ML20056H120

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Forwards Addl Info Re Final Survey for Decontamination Activities Performed in Yard Area Around Coal/Warehouse Bldg at Cimarron Facility
ML20056H120
Person / Time
Site: 07000925
Issue date: 09/02/1993
From: Still E
KERR-MCGEE CORP.
To: Gary Comfort
NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS)
References
NUDOCS 9309080254
Download: ML20056H120 (31)
v • d • e


Text

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To-98 h} KERR-McGEEOORPORATION KERR McGEE CENTER. OKLAHOMA CITY, OKLAHOMA 73125 ENVWONMEt.T AND HE ALTH MANAGEMEAT Div(5 EON September 2, 1993 vsCF PHf 5 CENT Afv0 DIRECTOR Mr. Gary Comfort, Project Officer Licensing Branch I

Division of Fuel Safety and Safeguards Office of Nuclear Material Safety and Safeguards U. S. Nuclear Regulatory Commission Washington, D. C.

20555 Re:

Docket No.79-925 License No. SNM-928 Cimarron Corporation

Dear Mr. Comfort:

The enclosed documents provide the additional information concerning the final survey for decontamination activities performed in the yard area around the Coal / Warehouse building et the Cimarron facility.

The information responds to the items raised by Ms.

Michelle Landis of ORISE, contractor to the Commission for the confirmatory survey and assessment.

The documents contain:

a.

Results of additional soil surface (0-6 inches) samples taken in July 1993 after completion of contamination removal and prior to any backfilling.

The samples were on a 10 X 10 meter grid and have been archived.

b.

A sketch showing the coordinates for the locations of the samples in a. above.

c.

Results of final gamma radiation survey obtained on a 5 X 5 meter grid spacing using a 3 inch sodium iodide detector.

d.

A description of the soil survey methods including instrumentation setup and calibration procedures for the gamma spectrum soil counter and tne 3 inch sodium iodide detector.

e.

Results of uranium analyses for soil used to backfill areas excavated during decontamination.

Samples have been archived.

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Mr. Gary Comfort Page 2 September 2, 1993 Based on our telephone discussions, we understand this submittal and the data previously provided are adequate for confirming the radiological status of the soil around the Coal / Warehouse building and that future soil borings will not be necessary. Cimarron is therefore proceeding with work related to installation of the titanium dioxide pilot plant we have described in earlier correspondence, to include pouring of concrete pads and walkways.

Please call me at 405/270-2934 or Joe Kegin at 405/282-2935 if you have questions about the submittal.

For your convenience, copies are enclosed for forwarding to ORISE.

Sincerely, ETS:lld Attachment copy to:

NRC - Glen Ellyn Office (France /McCann)

J. Kegin/T. Moore /K. Morgan R.

Smith J. Stauter/Cimarron File l

& KERR-McGEEOORPORAHON Q

RR McGEE CENTER

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September 2, 1993

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VICE PRE 5tDENT AND DIRtCTOR l

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Mr. Gary Comfort, Project Officer Licensing Branch l

Division of Fuel Safety and Safeguards j

Office of Nuclear Material Safety and Safeguards i

U. S. Nuclear Regulatory Commission 1

Washington, D. C.

20555 l

Re:

Docket No.79-925 i

License No. SNM-928 i

Cimarron Corporation i

Dear Mr. Comfort:

l The enclosed documents provide the additional information concerning the final survey for decontamination activities performed in the yard area around the Coal / Warehouse building at the Cimarron facility.

The information responds to the items raised. by Ms.

Michelle Landis of ORISE, contractor to the Commission for the-O confirmatory survey and assessment.

The documents contain:

9 1

l a.

Results of additional soil surface (0-6 inches) samples taken in July 1993 after completion of contamination removal and prior to any backfilling.

The samples were on a 10 X 10 meter < yid and have been archived.

j j

b.

A sketch showing the coordinates for the locations of the i

samples in a. above, c.

Results of final gamma radiation survey obtained on a 5 X 5 meter grid spacing using a 3-inch sodium iodide detector.

3 d.

A description of' the soil survey methods including instrumentation setup and calibration procedures for the gamma spectrum soil counter and the 3 inch sodium iodide detector.

e.

Results of uranium analyses for soil used to backfill areas excavated during decontamination.

Samples have been archived.

l Mr. Gary Comfort Page 2

()'

September 2, 1993 Based on our telephone discussions, we understand this submittal and the data previously provided are adequate for confirming the radiological status of the soil around the Coal / Warehouse building and that future soil borings will not be necessary. Cimarron is therefore proceeding with work related to installation of the titanium dioxide pilot plant we have described in earlier correspondence, to include l

pouring of concrete pads and walkways.

Please call me at 405/270-2934 or Joe Kegin at 405/282-2935 if you have questions about the submittal.

