DOCKET NO: A-98-49; II-A4-133 

WASTE CHARACTERIZATION REPORT 

TIER 1 CHANGE: 

EVALUATION OF THE EXTENSION OF THE CALIBRATION RANGE FOR THE 

BOX GAMMA SEGMENTED SYATEM (BSGS) OF THE NONDESTRUCTIVE ASSAY 

BOX COUNTER (NABC) AT THE CENTRAL CHARACTERIZATION PROJECT 

(CCP) AT SAVANNAH RIVER SITE (SRS) 

U.S. Environmental Protection Agency 

Office of Radiation and Indoor Air 

Center for Waste Management and Regulations 

1200 Pennsylvania Avenue, NW 

Washington, DC 20460 

September 2010
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TABLE OF CONTENTS 

Section Page

1.0 Executive Summary .............................................................................................................1

2.0 Purpose of Inspections .........................................................................................................1

3.0 Purpose of This Report ........................................................................................................1

4.0 Scope of Review ..................................................................................................................2

5.0 T1 Evaluation Personnel ......................................................................................................2

6.0 Evaluation of the NABC ......................................................................................................2

7.0 Summary of Results and Conclusions .................................................................................6

8.0 Approval ..............................................................................................................................7

LIST OF TABLES 

Table 1. Approval Summary for SRS-CCP CH Waste Characterization Program .........................1

Table 2. T1 Evaluation Personnel ....................................................................................................2

Table 3. Plutonium Mass Loading Contents for Container Type ....................................................5
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1.0 EXECUTIVE SUMMARY 

In accordance with 40 CFR 194.8(b), the U.S. Environmental Protection Agency (EPA or the 

Agency) conducted Baseline Inspection No. EPA-SRS-10.05-8 of the Central Characterization 

Project (CCP) waste characterization program for contact-handled (CH) transuranic (TRU) 

wastes at the U.S. Department of Energy (DOE) Savannah River Site (SRS) in Aiken, South 

Carolina, from October 31 through November 3, 2005. As a result of this baseline inspection, 

EPA approved the SRS-CCP CH TRU waste characterization program with conditions and 

limitations, as discussed in the SRS Baseline Final Inspection Report (see EPA Docket No. 

A-98-49, II-A4-64). This approval included two nondestructive assay (NDA) systems: the IQ3 

gamma system and the Imaging Passive Active Neutron (IPAN) system. 

On March 9, 2009, the Carlsbad Field Office (CBFO) requested EPA approval of a Tier 1 (T1) 

change to add the Nondestructive Assay Box Counter (NABC) at SRS. The NABC is a bimodal 

system consisting of a gamma detection mode referred to as the Box Segmented Gamma System 

(BSGS) and a neutron detection mode referred to as the Box Neutron Assay System (BNAS). On 

March 24–26, 2009, EPA conducted an onsite evaluation of the NABC at SRS and approved the 

NABC. A summary of all EPA approvals of SRS-CCP’s CH TRU waste characterization 

program is provided in Table 1, below. On July 8, 2009, the CBFO requested EPA approval of a 

T1 change to extend the calibration range of the BSGS aspect of the NABC to 7.18 grams of 

238Pu utilizing a reduced 20-minute assay time and that change is the subject of this evaluation. 

This report serves as EPA’s public notification of the results of the proposed T1 change and its 

evaluation. This information will be provided through the EPA web site and by sending e-mails 

to the WIPPNEWS list, in accordance with 40 CFR 194.8(b)(3). As a result of this approval no 

changes were made to the modified tiering table provided with the approval of S3000 (solid) 

waste in March 2010. 

Table 1. Approval Summary for SRS-CCP CH Waste Characterization Program 

Specific SRS-CCP CH Approval Date EPA Docket Number 

SRS CH Baseline Approval July 2006 A-98-49; II-A4-64 

Tier 1 Change – Approval of Segmented Gamma Scanner, 

Nondestructive Assay System August 2007 A-98-49; II-A4-90 

Tier 1 Change – Approval of Nondestructive Assay Box Counter, 

Nondestructive Assay System August 2009 A-98-49; II-A4-114 

Tier 1 Change – Addition of S3000 Solids March 2010 A-98-49; II-A4-123 
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2.0 PURPOSE OF INSPECTIONS 

Any changes to the waste characterization activities from the date of the baseline inspection must 

be reported to and, if applicable, approved by EPA according to the tiering requirements set forth 

in the SRS Baseline Final Report cited above. 

