U.S. NUCLEAR REGULATORY COMMISSION July 2010

Revision 1

REGULATORY GUIDE

OFFICE OF NUCLEAR REGULATORY RESEARCH

The NRC issues regulatory guides to describe and make available to the public methods that the NRC staff considers acceptable 

for use in implementing specific parts of the agency’s regulations, techniques that the staff uses in evaluating specific problems 

or postulated accidents, and data that the staff needs in reviewing applications for permits and licenses. Regulatory guides are not 

substitutes for regulations, and compliance with them is not required. Methods and solutions that differ from those set forth in 

regulatory guides will be deemed acceptable if they provide a basis for the findings required for the issuance or continuance of a 

permit or license by the Commission. 

This guide was issued after publication of the draft regulatory guide for public comment. 

Regulatory guides are issued in 10 broad divisions: 1, Power Reactors; 2, Research and Test Reactors; 3, Fuels and Materials 

Facilities; 4, Environmental and Siting; 5, Materials and Plant Protection; 6, Products; 7, Transportation; 8, Occupational Health; 

9, Antitrust and Financial Review; and 10, General. 

Electronic copies of this guide and other recently issued guides are available through the NRC’s public Web site under the 

Regulatory Guides document collection of the NRC’s Electronic Reading Room at http://www.nrc.gov/reading-rm/doccollections/ and through the NRC’s Agencywide Documents Access and Management System (ADAMS) at 

http://www.nrc.gov/reading-rm/adams.html under Accession No. ML101470167. The regulatory analysis may be found in 

ADAMS under Accession No. ML101470350. 

REGULATORY GUIDE 3.13 

(Draft was issued as DG-3040, dated February 2010) 

DESIGN, CONSTRUCTION, AND INSPECTION OF 

EMBANKMENT RETENTION SYSTEMS 

AT FUEL CYCLE FACILITIES 

A. INTRODUCTION 

This guide describes some engineering practices and methods generally considered by the 

U.S. Nuclear Regulatory Commission (NRC) to be satisfactory for the design, construction, and 

inspection of embankment retention systems used for retaining solid and liquid effluent from nuclear fuel 

cycle facility operations other than uranium recovery and milling operations. These practices and 

methods are the result of NRC review and action on a number of specific cases, and they reflect the latest 

general engineering approaches that are acceptable to the NRC staff. If future information results in 

alternative methods, the NRC staff will review such methods to determine their acceptability. 

Title 10, Section 20.1101, “Radiation Protection Programs,” of the Code of Federal Regulations

(10 CFR 20.1101) (Ref. 1) requires licensees who possess, process, refine, or use uranium ores and oxides 

in fuel cycle facilities to use, to the extent practical, procedures and engineering controls based on sound 

radiation protection principles to maintain occupational radiation exposure and radiation exposure to 

members of the public that are as low as is reasonably achievable (ALARA). In addition, Subpart B, 

“Environmental Standards for the Uranium Fuel Cycle,” of 40 CFR Part 190, “Environmental Radiation 

Protection Standards for Nuclear Power Operations” (Ref. 2) requires that the annual dose equivalent not 

exceed 25x10-5 sieverts (Sv) (25 millirem (mrem)) to the whole body, 75x10-5 Sv (75 mrem) to the 

thyroid, and 25x10-5 Sv (25 mrem) to any other organ of any member of the public as the result of 

exposures to radiation (radon and its daughters excepted) from nuclear fuel cycle operations, including 

planned discharges of radioactive materials to the general environment. Liquid and solid wastes 

generated at fuel cycle facilities typically contain radioactive materials in excess of the discharge limits 
Rev. 1 of RG 3.13, Page 2 

and are generally confined by an embankment retention system to allow the solids to precipitate. The 

liquid is sampled for radiological or hazardous contents prior to release to the environment. 

The NRC issues regulatory guides to describe to the public methods that the staff considers 

acceptable for use in implementing specific parts of the agency’s regulations, to explain techniques that 

the staff uses in evaluating specific problems or postulated accidents, and to provide guidance to 

applicants. Regulatory guides are not substitutes for regulations and compliance with them is not 

required. 