For your convenience, copies l

are enclosed for forwarding to ORISE.

l Sincerely, ETS:lld Attachment l

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e copy to:

l NRC - Glen Ellyn Office (France /McCann) l J. Kegin/T. Moore /K. Morgan R. Smith J. Stauter/Cimarron File I

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COAL /WAREHOUSC YARD AREA l

t FINAL SURVEY DATA I

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i CIMARRON FACILITY t

1 License No. SNM-928 i

j Docket No.79-925 i

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CIMARRON CORPORATION COAllWAREHOUSE YARD AREA s

10 METER X 10 METER GRID SURFACE SOIL SURVEY GAMMA SPECTRUM SOIL SAMPLE RESULTS IN PCl/ GRAM URANIUM SURFACE SURFACE SURFACE SURFACE GRID SAMPLE GRID SAMPLE GRID SAMPLE GRID SAMPLE LOCATION 0 - 6" LOCATION O - 6" LOCATION O - 6" LOCATION O - 6" 120N-40E 18.83 180N-60E 13.27 180N-90E 7.89 125N-114E 7.55 130N-40E 14.81 190N-60E 24.76 190N-90E 10.11 130N-114E 18.61 140N-40E 23.87 200N-60E 11.71 200N-90E 3.68 140N-114E 27.67 150N-40E 28.93 210N-60E 13.09 125N-100E 5.4 160N-114E 19.33 160N-40E 20.04 140N-70E 8.87 130N-100E 7.22 170N-114E 17.15 170N-40E 2_1.79 170N-70E 19.57 140N-100E 25.53 180N-114E 17.7 180N-40E 28.24 180N-70E 19.68 150N-100E 14.7 190N-114E 13.47 190N-40E 16.7 190N-70E 22.96 160N-100E 27.12 200N-114E 11.39 200N-40E 10.41 200N-70E 14.03 170N-100E 4.23 210N-40E 8.21 210N-70E 12.84 180N-100E 10.17 d

120N-50E 13.03 120N-80E 10.24 190N-100E 11.98 130N-50E 13.44 130N-80E 21.9 200N-100E 5.61 140N-50E 16.66 140N-80E 16.73 205N-100E 10.67 150N-50E 15.74 160N-80E 10.07 125N-110E 11.75 170N-50E 12.36 170N-80E 13.46 130N-110E 13.6 180N-50E 9.44 180N-80E 12.76 140N-110E 9.24 190N-50E 21.09 190N-80E 27.98 150N-110E 18.24 200N-50E 22.13 200N-80E 15.13 160N-110E 14.54 210N-50E 10 91

'120N-90E 15.22 170N-110E 8.11 120N-60E 13.13 130N-90E 9.33 180N-110E 23.88 130N-60E 10.82 140N-90E 17.08 190N-110E 8.58 140N-60E 5.49 160N-90E 12.99 200N-110E 11.14 170N-60E 20.77 170N-90E 2.89 205N-110E 19.11 1

NOTE: Site background of approximately 6 pCilg U not subtracted Surface samples were taken after completion of contamination removal and prior to backfill of area.

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CIMARRON CORPORATION COAL / WAREHOUSE YARD AREA 5 METER X 5 METER DOSE RATE & SCAN SURVEY O

GRID 3" Nal MICRO-GRID 3" Nal MICRO-LOCATION DET-CPM R/HR LOCATION DET-CPM R/HR 120N-40E 3930 2

120N-45E 4630 2

125N-40E 4700 2

125N-45E 4720 2.5 130N-40E 4130 2

130N-45E 4450 2.5 135N-40E 4460 1.5 135N-45E 4690 2

140N-40E 4850 1.5 140N-45E 4640 2

145N-40E 4930 2

145N-45E 4310 2

150N-40E 4870 2

150N-45E 4610 2

155N-40E 4380 15 155N-45E 4950 2

160N-40E 4740 2

160N-45E 4180 2

165N-40E 4650 2

165N-45E 3510 2

170N-40E 4790 2

170N-45E 3480 2

175N-40E 4220 2

175N-45E 2620 1.5 180N-40E 4940 2

180N45E 3710 2

185N-40E 2870 1.5 185N-45E 2930 1.5 190N-40E 3450 1.5 190N-45E 3640 2

195N-40E 2910 1.5 195N-45E 4900 2

200N-40E 2230 1.5 200N-45E 3150 1.5 205N-40E 4390 2

205N-45E 4080 2

210N-40E 3830 1.5 210N-45E 4600 2

Instruments:

j Ludlum 2220 S/N 48395 3" x I/2 Lead Shielded Nal Detector Micro-R Meter Ludlum Model 12-S S/N 9081 Bkg: 1 micro-R/Hr.

i Micro-R readings 1 meter above surface O

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CIMARRON CORPORATION COAL / WAREHOUSE YARD AREA 5 METER X 5 METER DOSE RATE & SCAN SURVEY

