Text

On-Site Cooling System Sediment Disposal
	ML20356A172
Person / Time
Site:	Columbia
Issue date:	12/21/2020
From:	Vance S; Energy Northwest
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	GO2-20-104
	Download: ML20356A172 (130)
	v • d • e

Scott A. Vance ENERGY P.O. Box 968, MD PE13 Richland, WA 99352-0968 Ph. 509.377-4650 l F. 509.372.5330 NORTHWEST savance@energy-northwest.com December 21, 2020 GO2-20-104 20 CFR 20.2002 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001

Subject:

COLUMBIA GENERATING STATION, DOCKET NO. 50-397 ON-SITE COOLING SYSTEM SEDIMENT DISPOSAL

Dear Sir or Madam,

In accordance with 10 Code of Federal Regulations (CFR) 20.2002, Method for obtaining approval of proposed disposal procedures, Energy Northwest (EN) requests NRC approval to dispose of sediments from the Circulating Water (CW) system cooling towers and Standby Service Water (SW) system spray ponds at Columbia Generating Station (Columbia)

(Enclosure). Analyses of the sediments have shown the presence of radionuclides at concentrations above the level of detection for environmental measurements. Because these materials are comprised of silt, sand, and organic material, and contain very low levels of radionuclides, continued on-site disposal of these materials as very low-level radioactive waste (VLLW) is the most appropriate and cost-effective method of disposal.

EN has been disposing of these sediments on-site since 1995, when the Washington State Energy Facility Site Evaluation Council (EFSEC) adopted Resolution No. 278. Resolution No.

278 approved ENs on-site disposal of slightly-contaminated CW system cooling tower sediments under authority delegated from the Atomic Energy Commission to the State of Washington under Section 274 of the Atomic Energy Act of 1954, as amended. In 2001, EFSEC terminated Resolution No. 278 and replaced it with Resolution No. 299, additionally authorizing the on-site disposal of SW system spray pond sediment.

In November 2019, NRC Region IV performed a Radiation Protection inspection, which included a review of ENs VLLW disposal practices. As a result of that inspection, EN received a minor violation for disposing of the sediments described above without first obtaining approval from the NRC. EN entered a related Condition Report in its Corrective Action Program, and has been working to resolve the minor violation. EN is submitting this request for approval as a corrective action in response to that minor violation, for which the NRC has not exercised enforcement discretion to date.

GO2-20-104 Page 2 of 2 Contrary to its longstanding position, the NRC is requiring reactor licensees to obtain NRC approval for the disposal of VLLW, even when their facilities are located in NRC Agreement States that previously have authorized the disposal of such VLLW (as in the case of ENs disposal of the sediments described above). EN notes that there is ongoing litigation between NRC and Nuclear Energy Institute (NEI) in the United States Court of Appeals for the District of Columbia Circuit, NEI v. NRC, No. 19-1240, challenging NRCs abandonment of its longstanding position and NRCs September 16, 2019 letter to NEI indicating that NRC intends to rely on Regulatory Issue Summary (RIS) 2016-11 as a basis for enforcement actions going forward. EN supports NEIs position in this litigation and retains a full reservation of rights to amend or withdraw this request for approval in accordance with the courts decision.

No new regulatory commitments are made in this letter. If there are any questions or if additional information is needed, please contact Ms. D.M. Wolfgramm, Regulatory Affairs Manager, at 509-377-4792.

I declare under penalty of perjury that the foregoing is true and correct.

Executed this 21st day of December, 2020.

Respectfully, Recoverable Signature Vance . . l. Scott* A*

X . .

Final Approver Signed by: Vance, Scott A.

Scott A. Vance Vice President, Corporate Governance and General Counsel

Enclosure:

Information in Support of 10 CFR 20.2002 Request for Disposal (includes 4 attachments) cc: NRC RIV Regional Administrator NRC NRR Project Manager NRC Senior Resident Inspector CD Sonoda - BPA A Kidder - EFSEC E Fordham - WDOH R Brice - WDOH L Albin - WDOH

GO2-20-104 Enclosure Information in Support of 10 CFR 20.2002 Request for Disposal TABLE OF CONTENTS

1. BACKGROUND 2 1.1 WASHINGTON STATE APPROVAL 2 1.2 LOCATION 2

2. 10 CFR 20.2002(a) 3 2.1 SOURCE OF SEDIMENT - COOLING TOWERS 3 2.2 SOURCE OF SEDIMENT - STANDBY SERVICE WATER SYSTEM SPRAY PONDS 3 2.3 PHYSICAL AND CHEMICAL PROPERTIES OF MATERIAL IMPORTANT TO RISK EVALUATION 4 2.4 PROPOSED MANNER OF WASTE DISPOSAL 4 2.5 CONDITIONS OF WASTE DISPOSAL 5 2.5.1 DISPOSAL CONCENTRATION LIMITS 5 2.5.2 DISPOSAL AREA DOSE LIMIT 6 2.5.3 PRE-DISPOSAL SCREENING 6 2.5.4 ROUTINE DISPOSAL CELL MONITORING 6 2.5.5 CHEMICAL SAMPLING 7 2.5.6 REPORTING 7

3. 10 CFR 20.2002(b) 7 3.1 SITE DESCRIPTION 7 3.2 ANALYSIS OF SEDIMENT 8 3.2 TABLE 1: RADIOCHEMICAL CHARACTERISTICS OF COOLING TOWER SEDIMENT, 1985-1994 8 3.2 TABLE 2: RADIONUCLIDE TESTING RESULTS FOR PRE-DISPOSAL SEDIMENT SAMPLING FROM 2010 TO 2019 8 3.3 ENVIRONMENTAL ASPECTS 9 3.3.1 EARTH 9 3.3.2 AIR 9 3.3.3 WATER 9 3.3.3.1 GROUNDWATER 9 3.3.4 FLORA AND FAUNA MONITORING 10 3.3.5

SUMMARY

10

4. 10 CFR 20.2002(c) 11

5. 10 CFR 20.2002(d) 12 5.1 SEDIMENT DISPOSAL AREA CONTROL 12 5.2 EFSEC RESOLUTION NO. 299 12 5.3 SEDIMENT SAMPLING AND ANALYSES 13 5.4 PROCEDURES TO ENSURE DOSES ARE MAINTAINED ALARA - DIRECT RADIATION MONITORING 14 5.4 TABLE 3: MEASUREMENTS OF DIRECT RADIATION AT THE DISPOSAL AREA USING TLD STATION 119B AND 119CTRL 15 5.4 FIGURE 1: DIRECT RADIATION MEASUREMENTS FOR REMP STATION 119B AND 119CTRL FOR 2010 THROUGH 2019 16 5.5 RADIOLOGICAL IMPACT EVALUATION (DOSE ASSESSMENT) 16 5.5.1 EXPOSURE CONSIDERATIONS 17 5.5.2 DOSE PROJECTION ASSUMPTIONS 18 5.5.3 METHOD OF CALCULATION 18 5.5.4 DOSE CALCULATION RESULTS 19 5.6 DECOMMISSIONING PLAN 19 GO2-20-104 Enclosure Page 1

GO2-20-104 Enclosure Information in Support of 10 CFR 20.2002 Request for Disposal Energy Northwest (EN) requests authorization from the Nuclear Regulatory Commission (NRC) for continued on-site disposal of sediment containing very low concentrations of radioactive materials.

The sediment results from periodic cleaning of cooling towers and Standby Service Water System spray ponds at the Columbia Generating Station (Columbia). The following contains information required under 10 Code of Federal Regulations (CFR) 20.2002 (Method for obtaining approval of proposed disposal procedures).

1. Background

1.1. Washington State Approval Operation of the cooling water systems at Columbia causes radionuclides contained in the source water or entrained from plant emissions to become concentrated in the sediment that accumulates in features of the cooling systems (e.g., tower decks, tower basins, pump basins, spray ponds, piping and system components). The concentrations of radionuclides in the sediment often exceed the lower levels of detection for environmental measurements. This requires that the material be managed as low-level radioactive waste when cooling system components are cleaned.

In March 1995, EN requested Washington State approval to dispose of contaminated cooling tower sediment on-site. In May 1995, the Energy Facility Site Evaluation Council (EFSEC) approved Resolution No. 278, authorizing the on-site disposal of slightly contaminated sediment cleaned from the Columbia circulating cooling water system cooling towers. In 2001, EFSEC replaced Resolution No. 2781 with Resolution No. 2992 (Attachment 1) additionally authorizing the on-site disposal of Standby Service Water System spray pond sediment.

1.2. Location Columbia is located in the southeast area of the U.S. Department of Energys (DOE) Hanford Site in Benton County, Washington. The reactor is located at 46° 28 18 north latitude and 119° 19 58 west longitude. The approximate Universal Transverse Mercator coordinates are 5,148,840 meters north and 320,930 meters east.

Disposal of sediment removed from the cooling towers and spray ponds would occur on the Columbia site within disposal cells approximately 250 feet south of the cooling towers. Attachment 2 (Site Map - Sediment Cells) shows the footprint of the disposal area with active and inactive (previously used, closed) cells flagged as notes 1 and 2, respectively. In April 20193, EN received approval from EFSEC to expand the disposal cells. This expansion was completed in November 2020 and the area is marked as a future use sediment cell (note 3 in Attachment 2).

1 EFSEC Resolution No. 278, WNP-2 Onsite Disposal of Cooling Tower Sediments, dated May 8, 1995 2 EFSEC Resolution No. 299, Columbia Generating Station Cooling System Sediment Disposal, dated August 13, 2001 3 Letter GI2-19-058, dated April 18, 2019, from A. Kidder (Energy Facility Site Evaluation Council) to S. Khounnala (EN),

Columbia Generating Station Resolution 299 Sediment Disposal Cell Expansion GO2-20-104 Enclosure Page 2

GO2-20-104 Enclosure Information in Support of 10 CFR 20.2002 Request for Disposal EN estimates approximately 200 cubic yards total remaining capacity in the two active cells. The estimated capacity of the future use cell is approximately 1,200 cubic yards. From 2010 through 2019, the average amount of dry sediment added to the disposal area is 198 cubic yards per year.

Based on this annual average, EN estimates the existing cells will allow for 7 more years of disposal. As the remaining capacity in the cells diminish, EN anticipates requesting additional EFSEC and NRC approval for expanding the sediment disposal area.

2. 10 CFR 20.2002(a): A description of the waste containing licensed material to be disposed of, including the physical and chemical properties important to risk evaluation, and the proposed manner and conditions of waste disposal.

2.1. Source of sediment - Cooling Towers The circulating water system is designed to provide cooling water for the condenser using the atmosphere as a heat sink via six circular mechanical-induced draft cooling towers. In addition, the cooling towers have the capacity to cool the plant service water during normal operation and the standby service water during shutdown operation. Makeup for tower evaporation, wind loss, and blowdown is obtained from the Columbia River by makeup pumps. The design of the cooling towers make them concentrators of material that either is entrained in the makeup water supply from the river or is scrubbed from the air drawn into the towers by the fans. This material collects in the low-flow regions of the tower decks and in the large basin below each cooling tower.

2.2. Source of sediment - Standby Service Water System Spray Ponds The Standby Service Water System is designed to remove heat from plant systems that are required for a safe reactor shutdown following a design basis accident or transient. The Standby Service Water System provides cooling water for the removal of heat from unit auxiliaries, such as Residual Heat Removal System heat exchangers, standby diesel generators, and heat exchangers/room coolers for Emergency Core Cooling System equipment and critical electrical equipment. In addition, the Standby Service Water System provides cooling to unit components (e.g., Reactor Core Isolation Cooling System), as required, during normal shutdown and reactor isolation modes.

The Standby Service Water cooling system consists of three independent pump and piping systems that utilize two large interconnected concrete ponds. Each pond is approximately 250 feet by 250 feet by 15 feet deep. Cooling is provided by water spray from 140-foot diameter spray rings located in the center of each pond. The two spray ponds are sized to have a combined equivalent storage for at least 30 days of operation, assuming no makeup and maximum evaporation and drift losses.

The spray ponds are provided with makeup water by the tower makeup system or the potable water system. The makeup water system supplies Columbia River water to the cooling towers or spray pond to replace water lost during normal operation due to evaporation and drift. The potable water system replaces normal spray pond evaporation and drift losses.

GO2-20-104 Enclosure Page 3

GO2-20-104 Enclosure Information in Support of 10 CFR 20.2002 Request for Disposal The ponds, with warm water and ample sunlight, provide an environment conducive to the growth of algae and bacteria. The build-up of sediment on the bottom of the ponds from the accumulation of organic material, silt/sand from the atmosphere, and solids entrained in the river water must be periodically removed to maintain the required water storage volume. A maximum average sediment depth of up to 6 inches (0.5 feet) is allowed on the bottom of the ponds. In order not to exceed that value, sediment depth is periodically measured and cleaning is initiated when necessary.

2.3. Physical and chemical properties of material important to risk evaluation Cooling tower sediments are estimated to contain between 10 and 25 percent organic material by weight and the remainder is silt and sand. Analyses have also shown that, although metals tend to accumulate in the cooling tower sediments, leachability relative to dangerous waste designation (per Washington Administrative Code [WAC] 173-303) is not a concern.

The sediment removed from the spray ponds consists of fine sand and silt sized particles and an organic fraction. Chemical analyses from 1995 have shown that metals tend to concentrate in this sediment with lead and chromium occurring at concentrations above background levels. These lead and chromium levels did not exceed WAC 173-340 (Model Toxics Control Act - Cleanup) standards nor did they exceed thresholds for dangerous waste designation (WAC 173-303-090) when tested by the Toxicity Characteristic Leaching Procedure (TCLP). Columbia samples the sediment cells every five years for total copper, zinc, and nickel, and other metals in accordance with EFSEC Resolution No. 299.

2.4. Proposed Manner of Waste Disposal Under EFSEC Resolution No. 299 EN is authorized to dispose of sediment removed from the cooling towers and spray ponds in the disposal cells. The corners of the disposal area are marked with posts and signs indicating the dedicated purpose of the area4. A fence with a locked gate encloses the disposal area to avoid inadvertent access to, or disturbance of, the disposal area.

Engineered barriers (e.g. soil linings) are not utilized.

The following summary describes typical methods used for removal and disposal of sediment.

Cooling tower sediment is typically removed using a vacuum truck or other mechanical means.

During each cooling tower cleaning event, the vacuum truck is filled and emptied multiple times in order to move all of the sediment. After all of the cooling tower sediment is moved to the disposal area, the vacuum truck will be rinsed with water. The water will be drained into the sediment disposal cell utilized for the cleaning event.

The typical method for removing sediment that collects at the bottom of the spray ponds is determined by Columbias operating status. When Columbia is offline and water has been drained from one of the ponds, the preferred and most effective method of cleaning is to use a vacuum truck or other mechanical means to remove the sediment. If the spray ponds cannot be drained, the sediment will be vacuumed by divers and the resulting slurry will be discharged to the disposal area. On some occasions, sediment will be pumped from the spray ponds to large filter bags 4

Reference:

EFSEC Resolution No. 299 Attachment 1, Condition 1 GO2-20-104 Enclosure Page 4

GO2-20-104 Enclosure Information in Support of 10 CFR 20.2002 Request for Disposal staged in the laydown area south of the spray ponds. The filter bags will be used to separate the water from the sediment. Secondary containment around the filter bags will be used to collect the water drained from the sediment. The water will then be pumped back to the spray ponds. Once dewatered, the sediment will be moved to the on-site sediment disposal cells. This method was utilized in 2013.

Sediment from both the cooling towers and the spray ponds is typically disposed in a single cell.

Each cell will be used until the level approaches the top of the berm. The wet sediment tends to dry to a consolidated mud-cake surface that has a low susceptibility to wind erosion. Therefore, cover material is not necessary. Local sand will be placed over the material if erosion becomes a concern.

2.5. Conditions of Waste Disposal 2.5.1. Disposal Concentration Limits On-site disposal will be limited to sediment which meet the conditions of EFSEC Resolution No. 299. Individual isotopic concentrations5 are limited to the following:

Co-60: 5 picoCurie per gram (pCi/g)

Mn-54: 30 pCi/g

Zn-65: 50 pCi/g

Cs-134: 10 pCi/g

Cs-137: 20 pCi/g The combined concentrations6 of the radionuclides are also limited such that the sum of the fractions of maximum concentration for each nuclide does not exceed unity:

A+B+C+D+E 1.0 A = actual concentration ÷ maximum concentration Co-60 (5 pCi/g)

B = actual concentration ÷ maximum concentration Mn-54 (30 pCi/g)

C = actual concentration ÷ maximum concentration Zn-65 (50 pCi/g)

D = actual concentration ÷ maximum concentration Cs-134 (10 pCi/g)

E = actual concentration ÷ maximum concentration Cs-137 (20 pCi/g) 5

Reference:

EFSEC Resolution No. 299 Attachment 1, Condition 3a 6

Reference:

EFSEC Resolution No. 299 Attachment 1, Condition 3b GO2-20-104 Enclosure Page 5

GO2-20-104 Enclosure Information in Support of 10 CFR 20.2002 Request for Disposal 2.5.2. Disposal Area Dose Limit The disposal limits in EFSEC Resolution No. 299 have been established to limit the annual dose directly attributable to the disposal operations to 15 millirem per year (mrem/year)7 to an occupational worker. This is the maximum dose above background that an individual would receive spending 2,000 hours0 days 0 hours 0 weeks 0 months at the disposal site. Actual doses are much lower as described in section 5.5.

2.5.3. Pre-disposal Screening EN adheres to the following pre-disposal screening criteria, which are outlined in EFSEC Resolution No. 299, Attachment 1, Condition 4a.1 through 4a.4.

Areas to be cleaned are sampled for pre-disposal screening. Sampling is conducted in a manner that discriminates among the areas to be cleaned (e.g., cooling tower basin samples are composited separately from tower deck samples). Wet composite samples will be taken in sufficient quantity to support additional dry analysis that may be required as described below.

If the analysis results of a wet composite sample are less than 20 percent of the disposal limits noted in section 2.5.1 and no other man-made radionuclides are found, the sediment from the respective area may be placed in the disposal cell without further pre-disposal analysis.

If the analysis results of a wet composite sample are equal to or greater than 20 percent of the disposal limits noted in section 2.5.1, the same sample (or a split of the same sample) will be dried and reanalyzed. If the dry results are less than the disposal limits and no other man-made radionuclides are found, the sediment from the respective area may be placed in the disposal cell.

If the analysis results of a dried composite sample exceed the disposal limits, the material will be held for decay before it is disposed on-site or it will be disposed by other means such as burial in a licensed low-level radioactive waste disposal facility.

2.5.4. Routine Disposal Cell Monitoring Routine disposal cell monitoring8 includes:

Direct Radiation Dose Rate - A thermoluminescent dosimeter (TLD) station is established in close proximity to the disposal cells. TLDs from this station are read quarterly.

Confirmatory Sampling - A composite sediment sample is taken from the disposal cell within thirty days following each cleaning episode and analyzed dry to confirm that the disposal criteria have not been exceeded.

7

Reference:

EFSEC Resolution No. 299 Attachment 1, Condition 2 8

Reference:

EFSEC Resolution No. 299 Attachment 1, Condition 4b GO2-20-104 Enclosure Page 6

GO2-20-104 Enclosure Information in Support of 10 CFR 20.2002 Request for Disposal 2.5.5. Chemical Sampling The accumulated sediment is sampled and analyzed for total copper, zinc, and nickel once every five years9.

2.5.6. Reporting Results of routine disposal cell monitoring are reported annually in the Columbia Radiological Environmental Monitoring Program (REMP) report10. The report also contains the annual quantity or volume and estimated in-place density of sediment, plus the annual activity of radionuclides placed in the disposal area.

Chemical sampling plans and analytic results are provided to EFSEC after each sampling event11.

3. 10 CFR 20.2002(b): An analysis and evaluation of pertinent information on the nature of the environment 3.1. Site Description The elevation of the disposal areas is approximately 435 feet Mean Sea Level (MSL). Soil and foundation investigations conducted prior to plant construction show that the site is underlain by glaciofluvial sediments.

These sediments consist of loose-to-medium dense, fine-to-coarse sand with scattered gravel.

Below approximate elevation 395 feet MSL, soils consist of very dense sandy gravel with interbedded sandy and silty layers. This zone, which is almost 200 feet thick, is known as the Ringold formation. The groundwater table is in this formation at approximately 380 feet MSL which is about 55 feet below the ground surface of the sediment disposal cells. Groundwater flow in this aquifer is toward the discharge boundary at the Columbia River approximately 31/2 miles to the east.

The climate at the disposal site is characterized as mid-latitude semiarid. The area is subject to low humidity, large diurnal and annual ranges of temperatures, and modest precipitation averaging 6 to 7 inches annually and occurring mostly as rain in the winter and spring months.

Natural recharge of the aquifer from precipitation is negligible since the evaporation potential averages 45 inches per year. The predominant winds are from the northwest quadrant and average 71/2 miles per hour.

9

Reference:

EFSEC Resolution No. 299, Attachment 1, Condition 4c 10

Reference:

EFSEC Resolution No. 299, Attachment 1, Condition 7a 11

Reference:

EFSEC Resolution No. 299, Attachment 1, Condition 7b GO2-20-104 Enclosure Page 7

GO2-20-104 Enclosure Information in Support of 10 CFR 20.2002 Request for Disposal 3.2. Analysis of Sediment The cooling towers act as concentrators or traps for material entrained in the air or the makeup water. Table 1 provides a summary of radionuclide concentrations measured in cooling tower sediment between 1985 and 1994 (See Attachment 3, Table 1).

Table 1: Radiochemical Characteristics of Cooling Tower Sediment, 1985-1994 Wet Sample Dry Sample Average Maximum Average Maximum Concentration Concentration Concentration Concentration Nuclide (pCi/cc) (pCi/cc) (pCi/g) (pCi/g)

Mn-54 0.03 0.14 0.03 0.03 Co-60 0.13 0.74 0.53 3.50 Zn-65 0.09 0.24 0.14 0.24 Cs-134 0.10 0.29 0.19 0.39 Cs-137 0.17 1.40 0.35 0.68 Table 2 provides a summary of radionuclide concentrations, in picocurie per kilogram (pCi/kg), for each onsite sediment cell disposal event from 2010 through 2019. Sediment samples are collected for pre-disposal screening in accordance with EFSEC Resolution No. 299 to validate that radionuclide concentrations meet the applicable disposal limits. The radionuclide testing results are reported annually in the REMP report and are submitted to the NRC. Many of the radionuclide testing results are less than the lower limit of detection and are designated by a < symbol.

