Page 1 of 26 

Advisory Committee on the Medical Use of Isotopes (ACMUI) 

Germanium-68 (Ge-68) Decommissioning Funding Plan (DFP) 

Final Report 

August 12, 2015 

Subcommittee Members: F. Costello; S. Langhorst; S. Mattmuller (Chair); C. Palestro; and P. 

Zanzonico 

Challenge: The restrictive aspects of a decommissioning funding plan (DFP) for Ge-68 that 

arise from the current Part 30 regulations are preventing and/or deterring the use of 

promising Gallium-68 (Ga-68) diagnostic imaging agents for patients. 

Charge: 

1) Estimate the number of potential Ge/Ga-68 generator licenses affected, and 

2) Recommend to the Committee on which route of action it believes NRC should pursue to 

address the decommissioning funding plan issue. 

Background: Neuroendocrine tumor imaging (NET), why Ge-68 is so important to NET patients. 

Neuroendocrine tumors (NET) present a difficult diagnostic challenge. For NET patients, it 

currently takes on average seven years for a proper diagnosis to be made and appropriate 

therapy prescribed. Fortunately, diagnostic imaging of patients with NET is on the verge of 

making dramatic advancements in this area. 

There is a new class of radiopharmaceuticals using a positron emitter radionuclide, Ga-68, that 

are nearing FDA approval. The Ga-68 is attached to one of several somatostatin receptor 

(SSR) binding peptides via the DOTA chelator, that is, DOTA-TATE, DOTA-TOC, and DOTANOC, (DOTAs). The advantages of these new radiopharmaceticals can be best demonstrated 

by a comparison of their images in the same patient (Figure 1). 

In the left two panels are images produced with In-111 DTPA-Octreotide (In-111 Octreotide), the 

current SSR radiopharmaceutical in routine clinical use today. In the right panel is a positron 

emission tomography (PET) image produced with the Ga-68 DOTA-TOC. 

The advantages of the Ga-68 imaging are readily apparent. This PET image leads to greater 

sensitivity and specificity resulting in superior accuracy for this diagnostic imaging procedure. 

There is also greater patient convenience as the Ga-68 DOTA image only takes one day versus 

two days needed for the In-111 Octreotide image. For a patient who has to travel several hours 

for this procedure, this shorter time can save them from a potential overnight stay. Finally, the 

radiation dosimetry burden to the patient is less for the Ga-68 DOTAs image versus the In-111 

Octreotide image, with a nearly a five-fold reduction in the effective dose to the patient (2.3 and 

10.8 mSv, respectively, for Ga-68 and In-111). 
Page 2 of 26 

Importantly, the source of Ga-68 is a generator, rather than a cyclotron. As a result, the 

availability and clinical utility is potentially far greater than those of current-generation PET 

isotopes. Ga-68 is continuously produced in this generator by the decay of its parent 

radionuclide Ge-68. Additional information regarding the Ga-68 generator is presented below in 

the section on the design and operation of a Ge-68 generator. 

 

 

Figure 1 

Background: Regulatory DFP trigger for a Ga-68 generator 

The regulations requiring licensees to submit decommissioning funding plans (10 CFR 30.35) 

became effective on July 27, 1988. The trigger level (i.e., a quantity of a given radionuclide) for 

a DFP comes from a calculation using a labeling quantity for a radionuclide listed in the 

appendix entitled, “Quantities of Licensed Material Requiring Labeling.” The calculation involves 

multiplying the labeling quantity by 105 to derive the trigger level. At this time, however, Ge-68 

is not listed on the table, so a very small default quantity of only 10 mCi (0.1 uCi x 105

) is 

derived as the trigger level. Initially, this was not problematic as Ge-68 was not regulated by the 

NRC. 

Prior to 2007, a site with a Ga-68 generator did not need a DFP since the NRC did not yet have 

the authority to regulate it. The NRC’s regulatory authority for Ge-68 came into effect in 2007, 

with the adoption of an expanded definition of by-product material to include acceleratorproduced radionuclides 
Page 3 of 26 

Despite now having authority over these additional radionuclides, the NRC did not amend 

Appendix B to Part 30 at that time. Appendix B continues to have no listing for Ge-68 and the 

same calculated 10 mCi trigger level exists as first established in 1988. This 27-year-old 10-

mCi trigger level persists and a DFP is thus required for the use of a new Ga-68 generator. 

Impact of DFPs on medical licensees 

For a medical licensee, the foregoing regulatory considerations creates a cascade effect leading 

to an extensive and expensive DFP, as a DFP must cover not only the one area where a Ga-68 

generator is used but also all areas where radioactive materials are used under the same 

license. 

Consider the example of a mid-size medical center and the various areas of use its license may 

include: 

- Nuclear Medicine facility, including SPECT imaging rooms and a radiopharmacy for 

the preparation of radiopharmaceuticals; 

- PET imaging rooms; 

- Multiple satellite cardiac imaging suites throughout the surrounding area; 

- Radiation Oncology, including gamma knife and brachytherapy; 

- Affiliated hospital with its own Nuclear Medicine facility, including SPECT imaging 

rooms and a radiopharmacy 

Without a Ga-68 generator, a DFP is very likely not needed for such a medical center. 

However, if such a center were to add a Ga-68 generator, it would have to develop a DFP and 

not just for the one room that would house the generator, but for all of the foregoing areas. A 

DFP thus becomes very extensive and very expensive, perhaps prohibitively so for a licensee 

with numerous areas of use. 

