ML061530383

In-Process Inspection Survey Results for the Reactor Support Structure Concrete Base and Inside Open Land Areas at the Yankee Nuclear Power Station, Rowe, Massachusetts (Docket No. 50-29; Rfta No.05-008)

ML061530383
Person / Time
Site:	Yankee Rowe
Issue date:	10/12/2005
From:	Adams W Oak Ridge Institute for Science & Education
To:	John Hickman NRC/NMSS/DWMEP
References
RFTA 05-008
Download: ML061530383 (11)

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O R f S E O A K R I D G E INSTITUTE F O R S C I E N C E AND E D U C A T I O N October 12,2005 r-- p t ;, h Mr. JohnHickman Division of Waste Management and Environmental Protection U.S. NucIear Regulatory Commission Two White Flint North Mail Stop: 7F27 11545 Rockville Pike Rockville, MD 20852-2738

SUBJECT:

IN-PROCESS INSPECTION SURVEY RESULTS FOR THE REACTOR '

SUPPORT STRUCTURE CONCRETE BASE AND INSIDE OPEN LAND AREAS AT THE YANKEE NUCLEAR POWER STATION, ROWE, MASSACHUSETTS [DOCKET NO. 50-29; RFTA NO. 05-0081

Dear Mr. Hickman:

The Environmental Survey and Site Assessment Program (ESSAP)of the Oak Ridge Institute for Science and Education (ORISE) performed in-process inspection survey activities on several Reactor Support Structure (RSS) Concrete Base and Inside Open Land (NOL) survey units at the Yankee Nuclear Power Station in Rowe, Massachusetts during the periods of August 9 and 10 and September 13 and 14,2005. These survey activities were requested and approved by the U.S.

Nuclear Regulatory Commission (NRC). The survey activities included beta and gamma surface scans, direct measurements for beta activity, and soil sampling. Enclosed are the in-process survey results documenting these survey activities.

If you have any questions or comments, please direct them to me at (865) 576-0065 or Scott Kirk at (865) 574-0685.

Sincerely, UJ082eC.k Wade C. Adams Health PhysicistRoject Leader Environmental Survey and Site Assessment Program WCA:ar Enclosure cc: T. McLaughlin, N R C / N M S S / T W F N T-7E18 E. Abelquist, ORISEESSAP E. Knox-Davin, NRC/NMSS/TWFN 8A23 A. Boerner, ORISE/ESSAP J. Kottan, NRC/Region I S. Kirk, ORISE/ESSAP File/l672 Distribution approval and concurrence: Initials I Technical Management Team Member Laboratory Manager Quality Manager P. 0. BOX 1 17, OAK RIDGE, TENNESSEE 3783 1-0117 Operated by Oak Ridge Associated Universities for the U.S. Department of Energy

IN-PROCESS INSPECTION SURVEY RESULTS FOR THE REACTOR SUPPORT STRUCTURE CONCRETE BASE AND INSIDE OPEN LAND AREAS AT THE YANKEE NUCLEAR POWER STATION ROWE, MASSACHUSETTS INTRODUCTION The U.S. Nuclear Regulatory Commission (NRC) requested that the Oak Ridge Institute for Science and Educations (ORISE) Environmental Survey and Site Assessment Program (ESSAP) perform an in-process inspection survey of the Reactor Support Structure (RSS) remaining concrete support base and the Inside Open Land (NOL) Area Excavations at the Yankee Nuclear Power Station (YNPS). The in-process inspection surveys were performed during the periods of August 9 and 10,2005 and September 13 and 14,2005. Figures 1 through 4 indicate the survey units that were part of these survey activities.

PROCEDURES The in-process inspection surveys were performed in accordance with a site-specific survey plan that was submitted to and approved by the NRC (ORISE 2005a). The ORISE/ESSAP Survey Procedures and Quality Assurance Manuals were also followed (ORISE 2004 and 2005b).

