Radiation-monitoring diagnostic hodoscope system for nuclear-power reactors

A radiation-monitoring diagnostic hodoscope system for producing an approximate image of radiation-producing components within and below a pressure vessel of shutdown nuclear plant, said system comprising:

• A) at least one gamma-radiation-monitoring hodoscope unit adapted to detect gamma radiation in a limited substantially-straight narrow radiation beam of less than 50 degrees and in at least one specific gamma-energy range, said at least one hodoscope unit comprising:
• 1) a collimating means adapted to produce said narrow radiation beam and
• 2) at least one radiation detector adapted to produce electrical signals corresponding to intensities of gamma radiation in said at least one specific gamma energy range;
• B) a positioning means for positioning said at least one hodoscope unit so as to accumulate sufficient radiation data representing radiation intensity and gamma energies in a sufficiently large number of narrow radiation beams to create said approximate image of said gamma radiation-producing sources within and below said pressure vessel;
• and
• C) a computer processor programmed with an algorithm adapted to associate said gamma or neutron radiation data so as to produce said approximate image of said radiation-producing components.