The soft errors such as SEU/SEL are very common across all SRAM products and thus it affects the nvSRAM as well since nvSRAM also consists of SRAM cell. Cypress nvSRAM also offers a special feature called Software Recall which can be utilized to do away with soft error issue. The nvSRAM stores data into NV cell during power off and recall the data into SRAM during power up. If the device is used only for read ( as in your application) then it will always have a copy of SRAM data in the NV cell. In case if data is corrupted in SRAM cell, software Recall can restore data back to SRAM.
Hope this helps you.