ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Effect of corrosion inhibitors on SA106 Grade B carbon steel in H₂SO₄-N₂H₄ solution for the hydrazine-based reductive metal ion decontamination process

Sung-Wook Kim, Sang-Yoon Park, Chang-Hyun Roh, Ji-Hyung Shim, and Sun-Byeong Kim

Korea Atomic Energy Research Institute, Yuseong-gu, Daejeon, Republic of Korea

E-mail: swkim818@kaeri.re.kr

Received: 1 May 2022  Accepted: 8 June 2022

Abstract:

The chemical stability of base metals in a nuclear facility is critical for chemical decontamination because the process typically utilizes a corrosive solution as a reaction medium. An electrochemical corrosion study on SA106 Grade B (SA106B) carbon steel, a feeder pipe material in a Canadian Deuterium Uranium (CANDU) pressurized heavy water reactor, was performed to examine its stability in a hydrazine (N₂H₄)-based reductive metal ion decontamination (HyBRID) process. The corrosion rate of SA106B in the HyBRID process was reduced by introducing corrosion inhibitors, such as chrysoidine G (CG) and CI#30. The corrosion current (I_corr) of SA106B in the H₂SO₄-N₂H₄ solution, a reaction medium of the HyBRID process, was reduced to approximately 30% and 20% in the presence of CG and CI#30, respectively. The I_corr obtained in the HyBRID solution containing the corrosion inhibitor was comparable to that obtained in the organic acid solution used for the commercial process, Canadian decontamination and remediation (CAN-DEREM). Our results indicate that sufficient material stability of SA106B against corrosion during the HyBRID process can be realized by adding a corrosion inhibitor for the chemical decontamination of the CANDU reactor.

Graphical abstract

Keywords: Chemical decontamination; Hydrazine-based reductive metal ion decontamination (HyBRID) process; Carbon steel; Corrosion inhibitor; Electrochemistry

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-022-02338-2

Chemical Papers 76 (10) 6517–6522 (2022)