AUDIT REPORT

Audit of NRC’s Oversight of 

Decommissioned Uranium Recovery Sites and

Sites Undergoing Decommissioning

OIG-12-A-06 December 13, 2011

All publicly available OIG reports are accessible through

NRC’s Web site at: 

http:/www.nrc.gov/reading-rm/doc-collections/insp-gen/
UNITED STATES

NUCLEAR REGULATORY COMMISSION

WASHINGTON, D.C. 20555-0001

OFFICE OF THE

INSPECTOR GENERAL

December 13, 2011

MEMORANDUM TO: R. William Borchardt

Executive Director for Operations

FROM: Stephen D. Dingbaum /RA/

Assistant Inspector General for Audits

SUBJECT: AUDIT OF NRC’S OVERSIGHT OF DECOMMISSIONED 

URANIUM RECOVERY SITES AND SITES UNDERGOING 

DECOMMISSIONING (OIG-12-A-06)

Attached is the Office of the Inspector General’s (OIG) audit report titled, Audit of NRC’s 

Oversight of Decommissioned Uranium Recovery Sites and Sites Undergoing 

Decommissioning. 

The report presents the results of the subject audit. Agency comments provided at the 

November 22, 2011, exit conference have been incorporated, as appropriate, into this 

report.

Please provide information on actions taken or planned on each of the 

recommendations within 30 days of the date of this memorandum. Actions taken or 

planned are subject to OIG followup as stated in Management Directive 6.1.

We appreciate the cooperation extended to us by members of your staff during the 

audit. If you have any questions or comments about our report, please contact me at 

415-5915 or Sherri Miotla, Team Leader, Nuclear Materials & Waste Safety Team, at 

415-5914.

Attachment: As stated 
Audit of NRC’s Oversight of Decommissioned Uranium Recovery Sites and 

Sites Undergoing Decommissioning

i

EXECUTIVE SUMMARY

BACKGROUND

The Nuclear Regulatory Commission (NRC) regulates uranium recovery 

operations. Through the 1980s, commercial uranium recovery mills 

operated in support of both a fledgling nuclear power industry and U.S. 

defense programs. The waste from the mills (uranium mill tailings) caused 

environmental contamination that the Federal Government continues to 

address.

In 1978, Congress enacted the Uranium Mill Tailings Radiation Control Act 

(UMTRCA) to provide for the disposal, long-term stabilization, and control 

of uranium mill tailings in a safe and environmentally sound manner, to 

minimize or eliminate radiation health hazards to the public. UMTRCA 

defines two categories of uranium mill tailings sites (Title I and Title II) and 

assigns differing responsibilities to three Federal agencies. 

Under Title I, the Federal Government assumed responsibility for cleanup 

at abandoned, inactive uranium milling sites. Once decommissioning is 

complete, the Department of Energy’s (DOE) Office of Legacy 

Management accepts the site for long-term care and maintenance under a 

general license from NRC.

Title II places responsibility for cleanup of sites with the licensees that 

were operating in 1978 or licensed by NRC or an Agreement State after 

1978. Licensees must conduct cleanup activities according to an NRCapproved reclamation plan. Once cleanup activities are complete, NRC

terminates the license and approves site transfer to DOE. 

NRC, the Environmental Protection Agency (EPA), and DOE have distinct 

responsibilities under UMTRCA.

NRC Responsibilities

NRC’s responsibility is to ensure that decommissioning at both Title I and 

Title II sites meets the standards for protecting human health and the 

environment. 
Audit of NRC’s Oversight of Decommissioned Uranium Recovery Sites and 

Sites Undergoing Decommissioning

ii

EPA Responsibilities

EPA’s responsibility is to set the standards for air and water quality. 

Additionally, EPA is responsible for administering the Comprehensive 

Environmental Response, Compensation and Liability Act, as amended 

(CERCLA), which impacts two uranium recovery sites undergoing 

decommissioning. EPA and NRC entered into memorandums 

of understanding (MOUs) regarding oversight of two sites. The MOUs 

outline EPA and NRC obligations to coordinate distinct regulatory 

responsibilities. 

DOE Responsibilities

DOE’s responsibility under UMTRCA is to remediate Title I sites and 

provide long-term custody for both Title I and Title II sites. 

OBJECTIVE

The audit objective was to determine the effectiveness of NRC’s 

regulatory oversight of decommissioned uranium recovery sites and sites 

undergoing decommissioning. 

RESULTS IN BRIEF

NRC’s oversight of Title I and Title II uranium recovery decommissioning 

is largely effective. In particular, recent NRC initiatives to improve 

knowledge management have addressed self-identified areas of 

inefficiency and have enhanced the agency’s oversight efforts. However, 

the Office of the Inspector General has identified two opportunities for 

more effective oversight of uranium recovery decommissioning by: 

Improving compliance with the terms of the site-specific MOUs with 

EPA.

