[Cz] Jaderne elektrarny vyuzivaji premeny klidove energie atomu vlivem zmeny usporadani jejich vnitrnich casti (protonu a neutronu) a to bud delenim, nebo slucovanim. Pri beznem spalovani jsme schopni ziskat pouze 0,0000001 % klidove energie, zatimco stepenim ziskame 0,1 %, nebo dokonce 1 % v pripade slucovani atomu.
[En] Nuclear power–plants use atom's binding energy by protons and neutrons position change (nuclear fission and fussion). Only 0.0000001 % of binding energy should be obtained by combustion but we can get 0.1 % by nuclear fission or 1 % by fussion.
[Cz] Prvni rizenou stepnou reakci provedl E. Fermi [2] 2.12.1942 v dreveno/cihlovem reaktoru (viz. patentovy nakres vyse) pod tribunou sportovniho stadionu v Chicagu. Ziskani energie z atomu je mnohem snadnejsi, nez jeji vyuziti, coz si lze dokazat i na prikladu prvniho pouziti stepeni atomu v jaderne bombe koncem druhe svetove valky, zatimco prvni elektrarna vyuzivajici rizenou stepnou reakci byla vytvorena v USA az roku 1951 (Idaho Falls) a na uzemi tehdejsi SSSR o 3 roky pozdeji (Obninsk, 5 MW). Proto, i kdyz silu atomu tusili jiz prvni filozofove a pote i fyzikove pred mnoha staletimi, je atom nejmladsim zdrojem energie.
[En] The first regulated nuclear fission made E. Fermi [2] on the 2nd December 1942 in wooden/brick reactor (see picture above) at the Chicago stadium. Obtaining nuclear energy is easier than its using - nuclear bomb has been made at the end of the second world war but the first nuclear power–plant was built in 1951 (Idaho Falls, USA) and three years later in the SSSR (Obninsk, 5 MW). Due to these reasons, nuclear power is the youngest energy source used by people.
[Cz] Zakladem jaderne elektrarny je stepna reakce (nejcasteji atomu obohaceneho uranu 235 nebo 238), ktera vytvari paru z vody, a ta roztaci turbiny a nasledne generatory. V prubehu reakce se volne pohybujici neutron srazi s atomem uranu, ktery rozstepi a dojde k uvolneni energie a nekolika dalsich neutronu. Ty pokracuji k dalsim atomum, cimz vznika stepna retezova reakce. Aby se rychly lehky neutron od velkych jader jen neodrazil, je nutne ho nejdrive zpomalit srazkou s tzv. moderatorem (jadro s podobnou velikosti jakou ma neutron), viz. nakres vyse. Pokud neni v okoli dostatek atomu uranu, ktere by volne neutrony zasahly (podkriticke mnozstvi materialu), nebo jsou volne neutrony odchytany jinym materialem (absorbatorem, nejcasteji bor nebo kadmium), je stepna reakce brzdena a posleze uplne zastavena. Srdcem jadernych elektraren je reaktor, ve kterem dochazi prave k teto stepne reakci. Narozdil od nebezpecne nerizene reakce vsak vhodnym rizenim mnozstvi absorbatoru uvnitr reaktoru (napriklad zasouvanim tyci absorbatoru) dochazi k nastaveni optimalniho pomeru nove vzniklych a zanikajicich neutronu a reakce je tak za bezneho stavu vyrovnana a plne pod kontrolou.
[En] The heart of nuclear power–plant is reactor where chain nuclear fission is realized for water steam generation for generator's driving. Free neutron has to be slown down (by moderator, particles with similar size as neutron) to collision with atom (Uranium 235 or 238 mostly). After collision, original atom is divided into two parts and new free neutrons are generated for next chain collisions (se picture above). Free neutrons should be absobed by absorber (Boron or Cadmium). If there are most of neutrons absorbed or if there is small amount of targeted atoms, nuclear fission will be stopped. The chain reaction should be stable and under control if we have balanced amount of generated and absorbed free neutrons.
[Cz] Nyni jiz vime, ze se v nejcasteji pouzivanych reaktorech nachazi palivo, moderator, absorbator. Palivo a absorbator je nejcasteji ve forme tyci, pricemz se v reaktoru krome regulacnich tyci nachazi absorbator i v tzv. havarijnich tycich, ktere jsou uvolneny pouze v pripade poruchy k okamzitemu odstaveni reakce. Aby nedoslo k roztaveni palivovych tyci a abychom byli schopni prenest vytvorene teplo k turbinam, nachazi se vsude v reaktoru chladivo (lehka/tezka voda, CO2, helium, atd.). Protoze chladivo v reaktoru byva pod velkym tlakem a zaroven je radioaktivni, byvaji chladici okruhy rozdeleny na vice mensich smycek, mezi kterymi se predava pouze teplo a k turbinam uz se dostava pouze para z vody neradioaktivni (viz. nakres vyse).
