HO RI S E
OAK RIDE INSTITUTE FOR SCIENCE AND EDUCATION
August 23, 2005
Mr. Thomas DragounNRR/DRIPU.S. Nuclear Regulatory Commission475 Allendale RoadKing of Prussia, PA 19406
SUBJECT: REVISED FINAL REPORT-CONFIRMATORY SURVEY OF THEUNIVERSITY OF VIRGINIA REACTOR, UNIVERSITY OF VIRGINIA,CHARLOTTESVILLE, VIRGINIA [DOCKET NO. 50-62; TASK NO. 2.10]
Dear Mr. Dragoun:
The Environmental Survey and Site Assessment Program (ESSAP) of the Oak Ridge Institute forScience and Education (ORISE) performed confirmatory survey activities of the University ofVirginia Research Reactor in Charlottesville, Virginia during the period March 8 to 10, 2005.Enclosed is the subject revised final confirmatory survey report with NRC/NRR commentsincorporated.
If you have any questions please contact me at (865) 576-3356 or Alex J. Boerner at (865) 574-0951.
Sincerely,
Timothy J. BauerHealth PhysicistEnvironmental Survey and
Site Assessment Program
TJB:ar
Enclosure
cc: A. Adams, NRC/NRR/OWFN 12G13S. Adams, NRC/NRR/OWFN 012E5W. Eresian, NRC/NRR/OWFN 012G13D. Hughes, NRC/NRR/OWFN 012G13
E. Abelquist, ORISE/ESSAPA. Boemer, ORISE/ESSAPFile/0981
P. 0. BOX 117, OAK RIDGE, TENNESSEE 37831-0117
Operated by Oak Ridge Associated Universities for the U.S. Department of Energy
to
to
REVISED FINAL REPORT
CONFIRMATORY SURVEYOF THEUNIVERSITY OF VIRGINIA REACTORUNIVERSITY OF VIRGINIACHARLOTTESVILLE, VIRGINIA
T. J. BAUER
PreparedU.S. NuOffice o0
for theclear Regulatory Commissionf Nuclear Reactor Regulation
Agendes and their conractors; other requests shallappmved by the ouiginating faclity or higher DOEprogrammatic authority.
The Oak Ridge Institute for Science and Education (ORISE) is a U.S. Department of Energy facility focusing onscientific initiatives to research health risks from occupational hazards, assess environmental cleanup, respond toradiation medical emergencies, support national security and emergency preparedness, and educate the nextgeneration of scientists. ORISE is managed by Oak Ridge Associated Universities. Established in 1946, ORAU isa consortium of 9 icolleges and universities.
NOTICES
The opinions expressed herein do not necessarily reflect the opinions of the sponsoring institutions of Oak RidgeAssociated Universities.
This report was prepared as an account of work sponsored by the United States Government. Neither the UnitedStates Government nor the U.S. Department of Energy, nor any of their employees, makes any warranty, expressedor implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of anyinformation, apparatus, product, or process disclosed, or represents that its use would not infringe on privatelyowned rights. Reference herein to any specific commercial product, process, or service by trade name, mark,manufacturer, or otherwise, does not necessarily constitute or imply its endorsement or recommendation, or favor bythe U.S. Government or any agency thereof. The views and opinions of authors expressed herein do not necessarilystate or reflect those of the U.S. Government or any agency thereof.
ORISE 05-1219
CONFIRMATORY SURVEYOF THE
UNIVERSITY OF VIRGINIA REACTORUNIVERSITY OF VIRGINIA
CHARLOTTESVILLE, VIRGINIA
Prepared by
T. J. Bauer
Environmental Survey and Site Assessment ProgramOak Ridge Institute for Science and Education
Oak Ridge, Tennessee 37831-0117
Prepared for the
U.S. Nuclear Regulatory CommissionOffice of Nuclear Reactor Regulation
REVISED FINAL REPORT
AUGUST 2005
This report is based on work performed under an Interagency Agreement (NRC Fin. No. J-3036)between the U.S. Nuclear Regulatory Commission and the U.S. Department of Energy. OakRidge Institute for Science and Education performs complementary work under contract numberDE-AC05-00OR22750 with the U.S. Department of Energy.
University of Virginia Reactor projects\981\Reports\2005-08-08 Revised Final Report.doc
CONFIRMATORY SURVEYOF THE
UNIVERSITY OF VIRGINIA REACTORUNIVERSITY OF VIRGINIA
CHARLOTTESVILLE, VIRGINIA
Prepared by: 4 4t".. • x.
P a. J. Bar'r, Health PhysicistEnvironmental Survey and Site Assessment Program
Reviewed by: C~ljA. Boemer, Acting Survey Projects ManagerEnvironmental Survey and Site Assessment Program
Reviewed by: YO •LA•R. D. Condra, Laboratory ManagerEnvironmental Survey and Site Assessment Program
-Reviewed by: ) {JAA. T. Payne, Quality ManagerEnvironmental Survey and Site Assessment Program
Reviewed by:E. W. Abelquist, Program D66torEnvironmental Survey and 9ite Assessment Program
Date: / C'
Date: J le) Oas-
Date: ?)I2/0
Date:
Date:
University of Virginia Reactor projects\O981\Reports\2005-08-08 Revised Final Report.doc
ACKNOWLEDGMENTS
The author would like to acknowledge the significant contributions of the following staffmembers:
FIELD STAFF
T. D. Herrera
LABORATORY STAFF
R. D. CondraJ. S. CoxW. P. IveyW. F. Smith
CLERICAL STAFF
D. K. HerreraK. L. PondA. Ramsey
ILLUSTRATORS
T. L. BrownT. D. Herrera
University of Virginia Reactor projects\0981\Reports\2005-08-08 Revised Final Reportdoc
TABLE OF CONTENTS
PAGE
List of Figures .................................................................................................................................. ii
List of Tables ................................................................................................................................. iii
Abbreviations and Acronym s ................................................................................................... iv
Introduction and Site History ....................................... ............................................................... 1
Site D escription ............................................................................................................................... 2
Objectives ....................................................................................................................................... 3
D ocum ent Review ........................................................................................................................... 3
Procedures ....................................................................................................................................... 3
Sam ple Analysis And D ata Interpretation ................................................................................. 6
Findings and Results ....................................................................................................................... 7
Com parison of Results with Guidelines ................................................................................... 10
Summ ary ....................................................................................................................................... 10
Figures ........................................................................................................................................... 12
Tables ............................................................................................................................................ 20
References ..................................................................................................................................... 26
Appendices:
Appendix A: Major Instrumentation
Appendix B: Survey and Analytical Procedures
Appendix C: Summary of Surface Soil Screening Values
University of Virginia Reactm i projects\098r\Reports\2005-OS-08 Revised Final Report.doc
LIST OF FIGURES
FIGURE 1:
FIGURE 2:
FIGURE 3:
FIGURE 4:
FIGURE 5:
FIGURE 6:
FIGURE 7:
PAGE
Location of the University of Virginia, Charlottesville, Virginia ..................... 13
UVA Reactor First Floor-Measurement and Sampling Locations .................. 14
UVA Reactor Mezzanine Floor-Measurement and Sampling Locations ..... 15
UVA Reactor Ground Floor, East Areas-Measurement and SamplingL ocations ................................................................................................................ 16
UVA Reactor Ground Floor, West Areas-Measurement and SamplingL ocations ................................................................................................................ 17
