I would set up a table with a column showing the earlier numbers and another showing the changed numbers, with references for all the numbers. Or maybe two tables: one with categories of how the plutonium was used (Nagasaki, weapons tests, research, lost to environment, etc.) and one with where the plutonium is. This sort of accounting for how much plutonium was produced against how much we know we have is called a mass balance.
Unfortunately, that is not what Robert Alvarez chose to do in his report claiming that the US plutonium inventory has gone up. I can’t make the numbers from Alvarez’s report add up to a mass balance, because he doesn’t supply all of them, and the ones he does supply are not all comparable. It’s possible he’s got a mass balance somewhere, but, if he does, he’s reporting only selected numbers.
Page van der Linden has compared Alvarez’s report and Matthew Wald’s New York Times article that seems to be based on it. I say “seems to” because Wald, in the MSM tradition, doesn’t make his sources available. It is possible that Wald interviewed Alvarez and based his article on that interview. I’ll concentrate in this post on problems I’ve found in the report.
Alvarez comes close to part of a mass balance in his Table 2, which gives plutonium in the waste inventories of the various DOE sites, comparing earlier and more recent numbers. The more recent numbers add up to his 12.7 metric tons, the basis for his claims and Wald’s article. What he says about how he arrived at his numbers is
Based on more recent waste characterization data (see bibliography), approximately 12.7 tons, more than 11 percent of the total amount of Pu-239 produced and acquired has gone into waste streams (Table 2). [p. 4 of report]“[S]ee bibliography,” however, is not an explanation of method. Which numbers did he take from the sources in the bibliography? How did he treat uncertainties? Why did he choose these sources? Further, two of the references in Table 2 are not in the bibliography, and there are eleven references in the bibliography that are not referred to in the table. The report also has footnotes that are not in the bibliography. Very confusing.
Alvarez throws other numbers into the report, and it’s not clear which are included in his 12.7 tons.
This paper does not address about 7.6 tons of plutonium contained in DOE spent reactor fuel, and 61.5 tons of plutonium declared excess for weapons purposes with the exception of 3.5 tons discarded at the Rocky Flats Plant which is included in the 61.5 tons “excess” declaration. About 41.8 metric tons of the U.S. excess plutonium is expected to be processed so it can be mixed with uranium for fabrication into mixed oxide fuel for use in commercial nuclear power plants and subsequently disposed. Disposition options for 5 tons of “non-pit” plutonium include mixing with defense high-level wastes to be vitrified or direct disposal in WIPP. [p. 2 of report]So there is a 3.5-ton exception to the exception, except it is included in the 61.5 tons to which it is an exception? Is it included in the 12.7 tons? Or is it somehow double-counted? A full mass balance would clarify this.
There are other points that are unclear and potentially misleading.
The dramatic increase from the DOE’s 1996 waste estimate appears to be due to: reclassification as waste of process residues originally set aside for plutonium recovery for weapons; underestimates of production losses; and improvements in waste characterization data. [p. 1 of report]If material was not considered waste in the earlier estimate and it is now, that doesn’t imply errors in the earlier estimate.
“Production losses” have been a question for as long as I can remember. Material held up in glove-box ventilation systems and other production piping has been an explanation for a lack of agreement between production figures and current inventories. Now that Rocky Flats and other production buildings have been torn down, better estimates must be available for those holdup amounts. I have asked some questions on this, and the numbers are not publicly available. It would seem that releasing these numbers, if they improve the mass balance, would be good for the Department of Energy, showing that they knew what they were talking about. Does Alvarez have access to those numbers? He doesn’t say.
As van der Linden notes, Alvarez suddenly brings in the idea of having the IAEA monitor WIPP. It’s only one of several off-topic insertions, another of the features of this report that doesn’t inspire confidence. But it’s actually a good point, in my opinion. Less so is his suggestion that better knowledge of the mass balance of plutonium produced and lost over the years will improve treaty verification.
Neither the United States nor Russia have adequate records of plutonium production. I’ve tried to work with original shipping records. Secrecy, poor analytical methods, and just not seeing those records as important at the time all are factors. We simply don’t know, and won’t ever know, the amounts of plutonium produced down to tolerances of several kilograms. What will happen in treaty negotiations is that numbers will be agreed upon for the purposes of the treaty.
Something that the arms control community might make more of is IAEA monitoring within the United States. As Alvarez comments, it would be a way of indicating our transparency to the international community. I don’t understand why the US allows relatively little, and why the list of monitored sites is so closely held. I need to do more research on this to write in a well-informed manner, but maybe I’ll get around to that in another post.