NASA’s Nuclear Frontier: The Plum Brook Reactor Facility

    There are three main types of nuclear reactors: power, research, and test. Research and test reactors as scientific tools are more common than most people realize. While power reactors frequently appear in newspaper headlines and are conspicuous because of their size and power, research reactors can be quietly tucked away, even in the midst of a college campus. Power reactors generate heat, which can easily be converted to other useable forms of energy, such as electricity. Research reactors operate at very low thermal power levels – so low, in fact, that they do not even require any type of forced cooling. They are used to measure nuclear parameters and other characteristics, which can then be used to build other reactors or to design experiments for test reactors. Test reactors are more powerful than research reactors and are able to produce much more intense radiation fields. Though they are still much less powerful than the power reactors, they generate enough heat to require a closed-loop forced-circulation coolant system. This system will remove the heat from the reactor by transferring it to a secondary cooling system, which releases it into the atmosphere through cooling towers.

NASA’s Nuclear Frontier: The Plum Brook Reactor Facility. Pages 36 to 40. 

NASA’s Nuclear Frontier: The Plum Brook Reactor Facility

    There are three main types of nuclear reactors: power, research, and test. Research and test reactors as scientific tools are more common than most people realize. While power reactors frequently appear in newspaper headlines and are conspicuous because of their size and power, research reactors can be quietly tucked away, even in the midst of a college campus. Power reactors generate heat, which can easily be converted to other useable forms of energy, such as electricity. Research reactors operate at very low thermal power levels – so low, in fact, that they do not even require any type of forced cooling. They are used to measure nuclear parameters and other characteristics, which can then be used to build other reactors or to design experiments for test reactors. Test reactors are more powerful than research reactors and are able to produce much more intense radiation fields. Though they are still much less powerful than the power reactors, they generate enough heat to require a closed-loop forced-circulation coolant system. This system will remove the heat from the reactor by transferring it to a secondary cooling system, which releases it into the atmosphere through cooling towers.

NASA’s Nuclear Frontier: The Plum Brook Reactor Facility. Pages 36 to 40. 

NASA’s Nuclear Frontier: The Plum Brook Reactor Facility

    There are three main types of nuclear reactors: power, research, and test. Research and test reactors as scientific tools are more common than most people realize. While power reactors frequently appear in newspaper headlines and are conspicuous because of their size and power, research reactors can be quietly tucked away, even in the midst of a college campus. Power reactors generate heat, which can easily be converted to other useable forms of energy, such as electricity. Research reactors operate at very low thermal power levels – so low, in fact, that they do not even require any type of forced cooling. They are used to measure nuclear parameters and other characteristics, which can then be used to build other reactors or to design experiments for test reactors. Test reactors are more powerful than research reactors and are able to produce much more intense radiation fields. Though they are still much less powerful than the power reactors, they generate enough heat to require a closed-loop forced-circulation coolant system. This system will remove the heat from the reactor by transferring it to a secondary cooling system, which releases it into the atmosphere through cooling towers.

NASA’s Nuclear Frontier: The Plum Brook Reactor Facility. Pages 36 to 40. 

França suspende entrega de navio de guerra para a Rússia

Governo hesitava em tomar medida que pune Moscou

por envolvimento na crise na Ucrânia

    O gabinete do presidente da França, François Hollande, anunciou a suspensão temporária da entrega de um navio porta-helicópteros para a Rússia em retaliação ao apoio russo aos separatistas no leste da Ucrânia. O anúncio foi feito na véspera do início de uma reunião de cúpula da OTAN (Organização do Tratado do Atlântico Norte) em Newport, no País de Gales. O gabinete de Hollande disse que “as condições que permitiriam à França autorizar a entrega do primeiro navio não foram cumpridas”.

    O contrato, assinado em 2011, prevê a construção dos dois navios, ao custo estimado de 1,2 bilhão de euros. A entrega do primeiro navio, batizado Vladivostok – que já está praticamente finalizado – estava marcada para outubro deste ano e a do segundo, o Sebastopol, para 2015. Cada navio tem capacidade de transportar dezesseis helicópteros, tropas e veículos blindados.

    Há meses o governo Hollande vinha hesitando em tomar tal medida, mesmo com a escalada das agressões da Rússia na Ucrânia. Deputados americanos chegaram a fazer apelos públicos para que a França suspendesse o contrato. Representantes da União Europeia fizeram pedidos semelhantes, mas a França afirmava que os navios já haviam sido pagos e que as sanções econômicas impostas pelos EUA e pela União Europeia a Moscou não eram retroativas.

    A imprensa francesa informou que a suspensão deve ser aplicada inicialmente até novembro e que a construção das embarcações não será interrompida – o processo envolve pelo menos 1.000 trabalhadores que, obviamente, não receberam bem o anúncio da suspensão. Em março, o vice-ministro da Defesa da Rússia, Yuri Borisov, chegou a afirmar que uma pesada indenização seria exigida, além da devolução dos gastos pelos navios caso a compra fosse cancelada.

    Além da construção, o contrato prevê o treinamento das tripulações russas que vão operar as embarcações e a transferência de tecnologia. Alguns marinheiros russos já estão na França para começar a aprender sobre o funcionamento do primeiro navio.

http://veja.abril.com.br/noticia/mundo/franca-suspende-entrega-de-navio-de-guerra-para-a-russia. 03/09/2014.