ML092670521

Draft Report, Confirmatory Survey of Two Soil Piles Proposed for On-Site Storage Kerr-McGee Corp, Cimarron Facility Crescent, Ok

ML092670521
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Site:	07000925
Issue date:	07/31/1994
From:	Ansari A Oak Ridge Institute for Science & Education
To:	Office of Nuclear Material Safety and Safeguards
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70-925 KERR-MCGEE CORPORATION, DRAFT REPORT CONFIRMATORY SURVEY OF TWO SOIL PILES FOR ON-SITE STORAGE REC'D W/LTR DTD 7/8/94....9408010286

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THE ATTACHED FILES ARE OFFICIAL RECORDS OF THE INFORMATION &

RECORDS MANAGEMENT BRANCH.

THEY HAVE BEEN CHARGED TO YOU FOR A LIMITED TIME PERIOD AND MUST BE RETURNED TO THE RECORDS & ARCHIVES SERVICES SECTION, T5 C3. PLEASE DO NOT SEND DOCUMENTS CHARGED OUT THROUGH THE MAIL. REMOVAL OF ANY PAGE(S) FROM DOCUMENT FOR REPRODUCTION MUST BE REFERRED TO FILE PERSONNEL.

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--F 94080102B8 940708 NMSS ADOCK 07000925 CF

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CONFIRMATORY SURVEY OF TWO SOIL PILES FOR ON-SITE STORAGE KERR-McGEE CORPORATION, CIMARRON FACILITY CRESCENT, OKLAHOMA Prepared by A. J. Ansari Environmental Survey and Site Assessment Program Energy/Environment System Division Oak Ridge Institute for Science and Education Oak Ridge, Tennessee 37831-0117 Prepared for the U.S. Nuclear Regulatory Commission July 1994 DRAFT REPORT This report is based on work performed under an Interagency Agreement (NRC Fin.

No. A-9076) between the U.S. Nuclear Regulatory Commission and the U.S. Department of Energy. Oak Ridge Institute for Science and Education performs complementary work under contract number DE-AC05-76OR00033 with the U.S. Department of Energy.

This draft report has not been given full review and patent clearance, and the dissemination of its information is only for official use.

No release to the public shall be made without the approval of the Office of Information Services, Oak Ridge Institute for Science and Education.

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ACKNOWLEDGEMENTS The author would like to acknowledge the significant contributions of the following staff members:

FIELD STAFF E. H. Bjelland A. L. Mashburn LABORATORY STAFF R. D. Condra J.

S.

Cox R. L. Epperson M. J.

Laudeman S. T. Shipley CLERICAL STAFF D. A. Cox R. D. Ellis K. E. Waters ILLUSTRATOR M. A. Henke T. D. Herrera Kerr McGee Corporation-Cimarron - July 8, 1994 h:\\essap\\reports\\creacent\\crescent.001

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f TABLE OF CONTENTS List of Figures...............

List of Tables Abbreviations and Acronyms....

Introduction and Site History.......

Site Description...............

Objectives...................

Document Review..............

Procedures Findings and Results Comparison of Results with Guidelines Summary...................

Figures Tables....................

References Appendices:

PAGE 111 iv 2

°,

2

° ° 3

4 7

,8 10 14 19

°

° Appendix Appendix Appendix A:

B:

C:

Major Instrumentation Survey and Analytical Procedures Guidelines for Residual Concentrations of Thorium and Uranium Wastes in Soil Kerr McGee Corporation-Cimarron - July 8, 1994 i

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0 LIST OF FIGURES FIGURE 1:

FIGURE 2:

FIGURE 3:

FIGURE 4:

PAGE Location of the Cimarron Facility, Crescent, Oklahoma...........

10 The Cimarron Facility-Plot Plan.........................

11 East Soil Pile-Sampling Locations........................

12 North Soil Pile-Sampling Locations 13 Kerr McGee Corporation-Cimnarron - July 8, 1994 ii h:\\essap\\rcports\\crescent\\crescent.001

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LIST OF TABLES PAGE TABLE 1:

TABLE 2:

TABLE 3:

TABLE 4:

Isotopic Uranium Concentrations in Soil Samples...............

14 Radionuclide Concentrations in Soil Samples-East Soil Pile.........

15 Radionuclide Concentrations in Soil Samples-North Soil Pile........

17 Radionuclide Concentrations in Soil Samples-Confirmatory Analyses..

18 Kerr McGee Corporation-Cimarron - July 8, 1994 ih:espratscsencecnL l

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ABBREVIATIONS AND ACRONYMS AEC Atomic Energy Commission ASME American Society of Mechanical Engineers cm centimeter cm 2 square centimeter cpm counts per minute D&D Decontamination and Decommissioning EML Environmental Measurement Laboratory EPA Environmental Protection Agency ESSAP Environmental Survey and Site Assessment Program ft3 cubic feet m

meter m 2 square meter m 3 cubic meter MDA minimum detectable activity Nal sodium iodide NIST National Institute of Standards and Technology NRC Nuclear Regulatory Commission ORISE Oak Ridge Institute for Science and Education pCi/g picocuries per gram SFC Sequoyah Fuels Corporation Kerr McGee Corporation-Cimarron - July 8, 1994 iv h:\\essap\\reports\\crescent\\crescent.001

CONFIRMATORY SURVEY OF TWO SOIL PILES FOR ON-SITE STORAGE KERR-McGEE CORPORATION, CIMARRON FACILITY CRESCENT, OKLAHOMA INTRODUCTION AND SITE HISTORY The Kerr-McGee Corporation operated the Cimarron facility in Crescent, Oklahoma to produce slightly enriched (approximately 3% U-235) uranium fuel and mixed oxide (uranium plus plutonium) fuel between 1965 and 1975.

