Analys av status hos spännsystem på Ringhals kärnkraftverk.
(2005)Division of Structural Engineering
- Abstract (Swedish)
- Today´s society depend on electric energy, in nuclear power plants this can be produced. Each nuclear reactor is situated inside a concrete containment reinforced with a post-tensioning system. The aim of this report is to analyse the state of the post-tensioning systems at Ringhals nuclear power plant. The purpose of a containment is to protect the outside world if an accident should occur. Tightness and integrity is vital in all reactor containments and safety depend directly upon the post-tensioning system. Post-tensioning systems have losses in
tendon force due to mechanisms such as shrinkage, creep and relaxation. To ensure that tendon force is sufficient regular in-service inspections (ISI) are preformed. The data gathered at... (More) - Today´s society depend on electric energy, in nuclear power plants this can be produced. Each nuclear reactor is situated inside a concrete containment reinforced with a post-tensioning system. The aim of this report is to analyse the state of the post-tensioning systems at Ringhals nuclear power plant. The purpose of a containment is to protect the outside world if an accident should occur. Tightness and integrity is vital in all reactor containments and safety depend directly upon the post-tensioning system. Post-tensioning systems have losses in
tendon force due to mechanisms such as shrinkage, creep and relaxation. To ensure that tendon force is sufficient regular in-service inspections (ISI) are preformed. The data gathered at inspection are thoroughly evaluated. One point on the inspection checklist is to measure tendon forces. The tendon force is measured with lift-off technique, where a jack is used to lift the end anchor. One difficulty, when doing the interpretation of the measuring results, is that influence of friction between tendon and duct can affect the force along the tendon. This friction can cause a redistribution of force along the tendon after the original tensioning. Using the measured lift-off force an estimation of the average force along the tendon can be made, the estimation is based upon the assumption that the force distribution along the tendon is the same as the original. To decide if this is correct the elongation of each tendon can be used to calculate the average force along the tendon. The state of the post tensioned system can then be decided trough comparison of the measured lift-off force to the calculated average force along the tendon. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/3172295
- author
- Lindgren, Sara
- supervisor
- organization
- year
- 2005
- type
- H3 - Professional qualifications (4 Years - )
- subject
- report number
- TVBK-5128
- ISSN
- 0349-4969
- language
- Swedish
- id
- 3172295
- date added to LUP
- 2012-12-04 14:40:45
- date last changed
- 2014-06-12 14:22:56
@misc{3172295,
abstract = {{Today´s society depend on electric energy, in nuclear power plants this can be produced. Each nuclear reactor is situated inside a concrete containment reinforced with a post-tensioning system. The aim of this report is to analyse the state of the post-tensioning systems at Ringhals nuclear power plant. The purpose of a containment is to protect the outside world if an accident should occur. Tightness and integrity is vital in all reactor containments and safety depend directly upon the post-tensioning system. Post-tensioning systems have losses in
tendon force due to mechanisms such as shrinkage, creep and relaxation. To ensure that tendon force is sufficient regular in-service inspections (ISI) are preformed. The data gathered at inspection are thoroughly evaluated. One point on the inspection checklist is to measure tendon forces. The tendon force is measured with lift-off technique, where a jack is used to lift the end anchor. One difficulty, when doing the interpretation of the measuring results, is that influence of friction between tendon and duct can affect the force along the tendon. This friction can cause a redistribution of force along the tendon after the original tensioning. Using the measured lift-off force an estimation of the average force along the tendon can be made, the estimation is based upon the assumption that the force distribution along the tendon is the same as the original. To decide if this is correct the elongation of each tendon can be used to calculate the average force along the tendon. The state of the post tensioned system can then be decided trough comparison of the measured lift-off force to the calculated average force along the tendon.}},
author = {{Lindgren, Sara}},
issn = {{0349-4969}},
language = {{swe}},
note = {{Student Paper}},
title = {{Analys av status hos spännsystem på Ringhals kärnkraftverk.}},
year = {{2005}},
}