Method of operating nuclear reactor

A method of operating a nuclear reactor, in which a boiling water reactor is operated while a pH of reactor water in said reactor is controlled on an alkali side and hydrogen is injected in said reactor water, characterized in that:

• a pH at room temperature of said reactor water is controlled at a relatively high level in a range of 8.5<pH≦9 at the beginning stage of start-up operation of one operating cycle, and then controlled at a relatively low level in a range of 7<pH≦8.5 until shutdown operation;
• and
• a hydrogen concentration of said reactor water is controlled in a range of 30 to 100 ppb in most of said operating cycle excluding a short period upon rated operation, and is increased to a value in a range of 100 to 200 ppb in said short period upon rated operation.

A method of operating a nuclear reactor, in which a boiling water reactor is operated while a pH of reactor water in said reactor is controlled on an alkali side and hydrogen is injected in said reactor water, characterized in that:

• a pH at room temperature of said reactor water is controlled in a range of 7<pH≦8.5 throughout one operating cycle;
• and
• a hydrogen concentration of said reactor water is controlled in a range of 30 to 100 ppb in most of said operating cycle excluding a short period upon rated operation, and is increased to a value in a range of 100 to 200 ppb in said short period upon rated operation.

A method of operating a nuclear reactor, in which a boiling water reactor is operated while a pH of reactor water in said reactor is controlled on an alkali side and hydrogen is injected in said reactor water, characterized in that:

• a pH at room temperature of said reactor water is controlled at a relatively high level in a range of 7<pH≦9 at the beginning stage of start-up operation of one operating cycle, and then controlled at a relatively low level in said range until shutdown operation;
• and
• a hydrogen concentration of said reactor water is controlled in a range of 30 to 100 ppb throughout said operating cycle.

A method of operating a nuclear reactor, in which a boiling water reactor is operated while a pH of reactor water in said reactor is controlled on an alkali side and hydrogen is injected in said reactor water, characterized in that:

• a pH at room temperature of said reactor water is controlled at a relatively high level in a range of 7<pH≦9 at the beginning stage of start-up operation of one operating cycle, and then controlled at a relatively low level in said range until shutdown operation;
• and
• a hydrogen concentration of said reactor water is controlled in a range of 30 to 100 ppb in most of said operating cycle excluding a short period upon rated operation, and is increased to a value in a range of 100 to 200 ppb in said short period upon rated operation.