DOCKET NO: A-98-49; II-A4-153 

WASTE CHARACTERIZATION TIER 1 CHANGE REPORT: 

EVALUATION OF THE SUPER HIGH EFFICIENCY NEUTRON COUNTER 

(SuperHENC) NON DESTRUCTIVE ASSAY SYSTEM AT 

THE LOS ALAMOS NATIONAL LABORATORY (LANL) CENTRAL 

CHARACTERIZATION PROJECT 

U.S. Environmental Protection Agency 

Office of Radiation and Indoor Air 

Center of Federal Regulations 

1200 Pennsylvania Avenue, NW

Washington, DC 20460 

October 2011
i

TABLE OF CONTENTS 

Section Page

Abbreviations, Acronyms and Initializations ................................................................................. ii

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

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

3.0 Purpose of This Report ....................................................................................................... 2

4.0 Scope of Evaluation ............................................................................................................ 2

5.0 Evaluation Team ................................................................................................................. 2

6.0 Evaluation of the LANL-CCP SuperHENC ....................................................................... 3

7.0 Summary of Results ............................................................................................................ 9

LIST OF TABLES

Table 1. Evaluation Personnel ........................................................................................................ 3 

ATTACHMENTS 

Attachment A.1 Replicate Testing SuperHENC Results for Container LASB01243 

Attachment A.2 Replicate Testing SuperHENC Results for Container LASB01263 

Attachment A.3 Replicate Testing SuperHENC Results for Container LASB01265 
ii

ABBREVIATIONS, ACRONYMS AND INITIALIZATIONS 

AaS Add-a-Source 

Am americium 

BDR batch data report 

CBFO Carlsbad Field Office 

CCP Central Characterization Project 

Cf californium 

CFR Code of Federal Regulations 

CH contact-handled 

Ci curie 

Cs cesium 

DOE U.S. Department of Energy 

EPA U.S. Environmental Protection Agency 

Eu europium 

FR Federal Register 

FRAM Fixed-Energy Response Function Analysis with Multiple Efficiencies 

FWHM Full-Width-at-Half-Maximum 

g gram 

HENC High Efficiency Neutron Counter 

HERTR High Energy Real-Time Radiography 

HPGe high-purity germanium 

keV kiloelectron volt 

LANL Los Alamos National Laboratory 

LLD lower limit of detection 

LOQI list of qualified individuals 

μCi microcurie 

MDA minimum detectable activity 

MDC minimum detectable concentration 

MGA MultiGroup Analysis 

NCC Neutron Coincidence Counting 

nCi nanocurie 
iii

NDA non-destructive assay 

NIST National Institute of Standards and Technology

NMED New Mexico Environmental Department 

Np neptunium 

PDP Performance Demonstration Program 

Pu plutonium 

SGEAS SuperHENC Gamma Energy Analysis System 

Sr strontium 

SuperHENC Super High Efficiency Neutron Counter 

SWB Standard Waste Box 

T1 Tier 1 

TMU Total Measurement Uncertainty 

TRU transuranic 

U uranium 

WG weapons grade 

WIPP Waste Isolation Pilot Plant 

WTS Washington TRU Solutions 
1

1.0 EXECUTIVE SUMMARY 

This report supports the U.S. Environmental Protection Agency (EPA or the Agency) approval 

of a Tier 1 (T1) change request in the form of the addition of the Super High Efficiency Neutron 

Counter (SuperHENC) non destructive assay (NDA) system. On July 5, 2011, the Carlsbad Field 

Office (CBFO) requested approval of this T1 change. EPA conducted a T1 evaluation of the 

SuperHENC onsite at Los Alamos National Laboratory (LANL) on August 16-17, 2011. 

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

conducted Baseline Inspection No. EPA-LANL-CCP-05.05-8 of the Central Characterization 

Project (CCP), located at LANL from May 3-5, 2005. As a result of this baseline inspection, 

EPA approved the LANL-CCP waste characterization program with conditions and limitations 

as documented in the LANL Baseline Final Inspection Report (see EPA Docket No. A-98-49, IIA4-88). This baseline approval specified three non-destructive assay (NDA) systems, two High 

Efficiency Neutron Counters (HENCs) and one portable tomographic gamma scanner for 

characterizing debris (S5000) and solid (S3000) wastes, respectively1

. LANL-CCP requested 

EPA approval of a Tier 1 (T1) change in the form of the addition of the Super High Efficiency 

Neutron Counter (SuperHENC) for assaying Standard Waste Boxes (SWBs). Based on EPA’s 

evaluation detailed in this report, EPA approves the SuperHENC for assaying contact-handled 

(CH) transuranic (TRU) wastes in SWBs containing four 55-gallon drums of retrievably stored 

S5000 debris waste and uncontained (loose) S5000 debris waste 

This report serves as EPA’s evaluation of the SuperHENC at LANL-CCP as a T1 change. Using 

the information provided in this report, EPA has determined that the SuperHENC is adequate for 

characterization of CH TRU waste. Changes to the approved components of the SuperHENC 

system at LANL-CCP must follow the tiering requirements described in the baseline inspection 

report issued for the LANL-CCP CH program (Docket No. A-98-49, II-A4-88, June 2007). 

