An apparatus (10, 110, 210) including a containment capsule (12, 112, 212) a support member (16, 116, 216) removably disposed within the capsule and carrying therein a solid state track recorder material (20, 120, 220) and a layer of fissile material (20, 120, 220), and means (52) on the exterior of the capsule adapted to be remotely grasped for positioning the capsule adjacent to the fuel. The capsule is lowered into close proximity to the fuel, and positioned at a predetermined location for a period of time between about one hour and one day. The capsule is withdrawn from the fuel, the support member and recording member are withdrawn from the capsule, and the recording member is processed to reveal the fission track density, which is readily correlated to fuel burnup.
A heavy ion generator is used with a plasma desorption mass spectrometer to provide an appropriate neutron flux in the direction of a fissionable material in order to desorb and ionize large molecules from the material for mass analysis. The heavy ion generator comprises a fissionable material having a high n,f reaction cross section. The heavy ion generator also comprises a pulsed neutron generator that is used to bombard the fissionable material with pulses of neutrons, thereby causing heavy ions to be emitted from the fissionable material. These heavy ions impinge on a material, thereby causing ions to desorb off that material. The ions desorbed off the material pass through a time-of-flight mass analyzer, wherein ions can be measured with masses greater than 25,000 amu.
A reactor cavity dosimetry system and method in a nuclear power plant having a reactor vessel and a primary biological shield substantially surrounding the reactor vessel thereby forming a reactor cavity between the vessel and the shield, the system and method providing for remotely and repeatedly positioning a plurality of neutron dosimeters at preselected locations within the cavity, and for withdrawing the dosimeters for analysis thereof and replacing them at the same preselected positions. Assessment of the long-term effects of neutron irradiation on the vessel is enhanced by accurate and repetitive placement of the dosimeters.
A heavy ion generator is used with a plasma desorption mass spectrometer to provide an appropriate neutron flux in the direction of a fissionable material in order to desorb and ionize large molecules from the material for mass analysis. The heavy ion generator comprises a fissionable material having a high n,f reaction cross section. The heavy ion generator also comprises a pulsed neutron generator that is used to bombard the fissionable material with pulses of neutrons, thereby causing heavy ions to be emitted from the fissionable material. These heavy ions impinge on a material, thereby causing ions to desorb off that material. The ions desorbed off the material pass through a time-of-flight mass analyzer, wherein ions can be measured with masses greater than 25,000 amu.
