NUREG-1620, Rev. 1

Standard Review Plan for 

the Review of a Reclamation 

Plan for Mill Tailings Sites

Under Title II of the Uranium

Mill Tailings Radiation Control 

Act of 1978

Final Report

 U.S. Nuclear Regulatory Commission

Office of Nuclear Material Safety and Safeguards

Washington, DC 20555-0001
 

 NUREG-1620, Rev. 1

Standard Review Plan for

the Review of a Reclamation

Plan for Mill Tailings Sites

Under Title II of the Uranium

Mill Tailings Radiation Control

Act of 1978

Final Report

Date Completed: June 2003

Date Published: June 2003

Prepared by

J. Lusher

J. Lusher, NRC Project Manager

 Division of Fuel Cycle Safety and Safeguards 

 Office of Nuclear Material Safety and Safeguards

 U.S. Nuclear Regulatory Commission

 Washington, DC 20555-0001 
1

NOTICE OF AVAILABILITY OF A STANDARD REVIEW PLAN (NUREG–1620) FOR STAFF

REVIEWS OF RECLAMATION PLANS FOR MILL TAILINGS SITES UNDER TITLE II OF

THE URANIUM MILL TAILINGS RADIATION CONTROL ACT 

AGENCY: U.S. Nuclear Regulatory Commission

ACTION: Notice of availability. 

SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) has developed a Standard

Review Plan (NUREG–1620) to provide guidance for staff reviews of reclamation plans for

uranium mill tailings sites covered by Title II of the Uranium Mill Tailings Radiation Control Act.

Under the provisions of Title 10 of the Code of Federal Regulations, Part 40 (10 CFR Part 40),

Domestic Licensing of Source Material, an NRC Materials License is required in conjunction with

uranium or thorium milling, or with byproduct material at sites formerly associated with such

milling. The licensee’s site Reclamation Plan documents how the proposed activities

demonstrate compliance with the criteria in Appendix A of 10 CFR Part 40. This information,

combined with the licensee’s Environmental Report, is used by the NRC staff to determine

whether the proposed activities will be protective of public health and safety and the

environment. The purpose of the Standard Review Plan (NUREG–1620) is to provide the NRC

staff with guidance on performing reviews of information provided by licensees. The use of the

Standard Review Plan is also intended to ensure a consistent quality and uniformity of staff

reviews. Each section in the review plan provides guidance on what is to be reviewed, the basis

for the review, how the staff review is to be accomplished, what the staff will find acceptable in a

demonstration of compliance with the regulations, and the conclusions that are sought regarding

the applicable sections in 10 CFR Part 40, Appendix A. NUREG–1620 will also assist in

improving the understanding of the staff review process by interested members of the public and

the uranium recovery industry. The review plan provides general guidance on acceptable

methods for compliance with the existing regulatory framework. As described in an NRC white

paper on risk-informed, performance-based regulation (SECY–98–144), however, the licensee

has the flexibility to propose other methods as long as it demonstrates how it will meet regulatory

requirements.

A draft of NUREG–1620 was issued in January 1999 for public comment. A final NUREG–1620,

which incorporated NRC staff responses to the comments received on the draft, was issued in

June 2000. On February 5, 2002 (FR5348), the NRC made the revised second draft of

NUREG–1620 available for a 75-day public comment. 

In preparing the final version of NUREG–1620, the NRC staff carefully reviewed and

considered about 120 written comments received by the close of the public comment period

on April 22, 2002. To simplify the analysis, the NRC staff grouped all comments into the

following major topic areas: 

(1) Editorial and Organizational Comments (31 comments)

(2) Policy Issues (including administrative, quality assurance, and surety/financial issues)

(51 comments)

(3) Geotechnical Stability (17 comments)
2

(4) Ground water (15 comments)

(5) Environmental aspects related to NRC responsibilities under NEPA (4 comments)

The following provides a more detailed discussion of the NRC evaluation of the major topic

areas and the NRC responses to comments.

1. Editorial and Organizational Comments

Issue: The standard review plan has a number of redundancies and editorial errors.

Comment: Several commenters identified editorial concerns, text omissions, or areas where

the organization of the standard review plan could be improved. Most of the organizational

comments addressed perceived redundancies in the standard review plan or opportunities to 

streamline the style. Most editorial comments addressed inconsistent terminology, identified

typographical and grammatical mistakes, or questioned the accuracy of reference documents.

Response: NUREG–1620 is structured consistent with NRC practice for standard review plan

style and format. While the style and format may be considered complex or redundant by some

commenters, no substantive changes have been made. This will preserve consistency with

other NRC standard review plans. The commenters have provided numerous suggestions for

improving the readability and clarity of the review plan. Most editorial comments that addressed

inconsistent terminology, typographical and grammatical mistakes, or the accuracy of reference

documents were accepted and incorporated in preparing the final standard review plan. The

individual editorial comments are not addressed in this comment summary document.

2. Policy Issues (Including Administrative, Quality Assurance, and

Surety/Financial Issues)

Issue: NRC is inappropriately examining economic assessments that are the prerogative of

the applicant.

Comment: The draft standard review plan asked the reviewer to examine the economic benefits

when slopes steeper than 5h:1v are proposed by an applicant. The NRC staff should be

concerned only with whether the slope design will be stable enough to protect the tailings.

Resolution: The NRC agrees with the commenter. The final standard review plan has been

edited to remove consideration of economic factors in slope design. 

Issue: Guidance provided on alternate feed materials and non-11e.(2) byproduct material is

not informative.

Comment: Commenters stated that information presented in Appendix I [Guidance on Disposal

of Alternate Feed Materials and Non-11e.(2) Byproduct Materials in Uranium Mill Tailings

Impoundments] of the draft standard review plan was not useful. The commenter suggested

that additional guidance was not needed and recommended that the appendix be deleted from

the review plan.
3

Resolution: The NRC staff agrees with the commenters to some extent. Appendix I did not

contain sufficient information to assist the reviewers in examining requests for disposal of these

materials in mill tailings impoundments. However, recent guidance from the Commission on

these subjects is relevant to such reviews. Accordingly, Regulatory Issue Summary 2000-23,

which presents Commission guidance on these matters has been included in the appendix to

facilitate staff reviews. 

Issue: NUREG–1620 should present guidance on examining multi-site problems.

Comment: One commenter noted that guidance on review of multi-site problems should be

included in the final standard review plan. The reviewer stated that if a group of licensees raise a

common issue, it would be cost effective to address it generically.

Response: The NRC staff agrees that addressing multi-site problems in an integrated manner

could be cost effective and potentially beneficial to public health and safety and the environment. 

Omitting this information from NUREG–1620 is not meant to reflect a lack of staff interest in

multi-site problems. Rather, the standard review plan is meant to address licensing reviews that

can be completed using well-accepted techniques. The staff believes that the technical and

regulatory aspects of multi-site problems are such that it is best to examine them on a case-bycase basis. 

Issue: The long-term custodian must accept transfer of property at termination of the

specific license.

Comment: One commenter expressed concern regarding language in NUREG–1620 that there

must be assurance that the long-term custodian will accept the property necessary to protect

public health and safety. The commenter was concerned that the language in the

standard review plan implied that the long-term custodian has the option to refuse transfer of

the property. 

Response: The language in the standard review plan is included to ensure that the reviewer

verifies that the long-term custodian is aware of the full extent of required land transfer prior to

termination of the specific license. The intent is to avoid delays in license termination because

the licensee and the long-term custodian may not have a mutual understanding on the extent of

land transfer, and the text has been clarified.

Issue: NUREG–1620 guidance on consideration of reasonably attainable corrective actions and

economic constraints is unclear.

Comment: One commenter was concerned that standard review plan guidance to not eliminate

potential corrective actions because of economic constraints is inconsistent with guidance to

assess three reasonably attainable, practicable corrective actions. The commenter notes that

in some cases there may not be three reasonably attainable, practicable corrective actions

to assess.

Resolution: While the NRC understands the commenter’s concern, the language in the

standard review plan on this matter is appropriate to the intent of the guidance and needs no

further detail. The guidance to evaluate three reasonably attainable, practicable corrective
4

actions is not a regulatory requirement. The NRC expects that an applicant will present

corrective action alternatives that are reasonable and practicable for a specific site and a

specific set of circumstances. 

Issue: Guidance that equipment owned by the licensee not be considered in reducing surety

cost evaluations is inappropriate.

Comment: One commenter expressed concern that in estimating costs to complete

reclamation by a third-party independent contractor, direction that the equipment owned by the

licensee and the availability of licensee staff should not be considered in reducing costs was

inappropriate. The commenter added that extreme interpretations of this approach could lead to

extravagantly expensive or even unattainable surety requirements.

Resolution: The language that is the subject of the comment is not intended to exclude

equipment and facilities that would reasonably be expected to be available to a third-party to

complete reclamation. However, if licensee plans call for removal of such equipment or facilities

prior to reclamation, then the associated costs may not be excluded from the surety estimate. 

The text has been clarified to address this issue.

Issue: NUREG–1620 should be used as a tool for public education.

Comment: Several commenters suggested that discussions could be expanded in various

sections of the standard review plan to improve public understanding of regulatory issues at

Title II uranium mill tailings sites.

Response: Discussions in several sections of the standard review plan were revised to improve

clarity and to correct editorial errors. Although it is made available to the public, the primary

intent of the Standard Review Plan is to provide guidance to the NRC staff, not to serve as a tool

for public education. The staff believes that the standard review plan contains the appropriate

level of detail for its intended purpose as a guide for staff reviews of reclamation plans for Title II

mill tailings sites.

3. Geotechnical Stability

Issue: NUREG–1620 requires additional flexibility in criteria for selection of rock erosion

protection materials.

Comment: One commenter suggested that criteria in the standard review plan should provide

more flexibility in selecting a less durable rock for erosion protection when obtaining more

durable rock is not practical.

Response: Flexibility in selecting rock types for erosion protection is implicitly provided in

several locations in NUREG–1620 (e.g., Section 3.5.3) as long as the applicant can demonstrate

with reasonable assurance that the radon barrier will be effective for 1,000 years, to the extent

reasonably achievable, and, in any case, for at least 200 years. Clarifying text has been added

to indicate explicitly that this option is available.

Issue: Terminology for erosion protection covers needs to be clarified.
5

Comment: One commenter requested clarification in use of the terms “unprotected soil cover”

and “vegetative soil cover.”

Response: The staff agrees with the commenter. Section 3.5 of the standard review plan has

been retitled “Design of Erosion Protection,” and the review guidance in that section has been

clarified to avoid confusion in the use of terms.

Issue: The NRC is requiring detailed seismic hazard analysis, even in zero seismic risk areas

identified in the Uniform Building Code.

Comment: One commenter noted that for cases where a given site is located in a “zero”

seismic risk area as identified in the Uniform Building Code, no further seismic characterization,

explanation, or description should be needed for the licensee or applicant.

Response: Maps for the maximum considered earthquake ground motion for the United States

in the most recent version of the building code (2000 International Building Code) are based on

probabilistic seismic hazard maps with additional modifications incorporating deterministic

ground motions in selected areas and the application of engineering judgement. These maps

were prepared for the National Earthquake Hazards Reduction Program by the United States

Geological Survey. Because it is based on probabilistic methods, within the new update, the

“zero” seismic risk areas no longer exist. 

The NRC is currently establishing risk-informed and performance-based regulations. One

example of this philosophy is the application of a risk-graded approach in developing seismic

design requirements for nuclear facilities. Under this approach for example, nuclear power

plants have to meet the most stringent design requirements because they pose the greatest

radiological risk to public health and safety. Other nuclear facilities like dry cask and canister

storage facilities or uranium mining operations could be designed to less stringent design criteria

because they pose substantially less radiological risk to public health and safety. This type of

graded approach to radiological hazard is described in U.S. Department of Energy (DOE)

Standard 1020–2002, “Natural Phenomena Hazards Design and Evaluation Criteria for

Department of Energy Facilities.” In that guidance, the DOE developed five performance

categories according to the relative risks posed by the potential failure of a structure, system, or

components (SSCs) to perform its intended safety function. Performance Category (PC)–2 is

intended for occupational safety and the design requirements for this category match those in

the IBC–2000. PC–3 SSCs are for hazard confinement and the design requirements go beyond

those within IBC–2000. Given the potential radiological hazards posed by Mill Tailing sites,

evaluations of seismic hazards should therefore exceed those prescribed in the IBC–2000 for

buildings. In addition, the National Earthquake Hazards Reduction Program maps do not take

site effects into account. Local site effects, such as soil amplification, can greatly increase the

level, spectral frequency content, and duration of vibratory ground motions at a site that is

produced during an earthquake. Therefore, these effects need to be understood in order to

accurately predict the seismic hazard at any site. 

Based on these two considerations (graded risk approach and possible site amplification

effects), staff conclude that site-specific seismic evaluations are necessary for all sites.

Issue: The NRC has not provided an adequate definition of the intent of using probabilistic
6

seismic hazard analysis to satisfy the consideration of the maximum credible earthquake.

Comment: One commenter noted that the draft standard review plan indicates that licensees

can use an alternative to the maximum credible earthquake, such as probabilistic seismic

hazard analysis, but does not indicate whether the intent is to allow probabilistic analyses

to satisfy 10 CFR Part 40, Appendix A, Criterion 4(e) or it is being considered as an

alternative requirement.

Response: The application of a probabilistic seismic hazard analysis in place of a deterministic

approach is is not intended to be an alternative requirement to, as defined in the question, but

another way of satisfying the existing move toward risk-informed and performance-based

regulations. In addition, other NRC regulations clearly recommend the use a probabilistic

approach as an acceptable way to account for uncertainties [e.g., 10 CFR 100.23(d)(1)].

Issue: The NRC has provided only general guidance to seismic hazard analysis, rather than

guidance specific to certain geographic provinces.

Comment: One commenter noted that references cited in the standard review plan did not

provide useful guidance with regard to site-specific seismicity issues, and suggested other

references specific to Wyoming and the intermountain region of the western United States.

Response: The standard review plan is intended to provide general guidance to the NRC staff

on reviewing license applications, license renewals, and amendment requests. The standard

review plan does not preclude licensees from providing additional site-specific information as

necessary in their license application or amendment requests, and identifying how this

information supports a specific licensing action.

4. Ground Water

Issue: NUREG–1620 should be consistent in use of terminology related to ground water.

Comment: The term “constituent of concern” seems to be used interchangeably with the term

“hazardous constituent.” Constituents of concern are not necessarily hazardous constituents

unless they have migrated into “non-exempted” aquifers.

Response: Section 4.2.1 of the standard review plan was revised to delete a sentence equating

constituents of concern with hazardous constituents. The term “hazardous constituent” is now

used consistent with the definition in 10 CFR Part 40, Appendix A, Criterion 5B(2)

Issue: The difference in an As Low As Reasonably Achievable (ALARA) analysis for radiological

and nonradiological parameters needs to be more clearly presented.

Comment: An ALARA analysis for a nonradiological parameter differs from that for a radiological

parameter in that once the concentration of a nonradiological parameter falls below the

maximum concentration limit, the licensee has no obligation to further reduce the parameter’s

concentration. NRC should distinguish between the two types of ALARA studies. 

Response: The NRC concurs with the commenter. A sentence was added to Section 4.3.3.3 of
7

the standard review plan to indicate that, when a nonradiological hazardous constituent

concentration is below its regulatory maximum concentration level, the licensee has no further

obligation to reduce the constituent concentrations.

Issue: The benefits of ground-water corrective action requirements at remote sites

are questionable.

Comment: Two commenters noted that NRC should provide further guidance on addressing

instances where the benefits of ground-water correction action may not justify the cost. One

comment referred to circumstances where restrictions on site access or site-specific physical

characteristics may make it infeasible for members of the public to access ground water. 

Another comment suggested that the future value of the ground water removed and evaporated

during corrective actions may exceed any risk posed by the contaminant.

Response: No changes to the standard review plan were made to address these comments. In

such site-specific circumstances as described by the commenters, the burden is on the

licensee to demonstrate that termination of ground-water corrective actions would pose no

significant threat to human health and the environment. Licensees may propose alternate

concentration limits that meet the requirements of 10 CFR Part 40, Appendix A, Criterion 5B(6). 

Consideration of the remoteness of a site, potential future water uses, and future value may be

included in a licensee’s basis for determining that alternate concentration limits are protective of

human health and the environment, and that limits are as low as reasonably achievable. These

and other factors for consideration by the Commission are specifically mentioned in

10 CFR, Part 40, Appendix A, Criterion 5B(6), which is appropriately cited in the standard review

plan. 

5. Comments related to NRC Responsibilities under the National Environmental

Policy Act

Issue: The NRC is reviewing information that is outside its areas of regulatory authority.

Comment: Several commenters noted that NRC is asking for information that appears to be

beyond its regulatory authority. This includes information on nonradiological hazardous

constituents and review of restoration plans for borrow areas.

Response: As a federal agency, the NRC is subject to the National Environmental Policy

Act (NEPA). This requires the NRC to consider impacts to the human environment as a part of

its decision making process. The regulations governing NRC implementation of NEPA are

described in 10 CFR Part 51. Guidance to the NRC staff on conducting environmental reviews

is also provided in NUREG–1748 “Environmental Review Guidance for Licensing Actions

Associated with NMSS Programs.” With regard to NEPA, the NRC must consider the

environmental impacts of both radiological and nonradiological aspects of a proposed action,

particularly with regard to assessment of direct, indirect, and cumulative impacts of the

proposed action. The exact nature of the information to be provided by a licensee, and the level

of NRC staff review will be determined on a site-specific basis. The standard review plan is

intended as general guidance to the staff on the type of information that is commonly acceptable

for evaluating the environmental impact of a proposed licensing action. Under the risk-informed,

performance-based licensing philosophy used by the NRC, the licensee is free to present
8

alternative approaches for NRC consideration.

With regard to restoration plans for borrow areas, the intent of the section of the standard review

plan identified by the commenter is to have staff review restoration plans for borrow areas as

part of characterizing the stratigraphy and materials at a given site, and fulfilling NRC

requirements under NEPA. The NRC also needs to consider the cumulative impacts of both

radiological and nonradiological hazardous constituents to meet its obligations under NEPA.

General guidance to NRC staff for the evaluation of cumulative impacts is provided in

Section 4.2.5 of NUREG–1748 “Environmental Review Guidance for Licensing Actions

Associated with NMSS Programs.” 
iii

ABSTRACT

A U.S. Nuclear Regulatory Commission source and byproduct materials license is required by

10 CFR Part 40 for the operation of uranium mills and the disposal of “tailings,” wastes

produced by the extraction or concentration of source material from ores processed primarily

for their source material content. Appendix A to Part 40 establishes technical and other criteria

relating to siting, operation, decontamination, decommissioning, and reclamation of mills and of

tailings at mill sites. The licensee’s site reclamation plan documents how the proposed

activities demonstrate compliance with the criteria in Appendix A to Part 40 and the information

needed to prepare the environmental assessment on the effects of the proposed reclamation

activities on the health and safety of the public and on the environment. 

This standard review plan is prepared for the guidance of staff reviewers in the Office of

Nuclear Material Safety and Safeguards in performing safety and environmental reviews of

reclamation plans for uranium mill tailings sites covered by Title II of the Uranium Mill Tailings

Radiation Control Act of 1978 as amended. It provides guidance for new reclamation plans,

license renewals, and license amendments. The principal purpose of this standard review plan

is to ensure the quality and uniformity of staff reviews and to present a well-defined base from

which to evaluate changes in the scope and requirements of a review.

This standard review plan is written to cover a variety of site conditions and reclamation plans. 

Each section contains a description of the areas of review, review procedures, acceptance

criteria, and evaluation findings. Revision 1 also incorporates information to address new

Commission policy on several issues related to uranium recovery.

Paperwork Reduction Act Statement

The information collections contained in this NUREG are covered by the requirements of 

10 CFR Part 40, which were approved by the Office of Management and Budget, approval

number 3150-0020.

Public Protection Notification

The NRC may not conduct or sponsor, and a person is not required to respond to, a 

request for information or an information collection requirement unless the requesting 

document displays a currently valid OMB control number.
v

CONTENTS

Page

ABSTRACT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii

EXECUTIVE SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi

1.0 GEOLOGY AND SEISMOLOGY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

1.1 Stratigraphic Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

1.1.1 Areas of Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

1.1.2 Review Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

1.1.3 Acceptance Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

1.1.4 Evaluation Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

1.1.5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

1.2 Structural and Tectonic Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

1.2.1 Areas of Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

1.2.2 Review Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

1.2.3 Acceptance Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

1.2.4 Evaluation Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

1.2.5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

1.3 Geomorphic Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

1.3.1 Areas of Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

1.3.2 Review Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

1.3.3 Acceptance Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

1.3.4 Evaluation Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

1.3.5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

1.4 Seismicity and Ground Motion Estimates . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

1.4.1 Areas of Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

1.4.2 Review Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

1.4.3 Acceptance Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9

1.4.4 Evaluation Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11

1.4.5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12

2.0 GEOTECHNICAL STABILITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

2.1 Site and Uranium Mill Tailings Characteristics . . . . . . . . . . . . . . . . . . . . . . . . 2-1

2.1.1 Areas of Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

2.1.2 Review Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

2.1.3 Acceptance Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

2.1.4 Evaluation Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

2.1.5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
vi

CONTENTS (continued)

 Page

2.2 Slope Stability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

2.2.1 Areas of Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

2.2.2 Review Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7

2.2.3 Acceptance Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8

2.2.4 Evaluation Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12

2.2.5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13

2.3 Settlement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-16

2.3.1 Areas of Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-16

2.3.2 Review Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-16

2.3.3 Acceptance Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17

2.3.4 Evaluation Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18

2.3.5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19

2.4 Liquefaction Potential . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-20

2.4.1 Areas of Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-20

2.4.2 Review Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-20

2.4.3 Acceptance Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-20

2.4.4 Evaluation Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-21

2.4.5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-22

2.5 Disposal Cell Cover Engineering Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23

2.5.1 Areas of Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23

2.5.2 Review Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23

2.5.3 Acceptance Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-24

2.5.4 Evaluation Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-26

2.5.5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-26

2.6 Construction Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-27

2.6.1 Areas of Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-27

2.6.2 Review Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-28

2.6.3 Acceptance Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-28

2.6.4 Evaluation Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-30

2.6.5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-31

2.7 Disposal Cell Hydraulic Conductivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-33

2.7.1 Areas of Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-33

2.7.2 Review Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-33

2.7.3 Acceptance Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-33

2.7.4 Evaluation Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-34

2.7.5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-35

3.0 SURFACE WATER HYDROLOGY AND EROSION PROTECTION . . . . . . . . . . . . . 3-1

3.1 Hydrologic Description of Site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
vii

CONTENTS (continued)

 Page

3.1.1 Areas of Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

3.1.2 Review Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

3.1.3 Acceptance Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

3.1.4 Evaluation Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

3.1.5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

3.2 Flooding Determinations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

3.2.1 Areas of Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

3.2.2 Review Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

3.2.3 Acceptance Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5

3.2.4 Evaluation Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6

3.2.5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7

3.3 Water Surface Profiles, Channel Velocities, and Shear Stresses . . . . . . . . . . 3-7

3.3.1 Areas of Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7

3.3.2 Review Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7

3.3.3 Acceptance Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8

3.3.4 Evaluation Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8

3.3.5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9

3.4 Design of Erosion Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9

3.4.1 Areas of Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9

3.4.2 Review Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10

3.4.3 Acceptance Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12

3.4.4 Evaluation Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13

3.4.5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14

3.5 Design of Erosion Protection Covers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14

3.5.1 Areas of Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14

3.5.2 Review Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14

3.5.3 Acceptance Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15

3.5.4 Evaluation Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-16

3.5.5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-16

3.6 General References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-16

4.0 PROTECTING WATER RESOURCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

4.1 Site Characterization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

4.1.1 Areas of Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

4.1.2 Review Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

4.1.3 Acceptance Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

4.1.4 Evaluation Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17

4.1.5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-19
viii

CONTENTS (continued)

Page

4.2 Ground-Water Protection Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-21

4.2.1 Areas of Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-21

4.2.2 Review Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-22

4.2.3 Acceptance Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-22

4.2.4 Evaluation Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-24

4.2.5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-24

4.3 Hazard Assessment, Exposure Assessment, Corrective Action Assessment,

and Compliance Monitoring for Alternate Concentration Limits . . . . . . . . . . 4-25

4.3.1 Areas of Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-25

4.3.2 Review Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-25

4.3.3 Acceptance Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-27

4.3.3.1 Hazard Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-27

4.3.3.2 Exposure Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-29

4.3.3.3 Corrective Action Assessment . . . . . . . . . . . . . . . . . . . . . . 4-34

4.3.3.4 Examination of the Compliance Monitoring Program . . . . . 4-36

4.3.4 Evaluation Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-36

4.3.5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-38

4.4 Ground-Water Corrective Action and Compliance Monitoring Plans . . . . . . 4-38

4.4.1 Areas of Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-38

4.4.2 Review Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-39

4.4.3 Acceptance Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-41

4.4.4 Evaluation Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-53

4.4.5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-55

5.0 RADIATION PROTECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

5.1 Disposal Cell Cover Radon and Gamma Attenuation and

Radioactivity Content . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

5.1.1 Areas of Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

5.1.2 Review Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2

5.1.2.1 Radon Attenuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2

5.1.2.2 Gamma Attenuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4

5.1.2.3 Cover Radioactivity Content . . . . . . . . . . . . . . . . . . . . . . . . 5-4

5.1.3 Acceptance Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4

5.1.3.1 Radon Attenuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
ix

CONTENTS (continued)

Page

5.1.3.2 Gamma Attenuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7

5.1.3.3 Cover Radioactivity Content . . . . . . . . . . . . . . . . . . . . . . . . . 5-7

5.1.4 Evaluation Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8

5.1.5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9

5.2 Decommissioning Plan for Land and Structures . . . . . . . . . . . . . . . . . . . . . 5-10

5.2.1 Areas of Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10

5.2.2 Review Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10

5.2.3 Acceptance Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15

5.2.4 Evaluation Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17

5.2.5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-18

5.3 Radiation Safety Controls and Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19

5.3.1 Areas of Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19

5.3.2 Review Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19

5.3.3 Acceptance Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21

5.3.4 Evaluation Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22

5.3.5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-23

APPENDICES

A RELATIONSHIP OF 10 CFR PART 40, APPENDIX A REQUIREMENTS TO

STANDARD REVIEW PLAN SECTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A–1

B GUIDANCE TO THE U.S. NUCLEAR REGULATORY COMMISSION STAFF FOR 

REVIEWING HISTORICAL ASPECTS OF SITE PERFORMANCE FOR LICENSE 

RENEWALS AND AMENDMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–1

C OUTLINE RECOMMENDED BY THE U.S. NUCLEAR REGULATORY COMMISSION 

STAFF FOR PREPARING SITE-SPECIFIC FACILITY RECLAMATION AND

STABILIZATION COST ESTIMATES FOR REVIEW . . . . . . . . . . . . . . . . . . . . . . . C–1

D GUIDANCE TO THE U.S. NUCLEAR REGULATORY COMMISSION STAFF FOR 

REVIEWING LONG-TERM SURVEILLANCE PLANS . . . . . . . . . . . . . . . . . . . . . . . D–1

E GUIDANCE TO THE U.S. NUCLEAR REGULATORY COMMISSION STAFF ON THE

LICENSE TERMINATION PROCESS FOR LICENSEES OF CONVENTIONAL

URANIUM MILLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E–1

F GUIDANCE TO THE U.S. NUCLEAR REGULATORY COMMISSION STAFF ON

EFFLUENT DISPOSAL AT LICENSED URANIUM RECOVERY FACILITIES:

CONVENTIONAL MILLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F–1
x

CONTENTS (continued)

Page

G NATIONAL HISTORIC PRESERVATION ACT AND ENDANGERED SPECIES

ACT CONSULTATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G-1

H GUIDANCE TO THE U.S. NUCLEAR REGULATORY COMMISSION STAFF ON

THE RADIUM BENCHMARK DOSE APPROACH . . . . . . . . . . . . . . . . . . . . . . . . . . . H-1

I REGULATORY ISSUE SUMMARY 2000–23 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-1

J TECHNICAL EVALUATION OF APPENDIX A CRITERIA . . . . . . . . . . . . . . . . . . . . . J-1

K CONTENT AND FORMAT FOR ALTERNATE CONCENTRATION

LIMIT APPLICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . K-1

FIGURE

1 Schematic of NRC Licensing and Inspection Process and Applicability to

Different License Documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv

TABLES

4.1.3-1 Common Uranium Mill Chemical Constituents . . . . . . . . . . . . . . . . . . . . . . . . 4-9

4.1.3-2 Non-Radiological Ground-Water Constituents That May Produce

Harm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10
xi

EXECUTIVE SUMMARY

A U.S. Nuclear Regulatory Commission (NRC) source and byproduct materials license is

required in accordance with the provisions of Title 10 of the U.S. Code of Federal Regulations,

Part 40 (10 CFR Part 40), “Domestic Licensing of Source Material,” in conjunction with uranium

or thorium milling, or with byproduct material at sites formerly associated with such milling. At

the termination of a uranium mill license, the mill tailings impoundment and some adjoining land

will be turned over to the U.S. Department of Energy (DOE), another Federal agency

designated by the President, or the State in which the site is located for long-term care. 

Requirements applicable to a license consist of the regulations in 10 CFR Part 40, Appendix A

to 10 CFR Part 40, and any license conditions. The specific sections in this standard review

plan that address the criteria of 10 CFR Part 40, Appendix A, are shown in Appendix A of the

review plan.

An application for a new license, license renewal, or an amendment to or termination of an

existing license should contain, as appropriate, proposed specifications relating to the milling

operations, and the information on the disposal of tailings or wastes resulting from such milling

activities and information on decommissioning of the site. General guidance on (i) contents and

filing of an application and (ii) producing an environmental report appears in 10 CFR 40.31,

“Application for specific licenses,” and in 10 CFR 51.45, “Environmental report,” respectively. 

The staff uses the information in the application to determine whether the proposed activities

will be protective of public health and safety and be environmentally acceptable. General

provisions for issuance, amendment, transfer, and renewal of licenses are described in

10 CFR Part 2, Subpart A. Guidance on considering environmental justice issues during

licensing of Title II uranium or thorium mills is presented in NUREG–1748 (NRC, 2001).

This standard review plan provides the staff in the Office of Nuclear Material Safety and

Safeguards with specific guidance on the review of reclamation plans and license amendments

related to reclamation plans. The reclamation plan, submitted by an applicant (in the case of a

new application) or a licensee (in the case of an amendment to a previously approved

reclamation plan or termination of an existing license) should demonstrate compliance with the

applicable criteria in Appendix A to 10 CFR Part 40. The introduction to 10 CFR Part 40

specifically states that “In many cases, flexibility is provided in the criteria to allow achieving an

optimum tailings disposal program on a site-specific basis. However, in such cases the

objectives, technical alternatives and concerns which must be taken into account in developing

a tailings program are identified.” The principal purpose of the standard review plan is to

present guidance to the NRC staff to ensure a consistent quality and uniformity in NRC reviews

of reclamation plans. Each section in this standard review plan contains guidance on what is to

be reviewed, the basis for the review, how the staff review is to be done, what the staff will find

acceptable in a demonstration of compliance with the regulations, and the conclusions that are

sought regarding compliance with the regulations in 10 CFR Part 40. This standard review plan

is intended to cover only those aspects of the NRC regulatory mission related to the

reclamation of mill tailings sites, including soil and ground-water cleanup, at conventional

uranium mills. As such, the standard review plan helps focus the staff review on determining if

a tailings impoundment can be constructed, operated, and reclaimed in compliance with the

applicable NRC regulations. The standard review plan is also intended to make information

about regulatory matters widely available to improve communication, and to help interested

members of the public and the uranium recovery industry gain a better understanding of the

staff review process. In any of these reviews, the staff will consider licensee-proposed

alternatives to Appendix A criteria as described in the Introduction in Appendix A to
xii

10 CFR Part 40. The review would cover the level of protection to the public health and safety

and the environment and the level of stabilization and containment of the site. All site-specific

licensing decisions based on Appendix A criteria or proposed alternatives will consider the risk

to health and safety and the environment and the economic costs involved. Staff guidance for

review of environmental reports and preparing environmental assessments is found in

NUREG–1748 (NRC, 2001).

For license amendments, the review should focus on the changes proposed in the amendment

[see NUREG–1748 (NRC, 2001) for guidance on reviewing historical aspects of site

performance]. Reviewers should not review previously accepted actions if they are not part of

the proposed amendment, unless the review of the amendment package identifies an impact on

previously accepted actions.

For changes to previously approved reclamation plans, the licensee need only submit

information pertinent to the proposed change. The licensee need not resubmit a complete

reclamation plan covering all aspects of site reclamation, but should present information on the

proposed changes to the previously approved plan and its updates as identified in the current

NRC license. Reviewers should also analyze the inspection history and operation of the site to

see if any major problems have been identified over the course of the license term that would

have an effect on reclamation. The operating history of the facility is often a valuable source of

information concerning the adequacy of site characterization, the acceptability of radiation

protection and monitoring programs, and the sufficiency of other data that may influence staff

determination of compliance. NUREG–1757, Volume I, Section 16.2 (NRC, 2002) presents

guidance for review of these historical aspects of facility performance. If the changes are found

to be acceptable, the license is then amended to identify the revised reclamation plan as the

required design for reclamation.

License termination usually involves a confirmation that all applicable reclamation requirements

have been met. This includes ensuring completion of stabilization work for the tailings

consistent with the accepted reclamation plan and a determination that the licensee has

complied with all standards applicable to land structures, and ground-water cleanup. As such,

the information in this review plan will be used to help make the necessary conclusions

concerning license termination. The four aspects of license termination addressed in this

review plan included (i) mill decommissioning, decontamination and disposal; (ii) surface soil

cleanup and post cleanup verification; (iii) mill tailings surface stabilization; and (iv) ground

water corrective action. Compliance with these four aspects of reclamation, taken together,

forms the basis for the staff finding that the design and ground-water cleanup program meet

applicable requirements, and that the design and cleanup program have been acceptably

completed at the sites and that the licensee has, therefore, met the applicable requirements.

The staff will prepare the following reports to document the review: a technical evaluation

report and an environmental assessment. The guidance in NUREG–1748 (NRC, 2001) will be

used to prepare the environmental assessment. The provisions of 10 CFR 51.21 require

preparation of an environmental assessment unless: (i) the staff finds, based on the

environmental assessment, that NRC needs to prepare an environmental impact statement;

(ii) another federal agency also involved in the action as a cooperating agency needs to prepare

an environmental impact statement; (iii) the effects on the quality of the human environment

are likely to be highly controversial; or (iv) 10 CFR 51.22 categorically excludes the necessity to

prepare an environmental assessment. Applications for new mills require NRC to prepare an

environmental impact statement in accordance with 10 CFR 51.20(b)(18). This standard review

plan is intended to guide the preparation of the technical evaluation report.
xiii

It is important to note that the acceptance criteria noted in this standard review plan are for the

guidance of the Office of Nuclear Material Safety and Safeguards staff responsible for the

review of license applications. Review plans are not substitutes for the Commission’s

regulations, and compliance with a particular standard review plan is not required. Methods

and solutions different from those set out in the standard review plan may be acceptable if they

provide a basis for the findings requisite to the issuance or continuance of a license by NRC. 

Use of this standard review plan does not obviate the need for professional judgement; it helps

assure overall completeness and uniformity of the staff review.

GENERAL REVIEW PROCEDURE

A licensing review is not intended to be a detailed evaluation of all aspects of facility operations. 

Specific information about implementation of a program or construction of a design outlined in

an application is obtained through the NRC review of procedures and operations done as part

of the inspection function. However, some procedures may be required during review of a

reclamation or decommissioning plan. The differences between licensing reviews and

inspections are shown in Figure 1. For a new license application, the staff will review the

proposed reclamation plan and ground water protection program for compliance with the criteria

in Appendix A to 10 CFR Part 40. For a license renewal or an amendment to an existing

license, the staff will only review proposed changes to the NRC-approved reclamation plan for

compliance with criteria in Appendix A to 10 CFR Part 40. If the changes proposed have an

adverse impact on the performance or functionality of some of the approved features at the

site, then the staff will review those items for their compliance with regulations.

In the case of an amendment application concerning confirmation of site or ground-water

cleanup or completion of construction, the reviewer will focus on ensuring that the applicable

activities have been completed consistent with the approved review plan. Reviewers will not

revisit accepted designs or plans unless the as-completed activity presents problems, such as

degradation or reconformation.

Changes to existing licensed activities and conditions require the issuance of an appropriate

license amendment. An application for such an amendment should describe the proposed

changes in detail and should discuss the potential environmental and health and safety

impacts. Amendment requests should be reviewed using the appropriate sections of this

document for guidance. NUREG–1757, Volume I (NRC, 2002), contains guidance for

examining the historical aspects of facility operations in connection with amendment reviews. 

The steps of the reclamation plan review are described in the paragraphs that follow.

Acceptance Review

The staff will conduct an acceptance review of a new reclamation plan or changes to a

previously approved plan to determine the completeness of the information submitted. The

reclamation plan will be considered acceptable for docketing if the information in it is sufficiently

complete to initiate a detailed technical review, and reflects an adequate reconnaissance and

physical examination of the regional and site conditions, and contains appropriate analyses and

design information to demonstrate that the applicable regulatory criteria will be met. 

Completeness of the environmental report will be determined using the information

requirements in 10 CFR 51.45 and the guidance in NUREG–1748 (NRC, 2001). The staff

should complete the acceptance review and transmit the results to the applicant within 30 days

of the receipt of the application, along with a projected schedule for the remainder of the review. 

In this transmittal, the staff should note any additional information needed to make the
xiv

reclamation plan or environmental report complete. Detailed technical questions, although not

required, can be included, if they are identified during the acceptance review. If the contents of

the reclamation plan or environmental report do not clearly demonstrate compliance with

applicable regulatory criteria, then the staff may decline to docket the reclamation plan and will

return it to the licensee for revisions.
xv

Figure 1. Schematic of NRC Licensing and Inspection Process and Applicability to Different License Documents
xvi

Detailed Review

Following completion of the acceptance review, the staff will conduct a detailed technical review

of the reclamation plan. During the detailed review, if there is a need for additional information,

the staff will send to the licensee a request for additional information identifying the issue or

concern, basis for the concern, and the kind of information needed to resolve the concern. 

After the staff receives a satisfactory response to the request for additional information, the

detailed review will be concluded. NRC documents the results of this review and the basis for

acceptance or denial of the requested licensing action in a technical evaluation report, and in an

environmental assessment (10 CFR 51.21) if there is a finding of no significant impact, or in an

environmental impact statement (10 CFR 51.20) if the reclamation plan is part of an application

for a new mill or if one of the other requirements for an environmental impact statement have

been met (10 CFR 51.20). The detailed review should evaluate the environmental, economic,

and technical evidence presented by the applicant to support the ability of the proposed facility

to meet applicable regulatory requirements. In the case of amendments to an existing license

as a result of changes to a previously approved reclamation plan, the need for an

environmental assessment will be determined on a case-by-case basis.

In determining the acceptability of any aspect of tailings reclamation, the staff will evaluate the

use of alternatives to meeting the specific requirements in 10 CFR Part 40, Appendix A. In

evaluating the use of alternatives, the staff will determine if the proposed reclamation design

satisfactorily demonstrates the requisite requirements of economic benefit and equivalent

protection. In this standard review plan, we identify alternatives that have been found to be

acceptable by the staff in previous reviews. Alternatives developed by licensees need not be

limited to those discussed here. Other alternatives can be proposed, as long as the economic

benefit and equivalent protection can be demonstrated.

The Standard Review Plan

The standard review plan is written to cover a variety of site conditions and reclamation

designs. Each section presents the complete review procedure and acceptance criteria for all

the areas of review pertinent to that section. The review plan is intended as general guidance

to the NRC staff, and does not contain regulatory requirements. For any given application, the

staff reviewer may select and emphasize particular aspects of each standard review plan

section as appropriate for the reclamation plan. Because of this, the staff may not carry out, in

detail, all of the review steps listed in each standard review plan section, in the review of every

reclamation plan.

I. Areas of Review

This subsection describes the scope of the review (i.e., what is being reviewed). It contains a

brief description of the specific technical information and analyses in the reclamation plan that

need to be reviewed by each technical reviewer.

II. Review Procedures

This subsection discusses the appropriate review technique. It is generally a step-by-step

procedure that the reviewer uses to determine whether the acceptance criteria have been met. 
xvii

III. Acceptance Criteria

This subsection delineates criteria that the reviewer can apply to determine the acceptability of

the applicant’s compliance demonstration. Although acceptance criteria are not regulatory

requirements, the technical bases for these criteria have been derived from 10 CFR Parts 20,

40, and 51, NRC regulatory guides, general design criteria, codes and standards, NRC branch

technical positions, standard testing methods (e.g., American Society for Testing and Materials

standards), technical papers, and other similar sources. These sources typically contain

solutions and approaches previously determined by the staff to be acceptable for making

compliance determinations for the specific area of review. These acceptance criteria have

been defined so that staff reviewers can use consistent and well-documented approaches for

review of all reclamation plans. In the absence of well-defined acceptance criteria, the staff will

rely on “professional judgment” and what is normally practiced in the profession. Licensees

may take approaches to demonstrating compliance that are different from those in this standard

review plan. However, they should recognize that, as is the case for regulatory guides,

substantial staff time and effort have gone into the development of these procedures and

criteria, and a corresponding amount of time and effort may be required to review and accept

new or different solutions and approaches. Thus, licensee-proposed solutions and approaches

to safety problems or safety-related design areas other than those described in this standard

review plan may require longer review times and NRC requests for more extensive supporting

information. The staff is willing to consider proposals for other solutions and approaches on a

generic basis, apart from a specific review, to avoid the impact of the additional review time for

individual cases.

IV. Evaluation Findings

This subsection presents the staff’s general conclusions and findings that result from review of

each area of the reclamation plan, as well as identification of the applicable regulatory

requirements. Conclusions and findings for a specific site and review area are dependent on

the site characteristics and type of licensing action being considered. For each standard review

plan section, a conclusion is included in the technical evaluation report/safety evaluation report

or in the environmental assessment/environmental impact statement, in which results of the

review are published. These documents contain a description of the review; the basis for the

staff findings, including aspects of the review selected or emphasized; where the reclamation

design or the licensee’s plans deviate from the criteria stated in the standard review plan; and

the evaluation findings.

Standard Review Plan Updates

The standard review plan will be revised and updated periodically as the need arises to clarify

the content or correct errors and to incorporate modifications approved by NRC management. 

References

NRC. NUREG–1757, “Consolidated NMSS Decommissioning Guidance.” Vol. I. 

Washington, DC: NRC. January 2002.

NRC Draft NUREG–1748, “Environmental Review Guidance for Licensing Actions Associated

with NMSS Programs.” Washington, DC: NRC, Office of Nuclear Material Safety and

Safeguards. 2001.
1-1

1.0 GEOLOGY AND SEISMOLOGY

The reclamation plan and its supporting documents must contain sufficient regional and

site-specific geologic and seismologic information related to the proposed disposal site and

reclamation design, including regional and site-specific stratigraphy, structure, geomorphology,

and seismology. This standard review plan establishes the requirements for staff of the

U.S. Nuclear Regulatory Commission (NRC) to conduct and document the review of new

reclamation plans for mill tailings impoundments, or amendments to previously approved

reclamation plans in the areas of geology and seismology. 

1.1 Stratigraphic Features

1.1.1 Areas of Review

The staff should review information presented in the reclamation plan on the regional and

site-specific stratigraphy and geology. The reclamation plans should describe surface and

subsurface strata and the interpretation of their orientation, occurrence, thickness, composition,

age, depositional environment, and interrelationships. The reviewer should coordinate the

stratigraphic information with the evaluation of the site’s geotechnical stability, surface water

and erosion protection, and ground-water resources protection information as described in

standard review plan Chapters 2.0, 3.0, and 4.0, respectively. The purpose of this review is to

determine if there has been an acceptable characterization of site and regional stratigraphy so

that sufficient information has been presented for use in the reclamation plan and design of the

tailings cell.

1.1.2 Review Procedures

The reviewer should examine the description and discussion of the regional and site-specific

features to determine if a thorough evaluation of the regional and site stratigraphy has

been presented.

The following specific descriptive information should be reviewed to determine its adequacy for

characterizing the regional and site-specific stratigraphic features:

(1) Description of regional stratigraphic units by rock classification and type.

(2) Distribution of regional stratigraphic units.

(3) Age relationships of regional and site-specific stratigraphic units.

(4) Detailed site stratigraphy based on outcrop and well borings conducted to determine

rock types and their texture, composition, distribution, thickness, and environment

of deposition.

The staff determination of compliance should be based in part on professional judgment,

considering the complexity of the subsurface conditions at the site. 
Geology and Seismology

1-2

1.1.3 Acceptance Criteria

The characterization of regional and site stratigraphy will be acceptable if the information

presented conforms to the following criteria:

(1) The regional and site-specific stratigraphy are described in sufficient detail to produce

an adequate understanding of the site-specific subsurface characteristics, including

descriptions of major stratigraphic units and their orientations, age relationships,

thicknesses, environments of deposition distributions, and any stratigraphic features

(e.g., facies changes) likely to affect site stability or ground-water resource protection.

(2) Stratigraphic units are described in sufficient detail to provide input to a geotechnical

stability analysis.

(3) Descriptions of regional and site-specific stratigraphic units contain sufficient information

for input to an analysis of ground water resources and the protection thereof.

(4) Regional stratigraphic information is discussed in sufficient detail to support

site-specific information.

(5) Descriptions of the regional and site stratigraphy are based on published literature and

site data and conform to standard geological classifications. 

(6) Discussions of regional stratigraphy are adequately referenced and supported by

published reports, maps, logs, and cross sections.

(7) Site descriptions are based on field investigations and adequate sampling to define

physical and chemical properties of surface and subsurface materials such as soils and

underlying geologic formations at the site.

(8) Maps are at a scale sufficient to show the locations of all site explorations such as

borings, geophysical surveys, trenches, and sample locations.

Where insufficient information is presented to support interpretations and conclusions, the

reviewer will request additional investigations or data gathering. Staff determination of

compliance should be based in part on professional judgment, considering the complexity of the

site conditions.

1.1.4 Evaluation Findings

If the staff review, as described in standard review plan Section 1.1, results in the acceptance

of the characterization of regional and site stratigraphy, the following conclusions may be

presented in the technical evaluation report.

The staff has completed its review of the characterization of the regional and site stratigraphy at

the uranium mill facility. This review included an evaluation using the review

procedures in Section 1.1.2 and the acceptance criteria outlined in Section 1.1.3 of this

standard review plan.
Geology and Seismology

1-3

The licensee has provided an acceptable description of the stratigraphic features by presenting

a description of the site and regional stratigraphy using published information and information

collected for the specific purpose of supporting determinations of geotechnical stability and

ground water analyses at the site. Data gathering, investigations, and analyses have used

acceptable standards and practices. Data and interpretations of data are presented to allow

effective incorporation into geotechnical and ground-water analyses.

On the basis of the information and analysis presented in the review plan on the stratigraphic

features at the uranium mill facility, the NRC staff concludes that the

information is sufficient to support a decision with reasonable assurance that the requirements

of 10 CFR Part 40, Appendix A, Criterion 4(e) have been met. These require that tailings

impoundments not be located near a capable fault that could cause a maximum credible

earthquake larger than that which the impoundment could reasonably be expected to withstand

, or that an acceptable alternate method of determination of seismic hazard has been used. If a

probabilistic seismic hazard analysis is used as an alternate method, the applicant has

presented sufficient information to support an analysis of the facility design for the operational

and post-operational periods. The description of the physical and chemical properties of the

underlying soils and geologic formations of the site is sufficient to meet the requirements of

10 CFR Part 40, Appendix A, Criterion 5G(2) with regard to the extent to which they will control

transport of contaminants and solutions. Reasonable assurance has also been provided that

the requirements of 10 CFR Part 40, Appendix A, Criterion 6(1), which requires that the design

of the disposal facility provide reasonable assurance of control of radiological hazards to be

effective for 1,000 years, to the extent reasonably achievable, and, in any case, for at least

200 years, have been met.

1.1.5 References

None.

1.2 Structural and Tectonic Features

1.2.1 Areas of Review

The staff should review information presented in the reclamation plan on the regional and

site-specific structural and tectonic setting. The reclamation plan should contain a definition of

surface and subsurface structural and tectonic features and an interpretation of their origin,

occurrence, age, and potential impacts, if any, on the stability of the site. Review of the

structural and tectonic information should be coordinated with the evaluation of the site’s

geotechnical stability, surface water and erosion protection, and ground-water resources

protection information as described in standard review plan Chapters 2.0, 3.0,and 4.0,

respectively. The reviewer will determine whether the information presented is sufficient to

support an analysis of geologic features as they affect the facility.

1.2.2 Review Procedures

The reviewer should examine the description and discussion of the regional and site-specific

information to determine if a thorough evaluation of structural and tectonic features has been

presented. This may include analyses of photogrammetric data, results of field reconnaissance
Geology and Seismology

1-4

and detailed mapping, review of pertinent literature, and

review of geophysical data and studies. Features that should be considered in the review

include structural features such as faults and fractures, crustal deformation, and volcanic

features that may affect the site stability or ground-water conditions.

The following specific descriptive information should be reviewed to determine its adequacy for

characterizing the regional and site-specific structural features necessary to support the

evaluations of reclamation system performance:

(1) Description and location of regional structural features based on published information

and field reconnaissance, including the geologic attitude of key stratigraphic units.

(2) Description and location of site subsurface structural features from sources such as

available borings, drill logs, geophysical logs and data, and existing literature.

(3) Description of any volcanic features such as flows, cones, plugs, or dikes located in the

site region.

(4) Age relationships of regional and site-specific structural and tectonic features.

(5) Discussion of published literature containing interpretations of any of the information in

previous Items 1, 2, 3, and 4.

Staff determination of compliance should be based in part on professional judgment,

considering the complexity of the subsurface conditions at the site.

1.2.3 Acceptance Criteria

The characterization of regional and site structural features will be acceptable if the information

presented in the reclamation plan conforms to the following criteria:

(1) Descriptions of regional and site-specific structural and tectonic features are based on

published literature and gathered data.

(2) Regional structural and tectonic features, particularly faults, are defined in sufficient

detail to present an adequate understanding of the structural geologic conditions that

may have a likelihood of affecting the site stability or ground-water regime.

(3) Site-specific structural and tectonic features, particularly faults, are described in

sufficient detail to present adequate information for an analysis of the site stability. 

Information presented adequately addresses the uncertainties and variability within the

site area and the potential impacts on the disposal facility.

(4) The structural and tectonic province or provinces that influence the site seismicity are

identified and described.

(5) The tectonic history of the pertinent province(s) is discussed in sufficient detail to

support an analysis of the potential for disruption of the site by tectonic activity.
Geology and Seismology

1-5

(6) Discussions of structural, tectonic, and volcanic features are adequately referenced and

are supported by maps, logs, and cross sections showing locations of all site

explorations and surveys, and depicting surface and subsurface structural and

tectonic features.

(7) Descriptions contain discussions of age relationships of structural and tectonic features. 

Where insufficient information is presented to support interpretations and conclusions, the

reviewer will request additional investigations or data gathering. Staff determination of

compliance should be based in part on professional judgment, considering the complexity of the

site conditions.

1.2.4 Evaluation Findings

If the staff review, as described in standard review plan Section 1.2, results in the acceptance

of the characterization of the structural and tectonic features of the region and site, the

following conclusions may be presented in the technical evaluation report.

The staff has completed its review of the characterization of structural and tectonic features at

the uranium mill facility. This review included an evaluation using the

review procedures in Section 1.2.2 and the acceptance criteria outlined in Section 1.2.3 of

this standard review plan.

The licensee has acceptably described the regional and site-specific structural and tectonic

features by presenting discussions and interpretations of pertinent data and reports that may

have an impact on the site or tailings disposal system. Information presented includes

descriptions of any faults capable of disrupting the site and any other information necessary to

support an analysis of the geotechnical stability or ground-water conditions at the site. In

addition, the staff concludes that the licensee has used acceptable methods of investigation

and analysis to support its conclusions.

On the basis of the information and analysis presented in the review plan on the structural and

tectonic features at the uranium mill facility, the NRC staff concludes that the

information is sufficient to support a decision with reasonable assurance that the requirements

of 10 CFR Part 40, Appendix A, Criterion 4(e) have 

been met. These require that tailings impoundments not be located near a capable fault that

could cause a maximum credible earthquake larger than that which the impoundment could

reasonably be expected to withstand, or that an acceptable alternate method of determination

of seismic hazard has been used. If a probabilistic seismic hazard analysis is used as an

alternate method, the applicant has presented sufficient information to support an analysis of

the facility design for the operational and postoperational periods. Reasonable assurance has

also been provided that the requirements of 10 CFR Part 40, Appendix A, Criterion 6(1), which

requires that the design of the disposal facility provide reasonable assurance of control of

radiological hazards to be effective for 1,000 years, to the extent reasonably achievable, and, in

any case, for at least 200 years, have been met.

1.2.5 References

None.
Geology and Seismology

1-6

1.3 Geomorphic Features

1.3.1 Areas of Review

The staff should review the information presented in the reclamation plan on the regional and

site-specific geomorphic features. The reclamation plan should analyze regional and local

landforms to determine evidence for geomorphic processes that may impact the long-term

stability of the site, including information to support an evaluation of the potential for any

destructive geomorphic processes, such as mass wasting, extreme erosion, and stream

encroachment. The reviewer should coordinate the geomorphic information with the

evaluation of the site’s geotechnical stability and surface water and erosion protection

information as described in standard review plan Chapters 2.0 and 3.0, respectively. The

results of this review will be used to determine the acceptability of the design during operation

and long-term stabilization.

1.3.2 Review Procedures

The reviewer should examine the description and discussion of the regional and site-specific

geomorphic information to determine if a thorough evaluation has been presented. Information

should be detailed enough for the reviewer to make a determination regarding the geomorphic

stability of the site.

The following specific descriptive information should be reviewed to determine the acceptability

of the assessment of the regional and site-specific geomorphology as it relates to geomorphic

stability of the site:

(1) Description of the physiographic (geomorphic) province(s) in which the site is located,

including a discussion of the distinguishing characteristics such as elevation and relief.

(2) Discussion of the active processes, such as erosion, mass wasting, and stream

encroachment within the site region and the nature and extent of those processes.

(3) Topographic maps depicting geomorphic surfaces, physiographic provinces,

landforms, drainage networks, rivers, surficial geologic units, areas of subsidence, and

geomorphic hazards.

(4) Aerial photographs of the site area.

(5) Discussion of the age, occurrence, and origin of geomorphic features, in particular those

that may adversely affect site stability.

1.3.3 Acceptance Criteria

The characterization of regional and site geomorphic features and geomorphic stability will be

acceptable if the information presented conforms to the following criteria:
Geology and Seismology

1-7

(1) Descriptions of the regional and site-specific geomorphology and geomorphic processes

include information sufficient to allow the reviewer to assess the nature and extent of

major active processes that may modify the present-day topography of the geomorphic

province(s) and the site area.

(2) The geomorphic features, particularly potential geomorphic hazards, are clearly

delineated on topographic base maps of adequate scale to enable the reviewer to

assess their occurrence and distribution. 

(3) Descriptions are adequately referenced and are supported by published reports and

maps or site data.

(4) The regional and site-specific geomorphology and geomorphic processes are described

in sufficient detail to support an analysis of the geomorphic and geotechnical stability of

the site.

Where insufficient information is presented to support interpretations and conclusions, the

reviewer will request additional investigations or data gathering. Staff determination of

compliance should be based in part on professional judgment, considering the complexity of the

site conditions.

1.3.4 Evaluation Findings

If the staff review, as described in standard review plan Section 1.3, results in the acceptance

of the characterization of the geomorphic features of the region and site and provides

information sufficient to support an assessment of the geomorphic stability, the following

conclusions may be presented in the technical evaluation report.

The NRC has completed its review of the information concerning the characterization of

geomorphic features at the uranium mill facility. This review included an

evaluation using the review procedures in Section 1.3.2 and the acceptance criteria outlined in

Section 1.3.3. of this standard review plan.

The licensee has acceptably described the geomorphic features by presenting an adequate

description of regional and site geomorphology using published information and information

collected for the specific purpose of supporting determinations of the stability of site. Data

gathering, investigations, and analyses have used acceptable standards and practices. Data

and interpretations are presented to allow effective 

incorporation into other site analyses.

On the basis of the information and analysis presented in the review plan on the geomorphic

features at the uranium mill facility, the NRC staff concludes that the

information is sufficient to support a decision with reasonable assurance that the requirements

of 10 CFR Part 40, Appendix A, Criterion 6(1), which requires that the design of the disposal

facility provide reasonable assurance of control of radiological hazards to be effective for

1,000 years, to the extent reasonably achievable, and, in any case, for at least 200 years, have

been met.
Geology and Seismology

1-8

1.3.5 References

None.

1.4 Seismicity and Ground Motion Estimates

1.4.1 Areas of Review

The staff should review information presented in the reclamation plan on the regional and

site-specific seismicity and the basis for determining the vibratory ground motion (peak

horizontal acceleration) at the site from seismic events. The purpose of this review is to

determine the potential for seismic events to affect the site. The reviewer will determine

whether the information presented is sufficient to support an analysis of the design for the

operational and closure periods.

1.4.2 Review Procedures

The reviewer should examine the description and discussion of the regional and site-specific

information to determine if a thorough evaluation of the potential for seismic activity has been

presented. The information should be sufficient to enable the reviewer to determine the

vibratory ground motion (peak horizontal acceleration) at the site from seismic events.

The following specific descriptive information should be reviewed to determine the acceptability

of the characterization of the seismicity and the assessment of the stability of the site and

geotechnical design:

(1) A listing of all recorded earthquakes in the tectonic province in which the site is located

and in other tectonic provinces within 200 km [124 mi] of the site. This listing should

contain the date of occurrence of the earthquake, its magnitude, and the location of the

epicenter. Since earthquakes have at times been reported in terms of intensity at a

given location, or effect on ground, structures, and people at a specific location, some of

this information may have to be 

estimated by use of appropriate empirical relationships.

(2) Data obtained by standard photogeologic analysis and field reconnaissance of the study

area and from review of the pertinent literature. Information in the form of maps,

papers, or other data, specific to the area or region, generated by state and federal

agencies or published in the literature, should be utilized.

(3) An association of epicenters or locations of highest intensity of historic earthquakes with

tectonic structures, where possible. Epicenters or locations of highest intensity that

cannot be reasonably identified with tectonic structures should be identified with

tectonic provinces.

(4) Maps on which the locations of epicenters of historic earthquakes, associated tectonic

structures, and tectonic provinces have been depicted.
Geology and Seismology

1-9

(5) The applicant proposed maximum earthquakes associated with each tectonic province

or capable fault or structure.

(6) Deterministic and/or probabilistic seismic hazard analyses. 

For a deterministic analysis, the potential ground motion at the site from capable faults

that might affect the licensed area should be assessed. The term “capable fault” as

used in 10 CFR Part 40, Appendix A, Criterion 4(e), has the same meaning as defined

in Section III(g) of Appendix A to 10 CFR Part 100. Alternatively, the licensee may

choose to use the term “capable tectonic source” as defined in Appendix A to

Regulatory Guide 1.165 (NRC, 1997) to conduct its analysis. 

A probabilistic seismic hazard analysis yields a curve of exceedence probability versus

peak horizontal acceleration. The 104

 value represents a 1 in 10 chance of the site

exceeding the peak horizontal acceleration in a 1,000-year period, which is appropriate

for a 1,000-year design life. The seismic hazard analysis of uranium recovery mill sites

by Bernreuter, et al. (1994), contains probabilistic analyses for Title II mill sites. The

study by Bernreuter, et al. (1994) is intended as a screening study; the probabilistic

seismic hazard estimates are not site specific and are only calculated for

random earthquakes. 

(7) Seismic design ground motion (peak horizontal acceleration).

Staff determination of compliance should be based in part on professional judgment,

considering the complexity of the regional and site-specific seismicity. The reviewer will

focus on evaluating the maximum credible earthquake, as required by 10 CFR Part 40,

Appendix A, Criterion 4(e), unless an alternate 

method of determining ground motion is presented as allowed in the Introduction to

Appendix A. One such alternative to the maximum credible earthquake is a probabilistic

seismic hazard analysis, which is presented in Section 1.4.3, below.

1.4.3 Acceptance Criteria

The regional and site-specific seismicity and ground motion estimates will be acceptable if the

following criteria are met:

(1) The information presented on the regional and site-specific seismicity contains sufficient

detail to allow the staff to determine the vibratory ground motion (peak horizontal

acceleration) at the site caused by seismic events and to further use that determination

to assess the geotechnical stability of the site. The geotechnical stability of the site is

sufficient to control radiological hazards for 1,000 years to the extent reasonably

achievable, and, in any case, for at least 200 years.

(2) In conducting this review, the staff will consider a deterministic and/or a probabilistic

seismic hazard analysis as an acceptable method for selecting the peak horizontal

acceleration for a site. An analysis of the geotechnical stability of the design proposed

in the reclamation plan will be based on the resultant peak horizontal acceleration
Geology and Seismology

1-10

(Chapter 2.0, “Geotechnical Stability,” of this standard review plan).

(a) Deterministic Analysis: The use of a deterministic seismic hazard analysis is

acceptable if:

(i) Capability is determined by suitable methods, such as those outlined by

Slemmons (1977). 

(ii) Fault length versus magnitude relationships for determining the maximum

magnitude earthquake that may be produced by each capable fault or

capable tectonic source are developed using acceptable approaches

such as those of Slemmons, et al. (1982); Bonilla, et al. (1984); or Wells

and Coppersmith (1994).

(iii) For each maximum magnitude earthquake, the peak horizontal

acceleration at the site is determined using the applicable attenuation

relationship between earthquake magnitude and distance for the site. 

Campbell (1997); Campbell and Bozorgnia (1994); and Boore, et al.

(1993, 1997) offer examples of acceptable attenuation relationships. In

applying the relationship, the site-to-source distance should be the

distance between the site and the 

closest approach of the fault. 

(iv) The peak horizontal acceleration value adopted for each capable fault

or tectonic source is not less than the median value provided by the

attenuation relationship. Possible soil amplification effects

are considered.

(v) To assess potential ground motion at the site from earthquakes not

associated with known tectonic structures (i.e., random or floating

earthquakes), the largest floating earthquakes reasonably expected

within the tectonic province are identified. In addition, the largest floating

earthquakes characteristic of any adjacent tectonic provinces are

identified, if such earthquakes cause appreciable ground motion at the

site. For each of these earthquakes, the peak horizontal acceleration at

the site is calculated as stated previously, with 15 km [9 mi] used as the

site-to-source distance for floating earthquakes within the host tectonic

province. For floating earthquakes in other tectonic provinces, the

distance between the site and the closest approach of the province

boundary is used as the site-to-source distance.

(vi) The peak horizontal acceleration for the site is the maximum value of the

peak horizontal accelerations determined for earthquakes from all

capable faults, tectonic sources, and tectonic provinces.

(b) Probabilistic Analysis: The use of a probabilistic seismic hazard analysis as an

alternative to the requirements of 10 CFR Part 40, Appendix A, Criterion 4(e), is

acceptable, as is stated in the Introduction to Appendix A, if:
Geology and Seismology

1-11

(i) It is shown that the design proposed by the licensee will achieve a level of

stabilization and containment, and a level of protection for public health

and safety and the environment, which is equivalent to, to the extent

practicable, or more stringent than that achieved by the requirements of

10 CFR Part 40, Appendix A. 

(ii) The licensee takes into account local conditions when estimating the

seismic design of the facility because peak horizontal acceleration values

are often calculated for hypothetical rock foundations. The effects of

local site conditions on the peak ground acceleration are reviewed in

Chapter 2.0 in the standard review plan.

