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Request for Comments on the Draft Policy Statement on the Protection of Cesium-137 Chloride Sources and Notice of Public Meeting

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Nuclear Regulatory Commission (NRC).


Request for public comment and notice of public meeting.


The U.S. Nuclear Regulatory Commission (NRC) is considering adopting a statement of policy on the protection of cesium-137 chloride (CsCl) sources. This statement would provide the Commission's policy regarding secure uses of these sources at the present and express the Commission's potential actions in the event that changes in the threat environment necessitate these actions. The purpose of this policy statement is to delineate the Commission's expectations for security and safety of these sources. This draft policy statement is being issued for public comment.

Additionally, the NRC is conducting a public meeting to solicit public input on major issues associated with the draft policy statement regarding the current use of certain forms of Cs-137 sources used by NRC- and Agreement State-licensees. Furthermore, the NRC is requesting names of individuals to participate at the public meeting in separate roundtable panel discussions of the issues identified in Sections III and IV of this notice.


1. Comments on the draft policy statement should be submitted by December 17, 2010. Comments received after this date will be considered if it is practical to do so, but the NRC is able to assure consideration only for comments received on or before this date.

2. Nominations for participation in the roundtable discussions of the public meeting should be submitted by October 8, 2010. For expeditious handling of the nominations, the NRC established a dedicated e-mail address. The nominations should be sent to the following NRC e-mail address:

3. Other participants, who wish to attend the public meeting, could also pre-register at the dedicated e-mail address: The Commission will appreciate pre-registration in order to properly plan for the conference facilities. However, pre-registration is not required and pre-registration is open until the opening day of the public meeting.

Public Meeting Dates: The NRC will take public comments on the issues raised in this document at a public meeting on November 16-17, 2010. The location of the public meeting has not been finalized. However, the location is planned to be near the NRC Headquarters in the Rockville, Maryland, area. The location and the agenda of the public meeting will be posted at the dedicated Web site​materials/​miau/​licensing.html#cc, as soon as this information is finalized. Please refer to the SUPPLEMENTARY INFORMATION section for additional information.


Please include Docket ID NRC-2010-0209 in the subject line of your comments. For instructions on submitting comments and accessing documents related to this action, see Section I, “Submitting Comments and Accessing Information” in the SUPPLEMENTARY INFORMATION section of this document. You may submit comments by any one of the following methods.

Federal Rulemaking Web Site: Go to and search for documents filed under Docket ID NRC-2010-0209. Address questions about NRC dockets to Carol Gallagher, telephone (301) 492-3668; e-mail

Mail comments to: Cindy Bladey, Chief, Rules, Announcements and Directives Branch, Office of Administration, MS: TWB-5 B1M, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001.

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Dr. John P. Jankovich, Office of Federal and State Materials and Environmental Management Programs, telephone (301) 415-7904, e-mail, or Dr. Cynthia G. Jones, Office of Nuclear Security and Incident Response, telephone (301) 415-0298, e-mail

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I. Submitting Comments and Accessing Information

Comments submitted in writing or in electronic form will be posted on the NRC Web site and on the Federal rulemaking Web site Because your comments will not be edited to remove any identifying or contact information, the NRC cautions you against including any information in your submission that you do not want to be publicly disclosed. The NRC requests that any party soliciting or aggregating comments received from other persons for submission to the NRC inform those persons that the NRC will not edit their comments to remove any identifying or contact information, and therefore, they should not include any information in their comments that they do not want publicly disclosed.

You can access publicly available documents related to this document, including the following documents, using the following methods:

NRC's Public Document Room (PDR): The public may examine and have copied for a fee, publicly available documents at the NRC's PDR, Room O-1F21, One White Flint North, 11555 Rockville Pike, Rockville, Maryland.

NRC's Agencywide Documents Access and Management System (ADAMS): Publicly available documents created or received at the NRC are available electronically at the NRC's Electronic Reading Room at​reading-rm/​adams.html. From this page, the public can gain entry into ADAMS, which provides text and image files of NRC's public documents. If you do not have access to ADAMS or if there are problems in accessing the documents located in ADAMS, contact the NRC's PDR reference staff at 1-800-397-4209 or 301-415-4737, or by e-mail to

Federal Rulemaking Web Site: Public comments and supporting materials related to this document can be found at by searching on Docket ID NRC-2010-0209.

