Abstract
Since actual research reactors are technically complicated and expensive facilities it is important to achieve savings by appropriate reactor lattice configurations. There is a number of papers, and practical examples of reactors with central reflector, dealing with spatial distribution of fuel elements which would result in higher neutron flux. Common disadvantage of all the solutions is that the choice of best solution is done starting from the anticipated spatial distributions of fuel elements. The weakness of these approaches is lack of defined optimization criteria. Direct approach is defined as follows: determine the spatial distribution of fuel concentration starting from the condition of maximum neutron flux by fulfilling the thermal constraints. Thus the problem of determining the maximum neutron flux is solving a variational problem which is beyond the possibilities of classical variational calculation. This variational problem has been successfully solved by applying the maximum principle of Pontrjagin. Optimum distribution of fuel concentration was obtained in explicit analytical form. Thus, spatial distribution of the neutron flux and critical dimensions of quite complex reactor system are calculated in a relatively simple way. In addition to the fact that the results are innovative this approach is interesting because of the optimization procedure itself.
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Strugar, P
[1]
- Institute of Nuclear Sciences Vinca, Beograd (Serbia and Montenegro)
Citation Formats
Strugar, P.
Maximum neutron flux at thermal nuclear reactors; Maksimum neutronskog fluksa kod termalnih reaktora.
Serbia and Montenegro: N. p.,
1968.
Web.
Strugar, P.
Maximum neutron flux at thermal nuclear reactors; Maksimum neutronskog fluksa kod termalnih reaktora.
Serbia and Montenegro.
Strugar, P.
1968.
"Maximum neutron flux at thermal nuclear reactors; Maksimum neutronskog fluksa kod termalnih reaktora."
Serbia and Montenegro.
@misc{etde_20743621,
title = {Maximum neutron flux at thermal nuclear reactors; Maksimum neutronskog fluksa kod termalnih reaktora}
author = {Strugar, P}
abstractNote = {Since actual research reactors are technically complicated and expensive facilities it is important to achieve savings by appropriate reactor lattice configurations. There is a number of papers, and practical examples of reactors with central reflector, dealing with spatial distribution of fuel elements which would result in higher neutron flux. Common disadvantage of all the solutions is that the choice of best solution is done starting from the anticipated spatial distributions of fuel elements. The weakness of these approaches is lack of defined optimization criteria. Direct approach is defined as follows: determine the spatial distribution of fuel concentration starting from the condition of maximum neutron flux by fulfilling the thermal constraints. Thus the problem of determining the maximum neutron flux is solving a variational problem which is beyond the possibilities of classical variational calculation. This variational problem has been successfully solved by applying the maximum principle of Pontrjagin. Optimum distribution of fuel concentration was obtained in explicit analytical form. Thus, spatial distribution of the neutron flux and critical dimensions of quite complex reactor system are calculated in a relatively simple way. In addition to the fact that the results are innovative this approach is interesting because of the optimization procedure itself. [Serbo-Croat] Savremeni reaktori za fizicka i tehnoloska istrazivanja predstavljaju tehnicki komplikovanu i skupu masinu. Iz tog razloga su opravdana nastojanja da se podesnim rasporedom goriva u jezgru reaktora dodje do sto ekonomicnijeg rjesenja. U literaturi postoji vise radova, cak i konkretnih realizacija u vidu reaktora sa reflektorom u centru, koji se bave odredjivanjem takve prostorne zavisnosti koncentracije goriva koja pod odredjenim uslovima daje najveci neutronski fluks. Zajednicki nedostatak svih pomenutih rjesenja je u tome sto se polazi od pretpostavljenih prostornih distribucija goriva, pa se na osnovu uporedjivanja rezultata odabira najbolja varijanta. Medjutim, slaba strana takvih indirektnih