{"id":8547,"date":"2020-08-24T14:13:31","date_gmt":"2020-08-24T13:13:31","guid":{"rendered":"https:\/\/www.vtei.cz\/?p=8547"},"modified":"2024-07-17T10:48:25","modified_gmt":"2024-07-17T09:48:25","slug":"a-computational-algorithms-used-for-improvement-of-the-system-for-continuous-monitoring-of-radioactive-contamination-of-surface-waters","status":"publish","type":"post","link":"https:\/\/www.vtei.cz\/en\/2020\/08\/a-computational-algorithms-used-for-improvement-of-the-system-for-continuous-monitoring-of-radioactive-contamination-of-surface-waters\/","title":{"rendered":"A computational algorithms used for improvement of the system for continuous monitoring of radioactive contamination of surface waters"},"content":{"rendered":"

<\/i> This article is available in Czech only. For translation or more information on this topic, please contact author.<\/h4>\n

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Souhrn<\/h2>\n

Sta\u0165 popisuje praktick\u00e9 aspekty uplatn\u011bn\u00ed algoritmu NASVD p\u0159i zpracov\u00e1n\u00ed gama spekter ze s\u00edt\u011b kontinu\u00e1ln\u00edch monitorovac\u00edch stanic gama aktivity v\u00a0\u0159\u00ed\u010dn\u00ed vod\u011b (SAGMA) s\u00a0d\u016frazem na p\u0159enos b\u00e1zov\u00fdch komponent mezi r\u016fzn\u00fdmi lokalitami. V\u00a0minulosti byl vliv dekonvolu\u010dn\u00ed metody NASVD na zlep\u0161en\u00ed citlivosti SAGMA ov\u011b\u0159en v\u00a0poloter\u00e9nn\u00edch podm\u00ednk\u00e1ch. Po um\u00edst\u011bn\u00ed s\u00edt\u011b p\u0159\u00edstroj\u016f SAGMA do\u00a0re\u00e1ln\u00fdch \u0159\u00ed\u010dn\u00edch podm\u00ednek byla metoda NASVD pou\u017eita tak\u00e9 na spektra z\u00a0t\u011bchto p\u0159\u00edstroj\u016f. Za t\u00edmto \u00fa\u010delem byl experiment\u00e1ln\u011b proveden p\u0159enos konvergovan\u00fdch b\u00e1zov\u00fdch komponent poza\u010fov\u00fdch spekter z\u00a0poloter\u00e9nn\u00edho provozu. V\u00fdsledky uk\u00e1zaly dobrou p\u0159enositelnost poza\u010fov\u00e9 b\u00e1ze v\u00a0r\u00e1mci\u00a0podm\u00ednek tekouc\u00ed \u0159\u00ed\u010dn\u00ed vody za dodr\u017een\u00ed pat\u0159i\u010dn\u00e9 hloubky ponoru sondy. Pro podm\u00ednky stojat\u00e9 p\u0159ehradn\u00ed vody nebyl p\u0159enos proveden \u00fasp\u011b\u0161n\u011b. Ukazuje se, \u017ee SAGMA m\u016f\u017ee za dodr\u017een\u00ed pat\u0159i\u010dn\u00fdch vlastnost\u00ed monitorovac\u00ed lokality fungovat tak\u00e9 jako mobiln\u00ed monitorovac\u00ed stanice s\u00a0mo\u017enost\u00ed vyu\u017e\u00edt metodu NASVD okam\u017eit\u011b po um\u00edst\u011bn\u00ed na novou lokalitu bez nutnosti zdlouhav\u00e9ho nab\u00edr\u00e1n\u00ed tr\u00e9novac\u00edch spekter.<\/p>\n

\u00davod<\/h2>\n

Za \u00fa\u010delem zlep\u0161en\u00ed havarijn\u00ed p\u0159ipravenosti \u010cesk\u00e9 republiky byl vyvinut monitorovac\u00ed syst\u00e9m ur\u010den\u00fd ke kontinu\u00e1ln\u00edmu in situ<\/em> stanovov\u00e1n\u00ed aktivity gama v\u00a0povrchov\u00fdch vod\u00e1ch. Monitorovac\u00ed syst\u00e9m sest\u00e1v\u00e1 z\u00a0monitorovac\u00edch stanic naz\u00fdvan\u00fdch akronymem SAGMA (z\u00a0anglick\u00e9ho Station for Artificial Gamma Activity Measurement). Jsou to monitorovac\u00ed stanice funguj\u00edc\u00ed na b\u00e1zi ponorn\u00e9ho NaI(Tl) detektoru m\u011b\u0159\u00edc\u00edho ve 4\u03c0 geometrii p\u0159\u00edmo v\u00a0mase analyzovan\u00e9 vody bez pou\u017eit\u00ed st\u00edn\u011bn\u00ed. SAGMA je vybaven autonomn\u00edm zdrojem elektrick\u00e9ho nap\u00e1jen\u00ed a\u00a0d\u00e1lkov\u00fdm p\u0159enosem dat, tak\u017ee spl\u0148uje krit\u00e9ria pro za\u0159azen\u00ed do skupiny \u201estand-alone\u201c p\u0159\u00edstroj\u016f [1]. Ze t\u0159\u00ed SAGMA byla sestavena provizorn\u00ed monitorovac\u00ed minis\u00ed\u0165 [2], naz\u00fdvan\u00e1 akronymem SCOMO (System for Continuous Gamma Acitivy Monitoring).<\/p>\n

