September 5, 2012 

Mr. Jim Folk, Deputy Assistant Manager 

Waste Disposition Programs Division 

U.S. Department of Energy 

Savannah River Operations Office 

P.O. Box A 

Aiken, SC 29802 

SUBJECT: U.S. NUCLEAR REGULATORY COMMISSION JUNE 12, 2012, ONSITE 

OBSERVATION REPORT FOR THE SAVANNAH RIVER SITE F-TANK FARM 

CLOSURE 

Dear Mr. Folk: 

The enclosed report describes the U.S. Nuclear Regulatory Commission’s (NRC’s) onsite 

observation activities on June 12, 2012, at the Savannah River Site (SRS) F-Tank Farm 

performed in coordination with the South Carolina Department of Health and Environmental 

Control. This onsite observation was conducted in accordance with Section 3116 of the Ronald 

W. Reagan National Defense Authorization Act for Fiscal Year 2005 (Section 3116), which 

requires NRC to monitor disposal actions taken by the U.S. Department of Energy (DOE) for the 

purpose of assessing compliance with the performance objectives set out in 10 CFR Part 61, 

Subpart C. The activities conducted during the site visit were consistent with those described in 

the NRC’s observation guidance at SRS F-Tank Farm, dated June 4, 2012, (Agencywide 

Documents Access and Management System (ADAMS) Accession No. ML12135A666) and 

NRC’s staff guidance for activities related to waste determinations (NUREG-1854, dated August 

2007). 

This onsite observation at SRS was focused on assessing compliance with the four 

performance objectives: (i) protection of the general population from releases of radioactivity 

(§61.41); (ii) protection of individuals from inadvertent intrusion (§61.42); (iii) protection of 

individuals during operations (§61.43); and (iv) stability of the disposal site after closure 

(§61.44). Meeting these performance objectives is predicated on the performance of the tanks 

and ancillary facilities as closed by DOE. 
J. Folk - 2 - 

If you have any questions or need additional information regarding this report, please contact 

James Shaffner of my staff at James.Shaffner@nrc.gov, or at (301) 415-5496. 

Sincerely, 

 /RA/ 

Andrew Persinko, Deputy Director 

Environmental Protection 

 and Performance Assessment Directorate 

Division of Waste Management 

 and Environmental Protection 

Office of Federal and State Materials 

 and Environmental Management Programs 

Enclosures: 

NRC Observation Report 

DOE Pre-briefing 

cc w /enclosure: 

WIR Service List 
J. Folk - 2 - 

If you have any questions or need additional information regarding this report, please contact 

James Shaffner of my staff at James.Shaffner@nrc.gov, or at (301) 415-5496. 

Sincerely, 

Andrew Persinko, Deputy Director 

Environmental Protection 

 and Performance Assessment Directorate 

Division of Waste Management 

 and Environmental Protection 

Office of Federal and State Materials 

 and Environmental Management Programs 

Enclosure: 

NRC Observation Report 

DOE Pre-briefing 

cc w /enclosure: 