Under the changes to 40 CFR 194.8 promulgated in the July 16, 2004, Federal Register notice, 

EPA must perform a single baseline inspection of a TRU waste generator site’s waste 

characterization program. The purpose of the baseline inspection is to approve the site’s waste 

characterization program based on the demonstration that the program’s components, with 

applicable conditions and limitations, can adequately characterize TRU wastes and comply with 

the regulatory requirements imposed on TRU wastes destined for disposal at the WIPP. An EPA 

inspection team conducts an onsite inspection to verify that the site’s system of controls is 

technically adequate and properly implemented. 

 

Following the EPA’s approval of waste characterization processes evaluated during the baseline 

inspection, EPA is authorized to evaluate and approve, if necessary, changes to the site’s 

approved waste characterization program by conducting additional inspections under the 

authority of 40 CFR 194.24(h). Under 40 CFR 194.24, EPA has the authority to conduct 

continued compliance inspections to verify that the site continues to use only the approved waste 

characterization processes to characterize the waste and remains in compliance with all the 

regulatory requirements. Based on the adequacies of the waste characterization processes 

demonstrated during the baseline inspection, including all conditions and limitations, EPA 

specified which subsequent waste characterization program changes or modifications must 

undergo further EPA inspection or approval under 40 CFR 194.24. This was accomplished by 

assigning a tier level to each aspect of the SRS-CCP’s characterization program. T1 activities 

have more stringent reporting requirements and require that DOE notify EPA, and that EPA 

provide approval prior to implementation. The rule under which baseline inspections are 

conducted can be found in the Federal Register (Vol. 69, No. 136, pages 42571–42583 of July 

16, 2004). 

3.0 PURPOSE OF THIS REPORT 

This report presents the results of EPA’s evaluation of a T1 change approving the extension of 

the BSGS aspect of the NABC calibration range for use in assaying CH TRU wastes at SRS. 

This report documents the basis for EPA’s approval decision and explains the results of the 

technical evaluation of the system, including any limitations. 

EPA’s approval decision regarding the SRS-CCP NABC calibration range extension has been 

conveyed to DOE separately by letter. As discussed previously, EPA will also announce the 

decision on its web site at www.epa.gov/radiation/WIPP, in accordance with 

40 CFR 194.8(b)(3). 

The DOE documents that EPA reviewed for this evaluation are cited in several places in the 

report. Any of these documents can be requested from: 
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Carlsbad Field Office 

Manager, National TRU Program 

US Department of Energy 

PO Box 3090 

Carlsbad NM 88221-3090 

4.0 SCOPE OF REVIEW 

The NABC is located at SRS, E Area, Building 643-43E, and is operated by SRS-CCP. It is a 

bimodal system consisting of the BSGS gamma detection mode and the BNAS neutron detection 

mode. The NABC is configured for CH TRU wastes in three container types (geometries): 

55-gallon (208-liter) drums; standard waste boxes (SWBs); and standard large boxes (SLB-2s). 

During this T1 evaluation, EPA assessed the BSGS aspect of the NABC with respect to 

extending the calibration range to 7.18 grams of 238Pu utilizing 20-minute assay time. This 

calibration range extension is only applicable to 55-gallon drums and SWBs. 

5.0 T1 EVALUATION PERSONNEL 

All personnel involved in this T1 evaluation are shown in Table 1, listed with their professional 

affiliation and function during the evaluation. 

Table 2. T1 Evaluation Personnel 

Personnel Name Affiliation TI Evaluation Function 

Ed Feltcorn US EPA EPA Lead Inspector 

Patrick Kelly SC&A/EPA EPA Technical Evaluator 

Rose Gogliotti SC&A/EPA EPA Technical Evaluator 

6.0 EVALUATION OF THE NABC 

EPA evaluated the documentation that had been prepared to support the approval of the 

calibration range change to the BSGS aspect of the NABC system that will be used to 

characterize CH TRU wastes at SRS-CCP. As part of the review, EPA assessed the technical 

adequacy of SRS-CCP documents to support the BSGS aspect of the NABC’s operation for the 

55-gallon drum and SWB container configurations with the extended calibration range. 

