Haneul Nuclear Reactor in MW4 DMZ: an atom sculpture in front of two cooling towers in radioactive fog — Screenshot: Call of Duty: Modern Warfare 4 © Activision (enhanced)

MW4 DMZ key · Haneul Nuclear Reactor

Reactor 02 Control Room Key Location in MW4 DMZ

The Reactor 02 Control Room Key opens the control room inside the Reactor 02 building. Its description names grid H4, at Haneul Nuclear Reactor.

Last updated October 23, 2026Game version: DMZ Early Access, day 3

◆ Fortress · ■ Compound · L Lieutenant Tower · U UAV Tower · A Ammo Armor Cache · G Gas Station · M Marine Gas Station. Rings show the highest threat level (Low, Medium, High, Critical, Extreme); the white ring is Haneul Nuclear Reactor. Smaller markers from Activision's official Hajin Tac Map. Screenshot: Call of Duty: Modern Warfare 4 © Activision (enhanced)

Where the Reactor 02 Control Room is

Location	Haneul Nuclear Reactor
Tac-Map grid	H4
Rarity	Rare
Highest threat at Haneul Nuclear Reactor	High

The Tac-Map grid runs letters from west to east and numbers from north to south, so H4 is column H, row 4. See Haneul Nuclear Reactor on the interactive Hajin map, and its threat level by area in our Haneul Nuclear Reactor location guide.

What the Reactor 02 Control Room Key opens

The control room inside the Reactor 02 building. The key card is Rare.

Confirmed by 2 sources, including video 1 at 0:00. Checked 2026-10-22 (DMZ Early Access, day 3).

How to get the Reactor 02 Control Room Key

No video we checked shows where this key drops yet. Keys turn up as loot, a Lieutenant you kill may drop the key to their own loot room, and some Story Missions pay keys as rewards. We add the drop here once two players show it.

Keys can go in your Stash between deployments, but anything outside a Secure Slot is lost if your exfil fails. Tick the keys you have in the MW4 DMZ key finder; the list stays in your browser.

Other keys at Haneul Nuclear Reactor

Reactor DRC Locker (grid H4): The DRC Weapons Locker inside Reactor 02's irradiated pool.
The Chemist's Secure Armory (grid I4): The secured bunker near the boat house at Haneul Nuclear Reactor.
Hazard Storehouse (grid I5): The material storage warehouse south of the reactor's cooling towers.
Utility Maintenance Storage: A maintenance storeroom at the reactor. One source so far, not yet verified.

Questions

Where is the Reactor 02 Control Room Key used in MW4 DMZ?

At Haneul Nuclear Reactor, grid H4 on the Tac-Map. It opens the control room inside the Reactor 02 building.

What rarity is the Reactor 02 Control Room Key?

Rare, as its key card shows.

Every confirmed MW4 DMZ key with its own page

Sources

Checked against the official posts on October 22, 2026. The key itself comes from players’ videos, linked above at the moment they show it; we only give a key its own page once two different sources agree.