TVA to participate in NNSA MOX studies

26 February 2010

The US National Nuclear Security Administration (NNSA) has signed an agreement with government-owned Tennessee Valley Authority (TVA) to study the use of mixed-oxide (MOX) fuel made from surplus weapons plutonium in TVA's nuclear power reactors.


The NNSA is an autonomous part of the Department of Energy (DoE) which is in charge of the plan to mix the plutonium oxide with fresh uranium oxide and make mixed-oxide nuclear fuel (MOX). It had for some time been cooperating with Duke Energy and the pair conducted two 18-month trials of MOX fuel assemblies in the Catawba 1 reactor, but Duke allowed the contract to lapse in March 2009.


TVA, Duke and two other utilities had expressed interest in picking the program back up. However, in July 2009, NNSA announced that a letter on intent had been signed by Shaw Areva MOX Services LLC and TVA to enter into contract negotiations for the irradiation of MOX fuel. The MOX fuel will be produced at the MOX Fuel Fabrication Facility, currently under construction at the DoE's Savannah River Site and due to be completed in 2017. Trial fuel assemblies would have to be made abroad. Those for the Duke trial were made by Areva in France.


Under its new agreement with NNSA, TVA will perform work on nuclear core design, licensing, environmental and reactor modification assessments, and other related activities to evaluate the use of MOX fuel in its reactors.


TVA is evaluating the use of MOX at Sequoyah 1 and 2, Browns Ferry 1, 2 and 3 as well as future reactors, NNSA said. The company is pursuing the construction of two new Westinghouse AP1000 reactors at Bellefonte, which would be able to operate on 100% MOX fuel loads.


TVA will have to draw up an environmental impact assessment for the use of the trial MOX assemblies and conduct tests similar to those at Catawba before being given permission from the Nuclear Regulatory Commission (NRC) to use MOX fuel as routine.


Ken Baker, NNSA's principal assistant deputy administrator for defence nuclear non-proliferation, said: "The MOX program is an important example of this Administration's commitment to irreversibly disposing of surplus nuclear weapons material in a way that realizes the energy value of the material and advances our nuclear non-proliferation agenda." He added, "This agreement is an important step in evaluating the use of MOX fuel in domestic nuclear reactors, and we look forward to working with the TVA as we move forward."


As weapons fuel, the 34 tonnes of US plutonium obviously represent an enormous amount of stored energy. NNSA said it would be enough for 8500 nuclear weapons or for 200 billion kWh of electricity - approximately equivalent to a large reactor's total output over 20 years. Russia is destroying an equivalent stock, but has decided to use its more directly as fuel for fast reactors instead.


Researched and written

by World Nuclear News