TOKYO — A government panel proposes additional measures to lessen the radioactive water crisis at Japan’s crippled nuclear power plant, saying Tuesday that current plans are not enough to prevent the risk of a disaster.

Officials on the Industry Ministry’s contaminated water panel also said that the Fukushima Dai-ichi plant could run out of storage space for contaminated water within two years if current plans are not fully workable.

A draft report proposes covering the ground with asphalt to reduce rain inflow, building giant tanks and other steps.

The proposal incorporates ideas from some of 780 sets of proposals sent from around the world at the request of the ministry to seek international expertise in tackling the problem of massive amounts of radioactive water, which experts say is hampering the plant’s decommissioning process. The first step of the process began last month.

Radioactive water has been leaking from the damaged reactors and mixing with groundwater since an earthquake and tsunami in 2011 destroyed the plant’s power and cooling systems, causing three reactors to melt.