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Enclosure - U.S. Nuclear Regulatory Commission Technical Evaluation Report for the Draft Waste Incidental to Reprocessing Evaluation for the Test Bed Initiative Demonstration (Docket No. PROJ0736)
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Site:	PROJ0736
Issue date:	07/31/2022
From:	George Alexander, Maurice Heath; NRC/NMSS/DDUWP/LLWPB
To:	Mullis J; US Dept of Energy, Office of Environmental Management
	Maurice Heath, 301-415-3137
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Enclosure Technical Evaluation Report Draft Waste Incidental to Reprocessing Evaluation for the Test Bed Initiative Demonstration Final Report U.S. Nuclear Regulatory Commission Office of Nuclear Material Safety and Safeguards Washington, DC 20555-0001 July 2022 Prepared by:

G. Alexander, M. Heath CONTENTS 1.

Introduction............................................................................................................................4 1.1.

Regulatory Framework....................................................................................................4 1.2.

NRC Review Approach...................................................................................................6 1.3.

Scope of the TER............................................................................................................6 2.

Review Context......................................................................................................................7 3.

Criterion A - Key Radionuclides Removed............................................................................7 3.1.

Key Radionuclides..........................................................................................................7 3.1.1.

DOE Identification of Key Radionuclides.................................................................7 3.1.2.

NRC Evaluation of Identification of Key Radionuclides...........................................8 3.2.

Removal to the Maximum Extent Practical.....................................................................9 3.2.1.

DOE Analyses of Removal to the Maximum Extent Practical..................................9 3.2.2.

NRC Evaluation of Removal to the Maximum Extent Practical.............................10 3.3.

NRC Conclusions for Criterion A..................................................................................11 4.

Criterion B - Compliance with 10 CFR Part 61 Performance Objectives............................12 5.

Criterion C - Assessment of Radionuclide Concentrations and Classification....................13 6.

Conclusions..........................................................................................................................14 7.

References...........................................................................................................................15 ABBREVIATIONS/ACRONYMS ADAMS Agencywide Document Access and Management System AEC Atomic Energy Commission Ba barium BBI Best Basis Inventory Bq becquerel C

carbon CFR Code of Federal Regulations Cs cesium CST crystalline silicotitanate DOE U.S. Department of Energy FR Federal Register FY fiscal year g

grams gal gallon GBq giga becquerel HLW high-level radioactive waste I

iodine IA Interagency Agreement ITPS in-tank pretreatment system IX ion exchange L

liters LLW low-level radioactive waste MBq mega becquerel NRC U.S. Nuclear Regulatory Commission PA performance assessment PNNL Pacific Northwest National Laboratory PRM Petition for Rulemaking Sr strontium TBI Test Bed Initiative Tc technetium TER Technical Evaluation Report TRU transuranic WA Washington WAC Waste Acceptance Criteria WIR waste incidental to reprocessing WMA waste management area WCS Waste Control Specialists Y

yttrium 1.

INTRODUCTION By letter dated October 29, 2021, the U.S. Department of Energy (DOE) requested that the U.S. Nuclear Regulatory Commission (NRC) conduct a consultative review of the Draft Waste Incidental to Reprocessing (WIR) Evaluation for the Test Bed Initiative (TBI)

Demonstration (DOE, 2021). The review was requested to be conducted in accordance with the Interagency Agreement (IA) (89304021SEM000008) between DOE and NRC.

This Draft WIR Evaluation is for approximately 7,600 liters (2,000 gallons) of supernate from Tank SY-101. Supernate is the uppermost tank liquid, which contains low levels of long-lived radionuclides. The supernate will be separated and pretreated, prior to offsite solidification and disposal. DOEs Draft WIR Evaluation assessed whether this separated, pretreated, and solidified supernate under the TBI Demonstration can be classified as WIR and managed as low-level waste (LLW).

1.1.

Regulatory Framework The overall concept of WIR is that some waste can be managed based on the risk to human health and the environment rather than based on the origin of the waste (e.g., reprocessing spent nuclear fuel (SNF)). Much of the waste in the tank farms at the Hanford Site is highly radioactive and needs to be treated and disposed as high-level waste (HLW). However, other waste may be demonstrated not to require disposal in a geologic repository by means of a DOE analysis called a waste determination. If it can be demonstrated that the waste poses a sufficiently small risk to human health and the environment and does not need to be disposed of as HLW, DOE may determine through the technical analyses documented in a waste determination that the waste is incidental (i.e., WIR) or non-HLW.

