U.S. Department of Energy 

Office of Inspector General 

Office of Audit Services 

Audit Report 

Potential Uses for Depleted Uranium 

Oxide 

DOE/IG-0810 January 2009 
Department of Energy 

Washington, DC 20585 

January 9, 2009 

MEMORANDUM FOR THYSECRETARY - I - 

FROM: 

Inspector General 

SUBJECT': INFORMATION: Audit Report on "Potential Uses For 

Depleted Uranium Oxide" 

BACKGROUND 

The Department of Energy's Office of Environmental Management (EM) manages 

approximately 700,000 metric tons of depleted uranium hexafluoride at the gaseous 

diffusion plants located near Paducah, Kentucky. and Portsmouth, Ohio. It plans to 

convert the depleted uranium hexafluoride to a stable material. The conversion process 

will produce approximately 55 1,000 metric tons of depleted uranium oxide - a relatively 

stable form that can be handled and disposed of by direct burial or, potentially, used in 

various materials or products. Over a period of about 13 years, the Department has 

conducted research which established that the oxide could possibly be used in catalysts, 

semiconductors, nuclear repository applications and radiation shielding products. 

In August 2002, the Department awarded a contract to Uranium Disposition Services, 

LLC (UDS) to perform the conversion. In July 2004, UDS started construction of 

conversion facilities in Paducah and in Portsmouth. As of June 2008, UDS planned on a 

May 201 0 start date for full operations at Portsmouth and a September 20 10 start date for 

operations at Paducah. The current life cycle cost of the conversion pro-ject is 

approximately $3.5 billion, including costs to dispose of the oxide by burial. 

The Department developed a strategy which included a continuing effort to explore 

potential uses for the converted product. We initiated this audit to determine whether the 

Department had adequately followed through on identifying potential uses for depleted 

uranium oxide. 

RESUL'I'S OF AUDIT 

Our audit disclosed that the Department had not taken adequate action to facilitate 

development of depleted uranium oxide-based products. In spite of iinding potential uses 

that have shown promise, the Department plans to dispose of virtually the entire 55 1,000 

metric tons of depleted uranium oxide produced by the conversion process as low-level 

waste at an estimated cost of about $428 million. In particular, we noted that: 

Beyond basic research, little action had been taken to develop practical 

applications for, or products involving the oxide; 
2

• For the single application area where research had extended to preliminary 

development and testing, all funding from outside sources had been expended. 

Yet, the Department had provided only a small portion of promised funding and 

had no plans for providing additional funding. Such funding would have 

supported the development of working or scale models to evaluate patented 

nuclear repository applications. 

Between 1994 and 2006, the Department evaluated multiple uses for the depleted 

uranium oxide. However, only one of these uses, spent nuclear fuel (SNF) shielding 

applications, was pursued to the point of being demonstrated as useful for application. In 

November 2006, researchers at the Oak Ridge National Laboratory reported, based on a 

27-month study, that depleted uranium aggregate could be successfully combined with 

concrete to produce a product known as DUCRETE, providing effective radiation 

shielding. Researchers noted that this product could be useful for a number of SNF 

applications in both the Federal and commercial sectors. 

Management officials informed us, however, that the Department had discontinued 

funding research for alternative uses for depleted uranium oxide in 2005 because EM's 

technology development budget had been significantly reduced. They also noted that the 

Department was not actively pursuing other uses because it believed that there were no 

alternatives that would consume the entire depleted uranium oxide inventory. In short, a 

piecemeal approach was unacceptable. Finally, they indicated that the Department had 

concluded that it was now the responsibility of the private sector to continue research and 

development for finding alternative uses for depleted uranium oxide. As discussed in the 

attached report, we did not find these reasons to be compelling in light of the potential to 

avoid significant disposal costs. 

Despite the results of research over the past few years demonstrating that there are viable 

re-use options, the Department currently does not plan to pursue any alternatives. Thus, 

absent additional action, the Department will be forced to incur $428 million in disposal 

costs over a 25-year period. The programmatic competition for the Department's finite 

resources is often intense; yet, the potential to avoid significant disposal costs through 

alternative uses of conversion oxides offers the promise of directing funds now targeted 

for disposal to other high-priority mission needs. 