Reactor Support Structure Concrete Base Beta surface scans were performed using gas proportional detectors coupled to ratemeter-scalers with audible indicators. Surface scans were performed on up to 25% of the RSS structural surfaces. Particular attention was given to cracks, joints, and scabbled areas in the evaluated structural surfaces where material may have accumulated. Direct measurements for beta activity were performed at five locations within each of the six RSS survey units (SU) which were available for confirmatory survey activities. At the discretion of the NRC site representative, smear samples were not deemed necessary. Locations where direct measurements were taken are indicated on Figure 1.

Inside Open Land Area RJOL) Excavations Gamma surface scans were performed over 90% of accessible portions of the NOL excavations consisting of SUs NOL-01, Units 1,2, and 3 and NOL-06, Unit 1 using sodium iodide (NaI) scintilIation detectors coupled to ratemeters with audible indicators. However, access to some areas was restricted due to safety concerns. Soil samples were collected from five locations within each of the four SU excavations which were available for confirmatory survey activities.

Locations where soil samples were taken are indicated on Figures 2 through 4.

SAMPLE ANALYSIS AND DATAINTERPRETATION Radiological data and sample media were returned to ESSAPs laboratory in Oak Ridge, TN for analysis and interpretation. Radioassays were performed in accordance with the ESSAP Laboratory Procedures Manual (ORISE 2005~).Soil samples were analyzed by gamma Yankee Nuclear Power Station 1672\Reports\2005-10-12In-ProcessInspection Survey Results

spectroscopy for the primary radionuclides of interest (i.e., CO-60and Cs-137). However, spectra were also reviewed for other gamma-emitting fission and activation products associated with the YNPS and other identifiable total absorption peaks. Soil sample results were reported in units of picocuries per gram (pCi/g). Direct measurement data were converted to units of disintegrations per minute per 100 square centimeters (dpd100 cm2).

FINDINGS AND RJZXILTS Reactor Support Structure Concrete Base Beta surface scans did not identify any areas of elevated activity on the RSS concrete base structures. The ranges of total net beta activity measurements for each of these SUs are as follows:

Range of Total Net Beta Activity Survey Unit" (dpd100 cm')

BRT-01 Unit 1 460 to 4,330 BRT-01 Unit 3 280 to 670 BRT-01 Unit 4 1,370 to 2,460 BRT-01 Unit 5 1,170 to 2.190 BRT-01 Unit 6 1,640 to 2,720 BRT-01 Unit 7 1,220 to 2,350 aBRT = Big Round Thing, the YNPS nomenclature for the Reactor Support Structure concrete base.

A complete listing of the surface activity level results is presented in Table 1.

Inside Open Land Area (NOL) Excavations Gamma surface scans identified eight locations of elevated direct gamma radiation on the soil surfaces within NOL-01 Units 1 , 2 and 3 and no elevated gamma activity locations on the soil surfaces in NOL-06 Unit 1,. Based on the gamma scan results, biased soil samples were collected at the eight locations exhibiting elevated gamma radiation. The remaining twelve sample locations were randomly selected. With the exception of the one location in NOL-01 Unit 1, the areas of elevated gamma activity identified on the soil surfaces were believed to be attributable to discrete particles within the soil. Further investigations by the licensee, and by the ESSAP laboratory, indicated that this assumption was correct. The elevated gamma activity in NOL-01 Unit 1 was believed to be attributable to naturally occurring radioactive material within a medium sized rock that YNPS personnel disposed of as radiological waste. The range of radionuclide concentrations for the five soil samples collected by ESSAP from each of the NOL SUs are as follows:

Yankee Nuclear Power Station 2 1672\Reports\2005-10-12 In-Process Inspection Survey Results

Range of Radionuclide Concentrations in Soil Samples (pCi/g)

Survey Unit CO-60 CS-137 NOL-01 Unit 1 0.00 to 0.19 0.00 to 0.22 NOL-01 Unit 2 0.01 to 357 0.17 to 0.99 NOL-01 Unit 3 0.01 to 14.02 0.04 to 347 NOL-06 Unit 1 0.00 to 0.02 0.00 to 0.06 A complete listing of the soil sample results is presented in Table 2.

