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Title: Statistical methods for determination of background levels for naturally occuring radionuclides in soil at a RCRA facility

Abstract

It is critical that summary statistics on background data, or background levels, be computed based on standardized and defensible statistical methods because background levels are frequently used in subsequent analyses and comparisons performed by separate analysts over time. The final background for naturally occurring radionuclide concentrations in soil at a RCRA facility, and the associated statistical methods used to estimate these concentrations, are presented. The primary objective is to describe, via a case study, the statistical methods used to estimate 95% upper tolerance limits (UTL) on radionuclide background soil data sets. A 95% UTL on background samples can be used as a screening level concentration in the absence of definitive soil cleanup criteria for naturally occurring radionuclides. The statistical methods are based exclusively on EPA guidance. This paper includes an introduction, a discussion of the analytical results for the radionuclides and a detailed description of the statistical analyses leading to the determination of 95% UTLs. Soil concentrations reported are based on validated data. Data sets are categorized as surficial soil; samples collected at depths from zero to one-half foot; and deep soil, samples collected from 3 to 5 feet. These data sets were tested for statistical outliers and underlying distributionsmore » were determined by using the chi-squared test for goodness-of-fit. UTLs for the data sets were then computed based on the percentage of non-detects and the appropriate best-fit distribution (lognormal, normal, or non-parametric). For data sets containing greater than approximately 50% nondetects, nonparametric UTLs were computed.« less

Authors:
;  [1]
  1. International Technology Corp., Knoxville, TX (United States)
Publication Date:
OSTI Identifier:
393998
Report Number(s):
CONF-9607135-
Journal ID: HLTPAO; ISSN 0017-9078; TRN: 96:028681
Resource Type:
Journal Article
Journal Name:
Health Physics
Additional Journal Information:
Journal Volume: 70; Journal Issue: Suppl.6; Conference: 41. Annual Meeting of the Health Physics Society, Seattle, WA (United States), 21-25 Jul 1996; Other Information: PBD: Jun 1996
Country of Publication:
United States
Language:
English
Subject:
05 NUCLEAR FUELS; 54 ENVIRONMENTAL SCIENCES; 99 MATHEMATICS, COMPUTERS, INFORMATION SCIENCE, MANAGEMENT, LAW, MISCELLANEOUS; SOILS; RADIOACTIVITY; NUCLEAR FACILITIES; REMEDIAL ACTION; SPECIFICATIONS; STATISTICS; RADIOACTIVE EFFLUENTS

Citation Formats

Guha, S, and Taylor, J H. Statistical methods for determination of background levels for naturally occuring radionuclides in soil at a RCRA facility. United States: N. p., 1996. Web.
Guha, S, & Taylor, J H. Statistical methods for determination of background levels for naturally occuring radionuclides in soil at a RCRA facility. United States.
Guha, S, and Taylor, J H. Sat . "Statistical methods for determination of background levels for naturally occuring radionuclides in soil at a RCRA facility". United States.
@article{osti_393998,
title = {Statistical methods for determination of background levels for naturally occuring radionuclides in soil at a RCRA facility},
author = {Guha, S and Taylor, J H},
abstractNote = {It is critical that summary statistics on background data, or background levels, be computed based on standardized and defensible statistical methods because background levels are frequently used in subsequent analyses and comparisons performed by separate analysts over time. The final background for naturally occurring radionuclide concentrations in soil at a RCRA facility, and the associated statistical methods used to estimate these concentrations, are presented. The primary objective is to describe, via a case study, the statistical methods used to estimate 95% upper tolerance limits (UTL) on radionuclide background soil data sets. A 95% UTL on background samples can be used as a screening level concentration in the absence of definitive soil cleanup criteria for naturally occurring radionuclides. The statistical methods are based exclusively on EPA guidance. This paper includes an introduction, a discussion of the analytical results for the radionuclides and a detailed description of the statistical analyses leading to the determination of 95% UTLs. Soil concentrations reported are based on validated data. Data sets are categorized as surficial soil; samples collected at depths from zero to one-half foot; and deep soil, samples collected from 3 to 5 feet. These data sets were tested for statistical outliers and underlying distributions were determined by using the chi-squared test for goodness-of-fit. UTLs for the data sets were then computed based on the percentage of non-detects and the appropriate best-fit distribution (lognormal, normal, or non-parametric). For data sets containing greater than approximately 50% nondetects, nonparametric UTLs were computed.},
doi = {},
journal = {Health Physics},
number = Suppl.6,
volume = 70,
place = {United States},
year = {1996},
month = {6}
}