United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 83-14: Dewatered Spent Ion Exchange Resin Susceptibility to Exothermic Chemical, Reaction

                                                            SINNS No.:  9197
                                                            IN 83-14 

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

                               March 21, 1985 

Information Notice No. 83-14:   DEWATERED SPENT ION EXCHANGE RESIN 
                                   SUSCEPTIBILITY TO EXOTHERMIC CHEMICAL , 
                                   REACTION 

Addressees:  

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

Purpose:  

This information notice is provided as an early notification of a 
potentially significant problem pertaining to the apparent susceptibility of 
certain spent ion exchange resin to undergo an exothermic chemical reaction. 
The Nuclear Regulatory Commission (NRC) staff is reviewing the problem and 
its effects. If the evaluation so indicates, the NRC may request further 
licensee action. In the interim the NRC recommends that recipients of this 
notice review the information herein for applicability to their facilities. 
An inadequate knowledge of the characteristics of a waste stream might 
result in adverse conditions such as similiar exothermic reactions, poor 
waste solidification, or incompatibility of wastes with container materials. 
No specific action or response is required at this time. 

Description of Circumstances: 

Spent ion exchange resin from Arkansas Power and Light's Arkansas Nuclear 
One (ANO) Unit 2 evidenced an exothermic chemical reaction on January 15, 
1983. Approximately 100 cubic feet of spent resin was stored in a 
high-integrity liner mounted in a shipping cask and covered with a tarp to 
protect it from inclement weather. The resin had completed its last 
dewatering cycle at 12:30 a.m. on January 15, 1983, and was considered 
adequately dewatered for shipment to the burial site. Later that same day, 
at 8:00 a.m., the oncoming shift of radwaste workers noted steam and smoke 
coming from under the tarp. The vapor was noted to be very odorous and sharp 
(heavy chemical smell). Licensee personnel immediately sampled, for airborne 
radioactivity and toxic gases; both proved negative. The pH of the water 
collected during the dewatering process was determined to be 3.5 to 4.0. A 
core sample of the resin was obtained and the core temperature was measured 
to be 365F. It was noted also that the resin at the top of the liner 
had formed a strong crust. The resin was finally cooled at about 11:00 a.m. 
when 150 gallons of demineralized water at 50F was added to the liner 
and recirculated. The temperature of the water stiblized at 80F and the 
pH of the water returned to 7.0. At this point, the licensee began sampling 
pH and monitoring temperature every 3 hours. 

8212060385 
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                                                           IN 83-14 
                                                           March 21, 1983 
                                                           Page 2 of 2 

A second liner full of spent resin from the same source as the resin that 
overheated was nearby but had not undergone any changes. The only apparent 
difference between the two batches of resin appears to be that the 
unaffected resin had only been partially dewatered. The spent resin in 
question came from the Unit 2 spent resin holding tank (2T13 tank), where it 
is believed to have been "caked" around the sides of the tank for a number 
of years. Specifically, since commercial power operation began in 1980, 
the,licensee was aware that only about 160 cubic feet of usable volume was 
available in this 350 cubic foot spent resin holding tank, indicating that a 
large amount of resin was retained in the tank during normal resin sluicing 
operations. The licensee's successful efforts to free this caked resin 
resulted in the two liners full of resin. Since this resin was used prior to 
commercial power operation, it had significantly lower specific 
radioactivity than is normal for spent resin; on the other hand, it was most 
probably exposed to chemicals and contaminants not normally associated with 
power operation. 

The licensee has consulted both the Chem-Nuclear Corp. and the Dow Chemical 
Corp. concerning this matter. Both companies have provided knowledgeable 
personnel to assist on-site. The complete analysis results from resin 
samples taken are not available at this time, and the licensee will wait 
until this phenomenon is better understood before determining the best means 
of final disposal for the affected resin. However, Chem-Nuclear Corp. has 
determined that there were oxidizing agents present in the affected resin in 
the form of nitrites (0.05 ppm) and nitrates (0.5 ppm) that apparently 
contributed to the exothermic reaction. Accordingly, Chem-Nuclear Corp. has 
notlfied its cus,tomers that nitric acid and other strong oxidizing agents 
can cause exothermic (and possibly explosive) reactions when mixed with 
organic material such as ion exchange resins. Chem-Nuclear has further 
cautioned its customers to consult with someone knowledgeable before using 
strong-oxidizing agents, and the company is placing a label with a suitable 
warning on its reusable containers. Additionally, Chem-Nuclear field 
personnel were instructed about this potential hazard, and warning/caution 
statements have been added to their procedures. 

If you have ahy questions regarding these matters, please contact the 
Regional Administrator of the appropriate NRC Regional Office. 


                         James M. Taylor, Director 
                         Division of Quality Assurance, Safeguards, 
                           and Inspection Programs  
                         Office of Inspection and Enforcement 

Technical Contact:  A. W. Grella 
                    492-7746 

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