On this Mother’s Day, I regret to inform you that the trucking of 23,000 litres of highly radioactive liquid material from Chalk River Laboratories (CRL) in Ontario to the Savannah River Site (SRS) in South Carolina has begun. The first truckload arrived at SRS last month (see the official communication copied below).
The lead “pig” is intended to provide radiological shielding to limit the exposure of workers to “acceptable levels” of penetrating gamma radiation given off by the radioactive liquid. The pig is also coated with a thin layer of plastic to prevent workers from touching the lead (a chemically toxic heavy metal) directly.
However, the radioactive shielding in one of these pigs was found to be defective, as a “hot spot” was detected that could give an unacceptably high level of gamma radiation exposure to SRS workers. That pig has been replaced with a spare pig.
The disocvery of an unexpected “hot spot” in one of the pigs is the result of a manufacturing defect. It underscores other equipment defects and malfunctions that have been discovered in the last two years, all connected with the same type of transport cask (the NAC-LWT cask).
In October 2015, the bottom of a “caddy” used to transfer solid irradiated nuclear fuel unexpectedly failed, dropping open and sending the highly radioactive spent fuel rods to the bottom of a high-level waste storage pool at Chalk River. The failure of the caddy was caused by poor welds, a manufacturing defect that was also evident on a number of other caddies designed to serve the same purpose. These caddies are manufactured by the same company (NAC) that makes the transport casks, and are part of the equipment that goes with the NAC-LWT cask
In April 2016, a grapple crane used to lift a “basket” of highly radioactive spent fuel for emplacement in an NAC-LWT cask suddenly failed, dropping the basket with its radioactive contents. Again, the grapple crane that failed was part of the equipment that accompanies the NAC-LWT cask.
The liquid contents of the first truckload have now been removed from the cask and have been transferred to the robotically operated chemical separation facility called the “H Canyon”.
The H Canyon is a reprocessing facility. It was originally designed to chemically extract weapons-grade plutonium from irradiated nuclear fuel (in liquid solution) to be used as a primary explosive in nuclear warheads and other nuclear weapons.
In this case, the H Canyon will be used to chemically separate the weapons-grade Highly Enriched Uranium (HEU) from the Chalk River liquid solution. Once extracted, the HEU will be “down-blended” to “low-enriched uranium” (LEU) that cannot be used as a nuclear explosive but can be used as a reactor fuel.
If the down-blending had been carried out at Chalk River, as originally planned, these shipments of extremely radioactive liquid waste over public roads and bridges could have been avoided altogether. In 2016, in a matter of months, Indonesia did exactly that: the Indonesian nuclear authorities down-blended their own stock of highly radioactive liquid containing weapons grade uranium. They did this on-site so that no transportation of liquid material was required!!
It is still not too late to do the same at Chalk River. We do not need to risk another hundred truckloads of highly radioavctive liquid passing through hundreds of communtiies and endangering the Great Lakes and other water bodies along the way. If spilled, two ounces of this liquid material from Chalk River is enough to ruin the drinking water supply of a city as large as Washington DC.
We should continue to insist that nuclear authorities do the right thing. Sending a hundred more shipments down the highway is like rolling a pair of dice a hundred times. Sooner or later our luck may give out and we will roll “snake-eyes”.
April 21, 2017
TO: S. A. Stokes, Technical Director
FROM: M. T. Sautman and Z. C. McCabe, Resident Inspectors
SUBJECT: Savannah River Site Resident Inspector Report for Week Ending April 21, 2017
Target Residue Material (TRM): H-Canyon personnel started processing the first shipment of liquid Highly Enriched Uranium (HEU) this week. Each container of HEU is pulled from the shipping cask into a shielded “pig” that provides radiological shielding for H-Canyon personnel. After loading a pig, radiological protection (RP) identified an unexpected hotspot on the side of the pig indicating that the pig was not providing adequate radiological shielding. RP labeled the hotspot before H-Canyon personnel relocated the pig so the hotspot would be facing the wall. H-Canyon personnel did not identify any similar issues on the other pigs and are planning to use the one spare pig for future evolutions. All of the containers have been removed from the cask and H-Canyon personnel have begun transferring the HEU into H-Canyon for processing.