 

2.0 PURPOSE OF TIER 1 EVALUATIONS 

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

be in the LANL-CCP Baseline Final Report cited above. Under the changes to 40 CFR 194.8 

promulgated in the July 16, 2004, Federal Register notice, EPA must perform a single baseline 

inspection of a TRU waste generator site’s waste characterization program and approve the 

program. EPA’s approval must be based on the demonstration that the program’s components, 

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

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

EPA inspection team conducts an on-site inspection to verify that the site’s system of controls is 

technically adequate and properly implemented. 

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

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

approved waste characterization program by conducting additional inspections under the 

 

1

 NDA systems are typically not matrix-specific in the same manner as other characterization techniques and 

their approval is not tied to specific waste matrix categories (i.e., S3000 or S5000). Specifically, virtually any 

material within the system’s matrix calibration range may be assayed. 
2

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

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

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

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

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

specified which subsequent waste characterization program changes or modifications must 

undergo further EPA approval under 40 CFR 194.24. This was accomplished by assigning a tier 

level to each aspect of LANL-CCP’s characterization program. Tier 1 (T1) activities have more 

stringent reporting requirements and require that DOE notify EPA, and that EPA provide 

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

be found in the Federal Register (Vol. 69, No. 136, pages 42571–42583 of July 16, 2004). 

3.0 PURPOSE OF THIS REPORT 

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

LANL SuperHENC NDA system (NDA PDP2 Registration Number LA08/LAN7) for assaying 

CH TRU wastes. This report documents the basis for EPA’s approval decision and explains the 

results of the technical evaluation of the SuperHENC at LANL-CCP. EPA’s final approval 

decision regarding the LANL-CCP SuperHENC 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). 

4.0 SCOPE OF EVALUATION 

The scope of this evaluation was the operation of the SuperHENC NDA system located at 

LANL-CCP. The SuperHENC was evaluated with respect to its ability to identify and quantify 

the activities of the 10 WIPP-tracked radionuclides, the lower limit of detection (LLD), total 

measurement uncertainty (TMU), and other related technical aspects, including the performance 

of replicate analyses of containers and the statistical evaluation of those replicates as described in

Section 6 of this report. 

5.0 EVALUATION TEAM 

All personnel involved in the SuperHENC evaluation are listed in Table 1, along with each 

person’s affiliation and function for the purpose of this inspection. 

 

2

 PDP is the CBFO sponsored NDA Performance Demonstration Program. 
3

Table 1. Evaluation Personnel 

Personnel Affiliation Evaluation Function - Area of 

Expertise 

Edward Feltcorn US EPA HQ EPA Evaluation Team Leader, NDA 

Rajani Joglekar US EPA HQ EPA Inspector, NDA 

Patrick Kelly SC&A EPA Inspector, NDA 

Rose Gogliotti SC&A EPA Inspector, NDA 

Dorothy Gill SC&A EPA Inspector, NDE 

Norma Castaneda DOE/CBFO Observer/NTP Manager 

Michael Sensibaugh CCP/WTS CCP Projects Manager 

Joe Harvill CCP/WTS Technical Support, SuperHENC 

Craig Simmons CCP/WTS Project Manager 

Neil Dickes CCP/WTS Technical Support, SuperHENC 

John Bevz CCP/WTS TRU Waste Engineering 

Sean Stanfield CCP/Canberra Technical Support, SuperHENC 

Daphne Brotheis CCP NDE Lead Operator/ Escort 

Tim Hall NMED Observer 

Ricardo Maestas NMED Observer 

6.0 EVALUATION OF THE LANL-CCP SUPERHENC 

EPA inspected one SuperHENC NDA system that will be used to characterize CH TRU wastes 

at LANL-CCP. The inspection occurred as an on-site evaluation of the SuperHENC system and 

associated records and personnel at LANL on August 16-17, 2011. As part of the inspection, 

EPA reviewed the following elements of the SuperHENC process: 

• Capability of the measurement hardware and software to perform the required analyses 

• Technical adequacy of the NDA documents and procedures 

• Knowledge and understanding of the personnel involved in the NDA program 

Attachment A identifies the objective evidence that was examined for EPA’s evaluation. The 

following documents were examined to assess the LANL-CCP SuperHENC: 

• CCP-CM-032, CCP SuperHENC (High-Efficiency Neutron Counter) Equipment 

Description, Draft, Revision 0), Draft D 

• CCP-TP-059, CCP Operating the Super High Efficiency Neutron Counter (SuperHENC) 

Using NDA 2000, Revision 0, May 4, 2011 

• CCP-TP-103, CCP Data Reviewing, Validating, and Reporting Procedure for the High 

Efficiency Neutron Counter and the Super High Efficiency Neutron Counter Using 

NDA2000, Revision 9, March 14, 2011 

• CCP-TP-103, CCP Data Reviewing, Validating, and Reporting Procedure for the High 

Efficiency Neutron Counter and the Super High Efficiency Neutron Counter Using 

NDA2000, Revision 10, DRAFT 
4

• CCP-TP-064, CCP Calibrating the High Efficiency Neutron Counter and the Super High 