Table 2: Radionuclide Testing Results for Pre-Disposal Sediment Sampling, 2010-2019 Disposal Date Co-60 Mn-54 Zn-65 Cs-134 Cs-137 (Month-Year) (pCi/kg) (pCi/kg) (pCi/kg) (pCi/kg) (pCi/kg)

Jun-10 < 7.6E+01 < 6.2E+01 < 1.6E+02 < 6.6E+01 2.7E+02 Oct-10 3.2E+02 < 6.5E+01 < 9.8E+01 < 5.3E+01 2.8E+02 Apr-11 < 4.8E+01 < 3.5E+01 < 1.3E+02 1.2E+02 3.2E+02 Jun-11 1.3E+01 < 4.3E+01 < 1.2E+02 1.2E+02 3.6E+02 Nov-11 < 3.9E+01 < 3.8E+01 < 4.5E+01 1.1E+02 2.8E+02 Jun-12 < 3.1E+01 < 2.6E+01 < 6.8E+01 7.2E+01 1.6E+02 Oct-12 < 3.3E+01 < 3.7E+01 < 5.6E+01 < 3.9E+01 1.4E+02 May-13 < 3.7E+01 < 3.4E+01 < 7.6E+01 < 3.6E+01 1.9E+02 Oct-13 2.8E+02 < 5.1E+01 < 9.1E+01 < 6.0E+01 2.9E+02 Jan-14 2.7E+03 < 9.1E+01 < 1.9E+02 < 8.9E+01 < 7.5E+01 Apr-14 2.1E+02 < 4.5E+01 < 1.3E+02 < 4.7E+01 1.3E+02 May-14 8.1E+01 < 2.8E+01 < 7.6E+01 < 6.0E+01 4.3E+01 Oct-14 < 4.5E+01 < 4.6E+01 < 1.1E+02 < 4.9E+01 9.2E+01 May-15 1.6E+02 < 3.6E+01 < 6.7E+01 < 2.3E+01 2.0E+02 May-15 1.3E+03 < 4.7E+01 < 1.4E+02 < 4.4E+01 < 5.1E+01 Oct-15 1.4E+02 < 4.1E+01 < 7.9E+01 < 3.8E+01 1.9E+02 Apr-16 8.0E+01 < 3.6E+01 < 5.0E+01 < 2.3E+01 2.3E+02 Oct-16 < 4.9E+01 < 4.5E+01 < 8.1E+01 < 4.1E+01 1.7E+02 GO2-20-104 Enclosure Page 8

GO2-20-104 Enclosure Information in Support of 10 CFR 20.2002 Request for Disposal Disposal Date Co-60 Mn-54 Zn-65 Cs-134 Cs-137 (Month-Year) (pCi/kg) (pCi/kg) (pCi/kg) (pCi/kg) (pCi/kg)

May-17 9.5E+01 < 3.4E+01 < 8.5E+01 < 2.7E+01 1.8E+02 Oct-17 7.7E+01 < 3.6E+01 < 8.3E+01 < 3.6E+01 1.5E+02 Apr-18 2.4E+02 < 3.6E+01 < 6.2E+01 < 3.6E+01 1.7E+02 Oct-18 < 4.2E+01 < 3.9E+01 < 8.3E+01 < 3.5E+01 1.5E+02 Oct-18 3.8E+02 < 3.9E+01 < 8.0E+01 < 3.7E+01 7.1E+01 May-19 < 6.3E+01 < 6.1E+01 < 2.1E+02 < 1.2E+02 < 7.7E+01 Oct-19 2.3E+02 < 7.0E+01 < 2.8E+02 < 1.4E+02 1.6E+02 3.3. Environmental Aspects EN utilizes a REMP to monitor and ensure no effects to the environment. The primary purpose of the REMP is to evaluate the radiological impact that Columbia operation may have on the environment. Sampling is performed as specified in the Offsite Dose Calculation Manual (ODCM) and agreements made with EFSEC. Additional sampling is also performed to meet Nuclear Energy Institute (NEI) guidelines or as an EN initiative. The program serves to validate Columbia effluent measurements and exposure pathway models and to provide a documented, historical record of Columbia impact on the environment. Columbias REMP includes monitoring, testing, and reporting of the onsite disposal of cooling system sediments. The following sections describe the potential exposures from sediment cell activities to the local flora and fauna.

3.3.1. Earth The soil at the sediment cells are comprised of sand, coarse sand and gravel. No farmland is near the location. Erosion of sediment deposited in the cells is negligible due to its tendency to dry as mud cake.

3.3.2. Air Dust erosion is not anticipated due to the sediment drying as mud cake. Air samples are collected weekly at eleven locations in the vicinity of Columbia. The control location is 28 miles WSW of Columbia. Air particulate filters are analyzed for gross beta and iodine cartridges for radioiodine on a weekly basis. Air filters are also composited and analyzed for gamma emitting radionuclides quarterly.

3.3.3. Water There are no water sources near the disposal cells. The Columbia River is located 3.5 miles to the east of the disposal cells.

3.3.3.1. Groundwater Water from sediment disposal activities may reach groundwater. The water table is approximately 50 feet below the surface. Groundwater is monitored throughout the site in accordance with the REMP. Note that groundwater below Columbia is contaminated with GO2-20-104 Enclosure Page 9

GO2-20-104 Enclosure Information in Support of 10 CFR 20.2002 Request for Disposal tritium from Hanford activities and there is also tritium source from the Hanford 618-11 burial ground immediately west of Columbia.

3.3.4. Flora and Fauna Monitoring The ODCM requires annual monitoring for the evaluation of licensed material releases to the environment. This process includes potential releases from the sediment cells. Sampling includes the following:

Annual fish sampling is usually performed in late summer or fall. Fish samples collected from the Columbia River serve as indicator samples, whereas fish collected on the Snake River serve as control samples. Only edible portions of the fish are used to prepare the samples for analysis. Fish samples are analyzed for gamma emitting radionuclides on a wet weight basis.

Three species of fish are collected; an anadromous species (salmon or steelhead), and two other resident species generally considered edible or potentially edible (typically bass, whitefish, carp, walleye, perch, or sucker). The same species are collected at each location.

Resident species have been collected using traditional hook and line fishing since 2012.

Milk samples are collected semimonthly during the spring and summer months (April through September) when cows are more likely to be grazing or on fresh feed. During the fall and winter months, milk samples are collected monthly. Milk samples are collected from both indicator and control locations for gamma isotopic and Iodine-131 analysis.

Food product samples are collected from indicator and control locations at time of harvest. A sample of each principal food class is collected, which has historically meant samples of fruits, leafy vegetables, and root crops. Only edible portions are used for gamma isotopic analysis.

3.3.5. Summary The 2019 REMP report summary of radiological impact from monitoring activities at Columbia are defined in four distinct impact areas. These four exposure pathways are summarized as follows:

Direct Radiation - No impact was identified at locations beyond the Columbia controlled area.

Within the controlled area, the only impact identified was at locations known to be influenced by the Independent Spent Fuel Storage Installation (ISFSI) or radiation from the turbine building during operation.

Airborne - No impact due to Columbia operation was identified. No radioiodines or other radionuclides related to Columbia operation were identified in any of the environmental air samples.

Ingestion - No impact due to Columbia operation was identified in any of the milk, fish, or food product sample results.

Waterborne - No impact was identified at surface/drinking water locations outside the Columbia controlled area. Low level tritium activity was identified in storm drain water GO2-20-104 Enclosure Page 10

GO2-20-104 Enclosure Information in Support of 10 CFR 20.2002 Request for Disposal contained in evaporation ponds and radionuclides related to Columbia operation were identified at low levels in evaporation pond and cooling tower sediment. The activity identified at these locations is due to recapture and concentration of Columbia effluent activity; the activity levels observed are consistent with levels historically identified. Tritium activity identified in groundwater samples was at levels historically observed and consistent with levels known to exist in Hanford groundwater. No evidence that Columbia operation contributed to groundwater tritium levels was identified. Radionuclide activity identified in river sediment is consistent with activity levels known to exist in Hanford area sediment and soils.

4. 10 CFR 20.2002(c): The nature and location of other potentially affected licensed and unlicensed facilities.

Columbia is located in a sparsely populated shrub-steppe region within the DOE Hanford Site in southeastern Washington. The DOE is responsible for the Hanford Site, one of the largest nuclear cleanup efforts in the world, managing the legacy of five decades of nuclear weapons production. The Hanford Site was established in 1943 to produce plutonium for atomic weapons during World War II and the Cold War. The site has restricted public access and provides a buffer area around facilities formerly used for nuclear materials production, waste storage, and waste disposal. The primary focus of the Hanford Site shifted from production to cleanup with the signing of the Hanford Facility Agreement and Consent Order (Tri-Party Agreement [TPA]) in 1989 (Ecology et al. 1989) by Washington State Department of Ecology (Ecology), Environmental Protection Agency, and DOE (collectively, TPA agencies). The Hanford Sites current mission focuses on environmental restoration, which includes remediation of contaminated areas, decontamination and decommissioning of Hanford Site facilities, waste management (i.e., waste storage, treatment, and disposal), and related scientific and environmental research and development of waste management technologies.

Columbia is approximately three miles west of the Columbia River and is surrounded on all sides by uninhabited desert land. The nearest large population centers are Richland, Pasco and Kennewick, which are 12 miles south, 18 miles southeast, and 21 miles southeast, respectively. The nearest privately owned lands are located approximately four miles east-northeast of the plant, across the Columbia River.

Due to the location of Columbia on the Hanford Site, there are other sources of reactor provided radionuclides in close proximity to the plant. Columbia is unique in the U.S. commercial nuclear power industry in this respect. Hanford related radionuclides in the vicinity of Columbia are not necessarily reflective of Columbia activity, changes in the levels of these radionuclides are monitored to assess any contribution that Columbia may be making to the established background. The DOE has an active environmental monitoring program for the Hanford Site that overlaps the Columbia REMP.

The materials proposed for disposal will remain within the fenced area of the Columbias owner-controlled area. The nearest Hanford Site facility is the Fast Flux Test Facility (Hanford Area 400) located approximately 2.2 miles to the south-southwest of Columbia. No impact to this facility or any other licensed or unlicensed facility is expected from this action.

GO2-20-104 Enclosure Page 11

GO2-20-104 Enclosure Information in Support of 10 CFR 20.2002 Request for Disposal

5. 10 CFR 20.2002(d): Analyses and procedures to ensure that doses are maintained ALARA and within the dose limits in this part.

The following sections describe the processes, procedures, and monitoring implemented at Columbia to ensure that doses are maintained as low as is reasonably achievable (ALARA). This section also describes the analyses utilized by Columbia to assure doses are maintained within the dose limits prescribed by Washington State and 10 CFR Part 20.

5.1. Sediment Disposal Area Control As explained in Section 4, the sediment disposal area is entirely located within a fenced industrial area with a locked gate within Columbias owner-controlled area. The immediate area is not occupied by workers except during sediment disposal events, sampling, TLD changeouts, and related activities. The fenced area has very limited access and no through-traffic. In accordance with EFSEC Resolution No. 299, the corners of the disposal area are marked with posts and signs indicating the dedicated purpose of the area.

The sediment disposal cell area is also posted as a Radiologically Controlled Area (RCA). The RCA boundary is delineated with a fence and posted with RCA caution signs. Columbias Health Physics (HP) department must be contacted prior to entry into the RCA. Entry requires the worker to be signed onto a Radiation Work Permit (RWP), wear a dosimeter of legal record, and utilize a self-reading dosimeter. The RWP is the administrative method for controlling work in RCAs to ensure that occupational radiation exposures are maintained ALARA. Eating, drinking, smoking or chewing are prohibited while within the RCA. Upon exit, a hand and foot frisk is required, followed by proceeding directly to the nearest whole body contamination monitor to perform whole body contamination monitoring as directed by HP.

5.2. EFSEC Resolution No. 299 Since May 1995, Columbia has been managing on-site disposals of cooling system sediments under the authorization of an EFSEC Resolution. EFSEC Resolution No. 299 is the current Resolution from Washington State that authorizes the on-site disposal of sediments containing low, but measurable, levels of radionuclides removed from cooling systems at Columbia. The Resolution provides for a single, monitored disposal location, and outlines sediment concentration limits, pre-disposal screening criteria, sampling requirements, routine disposal cell monitoring, and notification and reporting requirements. The Washington State Department of Health and Washington State Department of Ecology also reviewed ENs applications for on-site disposal of sediments and found that the proposed disposal plan provided sufficient protections for public health and the environment12.

The disposal limits discussed in Section 2.5.1 were established to limit the annual dose directly attributable to sediment disposal to 15 mrem/year. This is the maximum dose above background that an individual would receive spending 2,000 hours0 days 0 hours 0 weeks 0 months at the disposal site. See Section 5.5 for a more detailed summary of the dose assessments. Actual doses, as demonstrated by direct 12 Letter GI2-01-122, dated August 23, 2001, from M. Mills (Energy Facility Site Evaluation Council) to D. Coleman (EN),

Resolution No. 299 - Columbia Cooling System Sediment Disposal GO2-20-104 Enclosure Page 12

GO2-20-104 Enclosure Information in Support of 10 CFR 20.2002 Request for Disposal radiation monitoring (see Section 5.4), are much lower and confirm that doses have been maintained ALARA at Columbia.

5.3. Sediment Sampling and Analyses Prior to each campaign to remove sediments from either the Circulating Water System cooling towers or Standby Service Water System spray ponds, a sampling and waste management plan is prepared and approved by Columbia personnel. The sampling and waste management plan is prepared in accordance with Plant Procedure Manual (PPM) 17.1.1, Sampling of Hazardous Substances13, and PPM 12.5.38, Cooling System Sediment Disposal14. PPM 17.1.1 is utilized to establish standard methods for collecting representative sediment samples from the cooling systems for laboratory analysis. The purpose of PPM 12.5.38 is to provide a method of coordinating the sampling and analysis of cooling system sediment prior to cooling system cleaning and after final disposal from each cleaning episode. The procedure specifically addresses the requirements of EFSEC Resolution No. 299.

Typically, the sampling and waste management plan is prepared by a Project Manager from the Reactor and Major Maintenance department. The cooling system clean-out work is scheduled and personnel from the REMP, Chemistry/Radiation Protection, Environmental & Regulatory Programs (E&RP) are contacted prior to performing PPM 12.5.38. The basic elements of the sampling and waste management plan are the following:

Concurrence Signature Page

Introduction and Background

Scope of Work

Description of Work o Sampling Objective o Sampling Schedule o Organization Responsibilities o Sampling Strategy and Justification o Sampling Protocols, Parameters, and Methods o Identification of Waste Streams o Waste Stream Generation, Management, Storage, and Disposal

Results Reporting and Records

References 13 PPM 17.1.1, Sampling of Hazardous Substances, dated 10/01/20 14 PPM 12.5.38, Cooling System Sediment Disposal, dated 01/08/16 GO2-20-104 Enclosure Page 13

GO2-20-104 Enclosure Information in Support of 10 CFR 20.2002 Request for Disposal The Project Manager is responsible for the development and approval of the sampling and waste management plan. Columbia Managers from E&RP, Chemistry/Radiation Protection, Reactor and Major Maintenance, and Environmental Services review and approve each sampling and waste management plan.

Sediment sampling is conducted in a manner that discriminates among the areas to be cleaned 15 (e.g., separate composite samples are taken from each cooling tower). A representative sediment sample is collected by compositing multiple samples from the specific cooling system to be cleaned. For example, for cooling tower deck cleaning, 3-5 sediment samples are collected from separate areas from each cooling tower upper deck and composited for analysis.

An aliquot of each composite sample is then taken to the laboratory and counted for gamma emitting radionuclides. The gamma isotopic analysis is performed to achieve the environmental lower limit of detection for sediment listed in Columbias ODCM, table 6.3.1-3. The gamma isotopic analysis results are then reviewed and compared to EFSEC Resolution No. 299 disposal concentration limits. If the analytical testing results for individual and combined isotopic concentrations are less than 20% of the disposal concentration limits, disposal of the sediment in the disposal cells is permitted.

If the analysis results of a wet composite sample are equal to or greater than 20 percent of the disposal limits noted in section 2.5.1, the same sample (or a split of the same sample) will be dried and reanalyzed. If the dry results are less than the disposal limits and no other man-made radionuclides are found, the sediment from the respective area may be placed in the disposal cell.

If the analysis results of a dried composite sample exceed the disposal limits, the material will be held for decay before it is disposed on-site or it will be disposed by other means such as burial in a licensed low-level radioactive waste disposal facility16.

A composite sediment sample is taken from the disposal cell within thirty days following each cleaning episode and analyzed dry to confirm that the disposal criteria have not been exceeded.

The routine disposal cell monitoring results for direct radiation dose and confirmatory sampling is reported each year in the REMP Annual Radiological Environmental Operating Report to the NRC and EFSEC. The annual report also includes the mass and density of the sediment placed in the sediment disposal cells.

5.4. Procedures to Ensure Doses are Maintained ALARA - Direct Radiation Monitoring EN is committed to maintaining occupational and public radiation exposures as far below regulatory dose limits as is practicable while performing all activities related to the operation of Columbia. This commitment is reflected in a Radiation Protection Program that meets the requirements of 10 CFR Part 20.

15

Reference:

EFSEC Resolution No. 299 Attachment 1, Condition 4.a.1 16

Reference:

EFSEC Resolution No. 299 Attachment 1, Condition 4.a.4 GO2-20-104 Enclosure Page 14

GO2-20-104 Enclosure Information in Support of 10 CFR 20.2002 Request for Disposal The Chemistry Department is responsible for long-term monitoring of the disposal areas for environmental radiation via the REMP. The REMP for Columbia provides for measurements of radiation and radioactive materials in exposure pathways and for those radionuclides for which the highest potential dose commitment to a member of the public would result due to plant operations.

Environmental samples are collected in accordance with the provisions of the REMP. The program specifies the environmental sampling plan by sample type, sample location code, sampling and collection frequency, and type and frequency of analysis of samples collected within an exposure pathway.

An important aspect of the REMP is monitoring direct radiation. Direct radiation dose levels are monitored with TLDs. The TLDs are placed in the field between three and five feet above the ground. TLDs are wrapped in aluminum foil and sealed in plastic bags to prevent damage. TLDs are exchanged on a quarterly basis.

Measurements of direct radiation at the sediment disposal pit area are taken using TLDs and was added to the REMP in 1995. Two locations are used, an indicator location at the disposal cells (Station 119B) and a control location approximately 200 yards to the east (Station 119Ctrl). TLD data is presented in units of exposure (milli-Roentgen, mR) per standard quarter. Table 3 and Figure 1 summarize mean values of quarterly TLD data from 2010 through 2019. The negligible difference between the indicator Station 119B and the control Station 119Ctrl indicate that there is no measurable dose contribution above background due to material in the disposal cells 17.

Table 3: Measurements of direct radiation at the disposal area using TLD Station 119B and 119Ctrl TLD Station 119B TLD Station 119Ctrl milli-Roentgen (mR) per milli-Roentgen (mR) per Year standard quarter standard quarter (mean value) (mean value) 2010 21.94 21.74 0.20 2011 21.11 21.48 -0.37 2012 22.21 22.22 -0.01 2013 21.87 22.08 -0.21 2014 21.58 22.02 -0.44 2015 21.74 22.08 -0.34 2016 21.99 21.70 0.29 2017 20.30 21.06 -0.76 2018 21.34 22.82 -1.48 2019 21.66 22.15 -0.49 Average -0.36 17 ML20134J113, 2019 Annual Radiological Environmental Operating Report for the Columbia Generating Station, Section 5.9.3 GO2-20-104 Enclosure Page 15

GO2-20-104 Enclosure Information in Support of 10 CFR 20.2002 Request for Disposal REMP TLD Station 119B and 119Ctrl Measurements 23.5 119 B 119 Control Mean Values of Quarterly TLD Measurements 23 22.5 22 21.5 (mR/standard quarter) 21 20.5 20 19.5 19 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 Year Figure 1: Direct radiation measurements for REMP Station 119B and 119Ctrl for 2010 through 2019 5.5. Radiological Impact Evaluation (Dose Assessment)

As described in previous sections of this application, in the mid 1990s EN requested approval from EFSEC for on-site disposal of sediment containing very low concentrations of radioactive materials in accordance with WAC 246-221-180. The NRC Region IV Administrator as well as the NRC Senior Resident Inspector were included on copy for these letters and applications to EFSEC. The initial EN application18 requested approval for on-site disposal of sediments cleaned from the Columbias circulating cooling water system cooling towers. In May 1995, the EFSEC approved Resolution No. 278 authorizing the on-site disposal of cooling tower sediments. EN submitted a second application19 to EFSEC in December 1995 requesting approval for on-site disposal of sediments cleaned from Standby Service Water System spray ponds. In 2001, EFSEC replaced Resolution No. 278 with Resolution No. 299 additionally authorizing the on-site disposal of Standby Service Water System spray pond sediment. A copy of ENs initial and second application are included as Attachments 3 and 4, respectively.

18Letter GO2-95-052, dated March 14, 1995, from J. Parrish (EN) to J. Zeller (Energy Facility Site Evaluation Council),

Supply System Nuclear Plant No. 2 Application for Approval of Onsite Disposal of Very Low Level Radioactive Materials Letter GO2-95-291, dated December 29, 1995, from J. Parrish (EN) to J. Zeller (Energy Facility Site Evaluation 19 Council), Supply System Nuclear Plant No. 2 Application for Approval of Onsite Disposal of Very Low Level Radioactive Materials GO2-20-104 Enclosure Page 16

GO2-20-104 Enclosure Information in Support of 10 CFR 20.2002 Request for Disposal The information presented within this section describes how the radiological criteria for on-site disposal were derived and summarizes the radiological impact evaluations (i.e., dose assessments) conducted in support of these applications to EFSEC. A radiological impact evaluation was prepared and submitted to EFSEC for both cooling tower sediments 18 and later for Standby Service Water System spray pond sediments19. The calculations were based on a dose limit of 15 mrem/year although the standard for decommissioning has been established as 25 mrem/year total effective dose.

5.5.1. Exposure Considerations Possible pathways for radiological exposure include: (1) external exposure from standing on the ground above the disposal site; (2) internal exposure from inhalation of suspended radionuclides; (3) internal exposure from the ingestion of food grown on the disposal site; and (4) internal exposure from drinking potentially contaminated groundwater.

An internal exposure resulting from ingestion of food grown on the disposal site is not considered a realistic possibility. EN controls activities within a 1.2-mile radius of Columbia. No food crops are grown in the site area and food crop production is not anticipated in the future.

Inhalation of resuspended radionuclides is not considered a significant exposure pathway.

Calculations performed utilizing the RESRAD Version 5.0 program indicate that a person would receive less than 0.001 mrem/year from cooling system sediment inhalation even if each of the primary radionuclides were at the maximum disposal concentrations limits of EFSEC Resolution No. 299. Results of the inhalation dose calculation are shown in Figure 7 of Attachment 4.

An internal exposure due to consumption of groundwater is not considered plausible. There are no wells drawing from the unconfined aquifer near the sediment disposal site. The primary source of drinking water for Columbia is the Columbia River. There is a backup water supply well on the Columbia site. The well is about 2,100 feet north of the disposal location and, at a depth of 695 feet, draws from the confined aquifer. There are also two wells in use at the ENs Industrial Development Complex, 7,000 feet east, however, these wells are about 465 feet deep and, based on the stratigraphy and water quality data, appear to draw from a semi-confined aquifer in the Ringold conglomerates and the upper fractured basalt flow. While future groundwater withdrawals are possible, usage for human and animal consumption will be limited by the existing tritium contamination resulting from previous Hanford Site operations.

The direct external exposure of an individual working or standing on the disposal area represents the most significant exposure pathway (i.e., the maximally exposed individual or MEI). Accordingly, a dose assessment has been made for the MEI from the ground shine pathway using conservative assumptions to assure that the limiting disposal concentrations of EFSEC Resolution No. 299 will maintain exposures less than 15 mrem/year.

GO2-20-104 Enclosure Page 17

GO2-20-104 Enclosure Information in Support of 10 CFR 20.2002 Request for Disposal 5.5.2. Dose Projection Assumptions The dose projections used for the evaluation of the disposal areas were based on the following assumptions:

The only significant environmental pathway for delivering radiation dose to the MEI is direct radiation from the waste material in the soil.

The exposure duration is assumed to be 2,000 hours0 days 0 hours 0 weeks 0 months per year.

Source terms are individual nuclides at maximum disposal concentrations indicated in Table 2 of Attachments 3 and 4 at time of deposition. Each deposited layer is corrected for decay from date of deposition until facility closure.

The annual integrated dose considers decay of deposited radionuclides during prior years of deposition. The most recently deposited material is assumed to be on top, with older material at progressively deeper locations.

The total quantity of deposited sediment is assumed to be:

o Cooling Tower Sediment (CTS): 1,800 cubic yards (30 years of disposal at the rate of 60 cubic yards per year) o Spray Pond Sediment (SPS): 1,050 cubic yards (30 years of disposal at the rate of 35 cubic yards per year).

The calculation was stopped at a maximum deposited material age of 10 years since older material did not add significantly to the dose.

The dimensions of the deposited material were assumed to be 15 meters radius by 1.2 meters deep (2 meters for CTS dose projection). This is approximately 1,050 cubic yards (1,800 cubic yards CTS dose projection). A cylindrical geometry was chosen to maximize the dose per unit volume. This geometry was chosen for dose calculations only and does not represent the actual disposal geometry.

The density of the sediment is assumed to be 1.5 g/cm3

An isotropic geometry is assumed for calculating dose.

5.5.3. Method of Calculation Exposure rates at one meter above the ground surface and the corresponding dose rates were calculated using the computer code20 MicroShield Version 4. Maximum disposal concentrations for each nuclide were calculated by an iterative process to yield a dose of 15 mrem/year to the MEI.

