Patent Number: 053373367
Section: claims

1. A method of decreasing release of volatile radioactive iodine from a nuclear reactor pressure vessel containing a reactor core having a plurality of fuel rods submerged in reactor water, said method comprising the steps of: storing a stable iodide liquid solution in a reservoir operatively joined to said pressure vessel;  monitoring said pressure vessel to determine an accident condition which might lead to rupture of said fuel rods resulting in the discharge into said reactor water of said volatile radioactive iodine from said fuel rods; and  injecting into said pressure vessel upon occurrence of said accident condition said stable iodide liquid solution to mix with said reactor water for decreasing vaporization from said reactor water of said volatile radioactive iodine dischargeable therein from said fuel rods,  wherein said stored iodide has a quantity selected relative to the quantity of said reactor water is said pressure vessel to effect a final concentration of total iodine from said stored iodide and reactor iodine contained in said reactor core of greater than about 10.sup.-5 Moles.  storing a stable iodide liquid solution in a reservoir operatively joined to said pressure vessel, said stable iodide liquid solution comprising an iodide selected from the stable iodide group including sodium iodide (NaI) and potassium iodide (KI) and a stabilizer to inhibit oxidation of said stored iodide during storage;  monitoring said pressure vessel to detect an accident condition which might lead to rupture of said fuel rods resulting in the discharge into said reactor water of said volatile radioactive iodine from said fuel rods; and  injecting into said pressure vessel upon detection of said accident condition said stable iodide liquid solution to mix with said reactor water for decreasing vaporization from said reactor water of said volatile radioactive iodine dischargeable therein from said fuel rods,  wherein said stored iodide has a quantity selected relative to the quantity of said reactor water in said pressure vessel to effect a final concentration of total iodine from said stored iodide and reactor iodine contained in said reactor core of greater than about 10.sup.-5 Moles.  a pressure vessel;  a reservoir containing a stored stable iodide in a liquid solution;  a supply conduit joining said reservoir in flow communication with said pressure vessel; and  a normally closed valve disposed in said supply conduit and being selectively openable for allowing said stored solution to flow into said pressure vessel to mix with said reactor water,  wherein said stored iodide has a quantity selected relative to the quantity of said reactor water in said pressure vessel to effect a final concentration of total iodine from said iodide and reactor iodine contained in said reactor core of greater than about 10.sup.-5 Moles. 2. A method according to claim 1 wherein said iodide stored in said liquid solution in said reservoir is selected from the stable iodide group including sodium iodide (NaI) and potassium iodide (KI). 3. A method according to claim 2 wherein said stored liquid iodide solution further includes a stabilizer to inhibit oxidation of said stored iodide during storage in said reservoir. 4. A method according to claim 3, wherein said stored iodide is sodium iodide and said stabilizer is selected from the group including sodium hydroxide and sodium sulfite. 5. A method of decreasing release of volatile radioactive iodine from a nuclear reactor pressure vessel containing a reactor core having a plurality of fuel rods submerged in reactor water, said method comprising the steps of: 6. A nuclear reactor plant comprising: 7. An apparatus according to claim 6 wherein said stored iodide is selected from the stable iodide group including sodium iodide (NaI) and potassium iodide (KI). 8. An apparatus according to claim 7 wherein said stored solution in said reservoir includes a stabilizer to inhibit oxidation of said stored iodide during storage in said reservoir. 9. An apparatus according to claim 8 wherein said stored iodide is sodium iodide (NaI) and said stabilizer is selected from the group including sodium hydroxide (NaOH) and sodium sulfite (Na.sub.2 SO.sub.3).