Text

NRC Saltstone Disposal Facility Monitoring Plan, Rev. 2
	ML24310A235
Person / Time
Site:	PROJ0734
Issue date:	11/05/2024
From:	; Office of Nuclear Material Safety and Safeguards
To:	; US Dept of Energy (DOE)
References
	Download: ML24310A235 (1)
	v • d • e

U.S. Nuclear Regulatory Commission Plan for Monitoring Disposal Actions Taken by the U.S. Department of Energy at the Savannah River Site Saltstone Disposal Facility in Accordance with the Ronald W. Reagan National Defense Authorization Act for Fiscal Year 2005, Revision 2 MAY - 2025 U.S. Nuclear Regulatory Commission Office of Nuclear Material Safety and Safeguards Washington, DC 20555-0001

(Intentionally Left Blank)

ii TABLE OF CONTENTS SECTION PAGE FIGURES... iii TABLES..... iv ACRONYMS AND ABBREVIATIONS....

v DEFINITIONS AND DESCRIPTIONS..... vii EXECUTIVE

SUMMARY

..... x

1.0 INTRODUCTION

.......... 1-1 2.0 MONITORING TO ASSESS COMPLIANCE WITH 10 CFR 61.40... 2-1 3.0 MONITORING TO ASSESS COMPLIANCE WITH 10 CFR 61.41.......... 3-1 4.0 MONITORING TO ASSESS COMPLIANCE WITH 10 CFR 61.42....... 4-1 5.0 MONITORING TO ASSESS COMPLIANCE WITH 10 CFR 61.43... 5-1 6.0 MONITORING TO ASSESS COMPLIANCE WITH 10 CFR 61.44....... 6-1

7.0 REFERENCES

...... 7-1 8.0 LIST OF CONTRIBUTORS.. 8-1

iii FIGURES FIGURE PAGE Figure 1-1: Partial Organizational Chart for SCDES Bureau of Land & Waste Management.. 1-5 Figure 1-2: Partial Organizational Chart for SCDES Bureau of Water.... 1-6 Figure 1-3: Types of Non-Compliance 1-11 Figure 3-1: SDF Conceptual Closure Cap Design Configuration. 3-7 Figure 3-2: Surface and Subsurface Water Balance Components...... 3-8

iv TABLES TABLE PAGE Table ES-1: Overall Structure of SDF Monitoring Plan, Rev. 2.... xi Table ES-2: Monitoring Areas in SDF Monitoring Plan, Rev. 2..... xiv Table ES-3: Monitoring Factors in SDF Monitoring Plan, Rev. 2.... xv Table 1-1: List of Periodic DOE Documents. 1-7 Table 1-2: Examples of Upcoming DOE Activities and Unscheduled Events. 1-8 Table 1-3: Types of Notification Letters. 1-9 Table 1-4: Overall Structure of SDF Monitoring Plan, Rev. 2..... 1-13 Table 1-5: Monitoring Areas in SDF Monitoring Plan, Rev. 2.. 1-16 Table 1-6: Monitoring Factors in SDF Monitoring Plan, Rev. 2... 1-16 Table 1-7: NRC Prioritization of Monitoring Factors for Monitoring Areas 1 through 7.... 1-17 Table 1-8: NRC Prioritization of Monitoring Factors for Monitoring Areas 8 through 14...... 1-18

v ACRONYMS AND ABBREVIATIONS Acronym or Abbreviation Meaning Am-241 Americium-241 ATM Aquifer Transport Model CERCLA Comprehensive Environmental Response, Compensation, and Liability Act Cf-249 Californium-249 Cf-251 Californium-251 CFR Code of Federal Regulations CLSM Controlled Low Strength Material Cm-245 Curium-245 Cm-247 Curium-247 DOE United States Department of Energy DCFs Dose Conversion Factors EPA United States Environmental Protection Agency FEPs Features, Events, and Processes FFA Federal Facility Agreement Ft Feet FUAI Follow-Up Action Item GCL Geosynthetic Clay Liner g

Gram GSA General Separations Area HDPE High Density Polyethylene HLW High-Level Waste I-129 Iodine-129 Kd Distribution Coefficient LLDL Lower Lateral Drainage Layer LLW Low-Level Waste m

Meter MA Monitoring Area MCC Moisture Characteristic Curve MF Monitoring Factor mL Millilitres mrem Millirem mSv MilliSievert NDAA Ronald W. Reagan National Defense Authorization Act for Fiscal Year 2005 NRC United States Nuclear Regulatory Commission OOV Onsite Observation Visit PA Performance Assessment PGA Peak Horizontal Ground Acceleration Pu-239 Plutonium-239 Pu-240 Plutonium-240 PMP Probable Maximum Precipitation PO Performance Objective QA Quality Assurance QC Quality Control Ra-226 Radium-226 RAI Request for Additional Information RCRA Resource Conservation and Recovery Act

vi RSI Request for Supplemental Information RUSLE Revised Universal Soil Loss Equation SCDES South Carolina Department of Environmental Services SDF Saltstone Disposal Facility SDS Saltstone Disposal Structure SDU Saltstone Disposal Unit Sn-126 Tin-126 SRS Savannah River Site SWPF Salt Waste Processing Facility TCCZ Tan Clay Confining Zone Tc-99 Technetium-99 TEDE Total Effective Dose Equivalent TER Technical Evaluation Report Th-230 Thorium-230 TRR Technical Review Report U-234 Uranium-234 ULDL Upper Lateral Drainage Layer USDA United States Department of Agriculture UTRA-LAZ Upper Three Runs Aquifer-Lower Aquifer Zone UTRA-UAZ Upper Three Runs Aquifer-Upper Aquifer Zone WIR Waste Incidental to Reprocessing Yr Year

vii DEFINITIONS AND DESCRIPTIONS As Low As (Is) Reasonably Achievable: From 10 CFR 20.1003 - Making every reasonable effort to maintain exposures to radiation as far below the dose limits as practical, consistent with the purpose for which the licensed activity is undertaken, taking into account the state of technology, the economics of improvements in relation to state of technology, the economics of improvements in relation to benefits to the public health, and safety, and other societal and socioeconomic considerations, and in relation to utilization of nuclear energy, and licensed materials in the public interest.

Closed Monitoring Area: State of a monitoring area after the Nuclear Regulatory Commission (NRC) determines that the monitoring area is no longer appliable or all the monitoring factors under that monitoring area were Closed. Note that the NRC can Open that monitoring area again in the future if circumstances change.

Closed Monitoring Factor: State of a monitoring factor after the NRC determines and documents that the monitoring factor is no longer applicable or the technical issue or uncertainty has been resolved. Note that the NRC can Open that monitoring factor again in the future if circumstances change.

Disposal Structure: In the context of the Saltstone Disposal Facility, the NRC uses the term disposal structure to mean a self-enclosed entity used to contain saltstone and isolate it from the environment. A disposal structure could have more than one cell. The term disposal structure also refers to the disposal entities that Department of Energy (DOE) refers to as Vaults and can be used to refer to any new potential disposal entity design that meets this definition. The designation of a Saltstone Disposal Structure (SDS) is only used to refer to a specific disposal structure (e.g., SDS 1, SDS 4, SDS 2A, SDS 2B, SDS 3A, SDS 3B, SDS 5A, SDS 5B, SDS 6, SDS 7, SDS 8, SDS 9, SDS 10, SDS 11, SDS 12). The DOE uses the designation Saltstone Disposal Unit (SDU) to denote something that contains one or more disposal structures. For example, the DOE designation of SDU 4, also referred to by DOE as Vault 4, is a disposal structure. For example, the DOE designation of SDU 2, also referred to by DOE as SDU 2A/2B, includes two disposal structures (i.e., SDS 2A, SDS 2B).

