ML20249B784

Rev 1 to CY-HP-0025,HNP Health Physics Dept Technical Support Document, Background Cs-137 Concentration in Soil

ML20249B784
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Site:	Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png
Issue date:	06/12/1998
From:	Hollenbeck P, Martel C CONNECTICUT YANKEE ATOMIC POWER CO.
To:
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ML20249B782	List: CY-98-102, Forwards Rev 1 to CY-HP-0025, HNP Health Physics Dept Technical Support Document. Util Remains Committed to Fully Characterize,Remediate & Recover Any Licensed Matl & Concrete Shield Blocks Found at Offiste Locations ML20249B784
References
CY-HP-0025, CY-HP-25, NUDOCS 9806240197
Download: ML20249B784 (38)

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6 CONNECTICUT YANKEE ATOMIC POWER COMPANY RADIATION PROTECTION MANUAL Haddam Neck Plant Health Physics Department Technical Support Document Document Number: CY-HP-0025 Revision #: 01

Subject:

Background Cs-137 Concentration in Soil Da'.e: June 12,1998 Performed By: Chris Martel Date: June 12.1998 W["

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Date:

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I Date: G.//t,/79 Approved By:

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o CY-HP-0025 Revision # 01 Backeround Cs-137 Concentration in Soil 1.0 PURPOSE The,t pose of this document is to provide the technical basis for the method that will b applied to evaluate the presence of cesium-137 at off-site locations for the purpon s of recovering plant-related radionuclides and to support the final status survey of the property. The method was derived by establishing:

the distribution of soil background levels of cesium-137, e

a means of evaluating individual samples to ensure recovery of detectable e

plant-related radioactivity:and a means for comparing cesium-137 levels from an off-site location to the e

background reference distribution.

2.0 BACKGROUND

During the conduct of the historical site assessment required to support the safe and efficient decommissioning of the Haddam Neck Plant (HNP), it was discovered that, in the 1970's and 1980's, plant personnel obtained fill and other materials from the plant. Efforts were undertaken to identify and radiologically evaluate the concrete shield blocks, fill and other Connecticut Yankee Atomic Power Company (CYAPCO) materials that were removed from the HNP. The evaluations identified plant-related radionuclides cobalt-60 and cesium-137 in some fill and on some concrete shield blocks. In addition,it was determined that in some cases the radioactive contamination on the concrete shield blocks had spread to the immediately surrounding soil.

CYAPCO has committed to the Nuclear Regulatory Commission (NRC) and the l

Connecticut Department of Environmental Protection (CT DEP) to recover all licensed material. Any cobalt-60 detected using a Minimum Detectable Concentration (MDC) equal to the Environmental Lower Limit of Detection for cobalt-60) will be considered licensed material belonging to CYAPCO, and thus, will be recovered. Cesium-137, however, is present in soils from nuclear weapons testing that occurred from the 1950's through the 1970's, and is considered part of environmental background. The distribution of Cs-137 and concentration at a specific location in the environment is known to be influenced by many factors such as soil composition, chemical properties, whether or not the soil has been disturbed in the past 40 years, and the date and degree of the disturbance. These factors cannot be easily and consistently determined for any given area at an off-site location. Therefore, this document will serve as a technically defensible and practically implementable methodology to ensure that materials possessing CYAPCO-related cesium-137 are recovered, while minimizing the potential for unnecessarily continuing remediation at sites where only background cesium-137 concentrations remain.

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CY-HP-0025 Revision # 01 I

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3.0 DISCUSSION i

f in order to evaluate the distribution of background cesium-137 in surface soils at off-site locations, soil nmples were collected during the week of May 24,1998.

Results of the cesium-137 analyses for the soil samples, and a description of the sample locations and methods that were used to collect them, are provided. The l

method by which the data will be used is also presented.

Backcround Reference Area Selection and Sampline The sample locations for the reference background study were selected using the CYAPCO emergency planning map presented in Figure 1. The map has concentric circles drawn in one-mile rings extending to a distance of 10 miles, and is divided radially into 22.5* sectors. Each two-mile band within a sector was given a unique identifier. Using a random number generator, a total of 22 locations were chosen for sample collection. All locations within a two-mile radius from the plant were excluded from the 22 locations due to their proximity to the plant.

Members of the site characterization staff selected the actual sernple locations by driving to the sector identified on the map, and locating an area from which soil could be sampled. Such locations were selected along public roadways, at schools and recreation areas, and other areas accessible to the public.

After a location was selected, two areas were chosen, one within a wooded area, and one in an open grassy area. From each of the two areas, a 15 cm by 15 cm square was cut into the soil using a carbon steel trowel. The surface soil down to a depth of 15 cm was removed and placed into a clean plastic bag. Then, soil from a depth of 15 cm to 30 cm was removed from the same hole and was also placed into l

a separate clean plastic bag and was considered subsurface soil. The trowels were l

cleaned between sample depths and locations. This process was repeated at each of the 22 randomly selected locations. All soil samples were transferred to the Duke Engineering and Services Laboratory in Westborough, Massachusetts under a chain-of-custody procedure for analysis. Appendix A presents a geological description of each soil sample including an ASTM Unified Soil Classification, its general location, and the cesium-137 result.

Table 1 presents the cesium-137 analysis results for the 88 soil samples collected.

4 I

Equal numbers of samples were obtained from both open gressy areas and wooded areas. 'Ihe total distribution of surface soil samples (i.e.,0 -15 cm) ranged from 0 to 1.802 pCi/gm with a mean and standard deviation of 0.51610.479 pCi/gm.

l Since most off-site soil sampling will be surface soil samples ( 0-15 cm.), as recommended by the regulatory agencies and described by CY characterization procedure s, this surface soil data have been used in this repcrt. The data of the 44 subsurface soil samples was collected for information and are not included in the reference background data set. Evaluation for sub-surface soil samples will be on 2 of 5

l CY-HP-0025 Revision # 01 an individual basis. Figure 2 presents a histogram of all the surface soil cesium-137 results from open grassy or wooded areas. Figure 3 presents the cumulative percent distribution of the surface soil results for open grassy and wooded area samples combined. From the graph, the 98* percentile is equivalent to 1.68 pCi/gm.

ComDarison of Off-Site Location to Background Reference Data It was previously discussed that a soil sample from an off-site location will have background cesium-137 that could range from not detectable to the maximum deposited in the region from nuclear weapons testing in the 1950's,60's and 70's.

