ML20138E443

Environ Assessment & Finding of No Significant Impact Re 830714 Request for Disposal of Low Level Radwaste.Proposed Action Will Have No Significant Impact on Human Environ

ML20138E443
Person / Time
Site:	Davis Besse
Issue date:	09/30/1985
From:	Lainas G Office of Nuclear Reactor Regulation
To:
Shared Package
ML20138E417	List: ML20138E411 ML20138E443
References
TAC-52484, TAC-60875, NUDOCS 8510250024
Download: ML20138E443 (8)

Text

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7590-01 UNITED STATES NUCLEAR REGULATORY COMMISSION TOLEDO EDISON COMPANY AND THE CLEVELAND ELECTPIC ILLUMINATING COMPANY DOCKET NO. 50-346 ENVIRONMENTAL ASSESSMENT AND FINDING OF NO SIGNIFICANT IMPACT The U. S. Nuclear Regulatory Commission It he Commission) is considering the approval of a procedure for the disposal of Ice-level radioactive waste proposed by Toledo Edison Company. Toledo Edison Company and The Cleveland Electric Illuminating Company are the licensees for the Davis-Besse Nuclear Power Station, Unit No.1, located in Ottawa County, Ohio. The unit is operated by Toledo Edison Company.

ENVIPONMENTAL ASSESSMENT Identification of Proposed Action: The proposed action by the NRC would approve the disposal of low-level radioactive waste, as proposed by Toledo Edison Company's request dated July 14, 1983. Supplementary information was provided by the licensee by letters dated July 30, 1984, and January 29, 1985. The request for approval is submitted pursuant to 10 CFR 20.302. The i

licensee proposes to dispose of periodic low-level radioactive dredgings from the on-site settling basins onto land owned by Toledo Edison Company. Under the proposed method, Toledo Edison would continue the current practice of transferring each year approximately 1000 cubic feet of radioactively contaminated secondary-side clean-up resins and about 5800 cubic feet of nonradioactive wastes from the water treatment facility to on-site settling

, 8510250024 851015 ADOCK 05000346 PDR P PDR

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7590-01 basins. About six times over the remaining operating life of the facility, i.e., about once every five years, the settling basins would be dredged ard the removed material would be disposed of on land, at a minimum thickness of two feet, covered with four inches of clean soil, and seeded.

The Need for the Prcpesed Action: The secondary system at the Davis-Besse Nuclear Power Station is equipped with a demineralizer system for

, maintaininn purity of the secondary coolant. Although this clean-up system is not intended as a radicactive waste processing system, radioactive material, if present, will accumulate on the clean-up resins. For routine minor leakage typically associated with thermal expansion and contraction of the steam generator, the contamination level will be very low, but for larger tube leaks, the contamination level could be substantially greater.

The clean-up resins, when expended, are replaced with fresh resin. The expended resins are backwashed into a receiving tank and are sampled and analyzed for radioactivity. Depending upon the amount of radioactive contamination, the resins are either transferred for further processing and disposal at an off-site licensed radioactive waste burial site or are transferred to the on-site settling basins.

! Over the past years of operation at Davis-Besse Nuclear Power Station, very low levels of contaminated clean-up resins have accumulated in the

! on-site settling basins, and it is anticipated that the basins will require dredging in the near future and at approximately five-year intervals thereafter. Since the dredgings are slightly contaminated with radioactive materials, the resins must be handled as radioactive waste requiring disposal at a licensed burial site unless an alternative method of disposal is approved. '

The off-site disposal at a licensed radioactive waste burial site would l

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require that the dredged resins be further processed, packaged, and transported to the disposal site. These efforts would result in a certain

, level of personnel exposure to radioactive material which would be unavoidable. Disposal of the dredgings in the manner proposed, according to the licensee, could reduce the time and effort required of plant personnel in 1

radiation areas thereby reducing overall occupational radiation exposure.

