ML19239A118
| ML19239A118 | |
| Person / Time | |
|---|---|
| Site: | Vallecitos, Vallecitos Nuclear Center |
| Issue date: | 08/13/2019 |
| From: | Bailey E Oak Ridge Institute for Science & Education |
| To: | Jack Parrott Reactor Decommissioning Branch |
| Parrott J | |
| References | |
| DCN 5334-SR-01-1, DE-SC0014664, RFTA 19-003 | |
| Download: ML19239A118 (58) | |
Text
100 ORAU Way
- Oak Ridge
- TN 37830
- orise.orau.gov August 13, 2019 Mr. Jack Parrott, Sr. Project Manager U.S. Nuclear Regulatory Commission Office of Nuclear Material and Safeguards Division of Decommissioning, Uranium Recovery, and Waste Programs Reactor Decommissioning Branch TWFN Mail Stop: T-8F5 Rockville, MD 20852
SUBJECT:
DOE Contract No. DE-SC0014664 INDEPENDENT CONFIRMATORY SURVEY
SUMMARY
AND RESULTS FOR THE CALIFORNIA STATE ROUTE 84 FRONTAGE ASSOCIATED WITH THE GE HITACHI VALLECITOS NUCLEAR CENTER; SUNOL, CALIFORNIA DOCKET NO. 05000018 AND 05000183; RFTA NO.19-003; DCN 5334-SR-01-1
Dear Mr. Parrott:
The Oak Ridge Institute for Science and Education (ORISE) is pleased to provide the enclosed revised final report, which describes the procedures and results of the California State Route 84 frontage independent confirmatory survey that ORISE performed during the period of February 5-6, 2019 at the GE Hitachi Vallecitos Nuclear Center in Sunol, California. Additional U.S. Nuclear Regulatory Commission's (NRCs) comments were addressed in this revised version.
You may contact me at 865.576.6659 or Kaitlin Engel at 865.574.7008 if you have any questions or require additional information.
Sincerely, Erika N. Bailey Survey and Technical Projects Group Manager ORISE KME:jc electronic distribution:
K. Conway, NRC T. Vitkus, ORISE A. Huffert, NRC D. Hagemeyer, ORISE File/5334
INDEPENDENT CONFIRMATORY SURVEY
SUMMARY
AND RESULTS FOR THE CALIFORNIA STATE ROUTE 84 FRONTAGE ASSOCIATED WITH THE GE HITACHI VALLECITOS NUCLEAR CENTER SUNOL, CALIFORNIA K. M. Engel ORISE FINAL REPORT Revision 1 Prepared for the U.S. Nuclear Regulatory Commission AUGUST 2019 Further dissemination authorized to the NRC only; other requests shall be approved by the originating facility or higher NRC programmatic authority.
ORAU provides innovative scientific and technical solutions to advance research and education, protect public health and the environment and strengthen national security. Through specialized teams of experts, unique laboratory capabilities and access to a consortium of more than 100 major Ph.D.-granting institutions, ORAU works with federal, state, local and commercial customers to advance national priorities and serve the public interest. A 501(c) (3) nonprofit corporation and federal contractor, ORAU manages the Oak Ridge Institute for Science and Education (ORISE) for the U.S. Department of Energy (DOE). Learn more about ORAU at www.orau.org.
NOTICES The opinions expressed herein do not necessarily reflect the opinions of the sponsoring institutions of Oak Ridge Associated Universities.
This report was prepared as an account of work sponsored by the United States Government.
Neither the United States Government nor the U.S. Department of Energy, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe on privately owned 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 by the U.S. Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the U.S. Government or any agency thereof.
VNC Non-Impacted Land Area Confirmatory Survey Report 5334-SR-01-1 INDEPENDENT CONFIRMATORY SURVEY
SUMMARY
AND RESULTS FOR THE CALIFORNIA STATE ROUTE 84 FRONTAGE ASSOCIATED WITH THE GE HITACHI VALLECITOS NUCLEAR CENTER SUNOL, CALIFORNIA Prepared by K. M. Engel ORISE AUGUST 2019 FINAL REPORT Revision 1 Prepared for the U.S. Nuclear Regulatory Commission This document was prepared for the U.S. Nuclear Regulatory Commission (NRC) by the Oak Ridge Institute for Science and Education (ORISE) through interagency agreement number 31310018N0014 with the U.S. Department of Energy (DOE). ORISE is managed by Oak Ridge Associated Universities under DOE contract number DE-SC0014664.
VNC Non-Impacted Land Area Confirmatory Survey Report 5334-SR-01-1 INDEPENDENT CONFIRMATORY SURVEY
SUMMARY
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VNC Non-Impacted Land Area Confirmatory Survey Report i
5334-SR-01-1 CONTENTS FIGURES........................................................................................................................................................... ii TABLES.............................................................................................................................................................. ii ACRONYMS.................................................................................................................................................... iii EXECUTIVE
SUMMARY
............................................................................................................................. iv
- 1. INTRODUCTION....................................................................................................................................... 1
- 2. SITE DESCRIPTION................................................................................................................................. 1
- 3. DATA QUALITY OBJECTIVES............................................................................................................. 3 3.1 State the Problem.............................................................................................................................. 4 3.2 Identify the Decision........................................................................................................................ 4 3.3 Identify Inputs to the Decision....................................................................................................... 5 3.4 Define the Study Boundaries........................................................................................................... 6 3.5 Develop a Decision Rule.................................................................................................................. 6 3.6 Specify Limits on Decision Errors................................................................................................. 8 3.7 Optimize the Design for Obtaining Data...................................................................................... 9
- 4. APPLICABLE SITE GUIDELINES........................................................................................................ 9
- 5. PROCEDURES............................................................................................................................................ 9 5.1 Reference System.............................................................................................................................. 9 5.2 Surface Scans.................................................................................................................................... 10 5.3 Gamma Radiation Measurements and Soil Sampling................................................................ 10
- 6. SAMPLE ANALYSIS AND DATA INTERPRETATION............................................................... 10
- 7. FINDINGS AND RESULTS................................................................................................................... 11 7.1 Surface Scans.................................................................................................................................... 11 7.2 Gamma Radiation Measurements and Radionuclide Concentrations in Soil......................... 12
- 8.
SUMMARY
.................................................................................................................................................. 17
- 9. REFERENCES........................................................................................................................................... 18 APPENDIX A: FIGURES APPENDIX B: DATA TABLE APPENDIX C: SURVEY AND ANALYTICAL PROCEDURES APPENDIX D: MAJOR INSTRUMENTATION
VNC Non-Impacted Land Area Confirmatory Survey Report ii 5334-SR-01-1 FIGURES Figure 2.1. VNC Land Area Map.................................................................................................................... 2 Figure 2.2. California State Route 84 Frontage (Blue Outline)................................................................... 3 Figure 7.1. Q-Q Plot for Gamma Walkover Survey Data......................................................................... 12 Figure 7.2. Comparison of Cs-137, K-40, Th-232, and U-238 Concentrations..................................... 14 Figure 7.3. Comparison of Random and Judgmental Sample Populations............................................. 15 Figure 7.4. Comparison of Gross Alpha and Beta Results for California State Route 84 Frontage... 16 TABLES Table 3.1. VNC Confirmatory Survey Decision Process............................................................................. 5 Table 7.1. Summary of Scanning Results..................................................................................................... 11 Table 7.2. Summary of Soil Sampling Direct Measurements.................................................................... 12 Table 7.3. Summary of Radionuclide Concentrations (pCi/g).................................................................. 13
VNC Non-Impacted Land Area Confirmatory Survey Report iii 5334-SR-01-1 ACRONYMS AA alternative action CFR Code of Federal Regulation cm centimeter cpm counts per minute CU confirmatory unit DOE U.S. Department of Energy DQO data quality objective DS decision statement GEH GE Hitachi GPS global positioning system LLNL Lawrence Livermore National Laboratory HTD hard-to-detect MDC minimum detectable concentration NaI sodium iodide NIST National Institute of Standards and Technology NORM naturally occurring radioactive material NRC U.S. Nuclear Regulatory Commission ORAU Oak Ridge Associated Universities ORISE Oak Ridge Institute for Science and Education pCi/g picocurie per gram PSQ principal study question Q-Q quantile-quantile TAP total absorption peak ROC radionuclide of concern UCL upper confidence level VNC Vallecitos Nuclear Center
VNC Non-Impacted Land Area Confirmatory Survey Report iv 5334-SR-01-1 INDEPENDENT CONFIRMATORY SURVEY
SUMMARY
AND RESULTS FOR THE CALIFORNIA STATE ROUTE 84 FRONTAGE ASSOCIATED WITH THE GE HITACHI VALLECITOS NUCLEAR CENTER SUNOL, CALIFORNIA EXECUTIVE
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) requested that the Oak Ridge Institute for Science and Education (ORISE) perform an independent confirmatory survey of the California State Route 84, also known as Vallecitos Road, frontage of the GE Hitachi (GEH) Vallecitos Nuclear Center (VNC) in Sunol, California. In December 2018, GEH submitted a formal request to the NRC for approval to release for unrestricted use approximately 2.8 hectares of VNC property within a construction easement along California State Route 84. This land will be made available to Alameda County Transportation Commission to support road development and widening (GEH 2018).