UVA Reactor Ground Floor, Reactor Pool Walls-Measurement andSam pling Locations .......................................................................................... 18
UVA Reactor Pond-Sampling Locations ........................................................ 19
University of Virginia Reactor UV projects\0981\Reports\2005-08-08 Revised Final Report.doc
LIST OF TABLES
TABLE 1:
TABLE 2:
TABLE 3:
PAGE
Surface Activity Levels .................................................................................... 21
Radionuclide Concentrations in Soil-Interior Locations and Reactor Pond ........ 24
Radionuclide Concentrations in Soil-Split Samples from WasteTank Excavation .............................................................................................. 25
University of Virginia Reactor iii projects\J98l\Reports\2005-08-08 Revised Final Report.doc
ABBI9EVIATIONS AND ACRONYM
Ei
Etotalbi
CAVALIER
cmcm,cpmd'
DCGLDOEDPdpmdpmo100 cm2
ESSAPFSSISMISOITPJHAkeVkIn
MAPEPMDCMDCRMeVmminmgmg/cm
2
mmnMWNaINISTNRCNRIPNRRORISEpCi/gRAIS
instrument efficiencysurface efficiencytotal efficiencynumber of background counts in the intervalCooperatively Assembled Virginia Low IntensityEducational Reactorcentimetersquare centimetercounts per minuteindex of sensitivityderived concentration guideline levelU.S. Department of Energydecommissioning plandisintegrations per minutedisintegrations per minute per 100 square centimetersEnvironmental Survey and Site Assessment Programfinal status surveysintegrated safety managementInternational Standards OrganizationIntercomparison Testing Programjob hazard analysiskiloelectron voltkilometersquare meterMixed Analyte Performance Evaluation Programminimum detectable concentrationminimum detectable count ratemillion electron voltsmeterminutemilligrammilligrams per square centimetermillimetermegawattsodium iodideNational Institute of Standards and TechnologyNuclear Regulatory CommissionNIST Radiochemistry Intercomparison ProgramOffice of Nuclear Reactor RegulationOak Ridge Institute for Science and Educationpicocuries per gramrequest for additional informationsecond
University of Virginia Reactor iv projects5981\Repors2005-08-08 Revised Final Reportdoc
ABBREVIATIONS AND ACRONYMS (Continued)
SOF sum-of-fractionsTAP total absorption peakUVA University of VirginiaUVAR University of Virginia Reactor
University of Virginia Reactor V projects\0981\Reports\2005-08-08 Revised Final Reportdoc
CONFIRMATORY SURVEYOFTHE
UNIVERSITY OF VIRGINIA REACTORUNIVERSITY OF VIRGINIA
CHARLOTTESVILLE, VIRGINIA
INTRODUCTION AND SITE HISTORY
The University of Virginia (UVA) operated the University of Virginia Reactor (UVAR)
beginning in 1960 under U.S. Nuclear Regulatory Commission (NRC) License No. R-66 for
radiation research, activation analysis, isotope production, neutron radiography, radiation
damage studies, and training of nuclear engineering students. The UVAR was a light-water
cooled, moderated, and shielded pool-type nuclear reactor. Originally commissioned to operate
at a maximum power of one megawatt (MW), it was upgraded in January 1971 to operate at two
MW. The original fuel was aluminum clad high-enriched uranium, but was converted to low-
enriched uranium in early 1994.
The UVAR was permanently shut down in June 1998 and the fuel was removed by mid 1999.
The integrated power generation of the UVAR was an estimated 2,559 MW-days. A radiological
characterization survey was initiated in July 1999, with the report completed in April 2000.
UVA submitted a Decommissioning Plan (DP) to the NRC in February 2000. Decommissioning
began in March 2002 with the removal of extraneous fixtures, equipment, and materials, such as
the reactor grid plate, reactor support structure, and equipment and activated concrete from the
reactor pool. Final status surveys (FSS) were completed and the results presented to the NRC in
2004 (UVA 2000 and 2004a).
The CAVALIER (Cooperatively Assembled Virginia Low Intensity Educational Reactor) was
operated in the UVAR facility and separately decommissioned. A FSS was performed and a
license termination requested. The CAVALIER facility, NRC License R-123, was added within
the scope of the UVAR facility and included in the FSS (UVA 2004a).
The NRC's Headquarters Office of Nuclear Reactor Regulation (NRR) requested that the Oak
Ridge Institute for Science and Education's (ORISE) Environmental Survey and Site Assessment
Program (ESSAP) perform confirmatory surveys of the UVAR facility.
University of Virginia Reactor projects\0981\Reports\2005-08-08 Revised Final Report.doc
SITE DESCRIPTION
The UVA is located approximately 0.6 kilometers (kIn) west of the city limits of Charlottesville
in Albemarle County, Virginia (Figure 1). The UVAR facility is located on the northern grounds
of the UVA and includes approximately 2,030 square meters (m2) of interior floor space and
9,390 mi2 of fenced land.
The upper floor (first floor) contains the Reactor Confinement Room (Room 131), which housed
the former UVAR in the 9.8 m long by 3.7 m wide by 8.2 m deep reactor pool. This room also
held associated operating equipment, systems, and controls and is circular in shape with an
elevated ceiling (approximately 10 m). Most of the impacted reactor and support system
components were removed for disposal as radioactive waste or free released. Also located on the
upper floor are the Instrument Shop (Room 128), the Shipping Area (Room 127), and multiple
offices and other support facilities (UVA 2004a).
Below the upper floor is the Mezzanine level which includes the Demineralizer (Room M021),
Mechanical Room (Room M020), HP Laboratory (Room M019), several partially contaminated
laboratories (Rooms M005 and M008), and multiple offices and other support facilities for staff
and students. A crawl space is accessible from the stairwell. Adjacent to the Reactor
Confinement Room, there was a cooling tower located on the roof of the Mezzanine level that
provided cooling for the reactor secondary system water (UVA 2004a).
Below the Mezzanine level is the ground floor. This floor contains the Heat Exchanger (Room
G024), Rabbit Room (Room G005), Beamport/Experimental Area (Room G020), Hot Cell
(Rooms G025, G026, and G027), Counting Room (Room G004), Woodworking and Machine
Shop (Room G008), Source Storage (Rooms G007A, G018, and G022), the former CAVALIER
Facility (Room G007), and miscellaneous support facilities and areas (UVA 2004a).
The fenced land area included several underground tanks. Two of these tanks were used for
collection and holdup of facility discharges containing radioactive contamination and one,
located at ground level at the front of the facility, was used during fuel shipments. Exterior
construction of the UVAR facility is of metal and concrete block with brick veneer; interior
University of Virginia Reactor 2 projects\0981\Reports\2005-08-08 Revised Final Reportdoc
construction includes concrete slab floors and walls of block and drywall (UVA 2000 and
2004a).
OBJECTIVES
The objectives of the confirmatory survey were to provide independent contractor field data
reviews and radiological data for use by the NRC in evaluating the adequacy and accuracy of the
licensee's procedures and final status survey results.
DOCUMENT REVIEW
ESSAP reviewed the licensee's FSS plan (UVA 2004b) and report (UVA 2004a) for adequacy
and appropriateness taking into account the DP (UVA 2000) and MARSSIM guidance (NRC
2000). Data were evaluated to assure that areas exceeding guidelines were identified and had
undergone remediation. Final status survey results were compared with guidelines to ensure that
the data had been interpreted correctly.
PROCEDURES
ESSAP performed confirmatory surveys of the UVAR during the period March 8 to 10, 2005.
The survey was performed in accordance with the site-specific survey plan submitted to and
approved by the NRC and the ORISE/ESSAP Survey Procedures and Quality Assurance
Manuals (ORISE 2005a and 2004b and c). Additional information concerning major
instrumentation, sampling equipment, and survey and analytical procedures may be found in
Appendices A and B.
INTERIOR
ESSAP used the following procedures for the interior portions of the survey.