II. Background

Certain radioactive sources, including CsCl sources, have been identified by the International Atomic Energy Agency (IAEA) Code of Conduct on the Safety and Security of Radioactive Sources (Code of Conduct) (see​MTCD/​publications/​PDF/​Code-2004_​web.pdf) as sources that may pose a significant risk to individuals, society, and the environment if improperly handled or used in a malicious act. Consequently, the NRC considers it prudent to express its views on the safe and secure use of these sources. CsCl sealed sources are used in many applications, most commonly in irradiators, calibrators, and in devices for biological and medical research. To develop its draft policy statement, the NRC initiated and completed a number of initiatives. A significant element of these initiatives was an Issue Paper which was published in the Federal Register on July 31, 2008 (73 FR 44780), and discussed with stakeholders in a public workshop held on September 29-30, 2008. The NRC also received numerous written comments on the issues. The oral and written comments as well as the transcript of the workshop, along with other relevant information, are accessible at​materials/​miau/​licensing.html#cesium.

The NRC is seeking public input on the major issues associated with its policy involving CsCl to reduce the risk to individuals, society, and the environment. As a first step, the NRC has prepared a draft policy statement, contained in Section III of this document, which describes issues related to safety and security associated with IAEA Category 1 and 2 CsCl sources.[1] The intent of this document is to foster discussion about these issues and to solicit comments on the draft policy statement. The NRC will also use a public Web site,​materials/​miau/​licensing.html#cc to make documents, relevant to the draft policy statement and to the public meeting, accessible. This public Web site will be continually updated as new information becomes available. The exact location and the agenda of the public meeting will also be posted at this site as soon as they become finalized.

III. Draft Policy Statement of the U.S. Nuclear Regulatory Commission on the Protection of Cesium-137 Chloride Sources

The NRC's Role in Ensuring Security for Radioactive Materials

The NRC has the responsibility to license and regulate the civilian use of radioactive materials for commercial, industrial, academic, and medical purposes in a manner that protects public health and safety and promotes the common defense and security. The NRC and its predecessor, the Atomic Energy Commission, have regulated the use of radioactive materials since 1946. The use of radioactive materials is regulated by the NRC and 37 states, known as Agreement States. Agreement States enter into agreements with the NRC under Section 274 of the Atomic Energy Act to license and regulate the use of byproduct material within their borders.

The security and control of radiation sources is an essential part of the NRC's mission. The NRC's efforts in this regard continue to be effective, and there have been no security incidents involving risk-significant radiation sources. After September 11, 2001, the NRC imposed additional security requirements. In addition, the National Nuclear Security Administration (NNSA) has initiated a program to enhance security voluntarily beyond these requirements. One type of radioactive source, cesium-137 chloride (CsCl), has been the focus of increased attention in the U.S. because these sources are extensively used in a wide range of applications in medicine, industry, and research and, while unlikely, due to the physical and chemical characteristics of CsCl, these sources could be used by terrorists in a radiological dispersal device or “dirty bomb.”

The NRC supports and implements the recommendations of the international community regarding the safe use and protection of radioactive materials. In 2004, the International Atomic Energy Agency (IAEA) issued the Code of Conduct for the Safety and Security of Radioactive Sources (the Code), which prescribes a legislative framework, regulatory programs, and import/export provisions to achieve and maintain a high level of safety and security of radioactive sources. The U.S. Government is committed to the implementation of the Code. The Code applies to all radioactive sources that could pose a significant risk to individuals, society, and the environment. The Code establishes five categories of radioactive sources based on their potential to cause severe Start Printed Page 37485deterministic health effects if not managed in a safe and secure manner. Consistent with the Code, the NRC and the Agreement States have established national requirements for the enhanced security for Category 1 and 2 quantities of radioactive material, which, if misused, could pose a significant risk to individuals, society, and the environment.