Efficiency Neutron Counter Using NDA 2000, Revision 6, April 6, 2011 

• LANL-SHENC3-NDA-1003, Calibration Report for the SuperHENC at Los Alamos 

National Laboratory Including Passive Neutron and Gamma Spectrometer Calibration 

and Confirmation, Revision 0, May 12, 2011 

• CI-SHENC-TMU-102, Total Measurement Uncertainty for the Los Alamos SuperHENC 

with Gamma Spectroscopy, Revision 0, May 25, 2011 

• CCP-AK-LANL-006, Central Characterization Project Acceptable Knowledge Summary 

Report for Los Alamos National Laboratory TA-55 Mixed Transuranic Waste, Waste 

Streams: LA-MHD01.001, LACIN01.001, LA-MIN02-V.001, LA-MIN04-S.001, 

Revision 10, May 4 2010 

• CCP- LANL List of Qualified Individuals (LOQI), July 27, 2011 and August 11, 2011 

• CSM-01-06, Idaho National Laboratory Central Characterization Facility Standard Waste 

Box Matrix Surrogate Inspection Summary Report, September 18, 2006 

• Sample SuperHENC BDR Nos. 3LANDA0003, July 15, 2011; 3LANDA0004, July 20-

21, 2011; and 3LANDA0005, July 21, 2011 

During the inspection, the EPA inspection team members assessed several technical elements of 

the SuperHENC system that are detailed in Attachment A and are discussed below. 

(1) The design and operational history of the SuperHENC was assessed. 

The SuperHENC system is located in a trailer on site at LANL in TA 54 on Pad 10 in Area G, 

Building No. 547. The SuperHENC is a self-contained NDA unit that is physically housed in a 

mobile manufactured enclosure made up of a “High-Cube” freight container measuring 

approximately 48 feet long by 8-1/2 feet wide by 13-1/2 feet high. It has the capability to 

measure SWBs, 55-gallon and 100-gallon product drums and is used for TRU and non-TRU 

waste container sorting using integrated neutron/gamma algorithms. 

The SuperHENC was previously deployed at the Hanford Site’s Plutonium Finishing Plant, 

though it has never been certified for WIPP assays. It was moved to LANL where it was 

refurbished to operate under the Canberra NDA2000 Software. LANL-CCP will use this system 

to assay only SWBs, and LANL-CCP does not anticipate a need to use the SuperHENC to assay 

container types other than an SWB or wastes other than S5000 debris. The addition of other 

container types would require a T1 change. 

The possible assay configuration for the SuperHENC is as follows: 

• SWBs containing four 55-gallon drums of retrievably stored S5000 debris waste 

• SWBs containing S5000 debris waste 

This system consists of a passive neutron coincidence counter and two integral gamma-ray 

spectrometers, the SuperHENC Gamma Energy Analysis System (SGEAS). The passive neutron 

counter uses 260 3He proportional counters in a 4-π geometry and an external 252Cf source for 
5

the Add-a-Source (AaS) matrix correction function. The neutron component determines the mass 

of spontaneously fissioning material in waste containers, referred to as the 240PuEffective (

240PuEff). 

The 240PuEff is defined as the amount of 240Pu that would produce the observed true coincidence

rate, after correcting for the neutron moderation properties of the waste matrix. The system’s 

calibration is based on measurements of a non-interfering matrix and it includes a curve that 

relates the measured doubles rate for each container with the 240PuEff, as documented in LANLSHENC3-NDA-1003. An AaS correction factor is necessary to effectively correct for cases 

where the matrix and radioactive contents are non-uniform. The AaS correction curve is 

sufficiently robust to enable corrections over a wide range of materials or matrices. The 

SuperHENC is operated by a custom-tailored version of the LANL Neutron Coincidence 

Counting (NCC) software that controls data collection and analysis, AaS movements and all 

calibration and exception handling functions. 

 

The SGEAS consists of two high-purity germanium (HPGe) detectors that function in two 

modes: relative ratio mode, where isotopic ratios are determined using the PCFRAM3 isotopic 

code; and absolute mode, where the quantities of specific radionuclides are determined based on 

analyzing gamma spectra. The gamma ray spectrometers are appropriate for direct quantification 

of plutonium-238 (238Pu), 239Pu, 240Pu, americium-241 (241Am), uranium-233 (233U), 235U, 238U, 

cesium-137 (137Cs), and neptunium-237 (237Np). The detectors use a multi-curve efficiency 

calibration to compensate for variations in matrix density. The gamma spectrometers also are 

used to acquire spectra for the determination of plutonium isotopic ratios. Ratios are also 

determined through MultiGroup Analysis (MGA) and Fixed-energy Response-function Analysis 

with Multiple-efficiencies (FRAM) software. Each detector is covered with a combination tincopper filter. The filters are removable, although the instrument is not currently calibrated for use 

without the filters or with any other filters. 

Data acquisition and analysis are handled by Canberra Genie 2000 and NDA 2000 software 

working in concert. A reporting threshold is derived for those radionuclides that are not directly 

measured. Each waste container’s 234U content is performed by application of scaling factors that 

are based on observed values for 235U and 238U. The determination of 90Sr is performed by 

application of a scaling factor based on 137Cs. 

There are no EPA technical concerns regarding the design and ability of the SuperHENC to 

quantify the 10 WIPP-tracked radionuclides. 

(2) The passive neutron and gamma calibrations of the SuperHENC had been performed as 

required and adequately documented. 