Konstrukce SAGMA je pops\u00e1na v\u00a0\u010dl\u00e1nku Fejgla a\u00a0kol. [1]. Tato monitorovac\u00ed stanice je unik\u00e1tn\u00ed schopnost\u00ed pracovat v\u00a0autonomn\u00edm a\u00a0automatick\u00e9m re\u017eimu, co\u017e je v\u00fdhodn\u00e9 v\u00a0p\u0159\u00edpad\u011b havarijn\u00edho monitorov\u00e1n\u00ed, pro jeho\u017e pot\u0159eby je prim\u00e1rn\u011b ur\u010dena. Oproti dal\u0161\u00edm p\u0159\u00edstroj\u016fm stejn\u00e9ho ur\u010den\u00ed popsan\u00fdm v\u00a0literatu\u0159e vykazuje SAGMA vy\u0161\u0161\u00ed citlivost detekce [1, 3, 4]. To je zaji\u0161t\u011bno pou\u017eit\u00edm dekonvolu\u010dn\u00edho algoritmu NASVD (Noise Adjustment Singulat Value Decomposition), umo\u017e\u0148uj\u00edc\u00edm z\u00edsk\u00e1n\u00ed b\u00e1zov\u00fdch spekter z\u00a0v\u00fdsledk\u016f m\u011b\u0159en\u00ed pozad\u00ed, a\u00a0t\u00edm redukovat vliv odezvy detektoru na kol\u00eds\u00e1n\u00ed p\u0159\u00edrodn\u00edho pozad\u00ed [5].<\/p>\n

Kol\u00eds\u00e1n\u00ed p\u0159\u00edsp\u011bvku gama od pozad\u00ed je v\u00a0p\u0159\u00edpad\u011b kontinu\u00e1ln\u00edho in situ<\/em> m\u011b\u0159en\u00ed gama aktivity \u0159\u00ed\u010dn\u00edch vod zp\u016fsobeno p\u0159edev\u0161\u00edm kol\u00eds\u00e1n\u00edm aktivity radonu a\u00a0jeho p\u0159em\u011bnov\u00fdch produkt\u016f. Vzhledem k\u00a0tomu, \u017ee radon a\u00a0jeho p\u0159em\u011bnov\u00e9 produkty jsou obsa\u017eeny p\u0159\u00edmo v\u00a0analyzovan\u00e9 vod\u011b, toto kol\u00eds\u00e1n\u00ed ovliv\u0148uje i\u00a0anal\u00fdzy vod prov\u00e1d\u011bn\u00e9 nejen pomoc\u00ed p\u0159\u00edstroj\u016f s\u00a0ponornou detek\u010dn\u00ed sondou, ale i\u00a0pomoc\u00ed p\u0159\u00edstroj\u016f vybaven\u00fdch st\u00edn\u011bnou detek\u010dn\u00ed komorou, nap\u0159\u00edklad kontinu\u00e1ln\u00ed monitorovac\u00ed stanice vybaven\u00e9 st\u00edn\u011bnou Marinelliho n\u00e1dobou [3]. V\u00a0p\u0159\u00edpad\u011b ponorn\u00fdch monitorovac\u00edch stanic doch\u00e1z\u00ed tak\u00e9 k\u00a0v\u00fdznamn\u00e9mu kol\u00eds\u00e1n\u00ed dal\u0161\u00edch slo\u017eek p\u0159\u00edsp\u011bvku do poza\u010fov\u00e9 odezvy, a\u00a0to kosmick\u00e9ho z\u00e1\u0159en\u00ed zejm\u00e9na v\u00a0souvislosti s\u00a0kol\u00eds\u00e1n\u00edm vodn\u00ed hladiny a\u00a0terestri\u00e1ln\u00edho z\u00e1\u0159en\u00ed v\u00a0souvislosti s\u00a0kol\u00edsaj\u00edc\u00ed vzd\u00e1lenost\u00ed sondy ode dna a\u00a0se slo\u017een\u00edm dnov\u00fdch sediment\u016f. N\u00e1sledkem t\u011bchto vliv\u016f jsou monitorovac\u00ed stanice vyu\u017e\u00edvaj\u00edc\u00ed konstrukci ponorn\u00e9 sondy oproti monitorovac\u00edm stanic\u00edm se st\u00edn\u011bnou detek\u010dn\u00ed komorou m\u00e9n\u011b citliv\u00e9 [1,\u00a03, 4].<\/p>\n