O GRID 3" Nal MICRO-GRID 3" Nai MICRO-LOCATION DET-CPM R/HR LOCATION DET-CPM R/HR 120N-50E 4630 1.5 120N-55E 4750 2.5 125N-40E 4880 2

125N-55E 4360 2

130N-50E 4670 1.5 130N-55E 4830 2.5 135N-50E 4180 2

135N-55E 4350 2

140N-50E 3890 1.5 140N-55E 4490 2

145N-50E 4310 1.5 165N-55E 3170 1.5 i

150N-45E 4790 1.5 170N-55E 2680 2

155N-50E 3610 2

175N-55E 3060 2

l 170N-50E 3790 1.5 185N-55E 2480 1.5 175N-50E 2930 2

190N-55E 2520 2

180N-50E 3170 2

195N-55E 4610 2

185N-50E 2500 2

200N-55E 4760 2

i 190N-50E 3470 2.5 205N-55E 4720 1.5 195N-50E 4450 2

210N-55E 4280 2

200N-50E 4720 2

205N-50E 3860 2.5 210N-50E 3460 2

Instruments:

Ludlum 2220 S/N 48395 3" x I/2 Lead Shielded Nai Detector Micro-R Meter Ludlum Model 12-S S/N 9081 Bkg: 1 micro-R/Hr.

Micro-R readings 1 meter above surface O

CIMARRON CORPORATION COAL / WAREHOUSE YARD AREA 5 METER X 5 METER DOSE RATE & SCAN SURVEY GRID 3" Nai MICRO-GRID 3"Nal MICRO-LOCATION DET-CPM R/HR LOCATION DET-CPM R/HR 120N-60E 4640 2.5 135N-65E 4010 2

125N-60E 4420 2

140N-65E 4470 2

130N-60E 4320 2

165N-65E 4000 1

135N-60E 3160 1.5 170N-65E 3760 1.5 140N-60E 4570 1.5 175N-65E 39_6_0 1

165N-60E 5670 1.5 180N-65E 3270 1.5 i

170N-60E 4190 1.5 185N-65E 2440 1

4 175N-60E 4340 1

190N-65E 4410 1.5 i

180N-60E 3770 1.5 195N-65E 4290 1.5 185N-60E 4100 2

200N-65E-4670 1.5 190N-60E 4180 1.5 205N-65E 4340 1.5 195N-60E 4600 1.5 210N-65E 4560 1.5 200N-60E 5100 1.5 205N-60E 4350 1.5 210N-60E 5140

1.5 Instruments

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Ludlum 2220 S/N 48395 j

3" x I/2 Lead Shielded Nal Detector Micro-R Meter Ludlum Model 12-S S/N 9081 Bkg: 1 micro-R/Hr.

Micro-R readings 1 meter above surface O

6 CIMARRON CORPORATION COAL / WAREHOUSE YARD AREA i

5 METER X 5 METER DOSE RATE & SCAN SURVEY GRID 3" Nat MICRO-GRID 3" Nal MICRO-LOCATION DET-CPM R/HR LOCATION DET-CPM R/HR 135N-70E 3980 2

135N-75E 3940 2

140N-70E 4080 2

140N-75E 4390 1.5 165N-70E 2990 1.5 165N-75E 3170 1.5 170N-70E 4390 1.5 ' 170N-75E 3500 1.5 175N-70E 4560 1.5 175N-75E 3940 1.5 180N-70E 4260 1.5 180N-75E 4210 1.5 i

185N-70E 3360 1.5 185N-75E 2380 1

190N-70E 5240 1.5 190N-75E 4390 2

195N-70E 4860 2

195N-75E 4470 1.5 200N-70E 4470 2

200N-75E 4560 1.5 205N-70E 3830 1.5 205N-75E 4560 1.5 210N-70E 4540 1.5 O

Instruments:

Ludlum 2220 S/N 48395 3" x I/2 Lead Shielded Nai Detector Micro-R Meter Ludlum Model 12-S S/N 9081 Bkg: 1 micro-R/Hr.

Micro-R readings 1 meter above surface O

CIMARRON CORPORATION 2

COAL / WAREHOUSE YARD AREA 5 METER X 5 METER DOSE RATE & SCAN SURVEY O

GRID 3" Nal MICRO-GRID 3" Nai MICRO-LOCATION DET-CPM R/HR LOCATION DET-CPM R/HR i

130N-80E 3950 2

130N-85E 4010 1.5 135N-80E 4140 2

135N-85E 4950 2

1 140N-80E 4390 2

140N-85E 5460 2

160N-80E 4970 1.5 160N-85E 4100 1.5 165N-80E 3440 1.5 165N-85E 4440 1.5 170N-80E 4060 1.5 170N-85E 4050 1.5 l

175N-80E 2790 1.5 175N-85E 3860 1.5 180N-80E 3870 1.5 180N-85E 3160 1.5 185N-80E 2640 1.5 185N-85E 2630 1

190N-80E 4780 2

190N-85E 3690 1.5 195N-80E 3940 2

195N-85E 4450 1.5 200N-80E 4800 1.5 200N-85E 4840 1.5 205N-80E 4830 1.5 205N-85E 4950 1.5 O

Instruments:

Ludlum 2220 S/N 48395 3" x l/2 Lead Shielded Nal Detector Micro-R Meter Ludlum Model 12-S S/N 9081 Bkg: 1 micro-R/Hr.