To address the issues described in our report we made several recommendations designed 

to help increase the potential for reuse of the converted materials and avoidance of direct 

disposal costs. 

MANAGEMENT REACTION

Management concurred with our recommendations. Although Management stated that it 

currently could see no commercial use for the depleted uranium oxide, it agreed that it 

may be beneficial to reassess interest as conversion facilities near completion and can be 

expected to begin producing significant quantities of the oxide. To that end the Office of 

Environmental Management committed to issuing an expression of interest by January 

2010 to identify potential interest from industry for uses of depleted uranium oxide. 
Management's comments are summarized in the body of the report and are attached as 

Appendix 2. 

Attachment 

cc: Acting Deputy Secretary 

llnder Secretary of Energy 

Chief of Staff 

Team Leader, Office of Internal Review, CF-1.2 

Audit 1,iaison. Environnemental Management, EM-33 

Audit 1,iaison. Portsmouth/Paducah Pro-ject Office, PPPO 
REPORT ON POTENTIAL USES FOR DEPLETED URANIUM OXIDE 

TABLE OF 

CONTENTS 

Alternative Uses for Depleted Uranium Oxide 

. . Details of Flndlns .................................................................................................................. 1 

Recommendations ................................................................................................................ 4 

ConlJnents ............-...........-.....--.-................---...---...----...---........................-......-...................... 5 

Appendices 

. . 1. Oblectlve, Scope, and Methodology ............................................................................. 6 

2. Manasenlent Comments ................................................................................................ 8 
ALTERNATIVE USES FOR DEPLETED URANIUM OXIDE 

Investigating The Department of Energy (Department) had not adequately 

Alternative Uses followed through on investigating potential uses for the disposition 

of the depleted uranium oxide. While several potential uses have 

been identified and considered, we found that little had been done 

to pursue these alternatives. Only one technology, the use of 

depleted uranium oxide for shielding applications, was studied to 

the point of proven viability. However, rather than pursue this 

alternative, the Department plans to dispose of the ma-jority of the 

oxide as low-level waste at an estimated disposal cost of 

approximately $428 million. 

Potential Alternatives 

As required by a February 1998 Consent Order, the Department 

reports annually to the Ohio Environmental Protection Agency 

(EPA) on the status of its depleted uranium hexafluoride (DUF6) 

conversion activities, including its efforts to identify alternative 

uses. In its December 2007 report, the Department noted that a 

number of beneficial uses for the depleted uranium oxide 

conversion product had been identified to date. Among these were 

the use of depleted uranium in catalysts, semiconductors, 

repository applications and radiation shielding products. 

In 2000, the Department introduced the potential use of depleted 

uranium catalysts to decompose a range of volatile organic 

compounds. Research continued and in 2004 the Department 

reported that a catalyst formulation, based upon a mixed titanium 

uranium oxide, was found to be competitive with noble metal 

catalysts. However, the Department terminated further research at 

the beginning of Fiscal Year 2004. It was also believed that 

depleted uranium oxide had electronic properties equivalent to or 

better than conventional sen~iconductor materials. The Department 

conducted limited research to measure the semiconducting 

properties of solid-crystal depleted uranium dioxide and construct 

and test a uranium-based diode and transistor. In 2004, while 

research was in its fundamental stage and the concept not yet 

proven, the Department terminated efforts on this alternative. 

The Department also began evaluating the use of depleted uranium 

oxide for spent nuclear fuel (SNF) repository and shielding 

applications. These applications included using depleted uranium 

dioxide particulates as fill material for SNF repositories, as 

replacement components for steel in constructing the SNF waste 

packages, and as a chemical sorption barrier in SNF repositories. 

For example, using funding from the Department of State in 2003, 

Russian scientists initiated experiments resulting in a 2006 report 

Page 1 Details of Finding 
which showed that depleted uranium oxide can be successfully 

used as a chemical and physical sorption barrier in SNF 

repositories to reduce radionuclide releases. However, all 

available funding has been expended and work on the use of 

depleted uranium oxide for repository applications has now been 

discontinued. 

