February 3 2013

Proposed Import and transport of Liquid Radioactive Wastes

Bearing Highly Enriched Uranium (HEU) to the U.S. from Canada

Here are some historical background notes related to this topic.

1. AECL's use of HEU (weapons-grade uranium)

For many years, AECL has been using HEU as a "target material" to produce radioisotopes, specifically molybdenum-99 (Mo-99) -- which is the source material for the technetium-99m (Tc-99m) used in hospitals around the world for diagnostic procedures including bone scans. Millions of such diagnostic usages are made every year.

See http://www.ccnr.org/isotope_shortage.html .

The HEU target is inserted into specially engineered channels in the NRU reactor so that it can be exposed to neutrons from the core and withdrawn at will. During its exposure to neutrons, many of the U-235 atoms in the target fission and produce the usual spectrum of fission products -- dozens of them -- the same intensely radioactive byproducts that constitute the bulk of the high-level radioactive waste from nuclear reactors.

The irradiated targets are then chemically processed to remove one of those fission products, Mo-99. This requires dissolving the target in acid, yielding a highly radio- active liquid waste containing the other fission products (except the radioactive fission gases which escape) and the residual (unfissioned) HEU.

It is this highly radioactive liquid waste containing HEU that would be shipped to the Savannah River Site (SRS). The intense radioactivity is due to the fission products, but the real security problem is with the residual HEU.

2. The Security Problem with HEU

HEU is immediately usable as a nuclear explosive material in a rather simple "gun-type" atomic bomb, similar to the Hiroshima bomb, once it has been converted into a solid form. The gun-type design is so simple that it is "foolproof" -- testing is unnecessary. In fact the US never tested the gun-type atomic bomb before using it to destroy the city of Hiroshima on August 6 1945.

Given this fact, together with the fact that HEU can be handled (and smuggled) without elaborate radiation shielding, it is clear that any trafficking in HEU poses very serious security risks -- if this material falls into the hands of criminals, terrorists or governments desiring to acquire a nuclear weapons capability. Even sub-critical quantities are a matter of concern since several such quantities can be combined to make a super-critical mass (needed for an atomic explosion).

For many years now, the US Government has been trying to put an end to all civilian use of HEU in order to address these security concerns. Research reactor that previously used HEU as a fuel (including the NRU reactor at Chalk River) have had to convert to using LEU (low-enriched uranium) as fuel instead.

LEU is uranium that has been enriched to less than 20% uranium-235, so that over 80% of the mass is non-fissile, non-explosive uranium-238. Conventional wisdom is that LEU cannot be used to make an atomic bomb but HEU can be used for nuclear weapons purposes. Weapons-grade uranium is HEU with an enrichment of more than 90% U-235, and in fact the uranium targets used at Chalk River are (I think) 93.3% U-235. See http://ccnr.org/maple_heu.html .

Although it had to reconfigure the NRU reactor to use LEU fuel, AECL has refused to quit using HEU as "targets" for isotope production. In principle, LEU targets could be used but AECL says it would add greatly to the cost of production.

This argument overlooks the fact that isotope production is already a non-profitable business, highly subsidized by Canadian taxpayers. Even though the private company Nordion makes profits on sales of its so-called "molybdenum cows" which are used by hospitals as "technetium generators", they can only do so because they get their molybdenum-99 from AECL which loses money constantly on this on-going operation. Switching to LEU targets would either mean charging more for the technetium generators or increasing the subsidization of Mo-99 production at Chalk River.

Meanwhile, other techniques for producing Mo-99 on a commercial basis using accelerators rather than reactors have been (and are being) developed in Canada and elsewhere. None of these require HEU and some of them don't even require uranium at all.

3. Shipments of HEU from Chalk River to Savannah River

For many years -- especially when AECL was using HEU fuel in the NRU reactor -- there were regular shipments of irradiated HEU from Chalk River to Savannah River (SRS). However SRS is a military installation, and Canada has a 1955 bilateral agreement with USA not to use any nuclear materials from Canada for nuclear explosive purposes. Prior to 1955, a lot of plutonium produced at Chalk River was sold to the USA for use in their nuclear weapons program:

"The majority of the plutonium received from Canada came from the Chalk River Facility. Approximately, 252 kilograms of plutonium in spent reactor fuel was sent to the Savannah River Site where it was processed and blended with other materials in the main production streams for the United States nuclear weapons program. "

[citation from a US DOE letter dated March 4, 1996, addressed to Robert Del Tredici -- see http://www.ccnr.org/DOE.html ]

But shipments of irradiated HEU continued to be made from Chalk River to Savannah River for decades after the 1955 bilateral agreement was signed. The shipments were being sent over the Ivy Lea Bridge (in the 1000 Islands area of the St.Lawrence River). An NGO group in New York State protested against these shipments and succeeded in forcing the Thousand Island Bridge Authority to pass a regulation forbidding the transport of radioactive waste across the bridge unless there was a $500 million bond posted. At that point AECL started shipping the irradiated fuel through Montreal to the Eastern Townships Autoroute and then through Vermont. In Vermont, communities responded by passing mutually inconsistent bylaws as to which routes these shipments had to take and at which times they had to be made -- such a complicated patchwork of bylaws that it was virtually impossible to continue the shipments.

During this whole period of time, I personally investigated this situation from the point of view of non-proliferation agreements, knowing that Savannah River was a military establishment -- and discovered that the irradiated fuel was being used in the US nuclear weapons program. The HEU recovered from the irradiated shipments was being added to other HEU to make the "driver rods" used in the SRS military reactors, dedicated to producing weapon-grade plutonium to be used in the US nuclear arsenal. (These so-called "plutonium production reactors" use HEU "driver rods" and depleted uranium "target rods". The neutrons produced by the U-235 atoms fissioning in the driver rods, irradiated the U-238 in the DU "target rods", transforming the U-238 atoms into Plutonium-239 atoms. Voilà!)

CCNR put out press releases and background papers on this situation, and the press picked up the story. At first AECL officials told reporters that the HEU had been obtained from the USA and was in fact still US property, that AECL only "leased" the material and was obliged to return the irradiated material to the USA for recovery of the residual HEU -- because it was their property in the first place. I told the reporters to ask AECL officials to read them the wording of the contract which required AECL to return the HEU; whereupon AECL was forced to admit that the explanation previously given was wrong. HEU was in fact purchased from the USA, and had become AECL property -- and there was no obligation to return the material to the USA. The only reason the shipments were being made was because AECL obtained a "cash credit" that could be used against future purchases of HEU (to help defray the cost).

This was a shocking breach of Canada's obligations under the non-proliferation bilateral agreement with the US, and I revealed this breach personally -- and quite dramatically -- at an Ottawa meeting hosted by Canada's Ambassador for Disarmament Doug Roche, when I declared that Canada was sending nuclear materials from Chalk River to Savannah River that was ending up in the nuclear weapons program. The Ambassador turned to the AECL people who were there and said, "Is this true?" And they just went red in the face. The shipments were stopped and were not resumed as far as I know. But then President Obama held an important summit meeting in Washington DC in April 2010 to rein in the use of HEU:

See http://www.huffingtonpost.com/2010/04/12/obama-nuclear-summit-worl_n_533731.html