Micro-R readings 1 meter above surface t

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CIMARRON CORPORATION COAUWAREHOUSE YARD AREA 5 METER X 5 METER DOSE RATE & SCAN SURVEY O

GRID 3" Nal MICRO-GRID 3" Nal MICRO-LOCATION DET-CPM R/HR LOCATION DET-CPM R/HR 130N-90E 4430 2.5 130N-95E 4420 1.5 135N-90E 5030 2

135N-95E 3340 1.5 140N-90E 3640 1.5 140N-95E 3610 1.5

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160N-90E 4520 1

160N-95E 3020 1

165N-90E 3540

'1.5 165N-95E 3920 2

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170N-90E 3450 1.5 170N-95E 3740 1.5 175N-90E 3760 1.5 175N-95E 3690 2

180N-90E 3130 1.5 180N-95E 3340 1.5 l

185N-90E 2520 1

185N-95E 3630 2

190N-90E 3710 1.5 190N-95E 3520 1.5 i

f 195N-90E 4310 1.5 195N-95E 3390 1.5 200N-90E 4470 2

200N-95E 3920 1.5 205N-90E 4520 1.5 205N-95E 4740 1.5 Instruments:

Ludlum 2220 S/N 48395 3" x 1/2 Lead Shielded Nal Detector l

Micro-R Meter Ludlum Model 12-S S/N 9081 Bkg: 1 micro-R/Hr.

Micro-R readings 1 meter above surface l

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i CIMARRON CORPORATION COAL / WAREHOUSE YARD AREA 5 METER X 5 METER DOSE RATE & SCAN SURVEY l

GRID 3" Nat MICRO-GRID 3" Nai MICRO-LOCATION DET-CPM R/HR LOCATION DET-CPM R/HR 130N-100E 4350 2

130N-105E 3680 2

135N-100E 3760 2

135N-105E 3900 2

140N-100E 3800 1.5 140N-105E 3850 2

145N-100E 4060 2

145N-105E 3670 2

150N-100E 4300 1.5 150N-105E 3440 1.5 155N-100E 4720 2

155N-105E 4430 1.5 160N-100E 4330 1.5 160N-105E 4900 2

165N-100E 3770 1.5 165N-105E 3830 2

170N-100E 3540 15 170N-105E 3670 2

175N-100E 3650 1.5 175N-105E 3610 2

180N-100E 3510 1.5 180N-105E 3150 1.5 185N-100E 3420 2

185N-105E 3750 2

190N-1003 3150 1.5 190N-105E 4210 1.5 0

195N-100E 2610 1.5 195N-105E 4140 1.5 t

200N-100E 3800 1.5 200N-105E 4410 2

205N-100E 4410 1.5 205N-105E 4240 2

Instruments:

Ludlum 2220 S/N 48395 3" x I/2 Lead Shielded Nal Detector i

Micro-R Meter Ludlum Model 12-S S/N 9081 Bkg: 1 micro-R/Hr.

Micro-R readings 1 meter above surface

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CIMARRON CORPORATION COAL / WAREHOUSE YARD AREA 5 METER X 5 METER DOSE RATE & SCAN SURVEY GRID 3" Nal MICRO-GRID 3" Nat MICRO-LOCATION DET-CPM R/HR LOCATION DET-CPM R/HR 130N-108E 3940 2

130N-110E 4390 2

135N-108E 3760 1.5 135N-110E 4190 2

]

140N-108E 4250 1.5 140N-110E 4230 2

145N-108E 4270 2

145N-110E 5550 2

150N-108E 3930 2

150N-110E 3320 1.5 155N-108E 4570 2

155N-110E 3990 1.5 160N-108E 3760 2

160N-110E 5080 2

165N-108E 4540 1.5 165N-110E 4610 2

j 170N-108E 4890 2

170N-110E 4580 2

1 175N-108E 3880 1.5 175N-110E 4360 2

180N-108E 4420 1.5 180N-110E 3820 1.5 185N-108E 4110 1.5 185N-110E 3580 1.5 j

I 190N-108E 4100 2

190N-110E 3850 1.5 195N-108E 3810 1.5 195N-110E 4210 1.5 j

200N-108E 3550 1.5 200N-110E 3120 1.5 1

4 1

205N-108E 4730 2

205N-110E 3550 2

Instruments:

Ludlum 2220 S/N 48395 3" x I/2 Lead Shielded Nal Detector Micro-R Meter Ludlum Model 12-S S/N 9081 Bkg: 1 micro-RIHr.

