Sains Malaysiana 48(10)(2019): 2277–2284

http://dx.doi.org/10.17576/jsm-2019-4810-24

Source Term Atmospheric Release and Core Inventory Analysis for the PUSPATI TRIGA Reactor under Severe Accident Conditions

(Pengeluaran Atmosfera Source Term dan Analisis Inventori Teras bagi Reaktor PUSPATI TRIGA di bawah Keadaan Kemalangan yang Teruk)

SITI NUR AIN SULAIMAN¹, FAIZAL MOHAMED^1,2*, AHMAD NABIL AB RAHIM³, MOHAMMAD SUHAIMI KASSIM³ & NA’IM SHAUQI HAMZAH³

¹Nuclear Science Programme, School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan, Malaysia

²Institut Islam Hadhari, Kompleks Tun Abdullah Mohd Salleh, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan, Malaysia

³Reactor Technology Center, Malaysian Nuclear Agency, MESTECC, Bangi, 43000 Kajang, Selangor Darul Ehsan, Malaysia

Diserahkan: 8 November 2018/Diterima: 22 Ogos 2019

ABSTRACT

The estimation of core inventory and source term of nuclear reactor is a part of procedures for conducting a Level 2 Probabilistic Safety Assessment (PSA). Currently, there are not many studies in this area for nuclear research reactors, as it is yet to be made compulsory in the regulatory licensing process among the nuclear-powered countries. This assessment is important to be done in order to be informed about the severity of a nuclear accident. In this study, the type of radionuclides and their activities when unintentionally released to the atmosphere were calculated using the ORIGEN2 code. This work was carried out for PUSPATI TRIGA Reactor (RTP) under a hypothetical severe accident. The core inventory for RTP was determined by assuming the reactor to be operated continuously for 365 days at full power (1 MWt). 42 radionuclides were chosen due to their dominant effects in source term. The atmospheric release of radionuclides is not the same as another depending on the physical condition of the reactor after the accident. The effects of these radionuclides when exposed to the public may cause serious health concern.

Keywords: Atmospheric dispersion; core inventory; ORIGEN2; severe accident; source term

ABSTRAK

Anggaran inventori teras dan source term untuk reaktor nuklear merupakan sebahagian daripada prosedur dalam menjalankan Penilaian Kebarangkalian Keselamatan (PSA) Tahap 2. Pada masa ini, tidak banyak kajian sebegini dilakukan ke atas reaktor nuklear penyelidikan, memandangkan ia belum lagi diwajibkan dalam peraturan proses perlesenan dalam kalangan negara yang menggunakan tenaga nuklear. Penilaian sebegini adalah penting untuk dijalankan untuk mengetahui tahap keterukan situasi apabila berlakunya kemalangan nuklear. Dalam kajian ini, jenis radionuklid dan aktivitinya apabila berlaku perlepasan tidak sengaja dikenalpasti dengan menggunakan kod ORIGEN2. Kajian ini dilakukan ke atas Reaktor TRIGA PUSPATI (RTP) yang dianggap berada dalam keadaan kemalangan teruk hipotetik. Inventori teras untuk RTP ditentukan dengan andaian bahawa reaktor beroperasi selama 365 hari tanpa henti dengan kuasa penuh (1 MWt). 42 radionuklid dipilih berdasarkan kesan dominan dalam source term. Bergantung kepada keadaan fizikal reaktor selepas kemalangan terjadi, situasi perlepasan radionuklid ke atmosfera adalah tidak sama mengikut kes. Kesan daripada dedahan radionuklid ini kepada orang awam juga boleh menyebabkan masalah kesihatan yang serius.

Kata kunci: Inventori teras; kemalangan teruk; ORIGEN2; perlepasan atmosfera; source term

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*Pengarang untuk surat-menyurat; email: faizalm@ukm.edu.my