Reducing reliance on DOE’s inspection program to alert NRC to 

problems at decommissioned uranium recovery sites in DOE 

custody. 
Audit of NRC’s Oversight of Decommissioned Uranium Recovery Sites and 

Sites Undergoing Decommissioning

iii

NRC Does Not Fully Comply With NRC-EPA CERCLA Site MOUs

NRC does not fully comply with the conditions of the MOUs with EPA for 

uranium recovery sites subject to CERCLA. NRC agreed to conditions in 

the MOUs that would promote effective and efficient regulatory oversight. 

However, NRC lacks controls to ensure compliance with the terms of the 

MOUs. Therefore, NRC approaches oversight of remediation activities in 

a way that increases the risk that these activities will not occur in an 

effective and timely manner. 

NRC Relies on DOE’s Inspection Program

NRC relies on DOE’s inspection program at decommissioned uranium 

recovery sites in DOE custody. Although inspections are a key 

component of NRC’s oversight, NRC has chosen not to inspect the sites 

transferred to DOE. As a result, NRC may not know if all regulatory 

requirements are met regarding the protection of public health and safety 

and the environment.

RECOMMENDATIONS 

This report makes two recommendations to improve the agency’s 

oversight of decommissioned uranium recovery sites and sites undergoing

decommissioning. A consolidated list of these recommendations appears 

in Section IV of this report.

AGENCY COMMENTS 

An exit conference was held with the agency on November 22, 2011. At 

this meeting, agency management provided supplemental information that 

has been incorporated into this report as appropriate. As a result, agency 

management stated their general agreement with the findings and 

recommendations in this report and opted not to provide formal comments 

for inclusion in this report.
Audit of NRC’s Oversight of Decommissioned Uranium Recovery Sites and 

Sites Undergoing Decommissioning

iv

ABBREVIATIONS AND ACRONYMS

ACL alternate concentration limit

CERCLA Comprehensive Environmental Response, Compensation 

and Liability Act, as amended

CFR Code of Federal Regulations

DOE Department of Energy

EPA Environmental Protection Agency 

FSME Office of Federal and State Materials and Environmental 

Management Programs

MOU memorandum of understanding

NRC Nuclear Regulatory Commission

OIG Office of the Inspector General

UMTRCA Uranium Mill Tailings Radiation Control Act of 1978
Audit of NRC’s Oversight of Decommissioned Uranium Recovery Sites and 

Sites Undergoing Decommissioning

v

TABLE OF CONTENTS

EXECUTIVE SUMMARY ............................................................. i

ABBREVIATIONS AND ACRONYMS.........................................iv

I. BACKGROUND.................................................................. 1

II. OBJECTIVE ....................................................................... 6

III. FINDINGS........................................................................... 6

A. NRC DOES NOT FULLY COMPLY WITH NRC-EPA

CERCLA SITE MOUS .................................................. 7

B. NRC RELIES ON DOE’S INSPECTION PROGRAM .......... 11

IV. CONSOLIDATED LIST OF RECOMMENDATIONS......... 17

V. AGENCY COMMENTS..................................................... 17

APPENDIX

A. CONTAMINATION FROM URANIUM 

MILL TAILINGS...................................................... 18

B. CONVENTIONAL URANIUM RECOVERY 

MILLING OVERVIEW ............................................ 19

C. SITES DECOMMISSIONED AND UNDERGOING

DECOMMISSIONING ..................................... 20

D. OBJECTIVE, SCOPE, AND METHODOLOGY...... 21
Audit of NRC’s Oversight of Decommissioned Uranium Recovery Sites and 

Sites Undergoing Decommissioning

1

I. BACKGROUND

The Nuclear Regulatory Commission’s (NRC) mission is to 

regulate the Nation's civilian use of byproduct, source, and 

special nuclear materials to ensure adequate protection of 

public health and safety, to promote the common defense and 

security, and to protect the environment.

As part of its mission, NRC regulates uranium recovery 

operations. Through the 1980s, commercial uranium recovery 

mills operated in support of both a fledgling nuclear power 

industry and U.S. defense programs. The waste from the mills 

(uranium mill tailings) caused contamination that the Federal 

Government continues to address (see Appendix A for 

additional information on contamination). 

