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Title: RADIONUCLIDE DATA PACKAGE FOR PERFORMANCE ASSESSMENT CALCULATIONS RELATED TO THE E-AREA LOW-LEVEL WASTE FACILITY AT THE SAVANNAH RIVER SITE.

Abstract

The Savannah River Site disposes of low-level radioactive waste within on-site engineered disposal facilities. The Savannah River Site must demonstrate that these disposals meet the requirements of DOE Order 435 . 1 through a process known as performance assessment (PA). The objective of this document is to provide the radionuclide -specific data needed for the PA calculations . This work is part of an on-going program to periodically review and update existing PA work as new data becomes available. Revision of the E -Area Low-Level Waste Facility PA is currently underway. The number of radionuclides selected to undergo detailed analysis in the PA is determined by a screening process. The basis of this process is described. Radionuclide-specific data for half-lives, decay modes, daughters, dose conversion factors and groundwater concentration limits are presented with source references and methodologies.

Authors:
Publication Date:
Research Org.:
SRS
Sponsoring Org.:
USDOE
OSTI Identifier:
910931
Report Number(s):
WSRC-STI-2006-00162
TRN: US0800578
DOE Contract Number:
DE-AC09-96SR18500
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
12 MANAGEMENT OF RADIOACTIVE WASTES, AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES; DECAY; LOW-LEVEL RADIOACTIVE WASTES; PERFORMANCE; RADIOISOTOPES; SAVANNAH RIVER; WASTES

Citation Formats

Cook, J. RADIONUCLIDE DATA PACKAGE FOR PERFORMANCE ASSESSMENT CALCULATIONS RELATED TO THE E-AREA LOW-LEVEL WASTE FACILITY AT THE SAVANNAH RIVER SITE.. United States: N. p., 2007. Web. doi:10.2172/910931.
Cook, J. RADIONUCLIDE DATA PACKAGE FOR PERFORMANCE ASSESSMENT CALCULATIONS RELATED TO THE E-AREA LOW-LEVEL WASTE FACILITY AT THE SAVANNAH RIVER SITE.. United States. doi:10.2172/910931.
Cook, J. Tue . "RADIONUCLIDE DATA PACKAGE FOR PERFORMANCE ASSESSMENT CALCULATIONS RELATED TO THE E-AREA LOW-LEVEL WASTE FACILITY AT THE SAVANNAH RIVER SITE.". United States. doi:10.2172/910931. https://www.osti.gov/servlets/purl/910931.
@article{osti_910931,
title = {RADIONUCLIDE DATA PACKAGE FOR PERFORMANCE ASSESSMENT CALCULATIONS RELATED TO THE E-AREA LOW-LEVEL WASTE FACILITY AT THE SAVANNAH RIVER SITE.},
author = {Cook, J},
abstractNote = {The Savannah River Site disposes of low-level radioactive waste within on-site engineered disposal facilities. The Savannah River Site must demonstrate that these disposals meet the requirements of DOE Order 435 . 1 through a process known as performance assessment (PA). The objective of this document is to provide the radionuclide -specific data needed for the PA calculations . This work is part of an on-going program to periodically review and update existing PA work as new data becomes available. Revision of the E -Area Low-Level Waste Facility PA is currently underway. The number of radionuclides selected to undergo detailed analysis in the PA is determined by a screening process. The basis of this process is described. Radionuclide-specific data for half-lives, decay modes, daughters, dose conversion factors and groundwater concentration limits are presented with source references and methodologies.},
doi = {10.2172/910931},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Mar 20 00:00:00 EDT 2007},
month = {Tue Mar 20 00:00:00 EDT 2007}
}

Technical Report:

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  • The Savannah River Site disposes of certain types of radioactive waste within subsurface-engineered facilities. One of the tools used to establish the capacity of a given site to safely store radioactive waste (i.e., that a site does not exceed its Waste Acceptance Criteria) is the Performance Assessment (PA). The objective of this document is to provide the geochemical values for the PA calculations. This work is being conducted as part of the on-going maintenance program that permits the PA to periodically update existing calculations when new data becomes available. Because application of values without full understanding of their original purposemore » may lead to misuse, this document also provides the geochemical conceptual model, approach used for selecting the values, the justification for selecting data, and the assumptions made to assure that the conceptual and numerical geochemical models are reasonably conservative (i.e., reflect conditions that will tend to predict the maximum risk to the hypothetical recipient). The geochemical parameters describe transport processes for 38 elements (>90 radioisotopes) potentially occurring within eight disposal units (Slit Trenches, Engineered Trenches, Low Activity Waste (LAW) Vault, Intermediate Level (ILV) Vaults, TRU-Pad-1, Naval Reactor Waste Pads, Components-in-Grout Trenches, and Saltstone Facility). This work builds upon well-documented work from previous PA calculations (McDowell-Boyer et al. 2000). The new geochemical concepts introduced in this data package are: (1) In the past, solubility products were used only in a few conditions (element existing in a specific environmental setting). This has been expanded to >100 conditions. (2) Radionuclide chemistry in cementitious environments is described through the use of both the Kd and apparent solubility concentration limit. Furthermore, the solid phase is assumed to age during the assessment period (thousands of years), resulting in three main types of controlling solid phases, each possessing a unique set of radionuclide sorption parameters (Kd and solubility concentration limit). (3) A large amount of recent site-specific sorption research has been conducted since the last PA (McDowell-Boyer et al. 2000). These new data have replaced previous Kd values derived from literature values, thus reducing uncertainty and improving accuracy. Finally, because this document will be used by future PA calculations and external acceptance of the document will eventually be required, this document was extensively reviewed. The review process, including the internal review, site review, and external review process is described.« less
  • The Savannah River Site disposes of low-activity radioactive waste within subsurface-engineered facilities. One of the tools used to establish the capacity of a given site to safely store radioactive waste (i.e., that a site does not exceed its Waste Acceptance Criteria) is the Performance Assessment (PA). The objective of this document is to provide the geochemical values for the PA calculations. This work is being conducted as part of the on-going maintenance program that permits the PA to periodically update existing calculations when new data become available.
  • The Savannah River Site (SRS) disposes of low-level radioactive waste (LLW) and stabilizes high-level radioactive waste (HLW) tanks in the subsurface environment. Calculations used to establish the radiological limits of these facilities are referred to as Performance Assessments (PA), Special Analyses (SA), and Composite Analyses (CA). The objective of this document is to revise existing geochemical input values used for these calculations. This work builds on earlier compilations of geochemical data (2007, 2010), referred to a geochemical data packages. This work is being conducted as part of the on-going maintenance program of the SRS PA programs that periodically updates calculationsmore » and data packages when new information becomes available. Because application of values without full understanding of their original purpose may lead to misuse, this document also provides the geochemical conceptual model, the approach used for selecting the values, the justification for selecting data, and the assumptions made to assure that the conceptual and numerical geochemical models are reasonably conservative (i.e., bias the recommended input values to reflect conditions that will tend to predict the maximum risk to the hypothetical recipient). This document provides 1088 input parameters for geochemical parameters describing transport processes for 64 elements (>740 radioisotopes) potentially occurring within eight subsurface disposal or tank closure areas: Slit Trenches (ST), Engineered Trenches (ET), Low Activity Waste Vault (LAWV), Intermediate Level (ILV) Vaults, Naval Reactor Component Disposal Areas (NRCDA), Components-in-Grout (CIG) Trenches, Saltstone Facility, and Closed Liquid Waste Tanks. The geochemical parameters described here are the distribution coefficient, Kd value, apparent solubility concentration, k s value, and the cementitious leachate impact factor.« less