DOE 2020 Performance Assessment (PA): This refers to the DOE 2020 PA for the Saltstone Disposal Facility with all its associated documents, which includes the DOE: (1) references, (2) responses to the NRC Requests for Supplemental Information Comments, and (3) responses to the NRC Requests for Additional Information Questions.

DOE Final Basis for Waste Determination (or DOE Final Basis for Non-High-Level Waste Determination): The DOE documentation required by NDAA Section 3116, which will or will not demonstrate that a specific waste stream is not High-Level Waste.

DOE Waste Determination: The DOE document signed by the Secretary of Energy with their decision whether or not the specific waste stream is High-Level Waste. If the Secretary of Energy decision is that the specific waste stream is not High-Level Waste, then the specific waste stream can be managed as Low-Level Waste and both the DOE and the NRC refer to it as Waste Incidental to Reprocessing.

Follow-Up Action Item (FUAI): Item identified during monitoring that requires additional effort by the DOE or the NRC to resolve. Examples include the DOE providing answers to questions

viii generated during technical reviews, the DOE providing the results of a particular experiment after it becomes available, or the NRC setting up a future meeting on a technical topic. A DOE FUAI is generally less risk-significant than an Open Issue. The DOE FUAI can become an Open Issue if the FUAI is related to a technical issue that is later found to be risk-significant or if insufficient progress is being made by the DOE in addressing a risk-significant technical issue.

High-Level Radioactive Waste (HLW): (1) irradiated reactor fuel; (2) liquid wastes resulting from the operation of the first cycle solvent extraction system, or equivalent, and the concentrated wastes from subsequent extraction cycles, or equivalent, in a facility for reprocessing reactor fuel; and (3) solids into which such liquids have been converted.

Highly Radioactive Radionuclide (or Key Radionuclide): One of the radionuclides that contribute most significantly to risk to the public, workers, and the environment. In the context of the NDAA, the NRC considers Highly Radioactive Radionuclides, to be equivalent to Key Radionuclides used in the current DOE Manual 435.1 for the current DOE Order 435.1, the West Valley Policy Statement, and in some NRC reviews of DOE Draft Basis for Waste Determinations. In the context of an NRC review of a DOE Draft Basis for Waste Determination conducted under the NDAA, Highly Radioactive Nuclides are not (in general) limited to radionuclides with high specific activity.

Land Disposal Facility: From 10 CFR 61.2 - The land, building, and structures, and equipment, which are intended to be used for the disposal of radioactive wastes.

Monitoring Area: General feature or aspect of the disposal action identified by the NRC as being important to the DOE ability to meet the 10 CFR Part 61, Subpart C Performance Objectives. The designation of MA ## (e.g., MA 12) is used when referring to a specific monitoring area. A monitoring area may be associated with one or more performance objectives, is further divided into one or more specific monitoring factors, and is tracked as either Open or Closed.

Monitoring Factor: A specific feature or aspect of the disposal facility, site, or disposal action (e.g., conceptual model, mathematical model, selected parameter values, closure strategy) that the DOE used in the demonstration that the NRC has determined to be important to demonstrating compliance with the 10 CFR Part 61, Subpart C Performance Objectives. The designation of a MF ##.## (e.g., MF 14.12) is used when referring to a specific monitoring factor. The NRC typically identifies a monitoring factor through the review of a DOE Draft Waste Determination, a DOE Performance Assessment, information that the DOE generated during monitoring (e.g., technical report on laboratory or field experiment), or other information collected during monitoring (e.g., during an NRC Onsite Observation Visit). A monitoring factor may be associated with one or more performance objectives, may be associated with one or more monitoring areas, is numbered separately for each associated monitoring area; but, is counted as only one monitoring factor when counting the total number of monitoring factors in a monitoring plan, and is tracked as either Open or Closed.

Onsite: Area of the DOE site where monitoring activities will be carried out. That may include areas that have some relationship to, but are outside of, the physical boundaries of a particular Waste Incidental to Reprocessing (WIR)-related facility.

Onsite Observation Visit (OOV): A formal, pre-announced NRC visit to a DOE-WIR Location during monitoring for the purpose of observing the DOE facilities, activities, processes, or experiments related to compliance with 10 CFR Part 61, Subpart C Performance Objectives.

ix Open Issue: A concern that the NRC staff identifies during monitoring activities, which requires additional information from the DOE to address. Examples include a monitoring factor that the DOE has not taken sufficient action to address or an instance where data collected by the DOE are not consistent with assumptions (e.g., conceptual model assumptions, mathematical assumptions, parameter values) that the DOE made in the current Performance Assessment.

An Open Issue is generally more risk-significant than a DOE FUAI. An Open Issue could lead to an NRC finding that the DOE disposal actions are not in compliance with the 10 CFR Part 61, Subpart C Performance Objectives.

Performance Assessment (PA): A type of systematic risk analysis that addresses the following four questions: (1) what can happen?, (2) how likely is that to happen?, (3) what are the resulting impacts of that happening?, and (4) how do those impacts compare to defined standards?

Performance Objective (PO): One of five 10 CFR Part 61, Subpart C, requirements for low-level waste disposal facilities, which are: (1) General Requirement (§61.40), (2) Protection of the General Population from Releases of Radioactivity (§61.41), (3) Protection of Individuals from Inadvertent Intrusion (§61.42), (4) Protection of Individuals during Operations (§61.43), and (5) Stability of the Disposal Site after Closure (§61.44).

Savannah River Site DOE-WIR Location: This is either the Savannah River Site Saltstone Disposal Facility (SDF) or the Savannah River Site Tank Farms (i.e., F-Tank Farm, H-Tank Farm).

Technical Review: The NRC staff review of reports, studies, analyses, experiments, and other information prepared by the DOE; South Carolina Department of Health and Environmental Control; the public or other stakeholders; or Native American Tribal Governments that may be used by the NRC staff in determining the DOE ability to meet the 10 CFR Part 61, Subpart C Performance Objectives for DOE disposal actions.

Worker: The DOE, including staff or contractors, who carry out operational activities at the land disposal facility.

x EXECUTIVE

SUMMARY

Under Section 3116(a) of the Ronald W. Reagan National Defense Authorization Act for Fiscal Year 2005 (NDAA), the U.S. Department of Energy (DOE) must consult with the U.S. Nuclear Regulatory Commission (NRC) prior to the Secretary of Energy making the Waste Determination whether or not certain radioactive waste related to the reprocessing of spent nuclear fuel is not high-level waste (HLW). If so, then it can be managed as low-level waste (LLW) and both the DOE and the NRC refer to it as Waste Incidental to Reprocessing (WIR).

The NDAA applies specifically to DOE-WIR locations in the states of Idaho and South Carolina.

The NDAA does not apply to DOE-WIR locations in other states.

If the Secretary of Energy signs a Waste Determination that certain radioactive waste related to the reprocessing of spent fuel is not HLW, then NDAA Section 3116(b) requires the NRC to coordinate with the NDAA-Covered State (i.e., Idaho, South Carolina) to monitor the DOE disposal actions to assess compliance with the five Title 10, Code of Federal Regulations (CFR)

Part 61, Subpart C, Performance Objectives (POs).

