Information Notice No. 83-66: Fatality at Argentine Critical Facility

                                                           SSINS No.:  6835 
                                                           IN 83-66        

                               UNITED STATES 
                       NUCLEAR REGULATORY COMMISSION 
                    OFFICE OF INSPECTION AND ENFORCEMENT 
                           WASHINGTON, D.C. 20555 
                                     
                               October 7, 1983

Information Notice No. 83-66:   FATALITY AT ARGENTINE CRITICAL FACILITY 

Addressees: 

All nuclear power reactor facilities holding an operating license (OL) or 
construction permit (CP), and non-power reactor, critical facility, and fuel
cycle licensees. 

Purpose: 

This information notice is issued as an early notification of an accident 
involving a fatality at a zero-power critical facility owned and operated by
the CNEA (Argentine National Atomic Energy Commission). The information was 
obtained from the CNEA by phone through the NRC's Office of International 
Programs. CNEA plans to issue a written report after a detailed evaluation 
of the incident. It is expected that non-power reactor, critical facility 
and fuel cycle licensees will review the information for applicability to 
their facilities. No specific action, or response is required. 

Description of Circumstances: 

At 4:10 P.M. on September 23, 1983, a prompt criticality accident occurred 
at CNEA's RA-2 zero-power, critical facility in the Constituyentes Atomic 
Center near Buenos Aires, Argentina. RA-2 is a light-water-cooled test and 
training reactor, using 90% enriched uranium, MTR-type fuel.*  With the test
reactor sub-critical (shut down), an operator was making core configuration 
changes using an overhead crane. Facility procedures required that fuel and 
control rod alterations be performed without the moderator present. The 
qualified operator (14 years of experience) attempted to make core changes 
without draining the moderator water. The core went prompt critical 
(estimated integrated energy pulse approximately 10 megajoules). The 
moderator expanded rapidly, shutting down the reactor, followed by an 
automatic dump of the moderator. There was no equipment damage or 
significant radiation exposures to personnel other than the operator. 




*Information on fuel obtained from American Nuclear Society, Proceedings of 
 the Third Pacific Basin Conference, Acapulco, Mexico, February 16-18, 1981.





8308300752 
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                                                          IN 83-66         
                                                          October 7, 1983  
                                                          Page 2 of 2      

It is estimated the operator received an initial average whole body dose of 
1400 rads of fast neutrons and about 500 rads of gamma. He was reported 
conscious during the first day following the incident, and was unconscious 
the second day. The expected acute radiation sickness symptoms were 
observed, including some nervous disorders. He died on September 25, at 5:00 
P.M. Immediate cause of death was severe inflammation of the lungs. 


                                   Edward L. Jordan, Director 
                                   Division of Emergency Preparedness 
                                     and Engineering Response         
                                   Office of Inspection and Enforcement 

Technical Contact:  J. E. Wigginton, IE 
                    301-492-4967

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