae in the ponds.

**•** Catawba stated that they used to discharge treated sanitary wastewater via Outfall

003 ; however, the plant now transfers the sanitary wastewater to the county for

treatment.

**•** Outfall 006 discharges water from the SNSWP into Lake Wylie in the event of
overflow.

LandfillPage 8

**•** Catawba operates a landfill for the stor age of low

- level radiological w astes and sludges and asbestos from old piping insulation . The landfill is not lined and
therefore does not collect leachate. Additionally, the landfill is relatively small
and flat , compared to coal combustion waste landfills at coal

- fired power plants

.

**•** R adioactive wastes are stored in containers and buried in the landfill. The
contaminated resins and carbon materials were buried either in steel drums or B

25s. IHP sludge was not containerized.

**•** Low

- level radioactive wastes consist of material that h as become radioactive due
to neutron radiation at any point during plant operations and meet low

- level criteria established by the Nuclear Regulatory Commission (NRC). This includes material previously classified as high

- level radioactive waste that has be en stored on site long enough for the material to decay to low

- level classification. The SCDHEC RP Group reviews the lab analyses and pre

- approves each burial.

**•** Catawba stated that the wastes stored in the landfill are not significantly more
radioactive than the background radiation levels found in nature

.

**•** Catawba is required to monitor the groundwater around the perimeter of the
landfill semi

- annually (during March and October) . However, there are no water quality requirements for the groundwater. [QUE STION FOR CATAWBA: What parameters is the plant monitoring? Please provide the five most recent groundwater monitoring reports.]

 Monitoring reports are attached.

 The monitoring parameters are defined by SC Reg 61

- 107.19 Solid Waste Management: Solid W aste Landfills and Structural Fill.

 While CNS has historically been required to analyze for Appendix III constituents, in 2009 the site was required to analyze all wells for Appendix V constituents as well. After analyses from a minimum of 2 sequential sa mplings showed minimal contamination from Appendix V constituents, the site and SCDHEC have agreed the Appendix V sampling is no longer required for the existing wells. This subject is discussed in
detail in the 2009

- 2010 Annual Report.Page 9

Table 1. Site Visit Attendees

Name Organization (Representing) Telephone E

- mail

Tara Myers Catawba (803) 701

- 3940 tara.myers@duke

- energy.com

Darrell Davies Catawba (803) 701

- 3023 Darrell.Davies@duke

- energy.com

Steve Rodgers Catawba (803) 701

- 3370 Steven.Rodger@duke

- energy.com

Gary Sain Duke Energy (704) 382

- 3819 Gary.Sain@duke

- energy.com

David Vaught Duke Energy (980) 373

- 5302 David.Vaught@duke

- energy.com

Kim Hamm (intern) Duke Energy

Robert Wylie Duke Energy (704) 382

- 4669 Robert.wylie@duke

- energy.com

Marshall H uffstetler Duke Energy (803) 701

- 3334 david.huffstetler@duke

- energy.com

Josh Hall EPA/Office of Water (202) 566

- 1003 hall.josh@epa.gov

Je zebele Alicea EPA/Office of Water (202) 566

- 1755 alicea.jezebel e @epa.gov

TJ Finseth ERG (Contractor to EPA) (703) 633

- 1698 thomas.finseth@erg.com

Kurt Blohm ERG (Contractor to EPA) (703) 633

- 1675 kurtis.blohm@erg.com

Donna Hill UWAG (205) 257

- 5234 dbhil l@southernco.com

[QUESTION FOR CATAWBA: Please provide the missing phone numbers and e

- mail addresses.]

Kim Hamm was a co

- op student during EPA’s site visit. She is

, currently

, not employed by Duke Energy.