Those five POs are: (1) General Requirement (the §61.40 PO), (2) Protection of the General Population from Releases of Radioactivity (the §61.41 PO), (3) Protection of Individuals Against Inadvertent Intrusion (the §61.42 PO), (4) Protection of Individuals During Operations (the

§61.43 PO), and (5) Stability of the Disposal Site after Closure (the §61.44 PO).

For the DOE Savannah River Site (SRS) Saltstone Disposal Facility (SDF) under NDAA Section 3116(a), the DOE Consulted with the NRC in 2005, the NRC issued the SDF Technical Evaluation Report (TER), Rev. 0, in 2005, and the Secretary of Energy signed the DOE SDF Waste Determination that the SDF can be managed as LLW in 2006.

For the DOE SRS SDF under NDAA Section 3116(b), after the Secretary of Energy signed the SDF Waste Determination, the NRC, in coordination with the NDAA-Covered State of South Carolina, began monitoring the DOE disposal actions against the 10 CFR Part 61, Subpart C, POs in 2006. Based on the NRC 2005 SDF TER and the DOE 2006 Final Basis for Waste Determination, the NRC issued the SDF Monitoring Plan, Rev. 0, in 2007. The DOE updated the SDF Performance Assessment (PA) in 2009. The NRC reviewed the DOE 2009 SDF PA and issued the SDF TER, Rev. 1, in 2012. Based on the NRC 2012 TER, the NRC issued the SDF Monitoring Plan, Rev. 1, in 2013.

For the DOE SDF under NDAA Section 3116(b), the DOE updated the SDF PA in 2020. The NRC reviewed the DOE 2020 SDF PA and issued the SDF TER, Rev. 2, in 2023. In the NRC 2023 SDF TER, the NRC stated that if the DOE Closure Cap design and implementation achieve the DOE expected performance, as described in the DOE 2020 SDF PA, then the NRC concluded that it had reasonable assurance that the DOE disposal actions at the SDF met or would meet all the POs, including the §61.40 PO. Based on the six NRC Letters from 2017 to 2021 supplementing the NRC SDF Monitoring Plan, Rev. 1; the NRC WIR Periodic Monitoring Report, Rev. 6; and the NRC 2023 SDF TER, the NRC is issuing this NRC SDF Monitoring Plan, Rev. 2. Highlights of this NRC SDF Monitoring Plan, Rev. 2, include:

Same as in the NRC SDF Monitoring Plan, Rev. 1:

o provides the process for how the NRC will conduct monitoring activities at the SRS SDF

xi o

the structure/organization is: (1) from each PO to one or more monitoring areas; and (2) from each monitoring area to one or more monitoring factors o

if a monitoring factor applies to more than one monitoring area, then for the subsequent PO the detail of the monitoring factor that is the same will be stated as the same and the detail of the monitoring factor that is different will be fully described o

each monitoring area will be tracked as either Open or Closed o

each monitoring factor will be tracked as either Open or Closed o

the possible Priority of each monitoring factor is: High, Medium, Low, or Periodic o

if an NRC staff concern arises related to a monitoring factor, then the NRC staff may develop a Follow-Up Action Item or Open Issue to document that concern prior to the NRC sending a Notification Letter Changes from the NRC SDF Monitoring Plan, Rev. 1:

o there are only two types of monitoring activities, either a Technical Review or an Onsite Observation Visit, which means that a Data Review will be under either a Technical Review or an Onsite Observation Visit, which is how the NRC previously implemented Data Reviews o

except for Monitoring Area (MA) 8 (Environmental Monitoring), all the monitoring factors in a monitoring area relate to the same PO(s) o the NRC technical information about both the monitoring areas and the monitoring factors are different because the information was based on the DOE 2020 SDF PA rather than the DOE 2009 SDF PA The NRC information for MA 1 (Inventory), MA 8 (Environmental Monitoring), and MA 9 (Site Stability) changed since issuance of the NRC 2023 SDF TER; but, those changes did not affect the NRC Conclusions in the NRC 2023 SDF TER.

The Tables ES-1, ES-2, and ES-3 below update the Tables A-4, A-5, and A-6 in the NRC 2023 SDF TER Appendix to represent the status of the monitoring areas and monitoring factors as of when this SDF Monitoring Plan, Rev. 2 was issued.

Table ES-1: Overall Structure of SDF Monitoring Plan, Rev. 2 MONITORING AREA MONITORING FACTOR PERFORMANCE OBJECTIVE(S)

PRIORITY MA 1: Inventory 0 Closed monitoring factors MF 1.01: Inventory in Disposal Structures

§61.41 & §61.42 Periodic MF 1.02: Methods Used to Assess Inventory

§61.41 & §61.42 Medium MA 2: Infiltration and Erosion Control 0 Closed monitoring factors

xii MONITORING AREA MONITORING FACTOR PERFORMANCE OBJECTIVE(S)

PRIORITY MF 2.01: Hydraulic Performance of Closure Cap

§61.41, §61.42

& §61.44 Medium MF 2.02: Erosion Control of the SDF Engineered Surface Cover and Adjacent Area

§61.41, §61.42

& §61.44 High MF 2.03: Confidence in QA/QC for HDPE/GCL Composite Barrier and Drainage Layer Installation

§61.41, §61.42

& §61.44 High MF 2.04: Long-Term HDPE/GCL Composite Barrier and Drainage Layer Degradation

§61.41, §61.42

& §61.44 High MF 2.05: Potential Confined Conditions in the ULDL

§61.41, §61.42

& §61.44 High MF 2.06: Long-Term Erosion Barrier Performance

§61.41, §61.42

& §61.44 Medium MF2.07: Shallow Infiltration

§61.41, §61.42

& §61.44 Medium MA 3: Waste Form Hydraulic Performance 3 Closed monitoring factors: MF 3.01, MF 3.02, and MF 3.04 MF 3.03: Applicability of Laboratory Data to Field-Emplaced Saltstone

§61.41 & §61.42 Medium MA 4: Waste Form Physical Degradation 0 Closed monitoring factors MF 4.01: Waste Form Matrix Degradation

§61.41 & §61.42 High MF 4.02: Waste Form Macroscopic Fracturing

§61.41 & §61.42 High MF 4.03: Moisture Characteristic Curves for Saltstone

§61.41 & §61.42 Low MA 5: Waste Form Chemical Degradation 1 Closed monitoring factor: MF 5.05 MF 5.01: Radionuclide Release from Field-Emplaced Saltstone

§61.41 & §61.42 Low MF 5.02: Chemical Reduction of Tc by Saltstone

§61.41 & §61.42 Low MF 5.03: Reducing Capacity of Saltstone

§61.41 & §61.42 Low MF 5.04: Kd Values and Solubility Limits for Saltstone

§61.41 & §61.42 Medium MA 6: Disposal Structure Performance 1 Closed monitoring factor: MF 6.02 MF 6.01: Kd Values in Disposal Structure Concrete

§61.41 & §61.42 Medium

xiii MONITORING AREA MONITORING FACTOR PERFORMANCE OBJECTIVE(S)

PRIORITY MF 6.03: Performance of Disposal Structure Roofs and HDPE/GCL Layers

§61.41 & §61.42 Medium MF 6.04: Disposal Structure Concrete Fracturing

§61.41 & §61.42 Medium MF 6.05: Integrity of Non-Cementitious Materials

§61.41 & §61.42 Medium MF 6.06: Localized Contaminant Release

§61.41 & §61.42 Medium MF 6.07: Moisture Characteristic Curves for Disposal Structure Concrete