On-site disposal of the dredgings also would be less costly than off-site disposal at licensed burial sites.

Environmental Impacts of the Proposed Action: Toledo Edison plans to continue to transfer about 1000 ft3/yr of radioactively contaminated '

secondary-side clean-up resins to on-site settling basins. Larger volumes 3

(about 5,800 ft /yr) of nonradioactive wastes from the water treatment facility are also discharged to the on-site basins. Toledo Edison proposes to dredge the settling basins about six times over the operating life of the plant (i.e., one dredging about every five years). The principal radionuclides that would be in the dredgings and their average concentrations (pCi/cc) at the time of dredging are estimated to be as follows: Fn-54, 0.15; Co-58, 3.0; Co-60, 0.08; Cs-134, 2.4; and Cs-137, 3.2. The concentrations of these radionuclides would decrease with time due to radioactive decay. The volume of the dredged material is estimated to be ,

3 about 34,000 ft for a five-year period. The total activity of the dredged material for a five-year period is estimated to be about 8.5 mci with Co-58, Cs-134 and Cs-137 accounting for the largest fractions (i.e., 0.34, 0.27, and 0.36, respectively) of the total activity.

The Commission's staff has reviewed the potential pathways for exposure to members of the general public from the radionuclides in the disposed dredgings. These potential pathways include: (1) external exposure from l

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7590-01 standing en the ground above the disposal site; (2) internal exposure from ingestion of food grown on the disposal site; (3) internal exposure from inhalation of resuspended radionuclides; and (4) internal exposure from ingesting ground water. The models uscJ to estimate doses were taken from USNRC Regulatory Guide 1.109, " Calculation of Annual Doses to Man from Routine Releases of Reactor Effluents for the Purpose of Evaluatino I Compliance with 10 CFR part 50, Appendix I," Revision 1, October 1977. The dose to a member of the public from the most likely exposure pathway (i.e.,

external exposurel is conservatively estimated to be less than I mrem /yr to the total body (see Table 1, below). The dose to a member of the public from ingesting food grown on the disposal site is conservatively estimated to be less than 3 mrems/yr to the total body (see Table 2, below). However, this pathway of exposure is very unlikely since the licensee is required by its radiological effluent technical specifications to conduct an annual land use survey to detect changes in land use. Doses from inhalation of resuspended radionuclides are estimated to be minimal due to the proposed soil covering.

The licensee has estimated that the dose from drinking ground water would be less than 0.1 mrem /yr. The estimated doses from the potential pathways of exposure are small fractions of one year's exposure to natural background radiation (about 100 millirems for the State of Ohio). .

Toledo Edison Company has stated that the disposal of the clean-up resins on-site is most 'ikely to result in a decrease in occupational exposure because workers would spend less time controlling, processing and packaging i

these wastes. Doses to workers from exposure during the disposal operations will be limited by 10 CFR Part 20.

l TABLE 1 d

• ESTIMATED DOSES TO A'l INDIVIDUA* ThGil STANDII:G AB0VE Tile UNCOVERED BASIN DREDGIt'GS ,

Nuclide Average Concentration Average Surface External Dose Dose Rate, Annual Dose, pCi/cc Deposi tion, pCi/m2 Factor, mrem /hr mrem /hr mrem per pCi/m?

Mn-54 0.15 1.5 E+04 5.8 E-09 8.7 E-05 0.01 Co-58 3.0 3.0 E+05 7.0 E-09 2.1 E-03 0.21 Co-60 0.079 7.9 E403 1.7 E-08 1.3 E-04 0.013 i Cs-134 2.4 2.4 E405 1.2 E-08 2.9 E-03 0.29

$ Cs-137 3.2 3.2 E+05 4.2 E-09 1.3 E-03 0.13 j TOTAL 8.8 8.8 E+05 6.5 E-03 0.7 a

Average concentrations were taken from Table 2 of a letter from R. P. Crouse to J. F. Stolz, dated July 30, 1984. The average surface deposition was estimated by assuming that all cf the activities '

in the top 10 cm of sludge were deposited on the surface, and that the average concentrations of 4

i radionuclides in the dried sludge were the same as the measured concentrations (wet weight). These two assumptions tend to counter-balance each other. Dose factors were taken from Regulatory Guide i 1.109, Rev. 1, pp. 41-42. In estimating the annual dose the following conservative assumptions have been made: (1) an exposure of 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> / year; and (2) no soil covering.