The original calibration of the SuperHENC was performed at Hanford; this calibration was never 

used for WIPP waste characterization. The calibration of record for the LANL-CCP SuperHENC 

was completed on May 12, 2011. This calibration was confirmed at LANL, and is documented in 

LANL-SHENC3-NDA-1003. Calibration confirmation was performed with six measurements of 

an empty SWB over a range of Pu loadings from 0.006 to 34.01 g 240PuEff (0.1 to 190 g Pu 

 

3

 PCFRAM or FRAM is an initialization for Fixed-Energy Response Function Analysis with Multiple 

Efficiencies, a software code that is often used to determine the relative abundance (isotopic distribution) of 

radionuclides in weapons grade (WG) Pu. 
6

Total). The acceptance criteria for accuracy (Percent Recovery) and precision (Percent Relative 

Standard Deviation) were met for each of the six runs. The calibration itself is matrix 

independent, and additional testing will be performed in the future through the Weekly 

Interfering Matrix Checks that are required in DOE-WIPP-02-3122. The system’s stated 

operational range for neutron assays is from the Lower Limit of Detection or LLD (discussed 

below) to 34.0 g 240PuEff. The stated range for gamma assays is the LLD to 325 g weapons grade 

(WG) Pu, as stated in LANL-SHENC3-NDA-1003. 

The calibration for the HPGe was performed using a set of NIST traceable sources. Three photon 

lines from 152Eu at 121.8, 344.8 and 778.9 keV are used for this calibration. This relationship is 

checked daily to ensure that the 344.8 keV peak’s centroid and Full-Width-Half-Maximum 

(FWHM) are within predetermined criteria shown in LANL-SHENC3-NDA-1003, Table 2. 

Because the SGEAS is used in relative ratio mode only, there is no true gamma operational 

range, although between 1 and 5 g of WG Pu are needed to successfully execute FRAM, 

depending on the matrix. These efforts are documented in WTS CCP LANL SWB Summary 

Report WIPP1-406914, Idaho National Laboratory Central Characterization Facility Standard 

Waste Box Matrix Surrogate Inspection Summary Report dated September 18, 2006. This is a 

reasonable approach to procuring additional matrix standards suitable for the SuperHENC. At 

this time, LANL-CCP stated that there was no plan to calibrate the SuperHENC for other waste 

containers. 

There are no technical concerns regarding the passive neutron and gamma calibrations of the 

SuperHENC. 

(3) The total measurement uncertainty of assays performed on the SuperHENC had been 

determined and documented. 

The determination of the total measurement uncertainty (TMU) for the SuperHENC is 

documented in CI-SHENC-TMU-102, Revision 0. Section 3 of this document addresses the 

effects on the passive neutron assay of the contributions from source position, calibration 

uncertainty and counting statistics, background, self-shielding, systematic end and spatial effects, 

neutron multiplication and isotopics. The TMU is different for each measurement because of 

variations in matrix, radioactive content and measurements conditions. 

For the gamma component, the evaluation includes the propagation of both random and 

systematic uncertainties. Random uncertainties are derived from counting statistics and as 

calculated by the analysis software. Systematic uncertainties include those related to source 

distribution effects and matrix non-homogeneities. It is assumed that individual uncertainty 

components are statistically independent, allowing them to be added in quadrature. The primary 

sources of uncertainty in the gamma analysis include: counting statistics; inferences from other 

radionuclides present; matrix non-homogeneity; isotopic measurement uncertainty background 

fluctuations; calibration source uncertainties; source distribution within the matrix; and selfabsorption. These are discussed in detail in CI-SHENC-TMU-102, Section 4. There are no 

technical concerns regarding the determination and documentation of TMU for the LANL-CCP 

SuperHENC. 
7

(4) The Lower Limit of Detection, including the minimum detectable concentration, of the 

SuperHENC had been determined and documented. 

The LLD was defined in CCP-PO-002, “CCP Transuranic Waste Certification Plan,” as: 

That level of radioactivity which, if present, yields a measured value greater than 

the critical level with a 95% probability, where the critical level is defined as that 

value which measurements of the background will exceed with 5% probability. 

In order to be able to discriminate TRU and non-TRU wastes, an NDA system must have an 

LLD less than 100 nCi of TRU alpha activity per gram (nCi/g) of waste. The LLD of any given 

NDA measurement depends on the type of measurement (passive neutron or gamma), the 

properties of the waste matrix being assayed, the data acquisition (measurement) time, and the 

environmental background. For this reason, the LLD is expected to vary from drum to drum and 

also may vary between measurements of the same drum. To determine the minimum detectable 

activities (MDAs) for the ten WIPP-tracked radionuclides, sets of three replicate measurements 

were performed on one surrogate matrix SWB without radioactive sources. NDA 2000 software 

calculated the MDAs from these measurements and the MDAs were then used to calculate the 

minimum detectable concentrations (MDCs) based on the surrogate matrix’s net weight. The 

surrogate matrix used for the gamma MDA calculations was plywood and cardboard. MDCs for 

the gamma and neutron modalities were calculated in this way and are shown in LANLSHENC3-NDA-1003, Tables 7a and 7b. Only measured values that exceeded the reported LLD 

for a measurement will be reported and used in calculations of derived quantities, such as total 

TRU alpha activity and TRU alpha activity concentration. There are no technical concerns 

regarding the technical derivation and application of LLDs and LLD equivalents relative to the 

SuperHENC. 

