even under normal operation of nuclear power plants ( npps ) discharges of radioactive substances into the atmosphere take place . considerable attention is given to monitoring of radioactive noble gases , iodine , c , fission and activation products in particulate form in airborne effluents . the annual discharged activities of these radionuclides have been reported by individual npp . on the other hand , there is little information given on the monitoring of the release of biologically important pu , pu , am , and other transuranium nuclides ( tru ) from nnps under normal operation conditions . monitoring of tru in effluents discharged to air from npps started in our institute in 1985 . the main objective was to obtain discharge data on tru for each nuclear power plant operated in the czech republic and slovak republic . up to 2003 we had searched for tru in effluents discharged to air from five stacks ( stacks 1 and 2 of the former v1 and v2 , npp jaslovsk bohunice , stacks 3 and 4 , of the former v3 and v4 , npp dukovany and stack 5 of npp temelin ) . at four of these stacks ( stacks 14 ) the effluents come from the main production building ( with two pressurized water reactors of 440 mwe power of each reactor ) and from the auxiliary service building for the primary system . at stack 5 the effluents come from the main production building with one pressurized water reactor of 1,000 mwe power . the results obtained were from time to time published and observations made during all the study are summarized in the previous paper . they are : ( 1 ) pu , pu , am , cm and cm can be present in effluents discharged to air . their activity concentrations and discharged activities from individual stacks , however , vary in wide range . the presence of tru in effluents from the stack 5 was not proved at all and their activities in effluents from stacks 2 and 4 were either lower than their limits of detection or only slightly exceeded these limits in some monitoring periods . on the other hand , during all the nine years of study measurable activities of tru were found in the effluents discharged to air from stack 1 and from stack 3 since the third quarter of 1996 as a result of a defect in the fuel cladding . at the stack 3 further increases of tru activities in effluents occurred in the third quarter of 1999 and the third quarter of 2003 . ( 2 ) two phases can be distinguished in the time course of tru discharge : the first phase represents the first quarter when the increase begins and the second phase represents a further time period with lower discharges . in all the three events at the stack 3 the activity of cm reached the highest value in tru mixtures in the first phase of the discharge . nevertheless several other substantially lower increases of tru discharge with maximum cm content were also registered during the study . those however lasted for one or two following quarters only . ( 3 ) there exist definite activity ratios of tru in effluents discharged to air . so activity ratio of pu / pu in effluents from the stack 1 was approximately 1.0 during all the 9 years study . the activity ratios in effluents are given by the ratio of these radionuclides in fuel from which the contamination has originated . we calculated ( for definite conditions ) the activity ratios of pu / pu , am / pu , cm / pu and cm / pu in fuel for different burn - up values . ( 4 ) tru discharged to air from the studied stacks contribute very little to further contamination of the environment . for example , the largest annual discharge of pu , 66  kbq from the stack 1 was equivalent to the activity of these radionuclides from atmospheric nuclear tests fallout in top soil for an area 1,100  m in our geographic position . since 2004 the search for tru in effluents discharged to air has been extended to further stacks in npp temeln . two of them ( stacks 3 and 4 ) belong to npp dukovany and five ( stacks 59 ) to npp temelin . at the stack 7 the effluents come ( similarly to stack 5 ) from the main production building with one pressurized water reactor of 1,000 mwe power . at stacks 6 and 8 the effluents come also from the main production buildings and they are released mainly during shut - down periods . aerosol particles were collected ( by the npp staff ) using large volume samplers installed in the stacks above the npp air filtration system . after gamma spectrometry a part of each exposed filter was cut off and thus obtained portions were put together to yield quarterly samples in 20042005 , while since 