rating: +7+x
Item#: 3685
Containment Class:
Secondary Class:
Disruption Class:
Risk Class:


UMZ-1 reactor complex prior to its meltdown. SCP-3685 is the largest building on the right of the photograph.


UMZ-1 reactor housing prior to meltdown.

Special Containment Procedures:
The 2 kilometer exclusion zone surrounding SCP-3685 has been acquired and is now being maintained by Foundation security personnel. The entirety of this zone's perimeter has been fenced, and the only official entrance is located on the western edge of the zone. Persons without proper Foundation credentials are not to be allowed within the exclusion zone under any circumstances.

Disinformation is to be proliferated claiming that the complex containing SCP-3685 is an extremely hazardous chemical and nuclear weapons development site. Further disinformation is to be implanted into historical institutions about the factual personnel and outcomes of the Uranprojekt. Any historical evidence for the Uranprojekt constructing anything beyond simple reactor piles is to be suppressed.

The area surrounding SCP-3685 is affected by significant radioactive contamination. Personnel and equipment present within the zone are to be subjected to regular screening. If equipment cannot be decontaminated, it is to be buried within the nuclear waste repository present on-site. Personnel are to be cycled out if they exceed radioactivity exposure limits.

Primary and secondary containment of the SCP-3685 spacetime anomaly is currently being maintained by equipment not produced by the Foundation. Primary and secondary containment is being managed by an Uranprojekt containment devices. The location of the primary containment device is unknown. Secondary containment is being managed by a series of stabilization panels installed in the perimeter of the SCP-3685 structure. It is unknown if or when any of the containment equipment will fail.

Update - 1962: Foundation personnel are now strictly prohibited from entering SCP-3685. Personnel that unexpectedly emerge from SCP-3685 are to be quarantined and treated for psychological trauma and acute radiation syndrome.

Update - 1987: The Foundation is preparing to augment SCP-3685 containment through additional containment equipment. See Addendum 3685.2.

SCP-3685 refers to a structure within the Uranmaschinezüchter-11 reactor complex, located in the German province of Saxony. SCP-3685 is the largest facility belonging to the UMZ-1 complex. Its interior suffers from a severe entangled spacetime anomaly. The outside facilities belonging to the UMZ-1 complex are non-anomalous, but are nevertheless hazardous due to the unsafe levels of radioactivity present. Foundation clean-up crews have temporarily decontaminated and cleared sections of the complex for human usage.2

The interior of SCP-3685 is a radioactive, spatially entangled, discontinuous non-euclidean space. Consequently, a precise description of the internal architecture of SCP-3685 is not possible, as the internal space is being continuously transformed by spatial reorganization. However, the space can be vaguely described: The outer areas of SCP-3685 usually contain an interlocked series of miscellaneous control rooms, offices, and maintenance areas, and the inner area consistently contains the UMZ-1 reactor and its housing. All attempts to explore areas near the reactor have failed.

Various hazards are present within SCP-3685 that complicate exploration. These hazards include:

  • Ionizing radiation. Lowest measured was 15 mSv/hr, highest was 30 Sv/hr3. Average is approximately 500 mSv/hr4.
  • Constant spatial restructuring, which may make the facility impossible to reasonably navigate.
  • The poor and unstable condition of the facility, which makes exploration precarious and difficult.
  • Abnormal and extreme gravitational effects. Within some regions, the gravitational field might: rapidly oscillate in intensity, reverse, increase in magnitude, use a differing gravitational constant (G)5, or other anomalous effects. Objects introduced within these regions frequently become shredded or explosively atomized, while the SCP-3685 structure remains unaffected.
  • Spatial, temporal, or spatial-temporal loops.
  • Sudden dematerializations of non-temporally-linked entities (such as any introduced Foundation personnel or robotic units).

The apparent magnitude of these hazards increases with proximity to the reactor. To demonstrate, during Exploration 3685-12, an autonomous drone, which was approximately 2-3 rooms away from the reactor, simultaneously experienced: a 0.54x gravitational field region, 3 discrete temporal loops, 12 interlocked spatial loops, and 1 spatial-temporal loop. Additionally, the drone had entirely disappeared and reappeared - twice. Contact with the unit was lost permanently when the drone gravitationally imploded. The final transmitted gravimeter measurement showed a value for G approximately 1020 times stronger than would be normally expected.

Scranton Reality Anchors have proven incapable of stabilizing the anomaly present within SCP-3685, having no apparent effects. Further, Kant Counters frequently fail to output Hume level measurements within SCP-3685, seemingly caused by the Kant Counters failing to detect local reality. Some success with stabilization has been seen with the PL362 Deployable Spatial Rectifier6, but the enormous magnitude of the spacetime anomaly prevents the small device from being practical enough for containment or exploration.

The UMZ-1 complex was built by the covert Nazi German nuclear weapons program (Uranprojekt) under the administration of the Reichsforschungsrat7 during the spring of 1944, with direct authorization for its construction given from Hermann Göring.

In 1942, Nazi Germany began an attempt to construct a logistics and manufacturing chain capable of producing nuclear weapons. Hindered by the politicization of academia, denial of science due to antisemitism, and Allied sabotage, the Uranprojekt was ineffective and progress was severely stunted. The Reichsforschungsrat apparently felt unsatisfied with "traditional methods", and ultimately decided to resort to alternative and eccentric proposals that were previously put forward by small research groups.

The UMZ-1 complex was the outcome of one of these proposals. Its designed purpose was inexpensive Plutonium-239 synthesis, operating using anomalous physics. Recovered Uranprojekt documentation states that UMZ-1 was capable of 'n-local folds allowing for synthesis of currently infeasible to manufacture elements and materials using only minuscule amounts of dense radioactive elements for catalytic reaction.' It is unknown if the UMZ-1 reactor was ever functional or capable of element synthesis prior to its meltdown, and it is currently not possible to easily determine due to a lack of original documentation and the present condition of the complex.

In early 1945, the UMZ-1 reactor suffered a catastrophic meltdown. According to recovered Uranprojekt documentation, this caused an 'interlocked local space compression fracture', the Uranprojekt's explanation for SCP-3685's spacetime anomaly. Following the meltdown, the Nazi German authorities condemned the complex and formed a 2 kilometer exclusion zone around the complex, which is maintained to the present day by Foundation security.

Discovery and Acquisition:
UMZ-1's existence first became known to the Foundation after several Uranprojekt scientists defected in late 1944. Through contacts in the United States government, the Foundation was informed of the then recent Uranprojekt efforts. Accordingly, the Foundation aggressively pursued acquisition and containment. Enforced seizure agreements were made with all of the Allied nations, except for the USSR. The USSR repeatedly refused to any agreements, stating that it would handle containment itself8. Due to the progression of the war during 1945 and the location of the UMZ-1 complex, the Foundation was initially unsuccessful in acquiring SCP-3685, as it was captured by Soviet forces.

During 1951 as part of Operation FAIRBANKS, Foundation acquisition teams successfully seized, acquired, terminated, or integrated all remaining personnel9, equipment, documentation related to the Uranprojekt, and SCP-3685 itself from Soviet forces. During this time, Foundation tensions with the USSR increased to near complete hostility.

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