These activities were conducted under License SNM-928 with the Atomic Energy Commission (AEC), predecessor to the Nuclear Regulatory Commission (NRC). In 1983, Sequoyah Fuels Corporation (SFC) became the owner of the Cimarron Facility, when Kerr-McGee Nuclear Corporation was divided into SFC and Quivira Mining Corporation.

Subsequently, Cimarron Corporation, a subsidiary of the Kerr-McGee Nuclear Corporation, became responsible for the Cimarron Facility.

Cimarron Corporation has discontinued fuel production activities and is in the process of performing the decontamination to terminate the NRC licensing restrictions.

The decontamination and decommissioning (D&D) project was divided into several phases, which involved the Mixed Oxide Plant, the Uranium Plant, the On-site Burial Ground, and the Sanitary Lagoons. The D&D activities involving the Mixed Oxide plant, the Burial Ground, and the Sanitary Lagoons have been completed and activities involving the Uranium plant are nearing completion.

As part of the overall D&D effort, remediation of contaminated soil at Cimarron Facility began as early as 1976.' This soil is contaminated, primarily, with low-enrishment uranium; however, areas of thorium-contaminated soil, presumed to have been brought to the Cimarron facility from the Kerr-McGee site at Cushing, have been identified.' Plutonium contamination was confined, primarily, to the interior surfaces of the Mixed Oxide Plant. Isolated locations of elevated plutonium activity were identified in the soil areas immediately adjacent to that building and no elevated levels of plutonium were identified in the survey of the Sanitary Lagoons.2',3 Therefore, plutonium is not considered as a likely contaminant in these soil areas. The contaminated soil at this facility was characterized and sorted into Option 1, Option 2, and Option 4 categories, Kerr McGee Corporation-Cimarron - July 8, 1994 h:\\essap\\reports\\crescent\\crescent.001

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according to the NRC Branch Technical Position on "Disposal or Onsite Storage of Thorium and Uranium Wastes from Past Operations".' The Option 1 soil was left in place. Option 2 soil has been stockpiled for on-site disposal.

Option 4 soil has been removed and sent for off-site disposal.

The U.S. Nuclear Regulatory Commission requested that the Environmental Survey and Site Assessment Program (ESSAP) of the Oak Ridge Institute for Science and Education (ORISE) perform an independent confirmatory survey of the Option 2 soil piles which are kept at this facility, in anticipation of being permanently relocated to the on-site disposal cells. This report summarizes the procedures and results of that survey.

SITE DESCRIPTION The Cimarron Corporation facility is located on a site of approximately 450 hectares in Logan County, Oklahoma, about 8 kilometers south of Crescent (Figure 1). The main facilities at this site were the Uranium Plant and the Mixed Oxide Plant. Approximately, 350,000 ft3 (10,000 in3) of Option 2 soil are currently stockpiled in two separate piles, to the east and north of the Uranium Plant (Figure 2). Both soil piles are leveled on top and are approximately two meters high.

OBJECTIVES The objectives of the confirmatory process are to provide independent document reviews and radiological data, for use by the NRC in evaluating the adequacy and accuracy of the licensee's radiological survey data, relative to established guidelines.

DOCUMENT REVIEW As part of the confirmatory activities, ESSAP reviewed the licensee's analytical procedures and methods for adequacy and appropriateness.

Licensee's data were reviewed for accuracy, completeness, and compliance with applicable NRC guidelines.

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PROCEDURES On May 4 and 5, 1994, ESSAP performed a confirmatory survey of two soil piles, adjacent to the Uranium Plant at the Cimarron Corporation facility.

The survey was conducted in accordance with a survey plan which was submitted to and approved by the NRC.5 REFERENCE GRID A 5 m x 5 m reference grid was established by the licensee. The same grid system was used by ESSAP to reference measurement and sampling locations..

SURFACE SCANS Surface scans for elevated direct radiation were performed on 100% of both the East and North piles, using Nal detectors coupled to countrate meters with audible indicators.

Scans for elevated direct radiation were also performed in boreholes.

Locations of elevated direct radiation were noted for further investigation.

SOIL SAMPLING The analytical results of background soil samples, collected during a previous ESSAP survey of this facility, were used for comparison.2 Surface and subsurface soil samples were collected from boreholes at randomly selected locations and at locations of elevated direct radiation which were identified by surface scans and/or licensee's final survey data. Samples were collected from fifteen boreholes in the East Pile and eight boreholes in the North Pile; twenty six samples were collected from the East Pile and fourteen samples from the North Pile. Sampling locations are illustrated in Figures 3 and 4.

Sampling depths are indicated in Tables 2 and 3.

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CONFIRMATORY ANALYSIS Ten soil samples were selected, from those obtained by the licensee, for confirmatory analysis.

The basis of this selection was to provide samples with a wide range of activities.

