Safety Assessment Study in Nanoscopic Circumstances for an Accidental Cooling Loop Failure (ACLF) in a Lunar Nuclear Power Reactor (LNPR) - Atomic Nanoscale Technology in the Nuclear Industry - page 40

stock..This.is.the.simplest.dynamic.system.in.the.stock-low.struc-
ture..Both.informational.and.noninformational.objects.can.move.
through. lows. and. accumulation. in. stocks. in. SD.. It. is. thought.
that. the. feedback. loops. are. often. joined. together. by. nonlinear.
couplings. where. any. object. can. cause. counterintuitive. behavior,.
which.is.seen.as.the.backward.loop.in.Figure 4.7..A.plus.sign.sig-
niies.an.addition.to.the.EXAMPLE.feedback.value,.OUTPUT..If.it.
is.a.minus.sign,.the.feedback.value,.OUTPUT,.is.subtracted.from.
the.EXAMPLE.value.
There. are. some. publications. available. that. cover. the. transition. of. time.
(Forrester. 1961,. 1968,. 1969,. 1971).. There. are. also. some. papers. available. that.
relate.to.decision.making.(Forrester.1975,.Kampmann.1996,.Liehr.et.al..2001)..
The.dynamic.simulation.methods.using.SD.are.commercial.software.pack-
ages.such.as.Vensim.(2011),.Powersim.(2011),.and.ITHINK.(2011),.which.are.
used.for.quantiications..For.this.study,.Vensim.was.used.for.the.simulations.
4.3 Calculation
The.object.of.the.study.is.to.determine.the.possibility.of.success.of.an.event.
that.is.initiated.by.the.accident.of.interest..The.characteristics.of.SD.show.the.
relative.value.of.the.possibility.of.the.event..Figure 4.8.shows.the.fundamen-
tal.algorithm.of.problem.solving.using.SD..There.is.the.parallel.conigura-
tion.between.the.real.world.and.the.systems.thinking.world,.which.shows.
the. characteristics. of. the. construction. in. the. modeling.. Systems thinking . is.
any. problem-solving. process. that. views. “problems”. as. parts. of. an. overall.
system,.rather.than.reacting.to.outcomes.or.events.and.potentially.contrib-
uting.to.further.development.of.the.undesired.issue.or.problem..Therefore,.
SD.is.the.dynamic.algorithm.of.systems.thinking..In.SD,.the.simulation.is.
quantiied.in.the.time.step,.which.is.the.time.cycle.of.the.quantiication..The.
dynamic.simulation.is.performed.by.presetting.the.time.interval..As.seen.in.
Figure 4.6,.the.lunar.surface.temperature.changes.very.frequently.due.to.the.
solar.altitude,.which.is.written.as.the.radiator.sink.temperature..Therefore,.
it.is.necessary.to.analyze.the.event.scenario.by.the.cyclic.variation.method,.
which.is.like.SD.
Figure 4.9. shows. the. main. algorithm. of. the. scenario,. which. is. modiied.
from.Figure 4.5..Conventional.tree-type.analysis.requires.that.the.event.tree.
and.fault.tree.be.separate..In.SD,.the.event.low,.however,.can.be.expressed.
with. the. event. tree. and. fault. tree. simultaneously.. There. are. three. igures.
for.the.subscenarios.of.Figure 4.9..The.Figure 4.10.shows.the.scenario.for.an.
ACLF..Figure 4.11.is.the.scenario.for.criticality.stabilization..Figure 4.12.gives.
the.scenario.for.geological.stabilization..Each.igure.shows.the.combination.