The NRC staff provide a complete history of the WIR regulatory framework in NUREG-1854, NRC Staff Guidance for Activities Related to U.S. Department of Energy Waste Determinations (NRC, 2007). The concept of incidental waste has been recognized since 1969 when the Atomic Energy Commission (AEC), NRC's predecessor agency, issued for comment a draft policy statement regarding the siting of reprocessing facilities in the form of a proposed Appendix D to Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Domestic Licensing of Production and Utilization Facilities, which addressed a definition of HLW (AEC, 1969). The term "incidental waste" was first used in NRC's 1987 advance notice of proposed rulemaking to redefine the definition of HLW (NRC, 1987). However, in the 1989 final rulemaking action on disposal of radioactive waste, the Commission did not redefine HLW (NRC, 1989).

In 1990, the States of Oregon and Washington petitioned the Commission to amend 10 CFR Part 60, Disposal of High-Level Radioactive Wastes in Geologic Repositories, to redefine HLW. The petition concerned whether Hanford tank waste was subject to NRC licensing jurisdiction. In response to the petition, the Commission approved specific criteria for determining whether waste was incidental and issued a Staff Requirements Memorandum dated February 16, 1993, in response to SECY-92-391, "Denial of PRM 60-4: Petition for Rulemaking from the States of Washington and Oregon Regarding Classification of Radioactive Waste at Hanford." NRC published the criteria in the Federal Register (FR) as part of the petition denial, as follows (NRC, 1993):

(1) The waste has been processed (or will be further processed) to remove key radionuclides to the maximum extent that is technically and economically practical, (2) The waste will be incorporated in a solid physical form at a concentration that does not exceed the applicable concentration limits for Class C LLW as set out in 10 CFR Part 61, and (3) The waste is to be managed, pursuant to the Atomic Energy Act, so that safety requirements comparable to the performance objectives set out in 10 CFR Part 61, are satisfied.

In July 1999, DOE issued DOE Order 435.1, Radioactive Waste Management, and the associated Manual, DOE Manual 435.1-1, Radioactive Waste Management Manual, both of which were subsequently revised (DOE, 2021a; DOE, 2021b). DOE Manual 435.1-1 requires all radioactive waste subject to the Order to be managed as either LLW, transuranic (TRU) waste, or HLW. DOE Manual 435.1-1 also states that waste resulting from reprocessing SNF determined to be WIR is not HLW and shall be managed under DOEs regulatory authority as LLW. DOE Manual 435.1-1 discusses DOE's incidental waste evaluation process and the criteria for determining whether waste is incidental to reprocessing (see Section 1.2), which are based upon the criteria NRC issued above.

In 2004, Senator Lindsey Graham of South Carolina introduced legislation that would allow DOE to use a process similar to the incidental waste process in DOE Order 435.1 at the Savannah River Site. Congress passed the Ronald W. Reagan National Defense Authorization Act for Fiscal Year 2005 on October 9, 2004, and the President signed it on October 28, 2004. Section 3116 of the NDAA allows DOE to continue to use an incidental waste process to determine that waste is not HLW, and Section 3116(a) includes the requirement that DOE consult with the NRC on the DOE non-HLW determinations. However, the NDAA is applicable to only South Carolina and Idaho and does not apply to waste transported out of these states.

Although the NDAA only addresses consultation and monitoring activities within the NDAA-Covered States of Idaho and South Carolina,4 at the DOEs request the NRC also conducts technical reviews for WIR management and disposal at sites in non NDAA covered states (e.g., States of Washington and New York) following a similar process to that used at the covered states. For the Hanford Site, the criteria for DOE waste determinations are specified by DOE Order 435.15 and DOE Manual 435.1-1. Under DOE Manual 435.1, the DOE may consult with NRC on WIR determinations through an IA.

