OK, call 'em bunching onions if you like that awful name!

This morning whilst in a garden centre I got into conversation with somebody
who was buying some onion sets. He said that he'd given up planting seed
and now uses onion sets which produce spring onions in three to five weeks.
He said that he'd tried Japanese onions but considered them yuk and advised
me to buy Stuttgarter sets. He said he plants them 2 inches apart in a
largish tray (one about inches deep) of multipurpose compost. He grows
them by the window of his garden shed

I bought enough to last quite a few weeks for 31 pence which will save a lot
of mucking about with seeds!

I'd like to plant them in succession so need to store the unplanted ones.
If I kept them in a domestic fridge would they survive and be viable?

Regards

Geoff