Vyu\u017eit\u00ed algoritmu NASVD pro pot\u0159eby SAGMA bylo testov\u00e1no um\u00edst\u011bn\u00edm detek\u010dn\u00ed sondy p\u0159\u00edstroje do poloter\u00e9nn\u00edch podm\u00ednek v\u00a0are\u00e1lu V\u00daV TGM v\u00a0Praze [1]. Spektra z\u00a0dlouhodob\u00e9ho, p\u0159ibli\u017en\u011b jednolet\u00e9ho, kontinu\u00e1ln\u00edho m\u011b\u0159en\u00ed byla pou\u017eita jako tr\u00e9ninkov\u00fd dataset pokr\u00fdvaj\u00edc\u00ed celosezonn\u00ed kol\u00eds\u00e1n\u00ed pozad\u00ed pro tuto lokalitu. Vyu\u017eit\u00edm z\u00a0n\u011bj vygenerovan\u00fdch b\u00e1zov\u00fdch komponent pozad\u00ed metodou NASVD p\u0159ineslo velice p\u0159\u00edzniv\u00e9 v\u00fdsledky, jmenovit\u011b pokles hodnot NDA p\u0159ibli\u017en\u011b na polovinu oproti srovnateln\u00e9 monitorovac\u00ed stanici vybaven\u00e9 ponornou sondou [1, 4]. Ve srovn\u00e1n\u00ed s\u00a0monitorovac\u00ed stanic\u00ed se st\u00edn\u011bnou pr\u016fto\u010dnou m\u011b\u0159ic\u00ed komorou jsou p\u0159i desetiminutov\u00e9m integra\u010dn\u00edm \u010dase v\u00a0p\u0159\u00edpad\u011b SAGMA hodnoty NDA nav\u00fd\u0161eny faktorem p\u0159ibli\u017en\u011b 1,4 [1, 3]. D\u00e1le bylo shled\u00e1no, \u017ee desetiminutov\u00fd integra\u010dn\u00ed \u010das i\u00a0za nejm\u00e9n\u011b p\u0159\u00edzniv\u00fdch okolnost\u00ed posta\u010duje k\u00a0napln\u011bn\u00ed z\u00e1konn\u00fdch po\u017eadavk\u016f na havarijn\u00ed monitorov\u00e1n\u00ed um\u011bl\u00e9 aktivity gama, tedy 137<\/sup>Cs a\u00a0131<\/sup>I [6]. Takto v\u00fdznamn\u00e9 zv\u00fd\u0161en\u00ed citlivosti bylo umo\u017en\u011bno pr\u00e1v\u011b z\u00edsk\u00e1n\u00edm b\u00e1zov\u00fdch komponent z\u00a0dlouhodob\u00e9ho poza\u010fov\u00e9ho datasetu pokr\u00fdvaj\u00edc\u00edho v\u00a0podm\u00ednk\u00e1ch dan\u00e9 lokality v\u0161echna ro\u010dn\u00ed obdob\u00ed [1].<\/p>\n

V obdob\u00ed od \u010dervna do \u0159\u00edjna 2019 bylo uskute\u010dn\u011bno zprovozn\u011bn\u00ed t\u0159\u00ed SAGMA v prost\u0159ed\u00ed re\u00e1ln\u00fdch \u0159\u00ed\u010dn\u00edch podm\u00ednek. Jednotliv\u00e9 SAGMA byly um\u00edst\u011bny do monitorovac\u00edch bod\u016f vybran\u00fdch jako vhodn\u00e9 lokality k monitorov\u00e1n\u00ed aktivity gama v\u00a0\u0159ek\u00e1ch \u010cR z\u00a0hlediska potenci\u00e1ln\u00edho p\u0159\u00ednosu pro p\u0159ipravenost k\u00a0odezv\u011b na mimo\u0159\u00e1dnou radia\u010dn\u00ed ud\u00e1lost. T\u00edm byla vytvo\u0159ena provizorn\u00ed forma monitorovac\u00ed s\u00edt\u011b SCOMO [2]. Okam\u017eikem zprovozn\u011bn\u00ed jednotliv\u00fdch SAGMA bylo zah\u00e1jeno nep\u0159etr\u017eit\u00e9 m\u011b\u0159en\u00ed a\u00a0odes\u00edl\u00e1n\u00ed zm\u011b\u0159en\u00fdch spekter syst\u00e9mem d\u00e1lkov\u00e9ho p\u0159enosu na server. Integra\u010dn\u00ed \u010das m\u011b\u0159en\u00ed i\u00a0interval odes\u00edl\u00e1n\u00ed jsou nastaveny na hodnotu 10 minut.<\/p>\n