To maintain security of sources, the Energy Policy Act of 2005 (EPAct) directed the NRC to establish and lead the Radiation Source Protection and Security Task Force (Task Force) to evaluate and provide recommendations to the President and Congress periodically relating to the security of radiation sources in the U.S. from potential terrorist threats, including acts of sabotage, theft, or use of a radiation source in a radiological dispersal device. The EPAct named 12 Federal agencies to the Task Force. In addition to the named agencies, the NRC invited the U.S. Department of Health and Human Services and the White House Office of Science and Technology Policy to participate. To accomplish the mission in view of the regulatory responsibilities divided in the U.S. between the NRC and the Agreement States, the Task Force also invited a representative of the Organization of Agreement States and the Conference of Radiation Control Program Directors to participate as a non-voting member. NRC has coordinated with these partners consistent with its regulatory role, to enhance the security of sources, including CsCl. The Task Force issued its first report in 2006,[2] and is scheduled to issue another report in 2010. The NRC's security requirements for radioactive sources are aligned with the recommendations of the first Task Force report.

Statement of Policy

It is the policy of the Commission that its mission of ensuring adequate protection of public health and safety, common defense and security, and the environment while enabling the use of radioactive materials for beneficial civilian purposes is best accomplished with respect to CsCl by implementing or promoting the following principles:

  • The safety and security of risk significant sources is an essential part of the NRC's mission;
  • Licensees have the primary responsibility to securely manage and to protect sources in their possession from misuse, theft, and radiological sabotage;
  • Adequate protection of public health and safety is maintained if CsCl sources are managed in accordance with the security requirements of the NRC and the Agreement States. These requirements are based on vulnerability assessments of the various sources and follow the principles of the Code of Conduct on the Safety and Security of Radioactive Sources of the International Atomic Energy Agency;
  • While these sources are adequately protected under the current NRC requirements, design improvements could be made that further mitigate or minimize the radiological consequences;
  • The development and use of alternative forms of cesium-137, while not required for adequate protection, is prudent and the NRC intends to monitor these developments closely. In addition, the NRC recognizes that measures to verify effectiveness of the alternatives for solubility and dispersibility must be established to support future decision-making on this matter;
  • CsCl enables three specific classes of applications that benefit society: (a) Blood irradiation, (b) bio-medical and industrial research, and (c) calibration of instrumentation and dosimetry;
  • The NRC recognizes that currently there is no disposal capability for such commercial sources. The NRC considers it imperative to develop a pathway for the long term storage and disposal of these sources whether or not there are alternatives developed; and
  • The NRC monitors the threat environment and maintains awareness of international and domestic security efforts. In the event that changes in the threat environment necessitate regulatory action, the NRC is ready to issue additional security requirements to apply appropriate limitations for the use of CsCl in its current form.


Security and Control of Radioactive Sources

Strong measures and regulatory requirements are currently in place for ensuring security and control of radioactive sources. After the terrorist events of September 11, 2001, the NRC and Agreement States issued security requirements mandating that licensees who possess IAEA Category 1 or 2 quantities of radioactive materials implement increased security and control measures to reduce the risk of malevolent use and intentional unauthorized access to radioactive material. The additional requirements enhanced and supplemented existing regulations in 10 CFR 20.1801, “Security of Stored Material,” and 10 CFR 20.1802, “Control of Material Not in Storage,” which are primarily intended to prevent or mitigate unintended exposure to radiation.

Current security requirements include access controls and background checks for personnel; monitoring, detecting and responding to unauthorized access; delay; advance coordination with local law enforcement; and the tracking of transfers and shipments. The security requirements require licensees to establish and implement trustworthiness and reliability standards to determine who will have unescorted access to the radioactive material. An individual's trustworthiness and reliability is based upon a background investigation. The NRC and Agreement States have jointly developed materials protection and security regulatory requirements that reflect the experience gained through implementation of existing requirements.

In addition, the NRC has implemented new regulatory requirements for import/export licensing and for reporting to the National Source Tracking System (NSTS) which increase accountability of Category 1 and 2 radioactive material transactions and help to ensure that such transactions are only made by authorized entities. The NRC developed and maintains the NSTS, which provides information on sources from the time of manufacture through transportation and use to end-of-life disposition. The NSTS and other systems under development, such as Web-Based-Licensing and License Verification System, are key components of a comprehensive program for the security and control of radioactive materials. When complete, these systems will include information on all NRC, Agreement State, and import/export licensees and high risk radioactive sources.

