US4648425A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System and method of confirming operation of a steam relieving safety valve for a water-cooled nuclear reactor
Assignee: Doryokuro Kakunenryo Kaihatsu Jigyodan
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Filing: 1980-08-20
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Granted: 1987-03-10
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Expires: 2000-08-20
Abstract
Abstract A system and a method of confirming the operation of a steam relieving safety valve for a water-cooled nuclear reactor are provided. Acoustic vibration generated by steam relieved from the safety valve when the latter is opened is detected by an acoustic emission sensor. The acoustic emission sensor is mounted on the safety valve or a steam relief pipe connected to the safety valve.
Inventors
- 👤 Kenshu Watanabe
- 👤 Tadashi Uchikawa
- 👤 Masashi Takiyama
- 👤 Takashi Kurahashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:51
CPC Classifications
G; G21; G21C; G21C9/00; G21C9/004; F; F16; F16K; F16K37/00; Y; Y02; Y02E; Y02E30/00; Y02E30/30; Y10; Y10T; Y10T137/00; Y10T137/8158; Y10T137/8326
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
159 words
In a water cooled nuclear reactor of the type in which water is used as a primary coolant and including a steam drum, a steam relief pipe, and a steam relieving safety valve disposed between said steam drum and said relief pipe, said safety valve being opened to relieve the internal pressure in said steam drum when said interval pressure increases over a predetermined maximum pressure, the improvement comprising: means for detecting an opened condition of said safety valve and thereby for confirming proper operation thereof, said detecting and confirming means comprising contact type acoustic emission sensor means, mounted solely on the exterior of at least one of said safety valve and said steam relief pipe, for detecting acoustic vibrations which are generated by steam being relieved from said safety valve when said safety valve is opened and which are transmitted through a solid material of said at least one of said safety valve and said steam relief pipe.
Claim 2
Dependent Claim
159 words
In a water cooled nuclear reactor of the type in which water is used as a primary coolant and including a steam drum, a steam relief pipe, and a steam relieving safety valve disposed between said steam drum and said relief pipe, said safety valve being opened to relieve the internal pressure in said steam drum when said interval pressure increases over a predetermined maximum pressure, the improvement comprising: means for detecting an opened condition of said safety valve and thereby for confirming proper operation thereof, said detecting and confirming means comprising contact type acoustic emission sensor means, mounted solely on the exterior of at least one of said safety valve and said steam relief pipe, for detecting acoustic vibrations which are generated by steam being relieved from said safety valve when said safety valve is opened and which are transmitted through a solid material of said at least one of said safety valve and said steam relief pipe.
Claim 3
Dependent Claim
29 words
The improvement claimed in claim 1, wherein said acoustic emission sensor means is directly fastened to said at least one of said safety valve and said steam relief pipe.
Claim 4
Dependent Claim
35 words
The improvement claimed in claim 1, wherein said acoustic emission sensor means is connected to said at least one of said safety valve and said steam relief pipe by means of a solid waveguide member.
Claim 5
Dependent Claim
60 words
The improvement claimed in claim 1, wherein said acoustic emission sensor means is electrically connected to a voltmeter via an amplifier, whereby said acoustic vibrations generated by steam relieved from said safety valve are converted into an electric signal by said acoustic emission sensor means and then measured by said voltmeter after said electric signal is amplified by said amplifier.
Claim 6
Independent Claim
153 words
A method of confirming the operation of a steam relieving safety valve installed between a steam drum and a steam relief pipe of a water cooled nuclear reactor of the type in which water is used as a primary coolant, said safety valve being opened to relieve the internal pressure in said steam drum when said internal pressure increases over a predetermined maximum pressure, said method comprising: mounting a contact type acoustic emission sensor solely on the exterior of at least one of the safety valve and the steam relief pipe; detecting by means of said acoustic emission sensor vibrations which are generated by steam being relieved from said safety valve when said safety valve is opened and which are transmitted through a solid material of said at least one of said safety valve and said steam relief pipe; converting the thus detected vibrations into an electrical signal; and detecting said electrical signal.
Claim 7
Independent Claim
153 words
A method of confirming the operation of a steam relieving safety valve installed between a steam drum and a steam relief pipe of a water cooled nuclear reactor of the type in which water is used as a primary coolant, said safety valve being opened to relieve the internal pressure in said steam drum when said internal pressure increases over a predetermined maximum pressure, said method comprising: mounting a contact type acoustic emission sensor solely on the exterior of at least one of the safety valve and the steam relief pipe; detecting by means of said acoustic emission sensor vibrations which are generated by steam being relieved from said safety valve when said safety valve is opened and which are transmitted through a solid material of said at least one of said safety valve and said steam relief pipe; converting the thus detected vibrations into an electrical signal; and detecting said electrical signal.
Claim 8
Dependent Claim
25 words
A method as claimed in claim 5, further comprising amplifying said electrical signal, and measuring the thus amplified electrical signal by means of a voltmeter.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-03-09 | 1990-09-08 | 1991-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-09 | 1994-09-08 | 1995-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-09 | 1998-09-08 | 1999-03-10 | $7700.00 | Window Closed / Lapsed |