SAMPLE ANALYSIS AND DATA INTERPRETATION Samples and data were returned to ORISE's ESSAP laboratory in Oak Ridge, TN for analysis and interpretation. Soil samples were analyzed by gamma spectrometry. Spectra were reviewed for U-235, U-238, Th-232, Th-228, and any other identifiable photopeaks. Selected soil samples were analyzed by alpha spectrometry for uranium. Soil sample results were reported in units of picocuries per gram (pCi/g).

Additional information concerning major instrumentation, sampling equipment, and analytical procedures is provided in Appendices A and B. Results were compared to NRC guidelines which are provided in Appendix C.

FINDINGS AND RESULTS DOCUMENT REVIEW ESSAP reviewed the licensee's analytical procedures, methods and the radiological survey data.

This review was performed on-site. The licensee had not prepared a final "package" to review.

Some of the final survey data were being prepared as the document review was in process; however, all the information was either available or was provided to ESSAP by the end of survey activities on May 5, 1994.

The majority of ESSAP comments were clarification items, regarding MDA calculation for the gamma counting system, sample preparation procedure, method of averaging in 100 m2 areas, and total number of samples in survey data and summary sheets. All comments, except for two, were resolved on-site. These comments have been provided to the NRC.6 Kerr McGee Corporation-Cima-ron - July 8, 1994 4

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The two unresolved issues, as identified in the licensee's analytical data, were the presence of thorium in both soil piles (up to 21 pCi/g total thorium) and the presence of two areas with average uranium concentration in excess of 300 pCi/g.

These areas, identified from the licensee's survey results, were located on the surface of the East Pile (grid coordinates 85N, 165E), and the bottom northeast corner of the East Pile (grid coordinates 105N, 170E).

SURFACE SCANS Surface scans identified several locations with elevated direct radiation. The response of the Nal gamma scintillation detector ranged from 4,000 cpm (background) to 60,000 cpm. All locations of elevated direct radiation corresponded to locations identified by the licensee's final survey data.

RADIONUCLIDE CONCENTRATIONS IN SOIL SAMPLES Radionuclide concentrations in background soil samples, previously determined for this site, were <0.2 pCi/g for U-235, ranged from <0.3 to 0.9 pCi/g for U-238, and ranged from 0.9 to 2.1 for the thorium.2',7 ranged from <0.3 to 0.9 pCi/g for U-238.4 For this survey, five samples from both soil piles were analyzed by alpha spectrometry for isotopic uranium. The uranium concentrations for these samples are summarized in Table 1. This analysis indicated an U-234 to U-235 ratio of 19.1 with. a standard deviation of 3.1 which is consistent with ratios previously determined by ESSAP at this facility and the ratio of 21.7 which was used by the licensee.7',' 9 The same U-234 to U-235 ratio of 21.7 was used by ESSAP to calculate the total uranium concentrations in soil samples, based on gamma spectrometry analyses.

Concentrations of radionuclides in soil samples from the East and North Piles are summarized in Tables 2 and 3, respectively. Concentrations of radionuclides in both soil piles ranged from 0.5 to 15.9 pCi/g for U-235, 3.6 to 70.8 pCi/g for U-238, and 23 to 430 pCi/g for total uranium. Twenty of these samples were randomly obtained by ESSAP (i.e., sampling location was not biased by results of survey scans and/or licensee's data). The average concentrations of total uranium in these randomly collected samples were 53.3 + 6.4 (standard error of the Kerr McGee Corporation-Cimarron - July 8, 1994 5

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mean) pCi/g in the East Pile and 42.6 + 6.9 pCi/g in the North Pile. Based on a total sample size of 633, the licensee reported an average total uranium concentration of 46 + 1.5 pCi/g for the East Pile and 44 + 1.3 pCi/g for the North Pile.

For the statistical analysis of the data, the null hypothesis was that there were no differences between the average value of the licensee's and ESSAP's analytical results. By convention, the null hypothesis is rejected if the probability, p, is less than 0.05. Based on pair-wise comparison t-test, there are no statistically significant differences between the licensee and ESSAP's average values for the East (p > 0.4) and North (p > 0.9) Piles. Due to the large number of samples and the strong agreement between the average concentration values for each soil pile, any deviations from normal distribution of samples should have little effect on the conclusion of this statistical analysis. However, as it is shown below (under Confirmatory Analysis), for a small subgroup of these samples, the difference between the licensee's and ESSAP's analytical results are statistically significant.

Total thorium concentrations in both soil piles ranged from 0.8 to 75 pCi/g.

The average concentrations of total thorium in randomly collected soil samples were 1.8 + 0.1 (standard error of the mean) in the East Pile and 4.1 +/- 1.1 in the North Pile. The highest concentration of thorium (75 pCi/g) was located at grid coordinates 95N and 180E. This location corresponds to that identified by the licensee as having the highest concentration of thorium; however, the licensee had reported a total thorium concentration of 21 pCi/g at that location. Because there were no statistically significant differences between the licensee and ESSAP's analytical results for thorium (see Confirmatory Analysis), the difference between 75 and 21 pCi/g may be due to inhomogeneous distribution of the contaminant in the soil.

CONFIRMATORY ANALYSIS The results of the confirmatory analyses of soil samples, which were selected by ESSAP and provided by the licensee, are presented in Table 4.

It appears that for samples with total uranium concentrations greater than 100 pCi/g, values obtained by ESSAP are higher than those Kerr McGee Corporation-Cimaffon - July 8, 1994 6

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reported by the licensee; for five such samples in Table 4, ESSAP values for total uranium averaged 33% higher than the licensee's values.

