DOCKET NO: A-98-49; II-A4-177 

WASTE CHARACTERIZATION TIER 1 CHANGE REPORT 

EPA TIER 1 EVALUATION 

OF THE CENTRAL CHARACTERIZATION PROGRAM 

REMOTE-HANDLED TRANSURANIC WASTE CHARACTERIZATION PROGRAM 

FOR THE SAVANNAH RIVER SITE: 

ADDITION OF WASTE STREAM SR-RH-221H.01

U.S. Environmental Protection Agency 

Office of Radiation and Indoor Air 

Center for Federal Regulations 

1200 Pennsylvania Avenue, NW

Washington, DC 20460 

August 2013
i 

TABLE OF CONTENTS 

Section Page

Acronyms and Initializations .......................................................................................................... ii

1.0 Introduction ..........................................................................................................................1

2.0 Purpose of Tier 1 Evaluations ..............................................................................................3

3.0 Purpose of This Report ........................................................................................................3

4.0 Scope of the Tier 1 Evaluation.............................................................................................4

5.0 EPA Evaluation Personnel ...................................................................................................4

6.0 Radiological Characterization Technical Evaluation ...........................................................4

7.0 Findings and Concerns .......................................................................................................13

8.0 Conclusions ........................................................................................................................14

TABLES 

Table 1. EPA Tier 1 Evaluation Team Members ............................................................................ 4

Table 2. Dominant Waste Types for Containers in Waste Stream SR-RH-221H.01 ..................... 9

FIGURES 

Figure 1. Radiological Characterization Flow Diagram for Waste Stream SR-RH-221H.01 ........ 6

Figure 2. Scaling Factor Development for Waste Stream SR-RH-221H.01 .................................. 7

ATTACHMENTS 

Attachment A: Approval Summary for Savannah River Site Remote-Handled Waste 

Characterization Program 

Attachment B: List of Documents Reviewed by EPA during T1 Evaluation 
ii 

ACRONYMS AND INITIALIZATIONS 

AK acceptable knowledge 

AKSR acceptable knowledge summary report 

Am americium 

BDR batch data report 

CBFO Carlsbad Field Office 

CCP Central Characterization Program 

CFR Code of Federal Regulations 

CH contact-handled 

Ci curie 

CIS Characterization Information Summary 

Co cobalt 

CRR Characterization Reconciliation Report 

Cs cesium 

DOE U.S. Department of Energy 

DTC dose-to-curie 

EPA U.S. Environmental Protection Agency 

Eu europium 

HS heat source 

ISOCS In Situ Object Counting System 

MCNP5 Monte Carlo N-Particle Transport Code RSICC Computer Code 

Collection, Oak Ridge National Laboratory 

MCS Mobile Characterization Services 

MDA minimum detectable activity 

mR/hr/Ci milliroentgen per hour per curie 

mrem/hr millirem per hour 

NDA nondestructive assay 

Np neptunium 

Pu plutonium 

ORTEC Oak Ridge Technical Enterprise Corporation 

RH remote-handled 

RTR real-time radiography 
iii 

SC&A S. Cohen and Associates (SC&A, Inc.) 

SCG summary category group 

SF scaling factor 

Sr strontium 

SRS Savannah River Site 

T1 Tier 1 

T2 Tier 2 

TMU total measurement uncertainty 

TRU transuranic 

U uranium 

WIPP Waste Isolation Pilot Plant 

WSPF Waste Stream Profile Form 
1

1.0 INTRODUCTION 

This report supports the U.S. Environmental Protection Agency’s (EPA’s) approval of a Tier 1 

(T1) change to add Waste Stream SR-RH-221H.01 to the approved characterization program at 

the U.S. Department of Energy’s (DOE’s) Savannah River Site (SRS). In April 2012, EPA 

approved the Central Characterization Program (CCP)1 to characterize remote-handled (RH) 

waste at SRS. On May 30, 2013, the Carlsbad Field Office (CBFO) requested EPA’s approval of 

a T1 change to add Waste Stream SR-RH-221H.01. Using the EPA-approved waste 

characterization processes discussed in this report, SRS-CCP can characterize Waste Stream 

SR-RH-221H.01 for disposal at the Waste Isolation Pilot Plant (WIPP). 

In accordance with Title 40 of the Code of Federal Regulations [40 CFR 194.8(b)], EPA 

conducted Baseline Inspection No. EPA-SRS-CCP-RH-08.11-8 of the CCP waste 

characterization program at SRS on August 30–September 1 and December 6–7, 2011. The April 

2012 SRS baseline final inspection report (see EPA Docket No. A-98-49; II-A4-161) documents 

EPA’s approval of the acceptable knowledge (AK) process for RH transuranic (TRU) debris 

waste streams that have: 

• Companion2

 contact-handled (CH) debris waste streams. 

• A radiological characterization process that uses: 

o Dose-to-curie (DTC), 

o Scaling factors generated through use of the Mobile Characterization Services 

(MCS)/In Situ Object Counting System (ISOCS3

), and 

o Historical assays of companion CH debris waste streams for assigning 

radionuclide values for RH waste. 