prilaza ovom problemu sastoji se u odsustvu tacno definisanih kriterijuma optimalnosti. Direktan prilaz ovom problemu definisem na sledeci nacin: neposredno iz uslova maksimuma neutronskog fluksa odrediti prostornu distribuciju koncentracije goriva uz zadovoljenje termickih ogranicenja. Tako se problem odredjivanja maksimuma neutronskog fluksa svodi na rjesavanje jednog varijacionog zadatka, koji je takvog tipa da je njegovo rjesavanje van granica mogucnosti klasicnog varijacionog racuna. Primjenom principa maksimuma Pontrjagina postavljeni varijacioni problem je uspesno rijesen. Dobijeno je rjesenje za optimalnu distribuciju koncentracije goriva u eksplicitnoj analitickoj formi. Zahvaljujuci tome prostorna raspodjela neutronskog fluksa i kriticne dimenzije optimalnog, prilicno slozenog reaktorskog sistema se odredjuju relativno prosto. Pored originalnosti rezultata rad je interesantan i zbog samog optimizacionog postupka (author)}
place = {Serbia and Montenegro}
year = {1968}
month = {Oct}
}
title = {Maximum neutron flux at thermal nuclear reactors; Maksimum neutronskog fluksa kod termalnih reaktora}
author = {Strugar, P}
abstractNote = {Since actual research reactors are technically complicated and expensive facilities it is important to achieve savings by appropriate reactor lattice configurations. There is a number of papers, and practical examples of reactors with central reflector, dealing with spatial distribution of fuel elements which would result in higher neutron flux. Common disadvantage of all the solutions is that the choice of best solution is done starting from the anticipated spatial distributions of fuel elements. The weakness of these approaches is lack of defined optimization criteria. Direct approach is defined as follows: determine the spatial distribution of fuel concentration starting from the condition of maximum neutron flux by fulfilling the thermal constraints. Thus the problem of determining the maximum neutron flux is solving a variational problem which is beyond the possibilities of classical variational calculation. This variational problem has been successfully solved by applying the maximum principle of Pontrjagin. Optimum distribution of fuel concentration was obtained in explicit analytical form. Thus, spatial distribution of the neutron flux and critical dimensions of quite complex reactor system are calculated in a relatively simple way. In addition to the fact that the results are innovative this approach is interesting because of the optimization procedure itself. [Serbo-Croat] Savremeni reaktori za fizicka i tehnoloska istrazivanja predstavljaju tehnicki komplikovanu i skupu masinu. Iz tog razloga su opravdana nastojanja da se podesnim rasporedom goriva u jezgru reaktora dodje do sto ekonomicnijeg rjesenja. U literaturi postoji vise radova, cak i konkretnih realizacija u vidu reaktora sa reflektorom u centru, koji se bave odredjivanjem takve prostorne zavisnosti koncentracije goriva koja pod odredjenim uslovima daje najveci neutronski fluks. Zajednicki nedostatak svih pomenutih rjesenja je u tome sto se polazi od pretpostavljenih prostornih distribucija goriva, pa se na osnovu uporedjivanja rezultata odabira najbolja varijanta. Medjutim, slaba strana takvih indirektnih prilaza ovom problemu sastoji se u odsustvu tacno definisanih kriterijuma optimalnosti. Direktan prilaz ovom problemu definisem na sledeci nacin: neposredno iz uslova maksimuma neutronskog fluksa odrediti prostornu distribuciju koncentracije goriva uz zadovoljenje termickih ogranicenja. Tako se problem odredjivanja maksimuma neutronskog fluksa svodi na rjesavanje jednog varijacionog zadatka, koji je takvog tipa da je njegovo rjesavanje van granica mogucnosti klasicnog varijacionog racuna. Primjenom principa maksimuma Pontrjagina postavljeni varijacioni problem je uspesno rijesen. Dobijeno je rjesenje za optimalnu distribuciju koncentracije goriva u eksplicitnoj analitickoj formi. Zahvaljujuci tome prostorna raspodjela neutronskog fluksa i kriticne dimenzije optimalnog, prilicno slozenog reaktorskog sistema se odredjuju relativno prosto. Pored originalnosti rezultata rad je interesantan i zbog samog optimizacionog postupka (author)}
place = {Serbia and Montenegro}
year = {1968}
month = {Oct}
}