(5) EPA replicate testing of the SuperHENC was performed and evaluated. 

The purpose of the replicate testing performed as part of this inspection is to provide EPA with 

an independent means to verify that the SuperHENC can provide consistent, reproducible results 

for the determination of the quantity of 10 WIPP-tracked radionuclides (241Am, 137Cs, 238Pu, 

239Pu, 240Pu, 242Pu, 90Sr, 233U, 234U and 238U) and the TRU alpha concentration. This is normally 

accomplished by requesting that the site reassay drums that were previously characterized on the 

same system or instrument in order to demonstrate the following: 

• The instrument produces results consistent with the reported TMU by comparing the 

sample standard deviation for a number of replicate measurements taken over several 

hours or days to the reported TMU. 

• The instrument provides 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. 

EPA requested that LANL-CCP reassay three SWBs that EPA randomly selected from a list of 

nine containers previously assayed on the SuperHENC. Two of the nine SWBs were rejected 

from their initial assay and EPA chose the replicates from the remaining seven. Each SWB was 
8

packed with four 55-gallon drums containing S5000 waste, each of which had a valid assay from 

one of the LANL-CCP HENC NDA instruments. At the time of this evaluation, the LANL-CCP 

High Energy Real-Time Radiography (HERTR) unit was not operational. This unit is needed to 

determine the fill height of S5000 wastes that have been directly loaded in an SWB. The 55-

gallon drums had a fill height from their initial assay on the HENC and the fill heights of the four 

drums were used to determine the fill height of the SWB. This approach was used to demonstrate 

the functionality of the SuperHENC and although each SWB assay met WIPP acceptance 

criteria, none of the seven SWB assays will be used as the assay of record. This was discussed 

with LANL-CCP and CBFO personnel and EPA determined that the assays provided sufficient 

evidence of the SuperHENC’s functionality. As a courtesy, LANL-CCP agreed to provide EPA 

with the first BDR containing waste assayed on the SuperHENC when the HERTR is 

operational. 

Due to the system’s short operational history, the list of potential candidates for replicate assays 

was small, and the time between the original measurement and the five replicates was short. EPA 

chose four SWBs, Container Nos. LASB01243, LASB01263, and LASB01265, each of which 

contained four previously-assayed 55-gallon drums of S5000 debris waste, as discussed above. 

Each SWB was reassayed five times on the SuperHENC and two statistical tests, a chi squared 

(χ2) test and a t test, were performed on the replicate analyses. Analytical data for each assay 

event and results of the statistical analysis are included in Attachments A.1 through A.3. 

The chi squared test on SWB Containers Nos. LASB01243 and LASB01263 resulted in 

significant and highly significant flags, respectively, for the difference between the original 

measurement assay values and the average of the five replicate measurements for 237Np. The 

original 237Np assay value for Container No. LASB01243 was 27.6 μCi, while the sample mean 

for the five replicates was 28.7 μCi. This represents a relatively low activity of 237Np to be 

determined in the presence of concentrations of its progenitor (241Am) approximately 200 times 

higher (5.4 Ci), and the magnitude of the difference is small. The values for the five replicates 

for 237Np range from 20.3 to 32.8 μCi, with the original assay value occurring approximately in 

the center of this distribution. The original assay value for Container No. LASB01263 for 237Np 

was 8 μCi, while the sample mean for the five replicates was 7.8 μCi. Again, this represents a 

relatively low activity of 237Np to be determined in the presence of concentrations of its 

progenitor at significantly higher concentrations, and the magnitude of the difference is small. 

The values for the five replicates for 237Np range from 6.2 to 9.5 μCi, with the original value 

occurring approximately in the center of the distribution. In both instances, the flags are due to 

the variability in the five replicate assays. The 237Np flags are of minimal concern mainly 

because: 237Np is not a WIPP-tracked radionuclide; the differences among the values in absolute 

terms is small; and the decay of large concentrations of 241Am can produce variability in the 

237Np content as were observed here, the statistical results notwithstanding. All other replicate 

measurements for all three containers passed both statistical tests. There are no technical 

concerns regarding the ability of the SuperHENC to provide consistent, reproducible results for 

the determination of the quantity of 10 WIPP-tracked radionuclides. 
9

7.0 SUMMARY OF RESULTS 

During this T1 evaluation, EPA evaluated the performance of the LANL-CCP SuperHENC. The 

EPA evaluation did not identify any concerns or findings related to the operation of the LANLCCP SuperHENC. Based on the results of this evaluation, EPA is approving the LANL-CCP 

SuperHENC NDA system for assaying retrievably stored and/or newly generated wastes in the 

following configurations: 

• SWBs containing four 55-gallon drums of retrievably stored S5000 debris waste 

• SWBs containing S5000 debris waste 

This approval does not make any changes to the tiering table provided with the baseline 

approval, with the exception of adding the SuperHENC. Changes to the approved components of 

the SuperHENC system at LANL-CCP must follow the tiering requirements described in the 

LANL-CCP CH baseline inspection report.
Attachments A.1 through A.3
Attachment A.1 SuperHENC Replicate Testing Results for Container LASB01243 (SW