ORISE performed independent assessment activities during the period of February 5-6, 2019.
Confirmatory survey activities included gamma walkover scanning, gamma direct measurements, and soil sampling in the applicable land area.
Elevated direct gamma radiation levels above background were identified in the landscaped area near the road leading into the site. The elevated counts were attributed to naturally occurring radioactive material (NORM) in the lava rocks used in the landscaping. A total of 20 soil samples were collected throughout the land area: 13 random samples, one judgmental sample, and six additional confirmatory samples, as requested by the NRC.
Radionuclide concentrations in soil samples from the California State Route 84 frontage were evaluated for the presence of gamma-emitting mixed activation and fission products, with particular emphasis on Cs-137, which is a VNC radionuclide of concern (ROC). Samples also were analyzed for gross alpha and beta concentrations.
Cs-137 is ubiquitous in the environment from global atmospheric fallout from weapons testing and the Chernobyl and Fukushima nuclear releases. Therefore, Cs-137 concentrations in the California State Route 84 frontage soil samples were compared with soil samples collected from off-site background and other VNC non-impacted populations. The concentrations observed were compared to the Lawrence Livermore National Laboratorys (LLNL's) environmental surveillance
VNC Non-Impacted Land Area Confirmatory Survey Report v
5334-SR-01-1 program results and to C1/C2 non-impacted land area samples collected during a previous confirmatory survey in 2015. In addition to Cs-137, concentrations of naturally occurring radionuclides (K-40, Ra-226, Th-232, and U-238) also were examined between the LLNL, C1/C2, and California State Route 84 frontage land areas.
The concentration of Cs-137 in soil samples collected from the California State Route 84 frontage were within the same range as the 2017 LLNL off-site background environmental monitoring results for Cs-137. Furthermore, the Cs-137 concentrations in the California State Route 84 frontage were statistically demonstrated to be lower than the Cs-137 concentrations found in the C1/C2 area. The lower concentrations were likely due to routine tilling of the road frontage for a fire break. The statistical assessment objectively failed to reject the null hypothesis, thereby concluding that the California State Route 84 frontage land area Cs-137 concentrations are less than or equal to the non-impacted C1/C2 land area concentrations. Comparison of naturally occurring radionuclide concentrations showed that the California State Route 84 frontage soils shared similar natural radiological conditions as the land area outside of LLNL and the C1/C2 land area. Therefore, all results were consistent with the non-impacted determination.
VNC Non-Impacted Land Area Confirmatory Survey Report 1
5334-SR-01-1 INDEPENDENT CONFIRMATORY SURVEY
SUMMARY
AND RESULTS FOR THE CALIFORNIA STATE ROUTE 84 FRONTAGE ASSOCIATED WITH THE GE HITACHI VALLECITOS NUCLEAR CENTER SUNOL, CALIFORNIA
- 1. INTRODUCTION The GE Hitachi (GEH) Vallecitos Nuclear Center (VNC) in Sunol, California has been engaged in reactor research, development, testing operations, and post-irradiation examination of reactor fuel since the 1950s (GEH 2018). Much of the reactor-related activities have ceased. One test reactor remains operational while three are in a SAFeSTORage condition. VNC is currently licensed under 10 Code of Federal Regulation (CFR) 50 and 70 as well as a State of California radioactive materials license. In December 2018, GEH submitted a formal request to the U.S. Nuclear Regulatory Commission (NRC) for approval to unconditionally release for unrestricted use a construction easement along California State Route 84, also known as Vallecitos Road. This area is referred to as the California Route 84 frontage in this report. This land will be made available to Alameda County Transportation Commission to support road development and widening (GEH 2018).
The licensee categorized the 2.8 hectare (7 acre) area as non-impacted and, as such, plant-derived radionuclides in concentrations exceeding background should not be present. In support of the release request, GEH conducted an environmental assessment, which included a small-scale sampling campaign and a review of site operating history. The NRC requested that the Oak Ridge Institute for Science and Education (ORISE) perform confirmatory survey activities within the 2.8 hectare area that GEH is requesting for unconditional release. ORISE performed the confirmatory survey on February 5-6, 2019. A previous non-impacted site release request and associated ORISE confirmatory surveys involved Areas C1 and C2 (C1/C2) at the VNC site (ORISE 2015). The results from the survey of the C1/C2 area were used for comparison to the current confirmatory survey results. Results from Lawrence Livermore National Laboratorys (LLNL's) annual environmental surveillance program were used for comparison to the current confirmatory survey results as well.
- 2. SITE DESCRIPTION The VNC consists of approximately 650 hectare (1,600 acres) and is located at 6705 Vallecitos Road, Sunol, California. The site is approximately 56 kilometers (35 miles) east-southeast of San Francisco, California, in the Pleasanton quadrangle of Alameda County. The site is situated in a primarily
VNC Non-Impacted Land Area Confirmatory Survey Report 2
5334-SR-01-1 agricultural setting with a small residential population existing west of the site. The nearest sizable town is Pleasanton, California, located 6.4 kilometers (4.0 miles) north-northwest of the site. The sites boundaries have not changed since the property was purchased in 1956 and are delineated with fencing and No Trespassing signs (GEH 2018).
Only approximately 55 hectares of the 650 hectare VNC site were ever used for conducting licensed activities whereas the balance of the site is mostly undeveloped grasslands with hills ranging from 120 to 370 meters (400 to 1,200 feet) above sea level. Developed industrialized areas of the site exist at elevations between 120 and 180 meters (400 to 590 feet) and slope to the southwest. The property is primarily drained by ditches flowing into Vallecitos Creek.
Figure 2.1 presents the VNC land area delineations. The California State Route 84 frontage is located along the southern-most boundary of Areas A and B as shown in Figure 2.1. The 2.8 hectare VNC property area that is the focus of this survey effort is within an irregular construction easement along California State Route 84 frontage as shown on Figure 2.2.
Figure 2.1. VNC Land Area Map
VNC Non-Impacted Land Area Confirmatory Survey Report 3
5334-SR-01-1 Figure 2.2. California State Route 84 Frontage (Blue Outline)
- 3. DATA QUALITY OBJECTIVES The data quality objectives (DQOs) described herein are consistent with the Guidance on Systematic Planning Using the Data Quality Objectives Process (EPA 2006) and provide a formalized method for planning radiation surveys, improving survey efficiency and effectiveness, and ensuring that the type, quality, and quantity of data collected are adequate for the intended decision applications. The seven steps in the DQO process are as follows:
- 1. State the problem
- 2. Identify the decision
- 3. Identify inputs to the decision
- 4. Define the study boundaries
- 5. Develop a decision rule
- 6. Specify limits on decision errors
- 7. Optimize the design for obtaining data
VNC Non-Impacted Land Area Confirmatory Survey Report 4
5334-SR-01-1 3.1 STATE THE PROBLEM The first step in the DQO process defines the problem that necessitates the study, identifies the planning team, and examines the project budget and schedule. The licensee requested approval from the NRC to remove the 2.8 hectare, non-impacted survey area from its 10 CFR Part 50 license. The NRC requested that ORISE perform independent contractor document and field reviews and to conduct confirmatory surveys to generate radiological data to assist the NRC in evaluating the licensees request for partial site release. The NRC uses these data to assess the site radionuclides of concern (ROCs) and to determine the analytical suite for the samples collected from the non-impacted survey area. Therefore, the problem statement was formulated as follows:
Confirmatory surveys must be performed to generate independent radiological data to assist the NRC with their assessment of the non-impacted classification of the 2.8 hectare land area included in the licensees request for partial site release and assess the ratios between identified ROCs in the soil.
3.2 IDENTIFY THE DECISION The second step in the DQO process identifies the principal study questions (PSQs) and alternative actions (AAs), develops decision statements (DSs), and organizes multiple decisions, as appropriate.
This was done by specifying AAs that could result from a Yes response to the PSQs and combining the PSQs and AAs into DSs. PSQs, AAs, and combined DSs are organized based on the survey unit type (i.e., the associated final status survey methodology) and are presented in Table 3.1
VNC Non-Impacted Land Area Confirmatory Survey Report 5
5334-SR-01-1 Table 3.1. VNC Confirmatory Survey Decision Process Principal Study Questions Alternative Actions PSQ1: Are radionuclide concentrations in the non-impacted land area consistent with available regional background data and ROC statistical parameters of the confirmatory survey for the C1/C2 non-impacted area?