This scenario did, in fact occur last year at a large university-based medical center on the East 

Coast. This center attempted to acquire a Ga-68 generator for clinical investigation, but their 

DFP was very extensive because of all of their areas of use and would have been very 

expensive to fund. Hence they did not acquire the necessary financial assurances for a DFP 

and were restricted to acquiring a used Ga-68 generator of less than 10 mCi in activity. The 

center was not able to conduct their research in patients as initially planned and was only able 

to perform research in small animals. It was their radiation safety officer who was the first to 

succinctly and accurately describe a DFP as “extensive and expensive.” It was extensive as 

over 170 man-hours were required from the radiation safety office alone to prepare the DFP. 

This total does not include the large number of man-hours needed from numerous other 

departments for the preparation of the DFP. It was expensive, as the financial assurances in 

the form of a bond would need to be purchased to cover the decommissioning expenses of over 

one million dollars. This expense continues on an annual basis. 

 

The restrictive aspects arising from the current Part 30 regulations are preventing and/or 

deterring the use of promising Gallium-68 (Ga-68) diagnostic imaging agents for patients due to 

the decommissioning funding plan burden for its parent Ge-68. 
Page 4 of 26 

Charge 1: Estimate the number of potential Ge-68/Ga-68 generator licenses affected. 

At first glance, this appears to be a reasonable request, one that could be addressed by sending 

survey-type questionnaires to a sample of licensees so as to extrapolate to a number of 

licensees nationally. However, given how extensive of an effort it is to prepare a DFP, this 

actually is a very complex and time consuming effort for each licensee (as illustrated for the 

licensee discussed above). A DFP is unique to each licensee, and once prepared it is only 

applicable to that licensee and cannot be used by another licensee. Neither the licensees nor 

the subcommittee have the time or other resources to conduct and answer such a survey. Most 

likely the NRC does not either and it is therefore impractical to collect firm numbers on licensees 

affected. 

There are other ways we can estimate the effect of the extensive and expensive components of 

a DFP on the availability of the Ga-68 DOTAs. As we do know, it has already deterred the use 

of Ga-68 DOTAs in patients. For example in the case of the DFP on the university-based East 

Coast medical center discussed above, the impact was to effectively prevent the clinical use of 

Ga-68 radiopharmaceuticals. It has also been known to deter the use of Ga-68 DOTA 

radiopharmaceuticals elsewhere.1

 

 

1

 Personal communication with Josh Mailman, President of the NorCal CarciNet Community, a patient advocacy 

group for neuroendocrine tumor patients. https://norcalcarcinet.org/

“Currently in the US there are only three active sites that are reliably imaging patients 

with the Ga-68 DOTA radiopharmaceuticals. These sites include the National Institute 

of Health, Stanford University and the University of California in San Francisco. Three 

sites total within all of the United States. The current wait for a NET patient is over 2+ 

months at the NIH.” 
Page 5 of 26 

Although the subcommittee cannot project the future impact of the DFP requirement on future of 

Ga-68 DOTAs, the statement was submitted by one of the largest commercial radiopharmacy 

companies in the US, Triad Isotopes2

: 

This statement from Triad has added weight in that at four of their sites they do have a DFP in 

place; hence, they are well aware of how extensive and expensive a DFP can be. Patient 

access is already clearly hindered in the U.S. by the small number of licensees who can provide 

Ga-68 DOTAs. Regulatory relief from the DFP is urgently needed to increase patient access to 

these invaluable radiopharmaceuticals. 

 

2

 Personal communication with Fred Gattas, Director, Quality Control and Safety, Triad Isotopes 

Triad Isotopes, a leading commercial provider of radiopharmaceuticals, operates over 

50 nuclear pharmacies in markets throughout the United States. 

Under the current regulations, the complexity and cost of a DFP would potentially 

hinder our ability to provide Ga-68 radiopharmaceuticals from our nuclear pharmacies 

to all areas of the country. The net effect is that the DFP regulations would likely limit 

the availability of this radiopharmaceutical, for several reasons: 

First, economic pressures will impede adoption. The difficulty to compensate for 

the fixed costs of the DFP will limit the number of radiopharmacies that will be able 

to offer Ga-68 radiopharmaceuticals. 

Second, the short half-life of Ga-68 will make this a challenging radiopharmaceutical 

to distribute. To ensure good usage across the country, the product will need to be 

available through as many nuclear pharmacies as possible; however, it would be 

difficult to dispense and deliver through a long spoke-hub model due to that short 

half-life of 68 minutes.

Taking both cost and distribution challenges into account, it is unlikely that nuclear 

pharmacy networks such as ours would provide Ga-68 related radiopharmaceuticals 

to all areas of the country if a DFP was initiated; thus, every patient in need would 

not have equal access to these radiopharmaceuticals, most especially those in 

smaller and/or more rural markets.
Page 6 of 26 

Charge 2: Recommend to the Committee on which route of action it believes NRC should 

pursue to address the decommissioning funding plan issue. 

The subcommittee recommends the following language be added as a footnote to Appendix B 

Part 30 -- Quantities1

 of Licensed Material Requiring Labeling as the most expeditious, cost 

effective, and practical route to addressing the DFP issues. 

(Note: Given the title of Appendix B -- Quantities of Licensed Material Requiring Labeling the 2 

uCi will be considered a new “labeling” quantity for Ge-68) 

This new calculated limit of 200 mCi as a trigger amount for a DFP would only be allowed for 

Ge-68 in a Ga-68 generator for medical use. This limit would allow for the use of a Ga-68 

generator for clinical use and at the end of its one-year shelf-life allow it to be used for research 

such as in small animals. Regardless of its use, when the licensee is finished using the Ga-68 

generator, it would be returned to the manufacturer for final disposal. The new limit would also 

allow a licensee to possess more than one generator to maintain a higher useful amount of Ga68 available at all times for the preparation of Ga-68 DOTAs. 