An action level equal to the 98th percentile based on the cesium-137 reference background distribution was selected to ensure an appropriate degree of confidence that the proper recovery of HNP-related cesium-137 is performed at off-site locations, while minimizing the potential for unnecessarily continuing remediation at sites where only background cesium-137 concentrations remain. The 98%

I l

percentile action level (1.68 pCi/gm) will be applied to individual surface soil results in a sample-by-sample comparison. Cesium-137 levels below the 98*

pere:ntile will be considered evidence that no HNP material is present.

Due to the known high variability of environmental levels of cesium-137, an evaluation range has been established. If a surface soil sample from an off-site location exceeds the 98* percentile ction level and is less than 2.6 pCi/gm, the soil location possessing the cesium-13~' v 11 be evaluated. This value was selected based on the maximum concentration observed from approximately 90 surface soil samples obtained over an eleven year period from 1975 through 1985 under the Radiological Environmental Monitoring Program (REMP) decay corrected to the present. The 1975 - 1985 REMP data is presented in Table 3 and the graphical distribution of this data is shown in Figure 5. The evaluation of an individual soil sample that falls within the evaluation range will be performed by the cognizant survey design engineer and include consideration of:

the location from which the soil was obtained (i.e., open grassy areas or e

wooded areas and its proximity to such areas),

its proximity to known affected areas, e

its potential to become contaminated from surface runoff or other forms of e

migration of cesium-137 from affected areas, and the magnitude of the result (i.e., are other known affected areas at the site e

similar in magnitude).

If the result of the evaluation of the individual sample indicates that the presence of the cesium-137 is likely to have occurred from HNP-related materials, then the cesium-137 will be recovered. However, if the evaluation determines that the i

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C CY-HP-0025 Revision # 01 levels observed fall within the range of environmental background. no removal is required, and this data will be included in the statistical test applied to the site. The individual sample, however, will be included in the statistical test applied to the site. Evaluations will be documented, available for review, and the results discussed with the CT DEP and the NRC. All soil locations that possess a cesium-137 concentration greater than 2.6 pCi/gm will be recovered.

After known plant-related cesium-137 has been recovered, soil samples from the off-site location will be compared to the background reference distribution,. The Wilcoxon Rank Sum Test, as described in NUREG 1505 (Ref. 2) and MARSSIM (Ref.1), will be applied to determine whether cesium-137 at the off-site location is indistinguishable from background cesium-137. Figure 4 presents a flowchart of the decision process that will be applied to evaluating individual soil samples to accomplish recovery of plant-related cesium-137, and the evaluation of the off-site location data set with the reference background distribution.

Appendix B presents a hypothetical off-site location to illustrate the use of the flowchart. Appendix B shows several examples in the use of the Wilcoxon Rank Sum Test that are typical of the data that may be encountered at off-site locations and the results and methods that will be used to evaluate and use this data.

CYAPCO feels that this approach to analyzing the soil data is reasonable and scientifically correct.

)

Ouality Assurance Sampling

~~

A total of eight replicate samples were obtained for quality assurance purposes to assess the variability of sampling and analysis techniques by the site I

characterization staff. The samples were collected within a 50 cm radius from the original sample. This approach assumes that the cesium-137 concentration and depth profile within a one square meter area is homogeneous. The differences between the sample and it's replicate would be as a result of analytical error, sampling technique and the range of concentrations in the same area..

The results of the replicate samples and comparisons are presented in Table 2. The results were compared according to CHDP 2.0-7, Split Sample Program, which identifies if the sample and it's replicate overlap at the two sigma level (i.e.,95%

confidence interval). Overlap between the analytical results indicates that the two samples may have the same mean at the 2 sigma level. Two of the eight replicates did not pass the test at the two sigma level. In each of the two locations that failed,

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the corresponding replicate had to be located further from the original sample due to subsurface obstructions such as roots and rocks, and the volume of soil removed varied between the samples for similar reasons. Therefore, the differences may be due to the difficulty in obtaininb 3 true replicate sample. This test further demonstrated the high variability in measured Cs-137 levels at essentially the same location.

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CY-HP-0025 Revision # 01

4.0 CONCLUSION

S The final status survey for each off-site location will be acceptable once the following criteria have been met:

l There is no detectable cobalt-60, l

There is no individual sample possessing cesium-137 greater than the 98*

percentile or the sample has been evaluated, documented, and determined to be indistinguishable from background and less than 2.6 pCi/gm, and Cesium-137 levels in the final status survey sample results are statistically e

indistinguishable from reference background cesium-137 levels.

A final report documenting the status of each off-site location will be prepared and will include the results of the comparisons made as described in this technical basis document.

5.0 REFERENCES

1. Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM)

NUREG-1575, December 1997.

2. A Nonparametric Statistical Methodology for the Design and Analysis of Final Status Decommissioning Surveys, NUREG-1505 Rev.1.

3. Manual for Conducting Radiological Surveys in Suppon of License Termination, June 1992, NUREG/CR-5849

4. Cs-137 in Soil Samples, Northeast Utilities Memorandum NE-92-RA-474, dated November 10,1992.

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5. Split Sample Program, CHDP 2.0-7 i

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i APPENDIX A Location and Geological Description of Background Reference Soil Samples

e CY-HP-0025 Revision # 01 Appendix A Map Sector: Ub General Location: Intersection of Mott Lane and State Hwy.149 at northern end of Moodus Reservoir SamPe Sample Description fl[s Ug Sample No.

gp Brown fine sand with some (10-20%) silt; very poorly graded; many SM-OL 1.802 9600 BS 001 0"-6,,

very fine (mostly grass) roots; moderate organic content.

Reddish-brown sand and silt; poorly graded; some very fine roots; SM-OH

.531 9600 BS 002 6"- 12" moderate-high organic content.

Br wn medium sand with some (10-20%) silt; very poorly graded; SM-OL

.577 9600 BS 003 0"-6" some very fine roots; moderate organic content.

Light brown med. sand with some (10-20%) silt; very poorly graded; SM-OH

.093 9600 BS 004 6"- 12" some very fine roots; trod-high organic content.

Map Sector: C7-8 General Location: Day Pond State Park 3

Sample No.

Sample Description f3,

8 P p

D Light brown fine sand w/some (10 20%) silt; poorly-mod. graded; SM-OL

.746 9600 BS 005 0"-6" moderate amt. of very fine roots; moderate organic content.

Reddish-brown fine sand w/some (10-20%) silt; some small pebbles 9600 BS 006 6"-12" (avg. 3-4 mm); moderately graded; some very fine roots; moderate SM

.023 organic content.