WIR Service List 

DISTRIBUTION: GAlexander CBarr LParks CGrossman RPabalan 

ML12191A210 

OFC DWMEP:PM DWMEP:LA DWMEP:BC DWMEP:BC DWMEP:DD

NAME JShaffner TMoon CMcKenney GSuber APersinko

DATE 8/2/12 8/6/12 8/6/12 8/28/12 9/5/12

OFFICIAL RECORD COPY
WIR SERVICE LIST

Glenn Carroll, Coordinator 

Nuclear Watch South 

P.O. Box 8574 

Atlanta, GA 31106 

Tom Clements, Member 

Friends of the Earth 

1112 Florence Street 

Columbia, SC 29201 

Jim Hardeman, Manager 

Environmental Radiation Program 

Environmental Protection Division 

Georgia Department of Natural Resources 

4220 International Parkway, Suite 100 

Atlanta, GA 30354 

Karen Patterson, Environmental 

Appointment 

Governors' Nuclear Advisory Council 

 and Tetra Tech NUS 

900 Trail Road 

Aiken, SC 29803-5297 

Bobbie Paul, Executive Director 

Georgia Womens Action for New Directions 

250 Georgia Ave., SE 

Suite 202 

Atlanta, GA 30312 

Robert H. Pope 

Senior Remedial Project Manager 

U.S. Environmental Protection Agency 

Region 4, Superfund Division 

Federal Facilities Branch, Waste Division 

61 Forsyth Street 

Atlanta, GA 30303 

Jon Richards, Remedial Project Manager 

U.S. Environmental Protection Agency 

Region 4, Superfund Division 

Federal Facilities Branch, Waste Division 

61 Forsyth Street 

Atlanta, GA 30303 

Thomas Saporito, Executive Director 

P.O. Box 8413 

Jupiter, FL 33468 

John J. Schnabel, Saltstone Project 

 Inspector, Professional Engineer 

Division of Mining and Solid Waste 

 Management 

Bureau of Land and Waste Management 

South Carolina Department of Health 

 and Environmental Control 

2600 Bull Street 

Columbia, SC 29201-1208 

Shelly. Wilson 

Federal Facilities Liaison 

Environmental Quality Control 

Administration 

South Carolina Department of Health 

 and Environmental Control 

2600 Bull Street 

Columbia, SC 29201-1708 
Enclosure 

U.S. NUCLEAR REGULATORY COMMISSION JUNE 12, 2012, ONSITE OBSERVATION 

REPORT FOR THE SAVANNAH RIVER SITE F-TANK FARM CLOSURE 

EXECUTIVE SUMMARY: 

The U.S. Nuclear Regulatory Commission (NRC) staff conducted its first onsite observation visit 

to the F-Tank Farm at the Savannah River Site (SRS) on June 12, 2012. The purpose of this 

visit was to focus on Tank 18 and 19 grouting as it relates to compliance with performance 

objectives in 10 CFR Part 61, Subpart C: (i) protection of the general population from releases 

of radioactivity (§61.41); (ii) protection of individuals from inadvertent intrusion (§61.42), and 

(iii) protection of individuals during operations (§61.43). The NRC observed aspects of Tank 18 

and 19 grouting operations and discussed NRC concerns related to potential cracking and 

shrinkage of the grout and other cementitious materials. Shrinkage or cracking of these 

materials could form fast pathways through the engineered barrier system and lead to early 

release of key radionuclides from the disposal system and are, therefore, important to the 10 

CFR 61.41 and 61.42 performance objectives. 

Prior to the visit, The NRC and contractor staff reviewed a number of reports prepared by the 

U.S. Department of Energy (DOE) and its contractors related to grout specifications formulation, 

placement and anticipated performance. These reports are summarized in this report and will 

be evaluated in more detail in a separate technical review memoranda along with other 

technical reports previously provided to the NRC staff by DOE. In accordance with the onsite 

observation guidance (Agencywide Documents Access and Management System (ADAMS) 

Accession No. 12135A666), NRC staff had planned to accomplish the following objectives: 

1. Observe grout truck arrival and check-in protocols. 

2. Observe tests to ensure grout acceptability. 

3. Observe external processes (i.e. point of origin) to introduce grout to delivery system. 

4. Observe real time video of grout placement in tank(s). 

5. Observe health physics practices to ensure worker protection. 

6. Review and discuss specific measures to prevent in-tank grout shrinkage. 

7. Review and discuss practices to ensure proper grouting of in-tank structures, and 

equipment. 

8. Review and discuss practices to ensure proper grouting of tank vault features important 

to performance (e.g., basemat leak detection components). 

The NRC was unable to accomplish onsite observation objectives 3, 6, and 8 listed above due 

to time and logistical constraints. These objectives will be addressed during a future visit. 

It should be noted that this onsite observation was completed prior to the preparation of a formal 

monitoring plan. The monitoring plan is being prepared and will be used to inform onsite 

observations beginning in 2013. 

NRC staff created no open issues associated with this onsite observation. However, NRC staff 

did provide several follow-up actions requesting information from DOE. In addition, NRC 

agreed to provide DOE with information related to research conducted by its contractors related 

to tank grout performance and information regarding alkali-silica-reaction that could be adverse 

to FTF tank grout performance. 
- 2 - 

A summary of the staff’s observations and conclusions is provided below. 

1.0 BACKGROUND: 

Section 3116 of the National Defense Authorization Act for Fiscal Year 2005 (Section 3116) 

authorizes DOE, in consultation with the NRC, to determine that certain radioactive waste 

related to the reprocessing of spent nuclear fuel is not high-level waste, provided certain criteria 

are met. Section 3116 also requires NRC to monitor DOE disposal actions to assess 

compliance with the performance objectives in 10 CFR Part 61, Subpart C. 

