ML20205C221

Environ Assessment & Finding of No Significant Impact Re Release of Portion of Cushing Refinery Site for Unrestricted Use

ML20205C221
Person / Time
Site:	07003073
Issue date:	03/26/1999
From:	NRC
To:
Shared Package
ML20205C207	List: ML20205C205 ML20205C215 ML20205C221
References
NUDOCS 9904010114
Download: ML20205C221 (8)

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n. C U.S. NUCLEAR REGULAlORY COMMISSION

. DOCKET NO. 70-3073 LICENSE NO. SNM-1999 KERR-McGEE CORPORATION - ENVIRONMENTAL ASSESSMENT-RELEASE OF PORTION OF CUSHING REFINERY SITE FOR UNRESTRICTED USE BACKGROUND: The U.S. Nuclear Regulatory Commission (NRC) is considering the Kerr-McGee Corporations's (Kerr-McGee or the licensee) request to have property released, for unrestricted use, from the Cushing Refinery Site (Cushing) License SNM-1999. This action is taken in response to Kerr-McGee's license amendment requests, dated August 30,1996, and October 24,1996, to release the four unaffected arcss a nd the haul road corridor area for unrestricted use and to remove the areas from the license. These earlier requests were revised by 1

the licensee's letter dated November 6,1998. In that letter, the licensee requested that only l

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Unaffected Area 1, the portion of Unaffected Area 2 south of Skull Creek, Unaffected Area 3, Unaffected area 4, and the portion of the haul roac corridor area south of Skull Creek and partially surrounded by Unaffected Areas 2,3, and 4 (hereafter referred to as requested released areas (R.RA)) be released for unrestricted use. T! boundaries of the licensed areas excluding the RRA are shown in Figure 1," Cushing Site Map She ang Licensed Site Area," of the November 6,1998, letter.

Introduction:

i On April 6,1993, NRC issued Materials License SNM-1999 authorizing possession of contaminated soil, sludge, sediment, trash, building rubble, and any other contaminated material, at the licensee's Cushing site. The site contains four large areas, designated as the four unaffected areas, that were used for oil refining and storage during the years that nuclear 9904010114 990326 7 s

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2-processing and disposal took place. The haul road corridor area is located on portions of the site that were used for petroleum refining during the years that nuclear material processing was 1

performed. The haul roads located within the haul road corridor area are intended for

transporting waste material during site remediation.

l The licensee initially requested that the four unaffected areas and the haul road corridor be I l

removed from the license and released for unrestricted use. The licensee revised its earlier l

requests to limit the areas to be removed from the license and released for unrestricted use to the l RRA.

Proposed Action:

The propose ?.ction is the release for unrestricted use, and the removr.1 from License SNM-1999, de RRA. The proposed boundary of the licensed areas excluding the RRA is shown in the licensee's lett,:r dated November 6,1998, Figure 1," Cushing Site Map Showing Licensed l

Site Area."

The Need fo; Proposed Action:

i The licensee seeks to release property that is currently under license for unrestricted use.  !

This action is requested to remove the current limitations on the future use of the property.

Alternatives to Proposed Action:

1 The only alternative to the proposed action is to not release this area for unrestricted use and keep the area under license until all site radiological remediation is completed and the Cushing license is terminated. The environmental benefit of maintaining an NRC license for this portion of the Cushing Refinery Site is negligible, but would reduce options for future use of the property.

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3 Environmental Justice:

There are no environmental justice issues associated with this proposed action.

EnvironmentalImpact of Proposed Action: ,

1 An unaffected area, as defined in NUREG/CR-5849," Manual for Conducting Radiological Surveys in Support of License Termination,"is an area not expected to contain residual n dioactivity from licensed operations. The unrestricted use guidelines for enriched uranium and natural thorium are the Option 1 values in the 1981 Branch Technical Position on " Disposal or Onsite Storage of Thorium or Uranium Wastes From Past Operations"(46 ER 52061). The Option 1 guidelines are 30 picoCuries per gram (pCi/g) for enriched uranium and 10 pCi/g for natural thorium.

