Combating Nuclear Smuggling: Additional Actions Needed to Ensure Adequate Testing of Next Generation Radiation Detection Equipment
Published: 2007-09-18T00:00:00

Fast Facts:

Highlights:
section_title: Why GAO Did This Study
paragraphs: The Department of Homeland Security's (DHS) Domestic Nuclear Detection Office (DNDO) is responsible for addressing the threat of nuclear smuggling. Radiation detection portal monitors are key elements in our national defenses against such threats. DHS has sponsored testing to develop new monitors, known as advanced spectroscopic portal (ASP) monitors. In March 2006, GAO recommended that DNDO conduct a cost-benefit analysis to determine whether the new portal monitors were worth the additional cost. In June 2006, DNDO issued its analysis. In October 2006, GAO concluded that DNDO did not provide a sound analytical basis for its decision to purchase and deploy ASP technology and recommended further testing of ASPs. DNDO conducted this ASP testing at the Nevada Test Site (NTS) between February and March 2007. GAO's statement addresses the test methods DNDO used to demonstrate the performance capabilities of the ASPs and whether the NTS test results should be relied upon to make a full-scale production decision.
section_title: What GAO Found
paragraphs: Based on our analysis of DNDO's test plan, the test results, and discussions with experts from four national laboratories, we are concerned that DNDO's tests were not an objective and rigorous assessment of the ASPs' capabilities. Our concerns with the DNDO's test methods include the following: (1) DNDO used biased test methods that enhanced the performance of the ASPs. Specifically, DNDO conducted numerous preliminary runs of almost all of the materials, and combinations of materials, that were used in the formal tests and then allowed ASP contractors to collect test data and adjust their systems to identify these materials. It is highly unlikely that such favorable circumstances would present themselves under real world conditions. (2) DNDO's NTS tests were not designed to test the limitations of the ASPs' detection capabilities--a critical oversight in DNDO's original test plan. DNDO did not use a sufficient amount of the type of materials that would mask or hide dangerous sources and that ASPs would likely encounter at ports of entry. DOE and national laboratory officials raised these concerns to DNDO in November 2006. However, DNDO officials rejected their suggestion of including additional and more challenging masking materials because, according to DNDO, there would not be sufficient time to obtain them based on the deadline imposed by obtaining Secretarial Certification by June 26. 2007. By not collaborating with DOE until late in the test planning process, DNDO missed an important opportunity to procure a broader, more representative set of well-vetted and characterized masking materials. (3) DNDO did not objectively test the performance of handheld detectors because they did not use a critical CBP standard operating procedure that is fundamental to this equipment's performance in the field. Because of concerns raised that DNDO did not sufficiently test the limitations of ASPs, DNDO is attempting to compensate for weaknesses in the original test plan by conducting additional studies--essentially computer simulations. While DNDO, CBP, and DOE have now reached an agreement to wait and see whether the results of these studies will provide useful data regarding the ASPs' capabilities, in our view and those of other experts, computer simulations are not as good as actual testing with nuclear and masking materials.

section_title: Letter
paragraphs: I am pleased to be here today to discuss our assessment of the testing of  advanced spectroscopic portal (ASP) monitors conducted by the Domestic  Nuclear Detection Office (DNDO). The results of these tests, including the  methods by which they were conducted, are critically important because  they will serve as the primary support for a required Department of  Homeland Security (DHS) Secretarial Certification of the performance of  this equipment and, in turn, authorization to spend up to $1.2 billion for  the full-scale production of the next generation of radiation detection  technology to be deployed to U.S. ports of entry.
The radiation portal monitors in use today can detect the presence of  radiation, but they cannot distinguish between types of radiological  material. For example, they cannot tell the difference between harmless  products that emit radiation, such as ceramic tile, and dangerous  materials, such as highly enriched uranium that could be used to construct  a nuclear weapon. DNDO is primarily responsible for preventing  unauthorized nuclear or radiological materials from entering the United  States. U.S. Customs and Border Protection (CBP) is responsible for  screening cargo as it enters the nation at our borders, which includes  operating radiation detection equipment to intercept dangerous nuclear  and radiological materials. The Department of Energy (DOE) is the  primary agency responsible for the international deployment of radiation  detection equipment.