20 MicroShield Version 4 Users Manual, Grove Engineering, Inc., Rockville, MD, 1992 GO2-20-104 Enclosure Page 18

GO2-20-104 Enclosure Information in Support of 10 CFR 20.2002 Request for Disposal The RESRAD Version 5.19 computer code21 was used to calculate the decline in the expected MEI dose following closure of a disposal area beginning at the maximum limit of 15 mrem/year (Figure 8 of Attachment 4 and Figure 6 of Attachment 3). This code was also used to calculate the expected dose from the inhalation pathway assuming that every radionuclide was at maximum concentration (Figure 7 of Attachment 4 and Figure 7 of Attachment 3).

5.5.4. Dose Calculation Results Results of the MicroShield dose calculations to determine the limiting disposal concentrations are shown in Table 2 of Attachments 3 and 4. The concentrations determined by this method were proposed as disposal limits in 1995 to EFSEC and were later adopted as maximum disposal limits of EFSEC Resolution No. 299 as described in Section 2.5. The maximum disposal concentrations assure that the limiting dose of 15 mrem/year would not be exceeded.

The dose from multiple radionuclides is constrained to 15 mrem/year by the sum-of-the-fractions limitation as described in Section 2.5.

A calculation was performed utilizing the computer code RESRAD Version 5.19 to calculate the decline in the MEI dose over time following the closure of a disposal area. The starting dose rate for the calculation was assumed to be 15 mrem/year beginning one year after the last sediment has been placed in the disposal area. This starting rate was achieved by assigning each radionuclide an arbitrarily equal yearly dose rate. The results of this calculation are shown in Figure 8 of Attachment 4 and Figure 6 of Attachment 3.

RESRAD code was also used to perform a calculation of the inhalation dose with all radionuclides at the maximum disposal concentrations. This is a conservative assumption because the disposal concentrations would be apportioned by the sum-of-the-fractions limitation discussed in Section 2.5. The calculation indicates that a MEI would receive less than 0.001 mrem/year from the inhalation pathway. The results of the calculation are shown in Figures 7 of Attachments 3 and 4.

As demonstrated in this section, the NRC criterion of 15 mrem/year total effective dose equivalent (TEDE) to an average member of a critical group can be achieved in the sediment disposal area by the application of a limiting concentration for each radionuclide and the use of the sum-of-the-fractions limitation described in Section 2.5. Actual doses will be much lower since not all material will be disposed at the maximum concentrations, the actual disposal geometry is not cylindrical, and the areas are unoccupied.

5.6. Decommissioning Plan It is anticipated that the cooling system sediment disposal operations will go beyond the 30 year estimate used in the 1995 dose projection assumptions and will continue for the operating life of Columbia. Final disposition of the cooling system sediments at the end of plant life will depend on the requirements of the NRC and other agencies.

21 Manual for Implementing the Residual Radioactive Material Guidelines Using RESRAD, Version 5.0, Working Draft for Comment, Environmental Assessment Division, Argonne National Laboratory, Rept. No. ANL/EAD/LD-2, September 1993.

GO2-20-104 Enclosure Page 19

GO2-20-104 Enclosure Information in Support of 10 CFR 20.2002 Request for Disposal In 1997, the NRC published Subpart E, Radiological Criteria for License Termination, amending 10 CFR Part 20. This subpart provides radiological criteria for releasing a facility for unrestricted use. The regulation states that the site can be released for unrestricted use if radioactivity levels are such that the average member of a critical group would not receive a TEDE in excess of 25 millirem per year, and provided that residual radioactivity has been reduced to levels that are ALARA. The decommissioning plan for Columbia and cost estimates assume that the Columbia site will be remediated to a residual level consistent with the NRC-prescribed level.

Plant decommissioning criteria will include characterization of the site and surrounding environs.

Following completion of plant decommissioning operations, site restoration activities will be conducted. Areas with the potential for radionuclides in the subsurface and soil will be assessed and verified that residual radionuclide concentrations meet NRC site release requirements. The sediment disposal cells will be included in the site evaluation and restoration activities and is also included in records kept in accordance with 10 CFR 50.75(g). The sediments will be assessed and sampled and analyzed if necessary, to determine if the sediments need to be exhumed and disposed off-site as low-level radioactive waste. EN anticipates that the on-site disposal of cooling system sediments will conform to decommissioning criteria and will not require exhumation and removal. However, decommissioning estimates include the contingency for off-site disposal of approximately 7,460 cubic yards of soil as radioactive waste.

EN will also evaluate Ecologys regulations for solid waste (i.e., WAC 173-304) in effect at the time of site restoration to determine the appropriate disposition. If the material is to be left in place, some minor regrading may be required to give the area a natural appearance during the site restoration phase.

GO2-20-104 Enclosure Page 20

GO2-20-104 Enclosure, Attachment 1 EFSEC Resolution 299

61-2-0 I- lZZ.

STATE OF WASHINGTON ENERGY FACILITY SITE EVALUATION COUNCIL PO Box 43172

Olympia, Washington 98504-3172 August 23, 2001 Mr. D. W. Coleman Manager, Regulatory Affairs Energy Northwest Post Office Box 968 (MD PE20)

Richland, Washington 99352-0968

Subject:

Resolution No. 299 - Columbia Cooling System Sediment Disposal

Dear Mr. Coleman:

During its regular meeting of August 13, 2001, the Council approved Resolution No. 299 (see enclosed), thereby authorizing the onsite disposal of cooling system sediments from the Columbia Generating Station (Columbia). This action closes out Resolution No. 278 that permitted disposal of cooling tower sediments onsite, and expands the disposal authorization to include those sediments, plus other slightly contaminated cooling system sediments from the spray ponds and the Columbia service water-cooling system. The resolution provides for a single, monitored disposal location, while setting concentration limits and sampling and monitoring requirements.

The Council wishes to recognize the cooperation extended by Energy Northwest in working with state Health and Ecology staff in developing disposal and monitoring procedures that will allow for the safe disposal of cooling system sediments in a manner that is consistent with state regulations for the alternate disposal of slightly radioactive waste.

Thank you for your continued cooperation.

Sincerely, Mike Mills Compliance Manager Enclosure cc: John Arbuckle, Energy Northwest Lynn Albin, Health Jeff Ayres, Ecology (360) 956-2121 Telefax (360) 956-2158

...,.,.. 0

WASHINGTON STATE ENERGY FACILITY SITE EVALUATION COUNCIL (EFSEC)

RESOLUTION NO. 299 COLUMBIA GENERATING STATION COOLING SYSTEM SEDIMENT DISPOSAL Nature of Action. Resolution No. 278 permits the onsite disposal of slightly contaminated sediment cleaned from the Columbia Generating Station circulating cooling water system. This action closes Resolution No. 278 and approves this resolution for the purpose of expanding the scope of plant cooling water systems covered by the disposal authorization and amending some of the monitoring requirements.

Background. Operation of the open cooling water systems at Columbia Generating Station (CGS) causes radionuclides contained in the source water or entrained from plant emissions to become concentrated in the sediment that accumulates in features of the cooling systems (e.g.,

tower decks, tower basins, pump basins, spray ponds, piping and system components). The concentrations of radionuclides in the sediment often exceed the lower levels of detection for environmental measurements. This requires that the material be managed as low level radioactive waste when cooling system components are cleaned.

In March 1995, Energy Northwest (then the Washington Public Power Supply System) requested approval of its plan to dispose of contaminated cooling tower sediment onsite. This approval was sought under the existing regulatory framework (WAC 246-221-180) that provides for state review and approval of a site-specific disposal plan. After conferring with the Departments of Health and Ecology, the Council approved Resolution No. 278 on May 8, 1995.

In December 1995, Energy Northwest requested that the scope of the disposal authorization be expanded to include sediment removed from the service water spray ponds. In August 1996, the Council approved by motion the relocation of previously removed spray pond sediment to the designated onsite disposal area. In June 1999, Energy Northwest resubmitted a revised application for a long-term authorization to dispose of spray pond sediment onsite. In June 2000, Energy Northwest provided detailed responses to Department of Health questions concerning the revised application.

The Departments of Health and Ecology have reviewed the Energy Northwest application and supplemental information and found that the proposed disposal plan for service water cooling system sediments provides sufficient protections for public health and the environment. This judgement is also based on a review of the five years of experience with onsite disposal of circulating cooling water system sediments. Accordingly, Council staff has recommended that the requirements of Resolution No. 278 and its Attachment No. 1, be superseded by this resolution, No. 299, and Attachment 1. The following summarizes the changes resulting from Resolution No. 299:

1. Scope is amended to include the CGS service water system as a sediment source.

2. References to solid waste requirements are deleted as they are not applicable to clean soil and low-level radioactive waste. Also, the solid waste reporting expectations are deleted

since they are duplicated by the radiological monitoring reporting requirements.

3. Pre-operational baseline monitoring requirements are deleted because they have been completed. Data were submitted to the Council June 1995.

4. Once-per-year pressurized ion chamber measurements are deleted because the required the full -time monitoring of direct radiation by thermoluminescent dosimeter provides more useful and relevant information .

Resolution . The Council hereby closes Resolution No. 278 and authorizes the onsite disposal of cooling system sediments containing low levels of radionuclides at the Energy Northwest Columbia Generating Station subject to the conditions specified in Resolution No. 299, .

Dated and effective this 13th day of August, 2001. . Onsite Disposal of Contaminated Cooling System Sediments

Resolution No. 299, Attachment 1 Columbia Generating Station Onsite Disposal of Contaminated Cooling System Sediments Resolution No. 299 authorizes the on-site disposal of sediments removed from cooling systems containing low levels of radionuclides at Energy Northwest's Columbia Generating Station (CGS). This authorization is contingent upon compliance with the following conditions:

I. Disposal Area:

Sediment disposal is limited to disposal cells specifically constructed for this purpose. The cells are to be located in an inactive borrow pit located south of the CGS cooling towers.

The comers of the disposal area shall be marked with posts and signs indicating the dedicated purpose of the area. Interim storage of sediment in containers is allowed.

2. Disposal Area Dose Limit:

The disposal limits in Section 3 have been established to limit the annual dose directly attributable to this disposal operation to 15 mrem/year. This is the maximum dose above background that an individual would receive spending 2000 hours0.0231 days 0.556 hours 0.00331 weeks 7.61e-4 months at the disposal site. Actual doses are expected to be much lower and should be maintained as low as reasonably achievable.

3. Disposal Concentration Limits:

a. The following individual isotopic limiting concentrations have been established as the maximum values allowed for disposal:

Co-60 5 pCi/g Mn-54 30 pCi/g Zn-65 50 pCi/g Cs-134 10 pCi/g Cs-137 20 pCi/g

b. Since these radionuclides may not occur alone, the combined concentrations of the radionuclides will also be limited such that the sum of the fractions of maximum concentration for each nuclide does not exceed unity:

A+B+C+D+E # 1.0 A= actual concentration..,.. maximum concentration Co-60 (5 pCi/g)

B = actual concentration..,.. maximum concentration Mn-54 (30 pCi/g)

C = actual concentration..,.. maximum concentration Zn-65 (50 pCi/g)

D = actual concentration ..,.. maximum concentration Cs-134 (IO pCi/g)

E = actual concentration ..,.. maximum concentration Cs-13 7 (20 pCi/g)

c. This will assure that the incremental dose will remain below 15 mrem/yr. If additional radionuclides are detected, individual limiting concentrations will need to be established with concurrence from the state Department of Health prior to disposal.

4. Sample Analysis and Environmental Monitoring:

Monitoring of the sediment and the disposal site will be conducted per Energy Northwest's standard environmental monitoring procedures and practices.

a. Pre-Disposal Screening Criteria and Sample Requirements:

1. Areas to be cleaned shall be sampled for pre-disposal screening. Sampling shall be conducted in a manner that discriminates among the areas to be cleaned (e.g., cooling tower basin samples are composited separately from tower deck samples). Wet composite samples shall be taken in sufficient quantity to support additional dry analysis that may be required as described below.

2. If the analysis results of a wet composite sample are less than 20% of the disposal limits listed above and no other man-made radionuclides are found, the sediment from the respective area may be placed in the disposal cell without further pre-disposal analysis.

3. If the analysis results of a wet composite sample are equal to or greater than 20% of the disposal limits listed above, the same sample (or a split of the same sample) shall be dried and reanalyzed. If the dry results are less than the disposal limits and no other man-made radionuclides are found, the sediment from the respective area may be placed in the disposal cell.

4. If the analysis results of a dried composite sample exceed the disposal limits, the material shall be held for decay before it is disposed onsite or it shall be disposed by other means such as burial in a licensed low-level radioactive waste disposal facility.

5. If requested, Energy Northwest shall provide the state a split of any sample taken for analysis.

b. Routine Disposal Cell Monitoring:

I. Direct Radiation Dose Rate - A thermoluminescent dosimeter (TLD) station shall be established in close proximity to the disposal cells. TLDs from this station shall be read quarterly.

2. Confirmatory Sampling - A composite sediment sample shall be taken from the disposal cell within thirty (30) days following each cleaning episode and analyzed dry to confirm that the disposal criteria have not been exceeded.

c. Chemical Sampling:

Metals - Once every five (5) years, the accumulated sediment shall be sampled and analyzed for total copper, zinc, and nickel. Other constituents will be analyzed if requested by the state Department of Ecology.

5. Disposal Site Closure Disposal operations are anticipated throughout the operating life of Columbia Generating Station. The disposal site shall be closed in accordance with regulations in effect at the time of closure.

6. Notifications:

Information regarding unusual circumstances or testing data that exceeds the specified limits will be reviewed within ten (10) working days with the state.

7. Reporting:

a. Routine disposal cell monitoring (4.b above) shall be reported annually in the Radiological Environmental Monitoring Program (REMP) report. The report shall also contain the annual quantity or volume and estimated in-place density of sediment, plus the annual quantity of radionuclides placed in the disposal area.

b. Chemical sampling plans and analytic results shall be provided to the Council after each sampling event.

GO2-20-104 Enclosure, Attachment 2: Site Plan - Sediment Cells E -1750 E -1500 E -1250 3

N 10500 18' 2

20' 86' 1 1 .F.

6500 S 2

76' N 10250 PROJECT AREA NOT I>

1 ACTIVE SEDIMENT CELLS CGS - KEY PLAN I>

SCALE : N.T.S.

2 CLOSED SEDIMENT CELLS I>

3 FUTURE USE SEDIMENT CELL

~1-1-e----

1 SITE PLAN - SEDIMENT CELLS SCALE : 1"=60'-0" DECEM ER 2 2020

GO2-20-104 Enclosure, Attachment 3 March 1995 Application to EFSEC for cooling tower sediment

WASHINGTON PUBLIC POWER SUPPLY SYSTEM P.O. Box 968

3000 George Washington Way

Richland, Washington 99352-0968 * (509) 372-5000 March 14, 1995 GO2-95-052 Mr. Jason J. Zeller, Manager Energy Facility Site Evaluation Council P.O. Box 43172 Olympia, WA 98504-3172

Dear Mr. Zeller:

Subject:

SUPPLY SYSTEM NUCLEAR PLANT NO. 2 APPLICATION FOR APPROVAL OF ONSITE DISPOSAL OF VERY WW LEVEL RADIOACTIVE MATERIALS

Reference:

Letter dated December 30, 1994 from JV Parrish (Supply System) to JJ Zeller (EFSEC), same subject In accordance with WAC 246-221-180, the Washington Public Power Supply System requests approval of the disposal of sediment cleaned from the cooling towers at Nuclear Plant No. 2.

Analyses have shown that this material often contains radionuclides at concentrations above the level of detection for environmental measurements. Cooling system operation likely concentrates radionuclides contained in the river makeup water and the air drawn through the towers.

Regardless of source, the current regulatory framework requires that this sediment be managed as low-level radioactive waste. Given the nature of the material and its very low radioactive contamination, we believe that onsite disposal is the most appropriate and cost-effective method of disposal.

Enclosed , please find an application for onsite disposal of cooling tower sediment. Revisions have been made to our earlier submittal (reference letter) in response to comments made by the Department of Health. An Environmental Checklist is also enclosed for your use. Should you require additional information, please contact W.A. Kiel at (509) 377-4490.

Sincerely, It~&',,

J. V. Parrish (MD-1023)

Vice-President, Nuclear Operations Enclosures cc: J. Erickson (WDOH) L.J . Callan (USNRC-RIV)

L. Albin (WDOH) NRC Sr. Res. Inspctr. (927N)

L. Russell (WDOE-Kenn)

APPLICATION FOR APPROVAL TO DISPOSE OF VERY LOW-LEVEL RADIOACTIVE MATERIAL I. Introduction In accordance with WAC 246-221-180, the Washington Public Power Supply System (Supply System) requests authorization from the State of Washington for onsite disposal of sediment containing very low concentrations of radioactive materials. This sediment results from the cleaning of the cooling towers at the Supply System's Nuclear Plant No. 2 (WNP-2). Disposal would commence during the planned refueling and maintenance outage planned for April/May 1995 and would continue periodically (one to three times per year) throughout plant life. Disposal would occur in an area dedicated for sediment disposal.

Details on the disposal location, nature of the material, proposed manner of disposal, and impact assessments are provided below.

II. Site Description A. Location WNP-2 is located in Benton County about 12 miles north of Richland, Washington within Section 5, Township 11N, Range 28E. The proposed disposal location is within the WNP-2 controlled area on property leased from the U.S. Department of Energy. Disposal would occur within a former borrow pit approximately 250 feet south of the cooling towers. With reference to the Hanford Coordinate system, the location is N10350, W1500. The location is indicated on Figure 1 (general site map) and Figure 2 (aerial photo). Figure 3 shows the surveyed corner locations and dimensions of the designated disposal area.

B. Site Characteristics The elevation of the disposal area is approximately 435 feet MSL. Soil and foundation investigations prior to plant construction show that the site is underlain with approximately 40 feet (down to approximately 395 feet MSL) of glaciofluvial sediments (Section 2.5.1.2. 7 of Ref. A). These sediments consist ofloose-to-medium dense, fine-to-coarse sand with scattered gravel. Below approximate elevation 395 feet MSL, soils consist of very dense sandy gravels with interbedded sandy and silty layers. This zone, which is almost 200 feet thick, is known as the Ringold formation.

The groundwater table is located in this zone at approximately 380 feet MSL which is about 55 feet below the ground surface at the disposal location. Groundwater flow in the unconfined aquifer is toward the discharge boundary at the Columbia River approximately 31/2 miles to the east.

CTS Diaposal Appln Mar95

The climate at the disposal site is characterized as mid-latitude semiarid. The area is subject to low humidities, large diurnal and annual ranges of temperatures, and modest precipitation averaging 6 to 7 inches annually and occurring mostly as rain in the winter and spring months. Natural recharge of the aquifer from precipitation is negligible since the evaporation potential averages 45 inches per year. The predominant winds are from the northwest quadrant and average 71/2 miles per hour.

When winds are from the NNW to NNE, as they are approximately 20% of the time, humidity at the proposed disposal location can exceed natural humidity due to the overhead cooling tower vapor plume ..

C. Other Potentially Affected Facilities There are no other facilities in the vicinity of the disposal site that will be affected by the proposed activity. The disposal location lies adjacent to an area used by the Supply System for disposal of construction related debris. The activities will remain separated. A fence with a locked gate encloses the entire area (see Figure 1).

III. Waste Description A. Source and Quantity The condenser cooling cycle at WNP-2 employs six (6) mechanical draft cooling towers to reject heat by the evaporative process. Water flow through each tower is approximately 95,000 gpm at full power. The design makes the towers excellent concentrators of material that either is entrained in the makeup water supply from the river (approximately 14,000 gpm) or is scrubbed from the air drawn into the towers by the fans. This material (mostly silt) collects in the low-flow regions of the water distribution troughs and decks and in the large basin below each cooling tower.

Figure 4 shows the major features of the cooling towers.

The towers, with warm water and ample sunlight, also provide an environment conducive to the growth of algae and bacteria. The build-up of silt/sand and organic material must be removed from the towers periodically to maintain cooling efficiency.

The build-up is a particular problem for the water distribution decks where algae and entrained silt can block the nozzles which distribute the warm water to the tower fill.

The cooling tower sediment (CTS) is removed one to three times per year. Annual quantities of wet sediment are estimated to be 60 cubic yards. If processed as low level radioactive waste at a licensed waste disposal facility, the estimated total cost would be $200,000 to $250,000 per year.

B. Physical, Chemical, and Radiological Properties The organic (algal material) content of the CTS is variable. The sediment removed from cooling tower water distribution decks tends to have a higher percentage of biologic matter than either the troughs or the basins. Overall, the percentage of CTS Dilj)Oaal Appln M&r9.5

organic material is estimated to range between 10 and 25 percent by weight. The remainder is silt and sand. Analyses have shown that, although metals tend to accumulate in the CTS, leachability relative to dangerous waste designation (per WAC 173-303) is not a concern. Sample results are displayed in Appendix A. Also listed in Appendix A are comparable, though not necessarily applicable, regulatory limits on disposal.

As noted above, the cooling towers act as concentrators or traps for material entrained in the air or the makeup water. This is true of radioactive material regardless of the source. A summary of radionuclide concentrations measured in the sediment since 1985 is provided in Table 1. Appendix B lists radionuclide concentrations measured in CTS samples collected over the operating history of the plant.

Table 1. Radiochemical Characteristics of CTS Wet Sample Dry Sample Nuclide Avg. Cone. Max. Cone. Avg. Cone: Max. Cone.

(pCi/cc) (pCi/cc) (pCi/g) (pCi/g)

Mn~54 0.03 0.14 0.03 0.03 Co-60 0.13 0.74 0.53 3.50 Zn-65 0.09 0.24 0.14 0.24 Cs-134 0.10 0.29 0.19 0.39 Cs-137 0.17 1.40 0.35 0.68 IV. Waste Disposal A. Organization and Responsibilities Overall responsibility for the disposal of the cooling tower' sediment resides with the WNP-2 Plant General Manager. This individual has the Supply System staff resources within the WNP-2 organization to carry out the proposed disposal operation.

Implementation of the disposal plan will principally be through two Plant departments:

CTS Diapoul Appln Mar95

1. Chemistry The Chemistry Manager, in addition to other operational support duties, is responsible for monitoring heat transfer system performance as it relates to chemical/biological control. Therefore, Chemistry monitors the cooling towers for indications of sediment buildup and initiates the work orders by which tower cleaning is effected. Chemistry also samples and analyzes (or has an external laboratory analyze) the sediment for radioactivity prior to and after disposal. The Chemistry Department is responsible for monitoring the area for environmental radiation (see Section IV.F, below). The Department also has responsibility for monitoring the integrity of the disposal area (e.g., condition of disposal cells, indications of disturbance) and initiating corrective action, if needed.

2. Health Physics The Health Physics Department is managed by the Radiation Protection Manager (RPM). This department establishes and monitors work practices as they relate to radiation protection. The department is responsible for the proper storage, packaging, and disposal of contaminated materials. The HP Department will also provide technical support for CTS disposal (e.g., interpretation of radiochemical data, evaluation of dose). Additionally, reporting to the RPM is the labor support for developing and implementing the work orders (including specific task instructions) initiated by Chemistry.

B. Sediment Sampling and Analyses Representative CTS samples will be collected from the cooling towers prior to the start of cleaning. Given the design of the system and the origin and nature of the material, it is reasonable to expect homogeneous distribution of radiological constituents. Therefore, a composite sample will be prepared from samples collected from each tower that will be cleaned. The water distribution troughs and the basins will be treated as separate locations for sampling, compositing, and analysis.

Wet composite samples will be analyzed in a qualified laboratory operated under the quality assurance requirements of the Nuclear Regulatory Commission (Ref. B).

Samples will be analyzed for gamma-emitting fission and activation product radioactivity utilizing methods and counting systems capable of measuring to environmental levels as specified in Table 6.3.1.1.1-1 in the WNP-2 Offsite Dose Calculation Manual (Ref. C). The lower limits of detection (LLDs) specified for cobalt-60, cesium-134 and cesium-137 in wet sediment are 15 pCi/1, 15 pCi/1, and 18 pCi/1 (0.015 pCi/ml, 0.015 pCi/ml, and 0.018 pCi/ml) respectively. The results of the wet sample analysis will be used to determine the initial disposition of material to be removed from the towers.

