Operating experience and utilization programmes of the BAEC 3 MW TRIGA Mark-II research reactor of Bangladesh

The 3 MW TRIGA Mark-II research reactor of Bangladesh Atomic Energy Commission (BAEC) has been operating since September 14, 1986. The reactor is used for radioisotope production (''1''3''1I, ''9''9''mTc, ''4''6Sc), various R and D activities, manpower training and education. The reactor has been operated successfully since it's commissioning with the exception of a few reportable incidents. Of these, the decay tank leakage incident of 1997 is considered to be the most significant one. As a result of this incident, reactor operation at full power remained suspended for about 4 years. However, the reactor operation was continued during this period at a power level of 250 kW to cater the needs of various R and D groups, which required lower neutron flux for their experiments. This was made possible by establishing a temporary by pass connection across the decay tank using local technology. The reactor was made operational again at full power after successful replacement of the damaged decay tank in August 2001. At that time, several modifications of the reactor cooling system along with its associated structures were also implemented and then necessary testing and commissioning of the newly installed component/equipment were carried out. The other incident was the contamination of the Dry Central Thimble (DCT) that took place in March 2002 when a pyrex vial containing 50g of TeO2 powder got melted inside the DCT. The vial was melted due to high heat generation on its surface while the reactor was operated for 8 hours at 3 MW for trial production of Iodine-131 (131I). A Wet Central Thimble (WCT) was used to replace the damaged DCT in June 2002 such that the reactor operation could be resumed. The WCT was again replaced by a new DCT in June 2003 such that radioisotope production could be continued. The facility has so far been used to train up a total of 27 personnel including several foreign nationals to the level of Senior Reactor Operator (SRO) and Reactor Operator (RO). The reactor is operated 4 days a week at a power level of 3 MW for production of Iodine-131. During the other one weekday, the reactor is operated at lower power levels (250 - 500 kW) to cater the needs of NAA and NR groups. At present the total burn-up of the core stands at about 484 Megawatt Days. BAEC has a plan to increase the production of Iodine-131 to install more dry tubes in the core so as to meet the total demand of RI in the country. There is also plan to develop unused experimental facilities such as, thermal column and radial beam ports for strengthening the R and D activities around the reactor. A total of 1093 irradiation requests (IRs) have been catered so far for different reactor uses. The total amount of RI produced stands at about 4000 GBq. The total amount of burn-up-fuel is about 11607 MWh. Efforts are on to undertake an ADP project so as to convert the analog console and I and C system of the reactor into digital one. The paper summarizes the reactor operation, maintenance experiences and utilization programmes focusing on troubleshooting, rectification, modification, RI production, various R and D activities and training program being conducted at the facility. (author)