Yes:
Compile confirmatory data and report results to the NRC for their decision making. Provide independent interpretation that confirmatory field surveys did not identify anomalous areas of residual radioactivity and quantitative laboratory data are consistent with prior background and non-impacted area values, and/or that statistical sample population examination/assessment conditions were met.
No:
Compile confirmatory data and report results to the NRC for their decision making. Provide independent interpretation of confirmatory survey results identifying any anomalous field or laboratory data and/or when statistical sample population examination/assessment conditions were not satisfied for the NRCs determination of the adequacy of the GEH survey.
PSQ2: Are gamma-emitting ROCs present within collected samples, and/or non-gamma emitting hard-to-detect (HTD)ROCs, if applicable?
Yes:
Provide analytical results to the NRC that include identified radionuclides and, if applicable, ratios of HTDs to gamma-emitting ROCs.
No:
Provide analytical minimum detectable concentraions (MDCs) and the less-than-MDC results to the NRC.
Decision Statement Confirmatory survey results did/did not identify anomalous results or other conditions that refute the non-impacted classification of the subject land area.
Independent confirmatory survey results did/did not identify gamma-emitting ROCs in samples and include/do not include additional HTD ROCs for confirmatory samples collected from the non-impacted land area (California State Route 84 Frontage).
3.3 IDENTIFY INPUTS TO THE DECISION The third step in the DQO process identifies both the information needed and the sources of this information, determines the basis for action levels, and identifies sampling and analytical methods to meet data requirements. For this effort, information inputs included the following:
VNC Non-Impacted Land Area Confirmatory Survey Report 6
5334-SR-01-1
- GEH background assessment and soil sample analytical results collected along California State Route 84
- LLNL background datasets
- Area C1/C2 confirmatory survey analytical results
- ORISE gamma walkover surveys
- ORISE volumetric sample analysis results for soil
- Applicable instrumentation and survey and sampling procedures, method procedures, and data management procedures (ORAU 2016a)
- The Oak Ridge Associated Universities (ORAU) Environmental Services and Radiation Training Quality Program Manual (ORAU 2018)
- Applicable laboratory equipment and procedures (ORAU 2017) 3.4 DEFINE THE STUDY BOUNDARIES The fourth step in the DQO process defines target populations and spatial boundaries, determines the timeframe for collecting data and making decisions, addresses practical constraints, and determines the smallest subpopulations, area, volume, and time for which separate decisions must be made. The study boundary is based on the land area identified in the licensees request for approval of the partial site release and the supplemental information the site provided in response to an NRC request for additional information (GEH 2018 and 2019). This area, the 2.8 hectare California State Route 84 frontage, constituted the confirmatory survey decision boundary as a single confirmatory unit (CU). Temporal boundaries to complete this survey were limited to two 10-hour days on-site on February 5-6, 2019. The majority of the California State Route 84 frontage land area was accessible; inaccessible areas were due to muddy conditions.
3.5 DEVELOP A DECISION RULE The fifth step in the DQO process specifies appropriate parameters (e.g., mean, median), confirms action levels were above detection limits, and develops an "ifthen" decision rule statement. For this survey effort, the parameter of interest was the Cs-137 concentration in the California State Route 84 frontage. If non-impacted by site operations, Cs-137 concentrations for a representative sample population from the California State Route 84 frontage should be comparable to the concentrations attributable to atmospheric fallout that have been observed for local background or
VNC Non-Impacted Land Area Confirmatory Survey Report 7
5334-SR-01-1 other non-impacted areas. As such, the California State Route 84 frontage Cs-137 concentrations were directly compared to the LLNL environmental monitoring background concentrations and the previously investigated C1/C2 concentrations. In the event that results were too close to objectively call, hypothesis testing was planned with the previously collected data for the non-impacted C1/C2. Hypothesis testing adopts a scientific approach where the survey data are used to select between the baseline condition (the null hypothesis, H0) and an alternative condition.
The null and alternative hypotheses were stated as:
H0: California State Route 84 frontage Cs-137 concentration population mean (µCU) is less than or equal to the C1/C2 mean concentration. Mathematically, the null hypothesis is stated as µCU C1/C2.
HA: California State Route 84 frontage Cs-137 concentration population mean is greater than the C1/C2 mean concentration. Mathematically, the alternative hypothesis is stated as
µCU > C1/C2.
Identical H0 and HA statements also could be made to evaluate the California State Route 84 frontage mean concentration population parameter with the LLNL off-site background environmental monitoring data. However, ORISE did not specifically plan to include this additional two-sample statistical test because the pedigree of the LLNL off-site background data representing independent, random samples from the populationa necessary condition of the statistical test was not available. Rather these data served the purpose of direct comparison of the relative data dispersion (ranges).
The complete decision rule was stated as follows:
Compare data with the general distribution, including the maximum observed LLNL background data. Additionally, if the null hypothesis is not rejected and there are no outliers identified indicative of elevated Cs-137 concentrations for individual sample results, then conclude the California State Route 84 frontage Cs-137 concentrations are consistent with previous non-impacted VNC lands that have been released from the site license. Otherwise, perform further evaluation(s). For any noted statistical hypothesis rejections or
VNC Non-Impacted Land Area Confirmatory Survey Report 8
5334-SR-01-1 concentration anomalies, provide technical comments/recommendations to the NRC for their evaluation and decision making.
3.6 SPECIFY LIMITS ON DECISION ERRORS The sixth step in the DQO process specifies the decision makers limits on decision errors, which are then used to establish performance goals for the survey. There were two types of decision errors to consider: Type I (typically designated as alpha or ) and Type II (typically designated as beta or ).
A Type I error occurs when the null hypothesis is rejected when it should not be, also known as a false positive, and reflects the confidence level in the decision. A Type II error is incorrectly failing to reject the null hypothesis when the alternative hypothesis is true. It also is known as a false negative. The ability to reject the null hypothesis when it is false is known as the power of the test (power is defined as 1-).
Two orders of control were implemented to minimize decision errors regarding the DSs introduced in Table 3.1. The first order of control was to select decision error rates that were conservative yet still allowed for the project to be completed within the study boundaries. The Type I error rate was set to 0.05, that is, there is a 5% chance of concluding the CU is greater than the C1/C2 concentrations when it actually is not. The Type II error rate and subsequent power achieved was dependent on the number of samples collected and the concentration variability in the sample set.
The number of samples required was based on estimating the CU mean at the 95% confidence level within 0.025 picocuries per gram (pCi/g) above/below the true mean (i.e., a two-sided confidence interval). Based on the assumption that the California State Route 84 frontage was non-impacted, the radiological survey data collected during this survey should be similar to data previously collected in the non-impacted C1/C2 where the mean, upper confidence level (UCL), standard deviation, and maximum Cs-137 levels were 0.134, 0.156, 0.041, and 0.201 pCi/g, respectively (ORISE 2015). The difference between the C1/C2 mean and UCL provided the 0.025 confidence level width planning input discussed above together with the previously determined C1/C2 variability for sample size determination. Both inputs were adjusted for rounding and sample size optimization. For this investigation, 13 random sample locations were planned.
The second order of control was to optimize the confirmatory field measurement and laboratory analytical MDCs. Field scanning MDCs were minimized by following survey procedures for scan
VNC Non-Impacted Land Area Confirmatory Survey Report 9
5334-SR-01-1 speeds and liberal pausing in response to gamma radiation count rates distinguishable from background.
3.7 OPTIMIZE THE DESIGN FOR OBTAINING DATA The seventh step in the DQO process reviews the DQO outputs, develops data collection design alternatives, formulates mathematical expressions for each design, selects the sample size to satisfy DQOs, decides on the most resource-effective design of agreed alternatives, and documents requisite details. Survey design and laboratory analyses were optimized by implementing the procedures presented in Sections 5 and 6.
- 4. APPLICABLE SITE GUIDELINES The primary ROCs identified for the VNC were beta-gamma emittersfission and activation productsresulting from reactor operation. Previous review of the facility operating history, historical events, and the results of radiological surveys have been completed. As a result of the review, GEH defined the subject land area as non-impacted, meaning that any of the plant-derived ROCs should not be present in excess of background. The only plant-derived, gamma-emitting, fission product that GEH detected, Cs-137, is also detectable in background. If a land area has not been impacted by site activities, Cs-137 should only be present at concentrations attributable to global fallout (GEH 2018).
- 5. PROCEDURES The confirmatory survey activities, conducted during the period of February 5-6, 2019, were in accordance with the project-specific confirmatory survey plan, the ORAU Radiological and Environmental Survey Procedure Manual, and the ORAU Environmental Services and Radiation Training Quality Program Manual (ORISE 2019, ORAU 2016a, 2018). Appendices B and C provide additional information regarding survey instrumentation and related processes discussed within this section.
