KBRA Affirms National Storage Affiliates Ratings and Stable Outlook NEW YORK--(BUSINESS WIRE)--Kroll Bond Rating Agency (KBRA) has affirmed the BBB ratings for issuer NSA OP, LP—the operating partnership subsidiary of National Storage Affiliates Trust (NYSE:NSA)—and the issuer’s $150 million outstanding privately placed senior unsecured notes. KBRA has also affirmed the BBB- rating for parent NSA’s $218 million outstanding Series A redeemable preferred shares. The affirmations follow our analysis of the issuer’s financial profile and operating characteristics,