A-1 

Instrument: SuperHENC

Container: LASB01243, SWB 

Original Measurement Replicate #1 

Quantity of Reported Absolute Relative Reported Absolute Relative Reported Interest Value Uncertainty Uncertainty Value Uncertainty Uncertainty Value 233U Activity (Ci) N/A N/A 234U Activity (Ci) N/A N/A 238U Activity (Ci) N/A N/A 238Pu Activity (Ci) 5.30E+00 6.10E-01 1.15E-01 5.70E+00 3.30E-01 5.79E-02 6.10E+00 239Pu Activity (Ci) 8.78E+00 1.00E+00 1.14E-01 9.44E+00 5.25E-01 5.56E-02 1.02E+01 240Pu Activity (Ci) 2.67E+00 3.28E-01 1.23E-01 2.88E+00 2.06E-01 7.15E-02 3.10E+00 242Pu Activity (Ci) 1.09E-03 1.31E-04 1.20E-01 1.17E-03 4.40E-04 3.76E-01 1.26E-03 241Am Activity (Ci) 5.25E+00 6.00E-01 1.14E-01 5.13E+00 2.88E-01 5.61E-02 6.09E+00 90Sr Activity (Ci) N/A N/A 137Cs Activity (Ci) N/A N/A TRU Alpha Conc. (nCi/g) 1.16E+05 7.18E+03 6.19E-02 1.23E+05 3.78E+03 3.07E-02 1.35E+05 

Replicate #3 Replicate #4 

Quantity of Reported Absolute Relative Reported Absolute Relative Reported Interest Value Uncertainty Uncertainty Value Uncertainty Uncertainty Value 233U Activity (Ci) N/A N/A 234U Activity (Ci) N/A N/A 238U Activity (Ci) N/A N/A 238Pu Activity (Ci) 5.44E+00 3.14E-01 5.77E-02 4.84E+00 2.80E-01 5.79E-02 5.56E+00 239Pu Activity (Ci) 9.02E+00 5.00E-01 5.54E-02 8.01E+00 4.46E-01 5.57E-02 9.21E+00 240Pu Activity (Ci) 2.75E+00 1.96E-01 7.13E-02 2.44E+00 1.75E-01 7.17E-02 2.80E+00 242Pu Activity (Ci) 1.12E-03 7.47E-05 6.67E-02 9.94E-04 6.66E-05 6.70E-02 1.14E-03 241Am Activity (Ci) 5.39E+00 3.01E-01 5.58E-02 4.80E+00 2.69E-01 5.60E-02 5.51E+00 90Sr Activity (Ci) N/A N/A 137Cs Activity (Ci) N/A N/A TRU Alpha Conc. (nCi/g) 1.20E+05 3.65E+03 3.04E-02 1.06E+05 3.26E+03 3.08E-02 1.22E+05 
Attachment A.1 SuperHENC Replicate Testing Results for Container LASB01243 (SW

A-2 

Instrument: SuperHENC

Container: LASB01243, SWB

Original Measurement Sample Relative

Quantity of Reported Absolute Sample Standard StandardInterest Value Uncertainty Mean Deviation Deviation χ

2 Pr(

x <|χ

2|) 

233U Activity (Ci) 0.00E+00 N/A N/A N/A N/A N/A N/234U Activity (Ci) 0.00E+00 N/A N/A N/A N/A N/A N/238U Activity (Ci) 0.00E+00 N/A N/A N/A N/A N/A N/238Pu Activity (Ci) 5.30E+00 6.10E-01 5.53E+00 4.58E-01 8.28E-02 2.25E+00 6.89E-0239Pu Activity (Ci) 8.78E+00 1.00E+00 9.18E+00 7.91E-01 8.62E-02 2.50E+00 6.44E-0240Pu Activity (Ci) 2.67E+00 3.28E-01 2.79E+00 2.39E-01 8.55E-02 2.12E+00 7.13E-0242Pu Activity (Ci) 1.09E-03 1.31E-04 1.14E-03 9.61E-05 8.46E-02 2.15E+00 7.07E-0241Am Activity (Ci) 5.25E+00 6.00E-01 5.38E+00 4.80E-01 8.91E-02 2.56E+00 6.35E-090Sr Activity (Ci) 0.00E+00 N/A N/A N/A N/A N/A N/137Cs Activity (Ci) 0.00E+00 N/A N/A N/A N/A N/A N/TRU Alpha Conc. (nCi/g) 1.16E+05 7.18E+03 1.21E+05 1.03E+04 8.52E-02 8.28E+00 8.19E-0Quantity ofInterest χ

2 Test t Test 

233U Activity (Ci) Not Applicable Not Applicable 234U Activity (Ci) Not Applicable Not Applicable 238U Activity (Ci) Not Applicable Not Applicable 238Pu Activity (Ci) Not Significant Not Significant239Pu Activity (Ci) Not Significant Not Significant 240Pu Activity (Ci) Not Significant Not Significant 242Pu Activity (Ci) Not Significant Not Significant 241Am Activity (Ci) Not Significant Not Significant 90Sr Activity (Ci) Not Applicable Not Applicable 137Cs Activity (Ci) Not Applicable Not Applicable TRU Alpha Conc. (nCi/g) Not Significant Not Significant 
Attachment A.2 SuperHENC Replicate Testing Results for Container LASB01263 (SW

