Localization of the failed fuel subassembly in fast breeder test reactor by the analysis of fission gases in cover gas
- PDF / 1,226,378 Bytes
- 7 Pages / 595.276 x 790.866 pts Page_size
- 91 Downloads / 205 Views
Localization of the failed fuel subassembly in fast breeder test reactor by the analysis of fission gases in cover gas Ashok Kumar G. V. S.1 · Brahmaji Rao J. S.1 · Manish Chand1,3 · Bootharajan M.1 · Suriyanarayanan A.2 · Kumar R.1,3 Received: 7 May 2020 / Published online: 14 September 2020 © Akadémiai Kiadó, Budapest, Hungary 2020
Abstract Identification of a failed fuel subassembly due to the dry rupture of its fuel pin in Fast Breeder Test Reactor was accomplished from the measurement of the degree of burn-up of the fuel. In the present paper, a method for the measurement of krypton radionuclides ratios by means of gamma-ray spectrometry is suggested. The method has been applied both for determination of the degree of fuel burn-up through the analysis of fission gases released and identification of a problematic fuel subassembly that is responsible for the released gas. The burn-up of the failed fuel subassembly was found to be > 100 GWd/t which facilitated establishing the failed fuel subassembly with the dry rupture. Keywords FBTR · Fuel pin failure · Fission gas · Cover gas analysis · In-situ relative detection efficiency · Burn-up
Introduction Fast reactors are being operated worldwide by following several stringent safe-guard operating procedures [1]. One among the safe operating methodologies is the regular monitoring of sodium coolant and cover gas for the presence of fission products which can be an indication of fuel pin failure, in case of its occurrence. Loss of clad integrity of a fuel pin leads to the contamination of the primary coolant system by fuel elements and fission products, which causes an increased radiation dose levels in reactor building [1]. Also, fuel clad is the first physical barrier that is provided between the radioactive fission products and the public and operating personnel. The “defence in depth” philosophy adopted in the nuclear reactor design requires that each barrier shall be designed without assuming the availability of other barriers. This means that the fuel clad should retain its integrity under all circumstances. Therefore, it becomes utmost important * Kumar R. [email protected] 1
Materials Chemistry and Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu 603102, India
2
Reactor Facilities Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu 603102, India
3
Homi Bhabha National Institute, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu 603102, India
to remove the subassemblies containing failed fuel pins at the earliest possible time after the detection of its failure to minimize the contamination of the coolant and the associated man-rem problems. However, the shut-down time also costs the power reactor commercially, thus necessitating a rapid detection of the failed fuel subassembly and its subsequent replacement. The conventional method of detecting the failure of fuel subassembly (FSA) is by the detection of fission products in coolant stream as well as fission gases in cove
Data Loading...
