Scientists have recorded a rise in nuclear activity in the destroyed nuclear reactor at the Chernobyl power plant in Ukraine since it was covered over in 2017, but the rise has levelled off and does not exceed safety standards, staff said, writes Reuters.

Staff at the plant said the rise in “neutron flux density”, which if significant could indicate an uncontrolled nuclear reaction, did not pose a threat of such an event based on their mathematical models.

High levels of radiation and damage mean it is not possible to determine precisely the situation under the destroyed block.

“After the establishment of a new safe confinement which has been in the designed position for more than four years, an increase in the neutron flux density is actually observed”, - scientists at Ukraine’s Institute For Safety Problems Of Nuclear Power Plants said in a statement.

“At present, the readings of the sensors in all rooms have stable values without an upward trend. The current levels do not pose a threat of a self-sustaining chain reaction”, - the Chernobyl plant said in a separate statement.