CBP’s standard procedures require incoming cargo to pass through a  radiation portal monitor to screen for the presence of radiation. This  “primary inspection” alerts CBP officers when a radioactive threat might  be present. If there is a potential threat, CBP procedures require a  “secondary inspection.” To confirm the presence of radiation, this  secondary inspection usually includes a second screening by a radiation  portal monitor as well as a screening by CBP officers using handheld  radioactive isotope identification devices (RIIDs). These devices are used  to differentiate between types of radioactive material to determine if the  radiation being detected is dangerous. Both the radiation portal monitors  and handheld devices are limited in their abilities to detect and identify  nuclear material.
DNDO asserts that false alarms, or “nuisance alerts,” result in large  numbers of secondary inspections—especially at high-volume ports of  entry. CBP officials believe that the number of secondary inspections  required by the currently deployed system are resource intensive and  could be reduced, allowing CBP officers to focus on other border  enforcement responsibilities such as illegal immigration and drug  interdiction. Importantly, however, these officials acknowledged that the  current system provides the best possible radiological and nuclear  screening coverage available and that it does not have a significant impact  on commerce.
DHS would like to improve the capabilities of its portal monitors so that  they can perform the dual roles of detecting radiation and identifying  radiological materials. In this regard, DHS has sponsored research,  development, and testing activities designed to create ASP portal monitors  capable of performing both functions. In July 2006, DHS awarded  contracts to three vendors to develop the ASPs’ capabilities. These awards  were based mainly on performance tests conducted at DHS’s Nevada Test  Site in 2005, where ten competing ASP vendors’ monitors were evaluated.  At the same time, three currently deployed portal monitors that use  polyvinyl toluene plastic scintillators, known as PVTs, were also tested.
To ensure that DHS’s substantial investment in radiation detection  technology yields the greatest possible level of detection capability at the  lowest possible cost, in a March 2006 GAO report, we recommended that  once the costs and capabilities of ASPs were well understood, and before  any of the new equipment was purchased for deployment, the Secretary of  DHS work with the Director of DNDO to analyze the costs and benefits of  deploying ASPs. Further, we recommended that this analysis focus on  determining whether any additional detection capability provided by the  ASPs was worth the considerable additional costs. In response to our  recommendation, DNDO issued its cost-benefit analysis in May 2006 and  an updated, revised version in June 2006. According to senior agency  officials, DNDO believes that the basic conclusions of its cost-benefit  analysis showed that the new ASP monitors are a sound investment for the  U.S. government.
In an October 2006 GAO report, we concluded that DNDO’s cost benefit  analysis did not provide a sound basis for DNDO’s decision to purchase  and deploy ASP technology because it relied on assumptions of the  anticipated performance level of ASPs instead of actual test data, and that  it did not justify DHS’s plan to spend $1.2 billion to purchase and deploy  ASPs. We also reported that DNDO did not assess the likelihood that ASPs  would either misidentify or fail to detect nuclear or radiological material.  Rather, it focused its analysis on reducing the time necessary to screen  traffic at border check points and reduce the impact of any delays on  commerce. We recommended that DNDO conduct further testing of ASPs  and the currently deployed PVTs before spending additional funds to  purchase ASPs.
Mr. Chairman, my remarks today focus on the tests conducted by DNDO at  the Nevada Test Site between February and March of this year and the test  methods DNDO used to demonstrate the performance capabilities of the  ASPs. Specifically, I will discuss how the tests were conducted at the  Nevada Test Site, and whether these test results should be relied upon to  support Secretarial Certification or to make a full-scale production  decision. I will also discuss current DNDO testing efforts and how they  may impact future decision making.