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TABLE 2 ESTIMATED COSES TO Afi INDIVIDUAL FROM INGESTION OF FOOD Average Nuclide Concentration, DCi/kg Annual Dese, crem Highest Dose Slucge Vegetation Total Body to Any Organ Mn-54 150 4.4 0.002 0.04(GI-LLI)

Co-58 3000 28. 0.027 0.25(GI-LLI)

Co-c0 79 0.74 0.002 0.02 (GI-LLI)

Cs-134 2400 24. 1.7 2.1 (liver)

Cs-137 3200 32. 1.3 2.0 (liver)

TOTAL EE00 89 3 4 a

Based on the transfer factors in Table E-1, p. 37 of Regulatory Guide 1.109, Rev. 1, and assuming no soil covering, b

Based on an adult ingesting 580 Kg of fruits, vegetables & grain, and using the dose conversion factors in Regulatory Guide 1.109, Rev.1, pp. 55, 57.

Doses from ingesting milk or meat would be less than the doses from ingesting fruits, vegetables and grain. ~

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Based on the Commission staff's review of the proposed sludge disposal,

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the staff concludes that:

(1) The doses to members of the public as a result of exposure to radiation from the disposed dredgings will be well below regulatory limits and very small in comparison to doses members of the public receive each year from exposure to natural background radiation. At the time of decomissioning of the nuclear power plant, the land on which the sludge is disposed is capable of being released for unrestricted use.

(2) The licensee has taken appropriate steps to ensure that occupational

! doses will be maintained as low as is reasonably achievable and within the limits of 10 CFR part 20.

-l Alternatives to the Proposed Action: Since we have concluded that the environmental effects of the proposed action are very small, any alternatives with equal or greater environmental impacts need not be evaluated. The

, principal alternative would be to deny the requested approval. This would i

most likely increase the occupational exposure to the plant personnel since the dredgings from the basin would require additional processing and i

packaging necessary for shipment to an off-site disposal location.

Additionally, there would be increased costs to the consumer and '

transportation impacts related to the shipment between the Davis-Besse Station l

and the off-site disposal location.

Alternative Use of Resources: The principal result of this action

! involving the use of resources not previously considered in the Final l

l Environmental Statement Related to Operation of Davis-Besse Nuclear power Station, Unit 1, (NUREG-75/079) is the minor change in land use associated with operating support of the facility. This change in land use is not significant.

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1 Achncies and Persons Consulted: The Commission's staff reviewed the licensee's request and has not consulted other agencies or persons.

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FINDING OF L'O SIGNIFICANT IMPACT The Commission has detemined not to prepare an environmental impact staternent for the proposed action. '

Based upon the forecoing environmental assessment, the Cormission concludes that the proposed action will not have a significant effect on the quality of the human environment.

i For further details with respect to this action, see the licensees' i

initial reouest for approval dated July 14, 1983, and supplemental j

i infomation submitted July 30, 1984, and January 29, 1985, which are i

available for public inspection at the Commission's Public Docuraent Room, 1

1717 P Street, N.P., Washington, D.C. , and at the University of Toledo Library, Documents Department, 2801 Bancroft Avenue, Toledo, Ohic 43606.

Dated at Bethesda, M3ryland this 30th day of September 1985 r0R THE NUCLEAR REGl'LATORY C0vt ISSION

1. M

/us C. Lainas, Assistant Director

/ fo:- Operating Peactors Division of Licensing .

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