Lt gray and brown medium sand w/many pebbles (avg. 3-4 mm);

9600 BS 007 0"-6" moderately-well graded; some very fine roots; low-mod organic SW

.164 Content.

Gray and brown med. sand w/some pebbles (avg. 3-4 mm); some 9600 BS 008 6" 12" silt / clay nodules; moderately graded; some very fine roots; some SW-OH

.124 peat inclusions; mod-high organic content.

2 of13 L

CY-HP-0025 Revision # 01 Appendix A Map Sector: B9-10 General Location: North side of State Hwy. 2, approx. 0.5 miles west of Exit 16 (State Hwy.149) i b Pe Sample No.

Sample Description Cl s D

Brown and gray (mottled) f'me sand and some (10-20%) silt; few 9600 BS 009 0"-6" small pebbles; poorly-mod. graded; some very fine roots; low-mod.

SM

.499 organic content.

Reddish-brown fine sand and some (10-20%) silt; little (0-10%) clay; 9600 BS 010 6"- 12" very few small pebbles; mod. graded; very few small roots; mod.

SM-OL

.048 organic content.

Brown and tan sand, with some (10-20%) silt; poorly-graded; some SM-OL 400 9600 BS 011 0"-6" very fine roots; mod. orgame content Brown sand, with little (0-10%) silt; few small pebbles; poorly-mod.-

SP

.201 9600 BS 012 6".12.,

graded; low-mod. organic content.

Map Sector: A7-8 General Location: East Hans du High School, southwest comer behind tennis courts 8 P Sample No.

Sample Description Cl s g)'

Dg Brown medium sand, with little (0-10%) silt; some small pebbles; SP 1.705 9600 BS 013 0"-6" poorly-mod. graded; some very fine roots; low-mod. organic content.

Reddish-brown and gray (mottled) medium sand, with some (10-20%)

9600 BS 014 6"-12" sitt and small pebbles; poorly-mod. graded; some very fine roots; SM 0L

.279 moderate organic content.

Brown medium sand, with little (0-10%) silt; poorly graded; very 9600 BS 015 0"-6" few granules and very fine roots; low-moderate organic content SP

.190

/

(probably imported fill material)

Brown medium sand, with some (10-20%) silt; poorly graded; few 9600 BS 016 6" 12" small pebbles and roots; low-rnoderate organic content (probably SM

.111 imported fill material) 1 3 of13

e CY-HP-0025 Revision # 01 Appendix A Map Sector: A5-6 General Location: Skinner Cemetery off of State Hwy.196 l

USC Cs-137 Sample SamP e Descr.iption Clus (pC' g) v Sample N '

Depth Dark brown medium sand w/some (10-20%) silt; poorly graded; SM-OH "654 9600 BS 017 0"-6" some fine roots; moderate-high organic content Dark brown medium sand w/some (10-20%) silt; poorly graded; SM-OH

.345 9600 BS 018 6".12" some fine roots; moderate-high organic content Brown medium sand, w/little (0-10%) silt; poorly graded; some very SP-OL

.262 9600 BS 019 0"-6.,

fine roots; moderate organic content.

Brown medium sand w/some (10-20%) silt; poorly graded; some SM-OL

.099 9600 BS 020 6"- 12" very fine roots; moderate organic content.

Map Sector: A3-4 General Location: Southern edge of residential property ofr of Sexton Hill Rd., approx. 500 ft. north of Pine Brook.

8 SamP c Description Ci s i/g) l Sample No.

Dp Brown fine sand w/some (10-20%) silt; very poorly graded; some SM-OH

.690

%00 BS 021 0"-6" very fine roots; moderate-high organic content.

Brown and tan fine sand w/some (10-20%) silt; poorly graded; few SM-OL

.148 9600 BS 022 6"-12" very fine roots; moderate organic content.

I Brown and tan medium sand w/some (10-20%) silt; some small

%00 BS 023 0"-6" pebbles (2mm-5 mm) and cobbles (20-100 mm); mod.-well graded; SW-OL

.535 some very fine grass roots; moderate organic content.

j Reddish-brown and tan medium sand w/some (10-20%) silt; some l

9600 BS 024 6" 12" small pebbles and cobbles; numerous roots; moderate organic SW-OL

.078 content.

I i

4 of13 i

CY-HP-0025 Revision 0 01 Appendix A Map Sector: "J5-6 (Replicates of 001 through 004)

General Location: Intersection of Motr Lane and State Hwy.149 at northern end of Moodus Reservoir S**

• Sample Description Cl s Vg)

Sample No.

g SM-OL 1.288 9600 BS 025 Q 0"-6" QA replicate of 9600 BS 001.

SM-OH

.394 9600 BS 026 Q 6"-12" QA replicate of %00 BS 002.

SM-OL

.691 9600 BS 027 Q 0"-6" QA replicate of%00 BS 003.

SM-OH

.118

%00 BS 028 Q 6".12" QA replicate of 9600 BS 004 Map Sector: A3-4 General Location: West side of State Hwy.196, approx.1/8 mile north of Lower Old Young Street.

SaniP e Sample No.

Sample Description Class Vg gp Redd5h-brown medium sand w/some (10-20%) silt; few granules;

%00 BS 027 U 0"-6" moderately graded; moderate root material; low-mod organic SM

.151 content.

9600 BS 028 U 6"-12" Same as %00 BS 027 with slightly higher silt content.

SM

.212 Brown medium sand w/some granules and silt; mod.-well graded; 9600 BS 029 D 0"-6" some very fine roots; low-mod. organic content. (possibly imported SW

.130 road fill) 9600 BS 030 D 6"-12" Same as 9600 BS 029 with less root material.

SW

.093 5 of13

??

__.---------________J

CY-HP-0025 Revision # 01 Appendix A Map Sector: Q7-8 General Location: Southeast corner of State Hwy.66 and Payne Blvd.

8 SamP e Description Class l

Sample No.

Dep Brown medium sand with some (10-20%)sn:; poorly graded; very SM

.213 9600 BS 031 U 0"-6" few fine roots; low orpnic content.

Dark reddish-brown fine sand with some (10-20%) silt; poorly SM-OL

.293 9600 BS 032 U 6"- 12" graded; very few Tme roots; moderate organic content.

Brown medium sand with little (0-10%) silt; some small pebbles; 9600 BS 033 D 0"-6" poorly-mod.-graded; numerous very fine (grass) roots; low-mod.

SP

.040 organic content.