In conducting our review, we analyzed DNDO’s test plans and procedures  and interviewed senior DNDO officials responsible for managing the ASP  program, including the development and testing of ASP monitors. We  observed DNDO’s testing conducted at the Nevada Test Site and the New  York Container Terminal. We obtained information on DNDO’s test  methods from National Institute of Standards and Technology (NIST)  officials and discussed the efficacy of DNDO’s test methods with experts  from NIST, DOE, the private sector, and four national laboratories. We  also met with senior CBP and DOE officials as the main end users of portal  monitor equipment. We conducted our review in Washington, D.C. from  March to September 2007 in accordance with generally accepted  government auditing standards.
subsections: section_title: Background
paragraphs: The Department of Homeland Security Appropriations Act for Fiscal Year  2007 states that “none of the funds appropriated…shall be obligated for  full scale procurement of  monitors until the Secretary of Homeland  Security has certified…that a significant increase in operational  effectiveness will be achieved.” DNDO noted that certification would  meet DHS guidelines for the review and approval of complex acquisitions.  Specifically, DNDO stated that the Secretary’s decision would be made in  the context of DHS “Key Decision Point 3,” which details the review and  approval necessary for DHS acquisition programs to move from the  “Capability Development and Demonstration” phase to the “Production  and Deployment Phase.”
To meet the statutory requirement to certify the ASPs will provide a  “significant increase in operational effectiveness,” and requirements  outlined in DHS Management Directive 1400, DNDO, with input from  subject matter experts, developed a series of tests intended to  demonstrate, among other things, ASP performance and deployment  readiness. The tests were conducted at several venues, including the  Nevada Test Site, the New York Container Terminal, the Pacific Northwest  National Laboratory, and five ports of entry. DNDO stated that its request  for full-scale production approval would be based upon completed and  documented results of these tests. To meet the Secretary’s goal of  deploying 225 ASPs by the end of calendar year 2008, Secretarial  Certification was scheduled for June 26, 2007.
To guide the test operations, DNDO defined a set of Critical Operational  Issues that outlined the tests’ technical objectives and provided the  baseline to measure demonstrated effectiveness. The purpose of the  Critical Operational Issue 1 is to “verify operational effectiveness” of ASPs  and determine whether “ASP systems significantly increase operational  effectiveness relative to the current generation detection and identification  system.” DNDO conducted a series of tests at the Nevada Test Site, the  single focus of which, according to DNDO, was to resolve Critical  Operational Issue 1. According to DNDO, these tests began in February  2007 and concluded in March 2007. DNDO’s Nevada Test Site test plan,  dated January 12, 2007, identified three primary test objectives comparing  the operational effectiveness of the ASP systems with existing detection  and identification systems at current high-volume operational thresholds.  Specifically, DNDO sought to determine the ASPs’ probability to (1) detect  and identify nuclear and radiological threats (2) discriminate threat and  non-threat radionuclides in primary , and (3) detect  and identify threat radionuclides in the presence of non-threat  radionuclides.
section_title: How the Tests at the Nevada Test Site Were Conducted
paragraphs: The Nevada Test Site test plan had two key components. First, DNDO  developed guidelines for basic test operations and procedures, including  test goals and expectations, test tasks and requirements, and roles and  responsibilities of personnel involved in the testing, including the ASP  contractors. The second component involved the National Institute of  Standards and Technology developing test protocols that defined, among  other things, how many times a container carrying test materials would  need to be driven through portal monitors in order to obtain statistically  relevant results.
DNDO’s tests at the Nevada Test Site were designed to compare the  current system—using PVTs in primary inspections and a PVT and RIID  combination in secondary inspections—to other configurations including  PVTs in primary and ASPs in secondary, and ASPs in both primary and  secondary inspection positions. DNDO tested three ASPs and four PVTs.  The ASP vendors included Thermo, Raytheon, and Canberra. The PVT  vendors included SAIC, TSA, and Ludlum. According to the test plan, to  the greatest extent possible, PVT, ASP, and RIID handheld devices would  be operated consistent with approved CBP standard operating procedures.