Micro-R readings 1 meter above surface o

CIMARRON CORPORATION COAL / WAREHOUSE YARD AREA 5 METER X 5 METER DOSE RATE & SCAN SURVEY O

GRID 3" Nal MICRO-GRID 3" Nal MICRO-LOCATION DET-CPM R/HR LOCATION DET-CPM R/HR 3

130N-114E 4740 1.5 135N-114E 4380 1.5 140N-114E 3750 1.5 145N-114E 4030 2

150N-114E 4220 2

i 155N-114E 4680 2

l 160N-114E 3720 2

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165N-114E 4760 2

i 170N-114E 4090 2

175N-114E 4200 1.5 l

180N-114E 4240 1.5 185N-114E 3240 1.5 190N-114E 3920 2

195N-114E 4240 1.5 200N-114E 3010 1.5 1

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instruments:

Ludlum 2220 S/N 48395 3" x l/2 Lead Shielded Nal Detector Micro-R Meter Ludlum Model 12-S S/N 9081 l

Bkg: 1 micro-R/Hr.

Micro-R readings 1 meter above surface I

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INTRODUCTION The following is a general description of Cimarron Facility l

instrumentation, soil sampling and survey procedures for compliance with NRC's Branch Technical Position (46-FR-205, pp 52061-52063, October 23, 1981) Disposal or Onsite Storage of Thorium or Uranium Wastes From Past Operations, NUREG/CR-2082, June,1981, Monitoring for Compliance with Decommissioning Termination Survey Criteria, l

and NUREG/CR-5849,1992, Manual For Conducting Radiological Surveys In Support of License Termination.

SOIL SURVEY AND SORTING j

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1.

INSTRUMENTS AND EQUIPMENT WHICH MAY BE USED 2

Count Rate Meter (Ludlum 2220, etc.)

j Micro-R or Micro-Rem Meter (Bicron, Ludlum Models 19 & 12S)

Sodium Iodide Detectors (2"x2",

"x3",

1\\"x4" crystals)

Soil sampling equipment (hand core sampler, bobcat with l

auger, scoop, trowel, drill)

Sample bottles plastic bags, pens, labels, paper Tape measure, stakes, flags 2.

FIELD DETECTION INSTRUMENTS The following instrument types are used as a screening or i

scoping tool to identify areas of radiation above background levels.

t A.

Micro-R Meters l

Micro-R or micro-rem meters may be used for all four types of survey outlined in this procedure and to l

document personnel exposure.

Typical use includes grid I

surveys at one meter above ground and at the surface.

Micro-R meters are useful in locating elevated gamma fields and equating these fields to approximate personnel exposure.

Micro-R meters are calibrated quarterly at Cimarron.

Instrument battery. check must be made before use. Source response must be taken and recorded on maps or log cheets, along with instrument model and serial number, type of survey, and date, j

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i B.

Unshielded Sodium Iodide Detectors and Dirt Probes Unshielded sodium iodide detectors may be used when increased sensitivity is needed due to the gross counting capabilities of the count / rate meter. The instrument can l

also be calibrated to see specific energy ranges of i

interest.

t Examples of use include:

1 Walkover scan surveys of " unaffected" areas.

These l

areas are not expected to contain residual radioactivity based on a knowledge of site history and previous survey information.

l 2.

Encasing detector in pvc for sediment survey under water (pond or creek bottoms).

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3.

Plastic encased, metal tipped dirt probes are sodium iodide detectors which may be inserted in l

buckets of dirt, in dirt piles, or down bore holes.

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I Instrument battery check must be made before use. Source response must be taken and recorded on maps or log 4

sheets, along with instrument model and serial number, type of survey, and date.

l C.

Lead Shielded Sodium Iodide Detectors Shielded sodium iodide detectors are preferable over i

unshielded sodium iodide detectors because the lead shielding makes the detector more directional for i

detection of precise areas of elevated concentrations of material.

The lead shielding and window settings also reduce influence from background radiation that may be present.

The 3" x \\" shielded sodium iodide detector described in is set up to operate between approximately 50 kev and 250 kev because the isotopes of interest for t

this site are uranium and thorium.

D.

Field Instrument Limitations 1.

Small areas of low level uranium concentrations below 20 Mi/ gram are difficult to detect and identify with field gamma instrumentation.

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2.

Contribution from the naturally occurring Potassium-40 (K-40) isotope may increase as soil excavation depth increases, which can cause sorting l

problems.

i 3.

Soil moisture and environmental conditions such as temperature and humidity will affect field l

instrument sensitivity.

t 4.

Identification of the elevated isotope of interest i

is necessary to interpret net counts above background levels.

Each isotope or blend of isotopes will result in different net count results.

t 3.

RADIOIDGICAL SOIL SURVEYS There are fo,ur general survey categories which address the decommissioning criteria of facility soil. These are: Scoping l

Survey, Characterization Survey, Remediation Surveys and Final i

Release Survey.