These confirmatory samples were selected to provide a wide range of activities. Consequently, the radionuclide concentration values in these samples are not normally distributed. Therefore, in order to compare ESSAP and the licensee's analytical results, statistically, the nonparametric Wilcoxon rank sum test was more appropriate than a pair-wise comparison t-test. For this analysis, the null hypothesis was that there were no differences between the licensee's and ESSAP's analytical results. By convention, the null hypothesis is rejected if the probability, p, is less than 0.05.

The results of the Wilcoxon rank sum test indicated that, as a whole, the differences between ESSAP's and the licensee's analytical results for total uranium are statistically significant (p<0.05).

However, when only samples with total uranium concentrations of less than 100 pCi/g are considered, ESSAP's and the licensee's analytical results are statistically identical (p >0.1)

The analysis of total thorium concentrations indicated no statistically significant differences between ESSAP's and the licensee's data (p>0.05), based on the Wilcoxon rank sum test.

Because total thorium concentrations in these samples did not vary as they did for uranium and because the result of the nonparametric test was rather borderline, the pair-wise comparison t-test was also performed for these data; no statistically significant differences were observed (p > 0.05), consistent with the results from Wilcoxon rank sum test.

COMPARISON OF RESULTS WITH GUIDELINES The NRC guidelines for residual concentrations of radionuclides in soil, established for license termination or release of a facility for unrestricted use are presented in Appendix C. The two soil piles at this facility are being considered for on-site disposal (Option 2 material).4 The primary contaminant is enriched uranium and the site specific guidelines for total uranium are:"0 Kerr MeGee Corporation-Cimarron - July 8, 1994 7

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Total Uranium 100 pCi/g, averaged over 100m2 area 300 pCi/g, maximum at any one location The 100 pCi/g average criterion is applied to samples collected at the same depth (or plane) from the soil piles1°. This confirmatory survey identified four locations at which total uranium concentration may be in excess of these guidelines. These locations are at 1) East Pile, grid coordinates 85N, 170E at 0.5 m depth, 2) East Pile, grid coordinates 105N, 170E at 2 m depth (from document review), 3) East Pile, grid coordinates 105N, 175E, at 0.5 m depth, and 4)

North Pile, grid coordinates 147.5N, 141.5E, at 0.5m depth (the activity at this location is only 270 pCi/g which is less than the maximum criterion, but the average concentration in that 100 m2 area may have to be determined more accurately).

This survey also identified thorium at several locations in both soil piles. There are no site specific guidelines for concentrations of thorium.

The generic guideline for residual concentrations of thorium as Option 2 material is 50 pCi/g.4 The average concentration of total thorium in the East and the North Piles were 1.8 and 4.1 pCi/g, respectively.

The highest concentration of total thorium (75 pCi/g) was identified on the East Pile, grid coordinates 95N, 180E, at 0.75 m depth. In the North Pile, highest concentrations of thorium were along the grid line 152.5N; however, these total thorium concentration values were less than 10 pCi/g which is well within the 50 pCi/g limit for Option 2 materials.

SUMMARY

During the period May 4 and 5, 1994, at the request of the Nuclear Regulatory Commission, the Environmental Survey and Site Assessment Program of ORISE performed a confirmatory survey of the two soil piles at the Kerr McGee Corporation's Cimarron Facility in Crescent, Oklahoma. The activities consisted of document reviews, scans for elevated direct radiation, and surface and subsurface soil sampling.

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The average radionuclide concentrations in both soil piles, as determined by ESSAP, were statistically identical to those reported by the licensee. However, the confirmatory analysis of soil samples with varying levels of activity indicated that for samples with total uranium concentrations of greater than 100 pCi/g, ESSAP's analytical results were 33%

higher than those reported by the licensee.

The survey identified four locations at which total uranium concentrations were in excess of the guidelines. Total thorium concentration, in at least one location, was also in excess of the generic guideline for residual concentrations of thorium as Option 2 materials.2 In ESSAP's opinion, the licensee's survey data provide an adequate and accurate description of the radiological status of the two soil piles, except for samples with uncharacteristically high levels of activity (i.e., > 100 pCi/g total uranium).

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SFC77 EDM NDO-01 44 OKLAHO MA-,'.'.

44 NOT TO SCALE N

FIGURE 1: Location of the Cimarron Facility, Crescent, Oklahoma Kerr McGee Corporation-Cimarron - July 8, 1994 10 h:\\cssap\\reports\\crescent\\crescent.001

I.SFC86 (1)

MIXED OXIDE P LANT NORTH SOIL PILE TO FORMER BURIAL GROUND AREA EAST SOIL PILE N

X X

X FENCE NOT TO SCALE FIGURE 2: The Cimarron Facility -

Plot Plan Kerr McGee Corporation-Cimarron - July 8, 1994 11 h:\\essap\\Moru\\cresccnt\\crescent.001

SFC85 (2)..

115N 11ON 105N 95N 90N 85N 80N 75N 70N 65N 60N 55N 5ON 45N 40N 35N LU ifi U-)

LO to,.

0 LU LU LU LO 0

n~

(D r-r-

L.

0 00 UL to LU L

0 to-I SAMPLING LOCATIONS NI FEET 0

30 W

BOREHOLE FIGURE,3: East Soil Pile -

Sampling Locations Kerr McGee Corporation-Cimarron - July 8, 1994 12 h:\\essap\\reports\\crescent\\cresccni.(NHI

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.1 'SFC84 (2)'.

