Minn. Stat. § 65A.05: NUCLEAR REACTION, RADIATION OR RADIOACTIVE CONTAMINATION; ENDORSEMENT.

Loss or damage caused by nuclear reaction, nuclear radiation or radioactive contamination, all whether directly or indirectly resulting from an insured peril under the standard policy issued pursuant to sections 65A.01, 65A.02, 65A.03, and 65A.04, may be insured under said policy only by a written endorsement providing such insurance, with such endorsement affixed to said standard policy.