8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
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UNIVERSITÀ DI PISAUNIVERSITÀ DI PISADIPARTIMENTO DI INGEGNERIA MECCANICA,DIPARTIMENTO DI INGEGNERIA MECCANICA,
NUCLEARE E DELLA PRODUZIONENUCLEARE E DELLA PRODUZIONEVIA DIOTISALVI 2, 56100 PISAVIA DIOTISALVI 2, 56100 PISA
G r u p p o R i c e
r c a N u c l e a r e
S .
P i e r o a
G r u p p o R i c e
r c a N u c l e a r e
S .
P i e r o a
G r a d o
G r a d o
Atucha-2 PHWR threeAtucha-2 PHWR three
dimensional neutron kineticsdimensional neutron kinetics
coupled thermal-hydraulicscoupled thermal-hydraulics
modelling and analyses by themodelling and analyses by theRELAP5-3!RELAP5-3!
"# Parisi$"# Parisi$ A# el %e&o$A# el %e&o$ '# (a))antini$ *#'# (a))antini$ *#
+Auria$ ,# &ano&+Auria$ ,# &ano&
RELAP5-3 .ser /eminardaho .ni&ersity "ampus$ daho *alls$ ./A
01-2 %o&ember 21
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
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RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% &
G r u p p o R i c e r c a N u c l e a r e S .
P i e r o a
G r u p p o R i c e r c a N u c l e a r e S .
P i e r o a
G r a d o
G r a d o
Outline Introduction
Atucha II PHWR Features
280 channels TH model
HELIOS CrossSections Li!raries
"# $% TH model
Sam&le results
Conclusions
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
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RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% 3
G r u p p o R i c e r c a N u c l e a r e S .
P i e r o a
G r u p p o R i c e r c a N u c l e a r e S .
P i e r o a
G r a d o
G r a d o
Introduction Ar'entinean electric utilit( )$ucleoelectrica
Ar'entina * Societad Anonima+ ,$ASA- si'ned ana'reement .ith the San Piero a /rado $uclearResearch /rou& ,/R$SP/- o the 1niersit( o Pisa ,1$IPI- in 2003 or the deelo&ment o adancedsimulation models or the AtuchaII $PP
/R$SP/41$IPI deelo&ed hermal-hydraulics5%eutronics5 "* and /tructural (echanics models or the saet( anal(sis o the &lant
Currentl( /R$SP/41$IPI is also assistin' $ASA inthe deelo&ment o the "hapter 05 o the */AR
6estEstimate Plus 1ncertaint( ,6EP1- method&ursued or licensin' calculation deelo&ment o a6E RELAP7"# model or licensin' anal(ses
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
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RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% (
G r u p p o R i c e r c a N u c l e a r e S .
P i e r o a
G r u p p o R i c e r c a N u c l e a r e S .
P i e r o a
G r a d o
G r a d o
Atucha II PHWR Features AtuchaII is a 92 :We Siemens desi'ned PHWR under construction in
Lima5 Ar'entina
Constructions started in ;98;5 sus&ended in ;99<
Constructions resumed in 20075 =rst criticalit( scheduled or 20;0
Hea( .ater cooled5 hea( .ater moderated PWR
1ni>ue eatures?
Primar( circuit !ased on the %onoiPWR desi'n Circuit or moderator coolin' 4 FW &reheatin'
$atural 1ranium uel
@ertical Fuel Channels
Lar'e RP@ ,3" meter internal diam-
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
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RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% 5
G r u p p o R i c e r c a N u c l e a r e S .
P i e r o a
G r u p p o R i c e r c a N u c l e a r e S .
P i e r o a
G r a d o
G r a d o
Atucha II PHWR Features Primar( circuit characteristics B con='uration
2 1Tu!es S/5 2 :CP
Primar( side &ressure? ;;7 :Pa
Primar( side tem&eratures? 238 C at RP@ inlet5 ";""C at RP@ outlet
Total thermal &o.er transerred to the steam .ater c(cle ? 2;3< :W
Aera'e :oderator Tem&erature? ;30 C
< 1Tu!es HD or :oderator coolin' 4 FW &reheatin'
(oderator "ooling"ircuit
Primary "ircuit
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
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RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% )
G r u p p o R i c e r c a N u c l e a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e a r e S .