CTS Diaposal Applo Mar95

If the results indicate that the activity of the wet composite sample is within a factor of five 9f the disposal criteria (Section IV.C), then additional composite samples (approximately 2.2 kg each) will be dried and analyzed by a qualified offsite laboratory. These samples, if necessary, will be used to confirm the wet sample results and to assure the appropriate disposition of the sediment. The lower limits of detection (LLDs) specified for cesium-134 and cesium-137 in dry sediment are 150 and 180 pCi/kg (0.15 and 0.18 pCi/g), respectively. Following placement of the sediment in the disposal cell, another dried composite sample will be analyzed to confirm that the disposal criteria were not exceeded (see Section IV .E).

C. Disposal Criteria Sediment disposal criteria (i.e., maximum radionuclide concentrations) are based on the proposed decommissioning criterion of 15 mrem/yr total effective dose equivalent to the average member of a critical group (Ref. G). At this level and below, no actions will be necessary to protect the public (i.e., release of site for unrestricted use). Therefore, the disposal of CTS will be limited such that an individual exposure can not exceed 15 mrem per year. In determining the limiting concentrations, it is assumed that an individual spends 2000 hours0.0231 days 0.556 hours 0.00331 weeks 7.61e-4 months a year at the disposal location. It is also assumed that the maximum amount of material (60 cubic yards per year) is disposed for 30 years. Using dose projections methods discussed in Section V below, the following individual limiting concentrations are proposed for onsite disposal:

Co-60 5 pCi/g Mn-54 30 pCi/g Zn-65 50 pCi/g Cs-134 10 pCi/g Cs-137 25 pCi/g Since the radionuclides may not occur alone, the concentrations of the radionuclides will also be limited such that the sum of the fractions of maximum concentration for each nuclide does not exceed unity:

A +B+ C +D +E ~ 1.0 A = actual concentration + maximum concentration Co-60 (5 pCi/g)

B = actual concentration + maximum concentration Mn-54 (30 pCi/g)

C = actual concentration + maximum concentration Zn-65 (50 pCi/g)

D = actual concentration + maximum concentration Cs-134 (10 pCi/g)

E = actual concentration + maximum concentration Cs-137 (25 pCi/g)

This will assure that the total dose will remain below 15 mrem/yr. If additional radionuclides are found, a similar analysis will be performed to establish maximum concentrations for disposal.

CTS Diapooal Appln Mar95

In the unlikely event that the CTS analyses show any fission or activation product present in excess of the individual limiting concentrations or the sum-of-the-fractions limitation, the material will be held for decay before it is disposed onsite or it will be disposed of by other means, such as burial in a licensed low-level waste disposal facility.

D. Sediment Removal As explained in Section III.A above, sediment collects both in the basins and in the water distribution troughs on the tower decks. The cooling tower basins are only cleaned during outages after the towers have been dewatered. The method of removal from the tower decks is partially determined by the plant operating status. When the plant is shut down and water is not circulating ovet the towers, the preferred and most effective method of cleaning is to use a vacuum truck to suck the CTS up as a slurry.

If the plant is at power and the cooling towers are operating, the CTS on the tower decks can be removed with siphon hoses. In this case, rather than being collected in a truck-mounted tank, the slurry is piped to intermediate collection boxes (dumpsters).

Whether removal is by vacuum truck or by siphon hoses, the bulk of the water is removed by decanting to the tower basins.

E. Sediment Disposal As needed, unlined earthen disposal cells will be constructed in the designated area (Section II.A). Figure 5 is a typical plan and cross-sectional view of a disposal cell.

Lateral dimensions of individual cells will vary. Prior to construction, background/ambient radiation measurements will be acquired with pressurized ionization chamber readings. These measurements will provide a baseline of environmental measurements for the disposal site and allow trending of environmental radiation levels as the sediment material is disposed.

The wet CTS material will be transported to the disposal area (via vacuum truck, front-end loader, dump truck, or other method) and deposited in a disposal cell.

Subsequent batches will be deposited on top of or adjacent to previous deposits. Each cell will be used as a CTS receptacle until the level approaches the top of the berm.

It is estimated that approximately 20,000 gallons of water will be disposed with the sediment for each six-tower cleaning evolution. The wet sediment tends to dry to a consolidated mud-cake surface that has a low susceptibility to wind erosion.

Therefore, no cover material is anticipated to be needed. Local sand will be placed over the material if erosion becomes a concern.

After each cleaning episode, sediment samples will be collected from the surface layers of recently deposited material. A dried composite will be analyzed to confirm that the disposal criteria (Section IV.C, above) were not exceeded. If these results indicate an exceedance, a comprehensive sampling plan for the disposal cell will be prepared and implemented. Concurrently, EFSEC and the Department of Health will CTS Diapoaal Appln Mar95

be consulted for appropriate follow-up, including CTS removal and off-site disposal.

F. Environmental Monitoring The Chemistry Department will monitor the disposal area as part of the Radiological Environmental Monitoring Program (REMP). This monitoring will permit measurement of any significant contribution to radiation levels at the disposal site from materials deposited in the ground. Major elements of the environmental radiation monitoring program for the site include: 1) baseline measurements of direct radiation levels in the disposal area (discussed in Section IV.E); 2) operational monitoring of the site utilizing thermoluminescent dosimeters (TLDs) and periodic pressurized ion chamber (PIC) measurements of radiation levels; and 3) post-closure environmental radiation surveys of the site in preparation for decommissioning.

G. Disposal Area Control As explained in Section ILC, the CTS disposal area is within a fenced industrial area of very low traffic. The immediate area is not occupied by workers except during CTS disposal. The Supply System's.Facilities Maintenance organization controls the gate key and requires that each entry to the area be *logged. The comers of the disposal site will be marked with posts and signs will be erected indicating the dedicated purpose of the area. Because the area does not have through-traffic and because no hazards would be associated with unauthorized entry, additional controls (e.g., immediate area fence) are not necessary.

H. Disposal Site Closure It is anticipated that the disposal operation will continue for the operating life of WNP-2. Disposition of the CTS at the end of plant life will depend on the requirements of agencies such as the Nuclear Regulatory Commission (NRC), the Washington Department of Ecology (WDOE), and Washington Department of Health (WDOH). The NRC will establish plant decommissioning criteria which will likely require assessment of all contaminated areas of the site. As explained in Section IV.C, the Supply System anticipates that the CTS will conform to decommissioning criteria and will not require exhumation and removal. Because it is intended that the disposal site be operated within NRC and WDOH radiation criteria for decommissioning, there should be no need for institutional controls to limit access by "intruders." Neither should there be a need for remediation of radiological conditions at the site at the time of closure.

The Supply System will evaluate the WDOE's regulations for solid waste (i.e., WAC 173-304) in effect at the time of site closure to determine the appropriate disposition.

Although the CTS could be used as cover material for the adjacent landfill, the Supply System's preference is to leave the material in place. As discussed in Section IV.E, a disposal site cover is not planned. If, as contemplated, the material is to be left in crs Di1poaal Appia Mar9S

place, some minor regrading may be required to give the area a natural appearance during the site restoration phase.

I. Procedures to Minimize Upsets and Hazardous Exposures As shown in Appendix B and discussed in Section V below, the concentration of radioactive materials are so low that there is little potential for hazardous exposures.

Should an unanticipated condition arise, however, the Supply System has the radiation protection program and resources to respond. Elements of the program are discussed below.

The Supply System is. committed to maintaining occupational and public radiation exposures as far below regulatory dose limits as is practicable while performing all activities related to the operation of WNP-2. This commitment is reflected in a Radiation Protection Program that meets the requirements of 10 CPR Part 20 and provides for effective control of radiation exposure through:

Management direction and support;

Establishment of radiation control procedures;

Consideration during design and modification of facilities and equipment; and

Development of good radiation control practices, including preplanning and the proper use of appropriate equipment by qualified, well trained personnel.

The lladiation Protection Manager (RPM) is responsible for implementing the Radiation Protection Program. The Radiation Protection Manager reports to the Plant General Manager and has the responsibility and authority for ensuring that plant activities meet applicable radiation safety regulations and Radiation Protection Program requirements. This includes the responsibility for ensuring that radiation exposures are ALARA.

Supervisors that report to the RPM implement the Radiation Protection Program through direct supervision of the plant health physics technicians. Areas of responsibility include: characterization of plant radiological conditions; maintenance of radiological postings; maintenance of radiation exposure records; and detecting and evaluating radiological problems.

The Plant Health Physics Technicians provide a staff of competent personnel whose primary responsibilities are to provide radiological services and support for plant personnel and maintain radiological surveillance.

The Chemistry Department is responsible for monitoring the area for environmental radiation via the Radiological Environmental Monitoring Program (REMP). The REMP for WNP-2 provides for measurements of radiation and radioactive materials in exposure pathways and for those radionuclides for which the highest potential dose commitment to a member of the public would result due to plant operations.

CTS Dispoaal Appln Mac 9S

Environmental samples are collected in accordance with the provisions of the REMP.

The program specifies the environmental sampling plan by sample type, sample location code, sampling and collection frequency, and type and frequency of analysis of samples collected within a exposure pathway. Deviations from the sampling frequency detailed in the plan may occur due to circumstances such as hazardous conditions, malfunction of automatic sampling equipment, seasonal unavailability, or other legitimate reasons. When sample media is unobtainable due to equipment malfunction, special actions per program instruction are taken to ensure that corrective action is implemented prior to the end of the next sampling period. In some cases, alternate sample collection may be substituted for the missing specimen.

All individuals performing Supply System related activities at WNP-2 are required to follow the rules and procedures established for radiological protection and exposure minimii.ation. Each individual is responsible for ensuring radiation safety. The commitment to ALARA is implemented by employee training; audits, assessments, and reviews of the program; procedure development and reviews; enforcement of rules; and modifications to plant equipment or facilities where they will substantially reduce exposures at a reasonable cost.

In the unlikely event of an upset resulting in the release of contaminated water to the circulating water system, instrumentation and administrative controls provide for early detection and response. Contamination of the cooling tower system at levels that would produce hazardous exposures is an extremely remote possibility. However, if a significant level of contamination were to occur, it would be identified by sampling of the sediment before tower cleaning (Section IV .B) or after placement in the disposal cell (Section IV .E). Once identified, appropriate signs, barriers, and access controls would be established by plant procedure to prevent inadvertent exposures of employees or members of the public. A revised disposal plan could then be developed in consultation with the State.

Additional assurance that contaminated sediments (or other abnormal radiological conditions) are identified is provided by routine independent measurements conducted by the REMP (Section IV.F). Protection from inadvertent exposures is also enhanced by the remote location, controlled access, and infrequent occupation of the storage area. During normal operations, the concentration of radioactive materials in the disposal cells is so low that there is little potential for a hazardous exposure to a member of the public.

J. Records and Reports Records pertaining to the disposal site operation are maintained in a retrievable file.

No routine reports specific to the disposal operation are anticipated. Environmental monitoring results will be summarized in the annual REMP report.

CTS Dispollll Appia Mar9.5

V. Radiological Impact Evaluation A. Exposure Considerations Possible pathways for radiological exposure include: (1) external exposure from standing on the ground above the disposal site; (2) internal exposure from inhalation of suspended radionuclides; (3) internal exposure from the ingestion of food grown on the disposal site; and (4) internal exposure from drinking potentially contaminated groundwater.

An internal exposure resulting from ingestion of food grown on the disposal site is not considered a realistic possibility. The Supply System controls activities within a 1.2-mile radius of WNP-2. No food crops are grown in the site area and food crop production is not anticipated in the future.

Inhalation of resuspended radionuclides is not considered a significant exposure pathway. Calculations performed utilizing the RESRAD program (Ref.* D) indicate that a person would receive less than 0.001 mrem/yr from CTS inhalation even if each of the primary radionuclides were at the maximum proposed disposal concentrations (Section IV.C, above). Results of the inhalation dose calculation are shown in Figure 7.

An internal exposure due to consumption of groundwater is not considered plausible.

There are no wells drawing from the unconfined aquifer downgradient of the disposal site. The primary source of drinking water for the WNP-2 site is the Columbia River.

There is a backup water supply well on the WNP-2 site. The well is about 2100 ft north of the disposal location and, at a depth of 695 ft, draws from the confined aquifer. There are also two wells in use at the Supply System's WNP-I site about 7000 feet east, however, these wells are about 465 ft deep and, based on the stratigraphy and water quality data, appear to draw from a semi-confined aquifer in the Ringold conglomerates and the upper fractured basalt flow. While future groundwater withdrawals are possible, usage for human and animal consumption will be limited by the existing tritium contamination ( > 20,000 pCi/1) resulting from previous Hanford Site operations (Ref. E).

The dose assessment is based on an external exposure to an individual working or standing on the disposal cell. With the assumptions discussed below, this individual is referred to as the maximally exposed individual (MEI).

B. Assumptions

The only significant environmental pathway for delivering radiation dose to the MEI is direct radiation from the waste material in the soil.

The exposure duration is assumed to be 2000 hours0.0231 days 0.556 hours 0.00331 weeks 7.61e-4 months per year.

CTS Diopooal Appln

- IO - Mar95

Source terms are individual nuclides at a concentration of 5 pCi/g at time of deposition. Each deposited layer is corrected for decay from date of deposition until facility closure.

The annual integrated dose considers decay of deposited radionuclides during prior years of deposition. The most recently deposited material is assumed to be on top, with older material at progressively deeper locations.

The total quantity of deposited sediment is assumed to be 1800 cubic yards (30 years of disposal at the rate of 60 cubic yards per year). (Materials disposed to date were not included in the calculation because the contribution to dose was judged to be insignificant. The calculation was stopped at a maximum deposited material age of 10 years since older material did not add significantly to the dose.)

The dimensions of the deposited material were assumed to be 15 meters radius by 2 meters deep. This is approximately 1800 cubic yards. A cylindrical geometry maximizes dose per unit volume. This geometry was chosen for dose calculations only and does not represent the actual disposal geometry.

The density of the CTS is assumed to be 1.5 g/cm3 *

For calculating effective dose equivalent (EDE), isotropic geometry is assumed.

C. Method of Calculation Exposure rates at one meter above the ground surface and effective dose equivalent (EDE) rates were calculated using the computer code MicroShield Version 4 (Ref. F).

Maximum disposal concentrations for each nuclide are calculated by multiplying the disposal concentration assumed in the computer analysis (5 pCi/g) by the ratio of 15 mrem/yr to the calculated dose rate associated with a concentration of 5 pCi/g. For example, the calculated Mn-54 annual dose rate was 2.5 mrem/yr due to the assumed disposal concentration of 5 pCi/g. The maximum disposal concentration is calculated as follows:

[(15 mrem/yr) + (2.5 mrem/yr)] x [5 pCi/g) = 30 pCi/g D. Results Results of the dose calculations are shown in Table 2 below. These are more realistic results than would be produced by the RESRAD program since RESRAD does not consider a concentration gradient in the deposited material. Concentration data input to RESRAD was adjusted to produce an assumed realistic plot of ground shine dose rate vs time beginning one year after cessation of plant operation (Figure 6).

CTS Diapoaal Appln Mar95

Table 2. Calculated (via Ref. F) Dose Rates from CTS Disposal Exposure EDE Rate Half Annual EDE . Maximum Rate at at Life Rate at Disposal 5 pCi/g 5 pCi/g (yr) 5 pCi/g Concentration Nuclide (µR/hr) (µrem/hr) (mrem/yr) (pCi/g)

Mn-54 2.8 1.8 0.86 2.5 30 Co-60 11.7 7.7 5.27 14.4 5 Zn-65 1.7 1.1 0.67 1.4 50 Cs-134 6.4 4.0 2.06 6.8 10 Cs-137 2.5 1.5 30.17 3.0 25 A realistic calculation was performed utilizing the computer code RESRAD Version 5.19 (Ref. D) with disposal concentrations apportioned to_produce arbitrarily equal yearly dose rates beginning one year after cessation of plant operation. The results of the RESRAD calculation are shown in Figure 6. The RESRAD calculation projects the dose for many years into the future, beginning one year after cessation of plant operations.

RESRAD was also used to perform a calculation of the Inhalation Exposure Pathway dose with all nuclides at the maximum disposal concentrations. This is quite conservative because the disposal concentrations would be apportioned, as discussed in Section IV. C, so that the sum of the fractions of maximum concentration for each nuclide would not exceed unity. The results of the inhalation. pathway dose calculation are shown in Figure 7, below.

E. Discussion of Results As shown in Table 2, and Figures 6 and 7, the projected effective dose equivalent rates are within the proposed NRC criterion of 15 mrem/yr total effective dose equivalent (TEDE) to an average member of a critical group (Ref. G). Realistically, doses will be much lower since not all disposed material will be at the maximum concentrations and the actual disposal geometry will not be cylindrical.

If additional radionuclides are detected in significant concentrations in the CTS, maximum disposal concentrations will be calculated using methods similar to those described in this application. The actual limit on disposal concentrations will be such that the sum of the fractions of maximum concentration for each nuclide does not exceed unity.

CTS Diopoaal Appln Mar95

V. References A. WNP-2 Final Safety Analysis Report, prepared by Washington Public Power Supply System in 1978 with annual updates.

B. U.S. Nuclear Regulatory Commission, "Quality Assurance for Radiological Environmental Monitoring Program," Assessment Branch Technical Position Revision 1, November 1979 C. WNP-2 Offsite Dose Calculation Manual prepared by Washington Public Power Supply System.

D. Manual for Implementing the Residual Radioactive Material Guidelines Using RESRAD, Version 5.0, Working Draft for Comment, Environmental Assessment Division, Argonne National Laboratory, Rept. No. ANL/EAD/LD-2, September 1993.

E. Hanford Site Environmental Report for Calendar Year 1993, Battelle Pacific Northwest Laboratory, Rept. No. PNL-9823, June 1994.

F. MicroShield Version 4 User's Manual, Grove Engineering, Inc., Rockville, MD, 1992.

G. U.S. Nuclear Regulatory Commission, Proposed Revision of 10 CFR Part 20 Re:

Radiological Criteria for Decommissioning, Fed, Reg" Vol. 59, No. 161, P. 43200, August 22, 1994.

CTS Disposal Appln Mar95

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NORMAL OPERATiNG WATER LEVEL CK t.PRECAST OOVERS /Pf!ECAST CIRCUMFERENTIAL Pl.NELS ACB SPLASH BARS IN "IONCOMBUSTIBLE GRP SUPPORT GRIDS

&\SIN 1'\.000 *El.£v. 4440:----==it::1 rof> OF~ El.£V, 4480

~ 'WEIR ELEV.447.!I 7 NORMAL OPERATING Hfl!IHEO GRADE ELEV 444.0' :ei~,t~ll~t.

..........._,i...c;;;-~EL~439:o*,*;:z ~ , : - =-, ~-

. ~-

,,.,.<' -~ .. .,....;: .::~

~ .;._, ** :~~

.,.s,Qff T CONCRETE B A S I N -

TOWER SYMMETRICAL ABOUT Figure 4 Cooling Tower Cross-Section

7

"' /. :

.*""1"**-** .. #******-*

'f

/

PLAN VIEW APPROX ELEV 4:J!I FT MSL CROSS~SECTION (Not to Scale)

Figure 5 Typical Disposal Cell

DOSE: Ground Pathway All Isotopes Summed 20 ,----,--,--,-...,.,-,.,..,.~---.--..,_.....r-r...,....,....,.....,.---.,-......,.......,..-,....,,......_.,...,....,

15 D - Total A - Co-60

~ + - Cs-134

's Q) 10 o - Cs-137 X -

Mn-54 Zn-65 s

5 1 10 100 1000 Years CTSGND.D.AT 03/01/95 07:36 Figure 6 Calculated (via Ref. D) Ground Dose vs. Time after CTS Disposal

DOSE: Inhalation (w/ o radon) Pathway 0 _0008 .---.-----,-.-,-..,.....,....,...,.A..,..llr-Is_o_t..,..o_p_e,....s--.-S.,...u.,.m...,.,..mT"le_d_.....,.._,........,......,....,............,....

0.0006

- Total 6 - Co-:-60

~

.....,___ + - Cs-134 o - Cs-137 S 0.0004 s

X - Mn-54 Q) o - Zn-65 0.0002 10 100 1000 Years CTSINH.DAT 03/01/95 07:56 Figure 7 Calculated Inhalation Dose vs. Time after CTS Disposal

Appendix A WNP-2 Cooling Tower Sediment Metals Analyses CTS Dispoaal Appln Mar9.5

WNP-2 Cooling Tower Sediment Metals Analyses TCLP DW TCLP<c> EPA Sludge<dJ EPA Sludge<el Metals Concentrations (mg/kg, dry wt), Tota1<*>

(mg/1) Threshold Application Disposal I I Top of Disposal Disposal Disposal Disposal Concentration Limits Limits Tower Sample #1 Sample #2 Sample #3 Composite<b) (mg/I) (mg/kg) (mg/kg)

MewJ Cr 32 69 37 39 0.056 5 1200 600 Cu 940 460 540 240 NIA 1500 NIA Pb 48 50 47 40 0.11 5 300 NIA Hg 0.83

1.3 0.83 0.53 ND 0.2 17 NIA Ni 39 53 46 39 NIA 420 420 Tl 2.4 1.9 ND ND NIA NIA NIA Zn 270 330 300 230 NIA 2800 NIA others ND ND ND ND Notes: (a) Samples collected March 16, 1993. "Top of Tower" sample from cooling water distribution channel on tower deck.

"Disposal Samples" from sediment previously placed in landfill area. Analyses by Pacific Environmental Laboratory, Inc.

(b) Composite of Disposal Samples 1, 2, & 3. Analysis via TCLP (EPA Method 1311).

(c) Dangerous waste designation thresholds from WAC 173-303-090(8).

(d) Sewage sludge pollutant limits for land application from 40 CPR 503.13.