This regulatory guide contains information collection requirements covered by 10 CFR Part 20, 

Part 40, and Part 70 that the Office of Management and Budget (OMB) approved under OMB control 

numbers 3150-0014, 3150-0020, and 3150-0009 respectively. The NRC may neither conduct nor 

sponsor, and a person is not required to respond to, an information collection request or requirement 

unless the requesting document displays a currently valid OMB control number. 

B. DISCUSSION 

Background 

The manufacture of nuclear fuel results in the production of liquid and solid wastes. Fuel cycle 

facilities have used embankment retention systems for both temporary and long-term storage of solid and 

liquid discharge. Effluent from the various processes dictates the requirement for release or retention. 

Factors pertaining to safety, contamination, and environmental damage determine the minimum 

requirements in planning and constructing retention systems. 

Uranium hexafluoride (UF6) production and fuel fabrication effluent does not contain constituents 

of long-lived radionuclides (e.g., radium-226) associated with uranium recovery processes. 

Environmental processing facilities associated with the fuel production and fabrication are able to treat 

liquid effluent and release it to the environment in compliance with the requirements of Appendix B, 

“Annual Limits on Intake (ALIs) and Derived Air Concentrations (DACs) of Radionuclides for 

Occupational Exposure; Effluent Concentrations; Concentrations for Release to Sewerage,” to 

10 CFR Part 20, “Standards for Protection against Radiation” (Ref. 3). The variation in construction to 

allow for release to the environment or to retain and not release is the prerogative of the applicant. The 

NRC staff reviews such variations on a case-by-case basis, or a State reviews them in accordance with the 

terms contained in the applicant’s Ground Water Discharge Permit. 

1. General Planning, Siting, and Design Considerations 

The following general design considerations are based on the requirements of Appendix A, 

“Criteria Relating to the Operation of Uranium Mills and the Disposition of Tailings or Wastes Produced 

by the Extraction or Concentration of Source Material from Ores Processed Primarily for Their Source 

Material Content,” to 10 CFR Part 40, “Domestic Licensing of Source Material,” (Ref. 4). 

Because the prime functions of the retention system are to store radioactive solids and/or to 

provide temporary storage of contaminated water, the system must be designed and constructed to remain 

stable for its intended life. The retention system must be designed to provide sufficient storage capacity 

at any given time during its intended life, and it must provide sufficient control of seepage to prevent 

unacceptable contamination of adjacent land, waterways, and ground waters. The retention system must 

also be designed to be resistant to wind and water erosion during and after facility operations. The design 
Rev. 1 of RG 3.13, Page 3 

and construction considerations, along with the sound evaluation and inspection principles in this guide, 

should be used in embankment retention systems associated with fuel production facilities. 

The planning, siting, and design of each retention system must comply with any other regulatory 

and permitting requirements for a proposed impoundment that exist outside of the NRC’s regulations in 

Appendix A to 10 CFR Part 40. 

1.1 Site Evaluation 

In selecting any site for fuel cycle facility effluent retention, local conditions, including climate, 

ground water and surface water hydrology, geology, and seismology, should be assessed and their 

impacts evaluated. In site selection, features that should be considered include (1) hydrologic and other 

natural conditions as they contribute to continued immobilization and isolation of contaminants from 

ground water sources, (2) potential for minimizing erosion, disturbance, and dispersion by natural forces 

over the long term, and (3) security in the form of a fence to restrict access by animals and unauthorized 

individuals. 

1.2 Field Exploration 

Subsurface investigations at the site of the retention system should be of adequate scope to 

determine the suitability of the foundation and characteristics of embankment materials. Borings should 

be drilled along the axis of the retention structure and at critical locations perpendicular to the axis to 

establish geologic sections and ground water conditions. Borings should extend to a depth in the natural 

soils at least equal to the height of the planned embankment section. The investigations should cover 

classification, physical and chemical properties, location, and extent of soil and rock strata, and variations 

in ground water conditions. Evaluation of ground water should be focused on the uppermost aquifer. The 

field exploration should identify this aquifer, its flow direction, and the distance from the impoundment to 

potential downgradient users. In addition, the preoperational background quality of ground water in the 

uppermost aquifer should be ascertained. Observation of ground water conditions should be recorded 

over a sufficient period to permit the ground water depths and range of seasonal fluctuations to be 

established. 

