The covering, a tent-like structure made of steel frames and air-tight polyester sheets, is meant to prevent radioactive materials from spreading from the crippled reactor and stop rainwater from entering the reactor building, said Tokyo Electric Power Co.
When completed, the covering will be between 42 and 47 meters long and about 54 meters high.
About 60 components are being brought to the seaside plant via the Pacific.
On Wednesday, a steel structure about 6.9 meters high that weighs about 30 tons is expected to be pulled up by a crane and installed at the southeast corner of the No. 1 reactor building.
The building housing the No. 1 reactor and those housing the Nos. 3 and 4 reactors at the plant were badly damaged due to explosions after tsunami caused by a magnitude 9.0 earthquake struck the plant on March 11.
Once the installation is completed at the reactor, Tokyo Electric will consider installing similar coverings for the Nos. 3 and 4 reactors, the operator said.