IE Circular No. 80-14, Radioactive Contamination of Plant Demineralized Water System and Resultant Internal Contamination of Personnel

                                                            SSINS.: 6830 
                                                            Accession No.: 
                                                            8005050074

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

                                June 24, 1980

                                                     IE Circular No. 80-14 

RADIOACTIVE CONTAMINATION OF PLANT DEMINERALIZED WATER SYSTEM AND RESULTANT 
INTERNAL CONTAMINATION OF PERSONNEL 

This circular describes an event which occurred at a nuclear power facility;
however, the generic implications may be applicable to research reactors, 
and fuel cycle facilities. 

On March 17, 1980, a licensee informed the NRC resident inspector that 
portions of the plant demineralized water (DW) system were found to be 
radioactively contaminated.  A temporary hose used to add demineralized 
water to the spent fuel pool was the pathway for the cross-contamination.  
After this fuel pool makeup was completed on March 14, the temporary DW line 
(still connected to the DW header was inadvertently left submerged in the 
fuel pool. Since the DW header pressure at the point of supply was 
relatively low (a DW booster pump had been secured), a siphoning action 
occurred, resulting in radioactive contamination of portions of the DW 
header. 

On March 17, 1980,while performing routine secondary system chemical 
analyses, the licensee discovered that the demineralized water tap in the 
chemistry lab contained high levels of boron and had activity of 1.5 x 10-4 
uCi/ml (mainly Cs-134, Cs-137, Co-58, Co-60 and Mn-54).  It was subsequently 
discovered that demineralized water from the chemistry laboratory supply tap 
had been used to make five (5) pots of coffee.  The remaining coffee was 
confiscated and the twenty-three (23) individuals who had consumed this 
coffee were whole-body counted.  All involved individuals showed no intake 
greater than an equivalent 0.01 MPC-HRS.  Analysis performed by the 
licensee's radiation consultant, based on the maximum concentration of 
radioactivity found in the coffee, indicated that the resultant 50-year dose 
commitment of an individual drinking eight ounces of this coffee would be 
less than 1 millirem. 

Further licensee investigation revealed that the non-radiological chemistry 
DW supply tap was the only DW supply point outside the Auxiliary Building 
controlled area.  This DW supply tap was tagged prohibiting human 
consumption to prevent a similar event in the future. 

It is recommended that you review your facilities use of demineralized water
(DW) via temporary connections and give attention to the following: 

1.   Provisions should be made to assure that radioactive materials are not 
     inadvertently introduced into your facility's DW system via the 
     improper use of temporary connections.  A temporary cross connection 
     between 
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IE Circular No. 80-14                                       June 24, 1980 
                                                            Page 2 of 2 

     contaminated systems and the DW system without adequate physical 
     controls to prevent cross-contamination should be prohibited. 

2.   In addition to some physical means of preventing backflow into the DW 
     system, appropriate administrative controls should be established to 
     ensure that the DW supply valve is secured and temporary hosing is 
     disconnected from the DW supply header after use. 

3.   Use of plant-supplied DW for human consumption should be prohibited.  
     The potable water system should be the only authorized source of water 
     for human consumption. 

4.   Examine potable and demineralized water systems to determine if 
     pathways exist allowing or having the potential to allow contamination 
     of these systems including temporary connections whereby siphons could 
     cause situations described above. 

No written response to this Circular is required.  Your review of this 
matter to determine its applicability to your facility and any corrective 
and preventive actions taken or planned, as appropriate, will be reviewed 
during a subsequent NRC inspection.  If you desire additional information 
regarding this matter, contact the Director of the appropriate NRC Regional 
Office.