DOE and NRC have had a series of IAs where DOE requested that the NRC provide technical advice and consultation regarding DOE WIR determinations for disposal of waste onsite at the Hanford Site, as well as other tasks such as closure of the HLW storage tanks in Waste Management Area C. The NRC staff performs this consultive role by conducting an independent technical review so that the NRC can reach its own conclusions as to whether DOEs proposed waste management approach satisfies the DOE Order 435.1 criteria. The NRC staffs guidance for the consultation activities are documented in NUREG-1854, NRC Staff Guidance for Activities Related to U.S. Department of Energy Waste Determinations, (NRC, 2007). At the conclusion of the NRC staffs review of each WIR determination, the NRC provides DOE with a Technical Evaluation Report (TER) documenting its findings. NRC has no regulatory oversight over DOEs WIR evaluations at the Hanford Site.

1.2.

NRC Review Approach The WIR determination process used by DOE is based on the criteria that is provided in DOE Order 435.1 and the related DOE Manual 435.1-1. DOE uses the process to determine if WIR is not high-level radioactive waste (HLW) and can be managed as either LLW or TRU waste. The criteria in Section II.B.(2)(a) of DOE Manual 435.1-1 for determining if the waste can be managed as LLW include:

(A) Have been processed, or will be processed, to remove key radionuclides to the maximum extent that is technically and economically practical.

(B) Will be managed to meet safety requirements comparable to the performance objectives set out in 10 CFR 61, Subpart C, Performance Objectives; and (C) Are to be managed, pursuant to DOE authority under the Atomic Energy Act of 1954, as amended, and in accordance with the provisions of Chapter IV of this Manual, provided the waste will be incorporated in a solid physical form at a concentration that does not exceed the applicable concentration limits for Class C low-level waste as set out in 10 CFR 61.55, Waste Classification.

The NRC staff conducted a risk-informed review of DOEs Draft WIR Evaluation with respect to Criteria A, B, and C and documented the results in this TER. A risk-informed evaluation means that the review effort should be commensurate with the risk significance. For each criterion, NRC staff summarized DOEs approach in the Draft WIR Evaluation followed by the NRC staffs evaluation. The review of each criterion concludes with a summary of the NRC staffs review of that technical topic that identifies whether the NRC staff found DOEs approach to be reasonable. NRC staffs recommendations, if any, are provided as well for each criterion.

1.3.

Scope of the TER DOEs Draft WIR Evaluation applies to approximately 7,600 liters (2,000 gallons) of supernate from Tank SY-101. NRC staffs review focused on 7,600 liters (2,000 gallons) of supernate, but also included recommendations for potentially larger volumes of supernate to be treated in the future.

2.

REVIEW CONTEXT The review context typically includes a description of the disposal site (e.g., site location, natural environment, geology, and hydrogeology), a description of the disposal facility, present and future land use of the site, and an overview of the proposed wastes for disposal. For this Draft WIR Evaluation, DOE is proposing to dispose of the treated and solidified supernate either at the EnergySolutions disposal facility in Clive, Utah or Waste Control Specialists (WCS) disposal facility in Andrews, Texas. The disposal will be in accordance with both EnergySolutions and WCSs waste acceptance criteria (WAC). As Utah and Texas are Agreement States, which reviewed and approved the respective WAC, NRC staffs review of this TBI Demonstration did not include reviewing the performance assessments (PAs) and disposal facilities for EnergySolutions or WCS. NRC staffs review of the TBI Demonstration as it relates to EnergySolutions and WCS is with respect to the volume and activity of waste associated with this Draft WIR Evaluation and the licensed limits for those facilities. A description of the proposed wastes for disposal is included below in Section 3 of this report.

3.

CRITERION A - KEY RADIONUCLIDES REMOVED The first part of Criterion A requires identification of the key radionuclides present in the waste that must be processed or removed to achieve protection of public health and safety.

After key radionuclides are identified, then a demonstration that they have been removed to the maximum extent technically and economically practical must be provided to determine that the wastes may be managed as LLW.

3.1.

Key Radionuclides The criterion associated with key radionuclide removal in DOE Manual 435.1-1 states that wastes:

Have been processed, or will be processed, to remove key radionuclides to the maximum extent that is technically and economically practical.

