The results of measurements of the volume activity and dispersity of aerosol carriers of β-emitting
radionuclides during the acute phase of the accident and 20 years later are presented. It is determined that
in August–October 1986, when samples were taken 10–50 m from the surface of the destroyed reactor, the
concentration was about 1 kBq/m
3
,which is 100–1000 times higher than the value recorded in July–August
of the same year from an aircraft flying at altitudes 200–1000 m. Thus, already in mid-summer 1986,
because of the decrease in temperature, the aerosol emissions did not reach the survey altitude of the
aircraft. Therefore, the sampling performed from the aircraft did not permit a quantitative assessment of
the emissions of radioactive materials during this period of time. In 2003–2005, the total β activity was
10–100 times less than in fall 1986, because of the radioactive decay of
95
Zr,
95
Nb,
103,106
Ru,
134
Cs,
141,144
Ce, and other radionuclides. Since the
137
Cs concentration decreased negligibly, it seems that the
roof constructed in 1986 above the Shelter was of little use.
Radioactive aerosols and gases presented the greatest danger during the first few days after the accident [1]. A month
after the accident, construction of the Shelter started in order to isolate the nuclear fuel and accumulated fission products
remaining in the destroyed reactor, decreasing their effect on the environment. This object was put into operation on
November 30, 1986. The present article presents the results of observations of radioactive aerosols during the acute phase of
the accident and during the construction of the Shelter and its subsequent operation.
Monitoring of Emissions of Radioactive Aerosols During the Acute Phase of the Accident and During the
Construction of the Shelter in 1986. The first aerosol sample from the radioactive cloud was obtained on April 27, 1986,
using a FPP-15-1,5 filter, during the flight of an An-30rr aircraft belonging to Goskomgidromet of the SSSR. Systematic
monitoring was started during the night of April 27–28 using an An-24rr aircraft belonging to the Ministry of Defense and
continued for about 3 months [2]. The aerosols were caught with a FPP-15-1,5 filter in two gondolas [3], placed in the for-
ward part of the fuselage. About 15000 m
3
of air passed through the gondola during 1 h of flight time. The aircraft patroled
over the nuclear power plant at an altitude of 200–1000 m. In the period April 28 to May 19, aerosols were also obtained sev-
eral times from a Mi-8 helicopter [4].
According to Fig. 1, the total concentration of β-emitting nuclides varied by factors of 10–100 and sometimes by a
factor of 1000 over a period of one day [5]. The highest concentration 55 kBq/m
3
was recorded on May 4; a slightly lower
Atomic Energy, Vol. 100, No. 4, 2006
UDC 621.039.7
Translated from Atomnaya Énergiya, Vol. 100, No. 4, pp. 276–282, April, 2006. Original article submitted January 13,
2006.
1063-4258/06/10004-0264
©
2006 Springer Science+Business Media, Inc.
264
B. I. Ogorodnikov,
1
A. K. Budyka,
1
É. M. Pazukhin,
2
and V. A. Krasnov
2
AEROSOL EMISSIONS FROM THE DESTROYED
POWER-GENERATING UNIT OF THE CHERNOBYL
NUCLEAR POWER PLANT IN 1986 AND 2003–2005
1
State Science Center of the Russian Federation – L. Ya. Karpov Institute for Research in Physical Chemistry.
2
Institute for the Problems of the Safety of Nuclear Power Plants, National Academy of Sciences of Ukraine.