DOCKET NO: A-98-49; II-A4-114

WASTE CHARACTERIZATION REPORT

TIER 1 CHANGE:

EVALUATION OF THE GAMMA AND PASSIVE NEUTRON OPERATI ONAL MODES

OF THE NON DESTRUCTIVE ASSAY BOX COUNTER FOR THE NONDESTRUCTIVE ASSAY BOX COUNTER (NABC) AT THE CENT RAL CHARACTERIZATION PROJECT (CCP) AT SAVANNAH RIVER SI TE (SRS)



### March 24–26, 2009

U.S. Environmental Protection Agency

Office of Radiation and Indoor Air Center for Waste Management and Regulations 1200 Pennsylvania Avenue, NW Washington, DC 20460

August 2009i TABLE OF CONTENTS

Section Page

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

................................................... ........................... 1

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

................................................... ............................ 1

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

................................................... ............................ 2

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

................................................... ............................... 2

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

................................................... .......................... 2

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

................................................... ......................... 3

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

................................................... ............... 20

8.0 Approval.......................................

................................................... .................................. 20

LIST OF ATTACHMENTS

Attachment A: EPA Inspection Issue Tracking Form N o. SRS-CCP-NDA-T1-NABC-06-

001CR Attachment B.1: Replicate Testing Data for Containe r SR510464 – 55-gallon drum Attachment B.2: Replicate Testing Results for Cont ainer SR510464 – 55-gallon drum Attachment B.3: Replicate Testing Data for Containe r SR61125902 – SLB2 Attachment B.4: Replicate Testing Results for Conta iner SR61125902 – SLB2

LIST OF TABLES

Table 1. T1 Evaluation Personnel ...................

................................................... ......................... 3

Table 2. BNAS Calibration Confirmation Results for 55-gallon Drum.................................... 1 1

Table 3. BNAS Calibration Confirmation Results for SWB ................................................ .... 12

Table 4. BNAS Calibration Confirmation Results for SLB-2 .............................................. .... 13

Table 5. 252 Cf Values and 238 Pu Equivalences .................................... ...................................... 13 Table 6. Assay Results for 238 Pu Equivalent 252 Cf Standards for 55-gallon Drum................... 1 4 Table 7. Assay Results for 238 Pu Equivalent 252 Cf Standards for SWB............................... ..... 14 Table 8. Assay Results for 238 Pu Equivalent 252 Cf Standards for SLB-2............................. ..... 15

Table 9. Contributors to TMU for BSGS..............

................................................... ................. 16 Table 10. Contributors to TMU for BNAS for Typical Waste Matrices .................................... 1 71

1.0 EXECUTIVE SUMMARY

In accordance with 40 CFR 194.8(b), the U.S. Enviro nmental 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 co ntact-handled (CH) transuranic (TRU) wastes at the U.S. Department of Energy (DOE) Savan nah 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 characterizat ion 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 non destructive assay (NDA) systems, the IQ3 gamma system for assaying soil/gravel and debris wa ste, and the Imaging Passive Active Neutron (IPAN) system for assaying debris waste.

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 referre d 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 evalu ation of the NABC at SRS, during which an issue relating to the operational range for 238 Pu was identified. In late July EPA received a revised calibration report from SRS-CCP that docume nted additional performance testing, which more thoroughly characterized the 238 Pu range and technical justification for the correl ation of

252 Cf and 238 Pu neutrons. EPA reviewed this document and found it adequately addressed the

concern. Based on EPA’s evaluation of all SRS-CCP activities relative to the NABC, EPA approves the NABC for assaying CH TRU waste, consis tent with the limitations discussed in this

report.

This report serves as EPA’s public notification of the results of the proposed T1 change and its evaluation. This information will be provided thro ugh the EPA web site and by sending e-mails to the WIPPNEWS list, in accordance with 40 CFR 194 .8(b)(3). This approval does not make any changes to the tiering table provided with the baseline approval.

2.0 PURPOSE OF INSPECTIONS

Any changes to the waste characterization activitie s 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 th e 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 basel ine 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 adequate ly characterize TRU wastes and comply with the regulatory requirements imposed on TRU wastes d estined for disposal at the WIPP. An EPA inspection team conducts an on-site inspection to v erify that the site’s system of controls is technically adequate and properly implemented.2

Following the EPA’s approval of waste characterizat ion processes evaluated during the baseline inspection, EPA is authorized to evaluate and appro ve, if necessary, changes to the site’s approved waste characterization program by conducti ng 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 wast e and remains in compliance with all the regulatory requirements. Based on the adequacies o f the waste characterization processes demonstrated during the baseline inspection, includ ing all conditions and limitations, EPA specified which subsequent waste characterization p rogram 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-CC P’s characterization program. T1 activities have more stringent reporting requirements and requ ire 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 evaluatio n of a T1 change approving the NABC for use in assaying CH TRU wastes at SRS. This report docu ments the basis for EPA’s approval decision and explains the results of the technical evaluation of the system, including its range

limitation.

EPA’s approval decision regarding the SRS-CCP NABC h as 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).

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 a BSGS gamma detection mode and a 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). 1
Throughout this report, the term **all three container types** refers to these three container types. During this T1 evaluation, EPA assessed the NABC wi th respect to its ability to identify and quantify the activities of the 10 WIPP-tracked radi onuclides and their uncertainty, determine a technically appropriate lower limit of detection (L LD), and provide technical support for the system’s Total Measurement Uncertainty (TMU), as ap propriate. These aspects were assessed for the gamma and neutron detection modes for all t hree container types.

5.0 T1 EVALUATION PERSONNEL

All personnel involved in this T1 evaluation are sh own in Table 1, listed with their professional affiliation and function during the onsite evaluati on at SRS.

1 The NABC was also calibrated for the Ten-Drum Over pack (TDOP) geometry, but that container type is

not included in this T1 evaluation.3 Table 1. T1 Evaluation Personnel

Personnel Name Affiliation TI Evaluation Function Ed Feltcorn US EPA EPA Lead Inspector Patrick Kelly SC&A/EPA EPA Technical Consultant

Bob Ceo MCS NDA Senior Scientist

Joe Wachter MCS MCS Technical Director Dan Remington MCS NDA Senior Scientist Todd Shepley MCS NDA Lead Operator Steve Muse CCP NDA Quality Engineer Charlie Riggs CTAC CBFO Technical Support

Jim Oliver CTAC CBFO Surveillance Lead Joe Harvill WTS NDA Support Christa Chavez WTS NDA Support James Mobley CCP CCP VPM Tim Carlton MCS NDA Operations Wade Morris MCS BNAS Operations Kathy Johns-Hughes SWMF * Bert Crapse DOE-SR * Mark Pearcy CCP *

J.D. Chion SRNS *

Lee Fox SRNS *

Steve Goff DOE-SR * *These individuals were present at the entrance and /or exit meetings on March 24 or 26, 2009. These individuals were not actively involved in the T1 evaluation, and are listed for completeness.

6.0 EVALUATION OF THE NABC

EPA evaluated the documentation that had been prepa red to support the approval of the NABC system that will be used to characterize CH TRU was tes at SRS-CCP. The evaluation took place on March 24–26, 2009, in the Canberra Offices adjac ent to the SRS site in Aiken, South

Carolina. The EPA evaluation team observed the NABC on site operating in both the gamma and neutron modes for a 55-gallon drum and an SLB-2 . The evaluation consisted of reviewing technical documents prior to the onsite portion in March, followed by an onsite inspection of the NABC. As part of the review, EPA evaluated the foll owing elements of the NABC system:

• Capability of the hardware and software to perform the required analyses for both gamma

and neutron measurement modes for the three measure ment configurations, including identifying and quantifying the activities of the 1 0 WIPP-tracked radionuclides, i.e.,

241 Am, 137 Cs, 238 Pu, 239 Pu, 240 Pu, 242 Pu, 90 Sr, 233 U, 234 U, and 238 U, and the associated uncertainty of each

• Technical adequacy of the SRS-CCP documents and pro cedures to support the NABC’s operation in both measurement modes for the three m easurement configurations

• Knowledge and understanding of the personnel involv ed in the SRS-CCP NDA program4

The following documents were examined to assess the NABC:

• Savannah River Gamma Box Counter Calibration ReportAlternatives for NonDestructive Assay (NDA) of Large Containers to Allo w Shipping in TRUPACT III without Resizing and/or Repackaging, Canberra Docum ent No. 40945, Revision A

