ML082480153

UNITED STATES 

NUCLEAR REGULATORY COMMISSION 

OFFICE OF FEDERAL AND STATE MATERIALS 

AND ENVIRONMENTAL MANAGEMENT PROGRAMS 

WASHINGTON, D.C. 20555 

January 12, 2009 

NRC INFORMATION NOTICE 2008-22: MOLYBDENUM-99 BREAKTHROUGH IN 

MOLYBDENUM-99/TECHNETIUM-99M 

GENERATORS 

ADDRESSEES 

All U.S. Nuclear Regulatory Commission (NRC) medical, radiopharmacy, 

molybdenum-99/technetium-99m generator (generator) manufacturer, and master material 

licensees authorized to manufacture or use generators. All Agreement State radiation control 

program directors and State liaison officers. 

PURPOSE 

The NRC is issuing this information notice (IN) to inform addressees about elevated 

molybdenum-99 (Mo-99) breakthrough following the elution of generators. The NRC expects 

that recipients will review the information for applicability to their facilities and consider 

appropriate actions. However, the suggested actions contained in the IN do not constitute NRC 

requirements; therefore, the NRC requires no specific action or written response. 

The NRC is providing this IN to the Agreement States for their information, and for distribution to 

their medical, generator manufacturer, and radiopharmacy licensees, as appropriate. 

DESCRIPTION OF CIRCUMSTANCES 

The NRC has become aware of an unusual number of reports made by medical licensees to a 

generator manufacturer during the period of October 2006 through February 2007, and in 

January 2008, concerning increased concentrations of Mo-99 in generator eluates. A number of 

licensees reported that their generators have failed the Mo-99 breakthrough tests, i.e., the 

measurement exceeded the regulatory limit in Title 10 of the Code of Federal Regulations, 

Part 35, Section 35.204 (10 CFR 35.204), “Permissible molybdenum-99, strontium-82, and 

strontium-85 concentrations,” of 0.15 kilobecquerel of Mo-99 per megabecquerel of Tc-99m 

(0.15 microcurie (μCi) of Mo-99 per millicurie (mCi) of technetium-99m (Tc-99m)). 

Some licensees reported measurements for Mo-99 breakthrough that failed at the first elution, 

while other reported Mo-99 measurements were within regulatory limit at the first elution, but 

failure during subsequent elutions. The majority of the reports involved concentrations of Mo-99 

that did not exceed the regulatory limit at the time of elution but, due to the decay rate of 

Tc-99m, the ratio of Mo-99 to Tc-99m would have exceeded the regulatory limit of 0.15 μCi of 

Mo-99 per mCi of Tc-99m before the 12 hours post elution expiration time stated in the 

generator package insert. 
IN 2008-22 

Page 2 of 2 

DISCUSSION 

10 CFR Part 35, Section 35.204(b) requires licensees to measure the Mo-99 concentration of 

the first eluate after receipt of a generator. However, package inserts that accompanied each 

generator recommended that customers test each elution for Mo-99 breakthrough. These 

recent occurrences of Mo-99 breakthrough, especially those measurements that failed during 

subsequent elutions, emphasize the importance of following the manufacturer’s package insert 

and testing each elution for breakthrough. 

The NRC concluded that the safety significance of administering Mo-99 at the concentrations 

that were reported to the manufacturer between October 2006 and February 2007, and in 

January 2008, was low. However, the administration of higher levels of molybdenum-99 could 

potentially affect health and safety, as well as have an adverse effect on nuclear medicine 

image quality and medical diagnosis. 

The NRC staff will consider initiating a rulemaking to require Mo-99 breakthrough 

measurements of each elution to demonstrate compliance with the limit of 0.15 μCi of Mo-99 per 

mCi of Tc-99m, rather than just the first elution. The NRC will also consider initiating a 

rulemaking to require reporting of noncompliance with the concentration limit. In the interim, the 

NRC strongly encourages all licensees who use a Mo-99/Tc-99m generator to measure each

eluate for Mo-99 breakthrough before Tc-99m is administered to humans, and to report any 

concentrations that exceed the regulatory limits described in 10 CFR 35.204(a) to the generator 

manufacturer. NRC also encourages voluntary reporting by each generator manufacturer to the 

NRC of notifications provided to them by medical licensees who have measured concentrations 

of Mo-99 in the generator eluate that exceed the regulatory limits described in 10 CFR 

35.204(a). 

CONTACT 

This IN requires no specific action or written response. Please direct any questions to the 

technical contact(s) listed below. 

 /Terrence Reis for / 

 Robert J. Lewis, Director 

 Division of Materials Safety and State Agreements 

 Office of Federal and State Materials 

 and Environmental Management Programs 

Contacts: Robert Gattone, RIII Kevin Null, RIII 

 630-829-9823 630-829-9854 

robert.gattone@nrc.gov kevin.null@nrc.gov 

Enclosure: List of Recently Issued NRC Office of Federal and State Material and 

Environmental Management Programs (FSME) Generic Communications 
IN 2008-22 

Page 2 of 2 

DISCUSSION 

10 CFR Part 35, Section 35.204(b) requires licensees to measure the Mo-99 concentration of 

the first eluate after receipt of a generator. However, package inserts that accompanied each 

generator recommended that customers test each elution for Mo-99 breakthrough. These 

recent occurrences of Mo-99 breakthrough, especially those measurements that failed during 

subsequent elutions, emphasize the importance of following the manufacturer’s package insert 

and testing each elution for breakthrough. 

