K-159 Sank: What are the Radiation Risks to the Barents Sea?

Bellona Position Paper

The K-159 nuclear powered submarine has two VMA-type reactors, each with a thermal capacity of 70 megawatts. The reactor cores of these reactors contain approximately 800 kilograms of spent nuclear fuel with the radioactivity of 750 curies per kilogram.

In 1989, the K-159 was retired by the Russian Northern Fleet. During the dismantlement process the following technical operations aimed at maintaining the necessary level of nuclear and radiation safety were performed with the reactor compartment of the submarine, including the two reactors:

  • Isolation of the primary circuit with the use of a special solution
  • Locking of the control rods in the lower position
  • Severing of the power cables of the control rods

These procedures provide for nuclear and radiation safety while in the normal operations mode. However, no procedures have ever been developed or performed to this end for the situations of emergencies—like the kind that took place today with the K-159.

With this in mind, Bellona has the following concerns:

  • How firmly and reliably had the control rods been locked?
  • What may be the consequences of the potential sliding of the control rods off the lower switches as a result of the impact the submarine must have sustained when hitting the sea floor or in case of its capsizing?
  • What are the chances of an uncontrolled chain reaction in the reactor blocs?
  • How strong are the chances that the main circuit of the reactor becomes unsealed, which will result in a radioactivity leak?

Besides these concerns, Bellona is worried about the current state of the reactors, as well as the pipeline and the valves of the main circuit. How bad is the corrosional damage of these elements so far? Will these sealed elements&#151reactors and their components&#151stand the pressure of the water at the depth where the K-159 submarine sank?

So long as these questions remain unanswered it will be impossible to assert that the K-159’s reactors are indeed safe and do not present a considerable radioactive risk for the basin of the Barents Sea.