The Rio Algom uranium mill tailings site in Grants, NM 

Source: Office of the Inspector General (OIG), NRC

Uranium Mill Tailings

Uranium mill tailings are primarily the waste material created 

during conventional uranium recovery processing (see Appendix 

B for a process overview) and deposited in a mill tailings 

impoundment. The mill tailings contain heavy metal 

constituents and emit radon from the decay of radium, itself a 

decay product of uranium, thus creating potential adverse health 

and environmental effects. Uranium mill tailings impoundments

are large, ranging in size from 4 to 370 acres. Each uranium 
Audit of NRC’s Oversight of Decommissioned Uranium Recovery Sites and 

Sites Undergoing Decommissioning

2

mill tailings site has unique characteristics determined by factors 

such as the composition of the tailings and the specific 

topography, geology, and hydrology of the area. NRC and 

Agreement States1regulate approximately 200 million metric 

tons of uranium mill tailings, while the Department of Energy 

(DOE) oversees 26 million metric tons. 

The Uranium Mill Tailings Radiation Control Act 

Studies of the environmental impacts of uranium mill tailings 

during the early 1970s revealed potentially significant health 

hazards. The lack of regulations for managing and 

decommissioning2the resulting waste reflected the limited 

knowledge of the hazards involved. As a result, Congress 

enacted the Uranium Mill Tailings Radiation Control Act 

(UMTRCA) in 1978, giving NRC important responsibility in the 

oversight of uranium mill decommissioning and site remediation. 

UMTRCA provides for the disposal, long-term stabilization, and 

control of uranium mill tailings in a safe and environmentally 

sound manner, to minimize or eliminate radiation health hazards 

to the public. UMTRCA defines two categories of uranium mill 

tailings sites (Title I and Title II) and assigns differing 

responsibilities to three Federal agencies. 

Categories of Uranium Mill Tailings Disposal Sites

Under Title I, the Federal Government assumed responsibility 

for cleanup at abandoned, inactive uranium milling sites. Once 

decommissioning is complete, DOE’s Office of Legacy 

Management accepts the sites for long-term care and 

 

1

Agreement States are States that have entered into an agreement assuming regulatory 

authority from NRC. In accordance with Section 274 of the Atomic Energy Act, as amended, 

NRC may relinquish its authority to regulate byproduct, source, and limited quantities of 

special nuclear material to States. These States must first demonstrate that their regulatory 

programs are adequate to protect public health and safety and are compatible with NRC’s 

program.

2 Decommission means to remove a facility or site safely from service and reduce residual 

radioactivity to a level that permits (1) release of the property for unrestricted use and

termination of the license or (2) release of the property under restricted conditions and 

termination of the license.
Audit of NRC’s Oversight of Decommissioned Uranium Recovery Sites and 

Sites Undergoing Decommissioning

3

maintenance under a general license from NRC. As of June 

2011, decommissioning had been completed at 21 Title I sites.

A decommissioned Title I uranium mill tailings site in Canonsburg, PA 

Source: OIG, NRC

Title II places responsibility for cleanup of sites with the 

licensees that were operating in 1978 or licensed by NRC or an 

Agreement State after 1978. Licensees must conduct cleanup 

activities3according to an NRC-approved reclamation plan. 

Licensees must then provide funding for long-term surveillance, 

including annual inspections and environmental monitoring, in 

order for NRC to terminate the license and approve site transfer 

to DOE. As of June 2011, decommissioning had been 

completed at six Title II sites, which are now in long-term DOE 

custody. Decommissioning is underway at 11 other NRC 

regulated Title II sites. Appendix C of this report lists sites 

decommissioned and sites undergoing decommissioning. 

Federal Agency Responsibility

NRC, the Environmental Protection Agency (EPA), and DOE 

have distinct responsibilities under UMTRCA.

 

3

These activities may include wind blown mill tailings retrieval, dewatering or the removal of 

freestanding liquids, and final radon barrier construction. 
Audit of NRC’s Oversight of Decommissioned Uranium Recovery Sites and 

Sites Undergoing Decommissioning

4

NRC Responsibilities

NRC’s responsibility under UMTRCA is to ensure that 

decommissioning at both Title I and Title II sites meets the 

standards for protecting human health and the environment. 

Specifically,

Title I sites: NRC is required to evaluate DOE's site 

design and implementation and, following remediation, to 

concur that the site meets established standards.

Title II sites: NRC (or an Agreement State as appropriate) 

is required to oversee licensees’ operations and 

decommissioning, and conduct inspections and license 

reviews. 

NRC’s uranium recovery decommissioning inspectors are 

located in Region IV, and project managers overseeing license 

and technical reviews are located in the Office of Federal and 

State Materials and Environmental Management Programs 

(FSME) in NRC headquarters. Region IV has three qualified 

uranium recovery inspectors. FSME has budgeted 

approximately 5.5 full-time equivalents to the oversight program

for fiscal year 2012. 