SUMMARY

Since this was an in-process confirmatory survey, the licensee did not have final status survey (FSS) data available for review. Y N P S personnel provided preliminary direct measurement and soil sample results to ESSAP while on site.

Beta surface scans did not identify any areas of elevated beta activity on the RSS concrete base structural surfaces. Direct measurements were performed at 30 locations and all results were well within the derived concentration guideline levels (DCGLs) for CO-60and Cs-137 as provided in the License Termination Plan KTP (YAEC 2004)l.

Gamma surface scans identified eight locations of elevated direct gamma radiation within NOL-01 Units 1 , 2 and 3 and each of these locations were sampled. The soil contamination was determined to be non-uniformly distributed within the samples. With one exception, the elevated activity was due to discrete particles within the soil sample. The exception was a medium sized rock within NOL-01 Unit 1 which exhibited elevated gamma radiation believed to be attributable to naturally occurring radioactive materials within the rock. Regardless, Y N P S personnel disposed of the rock as radiological waste.

The in-process confirmatory surveys determined that detectable activity, in excess of the soil DCGLs, was present at several locations within NOL-01 Units 2 and 3. Three of the 20 soil samples exceeded the CO-60DCGL of 4.0 pCi/g and one sample exceeded the Cs-137 DCGL of 8.6 pCi/g. Therefore, the results of the survey activities for these SUs failed to confirm that the radiological conditions were suitable for unrestricted use in accordance with clean up criteria cited in the licensees LTP.

Yankee Nuclear Power Station 3 1672\Reports\2005-10-12In-Process Inspection Survey Results

MEASUREMENT LOCATIONS

1. SINGLE-POINT CONCRETE SlAB FLOOR BRT - BIG ROUND THING RSS CONCRETE BASE i; NOT TO SCALE I I FIGURE 1: Yankee Nuclear Power Station, Reactor Support Structure (RSS)

Concrete Base - Direct Measurement Locations Yankee Nuclear Power Station 1672\ReportS\2005-10-12 In-Process Inspection Survey Results 4

J672-004 (1)

. 9 1 7 SAMF'LING LOCATIONS

1. SURFACESOIL NOT TO SCALE I

FIGURE 2: Yankee Nuclear Power Station, Inside Open Land (NOL) Excavation, NOL-01, Unit 2 - Soil Sampling Locations Yankee Nuclear Power Station 1672ReportsYZ005-10-12In-Process Inspection Survey Results 5

,. 1672-005 (2)

SAMPLING LOCATIONS 1 #SURFACESOIL i

NOT TO SCALE

~

flGURE 3: Yankee Nuclear Power Station, Inside Open Land (NOL) Excavation, NOL-01, Unit 3 - Soil Sampling Locations Yankee Nuclear Power Station 1672Reports\2005-10-12In-Process Inspection Survey Results 6

1672-002 ( 2 )

SAMPLING LOCATIONS

1. SURFACE SOIL REACTOR SUPPORT CONCRETE SURFACES ;i NOT TO SCALE FIGURE 4: Yankee Nuclear Power Station, Inside Open Land (NOL) Excavations NOL-01, Unit 1 and NOL-06, Unit 1 - Soil Sampling Locations Yankee Nuclear Power Station 1672Reports~005-10-12In-Process Inspection Survey Results 7

TABLE 1 SURFACE ACTIVITY LEVELS REACTOR SUPPORT STRUCTURE CONCRETE BASE YANKEE NUCLEAR POWER STATION ROWE, MASSACHUSETTS Total Net Total Net Survey Unit/ Survey Unit/

Beta Activity Beta Activity Locationa Locationa (dpd100 cm2) (dpd100 cm')