On September 30, 2010, DOE submitted a “Draft Section 3116 Determination Closure of F-Tank 

Farm Savannah River Site” to demonstrate compliance with the Section 3116 criteria including 

demonstration of compliance with the performance objectives in 10 CFR Part 61, Subpart C 

(DOE, cite). In its consultation role, the NRC staff reviewed the draft waste determination and 

provided a number of recommendations that staff believed would be beneficial regarding DOE’s 

demonstration of compliance with long-term performance objectives. The NRC documented the 

results of its review in a Technical Evaluation Report issued in October 2011 (NRC, 2011). 

DOE issued a final waste determination March 2012 taking into consideration the assumptions, 

conclusions, and recommendations in NRC’s Technical Evaluation Report (DOE, 2012). DOE 

began grouting operations in April 2012. 

To carry out its monitoring responsibility under Section 3116, NRC performs technical reviews 

and onsite observations related to DOE disposal activities, in coordination with the State of 

South Carolina site regulator, South Carolina Department of Health and Environmental Control 

(SC DHEC). Technical reviews generally focus on evaluation of information and data collected 

to provide support for key assumptions made in DOE’s FTF Performance Assessment (PA) that 

are considered important to the compliance demonstration. Onsite observations generally are 

performed to: (i) observe the collection of information and data that are the subject of the 

technical reviews (e.g., observation of waste sampling used to generate radionuclide inventory 

data); or to (ii) observe key disposal (or closure) activities related to technical review areas or 

that are otherwise important to the compliance demonstration (e.g., slag and other material 

storage, grout formulation and preparation, and grout placement). 

2.0 NRC ONSITE OBSERVATION ACTIVITIES: 

2.1 Technical Focus: 

Staff focused on long-term concerns related to grout shrinkage and cracking and its impact on 

the ability to meet 10 CFR 61.41 and 61.42. Observation of tank grouting and protection of 

workers and members of the public in compliance with 10 CFR 61.43. 

2.2 Observation Scope: 

In accordance with the onsite observation guidance (ADAMS Accession No. 12135A666), NRC 

staff had planned to accomplish the following objectives during the June 12, 2012 site visit: 

1. Observe grout truck arrival and check-in protocols. 

2. Observe tests to ensure grout acceptability. 
- 3 - 

3. Observe external processes (i.e. point-of-origin) to introduce grout to delivery system. 

4. Observe real time video of grout placement in tank(s). 

5. Observe health physics practices to ensure worker protection. 

6. Review and discuss specific measures to prevent in-tank grout shrinkage. 

7. Review and discuss practices to ensure proper grouting of in-tank structures and 

equipment. 

8. Review and discuss practices to ensure proper grouting of tank vault features important 

to performance (e.g., basemat leak detection components). 

The NRC was unable to accomplish onsite observation objectives 3, 6, and 8 due to timing or 

other constraints. These objectives, and others that will be documented in the subsequent 

onsite observation guidance, will be addressed during a future visit, as is possible. 

2.1.2 On-Site Observation- DOE Grouting Activities for Tank 18:

The DOE began the onsite observation with an in-briefing that included an overview of the grout 

placement process, radiation protection, and contamination control, and quality control, as well 

as industrial and radiological safety considerations for site visitors. During the in-briefing 

participants were also able to observe “real time” video stream of grout placement including 

placement of grout in Tank 18. The presentations were followed by a tour of grouting 

operations, as discussed in more detail below: 

1. In re. Item 1 (Section 2.1.1, above), the NRC staff observed ongoing grouting operations 

(above ground) from several perspectives. The staff was able to observe the arrival and 

verification of grout trucks, the delivery of grout to above ground hoppers, and the 

pumping of grout into a slick line. 

2. In re. Item 2, NRC staff also observed an example of periodic testing of grout 

acceptability. Samples for testing are taken from the first grout batch of the day and at 

least one truck after the first 100 cubic yards of grout. Testing includes measurement of 

grout slump flow (to determine grout flowability and ability to self-level), temperature, unit 

weight/yield, bleed, and air content. Nine grout cylindrical samples also are prepared 

and archived for testing of compressive strength at 7, 28, and 91 days. These cylinders 

are stored under controlled temperature–humidity conditions prior to testing. 

3. In re. Item 3 (partial), during the site tour, some NRC staff was provided a brief overview 

of Quality Assurance (QA) oversight of the grout supplier. The vendor has an approved 

QA program and is subject to inspections and surveillances by DOE and SRR. 

