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US5084235A Expired / Lapsed US ⏱️ 0.0 years remaining

Direct cycle-type atomic power plant with means for suppressing transfer from a liquid phase to a vapor phase of radioactive nitrogen oxides

Assignee: Hitachi Ltd
•
Filing: 1990-07-19
•
Granted: 1992-01-28
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Expires: 2010-07-19
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Abstract

Abstract A direct cycle type atomic power plant provided with a means for suppressing transfer of radioactive nitrogen compounds generated by nuclear reaction in the core from the reactor water to steam, where an increase in the dose rate in the main steam system and the turbine system due to carry-over of radioactive nitrogen atom, 16 N, generated in the core can be suppressed, and the radioactivity therein can be reduced.

Inventors

  • 👤 Eishi Ibe
  • 👤 Hidetoshi Karasawa
  • 👤 Maroto Nagase
  • 👤 Masaharu Sakagami
  • 👤 Shunsuke Uchida
  • 👤 Minoru Miki
  • 👤 Yamato Asakura
  • 👤 Motoaki Utamura
  • 👤 Fumio Kawamura
  • 👤 Katsumi Ohsumi
  • 👤 Yoshinori Chiba

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 05:15
CPC Classifications
G; G21; G21C; G21C19/00; G21C19/28; G21C19/30; G21C1/00; G21C1/04; G21C1/06; G21C1/08; G21C1/084; Y; Y02; Y02E; Y02E30/00; Y02E30/30

