ABWR SAFETY SYSTEM ASSESSMENT FOR LOCA ANTICIPATION

ABWR SAFETY SYSTEM ASSESSMENT FOR LOCA ANTICIPATION
Ign. Djoko Irianto and Sarwo D.Danupoyo
Center for Nuclear Technology Assessment - BATAN
Email: igndjoko@batan.go.id
ABSTRACT
ABWR SAFETY SYSTEM ASSESSMENT FOR LOCA ANTICIPATION. Loss of coolant accident (LOCA) is the accident which is assumed as the event that initiated from pipe rupture of primary cooling system. One of the risk of LOCA is the increase of fuel cladding temperature that will destroy the integrity of fuel cladding and the release of fission product from the fuel. Emergency core cooling system (ECCS) on BWR has been designed to anticipate the accident such as LOCA. ECCS modification on ABWR is emphasized to improve the ECCS performance. ECCS of ABWR is designed on 3 independent division that operated simultaneously and be able to repair on line automatically until 72 hours without any action of operator. Internal pumps utilization as the recirculation pump make possible to reduce large break LOCA probability due to rupture of primary coolant piping. In this case, the accident risk which could not disparage is the breach that occurred in the High pressure Core Flooder (HPCF) system. In case of such accident occurred the reactor core can be maintain still submerged.

Keywords : Safety System, Loss of Coolant Accident, ABWR, ECCS, HPCF
Published : Proceeding "Seminar ke-III Teknologi dan Keselamatan PLTN Serta Fasilitas Nuklir", Serpong, 5-6 September 1995, ISSN No. : 0854-2910

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RADIATION EXPOSURE ESTIMATION AROUND THE REACTOR DUE TO LOSS OF COOLANT ACCIDENT (LOCA) ON ABWR

RADIATION EXPOSURE ESTIMATION AROUND THE REACTOR DUE TO LOSS OF COOLANT ACCIDENT (LOCA) ON ABWR
Ign. Djoko Irianto and Sarwo D.Danupoyo
Center for Nuclear Technology Assessment - BATAN
Email: igndjoko@batan.go.id
ABSTRACT
RADIATION EXPOSURE ESTIMATION AROUND THE REACTOR DUE TO LOSS OF COOLANT ACCIDENT (LOCA) ON ABWR. Loss of coolant accident in a nuclear reactor is an accident which is assumed be initialized by a leakage at the primary coolant piping or by a leakage at the reactor vessel. In this accident, the coolant will be released and can be followed by some radioactive fission product release to the primary containment, secondary containment and to the environment. Beside to the environment which be a risk to the public, fission product released also occurred to the control room that will be a risk to the operator. Releasing process, pathway, activity and the exposure dose to the environment and also to the control room are assessed and estimated in this paper. The activity which be released in the primary containment at the first two hours are 2.21E07 Ci for iodine and 3.43E08 Ci for noble gas. The increasing of the environment activity and in the control room are 3.1E04 Ci and 2.0E03 Ci for iodine and 7.0E06 Ci and 1.9E07 Ci for noble gas, respectively.

Keywords : Radiation Exposure, Loss of Coolant Accident, ABWR, Primary Coolant
Published : Proceeding "Presentasi Ilmiah Keselamatan Radiasi dan Lingkungan", Jakarta, 20-21 Agustus 1996, ISSN No. : 0854-4085

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DEFENCE-IN-DEPTH IN ABWR TYPE NPP FROM ENVIRONMENT SAFETY ASPECT POINT OF VIEW

DEFENCE-IN-DEPTH IN ABWR TYPE NPP FROM ENVIRONMENT SAFETY ASPECT POINT OF VIEW
Sarwo D.Danupoyo and Ign. Djoko Irianto
Center for Nuclear Technology Assessment - BATAN
Email: igndjoko@batan.go.id
ABSTRACT
DEFENCE-IN-DEPTH IN ABWR TYPE NPP FROM ENVIRONMENT SAFETY ASPECT POINT OF VIEW. Study about application of "defence-in-depth" concept in ABWR type NPP has been done. The study was carried out in order to understand the performance of protection and safety structures in ABWR type NPP from environment safety aspect point of view. The study stressed on simplification of coolant system design, fuel-cladding interaction, core-melt probability, and the possibility of fission product release distributed in environment. The strength of protection and safety structures were observed at loss of coolant accident and severe accident conditions. The result shows that design improvement has increased the ABWR defence-in-depth performance better than conventional BWR type. And so, the radiation release possibility to environment can be reduced.

Keywords : Defence-in-Depth, Safety Structure, Loss of Coolant Accident, Severe Accident, ABWR.
Published : Journal "Pengkajian Sains dan Teknologi Nuklir", Vol.3, No.2, 1998, Pusat Pengkajian Teknologi Nuklir, BATAN, ISSN No. : 0852-8047

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LOSS OF SECONDARY COOLANT ACCIDENT ANALYSIS FOR PIUS TYPE REACTOR USING RELAP5/MOD2

LOSS OF SECONDARY COOLANT ACCIDENT ANALYSIS FOR PIUS TYPE REACTOR USING RELAP5/MOD2

Ign. Djoko Irianto
Center for Nuclear Technology Assessment - BATAN
Email: igndjoko@batan.go.id

ABSTRACT
LOSS OF SECONDARY COOLANT ACCIDENT ANALYSIS FOR PIUS TYPE REACTOR USING RELAP5/MOD2. Process Inherent Ultimate Safety (PIUS) reactor concept is a reactor concept that intrinsically based on passive safety. This reactor refer to Pressurized Water Reactor (PWR) wherein the primary system is submerged in a pool of poison water. The operating principle is to maintain the pressure balance, so that no inflow from pool to the primary system. On loss of secondary coolant accident, primary coolant temperature increases, it is followed by the increase of primary pump speed. When the upper limit is reached, the pump is tripped. Due to the pressure balance disturbance, poison water flows from pool to the primary system, then reactor shut down. This accident condition was simulated by experimental and numerical simulation using RELAP5/MOD2. Numerical simulation was done to the experimental apparatus nodalization that was set on the norm of RELAP5/MOD2. This nodalization consist of 119 volumes, 127 junctions, and 106 heat structures. Analysis was carried out using both experimental and numerical simulation results. It can be concluded that PIUS type reactor is able to anticipate loss of coolant accident because its capability of self shut down.

Keywords : LOCA, PIUS type Reactor, RELAP5/MOD2, PWR.
Published : Proceeding of "Komputasi Dalam Sains dan Teknologi Nuklir VI", Jakarta, 16-17 Januari 1997.

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