5.1 REFERENCE SYSTEM ORISE referenced confirmatory measurement/sampling locations to global positioning system (GPS) coordinates, specifically NAD 1983 (CORS96) State Plane California. Other
VNC Non-Impacted Land Area Confirmatory Survey Report 10 5334-SR-01-1 prominent site features also were referenced. Measurement and sampling locations were documented on detailed survey maps.
5.2 SURFACE SCANS Surface scans of the CU land areas were performed with Ludlum Model 44-10 5 centimeter (cm) by 5 cm sodium iodide (NaI) scintillation detectors coupled to Ludlum Model 2221 ratemeter-scalers with audible indicators. Detectors also were coupled to GPS data logging systems that enabled real-time gamma count rate and spatial data capture. Medium-density surface scans were performed within the survey area as time and access permitted. Total scan coverage was dependent on accessibility of the CU. Areas of mud and water limited accessibility to some areas of the CU.
Overall scan coverage was 50% to 75%. It was noted during the survey that the California State Route 84 frontage had been routinely tilled to create a fire break.
5.3 GAMMA RADIATION MEASUREMENTS AND SOIL SAMPLING In total, 20 soil samples were collected from the CU: 13 random locations and seven judgmental locations of which one was based on gamma scan results and six corresponded with licensee sample locations. Site sampling locations were initially approximated using figures and later by using GPS coordinates after conversion to NAD 1983 (CORS96) State Plane California (hence, two samples at site sample location #2).
Samples were collected at a depth of 0 to 15 cm from the surface of the native soil using hand trowels. Sampling equipment was decontaminated in the field after each sample to minimize the potential for cross-contamination. Gamma measurements were performed prior to sample collection. Additional gamma measurements were made at the 15-cm depth after sample collection.
- 6. SAMPLE ANALYSIS AND DATA INTERPRETATION Samples and data collected on site were transferred to the ORISE facility for analysis and interpretation. Sample custody was transferred to the Radiological and Environmental Analytical Laboratory in Oak Ridge, Tennessee. Sample analyses were performed in accordance with the ORAU Radiological and Environmental Analytical Laboratory Procedures Manual (ORAU 2017). Soil samples were crushed and homogenized and analyzed by gamma spectrometry for gamma-emitting fission and activation products and for gross alpha and beta concentrations using a low-background
VNC Non-Impacted Land Area Confirmatory Survey Report 11 5334-SR-01-1 proportional counter. The gamma spectra also were reviewed for other identifiable photopeaks.
With NRC concurrence, no further analysis for HTD radionuclides was performed based on the radionuclide-specific results of the gamma spectroscopy and gross alpha and beta activity from low background proportional counting. Analytical results are reported as gross concentrations in units of pCi/g. Gamma radiation scan and static measurements are presented as gross counts per minute (cpm).
Scan data sets and radionuclide concentrations were graphed in quantile-quantile (Q-Q) plots, strip charts, and/or box plots for assessment. The Q-Q plot is a graphical tool for assessing the statistical distribution of a data set. For the scan data, the Y-axis represents gross gamma radiation levels in units of cpm. For the soil samples, the Y-axis represents the radionuclide concentration in units of pCi/g. The X-axis represents the data quantiles about the median value. Values less than the median are represented in the negative quantiles; values greater than the median are represented in the positive quantiles. A normal distribution that is not skewed by outliers will appear as a straight line, with the slope of the line subject to the degree of variability among the data population. More than one distribution, such as background plus contamination or other outliers, will appear as a step function. Section 7 provides specific analytical and scan data results and discussions.
- 7. FINDINGS AND RESULTS The results of the confirmatory survey are discussed in the following subsections.
Appendices A and B provide the survey data for the CU investigated. Appendices C and D provide additional details regarding field and laboratory instrumentation as well as additional information on calibration, quality assurance, survey and analytical procedures, and detection sensitivities.
7.1 SURFACE SCANS Table 7.1 provides a summary of the confirmatory gamma radiation scanning survey data.
Table 7.1. Summary of Scanning Results Area NaI Scan Range (cpm)
California State Route 84 frontage 3,600 to 11,000 Figures A.1 through A.9 in Appendix A provide the gamma walkover survey maps for the CU.
Elevated direct gamma radiation levels above background were identified in the landscaped area near the road leading into the site (Figure A.2). Figure 7.1 provides the Q-Q plot for the CUs data set and
VNC Non-Impacted Land Area Confirmatory Survey Report 12 5334-SR-01-1 shows a step function indicating more than one data population. The elevated counts in the plot are attributed to naturally occurring radioactive material (NORM) in the lava rocks used in the landscaping. The NRC staff flagged one area along the fence line for judgmental sampling based on scan results.
Figure 7.1. Q-Q Plot for Gamma Walkover Survey Data 7.2 GAMMA RADIATION MEASUREMENTS AND RADIONUCLIDE CONCENTRATIONS IN SOIL Figures A.10 through A.14 in Appendix A provide all soil sampling locations where gamma measurements and samples were collected. Table 7.2 provides a summary of the NaI direct measurements collected pre-and post-sampling.
Table 7.2. Summary of Soil Sampling Direct Measurements Measurement Type No. of Samples NaI Measurement (cpm)
Pre-Sample Post-Sample Random 13 4,700 to 6,200 4,800 to 7,500 Judgmental 7
4,400 to 5,300 4,800 to 5,700
VNC Non-Impacted Land Area Confirmatory Survey Report 13 5334-SR-01-1 The gamma direct measurements corresponded to the levels observed during surface scans, with no elevated count rates noted at sampling locations. Additionally, the post-sample measurements did not identify any subsurface anomalies.
Table 7.3 provides a summary of the Cs-137, gross alpha and gross beta concentrations. Review of the gamma spectra did not identify any additional fission/activation products or gamma-emitting transuranics. The only other radionuclides identified were NORM. Summary data for the primary NORM radionuclides also are provided in Table 7.3. Appendix B provides the individual sample data.
Table 7.3. Summary of Radionuclide Concentrations (pCi/g)
Measurement Type Cs-137 Gross Alpha Gross Beta K-40 Ra-226 (by Pb-214)
U-238 (by Th-234)
Th-232 (by Ac-228)
Random Samples Min 0.006 3.2 6.8 4.33 0.322 0.39 0.435 Max 0.103 8.5 13.9 10.35 0.520 1.18 0.699 Judgmental Min 0.010 3.2 9.8 6.57 0.361 0.32 0.411 Max 0.071 10.2 13.6 10.19 0.510 0.80 0.687 Figure 7.2 provides strip charts comparing the Cs-137, potassium-40 (K-40), thorium-232 (Th-232),
and uranium-238 (U-238) concentrations for the California State Route 84 frontage, the last 9 years of LLNL data, and the C1/C2. Ra-226 was not provided in the LLNL dataset; therefore, results were not depicted in Figure 7.2. The LLNL data used in the comparison represent the 2009 to 2017 environmental surveillance program results for soil samples collected from off-site areas that are known to be non-impacted by LLNL. (Gallegos 2010, Jones 2011-2015, Rosene 2016-2018).
VNC Non-Impacted Land Area Confirmatory Survey Report 14 5334-SR-01-1 Figure 7.2. Comparison of Cs-137, K-40, Th-232, and U-238 Concentrations Cs-137 is present in soil as the result of atmospheric fallout deposition and is typically present within the first few centimeters of soil. Therefore, comparison of the three populations is necessary to evaluate whether the Cs-137 identified in the California State Route 84 frontage samples is due to site operations. The California State Route 84 frontage results were compared with the LLNL population. Figure 7.2 also shows that the 2019 California State Route 84 frontage Cs-137 data are within range of the LLNL data from the previous years. It is noted that that the C1/C2 Cs-137 concentration upper bound is slightly higher than both the LLNL and California State Route 84 frontage Cs-137 data ranges. The reason for this can be attributed to differences between disturbed and undisturbed soils. Routine tilling that was performed along California State Route 84 frontage will result in blending surface soil with deeper strata (i.e., below 15 cm), thereby reducing the Cs-137 concentration within the 15-cm depth increment that the samples represent. Similarly, a number of LLNL off-site sample locations appear to be in developed areas where the soil is likely to have been disturbed, based on aerial photographs. In contrast, undisturbed surface soils are expected to exhibit higher concentrations of surface deposited Cs-137, such as in the C1/C2.
The second population comparison was between the California State Route 84 frontage and the C1/C2. Evaluation of Figure 7.2 illustrates that the California State Route 84 frontage random
VNC Non-Impacted Land Area Confirmatory Survey Report 15 5334-SR-01-1 sample Cs-137 concentration sample distribution shifted downward relative to the C1/C2 distribution. Overall, the California State Route 84 frontage population mean concentration is 2.5 times less than the C1/C2 population, with means of 0.05 pCi/g and 0.13 pCi/g, respectively.
