Changes: Radioisotope Thermoelectric Generator

Revision as of 23:27, 1 May 2016

A Radioisotope Thermoelectric Generator is an alternate type of power generator in use on Frontier worlds in various applications. It is also known as an "RTG pack" or "Thermo pack". RTGs generate energy by from the heat given off by radioactive isotopes as they decay. RTGs have been in use in various forms for many centuries, reaching back prior to the colonization of the Frontier.

Physical Description^[1]

An RTG may be manufactured in various configurations and sizes depending on need. One popular size for use in small- to medium-size dwellings and some ground vehicles is roughly cylindrical, measuring roughly .22 m³ ^[2] and massing approximately 45 kg.

The generator contains a number of modules containing radioactive isotopes^[3] encased in protective casings^[4] that not only shield the environment from the radiation emitted by the isotopes, but also prevent the isotopes from contaminating the environment in the event of an accident. As the isotopic "fuel" decays, the heat produced is converted into usable energy by an array of thermovoltaic cells.^[5]

Older models of RTG used thermocouples instead of cells, but they could only achieve half the efficiency of contemporary models.^[6]^[7]

Power from the generator is routed directly into a device or structure or it may be stored in one or more parabatteries, which would be purchased separately. Solar generators are also capable of recharging power beltpacks and backpacks.

Energy Output

Under optimal conditions modern RTGs operate at roughly 20% efficiency, yielding an energy output of 800 SEU per hour.^[8]

Maintenance

RTGs are designed to need little or no maintenance.^[9] What little work needs doing typically involves the power storage and distribution system rather than the RTG itself.

Operational Endurance

As the fuel elements decay, the output power decreases. Typically an RTG's output drops less than 1% per year.^[10] Most RTG applications are planned to have a "design life" of between 10-15 years. Beyond that, either the device is replaced entirely or a new RTG is installed.

Cost

The price of an RTG varies according to it's type (see table below).

Types

Generator Type	SEU/hour	SEU/second	Cost (Cr)	Mass	Volume	Maint (Cr/day)
AAA	50	0.0139	625	3	.01375m³	0.1
AA	100	0.0277	1250	6	.0275m³	0.15
A	200	0.0555	2500	10	.055m³	0.25
0	400	0.1111	5000	20	.11m³	0.50
1	800	0.2222	10000	40	.22m³	1
2	1600	0.4444	20000	80	.44m³	2
3	3200	0.8888	40000	160	.88m³	4
4	6400	1.1776	80000	320	1.76m³	8
5	12800	3.5550	160000	640	3.52m³	10
6	25600	7.1104	320000	1280	7.04m³	32
each additional	x2	x2	x2	x2	x2	x2

Notes and References

↑ I based this description on the current NASA MMRTG.
↑ 64 cm in diameter by 66 cm tall
↑ Plutonium-238, Curium-244 and Strontium-90 are popular choices for their balance of heat emission vs half-life.
↑ Federanium or other similar material
↑ Similar to photovoltaic cells, only using heat energy rather than light as a fuel source.
↑ This would place thermocouple RTGs at about the level of the original game's Type 1, but at only 40% of the mass.
↑ This is the current level of RTG development as represented by the MMRTG. Thermovoltaic cells are still in the developmental stages, but look promising.
↑ Based on performance tests done under laboratory conditions of real thermovoltaic cells.
↑ Ignore the Mainenance Requirements rules regarding power generators in general.
↑ Engineers and use 1% as a standard expectation at the design stage.

[1] I based this description on the current NASA MMRTG.

[2] 64 cm in diameter by 66 cm tall

[3] Plutonium-238, Curium-244 and Strontium-90 are popular choices for their balance of heat emission vs half-life.

[4] Federanium or other similar material

[5] Similar to photovoltaic cells, only using heat energy rather than light as a fuel source.

[6] This would place thermocouple RTGs at about the level of the original game's Type 1, but at only 40% of the mass.

[7] This is the current level of RTG development as represented by the MMRTG. Thermovoltaic cells are still in the developmental stages, but look promising.

[8] Based on performance tests done under laboratory conditions of real thermovoltaic cells.

[9] Ignore the Mainenance Requirements rules regarding power generators in general.

[10] Engineers and use 1% as a standard expectation at the design stage.

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@@ Line 6: / Line 6: @@
 The generator contains a number of modules containing radioactive isotopes<ref>Plutonium-238, Curium-244 and Strontium-90 are popular choices for their balance of heat emission vs half-life.</ref> encased in protective casings<ref>Federanium or other similar material</ref> that not only shield the environment from the radiation emitted by the isotopes, but also prevent the isotopes from contaminating the environment in the event of an accident. As the isotopic "fuel" decays, the heat produced is converted into usable energy by an array of thermovoltaic cells.<ref>Similar to  photovoltaic cells, only using heat energy rather than light as a fuel source.</ref>
-<nowiki> </nowiki>Older models of RTG used thermocouples instead of cells, but they could only achieve half the efficiency of contemporary models.<ref>This would place thermocouple RTGs at about the level of the original game's Type 1, but at only 40% of the mass.</ref><ref>This is the current level of RTG development as represented by the MMRTG.  Thermovoltaic cells are still in the developmental stages, but look promising.</ref>
+Older models of RTG used thermocouples instead of cells, but they could only achieve half the efficiency of contemporary models.<ref>This would place thermocouple RTGs at about the level of the original game's Type 1, but at only 40% of the mass.</ref><ref>This is the current level of RTG development as represented by the MMRTG.  Thermovoltaic cells are still in the developmental stages, but look promising.</ref>
 Power from the generator is routed directly into a device or structure or it may be stored in one or more [[Parabattery|parabatteries]], which would be purchased separately.  Solar generators are also capable of recharging [[Power beltpack|power beltpacks]] and [[Power Backpack|backpacks]].
 == Energy Output ==