The following documents were examined to assess the BSGS aspect of the NABC: 

• Nondestructive Assay Box Counter: Calibration Confirmation Report for the Gamma 

Modality Utilizing 20-Minute Count Assay Time, CCP-SRS-SRBC003, Revision 2, 

May 4, 2010 

• Waste Characterization Report: Tier 1 Change: Evaluation of the Gamma and Passive 

Neutron Operational modes of the Non Destructive Assay Box Counter for the 

Nondestructive Assay Box Counter (NABC) at the Central Characterization Project 

(CCP) at Savannah River Site (SRS), March 24–26, 2009 
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The NABC integrates two detection modes, gamma and neutron, the BSGS and the BNAS, 

respectively. It has a moving trolley, which travels on rails past two gamma counting stations, 

one for passive counting and one for transmission counting. The passive aspect is accomplished 

with a high-resolution gamma-ray counter that incorporates both density (multi-curve) and 

transmission-based matrix corrections, and uses Multi Group Analysis (MGA), Multi Group 

Analysis-Uranium (MGA-U), and FRAM1 software for plutonium (Pu) and uranium (U) isotopic 

determination. The BSGS consists of four high purity germanium (HPGe) detectors mounted on 

two opposite towers, with two detectors per tower each at the same vertical distance (height) 

from the floor. The BNAS consists of a high efficiency passive neutron counter with both 

coincidence and multiplicity analysis capabilities, including an Add-A-Source (AAS) option for 

matrix corrections. The separate gamma and passive neutron operational components of the 

NABC are equivalent to several NDA systems that EPA has evaluated and approved for CH 

TRU assays at other CCP sites, e.g., Idaho National Laboratory and Los Alamos National 

Laboratory. Radionuclide data for waste containers are derived in one of three ways: quantitative 

values from the BSGS alone; isotopic gamma values from the BSGS that are applied to BNAS 

neutron values; or acceptable knowledge (AK)-based isotopics applied to BNAS neutron values. 

The NABC quantifies specific radionuclides in all three container types. By design, the NABC 

quantifies Pu and other WIPP-tracked and TRU radionuclides, such as 238Pu, 239Pu, 240Pu, 233U, 

235U, 238U, 237Np, 241Am, 243Am, and 137Cs, using a combination of gamma and neutron data. 

Other radionuclides that cannot be quantified directly (234U, 90Sr, and 242Pu) are determined using 

AK, scaling factors, and/or correlation techniques. The design and operational range of the 

gamma and neutron modes are evaluated separately below. 

BSGS Design

This T1 change has no impact on the design of the BSGS. Further information on its design can 

be found in the initial EPA approval of the NABC, see EPA Docket No. A-98-49; II-A4-114. 

BSGS Range

The operational range of the BSGS is stated as the system’s lower limit of detection (LLD) to 

305 grams for 239Pu and the LLD to 7.18 grams for 238Pu in terms of (mass) activity using a 

20-minute assay time. This is a change to the previously approved range of the LLD to 204 

grams for 239Pu and the LLD to 0.44 grams for 238Pu. For density-based efficiency, an 

operational range of 0.02 g/cm3 to 1.62 g/cm3 was established, as summarized in CCP-SRSSRBC003, which was unchanged by the proposed range extension. Canberra Report No. 40945 

describes the details of the BSGS calibration that was performed using mixed gamma sources 

and the system’s operational range was determined by measurements of weapons grade (WG) 

and heat source (HS) Pu standards, as described in CCP-SRS-SRBC003. For WG Pu, 239Pu 

sources were assayed over a range of approximately 1 gram to 305 grams 239Pu to produce the 

stated operational range. For HS Pu, the operational range is the system LLD to 40 grams 238Pu. 

Note that operational or calibrated ranges may be stated in a variety of terms, i.e., WG Pu, 239Pu, 

 

1

 FRAM is an initialization for a gamma identification and quantification program that is called Fixed-Energy 

Response Function Analysis with Multiple Efficiencies. Both MGA and FRAM are available to the SRS-CCP 

personnel who perform data review and approval. 
4 

HS Pu, 238Pu or total Pu, all of which are interchangeable with the appropriate numerical 

adjustment for isotopics. 