(e) Sewage sludge pollutant limits for surface disposal from 40 CPR 503.23._

ND = Not Detected; NI A = Not Applicable

Appendix B Cooling Tower Sediment Sample Results CTS Diapoul Appln Mu-95

APPENDIX B1 : CTS WET SAMPLE ANALYSES RESULTS 4.4E-08 17.2 9.5E-06 1.9 3.9E-07 4.B 01 -Dec-94 94 03 3 .0E -08 22 .6 1.BE-07 9.6 11 -Nov-94 94 20 2.7E-08 2B .4 4.6E-06 2.9 1.5E-07 10.9 04-Nov-94 94 12 4.1E-08 19.8 4.7E-06 2.9 UE-07 10.9 28-0cl-94 94 57 2 .9E-08 24.5 4.3E-06 3.2 7.2E-08 17.5 14-0ct-94 94 18 4.0E *OB 18.4 1.1E-07 8.9 5.6E-06 2.6 1.6E-07 7.3 28-Sep-94 94-09-19 3.0E -08 26.1 4.BE-06 2.8 1.2E-07 9.9 30-Aug-94 94-06-26 1.3E-08 47.B 3 9E-OB 31 .3 5.4E-06 3.2 1.3E-07 9.9 28-Apt-94 94 29 2.6E-08 28.8 6.0E-06 2.9 1.8E-07 10.5 28-Feb-94 94 22 3.BE-08 28.6 5.8E-06 2.9 1.9E-07 10.9 31 -Jan-94 94 *01 -28 3.3E-08 18.8 6.2E-06 2.7 1.7E-07 9.3 28-Dec-93 93-12-56 5.8E-06 3.0 2.SE-07 5,9 03-Dec-93 93-12-04 4.0E *OB 21 .8 5.5E-06 3.0 1.9E-07 9.1 19-Nov-93 93-11 -18 4.JE-06 3.2 -5.BE-08 21 .3 28-0cl-93 93- 10-28 3.2E-08 28. 1 6.0E-06 2.9 2.9E-07 5.8 03-Sep-93 93 30 2.9E-OB 26.5 5.6E-06 3.0 1.JE-07 8.9 18-May-93 93-05-10 2.3E-07 9.1 6.6E-08 36.7 1.6E-05 2.8 B.3E-07 5.2 18-May-93 93 11 1.6E-07 11 .9 1.0E-05 3.6 7.5E-07 6.0 18-May-93 93 12 1.6E-07 10.7 9.9E-08 13.9 1.4E-05 3.0 9.0E-07 4.8 16-Mar-93 93-03-24 1.9E-07 8.9 6.BE-08 16-Mar-93 93-03-25 1.6E-07 13.2 UE-07 16-Mar-93 93 26 1.6E-07 13.6 1.6E-07 16-Mar-93 93-03-27 2.3E-07 7.3 6.BE-08 3. lE-08 16-Mar-93 93-03-29 5.0E-08 29.9 28-Jan-93 93-01 -36 7.4E-08 9.2 2.3E-08 30.8 7.3E*06 2.7 2.7E-07 6.0 29-0ec-92 93*01 -02 SOE-OB 44 .6 28-0ec-92 92-12*13 4.7E-08 16.5 2.5E-OB 36.9 2B*Dec*92 93*01 -03 4.0E-08 18.7 28-Dec -92 93-01-03 4.0E-08 18.7 2,2E-08 41 .8 28-Dec-92 93-01 -04 4.SE-08 29. 1 30 Nov-92 92-12-01 2.9E-08 23.0 2.5E-08 36.9 30*0c1*92 92-10-22 2.3E-08 31 .5 4.2E-08 27.7 l .4E-OB 50.3 02-0cl-92 92-10-08 2.0E-08 30 .1 1.9E-0B 29.8 07-Apr-92 92-04 -02 1.2E-07 7.9 6.6E-08 14.B 28-Feb-92 92-03-13 9.0E-08 9.0 B.2E-OB 13,8 04-Feb-92 92-02 *01 1.lE-07 10.0 1.8E-07 8.1 03-Jan-92 92-0\ -02 9 BE-OB 9.7 5.lE-08 19.5

APPENDIX 81: CTS WET SAMPLE ANALYSES RESULTS (CONT'D) 03-0ct-91 91 02 1.2E-07 9.1 28-Aug -91 91-08-10 1.1E-07 7.7 1.SE-07 7.8 1.9E-08 76.96 (<CL) 22-Apr-91 91-04-12 2 .6E-07 4.1 1.8E-07 7.7 02-Ap(-91 91-04 -01 1.6E-07 7.2 01 -Mar-91 91 01 1.4E-07 6 .9 3.9E*08 20,6 29-Jan-91 91-01-11 1.2E -07 6.6 2.1E-oa 38.9 15-Jan-91 91 *01-05 1.3E-07 7.6 03-0ec-90 90-12-01 1.0E-07 8.4 2.4E-08 28.3 30-0ct-90 90-10-19 1.2E-07 7.6 5. 1E-07 3.4 5.4E-08 40.0 28-Sep-90 90-09-17 20E -07 7.1 29-Aug -90 90-08*28 1.5E-07 4.5 1.4E-07 5.5 1.0E-08 45.8 1.8E-08 ~ .3 29-Aug*90 90*09-01 1.5E-07 7.3 01-Aug -90 90-08-01 1.9E-07 4.1 22-Jun-90 90-06-11 5.4E-07 4.9 2.3E-07 1.lE-08 02-Mar-90 90-03-01 3.BE*0B 40.1 02-Feb-90 90-02-04 9.9E-08 6.3 7.8E-08 7.5 02-Jan-90 90-01-01 1.2E-07 7.3 9. E-08 10.7 2.3E-08 51.9 01-0ec-89 89-12-01 8.GE-08 6.0 B.9E-08 8.1 2.0E-08 40.5 2.SE-08 20.5 27-Oct-89 89-10-25 6.2E-08 10.1 6.9E-08 1.3E-08 3.2E*08 30-Aug-89 89-08-33 1.1E-07 7.5 6.8E-08 11 .3 9.4E-08 34 .9 3.2E-OB 26.3 28-Jul-89 89-07-12 3.2E*0B 12.1 10-Jul-89 89-07-03 1.2E-07 6.2 9.9E-08 8.2 8.9E-09 30.8 4.7E-08 38.2 4.6E-08 20.7 24 -May-89 89-05-25 1.4E-06 2.7 5.3E-07 10.1 1.2E-07 21 .9 1.SE-07 43.0 2.9E-07 12.0 24 -May-89 89-05-26 1.4E*06 2,9 6.BE-07 7.1 1.4E-07 17.4 9.9E-08 69.8 2.BE-07 13.2 30-Apt-89 89-05-02 1.3E-07 6,3 l.3E-08 13.0 4.4E-08 32.4 1.1E-07 7.1 JO-Mat-89 89-03-30 2.SE-07 6,6 04 -Jan-89 89-01*03 1. lE-07 7.1 3.2E-08 19.8 2.1E-07 7.7 29-Nov-88 88*11-40 7.9E-08 10.3 1.2E-07 7.6 1. lE-07 16.3 04 -Nov-88 88-11 -06 4.7E-07 12.5 7.4E-07 8.9 8.2E-08 13.0 30-Sep-68 88-09-52 7.SE-08 8.6 7.8E*08 10.3 1.JE-08 39.,5 29 -Sep -88 88-09-46 3.1E-07 2.9 4.0E-07 7.0E-08 1.5E-07 1.2E-07 29-SepBB 88-09 -47 5. 1E-07 3.0 4.9E-07 7.6E*OB 1.7E-07 9.0E-08 29-Sep-88 BB 48 4. 1E -07 3.8 3.7E-07 4 .7 5.0E-08 16.7 1.4E-07 16.0 8.9E-08 13.0 29-Sep-88 88 49 4.3E -07 3.7 2.9E-o7 4.8 3. IE-08 3.2 1. 7E-07 12.7 7.3E-OB 17.2 29-Sep-88 88 50 4.2E*07 3.2 3.3E-07 4.3 4.BE-08 18.6 1.6E-07 20.1 7.8E-08 19.4 29-Sep -88 88-09-51 3. lE-07 4.4 3. tE -07 5.0 4.1E-0B 18.3 t .9E-07 10.2 7.4E-0B 17.1 26-Au *88 88-08-35 2 .9E*08 19.0 2.BE*0B 23.2

APPENDIX B1: CTS WET SAMPLE ANALYSES RESULTS (CONT'D)

ep-31 -Jul-87 87-07-25 1.6E-07 5.2 2.JE-07 4,4 8.9E-08 7.6 2.4E-07 5.8 9.2E-08 6.5 3.0E-08 16.0 1. E-07 35.3 03-Apr-87 87-04-02 6,6E-08 9.5 1.7E-08 22.8 03-Mar-87 87-03-01 1.4E-07 3.6 . 5E-08 16.2 3.1E-08 14.8 27-Jan-87 87-01-15 1. 1E-07 6.0 4.1E*08 17.7 5.2E-09 86.3 2.3E-06 17.5 30-0ec-86 86-12-18 1.6E-07 4.2 1.6E-07 5.9 4.2E-08 10.0 19-Nov-86 86-11-19 7.6E-08 8.7 3.4E-08 21. 2.6E-08 22.1 26-Sep-86 86-09-16 1.1E-07 6.7 3.6E-08 20.6 1.0E-08 41.6 5.6E-08 65.8 15-Aug-86 86-08-02 1.6E-07 3.6 2.1E-08 22.1 5.8E,08 6.5 2.7E-08 1 .0 1.9E-07 20.6 18-Jul-86 86 14 1.8E-07 3.5 2.9E-08 22.0 2.7E-08 40.0 6.0E-08 6.1 3.4E*08 13.3 2.6E-08 66.1 18-Jul-86 86-07-15 1.1E-07 5,2 1.9E-08 26.4 2.3E-08 32.6 4.3E-08 12.0 3., 1E-08 16.2 27-Jun-86 86-06-25 6.1E-07 2.0 1.4E-07 8.3 UE-08 54 .3 1.0E-07 14.2 1.2E-08 46:1 2.1E-o7 3.5 9.7E-08 7.5 1.8E-07 32.3 27-Jun-86 86-06-26 5.8E-07 2.1 1.1E-07 8.5 2.0E-08 31.7 1.lE-07 12.3 2.4E-08 27.0 2.2E-07 3.4 8.3E-08 10.0 20-Mar-86 86-03-12 UE-07 5.0 1.2E-07 9.0 1.7E-08 38 .9 5.7E-08 22.8 7.5E-09 45.3 20-Mar-86 86-03-13 1.5E-07 5.5 1.5E-07 6.4 2.6E-08 23.0 3.6E-08 28.4 14-Feb-66 B6-02-03 8.7E-08 8.7 8.4E-08 9.9 1.6E-08 28.5 16-Jan -86 86-01 -16 1.1E-07 6.9 1.5E-07 5.2 7.8E-09 62.1 1.3E-o7 8.3 7.0E-08 8 .0 16-Jan-86 B6-01 -17 9.8E-08 5.9 4.5E-08 13.5 4.3E -09 86.0 1B-Oec-85 85-9356 1.7E-07 4.4 1.5E-07 6.7 B.SE-09 64.2 4.5E-08 21 .1 2.2E-08 19.4 6.SE-06 2.1 UE-06 9.2 01-Nov-85 85- 11 -03 2.5E-08 17.0 18-0c1-85 85- 10-32 1 - E -07 3.9 9.6E-08 6.0 1.6E-08 22 .6 18-0ct-85 85-10-33 8.SE-08 6.7 5.7E-08 8.6 1.7E-08 18.5 18-0ct-85 B5-10-34 3.4E-07 2.1 1.2E-07 5.0 7.7E-09 42.9 18-0ct-85 85-10-35 2.2E-07 3.2 9.1E-08 7.0 17-0ct-85 85-10-31 1.5E-07 3.5 7.8E-08 7.6 2.0E-08 16.7 16-0cl-85 85-10-24 1.4E-07 4.3 1.2E-07 5. 1 3.1E-08 12.3 03-0cl-85 85-10-04 1.2E-07 5.2 9.8E-08 7.5 20-Sep-85 85-09-31 1.5E-07 4.3 8.7E-08 6.9 1.3E-08 23.6 05-Sep-85 85-09-02 2 4E-07 2.4 9.6E-08 5.4 2.0E-08 18.5 05-Sep-85 85-09-02 2.2E -07 13.7 04-Sep-85 85-09-03 6. 1E-o8 17.9 04 -Sep-85 B5-09 -03 1.9E-08 22.9 30-Aug-85 B5-08-49 2.5E-07 2.4 1. lE-07 5.4 2.2E-08 16.5 29-Aug-85 85-08-41 1.2E*07 3.7 6.8E *08 6.7 l .3E-08 21 .9 28-Aug-85 85-08-35 7.3E-OB 6.9 8.0E-08 6.1 1.SE-08 22.1 28-Aug-85 85-08-36 3.5E-07 1.8 1.1E*07 5.3 2.9E-08 10.4 28-Aug-85 85-08-37 1.2E-07 20.3 22-Aug-B5 l .9E -07 10.8 OI -Aug-85 J.7E-07 1.9 1.3E-07 4, 4 2.6E-08 13.2 6.7E-06 1.5 14-Jun-85 9.0 7.3E-08 65.3 1.SE-05 5.9

APPENDIX B2: CTS DAY SAMPLE ANALYSES RESULTS ay-06-May-94 52502 l.6E-07 17.7 1.0E-05 4.9 2.6E-06 21.6 06-May-94 52503 3 .0E-07 5.9 1.6E-07 10.1 1.3E-05 2.9 2.8E-06 10.9 29-Sep-93 27932 2.3E-07 3.4 t.6E*07 5.4 1.2E-05 1.5 2. lE-06 6.1 07-Jun-93 16051 l.4E-07 3.6 1.2E-07 5.0 9.SE-09 35.0 9.8E-06 1.3 1.6E-06 6.1 16-Mar-93 07735 3 2E-07 26 1.9E-07 4.9 1.2E-05 1.6 2.1E-06 6,6 16-Mar-93 07736 3.4E-07 3.4 2.0E-07 6.6 1.IE-05 2.1 2.2E-06 7.6 16-Mar-93 07737 4.JE-07 3.1 1.BE-07 6.0 1.2E*OS 1.8 1.7E*06 8.7 16-Mat-93 07738 6.BE-07 2.6 2.7E-07 5.8 1.4E-07 8.7 2.7E-05 1.3 4.1E-06 6.0 16-Mar-93 07739 3.0E-07 5.0 4.0E-07 4.3 1.2E--05 2.2 2.0E-06 10.6 16-Mar-93 07741 4.1 1.8E-06 2.0 l.tiE-05 2. 1 3,2E-06 7.9 tti -Mar-93 WDOH-CT 6.0 3.5E-06 1.4 2.4E-07 15.0 1.2E-05 58.3 WDOH -l f 5.2 I .SE-07 6.7 69-05-09 3.3 4.7 3 .4E-08 18.7 t.4E-07 13.5 1.5E-07 7.8 1.6 3.0 09 :os-10 3.1 5.2 3.4E-08 19.3 8.3E-08 20.6 1.5E-07 8,5 1.8 3.0 69-05-11 4,0 2.8E-08 24 .5 8.4E-08 14.8 1.2E-07 7.3 3.2 3.9E-07 8.8 4.7 3.9E-07 2.7E-OS 4. IE-06

SEPA ENVIRON.MENTAL CHECKLIST (from WAC 197-11-960)

A. Background

1. Name of the proposed project, if applicable:

Onsite Disposal of Cooling Tower Sediments

2. Name of applicant:

Washington Public Power Supply System

3. Address and phone number of applicant and contact person:

W.A. Kiel (Mail Drop PE20)

Washington Public Power Supply System P.O. Box 968 Richland, Washington 99352-0968 Telephone Nwnber: 509-377-4490

4. Date checklist prepared:

March 1, 1995

5. Agency requesting checklist:

Energy Facility Site Evaluation Council (EFSEC)

6. Proposed timing or schedule (including phasing, if applicable):

Onsite disposal of cooling tower sediment is scheduled to commence on about May 1, 1995 during the annual refueling and maintenance outage for the Supply System's Nuclear Plant No. 2 (WNP-2). Sediment will be removed from the towers and disposed on a periodic basis (approximately one to three times per year) throughout the life of the plant.

7. Do you have any plans for future additions, expansion, or further activity related to or connected with this proposal? If yes, explain.

Not at this time. Sediment will be removed from the towers on a periodic basis for the life of the plant. Although the designated disposal area (see Item A.11, below) is judged sufficient for the life of the plant, the area will be expanded if necessary.

Pagel

Cooling Tower Sediment Disposal

8. List any environmental information you know about that has been prepared, or will be prepared, directly related to this proposal.

Specific infonnation is included in the application to EFSEC prepared in accordance with WAC 246-221-180. Extensive documentation regarding the general site area was prepared pursuant to NEPA and SEPA to support decisions to construct WNP-2.

9. Do you know whether applications are pending for governmental approvals of other proposals directly affecting the property covered by the proposal? If yes, explain.

None. The proposed disposal location is within the WNP-2 exclusion area.

10. List any government approvals or permits that will be needed for your proposal, if known.

The disposal of low-level radioactive waste in Agreement States (per Section 274(b) of the Atomic Energy Act) such as Washington is authorized and regulated by the state. The existing Site Certification Agreement and the powers vested in EFSEC preempt the need for additional pennits from other jurisdictions (RCW 80.50.110 and RCW 80.50.120). EFSEC is expected to evaluate this proposal for confonnance with the guidance provided in WAC 246-221-180 and consult with knowledgeable state agencies prior to granting approval.

11. Give brief, complete description of your proposal, including the proposed uses and the size of the project and site. There are several questions later in this checklist that ask you to describe certain aspects of your proposal. You do not need to repeat those answers on this page. (Lead agencies may modify the form to include additional specific information on project description.)

The Washington Public Power Supply System is proposing onsite disposal of sediment cleanedfrom the WNP-2 cooling towers. Analyses have shown that this material often contains radionuclides at concentrations in excess of the level of detection for environmental measurements. This measurable contamination likely comes from the river makeup water and the air drawn into the towers (whether from suspended dust, fallout, or plant releases) and is concentrated through cooling tower operation. Under the current regulatory framework this sediment must be managed as low-level radioactive waste. Given the nature of the material and its very low radioactive contamination, the Supply System has detennined that onsite disposal is most appropriate.

If approved, the Supply System will place sediments cleaned from the cooling towers in a series of unlined earthen benned cells. These cells will be constructed within a 120 x 300 foot area located in an inactive borrow pit immediately south of the cooling towers. The cell berms will be 6 feet or less in height. Sediments removed from the towers will be dewatered to the extent practicable before being placed in the disposal cells. Access to the area will be controlled by fencing.

Pagel

SEPA Checklist

12. Location of the proposal. Give sufficient information for a person to understand the precise location of your proposed project, including a street address, if any, and section, township, and range, if known. If a proposal would occur over a range of area, provide the range boundaries of the site(s). Provide a legal description, site plan, vicinity map, and topographic map, if reasonably available.

While you should submit any plans required by the agency, you are not required to duplicate maps or detailed plans submitted with any permit applications related to this checklist.

The disposal cells will be constrncted within a 120 x 300 foot area immediately south of the WNP-2 cooling towers in an inactive borrow pit. This area is located approximately 12 miles north of Richland, Washington near the center of Section 5, Township 11 North, Range 28 East in Benton County. The location is indicated on figures included in the application submitted to EFSEC.

B. ENVIRONMENTAL ELEMENTS

1. Earth

a. General description of the site:

The proposed disposal cells will be located in an inactive borrow pit immediately south of the cooling towers at WNP-2. The pit has an irregular profile with a maximum depth of approximately 15 feet below the finished grade of the cooling tower area. To the west of the proposed site the borrow pit has been used as a constrnction landfill.

b. What is the steepest slope on the site (approximate percent slope)?

The project is located in flat rolling terrain with gentle slopes. The proposed disposal area will be located in an inactive borrow pit along the south perimeter of the WNP-2 plant site.

c. What general types of soils are found on the site (for example, clay, sand, gravel, peat muck)? If you know the classification of agricultural soils, specify them and note any prime farmland.

The soils in the disposal area are comprised of sand, coarse sand, and some gravel. No farmland is located near the proposed disposal site.

d. Are there any indications or history of unstable soils in the immediate vicinity? If so, describe.

None.

e. Describe the purpose, type, and approximate quantities of any filling or grading proposed. Indicate source of fill.

The disposal cells will be constrncted using local earth materials found within PageJ

CooliJll Tower Sedimeot Disposal the boundaries of the existing borrow pit. No construction fill will be necessary. Some grading and placement of gravel may be necessary to improve the existing roadways. The wet sediment quantity that will be deposited in the area is conservatively estimated to be 60 cubic yards per year. This will be an earth fill to the area. The proposed disposal location was, in part, selected to prevent disruption of previously undisturbed areas.

f. Could erosion occur as a result of clearing, construction, or use? If so, generally describe.

Limited wind erosion and fugitive dust is likely during movement of heavy equipment during construction of the cells. Wind erosion after placement of the cooling tower sediment is not expected because of its tendency to dry as mud-cake.

g. About what percent of the site will be covered with impervious surfaces after project (for example, asphalt or buildings)?

None.

h. Proposed measures to reduce or control erosion, or other impacts to the earth, if any:

Gravel may be placed to improve roads and reduce fugitive dust during operation.

2. Air

a. What types of emissions to the air would result from the proposal (i.e., dust, automobile, odors, industrial wood smoke) during construction and when the project is completed? If any, generally describe and give approximate quantities if known.

Limited wind erosion and fugitive dust is likely during movement of heavy equipment during construction of the cells. Wind erosion after placement of the cooling tower sediment is not expected because of its tendency to dry as mud-cake.

b. Are there any off-site sources of emissions or odor that may affect your proposal?

No.

Page4

SEPA Checklist

c. Proposed measures to reduce or control emissions or other impacts to air, if any:

Temporary measures such as water application may be necessary to control fugitive du.st during construction. Gravel may be placed to improve roads and reduce fugitive du.st during operation.

3. Water

a. Surface:

1) Is there any surface water body on or in the immediate vicinity of the site (including year-round and seasonal streams, saltwater, lakes, ponds, wetlands)? If yes, describe type and provide names. If appropriate, state what stream or river it flows into.

There are no suiface water bodies in the immediate vicinity of the site.

The Columbia River is located more than three miles east of the site.

2) Will the project require any work over, in, or adjacent to (within 200 feet) the described waters? If yes, please describe and attach available plans.

No.

3) Estimate the amount of fill and dredge material that would be placed in or removed from surface water or wetlands and indicate the area of the site that would be affected. Indicate the source of fill material.

None.

4) Will the proposal require surface water withdrawals or diversions? Give general description, purpose, and approximate quantities if known.

No.

5) Does the proposal lie within a 100-year floodplain? If so, note location on the site plan.

No.

6) Does the proposal involve any discharges of waste materials to surface waters? If so, describe the type of waste and anticipated volume of discharge.

No.

Page5

Cooling Tower Sediment Disposal

b. Ground:

1) Will groundwater be withdrawn, or will water be discharged to groundwater?

The proposed activity may result in periodic discharges to groundwater.

The sediments placed in the disposal cells will be saturated with water that will either evaporate or infiltrate the soil beneath the cell or evaporate.

During tower cleaning operation (one to three times a year) the active disposal cell may receive enough water to infiltrate as far as the groundwater table located approximately 55 feet below the ground suiface at the disposal location.

2) Describe waste materials that will be discharged into the ground from septic waste tanks or other sources, if any (for example domestic sewage; industrial, containing the following chemicals ... ; agricultural; etc.).

Describe the general size of the system, the number of such systems, the number of houses to be served (if applicable), or the number of animals or humans the system(s) are expected to serve.

The cooling tower sediment is about 10 - 25 percent by weight biologic material,* the rest is silt and sand. Analyses have shown that this material often contains metals as well as radionuclides at concentrations in excess of the level of detection for environmental measurements.

c. Water Runoff (including storm water):

1) Describe the source of runoff (including storm water) and methods of collection and disposal, if any (include quantities, if known). Where will this water flow? Will this water flow into other waters? If so, describe.

None. The climate at the disposal site is characterized as mid-latitude semiarid. The area is subject to low humidities, large diurnal and annual ranges of temperatures, and modest precipitation averaging 6 to 7 inches annually and occurring mostly as rain in the winter and spring months.

2) Could waste materials enter ground or surface waters? If so, generally describe.

No. Analysis and experience at WNP-2 leads to the conclusion that the groundwater (there are no surface waters) will not be contaminated by the onsite disposal of cooling tower sediments. Although analysis has shown that the cooling tower sediments often contain metals or radioactive elements above environmental detection levels, neither is expected to be carried to the groundwater.

Standard tests (per WAC 173-303 for solid waste designation) have shown that the sediment will not produce a potentially hazardous leachate.

Page6

SEPA Checklist Based on investigations at a stonnwater pond northeast of WNP-2, the radioactive contaminants will likely remain within the cooling tower sediments or be retained within the soils immediately below the disposal cells. Additional protection of the groundwater is provided by the i,ifrequent addition of water to the disposal cells and the adsorptive properties of the soil column between the cell and the groundwater.

d. Proposed measures to reduce or control surface, ground, and runoff water impacts, if any:

To the extent practicable, efforts will be made to reduce the water content of the sediments prior to placement.

4. Plants

a. Check the types of vegetation found on the site:

_ deciduous tree: alder, maple, aspen, other

_ evergreen tree: fir, cedar, pine, other

_x_ shrubs

.1L grass pasture crop or grain wet soil plants water plants other types of vegetation

b. What kind and amount of vegetation will be removed or altered?

Vegetation removal will be minor. The area, being a fonner earth borrow pit, is largely devoid of vegetation.

c. List threatened or endangered species known to be on or near the site.

No federally listed threatened or endangered plant species are on or near the project site.

d. Proposed landscaping, use of native plants, or other measures to preserve or enhance vegetation on the site, if any:

None.

5. Animals

a. Identify any birds and animals which have been observed on or near the site or are known to be near the site:

birds: meadowlark, sparrow, quail, magpie mammals: mule deer, coyote, jackrabbit, pocket mouse Page 7

Cooling Tower Sediment Disposal fish: none - fhe site is three miles from a water body

b. List any threatened or endangered species known to be on or near the site.