• Real-time radiography (RTR) processes specific to SRS-CCP’s RH waste 

characterization program. 

The companion CH waste stream for RH Waste Stream SR-RH-221H.01 is Waste Stream 

SR-W027-221H-HET. Because the AK and RTR processes have not changed since the baseline 

approval, EPA limited the scope of this T1 review to the radiological characterization process. 

Waste Stream SR-RH-221H.01 is characterized by DTC, as described in CCP-RC-SRS-601, 

“Central Characterization Program Remote-Handled Transuranic Radiological Characterization 

Technical Report for Savannah River Site Remote-Handled Transuranic Debris Waste, Waste 

 

1

 The Central Characterization Program was formerly known as the Central Characterization Project, and 

both names are used in the documentation reviewed for this evaluation. 

2

 A companion CH waste stream has the same summary category group, same waste stream definition and 

same radiological and physical properties as the subject RH waste stream. In this case, the only difference between 

containers in the companion CH waste stream and those in the subject RH waste stream is the waste’s external dose 

rate, i.e., less than or greater than 200 millirem per hour (mrem/hr), which makes the waste CH or RH, respectively. 

3

 Unlike other nondestructive assay (NDA) instruments in CH programs, the ISOCS is not a direct 

characterization method; it is used exclusively for obtaining the relative ratios of radionuclides, i.e., scaling factors. 

The ISOCS data had been confirmed by measurements done on an approved CH NDA system. 
2

Stream: SR-RH-221H.01,” Revision 1, dated June 05, 2013. The scaling factors are determined 

using the MCS/ISOCS when measurement data are available or were based on selected CH NDA 

results from characterization of the companion CH Waste Stream SR-W027-221H-HET. These 

15 drums of TRU waste are the subject of this T1 report, but EPA’s approval also includes any 

additional drums that are added to Waste Stream SR-RH-221H.01 in the future, provided they 

are characterized using the same processes.

Because there were no new equipment or additional new processes on site at SRS as part of the 

T1 request, EPA conducted a desktop review of this change, concluding that the SRS-CCP plan 

to use the EPA-approved system of controls to characterize the 55-gallon containers of Waste 

Stream SR-RH-221H.01 is acceptable. EPA did not identify any findings or concerns during this 

evaluation. 

As a result of this evaluation, EPA did not make any changes to the SRS-CCP RH T1 and Tier 2 

(T2) designations that were established during the baseline approval and modified in February 

2013 as presented in Table 1 of the report documenting EPA’s approval of the addition of Waste 

Stream SR-RH-235F.01 (See EPA Docket No: A-98-49; II-A4-170). 

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 website and by emails to the 

WIPPNEWS list, in accordance with 40 CFR 194.8(b)(3).
3

2.0 PURPOSE OF TIER 1 EVALUATIONS 

Certain changes to the waste characterization activities after the date of the site’s baseline 

inspection must be reported to and, if applicable, approved by EPA according to the tiering 

requirements set forth in 40 CFR 194.8 and incorporated into the SRS-CCP RH baseline final 

report (see EPA Docket No. A-98-49; II-A4-161). 

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

(Vol. 69, No. 136, pages 42571–42583), EPA must perform a single baseline inspection of a 

TRU waste generator site’s waste characterization program. The purpose of EPA’s 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. 

Following EPA’s baseline approval, EPA is authorized to evaluate and approve changes, if 

necessary, to the site’s approved waste characterization program by conducting additional 

inspections under the authority of 40 CFR 194.24(h). Changes requiring EPA notification and 

approval prior to implementation (T1) and those requiring post-implementation notification (T2) 

are identified in the site-specific baseline inspection reports. When evaluating proposed T1 

changes for approval, EPA may conduct a site inspection to observe at first hand the 

implementation of the change or can decide to conduct a desktop review of information provided 

specific to a change. DOE may choose to characterize and dispose of any previously approved 

TRU waste using processes, procedures or equipment implemented as T2 changes at risk of 

subsequent EPA disapproval. EPA reviews T2 changes on a quarterly basis and may conduct 

continued compliance inspections to evaluate implemented T2 changes to verify adequacy. 

Attachment A lists all of EPA’s non-T2 approvals of the SRS-CCP RH TRU waste 

characterization program. 

3.0 PURPOSE OF THIS REPORT 

This report presents the results of EPA’s evaluation of a T1 change to add Waste Stream SR-RH221H.01 to SRS-CCP’s approved waste characterization program. This report presents the 

technical basis for and results of EPA’s approval decision. EPA’s approval decision regarding 

the addition of Waste Stream SR-RH-221H.01 has been conveyed to DOE separately by letter. 