The foundation conditions should be evaluated to assess the ability of subsurface materials to 

support the embankments without failure and without excessive total or differential settlement. The 

permeability of foundation soils and rocks should be ascertained to estimate the seepage potential. 

Information is needed on the characteristics of the underlying soil as they will control transport of 

contaminants and solutions. 

1.3 Laboratory Tests 

Testing soil samples of foundation and embankment materials from the field investigation should 

provide detailed information on the physical and mechanical properties such as classification, gradation, 

shear strength, consolidation, permeability, sedimentation, compaction, piping and cracking 

susceptibility, and wind-water erosion characteristics. 
Rev. 1 of RG 3.13, Page 4 

2. Design Analysis 

Design analysis should consider stability, settlement, seepage, hydrologic analyses, liner stability, 

and liner compatibility. Specifically, the design should ensure that retention system failure will not occur. 

Historical records indicate that most failures associated with retention systems have been caused by 

overtopping by floodwaters, erosion, piping in the retention embankment or the foundation, foundation 

failure, slope failure, or liquefaction. 

2.1 Stability and Failure Analyses 

2.1.1 Slope Stability 

Stability analyses involve comparing the shearing stresses along potential failure surfaces with 

the available shearing resistance along those surfaces. The factor of safety is the ratio of the available 

shear strength to the developed maximum shear stress. A number of computer programs can be used to 

perform slope stability analyses. Commercially available programs also may allow calculation of the 

factor of safety. The output from a computer program should be checked carefully to verify that the 

critical surface with the lowest factor of safety has been identified, the critical surface represents a 

possible or realistic scenario, and computational problems resulting from the parameters used are 

minimized. In EM 1110-2-1902, “Engineering and Design Slope Stability,” issued October 2003, the 

U.S. Army Corps of Engineers describes pertinent basic design considerations, methods of stability 

analysis, and minimum factors of safety that provide an acceptable design basis for a safe settling or 

retention basin structure, (Ref. 5). 

2.1.2 Liquefaction 

The impact of liquefaction on stability should be considered, if potentially liquefiable soils exist 

below the site of a retention system. Evaluation of liquefaction potential should include laboratory 

testing, in situ testing, and comparisons to similar soil deposits. The U.S. Environmental Protection 

Agency report EPA/600/R-95/051, “RCRA Subtitle D (258): Seismic Design Guidance for Municipal 

Solid Waste Landfill Facilities,” issued April 1995, elaborates on five criteria for determining whether a 

site has potentially liquefiable soils—(1) geologic age and origin, (2) fines content and plasticity index, 

(3) saturation, (4) depth below ground surface, and (5) soil penetration resistance (Ref. 6). If liquefaction 

potential exists at a retention system site, additional subsurface investigation may be necessary. 

2.1.3 Settlement 

If the foundation beneath an embankment retention system consists of layers of compressible 

soils or weathered rock, or if the bedrock profile is very irregular, differential settlements could result 

from uneven loading or variable thicknesses in the compressible soils. Total settlement and differential 

settlements may cause cracking and/or excessive strain in the embankments or other retention system 

components that could lead to system failure. 

After settlement analyses have been performed, the engineered components of the waste retention 

system, such as geotextiles, geomembranes, clay liners, drainage layers, effluent collection piping, and 

waste piping, should be analyzed for tensile strain. The analysis should verify that the components can 

maintain their integrity when subjected to the induced strain associated with the settlement determined in 

the total and differential settlement analyses. If analysis indicates that settlement along any cross-section 

is likely to damage an engineered component, or to cause the engineered component to be unable to meet 

the minimum design criteria, then the retention system must be redesigned to eliminate the adverse effects 
Rev. 1 of RG 3.13, Page 5 

of total and differential settlement. Methods such as overbuilding, surcharging, removal of the material 

causing the problem, or engineered reinforcement may be used to mitigate the effects of settlement. 