The licensee performed final status surveys in the four unaffected areas and submitted the results to NRC in the " Final Radiation Survey of Four Unaffected Areas of the Cushing Refinery Site," dated April 17,1995. Gamma radiation scans, gamma exposure rate measurements, soit j radioactivity concentration measurements, and surface radioactivity survey were performed in each of the four unaffected areas. As a result of the surveys and analysis, one area of about one meter in diameter on the surface of the ground was found to be contaminated with Th-232. This spot was designated as a radioactive materials area and was removed from the areas that the licensee considered part of the four unaffected areas. The licensee's survey report provided data that indicated that the four unaffected areas rocet NRC's guidelines for unrestricted use.

The licensee performed final status surveys in the haul road corridor area and submitted the results to NRC in the " Final Radiation Survey of Haul Road Corridor," dated May 30,1996. The )

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resrJts of the ecposure rate surveys of the haul road corridor area indicated that no location was 1

.. 3 more .han 10 micoRoentgen per hour (pR/hr) above background. Gamma scans located areas of elevated activity. Biased soil samples were collected from these areas and analyzed using gamma spectroscopy. As a result of the analysis, two areas were designated as radioactive materials areas and were removed from the areas that the licensee considered part of the haul road corridor area. This licensee survey report provided data that indicated that the haul road 1

corridor area meets NRC's guidelines for unrestricted use.

At the request of NRC, its contractor, the Oak Ridge Institute for Science and Education (ORISE), performed a confirmatory survey of the four unaffected areas during the period of September 11 through 13,1995, and a confirmatory survey of the haul road corridor area during the period of August 26 through 29,1996. The results of the ORISE confirmatory surveys were j l

provided to NRC in " Confirmatory Survey for the Four Unaffected Areas of the Cushing i Refinery Site," dated May 1996, and " Confirmatory Survey for the Haul Road Corridor at the Oklahoma Refinery Site," dated December 1996.

For both the four unaffected areas and the haul road corridor area, ORISE performed scan smveys of 50 to 100 percent of the surface area of each selected survey unit. ORISE also performed exposurc rate measurements for at least five systematic locations within each survey unit. In addition, ORISE collected 20 soil samples from the four unafTected areas, and collected more than 60 surface soil samples and three subsurface soil samples from the haul road corridor area.

Concentrations of radionuclides in the soil samples from the four unaffected areas survey units are as follows: less than 0.1 to 0.5 pCi/g for U-235; 0.3 to 3.0 pCi/g for U-238; 0.6 to 9.0 pCi/g for Th-228; and less than 0.8 to 10.0 pCi/g for Th-232. One small area of thorium, in m

. j excess of the gmdelines (9.0 pCi/g of Th-228 and 10.0 pCi/g of Th-232), is in unaffected area i

number 2. This area of elevated thorium levels, surveyed by ORISE, is the same area that the 2

licensee designated as a radioactive materials area (abou; 400 m ) after it performed its final radiation survey, Thus, this small radioactive materials area is not part of the licensee's request for unrestricted release. Of the areas that ORISE surveyed that were part of the licensee's request for unrestricted release, the concentrations of radionuclides in the soil samples are as follows: 0.6 to 3.8 pCi/g for Th-228; and less than 0.8 to 3.0 pCi/g for Th-232. The soil samples are within the Option 1 soil guidelme for enriched uranium and natural thorimn. Further, the )

portion of the haul road corridor that is being considered for release from the license would service only equipment transportation, at most, Option 1 material.

I Concentrations of radionuclides in the soil samples from the haul road corridor area survey units are as follows: less than 0.8 pCi/g for U-235; less than 2.9 pCi/g for U-238; 0.5 to 2.9 pCi/g for Th-228; and less than 0.4 to 2.8 pCi/g for Th-232. For comparison purposes, l radionuclide concentrations in background soil samples are as follows: less than 0.1 pCi/g for U-235; 1.0 to 1.t; pCi/g for U-238; 0.5 to 1.0 pCi/g for Th-228; and 0.6 to 0.9 pCi/g for Th-232.

The scil samples yielded results indicating only backgrount or slightly above background concentrations of uranium and thorium. The soil samples are within the Option 1 soil guideline

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for enriched uranium and natural thorium.

NRC considered the potential for contamination of areas within the haul road corridor once NRC authorized the licensee to conduct activities within the haul road corridor v. :thout i

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implementation of the Cushing Radiation Safety procedures related to training. The staff agreed with the licensee that the Cushing Radiation Safety Program which requires all material and equipment be surveyed before leaving a " radioactive materials area" would provide reasonable assurance that the haul road corridor area would not become contaminated as a result of decommissioning activity.2 Groundwater under the Cushing site can be found in one of three water-bearing zones. The water-bearing zones are the shallow water-bearing zone (unconsolidated soil and the upper portion of the Vanoss Group), the lower portion of the Vanoss Group, and Vamoosa-Ada aquifer.