• Savannah River Box Gamma Box Counter Total Measurem ent Uncertainty Report for Alternatives for Non-Destructive Assay (NDA) of Lar ge Containers to Allow Shipping in TRUPACT III without Resizing and/or Repackaging, Ca nberra Document No. 40972,

Revision A

• Savannah River Box Neutron Assay System Total Measu rement Uncertainty Report for Alternatives for Non-Destructive Assay (NDA) of Lar ge Containers to Allow Shipping in TRUPACT III without Resizing and/or Repackaging, Ca nberra Document No. 41309,

Revision A

• Nondestructive Assay Box Counter: Calibration Valid ation and Confirmation Report for the Gamma Modality, CCP-SRS-SRBC001, Revision 0, Oc tober 23, 2008 and Revision 1, April 2, 2009

• Neutron Box Counter Calibration Report for Alternati ves for Non-Destructive Assay (NDA) of Large Containers to Allow Shipping in TRUPA CT III Without Resizing and/or Repackaging

, Canberra Document No. A40973, Revision 4, 2007

• Box Neutron Assay System, Factory Calibration and T otal Measurement Uncertainty: Neutron Box Counter Calibration Report for Alternati ves for Non-Destructive Assay (NDA) of Large Containers to Allow Shipping in TRUPA CT III without Resizing and/or Repackaging, A40973, Revision 04

• Nondestructive Assay Box Counter: Calibration Valid ation and Confirmation Report for the Neutron Assay Modality, CCP-SRS-SRBC002, Revisio n 0, December 19, 2008

• Phase II Acceptance Test Procedure Gamma and Neutro n Box Counting System for DOE/Savannah River, ACK# 0403973, Revision 7, Septe mber 27, 2007

• Nondestructive Assay Box Counter: Calibration Valid ation and Confirmation Report For the Neutron Modality, CCP-SRS-SRBC002, Revision 1, J une 4, 2009

• Nondestructive Assay Box Counter: Calibration Valid ation and Confirmation Report For the Neutron Modality, CCP-SRS-SRBC002, Revision 2, J uly 29, 2009

• Calibration Verification of the SRS-BSGS System Due to HPGe Detector Energy Gain Shift, MCS-SRS-BSGS-09-001, Revision 1, March 12, 2 009

• CCP-TP-189, CCP Box Segmented Gamma System (BSGS) O perating Procedure, Revision 0, April 30, 2008

• CCP-TP-190, CCP Box Segmented Gamma System Calibrat ion, Revision 1, August 29,

2008

• CCP-TP-191, CCP Box Neutron Assay System (BNAS) Oper ating Procedure, Revision 0, April 30, 20085

• CCP-TP-192, CCP Box Neutron Assay System Calibratio n Procedure, Revision 1, August 27, 2008

• CCP-TP-193, CCP Data Reviewing, Validating, and Rep orting Procedure for the Nondestructive Assay Box Counter, Revision 1, August 21, 2008

• NABC BDR SRLBC001: SLB-2 Nos. SR60685706, SR6112590 2 and FBLBOX3702

• NABC BDR SRLBC002: SWB Nos. SWB0114, SWB0113 and SWB 0058

• NABC BDR SRLBC003: 55-gallon drum Nos. SR502014 and SR510464

• NABC BDR SRLBC004: 55-gallon drum No. SR519002

• SRS List of Qualified Individuals (LOQI), March 10, 2009, 4:21:10 PM, including NDA/BSGS/BNAS, NDA SGS, NDE, Headspace Gas (Drum Ven ting and Summa Sampling), Flammable Gas for Transportation and Tra nsportation Personnel for SRS Only

• CBFO NTP Memorandum: Approval Status Notification – Supplementary Box Cycle B8B of the Nondestructive Assay Performance Demonst ration Program, March 27, 2009

The EPA inspection team assessed the technical elem ents of the NABC that are discussed below.

(1) The design and operational range of the NABC were a ssessed for both gamma and neutron assay modes, and were found to be adequate following modification of the 238 Pu range for the BNAS.

The NABC integrates two detection modes, gamma and n eutron, called the BSGS and the BNAS, respectively. It has a moving trolley, which travels on rails past two counting 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 correct ions, and uses Multi Group Analysis (MGA) Multi Group Analysis-Uranium (MGA-U), and FRAM 2 software for plutonium (Pu) and uranium (U) isotopic determination. The BNAS consis ts of a high efficiency passive neutron counter with both coincidence and multiplicity anal ysis 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 ND A 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 w aste containers are derived in one of three ways: quantitative values from the BSGS alone; iso topic gamma values from the BSGS that are applied to BNAS neutron values; or acceptable knowl edge (AK)-based isotopics applied to BNAS neutron values. The NABC quantifies specified radionuclides in all three container types. By design, the NABC quantifies Pu and other WIPP-tr acked and TRU radionuclides, such as

238 Pu, 239 Pu, 240 Pu, 233 U, 235 U, 238 U, 237 Np, 241 Am, 243 Am, and 137 Cs, using a combination of gamma and neutron data. Other radionuclides that c annot be quantified directly ( 234 U, 90 Sr, and

2 FRAM is an initialization for a gamma identificati on and quantification program that is called FixedEnergy Response Function Analysis with Multiple Eff iciencies. Both MGA and FRAM are available to the SRSCCP personnel who perform data review and approval.6

242 Pu) are determined using AK, scaling factors, and/o r correlation techniques using an adequate process. The design and operational range of the g amma and neutron modes are evaluated separately below.

BSGS Design

The BSGS consists of four high purity germanium (HP Ge) detectors mounted on two opposite towers, with two detectors per tower each at the sa me vertical distance (height) from the floor. The detectors are Broad Energy Germanium (BEGe) det ectors with relative efficiencies of 18.3%, 16.7%, 19.8%, and 19.3% for detector Nos. 1– 4, respectively, and all are fitted with 5.08 cm thick cylindrical lead shielding. The posi tions of the BEGe detectors relative to the axis of container movement through the NABC must be set manually for each of the three container types. The technical specifications of the BEGe de tectors are documented in CCP-SRSSRBC001. Spectra from the BEGe detectors are used to determine the Pu isotopic content of waste containers directly, or using MGA, MGAU, or F RAM for isotopic determination. If isotopic data are not available, default isotopics as defined by AK may be used.

The BSGS also has a transmission assembly consistin g of two 60 Co sources (~250 mCi each) mounted in lead shields on one tower, one on top of the other, approximately 1.5 meters apart. Directly opposite the sources (on the other side of the trolley holding the waste containers) are two thallium-drifted sodium iodide [NaI(Tl)] gamma d etectors. During assay, a waste container

is located between the 60 Co sources and the NaI(Tl) detectors, such that the sources shine through the sample and allow the effects of the mat rix on the source intensity to be quantified.

Each 60 Co source is housed in a shield containing a tungst en shutter that opens and closes to permit it to “shine” directly at a NaI(Tl) detector when open, or be shielded by the shutters in the closed position. The shutters can be manipulated t o optimize the source intensity for different

container sizes and matrix densities. Like the BEG e detectors, the transmission sources and NaI(Tl) detectors must be positioned manually for ea ch of the three container geometries, i.e., at different heights, depending on the container size being assayed. The transmission

measurements are relative determinations that are u sed for matrix corrections based on established regions of interest (ROIs) for the 1,17 3 and 1,332 keV peaks of 60 Co. The system is shown in Canberra Document No. 40945, Figures 1, 2, and 3. Canberra’s NDA 2000 software is used for acquiring, processing, and managing all ga mma data. There are additional components that control movement of the container (trolley) an d transmission source shutters.