EPA Responsibilities

EPA’s responsibility under UMTRCA is to set the standards for 

air and water quality. For air, the primary concern is radon gas, 

and for groundwater, the concerns are uranium and associated 

heavy metal constituents. EPA’s regulations were incorporated 

into NRC’s regulations in 10 Code of Federal Regulations (CFR) 

Part 40, Appendix A. Additionally, EPA is responsible for 

administering the Comprehensive Environmental Response, 

Compensation and Liability Act, as amended (CERCLA),4 which 

impacts two uranium recovery sites undergoing 

decommissioning. EPA and NRC entered into memorandums 

 

4 CERCLA was enacted in 1980 to provide for remedial action at chemically and radiologically 

contaminated sites. EPA initiates a multiphase evaluation and cleanup process when it 

identifies a site requiring remediation under CERCLA authority. 
Audit of NRC’s Oversight of Decommissioned Uranium Recovery Sites and 

Sites Undergoing Decommissioning

5

of understanding (MOUs) regarding oversight of two sites. The 

MOUs outline EPA and NRC obligations to coordinate distinct 

regulatory responsibilities. 

The Church Rock uranium mill tailings site in Gallup, NM

Source: OIG, NRC

DOE Responsibilities

DOE’s responsibility under UMTRCA is to remediate Title I sites 

and provide long-term custody for both Title I and Title II sites. 

Specifically, 

DOE’s Title I remediation actions must meet EPA 

standards with review and concurrence by NRC. 

DOE develops and NRC approves a long-term 

surveillance plan for Title I and Title II sites where 

reclamation is complete. 

DOE takes possession of the sites for long-term custody 

under a general license. Long-term custody includes 

monitoring, maintenance, and emergency measures 

necessary to protect public health and safety. There is 

no termination of this unique general license.
Audit of NRC’s Oversight of Decommissioned Uranium Recovery Sites and 

Sites Undergoing Decommissioning

6

II. OBJECTIVE

The audit objective was to determine the effectiveness of NRC’s 

regulatory oversight of decommissioned uranium recovery sites 

and sites undergoing decommissioning. Appendix D contains 

information on the audit scope and methodology.

III. FINDINGS 

NRC’s oversight of Title I and Title II uranium recovery

decommissioning is largely effective. In particular, recent NRC 

initiatives to improve knowledge management have addressed 

self-identified areas of inefficiency and have enhanced the 

agency’s oversight efforts. However, OIG has identified two 

opportunities for more effective oversight of uranium recovery 

decommissioning by: 

Improving compliance with the terms of the site-specific 

MOUs with EPA.

Reducing reliance on DOE’s inspection program to alert 

NRC to problems at decommissioned uranium recovery

sites in DOE custody. 
Audit of NRC’s Oversight of Decommissioned Uranium Recovery Sites and 

Sites Undergoing Decommissioning

7

A. NRC Does Not Fully Comply With NRC-EPA CERCLA Site MOUs

NRC does not fully comply with the conditions of the MOUs with 

EPA for uranium recovery sites subject to CERCLA. NRC 

agreed to conditions in the MOUs that would promote effective 

and efficient regulatory oversight. However, NRC lacks controls 

to ensure compliance with the terms of the MOUs. Therefore,

NRC approaches oversight of remediation activities in a way 

that increases the risk that these activities will not occur in an 

effective and timely manner. 

NRC Compliance With MOU Conditions 

Federal internal control standards5require agencies to establish 

and monitor internal controls and performance measures to 

assure effectiveness and efficiency of agency operations and 

the use of resources. Additionally, the standards require that 

managers compare actual performance to planned or expected 

results and analyze significant differences. 

Internal controls are integral components of an organization’s 

management that provide reasonable assurance of 

effectiveness and efficiency of operations. Internal control 

comprises the plans, methods, and procedures, to include 

performance measures, used to meet missions, goals, and 

objectives. 

NRC and EPA jointly developed and agreed to MOUs for 

promoting effective and efficient regulation of two uranium 

recovery sites in New Mexico undergoing decommissioning: (1) 

Church Rock and (2) Homestake. NRC and EPA regulate 

remediation activities at these sites through authorities given to 

both agencies in UMTRCA. EPA also possesses additional 

regulatory authorities through CERCLA. The objective of the 

MOUs is to promote effective regulation and assure that site 

remediation activities occur in an effective and timely manner. 

 

5 Office of Management and Budget Circular A-123, Management’s Responsibility for 

Internal Control, and U.S. Government Accountability Office Standards for Internal Control in 

the Federal Government.
Audit of NRC’s Oversight of Decommissioned Uranium Recovery Sites and 

Sites Undergoing Decommissioning

8

NRC has several obligations under the MOUs. One is to 

provide site remediation progress reports on a quarterly basis 

for Church Rock and on a semiannual basis for Homestake. 