4. In re. Item 4, the DOE contractor staff presented an overview of grouting operations for 

the tank, supplemented by real-time video of grouting operations. A camera and light 

array is used to monitor grout placement and the video is time stamped and archived 

onto DVDs. The use of a pneumatically launched “pig” was mentioned as the method to 

clean the grout slick line and tremie at the end of each shift. This method eliminates the 

need to wash the system with water, which could create local areas in the tank grout 

with higher water-to-cement ratio and higher permeability. 
- 4 - 

5. In re. Item 5, the DOE provided information on radiological controls and its radiation 

worker protection program. DOE indicated that a project-specific radiation work permit 

was created to track worker doses associated with Tanks 18 and 19 grout placement. 

6. In re. Item 7, the DOE contractor staff also described the grouting of the internals of insitu equipment, such as slurry pumps and transfer jets, and the procedure to be used for 

grouting tank risers 

7. The DOE contractor staff indicated that, as of June 7, 2012, Tank 18 is approximately 67 

percent full and has received a total of 699 truckloads of grout. Tank 19 is 

approximately 83 percent full and has received a total of 866 truckloads of grout. No 

risers in either tank have been capped 

2.1.3 Observation Results:

Technical Discussion – Long term concerns related to grout shrinkage and cracking and its 

impact on the ability to meet PO 61.411

The on-site observation focused on the ongoing grouting of Tank 18 in light of NRC staff 

concerns related to the potential for future cracking and/or shrinkage of emplaced grout 

material. Such shrinkage and cracking have the potential to create preferential fast-flow 

pathways for water through the bulk grout to the residual waste. Further, fast flow through 

localized paths in the grout could decrease the chemical reducing capability of the grout: 

1. In re. Items 1 and 2, DOE staff explained that for each batch (or truckload) of grout, a 

ticket is prepared documenting the mix description, amount of each component in the 

mix, and water to cement ratio. NRC staff examined representative batch tickets of 

grout that was accepted for placement into the tank, and verified that the measured 

weights of the engineered grout pour components (Portland cement, fly ash, slag, sand, 

granite aggregate, water, and admixtures) reported in the tickets are within 1 percent of 

the grout mix design specifications listed in C-DCF-F-01524 (Revise Tanks 18F and 19F 

Closure Grout Specification). The water to cement ratio recorded in the batch tickets 

was found to be consistent with the specification in C-DCF-F-01524. NRC staff also 

examined representative batch tickets of grout that was rejected for placement, and 

verified that the rejected grout batches did not meet the slump flow requirement 

(24 to 28 inches) listed in C-DCF-F-01524. 

 

1

 Preceding the out-brief with DOE, NRC staff internally met to discuss technical issues related to grout 

shrinkage, cracking, and other features that may lead to preferential or by-passing pathways through the 

grouted tanks. SC DHEC representatives supporting the observation were also in attendance and 

participated in the discussion. 
- 5 - 

2. In re. Item 4, the NRC staff noted mounding of grout in the center of Tank 18 due to 

placement of the grout through the center riser and what appeared to be an inability of 

the tank grout to completely self-level. NRC staff was concerned that filling the tank 

vaults may be difficult because DOE may be unable to deliver grout to the periphery of 

the tank due to premature filling of the grout access point in the center of the vault. DOE 

indicated that the domed roofs of the Type IV tank vaults will make it easier to fill all void 

space above the spring line of the tanks. However, DOE indicated that, if necessary, it 

would create additional access points in peripheral risers to ensure void space within the 

tank is minimized. 

3. In re. Item 4, the NRC staff also noted the appearance of “lobes”2

, which is accentuated 

by the: (i) limited ability of the tank grout to self-level and (ii) incomplete lateral delivery 

of grout from the center riser to the tank periphery near the walls. NRC staff indicated its 

concerns with this grout feature because the results of an NRC contractor field 

experiment using a previously proposed FTF grout formulation showed that the lobe 

interfaces, as well as interfaces between successive lifts, are subject to shrinkage and 

could form higher conductivity zones that are more conductive to water through the 

monolith (Dinwiddie, et al., 2012). 

4. In re. Item 4, the NRC staff also inquired about the potential for lower quality grout to 

form near the tank walls due to the use of process water to lubricate the tremies prior to 

the start of grouting each day. This water collects at the edge of the tank and could lead 

to locally higher water-to-cement ratios in the grout at the edges of the tank. 

