A nuclear steam supply system utilizing gravity-driven natural circulation for primary coolant flow through a fluidly interconnected reactor vessel and a steam generating vessel. In one embodiment, the steam generating vessel includes a plurality of vertically stacked heat exchangers operable to convert a secondary coolant from a saturated liquid to superheated steam by utilizing heat gained by the primary coolant from a nuclear fuel core in the reactor vessel. The secondary coolant may be working fluid associated with a Rankine power cycle turbine-generator set in some embodiments. The steam generating vessel and reactor vessel may each be comprised of vertically elongated shells, which in one embodiment are arranged in lateral adjacent relationship. In one embodiment, the reactor vessel and steam generating vessel are physically discrete self-supporting structures which may be physically located in the same containment vessel.

A passive safety system for a nuclear power plant (100) cools a nuclear power plant after shutdown (SCRAM) even when all primary water circulation has been disabled. The system comprises a source of compressed gas (112, 805) that can be its only source of operating energy, a source of water (106, 500), and a plurality of plumbing components. The system is located nearby but outside of the plant where it will not be damaged in the event of an accident inside the plant. In one embodiment, the system is located underground. In another embodiment, the system is portable so that the gas and water are carried in tanks (500, 510) on railroad cars or other wheeled conveyances. The portable system is located above ground, or optionally in a covered trench (705). In an alternative embodiment, only compressed gas is used to cool the plant.

A method for generating a fissile material is described. The method includes positioning a fertile, non-fissile material within outer space, the position within an area of proton or other high energy particle radiation, rather naturally or artificially occurring, allowing the high energy particle radiation to impinge the fertile but non-fissile material over a time, the time based on amount of high energy particle radiation at the position, such that the non-fissile material gradually transmutes into a fissile material due to the impingement, and deploying the fissile material within a spacecraft.

An auxiliary system for cooling a spent nuclear fuel pool through a submersible heat exchanger to be located within the pool. In each train or installation, a single loop or series of loops of cooling fluid (e.g., sea water or service water) is circulated. The system is modular, readily and easily installed during an emergency and can be self operating with its own power source. Multiple trains may be used in parallel in order to accomplish the required degree of spent fuel pool cooling required.

A verification method for an application logic provided with one or more macro logics configured to perform a predetermined operation, a macro operation control unit configured to instruct the one or more macro logics to start the operation to cause the one or more macro logics to perform the operation, and an operation data storage area configured to store data. In the application logic, static verification by property description of a formal verification language is performed for each of the one or more macro logic, the macro operation control unit, and the operation data storage area, and dynamic verification by simulation is further performed for at least one of the one or more macro logics.

A core monitoring system including: a TIP measuring a neutron amount in a nuclear reactor; a TIP drive device; a TIP panel; a neutron monitoring panel; and a process computer. The TIP panel includes: a TIP level processor and a TIP position processor that process a TIP level signal and a TIP position signal input from the TIP drive device, respectively; a time setting section synchronizing the TIP level signal and the TIP position signal; and a TIP level data storage section storing synchronized TIP level data. The neutron monitoring panel includes a time setting section setting collecting time of a LPRM level signal and an APRM level signal. The process computer compares the time and stores the TIP level data from the TIP panel and the LPRM and APRM level signals from the neutron monitoring panel corresponding in time, and calculates core performance based on the TIP level data.

A method regulates operating parameters comprising at least the mean temperature of the core (T.sub.m), and the axial power (AO) imbalance. The method includes development of a vector (U.sub.S) of control values of the nuclear reactor by a supervisor (31) implementing a predictive control algorithm; development of a vector (u.sub.K) of corrective values of the nuclear reactor controls by a regulator (33) implementing a sequenced gain control algorithm; development of a vector (U) of corrected values of the commands of the nuclear reactor, by using the vector (U.sub.S) of the values of the commands produced by the supervisor (31) and the vector (u.sub.K) of the corrective values of the commands produced by the regulator (33); and regulation of the operating parameters of the nuclear reactor, by controlling actuators using the vector (U) of the corrected values of the controls.

An apparatus for treating waste of a nuclear reactor pressure vessel includes: a suction unit inserted into the nuclear reactor pressure vessel through a plurality of through-pipes passing through a lower portion of the nuclear reactor pressure vessel to suck waste inside the nuclear reactor pressure vessel; a waste treatment part connected to the suction unit to treat the waste; and a lower collection part connected to the waste treatment part to be positioned under the nuclear reactor pressure vessel with the suction unit therebetween.

Exemplary embodiments provide automated nuclear fission reactors and methods for their operation. Exemplary embodiments and aspects include, without limitation, re-use of nuclear fission fuel, alternate fuels and fuel geometries, modular fuel cores, fast fluid cooling, variable burn-up, programmable nuclear thermostats, fast flux irradiation, temperature-driven surface area/volume ratio neutron absorption, low coolant temperature cores, refueling, and the like.

Systems and methods for upgrading power output of previously-deployed nuclear power plants are described. Systems and methods may include a base nuclear power plant with a predetermined base power output rating and a predetermined base whole core refueling interval. Systems and methods may also include a power upgrade kit for increasing the base power output rating from the base power output rating to an increased power output rating without a change in fuel charge, reactor structures, or civil structures.