Another responsibility is to conduct an annual review of the 

MOUs. These two responsibilities are part of several conditions 

in the MOUs intended to ensure long-term effectiveness of 

oversight and promote mutual communication. 

The Homestake uranium mill tailings site in Grants, NM 

Source: OIG, NRC

NRC Does Not Fully Comply With NRC-EPA CERCLA Site 

MOUs 

NRC does not fully comply with the conditions of the jointly 

developed and agreed upon MOUs with EPA for uranium 

recovery CERCLA sites. NRC has not provided required 

progress reports to EPA or conducted required annual reviews 

of the MOUs. 

NRC Has Not Provided Progress Reports to EPA

NRC has not met its responsibility to provide EPA with quarterly 

progress reports on site remediation for the Church Rock site 
Audit of NRC’s Oversight of Decommissioned Uranium Recovery Sites and 

Sites Undergoing Decommissioning

9

and semiannual progress reports for the Homestake site. An 

NRC senior manager acknowledged that NRC is not meeting 

this requirement. 

NRC Has Not Conducted an Annual Review of the MOUs

NRC has not met its responsibility to conduct an annual review 

of the MOUs. Conditions in the MOUs require NRC to review 

the MOUs annually in order to make modifications based on 

changes in regulatory authorities or priorities. NRC senior 

managers stated that agency staff never reviewed the MOUs.

NRC Lacks Controls To Ensure Compliance With the MOUs 

NRC does not fully comply with the MOUs for uranium recovery 

CERCLA sites because NRC does not have internal controls or 

performance measures in place to provide reasonable 

assurance that NRC is fulfilling its obligations. 

A water treatment plant at the Homestake site in Grants, NM 

Source: OIG, NRC

FSME is responsible for ensuring NRC compliance with the 

MOUs for uranium recovery CERCLA sites. FSME has baseline 

performance measures and an internal control plan to ensure 

that programs achieve intended results, resources are used 
Audit of NRC’s Oversight of Decommissioned Uranium Recovery Sites and 

Sites Undergoing Decommissioning

10

consistently with the agency’s mission, and laws and regulations 

are followed. However, neither the performance measures nor 

internal control plan include controls to provide reasonable 

assurance that NRC fully complies with and meets its 

obligations under the MOUs.

NRC Risks Hindering Effective Oversight 

Because NRC is not in full compliance with the conditions of the 

MOUs with EPA for uranium recovery CERCLA sites, effective 

and efficient oversight may be hindered. NRC not providing 

progress reports on site remediation and the lack of annual 

MOU reviews have contributed to an approach to oversight of 

remediation activities in a way not outlined in the MOUs. For 

example, NRC and EPA senior managers recently exchanged 

letters agreeing that the objective of the Homestake MOU is to 

ensure site remediation activities occur in an effective and 

timely manner, but staff from both agencies disagreed with the 

other agency’s approach to overseeing the activities at the site. 

NRC’s current approach to oversight of remediation activities in 

a way not outlined in the MOUs increases the risk that these 

activities will not occur in an effective and timely manner. 

Furthermore, because the MOUs have not been reviewed, they 

have not been updated.

Recommendation

OIG recommends that the Executive Director for Operations:

1. Establish performance measures to ensure compliance with 

the NRC-EPA CERCLA site MOUs.

.
Audit of NRC’s Oversight of Decommissioned Uranium Recovery Sites and 

Sites Undergoing Decommissioning

11

B. NRC Relies on DOE’s Inspection Program

NRC relies on DOE’s inspection program at decommissioned 

uranium recovery sites in DOE custody. Although inspections 

are a key component of NRC’s oversight, NRC has chosen not 

to inspect the sites transferred to DOE. As a result, NRC may 

not know if all regulatory requirements are met regarding the 

protection of public health and safety and the environment.

Rock cover testing at the Umetco uranium mill tailings site in Gas Hills, WY

Source: NRC

Inspection Is a Key Component of NRC Oversight 

Inspections constitute a key component of NRC’s regulatory 

process. The Atomic Energy Act of 1954, as amended, firmly 

establishes inspection of licensees as a primary monitoring tool. 

The act requires the agency to ―insure that the management of 

any byproduct material . . . is carried out in such a manner as 

the Commission deems appropriate to protect the public health 

and safety and the environment‖ and authorizes the agency to 

conduct inspections. NRC regulations require licensees to 

provide for inspections as may be necessary for NRC to ensure 

that licensees meet existing regulatory requirements. 
Audit of NRC’s Oversight of Decommissioned Uranium Recovery Sites and 

Sites Undergoing Decommissioning

12

General License Terms Allow Inspection

After a facility has been decommissioned, the site is transferred 

to DOE for long-term custody under the general license.6 The 

general license terms allow for inspection by NRC. Specifically, 

the regulation states that the ―the long-term care agency under 

the general license ... shall [g]uarantee permanent right-of-entry 

to Commission representatives for the purpose of periodic site 

inspections.‖7 This allows NRC to inspect the uranium mill 

tailings sites in DOE long-term custody under the general 

license. 