BSGS Range

The operational range of the BSGS is stated as the system’s LLD [see Item (6), below] to 204 grams for 239 Pu and the LLD to 0.44 grams for 238 Pu in terms of (mass) activity. For density-based efficiency, a range of 0.02 g/cm 3 to 1.62 g/cm 3 was established, as summarized in CCP-SRS-SRBC001. Canberra Report No. 40945 describ es the details of the BSGS calibration that was performed using mixed gamma sources [see I tem (2), below], and the system’s operational range is determined by measurements of weapons grade (WG) and heat source (HS) Pu standards, as described in CCP-SRS-SRBC001. For WG Pu, 239 Pu sources were assayed over a range of <1 gram to approximately 204 grams 239 Pu to produce the stated operational range. For HS Pu, the operational range is the system LLD to 40 grams 238 Pu.7

BNAS Design

The BNAS consists of 320 3 He proportional tubes in a polyethylene liner of th e assay enclosure (inner chamber dimensions are 81 inches wide by 120 inches long by 79 inches tall). The detector tube outputs are divided among 80 counting channels. This module of the NABC

determines the 240 Pu effective mass ( 240 Pu EFF ) of the item assayed. The original BNAS calibration was performed at the Canberra factory i n Meriden, Connecticut, using 252 Cf standards to determine the system’s basic neutron parameters. Once these were established, the AAS technique was used to correct for matrix effects on neutrons emitted within the waste container. The AAS mechanism accurately positions a 252 Cf source at different points in a tube located in the floor of the assay enclosure and, following a p reset time, retracts it into a shielded storage

box external to the enclosure. To calibrate the AA S, a small 252 Cf source (about 10 5 n/s) is introduced into the assay cavity with no container in the counter to provide a reference count rate. The count rate measurement is repeated with containers loaded with different matrices and the observed assay values both with and without a c ontainer are compared. The AAS matrix correction treats the waste matrix as a perturbatio n on the response from an empty container in the counter and provides a matrix-specific numerica l correction. The 252 Cf source is used to perform the AAS correction, and also serves as the reference standard for the system’s daily performance check. The result of the passive neutr on assay is a value expressed in terms of

240 Pu EFF for any of the three container types.

BNAS Operational Range

The operational range of the BNAS is stated as the system’s LLD [see Item (6), below] to 305 g

of 239 Pu for WG Pu and the LLD to 40 g for 238 Pu, as summarized in MCS-SRS-NDA-0810, Revision 2. Canberra Report No. A40973 describes t he details of the BNAS calibration that was performed using 252 Cf sources [see Item (2), below], and the system’s operational range is determined by measurements of WG and HS Pu standard s in conjunction with 252 Cf standards to

serve as 238 Pu surrogates for neutron emission, as described in MCS-SRS-NDA-0810, Revision 2, Attachment 2.

(2) The NABC’S calibrations for the gamma and neutron m odes were evaluated and were found to be adequate for all three container geomet ries.

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 i n this T1 evaluation. Mixed gamma sources supplied by North American Scientific Inc., were us ed, and the sources were of the appropriate pedigree. The gamma-emitting radionuclides include d 241 Am, 57 Co, 133 Ba, 137 Cs and 60 Co.

Three NBL CRM Pu standards were used to demonstrate successful MGA execution, and five NBS SRM 969 type U standards were used to demonstrat e successful execution of MGAU. Certificates for all mixed gamma, Pu, and U standar ds were provided and were acceptable.8

Q2-type matrix drums for the 55-gallon container si ze included the following five materials: empty container, ρ = 0.00 g/cm 3 ; foam, ρ = 0.045 g/cm 3 ; Homasote, ρ = 0.473 g/cm 3 ; particle board, ρ = 0.725 g/cm 3 ; and sand, ρ = 1.52 g/cm 3 . The matrices for the SWB and SLB-2 containers were composed of a variety of materials in varying percentages, as follows:

• 100% cardboard, ρ = 0.152 g/cm 3

• 42.55% plywood and 57.45% cardboard, ρ = 0.297 g/cm 3

• 32.65% poly, 48.98 % plywood and 18.73% cardboard, ρ = 0.580 g/cm 3

• 80.85% poly and 19.15% plywood, ρ = 0.780 g/cm 3

• Low density PE foam, ρ = 0.0027 g/cm 3

• High density PE foam, ρ = 0.64 g/cm 3

• Cardboard, ρ = 0.152 g/cm 3

• Plywood, ρ = 0.565 g/cm 3

The matrix efficiencies for the SWBs and SLB-2s wer e derived based on In-Situ Object Counting System (ISOCS) models over a range of ener gies from 59.5 keV to 1,332.5 keV and were compared to measured values for 55-gallon drum s, SWBs and SLB-2s as shown in Canberra Document No. 40945, Tables 9 and 10. Tran smission calibrations were performed using the low (shutter partially closed) and high ( shutter open) modes by measuring through a moderate density material.

BNAS Calibration

Calibration of the BNAS was performed at the Canber ra facility in Meriden, Connecticut, by determining Add-A-Source (AAS) calibration paramete rs and other system characteristics, including high voltage, counting efficiency, die-aw ay time, gate fractions, and dead-time parameters. These were determined for all three ge ometries. AAS calibration matrix correction factors were determined for each container type usi ng 252 Cf sources at a variety of (decaycorrected) neutron emission rates from 2.147E+03 to 2.054E+06 n/s, as listed in Canberra Report No. A40973, Appendix A, Table 1. Certificates for a ll 252 Cf standards were provided and were acceptable with one exception. The certification s heet for 252 Cf source No. A3-468 was not legible with respect to its stated activity in micr ocuries ( μ Ci), a fundamentally important aspect; the correct value activity of the source is 53.40 μ Ci as of January 1, 2002. This was discussed in the onsite evaluation at SRS in March of this year, but it was not corrected in Revision 1 of the calibration report. However, Revision 2 contained a legible copy of the certification sheet.

Q2-type matrix drums for the 55-gallon container si ze included the following materials and

densities:

• Polyethylene, ρ = 0.26 g/cm 3 and 0.73 g/cm 3

• Cellulose, ρ = 0.35 g/cm 3 and 0.66 g/cm 3

• Borosillicate glass, ρ = 0.26 g/cm 3 5 and 0.44 g/cm 3

• Lead, ρ = 2.0 g/cm 3

• Softboard, ρ = 0.04 g/cm 3

• Particle board, ρ = 0.72 g/cm 39

• 65 kg PolyVerm, ρ = 0.31 g/cm 3

• 29 kg PolyVerm, ρ = 0.13 g/cm 3

• 100% Poly, ρ = 0.59 g/cm 3

The matrices used in the SWB and SLB-2 container ge ometries for the neutron calibration and gamma calibration are the same as shown above. Acc eptable ranges of AAS correction factors were established for the three container types, and expert review is required for all assay values outside of these ranges, as shown in MCS-SRS-NDA-081 0, page 3.

After review of the revised the calibration report there are no technical concerns regarding the adequacy of the calibration of the gamma and neutro n modes of the NABC and its supporting

documentation.

(3) Calibration confirmation and verification of the NA BC had been performed and documented as required for the gamma and neutron mo des and for all three measurement configurations.

BSGS Calibration Confirmation

The approach taken by Canberra included calibration validation measurements and calibration confirmation measurements, which is more than what is required by DOE/WIPP-02-3122, Appendix A. EPA’s perspective is that there must b e technically credible objective evidence that the calibration has been verified, and CCP-SRSR-SRB C001 provides this for all three container types. What Canberra calls a **calibration validation** amounts to a demonstration of the system’s operational range in the efficiency-based and trans mission-corrected gamma modes. This was performed using the same set of NIST traceable mixe d gamma line sources that were used for the initial calibration in Connecticut, with the approp riate decay correction. Assays were performed in a cardboard or particleboard matrix in the effic iency-based and transmission-corrected modes. Precision and accuracy were demonstrated by determi ning the relative standard deviation (%RSD) and percent recovery (%R) of the average of three assays. All %RSD values were within ± 6.6% (based on three replicate assays) for all assay configurations for all three

containers. All %R values were within ± 30% for th e 55-gallon drum. The %R values were within ± 30% for the SWB and SLB-2 assays, except f or 241 Am for all assay configurations of the SWB and one assay configuration of the SLB-2. These %R values were considerably higher, e.g., as high as 217%. This was caused by quantify ing 241 Am on the basis of the most intense photon line at 59 keV, instead of using the higher energy lines at 125 keV, 662 keV and

722 keV. The 241 Am source was too weak to provide sufficient counts in the higher energy regions to enable their use in quantification, and the matrix is over corrected, resulting in a 241 Am value that is biased high. For routine assays, SRS -CCP personnel will have to monitor the use of

the 59 keV line. The validation values are shown i n CCP-SRS-SRBC001, Tables 6A and 6B for the 55-gallon drum; Tables 7A through 7D for the SW B; and, Tables 8A through 8D for the

SLB-2.

Calibration confirmation measurements were performe d using different sources from those used for calibration. Specifically, the 55-gallon drum and SWB used WG Pu source loadings of 1.001 g, 25.375 g, and 217.589 g. The SLB-2 source loadings were slightly different at 1.001 g,10

26.180 g, and 217.589 g WG Pu. All three container s used a 0.528 g HS Pu source. These source loadings were assayed in accordance with CCP -TP-189, 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 Tables 12A, 12B, and 12 C. All assays passed the %R criteria for accuracy and the %RSD criteria for precision.

