Reduction of radiation exposure probability at Tehran research reactor equipped with a second shutdown system

‎Boustani, ‎E‎hsan; ‎Khakshournia, S‎amad

doi:10.22034/rpe.2020.57887

Document Type : Research Article

Authors

¹ Nuclear Science and Technology Research Institute (NSTRI)‎, ‎Reactor and nuclear safety school‎, ‎Tehran‎, ‎Iran

² Nuclear Science and Technology Research Institute (NSTRI)‎, ‎Accelerator and physics school‎, ‎Tehran 14399-51113‎, ‎Iran‎

https://doi.org/10.22034/rpe.2020.57887

Abstract

‎A second shutdown system (SSS) is designed for the Tehran Research Reactor (TRR) completely independent and diverse from the existing First Shutdown System (FSS)‎. ‎Given limitations‎, ‎specifications‎, ‎and requirements of the reactor‎, ‎the design of SSS is based on the injection of liquid neutron absorber‎. ‎The plan has the ability to satisfy the major criterion of required negative reactivity worth‎, ‎to transfer the reactor to subcritical state in needed time‎, ‎with necessary shutdown margin and for the required duration‎. ‎Design calculations are performed using the stochastic code MCNPX2.6.0‎, ‎deterministic code PARET and Pipe Flow Expert software‎. ‎The ORIGEN2 code and HotSpot health physics code are also used for simulation of environmental pollution release‎. ‎The SSS chambers cause a decrease of about 5% and 15% in total and thermal neutron flux‎, ‎respectively‎. ‎To demonstrate the SSS role in enhancing reactor safety‎, ‎the probable accident of core meltdown is investigated‎. ‎As a consequence of this accident‎, ‎the radioactive pollution in and out of reactor containment is released‎. ‎Without existing the SSS and in case of failure of FSS‎, ‎the residents within 58000 m² of the reactor perimeter would receive about 1 mSv which is more than the annual limit of absorbed dose for the community‎.

Highlights

One independent and diverse shutdown system is designed for the Tehran Research Reactor.
Design of Second Shutdown System (SSS) is based on the injection of a liquid neutron absorber.
Design calculations are performed using the MCNPX code, PARET code and the Pipe Flow Expert software.
ORIGEN2 and HotSpot codes are also used for simulation of environmental pollution release.
After equipping the TRR with the SSS, it is forbidden from signicant release around the reactor.

Keywords

20.1001.1.26456397.2020.1.1.6.9

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Radiation Physics and Engineering

Reduction of radiation exposure probability at Tehran research reactor equipped with a second shutdown system

References

References

Volume 1, Issue 1
January 2020
Pages 33-38

Reduction of radiation exposure probability at Tehran research reactor equipped with a second shutdown system

References

References

Volume 1, Issue 1January 2020Pages 33-38

Volume 1, Issue 1
January 2020
Pages 33-38