A confirmatory survey by NRC or its designated agent is then performed to confirm the adequacy and accuracy of the facility final release program.

t A.

Scooina Survey O'

The scoping survey provides the basis for initial f

estimates of the level of effort required for decommissioning and for planning the characterization survey. The scoping survey typically consists of limited direct measurements (exposure rates and surface activity levels) and samples (smears, soil, water, and material with induced activity), obtained from site locations considered to be the most-likely to contain residual activity, and from other site locations both immediately adjacent to the radioactive materials use areas and in i'

areas not expected to have been affected by the site operations.

1 I

The scoping survey is used to identify areas of above j

background gamma radiation.

When an area of interest I

I (elevated counts) is located, a natural background level for the lead shielded sodium iodide detector (3" x crystal) must be established. Each area yielding readings l

l above twice background is flagged.

Within each such l

area, the locations yielding the highest readings are l

also flagged.

3

Soil samples are taken at the highest gamma locations and

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two samples are taken at areas of background and twice N

background.These samples are collected from 0 - 2" and 2"

6" depths. Soil samples are counted in the soil counter.

B.

Characterization Survey A characterization survey is used for areas identified by the scoping survey that require decontamination. The Characterization Survey identifies volume and depth of each classification of soil contamination as defined in NRC's Branch Technical Position, Disposal or Onsite Storage of Thorium or Uranium Wastes Prom Past Operations, as follows:

DISPOSAL OPTIONS KIND OF MATERIAL 1

2 3

4 5

Natural Thorium (Th-232 + Th-228)

With daughters present and in equilibrium......... 10*

50 500

>500 Natural Uranium (U-238 + U-234)

/G With daughters V

present and in equilibrium........

10 40 200

>200 Depleted Uranium Soluble.........

35 100 1,000

>1,000 Insoluole.......

35 200 3,000

>3,000 Enriched Uranium Soluble.........

30 100 1,000

>1,000 Insoluble.......

30 250 2,500

>2,500

  • opu c.t.oorr oo o tr.ti ar. i. e o.-curs por er..

s A one meter to ten meter grid is established over the affected area referenced to a certified surveyor's map. Sample locations are marked with a numbered stake or flag.

Soil samples may be collected from surface to depth

required, or at background level depths as indicated by soil counter results and field instrument j

readings to establish sort points for soil removal.

ph 4

Maps, field detector readings, and soil analysis will be b

evaluated and, if action is required, an action plan will be developed. The plan will identify areas and machinery best suited for removal of materials.

The objective is to remove the highest option soil first (greater than Option 2) for off-site disposal.

Option 2 soil will be removed and stockpiled. Option 1 soil will be left in place.

C.

Remediation Control and Dose Rate Surveys Remediation control surveys monitor decontamination work in progress and the effectiveness of the clean up efforts.

This type of survey assures that remediation workers, the public, and the environment are adequately protected against exposures to radiation and radioactive materials arising from decontamination activities.

Dose rate surveys using a micro-R meter will be taken daily during excavation. The more sensitive 3" detector is useful in alerting personnel of potential increase of exposure levels as excavation procJresses and helps the decontamination efforts by locating small amounts of hard-to-find contamination.

If 3"

detector readings increase significantly during excavation, additional dose rate surveys will be performed.

%J D.

Final Release Survey Final release documentation provides data to demonstrate that all radiological parameters satisfy the established guideline values and conditions for release of site for unrestricted use.

In areas where excavation or cleanup is not required, the original grid samples taken for the characterization survey will be incorporated into the final release grid survey report.

Only the remediated areas will need further gamma scans and release sampling for final documentation.

In areas where excavation and cleanup was undertaken, the grid is reestablished and samples taken to confirm remediation.

Final release status is based on samples counted on the soil counter.

Following remediation, all data are rompiled, maps completed and materials readied for review by the NRC or its contractor for the final confirmation and release survey.

5

j i

4.

SOIL SAMPLING A.

Surface samolina I

Surface soil sampling may be performed using scoop, j

trowel, shovel, auger, or core sampler.

Where composite soil samples are desired, aliquots will be mixed in a r'

plastic bag or stainless steel bowl to form the composite.

B.

Grid Samolina i

l Locations of known or suspected subsurface activity are l

sampled using the systematic grid block spacing pattern outlined in the Characterization Survey on Page 4. Grid sampling with a hydraulic or hand auger is performed as follows:

l 1

Bore Hole Sampling 1.

Using the auger, drill to the desired depth and extract the soil covered bit.

~

2.

Cover hole to prevent recontamination of the hole.

3.

Remove soil from bit. Bottle representative sample and label with date, location and depth of sample.

j 4.

Remove soil left on auger.

In-documented contaminated areas, auger - should be washed and scrubbed to prevent cross contamination of samples.

t 5.