170N 160N 150N 140N 130N U-PLANT SAMPLING LOCATIONS N

FEET 0

30 ME 10

)K BOREHOLE FIGURE 4: North Soil Pile -

Sampling Locations Kerr McGee Corporation-Cimarron - July 8, 1994 13 h:\\essap\\reports\\crescent\\crscent.OO1

0 TABLE 1 ISOTOPIC URANIUM CONCENTRATIONS IN SOIL SAMPLES KERR MCGEE CORPORATION, CIMARRON FACILITY CRESCENT, OKLAHOMA Location' Depth U

Uranium Concentration (pCi/g)b U-234 U-235 U-238 Total U East pile,85-100 cm 10.6 + 0.4c 0.6 + 0.1 2.4 + 0.2 13.7 + 0.5 92.5N, 172.5E East pile, 185-200 cm 33.6 + 0.8 1.5 + 0.2 9.1 + 0.4 44.2 + 0.9 57.5N, 187.5E East pile, 0-15 cm 49.2 +/- 1.0 2.5 + 0.3 11.5 + 0.5 63.2 + 1.2 97.5N, 162.5E East pile,85-100 cm 71.6 + 1.2 3.4 + 0.3 15.5 + 0.6 90.5 + 1.3 97.5N, 162.5E I

I

_II North pile,85-100 cm 108.4 + 1.6 7.4 + 0.5 23.7 + 0.7 139.5 + 1.8 137.5N, 126.5E

'Refer to Figures 3 and 4.

bBased on alpha spectrometry.

cUncertainties represent the 95 % confidence level, based only on counting statistics.

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TABLE 2 RADIONUCLIDE CONCENTRATIONS IN SOIL SAMPLES EAST SOIL PILE KERR MCGEE CORPORATION, CIMARRON FACILITY CRESCENT, OKLAHOMA Radionuclide Concentrations (pCi/g)

Location' U-235 U-238 Total Ub Ac-228c I TI-208d Total Th 40N, 180E 85-100 cm 1.7 + 0.1e 9.8 + 1.7 48 1.1 + 0.4 0.3 + 0.1 1.9 42.5N, 177.5E 0-15 cm 1.0 + 0.1 6.5 + 1.4 29 0.9 + 0.3 0.3 + 0.1 1.7 42.5N, 177.5E 85-100 cm 0.8 + 0.1 5.2 + 1.6 23 1.2 + 0.3 0.3 + 0.1 2.0 47.5N, 187.5E 85-100 cm 2.4 + 0.2 16.7 + 0.3 71 1.1 + 0.4 0.3 + 0.1 1.9 47.5N, 187.5E 185-200 cm 2.9 +- 0.1 17.1 + 1.7 83 1.1 + 0.3 0.3 + 0.1 1.9 52.5N, 167.5E 0-15 cm 1.6 + 0.1 5.6 +/- 2.4 42 1.0 + 0.3 0.3 + 0.1 1.8 52.5N, 167.5E 85-100 cm 2.4 + 0.2 10.6 + 1.8 65 0.9 + 0.3 0.4 + 0.1 2.0 57.5N, 187.5E 0-15 cm 1.8 + 0.1 9.5 + 1.8 50 1.2 + 0.4 0.3 + 0.1 2.0 57.5N, 187.5E 185-200 cm 1.7 + 0.1 10.6 + 1.7 49 0.7 + 0.3 0.2 + 0.1 1.3 62.5N, 162.5E 85-100 cm 1.7 + 0.1 10.5 + 2.0 49 0.9 + 0.3 0.2 + 0.1 1.5 62.5N, 162.5E 185-200 cm 1.1 + 0.1 6.3 + 1.3 31 0.5 + 0.2 0.1 + 0.1 0.8 62.5N, 172.5E 85-100 cm 2.2 + 0.1 11.0 + 1.9 61 0.9 + 0.3 0.3 +/- 0.1 1.7 62.5N, 172.5E 185-200 cm 1.0 + 0.1 5.1 +/- 1.6 28 1.2 + 0.3 0.3 + 0.1 2.0 72.5N, 162.5E 0-15 cm 2.0 + 0.1 9.6 + 1.8 55 0.8 + 0.3 0.3 + 0.1 1.6 72.5N, 162.5E 185-200 cm 1.1 + 0.1 6.7 + 1.9 32 1.2 + 0.6 0.4 + 0.1 2.3 85N, 170E 35-50 cm 11.9 + 0.3 59.8 + 3.5 330 1.1 + 0.3 0.3 +/- 0.1 1.9 92.5N, 172.5E 0-15 cm 3.2 + 0.2 16.0 _ 2.7 89 0.9 + 0.3 0.4 + 0.1 2.0 92.5N, 172.5E 85-100 cm 0.5 + 0.1 3.6 + 1.4 15 1.3 + 0.4 0.3 + 0.1 2.1 92.5N, 177.5E 15-30 cm 4.2 + 0.2 17.3 + 3.2 110 4.0 + 0.6 1.3 + 0.2 7.6 92.5N, 177.5E 85-100 cm 1.5 + 0.1 8.0 + 1.7 42 1.3 + 0.3 0.4 + 0.1 2.4 95N, 180E 60-75 cm 1.7 + 0.3 9.5 + 5.7 48 39.9 + 1.8 12.5 - 0.5 75 97.5N, 162.5E 0-15 cm 2.2 + 0.1 9.5 + 1.7 59 1.0 + 0.3 0.3 + 0.1 1.8 97.5N, 162.5E 85-100 cm 3.1 + 0.2 15.4 + 2.4 86 0.8 + 0.3 0.3 + 0.1 1.6 Kerr McGee Corporation--Cimarron - July 8, 1994 15 h:\\essap\\reports\\crescent\\creseent.001