5. In re. Item 4, the NRC requested DOE to provide a video record of tank filling that would 

be beneficial to NRC staff understanding of: (i) the evolution of grout mounding and lobe 

formation over time; and (ii) the potential for lower quality grout to form near the tank 

walls due to the use of process water (and resultant higher water-to-cement ratios of 

grout in contact with collected water at the tank walls) at the start of each day of 

grouting. SC DHEC officials noted that they are monitoring grouting operations on an 

on-going basis and will be glad to share resulting information with NRC. 

6. In re. Item 6, the NRC staff communicated its concerns with the potential formation of 

preferential fast-flow pathways along sidewalls, at the interfaces of residual equipment, 

and between grout lobes due to shrinkage. Although NRC staff intended to review and 

discuss with DOE measures to prevent in-tank grout shrinkage, DOE staff did not 

address grout shrinkage during its presentation, nor did it provide additional information 

during the out-brief when the issue was raised by NRC staff. NRC staff noted that DOE 

report SRNL-STI-2011-00551 recommended development and testing of a shrinkage 

compensating all-in-one grout mix design and described special test forms that were 

designed and instrumented to evaluate dimensional changes (shrinkage and expansion) 

as a function of time, temperature, and humidity. This topic will be evaluated in more 

detail in a separate technical review memorandum. 

 

2

 A grout flow lobe is a fan-shaped mass of grout that forms on a slope by the changing direction of flow.
- 6 - 

7. In re. Item 6, the NRC staff communicated its concern with the potential formation of 

cracks in the tank grout due to Alkali–Silica Reaction (ASR). ASR is a process whereby 

reactive aggregates breakdown under exposure to the highly alkaline pore solution in 

concrete, which can result in significant expansion and, in some cases, cause cracking 

of concrete. This concern arose because the grout being used to fill Tanks 18 and 19 

include 3/8-inch granite “pea gravel” as aggregates, instead of using only sand 

aggregate as described in the DOE PA document (SRS-REG-2007-00002), and 

because of recent observations of concrete cracking at the Seabrook nuclear power 

plant in Seabrook, New Hampshire. In that facility, granite aggregates also were used in 

the concrete mix. ASR is a slow process and its occurrence at Seabrook became 

evident only decades after the plant was constructed. The Tank 18 and 19 grout fill mix 

contain less Portland cement than the concrete mix used at Seabrook and likely would 

be less susceptible to ASR. 

Nevertheless, NRC staff is concerned that DOE’s criterion for acceptance of vendor 

supplied granite aggregate relies on short-term alkali reactivity tests (ASTM C1260), 

which is unlikely to predict the occurrence of ASR over the very long period of 

performance for compliance with PO 61.41. This topic will be evaluated in more detail in 

a separate technical review memorandum 

• In re. Item 2, the NRC staff noted that DOE report SRNL-TI-2011-00551 indicated that 

currently available Portland cements contain up to 5 wt% limestone. NRC staff 

communicated its concern that a reduction in the amount of Portland cement in the grout 

mix would lower the pH buffering capacity of the grout and could affect the timing of 

release of key radionuclides. This topic will be evaluated in more detail in a separate 

technical review memorandum. 

Technical Discussion – Ability to meet PO 61.43:

• In re. Item 5, DOE gave an overview of its radiation protection protocols specific to the 

grouting project during the in-briefing. However, NRC staff did not have an opportunity 

to analyze the program in any detail. It was agreed that a detailed discussion regarding 

specific aspects of DOE’s radiation protection program would be conducted during a 

future onsite observation when subject matter experts are included as members of the 

observation team. 

3.0 FOLLOW-UP ACTIONS AND CONCLUSION:

The NRC requested selected sample videos of Tank 18 grout pours to include at least 4 hours 

of continuous video for one operating day per week. Sample should include different calendar 

days (e.g. Monday one week; Friday; Wednesday etc.). NRC requests two examples of “end-of 

day-beginning-of-next-day video” and two examples of “end-of-week–beginning-of-next-week” 

video. 

The NRC requested a copy of an in‐tank daily inspection video from grout pouring operations. 

SCDHEC indicated that it will continue to monitor grouting activities as part of its own inspection 

process and would be willing to share resulting information with NRC. 
- 7 - 

NRC requested grout batch tickets from four accepted loads and four rejected loads. 

(completed) 

NRC will provide DOE with latest reports on grout and saltstone conducted by the CNWRA. 

