The leak check on TM4 and ITE is done. All primary vacuum vessel , secondary vacuum vessel on TM4 and ITE are leak tight. There is no any response had been found on leak detector(leak detector base LR 0.0xE-9 arm.cc/sec). All water lines had been pressurized to 70 psi helium for 3 minutes. They are all perfect leak tight( I cant find even a tiny response on leak detector) except GE water cooling line. On the GE water line, the leak detector got a instantaneous response once I applied the helium to the circuit.The leak rate climbed directly from 0.0xe-9 atm.cc/sec to 1.5 xe-5 atmcc/sec even if I stopped the helium pressurizing immediately. Once I purged the helium out of the line, the leak rate return to 0.0XE-9 atm.cc/sec quickly. I repeated the test on GE water line again and got exactly same result as the before. I would say the leak on the ITE GE water circuit isn't a small leak. The same test could be fulfilled once the TM4 is in CS later. |