A group of Japanese doctors on Friday urged workers at the Fukushima nuclear plant to have their blood stemcells stored as a safeguard should they be exposed to life-threatening levels of radiation.

The technique entails storing so-called autologous peripheral blood stem cells (PBSCs), which are immature cells that differentiate into blood cells.

PBSC transplants are often used in cancer treatment to boost depleted blood cell counts among patients who have had radiotherapy to destroy a tumour.

In a letter to the British medical weekly The Lancet, cancer specialists at four Japanese hospitals argued that it made sense to store blood from the hundreds of workers battling to save the Fukushima Daiichi nuclear plant from catastrophe.

These teams are working in extremely hazardous conditions, removing irradiated water from the site and trying to cool overheated fuel in three crippled reactors, they said.

"The process to completely shut down the reactors is expected to take years. The risk of accidental radiation exposure will thus accumulate for the nuclear workers and banking of their PBSCs will become increasingly important," they added.

The letter's five authors are led by Tetsuya Tanimoto of the Cancer Institute at the Japanese Foundation for Cancer Research and Shuichi Taniguchi of the Toranomon Hospital, both in Tokyo.

The doctors complained Japan's nuclear industry resisted storing the workers' PBSCs because it was fearful of what this could do its reputation.

"The most important mission is to save the nuclear workers' lives and to protect the local communities," the letter said.

"Such an approach would be the industry's best defence: if a fatal accident happened to the nuclear workers, the nuclear power industry of Japan would collapse."