2.2 Water Control and Management 

2.2.1 Impoundment Storage Capacity 

Some catchment areas contribute runoff into the retention system. This generally will be the area 

of the system itself, and the runoff will result from precipitation. This does not present a problem, as it 

only further dilutes any potential activity in the embankment retention system. Grading and diversion 

channels should be provided to enhance natural drainage if necessary. 

When the probability of occurrence of large floods on small drainage basins in arid regions is 

small and onsite personnel are available to repair any minor damage that could occur, the NRC staff may 

accept less conservative options for determining the design-basis flood. For small retention systems built 

in isolated areas where failure would neither jeopardize human life nor create damage to property or the 

environment beyond the licensee’s legal liabilities and financial capabilities, the design need not use 

extremely conservative flood design criteria. However, the selection of the design flood should be at least 

compatible with the hazard category guidelines set forth by the U.S. Army Corps of Engineers (Ref. 7). 

2.2.2 Seepage Control 

When retention systems are lined, seepage analysis for embankment stability purposes is 

unnecessary. However, special design features, such as impervious liners and collection systems, are 

needed to maintain the quality and quantity of seepage from the retention system within tolerable limits of 

water supply and pollution control requirements. If a clay liner is proposed, seepage into this layer must 

be assessed to ensure that seepage will not occur through the liner (Criterion 5 of Appendix A to 10 CFR 

Part 40). 

The potential for seepage at an embankment retention system can be controlled through 

installation of a liner system. The interior of each retention or settling basin should be lined with an 

essentially impervious synthetic lining material designed to prevent seepage. The number of construction 

joints and penetrations of the liner should be minimized, and protection from mechanical damage should 

be provided. The liner can be constructed of earthen material, such as compacted clay, or synthetic 

material, such as a high-density polyethylene geomembrane. The design of a liner system should 

consider subgrade material, type of liner system (earthen or synthetic), liner system protection, and leak 

detection. Both types of liner systems have advantages and disadvantages, and the choice of the liner 

system should consider several factors. A key factor is the liner material’s physical and chemical 

inertness when exposed to the materials within the retention system. The chemical qualities of the 

effluent must be assessed to determine the impacts on liners and/or the environment (Criterion 5 of 

Appendix A to 10 CFR Part 40). 

The advantages of a synthetic liner system include a significantly reduced thickness, a greater 

resistance to cracking, and a much lower hydraulic conductivity (typically several orders of magnitude 

lower than that of an earthen liner system). The design of a synthetic liner system should consider the 

method of placement, the seaming techniques, and the puncture resistance. Theory and design methods to 

evaluate puncture resistance have been developed and can be used to evaluate the puncture resistance of 

synthetics for different conditions (Refs. 8-10). 
Rev. 1 of RG 3.13, Page 6 

3. Construction Considerations 

The construction of embankment retention systems generally involves both excavation and filling 

in some specified order. Successful embankment retention system construction requires understanding 

the moisture/density relationships of the soils, providing adequate compaction, and preventing poorquality soils from being incorporated into the embankment retention system fill materials. Clearing and 

stripping operations provide much additional information on the characteristics of foundations, and this 

information may confirm or contradict design assumptions based on earlier geotechnical investigations. 

Weather and ground water conditions during construction may significantly alter water contents of 

proposed fill material or create seepage and/or hydraulic conditions necessitating modifications in design. 

Projects should be evaluated and “reengineered” continuously during construction to ensure that the final 

design is compatible with conditions encountered during construction. Construction supervision, 

management, and monitoring of the embankment and associated structures are a critical part of the overall 

project management plan. Once the facility is placed into operation, observations, surveillance, 

inspections, and continuing evaluation are required to ensure the satisfactory performance of the retention 

system (Criterion 12 of Appendix A to 10 CFR Part 40). 