Although unnecessary based on the above evidence, a hypothesis test was performed on the data.
The Student (pooled) t-test was used to compare the difference between the means of the two sample populations. This test is appropriate for small sets of data collected independently from one another, assumes equal variances between the data sets, and when both populations represent normal distributions. The null and alternative hypotheses, H0 and HA, respectively, are stated in Section 3.5. The test was performed using ProUCL 5.1.002 and is presented in Appendix A. Because the test statistic (t-test value) is less than the critical value (-5.774 and 1.717, respectively) and the p-value (1) is greater than 0.05, there is not enough evidence to reject H0 (null hypothesis); therefore, conclude that the CU1 mean concentration is less than or equal to the C1/C2 area mean.
Additional analysis of the California State Route 84 frontage data included comparisons of Cs-137 concentrations in random and judgmental samples for evidence of outliers. The Figure 7.3 box plot shows that judgmental samples were within the random sample population parameters.
Figure 7.3. Comparison of Random and Judgmental Sample Populations
VNC Non-Impacted Land Area Confirmatory Survey Report 16 5334-SR-01-1 In addition to Cs-137, the NORM concentrations were compared between the California State Route 84 frontage, the LLNL, and the C1/C2 sample populations. Figure 7.2 also provides the strip charts for the three populations for K-40, Th-232, and U-238. With the exception of K-40 and Th-232, the comparisons show the California State Route 84 frontage, LLNL, and C1/C2 have similar naturally occurring radiological conditions. For K-40 and Th-232, the California State Route 84 frontage concentrations are slightly lower than the C1/C2 concentrations, which is commonly observed for different soil types and/or due to spatial variability in natural background concentrations. Changes in NORM concentrations from tilling are expected to be minimal, as NORM is distributed throughout the soil column rather than only as a result of surface deposition.
The LLNL dataset did not provide gross alpha and beta results for the samples collected outside of LLNL boundaries. Therefore, only the gross alpha and beta results from GEHs investigation were compared to the ORISE California State Route 84 frontage results (GEH 2018).
Figure 7.4. Comparison of Gross Alpha and Beta Results for California State Route 84 Frontage
VNC Non-Impacted Land Area Confirmatory Survey Report 17 5334-SR-01-1 Figure 7.4 provides box plots of the gross alpha and beta results for both the licensees and ORISE's samples. Appendix B provides the datasets used for comparison. The ORISE gross alpha and beta results were generally lower than the licensees results. The observed differences are unremarkable.
Moreover, the gross activity data only serve as a qualitative screening tool that the site used to select a sample for more rigorous analyses. The licensees systematic higher results would result in a greater probability that the gross activity would exceed the investigation level that the site uses to require gamma spectroscopy. The differences are possibly a result of systematic bias between the analytical processes of the two laboratories.
- 8.
SUMMARY
At the NRCs request, ORISE conducted confirmatory survey activities of the California State Route 84 frontage at the GEH Vallecitos Nuclear Center in Sunol, California during the period of February 5-6, 2019. The survey activities included gamma scans, gamma direct measurements, and soil sampling.
Elevated direct gamma radiation levels above background were identified in the landscaped area near the road leading into the site. The elevated counts are attributed to NORM in the lava rocks used in the landscaping. Overall gamma scans ranged from 3,600 cpm up to 11,000 cpm. Twenty soil samples were collected throughout the CU: 13 random and seven judgmental sampling locations.
The radionuclide concentrations in the soil samples from the California State Route 84 frontage were compared to the radionuclide concentrations in soil samples collected as part of LLNLs environmental surveillance programs and from the C1/C2 area collected during a previous confirmatory survey. In addition to Cs-137, other background radionuclide concentrations were examined: K-40, Ra-226, Th-232, and U-238. The California State Route 84 frontage Cs-137 concentrations were within the range of the LLNL off-site environmental monitoring Cs-137 concentrations. The Cs-137 concentrations in the California State Route 84 frontage were lower than the Cs-137 concentrations found in the C1/C2. Thus, the null hypothesis was not rejected, concluding that the California State Route 84 frontage sample population was less than or equal to the C1/C2 sample population. Comparison of the NORM concentrations showed that the California State Route 84 frontage had similar radiological conditions as the LLNL off-site locations and the C1/C2. Therefore, all results were consistent with the non-impacted determination.
VNC Non-Impacted Land Area Confirmatory Survey Report 18 5334-SR-01-1
- 9. REFERENCES EPA 2006. Guidance on Systematic Planning Using the Data Quality Objectives Process. EPA QA/G-4.
U.S. Environmental Protection Agency. Washington, D.C. February.
Gallegos 2010. Lawrence Livermore National Laboratory Environmental Report 2009. Lawrence Livermore National Laboratory. Livermore, California. August.
GEH 2018. Unconditional Release of Route 84 Frontage Section of Vallecitos Nuclear Center Site. GE Hitachi.
Sunol, California. December 14. ADAMS Accession No. ML18348A425.
GEH 2019. GEH Response to NRC Request for Additional Information. GE Hitachi. Sunol, California.
December 14. ADAMS Accession No. ML19057A466.
Jones 2011. Lawrence Livermore National Laboratory Environmental Report 2010. Lawrence Livermore National Laboratory. Livermore, California. September.
Jones 2012. Lawrence Livermore National Laboratory Environmental Report 2011. Lawrence Livermore National Laboratory. Livermore, California. August.
Jones 2013. Lawrence Livermore National Laboratory Environmental Report 2012. Lawrence Livermore National Laboratory. Livermore, California. October.
Jones 2014. Lawrence Livermore National Laboratory Environmental Report 2013. Lawrence Livermore National Laboratory. Livermore, California. October.
Jones 2015. Lawrence Livermore National Laboratory Environmental Report 2014. Lawrence Livermore National Laboratory. Livermore, California. October.
ORAU 2014. ORAU Radiation Protection Manual. Oak Ridge Associated Universities. Oak Ridge, Tennessee. October.
ORAU 2016a. ORAU Radiological and Environmental Survey Procedures Manual. Oak Ridge Associated Universities. Oak Ridge, Tennessee. November 10.
ORAU 2016b. ORAU Health and Safety Manual. Oak Ridge Associated Universities. Oak Ridge, Tennessee. January.
ORAU 2017. ORAU Radiological and Environmental Analytical Laboratory Procedures Manual. Oak Ridge Associated Universities. Oak Ridge, Tennessee. August 24.
ORAU 2018. ORAU Environmental Services and Radiation Training Quality Program Manual. Oak Ridge Associated Universities. Oak Ridge, Tennessee. July 20.
ORISE 2015. Survey Report for the Independent Assessment of the GE Hitachi Vallecitos Nuclear Center Non-Impacted Land Areas C1 and C2; Sunol, California. Oak Ridge Institute for Science and Education.
Oak Ridge, Tennessee. October 19.
ORISE 2019. Project-Specific Plan for Confirmatory Survey Activities of Non-impacted Land Areas Associated
VNC Non-Impacted Land Area Confirmatory Survey Report 19 5334-SR-01-1 with the GE Hitachi Vallecitos Nuclear Center; Sunsol, California. Oak Ridge Institute for Science and Education. Oak Ridge, Tennessee. February 2019.
Rosene 2016. Lawrence Livermore National Laboratory Environmental Report 2015. Lawrence Livermore National Laboratory. Livermore, California. October.
Rosene 2017. Lawrence Livermore National Laboratory Environmental Report 2016. Lawrence Livermore National Laboratory. Livermore, California. October.
Rosene 2018. Lawrence Livermore National Laboratory Environmental Report 2017. Lawrence Livermore National Laboratory. Livermore, California. October.