No federally listed threatened or endangered birds or mammals are on or near the project site.

c. Is the site part of a migration route? If so explain.

No.

d. Proposed measures to preserve or enhance wildlife, if any:

None.

6. Energy and Natural Resources

a. What kinds of energy (electric, natural gas, oil, wood stove, solar) will be used to meet the completed project's energy needs? Describe whether it will be used for heating, manufacturing, etc.

None.

b. Would the project affect the potential use of solar energy by adjacent properties? If so generally describe.

No.

c. What kinds of energy conservation features are included in the plans of this proposal? List other proposed measures to reduce or control energy impacts, if any:

Not applicable.

7. Environmental Health

a. Are there any environmental health hazards, including exposure to toxic chemicals, risk of fire and explosion, spill, or hazardous waste, that could occur as a result of this proposal? If so, describe.

No. The proposal is to dispose of cooling tower sediment with very low levels of radioactive contamination. The projected radiological doses from this activity present no health hazard. Metal concentrations do not pose a hazard.

1) Describe special emergency services that might be required.

None.

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SEPA Checklist

2) Proposed measures to reduce or control environmental health hazards, if any:

The waste material will be sampled and analyzed prior to disposal to assure that it meets disposal criteria. The disposal site will be monitored for direct radiation.

b. Noise

1) What types of noise exist in the area which may affect your project (for example: traffic, equipment, operation, other)?

None.

2) What types and levels of noise would be created by or associated with the project on a short-term or long-term basis (for example: traffic, construction, operation, other)? Indicate what hours noise would come from the site.

No long-term noise would be created by or associated with the project.

The shon-term noise associated with disposal of cooling tower sediment would be indistinguishable from other sources of noise on the industrial site.

3) Proposed measures to reduce or control noise impacts, if any:

None.

8. Land and Shoreline Use

a. What is the current use of the site and adjacent properties?

The disposal site is an inactive borrow pit on propeny currently used for operation of a nuclear power plant (WNP-2). The location is about 2000 feet from the closest boundary for this propeny.

b. Has the site been used for agriculture? If so, describe.

No.

c. Describe any structures on the site.

None.

d. Will any structures be demolished? If so, what?

No.

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Cooling Tower Sediment Disposal

e. What is the current zoning classification of the site?

The WNP-2 site is zoned as Unclassified Use district by Benton County.

f. What is the current comprehensive plan designation of the site?

The 1985 Benton County plan designates the WNP-2 area as "Hanford Reservation. "

g. If applicable, what is the current shoreline master program designation of the site?

Not applicable.

h. Has any part of the site been classified as an "environmentally sensitive" area? If so, explain.

No.

i. Approximately how many people would reside or work in the completed project?

None.

J. Approximately how many people would the completed project displace?

None.

k. Proposed measures to avoid or reduce displacement impacts, if any:

Not applicable.

1. Proposed measures to ensure the proposal is compatible with existing and projected land uses and plans, if any:

Not applicable.

9. Housing

a. Approximately how many units would be provided, if any? Indicate whether high, middle, or low-income housing.

None.

b. Approximately how many units, if any, would be eliminated? Indicate whether high, middle, or low-income housing.

None.

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SEPA Checklist

c. Proposed measures to reduce or control housing impacts, if any:

None.

10. Aesthetics

a. What is the tallest height of any proposed structure(s), not including antennas; what is the principal exterior building material(s) proposed?

The sediment disposal cells will be constructed in a depression. The highest ponion of an i1Ulividual cell will be less than six feet above grade.

b. What views in the immediate vicinity would be altered or obstructed?

None.

c. Proposed measures to reduce or control aesthetic impacts, if any:

None.

11. Light and Glare

a. What type of light or glare will the proposal produce? What time of day would it mainly occur?

None.

b. Could light or glare from the finished project be a safety hazard or interfere with views?

No.

c. What existing off-site sources of light or glare may affect your proposal?

None.

d. Proposed measures to reduce or control light and glare impacts, if any:

None.

12. Recreation

a. What designated and informal recreational opportunities are in the immediate vicinity?

The project site is located within the exclusion area of WNP-2. The area is not used for recreating.

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Cooling Tower Sediment Disposal

b. Would the proposed project displace any existing recreational uses? If so, describe.

No.

c. Proposed measures to reduce or control impacts on recreation, including recreation opportunities to be provided by the project or applicant, if any:

None.

13. Historic and Cultural Preservation

a. Are there places or objects listed on, or proposed for, national, state, or local preservation registers known to be on or next to the site? If so, generally describe.

No.

b. Generally describe any landmarks or evidence of historic, archaeological, scientific, or cultural importance known to be on or next to the site:

None.

c. Proposed measures to reduce or control impacts, if any:

None.

14. Transportation

a. Identify public streets and highways serving the site, and describe proposed access to the existing street system. Show on site plans, if any.

WNP-2 has a paved access from Hanford Site Route 4.

b. Is the site currently served by public transit? If not, what is the approximate distance to the nearest transit stop?

The site is served by Ben Franklin Transit's commuter service.

c. How many parking spaces would the completed project have? How many would the project eliminate?

The project has no relationship to the availability of, or demand for, parking spaces on the site.

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SEPA Checklist

d. Will the proposal require any new roads or streets, or improvements to existing roads or streets, not including driveways? If so, generally describe (indicate whether public or private).

No.

e. Will the project use (or occur in the immediate vicinity of) water, rail, or air transportation? If so, generally describe.

No.

f. How many vehicular trips per day would be generated by the completed project? If known, indicate when peak volumes would occur.

None.

g. Proposed measures to reduce or control transportation impacts, if any:

None.

15. Public Services

a. Would the project result in an increased need for public services (for example: fire protection, police protection, health care, schools, other)? If so, generally describe.

No. Disposal of cooling tower sediment does not result in a demand for services.

b. Proposed measures to reduce or control direct impacts on public services, if any:

None.

16. Utilities

a. List utilities currently available at the site (electricity, natural gas, water, refuse service, telephone, sanitary sewer, septic system, etc.):

The WNP-2 site has all the facilities needed to suppon an industrial plant and the associated workforce.

b. Describe the utilities that are proposed for the project, the utility providing the service, and the general construction activities on the site or in the immediate vicinity which might be needed.

The proposal will require no utilities.

Page 13

Cooling Tower Sedimeot Disposal C. SIGNATURE The above answers are true and complete to be best of my knowledge. I understand that the lead agency is relying on them to make its decision.

Signature: JY. W. ~t:t..,,J7'r P.R8em ,:.s Date submitted: )?;~ It J'19'S" Page 14

GO2-20-104 Enclosure, Attachment 4 December 1995 Application to EFSEC for spray pond sediment

WASHINGTON PUBLIC POWER SUPPLY SYSTEM P.O. Box 968

3000 George Washington Way

Richland, Washington 99352-0968 * (509) 372-5000 December 29, 1995 002-95-291 Mr. Jason J. Zeller, Manager Energy Facility Site Evaluation Council P.O. Box 43172 Olympia, WA 98504-3172

Dear Mr. Zeller:

Subject:

SUPPLY SYSTEM NUCLEAR PLANT NO. 2 APPLICATION FOR APPROVAL OF ONSITE DISPOSAL OF VERY WW LEVEL RADIOACTIVE MATERIALS In accordance with WAC 246-221-180, the Washington Public Power Supply System requests approval of the disposal of sediment cleaned from the spray ponds at Nuclear Plant No. 2.

Analyses have shown that this material often contains radionuclides at concentrations above the level of detection for environmental measurements. Cooling system operation likely concentrates radionuclides contained in the river makeup water. Regardless of source, the current regulatory framework requires that this sediment be managed as low-level radioactive waste. Given the nature of the material and its very low radioactive contamination, we believe that onsite disposal is the most appropriate and cost-effective method of disposal. In accordance with WAC 173-304-015(8) this radioactive waste material is exempt from the minimum functional standards for solid waste handling (WAC 173-304).

Enclosed, please find an application for onsite disposal of spray pond sediment. An Environmental Checklist is also enclosed for your use. Should you require additional information, please contact W.A. Kiel at (509) 377-4490.

Sincerely,

~~t; Vice President, Nuclear Operations Enclosures cc: J. Erickson (WDOH) L.J. Callan (USNRC-RIV)

L. Albin (WDOH) NRC Sr. Res. Inspctr. (927N)

L. Russell (WDOE-Kenn)

APPLICATION FOR APPROVAL TO DISPOSE OF VERY LOW-LEVEL RADIOACTIVE MATERIAL I. Introduction In accordance with WAC 246-221-180 and NPDES permit condition S.1.Gf the Washington Public Power Supply System (Supply System) requests authorization from the State of Washington for onsite disposal of sediment containing very low concentrations of radioactive materials. This sediment results from the discharge of filter backwash (when installed) and intermittent cleaning of the spray ponds at the Supply System's .Nuclear Plant No. 2 (WNP~2). Disposal would commence whenever it becomes necessary to remove sediments from the spray ponds or following the installation of a water filtration system (not currently scheduled or funded). Disposal would occur in. an area dedicated for sediment disposal consistent with past practice. Details on the disposal location, nature of the material, proposed manner of disposal, and impact assessments are provided below.

Sedimentfrom the Standby Service Water spray ponds has been removed four times during the past 10 years of plant operation. Since the Standby Service Water System has been designed to prevent the introduction of radioactive contamination from the plant systems that it serves, these cleaning operations were conducted without regard to the radiological content of the sediment or the resulting accumulation in the disposal area. Sediment removed from the ponds during these four occasions was disposed either in a unlined trench south of the ponds or in the adjacent plant landfill.

Characterization of the chemical and radiological properties of this sediment was conducted in 1995 to support the permitting of this activity as a groundwater discharge in the WNP-2 NPDES permit (issued October 9, 1995). Analytical results indicated the presence of very low concentrations of radioactive material in the trench sediment. Identification of the source of this radioactivity has been indeterminate although activity entrained in the river makeup water is thought to be a significant contributing factor. Regardless of the source, the current regulatory framework requires that this sediment be managed by the Supply System as radioactive waste.

Disposal of this sediment as low level radioactive waste at a licensed waste disposal facility is estimated to cost approximately $80,000 per year based on an annual generation rate of 35 cubic yards per year. It is expected that this value will increase approximately $10,000 to $20,000 per year as disposal costs escalate.

Given the nature of the material and its very low radioactive contamination, the Supply System believes that onsite disposal is the most appropriate and cost-effective method of disposal. Accordingly, this application has been prepared to seek approval under the provisions of WAC 246-221-180 for the onsite disposal of spray pond sediment that contains radionuclides at concentrations above the level of detection for environmental SPS DilJ)Oaal Appln Doc 95

measurements. A similar authorization was granted by EFSEC in Resolution No. 278 for the disposal of cooling tower sediments (approved May 8, 1995).

ll. Site Description A. Location WNP-2 is located in Benton County about 12 miles north of Richland, Washington within Section 5, Township llN, Range 28B. The proposed disposal locations are within the WNP-2 controlled area on property leased from the U.S. Department of Energy. Disposal of sediment removed from the spray ponds would occur on the WNP-2 site within a former borrow pit (trench) located approximately 500 feet south of the spray ponds, or in disposal cells; constructed for cooling tower sediment (approximately-250 feet south of the cooling towers). The locations are indicated on Figure l (general site map) and Figure 2 (aerial photo). :Figure 3 shows a sketch of the cooling tower sediment disposal are.a and -Figure 4 shows a sketch of the spray pond disposal trench and sediment sampling locations.

B. Site Characteristics The elevation of the disposal areas is approximately 435 feet MSL for the cooling tower disposal cells and approximately 410 feet MSL for the spray pond discharge trench. Soil and foundation investigations conducted prior to plant construction show that the site is underlain by glaciofluvial sediments (Section 2.5.1.2.7 of Ref. A).

These sediments consist of loose-to-medium dense, fine-to-coarse sand with scattered gravel. Below approximate elevation 395 feet MSL, soils consist of very dense sandy gravel with interbedded sandy and silty layers. This zone, which is almost 200 feet thick, is known as the Ringold formation. The groundwater table is located in this formation at approximately 385 feet MSL which is about 25 feet below the ground surface at the trench and 50 feet below the disposal cells. *. Groundwater flow in this aquifer is toward the discharge boundary at the Columbia River approximately 3 1h miles to the east.

The climate at the disposal site is characterized as mid-latitude semiarid. The area is subject to low humidities, large diurnal and annual ranges of temperatures, and modest precipitation averaging 6 to 7 inches annually and occurring mostly as rain in the winter and spring months. Natural recharge of the aquifer from precipitation is negligible since the evaporation potential averages 45 inches per year. The predominant winds are from the northwest quadrant and average 71/2 miles per hour.

C. Other Potentially Affected Facilities There are no other facilities in the vicinity of the disposal site that will be affected by the proposed activity. The disposal location lies adjacent to an area used by the SPS Dispow Appln Dec 95

Supply System for disposal of construction related debris, an outdoor storage yard, and a battery maintenance building (see Figure 1). None of these areas are normally occupied.

m. Waste Description A. Source and Quantity The Standby Service Water (SSW) System at WNP.;2 removes reactor decay heat during periods of normal shutdown by providing a heat sink for the Residual Heat Removal (RHR)system and other cooling loads (see Figure 5). It also provides a heat sink for emergency* plallt equipment during and after transient and/or accident conditions. *The Standby Service Water cooling system consists of three independent pump and piping systems that utilize two large (250' x 250' x 15') interconnected concrete ponds each containing over 6 million gallons of water. Cooling is provided by water spray from 140 foot diameter spray rings located in the center of each pond.

Water from the Columbia River is used to fill the system and added to replace water lost during normal operation due to evaporation and drift. The system is equipped with an on-line monitoring system with a setpoint that corresponds to a water concentration of approximately 18 pCi/cc. The water in the system is sampled monthly with a lower limit of detection of approximately 15 pCi/1 or 0.015 pCi/ml..

The ponds, with warm water and ample sunlight, provide an environment conducive to the growth of algae and bacteria. The build-up of sediment on the bottom of the ponds from the accumulation of organic material, silt/sand from the atmosphere, and solids entrained in the river water must be periodically removed to maintain the required water storage volume. A maximum average sediment thickness of up to 6 inches (0.5 ft) is allowed on the bottom of the ponds (WNP-2 Technical Specification 3.7.l.3.c). In order not to exceed that value, sediment depth is measured quarterly and cleaning is initiated when necessary. Spray pond *sediment (SPS) has been removed four times since the beginning of commercial operations in 1984.

The sediment removed from the spray ponds has been either pumped to a trench located south of the ponds or hauled to the nearby plant landfill. Pond cleaning was initially performed using divers to vacuum the bottom of the ponds with the resulting slurry being discharged to the disposal trench. This type of cleaning was conducted in the A" Pond in March of 1989 and in the "B 11 Pond in November 1991.

An investigation of the quantity of sediment discharged to the trench revealed an elongated lens-shaped deposit approximately 160 feet long and 20 feet wide. The depth of the sediment varies from a thin layer of approximately 1/8 of an inch at the ends to 24 inches in the center. By dividing this area into three sections and using an average depth for each section, it is estimated that 120 cubic yards of material has been deposited in the trench.

SPS Diepoaal Appln Dcc9.5

During the R7 refueling outage (spring 1992) Pond "A" was drained and cleaned.

The sediment was piled in the bottom of the pond to remove the excess water and was then hauled to the landfill south of the cooling towers. An estimated 50 cubic yards of material was disposed in this manner. Pond "B" was drained and cleaned in the following year during the R8 outage (spring 1993). Sediment collected during this cleaning was dried in piles located outside of the ponds before being hauled to the landfill for disposal (Appendix C). An estimated 150 cubic yards of material was placed in the landfill at that time.

Approximately 320 cubic yards of sediment have been removed from the two spray ponds (125,000 square feet total surface area) during a ten year accumulation period (1983-1993). An annual accumulation rate of 35 cubic yards per year (approximately a 0.1 inch per year) has been assumed for the puipOse of this application. Because of the low accumulation rate, the ponds will not require frequent cleaning. It is expected that cleaning will normally occur in conjunction with the draining of the ponds for maintenance on the spray rings. On-line cleaning will be infrequently used.

Some portion of the sediment that would normally settle out in the ponds may be removed by filtration and subsequently discharged to the trench as filter backwash (NPDES discharge point no. 003). The installation of this water filter is currently not scheduled or funded.

B. Physical, Chemical, and Radiological Properties The sediment removed from the spray ponds consists almost entirely of fine sand and silt sized particles with a small organic fraction. Chemical analyses have shown that metals tend to concentrate in this sediment with lead and chromium occurring at concentrations above background levels. These lead and chromium levels did not exceed MTCA (WAC 173-340) cleanup standards nor did they exceed thresholds for dangerous waste designation (WAC 173-303-090) when tested by the Toxicity Characteristic Leaching Procedure (TCLP). Chemical sample locations and results are displayed in Appendix A.

As noted above, the spray ponds act as settling basins to concentrate or trap both radiological and non-radiological material entrained in the air or the makeup water.

Additional sorting and segregation by particle size is postulated to cause additional concentration of contaminants as this material settles from the water in the disposal trench. A summary of radionuclide concentrations measured in the trench sediment is provided in Appendix B and discussed below.

Radiological Investigation of Trench Sediments On May 16, 1995 sediment samples were collected from the spray pond disposal trench using a trowel and collecting the top one inch of soil in a one square foot area.

SPS Di,poaal Appia Dcc95

This collection technique results in a sample of approximately two kilograms as described in Environmental and Analytical Laboratory Instruction (ALI) 4.15.

Three sediment samples were initially collected from the trench along with a control (background) soil sample from outside the trench (Table B-1, sample locations 1-3).

The samples were shipped to Teledyne Brown Engineering Environmental Services for gamma spectrometry analysis. The results showed detectable amounts of cesium-137 and cobalt;.6() along with other naturally occurring radionuclides such as potassium-40. Cesium-137 was found in concentrations of 35 picocuries per kilogram (pCi/kg) under the discharge pipe and 416 pCi/kg in a composite of trench centerline samples. The cobalt-60 was found in concentrations of 95 pCi/kg under the discharge pipe and 5,570 pCi/kg in the composite centerline sample. A recount of the composite sample confirmed the cobalt-60 concentration in the centerline sample.

Four additional samples were collected from the centerline of the trench on July 7 and counted in the Plant Support Facility labo_ratory (Table B-1, samples 4-7). These samples were analyzed and confirmed the results found previously in the samples counted at Teledyne.

With the confirmation of the cobalt-60, another twenty samples (Table B-1, samples 8-27) were collected to characterize the bottom of the trench. The sample locations and results are summarized in Appendix B. Cobalt-60 was detectable in twenty-three of twenty-six samples collected from the trench sediments. Results ranged from 50 pCi/kg to 6,637 pCi/kg (dry). Cesium-137 was detectable in twelve samples with a range of values between 35 pCi/kg and 418 pCi/kg. The dose rates for this sediment were evaluated by pressurized ion chamber. The results are discussed below and reported in Appendix D.

Other soil samples were collected from the trench by hand auger for chemical analysis (Figure A- 1). These samples were examined by gamma spectrometry in the Plant Chemistry lab prior to shippfog to a contract lab for chemical. analysis. Two samples were collected at most locations, one from the spray pond sediment layer and one from the underlying soil. Two control samples were also collected outside the area of observable sediment and were below detection level. In general, the results for these samples agree with those taken previously (see Table A*l), Cobalt-60 concentrations ranged between 2,740 and 5,620 pCi/kg. Cesium-137 was found in concentrations between 168 and 380 pCi/kg. Differences in the results are likely due to the fact that all previous samples were collected from the surface (top 1 inch) while these auger samples are more representative of the average vertical distribution of contaminants. Auger samples taken from below the spray pond sediment layer showed detectable cobalt-60 in 3 of 8 samples. No cesium-137 was detected in any of these samples (Table A-1).

SPS Diapoaal Appia Dcc95

Radiologicaj Inv~tigayon of Spray Pond Sediment Few analyses have been performed on sediment taken directly from the spray ponds.

Results of three sediment samples taken in late March of 1989 found detectable quantities of manganese-54, zinc-65, cobalt-60, cesium-134 and cesium-137 (see Table 1 below). A more recent sediment sample taken in October 1995 found detectable cobalt-60. The other radionuclides previously detected were below the lower limit of detection (LLD).

Table 1. Radiochemical Characteristics of Spray Pond Sediment Wet Samples March 1989 Wet Sample October 1995 Nuclide Sample 1 Sample 2 Sample 3 (pCi/kg) (pCi/kg) (pCi/kg) (pCi/kg)

Mn-54 20.6 <LLD 22.3 <LLD Co-60 205.6 254 301.6 156 Zn-65 119.7 116.2 120.2 <LLD Cs-134 101.5 78.6 <LLD <LLD Cs-137 110.1 155.2 170.3 <LLD Other Soil Sample Results Soil samples were collected from eight locations around the spray ponds where sediment cleaned from the ponds had been temporarily piled to dry. These samples were taken to confirm whether any residual contamination remained. These areas were identified by an employee who had supervised the cleaning during the R7 and R8 outages. Residual amounts of cobalt-60 were detected in three of the eight locations with a low of 47 .1 pCi/kg and a high of 285 pCi/kg. The results of this survey and a map of the sample locations are shown in Appendix C.

An effort was also made to collect samples of the spray pond sediment that had been placed in the landfill area. It was discovered that this material has since been buried by several feet of fill. The attempts to collect samples with a hand auger were not successful. Because no samples were obtained, it has been assumed that the radiological properties of this sediment are similar to those found in the trench. Since soil samples were unobtainable, direct radiation measurements were taken in the area where the sediment was buried. Appendix D contains the results of the direct radiation measurements made at the disposal trench and in the landfill. The results of this survey are discussed below.

SPS Di1poaal Appln Dcc95

Pressuri~ Ion Chamber Results After the confirmation of the cobalt-60 results in the disposal trench, dose rate measurements were taken using a Reuter Stokes pressurized ion chamber (PIC) and RSS-112 electronics. Readings were taken in the. trench during July, August, and September. Three areas of the trench and a background station on the south bank of the trench were monitored. The average result for the trench area was 0.0137 mR/hr.

The background station average was 0.0103 mR/hr. This equates to a difference of approximately 0.0034 mR/hr or about 7 mR for 2000 hours0.0231 days 0.556 hours 0.00331 weeks 7.61e-4 months of exposure. These results and other (PIC) readings are listed in Appendix D, Table D- 1.

Readings taken from six locations around the landfill. on Septe~ber 7, 1995, had an average of 0.0106 mR/hr (Appendix D, Table D-2). Background readings taken prior to the addition of sediment at the nearby cooling tower sediment disposal cell during early 1995 (January - April) avenwed 0.0103 mR/hr. This suggests an increment of 0.0003 mR/hr in the area where the sediment was deposited in the landfill. The difference is expected to be insignificant because the sediments have been buried under several feet of fill.

Disposal Summm A total of approximately 320 cubic yards of material was removed from the spray ponds in four cleaning episodes. Of that amount, approximately 200 cubic yards was dried and placed in the landfill south of the cooling towers. It has since been buried by other landfill debris. The remaining 120 cubic yards resides in the trench south of the spray ponds.

Investigations of the trench sediment have shown it to be contaminated with primarily Cobalt-60 and Cesium-137 at concentrations above the level of detection for environmental samples. Measurements acquired with a pressurized ion chamber in the trench indicate that dose rates are currently half of the proposed disposal limit. Dose rates for the material buried in the landfill only slightly exceed background.

IV. Waste Disposal A. Organization and Responsibilities Overall responsibility for the disposal of the spray pond sediment resides with the WNP-2 Plant General Manager. This individual has the Supply System staff resources within the WNP-2 organization to carry out the proposed disposal operation.