§61.41 & §61.42 Low MA 7: Subsurface Flow and Transport 1 Closed monitoring factor: MF 7.01 MF 7.02: Kd Values for SRS Soil

§61.41 & §61.42 Low MF 7.03: Confidence in GSA Modeling Results

§61.41 & §61.42 Medium MF 7.04: Confidence in Local SDF Modeling Results

§61.41 & §61.42 Medium MF 7.05: Impact of Calcareous Zones on Contaminant Flow and Transport

§61.41 & §61.42 Low MA 8: Environmental Monitoring 0 Closed monitoring factors MF 8.01: Leak Detection

§61.41, §61.42,

& §61.43 Periodic MF 8.02: Groundwater Monitoring

§61.41, §61.42,

& §61.43 Periodic MF 8.03: Identification and Monitoring of Groundwater Plumes in the SRS Z-Area

§61.41, §61.42 High MA 9: Site Stability 0 Closed monitoring factors MF 9.01: Settlement Due to Static-Loading and Seismic Loading

§61.41, §61.42,

& §61.44 Medium MF 9.02: Settlement Due to Dissolution of Calcareous Sediment

§61.41, §61.42,

& §61.44 Medium MF 9.03: Gullying of the Closure Cap

§61.41, §61.42,

& §61.44 Medium MF 9.04: Sheet and Rill Erosion of the Closure Cap

§61.41, §61.42,

& §61.44 Medium MF 9.05: Slope Stability of the SDF Closure Cap

§61.41, §61.42,

& §61.44 High MF 9.06: Flow through the ULDL

§61.41, §61.42,

& §61.44 High

xiv MONITORING AREA MONITORING FACTOR PERFORMANCE OBJECTIVE(S)

PRIORITY MF 9.07: Degradation of the Erosion Barrier

§61.41, §61.42,

& §61.44 Medium MF 9.08: Settlement Due to Waste Bags in SDS 4

§61.41, §61.42,

& §61.44 Medium MA 10: CLOSED -

Obsolete with Rev. 2 14 Closed monitoring factors with 12 of those monitoring factors incorporated into other monitoring factors MA 11: Radiation Protection Program 0 Closed monitoring factors MF 11.01: Dose to Individuals During Operations

§61.43 Periodic MF 11.02: Air Monitoring

§61.43 Periodic MA 12: Biosphere 0 Closed monitoring factors MF 12.01: Ingestion Pathway Parameters

§61.41 & §61.42 Medium MF 12:02: Inhalation Pathway Parameters

§61.41 & §61.42 Low MA 13: Inadvertent Intrusion 0 Closed monitoring factors MF 13.01: Intrusion Source Terms

§61.42 Low MF 13.02: Intrusion Exposure Pathways

§61.42 Medium MA 14: Future Scenarios and Conceptual Models 0 Closed monitoring factors MF 14.01: Scenario Development and Defensibility

§61.41 & §61.42 Medium MF 14.02: Defensibility of Conceptual Models

§61.41 & §61.42 High MF 14.03: Implementation of Conceptual Models

§61.41 & §61.42 Medium MF 14.04: Identification and Screening of FEPs

§61.41 & §61.42 Medium MF 14.05: Future Designs and Analyses as They Pertain to Potential Degradation Processes and Performance

§61.41 & §61.42 High MF 14.06: Groundwater Yield of the UTRA-UAZ in the SRS Z-Area

§61.41 & §61.42 High Table ES-2: Monitoring Areas in SDF Monitoring Plan, Rev. 2 TOTAL # of Monitoring Areas 14

of OPEN Monitoring Areas 13

of CLOSED Monitoring Areas 1

xv Table ES-3: Monitoring Factors in SDF Monitoring Plan, Rev. 2 TOTAL # of Monitoring Factors 70

of OPEN Monitoring Factors 50

of CLOSED Monitoring Factors 20 This NRC SDF Monitoring Plan, Rev. 2, will be used by both the NRC and the NDAA-Covered State of South Carolina to continue to assess the DOE compliance with the POs in 10 CFR Part 61, Subpart C, under NDAA Section 3116(b) at the SRS SDF. The NRC may later send a letter to the DOE supplementing this monitoring plan prior to the NRC issuing a revision to this monitoring plan. The NRC issues a revised SDF monitoring plan only after: (1) the NRC reviews an updated DOE SDF PA; and (2) the NRC issues a revised SDF TER.

(Intentionally Left Blank)

1-1

1.0 INTRODUCTION

The Ronald W. Reagan National Defense Authorization Act for Fiscal Year 2005 (NDAA)

(https://www.congress.gov/108/plaws/publ375/PLAW-108publ375.pdf) allows the Secretary of Energy to determine whether radioactive waste resulting from the reprocessing of spent nuclear fuel is not high-level waste (HLW). If so, then it can be managed as low-level waste (LLW) and both the DOE and the NRC refers to it as Waste Incidental to Reprocessing (WIR). The NDAA-Covered States are currently Idaho and South Carolina. The citation for the full text of NDAA Section 3116 is: U.S. Congress, Public Law 108-375, Ronald W. Reagan National Defense Authorization Act for Fiscal Year 2005, Section 3116, Defense Site Acceleration Completion, October 2004.

The NDAA Section 3116(a) process includes that the U.S. Department of Energy (DOE) Consult with the U.S. Nuclear Regulatory Commission (NRC) on the DOE non-HLW determinations and plans. The NDAA Section 3116(a) process begins when the DOE issues a Draft Basis for Waste Determination along with other DOE documents, including the Performance Assessment (PA) for a proposed DOE-WIR Location. The NRC reviews the DOE information and the NRC review process may include meetings and/or technical calls with the DOE. During the review process, the NRC may issue Request for Supplemental Information (RSI) Comments and/or Request for Additional Information (RAI) Questions to the DOE and if so, then the DOE provides the NRC with Response to RSI Comments and/or Responses to RAI Questions. At the end of the NRC review process, the NRC issues a publicly available Technical Evaluation Report (TER) that may include: (1) conclusions about whether the DOE meets the NDAA-WIR Criteria, and (2) NRC recommendations to the DOE.

The NDAA Section 3116(a) process ends when the Secretary of Energy signs the Waste Determination and the DOE issues the associated Waste Determination along with the supporting Final Basis for Waste Determination. When the Waste Determination for a DOE-WIR Location is signed and, if it includes that the waste stream is not HLW, then the NDAA Section 3116(b) process begins. As of when this monitoring plan was issued, the DOE completed the NDAA-WIR Consultation process under NDAA Section 3116(a) with the NRC four times and each time the Secretary of Energy Waste Determination was that the waste stream was not HLW.

The NDAA Section 3116(b) process includes that the NRC, in coordination with the NDAA-Covered State, monitor the DOE disposal actions to assess compliance with the NRC regulations in Title 10 of the Code of Federal Regulations (10 CFR) Part 61, Licensing Requirements for Land Disposal of Radioactive Waste, Subpart C, Performance Objectives (POs). Note that NDAA-WIR Monitoring at a DOE-WIR Location continues in perpetuity; but, how that monitoring occurs may change over time. Besides the NRC reviews resulting in issuing TERs, the two major NRC and NDAA-Covered State monitoring activities of the DOE disposal actions at the DOE-WIR Location are: (1) a Technical Review of the DOE work products, experiments, and analysis, including collection of environmental data - followed by the NRC issuing a publicly available Technical Review Report (TRR); and (2) an Onsite Observation Visit (OOV) of aspects of the DOE disposal actions, and as appropriate related experiments -

followed by the NRC issuing a publicly available OOV Report.