4. Inspection and Maintenance 

Conditions can change throughout the life of the embankment retention system. Such changes 

can significantly affect the factors governing the stability of a retention system. Therefore, a continuous 

program of inspection of the retention system is strongly recommended, beginning at the start of 

construction. Each site and structure has its own characteristics and its own susceptibilities to problems, 

and the inspection program should be tailored to consider these. Thorough physical examination is an 

essential part of the inspection program. The optimal frequency of inspections depends on the size and 

condition of the facilities, the character of the foundation, the regional geological setting, and the 

consequences of failure, such as jeopardizing human health and safety and inflicting property and 

environmental damage. Monitoring and analysis of performance data are necessary to ensure detection of 

adverse conditions (Criterion 12 of Appendix A to 10 CFR Part 40). 

Before the operational use of the system begins, records of ground water levels (including 

seasonal fluctuations), ground water quality, ground elevations, and background radioactivities at the site 

should be compiled and compared with the operational conditions of the impoundment. Once operational 

activities begin, inspection should be performed at regular intervals to check the condition of the retention 

systems and associated facilities and to evaluate their structural safety and operational adequacy. A 

detailed, systematic inspection program should consist of, but not necessarily be limited to, the elements 

described in the sections below (10 CFR 40.27(b)(2)). 

4.1 Engineering Data Compilation 

Engineering data related to the design, construction, and operation of the retention systems should 

be compiled and, to the extent practicable, included in the initial inspection report. Most engineering data 

are readily available in documents filed for the license application. A detailed reference to the original 

documents kept at the project site should be adequate. These data should include the following items, as 

available and applicable: 

• general project data, including regional vicinity maps showing the project location and the 

upstream and downstream drainage areas and as-built drawings and photographs of the retention 

system 
Rev. 1 of RG 3.13, Page 7 

• hydrologic and hydraulic data, including drainage area and basin characteristics, storage volume, 

surcharge capacity for floods, rate of inflow, elevation of the maximum design pool, and 

freeboard height 

• foundation data and geological features, including boring logs, geological maps, profiles, and 

cross-sections 

• properties of embankment and foundation materials, including results of laboratory and field 

tests, and assumed design material properties 

• principal design assumptions and analyses, including hydrologic and hydraulic analyses, stability 

and stress analyses, and seepage and settlement analyses 

• pertinent construction photographs and records, including construction control tests, construction 

problems and modifications, and maintenance repairs 

4.2 Inspection Programs 

The embankment retention system inspection program should be established and conducted 

systematically to minimize the possibility of overlooking any significant features. A checklist should be 

developed and followed to document the observations of each significant feature. Photographs for 

comparison of previous and present conditions may be used as a part of the inspection program. The 

inspection program should include, but not be limited to, the following as appropriate: 

• Semiannual Inspection 

– Pond water elevations should be examined and recorded to ensure that minimum 

freeboard is maintained. 

– The transport system should be examined for any evidence of obstruction of the pipes or 

pumps caused by clogging or ice accumulation. The pipe couplings should be examined 

for leakage, and any flow rate sensor should be tested. 

– The liner system should be visually inspected to identify any damage to the liner and any 

operating practices that may contribute to liner damage. 

– Channels should be examined for channel bank erosion, bed aggradation or degradation 

and siltation, obstruction to flow, undesirable vegetation, or any unusual or inadequate 

operational behavior. 

– Any installed instrumentation, such as survey monuments, settlement plates or gauges, 

and/or piezometers, should be examined and tested for proper functioning. The available 

records and readings of these instruments should be reviewed to detect any unusual 

performance or distress of the structure. 

– The top of the embankment and downstream toe areas should be examined and surveyed, 

if necessary, for any evidence of unusual localized or overall settlement or depressions. 

– Embankment slopes should be examined for irregularities in alignment and variance from 

originally constructed slopes, unusual changes from original crest alignment and 
Rev. 1 of RG 3.13, Page 8 

elevation, evidence of movement at or beyond the toe, erosion, and surface cracks that 

indicate movement. 

– The slope protection should be examined for erosion-formed gullies and wave-formed 

notches and benches. The adequacy of slope protection against waves and surface runoff 

that may occur at the site should be evaluated. 

– The maintenance of operating facilities and features (such as pumps and valves) that 

pertain to the safety of the retention system should be examined to determine the 

adequacy and quality of the maintenance procedures followed in maintaining the 

retention system in a safe operating condition. 

– The general long-term performance of the liner, such as its resistance to degradation, 

should be examined. 

