Startup neutron source: Difference between revisions

Revision as of 00:05, 28 March 2010

Revision as of 00:06, 28 March 2010

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The sources can be of two types:<ref name="nucleng">http://books.google.com/books?id=EMy2OyUrqbUC&pg=PA27&dq=neutron+startup+source&lr=&as_drrb_is=q&as_minm_is=0&as_miny_is=&as_maxm_is=0&as_maxy_is=&num=50&as_brr=3&cd=4#v=onepage&q=neutron%20startup%20source&f=false</ref>

* '''Primary sources''', used for startup of a fresh reactor core; conventional [[neutron sourcessource]]s are used, usually [[californium]]-252 ([[spontaneous fission]]) or [[americium]]-beryllium (&alpha;,n [[nuclear reaction]]). The primary sources are removed from the reactor after the first fuel campaign, usually after few months.

* '''Secondary sources''', originally inert, become radioactive and neutron-producing only after [[neutron activation]] in the reactor

** [[Antimony|Sb]]-[[Beryllium|Be]] [[photoneutron]] source; antimony [[neutron activation|becomes radioactive]] in the reactor and its strong gamma emissions (1.7 MeV for ¹²⁴Sb) interact with [[beryllium-9]] by an (&gamma;,n) reaction and provide [[photoneutron]]s. In a PWR reactor one neutron source rod contains 160 grams of antimony, and stay in the reactor for 5-7 years.<ref>http://books.google.com/books?id=SJOE00whg44C&pg=PA147&dq=neutron+startup+source&lr=&as_drrb_is=q&as_minm_is=0&as_miny_is=&as_maxm_is=0&as_maxy_is=&num=50&as_brr=3&cd=22#v=onepage&q=neutron%20startup%20source&f=false</ref>