In order to maintain a higher useful amount of Ga-68, a licensee may purchase several Ga-68 

generators with staggered calibration dates. This would be done much in the same way a 

radiopharmacy currently maintains a higher useful amount of Tc-99m with the purchase of Tc99m generators with staggered calibrations dates, the difference being a staggered time interval 

of only 2-3 days for Tc-99m generators versus ~ 6 months for Ga-68 generators. For example, 

a licensee who also performs research may have the following Ga-68 generators on-hand if 

they purchase a new one every six months (Table 1). 

Table 1: Activity of Ga-68 Generators -- Use is for both clinical and research 

Age Decay Factor mCi of Ge-68 

new 1 50.0 

6 mos 0.63 31.5 

12 mos 0.39 19.5 

+new 1 50.0 

18 mos1 0.24 12.2 

24 mos1 0.15 7.6 

Total 170.8 

 1 These generators would only be used for research

3

This does not include Ge-68 in a Ge-68/Ga-68 medical use generators (limit less 

than 105 x 2 uCi) that are returned to the manufacturer at end of use. 
Page 7 of 26 

The three major factors that we believe serve as the basis for this recommendation for this new 

labeling quantity of Ge-68 are as follow. 

1. Under normal operation, the Ge-68 is stably bound within the generator. The design and 

operation of the Ga-68 generator thus ensures that it will have nearly the same safety 

profile as a sealed source device. 

2. At the end of its use, the generator is returned to the manufacturer for final disposal. This 

disposal step in essence eliminates any concern at a licensee regarding Ge-68 associated 

DFP. 

3. If Appendix B were to be revised, it would be appropriate to add Ge-68 with a labeling 

quantity of 10 uCi. However, the subcommittee currently recommends a more conservative 

number of only 2 uCi for the purposes of a Direct Final Rulemaking. 

Design and Operation of the Ga-68 Generator 

The Ga-68 generator is a device that serves as source of this important radionuclide. Ga-68 

decays by positron emission and thus can be used for called positron emission tomography 

(PET) diagnostic medical imaging procedures. The vast majority of radionuclides used for PET 

imaging require a large and expensive particle accelerator such as a cyclotron. One of the best 

advantages of the Ga-68 generator, therefore, is that it provides a PET radionuclide without a 

cyclotron. 

Currently, Ga-68 is used mainly in the preparation of the Ga-68 DOTAs, which have already 

emerged as the radiopharmaceutical of choice for NETs. The advantages of the Ga-68 DOTAs 

will greatly enhance the diagnosis and treatment of NET patients across the country. 

In this generator Ge-68 is the parent radionuclide and it has a half-life of 271 days. It decays by 

electron capture to its daughter radionuclide, Ga-68, which has a half-life of 68 minutes. The 

generator is a closed system device consisting of a column containing a resin on which the 

parent radionuclide Ge-is fixed. Ga-68 is continuously produced by the decay of its radioactive 

parent Ge-68. The Ga-68 is removed from the generator by eluting it off the column with a 

sterile hydrochloric acid solution. The Ga-68 is soluble in the hydrochloric solution and readily 

elutes off the column. The Ge-68 is insoluble in the hydrochloric solution and remains fixed on 

the column and continues to decay to provide additional Ga-68 in future elutions. The Ga-68 

generator is a device whose sole purpose is to provide Ga-68. Chemically, the Ga-68 is in the 

form of gallium chloride (GaCl3) and is used in the preparation of the Ga-68 DOTAs. The Ga-68 

as eluted cannot be used directly in patients. 
Page 8 of 26 

The physical characteristics of both the parent and daughter radionuclides are summarized in 

Table 2. 

Table 2: Physical characteristics of Ge-68 and Ga-68

 Ge-68 Ga-68 

Half-live 270.95 days 67.71 minutes 

Type of decay Electron capture Positron emission 

X-rays 

9.225 keV (13.1 %) 

9.252 keV (25.7 %) 

10.26 keV (1.64 %) 

10.264 keV (3.2 %) 

10.366 keV (0.03 %) 

8.616 keV (1.37 %) 

8.639 keV (2.69 %) 

9.57 keV (0.55 %) 

gammas 

511 keV (178.28 %), 

578.55 keV (0.03 %) 

805.83 keV (0.09 %), 

1077.34 keV (3.22 %) 

1260.97 keV (0.09 %) 

1883.16 keV (0.14 %) 

beta+ 

Energy max. Energy 

352.60 keV 821.71 keV (1.20 %) 

836.00 keV 1899.01 keV (87.94 %) 

Data derived from nudat (www.nndc.bnl.gov) 

The Ge-68 is easy to shield as during its decay it has no particulate or penetrating (i.e. highenergy) photon emissions, but only has low energy X-ray emissions. Shielding is, of course, 

needed for the Ga-68 as it decays by positron emission, with the subsequent production of 511-

keV annihilation gamma rays. 

A schematic of a generic Ga-68 generator is provided in Figure 2. Note that it has one inlet for 

the hydrochloric acid eluent and one outlet for the collection of the Ga-68. 
Page 9 of 26 

Figure 2. 