The identification of key radionuclides is important to establish which radionuclides must be processed or removed to achieve protection of public health and safety.

3.1.1. DOE Identification of Key Radionuclides In Section 4.2.1 of the Draft WIR Evaluation for the TBI Demonstration, DOE stated that the identification of key radionuclides was based on:

NRC requirements for classification of radioactive waste for near-surface disposal that appear in Table 1 and Table 2 of 10 CFR 61.55.

Radionuclides important to meeting the performance objectives in 10 CFR 61, Subpart C, the comparable provisions in the Utah Administrative Code and the Texas Administrative Code, and the waste acceptance criteria for the WCS FWF or the EnergySolutions facility.

Radionuclides present in Tank SY-101.

The list of key radionuclides for DOEs TBI Demonstration is reproduced below in Table 1.

Table 1. Key Radionuclides Identified by DOE 3.1.2. NRC Evaluation of Identification of Key Radionuclides DOEs approach to identify key radionuclides was consistent with the NRC staffs interpretation of key radionuclides. DOE considered key radionuclides to be those that could contribute significantly to radiological dose to workers, the public, and the environment. The list includes radionuclides found in the 10 CFR 61.55, Waste classification, Tables 1 and 2 and the WAC for EnergySolutions and WCS. The NRC staff evaluated DOEs approach to identifying key radionuclides and conclude that the approach is reasonable.

3.2.

Removal to the Maximum Extent Practical After key radionuclides are identified, then a demonstration that they have been removed to the maximum extent technically and economically practical must be provided to determine that the wastes may be managed as LLW. DOE plans to remove key radionuclides through a series of steps, including in-tank settling, decanting, and with the in-tank pretreatment system (ITPS) filtration and cesium removal using ion exchange.

3.2.1. DOE Analyses of Removal to the Maximum Extent Practical DOEs analyses for the removal of key radionuclides to the maximum extent practical included a description of the technologies and their effectiveness.

DOE discussed the technical practicality of the technologies and their economic practicality.

In the Draft WIR Evaluation, DOE discussed that the tank waste has separated under the long-term caustic storage conditions. The tank solids, which contain insoluble long-lived radionuclides (e.g., plutonium, americium, neptunium, and curium), have settled to the bottom with a liquid supernate fraction above, as shown in Figure 1 below. Based on the Best-Basis Inventory (BBI) baseline from 2001 and subsequent processing history, DOE concluded that sludge is not present in Tank SY-101. DOE then discussed that long-lived radionuclides are present in the saltcake in Tank SY-101 and that the supernate in Tank SY-101 contains relatively low amounts of longer-lived radionuclides.

Accordingly, DOE concluded that limiting the TBI Demonstration waste to only supernate will limit the amount of long-lived radionuclides in this waste demonstration. The subsequent decanting step separates the liquid supernate from the salt cake.

Figure 1. Tank SY-101 Supernate and Salt Cake Waste Volumes and Estimated Curie Content (Figure 2-3 from DOE, 2021)

DOE plans on decanting approximately 7,600 liters (2,000 gallons) of Tank SY-101 supernate via pumping. After decanting, the supernate will be filtered to remove any remaining solids as part of the ITPS process. After filtration, the majority of the remaining radionuclides present in the supernate will be soluble (e.g., Cs-137, Tc-99, I-129, H-3, C-14, and Sr-90). Following filtration, the supernate will be processed through crystalline silicotitanate (CST) ion exchange (IX) media within Tank SY-101 to remove Cs-137 (and daughter Ba-137m). The CST IX is designed to ensure removal of at least 99 percent of the Cs-137 (and daughter Ba-137m) (SESC-EN-RPT-005, SESC-E-RPT-006) and a significant fraction of the Sr-90 (and daughter Y-90), neptunium, and plutonium, if present in soluble form (Pacific Northwest National Laboratory (PNNL)-28783). Following pretreatment, DOE will characterize the waste to verify that the waste meets all applicable requirements for shipment to and receipt by the commercial treatment facility.

