A method for sealing an opening extending radially from an outer circumferential surface to an inner circumferential surface of a tubular object in a nuclear power plant includes inserting a stopper from outside of the outer circumferential surface through the opening into the tubular object; and actuating a fastener from the outside of the circumferential surface to force the stopper radially outward to seal the opening. A mechanical seal assembly for plugging an opening in a tubular object by contacting an inner circumferential surface of the tubular object includes a stopper configured for insertion into an interior of the tubular object for plugging the opening. The stopper includes a surface configured for matching the inner circumferential surface of the tubular object. The mechanical seal assembly also includes a fastener passing through a hole in the stopper such that the fastener is actuatable from outside of the tubular object to force the surface of the stopper against the inner circumferential surface of the tubular object.

A system for measuring radiation activity of a target radioisotope being produced in a reactor core is disclosed. The system includes a cable assembly and a radiation detector. The cable assembly includes a housing, a target cable configured to position the housing, and a drive cable couplable and decouplable with the target cable. The target radioisotope is positioned within the housing. The drive cable is configured to drive the target cable. The radiation detector is configured to periodically measure the radiation activity of the target radioisotope being produced.

A system for measuring radiation activity of a target radioisotope being produced in a reactor core is disclosed. The system includes a cable assembly and a radiation detector. The cable assembly includes a housing, a target cable configured to position the housing, and a drive cable couplable and decouplable with the target cable. The target radioisotope is positioned within the housing. The drive cable is configured to drive the target cable. The radiation detector is configured to periodically measure the radiation activity of the target radioisotope being produced.

A system for measuring radiation activity of a target radioisotope being produced in a reactor core is disclosed. The system includes a cable assembly and a radiation detector. The cable assembly includes a housing, a target cable configured to position the housing, and a drive cable couplable and decouplable with the target cable. The target radioisotope is positioned within the housing. The drive cable is configured to drive the target cable. The radiation detector configured to periodically measure the radiation activity of the target radioisotope being produced.

A system for measuring radiation activity of a target radioisotope being produced in a reactor core is disclosed. The system includes a cable assembly and a radiation detector. The cable assembly includes a housing, a target cable configured to position the housing, and a drive cable couplable and decouplable with the target cable. The target radioisotope is positioned within the housing. The drive cable is configured to drive the target cable. The radiation detector configured to periodically measure the radiation activity of the target radioisotope being produced.

A device that will enable material to be irradiated as needed to produce a desired transmutation product inside the core of a nuclear reactor. The device provides a means for monitoring neutron flux in the vicinity of the material being irradiated to allow determination of the amount of transmutation product being produced. The device enables the irradiated material to be inserted into the reactor and held in place at desired axial positions and to be withdrawn from the reactor when desired without shutting down the reactor. The majority of the device may be re-used for subsequent irradiations. The device also enables the simple and rapid attachment of unirradiated target material to the portion of the device that transmits the motive force to insert and withdraw the target material into and out of the reactor and the rapid detachment or the irradiated material from the device for processing.

A device that will enable material to be irradiated as needed to produce a desired transmutation product inside the core of a nuclear reactor. The device provides a means for monitoring neutron flux in the vicinity of the material being irradiated to allow determination of the amount of transmutation product being produced. The device enables the irradiated material to be inserted into the reactor and held in place at desired axial positions and to be withdrawn from the reactor when desired without shutting down the reactor. The majority of the device may be re-used for subsequent irradiations. The device also enables the simple and rapid attachment of unirradiated target material to the portion of the device that transmits the motive force to insert and withdraw the target material into and out of the reactor and the rapid detachment or the irradiated material from the device for processing.

The present invention relates to a nuclear power plant which includes a small modular reactor (SMR), the nuclear power plant comprising a water tank, wherein the water tank comprises: a first water tank filled with cooling water and forming a first space in which spent nuclear fuel is disposed; and a second water tank forming a second space which is separated from the first space and in which the small modular reactor (SMR) is disposed.

The present invention relates to a nuclear power plant which includes a small modular reactor (SMR), the nuclear power plant comprising a water tank, wherein the water tank comprises: a first water tank filled with cooling water and forming a first space in which spent nuclear fuel is disposed; and a second water tank forming a second space which is separated from the first space and in which the small modular reactor (SMR) is disposed.