(completed) 

NRC will provide DOE documentation on ASR in concrete of the Seabrook Station. (completed) 

There were no conclusions resulting from this on-site observation. 

4.0 PARTICIPANTS: 

In Brief and Tour of Grouting Operations (am) and Out-brief (pm) 

U.S. NRC:

George Alexander

Cynthia Barr

Leah Parks

Christepher McKenney

Janelle Jessie

James Shaffner 

Roberto Pabalan (CNWRA/SWRI)

U.S. DOE-SRS:

Sherri Ross

SRR:

Ginger Dickert (pm)

Steve Thomas

Stuart MacVean (pm)

Larry Romanowski

Kent Rosenberger

James Herbert (am)

Victor Franklin (pm)

Kim Hauer 

Bruce Dragon(pm)

Ron Campbell

Dan Wood

Andy Tisler

SOUTH CAROLINA DHEC

Barry Mullinax

Byron Amick

Scott Simons

U.S. DOE HQ

Linda Suttora

5.0 REFERENCES: 

U.S. Department of Energy (DOE) SRR-CWDA-2012-00093 Savannah River Site F-Tank Farm 

NRC Onsite Observation Visit: June 12, 2011. 

U.S. Nuclear Regulatory Commission, Onsite Observation Guidance for June 11-12, 2012; 

Waste Monitoring Visit to the Savannah River Site, F-Tank Farm. 

C-SPP-F-00047, Revision 2. 2003. “Tank Farm: Tank 18F and Tank 19F, Furnishing and 

Delivery of Tank Closure Mixes (U).” Aiken, South Carolina: Washington Savannah River 

Company. 

Dinwiddie, C.L., D.R. Bannon, M.K. Todt, G.R. Walter, and M.M. Roberts. 2012. “Draft Fiscal 

Year 2012 Meso- and Intermediate-Scale Grout Monolith Test Bed Experiments: Results and 

Recommendations.” San Antonio, Texas: Center for Nuclear Waste Regulatory Analyses. 
- 8 - 

Ganguly, A. 2012. “Technical Summary Report for Tanks 18F and 19F Closure — Initial Trial 

Batching (U).” C-TRT-F-00005, Revision 0. Aiken, SC: Savannah River Remediation, LLC. 

Guilherme, J.B. 2012. “SRR Subcontractor Surveillance Plan Furnishing and Delivery of Tank 

Closure Grout (TK 18/19).” SRR-LWP-2012-00034. Aiken, South Carolina: Savannah River 

Remediation, LLC. 

Langton, C. A. and D.B. Stefanko. 2011. “Bulk Fill Grout Recommendations for Tanks 18-F 

and 19-F.” SRNL-L3100-2011-00180. Aiken, SC: Savannah River National Laboratory. 

Stefanko, D.B. and C.A. Langton. 2011. “Tanks 18 and 19-F Structural Flowable Grout Fill 

Material Evaluation and Recommendations.” SRNL-STI-2011-00551, Revision 0. Aiken, South 

Carolina. Savannah River National Laboratory. 

Stefanko, D.B. and C.A. Langton. 2011. “Tanks 18 and 19-F Equipment Grout Fill Material 

Evaluation and Recommendations. SRNL-STI-2011-00592, Revision 0. Aiken, South Carolina. 

Savannah River National Laboratory. 

Stefanko, D.B. and C.A. Langton. 2011. “Tank 18-F and 19-F Tank Fill Grout Scale Up Test 

Summary.” SRNL-STI-2011-00749, Revision 0. Aiken, SC: Savannah River National 

Laboratory. 

Stefanko, D.B. and C.A. Langton. 2011. “Tanks 18-F and 19-F Grout Fill Engineering and 

Performance Requirements.” SRNL-RP-2011-00977, Revision 0. Aiken, South Carolina: 

Savannah River National Laboratory. 

Thaxton, G.D. 2012. “Tank 18F and 19F Closure Assurance Plan.” SRR-LWE-2012-00036, 

Revision 0. Aiken, SC: Savannah River Remediation, LLC. 

Work Order No. 01087939–16: Placement of Grout Tank 18 Center Riser. 2012. 

Work Order No. 01087938–15: Placement of Grout Tank 19 Center Riser. 2012. 

Work Order No. 01087939–17: Placement of Grout Tank 18 Various Equipment Locations. 

2012. 

Work Order No. 01087938–16: Placement of Grout Tank 19 Various Equipment Locations. 

2012.