It is a simple device that has no moving parts. The Ge-68, as a solid, is fixed onto the resin 

within the column by the chemical process of adsorption and thereby remains entirely within the 

generator and its heavy lead shielding. 

The first Ga-68 generator manufactured in accordance with a Drug Master File for use in the 

United States is the Galliapharm by Eckert and Ziegler. It is a relatively small and compact 

device measuring 9 inches x 5.2 inches x 5.2 inches (H x W x D). It weighs approximately 31 

pounds. See Figures 3-5. Again note the simplicity of the device, with only one inlet port and 

one outlet port and no moving parts. 

 
Page 10 of 26 

Figure 3. 
Page 11 of 26 

Figure 4. 

Once the generator is placed in position in the nuclear medicine facility, it is not moved but 

simply remains in place for its entire lifetime. Due to its compact size, the generator and the 

associated chemistry module are typically placed together in the same hot cell. This close 

placement also has a chemistry advantage; by keeping the outlet line connecting the generator 

to the chemistry module as short as possible, the yields of the syntheses of the drug product are 

maximized. 
Page 12 of 26 

The inlet line has a customized thread on its fitting to avoid a miss-connection; that is, it will only 

connect to the inlet port. Likewise, the outlet line will only connect to the outlet port. Because 

the generator remains in place once positioned, there are no mechanical stresses that could 

potentially lead to a leakage of activity. 

Figure 5. 
Page 13 of 26 

During the normal elution process of the Ga-68 generator, a very small amount of Ge-68 

measured in nanocuries does get displaced from the column; this is known as parent 

breakthrough and is a phenomenon associated with all radionuclide generators. Ge-68 

breakthrough is expressed as a percentage of total Ga-68 activity eluted from the column, 

corrected for decay. The specification for Ge-68 breakthrough is not more than 0.001% of the 

eluted Ga-68 activity. The breakthrough for this generator typically begins as low as 0.0001% 

when the generator is new and may rise slightly with the number of elutions. To minimize the 

breakthrough, it is recommended that the generator should be eluted at least once per working 

day. When used accordingly, the breakthrough should remain below the 0.001% limit for 12 

months. The volume of the elution is ~ 5 mL, and the recommended rate of elution no greater 

than 2 mL/min. The breakthrough amounts are so low that unlike other medical use generators 

(i.e., Tc-99m or Rb-82 generators) the breakthrough cannot be measured with a dose calibrator. 

More sensitive equipment must be used to measure the amount of Ge-68 in a Ga-68 elution. 

If an elution is not used for a Ga-68 radiopharmaceutical preparation, (i.e., was performed for 

maintenance of the column to minimize breakthrough), these unused elutions may be collected 

into a small waste vial and then stored for a day for decay (21 half-lives). For final disposal, 

since it is an acid solution it may need to be placed into a chemical waste container or, 

depending on a site’s location one may be able to dispose of it in the sanitary sewer via a sink. 

For example, for this latter scenario, with a breakthrough of 0.0001% when the generator is new 

and at its highest activity of 50 mCi the Ge-68 activity would only be a small amount of 0.03 μCi 

(or 30 nCi) of Ge-68 (= 50 mCi x 60% elution yield x 0.0001% breakthrough) per elution. The 

limits for disposal in sewerage are specified in § 20.2003 Disposal by release into sanitary 

sewerage and its associated Appendix B, see table 3. 

Table 3. 

This limit is calculated by dividing the amount of 0.03 μCi of Ge-68 by the concentration limit of 

0.0006 μCi/mL (from the appendix), which equals 50 mL of required sewerage volume to meet 

the monthly average concentration. 
Page 14 of 26 

In other words, less than two ounces (i.e., 1⁄4 cup) of sewerage are needed for dilution for each 

elution disposed of to maintain the concentration of Ge-68 below the sewerage limits of § 

20.2003. These conditions can easily be achieved if the elution is first held for one day for the 

decay of the Ga-68 and then disposed of in the sewerage. 

Despite these nanocurie amounts of Ge-68 that come off the column with each elution, the Ga68 generator could be considered for all practical purposes a sealed source device. As such it 

would be exempt from any DFP requirement pursuant to § 30.35 Financial assurance and 

recordkeeping for decommissioning. 

While the small footprint and the simplistic ease of use of a Ga-68 generator are significant 

advantages over a cyclotron in producing a PET radionuclide it does have one limitation: the 

relatively small quantity of Ga-68 that it is able to produce compared, for example, to the output 

of a cyclotron. The relatively small output of a Ga-68 generator (i.e., mCi vs. Ci) and Ga-68’s 

relatively short half-life will result in a radiopharmacy having a much smaller distribution area for 

Ga-68 radiopharmaceuticals than that for F-18 and/or Tc-99 radiopharmaceuticals. Therefore, 

there will be a need for a large number of radiopharmacies across the country to have the 

capability to prepare Ga-68 DOTA to provide equitable access for all patients nationwide. 

Disposal of the Ga-68 Generator 

Disposal by the licensee is very simple; at the end of its useful lifetime the generator is returned 

to the manufacturer for final disposal. Final disposal by the manufacturer in essence eliminates 

any concern regarding Ge-68 in regards to a DFP for the licensee. See, for example, the letter 

below from Eckert & Ziegler (Figure 6). 
Page 15 of 26 

Figure 6. 
Page 16 of 26 

Propriety of current default labeling quantity of 0.1 uCi for Ge-68 

The subcommittee reviewed the radionuclides currently listed in Appendix B. Table 4 below 

contains all of the radionuclides from Appendix B that have a labeling quantity of 10 uCi and a 

half-life greater than 120 days in order to assess the impact of changing the labeling quantity 

for Ge-68 from 0.1 uCi to 2 uCi. 

