Hmmm,"Rads" may work,"Atom" not so catchy...any specialized jargon is likely to cause confusion to some degree...I think your original use of "Rads" as fuel for the mutant powers is better.

yeah i'll leave it i think, tthanks.

Big entry (as the actress was heard to remark to the bishop)...

This is cut and pasted from my file. As such the mechanics probably won't make much sense. If it isn't explicitly stated, the point at which mutants reach Critical Mass is 10 Rads and they generate 1 per day anyway, regardless. These powers work by forcing the mutant to incur Rads per use. This at times might not always seem realistic (eg when dealing with physiology). These instances are cases where ideas defer to rules consistency and, hopefully, balance. Mutants here are not meant to be cute gamma world weird but clean hybrids; they are ostensibly humanoid (homo mutatis), just blessed with disgusting abilities. The rules explanations should make sense in the context of what's already posted. Here we go...

Rad Powers:

Gamma Rays - the character can emit strange rays from his eyes and mouth. Used as a ranged attack (incur rads to determine the dice pool for the action) the character can blast a man's 'soul'. The effect either: switches off a Norm's Experience and renders it unusable for x rounds, adds x to the character's Rad total, does xd6 damage to a Mindwalker (psychics fuel their powers with Hurt points), or decreases a Robots Memory limit by x (pushing them closer to Overload/Cooldown). The effect depends on the target.
Atomic Tonic - with an action (spent in some form of meditative pose) the mutant can gain Hurt points; healing himself for Rads. Each Rad taken (up to 6 per action) allows the mutant to heal 1d6 Hurt. All characters near the mutant take 1 point of damage per 6 points healed.
Invisible Isotope - the mutant incurs up to 5 Rads and takes an action to 'blend', disappearing from regular sight. They now cannot be perceived by characters with less Awareness than Rads incurred, unless they take an action to try. Other characters may attempt to locate them, as part of any action. In each case an Awareness roll is made opposed by a value equal to the Rads incurred. The effect remains until either the mutant cancels it (which can be done anytime without an action), gets hit, or combat (or the current scene) ends. Once a character has passed the above Awareness roll he needn't make it again, instead he receives +1 to all difficulties to target him though he can still track the mutant. Finally, while so invisible, the mutant's features shift; their appearance alters - and not for the best (at least in terms a Norm consider attractive). The GM has final say on the specifics of the change.
Curie's Curse - this is a suite of powers, from which the mutant can choose specific effects, that reflect aspects of an altered phsiology such as weird limb properties. Every mutant has a strange and twisted physique or appearance, but without a Power those changes are merely cosmetic. Consequently this power can be taken mutliple times (unlike the rest) with a different effect for each instance.
   Quick Draw McClaw: the mutant may incur the difference between the higher and the lower stat to choose the higher when using the aforementioned combat rule. This effect can only be chosen if the mutant has different scores for the two stats.
   Scuttlebutt: the mutant can incur Rads, on a 1 for 1 basis, to bolster his Reflexes/Guts when calculating movement for a round (or scene, if outside combat). The mutant may also employ unusual methods of moving, such as climbing walls just as easily. One such mode must be picked.
   Biowhip: the mutant can transform a mutant limbs into a tentacle which can be used to attack, restrain and pull targets close with an action (resolved as normal). Each instance of this effect allows the mutant can transform one limb into a 1m long tentacle. It attacks at whatever range the mutant extends it to (paying each time the process is used) but lasts only for the action, resolving the transformation as part of that resolution.
    Hands Free: the mutant can make use of an extra limb/tail or similar, perhaps to fire an extra gun or tool. Consequently the mutant can add half (round up) his acting stat again in exchange for incurring 2 Rads. This lasts for the action concerned. When using this effect in an action that makes use of Ammo, the total Ammo cost is also likewise; that total must be paid for or the effect cannot be used.
The mutant can make use of his unique physiology in ways analogous to these effects without having to incur Rads if the GM deems such use to be mundane or not otherwise giving the mutant a significant advantage.
Mentus Mutatis - with an action the mutant can attempt to take control over local Rad Entities. This requires a Command roll (difficulty determined by the size and nature of the local irradiated fauna in question) with the mos limiting the number of Rads the mutant can incur. In exchange for incurring up to that many Rads, the mutant can give 1 single individual command to that many entities. Once a command is resolved the entity returns to its normal behaviour uninfluenced (though maybe instinctually pissed off). While any such entity carries out its action the mutant cannot act (he remains entranced in some, weird, fashion, able to see and hear through the senses of any/all the entities he controls). Line of sight to all charges is required for this effect to work. While under the mutant's control, entities insert themselves into the Initiative order at that point acting at their own point. If their Initiative is higher than the current point they immediately act in an order set by the mutant, however where there is conflict with another character the entities defer. Mutants using this power start to resemble such entities themselves, often acquiring insect-like features.