NRC Relies on DOE’s Inspection Program

A DOE contractor conducts annual inspections of all uranium 

mill tailings sites in DOE long-term custody. Depending on site 

conditions and compliance requirements, these inspections may 

include the following: visual inspection and photographic 

documentation of conditions, routine maintenance, surveys to 

detect settlement of the mill tailings impoundment, groundwater 

monitoring, and rock quality monitoring. The contractor compiles 

the observations into separate reports on the Title I and Title II 

sites, and then DOE submits the inspection reports to NRC. 

Technical Challenges Revealed by DOE Inspections

DOE’s inspection program has revealed technical challenges at 

some sites, particularly in groundwater conditions and durability 

of covers and erosion protection structures.

Groundwater

Uranium mill tailings contaminated the groundwater at 

numerous sites. For such sites, the approved reclamation plan 

must include the post-remediation groundwater quality goal. The 

approach for addressing EPA standards depends on site 

conditions. In cases where the EPA standard for drinking water 

 

6

The general license is established and its terms are set forth in 10 CFR 40.27 and 

10 CFR 40.28.

7

The inspection reference appears in 10 CFR 40.27(c)(4) for Title I sites and 10 CFR 

40.28(c)(4) for Title II sites, using identical language.
Audit of NRC’s Oversight of Decommissioned Uranium Recovery Sites and 

Sites Undergoing Decommissioning

13

is not practicable with available remediation techniques, a 

licensee may apply for approval of alternative standards known 

as alternate concentration limits (ACLs) for one or more 

contaminants. 

Loose erosion fabric at the Shiprock uranium mill tailings site in New Mexico 

Source: DOE

Groundwater contaminant standards should be set at a level 

where normal fluctuation of concentration levels will not exceed 

the approved limits. However, groundwater contaminant levels 

at some sites transferred to long-term custody have shown

consistent increases (e.g., Bluewater) or broad fluctuations 

(e.g., Falls City and Tuba City). At one Title II site (Shirley 

Basin South) transferred to DOE custody, alternative standards

have been exceeded. Another Title II site (Bear Creek) has had 

its ―final inspection‖ by NRC, but the pending transfer to DOE is

delayed because of similar exceedences.

Durability

Uranium mill tailings are compacted into engineered disposal 

cells.8 To be approved, a site’s reclamation plan must include a 

site-specific design for the disposal cell that takes into account 

 

8 Disposal cells are engineered to encapsulate the mill tailings, reduce radon emanation, and 

prevent the movement of water through the tailings. 
Audit of NRC’s Oversight of Decommissioned Uranium Recovery Sites and 

Sites Undergoing Decommissioning

14

the characteristics of the uranium mill tailings and site

topography, among other factors. The goals are to prevent 

radon emissions and dispersion of the uranium mill tailings. The 

cell design specifies not only the dimensions of the 

impoundment, radon barrier, and rock cover, but also the 

structures for erosion control that will protect the disposal cell 

from surface runoff after construction. 

According to regulations, these engineered disposal cells should 

be effective for at least 200 years. However, several sites in 

DOE long-term custody have had problems with covers or with 

erosion control measures within less than 25 years of 

construction. In addition, a Title II site that has received its ―final 

inspection‖ in preparation for transfer to DOE has already 

experienced durability problems. Table 1 lists the sites with 

technical challenges.

Table 1: Sites with Technical Challenges

Site Name, State

UMTRCA 

Title

Year of 

Transfer 

to DOE

Year 

cell 

built Technical Challenge

Falls City, TX I 1997 1994 Groundwater—uranium fluctuations

Lakeview, OR I 1995 1989 Durability—rock degradation

Rifle, CO I 1998 1996 Durability—slopes, drainage

Salt Lake City, UT I 1997 1989 Durability—rock degradation

Tuba City, AR I 1996 1990

Durability—erosion

Groundwater—broad fluctuations

Bear Creek, WY II n/a * 1999 Groundwater—ACL exceeded

Bluewater, NM II 1997 1995 Groundwater-—rise in radium levels

L-Bar, NM II 2004 2000 Durability—erosion

Shirley Basin South, WY II 2005 2001 Groundwater—ACL exceeded

Umetco Gas Hills, WY II n/a * 2002 Durability—erosion

Source: OIG, compiled from NRC and DOE site documents.

* n/a: Pending transfer to DOE.