BNAS Calibration Confirmation

The BNAS operating range was verified by assaying W G Pu and HS Pu sources over a range of masses, which consist primarily of 239 Pu and 238 Pu, respectively, because WG Pu and HS Pu

have different 240 Pu EFF values. The calibration and/or operating ranges f or both Pu types begin at the system’s LLD [see Item (6)], and the discussion below focuses on establishing the upper end of the range for each Pu type.

WG Pu (High- 239 Pu) Range : Three nominal 239 Pu loadings of 1 g, 24 g, and 204 g were assayed for each of the three container types; 55-gal Drum, SWB, and SLB-2. The 1 g 239 Pu loading is near the low end of the calibration range, the 24-g 239 Pu loading is in the lower one-third of the calibration range, and the 204 g 239 Pu loading is in the upper one-third of the calibra tion range. The 204 g 239 Pu loading is the maximum quantity practically atta inable using the sources

available to SRS-CCP.

HS Pu (High- 238 Pu) Range : The total 238 Pu content in the three HS Pu sources available to SRSCCP is 0.4316 g. Using that quantity of 238 Pu to establish the upper assay limit would result in a limit of about 0.65 g 238 Pu, assuming that the measured value of 0.4316 g is equivalent to the mid point of the bottom third of the range. Based on t he expectation that waste containers will

contain 238 Pu masses well above 30 g, SRS-CCP wanted to establish a higher calibration limit for the BNAS. Accordingly, a 252 Cf source was used to simulate the neutron output o f a larger 238 Pu source, an approach that is technically acceptable. A CCP-SRS 252 Cf source (Source ID A3-468) had a decay-corrected neutron emission rate equival ent to 27 g 238 Pu, and using the data from this source, SRS-CCP personnel derived an upper cal ibration limit of 40 g for 238 Pu, based on the assumption that the highest measured point is equiv alent to the mid point of the upper third of the range. Using this approach, SRS-CCP derived a calibration range based on two points that were considerably far apart, i.e., 0.65 grams and 2 7 grams. However, the EPA technical specialist determined that these two points were in adequate to sufficiently characterize this operating/calibration range. Accordingly, EPA did not accept the LLD to 40 g operational range

for 238 Pu proposed by SRS-CCP. Following the onsite evalu ation, SRS-CCP obtained additional

252 Cf sources that were assayed as calibration validat ions, as discussed in Item (4), to further populate the 238 Pu calibration curve in response to EPA’s concern. The 0.4316 g 238 Pu assays were acceptable in all three container geometries. EPA ultimately accepted the upper limit of the operating range for 238 Pu as 40 g, as discussed in this report.

Precision and accuracy were demonstrated by determi ning the %RSD and %R of four source loadings: 0.9386 g, 23.7340 g, and 203.6807 g of W G Pu ( 239 Pu); and 0.4316 g HS Pu ( 238 Pu). Each source loading was assayed six times in each o f the three measurement geometries (containers) and the data were evaluated relative t o the appropriate criteria for six replicates in11

DOE/WIPP-02-3122, Appendix A, Table A.4.2. The res ults for each container are summarized

below.

55-gallon Drum : The %RSD values range from 0.2% to 3.5%, and all values are within the limit of 14% for six replicate measurements. The %R valu es range from 80.7% to 110.3%, and all are within the required 70% to 130% range. The 55-gall on results are shown in Table 2.

Table 2. BNAS Calibration Confirmation Results for 55-gallon Drum

Reference Value Assay Measured 240 Pu EFF g Measured 239 Pu g Results 0.9386 g 239 Pu 1 0.0551 0.852 Assay Average: 0.857

2 0.0550 0.851 Standard Deviation: 0.0091 3 0.0556 0.860 Precision (%RSD): 1.1% 4 0.0560 0.866 Accuracy (%R): 91.3%

5 0.0547 0.845

6 0.0561 0.868 23.7340 g 239 Pu 1 1.618 25.0 Assay Average: 25.0

2 1.620 25.0 Standard Deviation: 0.1378 3 1.628 25.1 Precision (%RSD): 0.6% 4 1.596 24.7 Accuracy (%R): 105.1%

5 1.613 24.9

6 1.617 25.0 203.6807 g 239 Pu 1 14.53 225 Assay Average: 225

2 14.49 224 Standard Deviation: 0.5164 3 14.55 225 Precision (%RSD): 0.2% 4 14.54 225 Accuracy (%R): 110.3%

5 14.46 224

6 14.58 225 0.4316 g 238 Pu 1 0.900 0.353 Assay Average: 0.349

2 0.910 0.357 Standard Deviation: 0.0121 3 0.842 0.330 Precision (%RSD): 3.5% 4 0.918 0.360 Accuracy (%R): 80.7%

5 0.902 0.354

6 0.861 0.337

SWB: The precision %RSD values range from 0.47% to 4.0% , and all values are within the limit of 14% for six replicate measurements. The % R values range from 91.6% to 116.4%, and all are within the required 70% to 130% range. The SWB results are shown in Table 3.

SLB-2: The precision %RSD values range from 0.5% to 3.1% , and all values are within the limit of 14% for six replicate measurements. The a ccuracy %R values range from 92.5% to 113.6%, and all are within the required 70% to 130% range. The SLB-2 results are shown in

Table 4.

Calibration confirmation results for all three meas urement geometries were acceptable. There are no issues regarding calibration confirmation of the NABC.12 Table 3. BNAS Calibration Confirmation Results for SWB

Reference Value Assay Measured 240 Pu EFF g Measured 239 Pu g Results 0.8580 g 239 Pu 1 0.0576 0.890 Assay Average: 0.902

2 0.0562 0.867 Standard Deviation: 0.0359 3 0.0560 0.866 Precision (%RSD): 4.0% 4 0.0580 0.896 Accuracy (%R): 105.1%

5 0.0609 0.940

6 0.0615 0.950 24.4627 g 239 Pu 1 1.844 28.5 Assay Average: 28.5

2 1.843 28.5 Standard Deviation: 0.133 3 1.843 28.5 Precision (%RSD): 0.47% 4 1.857 28.7 Accuracy (%R): 116.4%

5 1.842 28.4

6 1.834 28.3 203.6809 g 239 Pu 1 15.23 235 Assay Average: 235

2 15.18 235 Standard Deviation: 1.10 3 15.28 236 Precision (%RSD): 0.47% 4 15.17 235 Accuracy (%R): 115.4%

5 15.10 233

6 15.26 236 0.4316 g 238 Pu 1 1.152 0.451 Assay Average (g): 0.468

2 1.201 0.471 Standard Deviation: 0.169 3 1.169 0.458 Precision (%RSD): 3.6% 4 1.273 0.499 Accuracy (%R): 108.5%

5 1.173 0.460

6 1.199 0.47013 Table 4. BNAS Calibration Confirmation Results for SLB-2

Reference Value Assay Measured 240 Pu EFF g Measured 239 Pu g Results 0.8580 g 239 Pu 1 0.0500 0.772 Assay Average: 0.794

2 0.0499 0.771 Standard Deviation: 0.0229 3 0.0514 0.794 Precision (%RSD): 2.9% 4 0.0533 0.823 Accuracy (%R): 92.5%

5 0.0531 0.820

6 0.0508 0.784 24.4627g 239 Pu 1 1.788 27.6 Assay Average: 27.8

2 1.808 27.9 Standard Deviation: 0.1751 3 1.806 27.9 Precision (%RSD): 0.6% 4 1.781 27.5 Accuracy (%R): 113.5%

5 1.802 27.8

6 1.805 27.9 203.6809 g 239 Pu 1 14.91 230 Assay Average: 232

2 14.94 231 Standard Deviation: 1.0488 3 14.97 231 Precision (%RSD): 0.5% 4 15.09 233 Accuracy (%R): 113.6%

5 15.00 232

6 15.00 232 0.4316 g 238 Pu 1 1.122 0.440 Assay Average (g): 0.462 2 1.171 0.459 Std Dev (g): 0.0143 3 1.219 0.478 Precision (%RSD): 3.1% 4 1.217 0.477 Accuracy (%R): 107.0%

5 1.178 0.462

6 1.161 0.455

(4) Calibration validation for all three measurement ge ometries using 252 Cf sources had been performed and documented, as required for the NABC.