P i e r o a
G r a d o
G r a d o
Atucha II PHWR Features Fuel &laced in ue CRs
"R layout
*uel Element
RP4 Layout
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
7/49RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% *
G r u p p o R i c e r c a N u c l e a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e a r e S .
P i e r o a
G r a d o
G r a d o
Atucha II PHWR Features Emer'enc( 6oron Inection S(stem desi'ned to act durin' RIA ,e'5
L6LOCA-
To counteract &ositie reactiit( ecursion due to the reactor &ositie oidcoeGcient
< Lances inect hi'h &ressure solution o !oric acid into the moderatortan
S(stem reaction time reduced !( $ASA to rou'hl( 07 secs
oronn6ection
Lance 70 o8 9:
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
8/49RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% %
G r u p p o R i c e r c a N u c l e a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e a r e S .
P i e r o a
G r a d o
G r a d o
Rationale for the Nodalization
Structure $odaliation is the result o a !rainstormin' &rocess .here thecom&utational resources aaila!le and the e&erience o the user&la( a maor role consistentl( .ith the o!ecties o the anal(ses
Selected code .as RELAP7"#J deelo&ed or industrial
a&&lications in 1S5 inde&endent rom the code,s- used !( the
re'ulator
%e( role o?
:aimum allo.ed num!er o nodes5
:aimum alloca!le com&utercode memor(
T(&icalit( o the accident scenarios to !e anal(ed
DEGB LBLOCA – Initial Reactivity Excursion and Recovery
LBLOCA and other transients
1ser in su&&l(in' unaaila!le inormation
Proidin' suita!le >uali=cation
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
9/49RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% +
G r u p p o R i c e r c a N u c l e a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e a r e S .
P i e r o a
G r a d o
G r a d o
Rationale for the Nodalization
Structure )280 channels nodaliation+ consistent .ith thet(&icalit( o the accident scenarios to !e anal(ed,e' #E/6 L6LOCA * Initial Reactiit( Ecursionand Recoer(-
Com&uter resources not suGcient to im&lement allC$A2 ECCS and Lo'ics
)0 channels nodaliation+ consistent .ith thet(&icalit( o the accident scenario ,e' L6LOCAand other transients-
Code com&uter resources saturated !(
im&lementation o suita!le ECCS and Lo'ics5 so? )280 channels nodaliation+ or "# $% * TH anal(ses
)0 channels nodaliation+ or 0# $% * TH anal(ses
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
10/49RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% $'
G r u p p o R i c e r c a N u c l e a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e a r e S .