VNC Non-Impacted Land Areas Confirmatory Survey Report 5334-SR-01-1 APPENDIX A: FIGURES
VNC Non-Impacted Land Areas Confirmatory Survey Report A-1 5334-SR-01-1 Figure A.1. Gamma Walkover Data (1 of 9)
VNC Non-Impacted Land Areas Confirmatory Survey Report A-2 5334-SR-01-1 Figure A.2. Gamma Walkover Data (2 of 9) with Elevated Radiation Levels in the Landscaping
VNC Non-Impacted Land Areas Confirmatory Survey Report A-3 5334-SR-01-1 Figure A.3. Gamma Walkover Data (3 of 9)
VNC Non-Impacted Land Areas Confirmatory Survey Report A-4 5334-SR-01-1 Figure A.4. Gamma Walkover Data (4 of 9)
VNC Non-Impacted Land Areas Confirmatory Survey Report A-5 5334-SR-01-1 Figure A.5. Gamma Walkover Data (5 of 9)
VNC Non-Impacted Land Areas Confirmatory Survey Report A-6 5334-SR-01-1 Figure A.6. Gamma Walkover Data (6 of 9)
VNC Non-Impacted Land Areas Confirmatory Survey Report A-7 5334-SR-01-1 Figure A.7. Gamma Walkover Data (7 of 9)
VNC Non-Impacted Land Areas Confirmatory Survey Report A-8 5334-SR-01-1 Figure A.8. Gamma Walkover Data (8 of 9)
VNC Non-Impacted Land Areas Confirmatory Survey Report A-9 5334-SR-01-1 Figure A.9. Gamma Walkover Data (9 of 9)
VNC Non-Impacted Land Areas Confirmatory Survey Report A-10 5334-SR-01-1 Figure A.10. Soil Sampling Locations (1 of 5)
VNC Non-Impacted Land Areas Confirmatory Survey Report A-11 5334-SR-01-1 Figure A.11. Soil Sampling Locations (2 of 5)
VNC Non-Impacted Land Areas Confirmatory Survey Report A-12 5334-SR-01-1 Figure A.12. Soil Sampling Locations (3 of 5)
VNC Non-Impacted Land Areas Confirmatory Survey Report A-13 5334-SR-01-1 Figure A.13. Soil Sampling Locations (4 of 5)
VNC Non-Impacted Land Areas Confirmatory Survey Report A-14 5334-SR-01-1 Figure A.14. Soil Sampling Locations (5 of 5)
VNC Non-Impacted Land Areas Confirmatory Survey Report 5334-SR-01-1 APPENDIX B: DATA TABLE
VNC Non-Impacted Land Areas Confirmatory Survey Report B-1 5334-SR-01-0 Table B.1. Soil Sampling Measurement Locations Coordinates (ft)
Measurement Type Gamma Count (cpm)
Soil Sample Number Notes X
(Easting)
Y (Northing)
Pre-Sample Post-Sample 2044959 6172291 Random 5,500 6,100 5334S0001 2045913 6175097 Random 5,400 5,900 5334S0002 2045792 6174717 Random 5,400 6,200 5334S0003 2045453 6173792 Random 5,700 6,300 5334S0004 2047297 6177847 Random 5,200 5,600 5334S0005 2045472 6173831 Random 5,500 6,300 5334S0006 2045295 6173299 Random 6,200 7,500 5334S0007 2046184 6175801 Random 4,900 5,700 5334S0008 2045249 6173128 Random 5,800 6,600 5334S0009 2046292 6176076 Random 5,200 5,900 5334S0010 2046506 6176583 Random 4,700 4,800 5334S0011 2046771 6177039 Random 5,000 5,500 5334S0012 2046351 6176266 Random 4,800 5,300 5334S0013 Mean 5,300 6,000 Minimum 4,700 4,800 Maximum 6,200 7,500 6173364 2045927 Judgmental 5,300 5,700 5334S0014 Flagged by NRC 6173141 2043220 Judgmental 4,900 5,400 5334S0015 Site Loc. 2, Approx. Location 6172340 2044969 Judgmental 4,800 5,500 5334S0016 Site Loc. 10, using GPS coords.
6174783 2045803 Judgmental 5,000 5,400 5334S0019 Site Loc. 8, using GPS coords.
6177110 2046829 Judgmental 4,500 4,800 5334S0020 Site Loc. 9, using GPS coords.
6173133 2045219 Judgmental 4,900 5,400 5334S0021 Site Loc. 2, using GPS coords.
6172618 2045149 Judgmental 4,400 5,000 5334S0022 Site Loc. 7, using GPS coords.
Mean 4,800 5,300 Minimum 4,400 4,800 Maximum 5,300 5,700
VNC Non-Impacted Land Areas Confirmatory Survey Report B-2 5334-SR-01-1 Table B.2. Radionuclide Concentrations in Soil Samples Sample Measurement Type Cs-137 (pCi/g)
Gross Alpha (pCi/g)
Gross Beta (pCi/g)
Conc.
TPUa MDCb Conc.
TPU MDC Conc.
TPU MDC 5334S0001 Random 0.023
+/-
0.014 0.029 5.4 c
+/-
2.7 3.5 11.6
+/-
2.8 3.5 5334S0002 Random 0.063
+/-
0.019 0.034 6.7
+/-
2.8 3.4 11.5
+/-
2.8 3.4 5334S0003 Random 0.046
+/-
0.013 0.031 4.0
+/-
2.4 3.4 12.9
+/-
2.9 3.3 5334S0004 Random 0.006
+/-
0.028 0.062 3.2
+/-
2.4 3.5 6.8
+/-
2.4 3.4 5334S0005 Random 0.073
+/-
0.020 0.034 6.8
+/-
2.9 3.4 9.4
+/-
2.6 3.5 5334S0006 Random 0.023
+/-
0.009 0.025 8.5
+/-
3.1 3.4 11.1
+/-
2.7 3.2 5334S0007 Random 0.043
+/-
0.016 0.031 6.3
+/-
2.8 3.4 13.9
+/-
3.0 3.5 5334S0008 Random 0.103
+/-
0.021 0.031 5.4
+/-
2.7 3.4 7.2
+/-
2.4 3.3 5334S0009 Random 0.065
+/-
0.016 0.026 4.8
+/-
2.8 3.9 13.9
+/-
3.0 3.2 5334S0010 Random 0.059
+/-
0.014 0.029 5.7
+/-
2.8 3.7 11.0
+/-
2.7 3.3 5334S0011 Random 0.086
+/-
0.018 0.025 6.6
+/-
2.9 3.6 7.6
+/-
2.3 3.1 5334S0012 Random 0.057
+/-
0.019 0.034 6.6
+/-
2.9 3.6 9.0
+/-
2.5 3.1 5334S0013 Random 0.017
+/-
0.010 0.021 5.1
+/-
2.7 3.6 9.9
+/-
2.6 3.3 Mean 0.051 5.8 10.4 Minimum 0.006 3.2 6.8 Maximum 0.103 8.5 13.9 5334S0014 Judgmental 0.066
+/-
0.016 0.032 10.0
+/-
3.4 3.7 13.6
+/-
3.0 3.4 5334S0015 Requested by NRC 0.049
+/-
0.016 0.035 7.1
+/-
3.0 3.6 11.9
+/-
2.7 3.1 5334S0016 Requested by NRC 0.056
+/-
0.015 0.025 3.2
+/-
2.4 3.6 10.2
+/-
2.6 3.2 5334S0019 Requested by NRC 0.065
+/-
0.017 0.030 10.2
+/-
3.5 3.8 13.1
+/-
2.9 3.3 5334S0020 Requested by NRC 0.010
+/-
0.012 0.029 4.5
+/-
2.7 3.8 11.4
+/-
2.7 3.3 5334S0021 Requested by NRC 0.043
+/-
0.014 0.027 8.1
+/-
3.2 3.9 10.0
+/-
2.6 3.3 5334S0022 Requested by NRC 0.071
+/-
0.016 0.024 4.3
+/-
2.6 3.8 9.8
+/-
2.5 3.2 Minimum 0.010 3.2 9.8 Maximum 0.071 10.2 13.6 a Uncertainties are based on total propagated uncertainties at the 95% confidence level.
b MDC = minimum detectable concentrations.
c Results greater than MDC are bolded.
VNC Non-Impacted Land Areas Confirmatory Survey Report B-3 5334-SR-01-1 Table B.3. NORM Radionuclide Concentrations in Soil Samples Sample Measurement Type K-40 (pCi/g)
Ra-226 (pCi/g)
U-238 (pCi/g)
Th-232 (pCi/g)
Conc.
TPUa MDCb Conc.
TPU MDC Conc.
TPU MDC Conc.
