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Re: Characteristics of criticality accidents
Only to complement the information sent to Bjorn
After Chernobyl and Goiania accidents, documents on Emergency Planning and
Preparedness were reviewed by Countries and International Organization, to
take into account reasons, consequences, attitudes and lessons learned.
On this aim the IAEA published the TECDOC -953, July 1997, Method for the
development of emergency response preparedness for nuclear or radiological
accidents, to provide practical guidance.
The IAEA groups practice into five categories, each presenting common
features in terms of magnitude and timimg of the hazard. Table below defines
the five emergency planning categories
CATEGORY I - Facilities with the potential for very large releases resulting
in serious deterministic health effects off-site. In addition, areas near
the facility that should be prepared to take protective actions prompptly in
response to an accident at the facility also require this level of planning.
Examples (i)
a) Reactors with power levels greater than 100 MW(th) (power reactor,
nuclear ship and research reactors);
b) Spent fuel pools containing more than the equivalent of a 3000 MW(th)
reactor core; (ii, iii)
c) Inventories of unsealed radioactive material greater than 100 times the
activity listed in table IV (TEC-DOC 953, page 18)
(i) UF-6 is not considered because the chemical hazard is far more important
than the radiological hazard
(ii) Based on the average power level during the use of fuel
(iii) For spent fuel that is less than three years old
CATEGORY II - Facilities with the potential for releases resulting in
off-site above the urgent GILs but with little or no threat of doses
resulting in deterministic health effects off-site. In addition, the areas
that should take protective actions in response to an accident at the
facility also require this level of planning.
Examples
a) Reactors with power levels greater than 2 MW(th) (iv) and less than 100
MW(th)(power reactor, nuclear ship and research reactors);
b) Spent fuel pools containing between the equivalent of a 10 to 3000 MW(th)
reactor core; (ii, iii)
c) Inventories of unsealed radioactive material greater than the activity
listed in table IV (TEC-DOC 953, page 18)
(iv) Severe fuel damage and therefore a major off-site release is not
considered credible below 2 MW(th)
CATEGORY III - Facilities without significant off-site risk but with the
potential for accidents resulting in deterministic health effects on-site.
Jurisdictions that provide fire, police or medical support to these
facilities also require this level of planning.
Examples
Potential of unshielded dose rates more than 10 Sv/h at 30 cm
Potential for criticality accidents
Inventories of unsealed radioactive material greater than 0.10 times the
activity listed in table IV (TEC-DOC 953, page 18)
CATEGORY IV - Areas with little or no known threat. This is the minimum for
all countries because accidents involving lost or stolen sources or the
transportations of radioactive material are possible anywhere.
CATEGORY V - Areas with substantial possibility of needing to implement
interventions related to food in the event of accidents at the facilities
outside the country
===========
To Those interested I suggest to write to the Division of Public Information
e mail official.mail@iaea.org to ask a copy of the TECDOC 953
another possibility is:
I'll travel to IAEA next 05 March and I can ask to friends at the Emergency
Section to send a copy. In this possibility, please send me an e mail with
name and complete address.
Also the follow films are suggested, however in this case only directly with
the IAEA, please ask information with Division of Public Information e mail
official.mail@iaea.org
Film on Emergency Planning and Preparedness
U.S. - Film and Video Group, Argonne National Laboratory, for International
Atomic Energy Agency - 1985.
English - 55 min. - sd., col. + 1 discussion guide and 1 English script - 16
mm and video.
Pt.1. The radiological emergency (19 min.) - pt.2. Planning for the
emergency (18 min.) - pt.3. Preparing for the emergency (18 min.).
Target audience: general, semi-technical.
Copyright: Argonne Film and Video Group.
Subject(s): Nuclear power plants -- Accidents; Emergency management.
This information and training film in three parts deals with the technical
background for emergency planning, emergency planning concepts, and
emergency preparedness. It describes the technical characteristics of
radiological emergencies on which important emergency planning concepts are
based, and the purpose of those concepts. The film also demonstrates how
emergency organizations must work together to ensure adequate preparedness.
The programme reflects the standards, guidance and recommendations of the
International Atomic Energy Agency.
===========================
Austria - Argonne Film and Video Group for International Atomic Energy
Agency - 1987.
English - 14 min. - sd., col. + 1 script - video.
Target audience: semi-technical.
Copyright: International Atomic Energy Agency.
Subject(s): Nuclear accidents; Public information; Radioactive pollution --
Law and legislation; International Atomic Energy Agency.
Shows the efforts undertaken by the IAEA and its member states to implement
an effective early notification and emergency assistance program for the
case of nuclear emergencies.
========================
Jose Julio Rozental
joseroze@netvision.net.il
Israel
----- Original Message -----
From: Enrico SARTORI <sartori@nea.fr>
To: Multiple recipients of list <radsafe@romulus.ehs.uiuc.edu>
Sent: Friday, February 25, 2000 2:45 PM
Subject: Re: Characteristics of criticality accidents
> Bjorn
>
> a report describing all 60 accidents will be issued shortly by LANL. I
> suggest that you obtain a copy.
> As far as 'classification' is concerned it has a lot to do with
> definitions, which are often blurred by judgement. There are many ways
> accidents can be categorised. A classification by facility type (French)
> can be found in:
> http://www.ipsn.fr/presse/dossiers/dossiers/DP_CRITICITE.htm
>
> 1. criticality accidents in fuel cycle facilities
> 2. criticality accidents in research reactors and labs with critical
> assemblies
>
> This list contains 59 accidents. The 60th (JCO) belongs to the first
> type.
>
> Other sources of information are:
> 1) http://orion.lanl.gov/ncs/index.htm
> 2) Table of Criticality Accidents, 1945-1970:
> http://www.enviroweb.org/issues/nuketesting/accident/index.html
> 3) CRITICALITY ACCIDENTS IN USAEC FACILITIES:
> http://www.enviroweb.org/issues/nuketesting/accident/crittabl.htm
> >
> > Date: Fri, 25 Feb 2000 12:00:15 GMT
> > From: "Bjorn Cedervall" <bcradsafers@hotmail.com>
> > To: radsafe@romulus.ehs.uiuc.edu
> > Subject: Characteristics of criticality accidents
> > Message-ID: <20000225120015.48627.qmail@hotmail.com>
> >
> > According to the previous information here at Radsafers, a total of
about 60
> > criticality accidents have occurred. The one in Tokaimura was
characterized
> > by a "pseudo-stability" state and lasted for more than about 10 hours.
Other
> > criticality accidents may have involved pulsed states. Does any one have
an
> > overview of the number of criticality accidents of these different
> > sub-categories?
> >
> > Bjorn Cedervall bcradsafers@hotmail.com
>
> ----------------------------------------------------------
> Enrico Sartori Tel.: +33 1 45 24 10 72 or 78
> OECD NEA Data Bank Fax : +33 1 45 24 11 10 or 28
> 12 Bd des Iles
> 92130 Issy-les-Moulineaux e-mail: sartori@nea.fr
> France www--> http://www.nea.fr
> ----------------------------------------------------------
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