摘要 |
<p>The invention relates to a nuclear fuel assembly for use in a nuclear reactor core which has excess reactivity initially designed into it. …<??>The fuel assembly includes means for controlling the excess reactivity, comprising at least one hermetically sealed tubular member (40) containing a burnable poison (42) which is capable of generating gas under reactor operating conditions and is soluble in the moderating reactor coolant, the tubular member (40) having a wall region (50) adapted to rupture, thereby to admit reactor coolant to the burnable poison soluble therein, when the internal pressure of the tubular member has reached a predetermined level. …<??>This element functions as a spectral-shift rod capable of shifting at the proper time from an initial low reactivity part of the neutron spectrum to a high reactivity part thereof without the aid of any special means extraneous to the rod itself.</p> |