EPA will also announce the decision on its website 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 different sections 

throughout the report and are listed in Attachment B. Any of these documents can be requested 

from the following address: 

Manager, National TRU Program 

Carlsbad Field Office 

U.S. Department of Energy 

P O Box 3090 

Carlsbad, NM 88221-3090 
4

4.0 SCOPE OF THE TIER 1 EVALUATION 

The scope of EPA’s T1 evaluation is the radiological characterization approach used to 

characterize Waste Stream SR-RH-221H.01. Section 6.0 of this report details the radiological 

characterization technical elements assessed during this evaluation. 

5.0 EPA EVALUATION PERSONNEL 

The EPA evaluation team members consisted of the personnel listed in Table 2 with their 

affiliations and functions. EPA relied primarily on reviews of documents and information 

provided by SRS-CCP. When additional information or clarifications were needed, EPA had 

discussions with Irene Joo,4

 the CCP RH Project Manager, who served as the point of contact for 

this T1 evaluation. 

Table 1. EPA Tier 1 Evaluation Team Members 

6.0 RADIOLOGICAL CHARACTERIZATION TECHNICAL EVALUATION 

RH Waste Overview

Waste Stream SR-RH-221H.01 consists of RH TRU debris wastes generated by radiochemical 

analytical laboratory and research activities conducted in the H-Canyon facility at SRS from 

1973 to 2007. This waste stream was originally included in CH TRU Waste Stream SR-W027-

221H-HET, stored in 55-gallon drums and characterized under a CH TRU program using NDA. 

However, 15 drums had surface dose rates exceeding the 200 mrem/hr limit for CH waste and, 

therefore, were assigned to RH TRU Waste Stream SR-RH-221H.01. 

Documents, Waste Containers, and Batch Data Reports and Calculation Packages

EPA evaluated the SRS-CCP documentation that supported radiological characterization of 

Waste Stream SR-RH-221H.01. SRS-CCP provided CCP-RC-SRS-601, Revision 1, to EPA as 

the main document for review. Attachment B lists all documentation reviewed by EPA, 

including batch data reports (BDRs) and calculation packages. 

Waste Characterization Element Description

EPA evaluated the radiological characterization of SRS-CCP RH Waste Stream SR-RH-221H.01 

in terms of its technical adequacy, as supported by the program’s documents, procedures and 

controls, and the knowledge and understanding of the personnel involved in the RH waste 

 

4

 Irene Joo was formerly known as Irene Quintana and both names are used in the documentation reviewed 

to support this evaluation. 

Name Affiliation & Function 

Ed Feltcorn Lead Inspector, EPA 

Rose Gogliotti Technical Evaluator – Radiological Characterization, SC&A 

Patrick Kelly Technical Evaluator – Radiological Characterization, SC&A 

Amir Mobasheran Technical Evaluator – Radiological Characterization, SC&A 
5

characterization program. During this RH evaluation, the EPA team evaluated the following 

elements of the SRS-CCP radiological characterization program: 

• Overall radiological characterization. 

• ISOCS measurements made to determine scaling factors. 

• Derivation of radionuclide scaling factors using isotopic ratios from ISOCS assays. 

• Derivation of scaling factors not based on ISOCS through isotopic distributions from 

historical assays of companion CH Waste Stream SR-W027-221H-HET. 

• Representativeness and technical adequacy of the analytical data used to support the 

scaling factors. 

• Development of two DTC correlations for 55-gallon drums based on Monte Carlo 

N-Particle Transport Code (MCNP5) modeling of the drum’s gamma dose rate at one 

meter from the surface of drum using a one-curie (Ci) source of both americium-241 

(

241Am) and neptunium-237 (237Np), assumed to be the main contributors to the dose. 

• Uncertainty analysis. 

Each of these is discussed in the sections that follow. 

Technical Evaluation

The EPA evaluation team evaluated the following aspects: 

(1) The overall radiological characterization process and its documentation were evaluated 

and found to be adequate. 

The radiological characterization process for Waste Stream SR-RH-221H.01 uses DTC in 

conjunction with radionuclide-specific scaling factors developed from ISOCS measurements, a 

process that EPA approved at the SRS RH baseline. SRS-CCP scaled the measured and modeled 

radionuclide values to 241Am, correlating a drum’s external exposure (dose) rate and its contents 

of specific radionuclides. Development of the radionuclide-specific scaling factors is the main 

technical aspect of SRS-CCP’s radiological characterization. The SRS-CCP RH radiological 

characterization program incorporated five main aspects: 

• Development of 241Am-based scaling factors for plutonium-239 (239Pu), 240Pu, 241Pu, 

242Pu, 237Np and cesium-137 (137Cs) based on ISOCS measurements when detected. 

• Historical information (AK) for CH Waste Stream SR-W027-221H-HET, as summarized 

in CCP-AK-SRS-6005

 and associated source documents. 

• When radionuclides were not detected by ISOCS, development of scaling factors for 

239Pu, 240Pu, 241Pu, 242Pu, uranium-233 (233U), 234U, 238U, 137Cs and strontium-90 (90Sr) 

 

5

 “Central Characterization Program Acceptable Knowledge Summary Report for Savannah River Site 

Remote-Handled Transuranic Waste, Waste Streams: SR-RH-221H.01 and SR-RH-221H.02,” CCP-AK-SRS-600, 

Revision 1, November 27, 2012. 
6

were based on past assays of the RH waste stream’s CH counterpart, Waste Stream SRW027-221H-HET, and assumptions about the waste’s origins. 