Reference Grid
Measurement and sampling locations were referenced to the existing UVA-established grid
system.
University of Virginia Reactor 3 projects\0981Reports\2005-08-08 Revised Final Report.doc
Surface Scans
Surface scans for beta and gamma radiation were performed over selected areas of the UVAR
facility as summarized in the table below. Survey areas included areas with high potential for
residual contamination exceeding release criteria, such as the Reactor Confinement Room (Room
131) and adjacent rooms used for reactor operations and laboratories where radionuclides were
used during experiments.
Surface Scan Coverage forUVAR Facility Area Beta and Gamma Radiation
Floors Lower Walls Upper Walls and CeilingsReactor Confinement Room 50% a(Room 131)Reactor Pool 75% 5-10%Former HP Lab (Rooms M005 and 50%M005A) 100% 5%Former Hot Lab (Room M008) 75%Demineralizer Room (Rooms M021 25%and M021A)Rabbit Room (Room G005)CAVALIER Facility (Room G007) 10%Heat Exchanger Room (Room G024) 75%Hot Cell (Rooms G025, G026, and 50-100% 25-50%G027) 50-100% 25-50%
'Not performed
Particular attention was given to remediated and adjacent surfaces, cracks and joints in the floors
and walls, and other locations where residual radioactive material may have accumulated. In
addition to surfaces, the boreholes UVA installed into the reactor pool floor were gamma
scanned. Scans were performed using gas proportional and Nal scintillation detectors coupled to
ratemeters or ratemeter-scalers with audible indicators. Locations of elevated direct radiation
were noted for further investigation.
Surface Activity Measurements
UVA did not determine construction material-specific backgrounds for correcting surface
activity measurements to account for contributions from naturally occurring materials. Instead,
UVA performed a shielded and unshielded measurement at each location to correct for ambient
University of Virginia Reactor 4 projects\0981\Reports\2005-08-08 Revised F'mal Report.doc
gamma background contribution to the measurement count rate. ESSAP direct measurements
were corrected for ambient background using the same methodology.
Direct measurements for total beta activity were performed at 60 locations, chosen judgmentally,
that included areas of elevated direct radiation identified by surface scans. Dry smears were
collected at each direct measurement location for determining removable gross alpha and gross
beta activity, except for six locations measured on the upper walls of the reactor pool which were
not accessible; direct measurements were performed using an extension pole at these locations.
Direct measurements were performed using gas proportional detectors coupled to ratemeter-
scalers. Figures 2 through 6 show measurement locations.
Soil Sampling
Sub-surface soil samples were collected in increments of 15 cm from 0 to 30 cm in depth at
judgmental locations beneath the floor of the Reactor Confinement Room (Room 131) and
reactor pool floor. Sampled locations corresponded to locations UVA made accessible during
decommissioning activities. Figure 2 shows the soil sampling locations.
EXTERIOR
ESSAP used the following procedures for outdoor portions of the survey area.
Reference Grid
Measurement and sampling locations were noted on a UVA-drawn figure of the exterior areas.
Surface Scans
Surface scans of outdoor locations, including soil areas where the underground waste tanks were
removed and the reactor pond, were performed over approximately 25 to 100% of the accessible
areas using a NaI scintillation detector coupled to a ratemeter.
University of Virginia Reactor 5 projects\0981\Reports\2005-08-08 Revised Final ReporLdoc
Soil Samplin2
Surface soil (0-15 cm) and sub-surface soil (in increments of 15 cm from 15 cm depth to 45 cm
depth) samples were collected at judgmental locations from the reactor pond. Figure 7 shows the
soil sampling locations.
On January 21, 2003, UVA collected soil samples from the waste tank excavation during an
NRC inspection. The soil samples were split and the NRC requested UVA to store the NRC's
samples until a future date. During this confirmatory survey, the NRC inspector requested that
ESSAP analyze a limited number of the split samples. ESSAP chose three of the split samples
for which UVA reported positive Cs-137 concentrations, and two additional samples were
selected randomly. It should-be noted that UVA did not maintain a record of the chain-of-
custody for the NRC's split samples; however, the samples were stored in a container within the
UVAR facility and security seals on all of the split samples were intact.
SAMPLE ANALYSIS AND DATA INTERPRETATION
Samples and data were returned to ORISE's ESSAP Oak Ridge, Tennessee, facility for analysis
and interpretation. Sample analyses were performed in accordance with the ORISE/ESSAP
Laboratory Procedures Manual (ORISE 2004d). Dry smear samples were analyzed for gross
alpha and gross beta activity using a low-background gas proportional counter. Smear results
and direct measurements for total surface activity were converted to units of disintegrations per
minute per 100 square centimeters (dpm/100 cm 2). Soil samples were analyzed by gamma
spectroscopy. Spectra were reviewed for identifiable total absorption peaks. Soil sample results
were reported in units of picocuries per gram (pCi/g).
Confirmatory survey data were compared with the appropriate regulatory guidelines for release
of the site without radiological restrictions. Predominant radionuclides of concern found at the
UVAR facility include Co-60 and Cs-137, with lesser amounts of C-14, Fe-55, and Eu-152. The
radionuclides present and their relative ratios varied depending on the mechanism of
contamination and the medium type. Research projects in labs M005 and M008 included the use
of Tc-99 and Ni-63.
University of Virginia Reactor 6 projects\0981\Reports\2005-08-08 Revised Final Report.doc
The UVAR facility derived concentration guideline levels (DCGL) for building surfaces were
selected from NRC tables of screening values published in NUREG-1757, Volume 1 (NRC
2003). UVA calculated a gross activity DCGL of 6,320 dpm/100 cm 2, except for laboratories
M005 and M008, based on Final Status Survey Plan Addendum 004, Appendix A. UVA
calibrated surface activity measurement instrumentation to Tc-99. The contamination in
laboratories M005 and M008 was Tc-99 and Ni-63, respectively. UVA selected the gross
activity DCGL of 1.3E6 dpm/100 cm 2, based on the more conservative screening value for
Ni-63, for these laboratories, and calibrated surface activity measurement instrumentation to
Ni-63. Because screening values were selected to demonstrate compliance, UVA elected to not
allow areas of elevated activity; therefore, there are no included area factors (UVA 2004a).
Appendix C provides the screening values published in NUREG-1757, Volume 1 (NRC 2003)
that UVA must meet for unrestricted release of soil areas. UVA modified these screening values
to account for hard to detect radionuclides. The following modified DCGLs are applicable:
3.4 pCi/g for Co-60 in soil from beneath the Reactor Confinement Room (Room 131) and reactor
pool as well as soil from the waste tank excavation and 5.9 pCi/g for Cs-137 for the reactor pond
soil. These guidelines apply to the upper 15 cm of soil in the waste tank excavation. They also
apply to the upper 0 to 1 m of soil from the reactor pond, the soil beneath the Reactor
Confinement Room (Room 131), and reactor pool. While soil samples could not be collected
down to a full depth of 1 m, the upper sub-surface soils collected represented areas with the
highest contamination potential that could be used to identify areas requiring further
investigation (UVA 2004a).
FINDINGS AND RESULTS
DocuMENT REVIEW
ESSAP reviewed the licensee's FSS plan (UVA 2004b) and report (UVA 2004a). Comments
ESSAP identified in the project documentation were provided to NRC/NRR (ORISE 2003 and
2004a). UVA's responses to the NRC's Request for Additional Information (RAI) were
reviewed and determined to be acceptable (ORISE 2005b). The procedures, methods, and data
University of Virginia Reactor 7 projects\0981Reports\2005-08-08 Revised Final Report.doc
submitted by UVA were considered to be appropriate and adequately documented the
radiological status of the UVAR facility.