BNAS Design and Operational Range

The BNAS consists of 320 3He proportional tubes in a polyethylene liner of the assay enclosure 

(inner chamber dimensions are 81 inches wide by 120 inches long by 79 inches tall). The 

operational range of the BNAS is stated as the system’s LLD to 305 g of 239Pu for WG Pu and 

the LLD to 40 g for 238Pu, as summarized in MCS-SRS-NDA-0810, Revision 2. The BNAS 

component of the NABC is unaffected by the T1 change and further information on its design 

and operating range can be found in CCP-SRS-SRBC003. 

BSGS Calibration

The gamma calibrations were performed at Canberra’s facility in Meriden, Connecticut, for all 

three geometries. The NABC was also calibrated for the Ten-Drum Overpack (TDOP) geometry, 

but that container type is not included in this T1 evaluation. After reviewing the revised 

calibration report, there are no changes to the initial factory calibration for the BSGS. There are 

no technical concerns regarding the adequacy of the calibration of the BSGS aspect of the NABC 

and its supporting documentation.

BNAS Calibration

 

Calibration of the BNAS was performed at the Canberra facility in Meriden, Connecticut, by 

determining Add-a-Source (AAS) calibration parameters and other system characteristics, 

including high-voltage, counting efficiency, die-away time, gate fractions, and dead-time 

parameters. This module of the NABC is unaffected by the T1 change and further information on 

the BNAS calibration can be found in CCP-SRS-SRBC001, see EPA Docket No. A-98-49; IIA4-114. 

BSGS Calibration Confirmation

To comply with requirements established in DOE/WIPP-02-3122 Appendix A-1 Section A.3, 

calibration confirmation measurements must be preformed after each calibration or recalibration. The confirmation must meet the following criteria: 

• Replicate measurements must be made with a non-interfering matrix 

• Containers must be of the same nominal size as waste containers to be assayed 

• Number of replicates must be documented and technically justified 

• Items used for calibration confirmation must contain nationally recognized standards, or 

standards derived from nationally recognized standards, whose contents span the range of 

use 

• Standards used to establish accuracy shall not be the same as those used for calibration 

• Accuracy (%R of the content of record) shall not exceed ±30% 

• Precision (%RSD) must meet criteria listed in Table A 3.2, DOE/WIPP-02-3122 

Appendix A 
5 

Confirmation measurements were initially performed for three WG plutonium loadings, and one 

HS Pu loading, in each of the two container types, 55-gallon drums and SWBs. The WG and HS 

Pu mass loadings for each container type used in calibration confirmation are listed in Table 2. 

Table 3. Plutonium Mass Loading Contents for Container Type 

55-Gallon Drum SWB 

WG Pu 

1.001 g 1.001 g 

25.375 g 25.375 g 

217.589 g 217.589 g 

HS Pu 0.538 g 0.528 g 

Calibration confirmation measurements were performed using different sources from those used 

for system’s initial calibration. These sources were assayed in accordance with CCP-TP-189, 

Revision 1, and the resulting data were evaluated against the criteria in DOE/WIPP-02-3122, 

Appendix A, Table 3.2, as appropriate. The results are provided in CCP-SRS-SRBC003. The 

mass loadings for the initial 20-minute count time calibration confirmation measurements were 

determined by combining standards available through SRS to produce a range of values. Each 

55-gallon drum was continuously rotated during the 1200-second confirmation measurement. 

The WG and HS Pu configurations were each assayed six times to provide sufficient data for 

statistical analysis. All assays passed the ±30%R criteria for accuracy and the %RSD criteria for 

precision (14% for six repetitions). The calibration confirmation measurement results for the 20-

minute assays are documented in CCP-SRS-SRBC003. There are no concerns regarding the 

technical adequacy or documentation of the calibration confirmation for the BSGS aspect of the 

NABC. 

BNAS Calibration Confirmation

The BNAS operating range was unaffected by this T1 change. Calibration confirmation for 

BNAS was performed during the initial approval of the NABC at SRS, see EPA Docket No. A98-49; II-A4-114. 

