by CKR
Sillamäe is the reason I first came to Estonia in 1998. I had written a proposal on a possible cleanup strategy earlier, in 1993 or 1994, but the Estonians had too much else to do that early in their reacquired independence to deal with Sillamäe.
But in 1998, I was invited to join the Sillamäe International Expert Reference Group, which was overseeing the planning to remediate the immense tailings pile and other radioactive waste left by Soviet minerals-processing operations.
Sillamäe was one of those Cold War secret cities, like my workplace Los Alamos. That similarity has occasioned some knowing chuckles on my visits. Sillamäe remained a closed city long after Los Alamos, though, and its work remained secret.
I’ve wondered exactly what Sillamäe’s role was in the Soviet nuclear complex. I knew that its incoming material was ore and concentrate from a number of sites in the Soviet Union. The paper given by Endel Lippmaa (co-authored by Ello Maremäe) at our NATO conference in 1998 made that clear. But what did Sillamäe produce?
The first logical guess was yellowcake, U3O8. (Subscripts would be nice, TypePad!)
As I read Jeffrey’s speculations about UF4 production in Iran, I began to wonder. Although Sillamäe has the equipment that could be used to produce UF4, it also has a cascade of mixer-settlers that were nicely suited to rare-earth production. Could that cascade have been used to purify the uranium in preparation for conversion to UF4?
Silmet, the commercial successor to the mineral processing operations, inherited a roomful of old Soviet documents. I wanted to get into that room. My very limited Russian would allow me to decipher titles of reports and flag those that might hint at UF4 production, possibly more. But I wasn’t able to get into that room this trip.
Preparing my previous post on Sillamäe gave me another route, this one successful.
Googling “Sillamae uranium” produces a number of interesting-looking links. It turns out that a large number of those 380 or so links are to the book from our NATO conference, offered or reviewed by different sources, and to duplicates of Dan Bilefsky’s IHT/NYT article. Many of the links are subscription-only or rotted.
But, as befits an ore-processing operation, there is one gem among them. It was on Google’s page 14 when I found it.
Ello Maremäe and Hain Tankler have done what I wanted to and more. They worked through the Silmet archive to produce a report for the Estonian Radiation Protection Centre. The report also contains an article by Henno Putnik on the cleanup of Paldiski, a Soviet nuclear-submarine training center west of Tallinn that at one time included the reactor-containing portions of two nuclear submarines.
Maremäe and Tankler answered my question: yellowcake was the product. In the 1980s, some rejected reactor fuel elements were processed back to U3O8. These fuel elements contained low-enriched (2.0 to 3.5%) uranium.
This is the authoritative report. No enrichment operations, contrary to the rumors that have circulated forever. No UF4, contrary to my recent suspicions.