TABLE 2 (Continued)

RADIONUCLIDE CONCENTRATIONS IN SOIL SAMPLES EAST SOIL PILE KERR MCGEE CORPORATION CIMARRON FACILITY CRESCENT, OKLAHOMA Location' DeRadionuclide Concentrations (pCi/g)

Location a Depth U-235 U-238 Total Ub Ac-228c TI-208d Total Th 105N, 175E 40-55 cm 15.9 + 0.3 70.8 + 4.0 430 1.5 + 0.3 0.4 + 0.1 2.6 107.5N, 0-15 cm 2.1 + 0.1 9.9 + 1.5 58 0.9 + 0.3 0.3 + 0.1 1.7 167.5E 107.5N, 185-200 cm 5.2 + 0.2 24.7 + 2.9 140 0.8 + 0.3 0.3 + 0.1 1.6 167.53E aRefer to Figure 3.

bAn U-234: U-235 activity ratio of 21.7, established by the licensee, was used in this calculation.

cValues in this column represent Th-232 concentrations.

dValues in this column represent 36% of Th-228 concentrations.

gUncertainties represent the 95 % confidence level, based only on counting statistics.

Kerr McGee Corporation-Cimarron - July 8, 1994 16 h:\\essap\\reports\\crescent\\crescent.001

TABLE3 RADIONUCLIDE CONCENTRATIONS IN SOIL SAMPLES NORTH SOIL PILE KERR MCGEE CORPORATION CIMARRON FACILITY CRESCENT, OKLAHOMA Radionuclide Concentrations (pCi/g)

Locationa Depth Ir uIIJ____

Loh U-235 U-238 Total Ub Ac-228c T1 d

Total Th 132.5N, 131.5E 0-15 cm 1.0 + 0.1' 7.0 + 1.6 30 0.8 + 0.3 0.4 + 0.1 1.9 132.5N, 131.5E 85-100 cm 1.2 + 0.1 6.6 + 1.6 34 1.2 + 0.3 0.4 + 0.1 2.3 137.5N, 126.5E 85-100 cm 1.6 + 0.2 23.4 + 3.1 60 0.8 + 0.4 0.3 + 0.1 1.6 137.5N, 126.5E 185-200 cm 2.8 + 0.2 16.6 + 2.3 80 1.1 + 0.3 0.4 + 0.1 2.2 147.5N, 141.5E 0-15 cm 3.3 + 0.2 4.5 + 1.7 79 1.1 + 0.3 0.4 + 0.1 2.2 147.5N, 141.5E 35-50 cm 10.9 + 0.3 25.5 + 3.7 270 2.0 + 0.4 0.8 + 0.1 4.2 150N, 134E 65-80 cm 1.8 + 0.2 12.9 + 2.7 54 2.6 + 0.5 0.9 + 0.2 5.1 152.5N, 131.5E 85-100 cm 0.6 +/- 0.1 10.0 + 2.4 24 4.7 + 0.5 1.5 + 0.1 9.0 152.5N, 131.5E 110-125 cm 0.8 +/- 0.1 14.3 + 2.9 33 4.5 + 0.5 1.6 + 0.2 8.9 155N, 124E 85-100 cm 1.4 + 0.1 14.1 + 2.3 46 2.6 + 0.5 0.8 + 0.1 4.8 162.5N, 141.5E 0-15 cm 1.4 + 0.1 7.3 + 1.9 39 1.0 + 0.3 0.4 +/- 0.1 2.1 162.5N, 141.5E 85-100 cm 2.1 + 0.1 11.0 + 2.0 59 0.9 + 0.3 0.4 + 0.1 2.0 167.5N, 131.5E 0-15 cm 1.4 + 0.1 8.1 + 1.6 40 1.0 + 0.3 0.3 + 0.1 1.8 167.5N, 131.5E 185-200 cm 2.5 + 1.6 14.9 + 2.3 72 1.3 + 0.4 0.4 + 0.1 2.4 aRefer to Figure 4.

bAn U-234:U-235 activity ratio of 21.7, established by the licensee, was used in this calculation.

cValues in this column represent Th-232 concentrations.

dValues in this column represent 36% of Th-228 concentrations.

'Uncertainties represent the 95 % confidence level, based only on counting statistics.

