A DESCRIPTION OF THE TRU WASTE CERTIFICATION
PROCESS USED AT THE INEEL TO MEET
WIPP DISPOSAL REQUIREMENTS
T. L. Clements, Jr., R. E. Arbon, D. G. Pound, D. W. Parker
Lockheed Martin Idaho Technologies Company
Idaho National Engineering and Environmental Laboratory
J. L. Wells
U.S. Department of Energy-Idaho Operations Office
ABSTRACT
Information of known quality to support waste certification is required before disposal of transuranic (TRU) waste in the Waste Isolation Pilot Plant (WIPP). This paper describes the processes and methods used at the Idaho National Engineering and Environmental Laboratory (INEEL) to certify contact-handled (CH) stored TRU waste to requirements and criteria defined in the WIPP Waste Acceptance Criteria (WAC).
Capabilities to certify individual waste forms are dependent upon successful implementation of program requirements described in the WIPP WAC, WIPP Quality Assurance Program Description (QAPD), WIPP TRU Waste Characterization Quality Assurance Program Plan (QAPP), and Transuranic Package Transporter-II (TRUPACT-II) Certificate of Compliance (C of C).
The WIPP WAC describes the information required to successfully dispose of TRU waste. Information is obtained using waste characterization methods such as (a) acceptable knowledge documentation, (b) nondestructive examination and assay at the Radioactive Waste Management Complex (RWMC) Stored Waste Examination Pilot Plant (SWEPP) facility and Type I Storage Module (weigh station, radiological control station, passive-active neutron (PAN) system, gamma-ray spectrometry, real-time radiography (RTR), container integrity inspection, headspace gas sampling, drum venting, and gas generation testing), (c) visual examination, and (d) intrusive sampling and analysis.
Information on each container is accumulated at each certification process step, then reduced, analyzed, reconciled, and compared against appropriate WIPP operational and safety, environmental compliance, and transportation requirements. This paper provides a summary description of how information is generated, reduced, analyzed, dispositioned, assimilated, validated, reconciled, applied, controlled, and certified.
The INEEL has recently completed a series of upgrades to facilities and characterization systems/methods to improve performance and increase operational reliability and efficiencies. The systems, procedures, and personnel are in place, and demonstration of system performance with WIPP Quality Assurance (QA) objectives has been completed. Data of known quality are currently being generated in accordance with WIPP requirements to support production-level shipments of TRU waste to WIPP for disposal.
INTRODUCTION
Since 1970, the INEEL has provided interim storage capacity for transuranic (TRU)-contaminated wastes generated by activities supporting the United States national defense needs. Approximately 60% of the nation’s current inventory of TRU-contaminated waste is stored at the Idaho National Engineering and Environmental Laboratory (INEEL) Radioactive Waste Management Complex (RWMC), awaiting opening the Waste Isolation Pilot Plant (WIPP); the designated federal repository for permanent disposal of defense-generated TRU waste. Several activities are currently underway as part of production-level waste characterization, certification, and transportation operations to support shipment of untreated TRU waste to WIPP beginning in May 1998.
Production characterization operations were restarted in September 1997, and are currently staged to process a minimum of 4,500 drums per year needed to meet initial requirements of the October 1995 Settlement Agreement (SA) between the State of Idaho, Department of the Navy, and the Department of Energy (DOE). The following excerpts from the SA describe some milestones for TRU waste leaving the State of Idaho, and describe the consequences if the milestones are not completed:
DOE shall ship all transuranic waste now located at the Idaho National Engineering Laboratory (INEL), currently estimated at 65,000 cubic meters in volume, to the Waste Isolation Pilot Plant (WIPP) or other such facility designated by DOE, by a target date of December 31, 2015, and in no event later than December 31, 2018. DOE shall meet the following interim deadlines:
Consequences of missing milestones described in the SA include ... the sole remedy for DOE’s failure to meet any of the deadlines or requirements...shall be the suspension of DOE spent fuel shipments to INEL...