TPU MDC 5334S0001 Random 8.41 c
+/-
0.86 0.44 0.506
+/-
0.054 0.049 0.49
+/-
0.31 0.67 0.56
+/-
0.10 0.14 5334S0002 Random 8.28
+/-
0.80 0.49 0.460
+/-
0.049 0.049 0.76
+/-
0.29 0.48 0.67
+/-
0.10 0.12 5334S0003 Random 7.18
+/-
0.74 0.61 0.439
+/-
0.050 0.060 0.72
+/-
0.55 1.21 0.584
+/-
0.097 0.119 5334S0004 Random 6.43
+/-
0.83 0.83 0.322
+/-
0.048 0.060 0.42
+/-
0.27 0.59 0.45
+/-
0.11 0.17 5334S0005 Random 7.12
+/-
0.76 0.49 0.432
+/-
0.050 0.046 0.59
+/-
0.30 0.61 0.442
+/-
0.094 0.125 5334S0006 Random 8.06
+/-
0.73 0.44 0.449
+/-
0.047 0.057 0.64
+/-
0.24 0.40 0.567
+/-
0.085 0.088 5334S0007 Random 10.35
+/-
0.98 0.66 0.520
+/-
0.057 0.067 1.04
+/-
0.63 1.33 0.67
+/-
0.11 0.12 5334S0008 Random 5.94
+/-
0.68 0.44 0.382
+/-
0.049 0.052 0.58
+/-
0.28 0.54 0.514
+/-
0.098 0.110 5334S0009 Random 9.57
+/-
0.84 0.45 0.495
+/-
0.047 0.044 0.73
+/-
0.26 0.43 0.699
+/-
0.099 0.107 5334S0010 Random 7.34
+/-
0.74 0.59 0.512
+/-
0.052 0.055 1.18
+/-
0.59 1.16 0.517
+/-
0.090 0.115 5334S0011 Random 4.33
+/-
0.53 0.57 0.385
+/-
0.046 0.056 0.54
+/-
0.49 1.09 0.475
+/-
0.083 0.099 5334S0012 Random 7.30
+/-
0.77 0.43 0.444
+/-
0.051 0.049 0.39
+/-
0.26 0.57 0.53
+/-
0.10 0.13 5334S0013 Random 6.12
+/-
0.59 0.37 0.357
+/-
0.037 0.040 0.60
+/-
0.22 0.36 0.435
+/-
0.071 0.077 Mean 7.42 0.439 0.67 0.547 Minimum 4.33 0.322 0.39 0.435 Maximum 10.35 0.520 1.18 0.699 5334S0014 Judgmental 10.19
+/-
0.96 0.66 0.510
+/-
0.056 0.062 0.46
+/-
0.58 1.34 0.66
+/-
0.11 0.13 5334S0015 Requested by NRC 7.49
+/-
0.80 0.46 0.482
+/-
0.056 0.057 0.77
+/-
0.32 0.58 0.59
+/-
0.11 0.14 5334S0016 Requested by NRC 6.61
+/-
0.68 0.37 0.418
+/-
0.045 0.045 0.77
+/-
0.29 0.50 0.518
+/-
0.091 0.113 5334S0019 Requested by NRC 7.42
+/-
0.71 0.68 0.450
+/-
0.050 0.068 0.36
+/-
0.45 1.04 0.625
+/-
0.093 0.115 5334S0020 Requested by NRC 6.57
+/-
0.64 0.61 0.361
+/-
0.042 0.058 0.32
+/-
0.42 0.98 0.411
+/-
0.075 0.110 5334S0021 Requested by NRC 8.64
+/-
0.76 0.41 0.469
+/-
0.044 0.039 0.73
+/-
0.25 0.41 0.625
+/-
0.089 0.092 5334S0022 Requested by NRC 7.28
+/-
0.69 0.46 0.393
+/-
0.048 0.071 0.80
+/-
0.30 0.51 0.687
+/-
0.097 0.093 Minimum 6.57 0.361 0.32 0.411 Maximum 10.19 0.510 0.80 0.687 a Uncertainties are based on total propagated uncertainties at the 95% confidence level.
b MDC = minimum detectable concentrations.
c Results greater than MDC are bolded.
VNC Non-Impacted Land Areas Confirmatory Survey Report B-4 5334-SR-01-1 Table B.4. C1/C2 Cs-137 and NORM Concentrations (pCi/g)
C1/C2 Sample ID Year Cs-137 K-40 Ra-226 U-238 Th-232 5273S0001 2015 0.058 12.2 0.5 0.51 0.65 5273S0002 2015 0.186 9.4 0.452 0.54 0.65 5273S0003 2015 0.128 6.15 0.421 0.53 0.536 5273S0004 2015 0.093 13.1 0.424 0.56 0.79 5273S0005 2015 0.179 8.74 0.503 0.74 0.554 5273S0006 2015 0.129 11.7 0.508 0.8 0.68 5273S0007 2015 0.130 9.13 0.331 0.53 0.549 5273S0008 2015 0.129 15.4 0.554 0.87 0.83 5273S0009 2015 0.201 8.62 0.428 0.9 0.58 5273S0010 2015 0.123 8.43 0.366 0.34 0.479 5273S0011 2015 0.116 7.74 0.391 0.5 0.566 Table B.5. VNC Gross Alpha and Gross Beta Concentrations (pCi/g)
VNC Sample ID Year Gross Alpha Gross Beta S01 2018 10.5 16.2 S02 2018 14.8 12.5 S03 2018 10.3 8.60 S04 2018 8.00 8.13 S05 2018 8.95 13.3 S06 2018 7.34 10.8 S07 2018 14.3 13.7 S08 2018 14.4 16.7 S09 2018 8.06 33.2 S10 2018 11.9 37.9 S11 2018 7.12 6.19 S12 2018 6.38 9.33 S13 2018 9.5 19.7 S14 2018 14 12.3 S15 2018 12.2 12.9 S16 2018 13.3 15.3
VNC Non-Impacted Land Areas Confirmatory Survey Report B-5 5334-SR-01-1 Table B.6. 2009-2013 LLNL Concentrations (pCi/g)a LLNL Sample ID 2009 2010 2011 2012 2013 2014 2015 2016 2017 Cs-137 Concentrations Decay-Corrected to 2019 L-AMON-SO 0.0365 0.017 0.0630 0.018 0.087 0.0747 0.0567 0.101 0.0929 L-CHUR-SO 0.0580 0.0527 0.094 0.0575 0.099 0.0651 0.0838 0.0656 0.0800 L-FCC-SO 0.0408 0.017 0.016 0.02992 0.0235 0.0386 0.0271 0.0277 0.0284 L-HOSP-SO 0.0344 0.0242 0.0337 0.0391 0.0330 0.0313 0.0345 0.111 0.147 L-PATT-SO 0.0236 0.015 0.021 0.0322 0.020 0.018 0.018 0.0404 0.0284 L-TANK-SO 0.0430 0.0549 0.0495 0.0437 0.0518 0.0410 0.0592 0.0429 0.0516 L-ZON7-SO 0.0073 0.009 0.017 0.016 0.014 0.016 0.015 0.013 0.015 K-40 Concentrations L-AMON-SO 14.11 13.70 14.70 13.11 14.19 15.30 15.59 15.89 14.81 L-CHUR-SO 13.11 13.11 13.30 13.00 13.30 13.51 13.51 13.70 13.81 L-FCC-SO 11.30 9.378 10.00 10.19 10.41 10.70 9.351 9.2703 9.703 L-HOSP-SO 10.41 11.59 9.9459 12.70 10.486 10.405 10.486 11.189 11.89 L-PATT-SO 14.89 14.19 12.89 16.00 12.49 13.70 13.59 11.41 11.70 L-TANK-SO 8.8378 9.2432 8.270 8.8378 9.297 9.5135 9.081 8.0000 9.568 L-ZON7-SO 10.59 10.89 10.41 11.11 10.108 10.00 10.70 9.784 11.00 U-238 Concentrations L-AMON-SO 0.673 0.74 0.67 0.74 0.57 0.74 0.84 0.71 0.67 L-CHUR-SO 0.77 0.50 0.81 0.84 0.61 0.77 0.54 0.77 0.74 L-FCC-SO 0.77 0.47 0.54 0.50 0.57 0.437 0.44 0.30 0.370 L-HOSP-SO 0.64 0.639 0.47 0.606 0.606 0.471 0.81 0.370 0.47 L-PATT-SO 0.50 0.67 0.54 0.639 0.77 0.71 0.54 0.57 0.404 L-TANK-SO 0.54 0.538 0.538 0.505 0.54 0.538 0.64 0.370 0.54 L-ZON7-SO 1.6 2.5 2.6 1.9 2.0 2.6 1.7 1.9 2.3 Th-232 Concentrations L-AMON-SO 0.929 0.831 0.929 0.831 0.754 0.918 0.918 0.951 0.885 L-CHUR-SO 0.820 0.809 0.940 0.907 0.863 0.907 0.853 0.929 0.929 L-FCC-SO 0.656 0.634 0.721 0.689 0.656 0.710 0.590 0.579 0.656 L-HOSP-SO 0.623 0.645 0.634 0.678 0.546 0.557 0.557 0.514 0.568 L-PATT-SO 0.820 0.853 0.809 0.940 0.721 0.885 0.842 0.874 0.798 L-TANK-SO 0.700 0.743 0.667 0.634 0.754 0.787 0.754 0.634 0.820 L-ZON7-SO 0.831 0.863 0.896 0.929 0.787 0.896 0.907 0.798 0.940 a Ra-226 concentrations not available.
