Abstract
The report will describe the boilers, but will emphasise the problems encountered and the solutions. The boilers are 'once through' with start up drums. Some redundancy was provided but this advantage was lost due to downrating of gas temperature. The boilers are carbon steel suspended plattens (992 per reactor) tightly packed in the annular space between the core shielding and the spherical wall of the pressure vessel. This construction denies access to repair tube leaks. when a leak occurs the faulty platten has to be plugged off. This is done with the reactor at 60% power. The process will be described. Reactor 1 commenced operation in 1971, Reactor 2 in June 1971. Between 1972 and May 1984 21 leaks occurred which resulted in a major shutdown for investigation. This revealed the leaks were caused by gas flow induced vibration resulting in fretting of tubes in clips. Restraints and additional clamps were fitted. This has been successful but the modifications were extensive and in very difficult working conditions, the Reactor being shut down until May 1976. A family of leaks adjacent to personnel access ways commenced in Reactor 1 in 1975 which was later identified as erosion/corrosion on the water/steam side
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Razzell, R N
[1]
- Wylfa Power Station, Central Electricity Generating Board, Gwynedd (United Kingdom)
Citation Formats
Razzell, R N.
Design, construction and operating experience of boilers at Wylfa power station.
IAEA: N. p.,
1988.
Web.
Razzell, R N.
Design, construction and operating experience of boilers at Wylfa power station.
IAEA.
Razzell, R N.
1988.
"Design, construction and operating experience of boilers at Wylfa power station."
IAEA.
@misc{etde_20113019,
title = {Design, construction and operating experience of boilers at Wylfa power station}
author = {Razzell, R N}
abstractNote = {The report will describe the boilers, but will emphasise the problems encountered and the solutions. The boilers are 'once through' with start up drums. Some redundancy was provided but this advantage was lost due to downrating of gas temperature. The boilers are carbon steel suspended plattens (992 per reactor) tightly packed in the annular space between the core shielding and the spherical wall of the pressure vessel. This construction denies access to repair tube leaks. when a leak occurs the faulty platten has to be plugged off. This is done with the reactor at 60% power. The process will be described. Reactor 1 commenced operation in 1971, Reactor 2 in June 1971. Between 1972 and May 1984 21 leaks occurred which resulted in a major shutdown for investigation. This revealed the leaks were caused by gas flow induced vibration resulting in fretting of tubes in clips. Restraints and additional clamps were fitted. This has been successful but the modifications were extensive and in very difficult working conditions, the Reactor being shut down until May 1976. A family of leaks adjacent to personnel access ways commenced in Reactor 1 in 1975 which was later identified as erosion/corrosion on the water/steam side caused by the feed flow instability. This problem is common to both Reactors. Various modifications have been applied. Redistribution of feed flow using orifice plates and ferrules was only temporarily successful. Following extensive rig testing the feed water has been dosed with amino methyl proponal (AMP) since September 1983 with an immediate and sustained reduction in the leak rate. The amine provides protection through the steam/water phase. Rig testing continues to attain a better understanding of the erosion/corrosion. (author)}
place = {IAEA}
year = {1988}
month = {Jul}
}
title = {Design, construction and operating experience of boilers at Wylfa power station}
author = {Razzell, R N}
abstractNote = {The report will describe the boilers, but will emphasise the problems encountered and the solutions. The boilers are 'once through' with start up drums. Some redundancy was provided but this advantage was lost due to downrating of gas temperature. The boilers are carbon steel suspended plattens (992 per reactor) tightly packed in the annular space between the core shielding and the spherical wall of the pressure vessel. This construction denies access to repair tube leaks. when a leak occurs the faulty platten has to be plugged off. This is done with the reactor at 60% power. The process will be described. Reactor 1 commenced operation in 1971, Reactor 2 in June 1971. Between 1972 and May 1984 21 leaks occurred which resulted in a major shutdown for investigation. This revealed the leaks were caused by gas flow induced vibration resulting in fretting of tubes in clips. Restraints and additional clamps were fitted. This has been successful but the modifications were extensive and in very difficult working conditions, the Reactor being shut down until May 1976. A family of leaks adjacent to personnel access ways commenced in Reactor 1 in 1975 which was later identified as erosion/corrosion on the water/steam side caused by the feed flow instability. This problem is common to both Reactors. Various modifications have been applied. Redistribution of feed flow using orifice plates and ferrules was only temporarily successful. Following extensive rig testing the feed water has been dosed with amino methyl proponal (AMP) since September 1983 with an immediate and sustained reduction in the leak rate. The amine provides protection through the steam/water phase. Rig testing continues to attain a better understanding of the erosion/corrosion. (author)}
place = {IAEA}
year = {1988}
month = {Jul}
}