Based on data from the BBI and analysis of recent grab samples, the DOE estimated the inventory of radionuclides present in Tank SY-101. In Table 4-4 of the Draft WIR Evaluation (DOE, 2021), DOE provided an estimate of the radionuclide inventories in both the supernate and saltcake present in Tank SY-101 based on the BBI. In Table 4-5 of the Draft WIR Evaluation (DOE, 2021), DOE provided a comparison of the Tank SY-101 grab sample concentrations, which are prior to ITPS filtration and CST IX, versus the 10 CFR 61.55 Class A and C concentration limits. Prior to filtration and ion exchange, all of the radionuclide concentrations shown in this table are at least an order of magnitude below the Class C concentration limits.

After pretreatment of the supernate, DOE estimated that 1.8 Ci (66.6 GBq) will remain. A comparison of the remaining activity with the current activity limits for WCS and EnergySolutions licenses shows that the TBI Demonstration will constitute 0.00003 percent and 0.0002 percent of these activity limits, respectively.

In the Draft WIR Evaluation, the DOE stated that the radionuclides present in the pretreated and solidified waste will be present in trace quantities which individually, or in combination, would not contribute significantly to dose.

Accordingly, DOE concluded that a reduction of an already insignificant quantity of radionuclides would not outweigh the costs, which include financial costs, increase in amounts of additional waste to be disposed of, potential increase in dose to workers, and schedule delays.

3.2.2. NRC Evaluation of Removal to the Maximum Extent Practical The NRC staff performed a risk-informed review of the information DOE provided in the Draft WIR Evaluation for TBI. Removal of key radionuclides to the maximum extent technically and economically practical is analogous to NRCs As Low As Reasonably Achievable standard and it is implemented using a risk-informed approach. The risk-informed approach uses risk information, considering uncertainties, to inform the overall decision-making process to make prudent and practical decisions, while erring on the side of protection of public safety.

The NRC staff evaluated DOEs demonstration that wastes will be processed to remove key radionuclides to the maximum extent that is technically and economically practical, by evaluating the identification and the removal of key radionuclides.

DOEs TBI Demonstration addresses the Tank SY-101 supernate whereas much of the long-lived radioactivity is associated with tank solids. DOE has proposed to use in-tank settling, separation of the supernate by decanting, filtration, and ion exchange to achieve removal of key radionuclides. DOE stated that filtering will remove insoluble radionuclides. The radionuclides present in the resulting liquid will be those radionuclides that are partially or completely soluble, including Cs-137 (and daughter Ba-137m), Tc-99, I-129, H-3, C-14, and possibly Sr-90 (and daughter Y-90). The NRC staff agrees that the settling, separation, and filtration processes will remove most of the insoluble radionuclides. DOE would then use ion-exchange columns to remove most of the Cs-137, as wells as Sr-90 that is present in soluble form, and large fractions of neptunium and plutonium that is present in soluble form.

Prior to filtration and ion exchange, the radionuclide concentrations for the TBI Demonstration are significantly below the Class C limits and the radionuclide activities and waste volumes are significantly below the license requirements for EnergySolutions and WCS. The CST IX will significantly reduce the Cs-137 inventory in the supernate. NRC staff agrees that the radionuclides addressed within the TBI Demonstration will not contribute significantly to dose. NRC staff also agrees that a further reduction of radionuclides would not outweigh the associated costs, which include financial costs, additional waste for disposal, potential increases in dose to workers, and schedule delays.

DOE stated that based on the BBI estimates and grab sample data, 99.999 percent of the activity of key radionuclides in Tank SY-101 will be removed by settling, decanting, filtration, and IX. NRC staff notes that part of that 99.999 percent reduction is based on activities that are independent from new proposed disposal actions. For example, settling has already occurred due to long-term caustic storage conditions and settling accounts for almost 70 percent of the reduction in Table 4-6 of the Draft WIR Evaluation. In addition, part of the calculated 99.999 percent includes disposal of only 7,600 liters (2,000 gallons) versus the entire 3.37 million liters (891,000 gallons) of supernate. In other words, the treatment of 7,600 liters (2,000 gallons) of supernate is represented in Table 4-6 of the Draft WIR Evaluation as a 99.78 percent removal of radionuclide activity. Accordingly, disposal of greater amounts of supernate in the future would not be expected to yield the same 99.999 percent reduction in activity.

3.3.