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TABLE 4 0

0 a

Qo RADIONUCLIDE CONCENTRATIONS IN SOIL SAMPLES-CONFIRMATORY ANALYSES NORTH AND EAST SOIL PILES KERR MCGEE CORPORATION, CIMARRON FACILITY CRESCENT, OKLAHOMA Radionuclide Concentrations (pCi/g)

Locationa Depth Total Uranium Total Thorium U-235 U-238 ESSAP Ac-228 TI-208 EA C

ESAP Cimarron ESSAP Cimar 82.5N, 167.5E 35-50 cm 14.5 +/- 0.3b 85.4 + 3.6 420 293 1.4 + 0.4 0.4 + 0.1 2.5 2

95N, 180E 85-100 cm 1.4 + 0.2 8.1 + 0.3 40 51 13.6 + 1.0 4.3 + 0.3 26 21 105N, 170E 185-200 cm 21.1 + 0.5 110.7 + 5.9 590 442 0.7 + 0.4 0.4 + 0.1 1.8 3

IION, 175E 135-150 cm 5.8 + 0.2 37.1 + 2.4 170 137 1.2 + 0.3 0.3 + 0.1 2.0 1

lION, 175E 185-200 cm 6.1 + 0.2 29.9 +/-+ 3.0 170 128 1.0 + 0.3 0.3 + 0.1 1.8 1

140N, 122E 35-50 cm 0.4 + 0.1 5.9 + 1.4 15 14 1.0 + 0.3 0.3 + 0.1 1.8 2

140N, 122E 135-150 cm 4.2 + 0.2 21.9 + 1.9 120 90 1.1 + 0.3 0.4 + 0.1 2.2

< 1 145N, 139E 185-200 cm 1.0 + 0.1 8.7 + 1.9 31 29 1.5.+ 0.4 0.5 + 0.1 2.9 2

167.5N, 137.5E 35-50 cm 4.4 + 0.2 12.7 + 2.4 56 79 1.3 +/- 0.4 0.5 + 0.1 2.7 170N, 124E 85-100 cm 1.8 + 0.1 9.4 + 1.8 50 42 1.0 + 0.4 0.4 + 0.1 2.1 1

aThese samples were provided to ESSAP by the licensee. Refer to Figures 3 and 4.

bUncertainties represent the 95% confidence level, based only on counting statistics.

REFERENCES

1.

Cimarron Corporation, "Report of Characterization of Option 2 Stockpiled Soil,"

prepared by Karen Morgan, May 4, 1994.

2.

Oak Ridge Institute for Science and Education, "Confirmatory Survey of the Cimarron Corporation Mixed Oxide Fuel Fabrication Plant, Crescent, Oklahoma,"

January 1991.

3.

Oak Ridge Institute for Science and Education, "Confirmatory Radiological Survey of the Sanitary Lagoons at the Cimarron Corporation Facility, Crescent, Oklahoma,"

November, 1991.

4.

U.S. Nuclear Regulatory Commission, "Disposal or Onsite Storage of Thorium and Uranium Wastes from Past Operations," 46 FR 52061, Washington, D.C.,

October 23, 1981."

5.

Oak Ridge Institute for Science and Education, "Final Confirmatory Survey Plan for the Kerr-McGee Soil Pile, Cimarron, Oklahoma," April 29, 1994.

6.

Letter from A. Ansari (ORISE) to D. Fauver (NRC), reference: "Document Review -

Kerr McGee Soil Piles, Cimarron Facility, Crescent, Oklahoma," July 8, 1994.

7.

Oak Ridge Institute for Science and Education, "Confirmatory Radiological Survey, Former Burial Ground, Cimarron Corporation Facility, Crescent, Oklahoma,"

July 1992.

8.

Oak Ridge Institute for Science and Education, "Confirmatory Radiological Survey of the Wet Ceramics Area, Cimarron Corporation Facility, Crescent, Oklahoma,"

July 1993.

9.

Personal communication between J. Kegin and K. Morgan (Cimarron Corporation) and A. Ansari (ORISE) during on-site document review, May 4, 1994.

10.

Personal communication between D. Fauver (NRC) and A. Ansari (ORISE) by telephone, May 4, 1994.

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I0 APPENDIX A MAJOR INSTRUMENTATION Kerr McGee Corporation-Cimarron - July 8, 1994 h:\\essap\\reports\\crescent\\creseent.001

APPENDIX A MAJOR INSTRUMENTATION The display of a specific product is not to be construed as an endorsement of the product or its manufacturer by the authors or their employers.

DIRECT RADIATION MEASUREMENT Instruments Eberline Pulse Ratemeter Model PRM-6 (Eberline, Santa Fe, NM)

Detectors Victoreen NaI Scintillation Detector Model 489-55 3.2 cm x 3.8 cm Crystal (Victoreen, Cleveland, OH)

LABORATORY ANALYTICAL INSTRUMENTATION High Purity Extended Range Intrinsic Detectors Model No: ERVDS30-25195 (Tennelec, Oak Ridge, TN)

Used in conjunction with:

Lead Shield Model G-11 (Nuclear Lead, Oak Ridge, TN) and Multichannel Analyzer 3100 Vax Workstation (Canberra, Meriden, CT)

High-Purity Germanium Detector Model GMX-23195-S, 23% Eff.

(EG&G ORTEC, Oak Ridge, TN)

Used in conjunction with:

Lead Shield Model G-16 (Gamma Products, Palos Hills, IL) and Multichannel Analyzer r3100 Vax Workstation (Canberra, Meriden, CT)

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APPENDIX B SURVEY AND ANALYTICAL PROCEDURES Kerr McGee Corporatlion-Cimnarron - July 8, 1994 h:\\essap\\reporU\\crescent\\crescent.001

APPENDIX B SURVEY AND ANALYTICAL PROCEDURES SURVEY PROCEDURES Surface Scans Surface scans for gamma activity were performed by passing the probes slowly over the surface; the distance between the probe and the surface was maintained at a minimum. The scans were performed using NaI detectors coupled to countrate meters with audible indicators. Identification of elevated levels was based on increases in the audible signal from the recording and/or indicating instrument.