(3) The presentation on seismotectonic stability is acceptable if sufficient information is

presented to support interpretations and conclusions. If the staff should conclude that

the information presented is insufficient, it will request additional information or

investigations. Staff determination of compliance should be based, in part, on

professional judgment, considering the complexity of site and seismic conditions.

1.4.4 Evaluation Findings

If the staff review as described in standard review plan Section 1.4 results in the acceptance of

the characterization of the seismicity of the region and site and the seismic design ground

motion, the following conclusions may be presented in the technical evaluation report.

The staff has completed its review of the characterization of the seismicity at the

 uranium mill facility. This review included an evaluation using the review

procedures in Section 1.4.2 and the acceptance criteria outlined in Section 1.4.3 of this

standard review plan.

The licensee has presented information and investigations that support its conclusions about

the seismic characterization of the site and the seismic design value. Information presented

includes descriptions of historical earthquakes, locations of their epicenters, an analysis of the

seismic hazard at the site, and the design peak horizontal acceleration. The staff concludes

that the information presented is sufficient to support an analysis of the geotechnical stability. 

In addition, the staff concludes that the licensee has used acceptable methods of investigation

and analysis to support its conclusions.

On the basis of the information and analysis presented in the review plan on the seismicity and

ground motion estimates at the uranium mill facility, the NRC staff concludes

that the information is sufficient to support a decision with reasonable assurance that the

requirements of 10 CFR Part 40, Appendix A, Criterion 4(e), have been met. These require

that tailings impoundments not be located near a capable fault that would cause a maximum

credible earthquake larger than that which the impoundment could reasonably be expected to

withstand, or that an acceptable alternate method of determination of seismic hazard has been

used. If a probabilistic seismic hazard analysis is used as an alternate method, the applicant

has presented sufficient information to support an analysis of the facility design for the

operational and postoperational periods. Reasonable assurance has also been provided that

the requirements of 10 CFR Part 40, Appendix A, Criterion 6(1), which requires that the design
Geology and Seismology

1-12

of the disposal facility provide reasonable assurance of control of radiological hazards to be

effective for 1,000 years, to the extent reasonably achievable, and, in any case, for at least

200 years, have been met.

1.4.5 References

Bernreuter, D., E. McDermott, and J. Wagoner. “Seismic Hazard Analysis of Title II

Reclamation Plans.” Livermore, California: Lawrence Livermore National Laboratory. 1994.

Bonilla, M.G., R. K. Mark, and J.J. Lienkaemper. “Statistical Relations Among Earthquake

Magnitude, Surface Rupture Length, and Surface Fault Displacement.” Bulletin of the

Seismological Society of America. Vol. 74. pp. 2,379–2,411. 1984.

Boore, D.M., W.B. Joyner, and T.E. Fumal. “Estimation of Response Spectra and Peak

Acceleration From Western North American Earthquakes: An Interim Report.” Open-File

Report 93-509. U.S. Geological Survey. 1993.

–––––. “Equations for Estimating Horizontal Response Spectra and Peak Acceleration from

Western North American Earthquakes: A Summary of Recent Work.” Seismological Research

Letters. Vol. 68. pp. 128,153. 1997.

Campbell, K. “Empirical Near-Source Attenuation Relationships for Horizontal and Vertical

Components of Peak Ground Acceleration, Peak Velocity, and Pseudo-Absolute Acceleration

Response Spectra.” Seismological Research Letters. Vol. 68. pp. 154–179. 1997.

Campbell, K.W. and Y. Bozorgnia. “Near Source Attenuation of Peak Horizontal Acceleration

From Worldwide Accelerograms Recorded From 1975 to 1993." Fifth U.S. National Conference

on Earthquake Engineering, Chicago, Illinois, July 10–14. 1994.

NRC. Regulatory Guide 1.165, “Identification and Characterization of Seismic Sources and

Determination of Safe Shutdown Earthquake Ground Motion.” Washington, DC: NRC, Office

of Standard Development. March 1997.

Slemmons, D.B. ”State-of-the-Art for Assessing Earthquake Hazards in the United States: 

Report 6, Faults and Earthquake Magnitudes.” Miscellaneous Paper S-73-1. Vicksburg,

Mississippi: U.S. Corps of Engineers, U.S. Army Engineer Waterways Experiment

Station. 1977.

Slemmons, D.B., P. O’Malley, R.A. Whitney, D.H. Chung, and D.L. Bernreuter. “Assessment

of Active Faults for Maximum Credible Earthquakes of the Southern California-Northern Baja

Region.” Publication No. UCID 19125 University of California. Livermore, California: Lawrence

Livermore National Laboratory. 1982.

Wells, D.L. and K.J. Coppersmith. “New Empirical Relationships Among Magnitude, Rupture

Length, Rupture Width, Rupture Area, and Surface Displacement.” Bulletin of the Seismological

Society of America. Vol. 84. pp. 974–1,002. 1994.
2-1

2.0 GEOTECHNICAL STABILITY

The reclamation plan and its supporting documents must contain geotechnical information,

design details, and construction considerations related to the proposed disposal site and to all

materials associated with the reclamation design, including soil and rock cover, foundation

materials, contaminated materials, and other materials, for any zones (liners, filters, or capillary

breaks). Standard review plan Chapter 2.0 establishes the procedures for NRC staff to conduct

and document the review of geotechnical stability aspects of reclamation plans for mill tailings

impoundments, amendments to the approved reclamation plans, or license termination.

2.1 Site and Uranium Mill Tailings Characteristics

2.1.1 Areas of Review

The staff should review information presented in the reclamation plan on the geotechnical

aspects of the regional and site geology and stratigraphy, the geotechnical characteristics of

the uranium mill tailings and other materials designated for stabilization, and borrow area

material characteristics. “Other materials” are contaminated soil from site cleanup operations,

tailings from other sites accepted for disposal at this site, and any contaminated materials from

mill decommissioning activities to be disposed of at this site. This review should cover

exploration data, sampling and laboratory techniques, test results, descriptions of physical

properties, and static and dynamic geotechnical engineering parameters of the materials, as

well as discussions of ground-water conditions (e.g., perched, confined, or unconfined) for all

critical subsurface strata at the site, including information on the fluctuations of the hydraulic

head. Review of the ground-water information should be coordinated with the review of

information on ground-water resources protection, as described in standard review plan

Chapter 4.0. Review of geologic, stratigraphic, and seismologic information should be

coordinated with the review of the geology and seismology information as described in standard

review plan Chapter 1.0. Borrow area restoration plans should be evaluated.

2.1.2 Review Procedures

The information to be reviewed depends on whether the proposed tailings disposal is below

grade, either in mines or specially excavated pits, or in above ground impoundments. The

reviewer should focus on the appropriateness of the site characterization for the proposed

tailings disposal scheme. The reviewer should examine the site stratigraphy and evaluation of

engineering properties of the underlying materials at the site, uranium mill tailings, other

materials, and borrow materials to determine if appropriate methods were properly used in

characterizing the materials.

The reviewer should examine the following specific descriptive information to determine its

adequacy for characterizing the site and for supporting the evaluations of reclamation

system performance:

(1) Site stratigraphy, based on borings and other investigations conducted to determine the

type, location, and thickness of underlying materials.
Geotechnical Stability

2-2

(2) Regional and site-specific seismologic information to determine the potential for impact

on the geotechnical stability of the site and site structures.

(3) Stratigraphy specifying type, location, and thickness of borrow material and other

materials designated for stabilization in the tailings disposal cell.

(4) In situ testing programs and procedures conducted to determine the engineering

properties of underlying materials at the site, borrow area material, other materials,

and tailings.

(5) Sampling programs conducted to obtain laboratory samples for determination of

engineering properties of borrow materials, underlying materials at the site, other

materials, and tailings.

(6) Laboratory testing used to determine the engineering properties of borrow materials,

underlying materials at the site, other materials, and tailings.

(7) Physical and engineering properties of borrow materials, underlying materials at the site,

other materials, and tailings.

(8) Records of historical ground-water-level fluctuations at the site, to the extent that they

are available.

The reviewer should evaluate methods used to characterize the site to ensure that they comply

with generally accepted standards, such as those of the American Society for Testing and

Materials and those which are commonly used in the geotechnical engineering profession. 

Areas to be examined in this respect include the in situ and laboratory testing programs,

sampling techniques, and analyses for determining the physical and engineering properties of

materials at the site. Field investigations and laboratory testing procedures not commonly used

in the geotechnical engineering profession will be reviewed in detail.

Staff determination of compliance should be based in part on professional judgment,

considering the complexity of the site subsurface conditions. 

2.1.3 Acceptance Criteria

The site characterization information constitutes part of the input data needed for analysis and

design of the tailings impoundment facility. The site characterization will be acceptable if it

provides the needed input for the design and analysis of the disposal facility and meets the

following criteria:

(1) The site stratigraphy is described in sufficient detail to provide an understanding of the

site-specific subsurface features, including structural features and other characteristics

of underlying soil and rock.
2-3

(2) Information on regional and local faults and seismicity, as obtained from field data,

published literature, and historical records is presented in sufficient detail to effectively

incorporate that information into a geotechnical stability analyses. (Note: This aspect of

the review should be coordinated with the geology and seismology review performed in

accordance with standard review plan Chapter 1.)

(3) Sampling scope and techniques are appropriate and sufficient to ensure that samples

collected are representative of the range of in situ soil conditions, taking into

consideration variability and uncertainties in such conditions within the site. 

(4) For all soils that might be unstable because of their physical or chemical properties,

locations and dimensions are identified and the properties have been documented. 

(5) Investigations (including laboratory and field testing) are conducted using appropriate

standards published by the American Society for Testing and Materials or the

International Society for Rock Mechanics and are sufficient to establish the static and

dynamic engineering parameters of borrow materials, other materials, tailings, and

underlying soil and rock materials at the site (NRC, 1978, 1979). 

(6) A detailed discussion of laboratory sample preparation techniques is presented, when

standard procedures are not used. 

For critical laboratory tests, details such as how saturation of the sample was

determined and maintained during testing, or how the pore pressures changed are

provided. A detailed and quantitative discussion of the criteria used to verify that the

samples were properly taken and tested in sufficient number to define the critical soil

parameters for the site is presented. In the case of tailings material (e.g., license

amendment reviews), the evaluations of its strength and settlement characteristics are

presented in detail.

(7) Parameter values are presented to enable evaluation of properties of mill tailings,

borrow materials, other materials, and underlying soil and rock, including the following:

(a) Compressibility and rate of consolidation

(b) Shear strength, including, for sensitive soils, possible loss of shear strength

resulting from strain-softening

(c) Liquefaction potential

(d) Permeability

(e) Dispersion characteristics

(f) Swelling and shrinkage
Geotechnical Stability

2-4

(g) Long-term moisture content for radon barrier material

(h) Cover cracking

(8) Soil stratigraphy and relevant parameters that are used in the geotechnical evaluations

(settlement, stability, liquefaction potential, etc.) are discussed in detail.

(9) Records of historical ground-water-level fluctuations at the site as obtained from

monitoring local wells and springs and/or by analysis of piezometer and permeability

data from tests conducted at the site are presented in sufficient detail to effectively

incorporate the information into geotechnical stability analyses. (Note: This aspect of

the review should be coordinated with the hydrogeologic characterization review

performed according to standard review plan Chapter 4.0.)

The information should be sufficient to provide the required input for the design of the facility

and to enable the reviewer to assess compliance with the regulatory requirements, such as site

features contributing to waste isolation; facility location with respect to an active fault; and

reasonable assurance of control of radiological hazards to be effective for 1,000 years to the

extent reasonably achievable, and in any case, for at least 200 years.

2.1.4 Evaluation Findings

If the staff review as described in standard review plan Section 2.1 results in the acceptance of

the characterization of the site and uranium mill tailings sufficient to support a conclusion

regarding the geotechnical stability of the site, the following conclusions may be presented in

the technical evaluation report:

The staff has completed its review of the geotechnical characteristics of the site and uranium

mill tailings at the uranium mill facility. This review included an evaluation

using the review procedures in Section 2.1.2 and the acceptance criteria outlined in

Section 2.1.3 of this standard review plan.

The licensee has acceptably described the geotechnical characteristics of the site and uranium

mill tailings based on sampling techniques that are acceptable, and will ensure that a

representative range of in situ soil conditions will be examined. Unstable soils have been

identified. Investigations and analyses have used acceptable standards and practices. 

Laboratory sample preparation and testing techniques are appropriately described and include: 

(1) compressibility and rate of consolidation, (2) shear strength, (3) liquefaction potential,

(4) permeability, (5) dispersion characteristics, (6) swelling and shrinkage, and (7) physical

properties. Records of historic ground-water-level fluctuations are presented to allow effective

incorporation into geotechnical stability analyses.

On the basis of the information presented in the application and the detailed review conducted

of geotechnical the characteristics of the site and uranium mill tailings at the 

uranium mill facility, the NRC staff concludes that the geotechnical characterization of the site

and uranium mill tailings and associated conceptual and numerical models provide an

acceptable input which, along with other information such as results of design analysis, will
Geotechnical Stability

2-5

enable the staff to make a finding on the demonstration of compliance with the following criteria

in Appendix A to 10 CFR Part 40: (1) Criterion 1, which relates to the site features that

contribute to the permanent waste isolation characteristics of the site; (2) Criterion 3, which

states the primary option for disposal of tailings is placement below grade, either in mines or

specially excavated pits (if applicable for the site); (3) Criterion 4(e), which requires that the

impoundment not be located near a capable fault on which a maximum credible earthquake,

larger than one that the impoundment could reasonably be expected to withstand, might occur;

(4) Criterion 5(G)(2), relating to the permeability characteristics of the site; and

(5) Criterion 6(1), which requires reasonable assurance of control of radiological hazards to be

effective for 1,000 years to the extent reasonably achievable, and in any case for at least

200 years.

2.1.5 References

American Society for Testing and Materials Standards:

D 420, “Guide for Investigating and Sampling Soil and Rock.”

D 421, “Practice for Dry Preparation of Soil Samples for Particle-Size Analysis and

Determination of Soil Constants.”

D 422, “Method for Particle-Size Analysis of Soils.”

D 653, “Terminology Relating to Soil, Rock, and Contained Fluids.”

D 854, “Test Method for Specific Gravity of Soils.”

D 1140, “Test Method for Amount of Material in Soils Finer Than the No. 200 Sieve.”

D 1452, “Practice for Soil Investigation and Sampling by Auger Borings.”

D 1586, “Method for Penetration Test and Split-Barrel Sampling of Soils.”

D 1587, “Practice for Thin-Walled Tube Sampling of Soils.”

D 2113, “Practice for Diamond Core Drilling for Site Investigation.”

D 2166, “Test Method for Unconfined Compressive Strength of Cohesive Soil.”

D 2216, “Method for Laboratory Determination of Water (Moisture) Content of Soil, Rock

and Soil-Aggregate Mixtures.”

D 2217, “Practice for Wet Preparation of Soil Samples for Particle-Size Analysis and

Determination of Soil Constants.”

D 2487, “Test Method for Classification of Soils for Engineering Purposes.”
Geotechnical Stability

2-6

D 2488, “Practice for Description and Identification of Soils (Visual-Manual Procedure).”

D 2573, “Test Method for Field Vane Shear Test in Cohesive Soils.”

D 3441, “Method for Deep, Quasi-Static, Cone and Friction-Cone Penetration Tests

of Soil.” 

D 3550, “Practice for Ring-Lined Barrel Sampling of Soils.”

D 4221, “Test Method for Dispersive Characteristics of Clay Soil by

Double Hydrometer.”

D 4318, “Test Method for Liquid Limit, Plastic Limit, and Plasticity Index of Soils.”

D 4647, “Test Method for Identification and Classification of Dispersive Clay Soils by the 

Pinhole Test.”

D 4750, “Test Method for Determining Subsurface Liquid Levels in a Borehole or

Monitoring Well (Observation Well).”

NRC. Regulatory Guide 1.132, "Site Investigations for Foundations of Nuclear Power Plants." 

Rev. 1. Washington, DC: NRC, Office of Standards Development. March 1979. 

NRC Regulatory Guide 1.138, "Laboratory Investigations of Soils for Engineering Analysis and

Design of Nuclear Power Plants." Washington, DC: NRC, Office of Standards Development. 

April 1978. 

2.2 Slope Stability

2.2.1 Areas of Review

The staff should examine exploration data, test results, slope characterization data, design

details, and static and dynamic analyses related to the stability of all natural and manmade

earth and rock slopes whose failure, under any of the conditions to which they could be

exposed throughout the period of regulatory interest, could adversely affect the integrity of the

slopes or embankments. This review should also include examination of static and dynamic

materials properties, test and design methods, pore pressures within and beneath the

embankment, and the design seismic coefficient. Information on the design seismic event

should be obtained from results of the review completed using standard review plan

Chapter 1.0. The review will focus on (i) the design of the impoundment during operation when

a large volume of tailings liquor would be present and (ii) the stability of the impoundment over

the long term.
Geotechnical Stability

2-7

2.2.2 Review Procedures

The reviewer should examine data gathered from site investigations, such as borings: maps;

laboratory and field tests; soil profiles; site plans; results of seismic investigations; permeability

tests; and static, dynamic, or pseudostatic stability analyses to determine whether the

assumptions and analyses used in the reclamation plan are conservative. The degree of

conservatism required depends on the type of analysis used, the variability and uncertainty in

the values of the parameters considered in the slope stability analysis, the number of borings,

the sampling program, the extent of the laboratory testing program, and the resultant safety

factor. For instances in which safety factors are low, the reviewer should ensure that

reasonable ranges of soil properties have been considered. Other factors, such as flood

conditions, pore pressure effects, possible erosion of soils, and seismic amplification effects,

should be conservatively assessed. The design criteria and analyses should be reviewed to

ascertain whether the techniques employed are appropriate and represent commonly accepted

methods [e.g., U.S. Army Corps of Engineers (1970b)].

The reviewer should examine the spatial variability of the measured properties to ensure that it

has been adequately defined. The reviewer should also examine slope characterization data to

ensure that nearby slopes, the failure of which could adversely affect the stability of

impoundments, have been properly characterized.

The reviewer should determine whether the static and dynamic stability analyses demonstrate

that there is an adequate factor of safety against failure.

The reviewer should examine the slope stability analysis to determine that an appropriately

conservative approach has been used and that adverse conditions to which the slope might be

subjected have been considered. The reviewer should confirm that the static analyses include

calculations using appropriate assumptions and methods to assess the following:

(1) Uncertainties and variations in the shape of the slope, the boundaries and parameters of

the several types of soils within the slope, the forces acting on the slope, and the pore

pressures acting within and beneath the slope.

(2) The failure surface corresponding to the lowest factor of safety.

(3) The effect of the assumptions inherent in the method of analysis used.

The reviewer should ensure that the analysis is conservative and that possible failure modes

have been considered, including evaluation of the effect of the maximum credible earthquake,

or the appropriate design criteria found acceptable in standard review plan Section 1.4. The

reviewer will also verify that the impoundment will not be located near a capable fault on which

a maximum credible earthquake larger than that which the impoundment could reasonably be

expected to withstand might occur.

The reviewer should be aware that no single method of analysis is applicable for all stability

assessments. Therefore, no single method of analysis is recommended. If the staff review

indicates that questionable assumptions have been made or that non-standard or inappropriate
Geotechnical Stability

2-8

methods of analysis have been used, the staff may model the slope in a manner consistent with

the data and perform an independent analysis.

The reviewer should verify that disposal cell slopes will be relatively flat after final stabilization to

minimize the potential for erosion and to provide a conservative factor of safety. In evaluating

the slope, the reviewer will focus on determining if the slopes are 5 horizontal to 1 vertical

(5h:1v) as required by 10 CFR Part 40, Appendix A, Criterion 4(c). If slopes steeper than 5h:1v

are proposed, the reviewer must evaluate these steeper slopes as an alternative to the

requirements of Criterion 4(c). In conducting a review of steeper slopes, the reviewer must

evaluate the acceptability of the steeper slope using the applicable criteria in this standard

review plan and determine if there is an acceptable economic basis and an equivalent level of

protection available to justify an alternative to 10 CFR Part 40, Appendix A, Criterion 4(c). The

reviewer should evaluate whether a full self-sustaining vegetative cover can be placed over the

tailings pile, primarily to reduce the wind and water erosion to negligible levels. If a vegetative

cover is not suitable for the site conditions, the reviewer should verify that an appropriate rock

cover has been provided. This verification should be coordinated with the review using

standard review plan Chapter 3.0.

Because dams at operating facilities, or dams that continue to hold water after the cessation of

operations, are also subject to the National Dam Safety Program Act of 1996, the reviewer

should determine if the dam is classified as a structure with low hazard potential or high hazard

potential. If the dam is classified as high hazard, the reviewer should evaluate the emergency

action plan for the facility.

2.2.3 Acceptance Criteria

The analysis of slope stability will be acceptable if it meets the following criteria:

(1) Slope characteristics are properly evaluated.

(a) Cross sections and profiles of natural and cut slopes whose instability would

directly or indirectly affect the control of radioactive materials are presented in

sufficient number and detail to enable the reviewer to select the cross sections

for detailed stability evaluation.

(b) Slope steepness is a minimum of five horizontal units (5h) to one vertical

unit (1v) or less. The use of slopes steeper than 5h:1v is considered an

alternative to the requirements in 10 CFR Part 40, Appendix A, Criterion 4(c). 

When slopes steeper than 5h:1v are proposed, a technical justification should be

offered as to why a 5h:1v or flatter slope would be impractical and 

compensating factors and conditions are incorporated in the slope design for

assuring long-term stability.

(c) Locations selected for slope stability analysis are determined considering the

location of maximum slope angle, slope height, weak foundation, piezometric

level(s), the extent of rock mass fracturing (for an excavated slope in rock), and

the potential for local erosion.
Geotechnical Stability

2-9

(2) An appropriate design static analysis is presented.

(a) The analysis includes calculations with appropriate assumptions and methods of

analysis (NRC, 1977). The effect of the assumptions and limitations of the

methods used is discussed and accounted for in the analysis. Acceptable

methods for slope stability analysis include various limit equilibrium analysis or

numerical modeling methods.

(b) The uncertainties and variability in the shape of the slope, the boundaries and

parameters of the several types of soils and rocks within and beneath the slope,

the material properties of soil and rock within and beneath the slope, the forces

acting on the slope, and the pore pressures acting within and beneath the slope

are considered.

(c) Appropriate failure modes during and after construction and the failure surface

corresponding to the lowest factor of safety are determined. The analysis takes

into account the failure surfaces within the slopes, including through the

foundation, if any.

(d) Adverse conditions such as high water levels from severe rain and the probable

maximum flood are evaluated.

(e) The effects of toe erosion, incision at the base of the slope, and other

deleterious effects of surface runoff are assessed.

(f) The resulting safety factors for slopes analyzed are comparable to the minimum

acceptable values of safety factors for slope stability analysis given in NRC

Regulatory Guide 3.11 (NRC, 1977).

(3) Appropriate analyses considering the effect of seismic ground motions on slope stability

are presented.

(a) Evaluation of overall seismic stability, using pseudostatic analysis or dynamic

analysis, as appropriate (U.S. Army Corps of Engineers, 1977; NRC, 1977). 

Alternatively, a dynamic analysis following Newmark (1965) can be carried out to

establish that the permanent deformation of the disposal cell from the design

seismic event will not be detrimental to the disposal cell. The reviewer should

verify that the yield acceleration or pseudostatic horizontal yield coefficient

necessary to reduce the factor of safety against slippage of a potential sliding

mass to 1.0 in a “Newmark-type” analysis has been adequately estimated (Seed

and Bonaparte, 1992).

(b) An appropriate analytical method has been used. A number of different methods

of analysis are available (e.g., slip circle method, method of slices, and wedge

analysis) with several variants of each (Lambe and Whitman, 1979; U.S. Army

Corps of Engineers, 1970b; NRC, 1977; Bromhead, 1992). Limit-equilibrium
Geotechnical Stability

2-10

analysis methods do not provide information regarding the variation of strain

within the slope and along the slip surface. Consequently, there is no assurance

that the peak strength values used in the analysis can be mobilized

simultaneously along the entire slip surface unless the material shows ductile

behavior (Duncan, 1992). Residual strength values should be evaluated if

mobilized shear strength at some points is less than the peak strength. The

reviewer should ensure that appropriate conservatism has been incorporated in

the analysis using the limit equilibrium methods. The limit equilibrium analysis

methodologies may be replaced by other techniques, such as finite element or

finite difference methods. If any important interaction effects cannot be included

in an analysis, the reviewer must determine that such effects have been treated

in an approximate but conservative fashion. The engineering judgment of the

reviewer should be used in assessing the adequacy of the resulting safety

factors (NRC, 1983a,b). 

(c) For dynamic loads, the dynamic analysis includes calculations with appropriate

assumptions and methods (NRC, 1977; Seed, 1967; Lowe, 1967; Department of

the Navy, 1982a,b,c; U.S. Army Corps of Engineers, 1970a,b, 1971, 1972;

Bureau of Reclamation, 1968). The effect of the assumptions and limitations of

the methods used is discussed and accounted for in the analysis.

(d) For dynamic loads, a pseudostatic analysis is acceptable in lieu of dynamic

analysis if the strength parameters used in the analysis are conservative, the

materials are not subject to significant loss of strength and development of high

pore pressures under dynamic loads, the design seismic coefficient is 0.20 or

less, and the resulting minimum factor of safety suggests an adequate margin,

as provided in NRC Regulatory Guide 3.11 (NRC, 1977).

(e) For pseudostatic analysis of slopes subjected to earthquake loads, an

assumption is made that the earthquake imparts an additional horizontal force

acting in the direction of the potential failure (U.S. Army Corps of Engineers,

1970b, 1977; Goodman, 1989). The critical failure surface obtained in the static

analysis is used in this analysis with the added driving force. Minimum

acceptable values for safety factors of slope stability analysis are given in

Regulatory Guide 3.11 (NRC, 1977).

(f) The assessment of the dynamic stability considers an appropriate design level

seismic event and/or strong ground motion acceleration, consistent with that

identified in Chapter 1 of this review plan. Influence of local site conditions on

the ground motions associated with the design level event is evaluated. The

design seismic coefficient to be used in the pseudostatic analysis is either

67 percent of the peak ground acceleration at the foundation level of the tailings

piles for the site or 0.1g, whichever is greater.

(g) If the design seismic coefficient is greater than 0.20g, then the dynamic stability

investigation (Newmark, 1965) should be augmented by other appropriate

methods (i.e., finite element method), depending on specific site conditions. 
Geotechnical Stability

2-11

(h) In assessing the effects of seismic loads on slope stability, the effect of dynamic

stresses of the design earthquake on soil strength parameters is accounted for. 

As in a static analysis, the parameters such as geometry, soil strength, and

hydrodynamic and pore pressure forces are varied in the analysis to show that

there is an adequate margin of safety.

(i) Seismically induced displacement is calculated and documented. There is no

universally accepted magnitude of seismically induced displacement for

determining acceptable performance of the disposal cell (Seed and Bonaparte,

1992; Goodman and Seed, 1966). Surveys of five major geotechnical consulting

firms by Seed and Bonaparte (1992) indicate that the acceptable displacement is

from 15 to 30 cm [6 to 12 in.] for tailings piles. The reviewer should ensure that

this criterion is also augmented by provisions for periodic maintenance of

the slope(s).

(j) Where there is potential for liquefaction, changes in pore pressure from cyclic

loading are considered in the analysis to assess the effect of pore pressure

increase on the stress-strain characteristics of the soil and the post-earthquake

stability of the slopes. Liquefaction potential is reviewed using Section 2.4 of this

review plan. Evaluations of dynamic properties and shear strengths for the

tailings, underlying foundation material, radon barrier cover, and base liner

system are based on representative materials properties obtained through

appropriate field and laboratory tests (NRC, 1978, 1979).

(k) The applicant has demonstrated that impoundments will not be located near a

capable fault on which a maximum credible earthquake larger than that which

the impoundment could reasonably be expected to withstand might occur.

(4) Provision is made to establish a vegetative cover, or other erosion prevention, to include

the following considerations:

(a) The vegetative cover and its primary functions are described in detail.

This determination should be made with respect to any effect the vegetative

cover may have on reducing slope erosion and should be coordinated with the

reviewer of standard review plan Chapter 3.

If strength enhancement from the vegetative cover is taken into account, the

methodology should be appropriate (Wu, 1984).

(b) In arid and semi-arid regions, where a vegetative cover is deemed not

self-sustaining, a rock cover is employed on slopes of the mill tailings. If credit is

taken for strength enhancement from rock cover, the reviewer should confirm

that appropriate methodology has been presented.

The design of a rock cover, where a self-sustaining vegetative cover is not

practical, is based on standard engineering practice. Standard review plan
Geotechnical Stability

2-12

Chapter 3 discusses this item in detail.

(5) Any dams meet the requirements of the dam safety program if the application

demonstrates the following:

(a) The dam is correctly categorized as a low hazard potential or a high hazard

potential structure using the definition of the U.S. Federal Emergency

Management Agency.

(b) If the dam is ranked as a high hazard potential, an acceptable emergency action

plan consistent with the Federal Emergency Management Agency guide

(U.S. Federal Emergency Management Agency, 1998) has been developed.

(6) The use of steeper slopes as an alternative to the requirements in 10 CFR, Part 40,

Appendix A, will be found acceptable if the following are met:

(a) An equivalent level of stabilization and containment and protection of public

health, safety, and the environment is achieved.

(b) A site-specific need for the alternate slopes is demonstrated.

2.2.4 Evaluation Findings

If the staff review as described in standard review plan Section 2.2 results in the acceptance

of the slope stability, the following conclusions may be presented in the technical

evaluation report:

The staff has completed its review of the slope stability at the uranium mill

facility. This review included an evaluation using the review procedures in Section 2.2.2 and

the acceptance criteria outlined in Section 2.2.3 of this standard review plan.

The licensee has acceptably described the slope stability evaluation by (1) providing cross

sections and profiles of natural and cut slopes in sufficient detail and number to represent

significant slope and foundation conditions; (2) placing tailings below grade or in demonstrably

safe above-grade disposal facilities; (3) ensuring that slope steepnesses are five horizontal (5h)

to one vertical (1v) or less or by providing technical justification for a different slope ratio;

(4) providing measurements of static and dynamic properties of soil and rock using standards

such as those established by the American Society for Testing and Materials, International

Society of Rock Mechanics, NRC, or the U.S. Army Corps of Engineers; (5) selecting locations

for slope stability analyses while considering the location of maximum slope angle, slope height,

weak foundation, the extent of rock mass fracturing, and the potential for local erosion; and

(6) describing vegetative cover and its primary functions in detail. Where the licensee has

proposed use of steeper slopes as an alternative to the requirements of 10 CFR Part 40,

Appendix A, Criterion 4(c), the staff has evaluated the licensee's demonstration that steeper

slopes would result in economic savings and also ensure the long-term stabilization of the

tailings with a level of protection equivalent to that required in 10 CFR Part 40, Appendix A,

Criterion 4(c). Therefore, the use of steeper slopes complies with the alternates requirement in

10 CFR Part 40, Appendix A.
Geotechnical Stability

2-13

The static loads analysis is acceptable and includes (1) appropriate uncertainties and

variabilities in important rock/soils parameters; (2) consideration of appropriate failure modes;

(3) a discussion of the effect of the assumptions inherent in the method of analysis used;

(4) consideration of adverse conditions, including flooding, with appropriate safety factors; and

(5) the effects of toe erosion, incision of the base of the slope, and other deleterious effects of

surface runoff.

The dynamic and pseudostatic analyses are acceptable and include (1) calculations with

appropriate assumptions and methods; (2) treatment of important interaction effects in a

conservative fashion; (3) an accounting of the dynamic stresses of the maximum credible

earthquake on soil strength parameters; (4) for pseudostatic analyses of slopes subjected to

earthquake loads, consideration of the added driving horizontal force acting in the direction of a

potential failure; (5) determination that possible permanent deformation sustained in the slope

from a maximum credible earthquake will not damage the effectiveness of the disposal cell;

(6) determination that the magnitude of seismically induced displacement does not exceed

15 to 30 cm [6 to 12 in.]; (7) a selection of appropriate design-level seismic events or strong

ground motion accelerations; (8) evaluations of local site conditions; (9) evaluations of the

potential for liquefaction and the effect of pore pressure increase on the stress-strain

characteristics of the soil and post-earthquake stability of the slopes; (10) evaluations of the

dynamic properties and shear strength of the tailings, underlying foundation, radon barrier

cover, and base liner system; and (11) design of a self-sustaining vegetative or rock cover that

is consistent with commonly accepted engineering practice.

On the basis of the information presented in the application and the detailed review conducted

of the slope stability at the uranium mill facility, the NRC staff concludes that

the slope stability and associated conceptual and numerical models pertaining to design of the

impoundments provide an acceptable input to demonstration of compliance with the following

criteria in 10 CFR Part 40, Appendix A: Criterion 4(c), which provides requirements for the

long-term stability of the embankment and cover slopes for tailings; Criterion 4(d), which

requires establishment of a self-sustaining vegetative cover or employment of a rock cover to

reduce wind and water erosion to negligible levels, that individual rock fragments are suited for

the job, and that the impoundment surfaces are contoured to avoid concentrated surface runoff

or abrupt changes in slope gradient; Criterion 4(e), which requires that the impoundment not be

located near a capable fault on which a maximum credible earthquake larger than that which

the impoundment could reasonably be expected to withstand might occur; Criterion 5(A)(5),

which requires the structural integrity of slopes (dikes) to prevent massive failure of the dikes;

and Criterion 6(1), which requires that impoundment designs providing reasonable assurance of

control of radiological hazards to be effective for 1,000 years to the extent reasonably

achievable, and in any case for at least 200 years.

2.2.5 References

American Society for Testing and Materials Standards:

D 2850, “Test Method for Unconsolidated, Undrained Compressive Strength of

Cohesive Soils in Triaxial Compression.”

D 3080, “Method for Direct Shear Test of Soils Under Consolidated 
Geotechnical Stability

2-14

Drained Conditions.”

D 4767, “Test Method for Consolidated-Undrained Triaxial Compression Test on

Cohesive Soils.”

Bromhead, E.N. The Stability of Slopes. London, England: Blackie

Academic & Professional. 1992.

Bureau of Reclamation. Earth Manual. First Edition. Washington, DC: U.S. Department of the

Interior. 1968.

Department of the Navy. “Soil Mechanics.” NAVFAC DM 7.1. May 1982a.

–––––. “Foundations and Earth Structures.” NAVFAC DM 7.2. May 1982b.

–––––. “Soil Dynamics, Deep Stabilization, and Special Geotechnical Construction.” NAVFAC

DM 7.3. May 1982c.

Duncan, J.M. “State-of-the-Art: Static Stability and Deformation Analysis. Stability and

Performance of Slopes and Embankments-II, Volume 1.” Proceedings of a Specialty

Conference. R.B. Seed and R.W. Boulanger, eds. Geotechnical Special Publication No. 31.

New York, New York: American Society of Civil Engineers. 1992.

Goodman, R.E. Introduction to Rock Mechanics. 2nd edition. New York, New York: John

Wiley and Sons. 1989.

Goodman, R.E. and H.B. Seed. “Earthquake-Induced Displacements in Sand Embankments.”

ASCE Journal of the Soil Mechanics and Foundations Division. Vol. 92, No. SM2. March 1966.

Lambe, T.W. and R.V. Whitman. Soil Mechanics, SI Version. New York, New York: John

Wiley and Sons. 1979.

Lowe, J., III. “Stability Analysis of Embankments.” ASCE Journal of the Soil Mechanics and

Foundations Division. Vol. 93, No. SM4. 1967.

Newmark, N.M. “Effects of Earthquakes on Dams and Embankments.” Geotechnique. 

June 1965.

NRC. NUREG/CR–3199, “Guidance for Disposal of Uranium Mill Tailings: Long-Term

Stabilization of Earthen Cover Materials.” Washington, DC: NRC. 1983a.

–––––. NUREG/CR–3397, “Design Considerations for Long-Term Stabilization of Uranium Mill

Tailings Impoundments.” Washington, DC: NRC. 1983b.

–––––. Regulatory Guide 1.132, “Site Investigations for Foundations of Nuclear Power Plants.” 

Rev. 1. Washington, DC: NRC, Office of Standards Development. March 1979. 

–––––. Regulatory Guide 1.138, “Laboratory Investigations of Soils for Engineering Analysis
Geotechnical Stability

2-15

and Design of Nuclear Power Plants.” Washington, DC: NRC, Office of Standards

Development. April 1978.

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

Retention Systems for Uranium Mills.” Rev. 2. Washington, DC: NRC, Office of Standards

Development. December 1977.

Seed, H.B. “Slope Stability During Earthquakes.” ASCE Journal of the Soil Mechanics and

Foundations Division. Vol. 93, No. SM4. 1967.

Seed R.B. and R. Bonaparte. “Seismic Analysis and Design of Lined Waste Fills: Current

Practice. Stability and Performance of Slopes and Embankments--II, Volume 1.” Proceedings

of a Specialty Conference. R.B. Seed and R.W. Boulanger, eds. Geotechnical Special

Publication No. 31. New York, New York: American Society of Civil Engineers. 1992.

U.S. Army Corps of Engineers. “Earthquake Design and Analysis for Corps of Engineer Dams.” 

ER1110-2-1806. U.S. Department of the Army, Office of the Chief of Engineers. April 1977.

–––––. “Soil Sampling.” Engineering Manual EM1110-2-1907. Department of the Army, Office

of the Chief of Engineers. March 1972.

–––––. “Instrumentation of Earth and Rockfill Dams.” Engineering Manual EM1110-2-1908,

Part 1 and 2. Department of the Army, Office of the Chief of Engineers. August and

November 1971.

–––––. “Laboratory Soil Testing.” Engineering Manual EM1110-2-1906. Department of the

Army, Office of Chief Engineers. November 1970a.

–––––. “Engineering and Design Stability of Earth and Rock Fill Dams.” Engineering Manual

EM1110-2-1902. Department of the Army, Office of the Chief of Engineers. 1970b.

U.S. Federal Emergency Management Agency. “Federal Guidelines for Dam Safety:

Emergency Action Planning for Dam Owners.” Washington, DC: U.S. Federal Emergency

Management Agency. 1998.

Wu, T.H. “Effect of Vegetation on Slope Stability, "Soil Reinforcement and Moisture Effects on

Slope Stability.” Transportation Research Record 965. National Research Council,

Transportation Research Board. 1984.
Geotechnical Stability

2-16

2.3 Settlement

2.3.1 Areas of Review

The staff should review the methods and results of testing and analyses conducted to estimate

deformation of subsurface materials and uranium mill tailings. This should include examination

of material properties and thicknesses of compressible materials, factors used in stress

calculations, calculated pore pressures within and beneath the embankment, resulting total and

differential settlement of the tailings surface under both static and seismic conditions, and the

effects of such settlements on the radon barrier layer of the cover of the disposal cell and

erosion protection layer. Liquefaction and associated settlement are addressed in standard

review plan Section 2.4. One of the purposes of this review is to determine if the licensee has

an acceptable method for determining if tailings consolidation is sufficient to allow the

placement of a radon barrier.

2.3.2 Review Procedures

The reviewer should examine the assessments of the magnitudes and distributions of

settlement of the disposal cell and the analyses of the potential for cracking of the radon barrier

from tensile strains in order to determine the adequacy of the design. 

The reviewer should confirm that clay layers and slime in the tailings pile and foundations have

been considered in the assessment of both immediate and long-term settlement.

In reviewing the assessment of settlements, the reviewer should give particular attention to the

identification and thicknesses of compressible soil layers within the tailings and in the

foundation. Settlement should be calculated at several locations within the disposal cell to

enable a determination of the overall settlement pattern of the disposal cell cover. The

locations for settlement calculations should be selected considering the presence of sand/slime

tailings and foundation materials. The tailings are expected to be a hydraulically placed

material comprised of interspersed sand and slime tailings. The following specific items should

be reviewed to determine the acceptability of the assessment of the magnitudes and distribution

of settlement:

(1) The analysis of immediate settlement of tailings surfaces, considering rebound from

excavation and settlement from instantaneous compression of underlying materials and

the tailings pile. The computation of incremental tailings loading and the width of the

loaded area, as well as the determination of the undrained modulus and Poisson's ratio

should be examined. Calculations of the settlement of hydraulically placed tailings

should be examined.

(2) The analysis of consolidation settlement from delayed compression (caused by

pore-pressure dissipation) of underlying materials and the tailings pile.
Geotechnical Stability

2-17

The calculation of settlement should be reviewed to ensure that each compressible soil

layer within or underneath the tailings pile is considered and is assigned proper

thickness and that the appropriate level of stress change is applied at the mid-depth of

the soil layer.

(3) The estimate of the time at which the primary consolidation settlement of the tailings will

be essentially complete. Generally, the radon barrier and disposal cell cover may be

placed only after the settlement of tailings is essentially complete.

(4) The analysis of secondary settlement from long-term creep. 

(5) The distribution of settlement magnitudes for assessment of differential settlement.

(6) Evaluation of the potential for cracking of the radon barrier layer as a result of long-term

settlement of the cover.

2.3.3 Acceptance Criteria

The analysis of tailings settlement will be acceptable if it meets the following criteria:

(1) Computation of immediate settlement follows the procedure recommended in

NAVFAC DM–7.1 (Department of the Navy, 1982). If a different procedure is used, the

basis for the procedure is adequately explained. 

The procedure recommended in NAVFAC DM–7.1 (Department of the Navy, 1982) for

calculation of immediate settlement is adequate if applied incrementally to account for

different stages of tailings emplacement. If this method is used, the reviewer should

verify that the computation of incremental tailings loading and the width of the loaded

area, as well as the determination of the undrained modulus and Poisson’s ratio, have

been computed and documented.

Settlement of tailings arises from compression of soil layers within the disposal cell and

in the underlying materials. Because compression of sands occurs rapidly, compression

of sand layers in the disposal cell and foundations must be considered in the

assessment of immediate settlement. However, the contribution of immediate

settlement to consolidation settlement cannot be ignored. Clay layers and slime

undergo instantaneous elastic compression controlled by their undrained stiffness as

well as long-term inelastic compression controlled by the processes of consolidation and

creep (NRC, 1983a). 

(2) Each of the following is appropriately considered in calculating stress increments for

assessment of consolidation settlement:

(a) Decrease in overburden pressure from excavation

(b) Increase in overburden pressure from tailings emplacement
Geotechnical Stability

2-18

(c) Excess pore-pressure generated within the disposal cell

(d) Changes in ground-water levels from dewatering of the tailings

(e) Any change in ground-water levels from the reclamation action

(3) Material properties and thicknesses of compressible soil layers used in stress change

and volume change calculations for assessment of consolidation settlement are

representative of in situ conditions at the site.

(4) Material properties and thicknesses of embankment zones used in stress change and

volume change calculations are consistent with as-built conditions of the disposal cell.

(5) Values of pore pressure within and beneath the disposal cell used in settlement

analyses are consistent with initial and post-construction hydrologic conditions at

the site.

(6) Methods used for settlement analyses are appropriate for the disposal cell and soil

conditions at the site. Contributions to settlement by drainage of mill tailings and by

consolidation/compression of slimes and sands are considered. Both instantaneous and

time-dependent components of total and differential settlements are appropriately

considered in the analyses (NRC, 1983a,b,c).

The procedure recommended in NAVFAC DM–7.1 (Department of the Navy, 1982) for

calculation of secondary compression is adequate.

(7) The disposal cell is divided into appropriate zones, depending on the field conditions, for

assessment of differential settlement, and appropriate settlement magnitudes are

calculated and assigned to each zone.

(8) Results of settlement analyses are properly documented and are related to assessment

of overall behavior of the reclaimed pile.

(9) An adequate analysis of the potential for development of cracks in the radon/infiltration

barrier as a result of differential settlements is provided (Lee and Shen, 1969).

2.3.4 Evaluation Findings

If the staff review, as described in standard review plan Section 2.3, shows that the settlement

has no impact on the integrity and functionality of the radon barrier and disposal cell cover, then

the following conclusions can be presented in the technical evaluation report. If the settlement

impacts the cell cover integrity, then the licensee will be required to revise the design to ensure

the functionality of the cell cover before a technical evaluation report can be prepared.

The staff has completed its review of the settlement at the uranium mill

facility. This review included an evaluation using the review procedures in Section 2.3.2 and

the acceptance criteria outlined in Section 2.3.3 of this standard review plan.
Geotechnical Stability

2-19

The licensee has acceptably described settlement by presenting computations following the

procedure recommended in NAVFAC DM–7.1 (Department of the Navy, 1982) or by explaining

the technical merit for an alternate procedure. Material properties, thickness, and load

increments used to calculate settlement are representative of site conditions. The applicant has

acceptably considered each of the following: (1) decrease in overburden pressure from

excavation, (2) increase in overburden pressure from emplaced tailings, (3) excess

pore-pressure generated within the tailings disposal cell, (4) changes in ground-water levels

from dewatering of the tailings, and (5) changes in ground-water levels from reclamation

actions. Pore pressures within and beneath the disposal cell/embankment are consistent with

initial and as-built hydrologic site conditions. Methods used to determine settlement are

appropriate for the tailings embankment and soil conditions at the site. The results of the

settlement analyses are properly documented. The tailings embankment has been subdivided

acceptably into assessment zones with appropriately assigned settlement magnitudes. The

settlement data provide information to assess the possibility of surface ponding or sudden

change of gradient caused by settlement. An acceptable analysis for the development of

cracks in the radon/infiltration barrier is provided.

On the basis of information presented in the application and the detailed review conducted of

the characteristics of the settlement at the mill facility, the NRC staff

concludes that the settlement and associated conceptual and numerical models present

information needed to demonstrate compliance with 10 CFR Part 40, Appendix Ae. 

Criterion 6(1), which requires that impoundment designs provide reasonable assurance of

control of radiological hazards to be effective for 1,000 years to the extent reasonably

achievable, and in any case for at least 200 years.

2.3.5 References

American Society for Testing and Materials Standards:

D 2435, “Test Method for One-Dimensional Consolidation Properties of Soil.”

D 4719, “Test Method for Pressuremeter Testing in Soils.”

Department of the Navy. 1982. Soil Mechanics. NAVFAC DM–7.1. May 1982.

Lee, K.L. and C.K. Shen. “Horizontal Movements Related to Subsidence.” ASCE Journal of

Soil Mechanics and Foundations Division. Vol. 95, No. SM1. 1969.

NRC. 1983a. NUREG/CR–3204, “Consolidation of Tailings.” Washington, DC: NRC. 1983a.

–––––. NUREG/CR–3199, "Guidance for Disposal of Uranium Mill Tailings: Long-Term

Stabilization of Earthen Cover Materials." Washington, DC: NRC. 1983b.

–––––. NUREG/CR–3397, “Design Considerations for Long-Term Stabilization of Uranium Mill

Tailings Impoundments.” Washington, DC: NRC. 1983c.
Geotechnical Stability

2-20

2.4 Liquefaction Potential

2.4.1 Areas of Review

The staff should review the analysis of the liquefaction potential of subsurface, pile, and

embankment materials, and the associated test and data interpretations. Consequences of the

liquefaction of subsurface soils and/or uranium mill tailings affecting the settlements within and

stability of the disposal cell and the erosion protection layer should also be reviewed. Design

features or mitigation actions that address liquefaction potential should be examined. The

effect of settlements not induced by liquefaction is considered in standard review plan

Section 2.3 and is also considered in standard review plan Section 2.4.3.

2.4.2 Review Procedures

The reviewer should examine the analysis of liquefaction potential by studying the results of

geotechnical investigations and in situ tests such as standard penetration, cone penetration,

piezocone, density, and strength tests as well as boring logs, laboratory classification test data,

water table measurements, perched water zones, and soil profiles, to determine if any of the

site soils or the tailings pile material could be susceptible to liquefaction. 

If it is determined that there may be soils susceptible to liquefaction beneath the site or in the

tailings pile, the reviewer should examine the adequacy of site exploration programs, the

laboratory test program, and the analyses. Where global liquefaction potential exists, the

reviewer should determine that it has been mitigated or eliminated. Minor or local liquefaction

potential should be accounted for in settlement analyses.

The reviewer should compare the liquefaction potential analysis in the reclamation plan to an

independent study performed by the staff, if necessary.

2.4.3 Acceptance Criteria

The analysis of the liquefaction potential will be acceptable if the following criteria are met:

(1) Applicable laboratory and/or field tests are properly conducted (NRC, 1978, 1979;

U.S. Army Corps of Engineers, 1970, 1972).

(2) Data for all relevant parameters for assessing liquefaction potential are adequately

collected and the variability has been quantified.

(3) Methods used for interpretation of test data and assessment of liquefaction potential are

consistent with current practice in the geotechnical engineering profession (Seed and

Idriss, 1971, 1982; National Center for Earthquake Engineering Research, 1997). An

assessment of the potential adverse effects that complete or partial liquefaction could

have on the stability of the embankment may be based on cyclic triaxial test data

obtained from undisturbed soil samples taken from the critical zones in the site area

(Seed and Harder, 1990; Shannon & Wilson, Inc. and Agbabian-Jacobsen
Geotechnical Stability

2-21

Associates, 1972). 

(4) If procedures based on laboratory tests combined with ground response analyses are

used, laboratory test results are corrected to account for the difference between

laboratory and field conditions (NRC, 1978; Naval Facility Engineering

Command, 1983).

(5) The time history of earthquake ground motions used in the analysis is consistent with

the design seismic event.

(6) If the potential for complete or partial liquefaction exists, the effects such liquefaction

could have on the stability of slopes and settlement of tailings are adequately quantified.

(7) If a potential for global liquefaction is identified, mitigation measures consistent with

current engineering practice or redesign of tailings ponds/embankments are proposed

and the proposed measures provide reasonable assurance that the liquefaction

potential has been eliminated or mitigated.

(8) If minor liquefaction potential is identified and is evaluated to have only a localized effect

that may not directly alter the stability of embankments, the effect of liquefaction is

adequately accounted for in analyses of both differential and total settlement and is

shown not to compromise the intended performance of the radon barrier. Additionally,

the disposal cell is shown to be capable of withstanding the liquefaction potential

associated with the expected maximum ground acceleration from earthquakes. The

licensee may use post-earthquake stability methods (e.g., Ishihara and Yoshimine,

1990) based on residual strengths and deformation analysis to examine the effects of

liquefaction potential. Furthermore, the effect of potential localized lateral displacement

from liquefaction, if any, is adequately analyzed with respect to slope stability and

disposal cell integrity.

2.4.4 Evaluation Findings

If the staff review, as described in standard review plan Section 2.4, results in the acceptance

of the licensee liquefaction potential analysis and conclusions on the impact on the

performance of the disposal cell, the following conclusions may be presented in the technical

evaluation report:

The staff has completed its review of the liquefaction potential at the uranium

mill facility. This review included an evaluation using the review procedures in standard review

plan Section 2.4.2 and acceptance criteria outlined in Section 2.4.3 of this standard review plan. 

The licensee has acceptably evaluated liquefaction potential based on results from properly

conducted laboratory and/or field tests. The methods used for interpretation of test data are

consistent with current practice. Where global liquefaction is identified, mitigation measures or

redesign of tailings ponds/embankments are proposed and the new design provides reasonable

assurance that the liquefaction potential has been eliminated or mitigated. In the case of

minor/local liquefaction potential, its effect is accounted for in the analysis of both differential
Geotechnical Stability

2-22

and total settlement and is shown not to compromise the intended performance of the radon

barrier and erosion protection.

On the basis of the information presented in the application and the detailed review conducted

of the liquefication potential at the uranium mill facility, the NRC staff

concludes that the results of evaluation of liquefaction potential and associated conceptual and

numerical models present input to a demonstration of compliance with the following criteria in

10 CFR Part 40, Appendix A: Criterion 4(c), which provides long-term stability requirements for

the slopes of the tailings embankment and cover; and Criterion 6(1), which requires that 

impoundment designs povide reasonable assurance of control of radiological hazards to be

effective for 1,000 years to the extent reasonably achievable, and in any case for at least 200

years.

2.4.5 References

American Society for Testing and Materials Standards:

D 3999, “Test Method for the Determination of the Modulus and Damping Properties of

Soils Using the Cyclic Triaxial Apparatus.”

D 4015, “Test Method for Modulus and Damping of Soils by the 

Resonant-Column Method.”

Ishihara, K. and M. Yoshimine. “Evaluation of Settlements in Sand Deposits Following

Liquefaction During Earthquake.” Soil Foundations. Vol. 32, No. 1. Japanese Society of Soil

Mechanics and Foundation Engineering. 1990.

National Center for Earthquake Engineering Research. “Proceedings of the NCEER Workshop

on Evaluation of Liquefaction Resistance of Soils.” T.L. Youd and I.M. Idriss, eds. Technical

Report No. NCEER 97-002. Buffalo, New York: State University of New York. 1997.

Naval Facility Engineering Command. “Soil Dynamics, Deep Stabilization, and Special

Geotechnical Construction. NAVFAC DM–7.3. Alexandria, Virginia: Department of the

Navy. 1983.

NRC. Regulatory Guide 1.132, “Site Investigations for Foundations of Nuclear Power Plants.” 

Rev. 1. Washington, DC: NRC, Office of Standards Development. March 1979.

–––––. Regulatory Guide 1.138, “Laboratory Investigations of Soils for Engineering Analysis

and Design of Nuclear Power Plants.” Washington, DC: NRC, Office of Standards

Development. April 1978.

Seed, H.B. and I.M. Idriss. “Ground Motions and Soil Liquefaction During Earthquakes.” 

Earthquake Engineering Research Institute. Engineering Monograph: 5. 1982.

Seed, H.B. and I.M. Idriss. “A Simplified Procedure for Evaluating Soil Liquefaction Potential.”

Journal of Soil Mechanics and Foundation Division. Vol. 97, No. SM 9. pp. 1,249–1,274. 1971.
Geotechnical Stability

2-23

Seed, R.B. and L.F. Harder. “SPT-Based Analysis of Cyclic Pore Pressure Generation and

Undrained Residual Strength.” Proceedings of the H. Bolton Seed Memorial Symposium.

Berkeley, California: University of California, May 10–11. pp. 351–376. 1990.

Shannon & Wilson, Inc. and Agbabian-Jacobsen Associates. “Soil Behavior Under Earthquake

Loading Conditions: State-of-the-Art Evaluation of Characteristics for Seismic Responses

Analyses.” Washington, DC: U.S. Atomic Energy Commission. 1972.

U.S. Army Corps of Engineers. “Soil Sampling.” Manual EM 1110-2-1907. March 1972.

–––––. “Laboratory Soil Testing, Engineering.” Manual EM1110-2-1906. November 1970.

2.5 Disposal Cell Cover Engineering Design

2.5.1 Areas of Review

The staff should review information presented on disposal cell cover engineering design.

including field exploration data, laboratory test results, design details, and construction and

installation considerations pertinent to the geotechnical aspects of design and any associated

geomembranes (i.e., disposal cell configuration and thickness, compaction requirements,

gradations, permeability, and dispersivity).

2.5.2 Review Procedures

The reviewer should examine the disposal cell design and engineering parameters to assess

the geotechnical aspects of the disposal cell cover. Specific aspects of the review should

consider the following items:

(1) Determination that an adequate quantity of the specified borrow material has been

identified at the borrow source.

(2) Confirmation that placement density, specific gravity, moisture content, dispersivity, and

shrinkage properties used in the disposal cell design have been determined by suitable

laboratory testing so that long-term stability standards will be met. (Note that

permeability issues are discussed separately in standard review plan Section 2.7.)

(3) Confirmation that appropriate measures for controlling the effects of erosion, surface

water flows, and vegetative deep root penetrations have been taken.

(4) Verification that the particle size gradation of the disposal cell cover material, bedding

layers, other layers in the cover, and the rock layer are compatible to ensure stability

against particle migration during the period of regulatory interest.

(5) Determination that the disposal cell has been designed to accommodate the effects of

anticipated freeze-thaw cycles.

(6) Assessment, if bentonite amendment to the radon barrier material of the disposal cell

cover is proposed, of whether supporting discussions define appropriate laboratory
Geotechnical Stability

2-24

testing and field procedures associated with evaluating amended materials.

(7) Determination if the cracking potential of the disposal cell has been adequately

addressed. Cracking from both settlement and shrinkage should be evaluated using

standard review plan Section 2.3.

(8) Assessment of the acceptability of plans for installation and use of any geomembranes.

(9) Confirmation that the information used in the disposal cell cover design appropriately

reflects the staff findings on the information reviewed using standard review plan

Chapters 1.0, 2.0, 3.0, and 4.0.

Note that hydraulic conductivity aspects of the disposal cell cover design are assessed using

standard review plan Section 2.7 and that review of the disposal cell design features is

addressed in standard review plan Sections 2.2, 2.3, and 2.4. Review of the radon attenuation

aspects of the disposal cell design is addressed in standard review plan Chapter 5.0. 

2.5.3 Acceptance Criteria

The assessment of the disposal cell cover design and engineering parameters will be

acceptable if it meets the following criteria:

(1) Detailed descriptions of the disposal cell material types [e.g., Unified Soil Classification

System (Holtz and Kovacs, 1981)] and/or soil mixtures (e.g., bentonite additive) and the

basis for their selection are presented.

An analysis is included demonstrating that an adequate quantity of the specified borrow

material has been identified at the borrow source. The information on borrow material

includes boring and test pit logs and compaction test data.

The soils that are considered suitable include the Unified Classification System Classes

CL, CH, SC, and CL-ML, with desirable characteristics and limitations as listed in

Table 3-1 of the “Construction Methods and Guidance for Sealing Penetrations in Soil

Covers” (Bennett and Homz, 1991; Bennett and Kimbrell, 1991). The preferred material

for the low-permeability layers is inorganic clay soil. This soil should be compacted to a

low saturated hydraulic conductivity of at least 1 x 107

 cm/sec. For drainage layers,

cobble types GW, GP, SP, and SW are recommended, with GW and GP being the

preferred types (Bennett, 1991).

Measures for resisting cracking, heaving, and settlement, and providing protection

from burrowing animals, root penetration, and erosion over a long period of time

are described. 

(2) A sufficiently detailed description of the applicable field and laboratory investigations and

testing that were completed, and the material properties (e.g., permeability,

moisture-density relationships, gradation, shrinkage and dispersive characteristics,

resistance to freeze-thaw degradation, cracking potential, and chemical compatibility,

including any amendment materials) are identified (U.S. Army Corps of Engineers,
Geotechnical Stability

2-25

1970, 1972; Fermulk and Haug, 1990; NRC, 1978, 1979; Lee and Shen, 1969; Spangler

and Handy, 1982).

(3) Details are presented (including sketches) of the disposal cell cover termination at

boundaries, with any considerations for safely accommodating subsurface water flows.

(4) A schematic diagram displaying various disposal cell layers and thicknesses is provided.

The particle size gradation of the disposal cell bedding layer and the rock layer are

established to ensure stability against particle migration during the period of regulatory

interest (NRC, 1982).

(5) The effect of possible freeze-and-thaw cycles on soil strength and radon barrier

effectiveness is adequately considered (e.g., Aitken and Berg, 1968).

If the region experiences prolonged freezing, the disposal cell cover may be affected by

the freeze-thaw cycle. During freezing, ice crystals and lenses can form in the soil,

causing heaving. On the other hand, during melting and thawing, the soil may lose its

bearing capacity because of development of supersaturated conditions (Spangler and

Handy, 1982). Major factors affecting growth of ice in soil are the temperature below

the freezing point, the capillary characteristics of the soil, and the presence of water. 

The reviewer should check whether the soil is susceptible to frost heave, considering

that uniformly graded soils containing more than 10 percent of particles smaller than

0.02 mm and well-graded soils with more than 3 percent of particles smaller than

0.02 mm are susceptible (Holtz and Kovacs, 1981; Spangler and Handy, 1982). After

many freeze-thaw cycles, the soil may become a loose collection of aggregates with

significantly reduced overall strength.

(6) A description is given (with sketches) of any penetrations (e.g., monitoring wells)

through the disposal cell system, including details of penetration sealing and disposal

cell cover integrity. Bennett and Kimbrell (1991) suggest methods for seal design that

are acceptable.

(7) An adequate analysis is presented of the potential for development of cracks in the

disposal cell cover as a result of differential settlement and shrinkage. Note that

cracking issues associated with settlement are discussed in standard review plan

Section 2.3.3. 

(8) An adequate description of the geomembranes and their major properties

(e.g., physical, mechanical, and chemical) is provided if low permeability geomembranes

are proposed as a part of the disposal cell cover. Methods for installation of the

membranes in accordance with the manufacturer's recommendations are discussed. 

The shear strength of the interface between compacted clay and geomembranes used

in the stability analyses under both static and dynamic loads is noted. The expected

service life of the geomembrane is analyzed.

(9) Information on site characterization, slope stability, settlement, and liquefaction used in

the disposal cell cover design appropriately reflects the Licensee’s evaluation, and
Geotechnical Stability

2-26

therefore, constitutes inputs that would contribute to the demonstration of disposal cell

design compliance with the regulations.

2.5.4 Evaluation Findings

If the staff review as described in standard review plan Section 2.5 results in the acceptance of

the disposal cell cover design, the following conclusions may be presented in the technical

evaluation report:

The staff has completed its review of the disposal cell cover design at the

 uranium mill facility. This review included an evaluation using the review

procedures in Section 2.5.2 and acceptance criteria outlined in Section 2.5.3 of this standard

review plan.

The licensee has acceptably defined the disposal cell cover design by presenting detailed

descriptions of the disposal cell material types and/or soil mixtures, including the basis for their

selection. The applicant has identified an adequate quantity of the specified borrow material at

the borrow source. An acceptable schematic diagram displaying various disposal cell layers

and thicknesses is provided. A description of the applicable field and laboratory investigations

and testing is provided, including identification of material properties. The properties of the

cover materials have been measured properly using standards such as American Society for

Testing and Materials, NRC, or U.S. Army Corps of Engineers. Details (including sketches)

have been provided of (1) disposal cell termination boundaries; (2) penetrations, including

sealing and disposal cell integrity; and (3) geomembranes and their physical, mechanical, and

chemical properties. Methods of installation for the membranes have been discussed and the

expected service life has been justified. The analysis of the potential for development of cracks

in the disposal cell cover is acceptable. 

On the basis of the information presented in the application and the detailed review conducted

of the disposal cell cover design at the uranium mill facility, the NRC staff 

concludes that the disposal cell engineering parameters and associated conceptual and

numerical models are acceptable and provide input to demonstration of compliance with the

following criteria in 10 CFR, Part 40, Appendix A: Criterion 4(c), which provides requirements

for the embankment and cover slopes for tailings; and Criterion 6(1), which requires that

impoundment design provide reasonable assurance of control of radiological hazards to be

effective for 1,000 years to the extent reasonably achievable, and in any case, for at least 200

years.

2.5.5 References

American Society for Testing and Materials Standards:

D 75, “Practice for Sampling Aggregates.”

D 4992, “Practice for the Evaluation of Rock To Be Used for Erosion Control.”

Aitken, G.W. and R.L. Berg. “Digital Solution of Modified Berggren Equation to Calculate

Depths of Freeze or Thaw in Multi-layered Systems.” Special Report 122. Hanover, New
Geotechnical Stability

2-27

Hampshire: Cold Regions Research & Engineering Laboratory. 1968.

Bennett, R.D. NUREG/CR–5432, “Recommendations to the NRC for Soil Cover Systems Over

Uranium Mill Tailings and Low-Level Radioactive Wastes: Identification and Ranking of Soils

for Disposal Facility Covers.” Vol. 1. Washington, DC: NRC. 1991.