The measures described above are in place to ensure the security of all Category 1 and 2 radioactive sources, including CsCl sources. These measures have reduced the vulnerability of CsCl sources. In addition, the NRC and Agreement States are supporting the U.S. Department of Energy's (DOE's) NNSA voluntary program to retrofit existing CsCl irradiators with physical security enhancements and to incorporate these improvements into the designs of newly manufactured units. These modifications extend beyond current regulatory requirements. These efforts are often complemented by expert security guidance to licensees Start Printed Page 37486(assist visits) and table-top exercises that allow participants to share best practices.

The NRC and Agreement States also support the Federal Bureau of Investigation's ongoing Weapons of Mass Destruction (WMD) countermeasure effort to reach out to certain communities of licensees (including the CsCl irradiator licensee community). A critical aspect of this WMD countermeasure effort is information sharing through visits to licensees. These visits encourage communication and allow regulators, law enforcement, and licensees to gain an understanding of a licensee's security arrangements and how and when law enforcement would be engaged if there were a threat or an event at a licensee's site.

The NRC supports the security initiatives of international organizations (e.g., IAEA), and other countries, as well as the initiatives of Federal agencies aimed to further increase the protection of high risk sources overseas (e.g., NNSA's Global Threat Reduction Initiative). The NRC participates in the development of such protective measures in various international forums and will consider their applicability for use within the U.S. if the threat environment changes, warranting additional protective measures.

Uses of CsCl Sources

CsCl sources comprise approximately 3% of the IAEA Category 1 and 2 quantity sources in the U.S. Many in the medical and scientific communities indicate that these CsCl sources are important due to their application in blood irradiation, bio-medical and industrial research, and calibration of instrumentation and dosimetry, especially for critical reactor and first responder equipment. CsCl is used for these applications because of the properties of the nuclide cesium-137 (Cs-137), including its desirable single energy spectrum (662 keV), long half-life, low cost, and moderate shielding requirements relative to other nuclides. The CsCl used in these applications is in a compressed powder form that is doubly-encapsulated in two stainless steel capsules to ensure safety and security in normal use. This physical form is used because of its high specific activity (gamma emission per unit volume) and manufacturability. However, the powder is highly soluble and dispersible, which presents security concerns.

Blood irradiation is medically essential to prevent transfusion-associated Graft-Versus-Host disease, and some hospitals use only irradiated blood. CsCl blood irradiators are used in over 90% of all blood irradiation because they are the most reliable and efficient blood irradiation devices currently available.

In biomedical research, CsCl irradiation has been used for over 40 years in fields such as immunology, stem cell research, cancer research, in-vivo immunology, systemic drug research, chromosome aberrations, DNA damage/repair, human genome, and genetic factors. For most research there are no alternatives to Cs-137 irradiation because of the unique properties of Cs-137 radiation, such as high dose rates with uniform fields of linear energy transfer. No alternative technologies that can effectively replace CsCl sources for biomedical research have yet been developed.

The U.S. and international systems of radiation measurements are based on the energy spectrum of Cs-137. All American National Standards Institute standards and their associated test-and-evaluation protocols for radiation detection, instrumentation, and personal dosimetry rely on the use of Cs-137. In addition, all DHS-related standards for calibration of first responder and emergency response equipment, such as personnel self-reading dosimeters, portal monitors, and portable survey instruments, also require the use of Cs-137 for calibration purposes. Cs-137 was selected by the U.S. and the international community as the basis of calibration because of the optimal single energy spectrum of this nuclide and its long half-life. The National Institute of Standards and Technology (NIST) maintains the national measurement standards and calibrates the instruments for secondary laboratories. These instruments are sent to secondary and tertiary laboratories that, in turn, calibrate the instruments for end users. This network of facilities ensures that every radiation detection instrument that is used in the country measures correctly and is traceable to NIST.

Ensuring Secure Disposal for Disused CsCl Sources

The disposal of CsCl radioactive sources, which are currently in use, is a challenge because of the high cost of disposal and the lack of commercial disposal facilities. The vast majority of the CsCl sources in use today are classified as Greater-Than-Class C low-level radioactive waste. Today, used and unwanted CsCl sources are stored safely and securely at the users' sites under the applicable NRC and Agreement State control and security requirements until commercial options become available. To maintain source safety and security, the sites are routinely inspected in accordance with established NRC and Agreement State inspection procedures. The Commission considers it imperative to develop a pathway for the long term storage and disposal of these sources because long term storage at licensee facilities increases the potential for safety and security issues. To resolve these issues, the NRC will continue to participate with its Federal and State partners and representatives of the private sector in initiatives to explore medium- and long term-solutions to address the need for disposal and disposition of CsCl sources.