P i e r o a
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G r a d o
50°
CL axisHL axis
CL !L
CL"!L"
DC Nodalization & RPV Syetry
Due to the le#s #eo$etry not all the
coolant co$in# %ro$ a loo& exits %ro$
the sa$e loo&' A $ixin# ()et*een
inlet and outlet+ has to )e ta,en into
account
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
11/49RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% $$
G r u p p o R i c e r c a N u c l e a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r a d o
G r a d o
DC Nodalization !Hydraulics"
- vertical (do*n*ard oriented+ &i&es
axially su)divided in "5 volu$es
.oined )y cross/%lo* ($ulti&le+ .unctions
(co$&onent no' in the le%t %i#ure+
- )ranches re&resent the u&&er &art1 t*o
o% the$ lin,ed to the CL
DC/23 )y&ass connection
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
12/49RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% $&
G r u p p o R i c e r c a N u c l e a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
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G r a d o
#P Nodalization
4hree layers
+ Botto$ &art – hori6ontally oriented (red+ Level/ (L+
"+ Botto$ &art u& to the channel inlet – vertically oriented (#reen+ Level/" (L"+
7+ Channel inlet u& to the lo*er %ace o% core &late – vertically oriented ()lue+
Level/7 (L7+
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
13/49RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% $3
G r u p p o R i c e r c a N u c l e a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r a d o
G r a d o
#P Nodalization
L3 #rid nodali6ation a&&roach
8ive rin#s are identi%ied containin# an
9entire: nu$)er o% )oxes
"
7
;
5Withouth!""#$ i"$#t%&
CL1 'L1
CL2'L2
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
14/49RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% $(
G r u p p o R
i c e r c a N u c l e a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r a d o
G r a d o
#P NodalizationL3 #rid nodali6ation a&&roach
7- sectors (a$&litude o% each sector is
0° < =$axi$u$ co$$on divisor> %or
?0°1 ;0° and 50°+ divide the )oxes into
"00 &arts (su)/)ox+ re&resented )y
"00 9)ranches:
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
15/49RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% $5
G r u p p o R
i c e r c a N u c l e a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r a d o
G r a d o
#P NodalizationBottom partBottom part
5 radial rin#s (accordin# to L3 &late su)division+
- a6i$uthal &arts (accordin# to DC su)division+
"5 hori6ontal 9)ranches: constitutethe )otto$ L3
4he external rin# is connected to
DC &i&es (#reen circles+
Each hor' )ranch is connected to
the vert' )ranches %or$in# the L3
#rid (red circles+
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
16/49RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% $)
G r u p p o R
i c e r c a N u c l e a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r a d o
G r a d o
Core channels Nodalization8ive throttle ty&es
Green 6one Blue 6one "
Red 6one 7
Blac, 6one ;
Li#ht )lue 6one 5
Considering
-5 Boxes
7- Radial
sector 5 Rin#s
@ax &o*er channel
"0
euivalent
channels
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RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% $*
G r u p p o R
i c e r c a N u c l e a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r a d o
G r a d o
$P Nodalization
8our layers+ 8irst hori6ontal &art connected to the coolant channel outlets ()lue+
"+ 8irst vertical &art u& to the !L axis (oran#e+
7+ econd hori6ontal &art alon# the !L (#reen+
;+ econd vertical &art to account %or the nearly se$is&herical
sha&e (yello*+
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RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% $%
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r a d o
G r a d o
$P Nodalization
4he three di%%erent layers$odelled )y several )ranches
E'#'1 the %irst layer – hori6ontal
"5 9)ranches: connected to the
"0 euivalent core channel
(red circles+
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RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% $+
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r a d o
G r a d o
RPV Nodalization
Not !$$ h!""#$%(#)(#%#"t#*&
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RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% &'
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r a d o
G r a d o
#OOP Nodalization !includin%
S"9tandard: nodali6ation techniueGeneral rules %ollo*ed .unction only connected to a &i&e Ratio len#th o% t*o consecutive nodes
stays *ithin 0'5 – "'0 unction at inlet and outlet o% nodes only
G $odeled till the isolation valves
3u$& ho$olo#ous curves ta,en %ro$ FA/A nodali6ation
2 $oo)% +o*#$#*1 $oo) (#)(#%#"t#*
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RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% &$
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r a d o
G r a d o
'oderator syste
$oo)% +o*#$#* - 1 $oo) (#)(#%#"t#*
'#!t #.h!"/#(%P(i+!( %i*# o