A-3 

Instrument: SuperHENCContainer: LASB01263, SWB 

Original Measurement Replicate #1 

Quantity of Reported Absolute Relative Reported Absolute Relative Reported Interest Value Uncertainty Uncertainty Value Uncertainty Uncertainty Value 233U Activity (Ci) N/A N/A 234U Activity (Ci) N/A N/A 238U Activity (Ci) N/A N/A 238Pu Activity (Ci) 3.73E+00 9.94E-01 2.66E-01 3.73E+00 9.75E-01 2.61E-01 3.61E+00 239Pu Activity (Ci) 5.93E-01 1.58E-01 2.66E-01 5.94E-01 1.55E-01 2.61E-01 5.75E-01 240Pu Activity (Ci) 1.59E-01 4.23E-02 2.66E-01 1.59E-01 4.15E-02 2.61E-01 1.54E-01 242Pu Activity (Ci) 1.75E-04 4.66E-05 2.66E-01 1.75E-04 4.57E-05 2.61E-01 1.69E-04 241Am Activity (Ci) 5.39E-01 1.44E-01 2.67E-01 5.40E-01 1.41E-01 2.61E-01 5.21E-01 90Sr Activity (Ci) N/A N/A 137Cs Activity (Ci) N/A N/A TRU Alpha Conc. (nCi/g) 1.60E+04 3.25E+03 2.03E-01 1.60E+04 3.19E+03 1.99E-01 1.55E+04 

Replicate #3 Replicate #4 

Quantity of Reported Absolute Relative Reported Absolute Relative Reported Interest Value Uncertainty Uncertainty Value Uncertainty Uncertainty Value 233U Activity (Ci) N/A N/A 234U Activity (Ci) N/A N/A 238U Activity (Ci) N/A N/A 238Pu Activity (Ci) 3.66E+00 9.59E-01 2.62E-01 3.90E+00 1.01E+00 2.59E-01 3.74E+00 239Pu Activity (Ci) 5.82E-01 1.53E-01 2.63E-01 6.20E-01 1.61E-01 2.60E-01 5.95E-01 240Pu Activity (Ci) 1.56E-01 4.08E-02 2.62E-01 1.66E-01 4.30E-02 2.59E-01 1.59E-01 242Pu Activity (Ci) 1.72E-04 4.50E-05 2.62E-01 1.83E-04 4.74E-05 2.59E-01 1.75E-04 241Am Activity (Ci) 5.28E-01 1.38E-01 2.61E-01 5.62E-01 1.46E-01 2.60E-01 5.41E-01 90Sr Activity (Ci) N/A N/A 137Cs Activity (Ci) N/A N/A TRU Alpha Conc. (nCi/g) 1.57E+04 3.14E+03 2.00E-01 1.68E+04 3.31E+03 1.97E-01 1.61E+04 
Attachment A.2 SuperHENC Replicate Testing Results for Container LASB01263 (SW

A-4 

Instrument: SuperHENCContainer: LASB01263, SWB

Original Measurement Sample Relative

Quantity of Reported Absolute Sample Standard StandardInterest Value Uncertainty Mean Deviation Deviation χ2 Pr(x <|χ2|) 233U Activity (Ci) 0.00E+00 N/A N/A N/A N/A N/A N/234U Activity (Ci) 0.00E+00 N/A N/A N/A N/A N/A N/238U Activity (Ci) 0.00E+00 N/A N/A N/A N/A N/A N/238Pu Activity (Ci) 3.73E+00 9.94E-01 3.73E+00 1.10E-01 2.95E-02 4.89E-02 1.00E+0239Pu Activity (Ci) 5.93E-01 1.58E-01 5.93E-01 1.72E-02 2.89E-02 4.72E-02 1.00E+0240Pu Activity (Ci) 1.59E-01 4.23E-02 1.59E-01 4.55E-03 2.87E-02 4.63E-02 1.00E+0242Pu Activity (Ci) 1.75E-04 4.66E-05 1.75E-04 5.22E-06 2.98E-02 5.01E-02 1.00E+0241Am Activity (Ci) 5.39E-01 1.44E-01 5.38E-01 1.56E-02 2.90E-02 4.71E-02 1.00E+090Sr Activity (Ci) 0.00E+00 N/A N/A N/A N/A N/A N/137Cs Activity (Ci) 0.00E+00 N/A N/A N/A N/A N/A N/TRU Alpha Conc. (nCi/g) 1.60E+04 3.25E+03 1.60E+04 4.97E+02 3.10E-02 9.35E-02 9.99E-0Quantity ofInterest χ2 Test t Test 233U Activity (Ci) Not Applicable Not Applicable 234U Activity (Ci) Not Applicable Not Applicable 238U Activity (Ci) Not Applicable Not Applicable 238Pu Activity (Ci) Not Significant Not Significant 239Pu Activity (Ci) Not Significant Not Significant 240Pu Activity (Ci) Not Significant Not Significant 242Pu Activity (Ci) Not Significant Not Significant 241Am Activity (Ci) Not Significant Not Significant 90Sr Activity (Ci) Not Applicable Not Applicable 137Cs Activity (Ci) Not Applicable Not Applicable TRU Alpha Conc. (nCi/g) Not Significant Not Significant 
Attachment A.3 SuperHENC Replicate Testing Results for Container LASB01265 (SW

