Radioactivity monitoring in environmental water and air around QNPP

Available online at www.sciencedirect.comNUCLEARScienceDirectSCIENCEANDTECHNIQUESNuclear Scieoce andTechniques, VOlL.18, NoS (2007)316- 320Radioactivity monitoring in environmental water andair around QNPPXIANG Yuanyi WANG Kan ZHANG Yu CAO Zhonggang YE Jida WANG Hongfeng(Zhejiang Province Ervirorumental Radiation Monitoring Center Hangzhou 310012,China)Abstract Results of environmental radioactivity monitring around Qinshan Nuclear Power Plant (QNPP) are化ported in this paper. From 1992 to 2005, concentrations of 9Ssr, "'Cs and H in tresrial freshwater are <4.4+1.7)mBqL' , (0.3+0.1) mBq吣1 and (1.620.5) BqL', respectively, and (2.8+2.4) Bq吣' of H in rainwater. Concentra-tions of 9Ss, 137Cs and H in the scawater samples cllece from sca area nearby QNPP are (5.4+4.1) mBqL*,(0.7t0.2) mBqL" and (1.0+0.5) BqxL", respectively. Concentrations of 9Sst, 37Cs and H in the total waste water dis-charged from NPP-I ure (4.01.8) m BqL', (1.0x0.5) mBq+L:' and (2.8+2.2) BqL', respectively, and (1.4x0.4)BqL" of H in seawater sampled from No.1 outlet. Atomspheric H concentaion in 1993 ~ 2005 at two monitoriogsites is (78.9+96.3) and (64.2140.2) mBq.m^ , respectively, with an increasing trend after 2003. Almosphric "C con-centrations at the two sites are in the same levels as the background and data of the reference site.Key words Enviroument, Radioactivity, Monitoring, Water, Tritium in air, Carbon-14, QNPPCLC number X8371 Introduction2 Monitoring methodSince 1991 when the first 300 MW pressur-ized-water reactor at Qinshan Nuclear Power Plant2.1 Geographical location and monitoring sites(QNPP) began its commercial operation, continuousThe QNPP base is located at Qinshan Hill on themonitoring of Y-rays and radionuclides content in en-vironment of the QNPP Base has been conducted by●Drink waterWhyuan TowmPendwaterZhejiang Province Environmental Radiaion Monitor-。Sea watering Center (ZERMC), so as to know changes in envi-●H and "Cin airronmental radiation level and radionuclide accumula-tion, to verify the operation safety and the QNPP'smanagement in wastes discharged under routine op-Baitashan Heration, to evaluate the effect of unplanned dischargeof radioactive materials into the environment, and toinilageprovide monitoring data for competent authority ofQinshan Tomenvironment protection.i Xiajawan vilageIn this paper, radioactivity levels in water, and HCianyanzhanand 4C in ai, collected from 1992 to 2005 in the en-vironment around QNPP Base, are reported.》NiphanFig,1中国煤化工sics around QNPPBase aMHCNMHG* B-mail: xyy@rnargy.cnRecaived dat: 2007-03-07No.5XIANG Yuanyi et al: Radioactivity monitoring in environmental water and air around QNPP317north shore of Hangzhou Bay, 8 km to the Wuyuansampling is in Zhoushan City, Zhejiang Province.Town, Haiyan County, Zhejiang Province. The first,second and third nuclear power plant (abbreviated to2.2 Monitoring items, methods, and instrumentsNPP-I, NPP-I and NPP , respectively) of QNPP areThe samples, sampling frequencies, and monitor-located at the north, south, and ceast of the Qinshan Hill. ing items at sampling sites within 20 km of the QNPPFig.1 shows locations of the NPPs and the water andBase are given in Table 1. The methods and instru-air monitoring sites around QNPP The reference sitements for the radionuclide analysis are listed in Tablefor air and fresh water sampling is in Hangzbou City,2Zhejiang Province, and the reference site for sea waterTable 1 Sitcs and sampling frequencies of the samples collected from the QNPP Base and the monitoring itemsSamples"F2) SitesMonitoring itemsDrink water (3)1-2 Qinshan Town, Wuyuan Towmos,nCs, HPond water (3-5)1-2 Qinlian Vllage, Nanbei Pond, Yangliu Village, Xiajiawan Vllage9osc, I7Cs, hHWell water (34)Qinlian Vllage, Yangliu Vllage, Xiajiawan Vllge9sr, IB7Cs,HRain water(1-4)12 Qianyanzhan Station, Yangliu Village, Xigjiawan VillageSea water (1-8)-2 The sea area nearby the QNPP Base, Wuyuan Town and Ganpu Town 9sr, ICs, HSea water of outler (3)2 Oulet of the frst phase of QNPP Base9sr,"Cs,HTotal waste water (1)12 Sampling house of the first phase of QNPP BaseAir(4)Qianyanzhan Station, Yangliu Vllage, Xiajiawan Village1) Number of sampling sites, inchuding the reference site in Hangzhou for air and fresh water, and in Zhoushan for sea water, aregiven in parentheses; 2) Annval sampling frequency (imes/a).Table 2 Methods and instruments of the radionuclide analysis in the water samples of QNPP BaseItemns .MethodsLow background countersLLDUncertainty9OSrDi- (2-thyhexyI) phosphateMPC9604 or LB4100W /β 0.2 ~ 0.7 mBqL'3.5%I37CsAmmonium phosphomolybdat-caesiuma<5%iodobismuthate precipitation analysisLB4100W w/ .0.2 ~ 0.5 mBqL'β<13%Hin water Liquid sinilation couningLKB-1220Quantulus0.9- 1.5 BqL+2.4%H in airLiquid scinillation coumting19.6 Bqm'*CCO3 precipitation0.09 