+o*#(!to( oo$#(
S!#t i"#tio"
Mo*#(!to(
)u+)
Mo*#(!to(*o3"o+#(
S!#t i"#tio" )o(t
Pump homologous curves given by NA-SA
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
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RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% &&
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r a d o
G r a d o
Neutron (Sec #i)raries odel * eneration
ENDF/B-! N"#$N"#$%ulti& 'Sec
()* &roups+
,E!#S,E!#S
v. .0v. .0
'Secs ibraries'Secs ibraries
(1 &roups+(1 &roups+
1D 2ransport
Calculations
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RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% &3
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r a d o
G r a d o
Neutron (Sec #i)raries Code Adanced lattice &h(sics code HEL'/HEL'/ used to calculate the cross
section sets
HEL'/HEL'/ is a neutron and 'amma trans&ort code or lattice !urnu&5 in'eneral t.odimensional 'eometr(
#eelo&ed !( /./4, /./4,
;;
/candpo
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
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RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% &(
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r a d o
G r a d o
Neutron (Sec #i)raries odel Channel!(channel !urnu& distri!ution su&&lied !( $ASA
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
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RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% &5
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r a d o
G r a d o
Neutron (Sec #i)raries odel *or e&ery composition a cross section set is generated
Each "ross /ection set contains tables 8or>
Fast and Thermal #iMusion CoeGcients
Fast and Thermal Ca&ture Cross Sections
Fast and Thermal Fission Cross Sections
Fast and Thermal $uFission Cross Sections
Remoal Cross Sections ,/rou& ; 2-
Inerse $eutron @elocities
Assem!l( #iscontinuit( Factors ,A#Fs-
Photoneutron eMect ,su&&lied !( $ASA- to !e taen into account
directl( in $ESTLE in&ut
N (S #i) i d l
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
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RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% &)
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r a d o
G r a d o
Neutron (Sec #i)raries odel Seeral HEL'/HEL'/ in&ut decs deelo&ed?
Fuel Channel ,hea'onal lattice- Fuel Channel N :oderator
CR a!sor!ers ,!lac B 're( CR5 u&&er B lo.er &art-
ReKector? Radial5 6ottom5 and To&
8uel Channel 8uel Channel Re%lector 8uel Channel CR
N (S #i) i d l
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
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RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% &*
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r a d o
G r a d o
Neutron (Sec #i)raries odel
Inter&olation in Fie#imensional Ta!lesInter&olation in Fie#imensional Ta!les
For C$AII core model FieFie Inde&endent Parameters .ill !e
used?
;- Fuel Tem&erature ,#o&&ler Feed!ac-
2- Coolant #ensit( ,@oid EMect-
"- Coolant Tem&erature
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RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% &%
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r a d o
G r a d o
Cross Section 'odellin%
A42C!ACRO'exe
(8OR4RAF ?0 &ro#ra$+
3e4erence
Cross Section
alues
C3#SS
SEC2!#N
!B3A3!ES(nemtab5 nemtabr65
nemtabr615 nemtabr675
nemtabr6)+
Cross-Section
ariation
Coe44icients
5D LINEAR
INTERPOLATION ROUTINE
(LINT5D)
LEAST SQUARE
METHOD(MC)
?ref
Coolant ρ ∂
Σ∂
Moderator B∂
Σ∂
Fuel T ∂
Σ∂
Moderator T ∂
Σ∂
Coolant T ∂
Σ∂
C S i ' d lli
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RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% &+
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r a d o
G r a d o
Final @ersion o theAT1CHACROSS &ro'ram
5 lines Fortran&ro'ram
Automaticall( &erorm
adhoc inter&olations5
or seeral ones o thereactor core
@ariation coeGcientcalculation
$ESTLE in&ut .ritin'
Cross Section 'odellin%
?ref
Coolant ρ ∂
Σ∂
Moderator B∂
Σ∂
Fuel T ∂
Σ∂
Moderator T ∂
Σ∂
Coolant T ∂Σ∂
CR in%or$ation
(4y&e1 an#les1 nu$)er+
FE4LE IF324
+D N, .H l d d l
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
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RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% 3'
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r a d o
G r a d o
+D N, - .H cou/led odel "# $% nodes o!tainin' ).ei'hted+ eed!ac rom TH model
$ESTLE sendin' !ac &o.er distri!ution to FA heat structures
Po.er
%E/LE%E/LE
Fuel Channel
TH model
:oderator
TH model
Coolant#ensit(
Coolant Tem&erature
:oderator Tem&eratur
e
6oronConcentrati
on
Fuel Tem&eratur
e
RELAP5-3RELAP5-3
+D N t ,i ti d l
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
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RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% 3$
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r a d o
G r a d o
+D Neutron ,inetic odel $ESTLE "# $% model characteristics?