Prior to “formal” collection of the data that would be used to support the  resolution of Critical Operational Issue 1, DNDO conducted a series of  tests it referred to as “dry runs” and “dress rehearsals.” The purpose of the  dry runs was to, among other things, verify ASP systems’ software  performance against representative test materials and allow test teams  and system contractors to identify and implement software and hardware  improvements to ASP systems. The purpose of the dress rehearsals was to  observe the ASPs in operation against representative test scenarios and  allow the test team to, among other things:    develop confidence in the reliability of the ASP system so that  operators and data analysts would know what to expect and what data  to collect during the formal test,    collect sample test data, and    determine what errors were likely to occur in the data collection  process and eliminate opportunities for error.
In addition to improving ASP performance through dry runs and dress  rehearsals conducted prior to formal data collection, ASP contractors  were also significantly involved in the Nevada Test Site test processes.  Specifically, the test plan stated that “ contractor involvement was  an integral part of the NTS test events to ensure the systems performed as  designed for the duration of the test.” Furthermore, ASP contractors were  available on site to repair their system at the request of the test director  and to provide quality control support of the test data through real time  monitoring of available data. DNDO stated that Pacific Northwest National  Laboratory representatives were also on site to provide the same services  for the PVT systems.
DNDO conducted its formal tests in two phases. The first, called Phase 1,  was designed to support resolution of Critical Operational Issue 1 with  high statistical confidence. DNDO told us on multiple occasions and in a  written response that only data collected during Phase 1 would be  included in the final report presented to the Secretary to request ASP  certification. According to DNDO, the second, called Phase 3, provided  data for algorithm development which targeted specific and known areas  in need of work and data to aid in the development of secondary screening  operations and procedures. According to DNDO documentation, Phase 3  testing was not in support of the full-scale production decision. Further,  DNDO stated that Phase 3 testing consisted of relatively small sample  sizes since the data would not support estimating the probability of  detection with a high confidence level.
On May 30, 2007, following the formal tests and the scoring of their results,  DNDO told GAO that it had conducted additional tests that DNDO termed  “Special Testing.” The details of these tests were not outlined in the  Nevada Test Site test plan. On June 20, 2007, DNDO provided GAO with a  test plan document entitled “ASP Special Testing” which described the test  sources used to conduct the tests but did not say when the tests took  place. According to DNDO, special testing was conducted throughout the  formal Phase 1 testing process and included 12 combinations of threat,  masking, and shielding materials that differed from “dry run,” “dress  rehearsal,” and formal tests. DNDO also stated that the tests were “blind,”  meaning that neither DNDO testing officials nor the ASP vendors knew  what sources would be included in the tests. According to DNDO, these  special tests were recommended by subject matter experts outside the  ASP program to address the limitations of the original NTS test plan,  including    available time and funding resources,    special nuclear material sources, and  the number of test configurations that could be incorporated in  the test plan, including source isotope and activity, shielding  materials and thicknesses, masking materials, vehicle types,  and measurement conditions.
Unlike the formal tests, National Institute of Standards and Technology  officials were not involved in determining the number of test runs  necessary to obtain statistically relevant results for the special tests.
section_title: DNDO’s Test Methods Raise Concerns Regarding the Reliability of Test Results
paragraphs: Based on our analysis of DNDO’s test plan, the test results, and  discussions with experts from four national laboratories, we are  concerned that DNDO used biased test methods that enhanced the  performance of the ASPs. In the dry runs and dress rehearsals, DNDO  conducted many preliminary runs of radiological, nuclear, masking, and  shielding materials so that ASP contractors could collect data on the  radiation being emitted, and modify their software accordingly.  Specifically, we are concerned because almost all of the materials, and  most combinations of materials, DNDO used in the formal tests were  identical to those that the ASP contractors had specifically set their ASPs  to identify during the dry runs and dress rehearsals. It is highly unlikely  that such favorable circumstances would present themselves under real  world conditions.