INTERIOR
The results for interior surveys are discussed below.
Surface Scans
Three areas of elevated beta surface radiation were noted in the reactor pool. One area was
found on the lower portion of the gate frame, a second area was a debris pile found on the floor
on the northern side, and a third area was located on the southern side. UVA removed the debris
pile-follow-up scans did not note any residual elevated beta radiation. Five areas of elevated
beta surface radiation were noted in Room M008--each of these areas had been marked by
UVA. One area of elevated beta surface radiation was noted on a lower wall in the CAVALIER
facility (Room G007). One area of elevated gamma radiation at approximately eight times
background was noted in a partial floor core in the concrete of the northern side of the reactor
pool. After ESSAP's investigation, a hot particle was removed from the partial floor core. UVA
performed a gamma spectroscopy field measurement and identified the contaminant to be Co-60.
UVA hypothesized that this was a residual stainless steel "flea" from underwater cutting
operations performed in the 1980s. Two completed reactor floor bore holes had elevated gamma
radiation levels ranging from approximately four to eight times background--one borehole was
noted as number 10 in the UVA FSS documentation while the other was installed during
characterization per on-site discussion with UVA subcontractors. Scans of the remaining
surfaces did not identify any additional locations of elevated beta or gamma radiation.
Surface Activity Levels
Total and removable surface activity levels are provided in Table 1. Total beta activity levels
ranged from -240 to 33,000 dpm/100 cm2 for all areas., Removable activity levels ranged from
0 to 5 dpmr/100 cm 2 for gross alpha and from -5 to 30 dpm/100 cm2 for gross beta for all areas.
A summary of the total surface activity results for areas of interest is provided below and
includes the gross activity DCGL for each area.
University of Virginia Reactor 8 projects\0981\Reports\2005-08-08 Revised Final Report.doc
UVAR Area Range of Total Beta Activity Gross Activity DCGL(dpm/100 cm2) (dprn/100 cm 2)
Reactor Confinement Room(Ro11 6 to 1,300 6,320(Room 131)
Reactor Pool 300 to 4,900 6,320Former HP Labs (Room -240 to 33,000 1E6M005, MO05A, and M008)Remaining Areas 230 to 2,500 6,320
Radionucide Concentrations in Soil Samples
Table 2 shows the radionuclide concentrations in soils beneath the Reactor Confinement Room
(Room 131) and reactor pool for Co-60, Cs-137, Eu-152, and Eu-154 identified during the
analysis of the soil samples by gamma spectroscopy. Radionuclide concentrations in the soilsranged from -0.04 to 2.98 pCi/g for Co-60, -0.02 to 0.12 pdi/g for Cs-137, -0.09 to 0.14 pCi/g
for Eu-152, and -0.12 to 0.17 pCi/g for Eu-154. Using the sum-of-fractions (SOF) calculation to
compare to the unity rule, as discussed in Section 4.3.3 of MARSSIM (NRC 2000), the SOF
values ranged from 0.00 to 0.92. In addition, elevated levels of natural thorium (by Ac-228) and
natural uranium (by Th-234) were noted in the reactor pool samples. Concentrations in samples
S0006 through S0009 ranged from 3.38 to 6.47 pCi/g for Ac-228 and 1.95 to 4.60 pCi/g for
Th-234.
EXTERIOR
The results for exterior surveys are discussed below.
Surface scans
Gamma surface scans were within the range of ambient background levels.
Radionuclide Concentrations in Soil Samples
Table 2 shows the radionuclide concentrations in soils collected from the reactor pond for Co-60,
Cs-137, Eu-152, and Eu-154 identified during the analysis of the soil samples by gamma
spectroscopy. Radionuclide concentrations in the soils ranged from 0.00 to 5.50 pCi/g for
Co-60, 0.00 to 1.67 pCi/g for Cs-137, -0.07 to 8.11 pCi/g for Eu-152, and -0.05 to 0.70 pCi/g for
Eu-154. The SOF values ranged from 0.00 to 2.8.
University of Virginia Rewwr 9 projects\0981\Reports\2005-08-08 Revised Final Reportdoc
Table 3 shows the radionuclide concentrations in the NRC's split soil samples from the waste
tank excavation for Co-60, Cs-137, Eu-152, and Eu-154 identified during analysis of the soil
samples by gamma spectroscopy. Radionuclide concentrations in the soils ranged from -0.01 to
0.01 pCi/g for Co-60, 0.13 to 0.32 pCi/g for Cs-137, -0.07 to 0.02 pCi/g for Eu-152, and -0.09 to
0.13 pCi/g for Eu-154. The SOF values ranged from 0.01 to 0.05. The reported data for UVA's
split samples are also reported in Table 3 and were comparable with the ESSAP results.
COMPARISON OF RESULTS WITH GUIDELINES
Results of the survey were compared to the applicable guidelines. Confirmatory results for
building surfaces were all less than the applicable gross activity DCGLs. One surface soil
sample from the reactor pond (0981S0012) exceeded the screening value for Co-60; because this
elevated area was not identified during surface scans and the activity exceeding the screening
value was only identified in the upper 15 cm of the soil, the sample is not indicative of a large,
distributed source but rather a small isolated area. Based on these results and an evaluation of
the licensee's data, it is ESSAP's opinion that the soil from 0 to 1 m would meet the individual
radionuclide DCGLs and the unity rule. All other confirmatory soil samples and split soil
samples from the waste tank excavation met individual radionuclide DCGLs as well as the unity
rule. The elevated gamma levels noted in two boreholes in the northern section of the reactor
pool floor were caused by the elevated natural thorium and uranium concentrations. These
elevated levels were expected for the area per discussions with the licensee staff.
SUMMARY
At the request of the U.S. Nuclear Regulatory Commission, the Environmental Survey and Site
Assessment Program of the Oak Ridge Institute for Science and Education conducted
confirmatory survey activities for the University of Virginia Reactor in Charlottesville, Virginia.
Confirmatory activities included document and data reviews, and during the period March 8 to
10, 2005, independent surface scans, surface activity measurements, and soil sampling.
University of Virginia Reactm 10 projects\0981\Reports\2005-08-08 Revised Final Report.doc
000
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The findings of the confirmatory survey support UVA's final survey results for building surfaces
and soil areas, and in ESSAP's opinion, indicate that the radiological conditions of the surveyed
areas satisfy the NRC guidelines for release without radiological restrictions.
University of Vixginia Rmtw 11 projects\98l\Reportsm\2005-08-O5 Revised Fimal Reportdoc
FIGURES
University of Virginia Reactor projects\0981Reports\2005-08-08 Revised Final Report.doc
981-001 (2)
NIr
NOT TO SCALE
FIGURE 1: Location of the University of Virginia, Charlottesville, Virginia
University of Virginia Reactor 13 projects\0981\Reports\2005-08-08 Revised Final Reportdoc
981-002 (2)
FIGURE 2: UVA Reactor First Floor - Measurement and Sampling Locations
University of Virginia Reactor 14 projects\0981•Reports\2005-08-08 Revised Final Reportdoc
981-003 (1)
4+0.3
4
3
2
1
0
7+0.
7
6
5
4
3
2
1
0
A B C D E
ROOM M021A
8s
29
.-.2
30
31
A B C D E E+0.1
ROOM MOOS
o HL.