Drill into started hole to retrieve additional i

samples at deeper intervals.

Repeat above process l

for each sample.

l 1

5.

SOIL SAMPLE PREPARATION Soil samples are usually counted "as received".

However, the j

sample must ce representative of the soil.

Rocks, twigs, vegetation, samples weighing less-than 500

grams, and excessive liquid in the sample will not yield representative results.

Prepare sample for counting as follows:

1.

Clean sample bottle.

2.

Weigh sample and record weight on bottle. If weight is not between 500-1000

grams, examine contents for excessive liquid or foreign objects.

3.

Record sample information in logbook.

O e

l

O 6.

SCALE WEIGHT CHECK b)

Standards:

200 grams 500 grams 1000 grams (1Kg) l The scale used for sample weight is standard checked and recorded each day samples are counted.

The computer electronic digital scale reads out in grams and can be set to auto.aatically subtract the tare weight of the sample bottle.

l 7.

PERSONNEL TRAINING Training will be provided by the Health Physics Department in proper setup of grids, field instrument use and sampling techniques for personnel involved in these activities.

SOIL COUNTER SETUP 1.

INSTRUMENTATION I

The 4"

X 4" X 16" sodium iodide crystal detector is housed in a lead-lined cabinet measuring 25" wide X 44" tall X 25" O

deep. The sample is positioned 4.5" from the detector and sits i

(,/

on a turntable which revolves at one RPM.

The detector is computer linked to a multi-channel analyzer and uses an EG&G Ortec Computer Analysis Program.

2.

CS-137 SOURCE CHECK A source check using a 0.138 pCi Cs-137 pencil source No.G8.17 S/N 3137-12 is performed before and after sample counting. The j

source check prior to counting assures proper peak placement (Centroid).

3.

COUNTING SOIL STANDARDS After samples are weighed and source check performed, count the Background Soil Standard and the U-1-2 Soil Standard to verify the counter accuracy. The concentrations in these soil samples are an average of the results determined by certified laboratory analyses and Cimarron.

Background Standard 6.00 pCi/g Uranium

(

4.80 pCi/g U)

Minimum 1.20 pCi/g U Maximum 10.80 pCi/g U U-1-2 Standard 28.66 pCi/g Uranium

(

10.49 pCi/g U)

Maximum 39.15 pCi/g U - Minimum 18.17 pCi/g U 7

i i

I O'

If results obtained for both standards are within the 95%

confidence level parameters, proceed with sample cour.cing. If the results are not within the 95% confidence level, adjust high voltage vernier and start over with Cs-137 source check.

If necessary, repeat process until source, background and U 2 standards all are within the required parameters.

O l

l l

O e

l

A'ITAClINENT 1 SETUP AND CALIBRATION OF 3" x SODIUM IODIDE LEAD SHIELDED DETECTOR This detector is a 3" x

" sodium iodide (NaI) detector with lead shielding added to the sides and around the detector socket.

The shielding makes this detection unit as directional as possible in order to facilitate hot spot identification and to assist in quantifying the amount of a known radionuclide in soil.

l A Ludlum 2220 count / rate meter is connected to the detector and is set up using an Am-241 (0.17 pCi) source to assure that the threshold setting allows the entire 6f4 kev peak to be seen. A U-235

(=1.0 pCi) source is used to confirm that the entire 185 kev peak is included in this uindow setting.

A natural thorium source is used to assure the thorium 240 kev peak is also included in this l

window setting.

High voltage is adjusted only initially to assure separation of the noise peak and the 60 kev Am-241 peak.

The window width is determined from threshold to include all of the U-235 185 kev peax l

and all of thorium 240 kev peak.

This instrument is used with the window "IN" to limit influence from other isotopes.

Tyoical 3" Detector Readings Typical readings from 3" lead shielded sodium iodide detector are as follows:

1.

Shielded Background 325 CPM 2.

Office Background 900 CPM 3.

Site Background Soil 3100 CPM U - 6.00 pCi/g (0.711 Wt% U-135)

Th - 1.70 pCi/g 4.

U-1 Drum Standard 3725 CPM U - 28.66 pCi/g (2.74 Wt% U-235)

Th -

3.52 pCi/g i

S.

U-3 Drum Standard 5175 CPM i

U - 65.99 pCi/g (2.54 Wt% U-235)

Th -

3.17 pCi/g I

i High thorium concentrations or high uranium enrichment will dominate these readings for uranium.

Sort points are established on the basis of gamma spectrum soil counter results.

Daily source checks using the Am-241 (0.17 pCi) source and U-235

(=1.0 pCi) source are recorded in logbook with daily background readings.

