Hitachi, Ltd.

Hitachi Chemical Company, Ltd.

Hitachi Engineering Co., Ltd.

Isao Sumida

Yoshiyuki Kataoka

Masataka Hidaka

Masanori Naitoh

Hiroaki Suzuki

Tsuyoshi Niino

Tohru Fukui

Shigeo Hatamiya

Kenji Tominaga

Michio Murase

Toshitsugu Nakao

Masato Koshiishi

Shozo Yamanari

Shouichirou Kinoshita

Minoru Akita

Tetsuo Ito

Moriaki Tsukamoto

Koji Hashimoto

Kotaro Inoue

Tetsuo Horiuchi

Ryuhei Kawabe

Tadashi Fujii

Masaki Matsumoto

Kanehiro Ochiai

Naohisa Watahiki

Satoshi Miura

Shouichiro Kinoshita

Kazutake Imani

Takanobu Yamamoto

Takao Akiyama

A reactor containment facility having a reactor pressure vessel containing a core; a dry well in which the reactor pressure vessel is arranged; a suppression chamber holding suppression-pool water and forming above the suppression-pool water a wet well; and a plurality of vent pipes allowing the dry well to communicate with the suppression-pool water; a steel wall which is in contact with the suppression-pool water of the suppression chamber and which surrounds at least the pool water so as to form a containment vessel which houses the dry well and the suppression chamber; and an outer peripheral pool containing cooling water in contact with the outer peripheral surface of the steel wall. The facility further includes: a dividing structure for dividing the wet well of the suppression chamber into a first space which is in contact with the water surface of the suppression-pool water and a second space which is not in contact therewith; a first passage which allows the first space to communicate with the second space and which has an area smaller than that of the dividing device; and a cooling device for keeping the second space at a temperature lower than that of the first space.

Reactor containment facilities

There is disclosed a nuclear reactor installation. An accumulator-type emergency core cooling system, a gravity-driven core cooling system and an equalizing system for submerging a reactor core are provided within a primary containment vessel containing a reactor pressure vessel in which the reactor core is disposed. These cooling systems are automatically operated sequentially in accordance with the pressure in the reactor pressure vessel without the need for any particular powered source. The primary containment vessel is made of steel, and the interior of this containment vessel is divided into a space containing the reactor pressure vessel and a space containing an operation floor in such a manner that the two spaces are isolated from each other. An opening device is provided between the two spaces so as to communicate the two spaces with each other in the event of an accident, the upper portion of the primary containment vessel being air-cooled while the lower portion of this containment vessel being water-cooled.

Nuclear reactor installation

Disclosed is liquid filling apparatus for a high-temperature and high-pressure vessel. The apparatus comprises a high-temperature and high-pressure vessel, a closed liquid storage tank disposed at a level higher than that at which liquid is supplied to the high-temperature and high-pressure vessel, a liquid-filling flow passage for supplying liquid from the closed liquid storage tank into the high-temperature and high-pressure vessel, a pressure-feed flow passage for supplying a pressure from the high-temperature and high-pressure vessel to the closed liquid storage tank, valves equipped on the liquid-filling flow passage and the pressure-feed flow passage respectively, and a liquid-filling liquid source adapted to communicate with the interior of the closed liquid storage tank via a valve, whereby the environmental surroundings of the closed liquid storage tank are lower in temperature than the interior of the high-temperature and high-pressure vessel.

Liquid filling method for a high-temperature and high-pressure vessel

A pressure control chamber of a reactor containment vessel for receiving the atmosphere of the reactor containment vessel containing leakage steam developing in the event of an accident includes a pressure control pool, and a wet well disposed above the pressure control pool. The wet well is divided into an inner peripheral portion and an outer peripheral portion. The inner and outer peripheral portions are communicated with each other via the pressure control pool. An outlet port for flowing the atmosphere of the reactor containment vessel containing the leakage steam is provided at the inner peripheral side of the pressure control pool. When the atmosphere of the reactor containment vessel containing the leakage steam is introduced into the pressure control pool in the event of the accident, this atmosphere is condensed by the water in the pressure control pool, and the gas of this atmosphere not condensed is accumulated in the inner peripheral portion of the wet well. As a result, the pressure within the inner peripheral portion is increased to increase the water level of the pressure control pool at the outer peripheral portion, so that the area of contact of a reactor containment vessel wall with the pressure control pool water is increased, thereby enhancing a heat radiation performance of the reactor containment vessel.