ROOM M021
1+0.9
A B C D B F F40.2
ROOMS M005 & M005A
I
MEASUREMENT/SAMPLINGLOCATIONS
* # SINGLE-POINTLOWER WALLS AND FLOOR
D SURVEYED AREA
N
NOT TO SCALE
I ________________________________ L
FIGURE 3: UVA Reactor Mezzanine Floor - Measurement and Sampling Locations
University of Virginia Reactor 15 projects\0981\Reports\2005-08-08 Revised Final Report.doc
981-004 (1)
5340C
/4ý 541 I
A
4.3
3.5
25
B C D E 0
ROOM G024
4+0-3
4
H I I J+0.8
.10
D E E+0.5A B c
ROOM G025
07
3
2
1+0.3
0L
1Y I Y
I,012
oil
D~I
A A+0.9
ROOM G027
A B
I I _ _C D
ROOM G026
E E+0.5
MEASUREMENT/SAMPLINGLOCATIONS
LW# SINGL LAPOINTLOWER WALLS AND FLOOR
E SURVEYED AREA
k INACCESSIBLE AREA
N
NOT TO SCALE
FIGURE 4: UVA Reactor Ground Floor, East Areas - Measurement and Sampling Locations
University of Virginia Reactor 16 projects\0981\Reportso2005-08-08 Revised Final Report.doc
981-005 (1)
Rabbit Room
4-~U. ~ I--- - -
CAVALIERFacility 4
3
2
1
58 v6O58 60- -1- -
591
7.8
7
A B C D
ROOM G005
E E+0.75
6
4
3
2
0A B C D E F G H
ROOM 3007
MEASUREMENT/SAMPLINGLOCATIONS
# SINGLE-POINTLOWER WALLS AND FLOOR
l SURVEYED AREA
N
NOT TO SCALE
I I
FIGURE 5: UVA Reactor Ground Floor, West Areas - Measurement and Sampling Locations
University of Virginia Reactor 17 projects\098l\Reports\2005-08-08 Revised Final Report.doc
981-006 (1)
0
-1 - - - -
-2
-3
-4
-6
-7
-7-0.35A B C D ENorth Pool, North Wall
0
-1 - - - -
-2
-3
-4 -- -
-5 - 4
-6 26
-7-7-0.35 - _ 25
1-0.9 E+0.7 E D C B ANorth Pool, East Wall
0
-1
-2
-3
-4
-5
-6
-7-7-0.35
0
-1
-2
-3
-4
-5
-6
-7-7-0.35
6
,28
A B C D ENorth Pool, West Wall
3
1 i)20
A B C D ESouth Pool, West Wall
E+0.7
0
-I
-2
-3
-4
-5
-6
-7-I 15-
0
-1
-2
-3
-4
-5
-6
-7
2
-j17
7-S
-7-0.35A B C D E
South Pool, East Wall
-7-0.351 1E D C B A
South Pool, South Wall
MEASUREMENT/SAMPLINGLOCATIONS
# SINGLE-POINTLOWER WALLS AND FLOOR
A # SINGLE-POINTUPPER WALLS
[] SURVEYED AREA
N
NOT TO SCALE
FIGURE 6: UVA Reactor Ground Floor, Reactor Pool Walls - Measurement and Sampling Locations
University of Virginia Reactor 18 projects\0981\Reports\2005-08-08 Revised Final Report.doc
981-006 (1)
SAMPLING LOCATIONS
* # SURFACE/SUBSURFACE SOIL
N
II
NOT TO SCALE
FIGURE 7: UVA Reactor Pond - Sampling Locations
University of Virginia Reactor 19 projects\0981\Reports\2005-08-08 Revised Final Reportdoc
TABLES
University of Virginia Reactor projects\0981\Reports\2005-08-08 Revised Final Report.doc
TABLE 1
SURFACE ACTIVITY LEVELSUNIVERSITY OF VIRGINIA REACTOR
UNIVERSITY OF VIRGINIACHARLOTTESVILLE, VIRGINIA
Locationa Surfaceb Total Beta Activity Removable Activity(dpm/100 cm 2) (dpm/1O0cm 2)
Alpha 7 -Beta
Reactor Confinement Room (Room 131)
39 F 1,300 0 -1
40 F 1,100 0 -2
41 F 820 0 1
42 F 320 1 3
43 F 450 3 7
44 F 890 0 9
45 LW 460 0 -3
46 LW 840 0 -4
47 LW 16 0 3
48 LW .170 0 -1
Reactor Pool
1 UW 1,200 __c --
2 UW 1,100 ..--
3 UW 840 ..--
4 UW 1,400 ..--
5 UW 1,100 ..
6 UW 1,200 -- --
13 F 1,900 0 -4
14 F 1,200 1 10
15 LW 890 0 -3
16 LW 1,200 0 6
17 LW 300 1 6
18 LW 1,800 1 -3
19 LW 1,800 0 -1
University of Virginia Reactor 21 projeets\0981\Reports\2005-O8-08 Revised Final Report.doc
TABLE 1 (Continued)
SURFACE ACTIVITY LEVELSUNIVERSITY OF VIRGINIA REACTOR
UNIVERSITY OF VIRGINIACHARLOTTESVILLE, VIRGINIA
eb Total Beta Activity Removable ActivityLocationa Surface (dpm/100 cm2) (dpMIOOCM2 )
Alpha Beta
Reactor Pool - Continued
20 LW 1,100 0 2
21 F 4,400 1 5
22 F 2,100 0 7
23 LW 1,500 0 -2
24 LW 1,100 0 5
25 LW 1,500 0 3
26 LW 1,000 5 -1
27 F 4,900 0 6
28 LW 1,300 3 -5
Former HP Lab (Rooms M005 and M005A)
33 F -240 0 1
34 F 240 3 1
35 LW 790 1 -2
36 LW 1,000 0 6
37 F -48 1 -5
38 LW 790 0 -2
Former Hot Lab (Room M008)
29 F 210 3 1
30 F 2,100 3 3
31 LW 33,000 0 -1
32 LW 1,300 0 3
Demineralizer Room (Rooms M021 and M021A)
49 F 750 0 23
50 F 1,400 1 9
University of Virginia Reactor 22 projects\0981 Reports\2005-08-O8 Revised Final Report.doc
TABLE 1 (Continued)
SURFACE ACTIVITY LEVELSUNIVERSITY OF VIRGINIA REACTOR
UNIVERSITY OF VIRGINIACHARLOTTESVILLE, VIRGINIA
I 17
Demineralizer Room (Rooms M021 and M021A) - Continued
51 F 490 0 3
52 F 700 1 3
Rabbit Room (Room G005)
58 F 360 0 -1
59 F 230 0 6
60 LW 870 1 2
CAVALIER Facility (Room G007)
55 F 390 0 2
56 F 1,100 0 -4
57 LW 2,500 0 7
Heat Exchanger Room (Room G024)
53 F 1,000 1 2
54 F 1,400 1 30
Hot Cell (Rooms G025, G026, and G027)
7 LW 1,000 0 4
8 F 1,100 0 -1
9 LW 260 1 1
10 F 1,300 3 1
11 LW 1,700 0 1
12 F 1,300 0 2
'Refer to Figures 2 through 6.bF = floor; LW = lower wall; UW = upper wall.F- = Measurement not performed.