BSGS TMU Determination

The determination of the gamma component of the TMU for the NABC is addressed in 

Savannah River Gamma Box Counter Calibration Report Alternatives for Non-Destructive 

Assay (NDA) of Large Containers to Allow Shipping in TRUPACT III without Resizing and/or 

Repackaging, Canberra Document No. 40945. The BSGS TMU is unaffected by this T1 change. 

BNAS TMU Determination

The determination of the BNAS aspect of TMU for the NABC is addressed in Savannah River 

Box Neutron Assay System Total Measurement Uncertainty Report for Alternatives for Non 

Destructive Assay (NDA) of Large Containers to Allow Shipping in TRUPACT III without 

Resizing and/or Repackaging, Canberra Document No. 41309. The BNAS TMU was not 

affected by this T1 change. 
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BSGS LLD Determination

The 55-gallon drum filled with the Homasote matrix and no radioactive sources was assayed 

three times using the new 20-minute assay time and standard operating protocols, as documented 

in CCP-TP-189, Revision 1. For each assay, NDA 2000 software was used to calculate the LLDs 

and minimum detectable activities (MDAs) for the ten WIPP tracked radionuclides plus 235U. 

Each LLD value was corrected for the matrix (net weight) to determine the minimum detectable 

concentration (MDC) for each radionuclide. All results were acceptable and meet the CH-WAC 

TRU/non-TRU waste discrimination criterion of 100 nCi/g. Results are documented in Appendix 

E-1 of the calibration report. The SWB filled with a cardboard matrix and no radioactive sources 

was assayed three times using the standard operating protocols, as documented in CCP-TP-189, 

Revision 1. Each LLD value was corrected for the matrix (net weight) and MDC values were 

derived. All results were acceptable and meet the CH-WAC TRU/Non-TRU discrimination 

criterion of 100 nCi/g. Results are documented in Appendix E-1 of the calibration report. 

Reporting thresholds are required for the radionuclides that are not measured directly; 

specifically 242Pu, 234U and 90Sr. The 90Sr reporting threshold is computed from the reported 

137Cs LLD using an activity ratio determined from SRS-CCP AK NDA memoranda. For SRS 

waste, the activity ratio is taken as 1 unless specified differently in appropriate AK 

documentation. 234U is derived from the measured 235U and 238U values or lack thereof by 

algorithm. Since this is not a function of scaling an individual radionuclide, SRS-CCP personnel 

stated that it is not technically feasible to derive a reporting threshold for 234U. All gamma-based 

LLDs and reporting thresholds are documented in CCP-SRS-SRBC001. There are no concerns 

regarding the determination and/or documentation of gamma-based LLDs or reporting thresholds 

for the BSGS aspect of the NABC. 

BNAS LLD Determination 

Nominal BNAS LLDs were determined from three replicate counts of three container/matrix 

configurations without radioactive sources, using the Performance Demonstration Program 

(PDP2) Combustibles 55-gallon drum and cardboard matrices for the SWB. The BNAS LLD that 

was determined during the initial NABC approval was not affected by this T1 change. 

Additional information regarding the BNAS LLD determination is documented in CCP-SRSSRBC001, see EPA Docket No. A-98-49; II-A4-114. 

7.0 SUMMARY OF RESULTS AND CONCLUSIONS 

 There were no findings or concerns regarding the performance and documentation of 

performance testing for the gamma operational modes for the NABC resulting from this T1 

evaluation. 

 

2

 PDP sources are constructed by Los Alamos National Laboratory for use in the CBFO-sponsored NDA 

Performance Demonstration Program. 
7 

8.0 APPROVAL 

During this T1 evaluation, the EPA evaluated the BSGS aspect of the NABC calibration range of 

238Pu and reduced 20-minute count time. Based on this T1 evaluation, the NABC is approved for 

the extension of the calibration range of the BSGS aspect of the NABC to 7.18 grams of 238Pu 

utilizing a reduced 20-minute assay time. The NABC is approved to assaying CH TRU wastes in 

the gamma and neutron detection modes for two measurement configurations—55-gallon drum 

and SWBs—consistent with the limitations described in this report.