Bulletin 74-007: Personnel Overexposure - Irradiator Facility


                              UNITED STATES 
                         ATOMIC ENERGY COMMISSION 
                          WASHINGTON, D.C. 20545 

                                JUN 26 1974 

J. P. O'Reilly, Director of Region I 
N. C. Moseley, Director of Region II 
J. G. Keppler, Director of Region III  
E. M. Howard, Director of Region IV
R. H. Engelken, Director of Region V 


The enclosed RO Bulletin #74-7 should be transmitted to all Irradiator 
Licensees in your Region, that are listed on the enclosed List A and to 
those licensees on List B who rely on interlocks, radiation alarms and/or 
administrative controls to preclude exposure of personnel. These notices 
should be transmitted by certified mail, return receipt requested. 

                                   John G. Davis, Deputy Director 
                                        for Field Operations 
                                   Directorate of Regulatory Operations 

DRO Bulletin #74-7 

cc:  D. F. Knuth, RO 
     P. A. Morris, RO 
     B. H. Grier, RO 
     C. W. Kuhlman, RO 
     G. W. Roy, RO 
     S. H. Smiley, L 
     G. R. Grove, L 
     G. A. Blanc, L 

 NAME AND ADDRESS                                      Date: 6/26/74  
                                                       DRO Bulletin #74-7 
                                                       License No(s). 


The enclosed Directorate of Regulatory Operations Bulletin No. 74-7 
"Personnel Overexposure - Irradiator Facility" is sent to provide you with 
information obtained during an investigation. This information may have 
applicability to your facility(ies). The action to be taken by you is 
identified in Section B of the enclosed Bulletin. 

If you have any questions on the contents of this Bulletin, please do not 
hesitate to contact us. 



DRO Bulletin #74-7   

                              RO BULLETIN 


A recent investigation of a serious overexposure of an employee at an 
Irradiator Facility revealed safety problems which may exist at other plants
where radioactive materials are similarly utilized. 

A.   Description of Circumstances: 

     An experienced operator received a whole body exposure of from 300 to 
     400 rems when he entered a cell where a 120,000-Curie cobalt 60 source 
     was in the unshielded position. 

     This entry resulted from several significant contributing causes which 

     1.   A radiation alarm circuit required by the license had been 
          deactivated. If operating it would have alerted the operator to an
          unsafe condition. 

     2.   The operator failed to perform a physical radiation survey as he 
          entered the cell. 

     3.   The operator failed to follow approved pre-cell-entry operating 
          procedures, which required visual assurance that the source had 
          been returned to its shielded position. 

     4.   The cell operator was unaware that the radiation alarm circuit had
          been or could be deactivated. 

B.   Action Requested: 

     In view of the above you should take the following steps: 

     1.   Perform a complete operational test of all interlocks, radiation 
          alarms and other devices which have been installed to prevent 
          radiation exposure of personnel. 

     2.   Review your administrative controls to assure that all regulatory 
          requirements are being met. Such controls, if license conditions 
          permit, must provide conservative criteria under which any 
          protective devices may be bypassed or reduced in effectiveness. 

     3.   Conduct special training of all operating personnel on the proper 
          operation of all protective devices and safety related procedural 
          requirements to assure that these devices are properly operated 
          and procedures are followed. 


     4.   The above actions along with any necessary repairs, should be 
          completed within ten (10) days of the receipt of this notice. A 
          record detailing the actions taken, findings, and corrective 
          measures if any, shall be retained for review during the next 

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