Bennett, R.D. and R.C. Homz. NUREG/CR–5432, “Recommendations to the NRC for Soil

Cover Systems Over Uranium Mill Tailings and Low-Level Radioactive Wastes: Laboratory and

Field Tests for Soil Covers.” Vol. 2. Washington, DC: NRC. 1991.

Bennett, R.D. and A.F. Kimbrell. NUREG/CR–5432, “Recommendations to the NRC for Soil

Cover Systems Over Uranium Mill Tailings and Low-Level Radioactive Wastes: Construction

Methods for Sealing Penetrations in Soil Covers.” Vol. 3. Washington, DC: NRC. 1991.

Fermulk, N. and M. Haug. “Evaluation of In Situ Permeability Testing Methods.” ASCE Journal

of Geotechnical Engineering. Vol. 116, No. 2. pp. 297–311. 1990.

Holtz, R.D. and W.D. Kovacs. An Introduction to Geotechnical Engineering. Englewood Cliffs,

New Jersey: Prentice-Hall. 1981.

Lee, K.L. and C.K. Shen. 1969. “Horizontal Movements Related to Subsidence.” Journal of

Soil Mechanics and Foundation Division. Vol. 95, No. SM–1. New York, New York: American

Society of Civil Engineers. 1969.

NRC. NUREG/CR–2684, “Rock Riprap Design Methods and Their Applicability to Long-Term

Protection of Uranium Mill Tailings Impoundments.” Washington, DC: NRC. 1982.

–––––. Regulatory Guide 1.132, “Site Investigations for Foundations of Nuclear Power Plants.” 

Rev. 1. Washington, DC: NRC, Office of Standards Development. March 1979. 

–––––. Regulatory Guide 1.138, “Laboratory Investigations of Soils for Engineering Analysis

and Design of Nuclear Power Plants.” April 1978. Washington, DC: NRC, Office of Standards

Development. April 1978.

Spangler, M.G. and R.L. Handy. Soil Engineering. New York, New York: Harper and

Row. 1982.

U.S. Army Corps of Engineers. “Soil Sampling.” Engineering Manual EM1110-2-1907. 

March 1972.

–––––. “Laboratory Soil Testing.” Engineering Manual EM1110–2–1906. November 1970.

2.6 Construction Considerations

2.6.1 Areas of Review

The staff should review information on the geotechnical aspects of reclamation construction. 

These aspects should include details such as the sequence and schedule for construction
Geotechnical Stability

2-28

activities, material specifications and placement procedures, and quality control aspects of the

construction procedures. The geotechnical aspects of the planned construction operations

should be reviewed to identify any deviations from standard engineering practice for

earthworks, including measures to protect against erosion and provisions for a

vegetative cover, if appropriate.

2.6.2 Review Procedures

The reviewer should determine if all the tailings and contaminated materials at the site can be

placed within the configuration of the proposed stabilized pile. The construction sequence

should be reviewed to verify the feasibility of achieving the intended final configuration of the

tailings, particularly when tailings are to be relocated to new areas of the remediated pile, and

to determine whether the schedule for completion is reasonable. The reviewer should also

confirm that the construction schedule will allow the radon barrier to be completed as

expeditiously as practical after ceasing operations.

The reviewer should examine material placement, placement moisture content (drying, if

needed), placement density, and desired permeability to ensure that design specifications will

be met. If mixing of the fine tailings (slimes) with sand tailings is proposed, the specifications to

control the mixture and the determination of the engineering properties of this mixture should be

examined for adequacy.

The reviewer should examine the proposed construction quality control program to verify that

adequate provisions have been included to ensure that the construction will be in accordance

with the NRC-approved reclamation plan. In particular, details of the proposed testing and

inspection program, including the type and frequency of tests proposed, should be reviewed

and compared with NRC guidance on testing and inspection.

Methods and schedules for emplacing the vegetative cover should be reviewed if necessary, to

determine that they are reasonable, and that seeds for the planned vegetation are compatible

with the local climate.

2.6.3 Acceptance Criteria

The analysis of construction considerations will be acceptable if the following criteria 

are met:

(1) Engineering drawings are at appropriate scales to completely and clearly show the

design features (e.g., embankments, riprap, and channels).

(2) Sources and quantities of borrow material are identified, are shown to have been

adequately characterized and quantified through field and laboratory tests, and are

demonstrated to be adequate for meeting the geotechnical design requirements for the

disposal cell (NRC, 1978, 1979). The background levels of contamination in the borrow

materials, if any, are properly established.

(3) Methods, procedures, and requirements for excavating, hauling, stockpiling, and placing

of contaminated and non-contaminated materials and other disposal cell materials are
Geotechnical Stability

2-29

provided and are shown to be consistent with commonly accepted engineering practice

for earthen works (Department of the Navy, 1982a,b; Denson, et al., 1987).

Material placement and compaction procedures are adequate to achieve the desired

moisture content (drying, if needed) placement density and permeability. 

Recommendations made in NUREG/CR–5041 (Denson, et al., 1987) for gradation,

placement, and compaction necessary to achieve design drainage rates and volumes,

prevent internal erosion or piping, and allow for collection and removal of liquids, are

acceptable. Compaction specifications include restrictions on work related to adverse

weather conditions (e.g., rainfall, freezing conditions).

Specifications for controlling the mixture of fine tailings (slime) with sand tailings are

consistent with commonly accepted engineering practice and testing programs for

determination of engineering properties of this mixture.

(4) A plan for embankment construction is presented, that demonstrates embankments can

be constructed in accordance with the design.

(5) Plans, specifications, and requirements for disposal cell compaction are supported by

field and laboratory tests and analyses to assure stability and reliable performance.

(6) Testing and surveying programs to determine the extent of cleanup required are

adequate. The contamination cleanup plan includes the method for determining the

extent of the contaminated area and a confirmation program to demonstrate that the

contaminated material has been removed. Details of the site cleanup (radiological

aspects) are addressed in standard review plan Chapter 5.0. 

(7) A plan for settlement measurement is provided that is satisfactory for producing

representative settlement data throughout the area of the disposal cell. Settlement

measurement stations are of sufficient coverage and are strategically placed to yield

adequate information for determination of total, differential, and residual settlements. 

Monitoring monuments are designed to be durable. The reviewer should also determine

the reasonableness of the proposed monitoring frequency in accordance with

NUREG/CR–3356 (NRC, 1983). In the past, the staff has determined that the final

radon barrier may be emplaced once 90 percent of expected settlement has occurred.

(8) All tailings and contaminated materials at the site can be placed within the planned

configuration of the stabilized pile. 

(9) Procedures, specifications, and requirements for riprap, rock mulch, and filter production

and placement are provided and are shown to be consistent with commonly accepted

engineering practice and the design specifications (NRC, 1977, 1982).

(10) The construction sequence is described and demonstrated to be adequate to achieve

the intended configuration for the tailings, particularly when tailings are to be relocated

to new areas of the reclaimed pile. The proposed time to completion has been shown to

be reasonably achievable, and the construction schedule provides for completing the
Geotechnical Stability

2-30

radon barrier as expeditiously as practical after ceasing operations in accordance with

an approved reclamation plan.

(11) The vegetation program or rock cover design is described and demonstrated to be

adequate (Wu, 1984; NRC, 1982).

(12) Appropriate quality control provisions are provided to ensure that the construction will be

in accordance with the reclamation plan. The descriptions of the methods, procedures,

and frequencies by which the construction materials and activities are to be tested and

inspected are reasonable and appropriate records will be maintained (NRC, 1983).

(13) Tailings are placed below grade, or the licensee has demonstrated that the above-grade

disposal design provides reasonably equivalent isolation of the tailings from natural

erosional forces. Tailings pile topographic features take into account wind protection

and vegetation cover.

2.6.4 Evaluation Findings

If the staff review as described in this section results in the acceptance of the licensee

proposed construction considerations, the following conclusions may be presented in the

technical evaluation report.

The staff has completed its review of construction considerations at the _____________

uranium mill facility. This review included an evaluation using the review procedures in

Section 2.6.2 and the acceptance criteria outlined in Section 2.6.3 of this standard review plan.

The licensee has acceptably described the construction considerations by (1) providing

complete engineering drawings showing all design features; (2) describing sources and

quantities of borrow material, including acceptable field and laboratory testing; and

(3) identifying methods, procedures, and requirements for excavations, haulage, stockpiling,

and placement of materials and demonstrating that all are consistent with accepted engineering

practices for earthen works. An acceptable plan for embankment construction is provided. 

Disposal cell compaction plans are supported by field and laboratory tests that assure stability

and performance. The licensee has an acceptable program to determine the extent of cleanup

using appropriate testing and surveying programs. An acceptable plan for settlement

measurement is provided, including (1) proper coverage and placement of settlement

measurement stations, (2) durable monitoring monuments, and (3) reasonable monitoring

frequencies. All tailings and contaminated materials have been demonstrated to fit within the

planned configuration of the stabilized pile. Procedures, specifications, and requirements for

riprap, rock mulch, and filters are provided and are shown to be consistent with commonly

accepted engineering practices and design specifications. An acceptable construction

sequence, including a reasonable time to completion, has been described. An acceptable

vegetation program or rock cover design is proposed. Appropriate quality control provisions are

in place to ensure that construction will be in accordance with the reclamation plan and that

appropriate records will be maintained.
Geotechnical Stability

2-31

On the basis of the information presented in the application and the detailed review conducted

of the construction considerations at the uranium mill facility, the NRC staff

concludes that the construction considerations and associated conceptual and numerical

models provide input to a demonstration of compliance with the following criteria in

10 CFR, Part 40, Appendix A: Criterion 4(c), which provides requirements for the embankment

and cover slopes for tailings; Criterion 4(d), which requires establishment of a self-sustaining

vegetative cover or employment of a rock cover to reduce wind and water erosion to negligible

levels, that individual rock fragments are suited for the job, and that the impoundment surfaces

are contoured to avoid concentrated surface runoff or abrupt changes in slope gradient;

Criterion 6(1), which requires that impoundment designs provide reasonable assurance of

control of radiological hazards to be effective for 1,000 years to the extent reasonably

achievable, and in any case, for at least 200 years; and Criterion 6A(1), which requires that the

radon barrier be completed as expeditiously as practical after ceasing operations in accordance

with a Commission-approved reclamation plan.

2.6.5 References

American Society for Testing and Materials Standards:

D 698, “Test Method for Laboratory Compaction Characteristics of Soil Using

Standard Effort.”

D 1556, “Test Method for Density and Unit Weight of Soil In Place by the Sand

Cone Method.”

D 1557, “Test Method for Laboratory Compaction Characteristics of Soil Using

Modified Effort.”

D 2167, “Test Method for Density and Unit Weight of Soil In Place by the Rubber

Balloon Method.”

D 2922, “Test Methods for Density of Soil and Soil-Aggregate in Place by Nuclear

Methods (Shouldow Depth).”

D 2937, “Test Method for Density of Soil in Place by the Drive Cylinder Method.”

D 3017, “Test Method for Water Content of Soil and Rock in Place by Nuclear Methods

(Shouldow Depth).”

D 3740, “Practice for the Evaluation of Agencies Engaged in the Testing and/or

Inspection of Soil and Rock as Used in Engineering Design and Construction.”

D 4253, “Test Methods for Maximum Index Density and Unit Weight of Soils Using a

Vibratory Table.”

D 4254, “Test Method for Minimum Index Density and Unit Weight of Soils and

Calculation of Relative Density.”
Geotechnical Stability

2-32

D 4643, “Test Method for Determination of Water (Moisture) Content of Soil by the

Microwave Oven Method”

D 4718, “Practice for Correction of Unit Weight and Water Content for Soils Containing

Oversize Particles.”

D 4914, “Test Methods for Density of Soil and Rock In Place by the Sand Replacement

Method in a Test Pit.”

D 5030, “Test Method for Density of Soil and Rock in Place by the Water Replacement

Method in a Test Pit.”

Denson, R.H., et al. NUREG/CR–5041, “Recommendations to the NRC for Review Criteria for

Alternative Methods of Low-Level Radioactive Waste Disposal.” Washington, DC: NRC. 1987.

Department of the Navy. “Foundations and Earth Structures.” NAVFAC DM–7.2. May 1982a.

–––––. “Soil Dynamics, Deep Stabilization, and Special Geotechnical Construction.” NAVFAC

DM–7.3. May 1982b.

NRC. NUREG/CR–3356, “Geotechnical Quality Control: Low-Level Radioactive Waste and

Uranium Mill Tailings Disposal Facilities.” Washington, DC: NRC. 1983.

–––––. NUREG/CR–2684, “Rock Riprap Design Methods and Their Applicability to Long-Term

Protection of Uranium Mill Tailings Impoundments.” Washington, DC: NRC. 1982.

–––––. Regulatory Guide 1.132, “Site Investigations for Foundations of Nuclear Power Plants.”

Rev. 1. Washington, DC: NRC, Office of Standards Development. March 1979.

–––––. Regulatory Guide 1.138, “Laboratory Investigations of Soils for Engineering Analysis

and Design of Nuclear Power Plants.” Washington, DC: NRC, Office of Standards

Development. April 1978.

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

Retention Systems for Uranium Mills.” Rev. 2. Washington, DC: NRC, Office of Standards

Development. 1977.

Wu, T.H. “Effect of Vegetation on Slope Stability: Soil Reinforcement and Moisture Effects on

Slope Stability.” Transportation Research Record 965. National Research Council,

Transportation Research Board. 1984.
Geotechnical Stability

2-33

2.7 Disposal Cell Hydraulic Conductivity

2.7.1 Areas of Review

The staff should review test results, calculations, the technical bases for disposal cell design

hydraulic conductivity values, the field testing program, and the quality control program.

2.7.2 Review Procedures

The reviewer should examine the geotechnical design aspects of the disposal cell to ensure

that the disposal cell cover component has a minimal hydraulic conductivity, to limit radon

emissions from, and water infiltration into, stabilized mill tailings. The geotechnical reviewer

should coordinate with the water resources protection reviewer (see standard review plan

Chapter 4.0) to ensure that regulatory requirements for ground-water protection can be met by

the proposed radon barrier.

The reviewer should verify that an adequate technical basis has been presented for the design

hydraulic conductivity (K) value for the disposal cell cover. For any situation in which a K<107

cm/sec is proposed by the licensee, the staff should verify that either a test fill program will be

undertaken to verify the constructability to achieve the desired K value, or the reclamation plan

narrative and accompanying analyses have adequately demonstrated the acceptability of the

design K value, considering technical papers on this subject (e.g., Rogowski, 1990; Panno, et

al., 1991; Benson and Daniel, 1990). If the reclamation plan acceptably demonstrates that field

testing is not required, the reviewer should document the technical basis in the technical

evaluation report. If field testing is required, the staff should ensure that the test fill

specifications require that the hydraulic conductivity value be verified by in-place testing with

double-ring infiltrometers or other approved methods. 

The test reviewer should examine the test fill construction plan and verification program for

adequacy, including such aspects as (1) use of proper procedures and equipment for

placement and compaction operations; (2) verification of the material and thickness for the

barrier test zone; (3) comparison of gradation, bentonite amendment, and moisture/density

testing with specifications; (4) review of the quality control plan; and (5) review of the proposed

construction schedule.

2.7.3 Acceptance Criteria

The analysis of disposal cell hydraulic conductivity will be acceptable if it meets the

following criteria:

(1) A sufficient technical basis is provided for the design hydraulic conductivity (K) value for

the disposal cell.

The hydraulic conductivity is minimized by compacting fine-grained soil for a sufficient

depth above the stabilized tailings. Natural borrow soils having insufficient silt and clay

content to effectively reduce the hydraulic conductivity of the barrier can be amended

with bentonite for improved effectiveness. (Note that construction issues are discussed
Geotechnical Stability

2-34

separately using standard review plan Section 2.6.)

(2) A field testing program adequate to verify the constructability of the disposal cell with a

design hydraulic conductivity K<107

 cm/sec is provided unless the reclamation plan

demonstrates that field testing is not required (Benson and Daniel, 1990; NRC, 1979).

To meet the U.S. Environmental Protection Agency (EPA) ground-water standards,

designers of disposal cells for mill tailings sites are proposing increasingly smaller

design hydraulic conductivity (K) values. It is not unusual for laboratory permeability test

values to yield results of 108

 to 1010 cm/sec. Such tests are performed on compacted

soil samples considered by the design engineer to represent the soil to be used for the

disposal cell. However, several technical papers (Rogowski, 1990; Panno et al., 1991;

Benson and Daniel, 1990) have raised serious questions concerning the exclusive use

of laboratory testing for demonstrating hydraulic conductivity values in those cases in

which a radon barrier K-value less than 107

 cm/sec is specified. On the basis of these

technical papers, field testing is necessary to confirm the radon barrier hydraulic

conductivity, since construction operations and soil material variability can create

preferred pathways, joints, seams, holes, and flaws that effectively increase the value of

this parameter. Test results should take into consideration the variability and

uncertainty in site conditions and material properties. The test results should be

properly documented and available for inspection.

(3) An appropriate quality control program is followed for the field testing to determine

hydraulic conductivity (NRC, 1983).

For all cases in which K<107

 cm/sec and the test fill program requirement has been

defined, specifications and related documents (Remedial Action Inspection Plan, etc.)

will require an adequate quality control program. An acceptable quality control program

should contain mechanisms to ensure that as-built construction duplicates the test fill

construction techniques on the cell barrier (NRC, 1983). The objective of the quality

control program will be to provide assurance that uniform and high-quality construction

of the cell barrier has been achieved. Records for implementation of the quality control

program during the construction of the cell barrier should be properly maintained and

available for inspection.

(4) A reasonable construction schedule is proposed. The proposed construction schedule

should promote completion of the radon barrier as expeditiously as practical after

ceasing operations in accordance with a written, Commission-approved

reclamation plan.

2.7.4 Evaluation Findings

If the staff review as described in standard review plan Section 2.7 results in the acceptance of

the disposal cell hydraulic conductivity, the following conclusions may be presented in the

technical evaluation report:

The staff has completed its review of the disposal cell hydraulic conductivity at the 
Geotechnical Stability

2-35

 uranium mill facility. This review included an evaluation using the review

procedures in Section 2.7.2 and the acceptance criteria outlined in Section 2.7.3 of

this standard review plan.

The licensee has acceptably evaluated the disposal cell cover materials hydraulic conductivity

by providing a sufficient technical basis for the design K-value for the disposal cell. A field

testing program adequate to verify the constructability of the disposal cell with a hydraulic

design conductivity of K<107

 cm/sec is presented. The applicant followed an acceptable

quality control program for the field testing to determine the hydraulic conductivity.

On the basis of the information presented in the application and the detailed review conducted

of the disposal cell hydraulic conductivity at the uranium mill facility, the NRC

staff concludes that the disposal cell hydraulic conductivity and associated conceptual and

numerical models provide an acceptable input to the demonstration of compliance with the

following criteria in 10 CFR Part 40, Appendix A: Criterion 4(c), which provides requirements

for the embankment and cover slopes for tailings and Criterion 6(1), which requires that 

impoundment designs provide reasonable assurance of control of radiological hazards to be

effective for 1,000 years to the extent reasonably achievable, and in any case, for at least 200

years.

2.7.5 References

American Society for Testing and Materials Standards:

D 2434. “Test Method for Permeability of Granular Soils (Constant Head).”

D 3385. “Test Method for Infiltration Rate of Soils in Field Using DoubleRing Infiltrometers.”

D 5093. “Test Method for Field Measurement of Infiltration Rate Using a Double-Ring

Infiltrometer With a Sealed Inner Ring.”

Benson, C.H. and D.E. Daniel. “Influence of Clods on Hydraulic Conductivity of Compacted

Clay.” ASCE Journal of Geotechnical Engineering. Vol. 116, No. 8. pp. 1,231–1,248. 1990.

NRC. NUREG/CR–3356, “Geotechnical Quality Control: Low-Level Radioactive Waste and

Uranium Mill Tailings Disposal Facilities.” Washington, DC: NRC. 1983.

–––––. Regulatory Guide 1.132, “Site Investigations for Foundations of Nuclear Power Plants.”

Rev. 1. Washington, DC: NRC, Office of Standards Development. March 1979.

Panno, S.V., et al. “Field-Scale Investigation of Infiltration Into a Compacted Soil Liner.

Ground Water. Vol. 29, No. 6. pp. 914–921. 1991.

Rogowski, A.S. “Relationship of Laboratory- and Field-Determined Hydraulic Conductivity in

Compacted Clay Layer.” EPA/600/S2–90/025. Cincinnati, Ohio: Risk Reduction Engineering

Laboratory. 1990.
3-1

3.0 SURFACE WATER HYDROLOGY AND EROSION PROTECTION

3.1 Hydrologic Description of Site

Criterion 1 of 10 CFR Part 40, Appendix A, addresses the general goals of siting and designing

facilities to provide for permanent isolation of tailings, and minimizing the potential for

dispersion by natural forces, without the need for active maintenance. Information presented in

Section 3.1 will be used in later sections of this standard review plan to assess the ability of the

site and the site design to meet this and other requirements of 10 CFR Part 40.

It is important to note that the siting criteria presented in 10 CFR Part 40, Appendix A are

intended to apply to uranium mills that have not yet been constructed. For many, if not most,

uranium mills, reclamation plans are developed for sites that have existed for several decades. 

In fact, many mills were producing uranium before the siting criteria were developed. 

Therefore, the staff concludes that Criterion 1 is more relevant to new facilities (or modifications

to old facilities) than to facilities that existed before regulations were developed.

3.1.1 Areas of Review

The staff should review hydrologic site characterization information, including (1) identification

of the relationships of the site to surface-water features in the site area and (2) identification of

mechanisms, such as floods and dam failures, that may require special design features to be

implemented. This review requires identification of the hydrologic characteristics of streams,

lakes (e.g., location, size, shape, drainage area), and existing or proposed water control

structures that may adversely affect the long-term stability of the site design features.

3.1.2 Review Procedures

The staff should evaluate the completeness of the information and data, by sequential

comparison with information available from references. On the basis of the description of the

hydrosphere (e.g., geographic location and regional hydrologic features), potential site flood

mechanisms are identified. The information normally presented is not amenable to

independent verification, except through cross-checks with available publications related to

hydrologic characteristics of the site region and through observation during site visits. 

The staff should also analyze geomorphic considerations, as described in Section 1 of this

standard review plan. On the basis of these analyses, the staff should estimate the potential for

geomorphic instability to occur and to have a significant effect on the ability of the site and its

protective features to prevent flood intrusion and erosion over a long period of time. If

geomorphic problems are identified, the staff should give particular attention to several areas of

the design, depending on site conditions and potential for geomorphic changes to occur. These

areas include the (1) apron and toe of the disposal cell, (2) intersection of natural gullies with

erosion protection features, and (3) diversion channel outlets. A detailed discussion of the

erosion protection design for these and other features is given in Section 3.4.2 of this standard

review plan.
Surface Water Hydrology and Erosion Protection

3-2

3.1.3 Acceptance Criteria

The hydrologic description of the site will be considered acceptable if: 

(1) The description of structures, facilities, and erosion protection designs is sufficiently

complete to allow independent evaluation of the impact of flooding and intense rainfall. 

(2) Site topographic maps are of good quality and of sufficient scale to allow independent

analysis of pre- and post-construction drainage patterns. 

(3) The reclamation plan contains sufficient information for the staff to independently

evaluate the hydraulic designs presented. In general, detailed information is needed for

each method that is used to determine the hydraulic designs and erosion protection

provided to meet NRC regulations. NUREG–1623 (NRC, 2002) discusses acceptable

methods for designing erosion protection to provide reasonable assurance of effective

long-term control and, thus, conform to NRC requirements. NUREG–1623 (NRC, 2002)

also provides discussions and technical bases for use of specific criteria to meet the

1,000-year longevity requirement, without the use of active maintenance. Specific

design methods are provided and form the primary basis for staff review of erosion

protection designs. 

3.1.4 Evaluation Findings

If the staff evaluation of hydrologic and hydraulic engineering aspects of the reclamation plan

confirms that the information acceptably characterizes the site and the site design features, the

following conclusions may be presented in the technical evaluation report: 

The staff has completed its review of the flooding potential at the uranium

mill facility. This review included an evaluation using the review procedures in Section 3.1.2

and acceptance criteria outlined in Section 3.1.3 of this standard review plan. 

On the basis of the information presented in the application and the detailed review conducted

of the flooding potential for the uranium mill facility, the NRC staff concludes

that (1) the flood analyses and investigations adequately characterize the flood potential at the

site, (2) the analyses of hydraulic designs are appropriately documented, and (3) the general

reclamation plan with respect to surface-water hydrology and erosion considerations,

represents a feasible plan, for complying with the requirements of 10 CFR Part 40, Appendix A. 

The characterization of flood potential and the documentation of the site design conform to the

requirements of Criterion 1 of 10 CFR Part 40, Appendix A, which requires a design that

provides for permanent isolation of tailings and minimizes disturbance and dispersion by

natural forces. 

3.1.5 References

NRC. NUREG–1623, “Design of Erosion Protection for Long-Term Stabilization.” 

Washington, DC: NRC. 2002.
Surface Water Hydrology and Erosion Protection

3-3

3.2 Flooding Determinations

3.2.1 Areas of Review

The staff should assess the flooding potential for the site, and should determine precipitation

potential, precipitation losses, runoff response characteristics, and peak flow estimates for the

probable maximum flood or project design flood (if a flood less than the probable maximum

flood is used). The staff should review the following design analyses: (1) the analyses and

justification for the use of a flood less than the probable maximum flood, if applicable; (2) the

probable maximum precipitation potential and resulting runoff for site drainage and for drainage

areas adjacent to the site; and (3) the modeling of physical rainfall and runoff processes to

estimate flood conditions at the site.

The assessment of flooding also should include a review of possible geomorphic changes that

could affect the erosion protection design for the site. As applicable, the staff should review the

following: (1) identification of types of geomorphic instability; (2) changes to, and impacts

associated with, flooding and flood velocities from geomorphic changes; and (3) mitigative

measures to reduce or control geomorphic instability. This information must be reviewed

to determine the acceptability of hydraulic engineering designs to mitigate the

geomorphic conditions and to avoid the need for ongoing active maintenance.

The assessment of flooding should also include a review of potential dam failures, if upstream

reservoirs exist. Peak water levels, flood routing procedures, and velocities should be reviewed

in the determination of potential hazards because of failure of upstream water control structures

from either seismic or hydrologic causes. If an existing analysis concludes that seismic or

hydrologic events will not cause failures of upstream dams and produce the governing flood at

the site, the analysis should be reviewed to verify that information that supports such a

conclusion (e.g., record of contact with dam designers) is included. If an analysis is provided

that concludes that a dam failure flood from a probable maximum flood or a seismically induced

flood is the design-basis flood, the computations should be reviewed to verify that appropriate

and/or conservative model input parameters have been used.

3.2.2 Review Procedures

The evaluation of flooding is, for review purposes, separated into two parts: (1) flooding on

large adjacent streams, as applicable, and (2) localized flooding on drainage channels and

protective features. The acceptability of using the probable maximum flood as the design flood

event is presented in Section 2.2.1 of NUREG–1623 (NRC, 2002). The review procedure for

evaluating a probable maximum precipitation/probable maximum flood event is outlined in

Appendix D of NUREG–1623 (NRC, 2002). For large drainage areas, probable maximum flood

estimates approved by the U.S. Army Corps of Engineers and found in published or

unpublished reports of that agency, or generalized estimates, may be used instead of

independent staff-developed estimates. The staff should also assess flood history in the site

area by examining historic regional flood data. For many areas, historic flood peaks could be a

small percentage of the probable maximum flood. If the historic maximum floods exceed or

closely approximate the proposed probable maximum flood estimates, the staff should perform

a detailed evaluation to determine the basis for the estimates. The staff should compare basin
Surface Water Hydrology and Erosion Protection

3-4

lag times, rainfall distributions, soil types, and infiltration loss rates to determine if there is a

logical basis for the probable maximum flood values being less than historic floods. Without

such estimates, the staff should generally use U.S. Army Corps of Engineers models to

independently estimate probable maximum flood discharge and water levels at the site. If

detailed computer models are used, the staff should review the adequacy of the various input

parameters to the model, including, but not limited to, the following: drainage area, lag times

and times of concentration, design rainfall, incremental rainfall amounts, temporal distribution of

incremental rainfall, and runoff/infiltration relationships.

 

The staff should review the dam failure analyses presented in the reclamation plan or should

independently estimate the peak flows at the site. Often, it may be much easier to perform

simplified flood analyses assuming a dam failure, rather than detailed analyses of the seismic

resistance of a dam. In such cases, the staff should review those simplified flood analyses

using the procedures outlined in standard review plan Section 3.3.4. 

The staff should evaluate the information presented in the reclamation plan using procedures

found in Appendix C of NUREG–1623 (NRC, 2002) in those cases in which it is documented

that it is impractical to design erosion protection features for an occurrence of the probable

maximum flood. These procedures contain detailed information regarding justification of a

stability period of less than 1,000 years. To assure that minimum NRC requirements are met,

the staff should independently check and evaluate the ability of the design to resist such

flood events.

In the detailed review of flooding, the staff should carefully consider the following factors that

are important in determining a local probable maximum precipitation/probable maximum

flood event:

• Determination of Design Rainfall Event. The staff should consult appropriate

hydrometeorological reports and determine that correct values of the 1- and 6-hour

probable maximum precipitation events, as applicable, have been given.

• Infiltration Losses. The staff should check calculations to verify that appropriate values

of infiltration have been selected.

• Times of Concentration. The staff should verify that appropriate methods (depending on

the slope, configuration, etc.) have been selected. The staff should independently

verify that the methods selected compare reasonably well with various

velocity-based methods.

• Rainfall Distributions. The staff should verify that the rainfall distributions (particularly

the 21⁄2-, 5-, and 15-minute distributions) compare well with the distributions suggested

in Appendix D to NUREG–1623 (NRC, 2002).

For dam failures, the staff should review estimates of flood potential and water levels. 

Depending on the potential for flooding, the staff should verify that the dam failure analyses are

either realistic or conservative by determining locations and sizes of upstream dams, assuming
Surface Water Hydrology and Erosion Protection

3-5

an instantaneous failure (complete removal) of the dam embankment, and computing the peak

outflow rate.

If this simplified analysis indicates a potential flooding problem, the analysis may be repeated

using more refined techniques, and the staff may request additional information and data. 

Detailed failure models, such as those of the Army Corps of Engineers and National Weather

Service, will be used to identify the outflows, failure modes, and resultant water levels at

the site.

Assessments of flooding will be used to determine the acceptability of hydraulic engineering

design to avoid the need for ongoing active maintenance at the site.

If a flood less than a probable maximum flood can cause dam failure and is proposed as the

design-basis flood, the staff should employ the review procedures outlined above to determine

the impracticality of designing for a probable maximum flood and to determine the acceptability

of the flood used.

3.2.3 Acceptance Criteria

The flooding determinations for the site will be considered acceptable if: 

The designs conform to the suggested criteria in Appendix D to NUREG–1623 (NRC, 2002). 

NUREG–1623 (NRC, 2002) discusses acceptable methods for designing erosion protection to

provide reasonable assurance of effective long-term control and to meet NRC requirements. It

also presents discussions and technical bases for use of specific criteria to meet the 1,000-year

longevity requirement without the use of active maintenance. Acceptable design methods are

presented and form the primary basis for staff review of erosion protection designs. These

methods were derived from regulatory requirements, other regulatory guidance, staff

experience, and various technical studies.

Information pertinent to computation of the design flood is submitted in sufficient detail to

enable the staff to perform an independent flood estimate, Specifically:

• Model input parameters are adequate.

• Staff and the reclamation plan estimates of flood levels and peak discharges are

in agreement.

• Computational methods for design flood estimates are adequate.

“Worst conditions” postulated in the analysis of upstream dam failures are (1) an approximate

25-year flood on a normal operating reservoir pool level coincident with the dam-site equivalent

of the earthquake for which the remedial action project is designed, (2) a flood of about one-half

the severity of a probable maximum flood on a normal reservoir pool level coincident with the

dam-site equivalent of one-half of the earthquake for which the remedial action project is

designed; and (3) a probable maximum flood (or design flood) on a normal reservoir pool. 
Surface Water Hydrology and Erosion Protection

3-6

Conditions 1 and 2 are applied when the dam is not designed with adequate seismic resistance;

Condition 3 is applied when the dam is not designed to safely store or pass the design flood. 

If the proposed design is based on less than a probable maximum flood event, the licensee

offers reasonable assurance of conforming to the stability requirement of at least 200 years. 

Dam failure analyses are either realistic or conservative, and include locations and sizes of

upstream dams, instantaneous failure (complete removal) of the dam embankment, and

compute the peak outflow rate.

3.2.4 Evaluation Findings

If the staff evaluation of hydrologic and hydraulic engineering aspects of the reclamation plan

confirms that the assessments of flooding are acceptable, the following conclusions may be

presented in the technical evaluation report.

The staff has completed its review of the flooding potential at the uranium mill

facility. This review included an evaluation using the review procedures in Section 3.2.2 and

the acceptance criteria outlined in Section 3.2.3 of this standard review plan.

On the basis of information presented in the application and the detailed review conducted of

the flooding potential for the uranium mill facility, the NRC staff concludes

that the flood analyses and investigations adequately characterize the flood potential at the site

and that the surface water hydrology and flooding considerations represent a feasible plan for

meeting the requirements of 10 CFR Part 40, Appendix A. 

The mill tailings at the uranium mill facility will be protected from flooding

and erosion by an engineered rock riprap layer that has been designed in accordance with the

guidance suggested by the staff. Flood analyses presented by the licensee demonstrate that

this erosion protection is adequate, based on (1) selection of proper rainfall and flooding

events; (2) selection of appropriate parameters for determining flood discharges; and

(3) computation of flood discharges, using appropriate and/or conservative methods. 

The licensee presented analyses to show that the site is located in an area rarely flooded by

off-site floods and that it is protected from direct on-site precipitation and flooding. The erosion

protection is large enough to resist flooding from the shallow depths and minimal forces of

floods occurring from a probable maximum flood in the upstream drainage area. The staff

therefore concludes that the erosion potential at the proposed site has been acceptably

minimized, since any flooding at the site is mitigated by the erosion protection, and the forces

associated with off-site floods are minimal. The staff also concludes that, because the rainfall

and flooding events have very low probabilities of occurrence over a 1,000-year period, no

damage to erosion protection is expected from these, or more frequent, events. Therefore,

maintenance or repair of damage will not be necessary. 

On the basis of the information presented in the application and the detailed review conducted

of the flooding potential for the uranium mill facility, the NRC staff concludes

that the flood analyses contribute to meeting the following requirements of 10 CFR Part 40,
Surface Water Hydrology and Erosion Protection

3-7

Appendix A: Criterion 1, requiring that erosion, disturbance, and dispersion by natural forces

over the long term are minimized and that the tailings are disposed of in a manner that does not

require active maintenance to preserve conditions of the site; Criterion 4(a), requiring that

upstream rainfall catchment areas are minimized to decrease erosion potential and to resist

floods that could erode or wash out sections of the tailings disposal area; Criterion 6(1),

requiring that the design be effective for a period of 200–1,000 years; and Criterion 12,

requiring that active maintenance is not necessary to preserve isolation. 

3.2.5 References

NRC. NUREG–1623, “Design of Erosion Protection for Long-Term Stabilization.” 

Washington, DC: NRC. 2002.

3.3 Water Surface Profiles, Channel Velocities, and Shear Stresses

3.3.1 Areas of Review

Depending on the type of computational models used, the staff should review the model,

including the determination of flooding depths, channel velocities, and/or shear stresses used to

determine riprap sizes needed for erosion protection. The staff should review the various

detailed computations for each model and should review the acceptability of the input

parameters to the model. The staff should estimate the flood levels, velocities, shear stresses,

and magnitudes, as described below. The review should be oriented toward verifying that the

site will not require ongoing active maintenance.

3.3.2 Review Procedures

Using the guidance presented in Appendix D to NUREG–1623 (NRC, 2002) the staff should

verify that localized flood depths, velocities, and shear stresses used in models for rock size

determination or soil cover slope analysis are acceptable. For off-site flooding effects, the staff

should verify that computational models have been correctly and appropriately used and that

the data from the model have been correctly interpreted. The staff should verify that acceptable

models and input parameters have been used in all the various portions of the flood analyses

and that the resulting flood forces have been adequately accommodated. 

Staff estimates may be made independently from basic data, by detailed review and checking

of the reclamation plan analyses, or by comparison with other estimates that have been

previously reviewed in detail. The evaluation of the adequacy of the estimates is a matter of 
Surface Water Hydrology and Erosion Protection

3-8

engineering judgment, and is based on the confidence in the estimate, the degree of

conservatism in each parameter used in the estimate, and the relative sensitivity of each

parameter as it affects the flood level, flood velocity, or design of the erosion protection.

The staff review should evaluate whether ongoing active maintenance will be required at

the site.

3.3.3 Acceptance Criteria

The water surface profiles, channel velocities, and shear stresses calculated for the site will be

considered acceptable if: 

The proposed designs conform to the suggested criteria in Appendix D to NUREG–1623

(NRC, 2002). NUREG–1623 (NRC, 2002) discusses acceptable methods for designing erosion

protection to provide reasonable assurance of effective long-term control and to comply with

NRC requirements. This document also contains discussions and technical bases for use of

specific criteria to meet the 1,000-year longevity requirement without the use of active

maintenance. Specific design methods are presented, and reasonable similarity to these

methods forms the primary basis for staff acceptance of erosion protection designs.

Specifically:

• Localized flood depths, velocities, and shear stresses used in models for rock size

determination or soil cover slope analysis conform to the guidance presented in

Appendix D to NUREG–1623 (NRC, 2002). 

• For off-site flooding effects, computational models have been correctly and appropriately

used and the data from the models have been correctly interpreted. 

• Acceptable models and input parameters have been used in all the various portions

of the flood analyses and the resulting flood forces have been

adequately accommodated.

3.3.4 Evaluation Findings

If the staff evaluation of hydrologic and hydraulic engineering aspects of the reclamation plan

confirms that the assessments of flooding are acceptable, the following conclusions may be

presented in the technical evaluation report: 

The staff has completed its review of the flooding models at the uranium mill

facility. This review included an evaluation using the review procedures in Section 3.3.2 and

the acceptance criteria outlined in Section 3.3.3 of this standard review plan.

On the basis of the information presented in the application and the detailed review conducted

of the flooding models for the uranium mill facility, the NRC staff concludes that

flood velocities and forces associated with flooding at the site have been acceptably computed. 
Surface Water Hydrology and Erosion Protection

3-9

The mill tailings will be protected from flooding and erosion by an engineered rock riprap layer

that has been designed in accordance with the guidance suggested by the staff. Flood

analyses presented by the licensee demonstrate that adequate protection is provided by

(1) selection of proper models to assess rainfall and flooding events, (2) selection of

appropriate parameters for models for determining flood forces, and (3) computation of flood

forces using appropriate and/or conservative methods.

The staff considers that the riprap layers proposed will not require active maintenance over the

1,000-year design life, because the licensee adopted models that conservatively compute flood

forces used to design the erosion protection. Thus, the use of conservative design parameters

will result in no damage to the erosion protection designed using those methods. The staff

further concludes that the hydraulic design features are sufficient to protect the tailings from

flood forces that are very large and have very low probabilities of occurrence over a 1,000-year

period. Therefore, maintenance of the rock layers will not be necessary.

The staff concludes that the analyses and models used at the uranium mill

facility contribute to meeting the following requirements of 10 CFR Part 40, Appendix A: 

Criterion 1, requiring that erosion, disturbance, and dispersion by natural forces over the long

term are minimized and that the tailings are disposed of in a manner that does not require

active maintenance to preserve conditions of the site; Criterion 6(1), requiring the design to be

effective for a period of 200 to 1,000 years; and Criterion 12, requiring that active ongoing

maintenance is not necessary o preserve isolation of the tailings. 

3.3.5 Reference

NRC. NUREG–1623, “Design of Erosion Protection for Long-Term Stabilization.” 

Washington, DC: NRC. 2002.

3.4 Design of Erosion Protection

3.4.1 Areas of Review

Design details and analyses pertinent to the following aspects of erosion protection will be

reviewed, as applicable:

(1) Erosion protection for slopes and channel banks to protect against flooding from nearby

large streams.

(2) Erosion protection for the top and side slopes of the pile.

(3) Erosion protection for the apron/toe area of the side slope.

(4) Erosion protection for drainage and diversion channels, including channel outlets.

(5) Durability of the erosion protection.
Surface Water Hydrology and Erosion Protection

3-10

(6) Construction considerations, including specifications, quality assurance programs,

quality control programs, and inspection programs.

In Section 3.4.2.4 (below), sedimentation in diversion channels is also addressed. Criterion 4(f)

of 10 CFR Part 40, Appendix A, suggests that deposition of sediment in impoundment areas

should be considered for enhancing the cover thickness. The staff considers it important to

differentiate between beneficial and detrimental sediment accumulations. For example, if

sediment could be conveniently routed to the middle of an impoundment, without long-term

erosion or ponding of runoff that could affect ground-water conditions, such deposition may

enhance long-term cover thickness. However, this is difficult to actually achieve. The major

problem with sediment is that it tends to accumulate in diversion channels that are constructed

on relatively flat slopes. High-velocity runoff from steep slopes carries sediment into lowvelocity diversion channels, and that sediment can eventually accumulate and completely block

the channel. Thus, it can be seen that some sediment buildup is good and some is bad. The

review should evaluate the need for ongoing active maintenance of the site.

3.4.2 Review Procedures

The staff should check the analyses in the reclamation plan or perform independent review

analyses of floods, flood velocities, and rock durability according to the guidelines in

Appendix D to NUREG–1623 (NRC, 2002). The following areas should be evaluated.

(1) Banks of Natural Channels

The staff should review designs for riprap to be placed on the side slopes of a reclaimed

pile or on natural channel banks to protect against erosive velocities from floods on

large rivers. Guidance is presented in Appendix D to NUREG–1623 (NRC, 2002) for

assessing floods, determining input parameters to models, and determining

riprap requirements.

(2) Top Slope and Side Slopes 

The staff should review input parameters to calculations and models according to the

recommendations given in Appendix D to NUREG–1623 (NRC, 2002) and referenced

technical procedures. The staff should assess the design flow rate, the depth of flow,

angle of repose, specific gravity, and other parameters. For both the top and side

slopes, the rock sizes should be checked using the recently developed, simplified

procedures discussed in NUREG–1623 (NRC, 2002).

(3) Apron/Toe 

The design of the apron and toe is reviewed by verifying that several design features

in this area have been properly designed, in accordance with the recommendations

in NUREG–1623 (NRC, 2002). 

For the lower end of the side slope where it meets the toe, the staff should verify that

proper consideration has been given to the potential occurrence of increased shear
Surface Water Hydrology and Erosion Protection

3-11

forces resulting from turbulence and energy dissipation produced by hydraulic jumps,

when the flow transitions from supercritical to subcritical. The staff should verify that

appropriate design criteria have been used to increase the rock size to account for the

increased velocities or shear forces.

For the main area of the toe, the staff should assure that appropriate methods have

been used to design the riprap, depending on the magnitude of the slope of the toe.

For the downstream end of the toe, the staff should verify that acceptable assumptions

have been made regarding the assumed collapse of the rock into scoured areas to

prevent gully intrusion. Flow concentrations, collapsed slopes, and computational

models should be evaluated.

For the natural ground area at the downstream end of the toe, the staff should verify that

appropriate methods have been used to compute scour depths and that natural erosion

will not adversely affect long-term stability.

(4) Diversion Channels 

Using the criteria and guidance presented in Appendix D to NUREG–1623 (NRC, 2002),

the staff should evaluate the design of diversion channels in several critical areas.

For the main channel area, the staff should verify that appropriate models and input

parameters have been used to design the erosion protection. The staff should assure

that flow rates, flow depths, and shear stresses have been correctly computed.

For the channel side slopes, the staff should verify that the side slopes are capable of

resisting flow velocities and shear stresses from flows that occur directly down the side

slope. This occurs often when diversion channels are constructed perpendicular to

natural gullies (which discharge into the diversion channel). The shear forces in these

locations often greatly exceed the forces produced by flows in the channel, particularly

when the slope of the natural ground in the area is greater than the slope of the

diversion channel.

For the outlet of the diversion channel, the staff should evaluate the design of erosion

protection to assure that erosion in the discharge area (normally a natural gully, swale,

or channel) has been adequately addressed. Designs similar to apron/toe designs

should be evaluated to determine their resistance to erosion. Appendix D to

NUREG–1623 (NRC, 2002) discusses acceptable methods for designing channel

outlets.

For the entire length of the diversion channel, the staff should evaluate the effects of

sediment accumulations on flow velocities, channel capacity, and need for increased

rock size. Particular attention should be given to designs in which steep natural streams

discharge into relatively flat diversion channels, greatly increasing the potential for

blockage of the channel. Appendix E to NUREG–1623 (NRC, 2002) discusses

acceptable methods for assessing sedimentation in diversion channels.
Surface Water Hydrology and Erosion Protection

3-12

(5) Rock Durability 

The staff should review the results of durability testing of proposed rock sources to

assure that durable rock will be used. Appendix D to NUREG–1623 (NRC, 2002)

presents a detailed method for evaluating rock quality for various locations and 

applications. If durable rock is not available to the site, to the extent practical, the

reviewer should review the alternative proposed by the applicant and the associated

analysis to assure that the alternative provides reasonable assurance that the radon

barrier will be effective for 1,000 years, to the extent reasonably achievable, and in any

case, for at least 200 years.

(6) Construction Considerations

The staff should review the plans, specifications, inspection programs, and quality

assurance/quality control programs to assure that adequate measures are being taken

to construct the design features according to accepted engineering practices. The staff

should compare the information presented with typical programs used in the

construction industry. Appendix F to NUREG–1623 (NRC, 2002) contains examples of

acceptable specifications and testing programs that were approved by the staff and

actually applied at several sites.

(7) The review shall specifically evaluate whether the erosion protection design is sufficient

to avoid the need for ongoing active maintenance at the site.

3.4.3 Acceptance Criteria

The design of erosion protection for the site will be considered acceptable if: 

The proposed designs conform to the suggested criteria in NUREG–1623 (NRC, 2002) . 

NUREG–1623 (NRC, 2002) discusses acceptable methods for designing erosion protection to

provide reasonable assurance of effective long-term control and to comply with NRC

requirements. This document also contains discussions and technical bases for use of specific

criteria to meet the 1,000-year longevity requirement without the use of active maintenance. 

Specific design methods are presented, and reasonable similarity to these methods forms the

primary basis for staff acceptance of erosion protection designs. NUREG–1623 (NRC, 2002)

updates and expands the final staff technical position (NRC, 1990).

If active maintenance is proposed as an alternative to the designs suggested above, such an

approach will be found acceptable if the following criteria are met:

(1) The maintenance approach must achieve an equivalent level of stabilization and

containment and protection of public health, safety, and the environment. 

(2) The licensee must demonstrate a site-specific need for the use of active maintenance

and an economic benefit.
Surface Water Hydrology and Erosion Protection

3-13

(3) The licensee must provide funding for the maintenance by increasing the amount of the

required surety. The staff should determine if the licensee’s estimate of funding

required for active maintenance is adequate. The licensee should also work with the

long-term custodian to assess any additional funding requirements related to long-term

surveillance and monitoring.

3.4.4 Evaluation Findings

If the staff evaluation of hydrologic and hydraulic engineering aspects of the reclamation plan

confirms that the erosion protection designs are acceptable, the following conclusions may be

presented in the technical evaluation report: 

The staff has completed its review of the design of erosion protection at the

 uranium mill facility. This review included an evaluation using the review

procedures in Section 3.4.2 and the acceptance criteria outlined in Section 3.4.3 of this

standard review plan.

On the basis of the information presented in the application and the detailed review conducted

of the erosion protection features, the staff concludes that the designs are acceptable.

The mill tailings will be protected from flooding and erosion by an engineered rock riprap layer. 

The riprap has been designed in accordance with the guidance suggested by the NRC staff. 

The staff considers that erosion protection that meets that guidance will provide adequate

protection against erosion and dispersion by natural forces over the long term. In addition to

the adequacy of the flood analyses discussed in standard review plan Sections 3.2 and 3.3, the

staff concludes that adequate erosion protection designs are provided by (1) use of appropriate

methods for determining erosion protection needed to resist the forces produced by the design

discharge, and (2) selection of a rock type for the riprap layer that will be durable and capable

of providing the necessary erosion protection for a long period of time. Further, the staff

considers that the riprap layers proposed will be durable over the 1,000-year design life, for the

following reasons: (1) the rock proposed for the riprap layers was evaluated using rock quality

procedures suggested by the staff and is not expected to deteriorate significantly over the

1,000-year design life; (2) the rock fragments are dense, resistant to abrasion, and free from

cracks, seams, and other defects; and (3) during construction, the rock layers will be placed in

accordance with appropriate engineering and testing practices, minimizing the potential for

damage, dispersion, and segregation of the rock. 

The riprap for the relatively flat top and side slopes is designed to be sufficiently large to

minimize erosion potential. The rock will be capable of resisting flooding and erosion,

depending on the slope selected. Thus, the staff concludes that the relatively steep slopes,

with their corresponding rock designs, are acceptable.

On the basis of its review of the designs for the uranium mill facility, the staff

concludes that the hydraulic designs contribute to meeting the requirements of 10 CFR Part 40,

Appendix A: (1) Criterion 1, requiring that erosion, disturbance, and dispersion by natural

forces over the long term are minimized and that the tailings are disposed of in a manner that

does not require active maintenance to preserve conditions of the site; (2) Criterion 4(c),
Surface Water Hydrology and Erosion Protection

3-14

requiring embankments and cover slopes to be relatively flat after stabilization to minimize

erosion potential and to provide conservative factors of safety that ensure long-term stability;

(3) Criterion 4(d), requiring that the rock cover reduces wind and water erosion to negligible

levels, including consideration of such factors as the shape, size, composition, and gradation of

the rock particles; (4) Criterion 4(f), requiring the design to promote deposition, where feasible;

(5) Criterion 6(1), requiring the design to be effective for 200 to 1,000 years; and (5) Criterion

12, requiring that active on-going maintenance is not necessary to preserve isolation. 

3.4.5 References

NRC. NUREG–1623, “Design of Erosion Protection for Long-Term Stabilization.” 

Washington, DC: NRC. 2002.

–––––. “Design of Erosion Protection Covers for Stabilization of Uranium Mill Tailings Sites.” 

Washington, DC: NRC. 1990.

3.5 Design of Erosion Protection Covers

3.5.1 Areas of Review

If a soil or vegetative cover is proposed, the following design details, calculations, and analyses

will be reviewed:

(1) Determination of allowable shear stresses and permissible velocities for the cover.

(2) Determination of allowable shear stresses and permissible velocities for the cover in a

degraded state, including the effects of fires, droughts, vegetation succession, and other

impacts to the ability of the cover to function without maintenance.

(3) Information on types of vegetation proposed and their abilities to survive

natural phenomena.

(4) Information, analyses, and calculations of input parameters to models used.

The review will consider whether the design of covers is sufficient to avoid the need for ongoing

active maintenance at the site.

3.5.2 Review Procedures

If a soil cover is proposed, the staff should evaluate the design using the general criteria

outlined in Appendix A to NUREG–1623 (NRC, 2002). Particular attention should be given to

the input parameters to various models.

(1) The staff should verify that the design flow rate includes an appropriate flow

concentration factor that reflects consideration of settlement, soil removal by sheet flow

and wind, degradation of the vegetation cover, intrusion of trees, blockage of flows by

fallen trees, etc.
Surface Water Hydrology and Erosion Protection

3-15

(2) The staff should verify that estimates of Manning’s “n” value correspond to the

vegetation cover proposed and are proper for estimating allowable shear stresses and

permissible velocities. 

(3) The staff should verify that appropriate values of allowable shear stresses and

permissible velocities have been used and conservatively reflect potential changes that

could occur to the cover over a long period of time as a result of fires, droughts,

diseases, vegetation succession, or general cover degradation.

(4) The staff should check analyses and/or independently calculate allowable slopes using

several different methods and ranges of input parameters. Using a range of flow

concentration factors, shear stresses, permissible velocities, “n” values, and models, the

staff should check the sensitivity of the analyses and should verify that reasonable and

appropriate values of input parameters have been selected.

If a sacrificial soil cover is proposed to meet the minimum 200-year stability requirement, the

staff should check the calculations using Appendix B to NUREG–1623 (NRC, 2002) and the

justification for reduction of the stability period using Appendix C to NUREG–1623 (NRC, 2002).

(5) The reviewer shall determine whether the design is adequate to avoid the need for

ongoing active maintenance at the site.

3.5.3 Acceptance Criteria

The design erosion protection covers for the site will be considered acceptable if:

The designs conform to the suggested criteria in NUREG–1623 (NRC, 2002). NUREG–1623

(NRC, 2002) discusses acceptable methods for designing erosion protection to provide

reasonable assurance of effective long-term control and, thus, meet NRC requirements. This

document also provides discussions and technical bases for use of specific criteria to meet the

1,000-year longevity requirement without the use of active maintenance. Specific acceptance

criteria for many of the review areas are presented and form the primary basis for staff review

of erosion protection designs. These criteria were derived from regulatory requirements, other

regulatory guidance, staff experience, and various technical references. 

If active maintenance is proposed as an alternative to the designs suggested above, such an

approach will be found acceptable if the following criteria are met:

(1) The maintenance approach must achieve an equivalent level of stabilization and

containment and protection of public health, safety, and the environment.

(2) The licensee must demonstrate a site-specific need for the use of active maintenance.

(3) The licensee must provide funding for the maintenance by increasing the amount of the

required surety. The licensee should also work with the long-term custodian to assess

any additional funding requirements related to long-term surveillance and monitoring.
Surface Water Hydrology and Erosion Protection

3-16

3.5.4 Evaluation Findings

If the staff’s evaluation of erosion protection covers confirms that the cover designs are

acceptable, the following conclusions may be presented in the technical evaluation report:

 

The staff has completed its review of the design of erosion protection covers at the

 uranium mill facility. This review included an evaluation using the review

procedures in Section 3.5.2 and the acceptance criteria outlined in Section 3.5.3 of this

standard review plan.

On the basis of its review, the staff concludes that the designs are acceptable and meet the

requirements of 10 CFR Part 40, Appendix A. 

The mill tailings will be protected from flooding and erosion by an engineered soil cover. The

staff considers that a satisfactory cover will provide adequate protection against erosion and

dispersion by natural forces over the long term. In addition to the adequacy of the flood

analyses discussed in standard review plan Sections 3.2 and 3.3, the staff concludes that

adequate cover designs are provided by:

(1) Use of appropriate methods for determining cover slopes needed to resist the forces

produced by the design discharge.

(2) Selection of a cover that will be capable of providing the necessary erosion protection

for a long period of time.

On the basis of the information presented in the application and the detailed review conducted

of the erosion protection covers for the uranium mill facility, the NRC staff

concludes that the cover designs contribute to meeting the following requirements of

10 CFR Part 40, Appendix A: Criterion 1, requiring that erosion, disturbance, and dispersion by

natural forces over the long term are minimized and that the tailings are disposed of in a

manner that does not require active maintenance to preserve conditions of the site;

Criterion 4(b), requiring siting and design such that topographic features provide good wind

protection; Criterion 4(c), requiring that embankments and cover slopes are relatively flat after

stabilization to minimize erosion potential and to provide conservative factors of safety;

Criterion 6(1), requiring the design to be effective for 200 to 1,000 years; and Criterion 12,

requiring that active ongoing maintenance is not necessary to preserve isolation.

3.5.5 References

NRC. NUREG–1623, “Design of Erosion Protection for Long-Term Stabilization.” 

Washington, DC: NRC. 2002.

3.6 General References

American Nuclear Society. “American National Standard for Determining Design Basis

Flooding at Power Reactor Sites.” ANSI/ANS–2.8. 1981.
Surface Water Hydrology and Erosion Protection

3-17

Bureau of Reclamation. "Comparison of Estimated Maximum Flood Peaks with Historic

Floods." Washington, DC: U.S. Department of the Interior. 1986.

–––––. “Design of Small Dams.” Second Edition. Washington, DC: U.S. Department of the

Interior. 1973.

Chow, V.T. Open Channel Hydraulics. New York, New York: McGraw-Hill Book

Company. 1959.

Crippen, J.R. and C.D. Bue. “Maximum Floodflows in the Conterminous United States.”

U.S. Geological Survey Water Supply Paper No. 1887. 1977.

Fread, D.L. “DAMBRK: The National Weather Service Dam-Break Flood Forecasting Model.” 

Silver Spring, Maryland: National Weather Service. Continuously updated.

Henderson, F.M. Open Channel Flow. New York, New York: MacMillan Company. 1971.

Interagency Advisory Committee on Water Data, Hydrology Subcommittee Working Group on

Probable Maximum Flood Risk Assessment. “Draft Report on the Feasibility of Assigning a

Probability to the Probable Maximum Flood.” June 1985.

Nelson, J.D., R.L. Volpe, R.E. Wardell, S.A. Schumm, and W.P. Staub. NUREG/CR–3397,

ORNL–5979, “Design Considerations for Long-Term Stabilization of Uranium Mill Tailings

Impoundments.” Washington, DC: NRC. October 1983.

NRC. “Design of Erosion Protection Covers for Stabilization of Uranium Mill Tailings Sites.” 

Final Staff Technical Position. Washington, DC: NRC. 1990.

–––––. “Standard Format and Content for Documentation of Remedial Action Selection at

Title I Uranium Mill Tailings Sites." Washington, DC: NRC. February 1989.

Simons, D.B. and F. Senturk. Sediment Transport Technology. Fort Collins, Colorado: Water

Resources Publications. 1977.

Stephenson, D. “Rockfill Hydraulic Engineering Developments in Geotechnical Engineering.” 

No.27. Elsevier Scientific Publishing Company. 1979.

Temple, D.M., et al. “Stability Design of Grass-Lined Open Channels.” Agricultural Handbook

Number 667. U.S. Department of Agriculture. 1987.

U.S. Army Corps of Engineers. “Flood Hydrograph Package.” HEC–1. Davis, California: 

Hydrologic Engineering Center. Continuously updated.

–––––. “Water Surface Profiles.” HEC–2. Davis, California: Hydrologic Engineering Center. 

Continuously updated.
Surface Water Hydrology and Erosion Protection

3-18

–––––. “Reservoir System Operation for Flood Control.” HEC–5. Davis, California: Hydrologic

Engineering Center. Continuously updated.

–––––. “Hydraulic Design Criteria.” Continuously updated and revised.

–––––. “Runoff from Snowmelt.” EM1110–2–1406. January 1980.

–––––. “Additional Guidance for Riprap Channel Protection.” ETL1110–2–120. May 1971.

–––––. “Hydraulic Design of Flood Control Channels.” EM1110–1601. July 1970.

–––––. “Policies and Procedures Pertaining to Determination of Spillway Capacities and

Freeboard Allowances for Dams.” EC1110–2–27. February 1968.

–––––. “Hydraulic Design of Spillways.” EM1110–2–1603. March 1965.

–––––. “Standard Project Flood Determinations.” EM1110–2–1411. March 1965.

–––––. “Interior Drainage of Leveed Urban Areas: Hydrology.” EM1110–2–1410. May 1965.

–––––. “Routing of Floods through River Channels.” EM1110–2–1408. March 1960.

–––––. “Backwater Curves in River Channels.” EM1110–2–1409. December 1959.

–––––. “Flood Hydrograph Analysis and Computations.” EM1110–2–1405. August 1959.

–––––. “Stone Protection.” CE 1308. January 1948.

Weather Bureau. “Hydrometeorological Reports.” (Now U.S. Weather Service).

Hydrometeorological Branch: Nos. 43, 49, and 55.
4-1

4.0 PROTECTING WATER RESOURCES

The protection of water resources is a process that encompasses two distinct strategies. The

first strategy is to prevent the spread of contaminants from disposal and processing sites into

ground water or surface water. This strategy requires the staff to ensure that operations and

decommissioning are conducted in such a manner as to minimize threats to ground water.

The second strategy is to mitigate the threat to public health and the environment from

contaminants that have already been mobilized—particularly through ground water

pathways—before initiation of decommissioning activities. This strategy applies only to those

sites where ground-water contamination already exists and requires staff to review existing or

proposed ground-water restoration activities to ensure that they will result in compliance with

regulatory requirements. The NRC exercises exclusive, pre-emptive jurisdiction over all

radiological and non-radiological ground-water contaminants from uranium mill tailings facilities,

in accordance with Commission direction in Staff Requirements Memorandum SECY 099-277

(NRC, 2000).

Use of this chapter should be tailored to the specific situation and phase of operation at each

site. The reviewer will select and emphasize the various aspects of the areas covered by this

standard review plan chapter. The judgment on the areas to be given attention during the

review is to be based on the specific licensee submittal being reviewed, an inspection of the

material presented, and prior knowledge of the site and its operating history.

This chapter presents a standard approach for reviewing, evaluating, and documenting the

evaluation findings for issues pertaining to water resource protection during the various phases

of the license termination process at licensed uranium mill sites. Review of information

concerning the protection of water resources shall be coordinated with the evaluation of the site

stratigraphy, structural and tectonic information, and surface water and erosion protection

information as described in standard review plan Chapters 1.0 and 3.0, respectively. Review

procedures in this chapter pertain to the following four types of documents that are submitted

for review by the staff:

(1) Licensees submit reclamation plans to obtain approval of surface reclamation and

decontamination work, including stabilization of mill tailings, and elimination (or isolation)

of present or potential contaminant sources. 

(2) Licensees submit corrective action plans during operations or during the license

termination process to obtain approval of ground-water restoration strategies at sites

where ground-water contamination has been detected.

(3) Licensees submit ground-water restoration completion reports to confirm that the

ground-water quality will remain stable after ground-water restoration strategies have

been implemented and that ground-water protection standards have been

correctly established.

(4) Long-term custodians submit long-term surveillance plans to describe the ground-water

monitoring activities that will be implemented by the custodian.
Protecting Water Resources

4-2

The ultimate objective of the review is to determine if the proposed reclamation plans and

corrective action plans will result in long-term compliance with 10 CFR Part 40, Appendix A. As

stated in 10 CFR Part 40, Criterion 5, “Criteria 5A-5D and new Criterion 13 incorporate the

basic ground-water protection standards imposed by the Environmental Protection Agency in

40 CFR Part 192, Subparts D and E (48 FR 45926; October 7, 1983), which apply during

operations and prior to the end of closure. Ground-water monitoring to comply with these

standards is required by Criterion 7A.” To meet this regulatory objective, the following issues

must be evaluated:

(1) Site characterization.

(2) Ground-water protection standards.

(3) Hazard and as low as is reasonably achievable assessment for alternate concentration

limits, as defined by 10 CFR Part 40, Appendix A, Criteria 5B(5) and 5B(6).

(4) Ground-water corrective action and monitoring plans.

Accordingly, this chapter contains a section for each of these areas. Discussions in this

chapter incorporate acceptable practices from all previous staff technical positions and

guidance documents pertaining to uranium mill tailings reclamation. This standard review plan

supercedes those documents. The NRC exercises exclusive jurisdiction over all radiological

and non-radiological ground-water contaminants from uranium mill tailings facilities.

4.1 Site Characterization

4.1.1 Areas of Review

The staff should review the characterization information, given the circumstances and life cycle

of a particular site, and the nature of the document under review (reclamation plan,

corrective-action plan). The staff should also evaluate regional and site-specific hydrologic

information related to both the former processing site and the proposed disposal site if they are

different. The hydrologic information should include both surface-water and ground-water

systems, along with any interrelations among those systems. Complete site characterization

should include or reference the following:

(1) Site background data that include descriptions of:

(a) The site history of mining and/or milling operations.