Hea'onal lattice "'"; c$ &itch
;0 aial la(ers or actie core? 7"03 cm
; la(er or the 6ottom ReKector?
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
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RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% 3&
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r a d o
G r a d o
CR odelin% ;8 Control Rods
inserted dia'onall(,;327-
6lac CR Haniuma!sor!er
/re( CR Steela!sor!er
Each CR has upper and lo
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
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RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% 33
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r a d o
G r a d o
88 )) /9 8
)):
)70
/*9
/:
:0
:9
CR odellin% Four Cross Sections Li!raries calculated or CR modellin'
CR DSec corrections due to the "# 'eometr( eMects introduced usin' "#:C$P7 :onte Carlo Simulations
88 )) /9 8
)):
)70
/*9
/:
:0
:9
CR and Fuel Channels Section NESTLE modelling
+D N, .H l d d l F l Ch l
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
34/49
RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% 3(
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r a d o
G r a d o
+D N, - .H cou/led odel - Fuel Channels
Atucha II $PP 280 channel280 channel RELAP7"# TH model used
o TH channels modeled B cou&led accordin' to?
H(draulic characteristics ,throttled t(&e4unthrottled-
Rom!oidal su!&lena !elon'in'
Po.er distri!ution
Transient t(&e
Code resources0 0" 07 0; 05 0- 0 0 0? 0 " 7 ; 5 - ? "0 " "" "7 "; "5 "- " " "? 70 7 7" 77 7; 75 7- 7 7 7? ;0 ; ;" ;7 ;; ;5
BGB8
BE
BD
BC
BB
BA
BL
AH
A!
AG
A8
AE
AD
AC
AB
AA
AL
LH
L!
LG
L8
LE
LD
LC
LB
LA
" "
"
"
" "
"" "
7 - "
" "
" " 7-" " "
" " 7 7 " "7 7 7 7
"
" " " 7
7 7 " "7 7 7 7
" " 7 7 7 7
- " " "; 7 7 7; ; ; ;- 7 7 7 " "
7 " " ; ; 7 7; ; ; ;
" " 7 7 7 ; ;
7 7 7 "; ; ; ;; ; ; ;
7 -
" " 7 7 7 ;
; ; ; 7; ; ; ;; ;
" - 7 7 ;
; 7 7 "5 ; ; ;; ; 5 5
"
" " 7 7 ; ;
7 7 7 "5 ; ; ;; 5 5 5
"
" " 7 7 7 ; ;
; 7 7 "5 5 ; ;; 5 5 5
" "
" " 7 7 ; ;
; 7 7 75 5 ; ;; ; 5 5
"
" " 7 7 7 ;
; 7 7 "5 ; ; ;; ; 5 57 7 ; ; "
- " ; ; 7 7; ; ; ;; ; ; ; - 7 7
7 " " ; ; 7 7; ; ; ;7 ; ; ; " 7 7
" " 7 7 7 7; ; ; ;
" " 7 7 7 7 ; ;
- " " ; 7 7 7; ; ; ;- 7 7 7 " " "
" 7 7 7 "7 7 7 7
" " " 7 7 7
" " "
" " " " 7 7 7
" " " " - 7 7
" " "
" " " " " "
"
" " " "
"
-
7 7 7 7
"
"
" "
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
35/49
RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% 35
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r a d o
G r a d o
+D N, - .H cou/led odel - Fuel Channels
280 RELAP7 Fuel Channels cou&led .ith
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
36/49
RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% 3)
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r a d o
G r a d o
+D N, - .H cou/led odel - +D 'oderator tan0
:oderator :odel usin' RELAP7"# "# com&onents
&ossi!ilit( to simulate .ith hi'h de'ree o realism the !oron clouds calculated !(
CF# simulation o as(mmetric transients
@er( so&histicated ma&&in' scheme resulted rom the use o C(lindrical "# THCom&onents cou&led .ith Hea'onal $% cells
Q radial sectors radial sectors
Q 0B 0 B 0 C 02 aDial layers 8or0B 0 B 0 C 02 aDial layers 8or
ottom Reector$ "ore Acti&e )one$ottom Reector$ "ore Acti&e )one$
op reectorop reector
Q 0 a)imuthal sectors0 a)imuthal sectors3 (oderator ank F%E/LE mesh o&erlay
'odellin% the )oron eer%ency in1ection
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
37/49
RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% 3*
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r a d o
G r a d o
'odellin% the )oron eer%ency in1ection
syste 6oron Inection Clouds calculated !( a &reious CF#
CFD T:
code calculation
reconstructed !( adhoc T:#P1$ com&onents in the "# :oderator Tan
Inection onesInection ones
Com&arison CF# * RELAP7"#Com&arison CF# * RELAP7"#
inected mass o !oroninected mass o !oron
RELAP7"# :ass o !oronRELAP7"# :ass o !oron
distri!ution in diMerent la(ersdistri!ution in diMerent la(ers
2345 Channels6 Nodalization Resources
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
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RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% 3%
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r a d o
G r a d o
345 Channels Nodalization Resources
$um!er o H(draulic $odes? 753
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
39/49
RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% 3+
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r a d o
G r a d o
+D N, Cou/led .H SS Results
Core SS conditions?
Hot Full Po.er? 2;0 /W
$ominal alues or Fuel5 Coolant and :oderator Tem&eratures distri!ution
CR in ,$ASA con='uration-
G0 ?; in
G"0 - in
G70";'5 in
0 ;'"? in
hut/O%% ("0 70+ All Rods Out
6oron Concentration? 007 &&m
SS Radial Po7er
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
40/49
RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% ('
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r a d o
G r a d o
SS - Radial Po7er %eM 099770
F( ;"8
:aimum:aimum
:in ;0; :W:in ;0; :W
:a 7 :W:a 7 :W
:inimum
SS Radial Po7er
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
41/49
RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% ($
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r a d o
G r a d o
SS - Radial Po7er
Radial Po.er ? S&atial Form Function
SS Noralized Reactor A8ial Po7er
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
42/49
RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% (&
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r a d o
G r a d o
SS Noralized Reactor A8ial Po7er
ADial Po
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
43/49
RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% (3
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r a d o
G r a d o
Fuel Channels 'ass Flo7:ass Flo. &er Assem!l( %'4sU
SS Cou/led Codes .H
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
44/49
RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% ((
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r a d o
G r a d o
SS Cou/led Codes .H
ParaetersAll the main TH &arameters coner'ed to SSreerence aluesE'5 moderator Tan tem&erature distri!ution
Botto$ 4o& Re%lector
Active Core
#9#OCA 5 ;A in C#3 Sa/le Results
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
45/49
RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% (5
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r a d o
G r a d o
L6LOCA 0; A in CL2 ,reerence #6A or Atucha2-
Actuation oScram !( all CRs ? N003 s
Emer'enc( 6oron Inection S(stem ? N 0" s
:CP; B 2 rundo.n ? N003 s
CR com&letel( inserted ? N"< s
End o 6oron Inection in moderator tan ? N"9; s
%o /a8ety threshold eDceeded
#9#OCA 5:;A in C#3 - Sa/le Results
#9#OCA 5 ;A in C#3 Sa/le Results
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
46/49
RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% ()
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r a d o