A-5 

Instrument: SuperHENCContainer: LASB01265, SWB 

Original Measurement Replicate #1 

Quantity of Reported Absolute Relative Reported Absolute Relative Reported Interest Value Uncertainty Uncertainty Value Uncertainty Uncertainty Value 233U Activity (Ci) N/A N/A 234U Activity (Ci) N/A N/A 238U Activity (Ci) N/A N/A 238Pu Activity (Ci) 1.24E+00 3.27E-01 2.64E-01 1.19E+00 3.14E-01 2.64E-01 1.23E+00 239Pu Activity (Ci) 7.94E+00 2.10E+00 2.64E-01 7.62E+00 2.01E+00 2.64E-01 7.89E+00 240Pu Activity (Ci) 1.92E+00 5.06E-01 2.64E-01 1.84E+00 4.85E-01 2.64E-01 1.90E+00 242Pu Activity (Ci) 3.28E-04 8.66E-05 2.64E-01 3.15E-04 8.31E-05 2.64E-01 3.26E-04 241Am Activity (Ci) 1.90E+00 5.02E-01 2.64E-01 1.80E+00 4.76E-01 2.64E-01 1.89E+00 90Sr Activity (Ci) N/A N/A 137Cs Activity (Ci) N/A N/A TRU Alpha Conc. (nCi/g) 6.92E+04 1.19E+04 1.72E-01 6.62E+04 1.14E+04 1.72E-01 6.87E+04 

Replicate #3 Replicate #4 

Quantity of Reported Absolute Relative Reported Absolute Relative Reported Interest Value Uncertainty Uncertainty Value Uncertainty Uncertainty Value 233U Activity (Ci) N/A N/A 234U Activity (Ci) N/A N/A 238U Activity (Ci) N/A N/A 238Pu Activity (Ci) 1.22E+00 3.22E-01 2.64E-01 1.27E+00 3.36E-01 2.65E-01 1.23E+00 239Pu Activity (Ci) 7.82E+00 2.06E+00 2.63E-01 8.15E+00 2.15E+00 2.64E-01 7.87E+00 240Pu Activity (Ci) 1.89E+00 4.98E-01 2.63E-01 1.97E+00 5.19E-01 2.63E-01 1.90E+00 242Pu Activity (Ci) 3.23E-04 8.53E-05 2.64E-01 3.37E-04 8.88E-05 2.64E-01 3.25E-04 241Am Activity (Ci) 1.87E+00 4.95E-01 2.65E-01 1.95E+00 5.16E-01 2.65E-01 1.89E+00 90Sr Activity (Ci) N/A N/A 137Cs Activity (Ci) N/A N/A TRU Alpha Conc. (nCi/g) 6.81E+04 1.17E+04 1.72E-01 7.09E+04 1.22E+04 1.72E-01 6.86E+04 
Attachment A.3 SuperHENC Replicate Testing Results for Container LASB01265 (SW

A-6 

Instrument: SuperHENCContainer: LASB0126

5, SWB

Original Measurement Sample Relative

Quantity of Reported Absolute Sample Standard StandardInterest Value Uncertainty Mean Deviation Deviation χ

2 Pr(

x <|χ

2|) 

233U Activity (Ci) 0.00E+00 N/A N/A N/A N/A N/A N/234U Activity (Ci) 0.00E+00 N/A N/A N/A N/A N/A N/238U Activity (Ci) 0.00E+00 N/A N/A N/A N/A N/A N/238Pu Activity (Ci) 1.24E+00 3.27E-01 1.23E+00 2.86E-02 2.33E-02 3.07E-02 1.00E+0239Pu Activity (Ci) 7.94E+00 2.10E+00 7.87E+00 1.90E-01 2.41E-02 3.26E-02 1.00E+0240Pu Activity (Ci) 1.92E+00 5.06E-01 1.90E+00 4.64E-02 2.44E-02 3.36E-02 1.00E+0242Pu Activity (Ci) 3.28E-04 8.66E-05 3.25E-04 7.89E-06 2.43E-02 3.32E-02 1.00E+0241Am Activity (Ci) 1.90E+00 5.02E-01 1.88E+00 5.39E-02 2.86E-02 4.60E-02 1.00E+090Sr Activity (Ci) 0.00E+00 N/A N/A N/A N/A N/A N/137Cs Activity (Ci) 0.00E+00 N/A N/A N/A N/A N/A N/TRU Alpha Conc. (nCi/g) 6.92E+04 1.19E+04 6.85E+04 1.68E+03 2.45E-02 7.95E-02 9.99E-0Quantity ofInterest χ

2 Test t Test 

233U Activity (Ci) Not Applicable Not Applicable 234U Activity (Ci) Not Applicable Not Applicable 238U Activity (Ci) Not Applicable Not Applicable 238Pu Activity (Ci) Not Significant Not Significant 239Pu Activity (Ci) Not Significant Not Significant 240Pu Activity (Ci) Not Significant Not Significant 242Pu Activity (Ci) Not Significant Not Significant 241Am Activity (Ci) Not Significant Not Significant 90Sr Activity (Ci) Not Applicable Not Applicable 137Cs Activity (Ci) Not Applicable Not Applicable TRU Alpha Conc. (nCi/g) Not Significant Not Significant