Vsechny popsane komponenty jsou usporadany v ruznych formach v reaktorech mnoha typu, ktere si zde pro uplnost pouze vyjmenujeme. V pripade zajmu je mnoho detailnich informaci o jejich konstrukci mozne dohledat jak na internetu a v informacnich centrech, tak i v tistenych zdrojich. Mezi nejbeznejsi a nejcasteji pouzivane reaktory patri tlakovodni reaktory typu PWR (USA) nebo VVER (Ruský typ), varne reaktory BWR, tezkovodni reaktory CANDU. Ve Velke Britanii a Japonsku jsou vyuzivany plynem chlazene reaktory Magnox GCR a pokrocile plynem chlazene reaktory AGR. Mezi experimentalni a moderni reaktory pak patri vysokoteplotni reaktory HTGR a rychle mnozinove reaktory FBR. Naopak vybehovymi typy jsou reaktory typu RBMK, ktere byly pouzivany vyhradne na uzemi SSSR, napriklad take v Obninsku, nebo v Cernobylu.
[En] There is nuclear fuel, moderator and absorber in each reactor as it was mentioned before. Fuel and absorber is in the form of rod mostly. The chain reaction should be stopped in emergency case by protective absorber rods insertion. To prevent rods melting and for thermal energy transport, there is also refrigerant (e.g. light/heavy water, Carbon dioxide, Helium) in the reactor. There are more cooling circuits to the primary circuit radioctive water separation from outer devices and people (see picture above).
These components are located in many types of reactors which sould be found on the internet. We can found PWR type (USA), VVER (Russian), BWR or heavy water reactors CANDU. There are gas coolant reactors Magnox GCR and advanced gas coolant reactors AGR in the Great Brittain or Japan. Reactors HTGR and FBR are modern experimental types. Old reactor types with reached end of life are RBMK, used in the SSSR only (Obninsku, Cernobyl etc.).
[Cz] Poslednim druhem jadernych reaktoru jsou fuzni reaktory, tzv. TOKAMAKy (viz. obrazek vyse). U vsech predeslych typu dochazi ke stepne reakci, zatimco pri jaderne fuzi dochazi ke slucovani jader vodiku na jadro helia, coz je energeticky podstatne vykonnejsi jev, ktery probiha napriklad na Slunci. Nanestesti jsou v soucasne dobe tyto reaktory stale jen experimentalni, protoze nejsme schopni udrzet rizenou jadernou fuzi stabilni na dostatecnou dobu za predpokladu, ze bychom reaktoru dodali mene energie, nez jsme schopni z reakce realne vytezit.
[En] The last and still experimental reactors are TOKAMAKs (see picture above). There is nuclear fussion in this reactors (hydrogen atoms creates helium) by the same way as in the Sun.
[Cz] Jelikoz je tato problematika velice obsahla, dozvedeli jste se v ramci tohoto listingu pouze zakladni informace o jadernych elektrarnach. Kes samotna se nachazi nedaleko jaderne elektrarny Dukovany (4 bloky o celkovem vykonu 2000 MW), ktera Vas krome nekolika dalsich kesi vybizi k navsteve informacniho centra, kde se muzete dozvedet blizsi informace jak o Dukovanske elektrarne, tak i o ostatnich typech elektraren.
Z meho pohledu jsou jaderne elektrarny i pres bezpecnostni riziko spojene s jejich pouzivanim ekologickymi zdroji energie budoucnosti, ktere narozdil od "ekologickych" elektraren zabiraji minimalni prostor, jsou neustale monitorovane jak z hlediska radiace, tak i uniku nebezpecnych latek a napriklad v porovnani s uhelnymi elektrarnami generuji cca polovinu radioaktivnich latek (o zatizeni prostredi splodinami ani nemluve) a nejmensi palivova peleta (valecek o hmotnosti 5 g) vyprodukuje stejne mnozstvi energie jako 880 kg cerneho uhli. A co se tyka bezpecnosti, vzhledem k pozornosti vsech agentur, kterou na sebe jaderna energie vaze a poctu bezpecnostnich opatreni s ni spojenych, neni dle meho nazoru ceho se bat.
[En] Due to extremely wide technology of nuclear power–plants, there are basic informations only in the listing. This geocache is located near nuclear power–plant Dukovany (4 blocks with total power about 2000 MW) where you can get many additional informations about this and other nuclear power–plants in its information centre.
In my opinion, nuclear power–plants are ecological power supplies of the future despite the safety risk. Today's "ecological" power sources takes a lot of Earth surface area and traditional power sources are polluting. And what about radiation? Traditional coal power–plants generates two times more radioactivity than nuclear power–plant. The smalest nuclear fuel cell (5 g cell) generates the same amount of energy as 880 kg of black coal. The safety risk is negligible due to many international organizations which monitore all nuclear facilities of the world.
[Cz] Kes je soucasti planovane mystery kese „Elektrarenska“. Tato mystery kes neni doposud v provozu, ale bonusove cislo pro budouci kes plati, takze si jej opiste, mate‑li zajem.
[En] The Cache is part of Mystery Cache „Elektrarenska“ which is recently planned. Today it’s not in service but the Bonus Number for it holds so keep it in your notes if you are interested.
[Cz] P.S. Timto bych chtel podekovat geocacherovi Jalav2 za pomoc s vytvarenim teto kese.
[En] Special thanks to the geocacher Jalav2 which helped with creating of this Cache.
Pouzite zdroje / References:
[1] Velka kniha o energii, Plzen 2001, ISBN 80-238-6578-1
[2] http://cs.wikipedia.org/wiki/Enrico_Fermi
[3] http://jaderneinfo.webnode.cz/news/principy-jaderneho-reaktoru-vver-1000/
[4] http://ok1zed.sweb.cz/s/el_jaderna.htm
[5] http://www.cez.cz/edee/content/microsites/nuklearni/k35.htm