NRC Conclusions for Criterion A The NRC staff determined that DOE properly identified key radionuclides and demonstrated the removal of key radionuclides to the maximum extent technically and economically practical and therefore meets Criterion A of DOE Manual 435.1-1.

The NRC staff has the following recommendations associated with Criterion A:

Prior to potential disposal of larger quantities of supernate in the future, DOE should verify that the radionuclide concentrations and activities in the supernate are reasonably consistent with the grab samples discussed in the Draft WIR Evaluation.

Variability in the supernate could affect activities, concentrations, solids content, and the performance of the ITPS.

In the Draft WIR Evaluation, DOE referenced two reports on bench-scale testing of the CST IX (SESC-EN-RPT-005; SESC-EN-RPT-006). DOE should verify that larger-scale filtration and CST IX for Cs-137 removal is reasonably consistent with bench-scale test results.

Because: (1) the supernate composition from Tank SY-101 may differ from the supernate from Tank 241-AN-107 that was used in the CST IX bench-scale testing (SESC-EN-RPT-005) and (2) ion exchange could be affected by differing supernate compositions, DOE should verify that CST IX for Tank SY-101 is reasonably consistent with the projected Cs-137 removal.

The proposed Tc-99 and I-129 inventories in the 7,600 liters (2,000 gallons) of supernate are within the license limits for EnergySolutions and WCS. However, additional information regarding the risk significance of these radionuclides may be useful when considering the potential disposal of larger quantities of supernate.

Because of the long half-lives and relative mobility of these radionuclides in the environment and their potential dose impacts, additional risk information (e.g., assumed performance of the solidified waste over long timeframes) may be helpful.

4.

CRITERION B - COMPLIANCE WITH 10 CFR PART 61 PERFORMANCE OBJECTIVES This section summarizes the NRC staffs review of the information DOE submitted with respect to Criterion B of DOE Manual 435.1-1, which is demonstrating compliance with the 10 CFR Part 61, Subpart C, Performance Objectives, for the disposal of TBI Demonstration waste.

To demonstrate compliance with the 10 CFR Part 61, Subpart C, DOE discussed that:

The DOE requirements in 10 CFR Part 835, Occupational Radiation Protection, and DOE Order 458.1, Radiation Protection of the Public and the Environment, will apply to the pretreatment, transfer, and packaging operations at the Hanford Site for the TBI Demonstration.

The pretreatment of the waste will occur inside Tank SY-101, thereby minimizing the risk to workers due to shielding from the tank and soil.

The disposal of treated and solidified supernate from the TBI Demonstration will be in accordance with both EnergySolutions and WCS waste acceptance criteria.

The waste acceptance criteria for EnergySolutions and WCS are required to the comply with the regulations for the State the Utah and State of Texas, respectively.

The requirements and performance objectives set forth in the Utah Administrative Code §§R313-25-19 through R313-25-23 and the Texas Administrative Code Rules

§§336.723-727 parallel the 10 CFR Part 61 performance objectives.

Accordingly, DOE concluded that disposal of treated and solidified supernate from the TBI Demonstration will therefore provide reasonable assurance that 10 CFR Part 61 will be met.

As Utah and Texas are Agreement States, NRC staffs review of this TBI Demonstration did not include reviewing the PAs and disposal facilities for EnergySolutions or WCS. NRC staffs review of the TBI Demonstration as it relates to EnergySolutions and WCS is with respect to the volume and activity of waste associated with this Draft WIR Evaluation and the licensed limits for those facilities. In the Draft WIR Evaluation, DOE determined that the proposed TBI Demonstration pre-treated and solidified waste volumes and activities are significantly below the license limits for EnergySolutions and WCS. DOE also noted that the EnergySolutions and WCS WAC also addresses operations and regulatory parameters, pre-shipment requirements, documentation, and transportation. Based on DOEs analysis of the supernate waste, bench-scale testing results, and the margin between the disposal volumes and activities and the license limits, NRC staff agrees that the Draft WIR Evaluation meets Criterion B of DOE Manual 435.1-1.

The NRC staff has the following recommendation associated with Criterion B:

Prior to potential disposal of larger quantities of supernate in the future, DOE should verify that the actual grouted wasteform volumes at the commercial treatment facilities are reasonably consistent with the estimates in Table 5-1 of the Draft WIR Evaluation (DOE, 2021). Depending on the porosity of the grout, the volumes could be greater than assumed.