Following the onsite evaluation in March, SRS-CCP o btained additional 252 Cf standards to further populate the 238 Pu calibration curve between the two previously obt ained measurements of 0.44 g ( 238 Pu) and 27 g ( 252 Cf). Due to the general unavailability of 238 Pu, 252 Cf is used as a surrogate neutron source for 238 Pu, a technically acceptable practice that we have observed at other DOE sites (e.g., DWAS at ORNL). SRS-CCP pers onnel stated they were doing this to provide better technical support for the 238 Pu calibration curve, as had been requested during the

initial evaluation. Revision 1 of the calibration report did not include documentation of the method used to derive an equivalency for 252 Cf and 238 Pu neutrons. This conversion is not intuitively obvious, and it requires documentation that can be reviewed and verified by independent calculation. This information was supp lied in Revision 2 of the calibration report that was provided electronically, and was verified by independent calculation. The 252 Cf source activity values in μ Ci and their corresponding 238 Pu equivalency in grams are listed in Table 5.

Table 5. 252 Cf Values and 238 Pu Equivalences

252 Cf Source No. 252 Cf Activity, μ Ci 238 Pu Equivalent, g

GI-489 2.435 6.89

GI-490 5.671 16.0

D8-360 75 27.014

The 252 Cf sources were assayed in all three geometries, an d the results subjected to acceptance

criteria from DOE-WIPP-02-3122 DOE/WIPP-02-3122 for accuracy (%R) and precision (%RSD), as shown in Tables 6 through 8. All result s were acceptable.

Table 6. Assay Results for 238 Pu Equivalent 252 Cf Standards for 55-gallon Drum

238 Pu Equivalent 240 Pu eff 238 Pu Results 6.89 19.6 7.67 Assay Average: 7.62

19.3 7.57 Standard Deviation: 0.0455 19.3 7.57 Precision (%RSD): 0.6% 19.4 7.59 Accuracy (%R): 110.6%

19.5 7.64

19.5 7.66
16.0 46.1 18.1 Assay Average: 18.2

46.8 18.3 Standard Deviation: 0.0894 46.2 18.1 Precision (%RSD): 0.5% 46.5 18.2 Accuracy (%R): 113.8%

46.6 18.3

46.4 18.2
27.0 76.8 30.1 Assay Average: 30.0

76.6 30.0 Standard Deviation: 0.0577 76.6 30.0 Precision (%RSD): 0.2% Accuracy (%R): 111.2%

Table 7. Assay Results for 238 Pu Equivalent 252 Cf Standards for SWB

238 Pu Equivalent 240 Pu eff 238 Pu Results 6.89 19.7 7.73 Assay Average: 7.71

19.7 7.72 Standard Deviation: 0.0306 19.7 7.73 Precision (%RSD): 0.4% 19.7 7.72 Accuracy (%R): 111.9%

19.7 7.72

19.5 7.65
16.0 46.7 18.3 Assay Average: 18.3

46.6 18.3 Standard Deviation: 0.0548 46.6 18.2 Precision (%RSD): 0.3% 46.6 18.2 Accuracy (%R): 114.4%

46.6 18.3

46.5 18.2
27.0 76.7 30.0 Assay Average: 30.0 76.5 30.0 Standard Deviation (g): 0.0000 76.4 30.0 Precision (%RSD): 0.0% Accuracy (%R): 111.1%15

Table 8. Assay Results for 238 Pu Equivalent 252 Cf Standards for SLB-2

238 Pu Equivalent 240 Pu eff 238 Pu Results 6.89 19.3 7.56 Assay Average: 7.56 19.3 7.56 Standard Deviation (g): 0.0063 19.3 7.56 Precision (%RSD): 0.8% 19.3 7.55 Accuracy (%R): 109.7%

19.3 7.57

19.3 7.56
16.0 45.9 18.0 Assay Average: 18.0

45.9 18.0 Standard Deviation: 0.0000 46.0 18.0 Precision (%RSD): 0.0% 46.0 18.0 Accuracy (%R): 112.5%

45.9 18.0

45.9 18.0
27.0 73.8 28.9 Assay Average: 29.0

74.0 29.0 Standard Deviation: 0.0577 73.9 29.0 Precision (%RSD): 0.2% Accuracy (%R): 107.3%

There are no technical issues with the calibration, calibration confirmation, and calibration validation of the NABC in either the gamma or neutr on detection modes.

(5) SRS-CCP had documented all required performance tes ting for the NABC.

SRS-CCP had performed and documented technically ap propriate performance testing for the NABC for both the gamma and neutron operational mode s for all three container sizes, as required. These are documented in CCP-SRS-SRBC001 for the gamma mode operation and in CCP-SRS-SRBC002 for the neutron mode operation. Th e one exception was the exclusion of performing Weekly Interfering Matrix Checks (WMCs) for the SLB-2 geometry. This was discussed with SRS-CCP personnel during the evaluat ion and was captured on an EPA Inspection Issue Tracking Form (see Attachment A fo r a copy of this form), and it is discussed

below.

EPA Inspection Issue Tracking Form, Issue No. SRS-C CP-NDA-T1-NABC-06-001CR,

Final: The SRS-CCP Report CCP-SRS-SRBC001, Section 4.4.4, addresses WMCs that will be performed in 55-gallon drums and SLB-2s, but does n ot address performing WMCs in SWBs. SRS-CCP personnel stated they will perform WMCs in SWBs and that the lack of mention in CCP-SRS-SRBC001 was a simple omission. SRS-CCP per sonnel committed to revising CCPSRS-SRBC001 and to providing a revised copy to EPA upon completion.

Resolution: Following the onsite evaluation, SRS-CCP personnel provided an electronic copy of Revision 1 of CCP-SRS-SRBC001, which was modifie d to address EPA’s concern and which included other minor changes.

Status of Concern: SRR-CCP’s revision of CCP-SRS-SRBC001, Section 4.4. 4, adequately addressed EPA’s concern, and this concern is closed

.16

There were no concerns regarding the performance an d documentation of performance testing for the gamma and/or neutron operational modes for the NABC resulting from this T1

evaluation.

(6) The total measurement uncertainty (TMU) of assays p erformed on the NABC had been determined and documented, as required.

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. This rep ort was prepared by Canberra in Meriden, Connecticut, and it addresses TMU for all three container sizes. Consistent with what we have observed previously for other NDA systems, the sources of TMU are addressed with the assumption that all sources are independent, which allows them to be added in quadraure, i.e., taking the square root of the sum of the squares of each contributor to TMU. A summary of contributors listed by container size is shown in T able 9, and all values are listed in percent, stated at 1 σ (standard deviation):

Table 9. Contributors to TMU for BSGS

Contributor to TMU 55-Gallon Drum SWB SLB-2 Counting Statistics <5% <5% <5%

Calibration 3% 3% 3%

Rate Loss Correction <0.5% <0.5% <0.5% Matrix Inhomogeneity 20% 20% 20%

Non-Uniform Source Distribution * * * Background <1% <1% <1%

Radionuclide Interference <1% <1% <1% Self Attenuation/Lumps * * * Isotopic Determination * * * Fill Height 5% 5% 5%

Multi-Curve/Transmission Corrections 8% 8% 8%

Other * * *

Total TMU 27% 40% 50% *Variable, on the order of several percent, assay-e vent specific.

All aspects of TMU for the BSGS were technically ad equate and appropriately documented.

There are no issues with the determination and docu mentation of TMU for the BSGS aspect of

the NABC.

BNAS TMU Determination

The determination of the neutron of the TMU for the NABC is addressed in Savannah River Box Neutron Assay System Total Measurement Uncertainty R eport for Alternatives for NonDestructive Assay (NDA) of Large Containers to Allo w Shipping in TRUPACT III without Resizing and/or Repackaging, Canberra Document No. 41309. This report was prepared by Canberra in Meriden, Connecticut, and it addresses TMU for all three container sizes.17

Consistent with what we have observed previously fo r other NDA systems, the sources of TMU are addressed with the assumption that all sources are independent, which allows them to be added in quadraure. Each contributor was evaluated for two matrices—a low moderating matrix (ρ = 0.35 g/cm 3 ) and a highly moderating matrix (ρ = 0.59 g/cm 3 ), as shown in Table 10—and all values are listed in percents stated at 1 σ (standa rd deviation).

Table 10. Contributors to TMU for BNAS for Typical Waste Matrices

Contributor to TMU 55-Gallon Drum

Low 0.35 g/cm 3 55-Gallon Drum

High 0.59 g/cm 3 SWB-Low

0.35 g/cm 3 SWB-High

0.59 g/cm 3 SLB-2 Low

0.35 g/cm 3 SLB-2 High

0.59 g/cm 3
Counting Statistics 1% 2% 1% 5% 1% 5%

Calibration 2% 2% 2% 2% 2% 2%

AAS Correction 2% 8% 3% 7% 2% 5% Min/Average Ratio <1% <1% <1% <1% <1% <1% Max/Average Ratio 1% 4% 1% 5% 1% 6%

Matrix Source Dist 7% 27% 2% 35% 0% 50% Fill Height 1% 55% 5% 70% 3% 47% Background (100 kg Steel) <1% <1% <1% <1% 10% 50%

Isotopics 10% 10% 10% 10% <1% <1% Multiplication Effects 0% 0% 0% 0% 10% 10%
Total TMU,

Nominal 13 % 63 % 12 % 80 % 15 % 86 %

*Variable, on the order of several percent, assay-e vent specific.

