- Radiation trait (core rules p75) - gives a dose of 2D * 20 (*5 for spacecraft scale) rads to anyone close to the firer, the target or the line of fire between the two.
- Radiation damage (HG p13) - "This is simple to apply to the types of low tonnage ships most Travellers will be using,..."
- Radiation (core rules p77) - read across from the Immediate Exposure or Cumulative Exposure entry (whichever is worse) on the Radiation Effects table to determine how bad things get for the victim of a radiation attack (hint: it gets bad pretty quickly)
- Radiological protection #1 (HG p13) - a conventional hull reduces the rads taken by 500 (shielding doubles this protection to 1000).
- Radiological protection #2 (core rules p109) - a dose of anti-rad drugs reduces the damage taken by 100 rads if administered within 10 minutes of the attack.
- Radiological protection #3 (CSC pp10-35) - wearing protective gear can reduce damage by up to 310 rads depending upon what you have, civilian kit tops out at -185 rads (a TL14 HEnv Vacc Suit).
Items 4 and 6 suggest that approximately two fifths of the crew will be lucky enough to avoid rad damage (assuming they suit up for starship combat, which seems like a no brainer) and per item 5, prompt application of anti-rad meds will slightly mitigate the effects for the others, although an unlucky radiation effect roll is no joke. Passengers may well be reliant on emergency vaccuum protection however, so they will be more exposed and possibly harder to dose with anti-rads. Of course all of this only applies if a ship is hit once with a radiation weapon - multiple strikes will tend to inflict large cumulative doses, with rapid debilitation of both crew and pax (and death likely given the amount of damage rolled at the higher ends of the radiation effects table).
A ship with anti-rad shielding like the Harrier is much better placed, with crew-members only taking radiation damage 1 in 12 times (1 in 36 if they've got decent protection or a dose of anti-rads, falling to never if they are in battle-dress).
RAW don't mention aftereffects, but It seems reasonable to infer that a thoroughly irradiated target will be subject to secondary activation effects, in which case anyone on the ship should be making ongoing exposure rolls and any cargo containers looted may be 'hot' in more than the traditional sense....
Is there anything I've missed?