Bq* (gecarbon)-'2.0%* :Al 22C and in 80% hunidity.dehumidifier, purifed by distillation and processed for23 Sample collection and processingmeasurement. The analyte containing 8mL distillationAccording to requirements, terrestrial fresh waterand 12mL scintillation liquor of Hisafe II was put intoand seawater samples were collected at regular inter-a vial, and shaken to emulsion according to the“Pro-vals at the sites around QNPP. Rainwater and totalcedure of Analysis for Tritium in Water"ul.waste water, including tricycle cooling water dis-Air samples for I4C monitoring were treated incharged from NNP-I, were sampled on a daily basisthe following steps. The atmospheric C was trappedand mixed monthly. The specimens for measuring 9Srinto an alkali solution using a bubbling chamber, ad-and B3'Cs concenrations were prepared by itillation,10.5 with NH4CLincineration and weighting, and samples for H meas-CaCl2中国煤化ipitation, whichurement were purified by distillation.was fYHCNMHGiandground.TheAir samples for H monitoring are collectedCaCO3 of 2.0g was put into a 20mL vial of low potas-monthly. The samples were collected by an electric318NUCLEAR SCIENCE AND TBCHNIQUBSVoL18sium, adding 14mL scinillation liquor of Triton-X1001992~2005, respectively. The averaged "St concentra.toluene and 4mL tritium-free water, shaking to sus-tion in water is (4.4+1.7) mBqL* , with 3.5 mBqL' inpension, in accordance with the“Procedure of Collec-drink water, 6.3 mBqLT n pond water, and 3.3tion and Measurement for 4C in Airr2.mBqL;t in well water, The averaged 137Cs concentra-tion in water is (0.3+0.1) mBqL , with 0.4 mBqL'3 Resultsin drink water, 0.2 mBqL' in pond water, and 0.3mBqL=' in well water, Ane the averaged H concen-3.1 Terrestrial fresh watertration in water is (1.6+0.5) BqL' , with 1.2 BqLl inFig.2 ~ Fig.4 show that concntaions of the rdrink water, 2.1 BqL:' in pond water, and 1.4 BqL'dionuclides in water sample of drink water (tap water),in well water.pond water, and well water at the site around QNPP in口 Drink water。Welwater2015101992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 MeanB.G R.SFlg2 9sr concentrations in water around the QNPP in 1992-2005. B.G is background, and R.S is reference site.口Drink water.1 Pond water口Well water0.8 t0.6-0.4 t1992 1993 1994 1995 1996 19971998 1999 2000 2001 2002 20032004 2005 MeanB.G R.SYearFig3 137Cs concentrations in water around QNPP in 1992 2005. B.G is background and R.S is reference sit.p Drink water■Pond water.口Well water1992 1993 1994995 19961997 1998 1999 2000 2001 2002 2003 2004 2005 MeanB.G R.SFlg.4 H concentaions in water around QNPP in 1992-2005. B.G is background and R.S is referencc site.rainwater increased in 2003~-2005 when NPPII and3.2 Rain waterNPP-II started operation.Fig.5 shows that H concentrations in rainwatersamples collected in 1993-2005 from the Qian~3.3 Sea wateryanzhan Station (including the Xiajiawan Village) are中国煤化工! H concoraions1.1~10.1 BqL" with an average of 2.8 BqL", whichis higher than the background value and monitoringinthe Hangzhou Bay,.HC N M H Gmd in tbe seawalertvalue of the reference site. And the 3H concentration insamples collected from outlet of NPP-I, and referenceNo.5XIANG Yuanyi et al: Radioactivity monitoring in environmental water and air around QNPP319sites of Zhoushan City in 1992~2005.12「言10个口Xajowan Vllage员B-■ Relerence是annliLh1993 1994 19997 1998 1999 2000 2001 2002 2003 2004 2005 MeanFg.5 H concentrations in rainwaler around QNPP in 1993-2005.Table3 9sr, 137Cs and H concentraions in seawater samples around QNPP in 1992-2005)Samples name9St/ mBqeL-V'Ca/ mBqL*H/Bq叽n2RangeMean sISeawater Doartby QNPP<0.4-24.8 5.4 4.1 :<0S ~9.5)70.260 <1.3-4.0 1.0 0.Total waste water of NPP- 101403-175 4.0 1.8 118 <05~13.0 1.105127 <1.3-215 272:Sca wtr o outlet of NPP-I力44 <1.3~25.6 1.60Sum4.71.0174一).9 0.331 -1.8 0.Beackgrouad16-1330.5-331.121 1.0-5.2Refareoce site0__ <0.6-6.6 3.1<0.4-2.8 1.91 <15-4.5 1.1__-1) In the calculation, the half LLD was used instead if the measured values are 0.05 comparing with the reference site, after NPP-Idata processing. and data arangement in the surveil-and NPP-II started operation.lance monitoring.(3) In some periods in 2002 ~ 2005, the H con-Referencescentrations in seawater samples collected from themonitoring sites are higher than data of the reference1 The State Standard of PRC. Procedure of alysis for trit-site.ium in water, GB 12375-90 (in Chinese).(4) From 1993 to 2005, atmospheric 'H concen-2 The State Standard of PRC. Procedure of cllection andmeasurement for 1C in air, E/T 1008 -96 (in Chinese).tration of Xiajiawan Village and Yangliu Village is .respectively 1.7 and 2.8 times higher than the back-3 Kim Chang-Ryu, Han Man-Jung. Applied Radiation andground and the data of the reference site, and it in-Esotopes 999 50: 783-791.creased after 2003 when NPP-II and NPP-II started中国煤化工MYHCNMHG