ML20099L272
| ML20099L272 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 09/06/1995 |
| From: | GEORGIA POWER CO. |
| To: | |
| References | |
| OLA-3-A-171R, NUDOCS 9512200268 | |
| Download: ML20099L272 (2) | |
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VEGP - UN!951 DCT 20 P3 :09 e is is se se p # 2:4 w -... a s -
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plEtk sesequedtRtsst run of the DC on 3-30-90, one of the lf A9t:0
.l.11Wtt h allur# ped and would not reset. This appeared to be f
e because it subsequently mechanically reset.
In term This swit a
the leaking switch (75-19112) were replaced with new switches. All subsequent testing was conducted with no additional j
problems.
i A test of the jacket water systes temperature transtant during engine l
starts was conducted. The purpose of this test was to determine the 1
actual jacket water temperature at the switch locations with the engine in a normal standby Itneup, and then followed by a series of starts i
without air rolling the engine to repiteate the starts of 3-20-90. The I
test showed that jacket water temperature at the switch location 4
decreased from a standby temperature of 163 degrees F to approximately 156 degrees F and remained steady.
Numerous sensor calibrations (including jacket water temperatures).
j special pneusatte leak testing, and multiple engine starts and runs j
were performed under various conditions. In 3ddition, the Contr01 systems of both engines were subjected to a comprehensive test program.
1 Af er conoletian of the control logic test sequence, an undervoltage es a perPormedW4*ehdieg4he-enderveltage-tests M!A S:: i:::
4scoessivMy4 tarted 45-times-aa44GIS h:: i::: succes,sfuMy--eta-*^d !L i
4 lase-ee-of-4-14-90rwi th-no-s t ert-feilwreer j
Based on the above facts, it is concluded that the jacket water high j
temperature switches were the aest probable cause of both trips on j
3-20-90.
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E. ANALYS!$ 0F EVENT 2
The loss of offsite power to Class 1E bus 18A03 and the failure of DGIA to start and operate successfully, coupled with DG1B and RAT 1B being out of service for maintenance resulted in Unit I being without AC power to both l
Class 1E busses. With kth Class 1E busses deenergized, the Rigt Systes could not perform its required safety function. Based on a noted rate of i*
rise in the RCS temperature of 45 degrees F in 36 minutues, the RCS water would not have been expected to begin boiling untti approximately 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and j
36 minutes after the beginning of the event.
Restoratton of RPet and closu m of the contatnment equipsont hatch vers QMwvW wittrfrthresttertwt hour ent 39 striottr for-tfir.
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onset of boiling in the RCS. A review of inforsation obtained from t$e.M'"
r Process and Efnuent Radiation Monitoring System (PERMS)is event, no and grab sample analysts indicated all normal values. As a result of th i
increase in radioactive releases to either the containment or the i
env1ronment occurred.
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