The other application which showed significant promise was the 

use of depleted uranium oxide for radiation shielding products, 

specifically SNF casks. In 2003, the Department's research 

became focused on uses that had the potential to consume a 

significant portion of the stored inventory of DUF6 and in 

September 2004, the Acting Assistant Secretary for Environmental 

Management (EM) approved $420,000 of funding for the 

development of a new production technology for fabrication of 

depleted uranium aggregate. This new technology used an 

approach that had the potential to be a low-cost, high-throughput 

method for production of depleted uranium aggregate. Ultimately, 

only $125,000 of these funds was provided to the project and those 

funds have now been expended. 

In November 2006, researchers at the Oak Ridge National 

Laboratory (ORNL) reported, based on a 27-month study, that 

depleted uranium aggregate could be successfully combined with 

concrete (DUCRETE) to provide adequate radiation shielding and 

was useful for a number of SNF applications in both the federal 

and commercial sectors. For example, using DUCRETE to 

construct nuclear casks would not only provide adequate shielding 

but would result in smaller cask size and reduced weight. This 

could significantly reduce the cost of storage container loading by 

eliminating the need for transfer casks that have specific weight 

and size restrictions. Further, it could reduce occupational 

radiation dose associated with handling the SNF for transportation. 

Funding for Potential Alternatives 

In its 2007 report to the Ohio EPA, the Department stated it had 

approved $1 million of funding to fabricate and test a prototype 

DUCRETE transport and storage cask and that the work continued 

into 2007. However, we noted that the Department had not 

provided the funding to fabricate and test a DUCRETE cask. In 

fact, despite the success of the research over the past few years and 

the potential to reduce disposal costs, the Department currently 

does not plan to pursue any of the previously described 

alternatives. Currently, the Department plans to utilize about 1,200 

metric tons for the mixed oxide fuel project, recycle a portion of 

Page 2 Details of Finding 
DUF6, and dispose of the remaining volume as low-level waste. 

The Department's estimated cost for disposing of the oxide over a 

25-year period is approximately $428 million, if the inventory of 

DUF6 prior to conversion is not reduced by recycling or re-use. 

Discontinuation of 

Research Funding 

The Department decided to curtail its pursuit of uses for depleted 

uranium oxide in 2005 because: its Technology Development 

budget had been significantly reduced since 2002; it believed there 

were no alternatives that would consume the entire oxide 

inventory; and, it was now the responsibility of the private sector 

to continue research and development into finding alternative uses 

for the material. 

Reduction in Budget 

From 2002 through 2005, EM's Technology Development budget 

was reduced nearly 71 percent from approximately $200 million to 

$58 million. In 2007, the budget was further reduced to 

approximately $21 million. With limited funding, EM's 

management did not consider the effort for DUFb to be a high 

priority. While funding may be limited, based on discussions with 

the ORNL Project Manager, modest investments sufficient to 

continue the research for alternative use for depleted uranium 

oxide have the potential to avoid significant disposal costs. For 

example, in addition to avoiding disposal costs, using depleted 

uranium oxide for DUCRETE in nuclear shipping and storage 

casks provides additional benefits in other program areas that may 

not have been fully considered. Further, as confirmed by ORNL's 

recent study, the use of depleted uranium oxide as a radiation 

shielding material appears to be a viable alternative that has the 

potential to reduce the life-cycle cost of the DUF6 conversion 

project. 

Consumption of Inventory 

Management officials also indicated that another factor leading to 

their decision to discontinue research in uses of depleted uranium 

oxide was that the technologies under consideration would only 

make piecemeal or incomplete use of the entire inventory. 

However, our review disclosed that the ORNL study showed that 

the use of depleted uranium aggregate in radiation shielding has 

the potential for consuming the entire depleted uranium inventory. 

In addition, the studies for repository applications noted that these 

applications could consume half or more of the depleted uranium 

inventory. 

Page 3 Details of Finding 
Engagement of the Private Sector 

The Department stated that it believed it is now the responsibility 

of the private sector to continue research and development for 

finding alternative uses for depleted uranium oxide. Further, 

management officials informed us that even if there was a potential 

use for the depleted uranium oxide, they did not believe that there 

was a market for it. However, we found that the Department had 

not engaged private industry on further development of alternatives 

since 2005. Specifically, between 2003 and 2005, the Department 

pursued several Cooperative Research and Development 

Agreements (CRADAS) to commercialize the use of DUCRETE 

with SNF cask vendors. However. two of the CRADAs were 

never finalized because the parties either lacked the resources and 

manpower to complete the work at the time or the pro-ject extended 

beyond the company's business planning cycle. Even though the 

technology for DUCRETE has now been proven by ORNL. the 

Department has not re-engaged the private sector since 2005 and 

has no intention of doing so. 