During NDAA-WIR Monitoring, the NRC communicates either separately or together with the DOE and an NDAA-Covered State, including by: (1) email, (2) calls, (3) meetings, and (4) letters. For example, the NRC holds monthly calls with both DOE Headquarters and the DOE sites with both NDAA-WIR and non-NDAA-WIR Locations to share information regarding WIR activities at those DOE sites. For example, the NRC holds monthly calls with the South

1-2 Carolina Department of Environmental Services (SCDES), specifically about NDAA-WIR Monitoring activities at the Savannah River Site (SRS). Note that under South Carolina state law, on July 1, 2024, the NDAA-WIR responsibilities performed by the South Carolina Department of Health and Environmental Control were transferred to the SCDES.

The major DOE and NRC documents related to both the DOE NDAA-WIR Consultation with the NRC and the NRC NDAA-WIR Monitoring of the DOE disposal actions can be found at the NRC Public Website: https://www.nrc.gov/waste/incidental-waste.html and then clicking on the specific DOE-WIR Location on the top-right under Key Topics Also, when the NRC issues WIR documents, the NRC sends an email with links to the WIR documents to whoever signed up for the NRC WIR ListServ. To sign up for the WIR ListServ: (1) go to https://www.nrc.gov/public-involve/listserver.html, (2) type the email address in the box in the middle of the webpage, (3) select the box next to Waste Incidental to Reprocessing at the bottom of the webpage, and (4) click on the Subscribe button that will then appear at the bottom of the webpage.

1.1 Background

The DOE SRS is an 802 square kilometer (km) (310 square mile (mi)) facility located in south-central SC, which began operation in 1951 producing nuclear materials for national defense, research, medical, and space programs. Waste produced at the facility from spent nuclear fuel reprocessing for defense purposes has been commingled with non-reprocessing waste resulting from the production of targets for nuclear weapons and production of material for space missions. Significant quantities of radioactive waste are currently stored onsite in large underground waste storage tanks, which were placed in operation between 1954 and 1986. The waste stored in the tanks is a mixture of insoluble metal hydroxide solids, referred to as sludge, and soluble salt supernate. The supernate volume has been reduced by evaporation, which also concentrates the soluble salts to their solubility limits. The resultant solution crystallizes as salts and the resulting solid is referred to as saltcake. The saltcake and supernate combined are referred to as salt waste. The DOE removes the salt waste, treats it to remove highly radioactive radionuclides to the maximum extent practical, and disposes of the low-activity fraction onsite in the Saltstone Disposal Facility (SDF). The SDF is located in the SRS Z-Area, which is approximately 10 km (6.2 mi) from the nearest SRS site boundary on a local topographic high.

Under NDAA Section 3116(a), the NDAA Section 3116(a) Consultation for the DOE SRS SDF was completed when the Secretary of Energy issued the Waste Determination (ML17136A069),

which included the following:

Section 3116 of the NDAA authorizes the Secretary of Energy, in consultation with the NRC, to determine that certain waste from reprocessing is not high-level waste if it meets the criteria set forth in that Section: (1) that it does not require disposal in a deep geologic repository, (2) that it has had highly radioactive radionuclides removed to the maximum extent practical, (3) that it meets concentration limits and/or dose-based performance objectives for near-surface disposal of radioactive waste, and (4) that it will be disposed of pursuant to a State-issued permit or State-approved closure plan. In this document, the Secretary is determining that the treated, solidified low-activity salt waste from the tanks meets all of those criteria. Accordingly, the Secretary is determining that this material is not high-level waste and will be disposed in SDF.

Under NDAA Section 3116(b), the NRC, in coordination with the NDAA-Covered State of South Carolina, started monitored the DOE disposal actions before the NRC issued the SDF Monitoring Plan, Rev. 0 (ML070730363). The DOE issued an update to the SDF PA in 2009.

The NRC issued the TER, Rev. 1 (ML121170309) based on its review of the DOE 2009 SDF PA

1-3 (with associated documents). In the 2012 SDF TER, the NRC concluded that it did not have reasonable assurance that DOE salt waste disposal at the SDF would meet the POs, specifically the §61.41 PO. In the 2012 SDF TER, the NRC concluded that it did have reasonable assurance that the DOE will meet the §61.42 PO, §61.43 PO, and §61.44 PO.

When the NRC issued the 2012 SDF TER, it also issued an NRC Type-IV Notification Letter of Concern (ML120650576) to both the DOE and State of South Carolina with the NRC concerns about the DOE meeting the POs. The NRC, in coordination with the NDAA-Covered State of South Carolina, began monitoring the DOE disposal actions using the SDF Monitoring Plan, Rev. 1 (ML13100A113) when it was issued.

The DOE issued an update to the SDF PA in 2020 (ML20190A056). The NRC issued the SDF TER, Rev. 2 (ML23024A099) based on its review of the DOE 2020 SDF PA (and associated documents). Note that in the Acknowledgement Letter (ML20148M201) for the NRC staff review of the DOE 2020 SDF PA, the NRC Administratively Closed the NRC 2012 Type-IV Notification Letter of Concern because the DOE 2020 SDF PA, including the informational and design changes since the DOE 2009 SDF PA, represented a significant departure from the natural and engineered system that formed the basis for the NRC 2012 Type-IV Notification Letter of Concern. In the 2023 SDF TER (ML23024A099), the NRC concluded that if the DOE Closure Cap design and implementation achieve the DOE expected performance as described in the DOE 2020 SDF PA, then the NRC concluded that it had reasonable assurance that the DOE disposal actions at the SDF met or would meet all the POs, including the §61.40 PO.

1.2 Objective This SDF Monitoring Plan, Rev. 2 details the NRC, in coordination with the NDAA-Covered State of South Carolina, path forward in assessing the DOE compliance with the POs for the DOE SRS SDF. After this SDF Monitoring Plan, Rev. 2 document is issued, the NRC will follow it instead of SDF Monitoring Plan, Rev. 1, as supplemented by six NRC Letters from June 5, 2017 to October 18, 2021 (ML17097A351, ML18033A071, ML18107A161, ML18219B035, ML19150A295, and ML21279A173).

1.3 Roles and Responsibilities 1.3.1 Federal Facility Agreement Roles and Responsibilities for SRS The SRS Federal Facility Agreement (FFA) is a formal agreement between the DOE, the U.S.

Environmental Protection Agency (EPA), and the State of South Carolina with only those three entities having roles and responsibilities under the FFA. The EPA is a party to the FFA pursuant to its authority in accordance with the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), also known as Superfund, under which the EPA has been tasked to protect citizens from the dangers posed by abandoned or uncontrolled hazardous wastes. While Congress writes environmental laws, the EPA writes regulations to implement those laws, enforces the regulations, and sets national standards. The EPA role in the FFA is to provide oversight of any actions taken at SRS to ensure adherence with CERCLA, the FFA, and other guidance. The EPA is also responsible for providing technical and procedural assistance, information, and training as needed. More specifically, the EPA involvement with the State is focused on ensuring that proper disposal actions are taken, assisting the State with the design and installation of those actions, and monitoring and evaluating the effectiveness of those actions. The Executive Order 12580 delegates the responsibility to implement the provisions in CERCLA to the DOE and the U.S. Department of Defense. The CERCLA also names the DOE and the U.S. Department of Defense as the lead agencies for their respective areas. The DOE has several facilities in EPA Region IV. The SRS was added to the Superfund National Priorities

1-4 List in December of 1989, which was also the year that the SRS was required to have an FFA with the State of South Carolina and the EPA. The SCDES is the primary regulator of the DOE closure activities at the SRS. The State of South Carolina has authority for approval of wastewater treatment facility operational closure under Chapter 61, Articles 67 and 82 of the South Carolina Regulations.