What is quite surprising from this review are the number of radionuclides with substantially 

longer half-lives than Ge-68 but with a labeling quantity that is 100x greater than the current 

value for Ge-68 of 0.1 uCi. 

Licensed 

Material 

Quantity 

(μCi) 

Half-Life* Decay 

Mode* 

Sb-125 10 2.76 y βBa-133 10 10.6 y EC 

Ca-45 10 162.6 d βCs-135 10 2.3e6 y βCs-137 10 30.1 y βCl-36 10 3.01e5 y EC+, β+, βEu-155 10 4.75 y βGd-153 10 240 d EC 

Fe-55 10 2.74 y EC 

Mn-54 10 312 d EC, βNi-63 10 101 y βNb-93m 10 16.1 y IT 

Pr-147 10 2.62 y βRb-87 10 4.81e10 y βSm-151 10 90 y βTl-204 10 3.78 y EC, βTm-170 10 129 d EC, βTm-171 10 1.92 y βZn-65 10 244 d EC+, β+ 
Page 17 of 26 

Licensed 

Material 

Quantity 

(μCi) 

Half-Life* Decay 

Mode* 

Zr-93 10 1.61e6 y βGe-68 0.1 217 d EC 

 * http://www.nndc.bnl.gov/mird/

Table 4. 

In the past 27 years, Appendix B has not been revised, and Ge-68 may not have been included 

initially as the NRC did not have regulatory authority over it. Subsequently, in 1992-1994, 

Appendix C but not Appendix B added a labeling quantity for Ge-68. This occurred even though 

the NRC still did not have authority over Ge-68. Unfortunately, when the NRC did gain authority 

over Ge-68 in 2007, a revision of Appendix B was deemed “beyond the scope” of that action 

and did not occur. 

If a revision of Appendix B had ever taken place, it appears that Ge-68 would easily have been 

included among the group of radionuclides with a labeling quantity of 10 uCi. Our proposed 

labeling quantity of 2 uCi is thus conservative as it would still offer a five-fold “safety factor” 

versus a labeling quantity of 10 uCi, (i.e., a 200-mCi trigger limit versus a 1,000-mCi limit for a 

DFP). This new quantity would thus not adversely impact the safety or the ability of a licensee 

to decommission a Ge-68/Ga-68 generator. 

Relationship of the proposed rulemaking to NRC’s Strategic Plan 

The proposed rule supports NRC’s 2013-2018 Strategic Plan by supporting its Regulatory 

Effectiveness Strategy 1: Proactively identify, assess, understand, and resolve safety and 

security issues. The proposed rule supports these activities in the following ways: 

• Resolve generic safety and security issues and ensure implementation of enhancements 

within timeframes commensurate with their risk significance. 

The use of a more up- to-date value for labeling unsealed Ge-68 for limited use in 

Ge/Ga-68 generators used for medical use and returned to the manufacturer poses 

no decommissioning safety risk. The lack of decommissioning risk warrants the 

special circumstance of doing a direct final rule in order to minimize the significant 

risk of preventing patient access to the medical benefits received from Ga-68 

radiopharmaceuticals. 

• Emphasize the importance of developing and maintaining an effective nuclear-safety 

culture for all NRC-regulated activities and for activities regulated by the Agreement 

States. 
Page 18 of 26 

The 27-year-old labeling value used to require a DFP which for Ge-68 has resulted in 

the unintended regulatory impediment for medical use of the Ge/Ga-68 generator. 

Immediate correction of this unintended regulatory impediment will demonstrate 

NRC’s support of medical safety culture. 

The subcommittee’s recommendation to the Committee is that the following language be added 

as a footnote to Appendix B Part 30 -- Quantities1

 of Licensed Material Requiring Labeling. 

The subcommittee believes this recommendation has strong basis to support this regulatory 

change through the Direct Final Rulemaking process. This process should be initiated as soon 

as possible by the NRC to eliminate the deleterious effect the DFP process is having on patient 

access to Ga-68 radiopharmaceuticals. 

The ACMUI unanimously endorsed this report and addendum on August 12, 2015. 

3

This does not include Ge-68 in a Ge-68/Ga-68 medical use generators (limit less 

than 2 uCi x 105

) that are returned to the manufacturer at end of use. 
Page 19 of 26 

Germanium-68 (Ge-68) Decommissioning Funding Plan (DFP) 

Subcommittee

Report: Addendum 

August 12, 2015 

Submitted by: S. Langhorst; S. Mattmuller 

It was after the Subcommittee had submitted it first draft report that the proposed 2 uCi labeling value 

was determined not to be an appropriate value for all licensees. For example the large university-based 

medical center on the East Coast as described in the report would still have to prepare a DFP to 

determine their site-specific financial assurance even at the new proposed 2 uCi labeling value. By 

following the original methodology for calculating labeling values in Appendix B of Part 30 the 

Subcommittee proposed a labeling value of 10 uCi for Ge-68. The following questions and answers were 

reviewed and determined by the ACMUI to substantiate 10 uCi as the proposed labeling value and to 

provide justification for a direct rule making for the specific case of Ge-68 when contained in a medical 

use Ge/Ga-68 generator that is decommissioned by return to the manufacturer. 