Claims Analysis

Total Claims: 17
Claim 1
Independent Claim 146 words
A direct cycle type, atomic power plant, which comprises: a nuclear reactor pressure vessel provided with a nuclear fuel and reactor water therein; a turbine for driving a generator by steam from the nuclear reactor pressure vessel; a condenser for condensing the steam from the turbine; means for supplying water from the condenser to the nuclear reactor pressure vessel; and injection means for injecting into the reactor water an amount of a substance capable of suppressing transfer from a liquid phase to a vapor phase of radioactive nitrogen oxides generated in the reactor water by irradiation of the reactor water with neutrons generated during nuclear reactions of the nuclear fuel; and means for controlling said injection means such that the amount of said substance is controlled so that the concentration of nitrous acid or nitric acid in the reactor water can fall within a preset range.
Claim 2
Dependent Claim 146 words
A direct cycle type, atomic power plant, which comprises: a nuclear reactor pressure vessel provided with a nuclear fuel and reactor water therein; a turbine for driving a generator by steam from the nuclear reactor pressure vessel; a condenser for condensing the steam from the turbine; means for supplying water from the condenser to the nuclear reactor pressure vessel; and injection means for injecting into the reactor water an amount of a substance capable of suppressing transfer from a liquid phase to a vapor phase of radioactive nitrogen oxides generated in the reactor water by irradiation of the reactor water with neutrons generated during nuclear reactions of the nuclear fuel; and means for controlling said injection means such that the amount of said substance is controlled so that the concentration of nitrous acid or nitric acid in the reactor water can fall within a preset range.
Claim 3
Dependent Claim 20 words
A direct cycle type, atomic power according to claim 1, wherein the radioactive nitrogen oxides are molecular radioactive nitrogen oxides.
Claim 4
Dependent Claim 19 words
A direct cycle type, atomic power plant according to claim 1, wherein the radioactive nitrogen oxides include nitrogen monoxide.
Claim 5
Dependent Claim 104 words
A direct cycle type, atomic power plant which comprises a means for adding a hydrogen radical scavenger to convert radioactive nitrogen oxide in reactor water to anions, as provided in the core of a nuclear reactor of the direct cycle type, atomic power plant wherein the means for adding comprises a source of hydrogen radical scavenger and a means for injecting into the reactor water the hydrogen radical scavenger having a function to lower a concentration of hydrogen atoms through reaction with hydrogen atoms in the reactor water and, wherein the hydrogen radical scavenger is at least one of nitrogen monoxide and nitrogen dioxide.
Claim 6
Dependent Claim 104 words
A direct cycle type, atomic power plant which comprises a means for adding a hydrogen radical scavenger to convert radioactive nitrogen oxide in reactor water to anions, as provided in the core of a nuclear reactor of the direct cycle type, atomic power plant wherein the means for adding comprises a source of hydrogen radical scavenger and a means for injecting into the reactor water the hydrogen radical scavenger having a function to lower a concentration of hydrogen atoms through reaction with hydrogen atoms in the reactor water and, wherein the hydrogen radical scavenger is at least one of nitrogen monoxide and nitrogen dioxide.
Claim 7
Dependent Claim 18 words
A direct cycle-type, atomic power plan according to claim 4, wherein said hydrogen radical scavenger is nitrogen monoxide.
Claim 8
Dependent Claim 18 words
A direct cycle-type, atomic power plant according to claim 4, wherein said hydrogen radical scavenger is nitrogen dioxide.
Claim 9
Dependent Claim 44 words
A direct cycle-type, atomic power plant according to claim 4, further comprising a corrosion monitor for measuring a corrosion potential of structural material in said reactor water and means for controlling said means for adding based on a measured value of said corrosion potential.
Claim 10
Dependent Claim 119 words
A direct cycle-type, atomic power plant, which comprises: a nuclear reactor pressure vessel provided with a nuclear fuel and reactor water therein; a turbine for driving a generator by steam from the nuclear reactor pressure vessel; a condenser for condensing the steam from the turbine; means for supplying water from the condenser to the nuclear reactor pressure vessel; injection means for injecting into the reactor water at least one nitrogen compound selected from the group consisting of nitrogen monoxide, nitrogen dioxide, nitrogen molecules, dinitrogen monoxide and nitrous acid; and means for controlling the injection rate of the nitrogen compound so that the concentration of nitrous acid or nitric acid in the reactor water can fall within a preset range.
Claim 11
Dependent Claim 119 words
A direct cycle-type, atomic power plant, which comprises: a nuclear reactor pressure vessel provided with a nuclear fuel and reactor water therein; a turbine for driving a generator by steam from the nuclear reactor pressure vessel; a condenser for condensing the steam from the turbine; means for supplying water from the condenser to the nuclear reactor pressure vessel; injection means for injecting into the reactor water at least one nitrogen compound selected from the group consisting of nitrogen monoxide, nitrogen dioxide, nitrogen molecules, dinitrogen monoxide and nitrous acid; and means for controlling the injection rate of the nitrogen compound so that the concentration of nitrous acid or nitric acid in the reactor water can fall within a preset range.
Claim 12
Dependent Claim 20 words
A direct cycle-type, atomic power plant according to claim 8, wherein said at least one nitrogen compound is nitrogen monoxide.
Claim 13
Dependent Claim 20 words
A direct cycle-type, atomic power plant according to claim 8, wherein said at least one nitrogen compound is nitrogen dioxide.
Claim 14
Dependent Claim 128 words
A direct cycle type, atomic power plant, which comprises: a nuclear reactor pressure vessel provided with a nuclear fuel and reactor water therein; a turbine for driving a generator by steam from the nuclear reactor pressure vessel; a condenser for condensing the steam from the turbine; means for supplying water from the condenser to the nuclear reactor pressure vessel; and injection means for injecting at least one of nitrogen monoxide and nitrogen dioxide into the reactor water during plant operation for suppressing transfer from a liquid phase to a vapor phase of radioactive nitrogen oxides generated in the reactor water by irradiation of the reactor water with neutrons generated during nuclear reactions of the nuclear fuel in the presence of NO in the reactor water during plant operation.
Claim 15
Dependent Claim 128 words
A direct cycle type, atomic power plant, which comprises: a nuclear reactor pressure vessel provided with a nuclear fuel and reactor water therein; a turbine for driving a generator by steam from the nuclear reactor pressure vessel; a condenser for condensing the steam from the turbine; means for supplying water from the condenser to the nuclear reactor pressure vessel; and injection means for injecting at least one of nitrogen monoxide and nitrogen dioxide into the reactor water during plant operation for suppressing transfer from a liquid phase to a vapor phase of radioactive nitrogen oxides generated in the reactor water by irradiation of the reactor water with neutrons generated during nuclear reactions of the nuclear fuel in the presence of NO in the reactor water during plant operation.
Claim 16
Dependent Claim 128 words
A direct cycle type, atomic power plant, which comprises: a nuclear reactor pressure vessel provided with a nuclear fuel and reactor water therein; a turbine for driving a generator by steam from the nuclear reactor pressure vessel; a condenser for condensing the steam from the turbine; means for supplying water from the condenser to the nuclear reactor pressure vessel; and means for injecting at least one of nitrogen monoxide and nitrogen dioxide into the reactor water during plant operation for suppressing transfer from a liquid phase to a vapor phase of radioactive nitrogen oxides generated in the reactor water by irradiation of the reactor water with neutrons generated during nuclear reactions of the nuclear fuel in the presence of NO 2 in the reactor water during plant operation.
Claim 17
Dependent Claim 128 words
A direct cycle type, atomic power plant, which comprises: a nuclear reactor pressure vessel provided with a nuclear fuel and reactor water therein; a turbine for driving a generator by steam from the nuclear reactor pressure vessel; a condenser for condensing the steam from the turbine; means for supplying water from the condenser to the nuclear reactor pressure vessel; and means for injecting at least one of nitrogen monoxide and nitrogen dioxide into the reactor water during plant operation for suppressing transfer from a liquid phase to a vapor phase of radioactive nitrogen oxides generated in the reactor water by irradiation of the reactor water with neutrons generated during nuclear reactions of the nuclear fuel in the presence of NO 2 in the reactor water during plant operation.

References Cited (Backward Citations)

US4111830A Cited
US4364900A Cited
JPS5410886A Cited
US4722823A Cited
JPS6244693A Cited
US4992232A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1995-01-27 1995-07-29 1996-01-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1999-01-27 1999-07-29 2000-01-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2003-01-27 2003-07-29 2004-01-28 $7700.00 Window Closed / Lapsed

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