For the longest time I was using the No Reactor Limits mod, which is a great mod, but it has a flaw. When you add an extra reactor to your build, you're not JUST adding extra power. The reactors have other stats too, including HULL. Your reactor determines the bulk of your hull even, and that means that adding a second or third reactor causes your ship's health to skyrocket, and there's no way that anything can kill you then.

My solution to this problem is several new parts called "Supplemental Reactors", which have the bonus power, but also do not count as reactors at all. So you can put one on and you won't even need the No Reactor Limits mod enabled. The supplemental reactors will reduce hull by 10% of the value of what a primary reactor would add, as you have to compromise parts of the hull to wire the power systems together. They are also heavier than their primary counterparts. The Supplemental Reactors can be found in the Equipment tab. There are additional types of supplemental reactors as well, that are not based on existing primary reactors.

All Supplemental Reactors have an increased mass compared to their primary cousins (you have to have all of that equipment to interface with the power grid you know), they cost 50% more, and add only 10% of the hull value of a primary counterpart. In addition, a reactor that was class A as a primary reactor is a class B part, and a class B primary reactor is a class C part when it is used as a supplemental reactor.




Installation:

• Unzip the archive and put TNSupplementalReactors.esm into your Starfield/Data folder (most likely under Documents/My Games/Starfield/Data), or let your mod manager install the file.
• Ensure that archive invalidation is enabled in your StarfieldCustom.ini. (Look below if you don't)
• Either add the line sTestFileX=TNSupplementalReactors.esm under the [General] section of your StarfieldCustom.ini file (With X being replaced with the next available number 1-10), or add *TNSupplementalReactors.esm to your Plugins.txt file if you have the plugin.txt enabler. (Ensure it has the * in front of it.)
• Install Baka Achievement Enabler and SFSE if you don't want achievements disabled.
  

If you haven't already done it for another mod, this is what needs to go in your StarfieldCustom.ini:

[Archive]
bInvalidateOlderFiles=1
sResourceDataDirsFinal=

Supplemental Reactors:

• Power Systems Node: (A Class) -5 Hull, 8 Mass, 2 Power
• Xiang Tokamak series: (B Class)
  

• X-050: -35 Hull, 45 Mass, 16 Power
• X-100: -40 Hull, 47 Mass, 18 Power
• X-150: -45 Hull, 50 Mass, 20 Power
• X-200: -50 Hull, 53 Mass, 23 Power
• X-250: -65 Hull, 59 Mass, 26 Power
• X-300: -80 Hull, 65 Mass, 29 Power
• X-120s: -50 Hull, 50 Mass, 28 Power
  

• Nautilus Tower series: (B Class)
  

• R900: -10 Hull, 27 Mass, 5 Power
• R910: -15 Hull, 30 Mass, 8 Power
• R920: -20 Hull, 34 Mass, 10 Power
  

• DeepCore Fast Ignition series: (C Class)
  

• DC301: -55 Hull, 72 Mass, 18 Power
• DC302: -85 Hull, 80 Mass, 27 Power
• DC303: -105 Hull, 89 Mass, 35 Power
  

• Xiang Ion Beam series: (C Class)
  

• H-1010: -55 Hull, 72 Mass, 16 Power
• H-1020: -75 Hull, 80 Mass, 24 Power
• H-1030: -100 Hull, 89 Mass, 31 Power
• H-1040: -190 Hull, 99 Mass, 39 Power
  

• Also re-enables the Xiang Ion Beam H-1040 Primary reactor (which was cut content originally).
  

My Other Mods:

TN's Ship Modules All In One
TN's Class M Ship Building
TN's Space Mining and Salvage
TN's Hab Shells
TN's Supplemental Thrusters
TN's Hab Tweaks 
TN's Useful Ship Structure 
TN's Expanded Cargo Holds
TN's Supplemental Reactors
TN's Supplemental Cockpits
TN's Weapon To Module Snapping
TN's Separated Categories
TN's Aid and Ammo Crafting
TN's Melee Weapon Modifications
TN's Power Tools 
TN's Modular Starborn Suits
TN's Outpost Storage