C(

                                        • 02-JUL-93 ** 14:34:00 ********************

SAMPLE FILE SPECIFICATION: SOIL 572.SFC ACOUIRED 02-JUL-93 AT 14:28:35 DETECTOR #

1 LIVETIME:

300 SEC REALTIME:

301 SEC SAMPLE DESCRIPTION:

i FILL DIRT COMPOSITE SAMPLE

[

828 GRAMS REJECT COEFF 1.000. 2 CYCLESAUTO GAIN / SHIFT COMPENSATION STANDARD FILE: SY: SOIL 1.STD 255 CHANNELS START:

2 STOP:

254'

.r\\

t

'R$CLIDE PICOCURIES

+/- 1 SIGMA URANIUM 6.131E+03

+/- 2.1E+03 THORIUM 8.547E+02

+/- 2.6E+02 ANALYSIS OF RESIDUALS:

AVERAGE =

-0.9955E-01 GTD DEV =

1.236

% OF RESIDUALS UNDER 3 SIGMA = 98.4 SUSPICIOUS CHANNELS:

(),t>N) $ h'(

122 123 124 226 SUSPECTED NUCLIDES:

ELAPSED TIME:

25.5 SECONDS O

i

i i

t t

i l

r l

l l

\\

    • w**************+** 06-AUG-9S ** 09:12:50 ********************

SAMPLE FILE SPECIFICATION: SOILSO.SFC ACCUIRED 06-AUG-9S AT 08:07:27 DETECTOR

  • 1 lit /ETIME :

S00 SEC REALTIME:

S01 SEC SAMFLE DESCRIFTION:

COAL YD. FILL DIRT. FROM HENNESSEY READY MIX h[

796 GRAMS REJECT COEFF 1.000. R CYCLESAUTO GAIN / SHIFT COMFENSATION STANDARD FILE: SY : SO I L1. STD 255 CHANNELS START:

2 STOP:

254 (O,-_______________-__-____-_________________-_________-________

x e NDCLIDE PICOCURIES

+/- 1 SIGMA URANIUM 4.427E+0S

+/- 2.0E+0S THORIUM 2.9S4E 02

+/- 2.5E+02 ANALYSIS O RESIDLALS:

At/E0 AGE =

- 0. 70 71 E-01 STD DE'/ =

1.195 i; OF RESID'JALS UNDER 3 SIGMA = 98.4

[f h [-

SUSPICIOUS CHANNELS:

122 12S 124 226 4

SUSPECTED NUCLIDES:

l I

i 1

ELAPSED tit'E:

2S.5 SECONDS 1b e

l O

k i

1

                  • ++********* 06-AUG-95 ** 08:21:45 ***************++++*

SAMFLE FILE SPECIFICATICN: SOILS 1.SPC ACOUIRED 06-AUG-95 AT 08:16:20 DETECTOR #

1 LIVETIME:

500 SEC REALTIME:

501 SEC SAMPLE DESCRIPTION:

COAL YD. FILL DIRT. FROM HENNESSEY READY MIX h V 717 GRAMS REJECT COEFF 1.000. 2 CYCLESAUTO CAIN/ SHIFT COMPENSATION STANDARD FILE: SY: SOIL 1.STD 255 CHANNELS START:

2 STOP:

254 NUCLIDE PICOCURIES

+/- 1 SIGMA THORIUM

< 6.4E+02 URANIUM 5.55SE+0S

+/- 1.1E+00 ANALYSIS OF RESIDUALS:

AVERAGE =

-0.4401E-01 STD DEU =

1.005

/-

(p y

O e.,c. 2DL. Le e

,v,..,:.R, c. - %. =

.a

.o-e r

n a

ivu o sa w c

SUSPICIOUS CHANNEL 5:

1EQ 4 @,4 44,s e

SUSPECTED NUCLIDES:

ELAPSED TIME:

51.9 SECONDS m

w 9

b f

O t

                                        • 06-AUG-93 ** 08:55:42 ********************

SAMPLE FILE SPECIFICATION: SOIL 32.SPC ACOUIRED 06-AUG-93 AT 08:50:19 DCTECTOR #

1 LIVETIME:

300 SEC REALTIME:

301 SEC SAMFLE DESCRIPTION:

FROMHENNESSEYREADYMIX1%hfh COAL YD. FILL DIRT.

788 GRAMS REJECT COEFF 1.0'00. 2 CYCLESAUTC GAIN / SHIFT COMPENSATION STANDARD FILE: SY: SOIL 1.STD 255 CHANNELS START:

2 STOP:

254

((

l NUCLIDE PICOCURIES

+/- 1 SIGMA THORIUM

< 7.3E+02 URANIUM 5.596E+03

+/- 1.3E+03 ANALYSIS OF RESIDUALS:

h

([ h

(_

AVERAGE =

-0.1192 STD DEV =

1.060

% OF RESIDUALS UNDER 3 SIGMA = 98.4 7e [

/

l SUSPICIOUS CHANNELS:

-44 124 126 226 SUSPECTED NUCLIDES:

I ELAPSED TIME:

31.8 SECONDS

{

A

~s l

l l

L t

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