• Scaling factors for 238Pu were based on CH data in all cases, as discussed in (2), below. 

• MCNP5 modeling to determine the correlation between the amount of 241Am and 237Np 

in each drum and the drum’s dose rates at one meter. 

• Direct exposure rate measurements (DTC) of each waste drum. 

The EPA inspection team prepared two flow diagrams to accurately reflect this process, shown 

in Figures 1 and 2 below. EPA determined that the radiological characterization process for 

Waste Stream SR-RH-221H.01 was technically adequate and appropriately documented. 

Consistent with the T1 and T2 designations that were established during the baseline approval 

and modified in February 2013, any new RH waste stream not approved to date or the addition of 

containers to Waste Stream SR-RH-221H.01 that requires a different radiological 

characterization process from what is documented in CCP-RC-SRS-601 remains a T1 change. 

Similarly, any change to CCP-RC-SRS-601 that requires CBFO approval remains a T2 change. 

Figure 1. Radiological Characterization Flow Diagram for Waste Stream SR-RH-221H.0

Source: Based on CCP-RC-SRS-601, Revision 1

Use MCNP5 to separately model the 1-meter dose 

rates based on a 1-Ci source of 241Am and 237Np 

Develop the DTC conversion factors (mR/hr/Ci) as 

a function of the waste density for 241Am and 237Np 

Execute DTC to derive the 241Am activity in curies 

Multiply the 241Am activity by the SFs to 

determine activities of other radionuclides 

Determine the uncertainties in radionuclide 

activities and masses 

Develop drumspecific scaling 

factors (see 

Figure 2).
7

Figure 2. Scaling Factor Development for Waste Stream SR-RH-221H.01

Source: Based on SRS-RH-67, R

Use ISOCS to develop drum-specific 241Am-based SFs for 239Pu, 240Pu, 241Pu, 242Pu, 237Np and 137Cs 

 Use 241Am/237Np ratio 

determine if drum contheat-source (238Pu-dom

waste or a non-heat-so(237Np-dominant) wast

Decay correct 241 Am and 241Pu. Then 

calculate the SFs for 238Pu, 239Pu, 240Pu, 

241Pu, 242Pu 137Cs and 234U to 241Am for 

each assay 

The geometric means of MDAs for 233U, 235U and 238U were applied to CH data 

If detected: 

Sort CH database results into three “extractions’ based on the 241Am/237Np ratio -1st Extraction: 1.00E-2 ≤ SF ≤ 1.00E-1 

-2nd Extraction: 1.00E-1 ≤ SF ≤ 3.50E1 

-3rd Extraction: 1.00E3 ≤ SF ≤ 1.00E4 

Find the arithmetimean of the SF foeach isotope witheach extraction 

Uranium SFs Development: 

ISOCS Derived SFs: 

CH Database Derived SFs: 

Randomly select 20 assay results without 

positive U values from the 1st, 2nd and 3rd

extractions and calculate the geometric mean for U isotopes 

Sort CH data into three groups (“extractions”) based on their ratios of 241Am/237Np 

-1st Extraction: 1.00E-2 ≤ SF ≤ 1.00E-1 

-2nd Extraction: 1.00E-1 ≤ SF ≤ 3.50E1 

-3rd Extraction: 1.00E3 ≤ SF ≤ 1.00E4 
8

(2) Use of the In Situ Object Counting System to derive isotopic ratios (scaling factors) was 

found to be correctly implemented and appropriately documented. 

EPA previously approved an ISOCS instrument to assay WIPP-bound RH TRU waste drums at 

the SRS RH baseline during 2011 (see EPA Docket No. A-98-49; II-A4-161). During the SRS 

RH baseline, EPA approved the use of scaling factors relative to 241Am for 239Pu, 240Pu and 

241Pu, and subsequently approved the use of the ISOCS for any gamma-emitting radionuclide 

(see EPA Docket No. A-98-49; II-A4-170), including 238Pu. However, the characterization of 

these wastes was completed prior to EPA’s subsequent expanded approval of the use of ISOCS, 

and SRS-CCP relied exclusively on CH data to develop scaling factors for 238Pu. 

For RH Waste Stream SR-RH-221H.01, SRS-CCP used ISOCS measurements to scale TRU 

radionuclides to 241Am. It also scaled 242Pu, 237Np and 137Cs to 241Am when they were detected in 

levels above the minimum detectable activity (MDA). 242Pu and 237Np are not WIPP-tracked 

radionuclides but SRS-CCP must report their contribution to comply with shipping requirements 

for any radionuclide that contributes significantly to the radiological hazard of the drum.137Cs is 

a WIPP-tracked radionuclide with a strong gamma emission that is easy to detect. Each of the 15 

RH drums was assayed by the ISOCS; the results are shown in Table 3-1 of CCP-RC-SRS-601, 

Revision 1. 