Brown fine-med sand w/little (0-10%) silt; some pebbles; poorly-SP

.079 9600 BS 034 D 6" 12" mod. graded; some very fine roots; moderate organic content.

Map Sector: Q9-10 General Location: North of comer of Middlesex Ave. and Middlesex Avenue Extension, near abandoned lots.

phi /g) b SamP e Description Clus l

Sample No.

Dep Dark brown medium sand with some (10-20%) silt and small pebbles; SW

.327 9600 BS 035 U 0"-6" mod.-graded; low-mod. organic content.

Dark brown medium sand with some (10-20%) silt and small pebbles; SW

.237

%00 BS 036 U 6"- 12,.

mod.-graded; low-mod. organic content.

Reddish-brown fme sand, some (10-20%) silt; few granules and small 9600 BS 037 D 0" 6" pebbles; mod.-well graded; low organic content. (probably imported SW

.030 fill material).

Reddish-brown fme sand, some (10-20%) silt; few granules and small

%00 BS 038 D 6"- 12" pebbles; mod.-well grac'ed; low organic content. (probably imported SW

.012 fill material).

i 6 of13

CY-HP-0025 Revision # 01 Appendix A Map Sector: F3-4 General Location: Brainard Homestead State Park, southwest ofintersection of Creek Rd. and Maple Ave.

Pe Sample No.

Sample Description Class Ug)

Brown very fine sand and silt; very few granules; poorly graded; SM-OL

.733 9600 BS 039 U 0"-6" some very fine roots; moderate organic content.

Same as 9600 BS 039, but with more root matter and tan fibrous 9600 BS 040 U 6"-12" (woody) inclusions; very low density sample; mod.-high organic SM-OH

.294 content.

Dark brown medium sand, w/some (10-20%) silt; very poorly graded; SM 2 99 '

9600 BS 041 D 0"-6" some very fine roots; low-moderate organic content.

Reddish-brown and brown (mottled) fine sand wisome (10-20%) silt; SM-OL

.133

%00 BS 042 D 6"- 12.,

few very fine roots; moderate organic content.

Map Sector: F5-6 General Location: Adjacent to Silas Holmes Rd. approx.1/8 mile south ofintersection with Petticoat Lane.

8 Pe Sample No.

Sample Description Clus Fg)

Dep Brown fine and medium sand, with little (0-10%) silt; some granules; SP

~564

%00 BS 043 U 0"-6" poor-mod. Graded; some very fine roots; low-mod. organic content.

Dark brown fine and medium sand, with little (0-10%) silt; very-3p 7 94 9600 BS 044 U 6"-12" poorly graded; low-mod. orgame content.

SP

.688

%00 BS 045 UQ 0"-6" QA replicate of %00 BS 043 SP

.254 9600 BS 046 UQ 6" 12" QA replicate of 9600 BS 044 Reddish-brown medium sand, with few granules and pebbles (avg. 2-5 SP

.034 9600 BS 047 D 0"-6.,

mm); low organic content (probably unported road fill).

Reddish-brown medium sand, with few granules and pebbles (avg. 2 5 SP

.013 9600 BS 048 D

- 6"-12" mm); low organic content (probably imported road fill).

7 ofl3

J CY-HP-0025 Revision # 01 Appendix A Map Sector: FS-6 General Location: Approx.1/2 mile south of Petticoat Lane /Shanagham Road intersection.

SamP e Sample No.

Sample Description Clss

)

gp Dark reddish-brown fine sand and silt; some granules; poor-mod.

SM-OL

.920 9600 BS 049 U 0"-6" graded; some very fine roots; moderate organic content.

Reddish-brown fine :and and silt; some granules; poor-mod. graded; SM-OL

.288 9600 BS 050 U 6"-12" some very fine roots; moderate organic content.

Brown and tan medium sand w/some (10-20%) silt; few granules; SM

.078 9600 BS 051 D 0"-6" poor mod. graded; few very fine and fine roots; low organic content.

Reddish-brown medium sand w/some (10-20%) silt; few granules; SM

.036 9600 BS 052 D 6"- 12,,

mod. graded; few fine roots; low organic content.

Map Sector: G7-8 General Location: Adjacent to Joshuatown Rd. approx. % mile south of intersection with Selden Rd., at gated entrance to Nature Conservancy property.

b Pe Sample No.

Sample Description Clus

')

Dp Dark reddish-brown sand and silt; very poorly graded; few very fine SM

.893 9600 BS 053 U 0"-6" and fine roots; low-mod. organic content.

9600 BS 054 U 6"-12" Same as 9600 BS 053, but lighter reddish-brown color.

SM

.101 Reddish-brown and gray (mottled) medium sand w/little (0-10%) silt; SW

.165 9600 BS 055 D 0"-6 some granules; mod.-graded; low organic content.

Reddish-brown medium sand w/little (010%) silt; some granules:

SW

.297 9600 BS 056 D 6"- 12,.

mcd -graded; low organic content.

8 of13

I CY-HP-0025 Revision 0 01 Appendix A l

Map Sector: G3-4 General Location: At NW corner of State Hwy. 82 (Porges Rd.yBoardman Rd. intersection.

S Sample No.

Sample Description Clas

( Ci/g)

D Brown fine sand w/some (10-20%) silt; very poorly graded; some SM

.681 9600 BS 057 U 0"-6" very fine and fine roots; low-mod. organic content.

Brown fime sand w/some (10-20%) silt; very poorly graded; some SM

.381 9600 BS 058 U 6"- 12" very fine and fine roots; low-mod. organic content Dark reddish-brown medium sand; some pebbles (2 8 mm); mod.-

SW

.027 9600 BS 059 D 0"-6" graded; some fine roots; low organic content.

1 I

Dark reddish-brown medium sand; some pebbles (2-8 mm); mod.-

.023 9600 BS 060 D 6"4 2,,

graded; some fine roots; low organic content.

Map Sector: H9-10 General Location: On west side of State Hwy. 9 approx. 2/3 mile north of exit 3 (State Hwy.153).

@bi/ -

b"*

Sample No.

Sample Description C

p Tan and brown (mottled) fine-medium sand w/some (10-20%) silt; 9600 BS 061 U 0"-6" poorly graded; many very fine and fine roots; mod.-high organic SM-OH

.389 content.

Reddish-brown fine-medium sand w/some (10-20%) silt; few SM-OL

.161 9600 BS 062 U 6"- 12,,

granules; poorly-mod. graded; moderate organic content.