The Low-Level Radioactive Waste Policy Amendments Act of 1985 assigned responsibility for providing disposal of this type of waste to DOE. However, pending the availability of a disposal capability, DOE is not responsible for accepting disused sources for storage, transportation or other activities related to disposal except under special circumstances.[2] At the present time, no final decision has been made to proceed with approval, funding, and operation of a disposal facility. The Commission will actively support DOE in all phases of the process to establish a storage facility for permanent, safe and secure storage of used and unwanted sources.

The NRC's Perspective on Further Security Enhancements

The NRC believes that the current enhanced regulatory framework for security of radioactive sources has been very effective in enhancing and ensuring the security and control of risk-significant sources used in medical, industrial, and research activities in the U.S. The NRC encourages stakeholders to take an active role in source security and continue their efforts in maintaining the current security environment. As is necessary and practical, and in response to any change in the threat environment, the NRC will work with other Federal agencies to further enhance the secure use of Cs-137 sources. The NRC recognizes that it is prudent to maintain awareness of the status of research to identify alternative forms of CsCl. NRC will remain cognizant of these issues and appropriately consider whether there are safety and security benefits to further risk reduction. As part of NRC's Start Printed Page 37487responsibility to ensure the security of these sources, the NRC, in coordination with its Federal partners, continuously monitors the national threat environment and is prepared to take further regulatory actions should this environment change. Just as it did following the events following September 11, 2001, the NRC is prepared to take immediate action such as issuance of additional security requirements with orders or rulemaking to address such security-related issues, if necessary.

The NRC solicits stakeholder input into major issues associated with the use of CsCl. The Public Workshop on the Security and Continued Use of Cesium-137 Chloride Sources that the NRC held in September 2008, is an example of soliciting such input. The workshop was attended by a large number of stakeholders and, in addition to the oral presentations and comments, the NRC received a significant number of written submissions. The workshop provided valuable information for the formulation of this Policy Statement regarding the use of CsCl sources, security issues, and the diversity of impacts that licensees could experience as a result of potential further regulatory requirements.

While the current security requirements are adequate, the NRC recognizes that if the use of CsCl in its current form is to continue, the NRC encourages the source and device manufacturers to implement design improvements that further mitigate or minimize the radiological consequences of misuse or malevolent acts involving these sources given that such events, while unlikely, cannot be dismissed. Similarly, the NRC supports efforts to develop alternate forms of Cs-137 that would further reduce the risk of malevolent use associated with CsCl. The National Research Council of the National Academies (NA) issued a report [3] that supported these efforts, recommended that the NRC consider the potential economic and social disruption that changes to the CsCl requirements could cause, and supported a research and development program for alternative “matrices” for high-activity Cs-137 sources, which would provide lowered security hazards.

The NRC recognizes that objective measures of “solubility” and “dispersibility” need to be defined before alternate forms of Cs-137 that are less-soluble and less-dispersible than the compressed powder form can be developed. The Commission has already directed the NRC staff to work with Federal agencies to define these measures which must be readily expressible in physical and chemical terms and be demonstrated through well-defined test protocols. In addition, the criteria for the solubility and the dispersibility measures must be established at levels that ensure enhancement of security and reduction of risks of malevolent use. Consequently, the criteria must be developed and accepted by both the cognizant technical communities and the communities responsible for the Nation's security.

While it is outside the scope of NRC's mission to conduct developmental research, the Commission encourages stakeholder research to develop alternative chemical forms for large activity Cs-137 sources. One of the recommendations made by the NA was to investigate the development of alternate chemical forms of Cs-137. The NRC believes that such research should engage cognizant Federal agencies and should consider the practicality of producing an end product that would maintain the security as well as the societal benefits of the current applications of CsCl sources. The NRC considers that pursuit of alternate forms of cesium would provide benefits in the longer term, because the technology of manufacturing other forms of cesium is not yet available. Given the state of the current technology, NRC believes that, for the short term, it is more feasible to focus current security efforts on strengthening existing security of sources as necessary through cooperative efforts and voluntary initiatives of industries that currently manufacture and use irradiators with CsCl sources. While current NRC security requirements ensure the safety and security of these sources, it has been shown through the voluntary NNSA security initiative program that further security enhancements and future design improvements further minimize the potential misuse or malevolent acts involving these sources.