If ISOCS detected a radionuclide it was scaled to 241Am. Scaling factors generated from ISOCS 

results are listed in Table 3-2 of CCP-RC-SRS-601, Revision 1. If ISOCS did not detect a 

radionuclide, SRS-CCP used historical CH assays to generate scaling factors [see Item (3) 

below]. 

Additionally, SRS-CCP used ISOCS results to identify the origin of each drum. The AK 

summary report indicates that waste from CH Waste Stream SR-W027-221H-HET came from 

two major activities: (1) 238Pu heat source (HS) fabrication and (2) 237Np target fabrication 

(target). Based on what is known about these processes, waste from 237Np target fabrication 

would be expected to have a low 241Am/237Np ratio, while HS material would be expected to 

have a ratio as large as 1,000 to several thousands. Because 239Pu was not detected in 13 drums 

(Nos. SR570545, SR526227, SR570548, SR513955, SR526263, SR570546, SR570547, 

SR526225, SR526226, SR526264, SR522989, SR526224 and SR513961), they can be classified 

as originating from 237Np target production; they have 241Am/237Np ratios ranging from 2.59E-02 

to 3.46E+01. The remaining three drums (Nos. SR503513, SR522331 and SR545535) have 

241Am/237Np ratios ranging from 1.12E+03 to 4.45E+03, and these drums can be classified as 

originating from HS fabrication. These categories are used to better characterize scaling factors 

obtained through the use of historical CH data. 

(3) Use of nondestructive assay data from contact-handled Waste Stream SR-W027-221HHET to develop scaling factors for uranium isotopes, unmeasured plutonium isotopes and 

fission products, including cesium, was found to be technically adequate and correctly 

documented. 

SRS Waste Stream SR-W027-221H-HET is the CH equivalent of RH Waste Stream SR-RH221H.01, and all 15 of the 55-gallon RH drums in Waste Stream SR-RH-221H.01 were 
9

originally generated and managed as CH waste. They fell out of the waste stream when the 

drum’s contact dose readings exceeded the contact dose rate limit for CH of 200 mrem/hr. As 

such, these RH drums are assumed to have the same ratios of radionuclides as the CH drums 

generated from the same two dominant processes (HS and target fabrications), as stated in Item 

(2) above. This assumption is the basis for using historical CH assays to derive the ratios of Pu, 

U and fission products to 241Am for the RH drums. 

Approximately 2,900 CH assay records from Waste Stream SR-W027-221H-HET were available 

at the time CCP-AK-SRS-601 was completed. SRS-CCP selected two subsets (“First Extraction 

and Second Extraction”) of assays to represent wastes generated from target fabrication and one 

subset (“Third Extraction”) to represent waste generated from HS production. The 241Am/237Np 

ratios from the CH assays were used to identify drums most similar to the 15 RH drums. SRSCCP selected CH drums that had ratios ranging from 0.01 to 0.1 as belonging to the First 

Extraction and CH drums that had ratios ranging from 0.1 to 35 as belonging to the Second 

Extraction representing target material. Drums with ratios ranging from 1,000 to 10,000 

represented HS materials. This selection process resulted in three CH drums for the First 

Extraction and 71 CH drums for the Second Extraction representing target waste and 91 CH 

drums representing HS materials. SRS-CCP chose to use these three subsets of CH Waste 

Stream SR-W027-221H-HET (a total of 165 CH drums) on the assumption that they would most 

accurately reflect the distribution of radionuclides in the 15 drums in Waste Stream SR-RH221H.01. All 165 extracted assays were corrected for decay and in-growth from their assay date 

to May 15, 2012, to better reflect the current contents of the drums. Table 3 below shows the 

dominant waste type for each of the 15 drums in Waste Stream SR-RH-221H.01. Due to the 

complexities of the waste, each radionuclide scaling factor was calculated separately. The 241Am 

scaling factors are summarized in Table 3-6 of CCP-RC-SRS-601, Revision 1. 

Table 2. Dominant Waste Types for Containers in Waste Stream SR-RH-221H.01 

Container Dominant Waste* 

SR570545 Np Target 

SR526227 Np Target 

SR570548 Np Target 

SR513955 Np Target 

SR526263 Np Target 

SR570546 Np Target 

SR570547 Np Target 

SR526225 Np Target 

SR526226 Np Target 

SR526264 Np Target 

SR522989 Np Target 

SR526224 Np Target 

SR513961 Np Target 

SR522331 HS 

SR545535 HS 

* Target dominant waste had 241Am/237Np ratios from 0.01 to 3.5 and HS dominant waste had 241Am/237Np ratios from 

1,000 to 10,000 

Source: Based on SRS-RH-67, Revision 1 (Reference U001). 
10

Uranium Isotopes (excluding 234U) 

SRS-CCP expected U in trace quantities in this waste stream because of the nature of the wasteproducing processes. Higher concentrations would have been detected by ISOCS measurements. 