NRC Does Not Inspect 

NRC does not conduct inspections at the uranium recovery sites 

in DOE long-term custody under the general license. When a 

site is transferred to DOE long-term custody there is no formal
Audit of NRC’s Oversight of Decommissioned Uranium Recovery Sites and 

Sites Undergoing Decommissioning

15

mechanism for further inspection, and NRC oversight shifts from 

the regional inspection branch to project managers at 

headquarters. 

Project managers in FSME described their oversight activities 

as reviewing the DOE-submitted inspection reports and 

groundwater monitoring reports where applicable. They may 

follow up with DOE’s Office of Legacy Management if they have 

a question, but the primary contacts with DOE staff are in 

quarterly conference calls to review technical issues. Project 

managers sometimes visit the sites in DOE custody, but they 

clearly stated that such visits are not formal inspections. For 

example, one project manager reported recently touring a few 

sites in order to become more familiar with site-specific issues. 

The Maybell West uranium mill tailings site in Colorado

Source: DOE

NRC Chooses Not To Inspect Sites Transferred to DOE for 

Long-Term Surveillance 

NRC has chosen not to inspect sites transferred to DOE for 

long-term surveillance. NRC managers explained that the 

agency conducts extensive oversight during decommissioning 

so that the sites will not require scrutiny after transfer. They 
Audit of NRC’s Oversight of Decommissioned Uranium Recovery Sites and 

Sites Undergoing Decommissioning

16

contended that when regulatory requirements are met during 

decommissioning, NRC can certify that a site is stable and 

ready for closure with only minimal monitoring according to the 

long-term surveillance plan. The managers also concluded that 

DOE would be at least as effective in monitoring as NRC would 

be, and therefore NRC could rely on DOE to alert NRC to any 

problems and address them through the process of amending 

the long-term surveillance plan. 

NRC May Not Know If Regulatory Requirements Are Being 

Met 

Because NRC does not inspect sites transferred to DOE for 

long-term custody, NRC may not know if all regulatory 

requirements are being met regarding the protection of public 

health and safety and the environment. Some decommissioned 

uranium recovery sites have proven more dynamic than 

originally expected, and NRC may not have the best information 

regarding conditions at these sites. Transfer of all remaining 

Title II sites to DOE will result in approximately 226 million 

metric tons of radioactive and hazardous waste in DOE longterm custody. Given the current approach, NRC will not

independently verify that these sites are meeting regulatory 

standards that protect public health and safety and the 

environment.

Recommendation 

OIG recommends that the Executive Director for Operations:

2. Develop and document in inspection guidance a frequency 

for inspecting uranium recovery sites transferred to DOE for 

long-term surveillance.
Audit of NRC’s Oversight of Decommissioned Uranium Recovery Sites and 

Sites Undergoing Decommissioning

17

IV. CONSOLIDATED LIST OF RECOMMENDATIONS

OIG recommends that the Executive Director for Operations:

1. Establish performance measures to ensure compliance with 

the NRC-EPA CERCLA site MOUs.

2. Develop and document in inspection guidance a frequency 

for inspecting uranium recovery sites transferred to DOE for 

long-term surveillance.

V. AGENCY COMMENTS

An exit conference was held with the agency on November 22, 

2011. At this meeting, agency management provided 

supplemental information that has been incorporated into this 

report as appropriate. As a result, agency management stated 

their general agreement with the findings and recommendations 

in this report and opted not to provide formal comments for 

inclusion in this report.
Audit of NRC’s Oversight of Decommissioned Uranium Recovery Sites and 

Sites Undergoing Decommissioning

18

Appendix A

Contamination From Uranium Mill Tailings

Contamination occurs through five primary pathways: radon 

inhalation, dust migration, surface water runoff, ground seepage 

into aquifers, and radioactivity absorbed in vegetation and 

entering the food chain. The contamination pathways are 

illustrated below.

Source: The Long Term Stabilization of Uranium Mill Tailings, © IAEA, 2004, 

page 298 
Audit of NRC’s Oversight of Decommissioned Uranium Recovery Sites and 

Sites Undergoing Decommissioning

19

Appendix B

Conventional Uranium Recovery Milling Overview

Uranium recovery is the process of concentrating uranium from 

ore into a product called "yellowcake," which is later converted 

into fuel for nuclear reactors.

Conventional uranium mills crush the uranium ore, use an acid 

or alkaline solution to leach the uranium from the ore, and then 

concentrate the uranium from the solution into yellowcake. The 

uranium milling process is illustrated below.

