On Sun, Jun 17, 2018 at 06:44:03PM -0400, Kurt Feltenberger wrote:
> 1. Wouldn't the radiation have killed the bacteria that would cause
> decomposition?

Probably not.  Although some bacteria are no more radiation resistant
than our body's cells, a single-celled organism doesn't need the
support provided by billions of other functioning cells to survive.

Many bacteria are also inherently more resistant to radiation.  Most
of them also reproduce faster, especially in a relatively warm and
moist environment with abundant food.  That reduces the time for
radiation damage to accumulate.

Due to these factors, many bacterial colonies can maintain themselves
in environments with hundreds to thousands of grays per day.  A few
grays per day (depending upon type and exposure method) will generally
kill humans in less than a week.

Finally, it was stated that "some areas" of the ship were irradiated
to dangerous levels.  Even if the initial radiation in those areas
killed all bacteria, some may have migrated from less intensely
radiated areas in subsequent days, weeks, or years.

> 2. Wouldn't the radiation have gone down given the time (~100 years
> since the ship was attacked)?

It would depend upon the source of the radiation.  A lot of secondary
sources such as from neutron activation do have short half-lives and
most likely wouldn't be active anymore.

If the ship had a fission reactor then damage might contaminate parts
of the interior with substantial quantities of long-lived
radioisotopes.  Even fusion reactors of some types might produce
moderately long-lived isotopes, though I would expect the quantities
to be much smaller and probably beta emitters rather than more
difficult to shield gamma or neutron radiation.

If the cargo or other equipment included radioactive elements than
pretty much anything goes.

- Tim