Po \u0161esti a\u017e deseti m\u011bs\u00edc\u00edch provozu jednotliv\u00fdch stanic v\u00a0r\u00e1mci minis\u00edt\u011b byla provedena srovn\u00e1vac\u00ed anal\u00fdza poza\u010fov\u00fdch spekter, jej\u00edm\u017e c\u00edlem bylo stanovit detek\u010dn\u00ed citlivost jednotliv\u00fdch SAGMA stanic a\u00a0prov\u011b\u0159it p\u0159enositelnost b\u00e1zov\u00fdch komponent pozad\u00ed mezi monitorovac\u00edmi lokalitami bez nutnosti zdlouhav\u00e9ho m\u011b\u0159en\u00ed pozad\u00ed v\u00a0dan\u00e9m m\u00edst\u011b.<\/p>\n

Popis lokalit<\/h2>\n

Provizorn\u00ed podoba monitorovac\u00ed minis\u00edt\u011b SCOMO sest\u00e1v\u00e1 ze t\u0159\u00ed SAGMA um\u00edst\u011bn\u00fdch v\u00a0monitorovac\u00edch lokalit\u00e1ch na \u0159ek\u00e1ch \u010cesk\u00e9 republiky. Jsou to t\u00e1rovac\u00ed kan\u00e1l V\u00daV TGM v\u00a0Praze na \u0159ece Vltav\u011b (d\u00e1le jen Praha), n\u00e1hon vodn\u00ed elektr\u00e1rny Na R\u00e9n\u011b v\u00a0Ivan\u010dic\u00edch na \u0159ece Jihlav\u011b (Ivan\u010dice) a\u00a0v\u00fdpust p\u0159ehradn\u00ed n\u00e1dr\u017ee Ko\u0159ensko na \u0159ece Vltav\u011b (Ko\u0159ensko).<\/p>\n

Lokality Praha a\u00a0Ivan\u010dice maj\u00ed z\u00a0hlediska hydrologick\u00fdch pom\u011br\u016f podobn\u00e9 vlastnosti, sonda je zano\u0159ena do kan\u00e1lu o\u00a0hloubce p\u0159ibli\u017en\u011b 2 metry, dno kan\u00e1lu je vybetonovan\u00e9 a\u00a0vodn\u00ed hladina se nach\u00e1z\u00ed v\u00a0relativn\u011b stabiln\u00ed \u00farovni p\u0159ibli\u017en\u011b 80 cm nad horn\u00ed hranou detektoru. Kan\u00e1lem prot\u00e9k\u00e1 m\u011blk\u00e1 voda rychle proud\u00edc\u00edch \u0159ek Vltava, resp. Jihlava. Lokalita Ko\u0159ensko vykazuje zcela odli\u0161n\u00e9 hydrologick\u00e9 vlastnosti, je um\u00edst\u011bna v\u00a0bo\u010dn\u00ed st\u011bn\u011b p\u0159ehradn\u00ed n\u00e1dr\u017ee Ko\u0159ensko ve\u00a0vzd\u00e1lenosti p\u0159ibli\u017en\u011b 8 metr\u016f po proudu od v\u00fdpusti z\u00a0p\u0159ehrady. Spodn\u00ed hrana sondy je um\u00edst\u011bna asi 1,5 metru nad vybetonovan\u00fdm dnem kan\u00e1lu, horn\u00ed hrana sondy je od hladiny vzd\u00e1lena 2 a\u017e 6 metr\u016f, proto\u017ee hladina vody b\u011bhem sezony zna\u010dn\u011b kol\u00eds\u00e1. Kan\u00e1lem prot\u00e9k\u00e1 stojat\u00e1 voda z\u00a0p\u0159ehradn\u00ed n\u00e1dr\u017ee Ko\u0159ensko. Vypou\u0161t\u011bn\u00e1 voda se bezprost\u0159edn\u011b p\u0159ed vypu\u0161t\u011bn\u00edm nach\u00e1zela ve hloubce dvou a\u00a0v\u00edce metr\u016f pod hladinou p\u0159ehradn\u00ed n\u00e1dr\u017ee.<\/p>\n