2006 , half - year samples have been prepared . tru in the air filter samples were determined using radiochemical separation and alpha spectrometry as described in our previous paper . in table  1 the annual discharged activities of tru from the studied stacks in 20042009 are presented . as can be seen the annual discharged activities of pu , pu , am , cm and cm from the stack 3 varied in the range 9601800 , 320630 , 7601600 , < 320820 and 7203500 bq , respectively . similar values for annual discharge were obtained in 2001 and 2002 . there is no evidence for a decrease of the discharged activities within the time period from 2004 to 2009 . for example the discharge of pu in 2004 ( 670 bq ) is lower than the discharge in 2006 ( 950 bq ) and 2008 ( 890 bq ) . similarly , the pu discharge in 2004 ( 390  bq ) is lower than that in 2006 and in 2008 ( 450 bq).table  1annual discharged activities of transuranium nuclides from individual stacksstackyearannual discharged activities ( bq ) 
 pu 
 pu 
 am 
 cm 
 cm320049603909708101,50020051,200590910>630 < 7001,50020069504509003701,10020071,8006301,6008203,50020088904508004508402009670320780>280 < 32072042004<110>100 < 170>4,000 < 4,100<220>3,300 < 3,4002005>130 < 190>90 < 160>120 < 210>150 < 300>80 < 1702006>780 < 800>72 < 90>150 < 170<38>40 < 612007634564<27>38 < 5320081,5006701,300<705902009>42 < 67>130 < 150110<60<3252004<9<10<20<19<82005>45 < 71<53<172006<6<61600>17 < 29<52007>12 < 1545170<11<62008>24 < 27>8 < 11110<23<52009<515>2 < 4<5<362004<2480<31 < 63>400 < 440<162005<110 < 190<97<302006<23<1086>86 < 100<122007>6 < 8<71405142008<14<10>23 < 37>110 < 130<132009<3909<5<372004<29<32<29<27<92005<25>18 < 34<70<182006<7<752,000<33<72007<4<3100<3<22008<9<938<19<8200917<3>2 < 10<11<482004<35>32 < 59>18 < 38<45<16200520061708387,0002,3009020079544569043200826<314110102009<21<1115055<992004<230<250<100<130<442005<58<130<272006>150 < 160>70 < 9044,000>140 < 180<312007>62 < 861101,800>180 < 250<462008<27>330 < 340160<71<372009<28<2234<20<8 annual discharged activities of transuranium nuclides from individual stacks we did not find tru in effluents discharged to air from the stack 4 in the most of monitoring periods before 2004 . during 20042009 , tru were sometimes measurable in discharged effluents from this stack ( at the level similar to those for the stack 3 ) , sometimes not ( table  1 ) tru activities in effluents discharged to air from the stacks 59 were mostly either lower than the detection limit or only slightly exceeded this limit in 20042009 . there are however , two exceptions : ( 1 ) am appeared in discharged effluents from these stacks in 2006 . ( 2 ) besides am , other low activity tru appeared especially in the stack 8 in 2006 . in table  2 , activity concentrations of tru in effluents discharged to air and discharged tru activities from the stacks 59 in the first and the second half - year of 2006 are presented . it is obvious from table  2 that although in the first half - year tru were not measurable in effluents in the second half - year tru appeared in effluents from these stacks , with the maximum content of am . maximum concentration of am 520    23 bq.m was found in effluents from the stack 8 . maximum discharged activity of am amounted to 87000 bq . at the stack 8 , well measurable activities of cm , cm and plutonium nuclides were also found in the effluents discharged to air . discharged activities of am and other tru from the stacks 59 significantly decreased in further years ( table  1).table  2activity concentrations of tru in effluents discharged to air and discharged activities for stacks 59 in first and second half - year of 2006stackhalf - year 
 pu 
 pu 
 am 
 cm 
 cmconc.(bq.m)discharge ( bq)conc.(bq . m)discharge ( bq)conc.(bq.m)discharge ( bq)conc.(bq.m)discharge bqconc.(bq.m)discharge ( bq)51<0.009<3.7<0.008<2.9<0.009<3.7<0.030<11.7<0.008<2.92<0.006<2.5<0.007<2.93.9    0.116000.0420.0117<0.004<1.661<0.094<5.1<0.087<4.7<0.13<7.2<0.25<13.2<0.06<3.22<0.24<18<0.063<4.71.15    0.14861.15    0.0686<0.11<8.371<0.007<3.1<0.006<2.6<0.024<10.6<0.055<24.2<0.011<4.92<0.01<4.1<0.013<4.7120    3.052,000<0.02<8.5<0.004<1.781<0.27<4.8<0.20<3.5<0.11<1.9<0.23<3.9<0.09<1.621.0    0.031700.50    0.0583520    2387,00013.7    0.823000.544    0.099091<0.007<12.6<0.011<19.80.066    0.006120<0.022<37.4<0.008<14.420.089    0.0041500.041    0.0077025.7    1.1444,0000.082    0.013140<0.01<17quoted uncertainties are    1 sigma counting error activity concentrations of tru in effluents discharged to air and discharged activities