University of Virginia Reactor 23 projects\0981\Reports\2005-08-08 Revised Final Report.doc
TABLE2
RADIONUCLIDE CONCENTRATIONS IN SOILINTERIOR LOCATIONS AND REACTOR POND
UNIVERSITY OF VIRGINIA REACTORUNIVERSITY OF VIRGINIA
CHARLOTTESVILLE, VIRGINIA
ESSAP Sample Depth Radionuclide Concentration (pCi/g) SOFbNumber' (cm) I Co-60 Cs-137 Eu-152 Eu-154
Fill Beneath Reactor Confinement Room Floor (Room 131)
0981S0001 0-15 -0.02 ± 0.03c 0.02 ± 0.03 0.01 ±0.06 0.11 ±0.13 0.02
0981S0002 0-15 0.12 ± 0.06 0.91 ± 0.04 -0.01 ± 0.06 0.03 ± 0.13 0.04
0981S0003 15-30 0.08 ± 0.05 0 .0 0 d + 0.02 0.02 ± 0.06 -0.12 ± 0.12 0.03
0981S0004 0-15 0.03 ± 0.03 0.00 ± 0.02 -0.05 ± 0.05 0.00 ± 0.10 0.01
0981SO005 15-30 0.00 ± 0.03 -0.01 ± 0.03 -0.01 ± 0.06 0.05 ± 0.13 0.01
Soil Beneath Reactor Pool Floor
0981S0006 0-15 0.00±0.04 0.02 ± 0.04 -0.11 ±0.09 0.06 ± 0.16 0.01
0981S0007 15-30 -0.04 ± 0.05 -0.02 ± 0.04 -0.09 ± 0.09 -0.01 ± 0.19 0.00
0981S0008 0-15 2.98 ±0.14 0.12 ± 0.03 0.14 ±0.09 0.17 ±0.14 0.92
0981S0009 15-30 0.70 ±0.10 0.03 ± 0.04 0.10 ±0.09 -0.11 ±0.17 0.22
Reactor Pond
0981S0010 0-15 0.04±0.05 0.12 ± 0.03 -0.03 ± 0.08 0.05 ±0.15 0.04
0981S0011 15-30 0.00 ± 0.03 0.00 ± 0.03 -0.07 ± 0.07 -0.05 ± 0.15 0.00
0981S0012 0-15 5.50 ± 0.25 1.67 ± 0.13 8.11 ±0.43 0.70 ± 0.30 2.8
0981S0013 15-30 0.32 ± 0.09 0.55 ± 0.06 0.30 ± 0.09 0.27 ± 0.20 0.25
0981S0014 0-15 0.03 ± 0.05 1.05 ± 0.07 -0.01 ± 0.07 -0.03 ±0.14 0.19
0981S0015 15-30 0.03 ± 0.04 0.18 ± 0.06 0.05 ± 0.09 -0.04 ±0.16 0.04
0981S0016 30-45 0.01 ± 0.04 0.08 ± 0.04 -0.05 ± 0.07 0.03 ± 0.16 0.02
"Refer to Figures 2 and 7.bCalculated using the sum-of-fractions (SOF) to compare to the unity rule, as discussed in Section 4.3.3 of MARSSIM(NRC 2000). Refer to Appendix C for surface soil screening DCGLs. To account for hard to detect radionuclides, UVA appliedthe following modified DCGLs: 3.4 pCi/g Co-60 in soil beneath the Reactor Confinement Room (Room 131) and reactor poolfloor and 5.9 pCi/g Cs-137 for the reactor pond.
*Uncertainties are total propagated uncertainties at the 95% confidence level.dZero values are due to rounding.
University of Virginia Reactor 24 projects\O981lReports\2O05-08-08 Revised Final Report.doc
, - - -, - - -, -- - ~- -,-.' q~ - 4F 1 r '.- . -
01
TABLE 3
RADIONUCLIDE CONCENTRATIONS IN SOILSPLIT SAMPLES FROM THE WASTE TANK EXCAVATION
UNIVERSITY OF VIRGINIA REACTORUNIVERSITY OF VIRGINIA
CHARLOTTESVILLE, VIRGINIA
ESSAP ESSAP Radionuclide Concentration (pCi/g) UVA Sample UVA Radionuclide Concentration (pCi/g)bSample SOF4 IDNumber Co-60 Cs-137 Eu-152 Eu-154 Co-60 Cs-137
0981S0017 0.01 ± 0.03c 0.19 ± 0.04 0.02 ± 0.06 -0.07 ± 0.12 0.02 N.VA-WTFS- <0.16 <0.31N3.6-W23.7
0981SO018 -0.01 ± 0.04 0.15 ± 0.05 -0.06 ± 0.07 0.04 ± 0.16 0.02 UVA-WTFS1 <0.21 0.28N3.6-W18.7
0981S0019 0.01 ± 0.03 0.13 ± 0.04 -0.04 ± 0.06 -0.04 ± 0.20 0.01 UVA-WTFS- <0.12 0.1N0.7-WT1.2
0981S0020 0.01 ± 0.04 0.32 ± 0.05 -0.07 ± 0.07 0.13 ± 0.14 0.05 UVA-WTFS- <0.26 0.56NO.7-W21.2
0981S0021 0.00" ± 0.04 0.27 ± 0.05 -0.06 ± 0.07 -0.09 ±0.15 0.02 UVA-WTFS- <0.19 0.461 1 11 1 1NO.7-W6.2
'Calculated using the sum-of-fractions (SOF) to compare to the unity rule for the ESSAP data, as discussed in Section 4.3.3 of MARSSIM (NRC 2000). Refer to Appendix C forsurface soil screening DCGLs. To account for hard to detect radionuclides, UVA applied a modified DCGL of 3.4 pCi/g Co-60.
bUVA data from Table 4-2 of the Final Status Survey Report, Revision 1 (UVA 2004a).'Uncertainties are total propagated uncertainties at the 95% confidence level.dZero value is due to rounding.
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REFERENCES
Oak Ridge Institute for Science and Education (ORISE). Document Review-Master FinalStatus Survey Plan and Addendums 001-008, University of Virginia, Charlottesville, Virginia[Docket No. 50-62; Task No. 2.1]. Oak Ridge, TN; October 24, 2003.
Oak Ridge Institute for Science and Education. Document Review-Final Status SurveyDocumentation, University of Virginia, Charlottesville, Virginia [Docket No. 50-62; Task No.2.2]. Oak Ridge, TN; July 12, 2004a.
Oak Ridge Institute for Science and Education. Survey Procedures Manual for theEnvironmental Survey and Site Assessment Program. Oak Ridge, Tennessee; September 2,2004b.
Oak Ridge Institute for Science and Education. Quality Assurance Manual for the EnvironmentalSurvey and Site Assessment Program. Oak Ridge, Tennessee; August 31, 2004c.
Oak Ridge Institute for Science and Education. Laboratory Procedures Manual for theEnvironmental Survey and Site Assessment Program. Oak Ridge, Tennessee; August 31, 2004d.
Oak Ridge Institute for Science and Education. Final Confirmatory Survey Plan for theUniversity of Virginia Research Reactor, University of Virginia, Charlottesville, Virginia[Docket No. 50-62; Task No. 2.8]. Oak Ridge, TN; February 28, 2005a.
Oak Ridge Institute for Science and Education. Review of UVA Responses to NRC RAIs. OakRidge, TN; January 20, 2005b.
U.S. Nuclear Regulatory Commission (NRC). Multi-Agency Radiation Survey and SiteInvestigation Manual (MARSSIM). Washington, DC: NUREG-1575, Revision 1; August 2000.
U.S. Nuclear Regulatory Commission. Consolidated NMSS Decommissioning Guidance:Decommissioning Process for Materials Licensees. Washington, DC: NUREG-1757, Volume 1,Revision 1; September 2003.
University of Virginia (UVA). University of Virginia Decommissioning Plan. Charlottesville,VA; February 2000.
University of Virginia. Final Status Survey Report, Revision 1. Charlottesville, VA; November2004a.
University of Virginia. Master Final Status Survey Plan, UVA-FS-002. Charlottesville, VA;Revision 1, April 2004b.
University of Virginia Reactor 26 projects\0981lReports\2005-08-08 Revised Final Report.doc
APPENDIX A
MAJOR INSTRUMENTATION
University of Virginia Reactor projects\0981\Reports\2005-08-08 Revised Final Report.doc
APPENDIX A
MAJOR INSTRUMENTATION
The display of a specific product is not to be construed as an endorsement of the product or itsmanufacturer by the author or employer.