The NRC concluded that the safety significance of administering Mo-99 at the concentrations 

that were reported to the manufacturer between October 2006 and February 2007, and in 

January 2008, was low. However, the administration of higher levels of molybdenum-99 could 

potentially affect health and safety, as well as have an adverse effect on nuclear medicine 

image quality and medical diagnosis. 

The NRC staff will consider initiating a rulemaking to require Mo-99 breakthrough 

measurements of each elution to demonstrate compliance with the limit of 0.15 μCi of Mo-99 per 

mCi of Tc-99m, rather than just the first elution. The NRC will also consider initiating a 

rulemaking to require reporting of noncompliance with the concentration limit. In the interim, the 

NRC strongly encourages all licensees who use a Mo-99/Tc-99m generator to measure each

eluate for Mo-99 breakthrough before Tc-99m is administered to humans, and to report any 

concentrations that exceed the regulatory limits described in 10 CFR 35.204(a) to the generator 

manufacturer. NRC also encourages voluntary reporting by each generator manufacturer to the 

NRC of notifications provided to them by medical licensees who have measured concentrations 

of Mo-99 in the generator eluate that exceed the regulatory limits described in 10 CFR 

35.204(a). 

CONTACT 

This IN requires no specific action or written response. Please direct any questions to the 

technical contact(s) listed below. 

 R/A 

 Robert J. Lewis, Director 

 Division of Materials Safety and State Agreements 

 Office of Federal and State Materials 

 and Environmental Management Programs 

Contacts: Robert Gattone, RIII Kevin Null, RIII 

 630-829-9823 630-829-9854 

robert.gattone@nrc.gov kevin.null@nrc.gov 

Enclosure: List of Recently Issued NRC Office of Federal and State Material and 

Environmental Management Programs Generic Communications 

ML082480153

OFC FSME:DMSSA FSME:DMSSA FSME:DMSSA Tech Ed (QTE) RIII:DNMS 

NAME AMcIntosh CFlannery CEinberg HSpencer PPelke 

DATE 9/04/08 09/22/08 11/12/08 10/31/08 09/02/08 

OFC RIII:DNMS OGC - NLO FSME:DMSSA 

NAME SReynolds BJones RLewis 

DATE 09/02/08 11/19/08 01 /12/09 
IN 2008-22 

Enclosure 

Page 1 of 1 

List of Recently Issued NRC Office of Federal and State Material and Environmental Management Programs 

Generic Communications 

Date GC No. Subject Addressees 

05/13/08 RIS-2008-10 Notice Regarding Forthcoming 

Federal Firearms Background 

Checks 

All U.S. Nuclear Regulatory Commission 

licensees, certificate holders, and 

applicants for a license or certificate of 

compliance who use armed security 

personnel as part of their physical 

protection system and security 

organization. All radiation control program 

directors and State liaison officers 

05/12/08 RIS-2008-11 Precautions to Protect Children Who 

May Come in Contact with Patients 

Released After Therapeutic 

Administration of Iodine-131 

All U.S. Nuclear Regulatory Commission 

medical-use licensees, master material 

licensees, Agreement State radiation 

control program directors, and State liaison 

officers 

05/09/08 RIS-2008-12 Considerations for Extended Interim 

Storage of Low-level Radioactive 

Waste by Fuel Cycle and Materials 

Licensees 

All holders of U.S. Nuclear Regulatory 

Commission fuel cycle and materials 

licenses. All radiation control program 

directors and State liaison officers 

06/16/08 RIS-2008-13 Status And Plans for Implementation 

of NRC Regulatory Authority for 

Certain Naturally Occurring and 

Accelerator-Produced Radioactive 

Material 

All U.S. Nuclear Regulatory Commission 

materials licensees, radiation control 

program directors, State liaison officers, 

and the NRC’s Advisory Committee on the 

Medical Uses of Isotopes 

07/18/08 RIS-2008-17 Voluntary Security Enhancements 

for Self-Contained Irradiators 

Containing Cesium Chloride 

Sources 

All U.S. Nuclear Regulatory Commission 

materials licensees authorized to possess 

self-contained irradiators containing cesium 

chloride (CsCl) ; all Agreement State 

radiation control program directors and 

State liaison officers; all members of the 

Advisory Committee on the Medical Uses 

of Isotopes 

05/16/08 IN-2008-03 Precautions to Take Before Sharing 

Sensitive Security-Related 

Information 

All U.S. Nuclear Regulatory Commission 

licensees who are implementing U.S. 

Nuclear Regulatory Commission’s Order 

Imposing Increased Controls (IC Order) or 

implementing IC requirements by license 

condition; all Agreement State radiation 

control program directors and State liaison 

officers 

Note: This list contains the six most recently issued generic communications, issued by the NRC Office of Federal 

and State Materials and Environmental Management Programs (FSME). A full listing of all generic communications 

are available on the NRC public Web site at the following address: http://www.nrc.gov/reading-rm/doccollections/gen-comm/index.html