VNC Non-Impacted Land Areas Confirmatory Survey Report B-6 5334-SR-01-1 Table B.7. Results of the Student (Pooled) t-Test Date/Time of Computation ProUCL 5.1 7/2/2019 12:47:43 PM From File WorkSheet.xls Full Precision OFF Confidence Coefficient 95%
Substantial Difference (S) 0 Selected Null Hypothesis Sample 1 Mean <= Sample 2 Mean (Form 1)
Alternative Hypothesis Sample 1 Mean > the Sample 2 Mean Sample 1 Data: ORISE Sample 2 Data: C1/C2 Sample 1 vs Sample 2 Two-Sample t-Test H0: Mean of Sample 1 - Mean of Sample 2 <= 0 DF t-Test Value Critical t (0.05)
P-Value Method Pooled (Equal Variance) 22
-5.774 1.717 1
Pooled SD 0.035 Conclusion with Alpha = 0.050 Student t (Pooled) Test: Do Not Reject H0 Conclude Sample 1 <= Sample 2 Test of Equality of Variances Variance of Sample 1 8.09E-04 Variance of Sample 2 0.00172 Denominator DF F-Test Value P-Value Numerator DF 10 12 2.128 0.216 Conclusion with Alpha = 0.05 Two variances appear to be equal
VNC Non-Impacted Land Areas Confirmatory Survey Report 5334-SR-01-1 APPENDIX C: SURVEY AND ANALYTICAL PROCEDURES
VNC Non-Impacted Land Areas Confirmatory Survey Report C-1 5334-SR-01-1 C.1. PROJECT HEALTH AND SAFETY ORISE performed all survey activities in accordance with the ORAU Radiation Protection Manual, the ORAU Health and Safety Manual, and the ORAU Radiological and Environmental Survey Procedures Manual (ORAU 2014, ORAU 2016b, and ORAU 2016a). Prior to on-site activities, a Work-Specific Hazard Checklist was completed for the project and discussed with field personnel. The planned activities were thoroughly discussed with site personnel prior to implementation to identify hazards present.
Additionally, prior to performing work, a pre-job briefing and walk down of the survey areas were completed with field personnel to identify hazards present and discuss safety concerns. Should ORISE have identified a hazard not covered in the ORAU Radiological and Environmental Survey Procedures Manual (ORAU 2016a) or the projects Work-Specific Hazard Checklist for the planned survey and sampling procedures, work would not have been initiated or continued until the hazard was addressed by an appropriate job hazard analysis and hazard controls.
C.2. CALIBRATION AND QUALITY ASSURANCE Calibration of all field instrumentation was based on standards/sources, traceable to National Institute of Standards and Technology (NIST).
Field survey activities were conducted in accordance with procedures from the following documents:
- ORAU Radiological and Environmental Survey Procedures Manual (ORAU 2016a)
- ORAU Radiological and Environmental Analytical Laboratory Procedures Manual (ORAU 2017)
- ORAU Environmental Services and Radiation Training Quality Program Manual (ORAU 2018)
The procedures contained in these manuals were developed to meet the requirements of U.S. Department of Energy (DOE) Order 414.1D and the NRC Quality Assurance Manual for the Office of Nuclear Material Safety and Safeguards, and contain measures to assess processes during their performance.
VNC Non-Impacted Land Areas Confirmatory Survey Report C-2 5334-SR-01-1 Quality control procedures include:
- Daily instrument background and check-source measurements to confirm that equipment operation is within acceptable statistical fluctuations
- Participation in Mixed-Analyte Performance Evaluation Program and Intercomparison Testing Program laboratory quality assurance programs
- Training and certification of all individuals performing procedures
- Periodic internal and external audits C.3. SURVEY PROCEDURES C.3.1 SURFACE SCANS Scans for elevated gamma radiation were performed by passing the detector slowly over the surface.
The distance between the detector and surface was maintained at a minimum. Specific scan minimum detectable concentrations (MDCs) for the sodium iodide (NaI) scintillation detectors were not determined because the instruments were used solely as a qualitative means to identify elevated gamma radiation levels in excess of background. Identifications of elevated radiation levels that could exceed the site criteria were determined based on an increase in the audible signal from the indicating instrument.
C.3.2 SOIL SAMPLING Soil samples (approximately 0.5 kilogram each) were collected by ORISE personnel using a clean garden trowel to transfer soil into a new sample container. The container was then labeled and security sealed in accordance with ORISE procedures. ORISE shipped samples under chain-of-custody to the ORISE laboratory for analysis.
C.4. RADIOLOGICAL ANALYSIS C.4.1 GAMMA SPECTROSCOPY Samples were analyzed as received, mixed, crushed, and/or homogenized, as necessary, and a portion sealed into an appropriate volume Marinelli beaker or container. The quantity placed in the beaker was chosen to reproduce the calibrated counting geometry. Net material weights were
VNC Non-Impacted Land Areas Confirmatory Survey Report C-3 5334-SR-01-1 determined and the samples counted using intrinsic, high-purity, germanium detectors coupled to a pulse height analyzer system. Background and Compton stripping, peak search, peak identification, and concentration calculations were performed using computer capabilities inherent in the analyzer system. All total absorption peaks (TAPs) associated with the ROCs were reviewed for consistency of activity. Spectra also were reviewed for other identifiable TAPs. TAPs used for determining the activities of ROCs and the typical MDCs for a 1-hour count time for ROCs are presented in Table C.1.
Table C.1. Typical MDCs Total Absorption Peak for Gamma Emitters Radionuclide TAP (keV)a MDC (pCi/g)
Cs-137 661.66 0.05 U-238 by Th-234 63.29 0.75 Ra-226 by Pb-214 351.93 0.08 K-40 1,460.82 0.5 Th-232 by Ac-228 911.20 0.14 akilo electron volt C.4.2 LOW BACKGROUND PROPORTIONAL COUNTER Samples were dried and processed to provide homogeneity, and a known quantity was transferred to a planchet and counted in a low-background proportional counter. The activity determined by this method is not indicative of any specific nuclide, but, instead, gross alpha and gross beta. Samples were counted for 200 minutes. Typical MDCs are 3.8 pCi/g for alpha and 3.3 pCi/g for beta.
C.4.3 DETECTION LIMITS Detection limits, referred to as MDCs, were based on a 95% confidence level. 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.
VNC Non-Impacted Land Areas Confirmatory Survey Report 5334-SR-01-1 APPENDIX D: MAJOR INSTRUMENTATION
VNC Non-Impacted Land Areas Confirmatory Survey Report D-1 5334-SR-01-1 The display of a specific product is not to be construed as an endorsement of the product or its manufacturer by the author or his employer.
D.1. SCANNING AND MEASUREMENT INSTRUMENT/
DETECTOR COMBINATIONS D.1.1 GAMMA Ludlum NaI Scintillation Detector Model 44-10, Crystal: 5.1 cm x 5.1 cm (Ludlum Measurements, Inc., Sweetwater, Texas) coupled to: Ludlum Ratemeter-scaler Model 2221 (Ludlum Measurements, Inc., Sweetwater, Texas) coupled to: Trimble Geo 7X (Trimble Navigation Limited, Sunnyvale, CA)
D.2. LABORATORY ANALYTICAL INSTRUMENTATION Low-Background Gas Proportional Counter Series 5 XLB (Canberra, Meriden, Connecticut)
Used in conjunction with:
Eclipse Software Dell Workstation (Canberra, Meriden, Connecticut)
High-Purity, Extended Range Intrinsic Detector CANBERRA/Tennelec Model No: ERVDS30-25195 Canberra Lynx Multichannel Analyzer Canberra Gamma-Apex Software (Canberra, Meriden, Connecticut)
Used in conjunction with:
Lead Shield Model G-11 (Nuclear Lead, Oak Ridge, Tennessee) and Dell Workstation (Canberra, Meriden, Connecticut)
High-Purity, Intrinsic Detector EG&G ORTEC Model No. GMX-45200-5 Canberra Lynx Multichannel Analyzer Canberra Gamma-Apex Software (Canberra, Meriden, Connecticut)
Used in conjunction with:
Lead Shield Model G-11 (Nuclear Lead, Oak Ridge, Tennessee) and Dell Workstation (Canberra, Meriden, Connecticut)
VNC Non-Impacted Land Areas Confirmatory Survey Report D-2 5334-SR-01-1 High-Purity, Intrinsic Detector EG&G ORTEC Model No. GMX-30P4 Canberra Lynx Multichannel Analyzer Canberra Gamma-Apex Software (Canberra, Meriden, Connecticut)
Used in conjunction with:
Lead Shield Model G-11 (Nuclear Lead, Oak Ridge, Tennessee) and Dell Workstation (Canberra, Meriden, Connecticut)
High-Purity, Intrinsic Detector EG&G ORTEC Model No. CDG-SV-76/GEM-MX5970-S Canberra Lynx Multichannel Analyzer Canberra Gamma-Apex Software (Canberra, Meriden, Connecticut)
Used in conjunction with:
Lead Shield Model G-11 (Nuclear Lead, Oak Ridge, Tennessee) and Dell Workstation (Canberra, Meriden, Connecticut)