ML20099L259
| ML20099L259 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 09/06/1995 |
| From: | GEORGIA POWER CO. |
| To: | |
| References | |
| OLA-3-A-171M, NUDOCS 9512200257 | |
| Download: ML20099L259 (2) | |
Text
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UCENSEE EVENT REPORT (LERI fS$'u'.',%'.l'E" Z"e*'. Tin"8"'N.741"'s TEXT CONTINUATION
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.mmac e ~'. ausranm or ucRrTMY eq During the rtest;runrof the DG on 3-30-90, one of the N
t, switches (T MpTed aEd would not reset.
This appeared to be d.,Q. E an intermittent f ure >ecause it subsequently mechanically reset.
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This switch and the leaking switch (TS-19112) were replaced with new 5
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All subsequent testing was conducted with no additional
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A test of the jacket wateN system temperature transient during engine Ej y, Q*
starts was conducted. The purpose of this test was to determine the Eg actual jacket water temperature at the switch locations with the engine
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j g ]h in a normal standby lineup, and then followed by a series of starts without air rolling the engine to replicate the starts of 3-20-90. The a s U4e test showed that jacket water te:perature at the switch location 2gx decreased from,'a' standby temperature of 163 degrees F to approximately
-x 156 degrees F and remained steady.
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, kg Numerous. sens.or calibration.s (including jacket water temperatures),
special pneumatic leak testing, and multiple engine starts and runs I
were performed under varioul conditions. After the 3-20-90 event, the
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control'sistems of both'engihes have been subjected to a comprehensive j-(
test progra$. Subsequen,t,to this test program, DGIA and DGIB have been startehtht 10 thu-each and no failures or problems have p$ese.
occurred duHng' any of thes~e starts. in-N/an undervoltage
'^cWed start test without air rollewas conducted on 4-6-90 and DGIA started 1
and loaded pro LGAlc4
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7 YF Based on the above facts, it is concluded that the jacket water high temperature switches were the most probable cause of both trips on 3-20-90.,.1. J L-E.
ANALYSIS OF EVENT, b,.
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The loss of offsite power to Class 1E bus IBA03 and the failure of DGIA to start and operate successfully, coupled with DGIB and RAT IB being out of service for maintenance, resulted in Unit I being without AC power to both
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could not perfor(m,its. required safety function. Class IE busses, With both Based on a noted rate of rise in the would not h RCS temperature of 46 degrees F in 36 minutues, the RCS water 36 minutes a,ve been expected to begin boiling until approximately I hour and a
ft'er th'e beginning of the event.
iQ'y3 Q F M.Dy"CP-Restoration of. RHR and closure,of the containment equipment hatch were completed well, within the estimated I hour and 36 minutes for the projected onset of boiling ji.the RCS. A: review of information obtained from the Process and Effluent Radiation ~ Monitoring System (PERMS) and grab sample N
analysis indicated all norzaTvalues. As a result of this event, no increase in radioactive releases to either the containment or the 4
enyironment_occuryed.'M,'gg q;,
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