The INEEL has recently completed a series of upgrades to facilities and characterization systems/methods to improve performance, and increase operational reliability and efficiencies. The systems, procedures, and personnel are in place, and demonstration of system performance with WIPP Quality Assurance (QA) objectives has been completed. Data of known quality are currently being generated in accordance with WIPP requirements to support production-level shipments of TRU waste to WIPP for disposal.
TRU WASTE CERTIFICATION
The WIPP Waste Acceptance Criteria (WAC) requires that each site participating in the characterization, certification, and transportation of TRU waste for disposal in the WIPP perform the following functions:
The WIPP WAC also describes the process for sites to obtain certification authorization for TRU waste characterization, transportation, and certification for disposal in the WIPP. Obtaining site certification authorization from the DOE-Carlsbad Area Office (CAO) is a multistep process consisting of:
Final waste container certification is performed by comparing validated characterization data for each waste container to the appropriate WIPP waste acceptance criteria. Characterization data for containers identified as being WIPP-certifiable are transmitted to WIPP via the WIPP Waste Information System (WWIS) where the data are reviewed and approved by WIPP personnel.
TRU WASTE CHARACTERIZATION
Before transporting and disposing of TRU waste in the WIPP, specific waste parameters must be characterized in accordance with the current version of the WIPP QAPP and evaluated against WIPP WAC requirements. Parameters of interest include the waste physical, chemical, and radiological characteristics. Characterization is accomplished by the use of acceptable knowledge documentation, weigh station, radiological control station, passive-active neutron (PAN) system, gamma-ray spectrometry, real-time radiography (RTR), container integrity inspection, headspace gas sampling, intrusive examination and/or core sampling of the waste, and chemical characterization.
Characterization work performed at the RWMC Stored Waste Examination Pilot Plant (SWEPP) facility and Type I Storage Module includes the weigh station, radiological control station, PAN, gamma-ray spectrometry, RTR, container integrity inspection, headspace gas sampling using an on-line Fourier Transform Infrared Spectrometry (FTIRS) and Residual Gas Analyzer (RGA), and drum venting. A portion of the waste is selected for intrusive visual examination, needed to confirm the RTR-examination process, and/or core sampling at Argonne National Laboratory West (ANL-W). Core samples are transported to the Idaho Chemical Processing Plant Analytical Chemistry Laboratory (ICPP-ACL) for chemical and radiochemical analysis to confirm hazardous waste number assignments made using acceptable knowledge documentation and provide data used for total uncertainty evaluation of the assay system. Data on each container for each characterization step are reduced, analyzed, reconciled, and compared against appropriate WIPP QAPP and WAC requirements. Figure 1 provides a summary description of the INEEL contact-handled (CH)-TRU waste certification process.
Figure 1. INEEL contact-handled (CH)-TRU waste certification process summary
NONDESTRUCTIVE EXAMINATION AND ASSAY (NDE/A)
The characterization process begins with TRU waste retrieval at the RWMC. Potentially WIPP-certifiable TRU waste is retrieved from the Waste Storage Facilities (WSFs), radiological surveys performed, and transported to the drum preheat area located within the SWEPP facility. Drums are preheated within 18-29 ° C for a minimum of 72 hours ensuring any free liquids present can be detected during the winter months using RTR, and to meet headspace gas sampling requirements. Preheated drums are then transported to the radiological control station and surveyed for surface contamination. Drums with removable surface contamination are cleaned before proceeding to SWEPP characterization. The SWEPP characterization process can be summarized as follows:
Twenty drums are initially batched, weighed, and processed through nondestructive characterization systems. The RTR system provides capability for examining the physical characteristics of a waste drum to determine waste form and verify compliance with certain disposal and transportation requirements (packaging level, absence of pressurized containers, etc.). Assay of the waste is performed using PAN assay and gamma spectroscopy to determine fissile gram equivalents, thermal wattage, and isotopic distribution. Duplicate measurements, consisting of one drum out of a batch, are taken at each characterization station. Drums which do not pass (noncompliant) a characterization station are returned to storage. Only certifiable drums continue in the characterization process. Drums are added to replace rejected drums thereby maximizing the batch size to 20 at each characterization station. Maximizing batch size minimizes duplicate rates.