(b) Surrounding land and water uses.

(c) Site meteorological data.
Protecting Water Resources

4-3

(2) Ground-water and surface-water hydrology data, including:

(a) Descriptions of hydrogeology and ground-water conditions.

(b) Estimation of hydraulic and transport properties for each hydrogeologic unit.

(c) Descriptions of surface-water hydrology and estimations of ground-water and

surface-water interactions.

(d) Assessment of potential for flooding and erosion.

(3) Information concerning geochemical conditions and water quality, including: 

(a) Identification of constituents of concern.

(b) Determination of background ground-water quality.

(c) Confirmation of proper statistical analysis.

(d) Delineation of the nature and extent of contamination.

(e) Identification of contaminant source terms.

(f) Characterization of subsurface geochemical properties.

(g) Identification of attenuation mechanisms and estimation of attenuation rates.

(4) Human health and environmental risk evaluations, including:

(a) Radiological risks.

(b) Non-radiological risks.

(c) A summary of risk evaluations from the site environmental report.

4.1.2 Review Procedures

The level of effort necessary to adequately characterize a particular site depends on

site-specific circumstances. For example, if a particular site has no ground-water contamination

and tailings are disposed off site, there will be very little need for detailed site characterization in

support of water resources protection. Conversely, at a site with an existing source of

ground-water contamination, the site characterization must be sufficient to support selection of

cleanup strategies and to determine the level of risk to human health and the environment. 
Protecting Water Resources

4-4

There is not a single acceptable approach to conducting a site characterization, because the

appropriate level of site characterization is specific to the methods of tailings disposal and 

ground-water corrective action selected for a particular site. As such, the reviewer should:

(1) Thoroughly evaluate the characterization information using the acceptance criteria in

standard review plan Section 4.1.3, but reserve final judgment until all sections of the

application have been reviewed.

(2) Assess whether the level of detail and technical merit of the characterization are

sufficient to support the proposals, assumptions, and assertions in the application that

are used to demonstrate regulatory compliance.

4.1.3 Acceptance Criteria

Knowledge of the site is needed to evaluate the existing and potential contamination. This

characterization information shall include a description of activities and physical properties that

may affect water resources at the mill site. The site characterization will be acceptable if it

meets the following criteria:

(1) It contains a description of the site that is sufficient to assess the environmental impact

the former mill site may have on the surrounding area; the populations that may be

affected by such impacts; and meteorological conditions that may act to transport

contaminants off site. An acceptable site description will contain the following

specific information:

(a) A site history that includes:

(i) A list of the known leaching solutions and other chemicals used in the

milling process and their relative quantities in mill wastes. The list should

also identify any constituent listed in 10 CFR Part 40, Appendix A,

Criterion 13, that may have been disposed of in the tailings pile.

(ii) A description of the wastes generated at the site during milling

operations, waste discharge locations, types of retaining structures used

(e.g., tailings piles, ponds, landfills), quantities of waste generated, and a

chronology of waste management practices.

(iii) A summary of the known impacts of the site activities on the hydrologic

system and background water quality.

(iv) If applicable, descriptions of any human activities or natural processes

unrelated to the milling operation that may have altered the hydrogeologic

system. Such human activities include ground-water use, crop irrigation,

mine dewatering, ore storage, municipal waste land filling, oil and gas

development, or exploratory drilling. Natural processes include

geothermal springs, natural concentration of soluble salts by evaporation,

erosion processes, and ground-water/surface-water interactions.
Protecting Water Resources

4-5

(b) Information pertaining to surrounding land and water uses that includes:

(i) A general overview of water uses, locations, quantities of water available,

and the potential uses to which the quality of water is suited>

(ii) Definitions of the class-of-use category for each water source

(e.g., drinking water, agricultural, livestock, limited use).

(iii) Identification of potential receptors of present or future ground-water or

surface-water contamination.

(iv) Descriptions of non-mill-related human activities or natural processes that

may affect water quality or water uses (e.g., oil and gas development,

municipal waste landfills, crop irrigation, drought, and erosion).

Human water consumption is not the only water use that must be

considered in the review. Any use that may bring someone into contact

with the contaminated water must be considered when evaluating health

hazards. For example, non-potable, radon-contaminated water piped to

a public lavatory could pose a substantial health hazard. 

(c) Sufficient meteorologic data for the region, including rainfall, temperature,

humidity and evaporation data in sufficient detail to assess projected water

infiltration through the disposal cell.

Monthly averages are an acceptable means of presenting general meteorological

conditions; however, the reviewer shall ensure that extreme weather conditions

are adequately described.

(2) The ground-water and surface-water hydrology is described adequately to support

modeling predictions of likely contaminant migration paths; selection of monitor well

locations; and, when ground-water contamination exists, selection of a restoration

strategy. The following specific information is provided to support these objectives:

(a) A description of hydrogeologic units that may affect transport of contaminants

away from the site via ground-water pathways, including:

(i) Hydrostratigraphic cross sections and maps are included to delineate the

geometry, lateral extent, thickness, and rock or sediment type of all

potentially affected aquifers and confining zones beneath the processing

and disposal sites of such quality and quantity to support a technically

defensible interpretation.

(ii) The hydrogeologic units that constitute the uppermost aquifer (where

regulatory compliance will be evaluated) are identified. The uppermost

aquifer is the geologic formation nearest the natural ground surface that
Protecting Water Resources

4-6

is an aquifer, as well as lower aquifers that are hydraulically

interconnected with this aquifer within the facility property boundary.

(iii) If local perched aquifers are found at the site, their presence is noted. 

These formations may cause contaminated water to be diverted around

monitoring systems, or may be improperly interpreted as the uppermost

aquifer. Any saturated zone created by uranium or thorium recovery

operations would not be considered an aquifer unless the zone is or

potentially is (1) hydraulically interconnected to a natural aquifer,

(2) capable of discharge to surface water, or (3) reasonably accessible

because of migration beyond the vertical projection of the boundary of

the land transferred for long-term government ownership and care in

accordance with 10 CFR Part 40, Appendix A, Criterion 11.

(iv) Unsaturated zones, through which contaminants may be conveyed to the

water-bearing units, are described. This information is adequate to

support the assumptions used in estimating the source term for

contaminant transport pathways. This information includes identification

of potential preferential flow pathways that are either natural (e.g., buried

stream channels), or man-made (e.g., abandoned wells or mine shafts).

(v) Information is presented on geologic characteristics that may affect

ground-water flow beneath the former mill site. Examples of pertinent

geologic characteristics include identification of significant faulting in the

area, fracture and joint orientation and spacing for the underlying

bedrock, and geomorphology of soil and sedimentary deposits

(e.g., fluvial, glacial, or volcanic deposits).

(vi) Hydraulic-head contour maps, of both local and regional scale, for the

uppermost aquifer and any units connected hydraulically beneath the site

are sufficient to determine hydraulic gradients, ground-water flow

direction, and proximity to offsite ground-water users. These maps are

based on static water level observations at onsite and regional wells. 

Several measurements are taken at each observation well (American

Society for Testing and Materials Standards D 4750, D 5092, D 5521,

D 5787, and D 5978). These measurements are sufficiently spaced in

time to capture water-level fluctuations caused by seasonal changes or

local pumping of ground water. Enough observation wells are sampled to

produce an adequate water elevation contour map. The appropriate

number of wells is dependent on the size of the site and the choice of

contour interval. However, as a rough estimate, there is at least one

observation well for each contour line on the map. A more detailed

contour map (small contour interval) is produced for the site and

surrounding properties. The level of detail used for the regional contour

map may be limited by the number of observation wells available offsite. 

The reviewer shall bear in mind that calculations of hydraulic gradients
Protecting Water Resources

4-7

from hydraulic head contour maps are only rigorously valid for horizontal

flow in aquifers.

(b) Estimations of hydraulic and transport properties of the underlying aquifer

Hydrogeologic parameters used to support the choice of a ground-water

restoration strategy or to demonstrate compliance include hydraulic conductivity,

saturated thickness of hydro geologic units, hydraulic gradient, effective porosity,

storage coefficient, and dispersivity. The reviewer shall consider the influence of

each of these parameters on evaluating compliance with standards established 

pursuant to 10 CFR Part 40, Appendix A, and determine whether estimates for

each parameter are reasonably conservative, based on the data provided. 

(i) Hydraulic conductivity and storage coefficients are determined by

conducting aquifer pump tests on several wells at the site. Pump test

methods that are consistent with American Society for Testing and

Materials standards for the measurement of geotechnical properties and

for aquifer hydraulic tests are considered acceptable by the NRC. These

American Society for Testing and Materials Standards are D 4044,

D 4050, D 4104, D 4105, D 4106, D 4630, D 5269, D 5270, D 5472,

D 5473, D 5737, D 5785, D 5786, D 5850, D 5855, D 5881, and D 5912. 

Any other peer-reviewed method or commonly accepted practice for

aquifer parameter estimation may be used. When curve fitting is used to

analyze pump test data, deviations of observation data from ideal curves

are explained in terms of likely causes (e.g., impermeable or recharge

boundaries, leaky aquitards, or heterogeneities). When average

hydraulic parameters are reported, the reviewer shall consider that many

hydrogeologic parameters, including hydraulic conductivity, typically

exhibit a log-normal distribution. Consequently, the geometric mean may

be more representative of the overall conditions within a unit than the

arithmetic mean.

(ii) Horizontal components of hydraulic gradient are estimated by

measurement of the distance between contour intervals on hydraulic

head contour maps. Vertical components of hydraulic gradient are

estimated from head measurements in different aquifers or at different

depths in the same aquifer.

(iii) Generally, analyses considering steady-state conditions are acceptable

unless site conditions indicate otherwise. If transient conditions are

modeled, storage coefficients estimated from standard tests indicated in

(i) above are used.

(iv) If contaminant transport is modeled, then longitudinal and transverse

dispersivity values are either obtained from a tracer test or conservative

values based on published literature are used. Because dispersivities

depend on the size of the modeled region, the reviewer shall carefully
Protecting Water Resources

1

Smith, R.D. “Memorandum (February 9) Sampling of Uranium Mill Tailings Impoundments for Hazardous

Constituents.” 1987. 

4-8

compare the values for dispersivity used in the licensee transport

modeling with those values cited in survey studies such as Gelhar, et al. 

(1992), and verify that they represent conservative estimates for the site.

(c) Estimation of ground-water/surface-water interactions at sites with nearby

streams, rivers, or lakes.

The locations of surface-water bodies that are connected to the site groundwater flow system are identified. Surface-water elevations shall be used to help

describe the site ground-water flow system if a stream or other surface-water

body discharges into or drains the site ground-water flow system. Another

acceptable approach is to evaluate hydraulic head contour based on data from

monitor wells in the vicinity of streams.

(3) Geochemical conditions and water quality are characterized sufficiently to:

(a) Identify the constituents of concern.

Any chemical or radiological constituent that is reasonably expected to be in or

derived from the tailings is a potential constituent of concern. 10 CFR Part 40,

Appendix A, Criterion 13 provides a non-inclusive list of constituents of concern

which standards must be set and complied with. Criterion 13 also provides

flexibility to add constituents on a case-by-case basis.

Table 4.1.3-1 presents a list of constituents commonly associated with uranium

mill tailings.1

 This list is based on a chemical survey performed by NRC staff at

17 licensed mill tailings sites.

Most of the constituents in 10 CFR Part 40, Appendix A, Criterion 13 are organic

compounds that are not normally associated with uranium milling processes. 

The expected presence of organic compounds is assessed from knowledge of

the chemicals used during the milling process or other materials that may have

been disposed of in the tailings. If there is no record of organic compounds used

in the process, screening tests for volatile and semi-volatile organic compounds

are performed to confirm the absence of organic compounds in the tailings and

groundwater.
Protecting Water Resources

4-9

Table 4.1.3-1. Common Uranium Mill

Chemical Constituents

Inorganic Constituents Organic Constituents

Arsenic Carbon Disulfide

Barium Chloroform

Beryllium Diethyl Phthalate

Cadmium 2—Butanone

Chromium 1,2—Dichloroethane

Cyanide Naphthalene

Lead

Mercury

Molybdenum

Net Gross Alpha*

Nickel

Radium-226 and -228

Selenium

Silver

Thorium-230

Uranium

* Excluding Radon, Radium, and

 Uranium

Staff may require the addition of constituents associated with the milling process

that are not specifically listed in 10 CFR Part 40, Appendix A, Criterion 13, to

ground-water monitoring programs. These constituents may be added on a 

case-by-case basis, if they are capable of posing a substantial present or

potential hazard to human health or the environment. If the staff requires a

constituent to be added to the list in Criterion 13, the NRC must establish an

associated compliance limit for each added constituent at a level that will be

protective of human health and the environment.

Some constituents which typically do not present a hazard to human heath and

the environment may pose such a hazard to some specific human or

environmental populations, under site-specific circumstances. As an example,

three constituents associated with uranium mill tailings may be candidates for

site-specific evaluations during licensing reviews and potential NRC regulation

on a case-by-case basis, under specific circumstances. Illustrative constituents,

circumstances, and potential harm are tabulated in Table 4.1.3-2.
Protecting Water Resources

4-10

The above examples are not all inclusive. The reviewer should examine these

and other constituents that produce similar potential harm under specific

circumstances. Non-radiological constituents that degrade the water quality and

produce and impact on the designated water use beyond the proposed long-term

Table 4.1.3-2. Non-Radiological Ground-Water Constituents

That May Produce Harm

Constituent Exposure Circumstance Potential Harm

Sodium Drinking water pathway,

human exposure

Some segments of the

human population with

elevated blood pressure

may be sensitive to

sodium intake above a

recommended limit. The

EPA added sodium to its

Drinking Water

Contaminant Candidate

List for further evaluation.

Sulfate Drinking water pathway, human

exposure

Some segments of the

human population are

sensitive to elevated

sulfate in drinking water,

which can produce

osmotic diarrhea. The

EPA added sulfate to its

Drinking Water

Contaminant Candidate

List for further evaluation.

Ammonia, Ammonium ion Surface water pathway, aquatic

organism exposure

Various aquatic species

are sensitive to ammonia

levels as low as

0.38 mg/L. These levels

are far lower than

exposure limits that

would produce an

adverse impact to

human populations.
Protecting Water Resources

4-11

The above examples are not all-inclusive. The reviewer should examine these

and other constituents that produce similar potential harm under specific

circumstances. Non-radiological constituents that degrade the water quality and

produce and impact on the designated water use beyond the proposed long-term 

care boundary must also be evaluated to determine whether they should be

included in the license. The reviewer should consult with the appropriate

non-Agreement State agency on the designated water use for the ground-water

resource an any numerical limits the State has determined to be a hazard. 

Close coordination with the State may be needed to determine the need for

including such constituents in the license, along with evaluating the benefits and

costs of potential mitigative measures.

In identifying additional constituents, the staff should ensure that any additions

are made based on a sound technical and regulatory basis. Examples of sound

technical bases are the following:

(1) NRC and the U.S. Environmental Protection Agency agree to use one federal

contact with a licensee, which is NRC. This approach requires NRC to include

some constituents in its licenses, that are not normally licensed by the NRC.

(2) Trends in ground-water contamination show that after several years of

decreases in the level of contamination, the level of contamination is beginning

to rise again.

(3 )Surrogate parameters that cover a family of constituents show an increase in 

concentration in ground water. Therefore, the staff may require licensees to

monitor for all constituents found in that family.

(4) Some constituents used in the milling process, but not listed in Criterion 13,

may pose a hazard to some specific human and environmentally sensitive

populations, under site-specific circumstances, including degradation of a

designated water use beyond the proposed long-term care boundary.

Even if the criteria for identifying a constituent of concern are met, NRC may still

decide to exclude certain constituents on a site-specific basis if it can be shown

that the constituents are not capable of posing a substantial present or potential

hazard to human health or the environment. In considering such exclusions, the

reviewer must consider potential adverse effects on ground-water quality and

hydraulically connected surface-water quality. NRC may decide to exclude a

constituent if the dissolved concentration of the constituent in the tailing fluids is

equal to or less than the concentration of that constituent in the background

water quality. Alternately, NRC may decide to exclude a constituent if the

dissolved concentration of the constituent in the tailing fluids is equal to or less

than the maximum value for ground-water protection listed in 10 CFR Part 40,

Appendix A, Table 5C.
Protecting Water Resources

4-12

New constituents of concern should be added in a timely manner. This is done

either at the time the corrective action plan is accepted for review, or at some

time during the lifetime of the corrective action plan. New constituents will not be

required at the time of the license termination monitoring submittal, unless the

one-time, pre-termination ground-water sampling identifies constituents at

concentrations that pose a hazard to human health and the environment. The

reviewer should consult Appendix E (Section E3.3.2(1)) for those sites nearing

license termination, regarding the one-time, pre-termination ground-water

sampling and analysis. 

(b) Present a determination of background (baseline) water quality.

Background water quality is defined as the chemical quality of water that would

be expected at a site if contamination had not occurred from the uranium

milling operation.

Water quality data available from studies conducted in conjunction with initial

licensing for operation of the facility are used to establish the background. If

constituents of concern identified by NRC were not sampled in the original

background monitoring program, the licensee should have conducted additional

sampling to establish background levels. When adequate site-specific baseline

data cannot be obtained for identified constituents of concern, samples of

adjacent, and up-gradient, uncontaminated water are taken as proxies to onsite

baseline samples.

To determine acceptability of the determination of background water quality, the

following information is provided:

(i) Maps are of sufficient detail and legibility to show the background

monitoring locations.

(ii) Descriptions of sampling methods, monitoring devices, and quality

assurance practices are provided. Examples of acceptable methods are

those that are consistent with American Society for Testing and Materials

Standards D 4448, D 4696, and D 4840. Other methods, if used, are

properly referenced and justified.

(iii) When they exist, zones of differing background water quality are

delineated. The possible causes of these differing water quality zones

are discussed (e.g., changes from geochemically oxidizing to reducing

zones in the aquifer; changes in rock type across a fault boundary).

(iv) A table for each zone of distinct water quality, listing summary statistics

(i.e., mean, standard deviation, and number of samples) for baseline

water quality sampling for each constituent of concern, is provided.
Protecting Water Resources

2

Including a constituent which may pose a hazard to some specific human or environmentally sensitive populations,

under site-specific circumstances, and can, therefore, be added to the list in Criterion 13 on a case-by-case basis.

4-13

(v) A pre-operational monitoring program has been in place for 1 year,

consistent with the requirements of 10 CFR Part 40, Appendix A,

Criterion 7. Samples are taken at least monthly under this program. 

However, it is unlikely that mills in existence prior to the ground-water

compliance provisions of 10 CFR Part 40, Appendix A, will have one full

year of monthly baseline data from a pre-operational monitoring program.

Alternatively, background water quality may already be defined by a condition in

the license. If this is the case, background limits for a ground-water protection

standard have already been identified, and the reviewer should rely on those

along with any constituents and standards listed in Criterion 5(c) as the

regulatory limits applicable to this site.

(c) Confirm the proper use of statistical techniques for assessing water quality.

Statistical hypothesis testing methods used for (i) establishing background water

quality; (ii) establishing ground-water protection standards for compliance

monitoring; (iii) determining the extent of ground-water contamination; and

(iv) establishing the ground-water cleanup goals, are described in American

Society for Testing and Materials Standard D 6312.

(d) Define the extent of contamination.

 A hazardous constituent is defined in 10 CFR Part 40, Appendix A, 

Criterion 5B(2), as a constituent that meets all three of the following tests:

(i) The constituent is reasonably expected to be in or derived from the

byproduct material in the disposal area.

(ii) The constituent has been detected in the ground water in the

uppermost aquifer.

(iii) The constituent is listed in Part 40, Appendix A, Criterion 13.2

For each hazardous constituent, the licensee determines the extent of

contamination in ground water at the site. Ground-water contamination at

uranium mill sites is usually limited to the uppermost aquifer. Maps showing the

locations of sampling wells should be included, along with a discussion of

sampling practices. The most useful way to present this information is on a map

showing concentration contours for each hazardous constituent and water

surface elevation contours. In this manner, the reviewer readily examines the

size, shape, source, and direction of movement.
Protecting Water Resources

4-14

The extent of contamination is delineated in three dimensions. This typically

involves drilling a number of characterization wells and determining whether the

water quality in each of these wells meets background water quality or whether

the ground water is contaminated. It may not be necessary to sample all

hazardous constituents to delineate the extent of contamination. Two or three

indicator parameters (e.g., total dissolved solids, and chloride) might be

selected. These indicators should be conservative—meaning that they are

neither reactive, nor are they easily sorbed to soil—so that they provide a good

indication of the maximum extent of contamination.

The transition from contaminated to uncontaminated ground water is often

gradual. Thus, difficulty arises in determining where the contaminated water

ends and the background water begins. The background sample data provide

the easiest means for comparison of characterization well measurements to

background measurements for the indicator parameters. Statistical methods

described in American Society for Testing and Materials Standard D 6312 are

suitable for determining whether contaminant concentrations exceed

background levels.

Complications in delineating the extent of contamination arise at sites that have

zones of differing water quality, or where onsite background water quality is not

properly determined before discovery of ground-water contamination. Where

zones of differing water quality are present, the reviewer shall verify that

characterization wells are compared with the background sample from the

appropriate water quality zone. Where onsite background water quality has not

been properly determined, then upgradient or offsite samples are obtained.

The reviewer shall verify that the licensee has presented the following

information to support determining the extent of contamination.

(i) A map or maps showing the distribution of surface wastes and

contaminated materials at and near the site.

(ii) A map or maps showing the approximate shape and extent of

ground-water contamination (e.g., concentration contour maps for

indicator parameters in ground water).

(iii) Identification of any offsite sources of water contamination or other

factors that may have a bearing on observed water quality.

(e) Properly estimate the source term.

Existing sources of ground-water contamination are defined in terms of location

and rate of entry into the subsurface. At some sites, the contaminant sources

have been effectively eliminated through stabilization or removal of tailings piles. 

However, residual sources may still exist in contaminated subsurface soils at the

site. For ground-water contamination that originates from an onsite tailings pile,

the source term is determined based on the chemical properties of the leachate
Protecting Water Resources

4-15

and the rate at which leachate is released from the disposal area. The level

of review given to source term calculations is commensurate with the overall

importance of source term estimations to the selection of the restoration

strategy.

(i) Source terms are reasonably correlated to the history of ore processing. 

All facilities from which leakage can occur are identified. Leaking

constituents are identified based on the nature of the processing fluids. 

The volume of leakage is estimated in a realistic yet conservative

manner. This can be done using water balance calculations, infiltration

modeling, or seepage monitoring approaches.

(ii) When geochemical models are used to predict the fate and transport of

existing contamination where the original source has been eliminated, the

distribution of each hazardous constituent in place is taken as the

source term. 

(f) Characterize the subsurface geochemical properties.

To effectively model the fate and transport of contaminants in ground water, it is

important to characterize the geochemical properties of the natural waters and

the aquifer mineralogy. Characterization of the underlying lithologies includes

measurements of buffering capacity, total organic carbon, cation exchange

capacity, and identification of the clay mineralogy. The general chemical

characteristics of fluids within the lithologies are described by measurements of

pH, temperature, dissolved oxygen, redox potential, buffering capacity, and the

concentrations of major ions and trace metals. 

(i) Aquifer geochemistry data are adequate to model the attenuation of

contaminants. The values of the geochemical parameters used in

transport models are justified. Acceptable parameter estimation methods

are direct measurement, use of a conservative bounding estimate,

reference to literature values for similar aquifer conditions, and laboratory

studies of aquifer materials.

(g) Identify contaminant attenuation mechanisms.

The major attenuation mechanisms that work to mitigate the effects of

ground-water contamination are dilution in surrounding ground water, sorption of

contaminants to the soil matrix, and immobilization of contaminants from

geochemical and biochemical reactions.

(i) Claims that contamination is reduced by dilution are supported by a

sufficient technical basis. There are two mechanisms for dilution of a

contaminant plume in ground water: dispersion and mixing. Dispersion is

a process whereby contaminant plumes tend to spread out and become

less concentrated as they move away from the source. Mixing is the

result of uncontaminated water being added to the ground-water system
Protecting Water Resources

4-16

through natural recharge, injection, or upward movement of water from

underlying aquifers, which reduces the concentration of contaminants. 

Estimation of surface recharge or upward flow through leaky aquitards is

either established from field measurements, or through use of

conservative assumptions are used.

(ii) The values of sorption coefficients are based on the nature of the

constituent and site-specific geochemical conditions. The degree of

sorption of contaminants to the soil matrix depends on the affinity of each

constituent for the soil in a particular aquifer. Constituents that carry a

positive charge, as do most trace metals in solution, are good candidates

for cation exchange adsorption to clay and oxide surfaces. However,

because surface charges of clays and oxides decrease with decreasing

pH, the reviewer shall carefully examine claims of attenuation from cation

exchange under low pH conditions. Organic contaminants tend to be

hydrophobic and are strongly attenuated in soils that have high organic

carbon content. Most contaminant fate and transport models quantify the

affinity of contaminants for soil by use of a distribution coefficient or KD. 

Batch or column equilibria experiments, using representative leachate

and soil samples, are performed to support estimations of KD for each

hazardous constituent.

(iii) Attenuation from geochemical or biochemical equilibrium reactions is

estimated by use of acceptable modeling software packages such as

MINTEQA2 (Allison, et al., 1991) and PHREEQE (Parkhurst, et

al., 1980). However, these packages are limited in that they do not

consider transport of contaminants. Thus, results are only valid for

reactions within a confined space (e.g., within the disposal cell). More

recently developed reactive transport models [e.g., PHREEQC Version 2

(Parkhurst and Appello, 1999)] are also acceptable for constructing a

geochemical model for the site. The reviewer shall determine that all

model input parameters have sufficient technical bases and represent

reasonably conservative estimations. Additionally, conclusions drawn

from such models are supported by field observation; that is, they are

consistent with site characterization data. 

(iv) At sites from which the contamination source has been effectively

eliminated, monitoring data are used to assess attenuation of

contaminants. If the contaminant source has been eliminated by surface

reclamation, changes in the nature and extent of contamination over time

are monitored. In such situations the center of mass of the contaminant

plume moves along the direction of ground-water flow. The effects of

dispersion are also observable over time as a decrease in peak

concentrations near the center of the contaminant plume and a lateral

spreading of the plume. If significant precipitation or adsorption is

occurring, it is reflected in a decrease in the mass of contaminants in the

aqueous phase. 
Protecting Water Resources

4-17

4.1.4 Evaluation Findings

If the staff review, as described in standard review plan Section 4.1, results in the acceptance

of the site characterization, the following conclusions may be presented in the technical

evaluation report:

The staff has completed its review of the site characterization at the uranium

mill facility. This review included an evaluation using the review procedures in Section 4.1.2

and the acceptance criteria outlined in Section 4.1.3 of this standard review plan.

The licensee has presented an acceptable history of the site, including (1) a description of

leaching solutions and other chemicals used in the process and their relative quantities; (2) a

description of (a) the wastes generated at the site during the milling process, and (b) the waste

handling facilities; (3) a summary of the known impact of site activities on the hydrologic system

and water quality; and (4) a description of activities unrelated to uranium milling that may have

altered the hydrologic system.

The licensee has presented acceptable information pertaining to the surrounding land and

water use including (1) an overview of water uses, quantity available, and potential uses to

which the water is suited; (2) definitions of the class-of-use category of each water

source; (3) identification of potential receptors of ground-water or surface-water

contamination; (4) assessment of variations in dilution effects of stream flow on contaminants;

and (5) assessments of the effects of meteorological conditions on erosion, infiltration, and

water-table elevation. 

The licensee has presented acceptable meteorologic data, including (1) wind speed and

direction, (2) rainfall, (3) evaporation data (4) temperature, and (5) humidity, to allow an

evaluation of potential impacts of the meteorologic conditions on disposal cell performance.

The ground-water and surface-water hydrology is adequately described, including (1) geometry,

lateral extent, and thickness of potentially affected aquifers and confining units; (2) a

determination of which aquifers constitute the uppermost aquifer where regulatory compliance

will be evaluated; (3) descriptions of the unsaturated units that convey hazardous constituents

to the water-bearing units; (4) maps of acceptable detail showing the relative dimensions and

locations of hydrogeologic units that have been impacted by milling activities; (5) information on

geologic characteristics that may affect ground-water flow beneath the site; and (6) hydraulic

head contour maps of both local and regional scale for the uppermost aquifer beneath the site. 

The estimation of hydraulic and transport properties is acceptable and includes (1) hydraulic

conductivity and storage coefficients determined by conducting aquifer pump tests on several

wells; (2) determination of hydraulic gradients using hydraulic head contour maps;

(3) calculations of storage coefficients, as applicable; and (4) longitudinal and transverse

dispersivities, as appropriate. The evaluation of ground-water/surface-water interactions with

nearby streams, rivers, or lakes is acceptable. 

Geochemical conditions and water quality are adequately analyzed, including identification of

constituents of concern that are reasonably expected to be derived from the tailings. Each

constituent of concern is found in 10 CFR Part 40, Appendix A, Table 5C or 10 CFR Part 40,
Protecting Water Resources

4-18

Appendix A, Criterion 13, or has been included as a specific condition in the license. The

licensee has made an acceptable determination of baseline water quality, including (1) maps of

appropriate scale and legibility; (2) descriptions of sampling methods, monitoring devices, and

quality assurance practices; (3) where applicable, delineation of zones of differing water quality

and their possible origin; and (4) a table of summary statistics for each zone of differing quality. 

The applicant has presented an acceptable delineation of the extent of contamination supported

by appropriate samples, maps of surface wastes and contaminated materials, maps of the

approximate shape and extent of ground-water contamination, and identification of any off-site

sources of water contamination. The description of the source term is acceptable and includes

not only mill tailings constituents but those contaminants that might mobilize by contact with

tailings leachate. 

The characterization of the subsurface geochemical properties is acceptable. Attenuation

mechanisms have been described, including the technical bases for determining that

contamination will be reduced by dilution, sorption on the soil matrix, or geochemical or

biochemical reactions. The licensee has presented direct measurements in support of

attenuation of contaminants where the source has been eliminated by surface reclamation.

On the basis of the information presented in the application and the detailed review conducted

of the site characterization for the uranium mill facility, the NRC staff

concludes that the information is acceptable and is in compliance with the following criteria in

10 CFR Part 40, Appendix A: Criterion 5B, which requires the NRC to establish a list of

hazardous constituents, concentration limits, a point of compliance, and a compliance period;

Criterion 5C, which provides a table of concentration limits for certain constituents when they

are present in ground water above background concentrations; Criterion 5E, which requires

licensees conducting ground-water protection programs to consider the use of bottom liners,

recycle of solutions and conservation of water, dewatering of tailings, and neutralization to

immobilize hazardous constituents; Criterion 5F, which requires that, where ground-water

impacts caused by seepage are occurring at an existing site, action be taken to alleviate the

conditions that lead to seepage and restore ground-water quality. Technical specifications for

the seepage control system must be established, and a quality assurance, testing and

inspection program must be established to insure the specifications are met. Criterion 5G,

which requires that licensees/operators perform site characterization in support of a tailings

disposal system proposal; Criterion 5H, which requires steps be taken during stockpiling of ore

to minimize penetration of radionuclides into underlying soils; Criterion 7 which requires a year

of monitoring prior to mill operations; Criterion 7A, which requires three types of monitoring

systems: detection, compliance, and corrective action; and Criterion 13, which provides a list of

hazardous constituents that must be considered when establishing the list of hazardous

constituents in ground water at any site.
Protecting Water Resources

4-19

4.1.5 References

Allison, J.D., D.S. Brown, and K.J. Novo-Gradac. “MINTEQA2/PRODEFA2, A Geochemical

Assessment Model for Environmental Systems: Version 3.0 User’s Manual.” EPA Publication

EPA/600/3–91/021. Washington, DC: EPA. 1991.

American Society for Testing and Materials Standards:

D 4044, “Standard Test Method for (Field Procedure) for Instantaneous Change in Head 

(Slug) Tests for Determining Hydraulic Properties of Aquifers.”

D 4050, “Standard Test Method (Field Procedure) for Withdrawal and Injection Well

Tests for Determining Hydraulic Properties of Aquifer Systems.”

D 4104, “Standard Test Method (Analytical Procedure) for Determining Transmissivity of

Nonleaky Confined Aquifers by Overdamped Well Response to Instantaneous Change

in Head (Slug Tests).”

D 4105, “Standard Test Method (Analytical Procedure) for Determining Transmissivity

and Storage Coefficient of Nonleaky Confined Aquifers by the Modified Theis 

Nonequilibrium Method.”

D 4106, “Standard Test Method (Analytical Procedure) for Determining Transmissivity

and Storage Coefficient of Nonleaky Confined Aquifers by the Theis

Nonequilibrium Method.”

D 4448, “Standard Guide for Sampling Ground-water Monitoring Wells.”

D 4630, “Standard Test Method for Determining Transmissivity and Storage Coefficient

of Low-Permeability Rocks by In Situ Measurements Using the Constant Head

Injection Test.”

D 4750, “Standard Test Method for Determining Subsurface Liquid Levels in a Borehole

or Monitoring Well (Observation Well).”

D 4840, “Standard Guide for Sampling Chain-of-Custody Procedures.”

D 5092, “Standard Practice for Design and Installation of Ground Water Monitoring

Wells in Aquifers.”

D 5269, “Standard Test Method for Determining Transmissivity of Nonleaky Confined

Aquifers by the Theis Recovery Method.”

D 5270-96, “Standard Test Method for Determining Transmissivity and Storage

Coefficient of Bounded, Nonleaky, Confined Aquifers.”

D 5472, “Standard Test Method for Determining Specific Capacity and Estimating

Transmissivity at the Control Well.”
Protecting Water Resources

4-20

D 5473, “Standard Test Method for (Analytical Procedure for) Analyzing the Effects of

Partial Penetration of Control Well and Determining the Horizontal and Vertical

Hydraulic Conductivity in a Nonleaky Confined Aquifer.”

D 5521, “Standard Guide for Development of Ground-Water Monitoring Wells in

Granular Aquifers.”

D 5737, “Standard Guide for Methods for Measuring Well Discharge.”

D 5785, “Standard Test Method for (Analytical Procedure for) Determining

Transmissivity of Confined Nonleaky Aquifers by Underdamped Well Response to

Instantaneous Change in Head (Slug Test).”

D 5786, “Standard Practice for (Field Procedure) for Constant Drawdown Tests in

Flowing Wells for Determining Hydraulic Properties of Aquifer System.”

D 5787, “Standard Practice for Monitoring Well Protection.”

D 5850, “Standard Test Method for (Analytical Procedure for) Determining

Transmissivity, Storage Coefficient, and Anisotropy Ratio from a Network of Partially

Penetrating Wells.”

D 5855, “Standard Test Method for (Analytical Procedure for) Determining

Transmissivity and Storage Coefficient of a Confined Nonleaky or Leaky Aquifer by

Constant Drawdown Method in a Flowing Well.”

D 5881, “Standard Test Method for (Analytical Procedure) Determining Transmissivity of

Confined Nonleaky Aquifers by Critically Damped Well Response to Instantaneous

Change in Head (Slug).”

D 5912, “Standard Test Method for (Analytical Procedure for) Determining Hydraulic

Conductivity of an Unconfined Aquifer by Overdamped Well Response to Instantaneous

Change in Head (Slug).”

D 5978, “Standard Guide for Maintenance and Rehabilitation of Ground-Water

Monitoring Wells.”

D 6312, “Standard Guide for Developing Appropriate Statistical Approaches for GroundWater Detection Monitoring Programs.”

Gelhar, L.W., C. Welty, and K.R. Rehfeldt. “A Critical Review of Data on Field-scale Dispersion

in Aquifers.” Water Resources Research. Vol. 28, No. 7. 1992.

NRC. “Concurrent Jurisdiction of Non-Radiological Hazards of Uranium Mill Tailings.” Staff

Requirements Memorandum to SECY–99–0277. Washington DC: NRC; Office of the

Executive Director of Operations. August 11, 2000.
Protecting Water Resources

4-21

–––––. NUREG–1748, “Environmental Review Guidance for Licensing Actions Associated with

NMSS Programs.” Washington, DC: NRC, Office of Nuclear Material Safety and

Safeguards. 2001

Parkhurst, D.L. and A.A.J. Appello. “User’s Guide to PHREEQC (Version 2)—A Computer

Program for Speciation, Batch-Reaction, One-Dimensional Transport, and Inverse Geochemical

Modeling.” 99-4259. Washington, DC: U.S. Geological Survey. 1999.

Parkhurst, D.L., Thorstensen, and L.N. Plummer. “PHREEQEM-A Computer Program

for Geochemical Calculations.” U.S. Geological Survey Water Resources

Investigation 80-96. 1980.

4.2 Ground-Water Protection Standards

4.2.1 Areas of Review

Ground-water protection standards are established for each hazardous constituent. A 

hazardous constituent is defined in 10 CFR Part 40, Appendix A, Criterion 5B(2), as a

constituent that meets all three of the following tests:

(1) The constituent is reasonably expected to be in or derived from the byproduct material

in the disposal area.

(2) The constituent has been detected in the ground water in the uppermost aquifer.

(3) The constituent is listed in 10 CFR Part 40, Appendix A, Criterion 13.

Even when constituents meet the three aforementioned tests, the Commission may exclude a

detected constituent from the set of hazardous constituents, on a site-specific basis, if it finds

that the constituent is not capable of posing a substantial present or potential hazard to human

health or the environment. In deciding whether to exclude constituents, the considerations

identified in 10 CFR Part 40, Appendix A, Criterion 5B(3), must be considered. In addition, as

required by 10 CFR Part 40, Appendix A, Criterion 5B(4), any underground sources of drinking

water and aquifers exempted by the EPA will be considered. Relevant EPA guidance is

presented in 40 CFR 144.7, 144.3, and 146.4. The staff should review the technical basis the

licensee has presented for the following elements of acceptable ground-water protection 

standards:

(1) The list of hazardous constituents.

(2) A description of the point of compliance.

(3) Ground-water protection standards for hazardous constituents that may be either:

(a) Commission-approved background concentrations.

(b) Maximum concentration limits.
Protecting Water Resources

4-22

(c) Alternate concentration limits.

The staff should also review additional ground-water protection standards that contain

provisions for ground-water protection dealing with the design of surface impoundments and

tailings disposal cells. Evaluation of disposal system performance is addressed in standard

review plan Section 4.3.3.

4.2.2 Review Procedures

The reviewer should examine the ground-water protection standards to verify that they have

been defined consistent with the acceptance criteria in standard review plan Section 4.3.2. 

Specifically, the reviewer should reference the existing license or:

(1) Verify that the licensee has identified all constituents of concern that are present in the

tailings leachate.

(2) Verify that the point of compliance has been properly delineated.

(3) Evaluate whether the proposed concentration limits for each ground-water protection

standard are within a range that is reasonably expected to represent background

concentrations; or, if any alternate concentration limits are proposed, verify that the

appropriate evaluations have been presented in accordance with Criterion 5(B)(6) of

10 CFR Part 40, Appendix A.

4.2.3 Acceptance Criteria

Ground-water protection standards establish a concentration limit for each hazardous

constituent at the point of compliance. The development of ground-water protection standards

will be acceptable if it meets the following criteria:

(1) Hazardous constituents are identified using the definition given in 10 CFR Part 40,

Appendix A, Criterion 5(B).

(2) A point of compliance is established in accordance with 10 CFR Part 40, Appendix A,

Criterion 5B(1).

The point of compliance is the location at which the ground water is monitored to

determine compliance with the ground-water protection standards. The objective in

selecting the point of compliance is to provide the earliest practicable warning that the

impoundment is releasing hazardous constituents to the ground water. The point of

compliance must be selected to provide prompt indication of ground-water

contamination on the hydraulically downgradient edge of the disposal area. The point of

compliance is defined as the intersection of a vertical plane with the uppermost aquifer

at the hydraulically downgradient limit of the waste management area. 

The “uppermost aquifer” is defined in 10 CFR Part 40, Appendix A, as “the geologic

formation nearest the natural ground surface that is an aquifer, as well as lower aquifers

that are hydraulically interconnected with this aquifer within the facility’s property
Protecting Water Resources

4-23

boundary.” Therefore, a proper selection of the point of compliance includes

identification of point of compliance locations in the aquifer nearest to the ground

surface, as well as other aquifers that are hydraulically interconnected with that aquifer,

as warranted by site-specific conditions. 

When tailings are disposed of on site, the NRC generally interprets the downgradient

limit of the waste management area to be the edge of the reclaimed tailings side slopes. 

However, it is not recommended that licensees be required to compromise the cover

integrity to install monitoring wells at the actual edge of the reclaimed tailings. 

(3) A concentration limit is specified for each of the hazardous constituents. Those limits

may be:

(a) Commission-Approved Background Concentrations.

10 CFR Part 40, Appendix A, requires that the Commission-approved

background concentration be the concentration limit, except for constituents

listed in Table 5C of 10 CFR Part 40, Appendix A, which, if present in excess of

background, are subject to the respective maximum concentration limits listed in

Table 5C.

Proper statistical methods, such as those discussed in American Society for

Testing and Materials Standard D 6312, are used to determine the expected

range of naturally occurring background (baseline) concentrations for each

constituent of concern. Acceptable statistical techniques are also presented in

Haan (1977) and Hirsch, et al. (1992).

(b) Maximum Concentration Limits

The respective values given in the table in paragraph 5C of 10 CFR Part 40,

Appendix A, must not exceed if the constituent is listed in the table and if the

background level of the constituent is below the value listed. Note that the

U.S. EPA has revised some of these limits under the Safe Drinking Water Act,

therefore, for risk assessments used for an alternate concentration limit

proposal, where a drinking water exposure pathway is estimated, the reviewer

should refer to the most recent Safe Drinking Water Act maximum concentration

limits. 

(c) Alternate Concentration Limits

Alternate concentration limits are established on a site-specific basis, provided it

can be demonstrated that (i) the constituents will not pose a substantial present

or potential hazard to human health or the environment, as long as the alternate

concentration limits are not exceeded and (ii) the alternate concentration limits

are as low as is reasonably achievable, considering practicable corrective

actions. Licensees are required to implement detection monitoring programs to

detect and identify site-specific hazardous constituents, and compliance

monitoring programs to verify compliance with the established site-specific
Protecting Water Resources

4-24

standards for individual constituents. Standard review plan Sections 4.3.3 and

4.4.3 contain acceptance criteria for determining potential hazards, and for “as

low as is reasonably achievable” demonstrations, respectively.

When an applicant proposes alternate concentration limits, the reviewer should

recognize that additional site characterization may be necessary to demonstrate

the potential risk to human health and the environment is acceptable. Typically,

long-term ground-water monitoring will be required to assure that human health

and the environment are protected.

4.2.4 Evaluation Findings

If the staff review, as described in standard review plan Section 4.2, results in the acceptance

of the site ground-water protection standards, the following conclusions may be presented in

the technical evaluation report:

The staff has completed its review of the ground-water protection standards at the

 uranium mill facility. This review included an evaluation using the review

procedures in Section 4.2.2 and the acceptance criteria outlined in Section 4.2.3 of

this standard review plan.

The licensee has acceptably identified the hazardous constituents and has established

acceptable concentration limits and cleanup standards. Established background levels are

acceptable. Acceptable statistical methods have been used to establish the concentration

limits. If alternate concentration limits have been requested, the licensee has acceptably

supported the request with appropriate data and calculations. The licensee has established an

acceptable point of compliance at the edge of the tailings impoundment on the downgradient

direction of hydraulic flow. 

On the basis of the information presented in the application and the detailed review conducted

of the ground-water protection standards for the uranium milling facility, the

NRC staff concludes that the information is acceptable and is in compliance with the following

criteria in 10 CFR Part 40, Appendix A: Criterion 5B, which requires the NRC to establish a list

of hazardous constituents, concentration limits, a point of compliance, and a compliance period

and, which allows use of alternate concentration limits under certain conditions; Criterion 5C,

which provides a table of secondary concentration limits for certain constituents when they are

present in ground water above background concentrations; Criterion 7A, which requires three 

types of monitoring systems: detection, compliance, and corrective action; and Criterion 13,

which provides a list of hazardous constituents that must be considered when establishing the

list of hazardous constituents in ground water at any site.

4.2.5 References

American Society for Testing and Materials Standards

D 6312, “Standard Guide for Developing Appropriate Statistical Approaches for GroundWater Detection Monitoring Programs.”
Protecting Water Resources

4-25

Haan, C.T. Statistical Methods in Hydrology. Iowa State University Press. 1977.

Hirsch, R.M., D.R. Helsel, T.A. Cohn, and E.J. Gilroy. Statistical Analysis of Hydrologic Data,

Handbook of Hydrology. D.R. Maidment, ed. New York, New York: McGraw-Hill, Inc. 1992.

4.3 Hazard Assessment, Exposure Assessment, Corrective Action

Assessment, and Compliance Monitoring for Alternate

Concentration Limits

4.3.1 Areas of Review

The staff shall review the following elements of an alternate concentration limit application to

determine regulatory compliance with 10 CFR Part 40, Appendix A, Criterion 5B(6):

(1) Hazardous constituent(s) and the associated human and environmental risks of those

constituent(s), including human cancer risk and environmental hazards. 

Characterization of the hazardous constituent source term and the extent of groundwater contamination.

(2) Assessment of hazardous constituent transport in the ground water and hydraulically

connected surface waters, and its adverse effects on water quality, including present

and potential health and environmental consequences of exposure to the

identified hazards.

(3) A demonstration that a hazardous constituent concentration will not pose substantial

present or potential hazard to human health or the environment at the point of exposure,

and that the proposed alternate concentration limit is as low as is reasonably

achievable, considering practicable corrective actions.

In addition, the implementation of the proposed alternate concentration limit and any

modifications to the compliance monitoring program must be reviewed.

4.3.2 Review Procedures

Appendix K provides a description of a standardized content and format for an alternate

concentration limit application. Strict conformance with the standard format is not a

requirement, but review effectiveness and efficiency should be enhanced through its use. The

proposed alternate concentration limit should be supported by a hazard assessment, an

exposure assessment, and a corrective action assessment. Although separately listed, the

information contained within each assessment should be integrated with the information that is

developed in the subsequent assessment, so that all three assessments will collectively support

the proposed alternate concentration limit. Appropriate portions of standard review plan

Section 4.1 should also be consulted when performing a review of an alternate concentration

limit application. The reviewer shall examine the provided information and assessments to

determine that:
Protecting Water Resources

4-26

(1) The source term has been adequately characterized to provide a realistic estimate of

the types, characteristics, and the release rates of constituents of concern, which have

been, or are expected to be, released to the ground water.

(2) The risks and hazards that the released or potentially mobile constituents of concern

may have on human health and the environment have been identified.

(3) The extent of existing and potential ground-water contamination from the source term

has been defined. The rates and directions of hazardous constituent migration and

transport in the ground water and hydraulically connected surface waters have been

determined. The point of compliance and point of exposure are identified.

(4) The pathways for human and environmental exposure to the hazardous constituent(s)

have been identified, and exposure magnitudes and consequences, including the

human cancer risk, have been acceptably evaluated.

(5) The proposed alternate concentration limit(s) for the point of compliance will result in a

hazardous constituent concentration that is protective of human health and the

environment at the point of exposure. The attenuation capacity of the aquifer between

the point of compliance and the point of exposure has been adequately considered. 

There will be no adverse effects on the ground-water or on surface-water quality that

would cause unacceptable health or environmental hazards at or beyond the point

of exposure.

The applicant’s assessment of ground-water corrective action alternatives shall be reviewed in

conjunction with the hazard and exposure assessments. Previous, current, and potential future

practicable corrective actions shall be evaluated against the costs and benefits of those actions

to determine if the proposed alternate concentration limit is as low as is reasonably achievable. 

This demonstration should identify alternate corrective actions; assess their technical feasibility

for implementation, and evaluate all associated costs and benefits of those corrective actions.

An alternate concentration limit must be protective of human health and the environment at the

point of exposure, which is any location at or beyond the long-term care site boundary. A

proposed alternate concentration limit that is not protective of human health and the

environment, by itself, will not comply with the regulatory requirements for an alternate

concentration limit. In this instance the applicant must submit the proposed numerical limit and

any additional measures to protect human health and the environment to the Commission as an

alternative to the specific requirements of 10 CFR Part 40, Appendix A, Criterion 5B (6), as

permitted by section 84(c) of the Atomic Energy Act of 1954, as amended. The NRC staff will

evaluate these alternatives on a case-by-case basis and determine the acceptability of the

proposed alternative. A proposed alternate concentration limit that is not protective of human

health and the environment and does not include additional alternate measures to provide such

protection is not acceptable.

If the proposed alternate concentration limit is found acceptable, the compliance monitoring

program must be evaluated before the license is terminated to determine that it is properly

designed and implemented to ensure ground-water constituent concentrations in excess of the
Protecting Water Resources

4-27

approved alternate concentration limit will be detected and that human health and the

environment will be protected. Standard review plan Section 4.4 should be consulted.

4.3.3 Acceptance Criteria

The hazard assessment, exposure assessment, and corrective action assessment supporting a

proposed alternate concentration limit will be acceptable if they meet the following criteria:

4.3.3.1Hazard Assessment

The hazard assessment identifies all potential constituents of concern at a site. A potential

constituent of concern is any compound that may be in or could be derived from the uranium

mill tailings at a licensed site. A non-inclusive list of constituents of concern is in 10 CFR

Part 40, Appendix A, Criterion 13. The risks and hazards to human health and the environment

associated with those constituents are also identified and evaluated to determine whether an

alternate concentration limit should be proposed for those constituents, if the subsequent

exposure assessment concludes that an exposure is reasonably likely. Once a constituent of

concern is released into the ground-water, it is classified as a hazardous constituent for the

purpose of regulatory compliance, as described in 10 CFR Part 40, Appendix A, Criterion 5B(2).

The hazard assessment should include the following:

(1) The source term for all constituents of concern is adequately characterized and the

extent of existing and potential future ground-water contamination is determined. 

The source term characterization provides relevant information about the facility

including: (a) the mechanical and chemical processes used to recover the uranium,

(b) the types and quantities of the reagents used in milling, (c) the physical and chemical

composition of the uranium-bearing ore, and (d) the historical and current waste and

tailings management practices. This information is considered, in conjunction with the

physical and chemical composition of the tailings and the type and distribution of

existing contaminants, such as the location of waste discharge points, retaining

structures for wastes, and waste constituents. The source characterization should

provide reliable estimates of the release rates of hazardous constituents as well as

constituent distributions.

(2) The assessment identifies and evaluates the risks and hazards presented by the

identified constituents of concern, including the human cancer risk caused by exposure

to radioactive and non-radioactive constituents of concern, along with other health

hazards that may be caused by the chemical toxicity of those constituents. The human

cancer risk should be evaluated for individual constituents, including radioactive and

carcinogenic chemicals, and compared with the maximum permitted risk level. The

health effects of non-radioactive and non-carcinogenic constituents that are chemically

toxic will be evaluated considering their risk-specific dose levels. It may be necessary to

calculate a hazard index using the reference doses for those chemicals that have

threshold effects. The hazard index is the ratio of calculated intake to the reference

dose. An acceptable hazard index must be less than one. These evaluations

distinguish between the health effects associated with threshold and non-threshold
Protecting Water Resources

4-28

constituents. Mutagenic, teratogenic, and synergistic effects are considered in the

analysis, if applicable, based on toxicological testing, or structure-activity relationships.

The following additional information on constituent properties is provided, as applicable: 

(a) density, solubility, valence state, vapor pressure, viscosity, and partitioning

coefficient; (b) presence and effects of complexing ligands and chelating agents that

may enhance constituent mobility; (c) potential for a constituent to degrade because of

biological, chemical, and physical processes; and (d) constituent attenuation properties,

considering such processes as ion exchange, sorption, precipitation, dissolution,

and ultrafiltration. This information would also be applied in the exposure assessment.

(3) The assessment provides a reasonably conservative or best estimate of the potential

health effects caused by human exposure to the hazardous constituent. The potential

health effects for each constituent with a proposed alternate concentration limit must be

identified, and related to appropriate exposure limits and dose-response relationships

from available literature or databases. Sources of exposure limit and dose-response

information include the EPA’s maximum concentration limits for drinking water,

reference doses, or risk-specific doses. Reference doses are the amounts of

chemically toxic constituents to which humans may be daily exposed without suffering

adverse effects.

Risk-specific doses are the amounts of proven or suspected carcinogenic constituents

to which humans can be daily exposed, without increasing their risk of contracting

cancer above a specified risk level. The reference dose and risk-specific dose

assessment assume a human mass of 70 kg [154 lb] and consumption of 2 liters of

water per day [0.53 gal/day]. More stringent criteria may apply if sensitive populations

are exposed to hazardous constituents. Maximum concentration limits, reference

doses, and/or risk-specific doses, can be used to show compliance with the risk level

and hazard indexes. The technical basis for a risk assessment can be based on the

dose-response relationships described in the scientific literature searches or

toxicological research, in the absence of applicable maximum concentration limits,

reference doses, or risk-specific doses. The exposure analysis should distinguish

between threshold (toxic) and non-threshold (carcinogenic) effects associated with

human exposure, as well as teratogenic, fetotoxic, mutagenic, and synergistic effects.

The maximum concentration limits, reference doses, and risk-specific doses for most

hazardous constituents can be obtained from the EPA (http://www.epa.gov), the Agency

for Toxic Substances and Disease Registry (http://www.atsdr.cdc.gov/atsdrhome.html),

or other government institutions and universities. Effects from radioactivity can be

obtained from the International Commission on Radiological Protection, and the National

Council on Radiation Protection and Measurement.

Previously established and documented health-based constituent concentration limits

are used in the hazard assessment as a basis for proposing alternate concentration limit

values at specific sites.

(4) The assessment identifies and evaluates the risks posed by the hazardous constituents

to environmental populations. Adverse effects on aquatic and terrestrial wildlife, plants,
Protecting Water Resources

4-29

agricultural crops, livestock, and physical structures should be considered. Examples of

these adverse effects are: (a) contaminant-induced changes in the biota, (b) loss or

reduction of unique or critical habitats, and (c) jeopardy to endangered or threatened

species. The NRC must initiate special consultation with the U.S. Fish and Wildlife

Service, in accordance with 50 CFR Part 17, if endangered or threatened species occur

on the site or could be impacted by site activities. NUREG–1748 (NRC, 2001) should

be consulted for initiating this consultation.

Similar to the human risk evaluation, the environmental risk evaluation identifies any

acute and sub-chronic effects on environmental populations caused by exposure to the

hazardous constituents. Bioaccumulation and food chain interactions are considered

when evaluating adverse effects. A comparison of the estimated constituent

concentrations to the appropriate federal or State water-quality criteria should be part of

the evaluation of potential effects on aquatic wildlife.

When appropriate, the hazard assessment considers potential damage to physical

structures such as foundations, underground pipes, and roads. The applicant should

demonstrate that the forecasted constituent concentrations will not result in any

significant degradation or loss of function, as a result of contamination exposure. As an

example, excessive concentrations of dissolved salts could result in accelerated

corrosion of underground utility piping.

4.3.3.2Exposure Assessment

The purpose of the exposure assessment is to evaluate the potential harm to human health and

the environment from the hazards identified in the hazard assessment. The exposure

assessment takes into account site-specific circumstances that may reduce or enhance the

potential for exposure to hazardous constituents. This assessment identifies and evaluates

hazardous constituent exposure pathways, and provides forecasts of human and environmental

population responses, based on the projected constituent concentrations, dose levels, and

available information on the radiological and chemical toxicity effects of the constituents. The

assessment also addresses the underlying assumptions, variability, and uncertainty of the

projected health and environmental effects. Exposure pathways should be identified and

evaluated using water classification and water use standards, along with existing and

anticipated water uses. Agricultural, industrial, domestic, municipal, environmental, and

recreational water uses should also be considered, as they pertain to the site and surrounding

areas. The exposure assessment must provide adequate information regarding potential

effects on ground-water resources, and the above water uses, to support NRC’s environmental

review under 10 CFR Part 51. NUREG–1748 (NRC, 2001) should be consulted for the details

of this review.

Proposed human exposure levels should be reasonably conservative, defensible, and

sufficiently protective to avoid a substantial present or potential hazard to people for the

forecasted duration of the contamination. A proposed alternate concentration limit that does

not exceed an excess lifetime risk of fatal cancer on the order of 10-4 is acceptable for an

average exposed individual at the point of exposure, when considering the potential for the

health risks from human exposure to known or suspected carcinogens contained in untreated

ground-water used for drinking water.
Protecting Water Resources

4-30

The exposure assessment must identify the point of compliance, where the proposed alternate

concentration limit will be measured; and the points of exposure, where the human health and

environmental exposures could occur. The assessment identifies the maximum permissible

levels of hazardous constituents at the point of compliance that are protective of human health

and the environment at the point of exposure. This is accomplished by evaluating human and

environmental exposure to each of those constituents evaluated in the hazard assessment, and

then showing the proposed alternate concentration limit will not result in an unacceptable

exposure of human health or the environment to those hazards. The exposure assessment

should include the following:

(1) The exposure assessment evaluates the pathways the hazardous constituents will likely

follow and the concentration or dose those constituents will likely produce at the location

where humans or environmental populations could be reasonably exposed. All likely

pathways that could transport significant amounts of hazardous constituents in the

ground water and hydraulically connected surface water should be identified and

evaluated. The hazardous constituent concentrations and projected distributions for

each pathway should be best estimates or reasonably conservative representations of

the rate, extent, and direction of the constituent transport.

The ground-water pathway evaluation provides projected contaminant distributions,

including contaminant transport, degradation, and attenuation mechanisms between the

point of compliance and the point of exposure. The evaluation generally provides

information on: (a) site hydrogeologic characteristics, including ground-water flow

direction and rates; (b) background water quality; and (c) estimated transport rates,

geochemical attenuation, and concentrations of hazardous constituents in the ground

water and hydraulically connected surface water. Projections should be calibrated on

the basis of site-specific information. The projected attenuation rate may rely on

constituent concentration measurements at the point of compliance and the point of

exposure, taken over an adequate period of time, when there is great uncertainty in the

attenuation rate derived from laboratory measurements or literature sources.

(2) The pathway evaluation provides the spatial distribution of the various hazardous

constituents of existing contaminant plumes. This information can be used to calibrate

contaminant fate and transport models in the exposure assessment and also identifies

the components of the source term that have already been released from the tailings. 

The contaminant extent characterization includes: (a) the type and distribution of

hazardous constituents in the ground water and the source(s) of the contamination;

(b) the monitoring program used to delineate and characterize hazardous constituent

distribution; and (c) supporting documentation of the sampling, laboratory analysis, and

quality assurance programs that show the fulfillment of the site monitoring programs. 

Such information is used to assess present human and environmental population

exposure to elevated concentrations of hazardous constituents, calibrate contaminant

transport models, and evaluate projected future exposures. Computer codes may be

used to evaluate the pathways for hazardous constituent transport. The acceptance

criteria for ground-water fate and transport computer modeling are contained in

standard review plan Section 4.4.3.
Protecting Water Resources

4-31

(3) The human exposure evaluation considers two potential exposure pathways: 

(a) ingestion of contaminated water and (b) ingestion of contaminated foods. Other

pathways that may impact human health, such as dermal contact and inhalation, are

also to be considered, but need not always be assessed, unless it is determined that

these exposures could result in significant hazards to human health or the environment.

Human exposure is evaluated primarily on the basis of the extent to which people are

using, and are likely to use, contaminated water from the site. Site-specific water uses

are determined on the basis of the following considerations: (a) ground-water quality in

the site area and present water uses; (b) statutory or legal constraints and institutional

controls on water use in the site area; (c) federal, state, or other ground-water

classification criteria and guidelines; (d) applicable water-use criteria, standards, and

guidelines; and (e) availability and characteristics of alternate water supplies.

Exposure determinations should consider existing and potential water uses. Potential

uses include those that are reasonably expected to occur (i.e., anticipated use) and

uses that are compatible with the untreated background water quality (i.e., possible

use). Past water uses may be included as existing or potential uses. Water resource

classification of existing and potential water use should include (a) domestic and

municipal drinking water use; (b) fish and wildlife propagation, (c) special ecological

communities uses: and (d) industrial, agricultural, and recreational uses. The

classification of existing and potential water uses at the facility should be consistent with

federal, state, and local water use inventories.

The cumulative effects of human exposure to hazardous constituents at the proposed

alternate concentration limits, and to other constituents present in contaminated groundwater, will be maintained at a level adequate to protect public health. The combined

effects from both radiological and non-radiological constituents should be considered. 

Guidance for cumulative impact assessment is contained in NUREG–1748 (NRC, 2001)

and additional guidance is found in Council on Environmental Quality (1997).

(4) Potential responses of environmental or non-human populations to the various

hazardous constituents are evaluated if such populations can realistically be exposed to

contaminated ground water or hydraulically connected surface water. Terrestrial and

aquatic wildlife, plants, livestock, and crops are included in this evaluation. A detailed

environmental exposure evaluation should be performed in the absence of available

information that could readily be used to show there will be no substantial environmental

impacts caused by ground-water contamination from the site. The evaluation should

provide: (a) inventories of potentially exposed environmental populations;

(b) recommended tolerance or exposure limits; (c) contaminant interactions and their

cumulative effects on exposed populations; (d) projected responses of environmental

populations that result from exposure to hazardous constituents; and (e) anticipated

changes in populations, independent of the hazardous constituent exposure. 

Alternatively, the evaluation may demonstrate that environmental hazards are not

anticipated, because exposure will not occur.

The potential for adverse effects, such as (a) contamination-induced biotic changes;

(b) loss or reduction of unique or critical habitats; and (c) jeopardizing endangered
Protecting Water Resources

4-32

species, should also be described. Aquatic wildlife effects are evaluated by comparing

estimated constituent concentrations with federal and state water quality criteria. 

Terrestrial wildlife exposure to constituents through direct exposure and food-web

interactions should be considered. The NRC must initiate special consultation with the

U.S. Fish and Wildlife Service, in accordance with 50 CFR Part 17, if endangered or

threatened species occur on the site or could be impacted by site activities. 

NUREG–1748 (NRC, 2001) should be consulted for initiating this consultation.

Agricultural effects from both direct and indirect exposure pathways, crop impacts,

reduced productivity, and bioaccumulation of constituents should be considered. 

Reasonably conservative estimates of constituent concentrations are compared with

federal and state water quality criteria to estimate agricultural effects associated with

constituent exposure. Additionally, crop exposures through contaminated soil, shallow

ground-water uptake, and irrigation, along with livestock exposure through direct

ingestion of contaminated water and indirect exposure through grazing, should

be assessed.

(5) Points of exposure are identified. A point of exposure is any location where people,

wildlife, or other species could reasonably be exposed to hazardous constituents from

ground water contaminated by uranium mill tailings. For example, the point(s) of

exposure may be represented by one or more domestic wells that might withdraw

contaminated ground water; or it may be represented by springs, rivers, streams, or

lakes into which contaminated ground water might discharge. The point of exposure is

used to assess the potential hazard(s) to human health and the environment and effects

on the ground-water resource.

An alternate concentration limit for a hazardous constituent is established at the point of

compliance. The point of exposure may be situated at some distance from the point of

compliance, allowing hazardous constituent concentrations to diminish through

dispersion, attenuation, or sorption within the aquifer. As a result, an alternate

concentration limit may be set at a concentration that is higher at the point of

compliance location than a limit that would be protective of human health and

environment, as long as the hazardous constituent will not result in an unacceptable

hazard to human health and the environment at the point of exposure. In most cases,

the point of exposure is located at the downgradient edge of land that will be transferred

to either the federal government or the state for long-term institutional control.