1 BRT-01 Unit lb BRT-01 Unit 5 I 1 4,330 +. 520' 16 I 1,540k410 1 2 2,950 & 470 17 1,840 & 430 3 2,870 & 470 18 2,190 k 440 4 1,730 +. 420 19 I 1,480&410

~~~

5 460 +. 370 20 1,170 2 400 BRT-01 Unit 3 BRT-01 Unit 6 I 6 I 530 370

~~

21 2,720 +. 460 7 670 +- 380 22 2,390 -c 450 1 8 1 280+-360 I

~

9 470 2 370 24 1,890 2 430 10 520 & 370 25 1,790 f 430 I BRT-01 Unit 4 ~ ~~

11 2,460 2 450 26 2,140 +. 440 12 2,330 +. 450 27 2,350 & 450 13 2,180 2 440 28 1,520 & 410 14 2,380 f 450 29 1,220 +- 400 I 15 1,370 +. 410 30 1,400 -c 410 bBRT = Big Round Thing; the YNPS nomenclature for the Reactor Support Structure concrete base. The LTP DCGL values are 63,000d p d 1 0 0 cm2for Cs-137 and 18,000 d p d 1 0 0 cm2 for Co-60.

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

Yankee Nuclear Power Station 1672\Reports\2005-10-12In-proCess Inspection Survey Results 8

TABLE 2 Radionuclide Concentrations (pCi/g)b Sample Locationa I CO-60 CS-137 1672S0011 0.02 2 0.03d 0.02 f 0.02 1672S0012 0.19 f 0.05 0.03 +. 0.02 167230013 0.00 2 0.02e 0.00 2 0.02 1672S0014 0.05 rf: 0.04 0.22 +. 0.04 167230015 0.02 f 0.02 0.07 -e 0.03 1672S0004 0.03 2 0.05 0.19 +. 0.04 1672S0005 0.74 2 0.08 0.99 +- 0.07 1672S0007 0.01 f 0.03 0.17 f 0.03 1672S0008 357 +- 11 0.24 2 0.83 1672S0009 0.60 0.10 0.77 +. 0.08 167230001 8.75 +- 0.31 1.84 f 0.13 1672S0002 0.01 f 0.09 347 2"ll 1672S0003 14.02 +. 0.5 1 . 0.54 f 0.09 1672S0006 0.14 +- 0.05 0.43 f 0.04 1672s 00 10 0.17 2 0.04 0.04 f 0.02 167230016 0.02 f 0.03

• 0.00 0.02 1672s0017 0.02 k 0.02 0.06 f 0.03 1672S0018 0.01 fO.03 0.01 f 0.02 1672SOOl9 0.00 2 0.02 0.02 f 0.02 1672S0020 0.01 +. 0.03 0.02 2 0.01

REFERENCES Oak Ridge Institute for Science and Education (ORISE). Survey Procedures Manual for the Environmental Survey and Site Assessment Program. Oak Ridge, Tennessee; September 2, 2004.

Oak Ridge Institute for Science and Education. Confirmatory Survey Plan for the Open Land Area Survey Units, Yankee Nuclear Power Station, Rowe, Massachusetts [Docket No. 50-29; RFTA No. 05-0081. Oak Ridge, Tennessee; August 3,2005a.

Oak Ridge Institute for Science and Education. Quality Assurance Manual for the Environmental Survey and Site Assessment Program. Oak Ridge, Tennessee; July 28,2005b.

Oak Ridge Institute for Science and Education. Laboratory Procedures Manual for the Environmental Survey and Site Assessment Program. Oak Ridge, Tennessee; June 20,2005~.

Yankee Atomic Electric Company (YAEC). Yankee Atomic Electric Company (YAEC) License Termination Plan (LTP)for the Yankee Nuclear Power Station (YNPS). Revision 1. Rowe, Massachusetts; November 2004.

Yankee Nuclear Power Station 10 1672UZeports\2005-10-12In-Process Inspection Survey Results