A Word About Sealed Sources

AmBe Source Availability

Like most things the government gets involved in, the Off-Site Source Recovery Project (OSRP) discussed below under "Source Disposal" has had unintended consequences.  The OSRP had taken over 15,000 sealed sources out of circulation as of May of 2007, and over 20,000 by June of 2009 (not all are well logging sources, and not all are Americium-Beryllium chemical neutron sources).  This has created a profound shortage of good used AmBe sealed well logging sources now that the oil business is again in a boom cycle.  The OSRP has thus far refused requests to take AmBe sources out of storage, offering a number of excuses, among them cost and that they must not compete with companies selling new ones (there are none except QSA Global Inc. discussed below), but the real reason is probably fear that the news media would have a picnic if a source the OSRP recycled was involved in any kind of mishap.  At the same time the USDOE government labs have ceased the sale of Americium-241 to industry, and Gammatron, the last producer of AmBe sealed sources from domestic Americium for the well logging industry, says they are therefore effectively out of the AmBe source business (Gammatron has recycled some old sources they manufactured for owners).

The only current supplier of new AmBe sources is QSA Global Inc. (successor to Amersham), and they are using Americium of Russian origin.  Claims the Russian Americium is inferior to the material previously supplied by the US government are apparently false (QSA Global says the material is purer than the USDOE product ever was at greater than 99% purity), but regardless of quality, the exclusive reliance on a Russian supplied radioisotope to support the US oil industry is less than desirable.  Due to demand, lead time for delivery of a new AmBe source has been as much as two years recently, and of course prices for new AmBe sources have soared due to scarcity and lack of competition.

The Oil Field Services Industry Forum for Radiation Safety and Security (Industry Forum), originally formed to review proposed federal legislation and regulations concerning the safety and security of radioactive sources, was attempting to address the above discussed crisis.  See their August 5, 2005 letter to DOE, and DOE's August 24, 2005 response letterAnaLog Services, Inc. participated in this effort, but unfortunately the Industry Forum dissolved due to predicable differences of opinion (and aided by a gaggle of corporate lawyers with anti-trust nightmare fantasies).  The AESC has formed a committee in an attempt to replace the old Industry Forum.  Proposals to recycle those sources that pass regulatory muster, or to remove the americium oxide / beryllium powder for reuse have both been rejected at the urging of the major logging companies, and there are indications that separation of the americium oxide may be undertaken by one of the DOE labs and financed by one or more of the majors (AnaLog has commented that such an arrangement would penalize smaller independent loggers and has anti-trust implications).

Californium-252 is emerging as a possible replacement for AmBe in well logging neutron sealed sources.  See Californium-252, AmBe Substitute? for more information on neutron sources.  Unfortunately, there are now questions about continued supply of Californium-252 by government labs.

Source Disposal

If a source is usable (not listed on Enclosure 3 as discussed below, and not leaking), the best option is to find a licensee that needs it.  AnaLog Services, Inc. believes that it is good public policy to encourage the beneficial reuse of sealed logging sources to the extent practicable. 

The government lab folks at Los Alamos have a program to recover some sealed sources, formerly concentrating on the actinides as used in PuBe and AmBe chemical neutron sources, but now expanded to include other materials in the post 9/11 frenzy.  You must register to get on their waiting list.  There is considerable information at the Off-Site Source Recovery Project (OSRP) website, including an online registration form.

Aside from the two options above, plan on spending a bushel basket full of money to dispose of a sealed source.  Check out the NSSI website for some information about commercial source disposal.

Used Source Half-Life Considerations

Radioactive sealed sources are used in a variety of different well logging technologies.  At present, the two most common isotopes used by well loggers are Americium-241 (Am-241) and Cesium-137 (Cs-137).  Americium-241 is used with Beryllium (AmBe) as a "chemical" source for neutron generation; its half-life, about 458 years in AmBe form, is sufficiently long as to make it unnecessary to consider same from a practical standpoint.  Cs-137 is used for various types of density logging; its half-life, about 30 years, is short enough to make it a real consideration if acquiring sources made during the last oil patch boom (pre-1986).  Calculations of actual activity should be performed for old Cs-137 sources.

Wipe Tests

In acquiring a used sealed logging source, never assume that a wipe test has been done properly by the previous owner (or at all).  Always do your own wipe test prior to taking possession of the source if humanly possible; if not, be sure to have a written provision that you are not obligated to keep a leaking source.  Newly acquired sealed sources must be wipe tested according to the NRC and most, if not all, agreement states anyway.

Temporary Generic Exemption

Effective after July 14, 1989, pursuant to NRC regulations, many existing sealed sources were prohibited from further use.  On August 10, 1989, NRC issued a temporary generic exemption that allowed certain sealed logging sources to continue to be used.  On November 1, 1991, NRC updated the temporary generic exemption on a one-time-only basis.  Effective May 17, 2000, the temporary generic exemption became formally incorporated into the NRC regulations.  See the NRC Federal Register Notice of April 17, 2000.

The two generic exemption notices were accompanied by enclosures.  Enclosure 1 (The "A" List) contains logging sealed sources actually approved under the 10 CFR Part 39 requirements; Enclosure 2 lists sealed sources approved under the generic exemption; and Enclosure 3 lists sealed sources not approved for use in well logging.

Obviously, it would be foolish to acquire a sealed source listed on Enclosure 3.  We generally suggest acquiring sealed logging sources listed on Enclosure 1, in preference to those listed on Enclosure 2, if possible.  The venerable Gulf Nuclear 71-1 AmBe sources are included on Enclosure 1, along with many others.

Source Documentation

The NRC Sealed Source and Device Registry has been "indefinitely shut down pending a security review" since shortly after the events of September 11, 2001.  Access is available only to government agencies, and the regulated community is supposed to ask their state regulators for copies of Certificates of Competent Authority if they need same.  Good luck.  Fortunately, due to typical insane government logic, the very same DOT / IAEA Certificates of Competent Authority are available at the RAMPAC website on the Certificate Retrieval PageAnaLog Services, Inc. has current copies of the IAEA Certificate of Competent Authority documents for many of the common sealed logging sources; if you have problems obtaining certificates from the above link, we may be able to help.

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Last 10-20-10