Radioactive waste repository, Tammiku.
The waste management facility for low and intermediate level waste was established at Tammiku, 12 km south of Tallinn, in 1963. It was the central storage/disposal facility for the waste generated from the use of radionuclides in Estonia.
The accident:
On 21 October 1994, three brothers entered the radioactive waste repository at
Tammiku, Estonia, without authorization and removed a metal container enclosing a
radiation source. This action initiated the sequence of events in a radiological
accident.
The accident resulted in the death of one person and injury to a number of
others. The death was not originally attributed to radiation exposure. However, a
physician who examined the injuries of the stepson of the dead person realized the
radiological nature of the accident and initiated the rescue actions that limited the
extent of the consequences.
As soon as radiation induced injury was diagnosed, the police were notified of
the evident loss of control over a radioactive source. The police in turn notified the
Estonian Rescue Board, which immediately dispatched staff to Kiisa, who arrived at
approximately 23:30 on 17 November 1994. Initial dose rate measurements
confirmed that high gamma dose rates existed close to RiH's house, and neighbours
within 200 m of the house and in areas where the dose rate exceeded 0.4 n,Gy/h were
evacuated.
The recovery operation was completed by 14:30 on
18 November 1994 and neighbours were permitted to return to their houses. On the
same day a radiological inspection of all the scrap metal stockyards in the country
was carried out by the rescue and environmental authorities. No other sources were
found.
The storage facility was decommissioned in 2008 and 55TBq worth of radioactive waste was sorted and disposed of. Now the place is a part of recreation area and Saku health trail.
The task:
Two stable (non-radioactive) isotopes carrying the information about the location of the final coordinate have escaped the facility and have been caught by the magnetic surface of two different metal plates located near the posted coordinate. You need to locate them and retrieve the information that is required to locate the container:
- The first plate is located 60 meters from both the second plate and the posted coordinate (Magnet #1 from the gallery).
- The second plate is located 30 meters from the posted coordinate and 60 meters from the first plate (Magnet #2 from the gallery).
- Isotopes are invisible to a naked eye but Geocachers usually carry required instrumentation in their geo-backpack.
- Having retrieved periodic table names of the two elements you need to perform some additional calculations to get the final coordinate:
- Latitude is N59.29AABB where AA is the atomic number (Z) of the lightest element of the two and BB is the neutron (N) number of the lightest stable isotope of the element.
- Longitude is E24.71CCDDD where CC is the atomic number (Z) of the heaviest element of the two and DDD is the neutron (N) number of the heaviest stable isotope of the element.
NB! Leave your car at the Saku health trail parking place in front of the information board. Do not go to the posted coordinate, it is fenced and unreachable. No any information is placed there. Everything you need for solving and logging the cache is located outside the facility and it is safe to walk among the waypoints.
Happy discovering!