1.3.2 The DOE NDAA-WIR Monitoring Roles and Responsibilities Under the NDAA, only the DOE, the NRC, and the NDAA-Covered States, including South Carolina for the SRS, have roles and responsibilities.

The DOE will, pursuant to its authority, perform saltstone disposal actions and monitor its activities to ensure compliance with all requirements. The DOE relevant authority stems from the Atomic Energy Act of 1954, as amended, and the applicable DOE orders, manuals, and policies. Furthermore, the DOE uses a documented process to review and resolve any disposal questions and develop any mitigation measures, as appropriate. The DOE roles and responsibilities under NDAA with respect to monitoring are to respond to the NRC and the SCDES monitoring activities. Examples of those DOE NDAA roles and responsibilities include (1) providing fact check input on the NRC Monitoring Plans, OOV Reports, Call Summaries, and Meeting Summaries; (2) participating in the NRC OOVs, Calls, and Meetings; and (3) in a timely manner, communicating to the NRC and the SCDES any concerns about DOE disposal or monitoring actions.

1.3.3 The NRC NDAA-WIR Monitoring Roles and Responsibilities While the NRC is not given a formal regulatory role, the NDAA requires that the NRC monitor, in coordination with the SCDES, the DOE disposal actions to assess compliance with the 10 CFR Part 61, Subpart C, Performance Objectives.

Examples of NRC NDAA roles and responsibilities include: (1) drafting and issuing the NRC Monitoring Plans, including incorporating the SCDES input and the DOE Fact Check input; (2) drafting and issuing the NRC OOV Guidance emails, including incorporating the SCDES input; (3) performing the NRC OOVs; (4) drafting and issuing the NRC OOV Reports, including incorporating the SCDES input and the DOE Fact Check input; (5) performing the NRC technical reviews; (6) drafting and issuing the NRC TRRs; (7) leading Calls and Meetings; (8) drafting and issuing Call Summaries and Meeting Summaries, including incorporating the SCDES input and the DOE Fact Check input; (9) in a timely manner, communicating to the DOE and the SCDES any NRC concerns about the DOE not meeting the POs; and (10) notifying Congress if the NRC determines that the DOE is not in compliance with the POs.

The NRC will keep the SCDES informed of the status of NDAA-WIR Monitoring activities at the SRS SDF including any potential findings of the DOE non-compliance that require a Letter to Congress. At least two business days prior to the release and dissemination of such a Letter, the SCDES will be briefed by the NRC on the reason(s) for the Letter.

1.3.4 The SCDES NDAA-WIR Monitoring Roles and Responsibilities The SCDES is the primary State of South Carolina regulator of disposal activities at the SRS, including at the SDF. The NRC staff periodically meets with SCDES to discuss monitoring activities that the SCDES undertakes to monitor the DOE disposal actions at the SDF. Those discussions enabled the SCDES to gain a better understanding of the NRC monitoring activities.

1-5 The NRC continues to coordinate with the SCDES throughout the NDAA-WIR Monitoring process, including using documents generated by the SCDES Environmental Surveillance and Oversight Program as a source of information to supplement this monitoring plan. The SCDES uses a holistic monitoring approach with regard to the overall performance and safety of SRS.

The NRC NDAA-WIR Monitoring Program assesses the DOE disposal actions at a very small portion of the SRS. Ultimately, the NRC and the SCDES are concerned with the potential for environmental contamination in groundwater, surface water, air, crops, milk, and meat. While it is unlikely that any contribution to such contamination from the SDF could manifest itself offsite in the foreseeable future, it is important to consider and evaluate, to the extent practicable, the utility of environmental monitoring in assessing the DOE disposal actions at the SDF against the POs. To the extent that the SCDES resources allow, the NRC will request assistance in following up on certain monitoring activities that require a local or onsite presence.

The SCDES roles and responsibilities under NDAA-WIR Monitoring are to perform activities under the South Carolina Environmental Surveillance and Oversight Program and to coordinate with the NRC. Examples of those roles and responsibilities include: (1) providing input to the NRC Monitoring Plans, OOV Guidance emails, OOV Reports, Call Summaries, and Meeting Summaries; (2) participating in NRC OOVs, Calls, and Meetings; and (3) in a timely manner, communicate to the DOE and the NRC any concerns about the DOE not meeting the POs.

There are five organizations at SCDES that the NRC coordinates with to implement NDAA-WIR Monitoring at the DOE SRS SDF. Within the SCDES Environmental Affairs Administration, the NRC interacts with the Bureau of Land & Waste Management, the Bureau of Water, and the Bureau of Regional & Laboratory Services. Four organizations (i.e., sections) that the NRC coordinates with are located at the SCDES Headquarters in Columbia, South Carolina. The SCDES Bureau of Land & Waste Management has three of those sections (see Figure 1-1 below for a partial organizational chart of that bureau). The SCDES Bureau of Water has one of those sections (see Figure 1-2 below for a partial organizational chart of that bureau). The last organization that the NRC coordinates with is the Midlands Aiken Office that is located in Aiken, South Carolina under the Bureau of Regional & Laboratory Services.

Figure 1-1: Partial Organizational Chart for SCDES Bureau of Land & Waste Management Bureau of Land &

Waste Management Division of Waste Management RCRA Federal Facilities Section Division of Site Assessment, Remediation &

Revitalization Federal Remediation Section Division of Mining &

Solid Waste Management Solid Waste Permitting

& Monitoring Section

1-6 (NRC staff developed from SCDES public information)

Figure 1-2: Partial Organizational Chart for SCDES Bureau of Water (NRC staff developed from SCDES public information) 1.4 The NDAA-WIR Monitoring Process The NDAA-WIR Monitoring is an ongoing process consisting of technical reviews and OOVs at the SRS SDF. The NRC uses the information gathered from DOE and other publicly available sources to continuously assess the DOE compliance with the POs at the SDF. Many of the DOE documents, including the PA and environmental monitoring reports, are written to satisfy the DOE internal requirements or other regulatory requirements for the DOE regulators (i.e., EPA, SCDES). The NRC will continue to leverage those already created documents and analyses to assist the NRC in assessing the DOE compliance with the POs at the SDF.

1.4.1 Technical Reviews Technical reviews by the NRC include the review and evaluation of analyses conducted by the DOE or others that address one or more aspects of the SRS SDF performance. Technical reviews may be used to assess model support for assumptions made by the DOE in the PA that are considered important to the DOE compliance demonstration. The NRC will document each technical review in a publicly available TRR. Data reviews are a subset of technical reviews.

Data reviews focus on real-time monitoring data that may indicate future system performance or a review of records or reports that can be used to directly assess compliance with the POs (e.g., review of radiation records). The result of a Data Review may be included in either a TRR or an OOV Report.

1.4.2 Onsite Observation Visits OOVs are first-hand observations by the NRC staff or a representative of a specific activity that could be used to assess an aspect of current or future SRS SDF performance. An OOV is generally performed to: (1) ensure that data collected for a technical review are of sufficient Bureau of Water Division of Water Facilities Permitting Industrial Wastewater Permitting Section

1-7 quality; or (2) observe key DOE disposal actions that are important to the DOE compliance demonstration.