 

1. What purpose do the labeling values for Appendix B of Part 30 serve? 

The labeling values for those licensed materials with half-lives greater than 120 days are used to 

determine whether the possession limits approved for a license require the licensee to maintain 

financial assurance for decommissioning, and if so, what amount of financial assurance is 

required (§ 30.35). The labeling values for those licensed materials with half-lives less than or 

equal to 120 days serve no purpose. 

2. Where did values for Appendix B of Part 30 come from? 

Prior to 1994, Appendix B of Part 30 did not exist. Instead, the requirements in § 30.35 

referenced the old Appendix C of Part 20 which first appeared in the regulations in 1970. The 

regulatory history for Appendix B of Part 30 listed at the bottom of that table is the regulatory 

history of the old Appendix C of Part 20 prior to 1994. 

The current decommissioning funding plan (DFP) regulations in § 30.35 are based on values that 

were established 45 years ago. 

3. How were values for the old Appendix C of Part 20 derived? 
Page 20 of 26 

Description of how the values for the old Appendix C of Part 20 were chosen is specified in the 

proposed changes to Part 20 and Part 303

 published in 1968 (33 FR 11414, August 10, 1968): 

“Two basic criteria were used in deriving the quantities. Since inhalation is considered 

the most likely route of entry into the body, the quantity that would be inhaled by a 

standard man exposed for 1 year at the highest average concentration permitted in air 

(by 10 CFR Part 20) for members of the general public was computed. If the 

radioisotope emits gamma radiation, the quantity that, from a point source, would 

produce a radiation level of 1 milliroentgen per hour at a distance of 10 centimeters was 

also computed. The smaller of these two quantities was then logarithmically rounded to 

the nearest decade, in microcuries, and entered in § 30.71, Schedule B.”

4. Why was Ge-68 not included in the old Appendix C of Part 20? 

The air concentrations of licensed materials permitted in air were based on the International 

Commission on Radiological Protection Committee II (ICRP 2) recommended values for 

maximum permissible concentrations4

 . ICRP 2 was published in 1959; Ge-68 was not included 

in the list of radionuclides. The current Appendix B of Part 30 does not include a specific value 

for Ge-68 because data published 56 years ago did not include that radionuclide. 

5. Since Ge-68 is not specifically listed in Appendix B of Part 30, what labeling value applies for Ge-68? 

For Ge-68 (half-life 271 days) in unsealed form, the default labeling value for non-alpha emitting 

radionuclide is used. This default value of 0.1 uCi is used to determine what amount of financial 

assurance is required by § 30.35 for decommissioning a license possessing Ge-68. 

Ge-68 Possession Limit (mCi) Financial Assurance required (§ 30.35) 

Less than or equal to 0.1 none 

Greater than 0.1 to 1 $225,000 

Greater than 1 to 10 $1,125,000 

Greater than 10 Decommissioning Funding Plan is required to 

determine the amount of financial assurance 

 

3

 Schedule B of Part 30 “Exempt Quantities” was established at the same time as Appendix C of Part 20. 4

 “Report of Committee II on Permissible Dose for Internal Radiation (1959),” Health Physics Journal, Vol 3, Issue 1, 

April 1959. 
Page 21 of 26 

Note that if other radionuclides with half-lives greater than 120 days are also allowed to be 

possessed, then the sum of the ratios for those radionuclides must also be included in this 

calculation. 

6. Why is there an issue now with Ge-68 possession and financial assurance? 

New Ga-68 radiopharmaceuticals have been developed and are in widespread use in Europe. 

Currently they are under review by the Food and Drug Administration (FDA) for approval in the 

United States. 

 

These Ga-68 radiopharmaceuticals have proven to be the new standard for imaging certain 

cancers called neuroendocrine tumors (NET). In addition to greater diagnostic accuracy these 

new radiopharmaceuticals provide for greater patient comfort, convenience and a lower 

radiation dose compared to the current radiopharmaceutical in use today. 

Since Ga-68 has a short half-life of 68 minutes, medical use can only be accomplished by use of 

the Ge/Ga-68 generators in a similar fashion as the Mo/Tc-99m generators. The Ge-68 is 

designed to remain in the shielded generator and the Ga-68 is eluted from the generator. A 

Ge/Ga-68 generator can be supplied with 50 millicurie of Ge-68, and this quantity that would 

trigger the requirement for a DFP. Because a DFP is an extensive and expensive site-specific 

plan to produce, maintain and review (see Question 12), use of Ge/Ga-68 generators may be 

limited to a few medical licensees already maintaining a DFP and thus the availability of these 

valuable radiopharmaceuticals will not be widely offered to patients. 

7. How will decommissioning take place for Ge/Ga-68 generators? 

The Ge-68 in a Ge/Ga-68 generator is for all practical purposes a solid source within a sealed 

source. At the end of its useful life the generator will be returned to its manufacturer who will 

be responsible for its final disposal. The medical licensee will have no Ge-68 remaining at its 

site, hence the cost for decommissioning would not warrant the need to greatly increase the 

financial assurance needed by the medical licensee. 

8. If Ge-68 had been specifically listed in Appendix B of Part 30, what would the labeling value be? 

One option to choosing the labeling value for Ge-68 is to use the specific labeling value listed in 

the updated Appendix C of Part 20. This value for unsealed Ge-68 is 10 uCi. 

Another option is to calculate the value using the criteria specified in 1968 (see Question 3) and 

the highest average concentration of Ge-68 permitted in air (by Appendix B Part 20, Table 2, 

Column 1) for members of the general public, which is 5 x 10-9 uCi/ml. The first criteria 

calculation is: 

V1= 5 x 10-9 uCi/ml x 20,000 ml/min x 60 min/hr x 24 hr/day x 365 day = 53 uCi 
Page 22 of 26 

Considering that the Ge-68 in a Ge/Ga-68 generator is not your typical unsealed source, but is 

practically a solid within a sealed source, a calculated value based on air concentrations is very 

conservative. 

