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25-400: EM2 is an advanced modular reactor expected to produce 265 MW e (500 MW th ) of power with evaporative cooling (240 MW e with dry cooling) at a core outlet temperature of 850 °C (1,600 °F). The reactor will be fully enclosed in an underground containment structure for 30 years without requiring refueling. EM2 differs from current reactors in that it does not use water coolant but

50-461: A device is suitable for its application, and will withstand the environmental conditions in which it is used. Normal operating temperature ranges are affected by several factors, such as the power dissipation of the device. These factors are used to define a "threshold temperature" of a device, i.e. its maximum normal operating temperature, and a maximum operating temperature beyond which the device will no longer function. Between these two temperatures,

75-499: A large-scale deployment of the EM2 could reduce the long-term need for uranium enrichment and eliminate conventional nuclear reprocessing, which requires plutonium separation. Conventional light water reactors require refueling every 18 months. EM2's 30-year fuel cycle minimizes the need for fuel handling and reduces access to fuel material, thus reducing proliferation concerns. EM2 utilizes passive safety systems designed to safely shutdown

100-788: A material is "highly dependent on operating temperature", and creep analysis is thus an important part of design validation. Some of the effects of creep and thermal fatigue may be mitigated by integrating cooling systems into the device's design, reducing the peak temperature experienced by the metal. Commercial and retail products are manufactured to less stringent requirements than those for military and aerospace applications. For example, microprocessors produced by Intel Corporation are manufactured to three grades: commercial, industrial and extended. Because some devices generate heat during operation, they may require thermal management to ensure they are within their specified operating temperature range; specifically, that they are operating at or below

125-445: A new conversion technique in which an initial "starter" section of the core provides the neutrons to convert fertile material (used nuclear fuel, thorium, or depleted uranium ) into burnable fissile fuel. First generation EM2 units use enriched uranium starters (approximately 15 percent U235 ) to initiate the conversion process. The starter U235 is consumed as the fertile material is converted to fissile fuel. The core life expectancy

150-637: A source of cooling water. If the reactor is to become part of a hydrogen economy , the coolant outlet temperature of 850°C would allow the sulfur iodine cycle to be used which directly converts thermal energy into hydrogen (without electric or other intermediate steps) with an overall thermal efficiency around 50%. EM2 can burn used nuclear fuel , also referred to as " spent fuel " from current light water reactors . It can utilize an estimated 97% of unused fuel that current reactors leave behind as waste. Spent fuel rods from conventional nuclear reactors are put into storage and considered to be nuclear waste , by

175-407: A system fan)", though in "a properly designed system, this feature should never become active". Cooling and other thermal management techniques may affect performance and noise level. Noise mitigation strategies may be required in residential applications to ensure that the noise level does not become uncomfortable. Battery service life and efficacy is affected by operating temperature. Efficacy

200-666: Is approximately 30 years without refueling or reshuffling the fuel. Substantial amounts of usable fissile material remain in the EM2 core at the end of life. This material can be reused as the starter for the second generation of EM2s, without conventional nuclear reprocessing . There is no separation of individual heavy metals required and no additional enriched uranium needed. Only fission products would be removed, which would decay to near-background radiation levels in about 500 years compared to conventional spent fuel, which requires about 10,000 years. All EM2 heavy metal discharges could be recycled into new EM2 units, effectively closing

225-460: Is determined by comparing the service life achieved by the battery as a percentage of its service life achieved at 20 °C (68 °F) versus temperature. Ohmic load and operating temperature often jointly determine a battery's discharge rate. Moreover, if the expected operating temperature for a primary battery deviates from the typical 10 °C to 25 °C (50 to 77 °F) range, then operating temperature "will often have an influence on

250-410: Is instead a gas-cooled fast reactor , which uses helium as a coolant for an additional level of safety. The reactor uses a composite of silicon carbide as a fuel cladding material and zirconium silicide as neutron reflector material. The reactor unit is coupled to direct-drive helium closed-cycle gas turbine which drives a generator to produce electricity. The nuclear core design is based upon

275-440: Is the allowable temperature range of the local ambient environment at which an electrical or mechanical device operates. The device will operate effectively within a specified temperature range which varies based on the device function and application context, and ranges from the minimum operating temperature to the maximum operating temperature (or peak operating temperature ). Outside this range of safe operating temperatures

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300-815: The United States Department of Defense has defined the United States Military Standard for all products used by the United States Armed Forces. A product's environmental design and test limits to the conditions that it will undergo throughout its service life are specified in MIL-STD-810 , the Department of Defense Test Method Standard for Environmental Engineering Considerations and Laboratory Tests . The MIL-STD-810G standard specifies that

325-416: The basal body temperature , is achieved during sleep. In women, it is affected by ovulation, causing a biphasic pattern which may be used as a component of fertility awareness . In humans, the hypothalamus regulates metabolism , and hence the basal metabolic rate . Amongst its functions is the regulation of body temperature. The core body temperature is also one of the classic phase markers for measuring

350-625: The nuclear fuel cycle , which minimizes nuclear proliferation risks and the need for long-term repositories to secure nuclear materials. EM2 power costs are expected to be lower due to high power conversion (from thermal input to electric output) efficiency, a reduced number of components, and long core life. EM2 is expected to achieve a thermal efficiency of above 50% due to its high core outlet temperature and closed Brayton power cycle. The Brayton cycle eliminates many expensive components, including steam generators , pressurizers, condensers , and feedwater pumps. The design would utilize only 1/6th of

375-487: The "operating temperature stabilization is attained when the temperature of the functioning part(s) of the test item considered to have the longest thermal lag is changing at a rate of no more than 2.0 °C (3.6 °F) per hour." It also specifies procedures to assess the performance of materials to extreme temperature loads . Military engine turbine blades experience two significant deformation stresses during normal service, creep and thermal fatigue . Creep life of

400-479: The ambient temperature, and for integrated circuits , is given by the equation: in which T J is the junction temperature in °C, T a is the ambient temperature in °C, P D is the power dissipation of the integrated circuit in W , and R ja is the junction to ambient thermal resistance in °C/W. Electrical and mechanical devices used in military and aerospace applications may need to endure greater environmental variability, including temperature range. In

425-552: The device may fail. It is one component of reliability engineering . Similarly, biological systems have a viable temperature range, which might be referred to as an "operating temperature". Most semiconductor devices are manufactured in several temperature grades. Broadly accepted grades are: Nevertheless, each manufacturer defines its own temperature grades so designers must pay attention to datasheet specifications. For example, Maxim Integrated uses five temperature grades for its products: The use of such grades ensures that

450-411: The device will operate at a non-peak level. For instance, a resistor may have a threshold temperature of 70 °C (158 °F) and a maximum temperature of 155 °C (311 °F), between which it exhibits a thermal derating . For electrical devices, the operating temperature may be the junction temperature (T J ) of the semiconductor in the device. The junction temperature is affected by

475-435: The maximum operating temperature of the device. Cooling a microprocessor mounted in a typical commercial or retail configuration requires "a heatsink properly mounted to the processor, and effective airflow through the system chassis". Systems are designed to protect the processor from unusual operating conditions, such as "higher than normal ambient air temperatures or failure of a system thermal management component (such as

500-424: The nuclear concrete of a conventional light water reactor. Each module can be manufactured in either U.S. domestic or foreign facilities using replacement parts manufacturing and supply chain management with large components shipped by commercial truck or rail to a site for final assembly, where it will be fully enclosed in an underground containment structure. Dry cooling capability allows siting in locations without

525-415: The nuclear industry and the general public. Nuclear waste from light water reactors retains more than 95% of its original energy because such reactors cannot burn fertile U238, while fast reactors can. The current U.S. inventory of spent fuel is equivalent to nine trillion barrels of oil - four times more than the known reserves. By using spent nuclear waste and depleted uranium stockpiles as its fuel source,

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550-671: The plant against terrorism and other threats. EM2's high operating temperature can provide process heat for petrochemical fuel products and alternative fuels , such as biofuels and hydrogen . Gas-cooled fast reactor Too Many Requests If you report this error to the Wikimedia System Administrators, please include the details below. Request from 172.68.168.236 via cp1112 cp1112, Varnish XID 978162675 Upstream caches: cp1112 int Error: 429, Too Many Requests at Thu, 28 Nov 2024 11:01:31 GMT Operating temperature An operating temperature

575-595: The reactor in emergency conditions using only gravity and natural convection. Control rods are automatically inserted during a loss-of-power incident via gravity. Natural convection flow is used to cool the core during whole site loss of power incidents. No external water supply is necessary for emergency cooling. The use of silicon carbide as fuel cladding in the core ensures no hydrogen production during accident scenarios and allows an extended period of response when compared to Zircaloy metal cladding used in current reactors. Underground siting improves safety and security of

600-401: The timing of an individual's Circadian rhythm . Changes to the normal human body temperature may result in discomfort. The most common such change is a fever , a temporary elevation of the body's thermoregulatory set-point, typically by about 1–2 °C (1.8–3.6 °F). Hyperthermia is an acute condition caused by the body absorbing more heat than it can dissipate, whereas hypothermia

625-406: The type of battery selected for the application". Energy reclamation from partially depleted lithium sulfur dioxide battery has been shown to improve when "appropriately increasing the battery operating temperature". Mammals attempt to maintain a comfortable body temperature under various conditions by thermoregulation , part of mammalian homeostasis . The lowest normal temperature of a mammal,

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