The values in this table should be seen as bounding estimates. For example, the source

distribution values assume a worst-case scenario wi th small lumps of Pu in a metal matrix or a layered sludge, assuming approximately 10 g of WG P u and a ratio of alpha n-produced neutrons to spontaneous fission neutrons of 3 [(α,n)/(SF,n)] . In reality, routine assays would probably

exhibit less drastic conditions. Due to the short operating history of the NABC and the complexity of modeling several of the uncertainty c ontributors for a large geometry, EPA may examine Batch Data Reports at a later date to asses s the model’s accuracy.

All aspects of TMU for the BNAS were technically ad equate and appropriately documented.

There are no issues with the determination and docu mentation of TMU for the BNAS aspect of

the NABC.

(7) The LLD, including the minimum detectable concentra tion of the NABC, had been determined and documented for the gamma and neutron operational modes.

The LLD definition used by SRS-CCP is consistent wi th that specified in DOE/WIPP-02-3122 (CH WAC). Specifically, the LLD is defined as “tha t level of radioactivity which, if present, yields a measured value greater than the critical l evel with a 95% probability, where the critical

level is defined as that value which measurements o f the background will exceed with 5% probability.” The LLD of any given NDA measurement is a function of the type of measurement, the measurement time, the properties o f the waste matrix being assayed, and the environmental background. For this reason, the LLD will vary from container to container, and may even vary between measurements of the same cont ainer. The LLD for the BSGS and BNAS are discussed separately below.18

BSGS LLD Determination

The 55-gallon drum filled with the Homasote matrix and no radioactive sources was assayed three times using the standard operating protocols, as documented in CCP-TP-189. Each LLD value was corrected for the matrix (net weight) and MDC values were derived. 3 These assays were used to generate LLD values for 238 Pu, 239 Pu, 240 Pu, 233 U, 235 U, 238 U, 137 Cs, and 241 Am in both the efficiency-based and transition-corrected gamma modes. All results were acceptable.

The SWB filled with a cardboard matrix and no radio active sources was assayed three times using the standard operating protocols, as document ed in CCP-TP-189. Each LLD value was corrected for the matrix (net weight) and MDC value s were derived. These assays were used to generate LLD values for 238 Pu, 239 Pu, 240 Pu, 233 U, 235 U, 238 U, 137 Cs, and 241 Am in both the efficiency-based and transition-corrected gamma mod es. All results were acceptable.

The SLB-2 filled with a cardboard matrix and no rad ioactive sources was assayed three times using the standard operating protocols, as document ed in CCP-TP-189. Each LLD value was corrected for the matrix (net weight) and MDC value s were derived. These assays were used to generate LLD values for 238 Pu, 239 Pu, 240 Pu, 233 U, 235 U, 238 U, 137 Cs, and 241 Am in both the efficiency-based and transition-corrected gamma mod es. All results were acceptable.

Reporting thresholds are required for the radionucl ides that are not measured directly; specifically 242 Pu, 234 U and 90 Sr. Additionally, SRS-CCP determined a different 242 Pu threshold

for WG-Pu and HS-Pu. Since these radionuclides are scaled to one or more measured radionuclides, the reporting thresholds were determ ined by applying the appropriate correction to the measured values. SRS-CCP personnel stated that it is not technically feasible to derive a reporting threshold for 234 U.

All gamma-based LLDs and reporting thresholds are d ocumented in CCP-SRS-SRBC001. There are no concerns regarding the determination and/or documentation of gamma-based LLDs or reporting thresholds for the NABC.

BNAS LLD Determination

Nominal BNAS LLDs were determined from three replica te counts of three container/matrix configurations without radioactive sources, using t he PDP 4 Combustibles 55-gallon drum and

cardboard matrices for the SWB and SLB-2. To conve rt the observed values in 240 Pu eff to total plutonium mass, the values were corrected for eithe r WG Pu or HS Pu isotopics, and meaningful LLD values and reporting thresholds were derived. They are shown in MCS-SRS-NDA-0810, Tables 15–19, and these values are considered typic al or representative, i.e., the minimum detectable quantity of each measured radionuclide f or each waste container assay is calculated and reported, based on the data from that assay. A ll results were acceptable. The LLD values

for WG Pu for all containers are less than 100 nCi/ g, and the BNAS can be used to perform

3 MDC and MDA are the minimum detectable concentrati on and minimum detectable activity, respectively. Both can be considered equivalent to an LLD for the purpose of this report.

4 PDP sources are constructed by Los Alamos National Laboratory for use in the CBFO-sponsored NDA Performance Demonstration Program.19

TRU/Non TRU discrimination. However, for HS Pu, onl y materials that were heavier than what was used for the LLD determinations would provide a sufficient concentration to be less than 100 nCi/g, particularly for the 55-gallon drum. Ac cordingly, SRS-CCP has stated that the BNAS

will not be used to discriminate between TRU and No n-TRU for HS Pu-bearing wastes. All neutron-based LLDs and reporting thresholds are documented in MCS-SRS-NDA-0810. There are no concerns regarding the determination a nd/or documentation of neutron-based LLDs or reporting thresholds for the NABC.

(8) The NABC had successfully participated in the CBFO- sponsored PDP, as required.

The NABC participated in Cycle B8B of the CBFO-spons ored NDA PDP. This cycle included two matrices and two activity types, and one TRU al pha activity range; specifically, an SWB with a combustible matrix and WG Pu at greater than 2 Ci TRU alpha activity; and an SWB with a mixed metals matrix and HS Pu at greater than 2 C i TRU alpha activity. SRS-CCP submitted data for this cycle on March 5, 2009, and successfu l participation was documented in a March 27, 2009, approval letter. There are no issues wit h the participation of the NABC in the CBFOsponsored PDP.

(9) EPA replicate testing of the NABC unit was performe d and evaluated, and was found to comply with the criteria for the EPA Replicate Test ing Protocol.

The purpose of the replicate testing performed as p art of this inspection is to provide EPA with an independent means to verify that the NABC can pr ovide reproducible results for the determination of the quantity of 10 WIPP-tracked ra dionuclides ( 241 Am, 137 Cs, 238 Pu, 239 Pu,

240 Pu, 242 Pu, 90 Sr, 233 U, 234 U, and 238 U) and the TRU alpha concentration. 5 This is accomplished by re-assaying containers previously measured on th e same system, in order to demonstrate the system’s ability to do the following:

• Produce results consistent with the reported TMU by comparing the sample standard deviation for a number of replicate measurements ta ken over several hours or days to the reported TMU.

• Provide reproducible results over longer periods of time, such as weeks or months, by comparing the results of the replicate measurement( s) to the original reported values.

As part of EPA’s evaluation of the NABC, EPA reques ted that the NABC re-assay two containers that EPA randomly selected from a list o f previously assayed 55-gallon drums and SLB-2s. EPA did not select an SWB, because the int ention was to evaluate the NAB by focusing on the two ends of the system’s size range . It was assumed that the system’s response for the SLB-2 and the SWB would be equivalent. EPA chose 55-gallon drum No. SR510464 and SLB-2 No. SR61125902. Both containers were re-assay ed on the NABC unit five times, and the data for the five replicates and the original assaywere analyzed using two statistical tests, a chisquared (χ

2 ) test, and a t-test. The EPA inspection team obse rved operation of the NABC as it

5 Revision 2 of the EPA Replicate Testing Protocol p rovides the details of the replicate testing assay protocol

and data evaluation.20

performed the assay of SLB-2 No. SR61125902. Attac hments B.1–B.4 include data and results of the statistical analysis for all assays.

The t-test for both containers assayed on the NABC d id not show any statistically significant differences between the original measurement assay values and the average of the five replicate measurements for the activities of any of the targe t radionuclides or the TRU alpha activity concentration. The χ 2 test for all containers assayed on the NABC showed that the observed variances in the replicate measurements are less th an or equal to the reported uncertainties within

the statistical limits of the test. There are no t echnical issues associated with replicate testing o f

the NABC.