Reactor containment vessel

Disclosed is a liquid filling apparatus for high-temperature and high-pressure vessel. The apparatus comprises a high-temperature and high-pressure vessel, a closed liquid storage tank disposed at a level higher than that at which liquid is filled into the high-temperature and high-pressure vessel, a liquid-filling flow passage for supplying liquid from the closed liquid storage tank into the high-temperature and high-pressure vessel, a pressure-feed flow passage for supplying pressure from the high-temperature and high-pressure vessel to the closed liquid storage tank, valves equipped on the liquid-filling flow passage and the pressure-feed flow passage respectively, and a liquid-filling liquid source adapted to communicate with the interior of the closed liquid storage tank via a valve, whereby the environmental surroundings of the closed liquid storage tank are lower in temperature than the interior of the high-temperature and high-pressure vessel.

A primary containment vessel, comprising a reactor pressure vessel in which a core is accommodated, a dry-well volume covering the upper portion of the reactor pressure vessel, a suppression chamber provided with a suppression pool surrounding an intermediate portion of the reactor pressure vessel, has a plurality of vent tubes establishing a connection between the dry-well volume and the suppression pool and an annular baffle plate disposed in the suppression pool along the side wall of the suppression chamber, having its top end positioned at a height between a free surface of the suppression pool and an outlet of the vent tube opened in the suppression pool and its lower end positioned at a height between the outlet and the bottom of the suppression pool. If a loss of coolant accident occurs, hot steam discharged into the dry-well volume is discharged into the suppression pool through the vent tube so as to heat water on the inside of the baffle plate. The water head difference generated by the water temperature difference between the inside and the outside portions of the baffle plate causes a vertical convection passing through the baffle plate to be created. Therefore, the heat accumulating characteristics of pool water and the heat radiation performance of the containment vessel are improved, allowing the size of the containment vessel to be reduced.

Primary containment vessel with outer pool

Jet pumps and a feed water sparger are disposed in a reactor pressure vessel incorporating a core. A first feed water pipe supplies a portion of feed water to the jet pumps as their driving water. A second feed water pipe connected to the first feed water pipe supplies the remaining portion of the feed water to the feed water sparger. A first feed water heater is disposed in the first feed water pipe downstream of a connecting point of the first feed water pipe and the second feed water pipe. An amount of extracted steam introduced into the first feed water heater is controlled on the basis of a difference in the temperature between feed water flowing through the first feed water pipe and the feed water flowing through the second feed water pipe.

Nuclear power plant

A natural circulation reactor includes a reactor pressure vessel, a cylindrical shroud disposed within the reactor pressure vessel to surround a reactor core and to extend to a position above the reactor core, and a coolant descending passage defined between the reactor pressure vessel and the shroud for allowing the coolant discharged from the top of the reactor core to be again supplied to the bottom of the reactor core. In such a natural circulation reactor, a liquid level of coolant in the coolant descending passage is adjusted on the basis of a reactor power request signal at a position below a liquid level of coolant in the shroud, and thus reactor power is controlled so that it may reach a predetermined reactor power by adjusting the liquid level of coolant in the coolant descending passage.

Method of and apparatus for controlling power of natural circulation

A solar heat collector comprises an evacuated transparent pipe; a solar heat collection plate disposed in the transparent pipe; a heat pipe, disposed in the transparent pipe so as to contact with the solar heat collection plate, and containing an evaporable working liquid therein; a heat medium pipe containing a heat medium to be heated; a heat releasing member extending along the axis of the heat medium pipe and having thin fin portions extending from the axis to the inner surface of the heat medium pipe; and a cylindrical casing surrounding coaxially the heat medium pipe to provide an annular space which communicates with the heat pipe. The evaporable working liquid evaporates, receiving solar heat collected by the heat collection plate. The resultant vapor heats the heat medium through the heat medium pipe and the heat releasing member.

Solar heat collector

Growing community of inventors

Ibaraki, Japan

Isao Sumida