|
Ooops,
I meant to send this to radsafe yesterday
but forgot to add the radsafe address in the reply.
Regards
Julian
Ginniver
----- Original Message -----
From: julian ginniver
To: Morgan, Ben
Sent: Thursday, January 17, 2002 10:39 PM
Subject: Re: Nucl Week on French Acad of Med statement on LNT &
"Disinformation" The UK have also adopted a 100 mSv over 5 year limit.
The UK's legislation (The Ionsing Radiations Regulations 1999) is based on the
same Euratom directive that has to be enshrined in the National Legislation of
each member state. I as understood from the consultation stage of
the draft UK legislation this was at the specific request of a nuclear
operator. As Ben Morgan identified there may be differences
between consecutive years in the dose recieved by individuals. This
is particularly noticable on Nuclear power plants that have an operating
cycle of greater than 12 months. In this case there may be a year where
very little dose is recieved this would be followed by a period where very large
individual and collective doses were recieved. The use of the rolling 5
year limit would allow personnel to exceed the 20 mSv/y limit as long as over
the 5 rolling five years they did not exceed the 100 mSv limit.
In the UK it is necessary to identify in advance that an
operator might wish to apply the 100 mSv/5y limit and also to identify who
individual that will require the application of this dose limit and to notify
the NII (the UK NRC). The NII may require the employer to apply the
20 mSv/y limit (that is refuse the use of the 100 mSv/5y limit). In
addition the NII will require the employer to demonstrate that any dose recieved
by this employee is As Low As Reasonably Practicable(ALARP). BTW ALARP is the UK
term for ALARA as the phrase Reasonably Practicable is defined in English
Law. In addition when the identified employee exceeds the standard 20
mSv/y dose limt the employer must undertake an investigation (review) of the
exposure (this is despite the fact that the it was planned to exceed this limit
and that the NII had already been notified that this would occur).
All of these requirements are designed to limit the use of the
rolling 100 mSv/5y dose limit to pre-planned activities where it has been
demonstrated in advance that it is not practicable to comply the 20 mSv/y
limit. The 100 mSv/5y limit cannot be applied retrospectively in the event
of an accidental overexposure. In addition once it has been decided to
adopt the rolling 100 mSv/y to an employee there are restrictions on reverting
to an annual basis for the dose limit for this individual.
Regards
Julian
Ginniver
----- Original Message -----
|