Prior to each OOV, the NRC will prepare an OOV Guidance email that discusses the scope and specific activities that will be monitored during the OOV in more detail than is described in this monitoring plan. The activities will be based on many aspects, such as completion of the DOE technical reports, emergent issues, timely DOE actions related to a monitoring factor, availability of staff (i.e., NRC, SCDES, DOE), availability of locations at the SRS SDF, length of time since reviewing an item in a monitoring factor, scheduled FUAIs to previous OOVs, and available NRC resources. The NRC will coordinate with the SCDES in development of the OOV Guidance email to consider areas that the SCDES is interested in and availability of the SCDES experts in those areas of interest. The OOV Guidance email will be publicly available. During an OOV, the agenda may change based on what happens during the OOV (e.g., new areas of interest are identified) or unforeseen circumstances (e.g., weather). The NRC will document each OOV in a publicly available OOV Report.

1.4.3 The NRC Interest in Periodic DOE Documents and Upcoming DOE Activities/Events The DOE documents, including the PA and environmental monitoring, are written for the DOE or other regulatory requirements for the DOE regulators (i.e., DOE, EPA, SCDES) and the NRC is leveraging those already created documents and analyses to assist the NRC in assessing the DOE compliance with the POs. At the SRS SDF, the NRC has been performing monitoring activities since 2006. Based on that experience, both the NRC and the DOE agreed that it would be beneficial if the DOE were to provide to the NRC in a timely basis the following two sets of information:

certain original and updated DOE documents that are relevant to the NRC in performing its monitoring responsibilities (e.g., documents may be reviewed by the NRC at the NRC or during an OOV) that the NRC would periodically review timely notification that certain upcoming DOE activities/unscheduled events that will be occurring in the near-or long-term future (i.e., no surprises to the NRC, allowing enough time for the NRC to understand the DOE activities and let the DOE know if the NRC has any concerns about those activities) as well as timely notification when certain events happen Table 1-1 lists the periodic topical area, specific technical document(s), and the DOE expected availability of those documents used in NDAA-WIR Monitoring activities.

Table 1-1: List of Periodic DOE Documents Topical Area Document Approximate Availability/Frequency Groundwater

SDF Annual Groundwater Report

SDF Midyear Groundwater Report

SDF Performance Assessment Annual Review

SRS Annual Environmental Report January July March September Air Monitoring

SRS Annual Environmental Report September

1-8 Topical Area Document Approximate Availability/Frequency Inventory

SDF Performance Assessment Annual Review and Key Supporting Inventory References

Quarterly Composite Samples for Performance Assessment Sensitive Radionuclides

Salt Waste Processing Facility Decontaminated Salt Solution Semi-Annual Sample Analysis March Quarterly May and November Performance Assessment Maintenance

SRS Liquid Waste Facilities Performance Assessment Maintenance Annual Implementation Plan

SDF Performance Assessment Annual Review (includes the following):

- Inventory

- Unreviewed Waste Management Question Evaluations Performed

- Research and Development Performed

- Research and Development Planned March March Research and Development Testing/Studies Various Reports As issued (typically, September through December)

NOTE: The DOE adds the Annual Environmental Report and Summaries when issued to the following website: https://www.srs.gov/general/pubs/ERsum/index.html Table 1-2 provides examples of categories with specific DOE activities or unscheduled events that the NRC would like the DOE to keep the NRC informed about.

Table 1-2: Examples of Upcoming DOE Activities and Unscheduled Events Category Activity/Event General

DOE determines that an SDF special analysis will be performed

DOE starts saltstone disposal into a new disposal structure

Major work stoppages or unusual events occur (e.g., spills, disposal structure wall seeps)

Significant changes are made to the salt waste treatment processes that could affect treated salt waste composition (e.g., radionuclide inventories, aluminate concentration)

Environmental Monitoring

Unusual volumes of water are removed from a disposal structure sump

Unusual radionuclide concentrations are encountered in water removed from a disposal structure sump

Unexpected radionuclide concentrations, conductivity measurements, or nitrate concentrations are encountered in groundwater samples from SRS Z-Area wells Inventory

Changes are made to the methods used to assess the inventory of radionuclides disposed of at the SDF

Significant changes are made to the estimated inventory of Technitium-99 (Tc-99), Tin-126 (Sn-126), Iodine-129 (I-129), Radium-226 (Ra-226),

Thorium-230 (Th-230), Plutonium-239 (Pu-239), Plutonium-240 (Pu-240), or Americium-241 (Am-241) in a disposal structure Waste Form Changes are made to the saltstone formulation, including changes to admixtures

1-9 Category Activity/Event Disposal Structure Performance

DOE decides to use a new design of a disposal structure or significant changes are made to the design of a disposal structure

Major delays or unexpected events (e.g., unexpected hydrotest results) occur during construction of a disposal structure

Major construction stages of a disposal structure are about to begin:

- placing HDPE/GCL on a lower mud mat in a disposal structure

- pouring an upper mud mat on a lower mud mat in a disposal structure

- placing a floor in a disposal structure

- placing wall panels in a disposal structure

- constructing columns in a disposal structure

- placing roof panels in a disposal structure 1.5 Notification Letters The following updates the information in the NRC WIR Periodic Monitoring Report, Rev. 6 (ML19058A272), which updated the information in the NRC guidance document NUREG-1854

- NRC Staff Guidance for Activities Related to U.S. DOE Waste Determinations - Draft Final Report for Interim Use (ML072360184):

At times during the NDAA-WIR Monitoring, the NRC may decide to send a Notification Letter concerning the DOE non-compliance or the potential for the DOE non-compliance with the 10 CFR Part 61 POs. There are five types of Notification Letters. Three of the letters are non-compliance letters (i.e., Type-I, Type-II, Type-III) that the NRC developed to implement the authority it has inferred from the statutory language in NDAA Section 3116(b). The NRC may issue the other two letters (i.e., Type-IV, Type-V) as an interim step.

The NRC expects to issue a Letter of Concern (i.e., Type-IV) to allow the DOE sufficient time to respond to the NRC concern before issuance of one of the three non-compliant Notification Letters (i.e., Type-I, Type-II, Type-III). However, that may not be possible or appropriate in all situations. For example, if a worker were overexposed in an accident (i.e., received greater than 0.01 Sievert (5 rem) exposure) and therefore, the NRC was going to issue a Type-I Notification Letter of Evidence PO Not Met, then the NRC may decide to send that Type-I Notification Letter to Congress, the DOE, and the NDAA-Covered State, rather than first sending a Type-IV Notification Letter of Concern to the DOE and the NDAA-Covered State. The NRC would use other means of notification (e.g., calls, meetings) with both the DOE and the NDAA-Covered State before sending the Type-I Notification Letter. Table 1-3 below describes each type of Notification Letter, including the NRC conclusion for issuing the Notification Letter, the NRC basis for issuing the Notification Letter, who at the NRC signs the Notification Letter, and who receives the Notification Letter. Figure 1-3 below provides a graphic of the three non-compliance Notification Letters along with example reasons for each of those Notification Letters.

Table 1-3: Types of Notification Letters Typ e

Notification Signature Distribution Non-Compliance Notification Letters I

Basis - Evidence PO Not Met: The NRC concludes that direct evidence (e.g.,

environmental sampling data) exists that indicates the DOE disposal actions do not The NRC Chairman The DOE, the NDAA-Covered State, and Congress

1-10 Typ e

Notification Signature Distribution meet one or more POs in 10 CFR Part 61, Subpart C.

