Re: Firefighters and Dosemetry in the UK.

[Bob Flood <bflood@SLAC.Stanford.EDU>]

At 11:27 AM 2/15/97 -0600, you wrote:
>Radsafers, 
>                A request for some help, advice or opinions from across
>the pond....  ( At long last ) firefighters are moving away from the QFE
>and adopting Personal Electronic Dosimetry, with a few associated
>problems.!!. Firefighters may have a requirement to wear dosemeters at
>incidents as potentially radiologically serious as nuclear power plant
>accidents, or at less serious incidents such as a Road Traffic Accident,
>where radiopharmaceutical packages have been spilt, damaged,etc.
>
>                The advantage of real time dosimetry is lost if the
>instrument is worn in such a way that it cannot be seen;

Some ideas for discussion:

1. To be useful, a dosimeter must be able to survive in its working
environment, and for firefighting this means lots of water and serious
impacts. I have seen only one design that can take anything more than a
casual splash of water, but I can't remember the brand (memory is the last
thing to go...). It was developed for the US Navy. Perhaps someone else can
help here.

If the dosimeter is worn under the firefighter's protective clothing, the
need for waterproofing the dosimeter diminishes and perhaps even disappears.

2. Philosphical:  why does a firefighter need a real-time display of dose?
Is a firefighter likely to enter an environment where life-threatening
acute doses are a real problem? If the doses are less than lethal, wouldn't
the other hazards of the fire be of greater importance? It seems to me that
a firefighter is unlikely to abandon the fight or refuse to attempt saving
a life if the alarm on his/her electronic dosimeter goes off. Also, it's my
experience with electronic dosimeters that the alarm will not heard by a
firefighter because of the high noise environment. Also, the alarm is the
part of the dosimeter that is most likely to malfunction, i.e., the least
reliable.

Because of these things, it seems to me that wearing the device inside the
firefighter's outer clothing isn't necessarily a bad idea. Certainly the
survival rate for the dosimeters would go up.

3. If severe radiological conditions do exist at a fire, decisions must be
made about who can be permitted to attempt a property-saving or lifesaving
task, and those in charge would need to know individual doses of the
candidates for the job. At that time, having each firefighter access the
dosimeter under the protective clothing and read it (or having a third
party do this) shouldn't be a major problem. This approach is used for high
dose rate jobs in nuclear power plants. where a roving HP tech will read
individual electronic dosimeters of workers while they work to inform them
of their doses and to make decisions about continuing the work. This allows
realtime monitoring of doses without slowing the work.

BTW, an alternative would be the remote data logging available with some
electronic dosimeters - a laptop with radio communiation to the dosimeters.
A person not involved in the firefighting could monitor the doses of a
group of firefighters without the firefighters ever looking at their
dosimeters. The data could be used to identify lower and higher dose
aspects of the fire, and allow movement of firefighters from one area to
another to manage individual doses. All it would take is lots of money!

At SLAC, we use TLDs to monitor firefighters. The radiological conditions
here are such that high acute doses are not really an issue, so a TLD
measurement is not a problem. A supply of emergency dosimeters is
maintained just for this purpose, and are to given out at the gate where
the firefighters enter the site. Issuance paperwork is completed
after-the-fact; the only things that takes place on the way in is to hand
out the badges. We have had 2 fires in which emergency dosimeters were used
(both were electrical fires), with no measurable doses in either case.


Bob Flood
Stanford Linear Accelerator Center
(415) 926-3793     bflood@slac.stanford.edu
Unless otherwise noted, all opinions are mine alone.