P\u0159enos b\u00e1zov\u00fdch komponent \u2013 diskuse a v\u00fdsledky<\/h2>\n

Metodou NASVD byly z\u00a0tr\u00e9novac\u00edch spekter z\u00a0lokality Praha z\u00edsk\u00e1ny b\u00e1zov\u00e9 komponenty popisuj\u00edc\u00ed pozad\u00ed v\u00a0lokalit\u011b V\u00daV TGM (lokalita Praha byla pou\u017eita jako referen\u010dn\u00ed lokalita, d\u00e1le jen referen\u010dn\u00ed b\u00e1zov\u00e1 spektra). Obdobn\u011b byla zpracov\u00e1na m\u011b\u0159en\u00ed z\u00a0Ivan\u010dic a\u00a0Ko\u0159enska, \u010d\u00edm\u017e byly z\u00edsk\u00e1ny lok\u00e1ln\u00ed b\u00e1zov\u00e9 komponenty pozad\u00ed. Vzhledem k\u00a0odli\u0161nostem v\u00a0nastaven\u00ed a\u00a0typu elektroniky byla p\u0159ed samotnou NASVD anal\u00fdzou spektra p\u0159e\u0161k\u00e1lov\u00e1na tak, aby si odpov\u00eddaly \u010detnosti v\u00a0jednotliv\u00fdch kan\u00e1lech spekter z\u00a0r\u016fzn\u00fdch lokalit.<\/p>\n

Z\u00edskan\u00e9 b\u00e1zov\u00e9 komponenty byly pou\u017eity pro fitov\u00e1n\u00ed spekter v\u00a0testovac\u00edm datasetu za pou\u017eit\u00ed line\u00e1rn\u00edho regresn\u00edho modelu. V\u00a0modelu byly pou\u017eity jak lok\u00e1ln\u00ed, tak referen\u010dn\u00ed b\u00e1zov\u00e9 komponenty a\u00a0n\u00e1sledn\u011b bylo provedeno srovn\u00e1n\u00ed v\u00fdsledk\u016f pomoc\u00ed standardn\u00ed chyby rezidu\u00ed (RMSE) pro soubor testovac\u00edch spekter, viz obr. 1<\/em>.<\/p>\n\"\"<\/a>\n

Obr. 1. Vlevo \u2013 uk\u00e1zka fitu referen\u010dn\u00edmi a lok\u00e1ln\u00edmi b\u00e1zov\u00fdmi komponentami v Ivan\u010dic\u00edch a Ko\u0159ensku (integra\u010dn\u00ed doba 3 600 s); vpravo \u2013 souvisej\u00edc\u00ed pr\u016fb\u011bh RMSE nap\u0159\u00ed\u010d testovac\u00edm datasetem
\nFig. 1. Left \u2013 demonstration of local base component fit for the spectra from Ivan\u010dice and Ko\u0159ensko (integration time 3 600 s); right \u2013 related course RMSE across the testing dataset<\/h6>\n

Pro spektra z\u00a0lokality Ivan\u010dice bylo dosa\u017eeno pom\u011brn\u011b dobr\u00e9 shody a\u00a0souvisej\u00edc\u00ed nav\u00fd\u0161en\u00ed MDA pro vybran\u00e9 radionuklidy (131<\/sup>I, 134<\/sup>Cs, 137<\/sup>Cs) je rovn\u011b\u017e p\u0159ijateln\u00e9\u00a0\u2013 v\u00a0testovac\u00edm datasetu nep\u0159evy\u0161uje 10 a\u017e 15 %. Odli\u0161n\u00e1 je situace pro spektra z\u00a0Ko\u0159enska\u00a0\u2013 vzhledem k\u00a0hloubce ulo\u017een\u00ed a\u00a0tedy i\u00a0vy\u0161\u0161\u00edmu pod\u00edlu rozpt\u00fdlen\u00e9ho z\u00e1\u0159en\u00ed a\u00a0ni\u017e\u0161\u00edmu vlivu dce\u0159in\u00fdch produkt\u016f radonu se spektra z\u00a0Ko\u0159enska kvalitativn\u011b li\u0161\u00ed od zbyl\u00fdch dvou lokalit. Fitov\u00e1n\u00ed pomoc\u00ed referen\u010dn\u00ed b\u00e1ze selh\u00e1v\u00e1 a\u00a0metoda je pro tuto lokalitu nepou\u017eiteln\u00e1. Srovn\u00e1n\u00ed st\u0159edn\u00edch spekter z\u00a0jednotliv\u00fdch lokalit ilustruje obr. 2<\/em>.<\/p>\n\"\"<\/a>\n