  • Before a license can be obtained to construct a facility for the shallow-land burial of low-level wastes, the US Nuclear Regulatory Commission must be assured that the facility will meet both performance objectives and prescriptive requirements set forth in 10CFR61, ''Licensing Requirements for Land Disposal of Radioactive Waste.'' Subpart D, Section 61.50(a) (2) of 10CRF61 states that a ''disposal site shall be capable of being characterized, modeled, analyzed and monitored.'' In order to test the concept of ''site modelability,'' a 33-year old low-level radioactive waste disposal site, the ''A'' Disposal Area, at Chalk River Nuclear Laboratories (CRNL), Canada, was usedmore » as a field location for evaluating the process of site characterization and the subsequent modeling prediction of radionuclide transport from the site by groundwater. This report is the second of two such evaluations and was performed by comparing the actual measured radionuclide migration with predicted migration estimated from hydrologic/radionuclide transport modeling. Using a temporally varying /sup 90/Sr retardation factor to account for changing concentrations of acidity and competing ions in the source materials, a reasonably good agreement was obtained between observed and predicted /sup 90/Sr migration in the groundwater. However, trace amounts of /sup 137/Cs and /sup 239/minus/240/Pu have migrated faster than expected at this site. 31 refs., 54 figs., 15 tabs.« less
  • This Performance Assessment for the Savannah River Site E-Area Low-Level Waste Facility was prepared to meet requirements of Chapter IV of the Department of Energy Order 435.1-1. The Order specifies that a Performance Assessment should provide reasonable assurance that a low-level waste disposal facility will comply with the performance objectives of the Order. The Order also requires assessments of impacts to water resources and to hypothetical inadvertent intruders for purposes of establishing limits on radionuclides that may be disposed near-surface. According to the Order, calculations of potential doses and releases from the facility should address a 1,000-year period after facilitymore » closure. The point of compliance for the performance measures relevant to the all pathways and air pathway performance objective, as well as to the impact on water resources assessment requirement, must correspond to the point of highest projected dose or concentration beyond a 100-m buffer zone surrounding the disposed waste following the assumed end of active institutional controls 100 years after facility closure. During the operational and institutional control periods, the point of compliance for the all pathways and air pathway performance measures is the SRS boundary. However, for the water resources impact assessment, the point of compliance remains the point of highest projected dose or concentration beyond a 100-m buffer zone surrounding the disposed waste during the operational and institutional control periods. For performance measures relevant to radon and inadvertent intruders, the points of compliance are the disposal facility surface for all time periods and the disposal facility after the assumed loss of active institutional controls 100 years after facility closure, respectively. The E-Area Low-Level Waste Facility is located in the central region of the SRS known as the General Separations Area. It is an elbow-shaped, cleared area, which curves to the northwest, situated immediately north of the Mixed Waste Management Facility. The E-Area Low-Level Waste Facility is comprised of 200 acres for waste disposal and a surrounding buffer zone that extends out to the 100-m point of compliance. Disposal units within the footprint of the low-level waste facilities include the Slit Trenches, Engineered Trenches, Component-in-Grout Trenches, the Low-Activity Waste Vault, the Intermediate-Level Vault, and the Naval Reactor Component Disposal Area. Radiological waste disposal operations at the E-Area Low-Level Waste Facility began in 1994. E-Area Low-Level Waste Facility closure will be conducted in three phases: operational closure, interim closure, and final closure. Operational closure will be conducted during the 25-year operation period (30-year period for Slit and Engineered Trenches) as disposal units are filled; interim closure measures will be taken for some units. Interim closure will take place following the end of operations and will consist of an area-wide runoff cover along with additional grading over the trench units. Final closure of all disposal units in the E-Area Low-Level Waste Facility will take place at the end of the 100-year institutional control period and will consist of the installation of an integrated closure system designed to minimize moisture contact with the waste and to serve as a deterrent to intruders. Radiological dose to human receptors is analyzed in this PA in the all-pathways analysis, the inadvertent intruder analysis and the air pathway analysis, and the results are compared to the relevant performance measures. For the all-pathways analysis, the performance measure of relevance is a 25-mrem/yr EDE to representative members of the public, excluding dose from radon and its progeny in air. For the inadvertent intruder, the applicable performance measures are 100-mrem/yr EDE and 500 mrem/yr EDE for chronic and exposure scenarios, respectively. The relevant performance measure for the air pathway is 10-mrem/yr EDE via the air pathway, excluding dose from radon and its progeny in air. Protection of groundwater resources is addressed by comparing calculated compliance point concentrations in groundwater with the relevant performance measure, which was determined to be the Safe Drinking Water Act MCLs for beta-gamma and alpha-emitting radionuclides, and for radium and uranium. Radon fluxes for each disposal unit are calculated and compared to the average flux of 20 pCi/m{sup 2}/s upper limit specified in the relevant performance objective. Thirty-five parent radionuclides are addressed in the groundwater transport calculations, 15 radionuclides in the air pathway calculations, and 78 parent radionuclides in the intruder analysis for all disposal units. Radon-222 fluxes are also evaluated for all disposal units.« less