• Periodic Inspection (preferably bi-annual) should be performed by an independent geotechnical 

consultant to ascertain the condition of the embankment, which protects the retention basins. 

• Special Inspections 

– Unscheduled inspections should be performed after the occurrence of significant 

earthquakes, tornadoes, floods, intense local rainfalls, or other unusual events. 

– The NRC’s implementation of the National Dam Safety Program and its associated 

guidelines may require special inspections of any uranium fuel cycle facility 

embankments that fall within the scope of the program. 

4.3 Technical Evaluation 

The existing conditions of the retention system should be evaluated annually unless changing 

conditions dictate a shorter period. This evaluation should include an assessment of the hydraulic and 

hydrologic capacities, water quality, and structural stability and should take into account both existing 

conditions and any changing conditions. In addition, surface water and ground water sampling data 

should be collected at the time of the technical evaluation to detect any patterns that could be a sign of 

failure of seepage control measures or foundation distress. 

4.4 Inspection Reporting 

A report should be prepared to present the results of each technical evaluation and the inspection 

data accumulated since the last report. These documents should be kept at the project site for reference 

purposes, available for inspection by regulatory authorities, and retired only upon termination of the 

project. Any abnormal hazardous conditions observed during the inspection should be reported 

immediately to the NRC staff. 

4.5 Inspection Personnel 

An experienced professional who is thoroughly familiar with the investigation, design, 

construction, and operation of these types of facilities should direct the planning and conduct of the 

inspections and evaluations. At each facility, this individual should ensure that all field inspectors are 

trained to recognize and assess signs of possible distress or abnormality. 
Rev. 1 of RG 3.13, Page 9 

C. REGULATORY POSITION 

The following describes acceptable criteria for proposed construction, inspection, and 

performance of a fuel cycle facility waste retention system. If an applicant proposes the use of an 

alternative method or new information that may be developed in the future, the NRC will review the 

proposal and, if acceptable, approve its use. 

1. Basic Design Criteria 

a. The stability of the retention system is fundamental to design for construction and 

operation. In ensuring structural integrity, it should not be presumed that the liner system 

will function without leakage during the active life of the impoundment. 

b. Consider total and differential settlement within tolerable limits that will not result in 

harmful cracking and embankment instability. 

c. A liner’s design, construction, and installation should limit any uncontrolled migration of 

effluent out of the impoundment to the adjacent subsurface soil, ground water, or surface 

water. 

d. Recommended liner characteristics (Criterion 5 of Appendix A to 10 CFR Part 40): 

(1) The liner must be constructed of materials that have appropriate chemical 

properties and sufficient strength and thickness to prevent failure from pressure 

gradients, physical contact with the effluent to which they are exposed, climatic 

conditions, the stress of installation, and the stress of daily operation. 

(2) The liner must be placed on a foundation or base capable of providing support to 

the liner and resistance to pressure gradients above and below the liner to prevent 

failure of the liner from settlement, compression, or uplift. 

(3) The liner must be installed in such a way that it will cover all surrounding earth 

likely to be in contact with effluent. 

e. Consideration for installation of a leakage detection system to ensure that major liner 

failures are detected if they occur. 

f. Allow sufficient freeboard to minimize overtopping by flood inflows and wind-generated 

waves and should include an allowance for settlement of the foundation and 

embankments. 

g. Minimize upstream rainfall catchment areas to limit erosion potential and the size of the 

floods that could erode or wash out sections of the retention system. 

2. Methods of Analysis 

a. Wave runup may be determined using procedures discussed in the U.S. Army Corps of 

Engineers “Coastal Engineering Manual,” issued April 2002 (Ref. 11). 
Rev. 1 of RG 3.13, Page 10 

b. The static stability of the embankment should be analyzed using commonly accepted 

detailed stability methods. The analysis should use appropriate static soil and rock 

properties established on tested representative samples over anticipated in situ and 

placement conditions. 

c. Evaluation of liquefaction potential should include laboratory testing, in situ testing, and 

comparisons to similar soil deposits. Screening criteria should be used to determine 

whether there are potentially liquefiable soils at a site. The factor of safety for 

liquefaction potential should be greater than 1.0. 

d. Appropriate laboratory test results should be used to estimate the rate and magnitude of 

settlement. 