A key component of the NTS tests was to test the ASPs’ ability to detect  and identify dangerous materials, specifically when that material was  masked or “hidden” by benign radioactive materials. Based on our  analysis, the masking materials DNDO used at NTS did not sufficiently test  the performance limits of the ASPs. DOE national laboratory officials  raised similar concerns to DNDO after reviewing a draft of the test plan in  November 2006. These officials stated that the masking materials DNDO  planned to use in its tests did not emit enough radiation to mask the  presence of nuclear materials in a shipping container and noted that many  of the materials that DOE program officials regularly observe passing  through international ports emit significantly higher levels of radiation  than the masking materials DNDO used for its tests.
DNDO officials told us that the masking materials used at the Nevada Test  Site represented the average emissions seen in the stream of commerce at  the New York Container Terminal. However, according to data  accumulated as part of DOE’s program to secure international ports (the  Megaports program), a significant percentage of cargo passing through  one European port potentially on its way to the United States has emission  levels greater than the average radiation level for cargo that typically sets  off radiation detection alarms. Importantly, DNDO officials told us that the  masking materials used at the Nevada Test Site were not intended to  provide insight into the limits of ASP detection capabilities. Yet, DNDO’s  own test plan for “ASP Special Testing” states, “The DNDO ASP NTS Test  Plan was designed to… measure capabilities and limitations in current  ASP systems.”
In addition, the NTS tests did not objectively test the ASPs against the  currently deployed radiation detection system. DNDO’s test plan stated  that, to the greatest extent possible, PVT, ASP, and RIID handheld devices  would be operated consistent with approved CBP standard operating  procedures. However, after analyzing test results and procedures used at  the Nevada Test Site, CBP officials determined that DNDO had, in fact, not  followed a key CBP procedure. In particular, if a threat is identified during  a secondary screening, or if the result of the RIID screening isn’t definitive,  CBP procedures require officers to send the data to CBP’s Laboratories  and Scientific Services for further guidance. DNDO did not include this  critical step in its formal tests. CBP officials also expressed concern with  DNDO’s preliminary test results when we met with them in May 2007.
In regards to the special tests DNDO conducted, based on what DNDO has  told us and our own evaluation of the special test plan, we note that    because DNDO did not consult NIST on the design of the blind tests,  we do not know the statistical significance of the results, and  the tests were not entirely blind because some of the nuclear materials  used in the blind tests were also used to calibrate the ASPs on a daily  basis.
During the course of our work, CBP, DOE, and national laboratory  officials we spoke to voiced concern about their lack of involvement in the  planning and execution of the Nevada Test Site tests. We raised our  concerns about this issue and those of DOE and CBP to DNDO’s attention  on multiple occasions. In response to these concerns, specifically those  posed by DOE, DNDO convened a conference on June 27, 2007, of  technical experts to discuss the Nevada test results and the methods  DNDO used to test the effects of masking materials on what the ASPs are  able to detect. As a result of discussions held during that meeting, subject  matter experts agreed that computer-simulated injection studies could  help determine the ASPs’ ability to detect threats in the presence of highly  radioactive masking material.
According to a Pacific Northwest National Laboratory report submitted to  DNDO in December 2006, injection studies are particularly useful for  measuring the relative performance of algorithms, but their results should  not be construed as a measure of (system) vulnerability. To assess the  limits of portal monitors’ capabilities, the Pacific Northwest National  Laboratory report states that actual testing should be conducted using  threat objects immersed in containers with various masking agents,  shielding, and cargo. DNDO officials stated at the meeting that further  testing could be scheduled, if necessary, to fully satisfy DOE concerns.