The second criteria calculation involves use of a gamma exposure calculation. Germanium-68 

does not decay by emission of gammas, but its daughter, Ga-68, decays with photon emissions. 

The exposure rate constant5

 for Ga-68 is 5.43 R-cm2/mCi-hr. The second criteria calculation is: 

V2 = (0.001 R/h x 100 cm2

 x 1000 uCi/mCi) /5.43 R-cm2/mCi-hr = 18 uCi 

So, logarithmically rounding to the nearest decade for the smaller of these two values, V2, would 

mean the labeling value for Ge-68 should be 10 uCi. 

This is the same value that was listed for labeling unsealed Ge-68 in the new Appendix C of Part 

20 in 1994. Hence, 10 uCi would seem to be the appropriate labeling value for Ge-68. 

9. If 10 uCi is proposed for the specific labeling value for Ge-68 used in a Ge/Ga-68 generator meant for 

medical use, then that means the labeling value used would increase by a factor of 100 and the DFP 

trigger level would increase from 10 mCi to 1 Ci. Is that safe? 

Yes. Remember, the labeling values in Appendix B of Part 30 are only used to determine the 

level of financial assurance needed for decommissioning. These values are not used for any 

other regulatory requirement, and definitely are not used as any kind of radiological criteria for 

allowing a formerly licensed site to be released for unrestricted use under § 20.1402. 

Also, the substantial safety inherent to a Ge/Ga-68 generator (see Question 7) makes its use will 

far less likely to result in residual contamination than the unsealed uses allowed for other 

radionuclides6

 listed in Appendix B of Part 30 which also have a labeling quantity of 10 uCi. The 

cost for decommissioning a Ge/Ga-68 generator would not warrant the need to greatly increase 

the financial assurance needed by the medical licensee. 

10. What would it mean to a medical licensee if the labeling value for Ge-68 used in a Ge/Ga-68 

generator meant for medical use was changed to be 10 uCi? 

A value of 10 uCi used for Ge-68 to determine what amount of financial assurance is required by 

§ 30.35 for decommissioning a license possessing unsealed Ge-68 would be as follows. 

 

5

 Smith, D.S and Stabin, M.G., “Exposure Rate Constants and Lead Shielding Values for Over 1,100 Radionuclides,” 

Health Physics Journal, Vol 102, No 3, March 2012. 

6

 Examples of other radionuclides (half-life) with 10 microcurie labeling value in Appendix B of Part 30: Sb-125 (2.8 

years), Ba-133 (10.6 years), Ca-45 (163 days), Cs-137 (30 years), Cl-36 (300,000 years), Mn-54 (312 days), Ni-63 

(101 years), and Zn-65 (244 days). 
Page 23 of 26 

Ge-68 Possession Limit (mCi) Financial Assurance required (§ 30.35) 

Less than or equal to 10 none 

Greater than 10 to 100 $225,000 

Greater than 100 to 1,000 $1,125,000 

Greater than 1,000 Decommissioning Funding Plan is required to 

determine the amount of financial assurance 

Note again that if other radionuclides with half-lives greater than 120 days are also allowed to 

be possessed, then the sum of the ratios for those radionuclides must also be included in this 

calculation. Licensees providing Ga-68 diagnostic procedures would be required to maintain at 

least $225,000 in financial assurance which is more than enough funding to ship their final 

generators back to the manufacturer. Medical licensees who do large numbers of these Ga-68 

diagnostic procedures, or who are approved to possess other greater than 120-day half-life 

radionuclides, would most likely be required to maintain at least $1,125,000 in financial 

assurance. Again, this amount of financial assurance is more than adequate funding to 

decommission Ge/Ga-68 generators. 

11. What is a decommissioning funding plan? 

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

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

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

license (§ 20.1003). A decommissioning funding plan (DFP) is a site-specific cost estimate to 

fully decommission a license and is used to set a license-specific amount of financial assurance 

the licensee is required to maintain. 

12. What does it mean to develop and maintain a DFP? 

As stated in § 30.35(e)(1), each DFP is required to be submitted to and approved by the NRC. 

The DFP must contain the following: 

• a detailed cost estimate, in an amount reflecting – 

o cost of an independent contractor to perform all decommissioning activities; 

o cost of meeting criteria of unrestricted release (§ 20.1402), or for certain 

provisions, restricted use release (§ 20.1403); 

o the volume of onsite subsurface material containing residual radioactivity that 

will require remediation; and 

o an adequate contingency factor. 

• identification and justification for all key assumptions used; 
Page 24 of 26 

• description of method of assuring funding for decommissioning, including cost 

adjustments and associated funding levels periodically over the life of the facility; 

• certification by the licensee that financial assurance in the amount of the cost estimate; 

and 

• a signed original of the financial instrument. 

The DFP is required to be updated and resubmitted for NRC approval at the time of license 

renewal and at intervals not to exceed 3 years. The DFP must update the information submitted 

with the original or prior approved plan, and must specifically consider the effect of the 

following events on decommissioning costs: 

• spills of radioactive material producing additional residual radioactivity in onsite 

subsurface material; 

• waste inventory increasing above the amount previously estimated; 

• waste disposal costs increasing above the amount previously estimated; 

• facility modifications; 

• changes in authorized possession limits; 

• actual remediation costs that exceed the previous cost estimate; 

• onsite disposal; and 

• use of a settling pond. 