3. Construction Methods 

a. Conventional acceptable engineering practices of construction control for water retention 

dams (e.g., controls on foundation preparation, suitability of materials, proper placement, 

field moisture, and density). 

b. Installation of a synthetic liner system should focus on minimizing liner damage. 

Damage can occur in the form of wrinkles, improper seaming techniques, poor synthetic 

panel orientation, and punctures caused by construction equipment. 

4. Inspection and Maintenance 

a. A systematic inspection and maintenance program should be established to detect and 

repair damage that might lessen the integrity of the retention system. Generally, visual 

inspections performed on a regular basis and supplemented by adequate instrumentation 

are acceptable. 

b. Semiannual inspections of retention systems should be planned, conducted, evaluated, 

and documented under the direction of an experienced professional who is familiar with 

the design, construction, and operation of these types of facilities. The licensee should 

retain documentation (i.e., a record) of each inspection for 3 years after the 

documentation is made. 

c. Unscheduled inspections should be performed after the occurrence of significant 

earthquakes, tornadoes, floods, intense local rainfalls, or other unusual events. The 

NRC’s implementation of the National Dam Safety Program and its associated guidelines 

may require special inspections of any fuel cycle facility embankments that fall within 

the scope of the program. 

d. The inspection and maintenance program should start at the beginning of construction 

and continue at least through the operation of the facility. 

D. IMPLEMENTATION 

The purpose of this section is to provide information to applicants and licensees regarding the 

NRC’s plans for using this regulatory guide. The NRC does not intend or approve any imposition or 

backfit in connection with its issuance. 
Rev. 1 of RG 3.13, Page 11 

In some cases, applicants or licensees may propose or use a previously established acceptable 

alternative method for complying with specified portions of the NRC’s regulations. Otherwise, the 

methods described in this guide will be used in evaluating compliance with the applicable regulations for 

license applications, license amendment applications, and amendment requests. 
Rev. 1 of RG 3.13, Page 12 

GLOSSARY 

This guide uses the following definitions: 

Embankment: A dike or ridge of either natural or man-made materials used to prevent the movement of 

liquids, sludges, solids or other materials. 

Earthen Embankment Retention System: A watertight system of one or more settling and/or retention 

basins, including their associated engineered safety features. 

Retention Basin: A watertight basin in which liquid, sludge, or solid wastes are held for one or more of 

the following reasons – (1) analysis to verify activity levels permitting release, (2) evaporation, 

and (3) recycle for treatment. 

Settling Basin: A watertight basin designed for separating sludges and sediments as a layer on the 

bottom. The liquid is disposed of by overflow to the environment, transfer to a retention basin, or 

solar evaporation. 
Rev. 1 of RG 3.13, Page 13 

REFERENCES1 

1. 10 CFR 20.1101, “Radiation Protection Programs,” U. S. Nuclear Regulatory Commission, 

Washington, DC. 

2. 40 CFR Part 190, “Environmental Radiation Protection Standards for Nuclear Power 

Operations,” U. S. Nuclear Regulatory Commission, Washington, DC. 

3. Appendix B, “Annual Limits on Intake (ALIs) and Derived Air Concentrations (DACs) of 

Radionuclides for Occupational Exposure; Effluent Concentrations; Concentrations for Release to 

Sewerage,” to 10 CFR Part 20, “Standards for Protection against Radiation,” U.S. Nuclear 

Regulatory Commission, Washington, DC. 

4. Appendix A, “Criteria Relating to the Operation of Uranium Mills and the Disposition of Tailings 

or Wastes Produced by the Extraction or Concentration of Source Material from Ores Processed 

Primarily for Their Source Material Content,” to 10 CFR Part 40, “Domestic Licensing of Source 

Material,” U.S. Nuclear Regulatory Commission, Washington, DC. 

