ML19207A366
| ML19207A366 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 07/30/1979 |
| From: | Mceltoy J PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Beltracchi L Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7908170274 | |
| Download: ML19207A366 (4) | |
Text
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.s PHILADELPHI A ELECTRIC COM PANY 23O1 M ARKET STREET PHILADELPHIA. PA.19101 2?5 841-4000 t=ciattan=c amo af stancM Otraarmtmi July 30,1979 Mr. Leo 3eltracchi U.S. Nuclear Regulatory Cen:=ission
'a'achington, D.C.
20$55
Dear Leo,
As per our telephone conversation, I am submitting a very brief description of our system. When I return frcm vacation, I will be able to follow through in :::uch scre detail.
Sincerely yours,
=
John V. McElrcy, Research W.neer J4M:sv Enclosure s
1 n n.n.,
s
.m m.s
/'
lT 7 903170 /v
RELIET VALVE POS1'"ICN MCNITCRING
_.COUSTIC MCN!TCRING SYS"IM A
The following is a brief descriptien of_the accusti: =cnitoring syr-te= which for the past few years has been used to indica icn relief valve positien at Peach Bottom Nuclear Power Station.
Any further info =ation should be requested through the co-ordinater of the accustic progra= at Philadelphia Electric.
Through the application of a sensor, specifically one that can pre-vide frequency responce to 50 kHz, located en the discharge line cf the relief valve and the appropriate electronics, see figure 1, the rperater can have the capability of knowing the condition of each of the valves.
An actuation would sti=ulate the sensor by a signal to noise ratio of at least 1000. This simulatien results in the " valve open" light to energize and the " valve acknowledge" light to energize. The sti=ulatien also energizes voltage input for the plant cceputer to chr:nclogically reccrd the opening. When the valve closes the " valve closed" light energized, the." valve open" light goes off and the " valve acknowledge" light stays en until the cperator acknowledges the opening and reviews how =any and whentheopening(s)occurredentheplantec=puter. The system also pr:-
vides a readout to insure that the valve has resealed properly.
The benefits of such a system has been itecized by the nuclear in-dustry as follcws (assu,ing the plant ce=puter can accc==cdate these inputs).
1.
Provides an i==ediate signal of valve cperation to the plant operator.
2.
Prevides a record of the number of actuations and approxi= ate set and reset pressure for each valve (reactor pressure).
3 Prevides an accurate record of SR7 sequencing dring pressure transients en first as well as subsequent actuations en any giver valve.
700321
(Cent'd - P1ge
)
L.
Provides the factual data base whereby centainnent fatigue. - d-ing calculaticns nay use the actual number of SEV actuatienc rather than censervative design predictions for usage facter analyses. At one operating plant where instrunenta-icn hac been installed for three years, there has been a reducticn in the LO year projected usage factor of abcut 95%.
5 May per=it the use of nere realis+1e sav blowdewn valves (rather than ;cnservative estimates) in transient analyses. This w:uld permit the analysis to nere accurately predict actual trancient pressure respense.
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