{"id":3553,"date":"2024-03-31T03:35:15","date_gmt":"2024-03-31T03:35:15","guid":{"rendered":"https:\/\/wp.ccnr.org\/?page_id=3553"},"modified":"2024-04-01T00:21:38","modified_gmt":"2024-04-01T00:21:38","slug":"using-weapons-derived-plutonium-fuel-in-candu-reactors","status":"publish","type":"page","link":"https:\/\/wp.ccnr.org\/fr\/using-weapons-derived-plutonium-fuel-in-candu-reactors\/","title":{"rendered":"Using Weapons-Derived Plutonium Fuel in CANDU Reactors"},"content":{"rendered":"

Using Weapons-Derived
\nPlutonium Fuel
\nin CANDU Reactors<\/span><\/h1>\n

according to
\nAtomic Energy of Canada Limited<\/span><\/small><\/h3>\n
\n

extracts from<\/small><\/span><\/h2>\n

Advanced CANDU Systems
\nfor Plutonium Disposition<\/h3>\n

P. G. Boczar, M. J. N. Gagnon, P. S. W. Chan,
\nR. J. Ellis, R. A. Verrall, A. R. Dastur,<\/small><\/h6>\n
of Chalk River Laboratories
\nAtomic Energy of Canada Limited<\/span><\/small><\/h6>\n
<\/h6>\n

Canadian Nuclear Society Bulletin,
\nVol. 18, No. 1. (Winter 1997)<\/h4>\n
\n

Comments by
\nGordon Edwards, Ph.D., President,
\nCanadian Coalition for Nuclear Responsibility.<\/h6>\n

 <\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
 <\/p>\n

AECL TEXT<\/h2>\n

 <\/td>\n

 <\/p>\n

CCNR COMMENT<\/span><\/h2>\n

 <\/td>\n<\/tr>\n

\n

2. CANDU MOX<\/h3>\n

2.1. \u00a0 The 1994 CANDU MOX Study<\/p>\n

The objective of the MOX strategy is not to destroy the plutonium<\/span><\/b>, but to convert it to a form that has a high degree of diversion resistance through the characteristics of spent fuel, while producing electricity….<\/td>\n

Contrary to all the public statements by AECL and government spokespersons that the CANDU MOX plan is to ”destroy” weapons plutonium, we see that this is simply untrue.<\/span><\/b>Future generations of Canadians will have to guard the plutonium that remains in the irradiated fuel for millennia to come.<\/span><\/b><\/td>\n<\/tr>\n
In 1994, the United States Department of Energy (US DOE) commissioned an AECL-led team to examine the use of CANDU reactors for dispositioning excess weapons-derived plutonium.<\/span><\/td>\nThe AECL Washington team worked long and hard to get the DOE commission.<\/span><\/b>”Dispositioning” is jargon for ”treating the plutonium to make it less likely to be used for weapons”<\/span><\/b><\/td>\n<\/tr>\n
The target plutonium disposition rate was\u00a050 tonnes of plutonium metal in 25 years<\/span><\/b><\/span><\/td>\nThis amount of American weapons-derived plutonium would be matched by an equal amount of Russian weapons-derived plutonium, for a total of up to 100 tonnes.<\/span><\/b><\/td>\n<\/tr>\n
A detailed assessment was performed, including technical, economic, safety, licensing, safeguards, security, MOX fuel fabrication, transportation, and eventual disposal of the spent fuel. The team concluded that\u00a0two of the four 850-megawatt reactors at the Bruce “A” Station near Kincardine, Ontario, could achieve this<\/span><\/b>\u00a0….<\/span><\/td>\nFor technical reasons, the Bruce “A” reactors are the best-suited CANDU power reactors to burn plutonium (MOX) fuel.<\/span><\/b>Ironically, the four Bruce “A” reactors are among those that Ontario Hydro shut down in 1997 for safety-related reasons.<\/span><\/b><\/td>\n<\/tr>\n
The reference fuel … contains 232 grams of plutonium per bundle….<\/span><\/td>\n26 of these ”reference fuel bundles” would provide\u00a0enough weapons-grade plutonium<\/a>\u00a0for a Nagasaki-type atomic bomb<\/span><\/b><\/td>\n<\/tr>\n
An advanced MOX fuel design … contains 374 grams of plutonium in the fresh fuel….<\/span><\/td>\n16 of these ”advanced fuel bundles” would be enough for a Nagasaki-type bomb.<\/span><\/b>Using modern designs, even 8 bundles would be enough for a bomb with the same explosive power as the one that destroyed Nagasaki.<\/span><\/b><\/td>\n<\/tr>\n
As in the reference bundle, the plutonium is confined to the two outer rings of fuel: 3.5 percent plutonium in ring 3, and 2.1 percent in ring 4, mixed with depleted uranium.<\/span><\/td>\nIf plutonium were used in all four rings, the reactor might undergo a self-destructive ”power excursion” — like Chernobyl.<\/span><\/b>To prevent this kind of accident, ”poisons” — jargon for materials, like dysprosium, that absorb neutrons — are used in the inner rings to keep the nuclear reaction in check.<\/span><\/b><\/td>\n<\/tr>\n
The central eight elements contain 6 percent dysprosium, mixed with depleted uranium.<\/span><\/td>\n”Depleted uranium” is jargon for uranium-238, a waste product of uranium enrichment.<\/span><\/b>The use of\u00a0depleted uranium<\/a>\u00a0in the fuel automatically means that new plutonium-239 is created during operation of the reactor.<\/span><\/b><\/td>\n<\/tr>\n
In both cases,\u00a0the initial plutonium content is reduced by about one-third<\/span><\/b>\u00a0in the spent fuel….<\/span><\/td>\nThe plutonium remaining in the spent fuel — 2\/3 of the original amount — must be guarded for a period of time that exceeds the span of recorded human history, since the half-life of plutonium-239 is 24,000 years.<\/span><\/b><\/td>\n<\/tr>\n
\n