Less than 10% of the CH assays in Waste Stream SR-W027-221H-HET had positive U values. 

To develop the scaling factors for 233U, 235U and 238U, SRS-CCP randomly selected 20 MDA 

values from the CH drum assays representing target materials and 20 MDA values from the CH 

drum assays representing HS materials and pooled these into a set of 40 MDAs for each isotope. 

The MDA values of 235U, 233U and 238U in each of these 40 drums were divided by that drum’s 

decay-corrected 241Am value. When an assay did not have detectable levels of a radionuclide, the 

average MDA for that radionuclide was applied to that sample. Although an MDA does not 

represent a drum’s true radionuclide concentration, its use allows an upper-end estimate of the 

drum’s content. The use of this value eliminates underestimation of true averages due to the 

measurement system’s limitations. For the 40-drum subset, drum-specific scaling factors for 

each isotope were then averaged geometrically to produce 241Am-based scaling factors for 235U, 

233U and 238U. These averaged MDA scaling factors were then applied to every non-measured 

corresponding U isotope in the 165-drum subset (the 3-drum and 71-drum subsets representing 

target material plus the 91-drum subset representing HS material). The 165-drum subset was then 

arithmetically averaged per isotope to develop a set of 241Am-based U scaling factors. 

Plutonium Isotopes, 234U and 137Cs 

When Pu isotopes (excluding 238Pu) and/or 137Cs were not detected above the MDA on the 

ISOCS assay, CH data were used to bound the contents of a drum. HS and target scaling factors 

are generated differently for the Pu isotopes, 234U and 137Cs. The SFs for 238Pu were determined 

using CH data in all cases, irrespective of ISOCS results. Each is discussed below. 

Heat Source Scaling Factors 

After performing decay corrections for 241Am and 241Pu, the arithmetic mean of all 241Am-based 

scaling factors for each radionuclide in the 91-drum subset (Third Extraction) of the CH waste 

stream was calculated. Drums without reported values for any specific radionuclide were treated 

as blanks rather than zeros in averaging. This provides a conservative bounding of the drum’s 

radionuclide contents. 

Neptunium Target Scaling Factors 

After performing decay corrections for 241Am and 241Pu, the arithmetic mean of all 241Am-based 

scaling factors for each radionuclide in the 3-drum subset (First Extraction) and in the 71-drum 

subset (Second Extraction) was calculated. Drums without reported values for any specific 

radionuclide were treated as blanks rather than zeros in averaging. This provides a conservative 

bounding of the drum’s radionuclide contents. 

Strontium-90

The NDA system does not directly measure the beta-emitting radionuclide 90Sr; its contribution 

is inferred by assuming essentially a one-to-one ratio with 137Cs. This is a common practice in 
11

determining RH scaling factors because both radionuclides are fission products with comparable 

fission yields. 

(4) Computer modeling to develop the dose-to-curie correlation was evaluated and was 

found to be adequate. 

SRS-CCP used MCNP5 to develop the DTC correlation for a 55-gallon drum filled with debris 

in conjunction with its external dose rate at one meter. The modeling was based on the 

assumption that: either a one-Ci source of 241Am or a one-Ci source of 237Np (just one source in 

each model) was uniformly distributed within the drum; the only significant gamma emitters 

were 241Am and 237Np; and contributions of europium-154 (154Eu), cobalt-60 (60Co) or other 

gamma emitters were negligible. Using the scaling factor for 237Np, waste density and DTC 

correlations, and dose partitioning allows calculation of the dose and activity attributable to 

241Am. The 241Am activity is then used with the 241Am-based scaling factors to determine the 

activities of the other TRU radionuclides of interest. Each drum’s MCNP5 results are 

documented in calculation package SRS-RH-53 (Reference U015). 

Consistent with the T1 and T2 designations that were established during the baseline approval 

and modified in February 2013, the use of any method to determine scaling factors other than 

those documented in CCP-RC-SRS-601 remains a T1 change. 

(5) Execution and documentation of the dose-to-curie technique was assessed and found to 

be adequate. 

EPA observed the DTC technique on August 30, 2011, in the DTC alcove located in Area E, 

Pad 4, as part of the RH baseline inspection at SRS. Consistent with the T1 and T2 designations 

that were established during the baseline approval and modified in February 2013, the use of any 

alternate radiological characterization procedure other than DTC with procedure CCP-TP-5046 in 

conjunction with scaling factors documented in CCP-RC-SRS-601, or substantive modification 

thereof, remains a T1 change. 

(6) Radionuclide documentation in the dose-to-curie batch data report was assessed and 

found to be adequate. 

The DTC results for all 15 containers were documented in BDR Nos. SRSRHDTC11003, 

SRSRHDTC12001, SRSRHDTC12002 and SRSRHDTC12003. For logistical reasons, some 

containers had Waste Container Dose-to-Curie Conversion Records that had been superseded. 