Impact on Disposal The Department has the potential to significantly reduce disposal 

Costs of Depleted costs. For example, developing DUCRETE casks could reduce the 

Uranium Oxide planned disposal costs. According to the ORNL Pro-ject Manager, 

depending on the option taken, the effort to build, test, and license 

the DUCRETE cask is estimated to be somewhere between 

approximately $7 to $1 5.1 million. Conversely, the estimated cost 

to treat the material as low-level waste and bury it is approximately 

$428 million. While we recognize that additional costs may be 

required to commercialize SNF casks made from DUCRETE, the 

delta is significant enough to warrant the consideration of pursuing 

this and other alternatives further. 

RECOMMENDATIONS To help ensure that potential alternatives of depleted uranium 

oxide are fully evaluated, we recommend that the Assistant 

Secretary, Environmental Management: 

1. Re-engage industry on developing alternative uses for 

depleted uranium oxide; and, 

2. Clarify the current status of research for alternative uses for 

depleted uranium oxide to the Director of the Ohio EPA. 

Page 4 Recommendations 
MANAGEMENT The Acting Assistant Secretary for Environmental Management 

AND AUDITOR concurred with the recommendations in the final report. 

COMMENTS Regarding recommendation 1, management stated that the 

Department will issue an expression of interest, by January 201 0, 

related to the depleted uranium oxide to identify any potential 

interest from industry. Management also agreed to inform the 

Director of the Ohio EPA that work on the DUCRETE transport 

and storage cask in Russia has stopped and no further actions are 

expected for the foreseeable future due to lack of commercial 

interest. Our draft report also included an additional 

recommendation that the Department review and evaluate the 

feasibility to continue funding research for spent nuclear fuel 

shielding applications. In commenting on this recommendation, 

management stated that sufficient evaluation of alternative uses for 

depleted uranium oxide has been conducted and that it was not 

EM'S mission to develop and/or implement commercial 

applications. 

We consider Management's comments and planned actions to be 

responsive to the report's recommendations. Although the 

Department felt sufficient research had already been conducted, 

the issuance of an expression of interest should aid in the 

identification of any useful and economical commercial 

applications. For this reason, our recommendation to review and 

evaluate the feasibility of continuing funding for research of spent 

nuclear fuel shielding was removed from the final report. 

Management's verbatim comments are included in Appendix 2 of 

the report. 

Page 5 Comments 
Appendix 1 

OBJECTIVE The objective of this audit was to determine whether the 

Department of Energy (Department) had adequately followed 

through on investigating potential uses for the depleted uranium 

oxide. 

SCOPE We conducted the audit from November 2007 through August 

2008, at Department Headquarters in Washington, D.C., and the 

Portsmouth/Paducah Project Office in Lexington, Kentucky. The 

audit scope included all depleted uranium oxide disposition efforts 

since the inception of the program. 

METHODOLOGY To accomplish the audit objective, we: 

Reviewed regulations, directives, contract requirements, 

and performance measures relating to the DUF6 program 

and oxide disposition; 

Evaluated internal controls over the program; 

Reviewed prior audits and reviews relating to the depleted 

uranium hexafluoride (DUF6) program; 

Reviewed disposition alternatives identified by the 

Department with the associated studies, funding, risks, 

requirements, and current status; and, 

Held discussions with key Department officials responsible 

for disposition of the depleted uranium oxide. 

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 objective. We believe that the 

evidence obtained provides a reasonable basis for our findings and 

conclusions based on our audit objective. The audit included tests 

of controls and compliance with laws and regulations necessary to 

satisfy the audit objective. Because our review was limited, it 

would not necessarily have disclosed all internal control 

deficiencies that may have existed at the time of our audit. The 

disposition project for the depleted uranium oxide did not have 

specific performance measures associated with the Government 

Pecfi)rmunce and Results Act of lYY3 therefore we could not assess 

the Department's efforts in meeting these measures. Also, we did 

not rely upon computer processed data to accomplish our audit 

objective. 

