Hitachi is carrying out an
investigation after discovering that testing data on power equipment
it had supplied to two Japanese nuclear power plants had been falsified.
The doubts centre on inspection records for heat-welded pipes in moisture
separator heaters supplied for unit 5 at Chubu's Hamaoka plant and for
Chugoku's Shimane-3, still under construction. Moisture separator heaters
are not part of the nuclear reactor but are used to remove moisture
from and reheat steam passing into power generation turbines, helping
to improve the plant's thermal efficiency.
According to Hitachi, doubts have surfaced over weld inspection data,
which had been outsourced to another company, Japan Industrial Inspection
Inc. It appears that data about temperature drops during the heat treatment
process were not in line with expected standards. Some data also appears
to have been erased from the records.
Hitachi has apologised for the "inconvenience to everyone concerned"
and has said it is making efforts to prevent any recurrence.