Beam Port Leakage Problem in the BAEC TRIGA Mark-II Research Reactor and the Corrective Measures Implemented

2 Abstract—The 3MW TRIGA Mark-II research reactor (RR) of Bangladesh Atomic Energy Commission (BAEC), which has been in operation since 1986. It has four Beam Ports (BPs). Two of the BPs remained plugged with the beam port plugs (mainly a graphite shield plug) for about 23 years. When Beam Port plugs were removed, it was found to be leaking in Radial BP-1 and Leakage of water came to the notice of the reactor operation personnel after a couple of days. The leak developed due to corrosion was found in the aluminum part of the BP which is located inside the reactor pool at a depth of about 8 m. Condensate accumulated in the annular space between the graphite plug and inner wall of the aluminum beam port initiated the corrosion. Finally, water leakage was stopped by installing a split type encirclement clamp (STEC) around the damaged part of the BP by some remote handling mechanisms, designed and fabricated locally. The paper presents in detail the description of the leakage problem, root cause analysis and the remedial measures implemented so as to make the reactor operational again for normal operations.