Obr. 2. St\u0159edn\u00ed spektra z\u00a0jednotliv\u00fdch lokalit; spektrum Ko\u0159ensko vykazuje odli\u0161n\u00fd pr\u016fb\u011bh oproti lokalit\u00e1m Praha a\u00a0Ivan\u010dice
\nFig. 2. Mean spectra from the individual location; spectra from the location Ko\u0159ensko demonstrates different course compared to the locations Prague and Ivan\u010dice<\/h6>\n

D\u00e1le byla lok\u00e1ln\u00ed b\u00e1zov\u00e1 spektra z\u00a0Ivan\u010dic a\u00a0z\u00a0Ko\u0159enska pou\u017eita pro v\u00fdpo\u010det hodnot NDA v\u00a0t\u011bchto lokalit\u00e1ch. Tyto hodnoty jsou v\u00a0p\u0159\u00edpad\u011b Ivan\u010dic p\u0159ibli\u017en\u011b o\u00a040 a\u00a0v\u00a0p\u0159\u00edpad\u011b Ko\u0159enska o\u00a075 % ni\u017e\u0161\u00ed ne\u017e v\u00a0lokalit\u011b Praha [1]. V\u00a0tabulce 1<\/em> jsou uvedeny typick\u00e9 hodnoty NDA objemov\u00e9 aktivity pro 137<\/sup>Cs p\u0159i pou\u017eit\u00ed jednohodinov\u00e9ho integra\u010dn\u00edho \u010dasu. Pro ilustraci jsou pou\u017eita data z\u00a0mno\u017einy \u201ev\u0161echna spektra\u201c [1, 2].<\/p>\n

Tabulka 1. Typick\u00e9 hodnoty objemov\u00e9 aktivity NDA pro 137<\/sup>Cs p\u0159i pou\u017eit\u00ed NASVD metody pracuj\u00edc\u00ed s\u00a0lok\u00e1ln\u00edmi b\u00e1zov\u00fdmi komponentami, integra\u010dn\u00ed \u010das 1 hodina
\nTable 1. Minimal detectable activity values for 137<\/sup>Cs activity concentration typical for the individual locations; integration time is 60 minutes, NASVD deconvolution method is employed<\/h5>\n\"\"<\/a>\n

Vy\u0161\u0161\u00ed citlivost SAGMA p\u0159i um\u00edstn\u011bn\u00ed v\u00a0lokalit\u00e1ch Ivan\u010dice a\u00a0Ko\u0159ensko je d\u00e1na p\u0159edev\u0161\u00edm hydrologick\u00fdmi pom\u011bry v\u00a0dan\u00fdch lokalit\u00e1ch (vy\u0161\u0161\u00edm pr\u016ftokem), v\u00a0lokalit\u011b Ko\u0159ensko tak\u00e9 um\u00edst\u011bn\u00edm sondy do v\u011bt\u0161\u00ed hloubky.<\/p>\n

Z\u00e1v\u011br<\/h2>\n

P\u0159enos b\u00e1zov\u00fdch komponent poza\u010fov\u00fdch spekter z\u00a0referen\u010dn\u00ed lokality se ukazuje jako efektivn\u00ed metoda pro hodnocen\u00ed spekter po dobu, kdy je\u0161t\u011b pro danou lokalitu nen\u00ed k\u00a0dispozici dostate\u010dn\u011b velk\u00fd po\u010det (~104<\/sup>) spekter pro vytvo\u0159en\u00ed b\u00e1zov\u00fdch komponent. Podm\u00ednkou p\u0159enositelnosti je, \u017ee ob\u011b lokality vykazuj\u00ed podobn\u00e9 hydrologick\u00e9 charakteristiky a\u00a0z\u00e1rove\u0148 je dodr\u017eena podobn\u00e1 geometrie m\u011b\u0159en\u00ed. To v\u00a0p\u0159\u00edpad\u011b popisovan\u00e9 situace znamen\u00e1 pono\u0159en\u00ed sondy do voln\u011b tekouc\u00ed \u0159\u00ed\u010dn\u00ed vody do hloubky > 1 m.<\/p>\n

