By P. Smith
Published in AECL's Inter-comm, June 2, 1989. Thanks to Dr. I. Hastings for the scanned documents.
Another chapter is added to the history of nuclear energy, a story of intrigue and espionage -- the trail of T-7.
The story begins in France, early in 1940. A group of French scientists, including Frederic Joliot, Hans von Halban and Lew Kowarski, had recognized the potential of heavy water (D20) as a moderator in their experiments to produce a fission chain reaction. They persuaded the French government to buy up the total stock from the only company then producing quantities of heavy water, or "polymer". This was the Norwegian Hydro-Electric Company (Norsk Hydro) whose assets were largely controlled by the Banque de Paris et des Pays Bas. At the outbreak of World War II Norsk's total stock, which was virtually the world supply of heavy water, was approximately 180 kilograms. The Germans tried unsuccessfully to obtain it, plus an additional order. The French Ministry of Munitions ordered Lieutenant Jacques Allier of the French Secret Service to move the Norwegian supplies of heavy water -- l'eau lourde" -- to France. This he did a few weeks before the Germans invaded Norway.
The stock arrived in France and was entrusted to the French scientists, but France was soon to be invaded, and with Paris threatened, the scientists moved to Clermont-Ferrand, and planned an evacuation to England. Professor Joliot stayed in France, but van Halban, Kowarski and the 26 cans of heavy water embarked on the British collier "Broompark" for Falmouth, under the protection of the Earl of Suffolk, who had been the Scientific Liaison Officer with the French government.
The heavy water was first held at Wormwood Scrubs prison, then moved to the custody of the Windsor Castle librarian. Von Halban and Kowarski were established at the Cavendish Laboratory at Cambridge, where efforts were concentrating on the development of uranium for the war effort. The MAUD (Ministry of Aircraft Production's Uranium Development Committee) team at Cavendish included Dr. John Douglas Cockroft. In July, 1941, the MAUD Committee concluded that both an atomic bomb and an atomic reactor (called a "boiler") were practicable. On September 2, 1942, it was agreed that a team, under the direction of Dr. Hans von Halban, would be transferred to Canada to collaborate with Canadian scientists at Montreal on the production of plutonium in a reactor moderated with heavy water.
A supply list for the Montreal labs dated May 1, 1943 noted three tons of brown uranium oxide, ten tons of carbon and the much-travelled heavy water from Norway.
In 1944, Cockcroft succeeded von Halban as director of the Canadian laboratories. He persuaded Kowarski and other members of the Cavendish team to come to Montreal. Dr. Kowarski was charged with designing a simple reactor, the Zero Energy Experimental Pile (ZEEP), while plans for the National Research Experimental (NRX) reactor went forward. After inspecting several sites, Cockcroft recommended a point on the Ottawa River as a suitable site for an experimental plant incorporating reactors. Chalk River became the next stop for the Norwegian-French heavy water.
In 1946, Dr. Wilfrid Bennett Lewis became the director of the Chalk River project, and it was he who replied to a French request for the return of 100 grams of heavy water. In September of that year, Mr. B. Capdeville, chief of the Industrial Production Division of the French Supply Council forwarded from Montreal a request from the laboratories of Duc de Broglie. A memo to W.B. Lewis from N. Miller, dated 1946 September 30, noted that the polymer received from the French government was stored in drum number T-7, and that it was 99.5 per cent pure with respect to deuterium. The Polymer Control Sub-Committee at Chalk River agreed to give the French lab 100 millilitres. At once, the French Supply Council made arrangements to have the heavy water shipped to Paris via Trans-Canada Air Lines. Thus, some of the heavy water went "home".
Lewis decided in 1947 to send the rest of drum T-7 to the Consolidated Mining and Smelting Company in Trail, B.C. for reprocessing. When the material was returned, the "French Polymer" was stored, although a 1948 memo noted that the French heavy water had been treated at Trail and was not "identifiable as such". Sir John Cockcroft, who had become head of the Atomic Energy Research Establishment at Harwell, England, came back into the picture at that juncture, with a request that the French polymer be returned. In a letter of February 24, 1948, Lewis replied to him that it would be easier to compensate the French than to return the original heavy water. This did not sit well with Professor Joliot. He then requested an immediate return of 12 litres of heavy water, with an eventual return of "an amount of heavy water equivalent to that originally supplied from France, less losses". The last word on the saga of the heavy water exchange comes with a letter to John Cockcroft from Chalk River in 1948, stating that 32.5 pounds of heavy water in a stainless steel drum, which was to be returned, was being shipped to Harwell, for transfer to France.
This fascinating piece of history came to light as a result of an enquiry from the French atomic energy agency (CEA). Dr. Etienne Roth, who was helping prepare a history of the CEA, contacted his friend and colleague Dr. Ian Hastings, Fuel Materials branch at Chalk River for assistance in documenting "the French connection" with the early days of nuclear research in Canada. Ian was ably assisted in the search by Carol Lachapelle, Lise Hunter and Ruth Everson of Information Services, who culled through archive files to find correspondence from 1946 to 1948 on the French Polymer; by Mike Luke, who helped declassify some of the documents; and by Jack Schreader, then with Nuclear Materials Control, who is still on the trail of the drum designated T-7.
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