All containers used the initial DTC measurement event served as the basis for the radionuclide 

calculations, often in conjunction with more recently derived radionuclide scaling factors. The 

EPA inspection team verified that each BDR included the following: 

• Site Project Manager checklist, CCP-TP-504, Revision 13, Attachment 8. 

• BDR cover sheet, CCP-TP-504, Revision 13, Attachment 4. 

 

6

 CCP-TP-504, CCP Dose-to-Curie Survey Procedure for Remote-Handled Transuranic Waste, Revision 

13, September 17, 2012. 
12

• BDR table of contents, CCP-TP-504, Revision 13, Attachment 5. 

• BDR narrative summary, CCP-TP-504, Revision 13, Attachment 6. 

• Independent Technical Reviewer checklist, CCP-TP-504, Revision 13, Attachment 7. 

• Measurement control report with all parameters acceptable. 

• Container data sheets, CCP-TP-504, Revision 13, Attachment 2. 

• Concentrations and corresponding uncertainties for all WIPP-tracked radionuclides. 

• Waste Container Dose-to-Curie Conversion Records documenting: revision of 

spreadsheet indicating the use of correct radionuclide scaling factors; container weights; 

waste stream number; and TRU determination. 

• Evidence of signatures by the Independent Technical Reviewer and a Site Project 

Manager on CCP-TP-504, Revision 13, Attachments 7 and 8. 

• Correct revision of CCP-TP-504 (Revision 13). 

EPA noted large uncertainties associated with some containers, i.e., containers where the 

uncertainty exceeded the activity (or mass) value. This was observed in containers whose scaling 

factor determinations relied primarily on CH data as opposed to direct ISOCS measurements. 

There are three sub-populations in the CH database and each population has a unique set of 

scaling factor uncertainties that, when incorporated, yield high overall uncertainty values for the 

container. EPA noted a minor error regarding the incorporation of 237Np in the calculations for 

TRU Alpha Activity Concentration and its uncertainty, which SRS-CCP acknowledged. 

CCP-RC-SRS-601, Revision 1, presents radionuclide scaling factors and other data for container 

No. SR503513. However, SRS-CCP determined that this container was not RH by virtue of a 

measured external dose-rate less than 200 mrem/hr, as documented in SRSRHDTC12003, NCRRHSRS-0607-13. This container does not meet the definition of RH waste and was removed 

from DTC BDR SRSRHDTC12003, as discussed below. 

The four BDRs were technically adequate. 

(7) Remote-handled determinations were evaluated and found to be adequate. 

SRS personnel measured contact dose rates, and SRS-CCP provided the dose rate survey sheets 

for all 15 drums of Waste Stream SR-RH-221H.01. EPA reviewed the records, which indicated 

gamma-only dose readings at a distance of five centimeters for all 15 drums listed in CCP-RCSRS-601, Revision 1, Table 3-1. The values indicated that all 15 drums had contact dose reading 

clearly in excess of 200 mrem/hr, i.e., all drums were clearly RH. As noted above, container No. 

SR503513 is documented in CCP-RC-SRS-601, although SRS-CCP did not provide a dose rate 

survey sheet for this container. Based on SRSRHDTC12003, the container does not meet the 

definition of RH waste by virtue of a measured external dose-rate less than 200 mrem/hr, as 

documented in NCR-RHSRS-0607-13. 
13

(8) Transuranic determinations were evaluated and were found to be adequate. 

DTC BDRs Nos. SRSRHDTC11003, SRSRHDTC12001, SRSRHDTC12002 and 

SRSRHDTC12003 contained activity and mass values with the associated uncertainties for the 

10 WIPP-tracked radionuclides plus other radionuclides, as appropriate. In all cases, the TRU 

alpha concentration exceeded 100 nanocuries per gram. 

(9) The technical basis and documentation of total measurement uncertainty were evaluated 

and found to be adequate. 

The development of total measurement uncertainty (TMU) for Waste Stream SR-RH-221H.01 is 

based on the propagation of uncertainties present in the determination of the waste stream’s 

radiological constituents. These aspects are assumed to be independent, which allows them to be 

added in quadrature.7 The TMU determination included contributions of the following: 

•

241Am DTC correlation—uncertainties due to MCNP5® code, waste mass and source 

distribution within drum, and waste density. 

•

241Am activity measurement—dose rate measurement uncertainty and uncertainty due to 

the contribution of other gamma-emitting radionuclides. 

• Scaling factor uncertainty—ISOCS-derived scaling factor uncertainties, waste density 

uncertainties and CH-derived scaling factor uncertainties. 

A general treatment of TMU for Waste Stream SR-RH-221H.01 is presented in CCP-RC-SRS601, Section 5, and the detailed treatment of TMU is provided in “Uncertainty Analysis for SRRH-221H.01,” calculation package SRS-RH-70 (Reference U004). The overall uncertainties are 

consistent with what EPA has observed for RH determinations at other RH TRU generator sites. 