D\u00e1le je mo\u017en\u00e9 metodu v\u00fdhodn\u011b doplnit o\u00a0kontinu\u00e1ln\u00ed updatov\u00e1n\u00ed NASVD\u00a0\u2013 po instalaci sondy v\u00a0nov\u00e9 lokalit\u011b je nejprve pou\u017eit model s\u00a0referen\u010dn\u00edmi b\u00e1zov\u00fdmi komponentami, kter\u00fd se s\u00a0p\u0159ib\u00fdvaj\u00edc\u00edmi lok\u00e1ln\u00edmi spektry postupn\u011b p\u0159izp\u016fsobuje m\u00edstn\u00edm podm\u00ednk\u00e1m. Pro tyto \u00fa\u010dely existuj\u00ed pom\u011brn\u011b efektivn\u00ed v\u00fdpo\u010detn\u00ed algoritmy, kter\u00e9 lze je\u0161t\u011b d\u00e1le urychlit pomoc\u00ed paralelizace [6]. SAGMA byla koncipov\u00e1na jako \u201estand-alone\u201c monitorovac\u00ed stanice odoln\u00e1 v\u016f\u010di n\u00e1sledk\u016fm mimo\u0159\u00e1dn\u00e9 radia\u010dn\u00ed ud\u00e1losti. Vzhledem k\u00a0jednoduchosti konstrukce je mo\u017en\u00e9 SAGMA pou\u017e\u00edt tak\u00e9 jako p\u0159enosnou monitorovac\u00ed stanici. Na\u0161e p\u0159edchoz\u00ed publikace [1] p\u0159edpokl\u00e1d\u00e1, \u017ee p\u0159em\u00edst\u011bn\u00ed syst\u00e9mu na novou lokalitu znemo\u017e\u0148uje pln\u00e9 vyu\u017eit\u00ed metody NASVD pro zv\u00fd\u0161en\u00ed citlivosti syst\u00e9mu, dokud nedojde k\u00a0nahromad\u011bn\u00ed tr\u00e9ninkov\u00e9ho datasetu pokr\u00fdvaj\u00edc\u00edho celosezonn\u00ed p\u0159irozen\u00e9 variace pozad\u00ed.<\/p>\n

Experiment\u00e1ln\u00ed p\u0159enos referen\u010dn\u00edch b\u00e1zov\u00fdch komponent pro \u00fa\u010dely pou\u017eit\u00ed NASVD na spektra z\u00a0jin\u00e9 lokality prok\u00e1zal, \u017ee za dodr\u017een\u00ed charakteristick\u00fdch podm\u00ednek monitorovac\u00ed lokality NASVD lze metodu \u00fa\u010dinn\u011b vyu\u017e\u00edt i\u00a0po p\u0159em\u00edst\u011bn\u00ed SAGMA na novou lokalitu, a\u00a0to s\u00a0p\u0159ekvapiv\u011b n\u00edzk\u00fdm,\u00a0maxim\u00e1ln\u011b 15% nav\u00fd\u0161en\u00edm detek\u010dn\u00edch mez\u00ed. SAGMA t\u00edm z\u00edsk\u00e1v\u00e1 uplatn\u011bn\u00ed tak\u00e9 jako mobiln\u00ed monitorovac\u00ed stanice. To navy\u0161uje flexibilitu SCOMO v\u00a0r\u00e1mci jeho pl\u00e1novan\u00e9ho uplatn\u011bn\u00ed v\u00a0syst\u00e9mu p\u0159ipravenosti k\u00a0odezv\u011b na mimo\u0159\u00e1dnou radia\u010dn\u00ed ud\u00e1lost. Za nejm\u00e9n\u011b p\u0159\u00edzniv\u00fdch podm\u00ednek (po bou\u0159\u00edch \u010di pr\u016ftr\u017e\u00edch mra\u010den) v\u00a0r\u00e1mci t\u0159\u00ed studovan\u00fdch lokalit je p\u0159i pou\u017eit\u00ed p\u0159enesen\u00fdch b\u00e1zov\u00fdch komponent hodnota NDA pro stanoven\u00ed objemov\u00e9 aktivity 137<\/sup>Cs p\u0159i desetiminutov\u00e9m integra\u010dn\u00edm \u010dase maxim\u00e1ln\u011b 2,6 Bq\/L.<\/p>\n