Implementation of the disposal plan will principally be through two Plant departments:

SPS Diapoaal Appia Dec 9.S

L Chemistry The Chemistry Manager, in addition to other operational support duties, is responsible for monitoring Standby Service Water System performance as it relates to chemical/biological control and radioactivity. In addition, Chemistry will initiate the work order to clean the spray ponds when requested by Operations. Chemistry also samples and analyzes (or has an external laboratory analyze) the sediment for radioactivity prior to and after disposal. The Chemistry Department is responsible for monitoring the area for environmental radiation (see Section IV.F, below). The Department also has responsibility for monitoring the integrity of the disposal area (e.g., condition of disposal cells, indications of disturbance) and initiating corrective action, if needed.

2. Health Physics The Health Physics (HP) Department is managed by the Radiation Protection Manager (RPM). This department establishes and monitors work practices as they relate to radiation protection. The department is responsible for the proper storage, packaging, and disposal of contaminated materials. The HP Department will also provide technical support fot SPS disposal (e.g., interpretation of radiochemical data, evaluation of dose). Additionally, reporting to the RPM is the* labor support for developing and implementing the work orders (including specific task instructions) initiated by Chemistry.

B. Sediment Sampling and Analyses Representative sediment samples will be collected from the spray ponds prior to the start of cleaning by vacuum or by draindown. Given the design of the system and the origin and nature of the material, it is reasonable to expect homogeneous distribution of radiological constituents. Therefore, a composite sample will be prepared from samples collected from each pond that will be cleaned.

Wet composite samples will be analyzed in a qualified laboratory operated under the quality assurance requirements of the Nuclear Regulatory Commission (Ref. B).

Samples will be analyzed for gamma-emitting fission and activation product radioactivity utilizing methods and counting systems capable of measuring to environmental levels as specified in Table 6.3.1.1.1-1 in the WNP-2 Offsite Dose Calculation Manual (Ref. C). The lower limits of detection (LLDs) specified for cesium-134 and cesium-137 in dry sediment are 150 pCi/kg and 180 pCi/kg respectively. The results of the wet sample analysis will be used to determine the initial disposition of material to be removed from the ponds.

If the results of the wet composite sample analysis indicate that the activity is less than 20% of the disposal criteria (Section IV.C), the sediment will be placed in the designated disposal area. If the results indicate that the activity of the wet composite SPS Dispoaal Appln Doc 9S

~pie is greater than 20% of the disposal criteria, then, prior to disposal, additional composite samples (approximately 2.2 kg each) will be d.ried and analyzed by a qualified offsite laboratory. These samples, if necessary, will be used to confirm the wet sample results and to assure the appropriate disposition of the sediment. Post-disposal samples will also be collecte.d to confirm that the disposal criteria were not exceeded (see Section IV.E).

In the case of the continuous filter backwash (if installed), post-disposal samples of sediment accumulated in the disposal trench will be taken to confinn that the disposal criteria has not been exceeded. On-line monitoring or sampling for radioactivity from this dilute effluent stream is not considered viable because the expected levels of contamination fall well below the levels of detection for on-line monitors.

C. Disposal Criteria Sediment.disposal criteria (i.e., maximum radionuclide concentrations) are base.don the proposed decommissioning criterion of 15 mrem/yr total effective dose equivalent to the average. member of a critical group (Ref. G). At this level and below, no actions will be necessary to protect the public (i.e., release of site for unrestricted use). Therefore, the disposal of SPS will be limited such that an individual exposure can not exceed 15 mrem *per year. In determining the limiting concentrations, it is assumed that an individual spends 2000 hours0.0231 days 0.556 hours 0.00331 weeks 7.61e-4 months a year at the disposal location. It is also assumed that the maximum amount of material (35 cubic yards per year) is disposed for 30 years. Using dose projections methods discusse.d in Section V below (s.ee Table 2), the following individual limiting concentrations (dry) are proposed for onsite disposal:

Nuclide Disposal Typical Wet Typical Dry Limit (pCi/g) LLD (pCi/g) LLD (pCi/g)

Co-60 5 0.015 0.074 Mn-54 30 0.015 0.027 Zn-65 50 0.030 0.064 Cs-134 10 0.015 0.032 CS-137 20 0.018 0.057 Since the radionuclides may not occur alone, the concentrations of the radionuclides will also be limited such that the sum of the fractions of maximum concentration for each nuclide does not exceed unity:

A +B+C+D+E ::5 1.0 A = actual concentration + maximum concentration Co-60 (5 pCi/g)

B = actual concentration + maximum concentration Mn-54 (30 pCi/g)

C = actual concentration + maximum concentration Zn-65 (50 pCi/g)

D = actual concentration + maximum concentration Cs-134 (10 pCi/g)

E = actual concentration + maximum concentration Cs-137 (25 pCi/g)

SPS Dispoaal Appln Ott 95

This will assure that the total dose will remain below 15 mremlyr. If additional radionuclides are found, a similar analysis will be performed to establish maximum concentrations for disposal.

In the unlikely event that future dry SPS analyses of samples taken from the spray ponds show any fission or activation product present in excess of the individual limiting concentrations or the sum-of-the-fractions limitation, the material will be held for decay before it is disposed onsite or it will be disposed of by other means, such as burial in a licensed low-level waste disposal facility.

D. Sediment Removal As explained in Section ill.A above, sediment that collects in the bottom of the spray ponds requires periodic removal. The method of removal is determined by the plant operating status. When the plant is shut down and water has been drained from one of the ponds, the preferred and most effective method of cleaning is to use a vacuum truck or other mechanical means to remove the sediment. If the spray ponds cannot be drained, the sediment can be vacuumed by divers and the resulting slurry discharged to the existing disposal trench.

E. Sediment Disposal Wet sediment (without excess water) removed from the spray ponds will be disposed in the cooling tower sediment disposal cells (as described in EFSEC resolution No.

278) or in the spray pond discharge trench. The spray pond discharge trench will be used in the case of a slurry discharge (filter backwash or cleaning by vacuum). The trench is designated in the NPDES permit as a location (outfall 003) for discharges of wastewater to ground.

As needed, additional unlined earthen disposal cells will be constructed in the designated cooling tower sediment disposal area (Figure 3). Figure 6 is a typical plan and cross-sectional view of a disposal cell. Lateral dimensions of individual cells will vary. Prior to construction, background/ambient radiation measurements will be acquired with pressurized ionization chamber readings. These measurements will provide a baseline of environmental measurements for the disposal site and allow trending of environmental radiation levels as the sediment material is disposed. Soil in the disposal area will also be sampled to provide baseline information.

The wet sediment will be transported to the disposal area (via vacuum truck, front-end loader, dump truck, or other method) and deposited in a disposal cell. Subsequent batches will be deposited on top of or adjacent to previous deposits. Sediment from both the cooling towers and the spray ponds will be disposed in a single cell. Each cell will be used until the level approaches the top of the berm. The wet sediment tends to dry to a consolidated mud-cake surface that has a low susceptibility to wind erosion. Therefore, no cover material is anticipated to be needed. Local sand will be placed over the material if erosion becomes a concern.

SPS Diapoaal Applo Dec 95

After the completion of each cleaning episode, sediment samples will be collected from the surface layers of recently deposited material. A dried composite will be analyzed to confirm that the disposal criteria (Section IV.C, above) were not exceeded. If these results indicate an exceedance, a comprehensive sampling plan for the disposal cell will be prepared and implemented. Concurrently, EFSEC and the Department of Health will be consulted for appropriate follow-up, including sediment removal and off-site disposal.

F. Long-Term Environmental Monitoring In addition to the sampling associated with each cleaning epiwde, the Chemistry Department will monitor the disposal areas as part of the Radiological Environmental Monitoring Program (REMP). This monitoring will permit the detection of any significant change in radiation levels at the disposal sites. Major elements of the environmental radiation monitoring program for the site include: 1) baseline measurements of direct radiation levels and radionuclide concentrations in soil (new cells only, see Section IV.E); 2) monitoring of dose rates from the disposal sites utilizing thermolwninescent dosimeters (TLDs) and periodic pressurized ion chamber (PIC) measurements; and 3) post-closure environmental radiation surveys of the site in preparation for decommissioning (to be determined at that time).

Nonradiological monitoring of the disposal site will consist of chemical analyses of the accumulated sediment at a frequency of not less than once every five years. These analyses will include lead and chromium as well as copper, zinc, and nickel which are possible constituents originating from plant components.

G. Disposal Area Control The Standby Service Water discharge trench is located in an unfenced area in the remote southeast quadrant of the WNP-2 plant site. The trench is not visible from nearby areas nor accessible from public roadways. The area is not normally occupied by any workers except (infrequently) those associated with environmental monitoring.

Signs have been placed marking the trench as a "radioactive materials" area. Because of the isolation of the area, lack of adjacent human activity, and because no hazards would be associated with unauthorized entry, no additional access controls are necessary.

The sediment disposal cells and WNP-2 landfill area are within a fenced industrial area of very low traffic. The immediate area is not occupied by workers except during sediment disposal. The comers of the disposal areas will be marked with signs indicating the dedicated purpose of the area. Because the area does not have through-traffic and because no hazards would be associated with unauthorized entry, additional controls are not necessary.

H. Disposal Site Closure It is anticipated that the disposal operation will continue for the operating life of SPS Diaposal Appln Doc 95

WNP-2. Disposition of the SPS and CTS at the end of plant life will depend on the requirements of agencies such as the Nuclear Regulatory Commission (NRC), the Washington Department of Ecology (WDOE), and Washington Department of Health (WDOH). The NRC will establish plant decommissioning criteria which will likely require assessment of all contaminated areas of the site. As explained in Section IV.C, the Supply System anticipates that the SPS/CTS will conform to decommissioning criteria and will not require exhumation and removal. Because it is intended that the disposal site be operated within NRC and WDOH radiation criteria for decommissioning, there should be no need for institutional controls to limit access by "intruders." Neither should there be a need for remediation of radiological conditions at the site at the time of closure.

WAC 173-304-015(8) exempts this material {radioactive material) from the minimum functional standards for solid waste handling. The Supply System will evaluate the WDOE's regulations for solid waste (i.e., WAC 173-304) in effect at the time of site closure to determine the appropriate disposition. The SPS/CTS could be used as fill material during the closure of the adjacent landfill. As discussed in Section IV .E, a disposal site cover is not planned. If the material is to be left in place, some minor regrading may be required to give the area a natural appearance during the site restoration phase.

I. Procedures to Minimize Upsets and Hazardous Exposures As shown in Appendix B and discussed in Section V below, the concentration of radioactive materials are so low that there is little potential for hazardous exposures.

Should an unanticipated condition arise, however, the Supply System has the radiation protection program and resources to respond. Elements of the program are discussed below.

The Supply System is committed to maintaining occupational and public radiation exposures as far below regulatory dose limits as is practicable while performing all activities related to the operation of WNP-2. This commitment is reflected in a Radiation Protection Program that meets the requirements of 10 CPR Part 20 and provides for effective control of radiation exposure through:

Management direction and support;

Establishment of radiation control procedures;

Consideration during design and modification of facilities and equipment;

Development of good radiation control practices, including preplanning and the proper use of appropriate equipment by qualified, well trained personnel.

The Radiation Protection Manager (RPM) is responsible for implementing the Radiation Protection Program. The Radiation Protection Manager reports to the Plant General Manager and has the responsibility and authority for ensuring that plant activities meet applicable radiation safety regulations and Radiation Protection Program requirements. This includes the responsibility for ensuring that radiation exposures are ALARA.

SPS Diapoaal Appia Dec 95

Supervisors that report to the RPM implement the Radiation .Protection Program through direct supervision of the plant health physics technicians. Areas of responsibility include: characterizatiQn *of plant radiological conditions; maintenance of radiological postings; maintenance of radiation exposure records; and detecting and evaluating radiological problems.

The Plant Health Physics Technicians provide a staff of competent personnel whose primary responsibilities are to provide radiological services and support for plant personnel and maintain radiological surveillance.

The Chemistry Department is responsible for long~term monitoring of the disposal areas fOr environmental radiation via the Radiolqgical Environmental Monitoring Program (REMP). The REMP for WNPw2 provides for measurements of radiation and radioactive materials in .exposure pathways and for those radionuclides for which the highest potential dose commitment to a meml>er of the public would result due to plant operations.

Environmental samples are collected in accordance with the provisions of the REMP.

The program specifies the environmental sampling phm by sample type, sample location code, sampling and collection frequency, and type and frequency of analysis of samples collected within an exposure pathway. Deviations from the sampling frequency detailed in the plan may occur due to circumstances such as hazardous conditions, malfunction of automatic sampling equipment, seasonal unavailability t or other legitimate reasons. When sample media is unobtainable due to equipment malfunction, special actions per program instruction are taken to ensure that corrective action is implemented prior to the end of the next sampling period. In some cases, alternate sample collection may be substituted for the missing specimen.

All individuals performing Supply System related activities at WNP-2 are required to follow the rules and procedures established for radiological protection and exposure minimization. Each individual is responsible for ensuring radiation safety. The commitment to ALARA is implemented by employee training; audits, assessments, and reviews of the program; procedure development and reviews;. enforcement of rules; and modifications to plant equipment or facilities where they will substantially reduce exposures at a reasonable cost.

In the unlikely event of an upset resulting in the contamination of the Standby Service Water System, instrumentation (on-line monitor) and administrative controls provide for early detection and response. Contamination of the .spray ponds at levels that would produce hazardous exposures is an extremely remote possibility. However, if a significant level of contamination were to occur, it would be identified by sampling of the sediment before cleaning (Section N .B) or after placement in the disposal cell (Section IV.E). Once identified, appropriate signs, barriers, and access controls would be established by plant procedure to prevent inadvertent exposures of employees or members of the public. A revised disposal plan could then be developed in consultation with the State.

SPS Di,poul Appln Dec 95

Additional assurance that contaminated sediments (or other abnormal radiological conditions) are identified is provided by routine independent measurements conducted by the REMP (Section IV.F). Protection from inadvertent exposures is also enhanced by the remote location, limited access, and infrequent occupation of the storage areas.

During normal operations, the concentration of radioactive materials in the disposal cells is so low that there is little potential for a hazardous exposure to a member of the public.

J. Records and Reports Records pertaining to the disposal site o~ration are maintained in a retrievable file.

No routine reports specific to the disposal operation are anticipated. Environmental monitoring results will be summarized in the annual REMP report.

V. Radiological Impact Evaluation A. Exposure Considerations Possible pathways for radiological exposure include: (1) external exposure from standing on the ground above the disposal site; (2) internal exposure from inhalation of suspended radionuclides; (3) internal exposure from the ingestion of food grown on the disposal site; and (4) internal exposure from drinking potentially contaminated groundwater.

An internal exposure resulting from ingestion of food grown on the disposal site is not considered a realistic possibility. The Supply System controls activities within a 1.2-mile radius of WNP-2. No food crops are grown in the site area and food crop production is not anticipated in the future.

Inhalation of resuspended radionuclides is not considered a significant exposure pathway. Calculations performed utilizing the RESRAD program (Ref. D) indicate that a person would receive less than 0.001 mrem/yr from SPS inhalation even if each of the primary radionuclides were at the maximum proposed disposal concentrations (Section IV.C, above). Results of the inhalation dose calculation are shown in Figure 7.

An internal exposure due to consumption of groundwater is not considered plausible.

There are no wells drawing from the unconfined aquifer near the disposal sites. The primary source of drinking water for the WNP-2 site is the Columbia River. There is a backup water supply well on the WNP-2 site. The well is about 2100 ft north of the disposal location and, at a depth of 695 ft, draws from the confined aquifer.

There are also two wells in use at the Supply System's WNP-I site about 7000 feet east, however, these wells are about 465 ft deep and, based on the stratigraphy and water quality data, appear to draw from a semi-confined aquifer in the Ringold conglomerates and the upper fractured basalt flow. While future groundwater SPS Di1poaal Appia Dec95

withdrawals are possible, usage for human and animal consumption will be limited by the existing tritium contamination (>20,000 pCi/1) resulting from previous Hanford Site operations (Ref. E).

The direct external exposure of an individual working or standing on the disposal area represents the most significant exposure pathway (i.e., the maximally exposed individual or MEI). Accordingly, a dose assessment has been made for the MEI from the ground shine pathway using conservative assumptions to assure that the limiting disposal concentrations proposed in Section IV. C will maintain exposures less than 15 mrem/year. Assumptions for this calculation are listed below in Section V.B and the results are displayed in Table 2.

The projection of radionuclide decay over time in a closed disposal area is shown in Figure,8 beginning one year after the last sediment deposit. It was assumed tnat the disposal area was producing 15 mrem/year at the time of closure.

B. Dose Projection Assumptions The dose projections used for the evaluation of the disposal areas were based on the following assumptions:

The only significant environmental pathway for delivering radiation dose to the MEI is direct radiation from the waste material in the soil.

The exposure duration is assumed to be 2000 hours0.0231 days 0.556 hours 0.00331 weeks 7.61e-4 months per year.

Source terms are individual nuclides at maximum disposal concentrations indicated in Table 2 at time of deposition. Each deposited layer is corrected for decay from date of deposition until facility closure.

The annual integrated dose considers decay of deposited radionuclides during prior years of deposition. The most recently deposited material is assumed to be on top, with older material at progressively deeper locations.

The total quantity of deposited sediment is assumed to be 1050 cubic yards (30 years of disposal at the rate of 35 cubic yards per year). The calculation was stopped at a maximum deposited material age of 10 years since older material did not add significantly to the dose.

The dimensions of the deposited material were assumed to be 15 meters radius by 1.2 meters deep. This is approximately 1050 cubic yards. A cylindrical geometry was chosen to maximize the dose per unit volume. This geometry was chosen for dose calculations only and does not represent the actual disposal geometry.

SPS Diapoul Applo Dec 95

The density of the sediment is assumed to be 1.5 g/cm3 *

An isotropic geometry is assumed for calculating dose.

C. Method of Calculation Exposure rates at one meter above the ground surface and the corresponding dose rates were calculated using the computer code MicroShield Version 4 (Ref. F).

Maximum disposal concentrations for each nuclide were calculated by an iterative process to yield a dose of 15 mrem/yr to the MEI as shown in Table 2.

The RESRAD Version 5.19 computer code (Reference D) was used to calculate the decline in the expected MEI dose following closure of a disposal area beginning at the maximum limit of 15 mrem/year (Figure 8). This code was also used to calculate the expected dose from the inhalation pathway assuming that every radionuclide was at maximum concentration (Figure 7).

D. Results Results of the MicroShield dose calculations to determine the limiting disposal concentrations are shown in Table 2. The concentrations (column 2) determined by this method were proposed as disposal limits in Section IV. C to assure that the limiting dose of 15 mrem/year would not be exceeded (column 6). The dose from multiple radionuclides is constrained to 15 mrem/year by the sum-of-the-fractions limitation described in Section IV. C; Table 2. Calculated (via Ref. F) Dose Rates from SWS Disposal Maximum Exposure Dose Rate at . Half Annual Dose Disposal Rate at MDC Life Rate at Conc.(MDC) MDC MDC Nuclide (pCi/g) (µR/hr) (µrem/hr) (yr) (mrem/yr)

Mn-54 30 17 11 0.857 15 Co-60 5 12 8 5.271 15 Zn-65 50 17 11 0.67 14 Cs-134 10 13 8 2.062 14 Cs-137 20 6 5 30.17 10 SPS Diopoaal Appia Dec 95

A calculation was performed utilizing the computer code RESRAD Version 5.19 (Ref.

D) to calculate the decline in the MEI dose over time following the closure of a disposal area. The starting dose rate for the calculation was assumed to be 15 mrem/year beginning one year after the last sediment has been placed in the disposal area. This starting rate was achieved by assigning each radionuclide an arbitrarily equal yearly dose rate. The results of this calculation are shown in Figure 8.

RESRAD code was also used to perform a calculation of the inhalation dose with all radionuclides at the maximum disposal concentrations. This is a conservative assumption because the disposal concentrations would be apportioned by the sum-of-the-fractions limitation discussed in Section IV. C. The calculation indicates that a MEI would receive less than 0.001 mrem/year from the inhalation pathway. The results of the calculation are shown in Figure 7.

E. Discussion of Dose Calculation Results As demonstrated in Section V, the proposed NRC criterion of 15 mrem/year total effective dose equivalent (TEDE) to an average member of a critical group (Ref. G) can be achieved in the disposal areas by the application of a limiting concentration for each radionuclide and the use of the sum-of-the-fractions limitation described in Section IV. Actual doses will be much lower since not all material will be disposed at the maximum concentrations, the actual disposal geometry is not cylindrical, and the areas are unoccupied.

V. Refere.nces A. WNP-2 Final Safety Analysis Report, prepared by Washington Public Power Supply System in 1978 with annual updates.

B. U.S. Nuclear Regulatory Commission, "Quality Assurance for Radiological Environmental Monitoring Program," Assessment Branch Technical Position Revision 1, November 1979 C. WNP-2 Offsite Dose Calculation Manual prepared by Washington Public Power Supply System.

D. Manual for Implementing the Residual Radioactive Material Guidelines Using RESRAD, Version 5.0, Working Draft for Comment, Environmental Assessment Division, ArgonneNationalLaboratory, Rept. No. ANL/EAD/LD-2, September 1993.

SPS Diapoaal Applo Dcc95

E. Hanford Site Environmental Report for Calendar Year 1993, Battelle Pacific Northwest Laboratory, Rept. No. PNL-9823, June 1994.

F. MicroShield Version 4 User's Manual, Grove Engineering, Inc., Rockville, MD, 1992.

G. U.S. Nuclear Regulatory Commission, Proposed Revision of 10 CFR Part 20 Re:

Radiological Criteria for Decommissioning, Eed,~lu Vol. 59, No. 161, P. 43200, August 22, 1994.

SPS Di1J>Oul Appln Dcc95

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Figure 2 A,erial Photograph or WNP-2 (June 1990)

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CROSS-SECTION (Net to Sc:alel Typical Disposal Cdl Figure 6

DOSE: Inhalation (w/o radon) Pathway All Isotopes Summed

0. 0008 - - -.--------,,-....,---r.,,....._,..,,......----,.....c.......,-,-,.....,.-,-,-,-,-,-------,-- --......-.-.-.,.,-,.-.--,

- Total t:. - Co-60

+ - Cs-134 0.0006 o - Cs-137 X - Mn-54 o - Zn-65 8 0.0004 (I) s 0 .0000 1 10 100 1000 Years SPSJNH.DAT 12/04/95 13:25 Figure 7 Inhalation Pathway Dose Calculation

DOSE: Ground Pathway All Isotopes Summed 20 ---.----,.-,..-.-..-,-,...,....--....---,--'-,-..,..........,.....--.-,----,--,--..,..-,,......,...,.,..,,.....,

15 - Total A - Co-60

+ - Cs-134 o - Cs-137

~ X - Mn-54

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10 100 1000 Years SPSGND.DAT 12/05/95 02:23 Figure 8 Dose After Closure

Appendix A WNP-2 Spray Pond Disposal Trench Sediment Chemical Analyses

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Radiological Analysis of Chemical Samples - Spray Pond Sediment Discharge Trench Location Sample Cobalt-60 Result Cesium-137 Result Number Number (pCi/kg) (pCi/kg) 1 95110 3,320 326 95111 <lld2 <lid 2 95112 3,280 348 95113 225 <lld 3 95114 4,520 344 95115 383 <lld 4 95116 2,740 168 95117 513 <lld 5 95118 <lld <lld 6 95119 .2,930 317 95120 <lld <lld 7 95121 3,670 279 95122 <lld <lld 8 95123 3,800 380 95124 <Ild <lld 9 95125 5,620 214 95126 <lld <lld 10 95127 <lld <lld Table A-1 2

lld = Lower Limit of Detection

Table A-2 Spray Pond Discharge Trench Chemical Analysis Sample Collection Date - September 19, 1995 Sample Analysis Parameter in mg/kg No. 1 *----------

Ba Ag As Pb Notes:

1. The sample number (1-110) refers to the map location (1) followed by the sample number (110).

The Supply System sample number prefix was omitted (HW95110).

2. TCLP analysis for Pb and Cr was conducted for samples 110, 112, 114, and 119. All results were less than the detection limits (0.5 mg/I Pb; 0.1 mg/1 Cr).

3. Table Shading: At most locations, samples were taken from the spray pond sediment (unshaded rows) and from the underlying soil (shaded rows).