5. EM 1110-2-1902, “Engineering and Design Slope Stability,” U.S. Army Corps of Engineers, 

Washington, DC, October 2003. 2 

6. EPA/600/R-95/051, “RCRA Subtitle D (258): Seismic Design Guidance for Municipal Solid 

Waste Landfill Facilities,” U.S. Environmental Protection Agency, Washington, DC, April 1995.3

 

7. ER 1110-2-106, “Recommended Guidelines for Safety Inspection of Dams,” Table 3, U.S. Army 

Corps of Engineers, Washington, DC, September 1979. 

8. R.F. Wilson-Fahmy, D.B. Narejo, and R.M. Koerner, “Puncture Protection of Geomembranes, 

Part I—Theory,” Geosynthetics International, 3(5), 1996.4

 

9. D.B. Narejo, R.M. Koerner, and R.F. Wilson-Fahmy, “Puncture Protection of Geomembranes, 

Part II—Experimental,” Geosynthetics International, 3(5), 1996. 

10. R.M. Koerner, R.F. Wilson-Fahmy, and D.B. Narejo, “Puncture Protection of Geomembranes, 

Part III—Examples,” Geosynthetics International, 3(5), 1996. 

 

1 Publicly available NRC published documents are available electronically through the Electronic Reading room on the NRC’s 

public Web site at: http://www.nrc.gov/reading-rm/doc-collections/. The documents can also be viewed on-line or printed for a 

fee in the NRC’s Public Document Room (PDR) at 11555 Rockville Pike, Rockville, MD; the mailing address is USNRC PDR, 

Washington, DC 20555; telephone 301-415-4737 or (800) 397-4209; fax (301) 415-3548; and e-mail PDR.Resource@nrc.gov. 

2

Electronic copies of public U.S. Army Corps of Engineers (USACE) publications are available for free download from the 

Internet at http://www.usace.army.mil/inet/usace-docs/. This site is the only repository for all official USACE engineer 

regulations, circulars, manuals, and other documents originating from HQUSACE. Publications are provided in portable 

document format (PDF). 

3

Electronic copies of publicly available U.S. Environmental Protection Agency (EPA) publications are available for free 

download from the Internet at http://www.epa.gov/nscep/. Hard copies are available for purchase from the EPA National Library 

Network at US EPA, Mail Code 3404T, 1200 Pennsylvania Avenue NW, Washington, DC 20460; telephone 202-566-0556. 

4

Copies of listed Geosynthetics International journal articles are available for purchase from the Institute of Civil Engineers,

Thomas Telford Ltd., 40 March Wall, London, England, E14 9TP, telephone: +44 (0) 20 7665 2460 / 2418, or e-mail at 

Orders@icevl.com. 
Rev. 1 of RG 3.13, Page 14 

11. EM 1110-2-1100, “Coastal Engineering Manual,” U.S. Army Corps of Engineers, Washington, 

DC. 

12. NUREG/BR-0216, “Radioactive Waste: Production, Storage, and Disposal,” Rev. 2, U.S. 

Nuclear Regulatory Commission, Washington, DC, May 2002. 
Rev. 1 of RG 3.13, Page 15 

BIBLIOGRAPHY 

1. Regulatory Guide 3.11, “Design, Construction, and Inspection of Embankment Retention 

Systems at Uranium Recovery Facilities,” US Nuclear Regulatory Commission, Washington, DC. 

2 Regulatory Guide 1.127, “Inspection of Water-Control Structures Associated with Nuclear Power 

Plants,” US Nuclear Regulatory Commission, Washington, DC. 

3. Regulatory Guide 1.132, “site Investigations for Foundations of Nuclear Power Plants,” US 

Nuclear Regulatory Commission, Washington, DC. 

4. Regulatory Guide 1.138, “Laboratory Investigations of soils and rocks for Engineering analysis 

and Design of Nuclear Power Plants,” US Nuclear Regulatory Commission, Washington, DC. 

5. Regulatory Guide 1.198, “Procedures and Criteria for Assessing Seismic soil Liquefaction at 

Nuclear Power Plants,” US Nuclear Regulatory Commission, Washington, DC. 

6. Regulatory Guide 1.59, “Design Basis Floods at Nuclear Power Plants,” US Nuclear Regulatory 

Commission, Washington, DC.