7.0 SUMMARY OF RESULTS AND CONCLUSIONS

The EPA inspection did not identify any findings re lated to the NABC during this T1 evaluation. EPA did identify one concern, which is discussed in the preceding section. Attachment A of this report provides the EPA Inspection Issue Tracking F orm that documents this issue. EPA

received a revised document to address this issue f ollowing the onsite evaluation. EPA considers this issue to be closed, and there are no open conc erns related to the NABC at SRS-CCP resulting from this evaluation.

8.0 APPROVAL

During this T1 evaluation, the EPA inspection team evaluated the NABC located at DOE’s SRS, E Area, Building 643-43E that is operated by SRS-CC P. It is a bimodal system (neutron and gamma operational modes), and it is configured for CH TRU wastes in three container types (geometries); 55-gallon drums, SWBs, and SLB-2s. E PA assessed the operation of the NABC for all three container types. Based on this T1 ev aluation, the NABC is approved for assaying CH TRU wastes in the gamma and neutron detection mo des for the three measurement configurations—55-gallon drum, SWB, and SLB-2—consi stent with the limitations described in this report.A-1

ATTACHMENT A: EPA INSPECTION ISSUE TRACKING FORM NO. SRS-CCPNDA-T1-NABC-06-001CR

T1 Evaluation No.: SRS-CCP-T1-NABC-03-09 Issue Number: SRSCCPNDAT1NABC06001CR,

Final

Date: 3-25-09
Inspector: Patrick Kelly

Attachments?  Yes  No Sample Size: NA Population size (if known): NA

A. Description of Issue: The SRSCCP report CCPSRSSRBC001, Section 4.4.4, add resses Weekly Matrix Checks (WMCs) that will be performed in 55-g allon drums and SLB2s, but does not address WMCs in Standard Waste Boxes (SWBs). SRSCCP person nel stated that WMCs will be run in SWBs

.