Table A-2

Appendix B WNP-2 Spray Pond Disposal Trench Sediment Radionuclide Analysis

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Figure B-1 Radiological Sample Locations - Spray Pond Sediment Disposal Trench

Radiological Sample Results - Spray Pond Disposal Trench Location Nmnber Sample Date Cobalt-60 (pCi/kg) C~ium-137 (pCi/kg) 1 05/16/95 <Jldl <lld 2 05/16/95 95 35 3 05/16/9S 5,570 416 4 07/07/95 1,606 143 s 07/07/95 529 169 6 07/07/95 5,834 343 7 07/07/9S 5,811 267 8 07/13/95 6,637 418 9 07/13/95 2,749 208 10 07/13/95 2,083 216 11 07/18/95 179 <lid 12 fJ7/18/95 <lid <lld 13 07/18/95 <lid <lid 14 07/20/95 848 73 15 07/20/95 597 <lld 16 07/20/95 829 <lid 17 07/20/95 5,710 346 18 07/20/9S 6,030 277 19 07/20/95 407 <lid 20 07/20/95 57 <lld 21 07/20/95 61 <lld 22 07/20/95 198 <lid 23 07/20/95 257 <lid 24 07/20/95 50 <lid 25 07/20/95 <lld <lld 26 07/20/95 168 <lld 27 07/20/95 80 <lld Table B-1 1

lld = Lower Limit of Detection

Appendix C Soil Sample Results - Spray Pond Interim Storage Locations SP$ Dispow ApplD Dec 95

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Soil Sample Results - Spray Pond Sediment Stockpile Areas Location Number Cobalt-60 Result (pCi/kg) 1 53.2 2 <lld4 3 <lid 4 <lld 5 47.1 6 285 7 <lld 8 <lld Table C-1 4

lld = Lower Limit of Detection

Appendix D Disposal Site Dose Measurements SPS Dispow Appia De.:95

r----- --- ---- *-- *-- ---

1 Storage ____FENCELI~!:

Facility N ghest entration O' down

~-- t~~~ :~;: Sediment . ---i-------

.________ -----'i6fJ~E f Cooling Tower Sediment Disposal Area Figure 0-l Locnlion of Reuler Stokes PIC Mensurements taken 09/07/95 in lhe Lnndlill Aren

Reuter Stokes PIC Readings from Spray Pond Disposal Trench Date Location Average mR/hr 07/14/95 East End 0.0142 07/14/95 Middle 0.0126 07/14/95 West End 0.0136 07/20/95 South Bank - Control 0.0106 07/20/95 East End 0.0169 07/20/95 East End #1 0.0131 07/20/95 East End #2 0.0114 07/20/95 West End 0.0165 07/20/95 West End #1 0.0119 07/20/95 West End #2 0.0109 07/28/95 South Bank - Control 0.0100 07/28/95 East End 0.0151 08/24/95 South Bank - Control 0.0105 08/24/95 East End 0.0154 09/08/95 South Bank - Control 0.0101 09/08/95 East End 0.0138 Table D-1

Reuter Stokes PIC Landfill Readings for 09/07/95 Location Number Average mR/hr 1 0.0104 2 0.0110 3 0.0107 4 0.0105 5 0.0103 6 0.0106 Table D-2

SEPA ENVIRONMENTAL CHECKLIST (from WAC 197-11-960)

A. Background

1. Name of the proposed project, if applicable:

Service Water Spray Pond Sediment Disposal

2. Name of applicant:

Washington Public Power Supply System

3. Address and phone number of applicant and contact person:

W.A. Kiel (Mail Drop PE20)

Washington Public Power Supply System P.O. Box 968 Richland, Washington 99352-0968 Telephone Number: 509-377-4490

4. Date checklist prepared:

December 15, 1995

5. Agency .requesting checklist:

Energy Facility Site Evaluation Council (EFSEC)

6. Proposed timing or schedule (including phasing, if applicable):

Removal and disposal of spray pond sediment will occur infrequently but whenever necessary to maintain the average sediment dep1h less than 0.5 foot as specified by the U.S. NRCfor the Supply System's Nuclear Plant No. 2 (WNP-2). Sediment will be removed from the ponds and disposed throughout the life of the plant.

7. Do you have any plans for future additions, expansion, or further activity related to or connected with this proposal? If yes, explain.

Not at this time. Sediment will be removed from the ponds for the life of the planr.

Although the designated disposal areas (see Item A.11, below) are judged sufficient for the life of the plant, they will be expanded if necessary.

Pagel

Spray Pond Sediment Disposal

8. List any environmental information you know about that has been prepared, or will be prepared, directly related to this proposal.

Specific i,ifonnation is included in the application to EFSEC prepared in accordance with WAC 246-221-180. Extensive documentation regarding the general site area was prepared pursuant to NEPA and SEPA to suppon decisions to construct WNP-2.

9. Do you know whether applications are pending for governmental approvals of other proposals directly affecting the property covered by the proposal? If yes, explain.

None. The proposed disposal locations are within the WNP-2 exclusion area.

10. List any government approvals or permits that will be needed for your proposal, if known.

The disposal of low-level radioactive waste in Agreement States (per Section 274(b) of the Atomic Energy Act) such as Washington is authorized and regulated by the state. The existing Site Cenijication Agreement and the powers vested in EFSEC preempt the need for additional pennits from other jurisdictions (RCW 80.50.110 and RCW 80.50.120). EFSEC is expected to evaluate this proposal for co,ifonnance with the guidance provided in WAC 246-221-180 and consult with knowledgeable state agencies prior to granting approval,

11. Give brief, complete description of your proposal, including the proposed uses and the size of the project and site. There are several questions later in this checklist that ask you to describe certain aspects of your proposal. You do not need to repeat those answers on this page. (Lead agencies may modify the form to include additional specific information on project description.)

The Washington Public Power Supply System is proposing to license the onsite disposal of sediment removed from the WNP-2 service water spray ponds. Recent analyses have shown that this material often contains radionuclides at concentrations in excess of the level of detection for environmental measurements.

This low-level measurable contamination likely comes from the river makeup water, or is captured from the atmosphere (whether from suspended dust, fallout, or plant releases). Under the current regulatory framework this sediment must be licensed and managed as low-level radioactive waste regardless of its source of radionuclides. Given the nature of the material and its very low radioactive contamination, the Supply System has detennined that continued onsite disposal is most appropriate.

Pagel

SEPA Checklist When required, sediment will be removed from the spray ponds by one of three cleaning methods for disposal in either of two areas. Under nonnal circumstances, the ponds (one at a time) will be drained of water and the sediment removed by mechanical means. Once the sediment has been dewatered to the extent practicable, it will be placed in a series of unlined eanhen cells constrncted for the disposal of cooling tower sediment with similar levels of radioactive contamino.Jion (see EFSEC Resolution No. 278). These cells were constructed within a 120 x 300 foot area located in an inactive borrow pit about 250 feel south of the cooling towers.

If on-line cleaning is required, the ponds will be vacuumed by divers and the resulting ejj1uent will be pumped to the discharge trench located about 500/eet south of the spray ponds. Plans are also being developed for the installation of a water .filtration unit to reduce the amount of suspended sediment and organic material in order to lessen the dependence on biocides. Maintenance of this filter will require backwashing and the resulting eflluent would be discharged to the disposal trench. Backwashing may be periodic or continuous depending on the filter model selected. The discharge of ejj1uent to ground from the on-line cleaning and the filter backwash are activities pennitted by the facility's NPDES wastewater pennit.

Both disposal areas currently contain sediments with low levels of contamination.

Sediments from the cooling rowers were placed in the disposal cell as authorized by EFSEC Resolution No. 278. This proposal has been prepared in response to the recent discovery of contamination in the spray pond sediments which in tum requires that state approval be obtained in accordance with WAC 246-221-180.

The proposed action is to seek state authorization of a Supply System prepared application to dispose of spray pond sediments containing low-levels of radioactive contamination in either of the two existing disposal locations. Approval of this proposal will retroactively approve past disposal actions and establish Jonna/

controls and monitoring requirements for the future.

12. Location of the proposal. Give sufficient information for a person to understand the precise location of your proposed project, including a street address, if any, and section, township, and range, if known. If a proposal would occur over a range of area, provide the range boundaries of the site(s). Provide a legal description, site plan, vicinity map, and topographic map, if reasonably available.

While you should submit any plans required by the agency, you are not required to duplicate maps or detailed plans submitted with any permit applications related to this checklist.

The disposal cells and discharge trench are located immediately south of the WNP-2 plant site in inactive borrow pits created during construction of the facility.

This area is located approximately 12 miles nonh of Richland, Washington near the center of Section 5, Township 11 Nonh, Range 28 East in Benton County. The location is indicated on figures included in the application submitted to EFSEC.

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Spray Pond Sedillleat Disposal B. ENVIRONMENTAL ELEMENTS

1. .Earth

a. General description of the site:

The disposal cells and discharge trench are located in inactive borrow pits immediately south of the WNP-2 plant site. Both areas were originally disturbed during construction of the facility and currently contain sediments from previous cleaning operations. They have an irregular profile with a maximum depth of approximately 15 feet below the finished grade of the plant site area. To the west of the disposal cells the borrow pit has been used as a construction landfill.

b. What is the steepest slope on the site (approximate percent slope)?

The project is located in flat rolling terrain with gentle slopes. The disposal areas are located in inactive borrow pits along the south perimeter of the WNP-2 plant site.

c. What general types of soils are found on the site (for example, clay, sand, gravel, peat muck)? If you know the classification of agricultural soils, specify them and note any prime farmland.

The soils in the disposal areas are comprised of sand, coarse sand, and some gravel. No farmland is located near the proposed disposal sire.

d. Are there any indications or history of unstable soils in the immediate vicinity? If so, describe.

None.

e. Describe the purpose, type, and approximate quantities of any filling or grading proposed. Indicate source of fill.

The disposal areas have been constructed using local eanh materials found within the boundaries of the existing borrow pits. No construction fill will be necessary. Some grading and placement of gravel may be necessary to improve the existing roadways. The wet sediment quantity that will be deposited in the area is conservatively estimated to be 60 to 100 cubic yards per year. This will be an eanh fill to the area. The proposed disposal location was, in pan, selected to prevent disruption of previously undisturbed areas.

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SEPA Cbeckllit

f. Could erosion occur as a result of clearing, construction, or use? If so, generally describe.

Limited wind erosion and fugitive dust is likely during movement of heavy equipment during construction and use of the disposal cells. Wind erosion after placement of the sediment is not expected because of its tendency to dry as mud-cake.

g. About what percent of the site will be covered with impervious surfaces after project (for example, asphalt or buildings)?

None.

h. Proposed measures to reduce or control erosion, or other impacts to the earth, if any:

Gravel may be placed to improve roads and reduce fugitive dust during operation.

2. Air

a. What types of emissions to the air would result from the proposal (i.e., dust, automobile, odors, industrial wood smoke) during construction and when the project is completed? If any, generally describe and give approximate quantities if known.

Limited wind erosion and fugitive dust is likely during movement of heavy equipment during construction and use of the disposal cells. Wind erosion after placement of the sediment is not expected because of its tendency to dry as mud-cake.

b. Are there any off-site sources of emissions or odor that may affect your proposal?

No.

c. Proposed measures to reduce or control emissions or other impacts to air, if any:

Temporary measures such as water application may be necessary to control fugitive dust. Gravel may be placed to improve roads and reduce fugitive dust during operation.

3. Water

a. Surface:

1) Is there any surface water body on or in the immediate vicinity of the site (including year-round and seasonal streams, saltwater, lakes, ponds, PageS

Spny Pond Sediment Disposal wetlands)? If yes, describe type and provide names. If appropriate, state what stream or river it flows into.

There are no surface water bodies in the immediate vicinity of the site.

The Columbia River is located more than three miles east of the site.

2) Will the project require any work over, in, or adjacent to (within 200 feet) the described waters? If yes, please describe and attach available plans.

No.

3) Estimate the amount of fill and dredge material that would be placed in or removed from surface water or wetlands and indicate the area of the site that would be affected. Indicate the source of fill material.

None.

4) Will the proposal require surface water withdrawals or diversions? Give general description, purpose, and approximate quantities if known.

No.

5) Does the proposal lie within a 100-year floodplain? If so, note location on the site plan.

No.

6) Does the proposal involve any discharges of waste materials to surface waters? If so, describe the type of waste and anticipated volume of discharge.

No.

b. Ground:

1) Will groundwater be withdrawn, or will water be discharged to groundwater?

The proposed activity may result in small periodic discharges to groundwater from the disposal. cells. The sediments placed in the disposal cells from either the cooling towers or the spray ponds will be saturated with water that will either evaporate or infiltrate the soil beneath the cell.

During cooling tower cleaning operation (one to three times a year) the active disposal cell may receive enough water to infiltrate as far as the groundwater table located approximately 50 feet below the ground surface aJ the disposal location. The water table is approximately 25 feet below the disposal trench.

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SEPA Checldist On-line cleaning and pond .filtration will result in a liquid e.flluent being discharged to ground. During iefrequent on-line cleaning of the spray ponds (twice in ten years), the sediment is vacuumed from the bouom of the ponds and the resulting effluent is discharged to the disposal trench.

During spray pond.filtration, suspended sediment and organic material is filtered from the water to reduce the reliance on biocides. Maintenance of this filter will require backwashing and the resu/ring effluent would be discharged to the disposal trench. Backwashing may be periodic or continuous depending on the jilter model selected. The discharge to ground of the e.flluent from the on-line cleaning and the jilter backwash are activities permiued by the facility NPDES wastewater discharge permit (see NPDES Permit No. WA-002515-1, re: outfall 003).

2) Describe waste materials that will be discharged into the ground from septic waste tanks or other sources, if any (for example domestic sewage; industrial, containing the following chemicals ... ; agricultural; etc.).

Describe the general size of the system, the number of such systems, the number of houses to be served (if applicable), or the number of animals or humans the system(s) are expected to serve.

The spray pond sediment consists almost entirely offine sand and silt sized panic/es with a small organic fraction. Analyses have shown thar this material often contains metals as well as very low concentrations of radionuc/ides. Chemical analyses have shown that metals tend to concentrate in this sediment with lead and chromium occurring at concentrations above background levels but below dangerous waste designation levels.

Chemical treatment is currently used to control biofouling in the service water system. The discharge to ground of treated warer is permitted by rhe facility NPDES wastewater pennit. The pennit requires effluent and groundwater quality monitoring.

c. Water Runoff (including storm water):

1) Describe the source of runoff (including storm water) and methods of collection and disposal, if any (include quantities, if known). Where will this water flow? Will this water flow into other waters? If so, describe.

None. The climate at the disposal site is characterized as mid-latitude semiarid. The area is subject to low humidities, large diurnal and annual ranges of temperatures, and modest precipitation averaging 6 to 7 inches annually and occurring mostly as rain in the winter and spring months.

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Spray Pond Sedimmt Dt.po.,al

2) Could waste materials enter ground or surface waters? If so, generally describe.

No. Analysis and experience at WNP-2 leads to the conclusion that the groundwater (there are no surface waters) will not be contaminated by the onsite disposal of spray pond sediments. Although analysis has shown that the sediments often contain metals or radioactive elements above environmental detection levels, neither is expected to be carried to the groundwater.

Standard tests (per WAC 173-303 for solid waste designation) have shown that the sediment will not produce a potentially haz.ardous leachate.

Based on investigations at a stormwater pond nonheast of WNP-2, the radioactive contaminants will likely remain within the cooling tower sediments or be retained within the soils immediately below the disposal cells, Additional protection of the groundwater is provided by the infrequent addition of water to the disposal cells and the adsorptive properties of the soil column between the cell and the groundwater.

d. Proposed measures to reduce or control surface, ground, and runoff water impacts, if any:

To the extent practicable, ejfons will be made to reduce the water content of the sediments prior to placement in the disposal cells. Plans are also being considered to lessen the dependence on non-oxidizing chemical treatments to control biofouling in service water. A treatment regime of hydrogen peroxide and Water filtration has been proposed.

4. Plants

a. Check the types of vegetation found on the site:

_ deciduous tree: alder, maple, aspen, other

_ evergreen tree: fir, cedar, pine, other

.1L shrubs

.1L grass pasture crop or grain wet soil plants water plants other types of vegetation

b. What kind and amount of vegetation will be removed or altered?

Vegetation removal will be minor. If any removal is required, it will occur in areas previously disturbed by facility construction. The two disposal areas are located in former earth borrow pits and are largely devoid of vegetation.

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SEPA Checklist

c. List threatened or endangered species known to be on or near the site.

No federally listed threatened or endangered plant species are on or near the disposal site.

d. Proposed landscaping, use of native plants, or other measures to preserve or enhance vegetation on the site, if any:

None.

5. Animals

a. Identify any birds and animals which have been observed on or near tl}e site or are known to be near the site:

birds: meadowlark, sparrow, quail, magpie mammals: mule deer, coyote, jackrabbit, pocket mouse fish: none - the site is three miles from a water body .

b. List any threatened or endangered species known to be on or near the site.

No federally listed threatened or endangered birds or mammals are on or near the disposal site.

c. Is the site part of a migration route? If so explain.

No.

d. Proposed measures to preserve or enhance wildlife, if any:

None.

6. Energy and Natural Resources

a. What kinds of energy (electric, natural gas, oil, wood stove, solar) will be used to meet the completed project's energy needs? Describe whether it will be used for heating, manufacturing, etc.

None.

b. Would the project affect the potential use of solar energy by adjacent properties? If so generally describe.

No.

Paae9

Spray PoDd Sedhnmt Di.spow

c. What kinds of energy conservation features are included in the plans of this proposal? List other proposed measures to reduce or control energy impacts, if any:

Not applicable.

7. Environmental Health

a. Are there any environmental health hazards, including exposure to toxic chemicals, risk of fire and explosion, spill, or hazardous waste, that could occur as a result of this proposal? If so, describe.

No. The proposal is to dispose of spray pond sediment with very low levels of radioactive contamination. The projected radiological doses from this activity preseru no health hazard. Metal concentrations do not pose a hazard as demonstrated by sediment testing using the Toxicity Characteristic Leaching Procedure (]'CLP).

1) Describe special emergency services that might be requ_ired.

None.

2) Proposed measures to reduce or control environmental health hazards, if any:

The waste material will be sampled and analyzed prior to disposal to assure thaJ it meets disposal criteria. The disposal sites will be periodically monitored for direct radiation and concentration of metals.

b. Noise

1) What types of noise exist in the area which may affect your project (for example: traffic, equipment, operation, other)?

None.

2) What types and levels of noise would be created by or associated with the project on a short-term or long-term basis (for example: traffic, construction, operation, other)? Indicate what hours noise would come from the site.

No long-tenn noise would be created by or associated with the project.

The short-tenn noise associated with disposal of the sediment would be indistinguishable from other sources of noise on the industrial site.

3) Proposed measures to reduce or control noise impacts, if any:

None.

PaaelO

SEPA Checklist

8. Land and Shoreline Use

a. What is the current use of the site and adjacent properties?

The disposal sites are located in inactive bo"ow pits on property cu"ently used for operation of a nuclear power plant (WNP-2). Their location is about 2(X)() feet from the closest boundary for this property.

b. Has the site been used for agriculture? If so, describe.

No.

c. Describe any structures on the site.

None.

d. Will any structures be demolished? If so, what?

No.

e. What is the current zoning classification of the site?

The WNP-2 site is zoned as Unclassified Use district by Benton County.

f. What is the current comprehensive plan designation of the site?

The 1985 Benton County plan designates the WNP-2 area as "Hanford Reservation. "

g. If applicable, what is the current shoreline master program designation of the site?

Not applicable.

h. Has any part of the site been classified as an "environmentally sensitive" area? If so, explain.

No.

1. Approximately how many people would reside or work in the completed project?

None.

j. Approximately how many people would the completed project displace?

None.

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Spray Pood Sediment Duposa1

k. Proposed measures to avoid or reduce displacement impacts, if any:

Not applicable.

1. Proposed measures to ensure the proposal is compatible with existing and projected land uses and plans, if any:

Not applicable.

9. Housing

a. Approximately how many units would be provided, if any? Indicate whether high, middle, or low-income housing.

None.

b. Approximately how many units, if any, would be eliminated? Indicate whether high, middle, or low-income housing.

None.

c. Proposed measures to reduce or control housing impacts, if any:

None . .

10. Aesthetics

a. What is the tallest height of any proposed structure(s), not including antennas; what is the principal exterior building material(s) proposed'?

The sediment disposal cells will be constructed in a depression. The highest portion of an individual cell will be less than six feet above grade.

b. What views in the immediate vicinity would be altered or obstructed?

None.

c. Proposed measures to reduce or control aesthetic impacts, if any:

None.

11. Light and Glare

a. What type of light or glare will the proposal produce? What time of day would it mainly occur?

None.

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SEPA Check&t

b. Could light or glare from the finished project be a safety hazard or interfere with views'?

No.

c. What existing off-site sources of light or glare may affect your proposal?

None.

d. Proposed measures to reduce or control light and glare impacts, if any:

None.

12. Recreation

a. What designated and informal recreational opportunities are in the immediate vicinity?

The project site is located within the exclusion area of WNP-2. The area is not used for recreating.

b. Would the proposed project displace any existing recreational uses'! If so, describe.

No.

c. Proposed measures to reduce or control impacts on recreation, including recreation opportunities to be provided by the project or applicant, if any:

None.

13. Historic and Cultural Preservation

a. Are there places or objects listed on, or proposed for, national, state, or local preservation registers known to be on or next to the site? If so, generally describe.

No.

b. Generally describe any landmarks or evidence of historic, archaeological, scientific, or cultural importance known to be on or next to the site:

None.

c. Proposed measures to reduce or control impacts, if any:

None.

Page 13

Spray Pond Sediment D'-'posnl

14. Transportation

a. Identify public streets and highways serving the site, and describe proposed access to the existing street system. Show on site plans, if any.

WNP-2 has a paved access from Hanford Site Route 4.

b. Is the site currently served by public transit? If not, what is the approximate distance to the nearest transit stop?

The site is served by Ben Franklin Transit's commuter service.

c. How many parking spaces would the completed project have? How many would the project eliminate?

The project has no relationship to the availability of, or demand for, parking spaces on the site.

d. Will the proposal require any new roads or streets, or improvements to existing roads or streets, not including driveways? If so, generally describe (indicate whether public or private).

No.

e. Will the project use (or occur in the immediate vicinity of) water, rail, or air transportation? If so, generally describe.

No.

f. How many vehicular trips per day would be generated by the completed project? If known, indicate when peak volumes would occur.

None.

g. Proposed measures to reduce or control transportation impacts, if any:

None.

15. Public Services

a. Would the project result in an increased need for public services (for example: fire protection, police protection, health care, schools, other)? If so, generally describe.

No. Disposal of spray pond sediment does not result in a demand for services.

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SEPA Checklist

b. Proposed measures to reduce or control direct impacts on public services, if any:

N_one.

16. Utilities

a. List utilities currently available at the site (electricity, natural gas, water, refuse service, telephone, sanitary sewer, septic system, etc.):

The WNP-2 site has all the facilities needed to support an industrial plant and the associated workforce.

b. Describe the utilities that are proposed for the project, the utility providing the service, and the general construction activities on the site or in the immediate vicinity which might be needed.

The proposal will require no utilities.

C. SIGNATURE The above answers are true and complete to be best of my knowledge. I understand that the lead agency is relying on them to make its decision.

Signature:

Date submitted:

Paae 15

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MONTHYEAR2021-06-23 [Table View]

GO2-20-104, On-Site Cooling System Sediment Disposal

Text

Subject:

Dear Sir or Madam,

Enclosure:

SUMMARY

1. Background

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Subject:

Dear Mr. Coleman:

Dear Mr. Zeller:

Subject:

Reference:

Dear Mr. Zeller:

Subject:

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GO2-20-104, On-Site Cooling System Sediment Disposal

Text

Subject:

Dear Sir or Madam,

Enclosure:

SUMMARY

1. Background

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Subject:

Dear Mr. Coleman:

Dear Mr. Zeller:

Subject:

Reference:

Dear Mr. Zeller:

Subject:

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