Gray very f ne and fine sand; very poorly gnied; some very fine SM

.000 9600 BS 063 D 0"-6" roots; low organic content; (probably imported road fill)

Gray vey fme and fine d vey poorly graded; some very fine SM

.023 9600 BS 064 D 6"-12 roots; low organic content; (probably imported road fill) l l

9 of 13

CY HP-0025 4

RevisioM 01 Appendix A Map Sector: J7-8 General Location: Adjacent to State Hwy.145 (Cedar Lake Rd.) approx. % mile south of Winthrop Rd. intersection, with Cockaponset State Forest.

USC Cs-137 Sample Sample No.

Sample Description Class (pCi/g)

Brown fine sand w/some (10-20%) silt; very poorly graded; many 9600 BS 065 U 0"-6" very fine roots; many leaf fragments, partially decomposed; mod.-

SM-OH 1.349 high organic content.

Reddish-brown fine sand w/some (10 20%) silt; few pebbles (2-4 SM-OL

.120 l

9600 BS 066 U 6".12" mm); poorly graded; few very fine roots; moderate organic content.

l Reddish-brown medium sand w/little (0-10%) silt; very few granules; SP

.167

%00 BS 067 D 0"-6" poorly graded; very few very fine roots; low-mod. Orgame content.

9600 BS 068 D 6"- 12" Same as 9600 BS 067, but with more granules / pebbles.

SP

.018 MapSector: K9-10 General Location: Chatfield Hollow State Park main entrance off of State Hwy. 80.

Sample No.

b**('

Sample Description Clas Ug) gp Dark brown fine-med. sand w/some (10-20%) silt; some very fine

%00 BS 069 U 0"-6

roots; some wood particles; low density soil; mod.-high organic SM-OH

.817 contem.

9600 BS 070 U 6".12" Same as 9600 BS 069, but somewhat finer grain size distribution.

SM-OH

.385 Brown med.-coarse sand, w/many granules; mod.-graded; very few SW

.024

%00 BS 071 D 0"-6,,

roots; low organic content.

Br wn med.-coarse sand, w/many granules; mod.-graded; very few gg, g

9600 BS 072 D 6" 12.,

roots; low organic content.

f 10 of 13

I l

CY-HP-0025 Revision # 01 Appendix A l Map Sector: L7 l 1

I General Location: Within Cockaponset State Forest, approx.1/8 mile N of Little City Rd/Old County Rd. intersection.

amPe Sample No.

Sample Description Ci s Vg) p Dark brown and reddish brown fine sand and silt; very poorly graded; SM-OH

.825

%00 BS 073 U 0"-6.,

few very fine roots; mod.-high organic content.

Dark brown and reddish brown fine sand and silt; very poorly graded; SM-OH

.221 9600 BS 074 U 6".12" few very fine roots; mod.-high organic content.

Dark brown fine-med. Sand w/some (10-20%) silt; poorly graded; SM-OL

.402 9600 BS 075 D 0"-6" many very fine roots; moderate organic content.

Reddish brown fine sand and silt; very poorly graded; very few fine SM

.046 9600 BS 076 D 6"- 12" roots; low-mod. organic content.

Map Sector: MS-6 General Location: East side of Little City Rd. approx.1/3 mile S ofintersection with Cand!ewood Hill Rd.

SamPe Sample Descuption Clas V

Sample No.

gp Dark brown fine sand and silt; few pebbles (2-6 mm); mod. graded; SW-OH 1 431 9600 BS 077 U 0"-6.,

mod. amt. of very fine roots; mod..high organic cont.

Reddish-brown fine sand and silt; poorly-graded; few v. fine roots; SM-OL

.478 9600 BS 078 U 6"- 12.,

moderate organic content.

Brown / tan and gray (mottled) med.-coarse sand, w/some granules; n SP

.008 9600 BS 079 D 0"-6, roots; low organic content.

\\

9600 BS 080 D 6" 12" Same as 9600 BS 079, with few very fine roots.

SP

.030 l

Il ofl3 i

.__-_____-_______-_-__-_f

f i,

-r CY HP-0025

- Revision # 01 Appendix A Map Sector: P3-4 General Location: North side of State Hwy.154, approx.1/5 mile east of Walkley Hill Rd. intersection.

Sample No.

S**('

Sample Description Class

( i/g) gp Brown and some tan (mottled) medium sand w/some (10-20%) silt; SM

• 89

)

9600 BS 081 U 0"-6,,

poorly graded; very few fine and v. fine roots; low organic content.

Brown and some tan (mouled) medium sand w/some (10-2W) sm; SM

.092 9600 BS 082 U 6"- 12" poorly graded; very few fine and v. fine roots; low organic content.

Reddish-brown medium and coarse sand; poorly graded; few v. fine SP

.227 9600 BS 083 D 0"-6" roots; low organic content; (prob. imported road fill)

Reddish-brown medium and coarse sand; poorly-graded; few v. fine SP

.070 9600 BS 084 D 6"- 12.,

roots; low organic centent; (prob. imported road fill)

Map Sector: NS-6 General Location: Cockaponset State Forest off of Oxbow Rd., approx. 500 ft S of Stagecoach Rd. intersection.

SamP e Sampic Description C s

)-

Sample No.

gp Dark gray and reddish-brown (mottled) fine sand w/some (10-20%)

9600 BS 085 U 0"-6" silt; very poorly graded; many very fine roots; mod.-high organic SM-OH 1.153 Content.

Reddish-brown fine sand w/some (10-20%) silt; very poorly graded; SM-OL

.317

%00 BS OS6 U 6".12.,

some very fine roots; mod. organic content.

Dark brown and gray (mottled) fine sand w/little (0-10'4) silt; poorly SM-OL

.1.050 9600 BS 087 D 0"-6" graded; some very fine roots; mod. organic content.

Dirk gray and reddish-brown (mottled) fine-medium sand w/little (0-9600 BS 088 D 6"-12" 10%) silt; poorly-mod. graded; some v. fine roots; mod. organic SM-OL

.519 content.

i i

12 of13

V CY-HP-0025 Revision # 01 Appendix A Map Sector: L3-4 General Location: NW & SW of Beaver Meadow Rd., approx. % mile NE of Woods Rd. intersection SamP e Sample Description Cla s i/g)

Sample No.

gg Dark brown and tan (mottled) fine sand w/some (10 20%) silt; few 9600 BS 089 U '

0"-6" small pebbles; mod. graded; many fine and very fine roots; high SM-OH 1.197 organic content.