The NRC is continually working with its domestic and international partners to assess, integrate, and improve its security programs, and to make risk-significant radiation sources more secure and less vulnerable to terrorists. The NRC has the responsibility to ensure the safe and secure use and control of radioactive sources, including CsCl sources. The NRC has met this responsibility through imposition of additional security requirements. The NRC has articulated in the past that the use of alternative forms of Cs-137 is desirable. The NRC's actions to date have resulted in strong security measures being established, and the NRC recognizes that near term replacement of devices or CsCl sources in existing blood, research, and calibration irradiators is not practicable or necessary due to implementation of the additional requirements and considering a lack of a disposal capacity. A clear strategy for the end-of-life management of these sources, which is the responsibility of the DOE, is not mature and likely will not be for some time. Many medical, research, and emergency response stakeholders have indicated that short term replacement would be detrimental. Therefore, the NRC continues to believe that the security of these facilities should be maintained and enhanced as practical through the implementation of the regulatory requirements and through voluntary actions such as the physical security enhancements of existing devices and future designs against intrusion. The NRC supports efforts to develop alternate forms of Cs-137 that would reduce the security risks and will monitor these developments closely. The NRC will continue to work with its federal partners to ensure the safety and security of CsCl sources. In the event that changes in the threat environment necessitate regulatory action, the NRC is ready to issue additional security requirements to apply appropriate limitations for the use of CsCl in its current forms or for its replacement with suitable alternatives.

IV. Plans for a Public Meeting

The NRC is holding a facilitated public meeting on November 16-17, 2010, on the draft policy statement and the following issues:

  • The NRC's role in ensuring security for radioactive materials.
  • Statement of Policy.
  • Security and control of radioactive sources.
  • Uses of CsCl sources.
  • Ensuring secure disposal for disused CsCl sources.
  • NRC's perspective on further security enhancements.

During the public meeting, NRC will conduct roundtable panel discussion, with opportunity for audience participation, for each issue contained in Sections III and IV of this document. NRC is seeking the names of individuals interested in participating on these panels. Nominations by interested individuals or organizations should Start Printed Page 37488include the name of the proposed panel member, the issues they are interested in discussing, viewpoint(s) on the issue(s), and affiliation (if any). Roundtable panel participants will be selected with the goal of providing balanced viewpoints on each of the various issues. Please see the DATES section to submit nominations by October 8, 2010.

We encourage previous participants who attended, either as panel members or attendees, the prior public workshop, held on September 29-30, 2008, to also participate in this meeting. Information on the previous public meeting is accessible at​materials/​miau/​licensing.html#cesium.

Based on the comments received in both written and electronic form, and at the public meeting, the Commission will then be in a better position to proceed with the issuance of a final Policy Statement. The final Policy Statement, when issued by the Commission, will be published in the Federal Register.

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Dated at Rockville, Maryland, this 22 day of June 2010.

For the Nuclear Regulatory Commission.

Cynthia Carpenter,

Deputy Director, Office of Federal and State Materials and Environmental Management Programs.

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1.  An IAEA Category 1 cesium-137 source contains a minimum of 3000 Ci (100 TBq) and a Category 2 source contains a minimum of 30 Ci (1 TBq). See​MTCD/​publications/​PDF/​Code-2004_​web.pdf.

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2.  Report to the President and the U.S. Congress Under Public Law 109-58, The Energy Policy Act of 2005, The Radiation Source Protection and Security Task Force Report, NRC Reference No. ML062190349.

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2.  Under specified circumstances, and pursuant to other authority and responsibility under the Atomic Energy Act of 1954, DOE may recover excess or unwanted sealed sources (including CsCl sources) for reuse, storage or disposal that present threats to public health, safety or national security.

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3.  National Research Council of the National Academies, “Radiation Source Use and Replacement,” The National Academies Press, Washington, DC,

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[FR Doc. 2010-15734 Filed 6-28-10; 8:45 am]