for stacks 59 in first and second half - year of 2006 quoted uncertainties are    1 sigma counting error in our previous work we found that radionuclide composition of tru in discharged effluents is not random , but it is connected with burn - up values of fuel particles from which the contamination originated . the activity ratios of tru in effluents discharged to air from the stack 3 in studied years and in second half - year of 2006 from the stack 8 are presented . it can be seen that the activity ratios of pu / pu in effluents from stack 3 in 20042009 are close to value 2 . similar values for activity ratios of pu / pu in effluents from this stack were found since the 3 quarter of 1996 up to the second quarter of 1999 and in 20022003 . the obtained ratios of am / pu and cm / pu in the studied years ( table  3 ) are similar to those found since 3 quarter of 1999 up to 2003 .table  3activity ratios of tru in effluents discharged to air for stacks 3 and 8stackyearactivity ratio 
 pu / pu 
 am / pu 
 cm / pu 
 cm / pu320042.52.52.13.920052.01.51.12.520062.12.00.82.420072.92.51.35.520082.01.81.01.920092.12.40.92.3820062.0104827.71.1 activity ratios of tru in effluents discharged to air for stacks 3 and 8 activity ratios of pu / pu , am / pu , cm / pu and cm / pu in the effluents from the stack 8 in the second half - year of 2006 are 2.0 , 1048 , 27.7 , and 1.1 , respectively ( table  3 ) . using relations between the calculated activity ratios of tru and burn - up values/2/for activity ratios of pu / pu  =  2.0 the corresponding burn - up is 27 gwd / tu . for this burn - up value the calculated activity ratios ( using the relation between activity ratios and burn - up values/2/ ) of am / pu , cm / pu and cm / pu are 0.14 , 32 , and 1.2 , respectively . it can be seen that in the case of cm / pu ratios the measured ( 1.1 , table  3 ) and calculated values ( 1.2 ) are close , in the case of cm / pu ratio the measured ( 27.7 ) and calculated ( 32 ) values are similar , in the case of am / pu ratios , however , the measured value ( 1,048 ) considerably exceeds the calculated value ( 0.14 ) . for activity ratio am / pu  =  0.14 , in the case of 83 bq pu discharge ( data for stack 8 in the second half year , 2006 , table  2 ) the corresponding am discharge should be 11.6 bq . the measured am discharge is 87000 bq . we can not explain relatively high am discharge from the stack 8 from fuel - cycle . an explanation is even more difficult for the stack seven because in effluents discharged to air from this stack no pu , pu and cm were found . to get an idea of how the studied stacks contributed to further contamination of the environment , we compared the annual discharged activities with the activities of an area of soil surface contaminated by fallout from atmospheric nuclear tests ( in the case of pu also from snap-9a satellite burn - up ) . taking into account the fact that at latitudes 40 to 50n the fallout of pu , pu and am till 1978 amounted to 58 , 1.5 and 25 bq.m , respectively , the largest annual discharge of pu 670 bq in 20042009 ( stack 4 in 2008 ) is equivalent to the fallout of these radionuclides on an area of 11.6  m , in the case of pu the equivalent area ( maximum discharge 1,800 bq , stack 3 in 2007 ) is 1,200 m and in the case of am ( maximum discharge 87000 bq , stack 8 , 2006 ) this area is 3,480  m. it is evident that even the stacks with the largest annual discharges contribute to further contamination of the environment only to a very small degree .
in this work we present data on transuranium nuclides 238pu , 239,240pu , 241am , 242 cm and 244 cm in effluents discharged to air ( activity concentrations and annually discharged activities of individual radionuclides ) from 7 stacks in 20042009 . in the effluents discharged to air from one stack low activities of transuranium nuclides were observed throughout the studied period . 
 transuranium nuclides had been discharged to air from this stack also in previous years since 1996 when defect in the cladding of a fuel element and consequent contamination of the primary circuit occurred . in the effluents discharged to air from another stack transuranium nuclides were observed only in some monitoring periods of studied years . 
 we could not prove the presence of transuranium nuclides in the effluents of the other stacks up to 2006 . 
 the transuranium nuclides in discharged effluents were registered in the second half - year of 2006 . in 20072008 especially low activities of 241am 
 were found in these effluents .