when having an active seidr mission in the alphines (you should complete there the huldra4 mission if you are seidr), you need to get hel 1 solvent, 1 enzyme and 1 research and she will make you a "jotun genome data". after you have it (you may also find jotun genome data as a random loot from fighting jotuns) make another research and talk to hildr and the mission will be completed.
solvent can be only be found (by chance) in the alpines by scavenging the base while having an active seidr mission.