TMU varies slightly from drum to drum because scaling factors are developed on an individual 

drum basis. Table 5-4 of CCP-RC-SRS-601, Revision 1, provides an example of the TMU 

calculation for Drum No. SR570545. 

7.0 FINDINGS AND CONCERNS 

The EPA inspection team did not identify any findings or concerns relative to the addition of 

Waste Stream SR-RH-221H.01 during this T1 change evaluation. There are no open issues 

relative to this T1 evaluation. 

 

7

 Adding in quadrature is a standard statistical technique that allows one to combine the square root of the 

sum of each contributor to uncertainty squared, resulting in a lower value than what would be obtained if the values 

were simply added. For example, the TMU for 239Pu is derived by taking the square root of (25.0%)2

 plus (10.0%)2

plus (10.0%)2

 plus (100.0%)2 plus (6.6%)2 plus (26.0%)2, which equals 107.4%, which is less than the value

obtained by simply summing the individual uncertainty values (i.e., 177.6%, as shown in CCP Calculation Package: 

Uncertainty Analysis for SR-RH-221H.01, SRS-RH-70). 
14

8.0 CONCLUSIONS 

Changes to Tiering

As a result of this evaluation, EPA did not make any changes to the SRS-CCP RH T1 and T2 

designations that were established during the baseline approval and modified in the February 

2013 T1 approval (Docket No: A-98-49; II-A4-170). 

Approval

This T1 change consisted of the radiological characterization process to characterize SRS Waste 

Stream SR-RH-221H.01 using DTC and scaling factors based on MCS/ISOCS and historical 

assays of the companion CH debris waste stream (see footnote 1) for assigning radionuclide 

values. Based on the results of this evaluation, EPA approves this T1 change consistent with the 

limitations specified in this report. EPA’s approval addresses the 15 drums of TRU waste that are 

the subject of this T1 report. However, this approval also includes any additional drums that are 

added to Waste Stream SR-RH-221H.01 in the future, provided they are characterized using the 

same processes.
A-1 

ATTACHMENT A 

APPROVAL SUMMARY FOR SAVANNAH RIVER SITE REMOTE-HANDLED 

WASTE CHARACTERIZATION PROGRAM 

Approved Activity EPA Inspection Number, 

Approval Dates EPA Docket Number 

SRS RH Baseline Approval EPA-SRS-CCP-RH-08.11-8, 

April 2012 A-98-49; II-A4-161 

T1 Change – Addition of Waste Stream SR-RH-235F.01 February 11, 2013 A-98-49; II-A4-170 
B-1 

ATTACHMENT B 

LIST OF DOCUMENTS REVIEWED BY EPA DURING THE T1 EVALUATION 

CCP-AK-SRS-600, Central Characterization Program Acceptable Knowledge Summary Report 

for Savannah River Site Remote-Handled Transuranic Waste, Waste Streams: SR-RH-221H.01 

and SR-RH-221H.02, Revision 1, November 27, 2012 

CCP-AK-SRS-601, Central Characterization Program Remote-Handled Transuranic 

Radiological Characterization Technical Report for Savannah River Site Remote-Handled 

Transuranic Debris Waste, Waste Stream: SR-RH-221H.01, Revision 1, June 5, 2013 

CCP-CP-SRS-602, Central Characterization Program RH TRU Waste Certification Plan for 40 

CFR Part 194 Compliance for Savannah River Site Waste Stream: SR-RH-221H.01, Revision 0, 

April 16, 2013 

CCP-TP-005, Revision 24, CCP Acceptable Knowledge Documentation, Attachment 15 – CCP 

TRU Waste Correlation and Surrogate Form, SR-RH-221H.01, November 5, 2012 

CCP-TP-504, Dose-to-Curie Survey Procedure for Remote-Handled Transuranic Waste, 

Revision 13, September 17, 2012 

Radiological Survey Reports for Drum Nos. SR570545, SR526227, SR570548, SR513955, 

SR526263, SR570546, SR570547, SR526225, SR526226, SR526264, SR522989, SR526224, 

SR513961, SR522331 and SR545535, dates ranging June 28, 2007–June 26, 2012 

U001, CCP Calculation Package: Determination of the Scaling Factors for SRS-600, D. Ott, 

SRS-RH-67, Revision 1, June 27, 2013 

U002, CCP Calculation Package: Determination of Reportable Radionuclides, D. Ott, SRS-RH68, Revision 0, November 19, 2012 

U003, CCP Calculation Package: DTC and Related Calculations for SR-RH-221H.01, D. Ott, 

SRS-RH-69, Revision 1, June 20, 2013 

U004, CCP Calculation Package: Uncertainty Analysis for SR-RH-221H.01, D. Ott, SRS-RH70, Revision 1, May 20, 2013 

U015, CCP Calculation Package: DTC Modeling and Sensitivity Studies for SRS RH Debris 

Waste, D. Ott, SRS-RH-53, Revision 0, September 9, 2012 

Dose-to-Curie BDR Nos. SRSRHDTC11003, SRSRHDTC12001, SRSRHDTC12002 and 

SRSRHDTC12003