Autonomous operation

Combining the practice of preventive maintenance and total quality control and total employee involvement results in an innovative system for equipment maintenance that optimizes effectiveness, eliminates breakdowns, and promotes autonomous operator maintenance through day-to-day activities. This concept known as Total Productive Maintenance (TPM) was conceived by Seiichi Nakajima and is well-documented in his book Introduction of TPM and is highly recommended reading for all involved in the maintenance area. 

In several household appliances remote or autonomous operation will be introduced. So the first autonomous cleaning robots will be available, mainly for industrial purposes. Once the price of these autonomous devices have dropped, mass production for various applications can be expected. 

Not only must space MS be compact, low power, and autonomously operated, but they must survive launch by rocket. The trend over the past few decades has been toward solid-fueled rockets or boosters that have a much rougher ride than liquid-fueled rockets. Over-zealous specifications often require that space MS survive 15 g of random shake acceleration, which is about like lifting the instrument 10 cm and dropping it on the floor repeatedly. All those shims in a magnetic sector MS must be capable of being realigned in space, perhaps with stepper motors, which is what ESA had to fly in its 2011 comet mission [19]. Likewise, carbon foil technology took an additional 10 years to fly after it had been developed in the laboratory, primarily to ensure that it survived launch. 

Ion selective electrodes (ISEs) or, in a wider sense, potentiometric sensors have demonstrated its usefulness to yield information of chemical species in automated and autonomous operation. This feature has fostered their use in the monitoring of numerous processes, in the industrial, clinical and environmental fields, among others. Current practice with these devices relies on sensors with high selectivity only in this way, a simple determination of a single ion is possible in presence of its interferents. Some reluctances on the broadening of their use are surely due to the fact that ISEs are not specific but show high selectivity towards a reduced number of ions. 

Both hydrogen and oxygen were released to the atmosphere. The control components of the plant for its autonomous operation included ... 

The station should be capable of near automatic, autonomous operation, and require a minimum of local support. Work envisioned at a manual station is to change samples daily, prepare the sample for analysis (like pressing a filter into a disk) and then put it on the detector and push a button. This can be done in less than an hour each time. In areas where line power is unreliable and of bad quality a diesel generator to provide power would, however, probably require more hours for service, fuel filling and maintenance. Full automatic stations have also been designed. 

Lab experiments Assays ffnrapsiilatinnnT> tmp)pYitY nf luwtfflvino technologies Autonomous operation and management of IT system as a whole... 

The most complicated task in constructing polyfunctional systems is the coordination of the action of the diverse centers and prevention of their autonomous operation. The main approach to resolve this problem is through control of the spatial arrangement of the active centers, which determines the extent of the transfer pathways of reagents between them, regulates diffusional... 

The Project provides for the installation of facilities for nuclear refueling and spent nuclear fuel storage on board the FPU without using special service vessels. Radioactive production waste is also stored on board the FPU. Thus, the design autonomous operation period (operation without supplies replenishment) of the FPU is determined by the c q)acity of spent nuclear fuel and radioactive waste storage tanks and periodicity of docking. With -0.54 load factor, which corresponds to the pessimistic consumption forecast, the autonomous operation of the FPU is ensured by four nuclear core sets and makes 13-15 years. After the lapse of this period the FPU is replaced with a similar one. 

The infrastructure necessary to support conventional nuclear power development is very expensive, and beyond the resources of most developing countries. One of the primary goals of the proposed approach is to reduce the need for such an infrastructure. The system requirements of highly autonomous operation, simplified and minimized system maintenance, and elimination of all on-site refueling all significantly contribute to this goal. 

Successful resolution of such a problem requires a comprehensive systems approach diat considers all aspects of manufacturing, transportation, operation, and ultimate disposal. Some elements of this approach have been used previously in the development of propulsion (ship and space) nuclear power systems, with consideration given to many diverse requirements such as highly autonomous operation for a long period of time, no planned maint ance, no on-site refuelling and ultimate disposition. 

SMALL NUCLEAR REACTOR SAFETY DESIGN REQUIREMENTS FOR AUTONOMOUS OPERATION... 

The time interval during which the reactor could be left in autonomous operation would depend on design details and opotating needs. For example, periodic operator action would be needed to keep the primary cooling water chemistry from drifting beyond acceptable limits. If need be, a timer clock could be used to initiate reactor shutdown automatically if it is not reset by an operator at the required maintenance intervals. 

Of course, autonomous operation for extended periods would require that any essential functions nonnally provided by technical staff, such as instrument calibration or testing the availability of safety systems, would either have to be performed automatically by remote means or not be required for the duration of autonomous operation. Thus, cost savings from reducing staff requirements may be offset to some degree by the need for additional monitoring instrumentation. 

Concepmally, the nuclear safety risk presented by a 10-MW, pressurized water reactor may not be much different from that presented by a 10-MW, unpressurized pool-type reactor, provided adequate cooling provisions are available to absorb the additional stored thermal energy in the former system when required. However, for pressurized systems, additional regulatory issues arise as a result of existing regulations for the autonomous operation of nonnuclear steam heating plants. 

Implementation of autonomous operation of a specific reactor system would likely proceed gradually, following a prolonged period of supervised operation to demonstrate appropriate safety behaviour. 

Autonomous reactor operation requires that the reactor is in the normal operating state and that the transition to an accident which may lead to a potential release to the environment is sufficiently long for the response team to arrive and take appropriate action. In essence, the presence or absence of staff at the site should have no bearing on the progression of any foreseeable event for an extended period exceeding the authorized period of autonomous operation. 

During the specified autonomous operation interval, the control absorber devices could be kept at their maximum withdrawn positions (but available to drop into the core on safety system command). Operation in this manner would ensure that the maximum possible reactivity insertion rate would be limited by the maximum rate at which changes could be made to the physical state of the core, especially coolant temperature and density. Provided such changes are limited in magnitude and can only be introduced relatively slowly, it may be possible to demonstrate that the self-regulating characteristics of the reactor will ensure that any transient overpower is limited to acceptable values and that the stable end-state that is established does not exceed safety limits (e.g., RPV design pressure). 

The provision of adequate cooling of the reactor core for an extended period of autonomous operation imposes additional safety design requirements to ensure diat the core always stays covered by coolant Thus, a sufficiently large inventory of coolant must be available to absorb the heat generated by the fuel and a means provided to deliver it to the core during postulated accident events that disrupt the normal heat transport pathways. 

The primary cooling ciicuit in a PWR is a high-integrity, pressure-resistant system that will contain any fission products released from the fuel in an accident until the internal pressure exceeds the values that would actuate the pressure relief devices. A simple, conqiact primary system will be easier to qualify and inspect and to protect from seismic events and external hazards. The RPV penetrations should be as few as possible and of small diameter. All primary system openings would be kept sealed for die duration of autonomous operation. 

The reactor auxiliary systems are similar to those found on other PWRs and typically include a primary water volume control and inventory system, a primary water purification system, radioactive liquid and gaseous effluent treatment systems, and a ventilation system. At low power levels, many of these systems may be required only on an intermittent basis and would be valved out during periods of autonomous operation. 

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