The Vamoosa-Ada aquifer is the regional groundwater aquifer. The licensee notes that it appears that there is not a significant groundwater flow between the shallow water-bearing zone and the lower portion of the Vanoss Group. Further, the licensee notes that the Vamoosa-Ada aquifer is isolated from the uppermost water-bearing zone by low-permeability strata within the Vanoss.

Thus, the Vamoosa-Ada aquifer is unaffected by surface activities. The licensee based this finding on an evaluation of environmental tritium.

The State of Oklahoma, Depanment of Environmental Quality (DEQ)2 found the following:

. (1) the shallow groundwater unit yields low quantities of poor quality water; (2) it is highly

. unlikely that future residential or commercial drinking water wells will be established from the

! Letter'to Stuart (sic] Brown, NRC, from Jeff Lux, Kerr McGee Corporation, dated August 30,1996.

2 Letter to Jeff Lux, Kerr McGee Corporation, from Stewart Brown, NRC, dated i October 22,1996c 8 Letter to Jeff Lux, Kerr McGee Corporation. from Darrell Shults, DEQ, dated

. September 19,1997.

shallow groundwater at this site; and (3) no known drinking water wells are screened in the shallow groundwater at this site. Further, DEQ stated that the Vanoss should not be considered a viable drinking water source for the area and that DEQ would consider water quality standards other than maximum contamination levels as set by the U.S. Environmental Protection Agency (EPA) as appropriate for the shallow groundwater at this site. Further, based on EP A's guidance 4 ,

the Vanoss groundwater would be classified as a Class III - Groundwater Not a Potential Source of Drinking Water and of Limited Beneficial Use.

The staff has reviewed the site potentiometeric surface map of the upper zone5 and found that all portions of the RRA are up-gradient of any known significant sources of contamination.

Accordingly, it is very unlikely that the groundwater in these areas could have been contaminated. The assumption is supported by the results of the licensee's groundwater monitoring of several wells located either in the four unaffected areas orjust down-gradient of these areas. The licensee provided these sampling results in its letter dated November 6,1998.

Based on its review of that data, the staff round no indication of groundwater contamination.

The Other Industrial Waste (OlW) disposal cell is located within the RRA. Material from the remediation of Waste Acid Sludge Pit 4 (Pit 4) that meets V'.C's Option 1 criteria for unrestricted release will be disposed ofin the OIW, NRC reviewed this disposal activity as part ofits review of the Pit 4 remediation plan. On September 3,1998, NRC approved the Pit 4 remediation plan, License Amendment No. 8.

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" Guidelines for Ground-Water Classification Under the EPA Ground-Water Protection Strategy," Final Draft, dated November 1986, Office of Water, EPA.

5 Figure 2.5, "Potentiometeric Surface Map of the Upper Zone," Kerr-McGee Corporation's Site Decommissioning Plan Cushing, Oklahoma, dated August 1998.

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. s FN lly, a ditch in site grid blocks 132,133, and 140 was filled with rubble from refinery demolition. Also, placed into this ditch were concrete blocks from the thorium processing building slab. 'l te licensee in its letter dated November 13,1998, provided the final survey data of these concrett slab blocks. Based on its review of these data, NRC found that the concrete i

slab blocks met NRC's criteria for unrestricted release. l ORISE's confirmately survey results support the licensee's position that the four unafTected areas and the haul road corridor area meet NRC's unrestricted use criteria. Further, the licensee's groundwater monitoring sampling program results demonstrate that the groundwater under the RRA is not contaminated. Therefere, NRC finds that because the NRC's unrestricted release criteria have been met for these areas, there is no significant innpact on the environment, and this portion of the property can be released for unrestricted use.

Other Agencies or Persons Consulted:

This environmental assessment was prepared entirely by NRC. No other sources were used beyond those referenced in this environmental assessment. 'NRC provided a draft of this environmental assessment to DEQ for review. DEQ had no comments or suggestions on this environmental assessment.

Conclusions:

NRC finds that because the Commission's unrestricted release criteria have been met, there is no significant impact on the environment, and the property can be released for unrestricted use.