G r a d o
#9#OCA 5:;A in C#3 - Sa/le Results
Reactor Po.erReactor Po.er Pressure Trends in 1P andPressure Trends in 1P and
PRPR
Fuel Clad Tem& in Central and Hot ChannelFuel Clad Tem& in Central and Hot Channel@oid Fraction in Central and Hot@oid Fraction in Central and Hot
ChannelChannel
'CP Shaft seizure Sa/le Results
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
47/49
RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% (*
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r a d o
G r a d o
'CP Shaft seizure - Sa/le Results
:CP2 Shat seiure in ; s
:CP; continues o&eration
CRs scram? N0; s
CRs com&letel( inserted? N"3" s
%o /a8ety threshold eDceeded Reactor Po.erReactor Po.er
@oid Fraction in Central B Hot@oid Fraction in Central B Hot
ChannelChannel
: /.: 1.: 7.: ).: ;.: 8.: *.: 9.: 0.: /:.:
2ime (s+
-./:
:
./:
.1:
.7:
.):
.;:
.8:
o
i d
F r a c t i o n
JinGra% ;' / 0"/"-/"00A
KKK @C3Lha%tLei6ure void#"500;0000
K K K K K K K K K K K K K K K K K
MM M @C3Lha%tLei6ure void#"500A0000
M M M M M M M M M M M M M M M M M
NNN @C3Lha%tLei6ure void#"50"0000
N
N
N
N
N
N
N
N N
N
N
N
N
N
N
N
OO O @C3Lha%tLei6ure void#""0;0000
O O O O O O O O O O O O O O O O
EEE @C3Lha%tLei6ure void#""0A0000
E E E E E E E E E E E E E E E
!!! @C3Lha%tLei6ure void#"""0000
!
!
!
!
!
!
!!
!
!
!
!
!
!
!
Fuel Clad Tem& in Central and Hot ChanneFuel Clad Tem& in Central and Hot Channe
FC 9loc0a%e !9D9A" Sa/le Results
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
48/49
RELAP5-3D User Seminar – Idaho University Campus, Idaho a!!s, USA – "ovem#er $%-&', &''% (%
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r a d o
G r a d o
FC 9loc0a%e !9D9A" - Sa/le Results
Hot channel ," :W- total !loca'e in 02 s
$o scram si'nal actuated
/e&ere *uel Assembly damage
: .1; .;: .*; .:: .1; .;: .*; 1.:: 1.1; 1.;:
2ime (s+
-;.:
:
;.:
:.:
;.:
1:.:
1;.:
7:.:
7;.:
% a s s F l o < 3
a t e ( = g / s +
JinGra% ;' / 0/"/"00A
KKK CFA"8CBLOCHAGE $%lo*.""00000
K K K K K K K K K K K K K K K K K K K K
Fuel Clad Tem& in 6loced ChannelFuel Clad Tem& in 6loced Channel
6loced Channel Po.er6loced Channel Po.er
6loced Channel :ass Flo.6loced Channel :ass Flo.
Conclusions
8/17/2019 Atucha-2 PHWR Three Dimensional Neutron Kinetics Coupled Thermal-hydraulics Modelling and Analyses
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G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r u p p o R
i c e r c a N u c l e
a r e S .
P i e r o
a
G r a d o
G r a d o
Conclusions /R$SP/41$IPI deelo&ed or Ar'entinean electric utilit( $ASA so&histicated
RELAP7"# models or Atucha II $PP
"# $% TH )280 channel nodaliation+ .as &resented
"# $% TH model setu& re>uired stron' interactions .ith other technolo'(=elds ,e'5 CF#5 neutron DSecs 'eneration-
RELAP7"# models calculations .ill constitute the Cha&ter ;7 o the FSAR orthe Atucha II licensin'
RELAP7"# demonstrated to !e a er( so&histicated tool5 allo.in' a detailed
modellin' o all releant &henomena B &eculiarities o the Atucha II desi'n %e( &oints or the code im&roement .ere identi=ed and su''ested to I$L
E'?
Increase o the allo.a!le Tri& cards
Increase the num!er o "# @olumes &er :ulti# com&onent
Online Cross Section li!raries inter&olation
Automatic Calculation o Reactiit( com&onents ,e'5 #o&&ler reactiit(5 coolanttem& reactiit(5-
Further .ors are on'oin' at /R$SP/41$IPI in order to?
Com&lete models >uali=cation
Etend the model to a ull RP@ "# TH re&resentation5 includin' the simulation o all