The applicant for an alternate concentration limit should make every reasonable effort to

keep the point of exposure at the long-term care site boundary. If this cannot be

achieved, a good-faith effort must be made to acquire the land between the license area

boundary and the point of exposure, for ultimate transfer to the long-term custodian. If

the land cannot be acquired through a good-faith effort, then institutional controls other

than ownership by the long-term custodian may be initiated. These institutional controls

must be enforceable, durable, and legally defensible; and will be applied in addition to

the numerical limits of the proposed alternate concentration limit. This approach must

be reviewed as an alternative to the specific regulatory requirements contained in

10 CFR Part 40, Appendix A, Criterion 5B(6).
Protecting Water Resources

3

A distant point of exposure refers to a point of exposure that is spatially beyond the area that the appropriate federal

or State agency is required to accept for perpetual care under the land transfer provisions of the Uranium Mill

Tailings Radiation Control Act of 1978, as amended.

4-33

A distant point of exposure3

 may be justified when human or environmental exposure is

effectively impossible. This option could be justified on the basis that extremely rugged 

terrain cannot be physically accessed or the long-term care custodian would ensure that

ground water from the contaminated aquifers between the disposal site and the point of

exposure would not be used. In some rare instances, a distant point of exposure could

be established without invoking land ownership by a long-term custodian. Under these

circumstances, the previously described institutional controls should be invoked. 

Human and environmental exposure are considered effectively impossible when the

ground water is inaccessible or unsuitable for use. Land ownership or long-term

custody will not be an issue for establishing a distant point of exposure if human and

environmental exposure are effectively impossible.

When a distant point of exposure is involved, the applicant must coordinate the use of

this option with the NRC. The NRC and the applicant must verify whether the state or

the federal government will be the long-term site custodian, after the license is

terminated. The applicant must then secure a commitment from that party to take

custody of the site. The applicant or the NRC must then secure written assurance that

the appropriate federal or state agency will accept the transfer of the specific property,

including land in excess of that needed for tailings disposal. Alternate concentration

limits may not be established at sites involving a distant point of exposure until the

licensee agrees to transfer the title to the land, and the appropriate federal or state

government commits to take such land, including the land between the point of

compliance and point of exposure that is in excess of the land used for disposal of

byproduct material.

If the licensee chooses to keep the mill property under a specific license and apply for

an alternate concentration limit as part of a compliance monitoring program, the

licensee must still coordinate the use of a distant point of exposure with the NRC as

described above.

(6) The likelihood of human and environmental exposure is determined. The probability of

human and environmental exposure is often difficult to establish quantitatively. 

Consequently, defensible qualitative estimates of the exposure likelihood are often

necessary. These can be characterized as either:

(a) Reasonably likely—when exposure has or could have occurred in the past, or

available information indicates that exposure to contamination may reasonably

occur during the contamination period.

(b) Reasonably unlikely—when exposure could have occurred in the past, but will

probably not occur in the future, either because initial incentives for water use

have been removed, or because available information indicates that no
Protecting Water Resources

4-34

incentives for water use are currently identifiable, based on foreseeable

technological developments.

(7) Exposure impacts are adequately evaluated through time. It is acceptable to project

impacts at the point of exposure during a 1,000-year time frame. This is consistent with

the design standard of 10 CFR Part 40, Appendix A, Criterion 6(1).

4.3.3.3Corrective Action Assessment

The applicant’s assessment of ground-water corrective action alternatives should be reviewed

in conjunction with the hazard assessment and the exposure assessment. Past, current, and

proposed practicable corrective actions are identified and evaluated against the costs and

benefits associated with implementing each corrective action alternative. The corrective action

assessment should demonstrate that the proposed alternate concentration limit is as low as is

reasonably achievable, considering practicable corrective actions, as required by

10 CFR Part 40 Appendix A, Criterion 5B(6). A principal way of demonstrating this is by

estimating and comparing the benefits imparted by a corrective action measure against the cost

of implementing that measure.

For some sites, a corrective action assessment may have already been completed, as part of a

ground-water corrective action program under Criterion 5D of Appendix A to 10 CFR Part 40, as

described in standard review plan Section 4.4.3. A ground-water corrective action assessment

typically (a) identifies several practicable corrective action alternatives; (b) assesses the

technical feasibility, costs, and benefits of each alternative; and (c) selects an appropriate

corrective action for achieving compliance with the ground-water protection standards

established at the site. The corrective action assessment should include the following:

(1) A complete range of realistic and reasonable corrective action alternatives for achieving

compliance with the ground-water standards currently in the license and the proposed

alternate concentration limit is described and evaluated. The identified alternatives

should be comprehensive, including all engineering-feasible alternatives, both passive

and active, or any appropriate sequential combination of alternatives. The analyzed

corrective action alternative should not simply be a compendium of the most elaborate

and expensive alternatives. The description of each alternative should be conceptual in

nature, but contain sufficient detail so the reviewer can independently verify the

reasonableness of each corrective action measure. Although conceptual, the alternate

descriptions should also contain sufficient detail for completing a coarse cost estimate of

each alternative for the cost and benefit analysis.

For past and current corrective actions, site-specific operational and monitoring data

should be included to show the effectiveness of those measures. The evaluation may

include information from literature sources or documented experience from other sites

for those corrective actions that have not been implemented at the site but appear to be

practicable. The evaluation should also include projections of the hazardous constituent

concentration that each corrective action would likely produce at specific times at the

point of compliance and the point of exposure. It is important that the reviewer assure

that the range of reasonable corrective actions listed in the application is complete. The

suitability of a corrective action should be determined strictly on the technical and
Protecting Water Resources

4-35

engineering information needed to design and implement a particular measure. The

economic constraints for implementing a particular measure should not be used to

eliminate a corrective action method from the evaluation.

(2) The direct benefits of implementing the corrective actions have been determined by

estimating the current and projected resource value of the pre-contaminated ground

water. Estimates of pre-contaminated ground-water value should be based on water

rights, availability of alternate water supplies, and forecasted water use demands. The

value of a contaminated water resource is generally equal to the cost of a domestic or

municipal drinking water supply or the cost of water supplied from an alternate source to

replace the contaminated resource. The absence of available alternate water supplies

increases the relative value of a potentially contaminated water resource. The indirect

benefits are determined by assessing the avoidance of adverse health effects from

exposure to contaminated water, the prevention of land value depreciation, and

any benefits accrued from performing the corrective action, including timeliness

of remediation. The reviewer should verify the water yields; costs for developing

alternate water supply sources; and legal, statutory, or other administrative constraints

on the use and development of the water resources.

(3) The costs associated with performing a corrective action alternative to achieve the

target concentrations include (a) the capital costs for designing, and constructing the

alternative; (b) operation and maintenance costs; (c) costs associated with 

demonstrating compliance with the standards; and (d) decommissioning costs after the

corrective action is completed.

(4) The “as low as is reasonably achievable” analysis is performed on target concentration

levels that are at or below the limit determined to be protective of human health and the

environment. At least three target concentration levels that can reasonably be attained

by the practicable corrective actions should be evaluated. The goals should be

(a) meaningfully different, (b) reasonably attainable by practicable corrective action, and

(c) at or below the levels identified in the hazard assessment.

The “as low as is reasonably achievable” analysis typically considers (a) the direct and

indirect benefits of implementing each corrective action to achieve the target

concentration levels; (b) the costs of performing the corrective action to achieve the

target concentrations; and (c) a determination whether any of the evaluated corrective

action alternatives will reduce contaminant levels below the proposed alternate

concentration limit, considering the benefits and costs of implementing the alternative.

The applicant should also provide a comparison among the costs associated with

performing the various corrective action alternatives to achieve the target

concentrations, the value of the pre-contaminated ground-water resource, and the

benefits of achieving each target concentration. A proposed alternate concentration

limit is considered as low as is reasonably achievable if the comparison of the costs to

achieve the target concentrations lower than the alternate concentration limit are far in

excess of the value of the resource and the benefits associated with performing the

corrective action alternative. If the value and benefits clearly exceed the costs or the

comparison is nearly equal, the proposed alternate concentration limit should be revised
Protecting Water Resources

4-36

to the lower target concentration providing the greatest value and benefit compared to

the cost.

The cost and benefit analysis should not be limited to a simple financial accounting of

the costs for each corrective action alternative. Costs and benefits should also be

discussed for qualitative subjects, such as environmental degradation or enhancement. 

The cost and benefit analysis is not simply a mathematical formula from which to justify

economic parameters. Other qualitative factors should be discussed and weighed in the

decision. The cost and benefits analysis provides input to determine the relative merits

of various corrective action alternatives; however, the proposed alternate concentration

limit must ultimately assure protection of public health and the environment.

The as low as is reasonably achievable analysis for non-radiological constituents should

be similar to the as low as is reasonably achievable analysis for radiological constituents

except a “dollar per person-rem avoided” value would not be calculated. Additionally,

once nonradiological constituent are below regulatory maximum concentration levels,

the licensee ha no further obligation to reduce the constituent concentrations.

4.3.3.4Examination of the Compliance Monitoring Program

Standard review plan Section 4.4.3 provides the acceptance criteria for corrective action

assessments, corrective action monitoring, and compliance monitoring. The reviewer should

examine the existing compliance monitoring program at a licensed mill tailings facility, if a

proposed alternate concentration limit is found acceptable.

Specifically, the compliance monitoring program should monitor all ground-water exposure

pathways to assure that any potential exceedances of the proposed alternate concentration

limit will be detected before the license is terminated. The compliance monitoring well locations

should not be restricted solely to the point of compliance. Some locations between the point of

compliance and the points of exposure should be included to assure the identified aquifer

attenuation mechanisms are reducing the hazardous constituent concentrations to the predicted

levels. The applicable maximum contaminant level, background concentration, or other

maximum permissible limit should be used as the compliance monitoring limit for wells at the

points of exposure, in those cases where compliance monitoring is conducted at the points

of exposure.

4.3.4 Evaluation Findings

The following conclusions may be presented in the technical evaluation report, if the staff

review, as described in standard review plan Section 4.3 results in the acceptance of the hazard

assessment, exposure assessment, and corrective action assessment supporting the proposed

alternate concentration limit:

The staff completed its review of the proposed alternate concentration limit for ground-water

compliance at the uranium mill tailings facility. This review included an

evaluation using the review procedures in Section 4.3.2 and the acceptance criteria outlined in

Section 4.3.3 of this standard review plan.
Protecting Water Resources

4-37

The licensee conducted an acceptable hazard assessment by considering present and potential

human health and environmental hazards, including human cancer risk from exposure to

radioactive and non-radioactive constituents and other health hazards resulting from the

chemical toxicity of the constituents. The source term for constituents of concern and the

extent of ground-water contamination have been acceptably characterized.

The licensee conducted an acceptable exposure assessment. The point of exposure has been

identified and is acceptably sited at the downgradient edge of the affected land. When a distant

point of exposure is used, written assurance has been secured, either by the licensee or NRC,

that the appropriate federal or state agency will accept the transfer of the specific property,

including land in excess of that needed for tailings disposal. The transport of the hazardous

constituent in ground water and surface water has been defined and any adverse effects on

water quality, including present and future impacts have been assessed. 

The human cancer risk and other health and environmental hazards from exposures to

hazardous constituents have been evaluated and are acceptable, including (a) identification of

maximum levels permissible at the point of compliance; (b) evaluation of health and

environmental hazards using water classification and use standards and existing and

anticipated water uses; (c) appropriate consideration of impact, based on site-specific water

uses; (d) consideration of ingestion of contaminated water and food; (e) consideration of

response of environmental and non-human populations to the various hazardous constituents,

including terrestrial and aquatic wildlife, plants, livestock, and crops; and (f) consideration of

potential damage to physical structures.

The acceptable corrective action assessment includes (1) an assessment of ground-water

corrective actions dealing with identification of practicable corrective action alternatives; 

(2) an evaluation of ability of corrective action to reduce contaminant levels appropriately; 

(3) a demonstration that action will achieve desired concentration levels; and (4) demonstration

that practicable corrective actions are not likely to result in reduction of contamination below the

proposed alternate concentration limit, and that alternate concentration limits are, therefore, as

low as is reasonably achievable.

The NRC staff concludes that the information submitted to support the proposed alternate

concentration limit(s) at the uranium milling facility is acceptable and

complies with the following criteria in 10 CFR Part 40, Appendix A, Criterion 5B, which requires

NRC to establish a list of hazardous constituents, concentration limits, a point of compliance,

and a compliance period; Criterion 5C, which contains a table of secondary concentration limits

for certain constituents when they are present in ground water above background

concentrations; Criterion 5F, which requires that where ground-water impacts from seepage are

occurring at an existing site, action must be taken to alleviate the conditions that lead to

seepage, and ground-water quality must be restored, including technical specifications for the

seepage control system and implementation of a quality assurance program; Criterion 5G,

which requires licensees/operators to perform site characterization; Criterion 6(1), which

provides performance lifetime and radioactive material release standards; and Criterion 7A,

which establishes detection, compliance and corrective action monitoring programs in support

of a tailings disposal system proposal. The information also complies with 10 CFR 40.31(f),

which requires inclusion of an environmental report in the license application, and
Protecting Water Resources

4-38

10 CFR 51.45, which requires a description of the affected environment containing sufficient

data to aid the Commission in its conduct of an independent analysis.

4.3.5 References

Council on Environmental Quality. “Considering Cumulative Effects Under the National

Environmental Policy Act.” Washington, DC: Council on Environmental Quality. 1997.

NRC. NUREG–1748, “Environmental Review Guidance for Licensing Actions Associated with

NMSS Programs.” Washington, DC: NRC. 2001.

4.4 Ground-Water Corrective Action and Compliance Monitoring Plan

The staff should review any ground-water corrective action and compliance monitoring plans

that may be presented by the licensee either as a part of the reclamation plan, or as a separate

licensing submittal. A separately submitted corrective action and compliance monitoring plans

will contain much of the same information that is required for the reclamation plan (e.g., a site

characterization plan). Any information that was presented in a previously approved

reclamation plan may be incorporated by reference. For review of some information, the

reviewer may use review procedures in other chapters of this standard review plan.

4.4.1 Areas of Review

In determining compliance, the reviewers should consider the information specified in

Criteria 1–8 of Appendix A of 10 CFR Part 40 that is relevant to the technical adequacy of the

ground-water corrective action and compliance monitoring plans. Models of unsaturated flow

and transport can be used if the tailings pile is located in the unsaturated zone. A reactive

transport model of the plume of hazardous constituents for the saturated zone away from the

mill tailings pile should be constructed if the licensee takes credit for chemical processes that

may mitigate the spread of contaminants. The technical adequacy of any detailed models

should be reviewed. Findings from detailed models (that incorporate complexities not treated in

any large-scale numerical models) can be used as input to a large-scale numerical model of

ground-water flow and transport for the site. Models should be calibrated using site data.

The staff should review the following aspects of ground-water corrective action and compliance

monitoring plans.

(1) The sufficiency of data and parameters.

(2) The technical bases for parameter ranges.

(3) Descriptions of features and physical phenomena.

(4) Use of alternate models.

(5) Consistency of models.
Protecting Water Resources

4-39

(6) Waste management practices.

(7) Site access controls.

(8) Ground-water monitoring plans.

(9) Design, operation, and inspection of surface impoundments.

(10) Surety.

4.4.2 Review Procedures

In conducting the review of the technical adequacy of the ground-water corrective action and

compliance monitoring plans, the staff should recognize that review procedures and models

used in the technical assessment of the selected ground-water cleanup methods, cleanup time,

and sureties may range from detailed, small-scale process models to large-scale, simplified

models. The small-scale process models incorporate the important complexities and

mechanisms that govern the evolution of the hazardous constituent plume, while the large-scale

simplified models do not consider all the important complexities. Model adequacy should be

evaluated regardless of the level of complexity. The following areas should be evaluated:

(1) The staff should evaluate the sufficiency of the data and parameters supporting models

considered in any site-scale numerical model used to estimate the cleanup time. The

staff should also evaluate the technical basis for data on design features, physical

phenomena, geology, hydrology, geotechnical engineering, and geochemistry used to

model or assess ground-water cleanup. This basis may include a combination of

techniques such as laboratory experiments and site-specific field measurements.

The reviewer should evaluate whether additional data are likely to provide new

information that could invalidate the modeling results and significantly affect the

corrective action and compliance monitoring plans.

(2) The reviewer should evaluate the technical bases for parameter ranges, probability

distributions, or bounding values. The reviewer should determine whether the

parameter values are derived from site-specific data or, alternatively, an analysis is

included to show that the assumed parameter values lead to a conservative assessment

of performance.

The staff should examine the initial conditions and boundary conditions used in

sensitivity analyses for consistency with available data. The staff should also consider

the temporal and spatial variations in boundary conditions and source terms used to

support the ground-water corrective action and compliance monitoring plan.

The staff should evaluate the licensee assessment of uncertainty and variability in

parameters used in the modeling. The reviewer should determine whether uncertainty

in data due to both temporal and spatial variations in conditions affecting the

ground-water cleanup and estimation of cleanup time was incorporated into

parameter ranges.
Protecting Water Resources

4-40

(3) The staff should examine the descriptions of features and physical phenomena and the

descriptions of the geological, hydrological, geotechnical, and geochemical aspects of

the mill tailings and the underlying aquifer. The staff should verify that the descriptions

are adequate and that the conditions and assumptions used in the modeling are realistic

or reasonably conservative and are supported by the body of data presented in the

descriptions. The staff should assess the technical bases for these descriptions and for

incorporating them in the numerical model of the site.

The reviewer should examine the technical bases for the identification of hazardous

constituents from the mill tailings that have entered the underlying aquifer and surface

water bodies. The staff should evaluate how these constituents have been incorporated

into any detailed models. The staff should also verify that, given the concentrations and

locations of the hazardous constituents, estimates of cleanup time and surety amounts

are reasonable.

The reviewer should examine the assumptions used to develop any model of reactive

transport that accounts for site geochemical processes. These processes may include

phase changes induced by interaction of contaminants with ground water and surface

water. The modeling should consider available data about the native ground-water

downgradient of the tailings pile, the geochemical environment, hydraulic and transport

properties, and the spatial variations of properties of aquifers and ground-water

volumetric fluxes along the flow paths.

The staff should evaluate the initial and boundary conditions and how they have been

propagated through the models. For example, the reviewer should determine whether

the conditions and assumptions used in the site-scale model are consistent with other

conditions and assumptions used in any model that describes the flow and transport of

hazardous constituents from the mill tailings.

(4) The staff should evaluate models used for the ground-water cleanup and estimation of

cleanup time. The staff should examine the model parameters in the context of

available site characterization data, laboratory experiments, and field measurements. 

Where appropriate, and when surety estimates are highly uncertain, the reviewer should

use an alternate site model to evaluate the effects on the technical assessment of

ground-water cleanup and estimation of cleanup time.

(5) The staff should evaluate the output from any site model of ground-water cleanup and

the estimation of cleanup time and compare the results with an appropriate combination

of site characterization and design data.

The staff should examine the model results obtained by the licensee against

comparable mathematical models to judge their robustness. The reviewer should use

an alternate model to evaluate selected parts of the licensee model results, as

appropriate. The reviewer should evaluate whether the licensee has appropriately

reduced the dimensionality and complexity of models. The dimensionality of models,

heterogeneity of aquifer parameters, and significant process couplings may be reduced

if it is shown that the simplified model bounds the prediction of the more complex model. 
Protecting Water Resources

4-41

The staff should evaluate the acceptability of the sensitivity analyses used to support the

model of the ground-water cleanup and the estimation of cleanup time.

(6) The staff should verify that waste management practices are in compliance with

environmental protection regulations.

(7) The reviewer should assess whether site access controls during the cleanup period are

sufficient to prevent significant hazards to human health and the environment.

(8) The staff should evaluate whether the ground-water monitoring system is sufficient to

verify the performance of the selected cleanup strategy, and to monitor the long-term

performance of any on-site tailings disposal cells.

(9) The staff should ensure that any surface impoundments constructed as part of the

program are designed to meet the requirements of 10 CFR Part 40, Appendix A criteria

and are included in the dam safety program, if appropriate. The reviewer should also

verify that adequate inspection, documentation, and reporting procedures exist for

tailings or waste retention systems.

(10) The staff should confirm that the applicant has provided adequate financial surety. 

This confirmation may be conducted using cost estimating software such as the

RACER 2000TM computer code (Talisman Partners, Ltd., 2000). Guidance on the

preparation of sureties and cost estimates is available in Appendix C of this standard

review plan and in NRC (1988, 1997).

4.4.3 Acceptance Criteria

In 10 CFR Part 40, Appendix A, Criterion 5D, NRC requires tha,t if the ground-water protection

standards established under Criterion 5B(1) of 10 CFR Part 40, Appendix A are exceeded at a

licensed site, a corrective action program must be put into operation as soon as is practicable,

and in no event later than 18 months after the Commission finds that the standards have been

exceeded. Unless otherwise directed by the Commission, before putting the program into

operation, the licensee should submit the supporting rationale for the proposed corrective action

program. The objective of the program is to return hazardous constituent concentration levels

in ground-water to the concentration limits set as standards. The licensee should provide an

assessment of practicable corrective actions available for returning contaminant concentrations

to the standards established in the license. The corrective action assessment incorporates

information and findings from the site characterization activities, which are described in

standard review plan Section 4.1.3. Site specific characteristics may have a strong influence on

which corrective action alternative will be practicable for a particular site. If additional site

characterization is needed, details of the characterization plan should be included.

The corrective action should result in conformance with the established concentration limits,

address either removing the hazardous constituents or treating them in place, and should

include a program to monitor compliance with cleanup standards. Regulations do not require

any specific designs or methods to be used for the ground-water corrective action program.

Because of the nearly limitless possibilities for designing and implementing ground-water

corrective actions, staff reviewers should focus on the technical feasibility from an engineering
Protecting Water Resources

4-42

perspective and evaluate whether the proposed design is likely to result in timely compliance

with established concentration limits and whether the monitoring program is adequate to verify

the effectiveness of the design. Useful guidance for the application of ground-water flow and

transport modeling can be obtained from American Standard for Testing and Material D 5447,

D 5490, D 5609, D 5611, D 5718, D 5880, and D 5981.

The ground-water corrective action and compliance monitoring plans are acceptable if they

meet the following criteria.

(1) Sufficient data are available to adequately define relevant parameters and to support

models, assumptions, and boundary conditions necessary for developing detailed and

site-scale models of the ground-water cleanup and the estimation of cleanup time. The

data are also sufficient to assess the degree to which processes related to the

ground-water cleanup that affect compliance with the technical criteria in Appendix A of

10 CFR Part 40 have been characterized. Information required for site-scale reactive

transport models can include:

(a) Site description.

(i) Chronology/history of uranium milling operations.

(ii) List of known leaching solutions and other chemicals used in the

milling process.

(iii) Summary of known impacts of the site activities on the hydrologic system

and background water quality.

(iv) Quantity and chemical/textural characteristics of wastes generated at the

mill site.

(v) Information pertaining to surrounding land and water uses.

(vi) Meteorological data for the region including precipitation and other data

to support estimates of evapotranspiration.

(b) Description of hydrogeologic units.

(i) Hydrostratigraphic cross sections/maps.

(ii) Hydrogeologic units that constitute the aquifer(s).

(iii) Description of perched aquifers (areal/volumetric extent).

(iv) Description of the unsaturated zone (thickness, extent).

(v) Geologic characteristics (presence of layers, continuity, faults).

(c) Data on the hydraulic and transport properties of each aquifer.
Protecting Water Resources

4-43

(i) Hydraulic conductivity.

(ii) Thickness of each unit.

(iii) Hydraulic head contour maps (of each aquifer).

(iv) Information on background horizontal and vertical hydraulic gradients and

temporal variations to determine flow directions.

(v) Vertical hydraulic gradients and inter-aquifer flow within and between

multiple aquifer systems.

(vi) Effective porosity

(vii) Storativity or specific yield (for transient simulations).

(viii) Longitudinal, vertical and horizontal transverse dispersivity.

(ix) Retardation factors.

(c) Data on regional recharge rates and ground-water/surface-water interactions

with nearby streams, rivers, or lakes.

(i) Areal recharge rates.

(ii) Information on water fluxes to and from rivers, aquifers, and surface

water bodies.

(iii) Data on surface water bodies (e.g., stream flow rates, dimensions of

nearby surface water bodies).

(iv) Concentration of hazardous constituents in surface water bodies

(d) Characteristics of the mill tailings.

(i) Identification of contaminant source terms.

(ii) Hydraulic properties of mill tailings material.

(iii) Unsaturated flow and transport parameters of mill tailings material.

(iv) Design and materials for mill tailings cover.

(v) Information on the spatial and temporal distribution of seepage fluxes

from the mill tailings to the upper-most aquifer (including the historical

variation in rates).

(vi) Information on mill tailings draining mechanisms and drainage volume.
Protecting Water Resources

4-44

(vii) Geotechnical properties of the mill tailings and their temporal variation

due to drainage of leachates

(viii) Tailings volume.

(ix) Data on the volume, chemical and mineralogical characteristics, and

concentration of mill tailings and tailings solution/leachate.

(x) Mass of hazardous constituents placed in the tailings pile and other

disposal or storage areas.

(e) Data on geochemical conditions and water quality.

(i) Concentration of hazardous constituents.

(ii) Background (baseline) ground-water quality.

(iii) Delineation of the nature and extent of the hazardous constituent plume.

(iv) Characterization of subsurface geochemical properties.

(v) Identification of attenuation mechanisms and estimation of

attenuation rates.

(vi) Mass of hazardous constituents in the aquifer.

(f) Site cleanup data.

(i) Information on grout curtains, slurry walls, drains, interceptor ditches, and

other facilities designed to reduce the spreading of the hazardous

constituent plume (if used).

(ii) Information on pumping, injection, and sampling wells (coordinates,

depths, completion diagrams, flow rates).

(iii) Pumping/injection rates and rate history for each well (if pumping has

been ongoing).

(iv) Information on the presence or the absence of liners for the mill tailings

pile and evaporation ponds.

(v) Mass of hazardous constituents recovered to date.

Sufficient data are available to justify models used to validate the ground-water

corrective action plan. American Standard for Testing and Materials D 5490 provides

acceptable guidance for comparing model simulations to site-specific information. 

Alternatively, in the case of sparse data and/or low confidence in the quality of available

data or data interpretations, the licensee demonstrates by sensitivity analyses or other
Protecting Water Resources

4-45

methods that the proposed ground-water corrective action plan is appropriate, and the

contingency built into the surety is compatible with the uncertainties. American

Standard for Testing and Materials D 5611 provides acceptable guidance for conducting

sensitivity analyses on ground-water flow models. Guidance on preparing cost

estimates and establishing sureties for uranium mills is provided in the “Technical

Position on Financial Assurances and Reclamation, Decommissioning, and Long-Term

Surveillance and Control of Uranium Recovery Facilities” (NRC, 1988).

Sufficient information is provided to substantiate that any mathematical flow and

transport modeling approach is appropriate for site conditions considering (i) factors

pertaining to the specific purpose or intended use of the model(s); (ii) the flow media at

the site and along the flow path from the mill tailings to the point of compliance, and

downgradient to it, including aquifer properties and transport parameters (e.g., porous

media versus fracture flow, aquifer confinement, the number of active layers);

(iii) modeling assumptions (e.g., steady-state versus transient flow, assignment of initial

and boundary conditions); and (iv) model-related factors (e.g., underlying flow

equations; solution methods; model history; model verification, validation and calibration;

expertise and experience of the personnel responsible for model development; and

quality of model documentation). Amiercan Standard for Testing and Materials D 5718

provides guidance for documenting ground-water flow model applications.

An adequate assessment is provided of the low and high permeability features

(heterogeneities), their spatial distributions, and statistical properties; and the available

and acquired data are suitable and sufficient for modeling based on observations,

independent analyses, or published reports and databases of those features.

Initial and boundary conditions used by the licensee in modeling the ground-water

cleanup are justified by the available data, are used consistently throughout the

modeling process, and are adequately documented. American Standard for Testing and

Materials D 5609 provides acceptable guidance for defining boundary conditions for

ground-water flow models.

Where sufficient data do not exist, the definition of parameter values and conceptual

models are based on appropriate sources from the literature or are otherwise

technically justified.

Adequate site geochemical data are provided. Contaminants are identified sufficiently

to support the ground-water corrective action plan and models. In addition to helping

set cleanup goals, background water chemical data support assessments of

geochemical evolution as ambient ground water is restored in the subsurface. 

Generally, a three-dimensional delineation of contaminant distribution and a source term

are necessary for defining needed actions and for model development. The important

geochemical parameters that should be delineated for both contaminated and

background waters are pH, Eh, dissolved oxygen, temperature, major cation and anion

concentrations, and concentrations of potential contaminants. Host rock properties

affect both the water chemistry and the specific geochemical mechanisms affecting

contaminants. Identifying possible attenuation mechanisms ensures that cleanup is

based on reasonable models for contaminant transport.
Protecting Water Resources

4-46

(2) Parameter values, assumed ranges, probability distributions, and/or bounding

assumptions used in the modeling of ground-water cleanup are technically defensible

and reasonably account for uncertainties and variabilities. The technical bases for each

parameter value, ranges of values, or probability distributions used in the modeling of

the ground-water cleanup are provided.

Sensitivity analyses are provided that (i) identify aquifer flow and transport parameters

that are expected to significantly affect the site model outcome; (ii) test the degree to

which the performance of the ground-water cleanup may be affected if a range of

parameter values must be used as input to the model due to sparsity of, or uncertainty

in, available data; and (iii) test for the need for additional data.

Sufficient bases are provided for parameter values, representative parameter values are

taken from the literature, and the bounds and statistical distributions are provided for

hydrologic and transport parameters that are important to the estimation of cleanup time

and that are included in the modeling of the ground-water cleanup.

Site data fitted to theoretical models compare reasonably well. American Standard for

Testing and Materials D 5490 provides guidance for comparing ground-water flow model

simulations to site-specific information. If there is departure of site data from the

theoretical model, then an alternate model is considered. The assumptions used in

modeling are consistent with site data and observations.

Models used to describe local phenomena, such as the fluxes through the tailings pile,

are based on consistently applied conditions.

(3) Important design features, physical phenomena, and consistent and appropriate

assumptions are identified and described sufficiently for incorporation into any modeling

that supports the ground-water cleanup, including the estimate of cleanup time, and the

technical bases are provided. Detailed models and site-scale models used to support

the corrective action plan, or other supporting documents, and identify and describe

aspects that are important to the cleanup and the estimate of cleanup time. 

The licensee delineates the extent of the hazardous constituent plume, contaminant flow

paths in the aquifer considering natural site conditions, any effects that can be expected

to result from construction of additional facilities and operations (i.e., tailings ponds,

evaporation ponds, excavations), and events that may affect the spatial and temporal

distribution of the hazardous constituent plume. More specifically, the licensee’s models

of the ground-water cleanup consider and are consistent with (i) natural climatic,

geologic, and hydrologic conditions at the site and in the vicinity of the site; (ii) tailings

pile design and construction features and their potential impact on local recharge and

consequent flow paths in the aquifer; (iii) geochemical and other processes that can

affect the performance of the ground-water cleanup and estimation of cleanup time; and

(iv) future events, including additional construction and changes of plans for operations

that may occur at the site. The licensee also has determined the range of

concentrations of hazardous constituents that can be expected in the aquifer and their

changes with time during the ground-water cleanup.
Protecting Water Resources

4-47

The licensee estimates the total mass of hazardous constituents produced by the

leaching process and the quantity of the mass that is in the mill tailings, the aquifer, in

surface water bodies (including evaporation ponds, disposal cells, nearby ponds, and

rivers) and the portion that has been removed by means of the ground-water cleanup,

and accounts for the mass that will be removed for final disposal.

The licensee makes reasonable assumptions, if taking credit for dispersion of

hazardous constituents and consequent reduction of concentrations during transport

from the mill tailings to the point of compliance, for such processes as mechanical

dispersion and mixing with native ground water and surface water. These assumptions

are based on available data about the hydraulic and transport properties of the site and

the spatial variations of properties of aquifers and ground-water volumetric fluxes along

the flow paths.

The licensee provides an adequate basis for considering the effect of any reactive

transport and geochemical processes in simulating the ground-water cleanup operation,

if taking credit for sorption or any other geochemical reaction of hazardous constituents

and consequent reduction or retardation of concentrations during transport from the mill

tailings. Predicting the effects of proposed ground-water cleanup actions may include

forward, site-specific contaminant transport modeling. Often, such modeling has taken

a simple approach employing a retardation factor to describe all geochemical effects on

contaminant concentration. This approach may be too simplistic. The use of a constant

retardation factor and the neglect of speciation and water-mineral reactions is likely to

lead to prediction errors. Reactive transport models using codes such as PHREEQC

Version 2 (Parkhurst and Appello, 1999) are acceptable for constructing a geochemical

model for the site. Hostetler and Erickson (1993) discuss examples of the effect of

extending reactive transport models beyond simply including retardation in

advective-dispersive models. In one example involving cadmium transport at a uranium

mill tailings site, concentration profiles from the site suggest the importance of otavite

(CdCO3) solubility control on aqueous cadmium in the low-pH zones near the tailings

pond, and the inadequacy of modeling sorption alone.

Reactive transport models incorporate thermodynamic data on solid phases and

aqueous species, allowing the mass action calculations that determine estimated

aqueous concentrations and solid phase evolution. Thermodynamic parameters

constitute a major source of uncertainty in geochemical modeling [see Murphy and

Shock (1999) for a discussion of uranium], with potentially large effects on predicted

aqueous ion concentrations. Therefore, geochemical modeling supporting ground-water

corrective action plans includes sensitivity analyses that provide assurance that

contaminant concentrations will not be underestimated. Likewise, any kinetic models

employed are subjected to critical analysis because of the large influence of kinetic

effects at low temperatures.
Protecting Water Resources

4

Zhu C., F.Q. Hu, and D.S. Burden. “Multi-Component Reactive Transport Modeling of Natural Attenuation of an

Acid Ground-Water Plume at a Uranium Mill Tailings Site.” Journal of Contaminant Hydrology. 2001. Accepted

for publication.

4-48

Reactive transport model results are subject to the assumptions and limitations of the

conceptual and numerical models employed. For example, Zhu et al.4

 list model

limitations and briefly discuss how they may affect predictions. Geochemical

limitations include:

(a) The assumption of local equilibrium (i.e., kinetic rates were not employed).

(b) Modeled porosity not being affected by reactions affecting the solid phase.

(c) Omitting colloidal transport.

(d) Neglecting density effects due to varying total dissolved solids.

(e) Simplifying the mineralogical suite.

(f) Neglecting surface reactions such as ion exchange.

(g) Relying on bulk mineralogy rather than on mineral surface compositions.

Limitations such as these are typically due to factors such as lack of data, inadequate

computational equipment, or insufficient model development. Consideration of model

limitations and their effects on uncertainty is an important component of the review by

the NRC.

The numerical model of the site constructed by the licensee incorporates site-specific

information, is adequately validated and calibrated, and reasonably represents the

physical system. American Standard for Testing and Materials Reports D 5490 and

D 5981 provide guidance for ground-water flow model validation and calibration. The

professional experience and judgment of the reviewer should be applied in assessing

these aspects of the analyses.

The licensee identifies and properly integrates factors that are expected to affect, or that

are affected by, the ground-water cleanup. These include, but are not limited to, the

spatial and temporal variation of the flux of leachates from the mill tailings to the

underlying aquifer, drainage mechanisms of leachates from the mill tailings, spatial

variability in flow and transport properties of the aquifer underlying the mill tailings, and

geochemical processes that may affect the concentrations of hazardous constituents.

The licensee evaluates and documents the degree of conservatism in modeling the

ground-water cleanup, and the level of conservatism presumed by the licensee is

commensurate with the data and conceptual model uncertainty. 
Protecting Water Resources

4-49

(4) Alternate modeling approaches consistent with available data and current scientific

understanding are investigated where necessary, and results and limitations are

appropriately factored into the ground-water corrective action plan. The licensee

provides sufficient evidence that relevant site features have been considered, that the

models are consistent with available data and current scientific understanding, and that

the effects on cleanup time have been evaluated. Specifically, the licensee adequately

considers alternate modeling approaches where necessary to incorporate uncertainties

in site parameters and ensure they are propagated through the modeling.

Uncertainty in data interpretations is considered by analyzing reasonable conceptual

models that are supported by site data, or by demonstrating through sensitivity studies

that the uncertainties have little impact on the ground-water corrective action plan.

(5) The site-scale model for ground-water cleanup provides results consistent with the

output of detailed or site data. Specifically, the site model is consistent with detailed

models of geological, hydrological, and geochemical processes for the site. For

example, for flow and transport through the aquifer, hydraulic conductivity distributions

are reasonably consistent with sensitivity studies of the range of hydraulic

conductivities and varying statistical distributions, field observations, and laboratory

tests, when applicable.

The licensee documents how the model output is validated in relation to

site characteristics.

Where appropriate, in developing the site model for ground-water cleanup, the licensee

considers and evaluates alternate models that are reasonably justified by the available

database, with reasonable values assigned to distribution statistics to compensate for

limited data availability.

The licensee uses numerical and analytical modeling approaches reflecting varying

degrees of complexity consistent with information obtained from site characterization.

The licensee employs the upper and lower bounds of input parameter ranges to

examine the robustness of the modeling.

(6) Adequate waste management practices are defined.

The disposition of effluent generated during active remediation is addressed in the

corrective action plan. Appendix F to this standard review plan contains NRC staff

policy for effluent disposal at licensed uranium recovery facilities for conventional mills. 

When retention systems such as evaporation ponds are used, design considerations

from erosion protection and stability along with construction plans reviewed by a

qualified engineer are included. Evaporation and retention ponds should meet the

design requirements of 10 CFR Part 40, Appendix A, Criterion 5A. Ideally, the ponds

should have leak detection systems capable of reliably detecting a leak from the pond

into the ground water and should be located where they will not impede the timely

surface reclamation of the tailings impoundment.
Protecting Water Resources

4-50

If water is to be treated and reinjected, either into an upper aquifer or into a deep

disposal well, the injection program is approved by the appropriate State or Federal

authority. For release of this waste to surface waters, existing licensees must meet the

requirements of 10 CFR 20.1302(b)(2), and should demonstrate that doses are

maintained as low as reasonably achievable (ALARA). NRC has no specific

requirements for non-radiological constituents, and may adopt the appropriate State

limits. Anticipated discharge must be described in enough detail to evaluate

environmental impacts. Appropriate State and Federal agency permits should be

obtained in accordance with 10 CFR 20.2007.

(7) Appropriate site access control is provided by the licensee.

Site access control should be provided by the licensee until site closure to protect

human health and the environment from potential harm. Site access is controlled by

limiting access to the site with a fence and by conducting periodic inspections of the site.

(8) Effective corrective action and compliance monitoring programs are provided.

Licensees are required, by Criterion 7 of Appendix A to 10 CFR Part 40, to implement

corrective action and compliance monitoring programs. The licensee monitoring

programs are adequate to evaluate the effectiveness of ground-water cleanup and 

control activities, and to monitor compliance with ground-water cleanup standards. The

description of the monitoring program includes or references the following information:

(a) Quality assurance procedures used for collecting, handling, and analyzing

ground-water samples.

(b) The number of monitor wells and their locations.

(c) A list of constituents that are sampled and the monitoring frequency for each

monitored constituent.

(d) Action levels that trigger implementation of enhanced monitoring or revisions to

cleanup activities (i.e., timeliness and effectiveness of the corrective action).

For corrective action monitoring:

The same wells used to determine the nature and extent of contamination may

be used to monitor the progress of ground-water corrective action activities. 

However, once the extent of contamination is delineated, it may be possible to

adequately monitor compliance with fewer wells. Once selected, major changes

to monitored locations are avoided, because it is important to be able to directly

compare measurements made at different times. 

Licensees choose a monitoring interval that is appropriate for monitoring

corrective action progress. Not all hazardous constituents need to be monitored

at each interval. It is generally acceptable for licensees to choose a list of more

easily measured constituents that serve as good indicators of performance.
Protecting Water Resources

4-51

These indicators include conservative constituents that are less likely to be

attenuated, such as chloride, total dissolved solids, and alkalinity. However, if a

hazardous constituent is causing a demonstrated risk to human health or the

environment, that constituent must be monitored during the corrective action. 

Ground water at designated monitor wells is sampled for all hazardous

constituents at the end of each major phase of corrective action and again

before license termination and transfer of the site to the custodial agency for

long-term custody.

For compliance monitoring, after a corrective action program has been

terminated, compliance monitoring at the point of compliance will resume for the

duration of the compliance period, until license termination, as defined in 10 CFR

Part 40, Appendix A, Criterion 7A.

(9) Design of Surface Impoundments.

The reviewer should verify that any impoundment built as part of the corrective action

program to contain wastes is acceptably designed, constructed, and installed. The

design, installation, and operation of these surface impoundments must meet relevant

guidance in Regulatory Guide 3.11, Section 1 (NRC 1977). Materials used to construct

the liner should be reviewed to determine that they have acceptable chemical properties

and sufficient strength for the design application. The reviewer should confirm that the

liner will not be overtopped. The reviewer should also confirm that a proper quality

control program is in place.

The review should ensure that the applicable requirements of 10 CFR Part 40,

Appendix A, Criterion 5(A) have been met. If the waste water retention impoundments

are located below grade, the reviewer should determine that the surface impoundments

have an acceptable liner to ensure protection of ground water. The location of a surface

impoundment below grade will eliminate the likelihood of embankment failure that could

result in release of waste water. The reviewer should determine that the design of

associated dikes is such that they will not experience massive failure.

The design of a clay or synthetic liner and its component parts should be presented. At

a minimum, design details, drawings, and pertinent analyses should be provided. 

Expected construction methods, testing criteria, and quality assurance programs should

be presented. Planned modes of operation, inspection, and maintenance should be

discussed in the application. Deviations from these plans should be submitted to the

staff for approval before implementation.

The liner for a surface impoundment used to manage uranium and thorium byproduct

material must be designed, constructed, and installed to prevent any migration of

wastes out of the impoundment to the subsurface soil, ground water, or surface water at

any time during the active life of the surface impoundment. The liner may be

constructed of materials that allow wastes to migrate into the liner provided that the

impoundment decommissioning includes removal or decontamination of all waste

residues, contaminated containment system components, contaminated subsoils, and

structures and equipment contaminated with waste and leachate.
Protecting Water Resources

4-52

The liner must be constructed of materials that have appropriate chemical properties

and sufficient strength and thickness to prevent failure caused by pressure gradients,

physical contact with the waste or leachate, climatic conditions, and the stresses of

installation and daily operation. The subgrade must be sufficient to prevent failure of the

liner caused by settlement, compression, or uplift. Liners must be installed to cover all

surrounding earth that is likely to be in contact with the wastes or leachate. 

Tests should show conclusively that the liner will not deteriorate when subjected to the

waste products and expected environmental and temperature conditions at the site. 

Applicant test data and all available manufacturers test data should be submitted with

the application for this purpose. For clay liners, tests, at a minimum, should consist of

falling head permeameter tests performed on columns of liner material obtained during

and after liner installation. The expected reaction of the impoundment liner to any

combination of solutions or environmental conditions should be known before the liner is

exposed to them. Field seams of synthetic liners should be tested along the entire

length of the seam. Representative sampling may be used for factory seams. The

testing should use state-of-the-art test methods recommended by the liner

manufacturer. Compatibility tests that document the compatibility of the field seam

material with the waste products and expected environmental conditions should be

submitted for staff review and approval. If it is necessary to repair the liner,

representatives of the liner manufacturer should be called on to supervise the repairs.

Proper preparation of the subgrade and slopes of an impoundment is very important to

the success of the surface impoundment. The strength of the liner is heavily dependent

on the stability of the slopes of the subgrade. The subgrade should be treated with a

soil sterilant. The subgrade surface for a synthetic liner should be graded to a surface

tolerance of less than 2.54 cm [1 in.] across a 30.3-cm [1-ft] straightedge. NRC

Regulatory Guide 3.11, Section 2 (NRC, 1977) outlines acceptable methods for slope

stability and settlement analyses, and should be used for design. If a surface

impoundment with a synthetic liner is located in an area in which the water table could

rise above the bottom of the liner, underdrains may be required. The impoundment will

be inspected in accordance with Regulatory Guide 3.11.1 (NRC, 1980).

To prevent damage to liners, some form of protection should be provided, such as

(a) soil covers, (b) venting systems, (c) diversion ditches, (d) side slope protection, or

(e) game-proof fences. A program for maintenance of the liner features should be

developed, and repair techniques should be planned in advance.

The surface impoundment must have sufficient capacity and must be designed,

constructed, maintained, and operated to prevent overtopping resulting from (a) normal

or abnormal operations, overfilling, wind and wave actions, rainfall, or run-on;

(b) malfunctions of level controllers, alarms, and other equipment; and (c) human error. 

If dikes are used to form the surface impoundment, they must be designed, constructed,

and maintained with sufficient structural integrity to prevent their massive failure. In

ensuring structural integrity, the applicant must not assume that the liner system will

function without leakage during the active life of the impoundment.
Protecting Water Resources

4-53

Controls should be established over access to the impoundment, including access

during routine maintenance. A procedure should be developed that ensures

unnecessary traffic is not directed to the impoundment area. A program should be

established to ensure that daily inspections of tailings or waste impoundment systems

are conducted and recorded and that failures or unusual conditions are reported to

the NRC.

In addition, the reviewer should evaluate the proposed surface impoundment to

determine if it meets the definition of a dam as given in Regulatory Guide 3.11

(NRC, 1977). If this is the case, the surface impoundment should be included in the

NRC dam safety program, and be subject to Section 215, “National Dam Safety

Program,” of the Water Resources Development Act of 1996. If the reviewer finds that

the impoundment conforms to the definition of a dam, the dam ranking (low or high

hazard) should be evaluated. If the dam is considered a high hazard, an emergency

action plan is needed consistent with Federal Emergency Management Agency

requirements. For low hazard dams, no emergency action plan is required. For either

ranking of dam, the reviewer should also verify that the licensee has an acceptable

inspection program in place to ensure that the dikes are routinely checked, and that

performance is properly maintained.

A quality control program should be established for the following factors: (a) clearing,

grubbing, and stripping; (b) excavation and backfill; (c) rolling; (d) compaction and

moisture control; (e) finishing; (f) subgrade sterilization; and (g) liner subdrainage and

gas venting.

(10) Financial Surety Is Provided.

The licensee must maintain a financial surety, within the specific license, for the cleanup

of ground water, with the surety sufficient to recover the anticipated cost and time frame

for achieving compliance, before the land is transferred to the long-term custodian. The

financial surety must be sufficient to cover the cost of corrective action measures that

will have to be implemented if required to restore ground-water quality to the established

site-specific standards (including an alternate concentration limit standard) before the

site is transferred to the government for long-term custody. Guidance on establishing

financial surety is presented in NRC (1988, 1997). Appendix C to this standard review

plan provides an outline of the cost elements appropriate for establishing surety

amounts for conventional uranium mills. The financial surety review is acceptable if the

applicant’s assessment and any staff assessment of the surety amounts are reasonably

consistent.

4.4.4 Evaluation Findings

If the staff review, as described in standard review plan Section 4.4, results in the acceptance

of the ground-water corrective action plan and compliance-monitoring plans, the following

conclusions may be presented in the technical evaluation report:

The staff has completed its review of the ground-water corrective action and compliance

monitoring plans at the uranium mill facility. This review included an
Protecting Water Resources

4-54

evaluation using the review procedures in Section 4.4.2 and the acceptance criteria outlined in

Section 4.4.3 of this standard review plan. The ground-water corrective action program should

achieve the goal of returning hazardous constituent concentration levels in ground water to the

concentration limits set as standards in 10 CFR Part 40, Appendix A, Criterion 5D. The

monitoring program will provide reasonable assurance that, after the corrective actions have

been taken, the ground-water protection standard will not be exceeded.

The licensee has established a ground-water compliance strategy that is acceptable for the site. 

The strategy consists either of no remediation or active remediation when contaminants are

present at concentrations above background levels, maximum concentration limits, or alternate

concentration limits. When active remediation is necessary, the remedial action design and

implementation are acceptable. The licensee has acceptably presented pumping/injection

rates, treatment methods, equipment and maintenance requirements, and plans and schedules

for construction, and has produced maps showing locations of remediation equipment. An

analysis has been conducted that demonstrates (1) the chosen active remediation system

technology is appropriate for the site conditions, (2) design pumping rates are sustainable and

will control migration of contaminants away from the site, and (3) the natural heterogeneity of

the system has been acceptably accounted for in a conservative remediation strategy. The

licensee has identified acceptable waste management practices. Qualified engineers, state

authorities, and national agencies have provided appropriate oversight. Institutional controls

are appropriate for the site, including (1) controlling access to the site, (2) conducting periodic

inspections, and (3) periodically monitoring cleanup performance. The monitoring program

includes (1) a description of quality assurance procedures; (2) the number of monitoring wells

and their locations; (3) a list of constituents that will be sampled, along with the sampling

frequency for each monitored constituent; and (4) action levels for triggering enhanced

monitoring or revisions to cleanup activities. The licensee has described an acceptable scheme

for cleanup and compliance monitoring. The licensee will sample ground water at the point of

compliance for all hazardous constituents of concern. An adequate surety mechanism and

fund has been established to support the ground-water cleanup.

On the basis of the information presented in the application and the detailed review conducted

of the ground-water corrective action and compliance monitoring plans for the

 uranium mill facility, the NRC staff concludes that the information is

acceptable and is in compliance with the following criteria in 10 CFR Part 40, Appendix A:

Criteria 5A(4) and 5A(5), which require proper operation of impoundments and design of dikes;

Criterion 5B, which requires NRC to establish a list of hazardous constituents, concentration

limits, a point of compliance, and a compliance period; Criterion 5C, which provides a table of

secondary concentration limits for certain constituents when they are present in ground water

above background concentrations; Criterion 5(D), which provides requirements for a groundwater corrective action program; Criterion 5E, which requires licensees conducting

ground-water protection programs to consider the use of bottom liners, recycle of solutions and

conservation of water, dewatering of tailings, and neutralization to immobilize hazardous

constituents; Criterion 5F, which requires that, where ground-water impacts from seepage are

occurring at an existing site, action must be taken to alleviate the conditions that lead to

seepage, and ground-water quality must be restored, including providing technical

specifications for the seepage control system and implementation of a quality assurance

program; Criterion 5G, which requires licensees to perform site characterization in support of a

tailings disposal system proposal; Criterion 5H, which requires steps be taken during stockpiling
Protecting Water Resources

4-55

of ore to minimize penetration of radionuclides into underlying soils; Criterion 7A, which

provides for establishment of three types of monitoring systems: detection, compliance, and

corrective action; Criterion 8A, which requires proper inspection and documentation of the

operation of tailings and waste retention systems; and Criterion 13, which provides a list of

hazardous constituents that must be considered when establishing the list of hazardous

constituents in ground water at any site.

If surface impoundments are to be used at the facility to manage byproduct material, the design

of dikes used to construct surface-water impoundments has been demonstrated to comply with

Regulatory Guide 3.11, Sections 2 and 3 (NRC, 1977) and, therefore, comply with requirements

of 10 CFR Part 40, Appendix A, Criterion 5(A)5. In addition, because the impoundment dikes

may conform to the definition of a dam as given in the Federal Guidelines for Dam Safety, they

are subject to the NRC dam safety program, and to Section 215, “National Dam Safety

Program, of the Water Resources Development Act of 1966.”

Surety funds and funding methods proposed by the applicant comply with 10 CFR Part 40,

Appendix A, Criteria 9 and 10, which establish financial requirements for conventional

uranium mills.

4.4.5 References

American Society for Testing and Materials Standards

D 5447, “Standard Guide for Application of a Ground-Water Flow Model to a SiteSpecific Problem.”

D 5490, “Standard Guide for Comparing Ground-Water Flow Model Simulations to

Site-Specific Information.”

D 5609, “Standard Guide for Defining Boundary Conditions in Ground-Water

Flow Modeling.”

D 5611, “Standard Guide for Conducting a Sensitivity Analysis for a Ground-Water Flow

Model Application.”

D 5718, “Standard Guide for Documenting a Ground-Water Flow Model Application.”

D 5880, “Standard Guide for Subsurface Flow and Transport Modeling.”

D 5981, “Standard Guide for Calibrating a Ground-Water Flow Model Application.”

Hostetler, C.J. and R. L. Erickson. “Coupling of Speciation and Transport Models.” Metals in

Groundwater. H.E. Allen, E.M. Perdue, and D.S. Brown, eds. Chelsea, Michigan: Lewis

Publishers. pp. 173–208. 1993.

Murphy, W.M. and E.L. Shock. “Environmental Aqueous Geochemistry of Actinides.” Uranium:

Mineralogy, Geochemistry, and the Environment. P.C. Burns and R. Finch, eds. San Antonio,

Texas: Center for Nuclear Waste Regulatory Analyses. 1999.
Protecting Water Resources

4-56

Parkhurst, D.L. and A.A.J. Appello. “User’s Guide to PHREEQC (Version 2)—A Computer

Program for Speciation, Batch-Reaction, One Dimensional Transport, and Inverse Geochemical

Modeling.” 99-4259. Washington, DC: U.S. Geological Survey. 1999.

Talisman Partners, Ltd. “Introduction to RACER 2000TM (Version 2.1.0). A Quick Reference.”

Englewood, Colorado: Talisman Partners, Ltd. 2000.

NRC. “Technical Position on Financial Assurances for Restoration, Decommissioning, and

Long-Term Surveillance and Control of Uranium Recovery Facilities.” Washington DC:

NRC. 1988.

–––––. Regulatory Guide 3.11.1, “Operational Inspection and Surveillance of Embankment

Retention Systems for Uranium Mill Tailings.” Rev. 1. Washington, DC: NRC, Office of

Standards Development. 1980.

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

Retention Systems for Uranium Mills.” Washington, DC: NRC, Office of Standards

Development. 1977.
5-1

5.0 RADIATION PROTECTION

This chapter of the standard review plan establishes the guidelines for NRC staff to perform

and document its review of the proposed radiation protection design for disposal cell covers, for

the cleanup of soil and structures contaminated with byproduct material (soil removal, building

demolition and disposal or decontamination), and for the proposed radiation safety controls and

monitoring during reclamation and decommissioning activities. The radiation standards to be

addressed in the evaluation of the reclamation plan include 10 CFR Part 40, Appendix A,

Criterion 6(1), which establishes a long-term radon flux limit and direct gamma exposure

(background) level for the tailings disposal cell cover, and Criterion 6(5), which requires that the

radioactivity of near-surface cover materials be essentially the same as surrounding surface

soils. Also, the decommissioning plan, whether submitted as part of the reclamation plan or

provided in detail as a separate document, should comply with 10 CFR 40.42(g)(4) and (5,)

which requires a description or procedures indicating how the licensee will demonstrate that the

residual radioactivity levels in land and on structure surfaces meet Appendix A, Criterion 6(6)

(see Appendix H guidance in this standard review plan on the radium benchmark dose

approach for cleanup of residual radionuclides other than radium). In the review, the staff

should consider any licensee-proposed alternatives to Appendix A criteria as described in the

Introduction of Appendix A to 10 CFR Part 40. 

5.1 Disposal Cell Cover Radon and Gamma Attenuation and

Radioactivity Content

5.1.1 Areas of Review

The areas of review for radon attenuation (radon barrier design) are the radiological and

physical properties of the contaminated and cover materials and the application of the computer

code or other methods used for calculating the estimated long-term radon flux from the

completed disposal cell. The areas of review for the control of gamma radiation from the

disposed waste and for the radioactivity content of the cover are the proposed methods to

demonstrate compliance with the regulations. This area would also include consideration of

disposal of wastes from processing alternate feed materials and non-11e.(2) byproduct material

in uranium mill tailings impoundments, if such action is proposed.

The radon barrier portion of the disposal cell cover is the layer or layers designed to reduce

radon flux from the cell. Other cover layers contribute to radon attenuation and may be

considered in the flux calculation.

For the radon barrier design, the staff should review (1) the bases, assumptions, and

procedures for determining the input parameter values of the tailings and other wastes and

radon barrier materials (such as the sampling and testing programs); (2) procedures for

materials placement in the disposal cell, as presented in the reclamation plan construction

specifications; (3) the description of the model (numerical or analytical) used to approximate the

average long-term radon flux at the cover surface; and (4) if the standard computer codes for

estimating radon flux (RADON, RAECOM) are not used, references for the methodology used

to calculate the long-term radon flux from the cover.
Radiation Protection

5-2

For cover gamma attenuation, the staff reviews the proposed procedure to calculate or

measure the gamma level (exposure rate or count rate) on the cover. For the radioactivity

content, the staff should review the proposal for measurements in the upper 61 cm [2 ft] of

cover. Alternatively, the staff should review proposed control measures on the cover material

before placement to demonstrate that the average radioactivity content of this layer is not

distinguishable from local surface soil and to demonstrate that it does not include waste or rock

containing elevated levels of radium.

5.1.2 Review Procedures

5.1.2.1 Radon Attenuation

The radon barrier design, as presented in the reclamation plan, should be reviewed along with

the data supporting the design. Chapter 2.0 of this standard review plan presents review areas,

procedures, and acceptance criteria for geotechnical information related to material properties

and cell stability. The staff members assigned the health physics and geotechnical reviews

should coordinate the review of the radon attenuation design and analysis. The geotechnical

properties of the cover layers will be considered in the context of their influence on the cover

integrity by considering long-term moisture content of the radon barrier. Materials underlying

the radon barrier are evaluated for stability so that the cover will not experience cracking from

settlement or subsidence, as discussed in Chapter 2.0.

In addition, the health physics reviewer should:

(1) Evaluate the basis for selection of parameter values for tailings and cover material

properties to determine if the values are based on appropriate measurements or

estimates and will lead to a reasonably conservative estimate of the radon flux. The

scope and techniques used for site investigations should be examined to ensure that the

field investigation (boring, sampling, and surveying) and testing programs will produce

representative data needed to support the conclusions of the analyses. 

(2) Assess whether parameter values are consistent with anticipated construction

specifications and reflect expected long-term conditions at the site. The radon flux

estimate must represent the average flux, for periods of more than 1 year but less than

100 years, and consider that the cell design life is 1,000 years. 

(3) Determine whether the parameter values reflect the meteorological and hydrological

conditions at the disposal site, bulk density, type of material, and the influence of

overlying material layers. The cover material moisture content must be determined by

accurately measured values or reasonably conservative estimates. Preferably more

than one method is utilized, as there are limitations to each method and the long-term

moisture content of the radon barrier is one of the most important parameters in the

flux model. 

(4) Determine that the radium (Ra-226) activity concentration in picocuries per gram (pCi/g)

within the tailings cell has been, or will be, measured directly from representative tailings
Radiation Protection

5-3

samples, and other large-volume sources of contaminated material, utilizing an

acceptable method. If the tailings were placed so that specific areas in the pile contain

higher Ra-226 content (e.g., slime tailings), then Ra-226 values and the modeling

should represent the layering or localization of the significantly elevated Ra-226 levels in

the upper 3.6 m [12 ft], as deeper material generally has little effect on the radon flux.

This approach is necessary because modeling higher concentrations of Ra-226 in the

upper few feet of the pile would result in a higher radon flux estimate than using an

average Ra-226 value for the entire upper 3.6 m [12 ft]. Also, if large quantities of

material containing thorium-230 (Th-230) levels significantly higher than the Ra-226

levels are placed in the upper portion of the pile, the 1,000-year Ra-226 concentration

(Ra-226 remaining from the residual Ra-226 and from the decay of Th-230) should be

considered for that layer of material in the modeling.

In accordance with Footnote 2 of Criterion 6(1), the radon emissions from covering

materials should be estimated as part of developing a closure (reclamation and

decommissioning) plan. If any layer of the cover will contain material with

above-background levels of Ra-226 or Th-230, the licensee should model that layer with

a conservatively high estimated Ra-226 level, or should commit to measure the cover

radionuclide level(s) during or after placement to confirm the adequacy of the radon

attenuation design. A commitment from the licensee to confirm the cover Ra-226

content in the reclamation completion report should be present if the borrow site

measurements are limited and the possible cover Ra-226 level could prevent the radon

flux from being in compliance.

(5) Evaluate each code input parameter value, keeping in mind that the code default

parameter values are not always conservative, and then consider the set of parameter

values as a whole (balance of conservatism and uncertainty). It is the total flux model

that will be approved, not individual parameter values. Consider that the void ratio, the

density, porosity, and moisture saturation values should be typical of the soil type in

each layer of the cell. The radon flux model should result in a representative and a

reasonably conservative (given the uncertainty in some values) long-term radon

flux estimate.

(6) A measured, not a calculated, disposal cell average radon flux is required by

Appendix A, Criterion 6(2), as soon as practical after placement of the radon barrier, and

Criterion 6(3) stipulates that radon-222 release rates must be verified for each portion of

the pile or impoundment as the final radon barrier for that portion is placed, when

phased emplacement of the final radon barrier is included in the applicable reclamation

plan required by 10 CFR Part 40, Appendix A, Criterion 6A(1). Therefore, the reviewer

should document in the technical evaluation report whether the reclamation plan

stipulates if the radon barrier is to be placed in phases or as a fairly continuous

operation. In either case, the final radon barrier must be placed as expeditiously as

practicable. However, some tailings cells have evaporation ponds on top that can’t be

covered until the ground-water correct action is complete. A commitment to measure

and document the radon flux on the final radon barrier, as required by Criterion 6(2)

and (4), should be in the reclamation plan. Before the measurements are performed, a

map of the disposal cell indicating the measurement locations and outline of tailings and
Radiation Protection

5-4

cover extent should be reviewed by the NRC staff before the measurements

are performed.

(7) Guidance on the disposal of wastes from processing alternate feed materials and

non-11e.(2) byproduct materials in uranium mill tailings impoundments is presented in

Appendix I to this standard review plan. The staff should use this guidance when

evaluating requests to dispose of such materials and consider their impact on the radon

attenuation design.

5.1.2.2 Gamma Attenuation

Most radon barriers should be thick enough to reduce the gamma level of the disposal cell to

background. To demonstrate compliance with this aspect of Criterion 6(1), the cover gamma

attenuation can be calculated based on the shielding value of the cover soil. Alternatively, the

licensee commits to (1) measure the gamma level at 1 meter above the completed cover (or

radon barrier) with at least one measurement per acre and (2) demonstrate that the average

gamma level for the cell is comparable to the local background value.

5.1.2.3 Cover Radioactivity Content

At some mill facilities, uranium deposits, open pit uranium mines, overburden piles (soil moved

from the pit area), and/or reclaimed mining areas are on or near the site. All of these areas

would contain elevated levels of uranium, radium, and the other radionuclides in the uranium

decay chain. In determining what surrounding soil values may be compared to the radionuclide

content of the disposal cell cover, the mining areas reclaimed/restored under state regulations

may be included. Also, consideration of the low health risk of human exposure to the cell cover

and the perpetual custody of the cell by the government may be part of the risk-informed

approach. If the average radioactivity (mainly radium level) for the cover material exceeds the

average value for surrounding soil, the reclamation plan should contain a statistical analysis of

the distributions of surrounding soil (not necessarily undisturbed background) and cover

radioactivity to demonstrate that they are not significantly different.