Similar to 9600 BS 089, but less root matter; mod.-high organic SM-OL

.239

%00 BS 090 U 6"- 12.,

content.

Tan medium sand, w/some large pebbles (5-15 mm); poorly mod.-

9600 BS 091 D 0"-6" graded; very few v. fine roots; low organic content; (sample from SP.

.0189 abandoned sand & gravel pit).

SP 0120 l

9600 BS 092 D 6"-12" Similar to 9600 BS 091, but less root matter.

SM-OH

.721

%00 BS 093 UQ 0"-6" QA replicate of 9600 BS 089.

SP

.0099 9600 BS 094 DQ 0"-6" QA replicate of 9600 BS 091.

13 ofl3

?

m;

APPENDIX B i

Remediation Method Applied to an Off-site Location Example of Cs-137 Background Evaluation

CY-HP-0025 Revision # 01 Appendix B A hypothetical site has been developed to illustrate the recovery of CY radioactive material, and comparison of the site with the background reference distribution.

Backcround information A response to the questionnaire distributed to former CY employees identified that a former CY employee had received approximately 52 blocks in 1977. A member of the CY Site Characterization staffinterviewed the former employee and visited the property to observe and obtain preliminary radiological survey measurements of the blocks. The blocks were used for landscaping purposes in three discrete areas on the property. See Figure B-1. They had not been moved in the past 22 years. Preliminary surveys identified radiological contamination on a total 5 blocks in three locations, i.e., two in the first location, two in the second and one in the third.

A Work Plan to characterize the blocks and surrounding environs was developed and implemented by members of the CY Site Characterization staff. During the characterization, it was confirmed that 5 of the 52 blocks possessed radioactive contamination, and that the contamination had migrated to the underlying soil of each of the blocks. The cesium-137 in the soil underlying the blocks was recovered, such that no individual sample exceeded 2.6 pCi/gm for cesium-137 and did not have any detectable cobalt-60. After recovery was accomplished, final status survey samples of surface soil were obtained in the locations identified in Figure B-1.

The Wilcoxon Rank Sum (WRS) Test was applied by comparing the distribution of final status survey samples to the background reference distribution. The hypothesis tested by the WRS test is:

Null Hypothesis:

Ho: The median concentration for cesium-137 in the survey area is less than, or equal to the median (indistinguishable) in the reference area. (W 5 Critical Value)

Versus Alternate Hypothesis:

H.: The median concentration for cesium-137 in the survey area is greater than (distinguishable)in the reference area. (W > Critical Value)

Accepting the null hypothesis means that the median for cesium-137 in the survey area is less than, or equal to the cesium-137 median for the reference background area. It also means that the survey ama distribution of cesium-137 is indistinguishable from the reference area. Rejecting the null hypothesis means that the median cesium-137 for the survey area is greater than the cesium-137 median for the background reference area, and that they are distinguishable.

2 of 7

}

o.,

CY-HP-0025 Revision # 01 Appendix B i

i The WRS test is applied as follows:

1. The cesium-137 results that comprise the background reference distribution were ranked from lowest to highest.

2. The cesium-137 results for the final status survey samples were pooled with the background values, and ranked again in order ofincreasing size from 1 to N.

3. If measurements have the same value, they are assigned the average rank of that group of tied measurements.

4. The ranks of the survey area measurements are summed, W,.

5. Weis compared with the critical value given in Table A.4 in NUREG-1505 for the appropriate values of n, m, and cc. If W, is greater than the critical value, then the null hypothesis is rejected, and the median concentrations are considered distinguishable.

We decide that further recovery is necessary and the flowchart is followed.

When further recovery is necessary, the highest ranked value is assessed by taking additional samples within one meter from the original sample's location, and the three results are averaged. The average is substituted for the original into the distribution and the WRS test is perfonned again. If the null hypothesis is rejected again, then the area of the highest ranked cesium-137 concentration in the survey unit must be recovered. After the cesium-137 is recovered, a final status sample is obtained, and the new result is substituted for the average. The WRS test is repeated. If the null hypothesis is accepted, then no further action is necessary, and the site is released. If the null hypothesis is rejected, then additional sampling, retesting, and recovery is repeated until the null hypothesis is accepted.

A description of the method to evaluate the hypothetical site is provided below.

Three scenarios are presented to illustrate how the method responds under different situations.

Scenario 1 The final status survey results in scenario 1 are identified in Table B-1 by the letters A through H. None of the samples identified cobalt-60 greater than the MDC, but all of the samples did identify cesium-137. One result lies within the evaluation region. Based on observations of the area where this sample was taken, it was determined that the cesium-137 present could be consistent with background, i.e., it was taken adjacent to a wooded area and is upslope from I

known affected areas. The WRS test is applied to the survey area results.

First, the survey area distribution is compared to the reference background distribution following steps I through 5 outlined above. The results of the ranking of the survey area with the reference background distribution are presented in Table B-1.

3 of 7

_-_-_-____a

CY-HP-0025 Revision # O f Appendix B l

The number of survey area samples, m and reference area samples, n are as follows:

Survey area samples, m = 8 Reference area samples, n = 44 N=m+n = $2 The sum of the ranks of the survey area is 204 (i.e.,5+11+13+21+27+33+42+52

=204). The critical value is calculated by the equation in NUREG 1505, Table A.4 which is:

Critical Value = m(n+m+1)/2 = z(nm(n+m+1)/12)"

Using the data in scenario 1 in the above equation, we obtain a critical value of 289 for a of 0.025 and a of 1.96. (i.e., a = 0.05/2 = 0.025, : = 1.960).

The result is that the sum of the survey area ranks,204, is less than the critical value,289. Therefore, we accept the null hypothesis, that the cesium-137 median of the survey area distribution is indistinguishable from the reference background median. Although sample "A" exceeds the 98* pt.rcentile, it's cesium-137 concentration is consistent with cesium-137 in wooded areas, and since the sample was obtained adjacent to a wooded area, it was considered background.

No further action is necessary, and the site is released.

Scenario 2 The fmal status survey results in scenario 2 are identified in Table B-2 by the letters I through P. None of the samples identified cobalt-60 greater than the MDC, but all of the samples did identify cesium-137. Results from three samples (i.e., J = 1.870 pCi/gm, K = 1.902 pCi/gm, and I = 2.580 pCilgm) lie within the evaluation region. Based on observations of the area where the samples were taken, it was detennined that the cesium-137 result for K is probably not consistent with background because ofits magnitude in relation to other samples and their locations. Regardless, the WRS test is applied to the survey area results, The survey area distribution is compared to the reference background distribution following steps 1 through 5. The results of the rankmg of the survey area with the reference background distribution are presented in Table B-2.