SCANNING INSTRUMENT/DETECTOR COMBINATIONS
Alpha-Beta
Ludlum. Floor Monitor Model 239-1combined withLudlum Ratemeter-Scaler Model 2221coupled toLudlum Gas Proportional Detector Model 43-37, Physical Area: 550 cm2
(Ludlum Measurements, Inc., Sweetwater, TX)
Ludlum Ratemeter-Scaler Model 2221coupled toLudlum Gas Proportional Detector Model 43-68, Physical Area: 126 cm2
(Ludlum Measurements, Inc., Sweetwater, TX)
Gamma
Eberline Pulse Ratemeter Model PRM-6(Eberline, Santa Fe, NM)coupled toVictoreen Nal Scintillation Detector Model 489-55, Crystal: 3.2 cm x 3.8 cm(Victoreen, Cleveland, OH)
Ludlum Model 12(Ludlum Measurements, Inc., Sweetwater, TX)coupled toVictoreen NaI Scintillation Detector Model 489-55, Crystal: 3.2 cm x 3.8 cm(Victoreen, Cleveland, OH)
DIRECT MEASUREMENT INSTRUMENT/DETECTOR COMBINATIONS
Beta
Ludlum Ratemeter-Scaler Model 2221coupled toLudlum Gas Proportional Detector Model 43-68, Physical Area: 126 cm2
(Ludlum Measurements, Inc., Sweetwater, TX)
University of Virginia Reactor A-1 projects\0981lReports\2005-08-08 Revised Final Report.doc
LABORATORY ANALYTICAL INSTRUMENTATION
Low Background Gas Proportional CounterModel LB-5100-W(Oxford, Oak Ridge, TN)
High Purity Extended Range Intrinsic DetectorCANBERRA/Tennelec Model No: ERVDS30-25195(Canberra, Meriden, CT)Used in conjunction with:Lead Shield Model G-1 1(Nuclear Lead, Oak Ridge, TN) andMultichannel AnalyzerDEC ALPHA Workstation(Canberra, Meriden, CT)
High Purity Extended Range Intrinsic DetectorModel No. GMX-45200-5(AMETEK/ORTEC, Oak Ridge, TN)used in conjunction with:Lead Shield Model SPG-16-K8(Nuclear Data)Multichannel AnalyzerDEC ALPHA Workstation(Canberra, Meriden, CT)
High-Purity Germanium DetectorModel GMX-30-P4, 30% Eff.(AMETEK/ORTEC, Oak Ridge, TN)Used in conjunction with:Lead Shield Model G-16(Gamma Products, Palos Hills, IL) andMultichannel AnalyzerDEC ALPHA Workstation(Canberra, Meriden, CT)
University of Virginia Reactor A-2 projects\0981\Reports\2005-08-08 Revised Final Reportdoc
APPENDIX B
SURVEY AND ANALYTICAL PROCEDURES
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University of Virginia Reactor projects\O981\Reports\2005-08-08 Revised Final Report.doc
APPENDIX B
SURVEY AND ANALYTICAL PROCEDURES
PROJECT HEALTH AND SAFETY
The proposed survey and sampling procedures were evaluated to ensure that any hazards
inherent to the procedures themselves were addressed in current job hazard analyses (JHAs). All
survey and laboratory activities were conducted in accordance with ORISE health and safety and
radiation protection procedures.
A walkdown of the survey areas was performed in order to evaluate and identify potential health
and safety issues. UVA provided general site-specific safety awareness-falls into the floor
openings were of the greatest concern. Survey work was performed per the ORISE generic
health and safety plans, a site-specific integrated safety management (ISM) pre-job hazard
checklist, and the safety procedures discussed during the training.
QUALITY ASSURANCE
Analytical and field survey activities were conducted in accordance with procedures from the
following documents of the Environmental Survey and Site Assessment Program:
" Survey Procedures Manual, (September 2004)
" Laboratory Procedures Manual, (August 2004)
" Quality Assurance Manual, (August 2004)
The procedures contained in these manuals were developed to meet the requirements of
Department of Energy (DOE) Order 414.1B and the U.S. Nuclear Regulatory Commission
Quality Assurance Manual for the Office of Nuclear Material Safety and Safeguards and contain
measures to assess processes during their performance.
Quality control procedures include:
" Daily instrument background and check-source measurements to confirm that equipment
operation is within acceptable statistical fluctuations.
" Participation in MAPEP, NRIP, and ITP Laboratory Quality Assurance Programs.
University of Virginia Reactor B-1 projects\0981\Reports\2005-08-08 Revised Final Reportdoc
* Training and certification of all individuals performing procedures.
* Periodic internal and external audits.
CALIBRATION
Calibration of all field and laboratory instrumentation was based on standards/sources, traceable
to NIST, when such standards/sources were available. In cases where they were not available,
standards of an industry-recognized organization were used.
Detectors used for assessing surface activity were calibrated in accordance with ISO-7503 1
recommendations. The total efficiency (-total) was determined for each instrument/detector
combination and consisted of the product of the 2n instrument efficiency (Ei) and surface
efficiency (Fs): etota =- Ei x F,.
UVA selected Tc-99 as the calibration source (maximum beta energy of 292 keV) as it provides
a conservative representation of the radionuclide mixture for all areas except Rooms M005 and
M008 where Ni-63 was the chosen calibration source. ISO-7503 recommends an Es of 0.25 for
beta emitters with a maximum energy of less than 0.4 MeV (400 keV) and an F of 0.5 for
maximum beta energies greater than 0.4 MeV. UVA selected an F, of 0.25 in order to calculate a
conservative cttal. UVA calibrated their hand-held gas-proportional instrumentation using a
0.8 mg/cm2 Mylar window for all areas except laboratories M005 and M008 where a 0.4 mg/cm2
window was used. ESSAP calibrated instruments for the confirmatory survey using the same
methodology and detector window configuration as UVA.
Surface Scans
Hand-held detectors were placed on contact with the calibration sources. A postulated hot-spot
size of 100 cm2 was assumed a priori for determining scanning instrument efficiencies. The
scanning Fi values were 0.47 and 0.18 for Tc-99 and Ni-63, respectively, for the hand-held gas
proportional detectors; the calculated scanning E-,o values were 0.12 and 0.05 for Tc-99 and Ni-
lInternational Standard. ISO 7503-1, Evaluation of Surface Contamination - Part 1: Beta-emitters (maximum betaenergy greater than 0.15 MeV) and alpha-emitters. August 1, 1988.
University of Virginia Reactor B-2 projects\981\Reports\2005-08-08 Revised Final Reportdoc
63, respectively. Calibration source emission rates were not corrected for geometry when
sources larger than the detectors were used.
The scanning Fto was determined for the floor monitor in the same fashion as above for the
hand-held gas proportional detectors except typical efficiencies for the floor monitor were used
rather than specific calibrations for this survey. The scanning Ei for Tc-99 was 0.24; the
scanning stotw was 0.06.
Surface Activity Measurements
The calibration F, values for the hand-held gas proportional detectors used for the confirmatory
survey were 0.39 and 0.18 for Tc-99 and Ni-63, respectively. Calibration source emission rates
were corrected to the active area of the detector when the calibration source area exceeded the
detector area. The static etow values used were 0.10 and 0.05 for Tc-99 and Ni-63, respectively.