B. Regulatory Reference: 40 CFR 194.24 (c)(4)

C. Site requirement(s): Not Applicable

D. Discussed with: Daniel Remington, Bob Ceo, Joe Harvill, Christa C havez, Todd Shepley, and Joe

Wachter

E. Additional Comments: None

F. Site Response Information:

Site Response Required?  Yes  No Site Response Due Date: Not ApplicableB-1ATTACHMENT B.1: REPLICATE TESTING DATA FOR CONTAINERSR510464 – 55-GALLON DRUMInstrument:SRS NABCContainer:SR510464 (208-Liter Drum )Original Measurement Replicate #1 Replicate #2Quantity of InterestReportedValueAbsoluteUncertaintyRelativeUncertaintyReportedValueAbsoluteUncertaintyRelativeUncertaintyReportedValueAbsoluteUncertaintyRelativeUncertainty233U Activity (Ci)2.27E-03 0.00E+00 0.00E+00 2.25E-03 0.00E+00 0.00E+00 2.41E-03 0.00E+00 0.00E+00234U Activity (Ci)3.36E-05 0.00E+00 0.00E+00 3.33E-05 0.00E+00 0.00E+00 3.28E-05 0.00E+00 0.00E+00238U Activity (Ci)0.00E+00 N/A 0.00E+00 0.00E+00 N/A 0.00E+00 0.00E+00 N/A 0.00E+00238Pu Activity (Ci)4.08E-04 0.00E+00 0.00E+00 2.74E-04 0.00E+00 0.00E+00 4.78E-04 0.00E+00 0.00E+00239Pu Activity (Ci)5.73E-03 0.00E+00 0.00E+00 5.38E-03 0.00E+00 0.00E+00 6.71E-03 0.00E+00 0.00E+00240Pu Activity (Ci)1.30E-03 0.00E+00 0.00E+00 1.02E-03 0.00E+00 0.00E+00 1.41E-03 0.00E+00 0.00E+00242Pu Activity (Ci)1.81E-09 0.00E+00 0.00E+00 1.68E-09 0.00E+00 0.00E+00 1.48E-09 0.00E+00 0.00E+00241Am Activity (Ci)6.27E-01 0.00E+00 0.00E+00 6.42E-01 0.00E+00 0.00E+00 6.42E-01 0.00E+00 0.00E+0090Sr Activity (Ci)1.56E-05 0.00E+00 0.00E+00 1.58E-05 0.00E+00 0.00E+00 1.59E-05 0.00E+00 0.00E+00137Cs Activity (Ci)1.56E-05 0.00E+00 0.00E+00 1.58E-05 0.00E+00 0.00E+00 1.59E-05 0.00E+00 0.00E+00TRU Alpha Conc. (nCi/g)3.17E+04 0.00E+00 0.00E+00 3.25E+04 0.00E+00 0.00E+00 3.26E+04 0.00E+00 0.00E+00Replicate #3 Replicate #4 Replicate #5Quantity of InterestReportedValueAbsoluteUncertaintyRelativeUncertaintyReportedValueAbsoluteUncertaintyRelativeUncertaintyReportedValueAbsoluteUncertaintyRelativeUncertainty233U Activity (Ci)2.37E-03 0.00E+00 0.00E+00 2.28E-03 0.00E+00 0.00E+00 2.11E-03 0.00E+00 0.00E+00234U Activity (Ci)3.38E-05 0.00E+00 0.00E+00 3.36E-05 0.00E+00 0.00E+00 3.29E-05 0.00E+00 0.00E+00238U Activity (Ci)0.00E+00 N/A 0.00E+00 0.00E+00 N/A 0.00E+00 0.00E+00 N/A 0.00E+00238Pu Activity (Ci)3.71E-04 0.00E+00 0.00E+00 3.75E-04 0.00E+00 0.00E+00 3.64E-04 0.00E+00 0.00E+00239Pu Activity (Ci)6.18E-03 0.00E+00 0.00E+00 5.92E-03 0.00E+00 0.00E+00 5.25E-03 0.00E+00 0.00E+00240Pu Activity (Ci)1.32E-03 0.00E+00 0.00E+00 1.17E-03 0.00E+00 0.00E+00 1.13E-03 0.00E+00 0.00E+00242Pu Activity (Ci)3.43E-09 0.00E+00 0.00E+00 1.18E-09 0.00E+00 0.00E+00 2.21E-09 0.00E+00 0.00E+00241Am Activity (Ci)6.38E-01 0.00E+00 0.00E+00 6.48E-01 0.00E+00 0.00E+00 6.31E-01 0.00E+00 0.00E+0090Sr Activity (Ci)1.58E-05 0.00E+00 0.00E+00 1.58E-05 0.00E+00 0.00E+00 1.59E-05 0.00E+00 0.00E+00137Cs Activity (Ci)1.58E-05 0.00E+00 0.00E+00 1.58E-05 0.00E+00 0.00E+00 1.59E-05 0.00E+00 0.00E+00TRU Alpha Conc. (nCi/g)3.23E+04 0.00E+00 0.00E+00 3.28E+04 0.00E+00 0.00E+00 3.19E+04 0.00E+00 0.00E+00B-2ATTACHMENT B.2: REPLICATE TESTING RESULTS FOR CONTAINER SR510464 – 55-GALLON DRUMInstrument:SRS NABCContainer:SR510464 ( 208-Liter Drum )Original MeasurementQuantity of InterestReportedValueAbsoluteUncertaintySampleMeanSampleStandardDeviationRelativeStandardDeviationχ2Pr(x<| χ2|)233U Activity (Ci)2.27E-03 0.00E+00 2.28E-03 1.17E-04 5.12E-02 N/A N/A234U Activity (Ci)3.36E-05 0.00E+00 3.33E-05 4.32E-07 1.30E-02 N/A N/A238U Activity (Ci)0.00E+00 N/A 0.00E+000.00E+00 N/A #VALUE!#VALUE!238Pu Activity (Ci)4.08E-04 0.00E+00 3.72E-04 7.23E-05 1.94E-01 N/A N/A239Pu Activity (Ci)5.73E-03 0.00E+00 5.89E-03 5.97E-04 1.01E-01 N/A N/A240Pu Activity (Ci)1.30E-03 0.00E+00 1.21E-03 1.55E-04 1.28E-01 N/A N/A242Pu Activity (Ci)1.81E-09 0.00E+00 2.00E-09 8.85E-10 4.43E-01 N/A N/A241Am Activity (Ci)6.27E-01 0.00E+00 6.40E-01 6.26E-03 9.78E-03 N/A N/A90Sr Activity (Ci)1.56E-05 0.00E+00 1.58E-05 5.48E-08 3.46E-03 N/A N/A137Cs Activity (Ci)1.56E-05 0.00E+00 1.58E-05 5.48E-08 3.46E-03 N/A N/ATRU Alpha Conc. (nCi/g)3.17E+04 0.00E+00 3.24E+043.42E+02 1.06E-02 N/A N/AQuantity of Interest t Pr(x<|t|)χ2Testt Test233U Activity (Ci)-1.09E-01 9.18E-01 Not Applicable Not Significant234U Activity (Ci)6.76E-01 5.36E-01 Not Applicable Not Significant238U Activity (Ci)N/A N/A#VALUE! Not Applicable238Pu Activity (Ci)4.49E-01 6.76E-01 Not Applicable Not Significant239Pu Activity (Ci)-2.41E-01 8.21E-01 Not ApplicableNot Significant240Pu Activity (Ci)5.30E-01 6.24E-01 Not ApplicableNot Significant242Pu Activity (Ci)-1.92E-01 8.57E-01 Not ApplicableNot Significant241Am Activity (Ci)-1.92E+00 1.27E-01 Not ApplicableNot Significant90Sr Activity (Ci)-4.00E+00 1.61E-02 Not ApplicableSignificant137Cs Activity (Ci)-4.00E+00 1.61E-02 Not ApplicableSignificantTRU Alpha Conc. (nCi/g)-1.92E+00 1.27E-01 Not ApplicableNot SignificantB-3ATTACHMENT B.3: REPLICATE TESTING DATA FOR CONTAINERSR61125902 – SLB2Instrument:SRS NABCContainer:SR61125902 (SLB-2)Original Measurement Replicate #1 Replicate #2Quantity of InterestReportedValueAbsoluteUncertaintyRelativeUncertaintyReportedValueAbsoluteUncertaintyRelativeUncertaintyReportedValueAbsoluteUncertaintyRelativeUncertainty233U Activity (Ci)0.00E+00 N/A 0.00E+00 0.00E+00 N/A 0.00E+00 0.00E+00 N/A 0.00E+00234U Activity (Ci)1.06E-04 0.00E+00 0.00E+00 1.04E-04 0.00E+00 0.00E+00 1.05E-04 0.00E+00 0.00E+00238U Activity (Ci)0.00E+00 N/A 0.00E+00 0.00E+00 N/A 0.00E+00 0.00E+00 N/A 0.00E+00238Pu Activity (Ci)5.97E-01 0.00E+00 0.00E+00 5.87E-01 0.00E+00 0.00E+00 5.95E-01 0.00E+00 0.00E+00239Pu Activity (Ci)1.04E-02 0.00E+00 0.00E+00 9.72E-03 0.00E+00 0.00E+00 8.78E-03 0.00E+00 0.00E+00240Pu Activity (Ci)0.00E+00 N/A 0.00E+00 0.00E+00 N/A 0.00E+00 0.00E+00 N/A 0.00E+00242Pu Activity (Ci)1.83E-07 0.00E+00 0.00E+00 1.80E-07 0.00E+00 0.00E+00 1.82E-07 0.00E+00 0.00E+00241Am Activity (Ci)0.00E+00 N/A 0.00E+00 0.00E+00 N/A 0.00E+00 0.00E+00 N/A 0.00E+0090Sr Activity (Ci)3.19E-07 0.00E+00 0.00E+00 3.37E-07 0.00E+00 0.00E+00 3.44E-07 0.00E+00 0.00E+00137Cs Activity (Ci)3.19E-07 0.00E+00 0.00E+00 3.37E-07 0.00E+00 0.00E+00 3.44E-07 0.00E+00 0.00E+00TRU Alpha Conc. (nCi/g)7.66E+02 0.00E+00 0.00E+00 7.52E+02 0.00E+00 0.00E+00 7.62E+02 0.00E+00 0.00E+00Replicate #3 Replicate #4 Replicate #5Quantity of InterestReportedValueAbsoluteUncertaintyRelativeUncertaintyReportedValueAbsoluteUncertaintyRelativeUncertaintyReportedValueAbsoluteUncertaintyRelativeUncertainty233U Activity (Ci) 0.00E+00 N/A 0.00E+00 0.00E+00 N/A0.00E+00 0.00E+00 N/A 0.00E+00234U Activity (Ci)1.08E-04 0.00E+00 0.00E+00 1.06E-04 0.00E+00 0.00E+00 1.04E-04 0.00E+00 0.00E+00238U Activity (Ci)0.00E+00 N/A 0.00E+00 0.00E+00 N/A 0.00E+00 0.00E+00 N/A 0.00E+00238Pu Activity (Ci)6.10E-01 0.00E+00 0.00E+00 5.99E-01 0.00E+00 0.00E+00 5.85E-01 0.00E+00 0.00E+00239Pu Activity (Ci)8.75E-03 0.00E+00 0.00E+00 9.22E-03 0.00E+00 0.00E+00 9.55E-03 0.00E+00 0.00E+00240Pu Activity (Ci)0.00E+00 N/A 0.00E+00 0.00E+00 N/A 0.00E+00 0.00E+00 N/A 0.00E+00242Pu Activity (Ci)1.87E-07 0.00E+00 0.00E+00 1.83E-07 0.00E+00 0.00E+00 1.79E-07 0.00E+00 0.00E+00241Am Activity (Ci)0.00E+00 N/A 0.00E+00 0.00E+00 N/A 0.00E+00 0.00E+00 N/A 0.00E+0090Sr Activity (Ci)3.19E-07 0.00E+00 0.00E+00 3.33E-07 0.00E+00 0.00E+00 3.60E-07 0.00E+00 0.00E+00137Cs Activity (Ci)3.19E-07 0.00E+00 0.00E+00 3.33E-07 0.00E+00 0.00E+00 3.60E-07 0.00E+00 0.00E+00TRU Alpha Conc. (nCi/g)7.81E+02 0.00E+00 0.00E+00 7.67E+02 0.00E+00 0.00E+00 7.51E+02 0.00E+00 0.00E+00B-4ATTACHMENT B.4: REPLICATE TESTING RESULTS FOR CONTAINER SR61125902 – SLB2Instrument:SRS NABCContainer: SR61125902 (SLB-2)Original MeasurementQuantity of InterestReportedValueAbsoluteUncertaintySampleMeanSampleStandardDeviationRelativeStandardDeviationχ2Pr(x<| χ2|)233U Activity (Ci)0.00E+00 N/A 0.00E+00 0.00E+00 N/A#VALUE!#VALUE!234U Activity (Ci)1.06E-04 0.00E+00 1.05E-04 1.67E-06 1.59E-02 N/A N/A238U Activity (Ci)0.00E+00 N/A 0.00E+00 0.00E+00 N/A#VALUE!#VALUE!238Pu Activity (Ci)5.97E-01 0.00E+00 5.95E-01 1.01E-02 1.69E-02 N/A N/A239Pu Activity (Ci)1.04E-02 0.00E+00 9.20E-03 4.39E-04 4.77E-02 N/A N/A240Pu Activity (Ci)0.00E+00 N/A 0.00E+00 0.00E+00 N/A#VALUE!#VALUE!242Pu Activity (Ci)1.83E-07 0.00E+00 1.82E-07 3.11E-09 1.71E-02 N/A N/A241Am Activity (Ci)0.00E+00 N/A 0.00E+00 0.00E+00 N/A#VALUE!#VALUE!90Sr Activity (Ci)3.19E-07 0.00E+00 3.39E-07 1.50E-08 4.44E-02 N/A N/A137Cs Activity (Ci)3.19E-07 0.00E+00 3.39E-07 1.50E-08 4.44E-02 N/A N/ATRU Alpha Conc. (nCi/g)7.66E+02 0.00E+00 7.63E+02 1.23E+01 1.61E-02 N/A N/AQuantity of Interest t Pr(x<|t|)χ2Testt Test233U Activity (Ci) N/AN/A#VALUE! Not Applicable234U Activity (Ci) 3.27E-017.60E-01Not Applicable Not Significant238U Activity (Ci) N/AN/A#VALUE! Not Applicable238Pu Activity (Ci) 1.63E-018.78E-01Not Applicable Not Significant239Pu Activity (Ci) 2.49E+006.78E-02Not ApplicableNot Significant240Pu Activity (Ci) N/AN/A#VALUE! Not Applicable242Pu Activity (Ci) 2.34E-018.26E-01Not ApplicableNot Significant241Am Activity (Ci) N/AN/A#VALUE! Not Applicable90Sr Activity (Ci) -1.19E+003.00E-01Not ApplicableNot Significant137Cs Activity (Ci) -1.19E+003.00E-01Not ApplicableNot SignificantTRU Alpha Conc. (nCi/g) 2.52E-018.13E-01Not ApplicableNot Significant