Question about radiation damage

[vicky_molokh]

Originally Posted by Tyneras

How is that worse? That thread boils down to "There are 2 types or radiation, the stuff that acts close enough to gammas rays to be lumped together without a problem, and everything else which is too weak to treat as radiation unless you eat or inhale it." If anything it means you can simplify stuff easily, as you don't need multiple scales for different radiation types.

You missed the point. GURPS measures radiation sources (e.g. innate attacks and reactor 'brightness') in Rads.

[Tyneras]

Originally Posted by vicky_molokh

You missed the point. GURPS measures radiation sources (e.g. innate attacks and reactor 'brightness') in Rads.

It's a human centric measurement in a human centric game ('average' human stats cost zero points, after all). Either find some sort of scale (maybe normalize against HP or SM, as someone proposed) or rebuild it from the ground up to deal with amount absorbed.

I'd love to read whatever you come up with, might even use it, but radiation is a rare enough hazard that I have to re-read the section on it every time it comes up.

[Anthony]

Originally Posted by vicky_molokh

You missed the point. GURPS measures radiation sources (e.g. innate attacks and reactor 'brightness') in Rads.

That's fairly nonsensical to start with; presumably it means 'rads from a typical exposure' (there's also the problem that neutrons, while they can be treated like gamma rays for damage purposes, actually produce zero rads; they aren't ionizing radiation. This is one reason I choose to assume that 'rads' really means 'rems').

[Snargash Moonclaw]

Back in the latter half of the 80's when I served as a (US Army) Nuclear, Biological and Chemical Warfare Specialist (MOS 54B, previously 54E) the operational exposure guidelines set the limit at 90 rad - which was considered safe. Note that this is external exposure - crossing a dusty contaminated area without air filtration, ingesting food or water containing radiation emitters of any form (alpha, beta, or gamma) etc. is highly dangerous (if not deadly) at any level. Even alpha particles (helium atom nuclei), while too heavy to penetrate the epidermis, once inside your body even in small amounts can kill you.

N.B., the guidelines were concerned with (short term) operational effectiveness, i.e., to ensure that soldiers could continue to perform their missions unhindered by the effects of radiation until the end of the war. Long-term effects of exposure (to any NBC contaminant) beyond that time frame have always been considered irrelevant.

[lwcamp]

Originally Posted by Anthony

That's fairly nonsensical to start with; presumably it means 'rads from a typical exposure' (there's also the problem that neutrons, while they can be treated like gamma rays for damage purposes, actually produce zero rads; they aren't ionizing radiation. This is one reason I choose to assume that 'rads' really means 'rems').

Neutrons produce ionization when they collide with other nuclei. This transfers some of the neutron's energy to the nucleus, and the fast moving nucleus leaves a trail of ionization. They also produce capture radiation - when a neutron gets absorbed by a nucleus, a gamma ray comes off which can cause ionization. There is also activation, where an absorbed neutron results in an unstable nucleus that decays at a later time.

Of these, the nuclear recoil is likely the largest health threat, and is why neutrons have a fairly high relative biological effectiveness.

For GURPS modeling, there is the annoying problem that stuff that stops gamma rays is not very effective against neutrons, and stuff that stops neutrons is not very effective against gamma rays. Thus, a PF of 10 against gammas might not get you anything against neutrons, and vice versa.

Luke