A baffle plate was a component found in many starships in the 23rd and 24th centuries. The baffle plate was part of the warp drive systems. A warped or ruptured plate could cause a warp core breach, or flood parts of the ship with radiation.
Later that year, on board a J class training ship, the baffle plate ruptured. Because of the location of the blast doors - which was considered to be one of the design flaws in that type of ship - a good portion of the ship was flooded with delta radiation. Fleet Captain Christopher Pike entered the contaminated section and pulled out a number of the crew before suffering irreparable damage himself. (TOS episode: "The Menagerie, Part I"; TOS novel: Burning Dreams)
Baffle plates were still part of Galaxy-class starships in the 24th century. In 2368 the USS Venture's Chief Engineer Charles H. Logan discovered a baffle plate malfunction on board the Venture, the ship subsequently docked at Luxor IV for repairs. (TNG novel: The Devil's Heart)