Soil Sampling Approximately 1 kg of soil was collected at each sample location. Surface soil samples were collected at 0-15 cm depth. Samples from boreholes were collected from the surface (0-15 cm),

the center (85-100 cm), or the bottom (185-200 cm) of each borehole. The boreholes were also scanned for elevated direct radiation. If locations of elevated direct radiation were identified, soil samples were also obtained from those locations. Collected samples were placed in a plastic bag, sealed, and labeled in accordance with ESSAP survey procedures.

ANALYTICAL PROCEDURES Gamma Spectrometry Samples of soil were dried, mixed, crushed, and/or homogenized as necessary, and a portion sealed in 0.5-liter Marinelli beaker or other appropriate container. The quantity placed in the beaker was chosen to reproduce the calibrated counting geometry. Net material weights were determined and the samples counted using intrinsic germanium detectors coupled to a pulse height analyzer system. Background and Compton stripping, peak search, peak identification, Kerr McGee Corporation-Cimarron - July 8, 1994 B-1 h:\\essap\\reporu\\crescent\\crescent.001

4 0

and concentration calculations were performed using the computer capabilities inherent in the analyzer system. Energy peaks used for determination of radionuclides of concern were:

U - 235 0.186 MeV U - 238 0.063 MeV from Th-234*

Tl-208 0.583 MeV**

Ac-228 0.911 MeV**

• Secular equilibrium assumed.

"*Assuming secular equilibrium, total thorium was calculated by dividing the T1-208 concentration by 0.36 and adding the Ac-228 concentration.

Spectra were also reviewed for other identifiable photopeaks.

Alpha Spectrometry O

Soil samples were crushed, homogenized and analyzed for isotopic uranium.

Samples were dissolved by potassium fluoride and pyrosulfate fusion and the elements of interest were participated with barium sulfate. Barium sulfate participate was redissolved and the specific elements of interest were individually separated by liquid-liquid extraction and re-precipitated with a cerium fluoride carrier. The precipitate was then counted using surface barrier and ion implanted detectors (ORTEC), alpha spectrometers (Tennelec and Canberra), and a multichannel analyzer (Nuclear Data).

UNCERTAINTIES AND DETECTION LIMITS The uncertainties associated with the analytical data presented in the tables of this report represent the 95 % confidence level for that data based only on counting statistics. Additional uncertainties associated with sampling and measurement procedures, have not been propagated into the data presented in this report.

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Detection limits, referred to as minimum detectable activity (MDA), were based on 2.71 plus 4.66 times the standard deviation of the background count. When the activity was determined to be less than the MDA of the measurement procedure, the result was reported as less than MDA. Because of variations in background levels, measurement efficiencies, and contributions from other radionuclides in samples, the detection limits differ from sample to sample and instrument to instrument.

CALIBRATION AND QUALITY ASSURANCE Calibration of all field and laboratory instrumentation was based on standards/sources, traceable to NIST, when such standards/sources were available. In cases where they were not available, standards of an industry recognized organization were used.

Analytical and field survey activities were conducted in accordance with procedures from the following ESSAP documents:

Survey Procedures Manual, Revision 8 Laboratory Procedures Manual, Revision 8 Quality Assurance Manual, Revision 6 The procedures contained in these manuals were developed to meet the requirements of DOE Order 5700.6C and ASME NQA-1 for Quality Assurance and contain measures to assess processes during their performance.

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A Quality control procedures include:

0 Daily instrument background and check-source measurements to confirm that equipment operation is within acceptable statistical fluctuations.

Participation in EPA and EML laboratory Quality Assurance Programs.

0 Training and certification of all individuals performing procedures.

Periodic internal and external audits.

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APPENDIX C GUIDELINES FOR RESIDUAL CONCENTRATIONS OF THORIUM AND URANIUM WASTES IN SOIL Kerr McGee Carparatian-Cimaffon

- July 8, 1994

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4.

W w¸ Guidelines for Residual Concentrations of Thorium and Uranium Wastes in Soil On October 23, 1981, the Nuclear Regulatory Commission published in the Federal register a notice of Branch Technical Position on "Disposal or Onsite Storage of Thorium and Uranium Wastes from Past Operations." This document established guidelines for concentrations of uranium and thorium in soil, that will limit maximum radiation received by the public under various conditions of future land usage.

These concentrations are as follows:

Maximum Concentrations (pCi/g)

Material for various options 1a 2 b 3c 4d Natural Thorium (Th-232 + Th-228) 10 50 500 with daughters present and in equilibrium Natural Uranium (U-238 + U-234) 10 40 200 with daughters present and in equilibrium Depleted Uranium:

Soluble 35 100 1,000 Insoluble 35 300 3,000 Enriched Uranium:

Soluble 30 100 1,000 Insoluble 30 250 2,500 aBased on EPA cleanup standards which limit radiation to 1 mrad/yr to lung and 3 mrad/yr to bone from ingestion and inhalation and 10 jtR/h above background from direct external exposure.

b~ased on limiting individual dose to 170 mrem/yr.

cBased on limiting equivalent exposure to 0.02 working level or less.

'Based on limiting individual dose to 500 mrem/yr and in case of natural uranium, limiting exposure to 0.02 working level or less.

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