5.

CRITERION C - ASSESSMENT OF RADIONUCLIDE CONCENTRATIONS AND CLASSIFICATION This section summarizes the NRC staffs review of the information DOE submitted with respect to Criterion C of DOE Manual 435.1-1, which is demonstrating compliance that the TBI waste will be incorporated in a solid physical form at a concentration that does not exceed the applicable concentration limits for Class C LLW as set out in 10 CFR 61.55.

In the Draft WIR Evaluation for TBI, DOE discussed that the supernate from Tank SY-101 would be put into solid physical form by incorporating the waste into a grout matrix in 208-liter (55-gallon) drums at an offsite treatment facility.

DOE provided analysis for the solidified waste to demonstrate that it will meet the concentration limits for Class A LLW, which is below the limits for Class C LLW, as set out in 10 CFR 61.55, §§336.362 of the Texas Administrative Code, and §§R313-15-1009 of the Utah Administrative Code. Because the waste contains a mixture of short-and long-lived radionuclides, DOE followed the sum of fractions rule to determine the total concentration, as specified in the aforementioned regulations. In Table 6-1 of the Draft WIR Evaluation, DOE showed that no radionuclide concentration will exceed 0.1 times the value listed in Table 1 of 10 CFR 61.55. Therefore, the classification is determined by the concentration of nuclides listed in Table 2 of 10 CFR 61.55. For the mixture of radionuclides in the TBI Demonstration, DOE applied the sum of fractions for the pretreated and solidified waste.

The sum of fractions listed in Table 6-2 of the Draft WIR Evaluation were 0.224 for Class A and 0.0000264 for Class C with respect to Table 2 of 10 CFR 61.55. Accordingly, DOE concluded that the solidified waste would meet the concentration limits in 10 CFR 61.55 for Class A LLW. DOE further discussed that waste pretreatment will remove a greater percentage of Cs-137 and other key radionuclides than assumed in their calculations.

The NRC staff reviewed the information DOE provided and determined that the wastes generated by the TBI Demonstration will be incorporated into a solid physical form, provided that DOE verifies that the specific supernate from Tank SY-101 does not interfere with grout stabilization. Due to the complexity of cement chemistry and the unique chemical composition of supernate solutions, it is difficult to anticipate grout curing properties.

Accordingly, DOE should verify the solidification of the grout mixed with the supernate from Tank SY-101.

For classification of the TBI Demonstration waste, NRC staff determined that DOE used the correct methodology for waste classification in 10 CFR 61.55 for waste containing a mixture of short-and long-lived radionuclides. Based on the concentrations and sum of fractions presented by DOE, NRC staff determined that the TBI Demonstration waste will meet the Class A concentration limits for LLW, which is below the Class C concentration limits.

Accordingly, NRC staff agrees that the Draft WIR Evaluation meets Criterion C of DOE Manual 435.1-1.

The NRC staff has the following recommendation associated with Criterion C:

DOE should verify that the supernate from Tank SY-101 in the TBI Demonstration does not interfere with grout curing at the treatment facility to ensure that the waste will be stabilized in a solid physical form.

6.

CONCLUSIONS The NRC staff completed a risk-informed review of the Draft WIR Evaluation for the TBI Demonstration. For the TBI Demonstration, NRC staff concludes:

DOE demonstrated that the waste has been processed or will be processed to remove key radionuclides to the maximum extent that is technically and economically practical (Criterion A).

DOE demonstrated that the waste will be managed to meet safety requirements comparable to the performance objectives set out in 10 CFR Part 61, Subpart C (Criterion B).

DOE demonstrated that the waste will be managed pursuant to DOE's authority under the Atomic Energy Act of 1954, as amended, and in accordance with the provisions of Chapter IV of the DOE Radioactive Waste Management Manual. The waste will be incorporated in a solid physical form at a concentration that does not exceed the applicable concentration limits for Class C LLW as set out in 10 CFR 61.55 (Criterion C).

The NRC staff has the following recommendations associated with Criteria A, B, and C: