Talk:Safe affordable fission engine

What moderator material
If these are nuclear reactors, what neutron moderator material is used ? and how is power controlled or shutdown ? - Rod57 (talk) 14:48, 30 August 2011 (UTC)

mistake?
50x30 centimetres and 1.2 tonnes? there must be a mistake. — Preceding unsigned comment added by 92.225.95.99 (talk) 16:00, 21 August 2012 (UTC)

In: Stănculescu, Adrian (2005). The Role of Nuclear Power and Nuclear Propulsion in the Peaceful Exploration" it is mentioned that the SAFE reactor weights "only" 512kg but there are no measurements.--92.225.95.99 (talk) 16:15, 21 August 2012 (UTC)

1200 kg divided by 50X30^2 cm is 27 g/ml, no material on earth has a density that great (Iridium on 22.65 g/ml, Uranium 19.1 g/ml) the figures present are thus physically impossible and must be wrong! --BerserkerBen (talk) 18:42, 15 September 2012 (UTC)

"The SAFE-400 space fission reactor (Safe Affordable Fission Engine) is a 400 kWt HPS producing 100 kWe to power a space vehicle using two Brayton power systems—gas turbines driven directly by the hot gas from the reactor. Heat exchanger outlet temperature is 880°C. The reactor has 127 identical heatpipe modules made of molybdenum, or niobium with 1% zirconium. Each has three fuel pins 1 cm diameter, nesting together into a compact hexagonal core 25 cm across. The fuel pins are 70 cm long (fuelled length 56 cm), the total heatpipe length is 145 cm, extending 75 cm above the core, where they are coupled with the heat exchangers. The core with reflector has a 51 cm diameter. The mass of the core is about 512 kg and each heat exchanger is 72 kg." from the site http://www.eoearth.org/article/Nuclear_reactors_for_space --BerserkerBen (talk) 18:45, 15 September 2012 (UTC)