Oproti st\u00edn\u011bn\u00fdm pr\u016fto\u010dn\u00fdm monitorovac\u00edm stanic\u00edm jsou hodnoty NDA p\u0159i vyu\u017eit\u00ed NASVD s\u00a0p\u0159enesen\u00fdmi b\u00e1zov\u00fdmi komponentami pro 131<\/sup>I a\u00a0137<\/sup>Cs nav\u00fd\u0161eny p\u0159ibli\u017en\u011b faktorem 1,6, zat\u00edmco oproti jin\u00fdm monitorovac\u00edm stanic\u00edm vyu\u017e\u00edvaj\u00edc\u00edm ponornou sondu pracuj\u00edc\u00edm s\u00a0NaI(Tl) detektorem jsou hodnoty NDA sn\u00ed\u017eeny p\u0159ibli\u017en\u011b faktorem 1,8 [3, 4]. Je t\u0159eba zd\u016fraznit, \u017ee konstrukce \u017e\u00e1dn\u00e9 ze srovn\u00e1van\u00fdch monitorovac\u00edch stanic nen\u00ed vhodn\u00e1 k\u00a0okam\u017eit\u00e9mu p\u0159emis\u0165ov\u00e1n\u00ed mezi lokalitami, a\u00a0to p\u0159edev\u0161\u00edm kv\u016fli z\u00e1vislosti na zdroji elektrick\u00e9ho nap\u00e1jen\u00ed \u010di kv\u016fli absenci d\u00e1lkov\u00e9ho p\u0159enosu dat.<\/p>\n

P\u0159enos b\u00e1zov\u00fdch spekter pro podm\u00ednky hlubok\u00e9 vody je problematick\u00fd. Z\u00e1rove\u0148 je t\u0159eba zd\u016fraznit, \u017ee pro pot\u0159eby havarijn\u00edho monitorov\u00e1n\u00ed jsou podm\u00ednky hlubok\u00e9 vody v\u0161eobecn\u011b m\u00e9n\u011b vhodn\u00e9 (nedoch\u00e1z\u00ed k\u00a0prudk\u00fdm fluktuac\u00edm objemov\u00e9 aktivity po kontaminaci), a\u00a0tak pro tento typ lokality nen\u00ed pou\u017eit\u00ed SAGMA jako mobiln\u00ed monitorovac\u00ed stanice relevantn\u00ed. Na druhou stranu SAGMA um\u00edst\u011bn\u00e1 v\u00a0hlubok\u00e9 tekouc\u00ed vod\u011b dosahuje mimo\u0159\u00e1dn\u011b n\u00edzk\u00fdch detek\u010dn\u00edch mez\u00ed p\u0159i pou\u017eit\u00ed lok\u00e1ln\u00edch b\u00e1zov\u00fdch komponent (viz tabulka 1<\/em>, lokalita Ko\u0159ensko). V\u00a0t\u011bchto podm\u00ednk\u00e1ch je systematicky dosahov\u00e1no citlivosti pot\u0159ebn\u00e9 pro spln\u011bn\u00ed legislativn\u00edho po\u017eadavku na stanoven\u00ed objemov\u00e9 aktivity 137<\/sup>Cs (0,1 Bq\/L podle [6]) p\u0159i pou\u017eit\u00ed integra\u010dn\u00edho \u010dasu 24 hodin.<\/p>\n

Od kv\u011btna 2020 je SCOMO v\u00a0r\u00e1mci implementa\u010dn\u00edho pl\u00e1nu provozov\u00e1no jako dopl\u0148kov\u00fd prost\u0159edek pro anal\u00fdzy vod v\u00a0r\u00e1mci MRS. Srovn\u00e1n\u00edm s\u00a0p\u0159\u00edstroji popsan\u00fdmi v\u00a0liter\u00e1rn\u00edch zdroj\u00edch je mo\u017en\u00e9 SCOMO pova\u017eovat za \u201eState of the art\u201c prost\u0159edek pro havarijn\u00ed monitorov\u00e1n\u00ed aktivity gama v\u00a0povrchov\u00fdch vod\u00e1ch.<\/p>\n

Pod\u011bkov\u00e1n\u00ed<\/h3>\n

V\u00fdzkum byl podpo\u0159en projektem Ministerstva vnitra \u010cesk\u00e9 republiky (projekt VI20172020083).<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

The article describes practical aspects of the NASVD algorithm application in the processing of gamma spectra from the network of stations for continuous monitoring of gamma activity in river water (SAGMA).<\/p>\n","protected":false},"author":8,"featured_media":8545,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[87],"tags":[1759,1786,1784,1785,1756,1985],"coauthors":[1739,1740],"class_list":["post-8547","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-hydrochemistry-radioecology-microbiology","tag-137cs","tag-emergency-monitoring","tag-gamma-spectrometry","tag-monitoring-of-radiation-situation","tag-naitl","tag-portable-monitoring-station"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/8547","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/comments?post=8547"}],"version-history":[{"count":3,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/8547\/revisions"}],"predecessor-version":[{"id":30592,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/8547\/revisions\/30592"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media\/8545"}],"wp:attachment":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media?parent=8547"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/categories?post=8547"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/tags?post=8547"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/coauthors?post=8547"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}