The use of a DFP is applicable for licenses with complicated or extensive possession limits so 

that the financial assurance is adequate and continually updated to ensure decommissioning 

funds will be available to complete license termination. Developing and maintaining a DFP is 

time consuming and costly in the personnel time needed meet compliance with all the 

regulatory requirements. 

Review of DFPs is also costly for the NRC and Agreement States personnel. As an example, 

Washington University in St. Louis (WU) has a Broad Scope Type A Medical Use license and an 

Accelerator Production license issued by the NRC. WU maintains a DFP and financial assurance 

in the amount of $6.77 million. Not counting the cyclotron and large sealed source 

decommissioning costs, WU’s possession of greater than 120-day half-life radionuclides requires 

about $2 million in financial assurance. The last WU DFP approved by the NRC was submitted by 

WU September 2009. WU submitted an updated DFP December 2010 when a large sealed 

source device was added to the license. No review questions were requested by the NRC. 

Another updated DFP was submitted February 2013 when the license was renewed. NRC review 

questions were sent to WU September 2014 and answered by WU in December 2014. As of 

August 2015, NRC had not completed review of the 2010 or 2013 DFP updates. WU is required 

to submit the next DFP update by February 2016. 

This example of the time and resources needed by the NRC to review a DFP provides indication 

of what a large burden the NRC and the Agreement States be asked to take on if more DFPs 

were required. Given the ease and low cost of decommissioning a medical use Ge/Ga-68 
Page 25 of 26 

generator, requiring a DFP for this generator use does not make fiscal sense for the medial 

licensee or for the regulator. 

13. What would happen if the label value for Ge-68 in medical use Ge/Ga-68 generators was not 

changed from the current generic label value of 0.1 uCi? 

Licensees who did not already maintain a DFP would be required to develop and maintain a DFP 

in order to request possession of even one medical use Ge/Ga-68 generator. The cost to 

develop and maintain a DFP would be prohibitive to most medical licensees and the Ga-68 

diagnostic procedures would not be available to most patients 

That would mean patients would have to continue with an inferior radiopharmaceutical that 

would result in a less accurate diagnosis, take an extra day to complete the study and would 

result in a higher radiation dose to the patient. It would also mean that the current average 

length of time for a correct diagnosis for NET patients would not be improved. 

14. What would happen if the label value for Ge-68 in medical use Ge/Ga-68 generators was changed to 

2 uCi as originally suggested? 

If 2 uCi was chosen as the Ge-68 in medical use Ge/Ga-68 generators, a medical licensee who is 

not currently required to maintain any level of financial assurance would then be required to 

maintain $1,125,000 as shown here. 

Ge-68 Possession Limit (mCi) Financial Assurance required (§ 30.35) 

Less than or equal to 2 none 

Greater than 2 to 20 $225,000 

Greater than 20 to 200 $1,125,000 

Greater than 200 Decommissioning Funding Plan is required to 

determine the amount of financial assurance 

This amount of financial assurance does not seem logical given the ease and low cost of 

decommissioning a medical use Ge/Ga-68 generator. If a medical licensee has other 

radionuclides with half-lives greater than 120 day, a value of 2 uCi for Ge-68 results in 25% 

towards the ratio sum for each 50 mCi possession limit. Broad scope medical licensees who 

have structured their license possession limits so that they remain at the $1,125,000 level for 

financial assurance may not be able to absorb 25% - 50% towards the ratio sum without then 

having to do a DFP. This is the very situation that would still require the large university-based 
Page 26 of 26 

medical center on the East Coast that is described in the report (and others like it) to prepare a 

DFP. 

Instead, as shown in Question 10, use of 10 uCi for Ge-68 in a medical use Ge/Ga-68 generator 

would result in 10% toward the ratio sum for each 50 mCi possession limit. Most broad scope 

medical licensees who have structured their license possession limits so that they remain at the 

$1,125,000 level for financial assurance will most likely be able to absorb 10% - 20% towards the 

ratio sum and still remain at the $1,125,000 level for financial assurance. 

Given the ease and low cost of decommissioning a medical use Ge/Ga-68 generator, use of 10 

uCi for Ge-68 in a medical use Ge/Ga-68 generator would maintain financial assurance without 

hindering the development of Ga-68 radiopharmaceuticals. 

Conclusion - 

The cost of decommissioning a medical use Ge/Ga-68 generator does not warrant the need for, and the 

additional licensee and regulator costs associated with, a site-specific DFP. Use of the current generic 

label value for Ge-68 will continue to limit patient access to the use and further development of Ga-68 

radiopharmaceuticals. Changing to 10 uCi as the specific label value for Ge-68 used in medical use 

Ge/Ga-68 generators will guarantee that there is more than adequate financial assurance for 

decommissioning and will increase patient safety. With the current Ga-68 radiopharmaceuticals under 

FDA review, NET patients will receive lower radiation doses, and their physicians will gain superior 

diagnostic accuracy resulting in quicker diagnosis, earlier initiation of proper therapy, and improved 

patient outcomes. 

Thus, the Committee changed its recommendation to be stated as follows; the following language be 

added as a footnote to Appendix B Part 30 -- Quantities1

 of Licensed Material Requiring Labeling. 

3

This does not include Ge-68 in a Ge-68/Ga-68 medical use generators (limit less than 10 uCi 

x 105

) that are returned to the manufacturer at end of use.