5.1.3 Acceptance Criteria

5.1.3.1 Radon Attenuation

The radon attenuation design will be acceptable if it meets the following criteria:

(1) The one-dimensional, steady-state gas diffusion theory for calculating radon flux and/or

minimum cover thickness is used. An acceptable analytical method for determining the

necessary cover thickness to reduce radon flux to acceptable limits or to determine the

long-term radon flux from the proposed cover is the computer code RAECOM

(NRC, 1984) and the comparable RADON code (NRC, 1989). The main difference

between the two codes is that RADON does not have the optimization for cost benefit

calculations. The staff will use the RADON code to verify the analysis. Other methods

that estimate the average surface radon release from the covered tailings may be
Radiation Protection

5-5

acceptable, if it can be shown that these methods produce reliable estimates of

radon flux.

(2) With the RAECOM and RADON computer codes, the radon concentration above the top

layer is either set to a conservative value of zero or a measured background value is

used. The precision number (the level of computational error that is acceptable) is set

at 0.001.

(3) The estimates of the material parameters used in the radon flux calculations are

reasonably conservative, considering the uncertainty of the values. For all site-specific

parameters, supporting information describing the test method and its precision,

accuracy, and applicability is provided. The basis for the parameter values and the

methods in which the values are used in the analyses are adequately presented.

Moisture-dependent parameter values (e.g., radon emanation coefficient and diffusion

coefficient) are based on the estimated long-term moisture content of the materials at

the disposal site. 

The materials testing programs employ appropriate analytical methods and sufficient

and representative samples were tested to adequately determine material property

values for both cover soils and contaminated materials. In the absence of sufficient test

data, conservative estimates are chosen and justified. The quality assurance program

for parameter data is adequate and the data are available for inspection. All parameter

values are consistent with anticipated construction specifications and represent

expected long-term conditions at the site.

(4) The contaminated material thickness is determined from estimates of total tailings

production or waste placement and the areal extent, from boring logs, or changes in

elevation from pre- to post-operation. Either the estimated thickness of a tailings source

is used, or alternatively, the RADON code default value of 500 cm [16.4 ft] is used

(NRC, 1989).

(5) Dry bulk densities of the cover soils and tailings material are determined from Standard

Proctor Test data (American Society for Testing and Materials D 698) or Modified

Proctor Test data (American Society for Testing and Materials D 1557). Radon barrier

materials are usually compacted to a minimum of 95 percent of the maximum dry

density as determined by American Society for Testing and Materials D 698 or to a

minimum of 90 percent of the maximum dry density as determined by American Society

for Testing and Materials D 1557. Field or placement densities to be achieved based on

the construction specifications are used in the calculations. If the pile is stabilized in

place, the in situ bulk density for the tailings is used in the analysis.

Porosities are measured by mercury porosimetry or another reliable method, or the

method for estimating the porosity of cover soils and tailings materials using the bulk

density and specific gravity given in Regulatory Guide 3.64 (NRC, 1989) is used.

If a portion of the modeled cover (radon attenuation layers) could be affected by

freeze-thaw events, that portion is represented in the model with lower density and
Radiation Protection

5-6

corresponding higher porosity values than the unaffected portion. The U.S. Army Corps

of Engineers (1988) and the DOE (1988) have demonstrated that freeze-thaw cycles

can increase the permeability of compacted clay by 40 to 300 times the original value. 

For fine-grained soils with some sand (50-percent fines), the DOE conservatively

estimated that freeze-thaw cycles could lower the density by 14 percent (DOE, 1992). 

Also see the discussion in Section 2.5.3 of this standard review plan.

(6) The long-term moisture content that approximates the lower moisture retention

capacities of the materials or another justified value is used. Estimated values for the

long-term moisture content can be compared with present in situ values to assure that

the assumed long-term value does not exceed the present field value. Borrow samples

can be taken at a depth of 120 to 500 cm (3.9 to 16.4 ft), but not close to the water

table, and the borrow site conditions should be correlated to conditions at the

disposal site.

The following methods are acceptable for estimating the long-term soil moisture, but

each has limitations:

(a) Laboratory procedures American Society for Testing and Materials D 3152

(fine-textured soils) and American Society for Testing and Materials D 2325

(coarse and medium-textured soils) for capillary moisture test (15-bar suction)

corresponding to the moisture content at which permanent wilting of plants

occurs (Baver, 1956).

(b) The empirical relationship (Rawls and Brakensiek, 1982) that predicts water 

retention values of a soil on a volume basis (appears to be more suitable to

sandy and silty soil than to clayey soil) and is represented by:

c = 0.026 + 0.005x + 0.0158y 

 where

c = predicted 15-bar soil water-retention value (volumetric moisture content)

x = percent clay in the soil

 y = percent organic matter in the soil

This method takes into consideration the particle-size distribution of the soil. Clay

particle sizes are defined here as those less than 0.002 mm in diameter. Organic

content measurement is generally determined by reaction with hydrogen peroxide or

by exposure to elevated temperature. The volumetric moisture content value derived

from this equation should be converted to a weight percentage for application in the

RAECOM and RADON codes. Other empirical correlations (Section 7.1.3 of DOE,

1989), if adequately justified, may be acceptable.

(7) Values for Ra-226 activity (pCi/g) are measured directly from tailings samples and other

large volume sources of contaminated material, by radon equilibrium gamma

spectroscopy (allow at least 10 days for the sealed sample to equilibrate), wet chemistry
Radiation Protection

5-7

alpha spectrometry, or an equivalent procedure. If the tailings are fairly uniform in

Ra-226 content and the Ra-226 and uranium (U-238) in the ore were approximately in

equilibrium, the Ra-226 activity can be estimated from the average ore grade processed

at the site, as discussed in Regulatory Guide 3.64 (NRC, 1989). Generally, tailings

should be sampled at 90-cm [3-ft] intervals to a depth of 366 cm [12 ft], including

representative sampling of slime tailings. More than one layer of contaminated material

is represented in the flux model if there are significant differences in Ra-226 content

with depth.

Since the disposal cell performance standard deals only with radon generated by the

contaminated material, it is acceptable to neglect the Ra-226 activity in the cover soils

for modeling flux, provided the cover soils are obtained from materials not associated

with ore formations or other radium-enriched materials. If deep {below 61 cm [2 ft]}

cover layers contain elevated Ra-226 or Th-230, that material layer and its Ra-226 level

is represented in the flux model.

(8) The emanation coefficient has been obtained by using methods provided in Nielson, et

al. (1982) and properly documented, or otherwise set to the reasonably conservative (for

most soils) code default value of 0.35. A value of 0.20 may be estimated for tailings

based on the literature, if supported by limited site-specific measurements.

(9) The radon diffusion coefficient, D, represents the long-term properties of the materials.

The D value is determined from direct measurements or appropriately calculated. The

soil should be tested at the design compaction density, with a range of moisture content

values that includes the lower moisture retention capacity of the soil so that a radon

breakthrough curve can be obtained (DOE, 1989). The calculation of the diffusion

coefficient, based on the long-term moisture saturation, and porosity, as proposed in

Regulatory Guide 3.64, Section C.1.1.5 (NRC, 1989), and the optional calculation in the

RADON code, are acceptable.

(10) The soil cover thickness proposed in the reclamation design is such that the calculated

average long-term radon flux is reduced to a level that meets the requirement in

10 CFR Part 40, Appendix A, Criterion 6(1).

5.1.3.2 Gamma Attenuation

The proposed cover will reduce the gamma radiation from the byproduct material to local soil

background levels, and the licensee proposed an acceptable method to demonstrate this. The

data will appear in the reclamation completion report.

5.1.3.3 Cover Radioactivity Content

At least the upper 61 cm [2 ft] of the disposal cell cover will contain levels of radioactivity

essentially the same as surrounding soils, as demonstrated by an appropriate procedure. The

data will be in the reclamation completion report if not available for the reclamation plan.
Radiation Protection

5-8

5.1.4 Evaluation Findings

If the staff review, as described in this section, results in the acceptance of the radon and

gamma attenuation and cover radioactivity content assessments, the following conclusions may

be presented in the technical evaluation report:

The staff has completed its review of the disposal cell cover radiation control at the

 uranium mill facility. This review included an evaluation using the review

procedures in Section 5.1.2, and the acceptance criteria outlined in Section 5.1.3 of

this standard review plan.

The licensee has presented an acceptable radon attenuation design, and the staff evaluation

determines that (1) the method used for calculating radon flux or minimum cover thickness is

based on the one-dimensional, steady-state gas diffusion theory and appropriate input values;

(2) input values of the material parameters lead to a reasonably conservative estimate of the

long-term radon flux; (3) material parameters are consistent with construction specifications and

expected long-term conditions; (4) the long-term attenuating capability of cover materials is

justified using acceptable results of relevant tests or conservative estimates; (5) estimates of

contaminated materials thickness are determined utilizing a sufficient number of data or by use

of the default value; (6) if not measured, the estimated porosity of cover soils and tailings

materials is based on the method in Regulatory Guide 3.64; (7) soil moisture values represent

long-term moisture retention capacities; (8) Ra-226 activity has been measured in the tailings

and other large volume sources of contaminated materials using acceptable procedures; (9) the

emanation coefficient is obtained by either the equilibration method or the prediction method, or

is set to a reasonably conservative value of 0.35; (10) the radon diffusion coefficient of the

cover soil is determined from direct measurements or from a calculation based on Regulatory

Guide 3.64; and (11) the cover gamma level and radioactivity content will be correctly

determined and documented.

On the basis of the information presented in the application and in detailed review conducted of

the site characterization for the uranium mill facility, the NRC staff

concludes that the disposal cell cover radon and gamma attenuation and radioactivity content

are in compliance with 10 CFR Part 40, Appendix A, Criterion 6(1), which requires placement of

an earthen cover (or approved alternative) over tailings and wastes at the end of the milling

operations while providing assurance of control of radiological hazards for 1,000 years, to the

extent reasonably achievable (but no less than 200 years); and which limits releases of

radon-222 from uranium byproduct materials to the atmosphere so as not to exceed an average

rate of 20 picocuries per square meter per second (pCi/m2

-s); Criterion 6(2), which requires

demonstration of the effectiveness of the final radon barrier prior to emplacement of erosion

protection measures or other features; Criterion 6(3), which requires demonstration of the

effectiveness of phased placement of radon barriers as each phase is completed if phased

placement is in the plan; and Criterion 6(5), which requires that radon exhalation is not

significantly above background because of the cover material.
Radiation Protection

5-9

5.1.5 References

American Society for Testing and Materials Standards:

D 698-91, “Test Method for Laboratory Compaction Characteristics of Soil Using

Standard Effort.”

D 1557-91, “Test Method for Laboratory Compaction Characteristics of Soil Using

Modified Effort.”

D 2325-68, “Standard Test Method for Capillary-Moisture Relationships for Coarse- and

Medium-Textured Soils by Porous-Plate Apparatus.”

D 3152-72, “Standard Test Method for Capillary-Moisture Relationships for

Fine-Textured Soils by Pressure-membrane Apparatus.”

Baver, L.D. Soil Physics. New York, New York: John Wiley and Sons. pp. 283–303. 1956.

DOE. 1988. “Effect of Freezing and Thawing on UMTRA Covers.” Albuquerque, New Mexico: 

DOE, Uranium Mill Tailings Remedial Action Project. 1988.

–––––. “Technical Approach Document.” UMTRA–DOE/AL–050425.0002. Revision II. 

Albuquerque, New Mexico: DOE. December 1989.

–––––. “Remedial Action Plan and Site Design for Stabilization of the Inactive Uranium Mill

Tailings Site at Gunnison, Colorado.” Remedial Action Selection Report.

UMTRA–DOE/AL–050508. Albuquerque, New Mexico: DOE. October 1992.

Nielson, K.K., et al. “Radon Emanation Characteristics of Uranium Mill Tailings.” Proceedings

of the Symposium on Uranium Mill Tailings Management December 9–10. Ft. Collins,

Colorado: Colorado State University. 1982.

NRC. NUREG/CR–3533, “Radon Attenuation Handbook for Uranium Mill Tailings Cover

Design.” Washington, DC: NRC. 1984.

–––––. Regulatory Guide 3.64, “Calculation of Radon Flux Attenuation by Earthen Uranium Mill

Tailings Covers.” Washington, DC: NRC. 1989.

Rawls, W.J. and D.L. Brakensiek. “Estimating Soil Water Retention From Soil Properties.”

Proceedings of the American Society of Civil Engineers. Journal of the Irrigation and Drainage

Division. Vol. 108, No. IR2. 1982.

U.S. Army Corps of Engineers. “Effects of Freezing and Thawing on the Permeability of

Compacted Clay.” Hanover, New Hampshire: Cold Regions Research and Engineering

Laboratory. 1988.
Radiation Protection

5-10

5.2 Decommissioning Plan for Land and Structures

5.2.1 Areas of Review

The areas of review for the decommissioning (radiological cleanup and restoration) of land and

structures (e.g., towers and buildings) are the site conditions (nature and extent of the

contamination, soil background radioactivity, etc.); planned decommissioning activities (how

and what measurements will be made, quality assurance quality control program, gamma

guideline levels for soil cleanup, how “as low as is reasonably achievable” will be

demonstrated); methods to be used to protect workers, the public, and the environment;

verification (final status survey) plan with procedures; and the decommissioning cost estimate

and surety amount. Often, the detailed mill decommissioning plan and the soil cleanup and

verification plan are submitted for NRC approval a year before decommissioning is scheduled

to begin. However, the reclamation plan must describe the expected decommissioning

activities in enough detail to support the cost estimate needed for surety purposes. The

preliminary decommissioning plan in the reclamation plan should include commitments to

provide a detailed plan and cost estimate for NRC approval at least 9 months before

decommissioning is expected to begin.

5.2.2 Review Procedures

(1) Site Conditions (Characterization)

Based on the operational history (including radiation surveys) of the facility, the reviewer

determines that the plan describes the likely source and locations of residual byproduct

material such as spills, releases, waste burial, haul roads, diversion ditches, process

and yellowcake storage areas, ore stockpile areas, areas likely to be affected by

windblown tailings, and tailings solution evaporation ponds. Determine that the extent of

contamination (area and depth for soil) has been or will be established from adequate

representative sampling and surveying. Sample analysis should include uranium where

yellowcake or ore dust was present and thorium (Th-230) for acidic tailings pond

residue. The radiological analysis for the ore processed at the site should also be

reviewed for the ratios of Ra-226/U-238 and Ra-226/Th-230 to determine if

non-equilibrium conditions could exist in the contaminated soil. The U-238 activity can

be estimated by dividing the U-nat (total uranium) value by two. The reviewer should

also determine from this data if Th-232 could be elevated above background due to

windblown tailings and whether additional characterization data should be provided.

(2) Soil Background Radioactivity

Determine that the background level of Ra-226 (and U-nat, Th-230 and Th-232, as

needed) in surface {15 cm [6 in.]} soil has been estimated using representative soil

samples from nearby {within 3.2 km [2 mi] of site boundary} undisturbed areas that are

not affected by site activities and are geologically and chemically similar to the

contaminated areas. The number of samples will depend partly on the variability in

background values, but at least 30 samples should be obtained at the typical site to
Radiation Protection

5-11

determine the average value, standard deviation, and distribution. The arithmetic mean

of the sample data is used in the cleanup criteria unless appropriate statistical analysis

demonstrates a log normal distribution (three tests) of the data.

Several different background values may be required if contaminated areas have

distinctly different soil types. For example, if a portion of the site has a natural uranium

and/or radium mineralization zone in/near the surface, the cleanup criterion for that area

would use a background (reference) U-238 or Ra-226 value from a similarly mineralized

area. A geologic site map with the background values placed on the sample location

can be used to help identify whether more than one background value should

be considered.

If the plan indicates that in situ ore is in the clean-up area, it should be characterized by

Ra-226/U-238 ratios, visual criteria, and/or other means.

(3) Cleanup Requirements

For land cleanup, the residual Ra-226 [and/or Ra-228 if thorium (Th-232) byproduct

material is present] in soil must meet the concentration limits in 10 CFR Part 40,

Appendix A, Criterion 6(6), in areas that are not evaluated by the radon flux criterion

(i.e., areas other than the disposal cell). If the plan indicates that the subsurface

15 pCi/g Ra-226 standard will be used, its use should be justified. For structures to

remain on site, the staff reviews the proposed cleanup of mill-related radionuclides

(byproduct material) on surfaces (e.g., walls, floors, drains) as well as in underlying soil. 

For NRC uranium recovery licensees that did not have a decommissioning plan

approved by June 11, 1999, [Appendix A, Criterion 6(6) was expanded effective that

date], or that subsequently submit a revised plan, the radium benchmark dose applies

for cleanup of residual radionuclides other than radium [primarily uranium (U-nat) and

thorium (Th-230)] in soil and for surface activity on structures. For such licensees, the

reviewer should refer to Appendix H of this document for guidance on the benchmark

approach. This approach would also be evaluated if proposed by other uranium

recovery licensees to derive cleanup limits in order to demonstrate compliance with

10 CFR 40.42(k)(2).

Determine that the plan indicates that residual contamination will be reduced to “as low

as is reasonably achievable levels.” Usually, a low gamma guideline level is chosen so

that most grids are cleaned to near background levels of radiation, an approach that has

proven less costly for licensees than more extensive soil sampling and analysis. It is a

method acceptable to the staff to demonstrate compliance with the “as low as is

reasonably achievable” principle. The administrative limit for surface activity (10 to 
Radiation Protection

5-12

25 percent of the criteria) has been considered an “as low as is reasonably achievable” level in

the past but current policy should be confirmed by staff. The “as low as is reasonably

achievable” approach discussed in NUREG–1727 (NRC, 2000b), also may be considered.

(4) Gamma Guideline Level 

Because gamma measurements (in terms of exposure or count rates) can substitute for

some Ra-226 analyses [as recommended in 40 CFR 192.20(b)(1)] and such

measurements are not very reliable, the reviewer must be sure that the proposed

gamma guideline value is conservative, considering the measurement uncertainties

involved. Determine that the radium-gamma correlation that is used to derive the

gamma guideline was performed with at least 30 soil Ra-226 values from approximately

2 to 25 pCi/g and that the corresponding gamma values adequately represent the grid

(100-square-meter area) sampled. The proposed gamma guideline level must reliably

(95 percent confidence) result in grids meeting the 5 pCi/g [0.19 Bq/g] Ra-226 plus

background standard.

Confirm that the plan contains a commitment to perform a radium-gamma correlation on

the verification data, to track soil samples that fail the Ra-226 criteria, and to perform

additional cleanup after a verification soil sample exceeds the Ra-226 standard. Just

cleaning the failed grid is not adequate because the failed sample could indicate that the

gamma value may not be conservative and that some of the unsampled grids may also

fail to meet the standard. For example, the plan could indicate that neighboring grids

would also be analyzed for Ra-226 or, if the number of failed grids is excessive, the

gamma guideline would be adjusted downward and areas further remediated,

as necessary.

(5) Instruments and Procedures

Determine that the instruments and procedures used to determine the soil background

radioactivity and the radium-gamma correlation are the same or very similar to those

proposed for verification of compliance with Criterion 6(6) (final status survey). See

NUREG–1505, Section 4.5 (NRC, 1998a). Instrument sensitivity should be adequate to

reliably identify the proposed guideline levels [NUREG–1507 (NRC, 1998b)]. Survey

instruments are specified and will be properly calibrated and tested, including daily

checks during operations. The reviewer considers national standards (American Society

for Testing and Materials, American National Standards Institute, and National Council

on Radiation Protection as listed in Section 5.2.5) and the “Multi-Agency Radiation

Survey and Site Investigation Manual” [NUREG–1575 (NRC, 2000a)] that contains

general principles of soil sampling, determination of background, and gamma surveying

to be acceptable. 

Soil samples for uranium recovery sites can be composite samples (5 to 11 samples per

grid have been approved). Evaluate sampling procedures for completeness (ensure

proper depth, identification of sample and location, cleaning of equipment, chain-ofcustody, etc). Determine that soil preparation procedures indicate that rocks and 
Radiation Protection

5-13

vegetation should not be included in the sample to the extent that the additional volume would

dilute the soil sample. Generally, rocks greater than or equal to 1.27 cm [0.5 in.] in diameter

are excluded. Acceptable sample mixing, drying, and splitting methods are specified.

Evaluate the methods for soil radionuclide analysis. Standard analytical methods should

be used. Portions of each sample verifying compliance should be archived until the

NRC approves the decommissioning completion (final survey) report, as staff may want

to do confirmatory analysis on selected soil samples. The plan for the final disposal of

these archived samples should also be reviewed.

As required by 10 CFR 40.42(j)(2)(i), the gamma levels to be reported in the final survey

are as mSv (R) per hour at 1m [39.4 in.] from the surface. Measurements at 1 m

[39.4 in.] would allow calculation of an exposure dose, but the goal of the gamma survey

is to demonstrate compliance with the radium in soil criterion. Therefore, the staff has

approved alternate methods such as meter readings (counts/minute) taken near the

ground or at 0.45 m [18 in.]. These methods improve the quality of the gamma-radium

correlation by reducing “shine” and they allow the survey meter and equipment

associated with a global positioning system to be mounted on an all-terrain vehicle. 

Typically, measurements are made over the spot to be sampled, or the grid (100 m2

) is

scanned with 9 to 12 measurements. Integrated count rate gamma scan values have

also been approved if taken for at least one (1) minute within each grid.

Determine that gamma survey procedures indicate the speed, pattern, and spacing of

the measurements or scan path. The procedure should allow demonstration of

compliance with the radium standard. The reviewer should consider the thoroughness

of the gamma scan (remedial action survey) to be done during soil removal, such as

1.5-m [5-ft] scan path, when evaluating the final survey procedures and the percentage

of grids proposed for soil sampling. 

Determine that procedures for measuring alpha or beta-gamma radiation on structure

surfaces are detailed, reflect industry standards, and consider that smears for alpha

activity generally have an efficiency of 10 percent or less. Measurements of smears are

difficult to interpret quantitatively and should not be used for determining compliance but

for determining if further investigation is necessary [NUREG–1575, Sections 6.4.2 and

8.5.3 (NRC, 2000a)].

(6) Quality Assurance and Quality Control

Determine that the quality assurance/quality control program addresses all aspects of

decommissioning. The plan should indicate a confidence interval or that one will be

specified before collection of samples. At least 10 percent of the soil samples should be

split and a portion sent to an outside laboratory for quality assurance. To properly

assess the adequacy of radiological data, the uncertainties associated with the data

should be estimated statistically [NUREG–1501, Sections 3.2 and 5.2 (NRC, 1994)]. 

Evaluate the criteria for validating that the data to be used to demonstrate compliance

and the quality assurance procedures to confirm that compliance data are precise and
Radiation Protection

5-14

accurate (e.g., laboratory will analyze spiked and duplicate samples, etc.). Confirm that

management will ensure that approved procedures are followed (e.g., commitment to

check gamma surveyor and data management).

(7) Final Status Survey

Evaluate the details of the proposed final status survey (radiation surveys and soil

analyses) as discussed in Items 3–6 above, and determine whether the survey plan

complies with 10 CFR 40.42(j)(2). The reviewer should also determine that enough data

of the proper quality can be provided after decommissioning to demonstrate compliance

with Criterion 6(6) of Appendix A and 10 CFR 40.42(k)(2). For example, determine that

the proposed number and pattern of grids to be soil sampled and analyzed for Ra-226

are justified. Based on the degree of uncertainty (level of error in the measurements,

number of measurements), the gamma guideline level, and implementation procedures,

the staff has considered soil samples from 0.5 to 10 percent of the grids acceptable. 

Some verification soil sampling and surveying should be planned in presumably

uncontaminated areas (buffer zone of about 30 meters beyond excavated areas). 

[Refer to Section 3 in Inspection Procedure 87654 (NRC, 2002) for

additional information.]

Confirm that the licensee proposes to use the same instruments and procedures for the

verification (final status) survey as were used in determining background and for the

radium-gamma correlation, or justifies that they are comparable.

If buildings or other structures are to remain on site after license termination, determine

whether adequate measurement of the surface activity is planned. Preliminary modeling

by staff has indicated, that for habitable buildings, the average total (fixed plus

removable) alpha level should be below 2,000 dpm/100 cm2

 in order to achieve

0.25 mSv/yr [25 mrem/yr].

(8) Preliminary Versus Final Decommissioning Plan

A preliminary decommissioning plan shall be submitted with the reclamation plan and

may be updated for license renewal in order for the staff to better evaluate the

decommissioning cost estimate provided for surety purposes. Since the actual site

decommissioning may be years in the future and continued operation could change the

cleanup design, or evolving technology and Agency rules or guidance could change the

evaluation of procedures, the review of the preliminary plan should not be technically

rigorous. However, the reviewer should determine whether sufficient detail has been

provided in the plan to justify that the surety amount for decommissioning activities

is adequate.

Confirm that both the preliminary and final plans identify a location to keep the records

of information important to the decommissioning, as required by 10 CFR 40.36(f). 

These records would include documentation of spills or cleanup of contamination,

drawings or descriptions of modification of structures in the restricted area, and

locations of possible inaccessible contamination. 
Radiation Protection

5-15

When a final decommissioning plan is submitted, the reviewer should determine

whether the plan addresses the technical aspects discussed above [basically

10 CFR 40.42(g)(4) requirements] and whether it indicates that decommissioning will be

completed as soon as practicable. The reviewer follows Section 5.3 of this standard

review plan for the evaluation of the health and safety protection aspects of

decommissioning. The reviewer should also consider recommendations in Regulatory

Guide 3.65 (NRC, 1989) during the evaluation of the final decommissioning plan.

(9) Non-Radiological Hazardous Constituents

The decommissioning plan must address the non-radiological hazardous constituents of

the byproduct material according to 10 CFR Part 40, Appendix A, Criterion 6(7). For

windblown tailings areas, meeting the surface Ra-226 standard should be adequate to

control these constituents in soil. A tailings cell cover that meets Appendix A criteria

should control, minimize, or eliminate postclosure escape of non-radiological hazardous

constituents into surface water and the atmosphere. However, any unusual or

extenuating circumstances related to such constituents should be discussed in the

reclamation plan or decommissioning plan in relation to protection of public health and

the environment and should be evaluated by staff. The control of these substances in

ground water is addressed under Chapter 4.0 of this standard review plan.

(10) Decommissioning Cost Estimate

Determine whether the cost estimate is itemized in sufficient detail such that values for

soil sampling and preparation, Ra-226 analysis, gamma surveying, and data

management are presented. The items should reflect the proposed activities in the

plan. Also, the basis for each cost should be provided and verified by staff to be within

the range of current charges for such activities in the site region. The staff should verify

that adequate surety funds will be provided to cover these costs. Guidance on cost

estimates for sureties is provided in Appendix C of this standard review plan.

5.2.3 Acceptance Criteria

The decommissioning plan will be acceptable if it meets the following criteria:

(1) The plan contains procedures to identify and place within the disposal cell, all soils on

and adjacent to the processing site that are in excess of the standards in

10 CFR Part 40, Appendix A, Criterion 6(6), due to site activities. The plan is

substantiated by the radiological characterization data and site history.

(2) Appropriate soil background values (different geological areas may need separate

background values) for Ra-226, and for U-nat, Th-230, and/or Th-232, as appropriate,

have been proposed with supporting data.

(3) If elevated levels of uranium or thorium are expected to remain in the soil after the

Ra-226 criteria have been met, the licensee has used the radium benchmark dose

approach in Appendix H for developing decommissioning criteria for these radionuclides.
Radiation Protection

5-16

(4) To ensure consistency of measurement data, instrumentation and procedures used for

soil background analyses and the radium-gamma correlation are the same or very

similar to those proposed to provide verification data. The instrumentation has the

appropriate sensitivity, and procedures are adequate to provide reliable data.

(5) A detailed quality assurance and quality control plan for all aspects of decommissioning

is provided. In addition to the basis for accepting or rejecting data, a procedure for

sampling additional grids when a verification Ra-226 sample fails to meet the standard

is provided.

(6) Final verification (status survey) procedures are adequate to demonstrate compliance

with the soil and structure cleanup standards. Survey instruments are specified and will

be properly calibrated and tested. The proposed verification soil sampling density takes

into consideration detection limits of sample analyses, the extent of expected

contamination (unaffected area could have fewer measurements than affected areas),

and limits to the gamma survey for the potentially contaminated area to be sampled. 

The gamma guideline value to be used for verification has been appropriately chosen. 

Also, there is a commitment to provide the verification soil radium-gamma correlation

and the number of verification grids that had additional removal because of excessive

Ra-226 values, to confirm that the gamma guideline value was adequate. The plan

provides for adequate data collection beyond the excavation boundary (buffer zone).

For structures to remain onsite, adequate plans/procedures to demonstrate

compliance with the limits for the surface activity dose in Appendix H of this standard

review plan have been developed.

(7) The plan indicates the location of records important to decommissioning procedures for

protection of health and safety and demonstrates that decommissioning will be

completed as soon as practicable, as required by 10 CFR 40.42 and Appendix A,

Criterion 6A.

(8) The decommissioning cost estimate is itemized in sufficient detail and a basis (source)

for each cost is provided. The total cost is reasonable for the area of the site and the

expected decommissioning activities.

(9) The plan adequately describes the control of non-radiological hazards associated with

the wastes as required by 10 CFR Part 40, Appendix A, Criterion 6(7).

(10) As required by Appendix A, Criteria 9 and 10, the licensee must maintain a financial

surety, within the specific license, for the surface reclamation and decommissioning,

with the surety sufficient to recover the anticipated cost and time frame for achieving

compliance, and include the long-term surveillance. Guidance on establishing financial

surety is presented in NRC (1988, 1997). Appendix C to this standard review plan

provides an outline of the cost elements appropriate for establishing surety amounts for

conventional uranium mills. Any staff assessment of surety amounts is reasonably

consistent with the applicant’s assessment.
Radiation Protection

5-17

5.2.4 Evaluation Findings

If the staff review, as described in this section, results in the acceptance of the processing site

(soil and structures) decommissioning plan, the following conclusions may be presented in the

technical evaluation report:

The staff has completed its review of the site decommissioning plan for soil and structures at

the uranium mill facility. This review included an evaluation using the review

procedures in Section 5.2.2, and the acceptance criteria outlined in Section 5.2.3 of this

standard review plan.

The licensee has provided an acceptable site decommissioning plan, including (1) appropriately

substantiated site characterization data or plans to identify contaminated areas; (2) plans to

clean up and place within the disposal cell, all materials that are in excess of the standards and

approved guidelines, including hazardous material; (3) sufficient information concerning

instrumentation and procedures; (4) plans for post-reclamation survey and sampling for

verification that the soil and structures meet radiological limits; (5) location for retention of

records important to decommissioning; (6) methods to protect workers, the public, and the

environment; and (7) a cost estimate for all proposed decommissioning activities.

On the basis of the information presented in the reclamation plan and the detailed review

conducted of proposed decommissioning activities for the uranium mill

facility, the staff concludes that the information is acceptable and is in compliance with

10 CFR Part 40, Appendix A, Criterion 6(6), which requires that any portion of a licensed

uranium mill site not designed to control radon releases, contain a concentration of radium in

land, averaged over areas of 100 square meters, which, as a result of byproduct material, does

not exceed the background levels by more than (i) 5 pCi/g of Ra-226 averaged over the first

15 cm [6 in.] below the surface, and (ii) 15 pCi/g of Ra-226 averaged over 15-cm-thick layers

more than 15 cm below the surface. Also, the cleanup of other residual radionuclides in soil

and residual surface activity on structures to remain on site, meet the criteria developed with

the radium benchmark dose approach, including a demonstration of “as low as is reasonably

achievable” radiation levels and application of the unity test where applicable. For cases in

which the licensee has proposed an alternative to the requirements of Criterion 6(6) or the

approved guidance, the staff determines that the resulting level of protection is equivalent to

that required by this criterion. In addition, the plan demonstrates compliance with

10 CFR Part 40, Appendix A, Criterion 6(7), which requires prevention of threats to human

health and the environment from non-radiological hazards associated with the wastes.

The decommissioning plan specifies the location of records of information important to the

decommissioning as required by 10 CFR 40.36(f) and meets the criteria of 10 CFR 40.42(g)(4)

and (5). The plan sufficiently demonstrates that the proposed decommissioning activities will

result in compliance with 10 CFR 40.42(j)(2) requirements to conduct a radiation survey. The

plan complies with the 10 CFR 40.42(k)(1) and (2) requirements that source material be

properly disposed of and reasonable effort be made to eliminate residual radioactive

contamination. The decommissioning cost estimate meets the requirements of

10 CFR 40.42(g)(4)(v) and Appendix A, Criterion 9.
Radiation Protection

5-18

5.2.5 References

American National Standards Institute Standards:

N42.17A–1989, “Performance Specifications for Health Physics InstrumentationPortable Instrumentation for Use in Normal Environmental Conditions.”

N42.12–1994, “American National Standard Calibration and Usage of ThalliumActivated Sodium Iodide Detector Systems for Assay of Radionuclides.”

American Society for Testing and Materials Standards:

C 998-90 (reaffirmed 1995), “Standard Practice for Sampling Surface Soil

for Radionuclides.”

D 5283-92, “Standard Practice for Generation of Environmental Data Related to

Waste Management Activities: Quality Assurance and Quality Control Planning

and Implementation.”

E 181-93, “Standard Test Methods for Detector Calibration and Analysis

of Radionuclides.”

E 1893-97, “Standard Guide for Selection and Use of Portable Survey Instruments for

Performing In Situ Radiological Assessments in Support of Decommissioning.”

National Council on Radiation Protection and Measurements. “Calibration of Survey

Instruments Used in Radiation Protection for the Assessment of Ionizing Radiation Fields and

Radioactive Surface Contamination.” Report No. 112. 1991.

NRC. “Uranium Mill In-Situ Leach Uranium Recovery, and 11e(2) byproduct Material Disposal

Site Decommissioning Inspection.” Inspection Manual—Inspection Procedure 87654. 

Washington DC: NRC. March 2002.

–––––. NUREG–1575, “Multi-Agency Radiation Survey and Site Investigation Manual.” Rev. 1. 

Washington DC: NRC. 2000a.

–––––. NUREG–1727, “NMSS Decommissioning Standard Review Plan.” Washington, DC:

NRC. 2000b.

–––––. NUREG–1505, “A Nonparametric Statistical Methodology for the Design and Analysis

of Final Status Decommissioning Surveys.” Rev. 1. Washington DC: NRC. 1998a.

–––––. NUREG–1507, “Minimum Detectable Concentrations With Typical Radiation Survey

Instruments for Various Contaminants and Field Conditions.” Washington DC: NRC. 1998b.

–––––. “Annual Financial Surety Update Requirements for Uranium Recovery Licensees.” 

Generic Letter 97-03. Washington, DC: NRC. July 9, 1997.
Radiation Protection

5-19

–––––. Regulatory Guide 3.65, “Standard Format and Content of Decommissioning Plans

Under 10 CFR Parts 30, 40, and 70.” Washington DC: NRC, Office of Standards

Development. 1989.

–––––. “Technical Position on Financial Assurances for Restoration, Decommissioning, and

Long-Term Surveillance and Control of Uranium Recovery Facilities.” Washington, DC:

NRC. 1988.

5.3 Radiation Safety Controls and Monitoring

5.3.1 Areas of Review

The areas of review for radiation safety for protecting the site worker, the public, and the

environment during reclamation and decommissioning are the control of releases, the radiation

exposure and environmental monitoring programs, and the contamination control program. 

Decommissioning activities at mill sites involve occupational, and possibly public, exposures to

radioactive materials that may require different or additional monitoring and control procedures

than during site operation or standby status. Potential sources of exposure from working with

tailings material are caused by airborne particulate contamination, radon gas, and external

gamma radiation. Surface activity or dust on equipment and structures to be dismantled or

decontaminated could also be a source of exposure.

The reclamation and final decommissioning plans should contain the licensee’s evaluation of

the site current radiation safety/protection plan or program and any proposed changes to the

program for reclamation and decommissioning operations. The proposed measures should

keep exposures as low as is reasonably achievable and in compliance with the requirements of

10 CFR Part 20. Key components of the program should address hazards unique to the

reclamation or decommissioning work environment. Any new activities that could increase

hazards to general health and safety (e.g., cleanup in confined spaces, or removal of

hazardous or flammable chemicals) should be identified, considering the NRC Memorandum of

Understanding with the Occupational Safety and Health Administration.

5.3.2 Review Procedures

Determine that the proposed radiation safety controls and all monitoring programs and

procedures are sufficient to comply with the regulatory requirements during decommissioning

and reclamation. A licensee will already have an approved radiation safety program in place;

therefore, the focus of the review should be to ensure that the reclamation plan addresses

those aspects of worker and public protection that require special consideration in planning

reclamation and decommissioning activities. The environmental impacts of these activities will

be addressed in the environmental assessment, but any concerns requiring mitigation should

be addressed in the reclamation plan. The reclamation plan should confirm the applicability of

the radiation protection and monitoring programs to reclamation and decommissioning activities

or should propose changes to address new program needs based on review of the following:
Radiation Protection

5-20

(1) Control of Releases

Determine whether the proposed systems and procedures (e.g., tailings stabilization,

dust control) are sufficient to minimize environmental emissions from the tailings

impoundment construction activities or structure demolition, taking into consideration

important release mechanisms such as wind resuspension and surface erosion. Radon

gas emanating from the tailings pile is also a radiation safety concern for workers and

downwind off-site populations. However, because control of the source is not possible

during tailings recontouring or cleanup, the reviewer should examine the means

proposed to limit the worker inhalation hazard (i.e., limiting exposure time, or using dust

masks or respirators if required) and to establish an acceptable environmental

monitoring program for measuring off-site airborne concentrations. Also, liquid releases

can be created by rainwater runoff. Therefore, the review of the reclamation plan should

include an evaluation, taking all exposure pathways into account, of proposals for

ensuring off-site exposures are as low as is reasonably achievable.

(2) External Radiation Exposure Monitoring Program

Determine if changes to the existing program are needed or if proposed changes are

adequate. The reviewer should consider the types of surveys conducted, criteria for

determining survey locations, frequency of surveys, action levels, management audits,

and corrective action requirements. Also, consider if changes are required in the

program for personal/personnel monitoring (dosimeters and air samplers), including the

criteria for placing workers in the program.

(3) Airborne Radiation Monitoring Program for Work Areas

Evaluate whether the proposed sampling locations, frequencies, procedures, and

equipment are adequate to determine concentrations of airborne radioactive materials

(including radon) in work areas during construction, demolition, and cleanup activities. 

Action levels, audits, and corrective action requirements should also be evaluated.

(4) Bioassay Program

Review the existing bioassay program or proposed changes to determine whether the

proposed bioassay program is sufficient to protect employees performing

decommissioning activities in yellowcake processing areas.

(5) Contamination Control Program

Evaluate the occupational radiation survey program. This review should include

proposed housekeeping and cleanup requirements and specifications for clean areas to

control contamination. Action levels for clean areas and for the release of materials,

equipment, and work clothes from clean areas and/or the site should be evaluated.

(6) Environmental Monitoring Program
Radiation Protection

5-21

Determine whether the environmental monitoring program proposed for measuring

concentrations and quantities of both radioactive and non-radioactive materials released

to, and in, the environs of the proposed facility, are sufficient to protect employees and

the public. Potential releases during disposal cell construction and cleanup activities will

be primarily from resuspended tailings material and radon gas. The reviewer should

focus on the frequency of sampling and analysis, the types and sensitivity of analyses,

action levels, corrective action requirements, and the required number of effluent and

environmental monitoring stations (including criteria for determining monitor station

locations considering the reclamation work). The guidance in Regulatory Guide 4.20

(NRC, 1996) should be considered.

(7) Record Keeping

Determine whether the record keeping requirements for the radiation protection program

have been addressed; that is, records of the provisions of the program and audits or

other reviews of content and implementation are maintained for at least 3 years. Other

records are maintained according to Subpart L of 10 CFR Part 20 and 10 CFR Part 40,

Appendix A, Criterion 6(4).

5.3.3 Acceptance Criteria

The radiation safety controls and monitoring for site worker, public, and environmental

protection during reclamation and decommissioning will be acceptable if they meet the

following criteria:

(1) The reclamation plan identifies the radiation safety concerns that are unique to

reclamation and decommissioning activities. These concerns include characterization of

radiation hazards associated with inhalation of resuspended tailings material or

yellowcake, gamma exposure from working close to tailings, and inhalation of radon gas

and its progeny (decay products) emanating from tailings material. 

(2) The reclamation plan describes any changes to an existing radiation safety or

monitoring program that would be necessary to ensure worker or public safety during

reclamation or decommissioning activities.

(3) Standard dust control measures such as regular wetting and/or phased stabilization are

to be used for control of windblown tailings material or yellowcake dust.

(4) Any proposed changes to the established bioassay program will meet criteria of the

applicable parts of Regulatory Guide 8.22, “Bioassay at Uranium Mills” (NRC, 1988) and

Regulatory Guide 8.9, Revision 1, “Acceptable Concepts, Models, Equations, and

Assumptions for a Bioassay Program” (NRC, 1993), or an acceptable justification is

provided for selecting an alternate approach.

(5) Any proposed workplace airborne radiological monitoring program will support the

proposed bioassay program and is consistent with applicable parts of Regulatory Guide

8.25, “Air Sampling in the Workplace” (NRC, 1992) and Regulatory Guide 8.30, “Health
Radiation Protection

5-22

Physics Surveys in Uranium Mills” (NRC, 2002), or an acceptable justification is

provided for selecting an alternate approach. The monitoring program will provide

adequate protection of workers from radon gas or particulate exposures to maintain

compliance with the inhalation limits in 10 CFR Part 20. If sampling locations will be

revised, the reclamation plan contains one or more maps of the site that indicate the

location of samplers for airborne radiation and provide the justification for determining

the revised locations.

(6) Any proposed contamination control program is consistent with the guidance on

conducting surveys for contamination of skin and of personal clothing presented in

Regulatory Guide 8.30 (NRC, 2002).

(7) Any proposed environmental radiological monitoring program is consistent with

applicable parts of Regulatory Guide 4.14, “Radiological Effluent and Environmental

Monitoring at Uranium Mills” (NRC, 1980), or an acceptable justification is provided for

selecting an alternate approach. The licensee has adequately considered site-specific

aspects of climate and topography in determining locations of off-site airborne

monitoring stations and environmental sampling areas so that detection of maximum

off-site concentrations of windblown tailings material and contamination from any other

significant transport pathways applicable to the site is ensured.

(8) Any proposed radiation protection program contains plans for documentation of

exposures to all monitored workers and contractors and for availability of exposure

records in a single location for inspection. The program provides for recordkeeping that

meets the requirements of 10 CFR 20.2102; at least annual review of the program

content and implementation; and implementation of the “as low as is reasonably

achievable” requirements of 20.1101(d).

5.3.4 Evaluation Findings

If the staff review, as described in this section, results in the acceptance of the radiation safety

controls and monitoring for site worker, public, and environmental protection during disposal cell

construction and site cleanup, the following conclusions may be presented in the technical

evaluation report:

The staff has completed its review of the radiation safety controls and monitoring for site

worker, public, and environmental protection during reclamation and decommissioning at the

 uranium mill facility. This review included an evaluation using the review

procedures in Section 5.3.2 and the acceptance criteria outlined in Section 5.3.3 of

this standard review plan. 

The licensee has provided an acceptable evaluation of radiation safety controls and monitoring

required for worker, public, and environmental protection during reclamation and

decommissioning activities, including (1) identification of the radiation safety concerns that are

unique or likely to increase during reclamation construction and site decommissioning; (2) any

necessary changes and associated justifications in the radiation safety program, such as

personnel and environmental monitoring; (3) identification and discussion of any changes in an
Radiation Protection

5-23

existing radiation protection program; (4) control of potential contamination from windblown

tailings by regular wetting and/or phased stabilization; and (5) the monitoring and contamination

control programs will allow compliance with applicable portions of 10 CFR Parts 20 and 40.

On the basis of the information presented in the reclamation plan and the detailed review

conducted of the radiation safety controls and monitoring for worker, public, and environment

protection during reclamation and decommissioning for the uranium mill

facility, the NRC staff concludes that the information is acceptable and is in compliance with

10 CFR 20.1101, which requires development, documentation, and implementation of a

radiation protection program ensuring compliance with 10 CFR Part 20 requirements and the

use of procedures and engineering controls to achieve occupational and public doses that are

as low as is reasonably achievable. The 10 CFR Part 40, Appendix A, Criterion 8, requirements

for implementation of control measures to limit dust emissions from tailings that are not covered

by standing liquids, including wetting or chemical stabilization, will be met. [This requirement

may be relaxed for tailings impoundments that have surfaces that are sheltered from wind

exposure (i.e., below grade) or that have an interim cover.] The requirements in

10 CFR 40.42(g)(4)(iii), to describe methods that ensure protection of workers and the

environment against radiation hazards during decommissioning, have been met.

5.3.5 References

NRC. Regulatory Guide 8.30, “Health Physics Surveys in Uranium Mills.” Washington, DC: 

NRC, Office of Nuclear Regulatory Research. 2002

–––––. Regulatory Guide 4.20, “Constraint on Releases of Airborne Radioactive Materials to

the Environment for Licensees Other Than Power Reactors.” Washington, DC: NRC, Office of

Standards Development. 1996.

–––––. Regulatory Guide 8.9, “Acceptable Concepts, Models, Equations, and Assumptions

for a Bioassay Program.” Rev. 1. Washington DC: NRC, Office of Standards

Development. 1993.

–––––. Regulatory Guide 8.25, “Air Sampling in the Workplace.” Rev. 1. Washington, DC:

NRC, Office of Standards Development. 1992.

–––––. Regulatory Guide 8.22, “Bioassay at Uranium Mills.” Rev. 1. Washington, DC: NRC,

Office of Standards Development. 1988.

–––––. Regulatory Guide 4.14, “Radiological Effluent and Environmental Monitoring at Uranium

Mills.” Rev. 1. Washington, DC: NRC, Office of Standards Development. 1980.
APPENDIX A
A–1

RELATIONSHIP OF 10 CFR PART 40, APPENDIX A REQUIREMENTS

TO STANDARD REVIEW PLAN SECTIONS

This appendix identifies the specific standard review plan sections where the criteria of

10 CFR Part 40, Appendix A are addressed.

10 CFR Part 40, Appendix A Criterion

Locations in NUREG–1620

Where the Criterion is

Addressed

Criterion 1: Optimize site selection to achieve

permanent isolation of tailings without

maintenance.

2.1.4, 3.1.4, 3.2.4, 3.3.4, 3.4.4,

3.5.4

Criterion 2: Avoid proliferation of small waste

disposal sites.

Not applicable to this standard

review plan.

Criterion 3: Dispose of tailings below grade or

provide equivalent isolation.

2.1.4 

Criterion 4: Adhere to siting and design criteria.

(a) Minimize upstream rainfall catchment areas.

(b) Select topographic features that provide good

wind protection.

(c) Provide relatively flat embankment and

cover slopes.

(d) Establish a self-sustaining vegetative cover or rock

cover considering stability, erosion potential,

and geomorphology.

(e) Locate away from faults capable of causing

impoundment failure.

(f) Design to promote deposition, where feasible.

3.2.4

3.5.4

2.2.4, 2.4.4, 2.5.4, 2.6.4, 2.7.4,

3.4.4, 3.5.4

2.2.4, 2.6.4, 3.4.4

1.1.4, 1.2.4, 1.4.4, 2.1.4, 2.2.4

3.4.4

Criterion 5A: Meet the primary ground-water

protection standard.

(1) Design, construct, and install an impoundment liner

that prevents migration of wastes to subsurface

soil, ground water, or surface water.

(2) Construct liner of suitable materials, place it on an

adequate base, and install it to cover surrounding

earth likely to be in contact with wastes or leachate.

Not applicable to this standard

review plan.

Not applicable to this standard

review plan.
Appendix A

10 CFR Part 40, Appendix A Criterion

Locations in NUREG–1620

Where the Criterion is

Addressed

A–2

(3) Apply alternate design or operating practices that

will prevent migration of hazardous constituents into

ground water or surface water.

(4) Design, construct, maintain, and operate

impoundments to prevent overtopping.

(5) Design, construct, and maintain dikes to prevent

massive failure.

Not applicable to this standard

review plan.

4.4.4

2.2.4, 4.4.4

Criterion 5B: Conform to the secondary

groundwater protection standards.

(1) Prevent hazardous constituents from exceeding

specified concentration limits in the uppermost

aquifer beyond the point of compliance.

(2) Define hazardous constituents as those expected to

be in or derived from the byproduct material, those

detected in the uppermost aquifer, and those listed

in Criterion 13.

(3) Exclude hazardous constituents if they are not

capable of posing a substantial present or potential

hazard to human health or the environment.

(4) Consider identification of underground sources of

drinking water and exempted aquifers.

(5) Ensure hazardous constitutents at the point of

compliance do not exceed the background

concentration, the value in Paragraph 5C, or an

approved alternate concentration limit.

(6) Establish alternate concentration limits, if

necessary, after considering practical corrective

actions, as low as is reasonably achievable

requirements, and potential hazard to human health

or the environment.

4.1.4, 4.2.4, 4.3.4, 4.4.4

4.1.4, 4.2.4, 4.3.4, 4.4.4

4.1.4, 4.2.4, 4.3.4, 4.4.4

4.1.4, 4.2.4, 4.3.4, 4.4.4

4.1.4, 4.2.4, 4.3.4, 4.4.4

4.1.4, 4.2.4, 4.3.4, 4.4.4

Criterion 5C: Comply with maximum values for

ground-water protection.

4.1.4, 4.2.4, 4.3.4, 4.4.4
Appendix A

10 CFR Part 40, Appendix A Criterion

Locations in NUREG–1620

Where the Criterion is

Addressed

A–3

Criterion 5D: Implement a ground-water corrective

action program if secondary ground

water protection standards

are exceeded.

4.4.4

Criterion 5E: Consider appropriate measures when

developing and conducting a

ground-water protection program.

(1) Incorporate leak detection systems for synthetic

liners and conduct appropriate testing for clay/

soil liners.

(2) Use process designs that maximize solution

recycling and water conservation.

(3) Dewater tailings by process devices or properly

designed and installed drainage systems.

(4) Neutralize hazardous constituents to

promote immobilization.

4.1.4, 4.4.4

4.1.4, 4.4.4

4.1.4, 4.4.4

4.1.4, 4.4.4

Criterion 5F: Alleviate seepage impacts where they

are occurring and restore groundwater quality.

4.1.4, 4.3.4, 4.4.4

Criterion 5G: Provide appropriate information for a

tailings disposal system.

(1) Define the chemical and radioactive characteristics

of waste solutions.

(2) Describe the characteristics of the underlying soil

and geologic formations.

(3) Define the location, extent, quality, capacity, and

current uses of ground water.

4.1.4, 4.3.4, 4.4.4

1.1.4, 2.1.4, 4.1.4, 4.3.4, 4.4.4 

4.1.4, 4.3.4, 4.4.4

Criterion 5H: Minimize penetration of radionuclides

into underlying soils when stockpiling.

4.1.4, 4.4.4

Criterion 6: Install an appropriate cover and close

the waste disposal area.

(1) Ensure the cover meets lifetime and radon flux 1.1.4, 1.2.4, 1.3.4, 1.4.4, 2.1.4,
Appendix A

10 CFR Part 40, Appendix A Criterion

Locations in NUREG–1620

Where the Criterion is

Addressed

A–4

release specifications.

(2) Demonstrate the effectiveness of the final radon

barrier prior to placement of erosion protection

barriers or other features.

(3) Demonstrate the effectiveness of phased

emplacement of radon barriers as each section

is completed, if applicable.

(4) Document verification of radon barrier effectiveness

to the U.S. Nuclear Regulatory Commission (NRC)

and maintain records of this verification.

(5) Ensure that radon exhalation is not significantly

above background because of the cover material.

(6) Clean up residual contamination from byproduct

material consistent with the radium

benchmark dose.

(7) Prevent threats to human health and the

environment from non-radiological hazards.

2.2.4, 2.3.4, 2.4.4, 2.5.4, 2.6.4,

2.7.4, 3.2.4, 3.3.4, 3.4.4, 3.5.4,

4.3.4, 5.1.4

5.1.2.1(b)

5.1.4

2.7.4

5.1.4

5.2.4

5.2.4

Criterion 6A: Ensure expeditious completion of the

final radon barrier.

(1) Complete the radon barrier as expeditiously as

practical after ceasing operations in accordance

with a written, Commission-approved

reclamation plan.

(2) Extend milestone completion dates if justified by

radon release levels, cost considerations consistent

with available technology.

(3) Authorize disposal of byproduct materials or similar

materials from other sources if appropriate criteria

are met.

2.6.4, 5.2.4

Requirement on Commission.

Requirement on Commission.
Appendix A

10 CFR Part 40, Appendix A Criterion

Locations in NUREG–1620

Where the Criterion is

Addressed

A–5

Criterion 7: Conduct pre-operational and

operational monitoring programs.

4.1.4

Criterion 7A: Establish a detection monitoring

program to set site-specific

ground-water protection standards, a

compliance monitoring system once

ground-water protection standards

have been established, and a

corrective action monitoring program

in conjunction with a corrective action

program.

4.1.4, 4.2.4, 4.3.4, 4.4.4

Criterion 8: Conduct milling operations, including

ore storage, tailings placement, and

yellowcake drying and packaging

operations so that airborne releases

are as low as is reasonably

achievable .

Not applicable to this standard

review plan.

Criterion 8A: Conduct and record daily inspections

of tailings or waste retention systems

and report failures or unusual

conditions to NRC.

4.4.4

Criterion 9: Establish appropriate financial surety

arrangements for decontamination,

decommissioning, and reclamation.

4.4.4, 5.2.4

Criterion 10: Establish sufficient funds to cover the

costs of long-term surveillance

and control.

4.4.4

Criterion 11A: Comply with effective date for site

and byproduct material

ownership requirements.

Requirement on Commission.

Criterion 11B: Establish license conditions or terms

to ensure that licensees comply with

ownership requirements prior to

license termination for sites used for

tailings disposal.

Requirement on Commission.

Criterion 11C: Transfer title to byproduct material

and land to the United States or the

state in which the land is located.

Not applicable to this standard

review plan.
Appendix A

10 CFR Part 40, Appendix A Criterion

Locations in NUREG–1620

Where the Criterion is

Addressed

A–6

Criterion 11D: Permit use of surface and subsurface

estates if the public health, safety,

welfare, or environment will not

be endangered.

Requirement on Commission.

Criterion 11E: Transfer material and land to the

United States or a State without cost

other than administrative legal costs.

Not applicable to this standard

review plan.

Criterion 11F: Follow specific requirements for land

held in trust for or owned by

Indian Tribes.

Requirement on Commission.

Criterion 12: Minimize or avoid long-term active

maintenance and conduct and report

on annual inspections.

3.2.4, 3.3.4, 3.4.4, 3.5.4

Criterion 13: Establish standards for constituents

reasonably expected to be in or

derived from byproduct materials and

detected in ground water.

4.1.4, 4.2.4, 4.4.4
APPENDIX B
B–1

GUIDANCE TO THE U.S. NUCLEAR REGULATORY COMMISSION

STAFF FOR REVIEWING HISTORICAL ASPECTS OF SITE

PERFORMANCE FOR LICENSE RENEWALS AND AMENDMENTS

For license renewals and amendments, the historical record of site operations contains valuable

information for evaluating the licensing actions. Following are specific areas in which a

compliance history or record of site operations and changes should be presented for review:

• Amendments and changes to operating practices or procedures. 

• License violations identified during U.S. Nuclear Regulatory Commission (NRC) or

Agreement State site inspections. 

• Cleanup histories or status.

• Exceedances of any regulatory standard or license condition pertaining to radiation

exposure, contamination, or release limits.

• Exceedances of any regulatory standard or licenses condition pertaining to non-radiation

contaminant exposure or release limits.

• Changes to any site characterization information important to the evaluation of the

reclamation plan, such as changes to site location and layout, uses of adjacent lands

and waters, meteorology, seismology, the geologic or hydrologic setting, ecology,

background radiological or non-radiological characteristics, and other

environmental features.

• Results of site operations such as data on radiological and non-radiological effects,

accidents, and the economic effects of operations.

• Changes to factors that may cause reconsideration of alternatives to the

proposed action.

• Changes to the economic costs and benefits for the facility since the last application. 

If, after reviewing these historical aspects of site operations, the staff concludes that the site

has been operated so as to protect health, safety, and the environment, and that no unreviewed

safety-related concerns have been identified, only those changes proposed by the license

renewal or amendment or application should be reviewed, using the appropriate sections of this

standard review plan. Aspects of the facility and its operations that have not changed since the

last license renewal or amendment should not be reexamined. 
APPENDIX C
C–1

OUTLINE RECOMMENDED BY THE U.S. NUCLEAR REGULATORY

COMMISSION STAFF FOR PREPARING SITE-SPECIFIC FACILITY

RECLAMATION AND STABILIZATION COST ESTIMATES FOR REVIEW

As required by Criteria 9 and 10 of 10 CFR Part 40, Appendix A, the licensee shall supply

sufficient information for the U.S. Nuclear Regulatory Commission (NRC) to verify that the

amount of coverage provided by the financial assurance will permit the completion of all

decontamination, decommissioning, and reclamation of sites, structures, and equipment used

in conjunction with byproduct material. Cost estimates for the following items (where

applicable) should be submitted to NRC with the initial license application or reclamation plan,

and should be updated annually as specified in the license. Cost estimates must be calculated

on the basis of completion of all activities by a third party. Unit costs, calculations, references,

assumptions, equipment and operator efficiencies, et cetera, must be provided. The annual

surety estimate must be prospective of all work to be performed at the site. The licensee must

provide estimated costs for all decommissioning, reclamation, and ground-water cleanup work

remaining to be performed at the site, not simply deduct the cost of work already performed

from the previous surety estimate [see NRC Generic Letter 97-03 (NRC, 1997)]. The licensee

can propose to deduct for work done and approved by NRC as meeting specifications.

The detailed cost information necessary to verify the cost estimates for the preceding

categories of closure work is summarized in the recommended outline that follows. For each

area, estimates should the include costs for equipment; materials; labor and overhead;

licenses, permits, and miscellaneous site-specific costs; and any other activity or resource that

will require expenditure of funds. 

(I) Facility Decommissioning

This includes dismantling and decontamination, or disposal of all structures and

equipment. This work may be done in two phases. In the first phase, only the

equipment not used for ground-water cleanup (including the stability monitoring period)

is removed. Removal of the remaining equipment would be performed in a second

phase, after the approved completion of ground-water cleanup. The buildings may be

decontaminated and released for unrestricted use.

(A) Salvageable building and equipment decontamination. For each building or

piece of equipment listed, the following data should be provided:

(1) Area of contamination

(2) Survey costs

(3) Decontamination costs

(B) Non-salvageable building and equipment demolition and disposal:

(1) List of major categories of building and equipment to be disposed of and

their corresponding quantities:
Appendix C

C–2

(a) Structures (list each major), metric tons [tons(short)] of material,

and building volume cubic meters (cubic yards)

(b) Foundation concrete [cubic meters (cubic yards)]

(c) Process equipment [metric tons (tons (short)]

(d) Piping and insulation (lump sum)

(e) Electrical and instrumentation (lump sum)

(2) Disposal of chemical solutions within the facility.

(C) Cleanup of contaminated areas (ore storage pad, access roads, process area,

evaporation pond residues, etc.).

Reclamation—This entails recontouring the tailings disposal cell and evaporation

ponds and placing top soil or other materials acceptable to NRC. Reclamation

may also include cleanup of windblown materials and revegetation, including:

(1) Cleanup of windblown materials (e.g., volume and area, unit

cost/cubic yard).

(2) Placement of borrow materials removal (e.g., rental rate, cost/cubic yard).

(3) Dust suppression and site maintenance.

(4) Monitoring and testing of construction.

(5) Regrading. 

(6) Placement of the frost barrier.

(7) Placement of the radon barrier.

(8) Installation of erosion protection and armor.

(9) Installation of any vegetative cover.

(10) Design and construction of drainage ditches. 

(11) Recontouring of land surfaces.

(12) Revegetation.

(II) Ground-Water Cleanup and Well Decommissioning
Appendix C

C–3

Ground-water cleanup is done in accordance with an approved corrective action plan. 

The costs include water treatment equipment, operation, maintenance, and

component replacement. 

(A) Method of cleanup

(B) Volume of aquifer required to be restored, area and thickness of aquifer, number

of required pumping cycles, and cycling time 

(C) Verification sample analysis

(D) Well decommissioning:

(1) Number of drill holes to be plugged

(2) Depth and size of each drill hole

(3) Material to be used for plugging including acquisition, transportation,

and plugging

(III) Radiological Survey and Monitoring

Radiological Survey—Surveys and soil samples for radium in areas to be released for

restricted use. Soils around the tailings disposal cell, evaporation ponds, and process

buildings should be analyzed for radium content. A gamma survey of all areas should

be made before release for unrestricted use. All equipment released for unrestricted

use should be surveyed and records maintained.

(A) Soil samples for radium (and uranium and thorium, if needed) (e.g., number,

cost to collect, and analyze)

(B) Decommissioning equipment and building smear samples and alpha

surface surveys

(C) Gamma survey frequency, location, and techniques (e.g., type, number,

unit cost)

(D) Environmental monitoring

(E) Personnel monitoring
Appendix C

C–4

(IV) Project Management Costs and Miscellaneous

Itemize estimated costs associated with project management; engineering design,

review, and change; mobilization; legal expenses; power during reclamation; quality

control; radiological safety; and any costs not included in other estimation categories. 

costs should include preparation of completion report and license termination activities.

Potential needs for future well maintenance or replacement are identified. If periodic

well replacement is projected, an increase in the long-term care payment is included

(American Society for Testing and Materials Standard D 5978).

(V) Labor and Equipment Overhead, Contractor Profit

Overhead costs for labor and equipment and contractor profit may be calculated as

separate items or loaded into hourly rates. If included in hourly rates, the unit costs

must identify the percentages applied for each area.

(VI) Long-term Surveillance Fee

The fee required by 10 CFR Part 40, Appendix A, Criterion 10, to include cost of any

required long-term monitoring (e.g., ground water) or maintenance (e.g., fences,

vegetation control).

(VII) Contingency

The licensee should add a contingency amount to the total cost estimate for the final

site closure. The staff currently considers a 15 percent contingency to be an acceptable

minimum amount.

(VIII) Adjustments to Surety Amounts

The licensee is required by 10 CFR Part 40, Appendix A, Criterion 9, to adjust cost

estimates annually to account for inflation and changes in reclamation plans. The

submittal should be in the form of a request for amendment to the license.

(A) Adjustments for inflation: The licensee should submit a revised surety

incorporating adjustments to the cost estimates for inflation 90 days before each

anniversary of the date on which the first reclamation plan and cost estimate was

approved. The adjustment should be made using the inflation rule indicated by

the change in the Urban Consumer Price Index published by the

U.S. Department of Labor, Bureau of Labor Statistics.

(B) Changes in Plans:

(1) Changes in the process, such as size or method of operation.
Appendix C

C–5

(2) Licensee-initiated changes in reclamation plans or reclamation/

decommissioning activities performed.

(3) Adjustments to reclamation plans required by NRC.

(4) Proposed revisions to reclamation plans must be thoroughly documented

and cost estimates and the basis for cost estimates must be detailed for

NRC review and approval.

To avoid unnecessary duplication and expense, NRC shall take into account surety

arrangements required by other federal agencies, state agencies, or other local governing

bodies. However, the Commission is not required to accept such sureties if they are not

sufficient. Similarly, no reduction to surety amounts established with other agencies shall be

effected without NRC approval. Copies of all correspondence relating to the surety between

the licensee and the state should be submitted to NRC. If authorized by NRC to maintain a

surety with the state as the beneficiary, it is the responsibility of the licensee to give NRC

verification of that surety; ensure that the agreement with the State specifically identifies the

financial surety’s application, uranium mill tailings site, and decommissioning/reclamation

requirements; and transfer the long-term surveillance and control fee to the U.S. Department of

the Treasury before license termination.