SURVEY PROCEDURES
Surface Scans
Surface scans were performed by passing the detectors slowly over the surface; the distance
between the detector and the surface was maintained at a minimum - nominally about 1 cm. A
large surface area, gas proportional floor monitor with a 0.8 mg/cm2 window and a NaI
scintillation detector was used to scan the floors of the surveyed areas. Wall surfaces were
scanned using small area (126 cm 2) hand-held detectors with a 0.8 mg/cm2 window. For Rooms
M005 and M008, hand-held detectors with 0.4 mg/cm2 windows were used to scan the floors,
walls, and ceilings. Identification of elevated levels was based on increases in the audible signal
from the recording and/or indicating instrument.
Scan minimum detectable concentrations (MDCs) were estimated using the calculational
approach described in NUREG-15072 . The scan MDC is a function of many variables, including
the background level. Site beta background levels were within the typical range of 800 to 1,400
cpm for the large area gas proportional detectors (floor monitors) and 250 to 450 cpm for the
2NUREG- 1507. Minimum Detectable Concentrations with Typical Radiation Survey Instruments for VariousContaminants and Field Conditions. US Nuclear Regulatory Commission. Washington, DC; June 1998.
University of Virginia Reactor B-3 projects\0981lReports\2005-08-08 Revised Final Report.doc
hand-held gas proportional detectors. Additional parameters selected for the calculation of scan
MDC included a one-second observation interval, a specified level of performance at the first
scanning stage of 95% true positive rate and 25% false positive rate, which yields a d' value of
2.32 (NUREG-1507, Table 6.1), and a surveyor efficiency of 0.5. To illustrate an example for
the hand-held gas proportional detectors with 0.8 mg/cm 2 windows, the minimum detectable
count rate (MDCR) and scan MDC can be calculated as follows:
bi = (250 cpm) (1 s) (1 min/60 s) = 4.2 counts
MDCR = (2.32) (4.2 counts)½ [(60 s/min) / (1 s)] = 285 cpm
MDCRsu-veyor = 285 1(0.5) Y = 403 cpm
The scan MDC is calculated using the total scanning efficiency (ctotai) of 0.12:
Scan MDC = MDCRsunveyor dpm/100 cm 2
etota
The scan MDC was calculated to be 3,400 dpm/100 cm 2. For the given background ranges, the
following table summarizes the calculated scan MDC values.
Detector Scan MDC Range (dprn/100 cmr)0.8 m•m/cm 2 Window 0.4 mg/cm2 Window
Hand-Held Gas Proportional 3,300 to 4,500 8,000 to 11,000Floor Monitor 12,000 to 16,000 N/Aa
a Not applicable
The scan MDCs for the NaI scintillation detector for the contaminants of concern in surface soil
were obtained directly from NUREG-1507 when available. The scan MDCs provided in
NUREG-1507 were 5.8 and 10.4 pCi/g, respectively, for Co-60 and Cs-137. For Eu-152 in soil,
the scan MDC was approximately 5.8 pCi/g3. The scan MDCs for other major gamma-emitting
contaminants of concern were not provided in NUREG-1507. In such a case, it is standard
procedure for ESSAP staff to pause and investigate any locations where gamma radiation is
distinguishable from background levels.
3The scan MDC for Eu-152 was estimated based on empirical calculations for Nal response versus gamma energyprovided in Decommissioning Health Physics: A Handbook for MARSSIM Users, E.W. Abelquist; 2001.
University of Virginia Reactor B-4 projects\0981\Reports\2005-08-08 Revised Final Reportdoc
Surface Activity Measurements
Surface activity measurements were performed on poured concrete, cinderblocks, tile, wall
board, and corrugated metal. To account for the ambient gamma background, unshielded and
shielded measurements were performed at each location. A 3/8-inch Plexiglas shield was used to
determine the gamma count rate associated with the unshielded count rates. This thickness was
demonstrated to block the beta particles from Sr-90, including the beta particles from the
progeny Y-90. Since Y-90 emits beta particles higher in energy than Cs-137, the Plexiglas
shield completely shielded measurement of the Cs-137 beta emissions. Surface activity was
calculated by determining the net count rate, subtracting the shielded measurement from the
unshielded measurement, then correcting for total efficiency and detector area size.
The static beta MDCs--calculated using the calibration check-out count rate-for the gas
proportional detectors used for direct measurements are shown in the table below. The physical
surface area assessed by the gas proportional detector used was 126 cm2.
Detector Window Calibration Check-Out Static MDC(mg/cm2 ) Count Rate (cpm) (dpm/100 cm2)
0.4 392 1,5000.8 380 740
Removable Activity Measurements
Removable gross alpha and gross beta activity levels were determined using numbered filter
paper disks, 47 mm in diameter. Moderate pressure was applied to the smear and approximately
100 cm 2 of the surface was wiped. Smears were placed in labeled envelopes with the location
and other pertinent information recorded.
RADIOLOGICAL ANALYSIS
Gross Alpha/Beta
Smears were counted for two minutes on a low-background gas proportional system for gross
alpha and beta activity. The MDCs of the procedure were 9 dpm/100 cm 2 and 15 dpm/100 cm 2
for gross alpha and gross beta, respectively.
University of Virginia Reactor B-5 projects\0981\Reports\2005-08-08 Revised Final Report.doc
Gamma Spectroscopy
Samples of soil were dried, mixed, crushed, and/or homogenized as necessary, and a portion
sealed in a 0.5-liter Marinelli beaker or other appropriate container. The quantity placed in the
beaker was chosen to reproduce the calibrated counting geometry. Net material weights were
determined and the samples counted using intrinsic germanium detectors coupled to a pulse
height analyzer system. Background and Compton stripping, peak search, peak identification,
and concentration calculations were performed using the computer capabilities inherent in the
analyzer system. All total absorption peaks (TAP) associated with the radionuclides of concern
were reviewed for consistency of activity. Total absorption peaks used for determining the
activities of radionuclides of concern and the typical associated MDCs for a one-hour count time
were:
Radionuclide TAP (MeV) MDC (pCi/g)Co-60 1.173 0.05Cs-137 0.662 0.05Eu-152 0.344 0.11Eu-154 0.723 0.13
Spectra were also reviewed for other identifiable TAPs.
DETECTION LIMITS
Detection limits, referred to as minimum detectable concentration (MDC), were based on 3 plus
4.65 times the standard deviation of the background count [3 + (4.65$tBKG)]. Because of
variations in background levels, measurement efficiencies, and contributions from other
radionuclides in samples, the detection limits differ from sample to sample and instrument to
instrument.
University of Virginia Reactor B-6 projects\0981\Reports\2005-08-08 Revised Final Reportdoc
40
4040
10
10
APPENDIX C
SUMMARY OF SURFACE SOIL SCREENING VALUES
University of Virginia Reactor projects\0981\Reports\2005-08-08 Revised Final Report.doc
APPENDIX C
SUMMARY OF SURFACE SOIL SCREENING VALUES
The following table lists the contaminants of concern and their associated surface soil screeningvalues published in NUREG-1757, Volume 11.
Radionucide Guideline Value (pCi/g)H-3 110
Fe-55 10,000Pu-239/240 2.3U-233/234 13.0
U-238 14.0Ni-59 5,500
Cs-134 5.7Cs-137 11.0Co-60 3.8
Eu-152 8.7Eu-154 8.0Mn-54 15.0
Ag-110m 3.9Zn-65 6.2Sr-90 1.7C-14 12.0Ni-63 2,100Tc-99 19.0
'U.S. Nuclear Regulatory Commission. Consolidated NMSS Decommissioning Guidance: DecommissioningProcess for Materials Licensees. Washington, DC: NUREG-1757, Volume 1, Revision 1; September 2003.
University of Virginia Reactor C-1 projects\0981\Reports\2005-08-08 Revised Final Reportdoc