iso-400 film storage

I have to store 35mm iso-400 film (30 m roll) for years. The intention is to freeze it in the refrigetaor. But 400 speed can be problem due to cosmic rays, and it is gone around 4 times faster than iso-100.
What is the best way to protect iso-400 film for many years (for some 10-15 years). Are that X-rays pouches reliable, and which one is the best?

Daniel OB
www.Leica-R.com

Huh? Why? Just keep buying it fresh.

For the record, I just exposed and developed some rolls of Kodak Tmax p3200 that expired in 2000. Refrigerated only. I exposed them at 1600. The negatives look ok to me.

I have read on several forums several times that the x-ray pouches will do little or nothing to block cosmic rays.

Good luck!

I also have to ask "Why not just buy it when you need it?"

If you must do this, just throw the whole box of 100' (30m) in the *FREEZER*, not the fridge. In the freezer, it will last for years.