Notification: If the DOE cannot demonstrate that executed disposal actions currently meet the requirements specified in the PO, then the NRC will issue a Type-I Letter of Non-Compliance.

II Basis - Lack of Compliance Demonstration: The NRC concludes that indirect evidence (e.g., data regarding key modeling assumptions) exists that indicates the DOE disposal actions do not meet one or more POs in 10 CFR Part 61, Subpart C.

Notification: If the DOE cannot adequately address the NRC technical concerns, then the NRC will issue a Type-II Letter of Non-Compliance.

The NRC Chairman The DOE, the NDAA-Covered State, and Congress III Basis - Insufficient Information: The NRC concludes that insufficient information is available to assess whether the DOE disposal actions meet the POs in 10 CFR Part 61, Subpart C. It is not clear to the NRC that either the DOE: (1) has plans to, or (2) is able to provide the information in a reasonable timeframe to allow the NRC to assess compliance.

Notification: If the DOE cannot adequately address the NRC technical concerns, then the NRC will issue a Type-III Letter of Non-Compliance.

The NRC Chairman The DOE, the NDAA-Covered State, and Congress Other Notification Letters IV Basis - Concern: The NRC concludes that there are concerns with the DOE demonstration of meeting the POs in 10 CFR Part 61, Subpart C.

Notification: If the DOE cannot adequately address the NRC concerns, then the NRC will issue a Type-IV Letter of Concern.

The NRC Management or the NRC Staff The DOE and the NDAA-Covered State V

Basis - Resolution: The NRC concludes that the DOE has provided sufficient information to resolve the concerns in the Type-IV Letter of Concern regarding the DOE demonstration of meeting the POs in 10 CFR Part 61, Subpart C.

The NRC Management or the NRC Staff The DOE and the NDAA-Covered State

1-11 Typ e

Notification Signature Distribution Notification: If the DOE adequately addresses the NRC concerns in a Type-IV Letter of Concern, then the NRC will issue a Type-V Letter of Resolution.

Figure 1-3: Types of Non-Compliance

1-12 1.6 The Monitoring Plan This SDF Monitoring Plan, Rev. 2 is structured from each PO, to a monitoring area, to monitoring factor(s), including the priority of monitoring factor(s). Each monitoring area is supported by one or more monitoring factor. Each monitoring area will be tracked as either Open or Closed. Each monitoring factor is a smaller, more specific item that will be monitored in more detail. Each monitoring factor will be tracked as either Open or Closed. If the NRC staff concerns arise related to a monitoring factor, then the NRC staff may develop an FUAI or Open Issue to document those concerns. Thus, the NRC has a mechanism to communicate to DOE early of the need for corrective action, prior to issuance of a Notification Letter.

This SDF Monitoring Plan, Rev. 2 is organized by PO with a chapter devoted to each of the five POs. Each chapter has the associated monitoring areas and their associated monitoring factors.

Each monitoring area supports one or more POs. If a monitoring area supports multiple POs, then this monitoring plan indicates whether or not the monitoring area is an exact duplicate of a previously listed monitoring area (i.e., whereby the details of the monitoring area and its associated monitoring factors will be referenced rather than repeated) or if there are unique aspects of the monitoring area or associated monitoring factors that pertain to that PO. At the end of each monitoring factor, there is specific information that provides the NRC staff expectations of how and/or when the monitoring factor will be closed. When this monitoring plan mentions the DOE 2020 PA, this refers to the DOE 2020 PA with all its associated documents, including the DOE: (1) references; (2) Responses to the NRC RSI Comments; and (3) Responses to the NRC RAI Questions.

The NRC information for Monitoring Area (MA)) 1 (Inventory), MA 8 (Environmental Monitoring), and MA 9 (Site Stability) changed since issuance of the NRC 2023 TER; but, those changes did not affect the NRC Conclusions in the NRC 2023 TER. For Monitoring Factor (MF) 1.01, the DOE changed the periodic sampling of treated salt waste, which changed the NRC information in this monitoring plan from the information in the TER. For MF 8.03, in this monitoring plan, the NRC decided to clarify the NRC information from what was in the TER. In this monitoring plan, the NRC combined MF 9.08 with MF 9.01 from the NRC 2023 TER Appendix and then renumbered MF 9.09 from the TER Appendix to be MF 9.08.The Tables ES-1, ES-2, and ES-3 below update the Tables A-4, A-5, and A-6 in the 2023 NRC SDF TER Appendix to represent the status of the monitoring areas and monitoring factors as of when this SDF Monitoring Plan, Rev. 2 was issued.

1-13 Table 1-4: Overall Structure of SDF Monitoring Plan, Rev. 2 MONITORING AREA MONITORING FACTOR PERFORMANCE OBJECTIVE(S)

PRIORITY MA 1: Inventory 0 Closed monitoring factors MF 1.01: Inventory in Disposal Structures

§61.41 & §61.42 Periodic MF 1.02: Methods Used to Assess Inventory

§61.41 & §61.42 Medium MA 2: Infiltration and Erosion Control 0 Closed monitoring factors MF 2.01: Hydraulic Performance of Closure Cap

§61.41, §61.42

& §61.44 Medium MF 2.02: Erosion Control of the SDF Engineered Surface Cover and Adjacent Area

§61.41, §61.42

& §61.44 High MF 2.03: Confidence in QA/QC for HDPE/GCL Composite Barrier and Drainage Layer Installation

§61.41, §61.42

& §61.44 High MF 2.04: Long-Term HDPE/GCL Composite Barrier and Drainage Layer Degradation

§61.41, §61.42

& §61.44 High MF 2.05: Potential Confined Conditions in the ULDL

§61.41, §61.42

& §61.44 High MF 2.06: Long-Term Erosion Barrier Performance

§61.41, §61.42

& §61.44 Medium MF2.07: Shallow Infiltration

§61.41, §61.42

& §61.44 Medium MA 3: Waste Form Hydraulic Performance 3 Closed monitoring factors: MF 3.01, MF 3.02, and MF 3.04 MF 3.03: Applicability of Laboratory Data to Field-Emplaced Saltstone

§61.41 & §61.42 Medium MA 4: Waste Form Physical Degradation 0 Closed monitoring factors MF 4.01: Waste Form Matrix Degradation

§61.41 & §61.42 High MF 4.02: Waste Form Macroscopic Fracturing

§61.41 & §61.42 High MF 4.03: Moisture Characteristic Curves for Saltstone

§61.41 & §61.42 Low MA 5: Waste Form Chemical Degradation 1 Closed monitoring factor: MF 5.05 MF 5.01: Radionuclide Release from Field-Emplaced Saltstone

§61.41 & §61.42 Low MF 5.02: Chemical Reduction of Tc by Saltstone

§61.41 & §61.42 Low

1-14 MONITORING AREA MONITORING FACTOR PERFORMANCE OBJECTIVE(S)

PRIORITY MF 5.03: Reducing Capacity of Saltstone

§61.41 & §61.42 Low MF 5.04: Kd Values and Solubility Limits for Saltstone

§61.41 & §61.42 Medium MA 6: Disposal Structure Performance 1 Closed monitoring factor: MF 6.02 MF 6.01: Kd Values in Disposal Structure Concrete

§61.41 & §61.42 Medium MF 6.03: Performance of Disposal Structure Roofs and HDPE/GCL Layers