A major electricity operator in the UK had at the top of its agenda finding a better way to clean a number of components in its fuel route – gag pistons, spent fuel flasks (bottles), and in particular the articulated joints on the fuel route pipes themselves.
The problem they had in general was common to the industry: How to reduce the levels of contamination such that they could safely work on the pipes. In the case of the articulated joint, operating procedures required them to re-weld all the joints on the pipe so that they could be assured that time within the reactor had not de-graded the seams). This meant that they had to manually transport the articlated joint and attached pipes from the reactor to the maintenance area, and then, after some basic manual cleaning, grind out the weld seams and re-weld them. This created a lot of personnel odoses, and with the dust released by the process, also required expensive air handling treatment.
The client also wanted to reduce secondary waste caused by the cleaning process. The existing process meant that a lot of liquid and hard secondary waste had to be sent to the main plant’s waste center for onward disposal, which was costly.
Vicosonic’s management team visited the client site, and inspected all of the parts that required cleaning, as well as going in to the ‘hot’ side of the reactor to look at the existing cleaning process. It also closely inspected the articulated joints to determine what type and size of machine, and what cleaning liquids might be used.
It then came up with detailed recommendations and drawings for a pilot scheme to develop a proof of concept test centre within the plant. This test machine was designed to be stand-alone at the test phase, thereby minimising the decision making time to gain approval for the test machine.
The test machine was equipped with a special double filter system that allowed the levels of secondary waste contamination to be monitored easily, and the filters to be changed (disposed of) easily.
Once the test was complete, plant senior management’s wish is to create a decontamination centre within the maintenance section with Vicosonic’s help in designing, fabricating, and training operators.
- Greatly reduced contamination on very hard to reach parts
- Vastly reduced cleaning times
- Reduction of personnel doses
- Reduction of secondary waste
- Reduction of cost
- Improved health and safety