A Study on the Explosive Plugging of A Repair for Defective Tube/Tubeplate on the Nuclear Steam Generator

원자력 증기발생기 결함 세관 보수용 폭발 Plugging에 관한 연구

  • 이병일 ;
  • 심상한 ;
  • 강정윤 ;
  • 이상래
  • Published : 1999.12.01

Abstract

The explosive forming has been used for many year to expand tubes into tubesheets. this process has demonstrated ability to direct carefully the energy of an explosive to expand tubes into tubesheet holes without damaging the tubesheet and without causing the excessive cold work at the tube I.D. that is normally associated with mechanical expansion. The success of explosive tube expansion provided the background for the development of the explosive tube plug. The main results are as follows : (1) The optimum explosives and explosive qualities are PETN, RDX, HMS and about 18~31gr/ft of explosive plugging in nuclear steam generator. (2) Explosive plugging's thickness is 0.9~1.8mm. If groove of 0.4 mm formed in plug outside, For the hydraulic leakage is go up, explosive plugging of formed groove are applicate tube and tubrplate. (3) Sheath is designed on the polyethylene of low density, In thermal impact test of the $430^\circ{C}$, hydraulic leakage is $300kg/cm^2$. (4) About 10~60mm oxide inclusions are existed on the space of explosive plug and tube protect to the leakage.

Keywords

Explosive Plugging;PETN;Groove;sheath;Plug Assy;Pull-out Load;Hydraulic Leakage;Stand-off Distance;Stress Corrosion Cracking