The number of survey area samples, m and reference area samples, n are as follows:

Sun'ey area samples, m = 8 Reference area samples, n = 44 N=m+n = 52 4 of 7

1

+*

CY-HP-0025 -

1 Revision # O!

Appendix B The sum of the ranks of the survey area is 293 (i.e.,9+19+29+39+44+50+51+52

=293). The calculation of the critical value yields 289 as in scenario 1 for a of 0.025 and a z of 1.96. (i.e., a= 0.05/2 = 0.025, z=1.960).

The sum of the survey area ranks,293, is greater than the critical value,289.

Therefore, we reject the null hypothesis, that the medians of the survey area distribution and reference background are indistinguishable. Further action is necessary.

As described by the flowchart, two samples are obtained within a radius of one meter from the highest ranked location. The average of the three results yields a similar concentration, and the result of the repeated WRS test is to reject the null hypothesis. The decision to recover the cesium-137 in that area is made.

After recovery, a soil sample is obtained and the result (i.e.,0.687 pCi/gm) is substituted for the original value (i.e.,2.580 pCi/gm) and the WRS test is performed again (see Table B-3). The post recovery WRS test results in a W.

value of 279 which is less than the critical value of 289, and the null hypothesis is accepted. Although samples "J" and "K" are greater than the 98* percentile, we cannot be certain if the results are indicative of the presence of plant-related material given that their magnitude is close to the maximum value observed in the reference background distribution. Since the site is considered indistinguishable from background, no further action is necessary, and the site is released.

Scenario 3 The final status survey results in scenario 3 are identified in Table B-4 by the letters Q through X. None of the samples identified cobalt-60 greater than the MDC, but all of the samples did identify cesium-137. Although the cesium-137 results do not exceed the 98* percentile, they are clustered just below it. The WRS test is applied to the survey area results.

The survey area distribution is con 4 pared to the reference background distribution following steps I through 5. The results of the ranking of the survey area with the reference background distribution are presented in Table B-4.

The number of survey area samples, m and reference area samples, n are as follows:

Survey area samples, m = 8 Reference area samples, n = 44 N=m+n = 52 5 of 7 i

______-__ a

i

.4 CY-HP-0025 Revision # 01 Appendix B The sum of the ranks of the survey area is 293 (i.e.,19+23+33+37+41+44+47+49

=293). The calculation of the critical value yields 289 as in scenario 1 and 2 for a of 0.025 and a : of 1.96. (i.e., a= 0.05/2 = 0.025, z=1.960).

The result is that the sum of the survey area ranks, 293, is greater than the critical value,289. Therefore, we reject the null hypothesis, that the medians of the survey area distribution and reference background are indistinguishable. Further action is necessary.

Ar described by the flowchart, two samples are obtained within a radius of one meter from the highest ranked location. The average of the three results yields a corwentration of 0.502 pCi/gm. The average result is st.bstituted for the original value of 1.378 pCi/gm, and the WRS test is repeated. The new sum of the ranks, W, shown in Table B-5, yields 277. A W,value of 277 is less than the critical -

value of 289, and the null hypothesis is accepted. No further action is necessary, and the site is released.

J l

6 of 7

. s..

CY.HP-0025 Revision # 01 Appendix B Figure B Hypothetical OK-site Location Layout and Final Status Survey Sample Locations Wooded Area 2 Final

+

Status Row of 18 i

S"'"'Y

/

Samples blocks used Stack of four 3 Final Status as border of blocks - 2

-~~->

Survey garden - 2 contaminated contaminated blocks Samples blocks Patio consisting of 30 blocks - 1 contaminated 3 Final block Status Survey Samples House 1

7 of 7

on.

l Table B-1 : Scenaria 1

~ ~ ~ ~ ~ - "

Cs-137 All W.

Samc!e foCl/a) Ranks Ranks

_ _Anajysis 8

63 0.000 1

m = no. survey unit samples =

l 79 0.008 2

n = no.ref area samples =

44 7

0 016 3

Nam +ns 52 91 0 019 4

B 0 022 5

5 71 0 024 6

W,= sum of ranks of survey unit meas =

204 59 0027 7

l 37 0 030 8

W, = sum of ranks of ref. area meas.

_ 47 0 034 9

= N(N+1)/2-W = 1174 33 0.040 10 H

0048 11 11 51 0 078 12 E

0.114 13 13 Cntical

_29 0.130 14 Value =

m(n+m+1)/2 + z(nm(n+m+1)/12)*

~27 0.151 15

= 289

~55 0.165 16 67 0.167 17 (For a = 0 05/2 = 0.025, z = 1.960) 15 0.190 18 31 0.213 19 83 0.227 20 F

0.245 21 21 19 0.262 22 Result:

81 0.289 23 41 0.299 24 W,= 204 < Cntical value = 289 35 0.327 25 61 0.389 26 G

0.391 27 27

==

Conclusion:==

11 0.400 28

_ _ _.75 0 402 29 Site meets release entena 9

0 499 30 23 0535 31 43 0 564 32 C

0.570 33 33 3

0 577 34 17 0 654 35 57 0681 36 21 0.690 37 39 0.733 38 5

0.746 39 69 0.817 40 73 0 825 41 D

0837 42 42 53 0.893 43 49 0.920 44 67 1.050 45 85 1.153 46 j

89 1.197' 47 65 1.349: 48 77 1.431' 49 13 1.705 50 y

1 1802 51 A

2.260 52 52

, Fam:

1378 204 i

l

oc.:.

Tcble C-2 : Scintris 2 Cs 137 All W.

SamDis (GCWE) Bauha Banks Analysis 63 0 000 1

m = no. survey unit samples = 8 79 0.006 2

n = no,ref area samples =

44 7

0.016 3

N=m+ns 52 91 0.019 4

71 0.024 5

59 0.027 6

W,a sum of ranks of survey unit mess.=

293 37 0.030 7

47 0.034 8

W, a sum of ranks of ref. area mess.