The characterization process sequence of operations occurring at SWEPP is designed to be flexible (i.e., unit operations do not require performance in a specific order) to allow for operational efficiencies. At the INEEL, TRU waste containers are processed in order of expected descending waste container rejection rates, which minimize unnecessary container processing.
HEADSPACE GAS SAMPLING
Headspace gas sampling occurs for H2, CH4, and selected volatile organic compounds (VOCs) to support both transportation and characterization. Headspace sampling and analysis occur at the Drum Vent Facility (DVF). The function of the facility is to remotely vent TRU waste drums by puncturing a hole in the drum lid and liner, collecting a gas sample, and inserting a carbon-bonded filter assembly into the hole. Analysis of the headspace is performed by an online integrated FTIRS and RGA system.
INTRUSIVE EXAMINATION AND SAMPLING
A statistically selected sample of the waste population is chosen for intrusive examination and/or sampling in accordance with WIPP QAPP requirements. Selected waste drums are shipped using TRUPACT-II shipping containers to the ANL-W Waste Characterization Area for visual examination and/or core sampling. Visual examination is used to confirm the RTR examination process.
Core samples obtained from sampling solidified waste forms (e.g., inorganic and organic sludges, cemented solids, etc.) are transported to the ICPP-ACL for Resource Conservation and Recovery Act (RCRA) analysis including VOCs, semi-VOCs, metals, and polychlorinated biphenyls (PCBs), if required, and radiochemistry. Data generated by analytical operations are used for verifying and/or determining Resource Conservation and Recovery Act (RCRA) hazardous constituents in the waste, preparing waste stream profiles, identifying future sampling needs, and providing data used for total uncertainty evaluation of the assay system. RCRA characterization is performed most effectively by combining similar waste types into waste streams. Appropriate grouping of similar waste types based on physical and regulated chemical composition allows the resulting waste stream to be more efficiently and accurately characterized and profiled. The key to success is to combine only those waste types similar in analyte concentration distributions, such that the variance, as measured by the coefficient of variation, for the respective chemical constituents will be minimized. Using this approach reduces the number of drums requiring coring and analysis and consequently reduces funding needs.
To accomplish this waste type consolidation, accurate acceptable knowledge is critical. More than 300 information sources were collected and reviewed during the development of the INEEL acceptable knowledge document. Discrepancies between sources were resolved by contacting cognizant personnel or by collecting additional information. Using acceptable knowledge, the INEEL has grouped waste into waste streams based on similar physical composition and chemical characteristics creating large homogeneous waste streams. Drums are randomly selected from the large waste streams and set aside during waste handling operations. Coring and analysis of the statistically-selected drums to date have confirmed low variability of RCRA-regulated constituents within our largest waste stream. The low variability of RCRA constituents has resulted in a significant reduction of the number of drums requiring coring/RCRA characterization and, as a result, a significant reduction in characterization cost and time.
DATA MANAGEMENT
Effective management of data collected at all characterization stations is required to meet WIPP requirements. Validation and verification of data are performed at three different levels: data generation, data verification and reporting, and final verification. Level I validation and verification occur at the level of data generation, such as the RTR or headspace gas sampling station. Level-I validation is more detailed than either the Level-II or Level-III reviews and requires expertise with the process generating the data. At Level I, release of data requires signature releases from a qualified independent technical reviewer, a technical supervisor, and a QA officer. The independent technical reviewer must be qualified to have performed the initial work. This person ensures that the data are technically correct, complete, within established control limits, and that variances from accepted methods are adequately documented. The technical supervisor ensures that the data are technically reasonable, complete, and have been through independent review. The QA officer ensures that the independent technical and technical supervisor reviews are complete, appropriate QA documentation is complete, and that the program QA objectives have been met. To ensure consistency, these checks are performed in accordance with procedures and documented through the use of checklists.
