ML19221A462
| ML19221A462 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 04/02/1979 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| To: | |
| References | |
| OLS-790402, NUDOCS 7905230044 | |
| Download: ML19221A462 (2) | |
Text
.
Noise Analysis Summary 1500 hours0.0174 days <br />0.417 hours <br />0.00248 weeks <br />5.7075e-4 months <br /> April 2, 1979 No significant Loose Parts noises have been detected at the bottom and top of the reactor vessel and top and bottom of steam generators.
Primary Coolant pressure fluctuations have been observed with the following characteristics:
e 1)
Increase and decreases o'f reactor coolant system pressure noise were noted with normal. operating increases and decreases in reactor coclant system pressure.
2)
The peak magnitude of the reactor coolant system pressure fluctuation increased in magnitude over a period of 13 hours1.50463e-4 days <br />0.00361 hours <br />2.149471e-5 weeks <br />4.9465e-6 months <br /> reaching a maximum typical value of 55 psig peak-to-peak with the maximum observed excursion of 137 psig peak-to peak for the Reactor Coolant Loop "A" pressure signal.
The typical peak to peak fluctuation for the Reactor Coolant Loop "B" pressure was 3 PSI and the maximum peak to peak value observed over a 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> period was 8.5 psi peak-to-peak.
7 90523 007$
=
~
i*
3)
The typical peak to peak amplitude of the reactor coolant system pressure fluctuations has not increased in the last 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
- 4) The onset of the pressure fluctuations appears to occur at a threshold value of the absolute value of the reactor coolant system pressure.
This onset pressure value has shown a slow decrease in tin.e and at 0500 hours0.00579 days <br />0.139 hours <br />8.267196e-4 weeks <br />1.9025e-4 months <br /> of 4/2/79 the threshold value was approximately 850 psig.
- 5) After the pressure fluctuations have increased to the typical 55 pr ig peak to peak values, no further increase in the fluc-t
-lon magnitudec have been observed with increasing reactor c'
coolant system pressure up to 1100 psig.
6)
Spectral Analysis were performed and revealed that most of the pressure fluctuation amplitude power in essentially randou fluctuations below 2 II: with low coherence between the pressure fluctuations of the two reactor coolant system loops.
b M%% W9 81m[
aNO@
m ey