0 0.037 9

9

= N(N+1)/2-W,= 1085 33 0.040 10

$1 0 078 11 29 0.13 12 27 0.151 13 Cntical 75 0.165 14 Value =

m(n+m+1)/2 + z(nm(n+m+1)/12)"

67 0.167 15

= 289 15 0.190 16 31 0.213 17 (For a = 0.05/2 = 0.025, z = 1.960) 83 0.227 18 N

0.229 19 19 19 0.262 20 81 0.289 21 41 0.299 22 Result:

35 0.327 23 61 0.389 24 W.=293 > Cntical value = 289 11 0 400 25 75 0.402 26 9

0.499 27

==

Conclusion:==

23 0.535 28 L

0.547 29 29 Take additional samples 43 0.564 30 3

0.577 31 17 0.654 32 57 0.681 33 21 0.690 34 39

' O.733 35 1

5 0.746 36 69 0.817 37 73 0.825 38 P

0.881 39 39 53 0.893 40 49 0 920 41 87 1.050 42 J

85 1.153 43 M

1.162 44 44 89 1.197 45 1.349 46 65 t

77 -

1.431 47 13 i 1.705, 48 1

1.802 49 1.870 50 50 J

K 1.902 51 51 l-2.580 52 52 i

Sum:

1378 293 l

.I

eb. e Table B-3 : Scenario 2

~

Cs-137 All W.

Samgja (DCds) BaDha Ranks Analysis 63 0 000 1

m = no survey unit samples = 8 79 0.008 2

n = no.ref area samples =

44 7

0.016 3

N=m+n=

52 I

91 0019 4

71 0.024 5

59 0.027 6

W,= sum of ranks of survey unit naas.=

279 37 0 030 7

47-0 034 8

W, = sum of ranks of ref area mess.

O O037 9

9

= N(N+1)/2-W = 1099 33 0.040 10 51 0 078 11 29 0.13 12 l

27 0.151 13

~

Value =

m(n+m+1)/2 + z(nm(n+m+1)/12)"

Cntical

~

55 0.165 14 l

67 0.167 15

= 289 l

' 15 0.190 16 31 0.213 17 (For a = 0.05/2 = 0.025, z = 1.960) 83 0.227 18 N

0.229 19 19 19 0.262 20 81 0.289 21 41 0.299 22 Result:

35 0.327 23 61 0.389 24 W =279 < Cntical value = 289 11 0.400 25 75 0 402 26 9

0 499 27

==

Conclusion:==

23 0.535 28 L

0.547 29 29 Site meets release entena 43 0.564 30 3

0.577 31 17 0654 32 57 0.681 33 1

0.687 34 34 21 0 690 35 39 0.733 36 5

0.746 37 69 0.817 38 73 0 825 39 P

0.881 40 40 53 0 893 41 49 0.920 42 87 1.050 43 85 1.153 44 M

1.162 45 45 89 a 1.197 46 i

i 65 1.349 47 77 1.431 48 1

13 1.705 49 l

1 1.802 50 1

J 1.870 51 51 K

1.902 52 52 Sum:

1378 279 l

)

6,*

,s Table B4 : Scenario 3 Cs 137 All W,

i.

Sample (Dfdg) Ranks BADh5 Ana!vais 63 0.000 1

m = no. survey unit samples = 8 79 0.008 2

n = no.ref area samples =

44 7

0 016 3

N=m+ns 52 1

91 0.019 4

71 0.024 5

' 59 0.027 6

W,= sum of ranks of survey unit meas = 293

~-37 0.030 7

i 47 0.034 8

W,= sum of ranks of ref. area meas.

33 0.04 9

= N(N+1)/2-W = 1085 51 00?a 16 -

29 0.13 u

27 0.151 12 55 0 165 13 Cntical

~67 0,167 14 Value =

m(n+m+1)/2 + z(nm(n+m+1)/12)"'

15 0.190 15

= 289 31 0.213 16 83 0.227 17 (For a = 0.05/2 = 0.025. z = 1.960) 19 0.262 18 l

X 0.279 19 19 81 0.289 20 41 0.299 21 35 0327 22 Result:

Q O336 23 23 61 0.389 24 W,= 293 > Cntical value = 289 11 0 400 25

~, 5 0 402 26

==

Conclusion:==

9 0.499 27 23 0535 28 Take additional samples 43 0.564 29 3

0.577 30 17 0.654 31 57 0681 32 S

0 685 33 33 21 0690 34 39 0.733 35 1

5 0.746 36 l

W 0.753 37 37 69 0.817 38 73 0.825 39 53 0 893 40 U

0 910 41 41 49 0.920 42 87 1.050 43 R

1.117 44 44 85 1.153 45 89 1.197 46 T

1.294 47 47 65 1.349 48 V

1.378 49 49

_ 77 1.431 50 13 1.705 51 1

1.802 52 Sum:

1378 293 Scenario 3: No sample concentrations within Evaluation Region l'

f*. a-(

Table B-5 : Scenario 3 -

ITERATION 1 Cs-137 All W.

Samole (gralg) ~Bauha ' Ranks Analysis 63 0.000 i

m = no. survey unit samples = 8

}79 0.008 2

n = no ref area samples =

44 7

0 016 3

N=m+ns 52 91 0.019

-4 71 0.024 5

59 0 027 6

W,= sum of ranks of survey unit mess.= 277 37 0.030 7

47 0.034 8

W, = sum of ranks of ref area mess.

33 0.04 9

= N(N+1)/2-W.= 1101

~ 51 0 078 10 29 0.13 11 27 0.151 12 55 0.165 13 Cntical 67 0.167 14 Value =

m(n+m+1)/2 + z(nm(n+m+1)/12I'

~

15 0.190 15

= 289

~

3*

0.213 16 81 0.227 17 (For a = 0 05/2 = 0.025. z = 1.960) 11 0.262 18 X~

0.279 19 19 81 0 289 20 41 0.299 21 35 0.327 22 Result:

Q 0336 23 23 61 0.389 24 W,= 277 < Cntical value = 289 11 0 400~ 25 75 0 402 26 9

0 499 27

==

Conclusion:==

V 0 502 28 28 23 0.535 29 Site meets release entena 43 0 564 30 3

0.577 31 17 0.654 32 57 0681 33 S

0.685 34 34 21 0'690 35 39 0.733 36 5

0746 37 W

0.753 38 38 69 0 817 39 73 0 825 40 53 0.893 41 U

0 910 42 42 49 0.920 43 87 1.050 44 R

1.117 45 45 85 1.153 46 89 1.197 47 l !

T 1.294 48 48 !

65 1.349 49 i

77 1.431 50 t

t 13 1.705 51 1

1.802 52 Sum:

1378 277

- - - - _ _ _ _. - _ _ _. _ _ _ _ _ - _ - _ _ _