On July 20, 2007, DHS Secretary Chertoff notified certain members of the  Congress that he planned to convene an independent expert panel to  review DNDO’s test procedures, test results, associated technology  assessments, and cost-benefit analyses to support the final decision to  deploy ASPs. In making this announcement, Secretary Chertoff noted the  national importance of developing highly effective radiation detection and  identification capabilities as one of the main reasons for seeking an  independent review of DNDO’s actions. On August 30, 2007, the DHS  Undersecretary for Management recommended that the Secretary of  Homeland Security delay Secretarial Certification of ASPs for an  additional two months. According to DHS, the current delay is in order to  provide CBP more time to field ASP systems, a concern CBP had raised  early in our review.
section_title: Conclusions
paragraphs: Effectively detecting and identifying radiological or nuclear threats at U.S.  borders and ports of entry is a vital matter of national security, and  developing new and advanced technology is critical to U.S. efforts to  prevent a potential attack. However, it is also critical to fully understand  the strengths and weaknesses of any next generation radiation detection  technology before it is deployed in the field and to know, to the greatest  extent possible, when or how that equipment may fail.
In our view, the tests conducted by DNDO at the Nevada Test Site between  February and March 2007 used biased test methods and were not an  objective assessment of the ASPs’ performance capabilities. We believe  that DNDO’s test methods—specifically, conducting dry runs and dress  rehearsals with contractors prior to formal testing—enhanced the  performance of the ASPs beyond what they are likely to achieve in actual  use. Furthermore, the tests were not a rigorous evaluation of the ASPs’  capabilities, but rather a developmental demonstration of ASP  performance under controlled conditions which did not test the limitations  of the ASP systems.
As a result of DNDO’s test methods and the limits of the tests—including a  need to meet a secretarial certification deadline and the limited  configurations of special nuclear material sources, masking, and shielding  materials used—we believe that the results of the tests conducted at the  Nevada Test Site do not demonstrate a “significant increase in operational  effectiveness” relative to the current detection system, and cannot be  relied upon to make a full-scale production decision.
section_title: Recommendations
paragraphs: We recommend that the Secretary of Homeland Security take the  following actions:    Delay Secretarial Certification and full-scale production decisions of  the ASPs until all relevant tests and studies have been completed and  limitations to these tests and studies have been identified and  addressed. Furthermore, results of these tests and studies should be  validated and made fully transparent to DOE, CBP, and other relevant  parties.
Once the tests and studies have been completed, evaluated, and  validated, DHS should determine in cooperation with CBP, DOE, and  other stakeholders including independent reviewers, if additional  testing is needed.
If additional testing is needed, the Secretary should appoint an  independent group within DHS, not aligned with the ASP acquisition  process, to conduct objective, comprehensive, and transparent testing  that realistically demonstrates the capabilities and limitations of the  ASP system. This independent group would be separate from the  recently appointed independent review panel.
Finally, the results of the tests and analyses should be reported to the  appropriate congressional committees before large scale purchases of  ASP’s are made.
Mr. Chairman, this concludes our prepared statement. We would be happy  to respond to any questions you or other members of the subcommittee  may have.
section_title: GAO Contact and Staff Acknowledgements
paragraphs: For further information about this testimony, please contact me, Gene  Aloise, at (202) 512-3841 or at aloisee@gao.gov. Contact points for our  Offices of Congressional Relations and Public Affairs may be found on the  last page of this statement. Erika D. Carter, Alison O’Neill, Jim Shafer,  Daren Sweeney, and Eugene Wisnoski made key contributions to this  statement.
section_title: Related GAO Products
paragraphs: Combating Nuclear Smuggling: DHS’s Decision to Procure and Deploy  the Next Generation of Radiation Detection Equipment Is Not Supported  by Its Cost-Benefit Analysis. GAO-07-581T. Washington, D.C.: March.14,  2007.
Nuclear Nonproliferation: Focusing on the highest Priority Radiological  Sources Could Improve DOE’s Efforts to Secure Sources in Foreign  Countries. GAO-07-580T. Washington, D.C.: March. 13, 2007.
Combating Nuclear Smuggling: DNDO Has Not Yet Collected Most of the  National Laboratories’ Test Results on Radiation Portal Monitors in  Support of DNDO’s Testing and Development Program. GAO-07-347R.  Washington, D.C.: March 9, 2007.