Management waived an exit conference. 

Page 6 Objective, Scope, and Methodology 
Appendix 2 

Department of Energy 

Wash~ngton. DC 20585 

November 26, 2008 

MI.:MORANI)UM FOK I<ICIKEY R. FIASS 

ASSISTAN'I' INSPI<C'I'OR CiENliRAl, 

1:01< ENVIKONMENI'AI,, SC[t<NCl<, 

AN11 C0RI'ORA'~PI~ AIJDI'1.S 

0FI:ICI: 01: TI IF INSI'ECTOK GENERAI. 

FROM 

S[JI3Jl<C'l': hali Kcport on "Audit of Potential lises for 1)cplctcd 

[Jranium Oxide" 

I'hank you for the opportunity to review the draft rcport on thc subject audit. 'l'he 

rcport statcs that thc I)epartnient has not adequately followed through on 

investigating potential i~scs for depleted uranium oxidc, and that while several 

potcntial uses have been idcntilicd and considered, little has been done to pursue 

these alternatives. 'l'he report also states that the Department plans to dispose of 

the majority of the oxide as low-level waste. We have evaluated the contents of 

the drati rcport and provide the k~llowing Ibr your consideration. 

The 1)epartment consiclers that sufficient cvaIuation of alternative uses for dcplctcd 

uranium oxidc has been conducted and that no substantive basis exists for pursuing 

new studies at this time. The lack of commercial intercst in the use of this material 

does not warrant fi~rthcr investigation at this time. 

'l'hc Depleted Uranium Research and Development Activities for I:iscal Year 2007 

rcport sent to the Ohio Environmental Protection Agency (EPA) notes that work 

on the DIJCRI:'I'E transport and storage cask in Russia continued in 2007 but the 

long-term viability ofthe project is contingent upon finding a linited States 

commercial cask supplier company with which to partner. The Department of 

llncrgy (DOI:) expects to inform the Ohio EPA in the 2008 report that this work 

has stopped and no fi~rthcr actions arc expected for the foreseeable fi~ti~rc due to 

lack of commercial interest. 

Whilc we currently see no commercial use for the depleted uranium oxidc, we 

believe it may be bcncticial to reasscss interest as the conversion ljcililics near 

completion and can be expected to begin producing signiticant quantities of oxidc. 

I'o this end, the IIOE Ofticc of Environmental Management will issue an 

expression of interest related to the depleted uranium oxide to identify any 

potcntial interest from industry for this material. IIOE expects to issue this 

expression of interest by January 20 10. 

Page 7 Management Comments 
Appendix 2 (continued) 

I<cconimcndation 1. Kc-engage industry on developing alternativc uscs for 

depleted uranium oxide; 

I.:M KESPONSE: EM will issuc an expression ol'interest related to the depleted 

uranium oxidc to identify any potcntial interest fiom industry lor this material. 

Iluc Ilatc: .lanuary 20 10. 

Kcco~nmc~lclation 2.Review and evaluate the feasibility to continue Iunding ti)r 

thc shielding applications associated with the storage, transport and disposal of 

spent nuclear li~cl: 

liM RIiSPONSE: Development and/or implc~ncntation ol'commercial 

applications are not an appropriate mission of EM. 'L'hc current statc of research 

and dcvcloprnent in this area is mature enough for industry to develop 

com~nercially viable applications. No action required. 

Recommendation 3. ClaritL thc current status of rescarch for alternative uscs for 

depleted uranium oxide to the Director of thc Ohio EPA. 

tiM KESPONSt.:: I'ortsmouth/f'aducah Project Office will clarify the currcnt 

status of research regarding potential uscs Sor the depletecl uranium oxidc in thc 

2008 annual report to the Director of the Ohio EI'A. Iluc Llatc: January 30, 2009. 

We believe these actions are rcsponsivc in addressing the concerns identitiecl in the 

report. 

Aclditional comments arc provided in the attachment. 

If you have any Li~rther q~~estions, please call me at (202) 586-0738 or 

Mr. Barry Smith, Dircctor. Ofticc of Site Support at (301) 903-4482. 

Attachment 

Page 8 Management Comments 
IG Report No. DOEIIG-0810 

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