Can an organic system utilize nuclear power? There are many techniques for exploiting nuclear reactions. Could any of them be accomplished biologically?

From a biological standpoint all nuclear energy technologies are very simple. A conventional nuclear reactor consists of a nuclear pile, coolant, and control rods. Sufficiently enriched fuel is kept in close enough proximity to create a sustained reaction, coolant absorbs heat from the reaction and transfers it to a secondary loop to turn turbines and make electricity. Neutron absorbing control rods are dispersed in the pile to control the rate of reaction.

Biology does not use heat for energy it uses sugars and ATP. Sugars are made by the chloroplasts in green plant. Chloroplasts are organs in the plant cells that utilize various wavelengths of electromagnetic radiation to synthesize the sugars. The mitochondria in each cell synthesize ATP using the energy in the sugar molecule.

All organisms have some radioactive elements in them. What if an organism could utilize the heat and radiation of this material? Heat could be utilized to keep the organism warm and radiations could be used directly to create sugars. This could occur on a cellular level or in reactor organs.

I welcome you comments and ideas.

Any radioisotope utilizing organism (and I'm assuming it would be some sort of natural decay utilization, at least at first) would have to be capable of withstanding it's own radiation. Whatever nuclear material it eats and organizes to produce power would have to put out radiation at a slow enough rate to give the cell time to reproduce effectively and/or repair itself. Even the relatively benign penetration rate of alpha particles can go quite a ways over single-cellular distances. The genes of such a cell would have to have very good mutation repair/censor mechanisms to remain genetically stable.

It would have to absorb radiation from a decayed particle, then use that activity to sling CO2 and H2O together into sugar or something. The decayed atom would likely jerk rather violently and ionize when it emmits an alpha or a beta. Such activity would probably also be intermittant compared to sunlight. The protein mechanism of converion would have to survive that transformation. Perhaps the radioisotope would have to be separate from the conversion protein.

This shielding could be accomplished in many ways. Perhaps a bonelike encasement sufficiently dense of composed of radiation absorbing molecules.Perhaps the organism would control the rate and timing of the decay.Perhaps a special resistant cell would be employed. Maybe a special cell membrane or cellular fluid. How about multiple nuclei. Maybe clone cells. Consider a kind of drone cell without a nucleus.Perhaps some substance could absorb the jerky output and release a more appropriate form of energy.

Are you talking about a single cell mechanism, or some sort of macroscopic organ that uses heat from an atomic pile to drive a reaction? There are all sorts of ways to do this on a macroscopic level. On a single cellular level, things get more difficult. But perhaps that is just my bias as an engineering student of macroscopic devices.

For example, if the organism in question lived in a sufficiently cold environment, and grew around a radioactive heat source of sorts, with a buffer region of dead cells in between it and the fission source, it could use the temperature difference the same way hydrothermal vent organisms do to drive an energy-storage reaction. Perhaps envisioning the organism's "leaves" as a tube around the radioactive source. If the radioactive source was on an alpha-beta decay sequence, the organism would probably be able to protect itself from it's power source with a very thin buffer layer.

Of course, the organism in question would have to be capable of finding and eating sufficient quantities of a radioactive substance to keep itself alive, and be able to expel cold dead fuel material. Given that a quantity of radioisotope material, or fissioning material (if the organ is a full reactor), is good for a few years, the creature has plenty of time to do this, just not forever.

In a sense, one might argue that we already have such life-- the aforementioned hydrothermal vent organisms. After all, hydrothermal vents are heated by the hot interior of the Earth, which in turn is heated by radioactive decay. (Of course, in some sense even photosynthesis is utilizing solar fusion reactions, but that's stretching the chain to an absurd degree). My point is just, if you have a "hot" zone due to fissionable material, then you may have hydrothermal-vent analogies in your environment, and you may get life using those temperature gradients. But it sounds like that would be a cheat in what JHotz is talking about-- you want the decay energy to directly enter the cells, not just heat their environment. It would probably only be interesting if the cells acquired the ability to forage through the environment for a relatively low concentration of radioactive "food", which they then concentrate and use. Are there places on Earth where such a niche exists?