Source: U.S. Energy Information Administration
Audit of NRC’s Oversight of Decommissioned Uranium Recovery Sites and 

Sites Undergoing Decommissioning

20

Appendix C

Sites Decommissioned and Undergoing Decommissioning

Decommissioned Uranium Recovery Sites in DOE Long-Term Custody

Title I Title II

Site Name, State Fiscal Year 

Transferred Site Name, State Fiscal Year Transferred

1 Ambrosia Lake, NM 1998 Bluewater, NM 1997

2 Burrell, PA 1994 Edgemont, SD 1996

3 Canonsburg, PA 1996 L-Bar, NM 2004

4 Durango, CO 1996 Maybell West, CO 2010

5 Falls City, TX 1997 Sherwood, WA 2001

6 Grand Junction, CO 1999 Shirley Basin South, WY 2005

7 Green River, UT 1998

8 Gunnison, CO 1997

9 Lakeview, OR 1995

10 Lowman, ID 1994

11 Maybell, CO 1999

12 Mexican Hat, UT 1997

13 Monument Valley, AZ 1997

14 Naturita, CO 1999

15 Rifle, CO 1998

16 Riverton, WY 1991

17 Salt Lake City, UT 1997

18 Ship Rock, NM 1996

19 Slick Rock, CO 1998

20 Spook, WY 1993

21 Tuba City, AZ 1996

Source: DOE Office of Legacy Management, Site Management Guide, June 2011. According to this 

guide, the above listing is accurate as of September 30, 2010.

NRC Licensed Title II Sites Undergoing Decommissioning

NRC-Licensed Sites

Site Name, State

1 American Nuclear, WY

2 Bear Creek, WY

3 ExxonMobil Highlands, WY

4 Homestake, NM

5 Pathfinder–Lucky MC, WY

6 Pathfinder–Shirley Basin, WY

7 Rio Algom–Ambrosia Lake, NM

8 Sequoyah Fuels Corporation, OK

9 Umetco Minerals, WY

10 United Nuclear–Church Rock, NM

11 Western Nuclear–Split Rock, WY

Source: NRC’s Web site, "NRC-Regulated Uranium Recovery Sites Undergoing Decommissioning," 

May 20, 2011
Audit of NRC’s Oversight of Decommissioned Uranium Recovery Sites and 

Sites Undergoing Decommissioning

21

Appendix D

OBJECTIVE, SCOPE, AND METHODOLOGY

Objective

The audit objective was to determine the effectiveness of NRC’s 

regulatory oversight of decommissioned uranium recovery sites 

and sites undergoing decommissioning.

Scope

The audit focused on reviewing the oversight of 

decommissioned uranium recovery sites and sites undergoing 

decommissioning. We conducted this performance audit at 

NRC headquarters and at uranium recovery sites in Gallup, NM; 

Grants, NM; Canonsburg, PA; Carbon County, WY; and 

Converse County, WY, from April 2011 through September 

2011. Internal controls related to the audit objective were 

reviewed and analyzed. Throughout the audit, auditors were 

aware of the possibility or existence of fraud, waste, or misuse 

in the program.

Methodology

OIG reviewed relevant Federal legislation pertaining to NRC’s 

regulatory authorities to oversee uranium recovery sites, 

including the Atomic Energy Act of 1954, as amended, and the

Uranium Mill Tailings Radiation Control Act of 1978. OIG also 

reviewed agency guidance including office instructions, 

inspection manual chapters, and inspection procedures 

pertaining to the oversight of uranium recovery sites. Reports, 

briefings, presentations, and communications between NRC 

and representatives from both DOE and EPA that address the 

relevant aspects of uranium recovery oversight were also 

reviewed. 

OIG interviewed NRC staff and managers from headquarters 

(Rockville, MD) and Region IV (Arlington, TX) who participate in 

activities related to uranium recovery oversight. OIG also 

interviewed licensees, and representatives from the DOE, EPA, 
Audit of NRC’s Oversight of Decommissioned Uranium Recovery Sites and 

Sites Undergoing Decommissioning

22

and the Navajo Nation. These interviews were conducted to 

obtain insights into NRC’s oversight of uranium recovery 

decommissioning.

The audit team also observed the following inspection activities:

An NRC safety inspection at the ExxonMobil-Highland 

uranium recovery site in Converse County, WY.

An NRC safety inspection at the Pathfinder-Shirley Basin 

uranium recovery site in Carbon County, WY.

 

We conducted this performance audit in accordance with 

generally accepted Government auditing standards. Those 

standards require that we plan and perform the audit to obtain 

sufficient, appropriate evidence to provide a reasonable basis 

for our findings and conclusions based on our audit objectives. 

We believe that the evidence obtained provides a reasonable 

basis for our findings and conclusions based on our audit 

objective. 

The audit work was conducted by Sherri Miotla, Team Leader; 

Robert Woodward, Audit Manager; Kevin Nietmann, Senior 

Technical Advisor; Levar Cole, Senior Management Analyst; 

and Amy Hardin, Auditor.