All costs (unit and total) are to be estimated on the basis of third party independent contractor

costs (include overhead and profit in unit costs or as a percentage of the total). Equipment

owned by the licensee and the availability of licensee staff should not be considered in the

estimate to reduce cost calculations. All costs should be based on current-year dollars. Credit

for salvage value is generally not acceptable on the estimated costs.

NRC staff review may include a comparison of unit cost estimates with standard construction

cost guides (e.g., R.S. Means, Dodge Guide, Data Quest) and discussions with appropriate

state or local authorities (e.g., highway cost construction). The licensee should provide

supporting information or the basis for selection of the unit cost figures used in estimates. The

staff may elect to use a publicly available computer code such as RACERTM (Talisman Partners,

Ltd., 2000) or spreadsheet to assess these costs.

References

American Society for Testing and Materials Standards

D 5978, “Standard Guide for Maintenance and Rehabilitation of Ground-water

Monitoring Wells.”

NRC. “Annual Financial Surety Update Requirements for Uranium Recovery Licensees.”

Generic Letter 97-03. Washington, DC: NRC. July 1997.

Talisman Partners, Ltd. “Introduction to RACER 2000TM (Version 2.1.0)—A Quick Reference.” 

Englewood, Colorado: Talisman Partners, Ltd. 2000.
APPENDIX D
D–1

GUIDANCE TO THE U.S. NUCLEAR REGULATORY COMMISSION

STAFF FOR REVIEWING LONG-TERM SURVEILLANCE PLANS

D1.0 BACKGROUND

The Atomic Energy Act of 1954, as amended (hereafter, the Act), contains the statutory

requirements for transfer of the title and custody of byproduct material and any land used for

the disposal of such byproduct material from a uranium mill licensee to either federal or state

control, before termination of the licensee-specific license. These requirements are codified in

10 CFR Part 40, at Section 40.28, “General license for custody and long-term care of uranium

or thorium byproduct materials disposal sites.” Section 40.28, along with pertinent

requirements stated in Appendix A to 10 CFR Part 40 (hereafter Appendix A), requires the

completion of certain licensing actions before the transfer of the land and byproduct material to

the United States or the appropriate state for long-term care. As part of the license termination

process, the intended custodial agency, federal or state government, will prepare a long-term

surveillance plan for review and concurrence/acceptance by the U.S. Nuclear Regulatory

Commission (NRC). The long-term surveillance plan must document the general licensee’s

plan for long-term care, including inspection, monitoring, maintenance, and emergency

measures necessary to protect public health and safety. This document presents guidance to

the NRC staff on review of the long-term surveillance plan. Standard review plan Appendix E

presents guidance on the license termination process, and presents the role of the long-term

surveillance plan in the overall context of the license termination process.

Review and acceptance of long-term surveillance plans is the sole responsibility of the NRC. 

However, Agreement State comments prepared using this guidance are welcomed and will be

considered, if provided.

D2.0 REVIEW OF LONG-TERM SURVEILLANCE PLAN

D2.1 Areas of Review

In accordance with 10 CFR 40.28(b), the long-term surveillance plan should present the

following information:

(1) A legal description of the disposal site to be transferred and licensed

(2) A detailed description of the final conditions of the disposal site, including existing

ground-water characterization

(3) A description of the long-term surveillance program, including proposed inspection

frequency and reporting to the Commission; frequency and extent of ground-water

monitoring, if required; appropriate constituent limits for ground water; inspection

personnel qualifications; inspection procedures; record keeping; and quality

assurance procedures

(4) The criteria for followup inspections in response to unusual observations from routine

inspections or extreme natural events
Appendix D

D–2

(5) The criteria for instituting maintenance or emergency measures

D2.2 Information Reviewed

D2.2.1 Legal Description and Ownership of the Land 

The reviewer should examine the documents to ensure that the ownership and legal description

of the land are satisfactory. The review should include review of (1) the legal description of the

disposal site; (2) a brief narrative of the disposal area land ownership, including the number of

acres involved and the type of real estate instruments associated with the acquisitions;

(3) information associated with the land transaction [i.e., book, page, county, State, and date of

deeds; and agreement number and date associated with DOE/tribe agreement (waiver of

liability from tribe when land is part of a reservation or has trust status)]; and (4) a statement

that real estate correspondence and instruments are maintained and filed by the property

management branch of the pertinent custodial agency. The documentation should clearly

establish the custodial agency’s land ownership when the land transfer takes place. 

D2.2.2 Final Condition of the Disposal Site

The reviewer should examine the following: (1) documentation of defined and characterized

final closure site condition; (2) as-built drawings; (3) description of disposal cell design; (4) final

topographic maps; (5) vicinity maps; (6) ground and aerial photographs; (6) number, location,

and condition of survey monuments, site markers, and signs; and (7) existing ground-water

characterization and protection activities (if necessary), ground-water monitoring well network to

detect changes in ground-water quality from tailings (including evaluating the monitoring data to

quantify the rate and magnitude of change). Some of the information may be referenced to the

information already submitted to NRC (such as the completion report), and the staff findings on

the previously submitted information may be used in this review. It is noted that the final

disposition of the tailings residual radioactive material, or wastes at the milling site, should be

such that ongoing active maintenance is not necessary to preserve isolation. The descriptions

of the final disposal site condition, the ground-water condition, and the proposed ground-water

monitoring program should be of sufficient detail that future inspectors have a baseline to

determine changes to the site.

D2.2.3 Long-Term Surveillance Program

The staff should review the surveillance (inspection and monitoring) program for:

(1) Frequency of Inspection—The physical condition of the site (fence, site markers,

drains/ditches, rock-mulch/vegetative cover, etc.) should be inspected annually to

determine any need for maintenance or monitoring or both. In addition, an inspection

should follow an unusual event, such as a heavy storm or an earthquake. On the basis

of a site-specific evaluation, NRC may require more frequent site inspections because of

the particular features of a disposal site.

(2) Reporting to the Commission—Results of the inspections for all the sites under the

licensee’s jurisdiction will be reported to NRC annually within 90 days of the last site

inspection in that calendar year. However, any site at which unusual damage or
Appendix D

D–3

disruption is discovered during the inspection requires a preliminary site inspection

report to be submitted within 60 days.

(3) Ground-Water Monitoring—The reviewer should examine long-term surveillance plans

to ensure that a ground-water monitoring program is in place to verify that the groundwater quality at the site will continue to meet applicable standards. In particular, the

reviewer should determine whether:

(a) Background, point of compliance, and, if applicable, point of exposure

wells have been located as described in the existing license. Wells

should be correctly placed as to surface locations and aquifer

completions. Well locations should be surveyed and located on site

maps drawn to scale. 

(b) The same ground-water protection standards (point of ground-water

protection standards or alternate concentration limits) as in the existing

license continue to apply. If there has been no leakage from the

impoundment into the ground-water, appropriate ground-water

parameters should be monitored and detection concentrations should be

established that will give early warning of leakage. Appropriate

parameters should be indicative of the tailings material and not

significantly affected by retardation reactions. For acid tailings,

appropriate detection parameters might include total dissolved solids,

chloride, or sulfate.

(c) The sampling frequency is sufficient to protect the public and

environment at the point of exposure and sufficient to ensure that the

ground-water downgradient of the point of compliance will not be

degraded to any great extent before contamination is detected. This will

require a knowledge of potential contaminant plume velocities. It is

anticipated that the calculation of potential contaminant plume velocities

will be based on advective calculations (e.g., American Society for

Testing and Materials Standards D 5447, D 5490, D 5609, D 5610, D

5611, D 5718, E 978; and Anderson and Woessner, 1992). However,

more complex calculations that include such processes as dispersion and

retardation may be performed if site conditions warrant them. For sites

with alternate concentration limits, the sampling frequency should be

sufficient to detect a potential contaminant plume, well before ground

water at the point of exposure is degraded.

It is anticipated for most sites that routine monitoring once every 3 years will be

acceptable unless site-specific conditions warrant an increased or decreased

frequency of monitoring. If more frequent monitoring is required, the reviewer should

assess the increase in the long-term care payment that must be made to support the

more frequent monitoring. This increase should be included in the existing surety in

addition to the long-term care payment made at the time of license termination.
Appendix D

D–4

(d) Water quality sampling and analysis procedures use appropriate

American Society for Testing and Materials or equivalent standards. 

Wells are constructed to prevent surface-water contamination and are

capped and secured to prevent tampering (American Society for Testing

and Materials Standard D 5787).

(e) Actions that the long-term custodian would take should ground-water

protection standards be exceeded are described.

If the staff review results in acceptance of the long-term surveillance plan, the staff may

conclude that the DOE will conduct long-term surveillance that will confirm that

constituents of concern will remain below the relevant standards in 10 CFR Part 40,

Appendix A, Criteria 5B(5) and (6). The staff may also conclude that enough funds are

available to cover the costs of long-term surveillance and control as required in

10 CFR Part 40, Appendix A, Criterion 10, and that site inspections are planned as

required in 10 CFR Part 40, Appendix A, Criterion 12.

(4) Inspection Personnel Qualifications—The inspection team should be qualified to inspect

such site features as subsidence and cracking; erosion by surface water; degradation of

erosion protection (rock mulch cover or vegetative cover); integrity of site markers,

fences, and settlement plates; and monitoring to verify the presence and concentration

limits of hazardous constituents in the ground water. For inspections that follow unusual

events, the team should consist of technical personnel of appropriate disciplines. 

(5) Inspection Procedures—The long-term surveillance plan should present details of the

inspection procedures such as checklists of items to be inspected, measurements or

observations to be made, procedures for documenting the inspection data (photo, video,

aerial photo as needed); and duration of inspection (1 to 2 days).

(6) Recordkeeping and Quality Assurance Procedures—Inspection data should be retained

in a format suitable for future retrieval on a long-term basis. The quality assurance

aspect of the collection of site and ground-water data, interpretation of the collected

data, report preparation, and long-term retention of data should be reviewed. 

D2.2.4 Criteria for Follow-up Inspections

The criteria for followup inspections in response to unusual observations from routine

inspections or extreme natural events should be reviewed.

(1) If any unusual observation from the inspection warrants a detailed evaluation, then an

unscheduled inspection (followup inspection) will be conducted for a detailed evaluation

of the unusual observation encountered in the earlier inspection. The plan should

discuss the level of physical distress to the site (settlement/crack magnitude, extent of

subsidence, extent of degradation of erosion protection, etc.) and limits of the

constituents not to be exceeded in the ground-water that would warrant a further

detailed evaluation of the problem to determine the need for a cleanup activity.
Appendix D

D–5

(2) Occurrence of extreme natural events, such as large-magnitude storms and

earthquakes or drought, warrants an inspection to verify the physical condition/integrity

of the disposal site. The plan should present the magnitude of the natural events that

would trigger this inspection. 

D2.2.5 Criteria for Instituting Maintenance or Emergency Measures

The plan should present the criteria or the events that will trigger the initiation of maintenance

and other emergency measures to restore the integrity of the disposal site and to protect the

health and safety of the public. Quantitative and, if not practical, qualitative criteria that would

trigger these measures should be discussed in the long-term surveillance plan.

D3.0 CONCLUSIONS

On the basis of its review of the long-term surveillance plan, the staff should be able to

conclude that the long-term surveillance plan is in compliance with (1) the content requirements

in 10 CFR 40.28(b), (2) the ownership of site and byproduct material requirement in Criterion 11

of Appendix A, and (3) the surveillance plan requirement in Criterion 12 of Appendix A. If the

long-term surveillance plan is in compliance with these requirements, the staff can accept it.

D4.0 REFERENCES

American Society for Testing and Materials Standards

D 5447, “Standard Guide for Application of a Ground-water Flow Model to a

Site-Specific Problem.”

D 5490, “Standard Guide for Comparing Ground-water Flow Model Simulations to

Site-Specific Information.”

D 5609, “Standard Guide for Defining Boundary Conditions in Ground-water

Flow Modeling.” 

D 5610, “Standard Guide for Defining Initial Conditions in Ground-water Flow Modeling.”

D 5611, “Standard Guide for Conducting a Sensitivity Analysis for a Ground-water Flow

Model Application.”

D 5718, “Standard Guide for Documenting Ground-water Flow Model Application.”

D 5787, “Standard Practice for Monitoring Well Protection.”

E 978, “Standard Practice for Evaluating Mathematical Models for the Environmental

Fate of Chemicals.”

Anderson, M.P. and W.W. Woessner. Applied Ground-Water Modeling: Simulation of Flow

and Transport. New York, New York: Academic Press. 1992.
APPENDIX E
E–1

GUIDANCE TO THE U.S. NUCLEAR REGULATORY COMMISSION

STAFF ON THE LICENSE TERMINATION PROCESS FOR LICENSEES

OF CONVENTIONAL URANIUM MILLS

E1.0 BACKGROUND

The Atomic Energy Act of 1954, as amended, contains the statutory requirements for the

transfer of the title and custody to byproduct material and any land used for the disposal of such

byproduct material from a uranium mill licensee to either Federal or State control, before

termination of the licensee's specific license. These requirements are codified in

10 CFR Part 40, at Section 40.28, “General license for custody and long-term care of uranium

or thorium byproduct materials disposal sites.” Section 40.28, along with pertinent

requirements stated in Appendix A to 10 CFR Part 40 (hereafter Appendix A), provides for the

completion of certain licensing actions before the transfer of the land and byproduct material to

the United States or the State where the disposal site is located for long-term care.

This document gives the U.S. Nuclear Regulatory Commission (NRC) staff specific directions to

be applied in the course of the license termination process for Uranium Mill Tailings Radiation

Control Act of 1978 Title II sites that are under NRC jurisdiction. For the license termination of

Title II sites that are under Agreement State jurisdiction, guidance is provided in the Office of

State and Tribal Programs SA–900 Procedure (NRC, 2001). The license termination process,

including the roles of the respective agencies and organizations involved in this process, is

discussed in general. Various relevant issues are addressed in greater detail. This is the initial

version of this guidance document, and as specific uranium mill licenses are terminated and

title to the land and byproduct material is transferred to the appropriate government agency,

future revisions are likely to be necessary. These revisions will address not only issues yet to

be identified, but also will provide any additional necessary clarification of issues

discussed herein. 

E2.0 ROLES OF INVOLVED ORGANIZATIONS

E2.1 NRC

In accordance with Section 83c of the Atomic Energy Act, as amended, NRC determines

whether the licensee has met all applicable standards and requirements or whether a

licensee-proposed alternative meets the standards. This will involve NRC review of licensee

submittals relative to the completion of decommissioning, reclamation, and, if necessary,

ground-water cleanup.

In addition, the staff should review the site long-term surveillance plan submitted by the

custodial agency, for both NRC and Agreement State sites. On NRC acceptance of the

long-term surveillance plan, NRC terminates the specific license and places the long-term care

and surveillance of the site by the custodial agency under the general license provided at

10 CFR 40.28.

A final NRC responsibility is the determination of the final amount of long-term site surveillance

funding. Criterion 10 of Appendix A specifies a minimum charge of $250,000 (1978 dollars),

revised to reflect inflation, which may be escalated on a site-specific basis because of
Appendix E

E–2

surveillance and long-term monitoring controls beyond those specified in Criterion 10 of

Appendix A. Detailed discussion of the bases used in developing the minimum charge and any

escalated costs appears in Section E3.4 (below).

E2.2 Uranium Mill Licensees

Before license termination, licensees are required by license conditions to complete site

decontamination and decommissioning and surface and ground-water remedial actions

consistent with decommissioning, reclamation, and ground-water corrective action plans.

Licensees must document the completion of these remedial actions in accordance with

procedures developed by NRC. As discussed in Section E3.1 (below), this information will

include a report documenting completion of tailings disposal cell construction, as well as

radiation surveys and other information required under 10 CFR 40.42.

Because the long-term surveillance plan must reflect the remediated condition of the site, the

licensee will work with the custodial agency in preparing the long-term surveillance plan. Most

likely, this will involve supplying the custodial agency with appropriate documentation

(e.g., as-built drawings) of the remedial actions taken and reaching agreements (formal or

informal) with the custodial agency regarding the necessary surveillance control features of the

site (e.g., boundary markers, fencing). It is the custodial agency responsibility to submit the

long-term surveillance plan to NRC for approval. However, the licensee may elect to help

prepare the long-term surveillance plan, to whatever degree is agreed between the licensee

and the custodial agency.

Finally, the licensee provides the funding to cover long-term surveillance of the site, in

accordance with Criterion 10 of Appendix A. NRC will determine the final amount of this charge

on the basis of final conditions at the site.

After termination of the existing license and transfer of the site and byproduct materials to the

custodial agency, the licensee remaining liability extends solely to any fraudulent or negligent

acts committed before the transfer to the custodial agency, as provided for in Section 83b(6) of

the Atomic Energy Act, as amended.

E2.3 Custodial Agency

Section 83 of the Atomic Energy Act, as amended, states that before termination of the specific

license, title to the site and byproduct materials should be transferred to either (1) the

U.S. Department of Energy (DOE); (2) a Federal agency designated by the President; or (3) the

state in which the site is located, at the option of the State. It is expected that the DOE will be

the custodial agency for most, if not all, of the sites.

It is the responsibility of the custodial agency to submit the long-term surveillance plan to NRC

for review and acceptance. Provisions and activities identified in the final long-term surveillance

plan will form the bases of the custodial agency long-term surveillance at the site. The NRC

general license in 10 CFR 40.28(a) becomes effective when the licensee’s current specific

license is terminated and the Commission accepts the long-term surveillance plan. Custodial
Appendix E

E–3

agencies are required, under 10 CFR 40.28(c)(1) and (c)(2), to implement the provisions of the

long-term surveillance plan. These activities could include not only those reflected in the longterm surveillance plan, but also activities voluntarily committed to by the custodial agency.

E2.4 States

As discussed in Section 2.3 (above), the State in which the disposal site is located has the

option of becoming the custodial agency. This “right of first refusal” may be exercised either on

a site-by-site basis or generally, covering all sites within the State’s limits. This option should

be exercised early enough in the license termination process so that termination of the specific

license and transfer of the site to the appropriate custodial agency are not delayed

unnecessarily. Written confirmation of a State decision should be documented in a letter to the

DOE, from the governor of the State, or another State official to whom the authority for this

decision has been appropriately delegated. A copy of this letter must be sent to NRC.

The NRC has exclusive jurisdiction over both the radiological and non-radiological hazards of

11e.(2) byproduct material (NRC, 2000).

E3.0 THE LICENSE TERMINATION PROCESS

A licensee considering termination of its source material license should have in place an

acceptable (by NRC) site decommissioning and reclamation plan and, if necessary, an

acceptable ground-water corrective action program. This section describes the termination

process that follows an NRC licensee completion of decommissioning, reclamation, and

ground-water corrective action in accordance with the approved plans.

E3.1 Licensee Documentation of Completed Remedial and Decommissioning 

Actions

E3.1.1 Documentation of Completed Surface Remedial Actions

To ensure a timely and efficient NRC review, when reclamation of the tailings disposal cell is

completed, the licensee should submit to NRC, for review, a report detailing the conduct and

completion of the reclamation construction activities. This Construction Completion Report

would consist primarily of a summary of quality assurance/quality control records and as-built

drawings. A licensee may refer to the reports prepared by the DOE to document completion of

remedial actions at Title I Project sites as guidance in developing its Construction Completion

Report. However, some of the information presented in DOE reports (e.g., original design

calculations) has been meant to ease the staff review rather than to meet

documentation requirements.

If a Construction Completion Report or similar report is not submitted, it will be necessary for

the staff to conduct a detailed technical review to meet its responsibilities under Section 83c of

the Act. This review could involve several site visits and significant confirmation testing and

would likely involve staff in the following technical disciplines: geotechnical engineering,

surface water and erosion protection, radon barrier design, and soil radiation cleanup. Accurate
Appendix E

E–4

quality assurance/quality control records and photographs kept by a licensee during cell

construction will be important input into the staff determination that reclamation has been

conducted and completed in accordance with the approved plan.

If the NRC determines, as part of its review of the Construction Completion Report or during a

site inspection, that a licensee has neglected to compile quality assurance/quality control

records or has inadequate records, it may require the licensee to conduct appropriate sampling

of those portions of the completed cell that are in question (e.g., of the radon barrier). If a

licensee is unwilling or unable to comply, the staff or NRC contractors will conduct the

sampling, and the costs involved will be included in the licensing and inspection fees assessed

under 10 CFR 170.31. In addition, if a requirement to maintain quality assurance/quality control

records is part of an approved reclamation plan, a licensee’s lack of such records may be

interpreted as a violation of the relevant license condition. This situation will be evaluated as

part of the NRC inspection program. Appropriate NRC action would be taken in such instances.

E3.1.2 Documentation of Completed Site Decommissioning

Licensees are also required, under 10 CFR 40.42(j), to document the results of site

decommissioning, which is done by conducting a radiation survey of the premises where the

licensed activities were carried out. The results of this survey, the contents of which are

specified at 10 CFR 40.42(j)(2), are submitted to NRC for review. A licensee has the option of

demonstrating that the premises are suitable for release in a manner other than that specified

at 10CFR 40.42. Additional documentation pertinent to site decommissioning and soil cleanup

may be required by a specific license condition.

E3.1.3 Documentation of Completed Ground-Water Corrective Actions

Criteria 5A–5D, along with Criterion 13, of Appendix A incorporate the basic ground-water

protection standards imposed by the U.S. Environmental Protection Agency (EPA) in

40 CFR Part 192, Subparts D and E (48 FR 45926, October 7, 1983). These standards apply

during operations and before the end of closure. At a licensed site, if these ground-water

protection standards are exceeded, the licensee is required to put into operation a ground-water

corrective action program (Criterion 5D of Appendix A). The objective of the corrective action

program is to return the hazardous constituent concentration levels to the concentration limits

set as standards.

For licensees with continuing ground-water cleanup, NRC approval is required for the

termination of corrective action. A licensee should submit appropriate ground-water monitoring

data and other information that produce reasonable assurance that the ground water has been

cleaned to meet the appropriate standards. This may include an application for alternate

concentration limits if the licensee concludes that some alternate concentration limits for certain

constituents are necessary. The staff will review alternate concentration limits in accordance

with the most current version of the NRC staff technical position, “Alternate Concentration

Limits for Title II Uranium Mills: Standard Format and Content Guide, and Standard Review

Plan for Alternate Concentration Limit Applications” (NRC, 1996).
Appendix E

E–5

E3.2 NRC Review of Completed Closure Actions

On receipt of the Construction Completion Report, decommissioning report, ground-water

completion report, or alternate concentration limit monitoring data, the staff will review the

document for completeness and level of detail. Given a favorable finding, the staff will then

review the content of the report for documentation that the action has been conducted in

accordance with the license requirements and regulations. If that is the case, NRC will notify

the licensee by formal correspondence, and, if the licensee so requests, amend the specific

license, by deleting applicable license requirements for reclamation, decommissioning, or

ground-water cleanup, and identifying requirements for any disposal cell observational period

and/or environmental monitoring. The staff may conduct site inspections, examining first-hand

the closure actions taken, including the quality assurance/quality control records.

Additionally, the staff should conduct a final construction completion inspection, which is

expected to consist of a site walk-over and an examination of construction records. No

independent verification of completed actions (e.g., confirmatory coring of the radon barrier) is

expected, except on a case-by-case basis, as discussed previously.

With respect to construction of the tailings cell, the staff review of the Construction Completion

Report, coupled with site inspections, will ensure that disposal cells are constructed in

accordance with the approved design and plan (e.g., a summary of quality assurance/quality

control records shows the appropriate number of material lifts have been placed).

The staff will rely on site inspections as the primary means of determining acceptable

implementation of the licensee’s approved decommissioning plan, especially in regard to soil

cleanup. These inspections will consist of (1) reviews of procedures, (2) evaluations of

procedure implementation, (3) evaluations of records and quality assurance, and (4) limited

gamma surveys and soil sampling. In this way, the staff will gain the needed level of

confidence in the licensee’s performance to support its evaluation of the final decommissioning

survey report. Confirmatory sampling, either by NRC or its contractors, should be conducted at

sites for which additional confirmation beyond inspections is necessary. Specific criteria will be

employed to identify those sites requiring confirmatory sampling.

E3.3 Observation Periods

E3.3.1 Following Completion of Surface Remedial Actions

The length of an observation period following completion of surface remediation will be

determined on a site-specific basis, with a minimum period of 1 year, commencing at the

completion of the erosion cover. Licensees should report significant cell degradation (e.g., the

development of settlement or erosional features) occurring during this period.

Sites employing a full self-sustaining vegetative cover (Criterion 4 of Appendix A) may have an

observation period of at least 2 years, and possibly as long as 5 years, based on specific site

conditions and the requirements of 10 CFR Part 40, Appendix A.
Appendix E

E–6

A de facto observation period may exist at most sites where cleanup of ground-water

contamination continues following the completion of surface reclamation (i.e., construction of

the tailings disposal cell).

E3.3.2 Following Ground-Water Remediation

The reviewer should examine (1) ground-water completion reports, (2) ground-water corrective

action reports, or (3) alternate concentration limit applications to verify that ground-water quality

corrective actions have produced a stable water quality and that ground-water monitoring and

analysis have been done to confirm the concentration of these contaminants in the ground

water and to verify that they meet applicable standards. This should be done at the end of the

1-year stability ground-water monitoring period.

Ground-water stability monitoring and confirmation of constituents of concern will be

acceptable if:

(1) A one-time measurement of all constituents of concern has been collected and

analyzed from all point-of-compliance wells. A constituent of concern is one that is

(a) either (i) currently identified in 10 CFR Part 40, Appendix A, Criterion 13; or (ii) is not

listed in Criterion 13, but is placed in a license condition as part of the staff review of the

Corrective Action Plan; and (b) has been identified in the tailings liquor. NRC has

flexibility to add other constituents not identified in Criterion 13. However, in identifying

this second set of constituents, the staff should ensure that any additions are made

based on a sound technical and regulatory basis. New constituents should be added in

a timely manner, either when the corrective action plan is accepted for review, or at

some time during the lifetime of the corrective action program. New constituents will not

be required at the time of the license termination monitoring submittal.

Some examples of sound technical bases for new constituents follow:

(a) For the Homestake/Grants and United Nuclear Corporation/Churchrock sites, the

NRC staff, the DOE, and the EPA will work together to develop an interagency

policy on closure and postclosure issues that will comply with the statutory and

regulatory missions and requirements of all three agencies. For the

Cotter/Canon City and UMETCO/Uravan sites, the State of Colorado is the

primary regulatory authority and the NRC has a more limited role. Once all

applicable NRC requirements are met, the NRC will have no basis for denying a

request to terminate any specific license. However, before the NRC terminates

any license for a site that is on the National Priority List or that is subject to

continuing regulation by the EPA, the NRC will inform the DOE of the pending

action, and where possible, will provide additional time for the DOE to resolve

site issues it may have with the EPA.

(b) Trends in ground-water contamination show that after several years of

decreasing contamination, the levels of contamination begin to rise again.
Appendix E

E–7

(c) Surrogate parameters that cover a family of constituents show an increase in

the concentration in ground water. Therefore, the staff may require licensees to

monitor for all constituents found in that family.

(d) Some constituents used in the milling process, but not listed in Criterion 13, such

as ammonia and nitrate, must be addressed.

Constituents should not be added just because an individual state regulatory

body is concerned about that constituent. Having a state identify a constituent

as one of concern to the state is not necessarily a proper basis for NRC to

include that constituent.

(2) The results of the one-time measurement sampling should be compared with the

pre-operational applicable standards as specified in Criterion 5(C) or the license. 

All hazardous constituents must be shown to meet the standards specified in

Criterion 5(C) or the license. If this measurement is taken sometime before

license termination (3 or more years), the reviewer should ensure that

recontamination has not occurred. This may be done by taking additional

measurements or making analytical calculations.

(3) The stability monitoring data should be inspected for any trends in increasing

ground-water concentrations for those constituents of concern in the ground

water that were being cleaned up by the corrective action plan.

If the staff reviews result in acceptance of confirmation and stability monitoring, the staff may

conclude that:

(1) The licensee has monitored all previously identified constituents of concern at the points

of compliance.

(2) The post-corrective action plan stability monitoring shows that the constituents of

concern that were remediated will remain below compliance or alternate concentration

limit standards.

(3) The one-time sampling for constituents of concern shows that constituents of concern

are below, and will remain below, relevant standards in 10 CFR Part 40, Appendix A,

Criteria 5B(5) and 5B(6).

(4) All ground-water corrective action programs have ceased operation.

(5) All identified constituents of concern for which compliance sampling is being conducted

have been returned to the concentration limits set as standards.

E3.4 Long-Term Site Surveillance Funding

Before termination of the specific license, NRC will set the final amount of the long-term site

surveillance charge to be paid by the licensee in accordance with Criterion 10 of
Appendix E

E–8

10 CFR Part 40, Appendix A. The NRC process for determining this amount will include

consultations with the licensee and the custodial agency. This charge must be paid to the

United States general treasury or to the appropriate state agency before the specific license

can be terminated.

Notify NRC and custodial agency 2 years before estimated date of license termination. When a

licensee has completed site reclamation, decommissioning, and, if necessary, ground-water

corrective action, and is ready to terminate its specific source material license, it must formally

notify NRC of its intentions. Such notification should be accompanied by a completed NRC

Form 314, “Certificate of Disposition of Materials” or approved alternate.

E3.4.1Bases for Determination of Surveillance Charge

The basic criterion for tailings disposal is to avoid dependance on perpetual human care and 

on-going maintenance to preserve the isolation of the tailings. NRC, in Criterion 1 of Appendix

A, concludes that:

The general goal or broad objective in siting and design decisions is permanent

isolation of tailings and associated contaminants by minimizing disturbance and

dispersion by natural forces, and to do so without ongoing maintenance.

However, as further indicated in Criterion 1, for practical purposes, specific design and siting

considerations must involve finite time limits. For this reason, Criterion 6 contains longevity

standards for design of disposal cells.

In order that the isolation of the tailings and associated contaminants can be preserved to the

extent possible, the Atomic Energy Act, as amended, provides that title to the byproduct

material and associated land be transferred to the care of the United States, the State, or the

tribe, as discussed previously. NRC has interpreted such long-term custody by a governmental

agency, whether Federal or State, as “a prudent, added measure of control” (NRC, 1980), so

that land uses that might contribute to the degradation of the cover or lead to direct human

exposures can be prevented.

In the “Final Generic Environmental Impact Statement on Uranium Milling” (NRC, 1980), NRC

staff developed the bases for the long-term surveillance charge, given the intent that no

ongoing active maintenance of site conditions should be necessary to preserve waste isolation. 

In the final generic environmental impact statement, the following actions are assumed for the

“passive monitoring” approach to surveillance of the site are as follows:

(1) An annual visual inspection of the site, either as a site visit or a visual inspection from

an aircraft, should be conducted.

(2) No maintenance of equipment or facilities, no fence replacement, no sampling, and no

airborne environmental monitoring would be expected.
Appendix E

E–9

(3) Essentially, the only costs for continued surveillance/maintenance would consist of time

spent in preparing for the inspection, travel to the site, conduct of the inspection, and

annual report writing.

(4) Minimal NRC oversight would be required.

Passive monitoring, thus, would not involve such activities as irrigation, hauling of fill, regrading,

or seeding.

Finally, as discussed previously, licensees will contribute the funds necessary to cover the costs

of long-term surveillance of their sites. The charge assessed is a one-time fee, which will yield

interest on the funds, assuming a 1-percent annual real interest rate, sufficient to cover the

annual costs of site surveillance. The final generic environmental impact statement contains

more detailed discussion regarding the determination of this interest rate.

E3.4.2 Determination of Surveillance Charge Amount

On the basis of the assumptions discussed in Section E3.4.1 (above), NRC developed the

minimum long-term surveillance charge of $250,000 (1978 dollars) as stated in Criterion 10 of

Appendix A. It is this charge, adjusted to account for inflation, that the licensee is required to

pay into the general treasury of the United States, or alternately, to the appropriate State

agency (if the State is to become the long-term site custodian). The methodology the staff will

use to determine the adjusted surveillance charge that accounts for inflationary increases since

1978 includes (1) using the Consumer Price Index available at the time the licensee requests

termination and (2) applying the rate of increase for the last month for which it has been

calculated to any following month leading to license termination. For example, in June 1996,

NRC determined the final surveillance charge for the TVA/Edgemont site. In doing this, the

staff used the April 1996 Consumer Price Index and applied the rate of increase between March

and April to the following months.

Criterion 10 allows for the escalation of this minimum charge if, on the basis of a site-specific

evaluation, the expected site surveillance or control requirements are determined to be

significantly greater than those specified in Criterion 12 of Appendix A (i.e., annual inspections

to confirm site integrity and determine the need, if any, for maintenance or monitoring).

Escalation could result from a licensee’s proposal of alternatives to the requirements in

Appendix A, as allowed under Section 84c of the Atomic Energy Act, as amended. For

example, a licensee could demonstrate by analysis that the only mechanism for achieving a

minimum disposal cell design life of 200 years at its site is through the use of ongoing

maintenance. NRC may approve such a design if it finds that the design will achieve a level of

stabilization and containment for the site concerned, and a level of protection of public health

and safety, and of the environment, that is equivalent to, to the extent practicable, or more

stringent than, the level of protection that would be achieved by meeting NRC requirements. 

However, the licensee would likely be required to place additional funds in the long-term

surveillance charge to cover the costs of the ongoing maintenance.
Appendix E

E–10

Another situation that may lead to the escalation of the minimum charge is the recognition that

some degree of active care (e.g., vegetation control, maintenance of erosional control

measures) is necessary to preserve the as-designed conditions of the site. This need should

become apparent in the course of site observations during the reclamation and

observational periods.

In any case, any escalation in the minimum charge will be discussed with the licensee and longterm custodian, before license termination. Any final variance in the funding requirements will

be determined solely by NRC.

A situation may arise in which the custodial agency wants to have commitments in the

long-term surveillance plan that are beyond those required in Appendix A and that NRC does

not determine are necessary. In such a case, the amount of the long-term surveillance charge

would not be affected (NRC, 1990, “Detailed Comment Analysis,” Comment 1.2). The custodial

agency must identify a mechanism for funding these additional self-imposed requirements.

E3.4.3 Payment of Long-Term Surveillance Charge

Licensees may pay the final site surveillance charge to the NRC or the custodial agency. If

paid to NRC, the funds will be deposited, in accordance with the Miscellaneous Receipts Act, in

the U.S. General Treasury. A custodial agency receiving payment from the licensee will need

to document receipt and subsequent deposition of the payment. Copies of such documentation

should be sent to NRC.

E3.5 Preparation of the Long-Term Surveillance Plan

While surface remediation and ground-water cleanup activities are ongoing, it is in the best

interest of the licensee to contact the custodial agency with regard to that agency preparation of

the site long-term surveillance plan. The custodial agency responsibilities under the general

license are defined in the long-term surveillance plan, the required contents of which are

provided at 10 CFR 40.28 and in Criterion 12 of Appendix A, as follows:

• A legal description of the site to be transferred and licensed

• A detailed description of the site, as a baseline from which future inspectors can

determine the nature and seriousness of any changes {licensees may reference

previously submitted information, to the extent applicable, in providing this description

[10 CFR 40.31(a)]}

• A detailed description of the long-term surveillance program, including (1) the frequency

of inspections and reporting to the NRC; (2) the frequency and extent of ground-water

monitoring, if required; (3) appropriate ground-water concentration limits; and

(4) inspection procedures and personnel qualifications

• The criteria for follow-up inspections in response to observations from routine

inspections or extreme natural events
Appendix E

E–11

• The criteria for instituting maintenance or emergency measures

In addition to these regulatory requirements (also see Appendix D of this standard review plan),

NRC will also require that the long-term surveillance plan contain documentation of title transfer

of the site from the licensee to the custodial agency. This requirement does not apply to sites

located on tribal lands, since transfer does not occur for such sites (Criterion 11F of

Appendix A).

Because the long-term surveillance plan must reflect the remediated condition of the site, it is

expected that the existing licensee will work with the custodial agency to prepare the long-term

surveillance plan. As discussed in Section E2.2 (above), this will likely involve supplying the

custodial agency with appropriate documentation (e.g., as-built drawings) of the remedial

actions taken and reaching agreements (formal or informal) with the custodial agency regarding

the necessary surveillance control features of the site (e.g., boundary markers, fencing).

As the likely custodial agency for most, if not all, of the sites, the DOE has developed a generic

long-term surveillance plan shell. For sites under the long-term care of the DOE, significant

portions of the long-term surveillance plan will not change from site to site (e.g., criteria for

follow-up inspections and for instituting maintenance or emergency measures). Therefore, the

staff may focus its review on the site-specific information in the long-term surveillance plan. 

This information would include site-specific activities that are not to be reflected in the long-term

care charge, but are voluntarily committed to by the custodial agency. 

E3.6 Termination of the Specific License/Issuance of the General License

Actual termination of a licensee-specific license and the subsequent placement of the site

under the general license provisions of 10 CFR 40.28 will involve a number of separate actions

to be completed by the NRC. Significant internal coordination (and external, if Agreement State

licensees are involved) will be required so that these actions will be completed in an efficient

and timely manner, thereby ensuring that the byproduct material and any land used for the

disposal of such byproduct material remain under NRC license throughout the process.

E3.6.1 NRC Determination Under Section 83c of the Act

Under Section 83c of the Atomic Energy Act, as amended, NRC must determine whether all

applicable standards and requirements have been met by the licensee in the completion of site

reclamation, decommissioning, and ground-water corrective action before a licensee’s license

can be terminated. Necessarily, this determination will rely primarily on NRC reviews and

acceptance of the documentation presented by the licensee. In addition, NRC site closure

inspection activities, potentially including limited confirmatory radiological surveys, will provide

supplemental information for NRC determination.

E3.6.2 NRC Review and Acceptance of the Long-Term Surveillance Plan

A long-term surveillance plan is required before termination of the specific license and

placement of the site and byproduct material under the 10 CFR 40.28 general license. Review
Appendix E

E–12

and acceptance of the long-term surveillance plan is the sole purview of NRC. Lack of NRC

acceptance of a site long-term surveillance plan can delay termination of the specific license.

NRC staff acceptance of a long-term surveillance plan will be documented in written notification

to the custodial agency, and, separately, by noticing the action in the Federal Register.

E3.6.3 Issuance of a Specific Order Under 10 CFR 40.28

If NRC has not received an acceptable long-term surveillance plan for a reclaimed site ready for

transfer to the custodial agency, the agency has two options available to it. First, if appropriate,

the Commission may choose not to terminate the existing license for a short period of time,

while awaiting an acceptable long-term surveillance plan. Alternately, under 10 CFR 40.28,

NRC may issue a specific order to the custodial agency to take custody of the site and to

commence long-term surveillance, while the agency prepares the long-term surveillance plan

for final NRC approval.

NRC would require substantial basis to support issuance of an order. The basis would include

an understanding of the circumstances leading to the custodial agency inability to take the site. 

Factors that the NRC would consider include whether:

(1) Adequate notice (at least 16 months) has been provided by the existing licensee to allow

the custodial agency to effect title transfer to the land and byproduct material.

(2) Sufficient time (at least 2 years) has been allowed for the custodial agency to prepare,

and the NRC to review, the long-term surveillance plan.

(3) NRC has reviewed the Construction Completion Report, decommissioning report, and

ground-water cleanup report and has conducted the final license-termination inspection

and found that the closure actions were completed in an acceptable manner.

(4) Site degradation has occurred, and whether appropriate repairs have been completed.

(5) The required long-term surveillance funding payments have been made to the

U.S. General Treasury or to the designated state agency.

(6) The custodial agency has an acceptable rationale for delaying inclusion of the site under

the general license.

In cases in which the DOE or another presidentially designated Federal agency will be the

long-term custodian and is unable to take custody of the site because of lack of funding, NRC

may still order the agency to take custody. The intended custodial agency will have at most

1 year (i.e., the time by which an annual site inspection is to have been completed) in which to

obtain the funds through the necessary appropriations process.
Appendix E

E–13

E3.6.4 Transfer of Site Control to the Custodial Agency

Given a determination that all applicable standards and requirements have been met and

acceptance of the site long-term surveillance plan, NRC will need to complete the following

remaining relevant licensing actions: (1) terminating the specific license by letter of termination

addressed to the specific licensee, or concurring in the Agreement State termination of the

specific license; (2) placing the site under the general license in 10 CFR 40.28; (3) noticing, in

the Federal Register, the completion of these licensing actions; and (4) informing appropriate

Federal and State officials directly of the termination of the specific license and the placement

of the site under the general license.

The long-term custodian, for its part, should be prepared to accept title to the land and

byproduct material. These final actions should be completed within a relatively short period of

time (i.e., within a week).

E4.0 ADDITIONAL ISSUES

E4.1 Uranium Mill Tailings Radiation Control Act of 1978, As Amended, Title II

Sites on Tribal Lands

For Uranium Mill Tailings Radiation Control Act of 1978,, as amended, Title II disposal sites on

tribal lands, long-term surveillance will be accomplished by the Federal government. The

custodial agency is required to enter into arrangements with NRC to ensure this surveillance. 

The Uranium Mill Tailings Radiation Control Act of 1978, as amended, does not state explicitly

which Federal agency is responsible for the disposal site. In addition, because these sites are

located on tribal lands, no title transfer will occur.

Currently, the only site on tribal lands is the previous Western Nuclear, Inc., Sherwood uranium

mill, located on the Spokane Indian tribe reservation in eastern Washington State. The

Western Nuclear, Inc. Sherwood license was terminated in early 2001. Under long-term care,

arrangements for the Sherwood site involve a site access agreement between the Indian tribe

and DOE. DOE is allowed to conduct the required site surveillance and the site is accessible

to NRC.

E4.2 Exclusive Jurisdiction

The Commission has determined that NRC has exclusive jurisdiction over both the radiological

and non-radiological hazards of 11e.(2) byproduct material (NRC 2002). Notwithstanding this 

determination, the NRC staff intends to work with the states on issues related to a licensee’s 

completion of remedial actions and preparation for license termination. Although the NRC will,

to the extent possible, accommodate a state’s interest or perspective, it retains the right to

terminate a specific license should a licensee have completed closure activities in accordance

with NRC-approved closure plans.Where the issues involved are not those of direct NRC

concern, NRC will address such issues with the states or other federal agencies on a case-bycase basis.
Appendix E

E–14

Currently, four sites (two NRC licensees: the United Nuclear Corporation/Church Rock site and

the Homestake Mining Company/Grants site; and two Agreement State licensees: the

Cotter Corp./Canon City and the UMETCO/Uravan sites, both in Colorado) are on the

Superfund National Priorities List. For these sites, NRC will work with states and Superfund

administering agencies to determine if it is appropriate to terminate the licenses.

E5.0 REFERENCES

NRC. “Termination of Uranium Milling Licenses in Agreement States.” STP SA–900

Procedure. Washington, DC: NRC, Office of State and Tribal Programs. December 2002.

–––––. SECY–99–0277. “Concurrent Jurisdiction of Non-Radiological Hazards of Uranium Mill

Tailings.” Washington, DC: NRC. August 2000.

–––––. “Staff Technical Position: Alternate Concentration Limits for Title II Uranium Mills:

Standard Format and Content Guide, and Standard Review Plan for Alternate Concentration

Limit Applications.” Washington, DC: NRC. February 1996.

–––––. SECY–90–282. “Rulemaking Issue (Affirmation): Amendments to 10 CFR Part 40 for

General Licenses for the Custody and Long-Term Care of Uranium and Thorium Mill Tailings

Disposal Sites.” Washington, DC: NRC. August 1990.

–––––. NUREG–0706, “Final Generic Environmental Impact Statement on Uranium Milling.”

Washington, DC: NRC. 1980.
 APPENDIX F
F–1

GUIDANCE TO THE U.S. NUCLEAR REGULATORY COMMISSION

STAFF ON EFFLUENT DISPOSAL AT LICENSED URANIUM 

RECOVERY FACILITIES: CONVENTIONAL MILLS

F1.0 BACKGROUND

U.S. Nuclear Regulatory Commission (NRC)-licensed uranium mill recovery facilities produce

liquid wastes (i.e., effluent) that require proper disposal. NRC Office of Nuclear Material Safety

and Safeguards policy is presented below.

F1.1 Purpose and Applicability

This appendix presents guidance and discusses the technical and regulatory basis for review

and evaluation of applications for the disposal of liquid waste. It is primarily intended to guide

NRC staff reviews of site-specific applications for disposal of liquid waste.

F1.2 On-Site Evaporation

Applications for on-site evaporation systems must demonstrate that the proposed disposal

facility is designed, operated, and closed in a manner that prevents migration of waste from the

evaporation systems to subsurface soil, ground water, or surface water in accordance with

10 CFR Part 40, Appendix A. Applicants must also demonstrate that site-specific ground-water

protection standards and monitoring requirements are adequately established to detect any

migration of contaminants to the ground water and to implement corrective action to restore

ground-water quality if, and when, necessary, as required by the regulations.

If surface impoundments are employed for liquid waste and solid wastes (sludge) that are

11e.(2) byproduct material. Licensees must demonstrate that surface impoundments are

designed, operated, and decommissioned in a manner that prevents migration of waste from

the surface impoundment to subsurface soil, ground-water, or surface water in accordance with

10 CFR Part 40, Appendix A. Applicants must also demonstrate that monitoring requirements

are adequately established to detect any migration of contaminants to the ground-water. Solid

waste material must be disposed of in an existing tailings impoundment or 11e.(2) disposal cell

in accordance with 10 CFR Part 40, Appendix A, Criterion 2.

If surface impoundments are employed for evaporation, but they are not used for waste

disposal, they must comply with the design provisions for surface impoundments

[Criterion 5A(1) through Criterion 5A(5)]; measures for ground-water protection programs

(Criterion 5E); and seepage control (Criterion 5F) of 10 CFR Part 40, Appendix A. However, if

surface impoundments are employed for evaporation and waste disposal, they must comply

with the regulatory requirements in 10 CFR Part 40, Appendix A. These include the design

provisions for surface impoundments [Criterion 5A(1) through Criterion 5A(5)]; measures for

ground-water protection programs (Criterion 5E); and seepage control (Criterion 5F). In

addition, evaporation ponds must also meet other generally applicable regulatory provisions in

Appendix A, in particular, the site-specific ground-water protection standards and leak detection

requirements (Criterion 5B and Criterion 5C); corrective action programs (Criterion 5D); groundwater monitoring requirements (Criterion 7); and closure requirements (Criterion 6).
Appendix F

F–2

F1.3 Release in Surface Waters

Process waste water resulting from operations is 11e.(2) byproduct material. The U.S.

Environmental Protection Agency (EPA), in accordance with 40 CFR 440.34, does not allow

new facilities to discharge process waste water to navigable waters. For release of this waste

to surface waters, existing licensees must meet the requirements of 10 CFR 20.1302(b)(2), and

should demonstrate that doses are maintained as low as reasonably achievable (ALARA). 

NRC has no specific requirements for non-radiological constituents, and may adopt the

appropriate State limits. Anticipated discharge must be described in enough detail to evaluate

environmental impacts. Appropriate State and Federal agency permits should be obtained in

accordance with 10 CFR 20.2007.

F1.4 Land Applications

For the land application of process waste water, the applicant must meet the regulatory

provisions in 10 CFR 20.2002 and demonstrate that doses are ALARA and within the dose

limits in 10 CFR 20.1301. Proposed land application activities should be described in sufficient

detail to satisfy the NRC need to assess environmental impacts. This may require analysis to

assess the chemical toxicity of radioactive and nonradioactive constituents. Specifically,

licensees must provide: (i) a description of the waste, including its physical and chemical

properties that are important to risk evaluation; (ii) the proposed manner and conditions of

waste disposal; (iii) projected concentrations of radioactive contaminants in the soil; and (iv)

projected impacts on ground-water and surface-water quality and on land uses, especially

crops and vegetation. In addition, projected exposures and health risks that may be associated

with radioactive constituents reaching the food chain must be analyzed to ensure that doses are

ALARA. Proposals should include provisions for periodic soil surveys to verify that contaminant

levels in the soil do not exceed those projected, and should also include a remediation plan that

can be implemented if projected levels are exceeded. Appropriate State and Federal agency

permits must be obtained in accordance with 10 CFR 20.2007. The applicant must also comply

with NRC regulatory provisions for decommissioning. The applicant should also address

whether the proposed land applications methodologies will comply with 10 CFR Part 40,

Appendix A, Criterion 6(6), at the time of decommissioning.

F1.5 Deep Well Injection

Proposals for disposal of liquid waste from process water by injection in deep wells must meet

the regulatory provisions in 10 CFR 20.2002 and demonstrate that doses are ALARA and within

the dose limits in 10 CFR 20.1301. The injection facility should be described in sufficient detail

to satisfy the NRC need to assess environmental impacts. Specifically, proposals must include:

(i) a description of the waste, including its physical and chemical properties important to risk

evaluation; (ii) the proposed manner and conditions of waste disposal; (iii) an analysis and

evaluation of pertinent information on the nature of the environment; (iv) information on the

nature and location of other potentially affected facilities; and (v) analyses and procedures to

ensure that doses are ALARA and within the dose limits in 10 CFR 20.1301.
F–3

In addition, pursuant to the provisions of 10 CFR 20.2007, proposals for disposal by injection in

deep wells should also meet any other applicable Federal, State, and local government

regulations pertaining to deep well injection. Applicants must obtain any necessary permits for

this purpose. In particular, proposals must satisfy the EPA regulatory provisions in 40 CFR Part

146: Underground Injection Control (UIC) Program: Criteria and Standards, and applicants

must obtain necessary permits from EPA and/or States authorized by EPA to enforce these

provisions. In general, applications that satisfy EPA regulations under the UIC Program, which

are approved by the EPA or an EPA-authorized State issuing the UIC permit and the applicable

provisions of 10 CFR Part 20, will also be approved by the staff. Licensees and applicants

disposing of liquid waste from process water by injection in deep wells are further required to

comply with NRC regulatory provisions for decommissioning.
APPENDIX G
G–1

NATIONAL HISTORIC PRESERVATION ACT AND ENDANGERED

SPECIES ACT CONSULTATIONS

G1.0 BACKGROUND

The National Historic Preservation Act requires federal agencies to consider the effects of

actions licensed by Federal agencies on properties included in or eligible for the National

Register of Historic Places. The reclamation of a mill could impact historic properties directly

(e.g., destruction or alteration of the integrity of a property) or indirectly (e.g., prohibiting access

or increasing the potential for vandalism). Similarly, the Endangered Species Act requires that

federal agencies consult with the U.S. Fish and Wildlife Service on any Federal action that

could impact endangered species or their habitats. This appendix presents guidance to the

U.S. Nuclear Regulatory Commission (NRC) staff on how to fulfill the NRC obligations under

the National Historic Preservation and Endangered Species Acts.

G2.0 NATIONAL HISTORIC PRESERVATION ACT

G2.1 Review Procedures

The reviewer should ensure that those historic and cultural resources that could be impacted by

proposed mill reclamation have been identified, located, and described in sufficient detail to

serve as the basis for subsequent analysis and assessment of these impacts. Historic and

cultural resources include districts, sites, buildings, structures, or objects of historical,

archaeological, architectural, or cultural significance. The staff should review the results of any

surveys conducted by the applicant, the location and significance of any properties that are

listed in or eligible for inclusion in the National Register of Historic Places (National Register) as

a historic place, and any additional information pertaining to the identification and description of

historic properties that could be impacted by reclamation of the proposed mill. The descriptions

to be examined by this review should be of sufficient detail to permit staff assessment and

evaluation of specific impacts to historic and cultural resources from reclamation of the mill.

Regulatory criteria for the review of the historic properties that could be impacted by proposed

reclamation of mills are based on the relevant requirements of the following:

• 36 CFR Part 800 defines the process by which a Federal agency conforms to the

requirements under Sections 106 and 110 of the National Historic Preservation Act to

ensure that agency-licensed undertakings consider the effects of the undertaking on

historic properties included in or eligible for the National Register. Under this regulation,

the Federal agency is required to identify and evaluate all historic properties in the

project areas and take measures to mitigate adverse affects.

• 36 CFR Part 63 contains guidance by which historic properties are evaluated and

determined eligible for listing on the National Register.
Appendix G

G–2

The reviewer should take the following steps to obtain the necessary information:

(1) Contact the appropriate State historic preservation officer to determine if there are any

historic or cultural properties near the proposed mill site. In areas of Indian tribal land,

the Indian tribal agencies may act as the State historic preservation officer. State

historic preservation officer and tribal historic preservation officer lists are found on the

Advisory Council on Historic Preservation Internet Home Page (http://www.achp.gov). 

(a) NRC can authorize the applicant to initiate consultation with the State historic

preservation officer or tribal historic preservation officer, but remains legally

responsible for all findings. Notify the State historic preservation officer/tribal

historic preservation officer when an applicant is so authorized.

(b) Make initial contact by phone and invite the State historic preservation officer to

participate in the site visit. Then request information from the State historic

preservation officer by letter.

(c) If the State historic preservation officer has comments or information that add to

or amplify information given to the applicant, request that the State historic

preservation officer forward, by letter to the staff, these additional comments. 

(2) Contact the Archeology and Ethnography Program of the National Park Service,

U.S. Department of Interior (http://www.cr.nps.gov/aad/). This office has expertise in the

area of historic and cultural preservation and is staffed with professionals who can assist

in the environmental review and in analyzing the results of applicant surveys and

investigations.

(3) In consultation with the State historic preservation officer, apply the National Register

criteria outlined by the U.S. Department of the Interior (National Park Service, 1990,

1991) to all identified historic properties that are on the facility site or that will be directly

affected by facility construction. If a property appears to meet the criteria, or if it is

questionable whether the criteria are met, the staff should request, in writing, an opinion

from the U.S. Department of the Interior about the property eligibility for inclusion in the

National Register. The request for determination of eligibility should be sent directly to

the Keeper of the National Register of Historic Places, National Park Service,

U.S. Department of the Interior, Washington, DC, 20013-7127.

(4) Have the National Park Service–Archeology and Ethnography Program staff assist in

defining the requirements of additional surveys and investigations that the staff decides

should be completed by the applicant and in reviewing the results of these surveys.

(5) Consult the National Register to verify the list of National Register properties presented

by the licensee. Since a proposed facility can have a visual or audible effect on historic

and cultural resources that are located some distance from the proposed facility site, all

National Register properties within the area of potential effects of the proposed facility or

off-site areas should be identified.
Appendix G

G–3

(6) Discuss with the State historic preservation officer and, where appropriate, the State

archaeologist and State historian, the information presented to the aplicant by the State

historic preservation officer. The State historic preservation officer can alert the staff to

relevant State and local laws, orders, ordinances, or regulations aimed at the

preservation of cultural resources within the licensee State. Discuss with the State

historic preservation officer any organizations or individuals that might be able to assist

in identifying and locating archaeological and historic resources (e.g., university, Indian

tribal archaeological and historical staffs, and regional U.S. Bureau of Land

Management archaeologists).

(7) To discourage property vandalism and scavenging, it is necessary to present

information on location of artifacts to the State historic preservation officer in a

confidential manner. Summary information, which does not include site-specific

information, could be included in the licensee and NRC staff documentation.

(8) Contact the Advisory Council on Historic Preservation if guidance is needed, if there are

substantial impacts on important properties, in the event of a disagreement, or if there

are issues of concern to Indian tribes.

For license renewals and amendment applications, Appendix A to this standard review plan

provides guidance for examining facility operations and the approach that should be used in

evaluating amendments and renewal applications.

G2.2 Acceptance Criteria

The kinds of data and information needed will be affected by site- and facility-specific factors

and the degree of detail should be modified according to the anticipated magnitude of the

potential impact. Guidance can be found on the National Park Service Internet Home Page at

http://www.cr.nps.gov/nr/nrpubs.html and in NUREG–1748 (NRC, 2001). The licensee should

present the following data or information:

(1) A detailed description of any archaeological or historical surveys of the proposed site,

including the following:

(a) The physical extent of the survey: If the entire site was not surveyed, the basis

for selecting the area to be surveyed.

(b) A brief description of the survey techniques used and the reason for the

selection of the survey techniques used.

(c) The qualifications of the surveyors.

(d) The findings of the survey in sufficient detail to permit a subsequent independent

assessment of the impact of the proposed project on archaeological and

historic resources.

(2) The results of consultation with Federal, State, local, and affected Indian tribal agencies. 
Appendix G

G–4

(3) The comments of any organizations contacted by the licensee to locate and assess

archaeological and historic resources located on or near the proposed mill site.

(4) A description of any historic property within the area of potential effects of the mill that

are in or have been determined eligible for inclusion in the National Register or that are

included in state or local registers or inventories of historic and cultural resources.

(5) A map indicating the location of all identified historic landmarks and historic places with

respect to the location of facilities such as buildings, new roads, well fields, pipelines,

surface impoundments, and utilities (not to be made public).

(6) A license condition prohibiting work if cultural artifacts are found in locations other than

those already identified.

(7) The likely impact of the presence of new roads, pipelines, or other utilities on historic

and cultural resources.

(8) A rating of the aesthetic and scenic quality of the site in accordance with the

U.S. Bureau of Land Management Visual Resource Management System (U.S. Bureau

of Land Management, 1984, 1986a,b).

(9) The following information should usually be briefly described in the

environmental assessment:

(a) Historic properties listed in or eligible for inclusion in the National Register. Any

resource considered to be eligible for the National Register should have

concurrence from the appropriate state historic preservation officer.

(b) Historic properties included in state or local registers or inventories.

(c) Any additional important historic or cultural properties.

(d) The efforts to locate and identify previously recorded archaeological and

historic sites.

(e) The overall results and adequacy of any surveys (archival or field) that were

conducted by the applicant.

(f) A list of organizations and individuals contacted by the applicant or the NRC staff

who provided significant information concerning the location of historic and

cultural properties.
Appendix G

G–5

G2.3 Evaluation Findings

If the staff review results in the acceptance of the characterization of the historic and cultural

resources, the following conclusions may be presented in the environmental assessment.

The staff has completed its review of the site characterization information concerned with

historic and cultural resources near the uranium mill facility. This review

included an evaluation using the review procedures and the acceptance criteria outlined in

Sections 2.1 and 2.2 of Appendix G of NUREG–1620. The licensee has acceptably described

the historic and cultural resources near the site. A listing of all nearby areas and properties

included or eligible for inclusion in the National Register of Historic Places is provided. A map

indicates where all historic and cultural resources are located with respect to facilities. A record

of the investigation of places and properties with historic and cultural significance, which follows

guidance equivalent to that of the National Park Service, is provided. Contact with local tribal

authorities is acceptably documented. A letter from the State historic preservation officer

addressing any issues related to the properties that might be affected by the reclamation is

included. The licensee has acceptably demonstrated that the State historic preservation officer

and tribal authorities agree with the planned protection from, or determination of lack of conflict

with, facilities and activities and with any places of importance to the State, Federal, or tribal

authorities. The licensee has acceptably rated the aesthetic and scenic quality of the site in

accordance with the U.S. Bureau of Land Management Visual Resource Inventory and

Evaluation System.

On the basis of the information presented in the application, and the detailed review conducted

of the characterization of historic and cultural resources near the uranium mill

facility, the staff concludes that the information is acceptable and is in compliance with

10 CFR 51.45, which requires a description of the affected environment containing sufficient

data to aid the Commission in its conduct of an independent analysis.

G2.4 References

10 CFR 51.45, “Environmental report.”

36 CFR Part 63, “Determination of Eligibility for Inclusion in the National Register of 

Historic Places.”

36 CFR Part 800, “Protection of Historic and Cultural Properties.”

National Historic Preservation Act, as amended. 16 USC 470 et seq.

National Park Service. “How to Apply the National Register Criteria for Evaluation.” National

Register. Bulletin No. 15. Washington, DC: U.S. Department of the Interior. 1991.

–––––. “Guidelines for Evaluating and Documenting Traditional Cultural Properties.” National

Register. Bulletin No. 38. Washington, DC: U.S. Department of the Interior. 1990.
Appendix G

G–6

–––––. “Guidelines for Local Surveys: A Basis for Preservation Planning.” National Register. 

Bulletin No. 24. Washington, DC: U.S. Department of the Interior. 1985.

NRC. NUREG–1748, “Environmental Review Guidance for Licensing Actions Associated with

NMSS Programs.” Draft. Washington, DC: NRC. 2001.

U.S. Bureau of Land Management. “Visual Resource Inventory.” BLM

Report H–8410–1. 1986a.

–––––. “Visual Resource Contrast Rating.” BLM Report H–8431–1. 1986b.

–––––. “Visual Resource Management.” BLM Report 8500. 1984.

U.S. Department of the Interior. “Archeology and Historic Preservation; Secretary of the

Interior’s Standards and Guidelines.” 48 FR 44716. pp. 44,716–44,742. 1983.

G3.0 ENDANGERED SPECIES ACT

G3.1 Review Procedures

Federal agencies must determine if any proposed actions could impact endangered species or

their habitats. For uranium mills, the NRC staff should take into consideration impacts resulting

from excavation of clay used in constructing radon barriers or procurement of rocks used in

riprap. Other surface reclamation work, such as the cleanup of windblown tailings, has the

potential to impact endangered animals or plants. Also, the staff should review the processing

of any alternate concentration limit application if the proposed site is located on or near surface

water that contains endangered animal or plant species. 

Procedures for conducting consultations with the U.S. Fish and Wildlife Service are contained in

the endangered species consultation handbook (U.S. Fish and Wildlife Service/National Marine

Fisheries Service, 1998). The reviewer analysis should consist of the following steps:

(1) Contact the U.S. Fish and Wildlife Service regional office or field office to obtain the list

of threatened or endangered plant and animal species that may be present near the

site. The attached table indicates the States in each U.S. Fish and Wildlife Service

regional office and provides contact information.

(2) The licensee may request the species list; however, the NRC must formally designate

the licensee in writing (U.S. Fish and Wildlife Service/National Marine Fisheries Service,

1998, pp. 2–13).

(3) If there may be endangered or threatened animal or plant species on or near the site,

the reviewer should discuss the proposed action with the U.S. Fish and Wildlife Service

and may need to ask the licensee to perform a survey and a biological assessment 
Appendix G

G–7

(50 CFR 402.12) to evaluate the potential effects of the action on threatened and endangered

species. Either the NRC or the licensee can prepare the biological assessment (U.S. Fish and

Wildlife Service/National Marine Fisheries Service, 1998, pp. 3–11).

(4) Each State should be consulted about its own procedures for considering impacts to

state-listed species.

G3.2 Acceptance Criteria

Consultations on identifying threatened and endangered species under the Endangered

Species Act of 1973, as amended, are acceptable if the following criteria are met:

(1) The environmental impact assessment provides sufficient information to ensure that the

licensing action is not likely to jeopardize the continued existence of any endangered

species or threatened species or result in the destruction or adverse modification of the

habitat of such species. The demonstration of compliance with this objective requires

consultation with the U.S. Fish and Wildlife Service and/or the National Marine Fisheries

Service. The U.S. Fish and Wildlife Service will coordinate with the National Marine

Fisheries Service.

(2) The licensee provides adequate discussion of the status of compliance with applicable

permits, licenses and other environmental requirements that have been imposed by

Federal agencies.

(3) There is adequate information on interagency cooperation and consultations with

Federal, State, and local agencies with regard to the Endangered Species Act.