2.2 \u00a0 The 1996 CANDU MOX Study<\/h3>\n

The AECL-led team conducted additional studies for the US DOE in 1996, aimed at further increasing the plutonium disposition rate. A 50 percent increase in the plutonium disposition rate was achieved by increasing the plutonium content of the bundle. To compensate for the excess reactivity, the burnable poison content in the central elements was increased from 7 percent to 15 percent, and the purity of the [heavy water] coolant and moderator was downgraded from 99.75 percent to 97 percent….<\/td>\n

By increasing the concentration of plutonium in the MOX fuel,<\/span><\/b><\/p>\n
    \n
  • the fast ”safe shutdown” of reactors under abnormal conditions becomes more demanding;<\/li>\n
  • the inventory of radioactive poisons that can be released from each fuel bundle under accident conditions is greatly increased;<\/li>\n
  • the heat and radiation levels of the resulting irradiated fuel is significantly elevated.<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n
\n

2.3 \u00a0 Status of CANDU MOX Option for Plutonium Dispositioning<\/h3>\n

…\u00a0Preparations are now in place for the first physical tests<\/span><\/b>\u00a0towards qualifying the use of CANDU MOX fuel, fabricated from weapons-surplus plutonium. The program consists of the fabrication of a small amount of CANDU MOX fuel in the United States and in Russia, for testing under simulated CANDU reactor conditions in AECL’s NRU research reactor at the Chalk River Laboratories.<\/td>\n

Even if weapons plutonium is donated free of charge, the handling of plutonium is so dangerous that\u00a0MOX fuel fabrication has to take place in a glovebox<\/a>\u00a0— an operation which is extraordinarily expensive.<\/span><\/b>As a result, MOX fuel is much costlier (from three to seven times greater) than the natural uranium fuel now used in CANDU reactors.<\/p>\n

It is also much trickier to make MOX — serious quality control problems have already begun to emerge, resulting in defective fuel pellets. Due to the elevated cost, there is a financial incentive to ”cut corners”.<\/span><\/b><\/td>\n<\/tr>\n

Although\u00a0AECL has tested MOX fuel for decades<\/span><\/b>, these new tests will confirm the behaviour of fuel using weapons-grade plutonium. This type of small-scale experimental test was endorsed by the G7 leaders at the Nuclear Summit in Moscow in\u00a01996 April<\/a>.<\/span><\/td>\nAECL is careful not to discuss\u00a0WHY<\/a>\u00a0they have been testing MOX fuel for decades.<\/span><\/b>At the April 1996 Moscow meeting, Prime Minister\u00a0Jean Chr\u00e9tien signed a paper<\/a>\u00a0saying that Canada is in favour of burning weapons plutonium in CANDU reactors. He had no political mandate to do so.<\/span><\/b><\/td>\n<\/tr>\n
There is a\u00a0real interest in Russia in the CANDU option<\/span><\/b>. A joint\u00a0Canada-Russia feasibility study<\/a>\u00a0sponsored by the Canadian government builds upon previous US DOE studies. Its aim is to establish the viability of a CANDU MOX fuel fabrication plant in Russia, addressing related safeguards and security issues.<\/span><\/td>\nUsing a controversial two million-dollar grant from CIDA, the Canadian International Development Agency (set up to assist needy countries with economic development), AECL sent 13 teams of experts on junkets to Russia, and brought Russian scientists to Canada.<\/span><\/b>Russia needs American capital to get its own domestic MOX industry established; if the Canadian project can be helpful in achieving that goal, Russia is interested.<\/span><\/b><\/td>\n<\/tr>\n
The first interim report, issued in the fall of 1996, establishes the\u00a0feasibility of CANDU MOX fuel fabrication in Russia<\/span><\/b>.<\/span><\/td>\nEvidently, AECL’s activities are designed to increase expectations year by year until the momentum behind the project will be difficult to overcome.<\/span><\/b><\/td>\n<\/tr>\n
\n

4. CANDU Plutonium-Thorium<\/h3>\n

The final CANDU plutonium-annihilation option to be considered in this paper employs the use of thorium dioxide as a carrier for the plutonium.<\/td>\n

Thorium is a naturally-occurring radioactive material, about 3 times more abundant than uranium. Thorium is not a nuclear fuel, but it can be transmuted into uranium-233 inside a nuclear reactor. U-233 is a human-made element that, like plutonium, can be used either as a nuclear explosive or as a nuclear fuel.<\/span><\/b><\/td>\n<\/tr>\n
This is a responsible, forward-looking strategy that uses plutonium to convert thorium-232 into uranium-233, to be used as a future energy resource…. Uranium-233 is the best fissile material in a thermal reactor [such as CANDU]…. This CANDU “near-breeder”\u00a0fuel cycle<\/a>\u00a0provides long-term assurance of fissile fuel supplies….<\/span><\/td>\nAccording to this scheme — not likely to be utilized in the foreseeable future — plutonium would be mixed with thorium as fuel to breed fissile uranium-233 (U-233), an artificial isotope of uranium that is similar to plutonium in many respects:<\/span><\/b><\/p>\n