United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 83-49: Sampling and Prevention of Intrusion of Organic Chemicals into Reactor Coolant Systems

                                                            SSINS No.: 6835 
                                                            IN 83-49       

                                UNITED STATES
                        NUCLEAR REGULATORY COMMISSION
                    OFFICE OF INSPECTION AND ENFORCEMENT
                           WASHINGTON, D.C., 20555
                                     
                                July 25, 1983

Information Notice No. 83-49:   SAMPLING AND PREVENTION OF INTRUSION OF 
                                   ORGANIC CHEMICALS INTO REACTOR COOLANT 
                                   SYSTEMS 

Addressees: 

All nuclear power reactor facilities holding an operating license (OL) or 
construction permit (CP). 

Purpose: 

This information notice is, provided to inform licensees of two events 
involving the contamination of nuclear plant water systems. The first event 
illustrates the advantages of sampling programs for the detection of organic
contaminants in reactor water cleanup and storage systems. The second event 
illustrates the problems that can result from the failure to detect such 
contaminants before they are conveyed into the reactor or other vital water 
systems. It is expected that recipients will review the information for 
applicability to their facilities. No specific action or response is 
required. 

Description of Circumstances: 

On February 13, 1983, at the Hatch 1 facility, 3000 gallons of glycol and 
water mixture were spilled as the result of a faulty valve lineup. The spill
flow path was through an opening left by the removal of a relief valve in 
the "B" train of the off-gas system condenser cooler. The mixture ran into 
the floor drains and was transported to the radwaste system where it mixed 
into a total volume of 47,000 gallons of radwaste. Glycol, being nonionic, 
is not removed by the radwaste demineralizers. However, the contaminant was 
detected by a subsequent, sample analysis for total organic carbon. This 
prevented the transfer of the glycol to the condensate storage tank and then 
to the reactor coolant system. 

The practice of conducting sample analyses for total organic carbon was 
initiated as a result of the chemical intrusion incident at Hatch 1 in April
1982 (Information Notice No. 82-32). 

The second event which occurred at the LaSalle 1 facility on May 5, 1983 
involved the intrustion of an organic dry cleaning solvent into the reactor 
coolant. At 1210 hours, with the reactor shut down, the reactor water pH 



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dropped to 5.2 which is below the limiting condition for operation of 5.3. 
At the same time there was an increase in both conductivity and the chloride
concentration. Except for brief periods, the pH remained below 5.3 until 
0001 hours on May 8, when it was brought back, and stayed, within 
specifications. 

As a result of extensive investigation, it was determined that the 
contaminants were freon and other organic solvents in the condensate storage
tank and that they entered the reactor with the control rod drive cooling 
water. The freon is used as a dry cleaning solvent in the laundry system. It
is believed that the solvents may have entered the radwaste discharge tank 
through the floor drains. Water from the radwaste was processed through a 
flash evaporator, where some of the volatile organic material was carried 
over with the steam. The evaporator condensate was eventually routed to the 
condensate storage tank. Some of the condensate storage tank water was 
routed to the suppression pool causing this water to become contaminated 
too. 

When the organic contaminants were injected into the reactor, they were 
broken down by the action of the heat and radiation causing the observed 
decrease in pH and increase in conductivity and chloride concentration. The 
reactor water was cleaned up using the normal water cleanup system. The 
condensate storage tank was drained and vacuum cleaned. The suppression pool
was circulated and heated to 105 degrees F, and the pool spray and an air 
sparge were run to evaporate the organic material out of solution. 

Information on other previous intrusions of organic contaminants into 
reactor coolant systems is provided by INPO Significant Operating Experience 
Report 82-13, which discusses seven such events. 

No written response to this notice is requested. If you have any questions 
regarding these two events, please contact the Regional Administrator of the
appropriate NRC Regional Office, or this office. 


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

Technical Contact:  D. C. Kirkpatrick, IE
                    492-24510

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