Chernobyl Carapace - the mutant can activate armour, during Initiative and requiring an action, by incurring Rads. Each point adds 1 point of Armour but reduces Reflexes (and accordingly all move rates) by 1 simultaneously. The effect lasts for the round, cancelling it requires an action however.
Toxic Touch - with a succesful unarmed attack, the character can incur Rads to increase the damage. Incurring 2 points adds 1d6 damage. The mutant must be unarmed and make skin to skin physical contact for this to occur. If the mutant restrains a target he can use an action, while he has the target under restraint, to incur 2 Rads and automatically inflict 1d6 damage, again skin contact must be made. This character cannot wear Armour without corroding it (except Armour created by his own mutation. Each Rad incurred reduces, permanently, the value of any Armour the mutant happens to be wearing currently (for the sake of convenience, he doesn't need to go entirely naked - he wears Phlux weave).
Gamma Gills - the character can incur Rads to manifest gills, webbed feet and hands, and be fully aquatic for an hour per point. Any mutant with this power also enjoys +1 Reflexes while immersed in a heavy storm outdoors.
Junk Feeder - the mutant can eat junk and as a result gain Rads to exercise some sense of Postcognition. By consuming points of Ammo the mutant can somehow perceive the recent history of a specific and small locality (a room, or inside a vehicle, for example).
Atomic Bile - the character can 'exude' a pool of internal liquid, toxic/acidic (ie hazardous to the touch), in nature beside him. The pool extends 1m and also does d6 damage, per Rad, to anything that comes in contact. It even erodes armour, reducing the Armour value (except Biohazard Armour) by the same d6 amount, permanently. when applied to structures it does Rust damage in the same way which the GM may deem enough to create an entrance of commensurate (1m radius/rad spent) size. To have this manifest as an attack the mutant must take Toxic Touch.
Half-Life Blind - the mutant has access to abnormal modes of perception. By tuning out his normal sight and incurring Rads, the mutant is then able to see in total darkness, or see in infrared, or any other exceptional vision mode. Each Rad allows the mutant to operate in this way for 1 round.
Cancer Kinetic - the mutant's touch can excite inanimate objects on a molecular level. This allow them to operate according to their normal function just by touch. Each use of the ability incurs Rads commensurate with the GM's judgement of the complexity of the process involved: for example, switching on a computer that isn't plugged in isn't too difficult, but doing so while getting passed password requirements and into the main OS is much harder  - unless the mutant has that information already (his power manifests that knowledge instinctively). However the GM shouldn't tell the mutant the required cost leaving him to continue incruring Rads until the GM says otherwise. This way, if the character overspends significantly, the GM is free to rule that the device overloads - perhaps spectacularly. However once a cost has been determined this cost should remain consistent throughout the mutant's experience.
Cthonic Inclination - By exuding a disgusting coating (over all clothing as well) over themselves, the mutant is able to burrow into the earth and transit across distance at twice normal speed. This requires an action to exit and enter and cannot be done while wearing any armour (except provided by another power). The mutant cannot be completely clothed (ie wearing a full body suit+mask). The coating can be employed without having to burrow; this too requires an action and allows the mutant to double the opposing stat on any attempt to restrain him. Coating oneself incurs the mutant 1 Rad per instance of resisting restraing (incurred when this would resolve, not at the point of coating). Travel using this power includes the act of coating as part of the burrowing action, and incurs 1 Rad per round while submerged. While underground the mutant cannot be attacked and may remain burrowed without actually moving. Needless to say the mutant must be on the ground to perform this, even if that doesn't mean on earth itself (the effect can penetrate pretty much anything while on the ground).

Using Rad Powers adds to the Mutant's daily Rad total (each Mutant naturally generates 1 rad per day). The only way mutants have to ease the pressure (and avoid Critical Mass) is to release the Rads in a way that is deleterious to either nearby characters or to the enviroment (causing lingering effects that can allow the mutant to be tracked as well, potentially attracting Rad Entities and sentient mutants. These creatures are always bolstered by the current Scientific Advancement Guage score). The closer the mutant is to Critical Mass (10 rad points) the more spectacular the effects (including Rad Storms); use the chart as a guide to creating the effects of a mutant burning off his Rads. This level determines the effect: ie the current level, not the number of points burned off in the process, determines the effect that process generates.

Each mutant has a uniquely non-human appearance. This is merely a cosmetic aspect that the player should decide upon and in relation to the powers they possess. There is no mechanical advantage to the choice of appearance. Also each Power can be fashioned into whatever the player chooses - the rules are a framework for how the player wishes to interpret that ability so long as the GM agrees. For instance Toxic Touch could easily represent a mutant vampire feeding on blood as a way to transfer Rads to damage to the target. As long as the Power works as listed anything is is just pure colour.