Level-I data are transmitted to the Site Office Project (SPO) for further validation, reconciliation, and storage. Processing these data at the SPO represents Level-II validation. Level-II data validation confirms that the data generation level validation was conducted appropriately and evaluates sampling batch quality control (QC) checks that require information from more than one facility. A general review that looks for completeness and acceptability of the data as reported is also performed. On a periodic basis, the project office conducts a repeat of the Level-I validation for each of the facilities to ensure that the implementing procedures at the facility level are adequate. Activities include reconciliation of waste stream data quality objectives, and preparation of the WIPP waste stream profile form. Reconciliation of the data requires summarizing specific types of data for a waste stream and determining if enough data have been collected to characterize the waste stream and to meet some specified data quality objectives. For instance, one of the data quality objectives that must be determined for a waste stream is to determine the average concentration in the headspace gas for each of the target analytes in the QAPP. The reconciliation process would average all headspace gas concentrations for each analyte.
The SPO Manager reviews the data and decides if sufficient data have been collected for the waste stream. If sufficient data have been collected and meet all required parameters, a waste stream profile form can be generated. The waste stream profile form uses acceptable knowledge documentation and data generated during the characterization/reconciliation process to describe a waste stream. Data released from the SPO to WIPP include a signature release from the site Project Manager and the Site QA Officer (SQAO). These signature releases ensure that the data have been Level-II validated and properly reconciled for the waste stream.
Level-III validation of waste characterization data occurs at WIPP and is essentially an inventory check to ensure that the data received are complete. Additional checks may occur to ensure that data have been appropriately reconciled.
TRU WASTE TRANSPORTATION
TRU waste shipments are performed at the INEEL in compliance with Department of Transportation regulations. The method of compliance is the TRUPACT-II, which is a certified Type B package by the Nuclear Regulatory Commission. Fourteen drums or two standard waste boxes can be shipped in each TRUPACT-II. Each shipment consists of three TRUPACT-IIs per truck. The standard waste boxes can be loaded directly with waste or may be used to overpack four drums per box.
The INEEL TRUPACT-II Loading Facility was constructed in October 1988. Certification authorization for the use of TRUPACT-II was obtained in April 1992. Since that time, the INEEL has safely completed approximately 89 onsite shipments between ANL-W and RWMC using the TRUPACT-II.
Each site using the TRUPACT-II is required to develop a site-specific TRAMPAC document. This document describes the methods implemented for payload compliance. The site Transportation Certification Official (TCO) reviews the certification data for each container for compliance with the TRAMPAC criteria. Following the review, the TCO completes a certification document for each container and TRUPACT-II assembly included in the shipment.
TRU WASTE INFORMATION MANAGEMENT
A primary and fundamental part of TRU waste storage, characterization, transportation, and certification is managing waste container information. Data of known quality, from data generation through final reporting, are necessary to prepare TRU waste for disposal in the WIPP.
Existing legacy information systems for TRU waste are currently being replaced by the Transuranic Reporting Inventory Processing System (TRIPS). At a planned production rate of 4,500 drums per year, an alternative means of managing information was needed. TRIPS will electronically integrate the current hard copy of TRU waste data collection, validation, and certification process (both automated and manual) that exists, ensuring that users can readily access characterization, transportation, and certification information. TRIPS will provide an electronic capability to collect characterization data from geographically dispersed locations, increase the speed and efficiency of the data review process, and provide reporting capabilities to WIPP via the WWIS. Additionally, TRIPS will support other key TRU waste operations activities such as container tracking, inventory control, and certification process status.
TRIPS is being designed in compliance with American Society of Mechanical Engineers (ASME) Nuclear Quality Assurance (NQA) - 2a, Part 2.7 requirements, and will provide capabilities to support the following certification process operations:
TRIPS is currently being implemented in a phased approach to avoid schedule impact on production operations, and is expected to be fully operational by December 1998.
CONCLUSION
The INEEL has successfully implemented capabilities and requirements to support production-level TRU waste characterization, certification, and transportation operations for shipment of waste to WIPP. Current program status includes:
The INEEL is currently staged to process a minimum of 4,500 drums per year needed to meet initial requirements of the SA between the State of Idaho, Department of the Navy, and the DOE. Initiation of shipment of stored TRU waste to WIPP will begin once WIPP is opened and authorization to ship is received.
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