Technology Assessment: Securing the Transport of Cargo Containers.  GAO-06-68SU. Washington, D.C.: January 25, 2006.
Combating Nuclear Smuggling: DHS’s Cost-Benefit Analysis to Support  the Purchase of New Radiation Detection Portal Monitors Was Not Based  on Available Performance Data and Did Not Fully Evaluate All the  Monitors’ Costs and Benefits. GAO-07-133R. Washington, D.C.: October  17, 2006.
Combating Nuclear Terrorism: Federal Efforts to Respond to Nuclear  and Radiological Threats and to Protect Emergency Response  Capabilities Could Be Strengthened. GAO-06-1015. Washington, D.C.:  September 21, 2006.
Border Security: Investigators Transported Radioactive Sources Across  Our Nation’s Borders at Two Locations. GAO-06-940T. Washington, D.C.:  July 7, 2006.
Combating Nuclear Smuggling: Challenges Facing U.S. Efforts to Deploy  Radiation Detection Equipment in Other Countries and in the United  States. GAO-06-558T. Washington, D.C.: March 28, 2006.
Combating Nuclear Smuggling: DHS Has Made Progress Deploying  Radiation Detection Equipment at U.S. Ports-of-Entry, but Concerns  Remain. GAO-06-389. Washington, D.C.: March 22, 2006.
Combating Nuclear Smuggling: Corruption, Maintenance, and  Coordination Problems Challenge U.S. Efforts to Provide Radiation  Detection Equipment to Other Countries. GAO-06-311. Washington, D.C.:  March 14, 2006.
Combating Nuclear Smuggling: Efforts to Deploy Radiation Detection  Equipment in the United States and in Other Countries. GAO-05-840T.  Washington, D.C.: June 21, 2005.
Preventing Nuclear Smuggling: DOE Has Made Limited Progress in  Installing Radiation Detection Equipment at Highest Priority Foreign  Seaports. GAO-05-375. Washington, D.C.: March 31, 2005.
Homeland Security: DHS Needs a Strategy to Use DOE’s Laboratories for  Research on Nuclear, Biological, and Chemical Detection and Response  Technologies. GAO-04-653. Washington, D.C.: May 24, 2004.
Homeland Security: Summary of Challenges Faced in Targeting  Oceangoing Cargo Containers for Inspection. GAO-04-557T. Washington,  D.C.: March 31, 2004).
Homeland Security: Preliminary Observations on Efforts to Target  Security Inspections of Cargo Containers. GAO-04-325T. Washington,  D.C.: December 16, 2003.
Homeland Security: Radiation Detection Equipment at U.S. Ports of  Entry. GAO-03-1153TNI. Washington, D.C.: September 30, 2003.
Homeland Security: Limited Progress in Deploying Radiation Detection  Equipment at U.S. Ports of Entry. GAO-03-963. Washington, D.C.:  September 4, 2003).
Container Security: Current Efforts to Detect Nuclear Materials, New  Initiatives, and Challenges. GAO-03-297T. Washington, D.C.: November  18, 2002.
Customs Service: Acquisition and Deployment of Radiation Detection  Equipment. GAO-03-235T. Washington, D.C.: October 17, 2002.
Nuclear Nonproliferation: U.S. Efforts to Combat Nuclear Smuggling.  GAO-02-989T. Washington, D.C.: July 30, 2002.
Nuclear Nonproliferation: U.S. Efforts to Help Other Countries Combat  Nuclear Smuggling Need Strengthened Coordination and Planning.  GAO-02-426. Washington, D.C.: May 16, 2002.
This is a work of the U.S. government and is not subject to copyright protection in the  United States. The published product may be reproduced and distributed in its entirety  without further permission from GAO. However, because this work may contain  copyrighted images or other material, permission from the copyright holder may be  necessary if you wish to reproduce this material separately.