G3.3 Evaluation Findings

If staff review results in acceptance of compliance with the Endangered Species Act, the

following conclusions may be presented in the environmental assessment:

The staff has completed its review of the site characterization information concerned with the

threatened and endangered species near the uranium mill facility. This

review included an evaluation using review procedures and acceptance criteria outlined in

Sections 3.1 and 3.2 of Appendix G of NUREG–1620. The licensee has acceptably described

the presence of threatened and endangered species near the site. Consultations with the

U.S. Fish and Wildlife Service and/or the National Marine Fisheries Service on threatened and

endangered species were conducted and are documented in an acceptable manner. Any

impacts on these species and their habitats have been identified, and mitigation measures

necessary to avoid adverse impacts have been described.

On the basis of the information presented in the application, and the detailed review conducted

of the characterization of threatened and endangered species near the

 uranium mill facility, the staff concludes that the information is acceptable and
Appendix G

G–8

is in compliance with 10 CFR 51.45, which requires a description of the affected environment

containing sufficient data to aid the Commission in its conduct of an independent analysis.

G3.4 References

10 CFR 51.45, “Environmental Report.”

40 CFR 1502.25, “Environmental Review and Consultation Requirements.”

50 CFR Part 402, “Interagency Cooperation-Endangered Species Act of 1973, as Amended.”

Endangered Species Act of 1973, as amended, 16 USC 1531 et seq.

U.S. Fish and Wildlife Service/National Marine Fisheries Service. "Endangered Species

Consultation Handbook, Procedures for Conducting Consultation and Conference Activities

Under Section 7 of the Endangered Species Act." Washington, DC: U.S. Fish and Wildlife

Service/National Marine Fisheries Service. 1998.

U.S. Fish and Wildlife Service

Endangered Species Program Contacts

Washington, DC Office

U.S. Fish and Wildlife Service

Division of Endangered Species

Mail Stop 420ARLSQ

1849 C St., N.W., Washington, DC 20240

http://www.fws.gov

Region One (CA, HI, ID, NV, OR, WA)

Chief, Division of Endangered Species

Eastside Federal Complex, 911 NE 11th Ave, Portland, OR 97232

http://pacific.fws.gov

Contact: Call field office

Region Two (AZ, NM, OK, TX)

Chief, Division of Endangered Species

P.O. Box 1306, Albuquerque, NM 87103

http://southwest.fws.gov

Contact:: Species list on Internet for each county

Call field supervisor if there are questions
Appendix G

G–9

Region Three (IA, IL, IN, MI, MN, MO, OH, WI)

Chief, Ecological Services Operations

Federal Building, Ft. Snelling, Twin Cities, MN 55111

http://midwest.fws.gov

Contact: Species list on Internet by county, (except Missouri)

Call field supervisor if there are questions or if the site is in Missouri

Region Four (AL, AR, FL, GA, KY, LA, MS, NC, PR, SC, TN, U.S. VI)

Programmatic Assistant

Regional Director for Ecological Services

1875 Century Blvd., Suite 200, Atlanta, GA 30345

http://southeast.fws.gov

Contact: Letter to Programmatic Assistant

Region Five (CT, DC, DE, MA, MD, ME, NH, NJ, NY, PA, RI, VA, VT, WV)

Chief, Division of Endangered Species

300 Westgate Center Drive, Hadley, MA 01035

http://northeast.fws.gov

Contact: Call field office

Region Six (CO, KS, MT, NE, ND, SD, UT, WY)

Division of Endangered Species

P.O. Box 25486, Denver Federal Center, Denver, CO 80225

http://mountain-prairie.fws.gov

Contact: Call field office

Region Seven (AK)

Division of Endangered Species

1011 E. Tudor Rd., Anchorage, AK 99503

http://alaska.fws.gov

Contact: Letter to Division of Endangered Species
APPENDIX H
H–1

GUIDANCE TO THE U.S. NUCLEAR REGULATORY COMMISSION

STAFF ON THE RADIUM BENCHMARK DOSE APPROACH 

H1.0 BACKGROUND

In 10 CFR 40.4, byproduct material is defined as the tailings or waste produced by the

extraction or concentration of uranium or thorium from any ore processed primarily for its

source material content, including discrete surface wastes resulting from uranium solution

extraction processes. Uranium milling is defined as any activity resulting in byproduct material. 

Therefore, 10 CFR Part 40, Appendix A, applies to in situ leach, heap leach, and ion-exchange

facilities that produce byproduct material, as well as to conventional uranium and thorium mills. 

This guidance only addresses uranium recovery facilities because there are no currently

licensed or planned thorium mills.

The final rule, “Radiological Criteria for License Termination of Uranium Recovery Facilities,”

became effective on June 11, 1999, and added the following paragraph after the “radium in soil”

criteria in Appendix A, Criterion 6(6):

Byproduct material containing concentrations of radionuclides other than radium

in soil, and surface activity on remaining structures, must not result in a total

effective dose equivalent (TEDE) exceeding the dose from cleanup of radium

contaminated soil to the above standard (benchmark dose), and must be at

levels which are as low as is reasonably achievable. If more that one residual

radionuclide is present in the same 100-square-meter area, the sum of the ratios

for each radionuclide of concentration present to the concentration limit, will not

exceed 1 (unity). A calculation of the peak potential annual TEDE within

1,000 years to the average member of the critical group that would result from

applying the radium standard (not including radon) on the site, must be

submitted for approval. The use of decommissioning plans with benchmark

doses which exceed 100 mrem/yr, before application of as low as is reasonably

achievable, requires the approval of the Commission after consideration of the

recommendation of NRC staff. This requirement for dose criteria does not apply

to sites that have decommissioning plans for soil and structures approved before

June 11, 1999.

H2.0 RADIUM BENCHMARK DOSE APPROACH

The general requirements for a decommissioning plan, including verification of soil

contamination cleanup, are addressed in Chapter 5.0 of this standard review plan. This

appendix discusses the NRC staff evaluation of the radium benchmark dose approach,

specifically dose modeling and its application to site cleanup activities that should be addressed

in the decommissioning plan for those uranium recovery facilities licensed by the NRC and

subject to the new requirements for cleanup of contaminated soil and buildings under

10 CFR Part 40, Appendix A, Criterion 6(6), as amended in 1999. The facilities that did not

have an approved decommissioning plan at the time the rule became final are required to

reduce residual radioactivity, that is, byproduct material, as defined by 10 CFR Part 40, to levels

based on the potential dose, excluding radon, resulting from the application of the radium

(Ra-226) standard at the site. This is referred to as the radium benchmark dose approach. 
Appendix H

H–2

This guidance also applies to any revised decommissioning plan submitted for NRC review and

approval, after the final rule was effective. However, if a subject licensee can demonstrate that

no contaminated buildings will remain, and that soil thorium-230 (Th-230) does not exceed

5 pCi/g (above background) in the surface and 15 pCi/g in subsurface soil in any

100-square-meter area that meets the radium standard, and the natural uranium (U-nat, that is,

U-238, U-234, and U-235) level is less than 5 pCi/g above background, radium benchmark

dose modeling is not required. If future modeling with site-specific parameters for uranium

recovery sites indicates that this is not a protective approach, the guidance will be revised. 

Therefore, it would be prudent for a uranium recovery licensee to consider the potential dose

from any residual thorium and uranium. 

The unity “rule” mentioned in the new paragraph of Criterion 6(6) applies to all licensed residual

radionuclides. Therefore, if the ore (processed by the facility), tailings, or process fluid

analyses indicate that elevated levels of Th-232 could exist in certain areas after cleanup for

Ra-226, some verification samples in those areas should be analyzed for Th-232 or Ra-228. 

The thorium (Th-232) chain radionuclides (above local background levels) in milling waste

would have soil cleanup criteria similar to the uranium chain radionuclides. The staff considers

the EPA memorandum of February 12, 1998, (Directive No. 9200.4–25) concerning use of

40 CFR Part 192 soil criteria for Comprehensive Environmental Response, Compensation and

Liability Act sites, an acceptable approach. This means that the Th-230 and Th-232 should be

limited to the same concentration as their radium progeny with the 5 pCi/g (0.19 Bq/g) criterion

applying to the sum of the radium constituents (Ra-226 plus Ra-228) as well as the sum of the

thorium constituents (Th-230 plus Th-232) above background.

H2.1 Radium Benchmark Dose Modeling 

H2.1.1 Areas of Review

The radium benchmark dose approach involves calculation of the peak potential dose for the

site resulting from the 5 pCi/g [0.19 Bq/g] concentration of radium in the surface 15 cm [6 in.] of

soil. The dose from the 15 pCi/g [0.56 Bq/g] subsurface radium would also be calculated for

any area where the criterion is applied. The dose modeling review involves examining the

computer code or other calculations employed for the dose estimates, the code or calculation

input values and assumptions, and the modeling results (data presentation).

Evaluation of the radium benchmark dose modeling as proposed in the decommissioning plan,

requires an understanding of the site conditions and site operations. The relevant site

information presented in the plan or portions of previously submitted documents

(e.g., environmental reports, license renewal applications, reclamation plan, and

characterization survey report) should be reviewed. 
Appendix H

H–3

H2.1.2 Review Procedures

The radium benchmark dose modeling review consists of ascertaining that an acceptable dose

modeling computer code or other type of calculation has been used, that input parameter

values appropriate (reasonable considering long-term conditions and representative of the

application) for the site have been used in the modeling, that a realistic (overly conservative is

not acceptable as it would result in higher allowable levels of uranium or thorium which would

not be as low as is reasonably achievable) dose estimate is provided, and that the data

presentation is clear and complete.

H2.1.3 Acceptance Criteria

The radium benchmark dose modeling results will be acceptable if the dose assessment

(modeling) meets the following criteria:

(1) Dose Modeling Codes and Calculations

The assumptions are considered reasonable for the site analysis, and the calculations

employed are adequate. Reference to documentation concerning the code or

calculations is provided [e.g., the RESRAD Handbook and Manual (Argonne National

Laboratory, 1993a,b)]. 

The RESRAD code developed by the U.S. Department of Energy (Version 6.1, 2001)

may be acceptable for dose calculations because, although the RESRAD ground-water

calculations have limitations, this does not affect the uranium recovery sites that have

deep aquifers (ground-water exposure pathway is insignificant). The DandD code

developed for the NRC provides conservative default values, but does not, at this time,

allow for modeling subsurface soil contamination and does not allow calculation of

source removal due to soil erosion. The DandD code would not be adequate to model

the dose from off-site contamination, but codes such as GENII are acceptable. See

Appendix C of NUREG–1727 (NRC, 2000) for additional information.

If the code or calculations assumptions are not compatible with site conditions,

adjustments have been made in the input to adequately reflect site conditions. For

example, the RESRAD code assumes a circular contaminated zone. The shape factor

(external gamma, code screen R017) is adjusted for an area that is not circular. 

The code and/or calculation provides an estimated annual dose as total effective dose

equivalent in mrem/yr. The DandD code provides the annual dose, but RESRAD

calculates the highest instantaneous dose. However, RESRAD results are acceptable

for long-lived radionuclides that do not move rapidly out of surface soils.

(2) Input Parameter Values

The code/calculation input data are appropriate for the site and represent current or

long-term conditions, whichever is more applicable to the time of maximum dose. When

code default values are used, they are justified as appropriate (representative) for the

site. Excessive conservatism (i.e., upper bound value) is not used, as this would result
Appendix H

1

As defined in 10 CFR Part 20, “the group of individuals reasonably expected to receive the greatest exposure to

residual radioactivity for any applicable set of circumstances.”

H–4

in a higher dose and thus higher levels of uranium and thorium could be allowed to

remain on site.

Previously approved MILDOS code input parameter values may not be appropriate,

because derived operational doses in the restricted area may be an order of magnitude

higher than acceptable doses for areas to be released for unrestricted use.

Site-specific input values are demonstrated to be average values of an adequate

sample size. Confidence limits are provided for important parameters so that the level

of uncertainty can be estimated for that input value. Alteration of input values considers

that some values are interrelated [see draft NUREG–1549, Appendix C (NRC, 1998)],

and relevant parameters are modified accordingly. The preponderance of important

parameter values are based on site measurements and not on conservative estimates. 

One or more models consider the annual average range of parameter values likely to

occur within the next 200 years, for important parameters that can reasonably be

estimated. Some other considerations for the input parameter values follow:

(a) Scenarios for the Critical Group and Exposure Pathways

The scenario(s) chosen to model the potential dose to the average member of

the critical group1

 from residual radionuclides at the site reflect reasonable

probable future land use. The licensee has considered ranching, mining,

home-based business, light industry, and residential farmer scenarios, and has

justified the scenarios modeled. 

On the basis of one or more of these projected (within 200 years is reasonably

foreseeable) land uses to define the critical group(s), the licensee has

determined and justified what exposure pathways are probable for potential

exposure of the critical group to residual radionuclides at the site. Dairies are

not likely to be established in the area of former uranium recovery facilities

because the climate and soil restrict feed production. Even if some dairy cows

were to graze in contaminated areas, the milk would probably be sent for

processing (thus diluted), and not be consumed directly at the site. Therefore,

milk consumption is not a likely ingestion exposure pathway. Also, a pond in the

contaminated area providing a significant quantity of fish for the resident’s diet is

not likely, so the aquatic exposure pathway may not have to be modeled. 

However, the external gamma, plant ingestion, and inhalation pathways are likely

to be important.

The radon pathway is excluded from the benchmark dose calculation as defined

in Criterion 6(6) of Appendix A to 10 CFR Part 40. This also reflects the

approach in the decommissioning rule (radiological criteria for license

termination, 10 CFR Part 20, Subpart E). 
Appendix H

H–5

(b) Source Term

If the RESRAD code is used, the input includes lead-210 (Pb-210) at the same

concentration input value as for Ra-226. The other radium progeny are

automatically included in the code calculations. The chemical form of the

contamination in the environment is considered in determining input values

related to transport, or inhalation class (retention in the lung) for dose

conversion factors.

(c) Time Periods

The time periods for calculation of the dose from soil Ra-226 include the

1,000-year time frame. The calculated maximum annual dose and the year of

occurrence are presented in the results.

(d) Cover and Contaminated Zone

A cover depth of zero is used in the surface contamination model, and a depth of

at least 15 cm [6 in.] is used for the subsurface model. The values for area and

depth of contamination are derived from site characterization data. The erosion

rate value for the contaminated zone is less than the RESRAD default value

because in regions drier than normal, the erosion rate is less, as discussed in

the RESRAD Data Collection Handbook (Argonne National Laboratory, 1993a),

and the proposed value is justified. The soil properties are based on site data

(sandy loam or sandy silty loam are typical for uranium recovery sites), and other

input parameters are based on this demonstration of site soil type [see RESRAD

handbook, pp., 23, 29, 77, and 105 (Argonne National Laboratory, 1993a)].

The evapotranspiration coefficient for the semi-arid uranium recovery sites is

between 0.6 and 0.99. The precipitation value is based on annual values

averaged over at least 20 years, obtained from the site or from a nearby

meteorological station.

The irrigation rate value may be zero, or less than a code’s default value, if

supported by data on county or regional irrigation practices (e.g., zero is

acceptable if irrigation water is obtained from a river not a well). The runoff

coefficient value is based on the site’s soil type, expected land use, and

regional morphology.

(e) Saturated Zone

The dry bulk density, porosity, “b” parameter, and hydraulic conductivity values

are based on local soil properties. The hydraulic gradient for an unconfined

aquifer is approximately the slope of the water table. For a confined aquifer, it

represents the difference in potentiometric surfaces over a unit distance. 
Appendix H

H–6

If the RESRAD code is used, the non-dispersion model parameter is chosen for

areas greater than 1,000 square meters (code screen R014), and the well pump

rate is based on irrigation, stock, or drinking water well pump rates in the area.

(f) Uncontaminated and Unsaturated Strata

The thickness value represents the typical distance from the soil contamination

to the saturated zone. Since the upper aquifer at uranium recovery sites is often

of poor quality and quantity, the depth of the most shallow well used for irrigation

or stock water in the region is chosen for the unsaturated zone thickness. A

value of 18 m [60 ft] is typical for most sites {15 m [50 ft] for the Nebraska site},

but regional data are provided for justification. The density, porosity, and “b”

parameter values are similar to those for the saturated zone, or any changes

are justified. 

(g) Distribution Coefficients and Leach Rates

The distribution coefficient (Kd) is based on the physical and chemical

characteristics of the soil at the site. The leach rate value of zero in the

RESRAD code is acceptable as it allows calculation of the value. If a value

greater than zero is given, the value is justified. 

(h) Inhalation 

An average inhalation rate value of approximately 8,395 m3

/yr is used for the

activity assumed for the rancher or farmer scenario based on a draft letter report

(Sandia National Laboratories, 1998a). The mass loading for inhalation (air dust

loading factor) value is justified based on the average level of airborne dust in

the local region for similar activities as assumed in the model. 

(i) External Gamma

The shielding factor for gamma is in the range of 0.3 to 0.6 (70 to 40 percent

shielding) (the DandD code screening default value is 0.55 and EPA has

recommended 0.4). The factor is influenced by the type (foundation, materials)

of structures likely to be built on the site and the gamma energy of the

radionuclides under consideration.

The time fractions for indoor and outdoor occupancy are similar to default values

in RESRAD and draft guidance developed for the decommissioning rule

[NUREG/CR–5512, Volume 3 (NRC, 1999b)]. For example, the staff would

consider fraction values approximating 0.7 indoors and 0.15 outdoors for a

resident working at home, and 0.5 outdoors and 0.25 indoors for the farmer

scenario (the remaining fraction allocated to time spent offsite).

The site-specific windspeed value is based on adequate site data. The average

annual windspeed for the uranium recovery sites varies from 3.1 to
Appendix H

H–7

5.5 meters/sec [7 to 13 mph]. The maximum and annual average windspeed are

also considered when evaluating proposed erosion rates.

(j) Ingestion

Average consumption values (g/yr) for the various types of foods are based on

average values as discussed in NUREG/CR–5512, Volume 3 (NRC, 1999), or

the Sandia Draft Letter Reports (Sandia National Laboratories,1998a,b), or are

otherwise justified. Livestock ingestion parameters are default values, or are

otherwise justified. 

For sites with more than 100 acres of contamination, the fraction of diet from the

contaminated area is assumed to be 0.25 for the farmer scenario (Sandia

National Laboratories, 1998a), or is otherwise justified based on current or

anticipated regional consumption practices for home-grown food. Because of

the low level of precipitation in the areas in which uranium recovery facilities are

located, extensive gardens or dense animal grazing is not likely, so the

percentage of the diet obtained from contaminated areas would be lower than

the code default value. 

Note that the default plant mass loading factor in the DandD code can

reasonably be reduced to 1 percent (Sandia National Laboratories, 1998c). The

depth of roots is an important input parameter for uranium recovery licensees

using the RESRAD code. The value is justified based on the type of crops likely

to be grown on the site in the future. For vegetable gardens, a value of 0.3 is

more appropriate than the RESRAD default value of 0.9 meters that is

reasonable for alfalfa or for a similar deep-rooted plant.

(3) Presentation of Modeling Results

The radium benchmark dose modeling section of the decommissioning plan includes the

code or calculation results as the maximum annual dose (total effective dose equivalent)

in mrem/yr, the year that this dose would occur, and the major exposure pathways by

percentage of total dose. The modeling section also includes discussion of the

likelihood of the various land-use scenarios modeled (reflecting the probable critical

groups), and provides the variations in dose (dose distribution) created by changing key

parameter values to reflect the range of dose values that are likely to occur on the site in

the future. The section also contains the results of a sensitivity analysis (RESRAD can

provide a sensitivity analysis via the graphics function) to identify the important

parameters for each scenario.

H2.1.4 Evaluation Findings

If the staff review, as described in this section, results in the acceptance of the radium

benchmark dose modeling, the following conclusions may be presented in the technical

evaluation report.
Appendix H

H–8

The staff has completed its review of the site benchmark dose modeling for the

 uranium mill facility. This review included an evaluation using the review

procedures and the acceptance criteria outlined in Section H2.1 of Appendix H of this standard

review plan.

The licensee has provided an acceptable radium benchmark dose model, and the staff

evaluation has determined that (1) the computer code or set of calculations used to model the

benchmark dose is appropriate for the site, (2) input parameter values used in each dose

assessment model are site-specific or reasonable estimates, and (3) the dose modeling results

include adequate estimates of dose uncertainty.

On the basis of the information presented in the application, and the detailed review conducted

of radium benchmark dose modeling for the uranium mill facility, the staff

concludes that the information is acceptable and is in compliance with 10 CFR Part 40,

Appendix A, Criterion 6(6), which provides requirements for soil and structure cleanup.

H2.2 Implementation of the Benchmark Dose

H2.2.1 Areas of Review

The results of the radium benchmark dose calculations are used to establish a surface and

subsurface soil dose limit for residual radionuclides other than radium, as well as a limit for

surface activity on structures that will remain after decommissioning. The staff should review

the licensee’s conversion of the benchmark dose limit to soil concentration (pCi/g) or surface

activity levels (dpm/100 cm2

) as a first step to determine cleanup levels. Alternatively, the

licensee can derive the estimated dose from the uranium or thorium contamination (as

discussed in Section 2.1.3) and compare this to the radium benchmark dose. 

The reviewer should also evaluate the proposed cleanup guideline levels (derived concentration

limit) in relation to the “as low as is reasonably achievable” requirement and the unity rule. 

H2.2.2 Review Procedures

The decommissioning plan section on cleanup criteria will be evaluated for appropriate

conversion of the radium standard benchmark dose to cleanup limits for soil uranium and

thorium and/or surface activity. The plan will also be examined to ensure reasonable

application of “as low as is reasonably achievable” to the cleanup guideline values and

application of the unity rule where appropriate.

H2.2.3 Acceptance Criteria

(1) The soil concentration limit is derived from the site radium dose estimate. The modeling

performed to estimate mrem/year per pCi/g of Th-230 and/or U-nat follows the criteria

listed in Section 2.1.3. In addition, the U-nat source term input is represented as

percent activity by 48.9 percent U-238, 48.9 percent U-234, and 2.2 percent U-235, or is

based on analyses of the ore processed at the site. For a soil uranium criterion (derived
Appendix H

H–9

concentration limit), the chemical toxicity is considered in deriving a soil concentration

limit if soluble forms of uranium are present.

(2) Detailed justification for the inhalation pathway parameters is provided, such as the

determination of the chemical form in the environment, to support the inhalation class.

(3) The derived Th-230 soil limit will not cause any 100 square meter (m2

) area to exceed 

the Ra-226 limit at 1,000 years (i.e., current concentrations of Th-230 are less than

14 pCi/g surface and 43 pCi/g subsurface, if Ra-226 is at approximately

background levels).

(4) In conjunction with the activity limit, the “as low as is reasonably achievable” principle is

considered in setting cleanup levels (derived concentration guideline levels). The as low

as is reasonably achievable guidance in NUREG–1727, Appendix D (NRC, 2000) is

considered. The proposed levels allow the licensee to demonstrate that the

10 CFR 40.42 (k) requirements (the premises are suitable for release, and reasonable

effort has been made to eliminate residual radioactive contamination) can be met. 

(5) In recent practice at mill sites, the as low as is reasonably achievable principle is

implemented by removing about 2 more inches [5 cm] of soil than is estimated to

achieve the radium standard (reduce any possible excess or borderline contamination). 

At mills, it is generally cheaper to remove more soil than to do sampling and testing that

may indicate failure and require additional soil removal with additional testing.

(6) The unity rule is applied to the cleanup if more than one residual radionuclide is present

in a soil verification grid (100 m2

). This means that the sum of the ratios for each

radionuclide of the concentration present/concentration limit may not exceed 1

(i.e., unity).

(7) The subsurface soil standard, if it is to be used, is applied to small areas of deep

excavation where at least 15 cm [6 in.] of compacted clean fill is to be placed on the

surface and where that depth of cover is expected to remain in place for the foreseeable

future. The long-term cover depth used in the model is justified.

(8) The surface activity limit for remaining structures is appropriately derived using an

approved code or calculation. Because recent conservative dose modeling by NRC

staff has indicated that more than 2,000 dpm/100 cm2

 alpha (U-nat or uranium chain

radionuclides) in habitable buildings [2,000 hr/yr] could exceed an effective dose

equivalent of 25 mrem/yr, the licensee proposes a total (fixed plus removable) average

surface activity limit for such buildings that is lower than 2,000 dpm/100 cm2

, or a higher

value is suitably justified.

(9) If the DandD code is used, data are provided to support that 10 percent or less of the

surface activity is removable; otherwise the resuspension factor is scaled to reflect the

site-specific removable fraction. Note that this code assumes that the contamination is

only on the floor, which can be overly conservative. If the RESRAD-Build code is used,

the modeled distribution of contamination on walls and floor is justified. 
Appendix H

H–10

H2.2.4 Evaluation Findings

If the staff review, as described in this section, results in the acceptance of the application of

the radium benchmark dose modeling to the site cleanup criteria, the following conclusions may

be presented in the technical evaluation report.

The staff has completed its review of the proposed implementation of the benchmark dose

modeling results for the uranium mill facility. This review included an

evaluation using the review procedures and the acceptance criteria outlined in Section H2.2 of

Appendix H of this standard review plan.

The licensee has provided an acceptable implementation plan of the benchmark dose modeling

results to the proposed site cleanup activities, and the staff evaluation has determined that (1)

the cleanup criteria will allow the licensee to meet 10 CFR Part 40.42(k) and 10 CFR Part 40,

Appendix A, Criterion 6(6) requirements; (2) the soil and structures of the decommissioned site

will permit termination of the license because public health and the environment will not be

adversely affected by any residual radionuclides.

H3.0 REFERENCES

Argonne National Laboratory. “Data Collection Handbook to Support Modeling the Impacts of

Radioactive Material in Soil.” ANL/EAIS–8. Washington, DC: U.S. Department of Energy. 

April 1993a.

–––––. “Manual for Implementing Residual Radioactive Material Guidelines Using RESRAD,

Version 5.0.” ANL/EAD/LD–2. Washington, DC: U.S. Department of Energy. 

September 1993b.

NRC. NUREG/CR–5512, “Residual Radioactive Contamination from Decommissioning—User’s

Manual.” Vol. 2. Washington, DC: NRC. April 2001.

–––––. NUREG–1727, “NMSS Decommissioning Standard Review Plan.” Washington, DC:

NRC. September 2000.

–––––. NUREG/CR–5512, “Residual Radioactive Contamination from

Decommissioning—Parameter Analysis.” Draft. Vol. 3. Washington, DC: NRC. October 1999.

–––––. Draft NUREG–1549, “Decision Methods for Dose Assessment to Comply With

Radiological Criteria for License Termination.” Washington, DC: NRC. July 1998.

Sandia National Laboratories. “Review of Parameter Data for the NUREG/CR–5512

Residential Farmer Scenario and Probability Distributions for the DandD Parameter Analysis.” 

Draft Letter Report. January 30, 1998a.
Appendix H

H–11

–––––. “Review of Parameter Data for the NUREG/CR-5512 Building Occupancy Scenario

and Probability Distributions for the DandD Parameter Analysis.” Draft Letter Report. 

January 30, 1998b.

–––––. “Comparison of the Models and Assumptions Used in the DandD 1.0, RESRAD 5.61,

and RESRAD-Build Computer Codes with Respect to the Residential Farmer and Industrial

Occupant Scenarios Provided in NUREG/CR–5512.” Draft Report. October 15, 1998c.
APPENDIX I
I–1

REGULATORY ISSUE SUMMARY 2000–23

In Regulatory Issue Summary 2000–23 (NRC,2000), the Commission promulgated staff

requirements to revise previously published guidance on matters related to regulation of

uranium recovery facilities. This appendix presents that revised guidance as it relates to

uranium mills and is included to assist the staff and operators when considering related actions. 

The issues and policies addressed are:

(1) Part 41 Rulemaking (SECY–99–011)

(2) Disposal of Non-11e.(2) Byproduct Material in Tailings Impoundments

(SECY–99–012)

(3) Processing of Material Other Than Natural Uranium Ores (SECY–99–012)

(4) Concurrent Jurisdiction of Non-Radiological Hazards of Uranium Mill Tailings

(SECY–99–277) 

Reference

NRC. Regulatory Issue Summary 2000-23. “Recent Changes to Uranium Recovery Policy.” 

Washington, DC: NRC. November 2000.
Appendix I

I–2

Recent Changes to Uranium Recovery Policy

November 30, 2000

• ADDRESSEES

• INTENT

• BACKGROUND

• PART 41 RULEMAKING (SECY–99–011)

• DISPOSAL OF NON-11e.(2) BYPRODUCT MATERIAL IN TAILINGS IMPOUNDMENTS

(SECY–99–012)

• PROCESSING OF MATERIAL OTHER THAN NATURAL URANIUM ORES

(SECY–99–012)

• CLASSIFICATION OF LIQUID WASTES AT ISL FACILITIES (SECY–99–013)

• GROUND-WATER ISSUES AT ISL FACILITIES (SECY–99–013)

• CONCURRENT JURISDICTION OF NON-RADIOLOGICAL HAZARDS OF URANIUM

MILL TAILINGS (SECY–99–277)

• SUMMARY OF ISSUES

ADDRESSEES

All holders of materials licenses for uranium and thorium recovery facilities.

INTENT

The U.S. Nuclear Regulatory Commission (NRC) is issuing this regulatory issue summary (RIS)

to inform materials licensees of the Commission's decisions on four Commission Papers

prepared by the Uranium Recovery staff and the Office of the General Counsel (OGC). All the

policy decisions will be codified in the 10 CFR Part 41 rulemaking that has been initiated. No

specific action nor written response is required.

BACKGROUND

NRC staff prepared four Commission Papers in 1999 to address various uranium

recovery issues. One Commission Paper (SECY–99–011, “Draft Rulemaking Plan; Domestic

Licensing of Uranium and Thorium Recovery facilities—Proposed New 10 CFR Part 41”)

addressed the need to revise and update uranium recovery regulations, particularly with respect

to in situ leach (ISL) facilities and recommended the initiation of rulemaking to create a new

Part 41 specific to uranium recovery. The other three Commission Papers addressed issues

raised by the National Mining Association (NMA) in its April 1998 paper, “Recommendations for

a Coordinated Approach to Regulating the Uranium Recovery Industry.“ The first of those

papers (SECY–99–012, “Use of Uranium Mill Tailings Impoundments for the Disposal of Other

Than 11e(2) Byproduct Materials, and Reviews of Applications to Process Material Other Than

Natural Ore”) discussed the disposal of radioactive waste, other than byproduct material,

defined in section 11e.(2) of the Atomic Energy Act (AEA) of 1954, as amended, in mill tailings

impoundments, and the processing of material, other than natural ore, for source material at

licensed uranium mills. The second of those papers (SECY–99–013, “Recommendations on
Appendix I

I–3

ways to Improve the Efficiency of NRC Regulation at In Situ Leach Uranium Recovery

Facilities”) discussed the regulation of ground water at ISL sites and the issue of which waste

streams at ISL facilities come under NRC regulatory jurisdiction as 11e.(2)

byproduct material. The last paper (SECY–99–277, “Concurrent Jurisdiction of

Non-Radiological Hazards of Uranium Mill Tailings) addressed the issue of concurrent

jurisdiction (with States that do not have Agreement State regulatory authority for 11e.(2)

material under section 274 of the AEA) over the non-radiological hazards of uranium

mill tailings.

On July 13, 2000, the Commission issued a Staff Requirements Memorandum (SRM) on

SECY–99–011. On July 26, 2000, the Commission issued SRMs on SECY–99–012 and

SECY–99–013, and on August 11, 2000, the SRM on SECY–99–277 was issued.

The decisions and directions in these SRMs and the staff actions in response are discussed in

sections that follow.

PART 41 RULEMAKING (SECY–99–011)

SECY–99–011 approved the staff’s recommendation to provide a draft Rulemaking Plan (RP)

for comment to the Agreement States, with the preferred option being the creation of a new

Part 41 dedicated to uranium recovery regulation. The Commission directed the staff to revise

the draft RP to reflect the Commission's guidance in the other uranium recovery SRMs.

On September 11, 2000, the staff transmitted the draft RP to all States for comment. The

staff sent the draft RP to all States rather than just Agreement States because the issue of

concurrent jurisdiction regarding non-radiological hazards primarily affects non-Agreement

States, and the staff wanted to give those States an opportunity to comment on the draft RP. 

Comments have been received from several States. In addition, the NMA and two licensees

provided comments on the draft RP. The staff will consider all the comments received in

preparing its final RP, which it expects to issue in early 2001.

DISPOSAL OF NON-11e.(2) BYPRODUCT MATERIAL IN TAILINGS IMPOUNDMENTS

(SECY–99–012)

In 1995, the staff published guidance, in the Federal Register [exit icon] (60 FR 49296), for the

disposal, in uranium mill tailings impoundments, of radioactive material that is not byproduct

material, as defined in section 11e.(2) of the AEA. The guidance consisted of 10 criteria to

determine whether to approve a proposed disposal of non-11e.(2) byproduct material in a

uranium mill tailings impoundment. In its 1998 white paper, the NMA emphasized that the

criteria were too restrictive, pointing out that no requests for such disposals have been made

since the guidance was issued. The Commission, in the SRM for SECY–99–012, approved an

option that would allow more flexibility in permitting non-11e.(2) material to be disposed of in

tailings impoundments. The NRC intends to incorporate the criteria into the new Part 41. In the

interim, the Commission directed the staff to implement the SRM.
Appendix I

I–4

To comply with the direction in the SRM, the staff is revising the 1995 guidance in the

following manner:

• The staff will remove the prohibitions, found in items 2, 4, and 5, regarding non-AEA

radioactive material and material subject to regulation under other legislative authorities,

such as the Toxic Substance Control Act (TSCA) or the Resource Conservation and

Recovery Act (RCRA).

• The staff will add a criterion regarding approval from the appropriate regulators of 

TSCA, RCRA, and non-AEA radioactive material for disposal of such material in the 

tailings impoundment.

• The staff will revise the criterion, in item 8, regarding approval by Low-Level Waste

Compacts, to allow for the situation in which material proposed for disposal does not fall

under the jurisdiction of Low-Level Waste Compacts (e.g., radioactive material not

regulated under the AEA).

• The Commission directed the staff to pursue a generic exemption to NRC's disposal

requirements for low-level radioactive waste in 10 CFR Part 61, rather than having to

grant an exemption, under 10 CFR 61.6, as identified in item 10. A generic exemption

to regulations must be issued through a rulemaking process. Therefore, the staff will 

pursue incorporating the generic exemption in the new Part 41. In the interim, the

requirement for a specific exemption will remain in the guidance, with addition of a

caveat for material not regulated under Part 61.

The staff therefore is revising its 1995 guidance. The complete revised guidance, is in

Attachment 1.

PROCESSING OF MATERIAL OTHER THAN NATURAL URANIUM ORES (SECY-99-012)

In 1995, the staff published its position and guidance, in the Federal Register (60 FR 49296),

on the use of uranium feed material other than natural ores (alternate feed material), in uranium

mills. The guidance identified three determinations that the staff had to make in order to

approve an alternate feed request. The third determination—whether the ore is being

processed primarily for its source material content—generated considerable controversy. This

determination was required to address the concern that wastes that would otherwise have to be

disposed of as radioactive or mixed waste would be proposed for processing at a uranium mill

primarily to be able to dispose of them in the tailings pile as 11e.(2) byproduct material. This

determination was essentially a determination of the motives of the mill operator in requesting

approval of a specific stream of alternate feed material. In many cases it involved questioning

the financial aspects of acquiring and processing the alternate feed material, and selling the

resultant uranium product.

In its 1998 white paper, the NMA emphasized that NRC should not be looking to a licensee’s

motives in processing alternate feed material. After careful consideration of stakeholder

comments and the staff's analysis, the Commission, in the SRM for SECY–99–012, directed the

staff to allow processing of alternate feed material without inquiry into a licencee’s economic
Appendix I

I–5

motives, and referred to a Commission decision ( CLI–00–01 51 NRC 9) on a specific instance

of proposed processing of alternate feed, that was brought before the Atomic Safety Licensing

Board and then appealed to the Commission. The Commission also addressed the second

determination in the 1995 guidance (i.e., whether the feed material contains hazardous waste). 

It directed the staff to allow more flexibility with regard to this issue consistent with its direction

to the staff on the disposal of non-11e.(2) byproduct material in tailings piles.

The Commission directed the staff to revise, issue, and implement final guidance on the

processing of alternate feed as soon as possible and to codify the guidance in the new Part 41.

To comply with the SRM, the staff is revising the 1995 position and guidance in the

following manner:

The staff will modify the prohibition in item 2 on feed material containing hazardous waste, to

allow such feed material provided that the licensee obtains approval of the U.S. Environmental

Protection Agency (EPA) or the State, and a commitment from the long-term custodian to

accept the tailings after site closure.

The staff will revise the manner in which it determines whether the ore is being processed

primarily for its source material content, to focus on the product of the processing, and eliminate

any inquiry into the licensee’s economic motives for the processing.

The staff therefore is revising its 1995 guidance. The complete revised guidance, is in

Attachment 2.

CLASSIFICATION OF LIQUID WASTES AT ISL FACILITIES (SECY–99–013)

Before 1995, the staff practice for addressing the disposal of evaporation pond sludges at ISL

facilities relied on a broad reading of the definition of 11e.(2) byproduct material. This broad

reading only addressed discrete surface wastes capable of controlled disposal and did not

distinguish between wastes generated at various phases of an ISL operation. All waste

materials generated during ISL operations and ground-water restoration activities were

designated 11e.(2) byproduct material and disposed of at licensed uranium mill tailings

impoundments, in accordance with 10 CFR Part 40, Appendix A, Criterion 2.

The staff issued two guidance documents in 1995 to address issues raised by the industry in

the uranium recovery program. The first, “Staff Technical Position on Effluent Disposal at

Licensed Uranium Recovery Facilities” (hereinafter, the effluent guidance), was intended to

ensure protection of the environment and public, while providing uranium recovery licensees

with flexibility regarding the disposal of various types of liquid effluents generated during the

operation of their facilities. In issuing this guidance, the staff took a more narrow view of the

definition of 11e.(2) byproduct material. It differentiated between the various waste waters

generated during ISL operations on the basis of their origin and whether uranium was extracted

for its source material content during that phase of the operation. Waste waters and the

associated solids produced during the uranium extraction phase of site operations, called

“production bleed,” were classified as AEA Section 11e.(2) byproduct material and therefore

subject to regulation by NRC. Conversely, waste waters and the resulting solids produced after
Appendix I

I–6

uranium extraction (i.e., during ground-water restoration activities) were classified as “mine

waste waters,” and therefore were subject to regulation by individual States under their

applicable mining programs. These wastes were considered naturally occurring radioactive

material (NORM). However, because licensees often dispose of waste waters from uranium

extraction and post-extraction activities in the same evaporation ponds, the resulting solids are

a commingled waste consisting of 11e.(2) byproduct material and sludges derived from mine

waste water.

In the second guidance document, “Final Revised Guidance on Disposal of Non-Atomic Energy

Act of 1954, Section 11e.(2) Byproduct Material in Tailings Impoundments” (hereinafter, the

disposal guidance), the staff identified 10 criteria that licensees should meet before NRC could

authorize the disposal of AEA material other than 11e.(2) byproduct material in tailings

impoundments. One of these criteria prohibited the disposal of radioactive material not covered

by the AEA, including NORM (see earlier discussion for policy revisions). This criterion was

intended to avoid the possibility of dual regulation of the radioactive constituents in the

impoundments, since individual States are responsible for radioactive materials not covered by

the AEA.

The industry expressed concerns, in NMA's white paper, that, taken together, these two

guidance documents leave no option for the disposal of radioactively contaminated sludges

from ISL evaporation ponds. The reason for this concern is that the 11e.(2) byproduct material

was commingled with a NORM waste, which the disposal guidance prohibits from disposal in a

tailings impoundment. The industry emphasized that the staff’s waste classification, based on

the origin of the waste water (i.e., from the extraction or restoration phase) at an ISL facility,

makes the disposal of such sludges in a mill tailings impoundment, as required under

Criterion 2 of 10 CFR Part 40, Appendix A, impossible—even though the sludges derived from

waste waters produced throughout a facility's life cycle are physically, chemically, and

radiologically identical.

The staff analyzed several options in SECY-99-013 for addressing the industry's concerns. In

the SRM for SECY–99–013, the Commission determined that all liquid effluents at ISL uranium

recovery facilities are 11e.(2) byproduct material. NRC takes the position that any waste water

generated during or after the uranium extraction phase of site operations, and all evaporation

pond sludges derived from such waste waters, are classified as 11e.(2) byproduct material. 

The staff will make no legal distinction among the waste waters produced at different stages in

a facility’s life cycle.

This revised policy is effective immediately. The staff intends to codify this policy in the new

rulemaking for Part 41 and associated regulatory guidance.

GROUND-WATER ISSUES AT ISL FACILITIES (SECY–99–013)

Over the past several years, the industry has expressed concern that NRC's regulation of

ground water at ISLs is duplicative of the ground-water protection programs required by the

Safe Drinking Water Act (SDWA), as administered by EPA or EPA-authorized States. EPA and

the States protect ground-water quality through the Underground Injection Control (UIC)

program, under the SDWA. The States often require additional measures in the UIC program
Appendix I

I–7

that are more stringent than the Federal program. As presented in NMA’s white paper, the

industry contended that NRC’s review and licensing activities are a duplicative form of

regulation covering the same issues. Additionally, NMA also expressed the view that NRC did

not have authority to regulate ground water at ISLs.

Historically, NRC has imposed conditions on ISL operations to ensure that ground-water quality

is maintained during licensed activities and that actions are taken to ensure the restoration of

ground-water quality before the license is terminated. The specific conditions imposed in an

ISL license have typically been the result of NRC’s independent review, as documented in

safety evaluation reports and appropriate environmental evaluations.

In addition to NRC’s review, licensees must also obtain a UIC permit from EPA or the

EPA-authorized State before uranium recovery operations can begin. EPA or the authorized

State conducts many of the same types of reviews as NRC. This is evidenced by NRC

incorporating ground-water protection limits from a State’s permitting program into specific

license requirements, after conducting its own review of the licensee’s groundwater protection

program, including the use of State-imposed standards—and staff routinely accepting specific

methodologies and guidance developed by EPA or States for ground-water monitoring

programs and well construction.

In the SRM for SECY–99–013, the Commission approved the staff continuing discussions with

EPA and appropriate States to determine the extent to which NRC can rely on the EPA UIC

program for ground-water protection issues, thereby potentially minimizing duplicative review of

ground-water protection at ISL facilities. Part of the discussions with EPA and appropriate

States should include appropriate methods to implement any agreements, including

Memoranda of Understanding (if necessary) and potential requirements that could be

incorporated in the new Part 41. In the interim, it is recognized that some NRC/EPA dual

regulation of the ground-water at ISL facilities will continue until such time that NRC can defer

to EPA’s UIC program.

NRC has initiated a new round of discussions with the EPA since the Commission decision in

July 2000, and discussions with the appropriate States should begin in early to mid 2001.

In February 1998, staff documented its review process for ISLs, including a detailed evaluation

of ground-water activities, in a draft Standard Review Plan (draft SRP) for ISL facility license

applications (NUREG–1569), that was published for public comment. Following the comment

period, staff held a public workshop on the SRP to discuss the issues raised. The staff intends

to use the draft SRP in licensing reviews until the rulemaking for new Part 41 (SECY–99–011)

has been completed and NUREG–1569 is finalized.

CONCURRENT JURISDICTION OF NON-RADIOLOGICAL HAZARDS OF URANIUM MILL

TAILINGS (SECY–99–277)

In 1980, the staff considered the issue of whether the Uranium Mill Tailings Radiation Control

Act (UMTRCA) preempts a non-Agreement State's authority to regulate the non-radiological

hazards associated with 11e.(2) byproduct material and concluded that it did not. The NRC

concluded that NRC and the State both exercised this authority. As a result, the staff has
Appendix I

I–8

followed the practice of sharing jurisdiction of the non-radiological hazards with States. In its

1998 white paper, the NMA questioned the 1980 staff interpretation of UMTRCA. The

Commission, in the SRM for SECY–99–0277 determined that NRC has exclusive jurisdiction

over both the radiological and non-radiological hazards of 11e.(2) byproduct material.

As a result of this decision, the staff will implement its exclusive authority over the

non-radiological hazards of 11e.(2) byproduct material and not recognize State authority in

this area.

SUMMARY OF ISSUES

The Commission has evaluated a range of uranium recovery issues and the staff evaluation

and has directed, through SRMs, the staff to take various actions that will ultimately be

incorporated into the new Part 41 rulemaking and existing uranium recovery SRPs.

In the interim, this RIS informs the licensees of the Commission's decisions. These are: (1) to

allow more flexibility in the disposal of non-11e.(2) material in tailings impoundments, subject to

certain considerations; (2) to allow alternate feed material to be processed for uranium

(or thorium) without any inquiry into a licensee's economic motives; (3) to classify all waste

water and sludges generated during or after the uranium (or thorium) extraction phase of in situ

leach operations as 11e.(2) byproduct material; (4) to continue discussions with EPA and

appropriate States to determine the extent that NRC can rely on the EPA UIC program for

ground-water protection at ISL facilities; and (5) to note that NRC has exclusive jurisdiction over

both the radiological and non-radiological hazards of 11e.(2) byproduct material.

This regulatory issue summary requires no specific action nor written response. If you have

any questions about this summary, please contact the technical contact listed below.

Michael F. Weber, Director

Division of Fuel Cycle Safety & Safeguards

Office of Nuclear Material Safety and Safeguards

Technical Contact:

Kenneth R. Hooks, NMSS

301-415-7777

E-mail: krh1@nrc.gov

Attachments:

1. Interim Guidance Non-11e.(2)

2. Interim Position Alternate Feed

3. List of Recently Issued NRC Regulatory Issue Summaries

(ADAMS Accession Number ML003773008)
Appendix I

I–9

ATTACHMENT 1

Interim Guidance on Disposal of Non-Atomic Energy Act of 1954, Section 11e.(2)

Byproduct Material in Tailings Impoundments

1. In reviewing licensee requests for the disposal of wastes that have radiological

characteristics comparable to those of Atomic Energy Act of 1954, Section 11e.(2)

byproduct material [hereafter designated as “11e.(2) byproduct material”] in tailings

impoundments, the Nuclear Regulatory Commission staff will follow the guidance set

forth below. Since mill tailings impoundments are already regulated under

10 CFR Part 40, licensing of the receipt and disposal of such material [hereafter

designated as “non-11e.(2) byproduct material”] should also be done under

10 CFR Part 40.

2. Special nuclear material and Section 11e.(1) byproduct material waste should not be

considered as candidates for disposal in a tailings impoundment, without compelling

reasons to the contrary. If staff believes that such material should be disposed of in a 

tailings impoundment in a specific instance, a request for Commission approval should

be prepared.

3. The 11e.(2) licensee must provide documentation showing necessary approvals of other 

affected regulators (e.g., the U.S. Environmental Protection Agency or State) for

material containing listed hazardous wastes or any other material regulated by another

Federal agency or State because of environmental or safety considerations.

4. The 11e.(2) licensee must demonstrate that there will be no significant environmental

impact from disposing of this material.

5. The 11e.(2) licensee must demonstrate that the proposed disposal will not compromise

the reclamation of the tailings impoundment by demonstrating compliance with the

reclamation and closure criteria of Appendix A of 10 CFR Part 40.

6. The 11e.(2) licensee must provide documentation showing approval by the Regional 

Low-Level Waste Compact in whose jurisdiction the waste originates as well as approval 

by the Compact in whose jurisdiction the disposal site is located, for material which

otherwise would fall under Compact jurisdiction.

7. The U.S. Department of Energy (DOE) and the State in which the tailings impoundment

is located, should be informed of the U.S. Nuclear Regulatory Commission findings and 

proposed action, with a request to concur within 120 days. A concurrence and

commitment from either DOE or the State to take title to the tailings impoundment after

closure must be received before granting the license amendment to the 11e.(2)

licensee.

8. The mechanism to authorize the disposal of non-11e.(2) byproduct material in a tailings

impoundment is an amendment to the mill license under 10 CFR Part 40, authorizing

the receipt of the material and its disposal. Additionally, an exemption to the
Appendix I

I–10

requirements of 10 CFR Part 61, under the authority of 10 CFR 61.6, must be granted, if

the material would otherwise be regulated under Part 61. (If the tailings impoundment is

located in an Agreement State with low-level waste licensing authority, the State must

take appropriate action to exempt the non-11e.(2) byproduct material from regulation as

low-level waste.) The license amendment and the 10 CFR 61.6 exemption should be

supported with a staff analysis addressing the issues discussed in this guidance.
Appendix I

I–11

ATTACHMENT 2

Interim Position and Guidance on the Use of Uranium Mill Feed Material Other

Than Natural Ores

In reviewing licensee requests to process alternate feed material (material other than natural

ore) in uranium mills, the Nuclear Reguatory Commission staff will follow the guidance

presented below. Besides reviewing to determine compliance with appropriate aspects of

Appendix A of 10 CFR Part 40, the staff should also address the following issues:

1. Determination of whether the feed material is ore.

For the tailings and wastes from the proposed processing to qualify as 11e.(2) byproduct

material, the feed material must qualify as "ore." In determining whether the feed material is

ore, the following definition of ore will be used:

Ore is a natural or native matter that may be mined and treated for the extraction of any of its

constituents or any other matter from which source material is extracted in a licensed uranium

or thorium mill.

2. Determination of whether the feed material contains hazardous waste.

If the proposed feed material contains hazardous waste, listed under subpart D

Sections 261.30-33 of 40 CFR (or comparable Resource Conservation and Recovery Act

(RCRA) authorized State regulations), it would be subject to the U.S. Environmental Protection

Agency (EPA) or State regulation under RCRA. If the licensee can show that the proposed

feed material does not contain a listed hazardous waste, this issue is resolved.

Feed material exhibiting only a characteristic of hazardous waste (ignitable, corrosive, reactive,

toxic) would not be regulated as hazardous waste and could therefore be approved for recycling

and extraction of source material. However, this does not apply to residues from water

treatment, so determination that such residues are not subject to regulation under RCRA will

depend on their not containing any characteristic hazardous waste. Staff may consult with EPA

(or the State) before making a determination of whether the feed material contains

hazardous waste.

If the feed material contains hazardous waste, the licensee can process it only if it obtains EPA

(or State) approval and provides the necessary documentation to that effect. Additionally, for

feed material containing hazardous waste, the staff will review documentation from the licensee

that provides a commitment from the U.S. Department of Energy or the State to take title to the

tailings impoundment after closure.

3. Determination of whether the ore is being processed primarily for its source-material 

content.

For the tailings and waste from the proposed processing to qualify as 11e.(2) byproduct

material, the ore must be processed primarily for its source-material content. If the only product
Appendix I

I–12

produced in the processing of the alternate feed is uranium product, this determination is

satisfied. If, in addition to uranium product, another material is also produced in the processing

of the ore, the licensee must provide documentation showing that the uranium product is the

primary product produced.

If it can be determined, using the aforementioned guidance, that the proposed feed material

meets the definition of ore, that it will not introduce a hazardous waste not otherwise exempted,

or if it has been approved by the EPA (or State) and the long-term custodian, and that the

primary purpose of its processing is for its source-material content, the request can

be approved.
APPENDIX J
J–1

TECHNICAL EVALUATION OF APPENDIX A CRITERIA

During the review process, U.S. Nuclear Regulatory Commission (NRC) staff will verify that

specific criteria of 10 CFR Part 40, Appendix A have been met. It is suggested that the

technical reviewer prepare a list of the specific technical criteria and the method or design used

to meet these criteria to be included in the technical evaluation report. The example offered

shows one method of documentation.

J1.0 EXAMPLE OF TECHNICAL EVALUATION OF APPENDIX A CRITERIA

The following text is from an NRC technical evaluation report for a uranium mill facility, and

represents the type of conclusions related to meeting specific technical criteria in

10 CFR Part 40, Appendix A.

CONCLUSIONS RELATED TO MEETING APPENDIX A CRITERIA 

The staff further concludes that the specific criteria of 10 CFR Part 40 Appendix A are met

as follows. 

J1.1 Criterion 1

Demonstrate that erosion, disturbance, and dispersion by natural forces over the long

term are minimized. 

The contaminated tailings will be protected from flooding and erosion by an engineered rock

riprap layer. The riprap has been designed in accordance with the guidance suggested by the

NRC staff (NRC, 1990). The staff considers that erosion protection that meets that guidance

will provide adequate protection against erosion and dispersion by natural forces over the long

term. As discussed in technical evaluation report Sections 4.3 and 4.5, adequate protection is

provided by (1) selection of proper rainfall and flooding events, (2) selection of appropriate

parameters for determining flood discharges, (3) computation of flood discharges using

appropriate and/or conservative methods, (4) computation of appropriate flood levels and flood

forces associated with the design discharge, (5) use of appropriate methods for determining

erosion protection needed to resist the forces produced by the design discharge, (6) selection

of a rock type for the riprap layer that will be durable and capable of providing the necessary

erosion protection for a long period of time, and (7) placement of a riprap layer in accordance

with accepted engineering practice and in accordance with appropriate testing and quality

assurance controls. 

Demonstrate that the tailings are disposed of in a manner that does not require active

maintenance to preserve conditions at the site.

As discussed in technical evaluation report Sections 4.3 and 4.5, the staff considers that the

riprap layers proposed will not require active maintenance over the 1,000-year design life, for

the following reasons: (1) the riprap has been designed to protect the tailings from rainfall and

flooding events which have very low probabilities of occurrence over a 1,000-year period,

resulting in no damage to the layers from those rare events; (2) the rock proposed for the riprap

layers is designed to be durable and is not expected to deteriorate significantly over the with

1,000-year design life; and (3) during construction, the rock layers will be placed in accordance
Appendix J

J–2

with appropriate engineering and testing practices, minimizing the potential for damage,

dispersion, and segregation of the rock. 

J1.2 Criterion 4

Demonstrate that the upstream rainfall catchment areas are minimized to decrease

erosion potential and the size of the floods that could erode or wash out sections of the

tailings disposal area. 

The site is located in an area that is flooded by off-site floods from Moab Wash and the

Colorado River. However, as discussed in the technical evaluation report, the site is protected

from direct on-site precipitation and flooding by engineered riprap layers for the top and side

slopes; the tailings disposal cell will need this protection regardless of where it is located. The

riprap for the side slopes and drainage ditches is large enough to resist flooding from the

minimal flow velocities of floods occurring from a probable maximum flood on the Colorado

River. A large rock apron has been provided to provide protection against the potential

migration of Moab Wash and the Colorado River. The staff therefore concludes that the

erosion potential at the site has been acceptably minimized, since any flooding at the site is

mitigated by the erosion protection, and the forces associated with off-site floods are minimal. 

Demonstrate that topographic features provide good wind protection. 

The staff considers that the site is adequately protected from wind erosion by the placement of

an engineered riprap layer that protects the tailings from surface water erosion. Studies

performed for the NRC staff have shown that an engineered riprap layer designed to protect

against water erosion will be capable of providing adequate protection against wind erosion. 

Demonstrate that embankments and cover slopes are relatively flat after stabilization to

minimize erosion potential and to provide conservative factors of safety assuring

long-term stability. 

The relatively flat top and side slopes of the covers will be protected from erosion by an

engineered riprap layer which is designed to provide long-term stability (technical evaluation

report Section 4.3). The erosion potential of the covers is minimized by the designing the rock

to be sufficiently large to resist flooding and erosion, based on the slope selected. Thus, the

staff concludes that the slopes, with their corresponding rock designs, are sufficiently flat to

meet this criterion.

Demonstrate that the rock cover reduces wind and water erosion to negligible levels,

including consideration of such factors as the shape, size, composition, and gradation

of the rock particles; rock cover thickness and zoning of particle size; and steepness of

underlying slopes. Demonstrate that rock fragments are dense, sound, and resistant to

abrasion, and free from cracks, seams, and other defects.

The contaminated tailings will be protected from flooding and erosion by an engineered rock

riprap layer. The riprap has been designed in accordance with the guidance suggested by the

NRC staff (NRC, 1990). As discussed in Sections 4.3 and 4.5 of the technical evaluation
Appendix J

J–3

report, the staff considers that erosion protection which meets that guidance will provide

adequate protection against erosion and dispersion by natural forces over the long term. 

Adequate protection is provided by (1) selection of proper rainfall and flooding events,

(2) selection of appropriate parameters for determining flood discharges, (3) computation of

flood discharges using appropriate and/or conservative methods, (4) computation of

appropriate flood levels and flood forces associated with the design discharge, (5) use of

appropriate methods for determining erosion protection needed to resist the forces produced by

the design discharge, (6) selection of a rock type for the riprap layer that will be durable and

capable of providing the necessary erosion protection for a long period of time, and

(7) placement of a riprap layer in accordance with accepted engineering practice and in

accordance with appropriate testing and quality assurance controls. 

J1.3 Criterion 12

Demonstrate that active on-going maintenance is not necessary to preserve isolation. 

As discussed in Sections 4.3 and 4.5 of the technical evaluation report, the staff considers that

the erosion protection will not require active maintenance over the 1,000-year design life, for the

following reasons: (1) the riprap has been designed to protect the tailings from rainfall and

flooding events which have low probabilities of occurrence over a 1,000-year period, resulting in

no damage to the layers from those rare events; (2) the rock proposed for the riprap layers is

designed to be durable and is not expected to deteriorate significantly over the 1,000-year

design life; and (3) during construction, the rock layers will be placed in accordance with

appropriate engineering and testing practices, minimizing the potential for damage, dispersion,

and segregation of the rock.
APPENDIX K
K–1

CONTENT AND FORMAT FOR ALTERNATE CONCENTRATION LIMIT

APPLICATIONS

Application Content

The application should contain sufficient information to show that a hazardous constituent will

not pose a substantial present or potential harm to human health or the environment, as long as

the proposed Alternate Concentration Limit is not exceeded; and the proposed Alternate

Concentration Limit is as low as reasonably achievable, considering practicable corrective

actions. This demonstration should assess the hazards of the constituent in question and

evaluate the consequences presented by potential exposures to the constituent. The

application must consider the 19 factors listed in 10 CFR Part 40, Appendix A, Criterion 5B(6).

For ease of review, the application should address these factors through the following

assessments. The Hazard Assessment should evaluate the radiological dose and toxicity of

the constituents in question and the risk to human health and the environment posed by the

constituents. The Exposure Assessment should examine the existing distribution of hazardous

constituents, as well as the potential source(s) for future constituent releases. This

should include the fate and transport of the hazardous constituents in ground water and

hydraulically-connected surface water; and the potential consequences associated with human

and environmental exposure to the hazardous constituents. The Corrective Action Assessment

should (1) identify all realistic corrective action scenarios available; (2) assess their technical

feasibility; (3) determine the costs and benefits associated with each scenario; and (4) select a

practicable corrective action to achieve the hazardous constituent concentration that is

protective of human health and the environment. The outcome of this assessment is a

determination that the selected corrective action is as low as reasonably achievable.

There should be enough detailed information in the application to allow the NRC reviewer to

independently verify that the proposed Alternate Concentration Limit will not pose a significant

present or future hazard to human health or the environment, and that the limit is as low as

reasonably achievable, considering practicable corrective actions. Site characteristics, milling

processes, disposal operations, and ore composition should be discussed in the application. 

Information related to each of the 19 factors listed in 10 CFR Part 40, Appendix A,

Criterion 5B(6) should be addressed; however, all of these factors may not be applicable to

every site. If this is the case, the applicant must explain why a particular factor is not

appropriate. For example, ground-water discharging into surface waters may not occur near a

mill tailings site. Therefore, stream flow characteristics and transport assessments within the

surface water may not be necessary. In any regard, the burden of proof resides with the

applicant to demonstrate that selected factors do not need to be considered.

Much of this detailed information may already be available in existing licensing documents,

such as environmental reports, license applications, or annual compliance monitoring reports. 

This information can be readily incorporated into the Alternate Concentration Limit application to

produce a stand-alone document. The applicant may simply reference this existing information;

however, additional time and NRC resources will be needed to collect the information from the

licensee’s docket file in order to proceed with the detailed review.
Appendix K

K–2

Application Format

A standard application format helps to assure the application contains information that

addresses all applicable regulatory requirements, and helps to guide both the reviewer and

interested stakeholders to pertinent and crucial information. A standard format also greatly

contributes to the time efficiency and effectiveness of the review process. The applicant is not

required to follow this standard format. Any application, regardless of format, that adequately

addresses the suitability of a proposed Alternate Concentration Limit is acceptable for NRC

review; however, reviewing an application with a significantly different format will likely require

considerably more NRC staff time and resources to conduct the review. An applicant is

strongly encouraged to provide a cross-reference table comparing the standard format to the

format used in the application, if that format significantly differs from the standard format.

The applicant should present the technical information as clearly as possible and assure it

supports compliance with the requirements in 10 CFR Part 40, Appendix A, Criterion 5B(6).

Applicants are encouraged to follow the numbering system and headings of the standard format

and use appendices for including supporting data not specifically included in a particular

section. Conventional abbreviations should be used consistently throughout the application. 

Any abbreviations, symbols, or special terms should be defined where they first appear in the

text. Where appropriate, calculated error bands or estimated uncertainties should be included

along with numerical values. Some types of information are better presented clearly and

concisely in a graphical manner by using maps, graphs, drawings, or tables and appropriate

citations in the text descriptions. Applicants should ensure that graphical materials are legible

and that the physical scales are adequate to clearly show details and notations. Symbols

should be clearly defined and referenced.

Table 1 shows the standardized outline for an Alternate Concentration Limit application. It

includes chapters for supporting information on the site and its setting, a hazard assessment,

an exposure assessment, a review of realistic corrective action alternatives, and the proposed

concentration limits.

The application should also be structured to allow ready substitution of pages in response to

reviewer comments and information requests. Pages should be punched for a standard looseleaf binder. Revisions should be provided on pages that will replace the original pages, with the

changes indicated by a “line change” demarcation in the margin. The date and revision number

should be indicated in the bottom outside margin of each revised page, and the package of

submitted revisions should include a list of all page replacements for the application. The font

style and text size should be plain and large enough to allow the document to be scanned

electronically for easy inclusion in the Agencywide Documents Access and Management

System (ADAMS). All figures and diagrams should also be clearly presented to assist in

electronic scanning.

A legible base map is essential for all applications. The base map should include the tailings

disposal area, the location of the reclaimed slopes, the Point of Compliance locations, the Point

of Exposure locations, monitoring wells locations, and the proposed long-term control boundary. 

Pertinent site data, such as potentiometric surfaces, isoconcentration contours, and forecasted

concentrations should use the base map as the common reference.
Appendix K

K–3

Table K–1. Standard Format of an Alternate Concentration Limit

Application

EXECUTIVE SUMMARY

TABLE OF CONTENTS

1. General Information

1.1 Introduction

1.2 Facility Description

1.3 Extent of Ground-Water Contamination

1.4 Current Ground-Water Protection Standards

1.5 Proposed Alternate Concentration Limit(s)

2. Hazard Assessment

2.1 Source and Contamination Characterization

2.2 Constituent(s) of Concern

2.3 Health and Environmental Risk(s) of Constituent(s)

3. Exposure Assessment

3.1 Transport and Pathway Assessment

3.2 Human Exposure Potential

3.3 Environmental Exposure Potential

3.4 Consequences of Exposure

4. Corrective Action Assessment

4.1 Previous and Current Corrective Action Programs

4.1 Potential Corrective Action Alternatives

4.2 Feasibility of Corrective Action Alternatives

4.3 Costs and Benefits of Corrective Action Alternatives

4.4 As Low As Reasonably Achievable Demonstration

5. Alternate Concentration Limit(s)

5.1 Proposed Alternate Concentration Limit(s)

5.2 Proposed Implementation and Ground-Water Monitoring Measures

6. References

7. Appendixes and Supporting Information