ML19305E751
| ML19305E751 | |
| Person / Time | |
|---|---|
| Site: | Marble Hill |
| Issue date: | 05/12/1980 |
| From: | Pappas H NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Shields S PSI ENERGY, INC. A/K/A PUBLIC SERVICE CO. OF INDIANA |
| References | |
| NUDOCS 8005200355 | |
| Download: ML19305E751 (1) | |
Text
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,y, UNITED STATES
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7 NUCLEAR REGULATORY COMMISSION
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GLEN ELLYN,lLLINOIS 60137 AY I 2 1980 Docket No. 50-546 Docket No. 50-547 Public Service of Indiana ATTN:
Mr. S. W. Shields Vice President - Electric System 1000 East Main Street Plainfield, IN 46168 Gentlemen:
Due to an oversight, the attached " Enclosure A" to IE Information Notice No. 80-20 was omitted from our letter dated May 8, 1980.
Sincerely, Helen Pappas, Chief Administrative Branch
Enclosure:
Attachment A to IE Information Notice No. 80-20 cc w/ enc 1:
Mr. Steve J. Brewer, Nuclear Safety and Licensing Supervisor Central Files Director, NRR/DPM Director, NRR/ DOR PDR Local PDR NSIC TIC LeBoeuf, Lamb, Leiby & MecRae Mr. Dave Martin, Office of the Attorney General Mr. John R. Calloway, Staff Director, Environment, Energy and Natural Resources Subcommittee
IE Information Notice No. 80-20 Enclosure A DAVIS-BESSE EVENT OF APRIL 19, 1980 STATUS OF DAVIS-BESSE 1 PRIOR TO LOSS OF POWER TO BUSSES E-2 AND F-2:
1.
Refueling mode with RCS temperature at 90 F and level slightly below vessel head flange.
Read detensioned with bolts in place.
Manway cover on top of OTSG removed.
Tygon tubing attached to. lower vents of RCS hot leg for RCS level indication.
Decay heat loop 2 in service for RCS cooling.
]
2.
All non-nuclear instrument (NNI) power and Static Voltage Regulator YAR supplied from 13.8 KV Bus B via HBBF2.
13.8 K Bus A energized but not l
connected.
RPS and SFAS Channels 1 and 3 being supplied from YAJt.
3.
Equipment Out of Service l
a.
Source Range Channel 2 - Surveillance b.
Emergency Diesel Generator 1 - Maintenance, c.
Decay Heat Loop 1 - Maintenance.
4.
Breakers for containment spray and HPI pumps racked out.
__ OUENCE OF EVDITS TIME EVENT CAUSE/ COMMENTS 2:00 p.m.
Loss of power to Ground short on 13.8 KV breaker HBBF2 Busses E-2 and F-2 which caused breaker to open.
This (non-essential 480 interrupted power to busses E-2 and F-2 VAC) which were supplying all non-nuclear ~
instrument (NNI) power, channels 1 and 3 of the Reactor Protection System (RPS) and
.the Safety Features Actuation Signal (SFAS),
the computer, and much of the control room indicators.
2:00 p.m.
SFAS Level 5 (recircu-Two out of four logic tripped upon loss lation mode) actua-of Busses E-2 and F-2.
Actuation caused tion.
ECCS pump suction valves frcm ccatainment sump to open and ECCS pump suction valves from Borated Water Storage Tank to close.
During valve travel times, gravity flow path existed from BWST to containment sump.
2:02 p.m.
Decay Heat (low Operator turned off only operating DH
{
pressure safety in-pump to avoid spillage of RCS water to jection) flow secured containment via the tygon tubing for RCS by operator level indication and open SG manway.
2:33 p.m.
Partial restoration of power Power to Bus E 2 and SFAS channels 1 and 3 restored along with one channel of NNI.
This restored all essential power for ECCS.
2-TliE EVENT CAUSE/ COMMENTS 2:44 p.m.
Attempt to reestab-Started DH pu=p 1-2 then st~opped it when lish DH flow it was determined that air was in suction line.
Pump secured to prevent da= age.
3:34 p.m.
Source Range Channel 2 energized.
4:00 p.m.
Restoration of Busses Busses restored sequentually as efforts
}
to (480 VAC) F-2, F-21, progressed to isolate ground fault.
)
4:06 p.m.
F-22, and F-23 4:25 p.m.
DH flow restored DH pump 1-2 started after venting. RCS temperature at 170 F.DH flow bypassing 28 1756r. '"" "* ' b* *"8 ""*** ""d ""***""
4:46 p.m.
Containment sump Pre:autionary measure to assure containment.
pump breakers sump water from BWST remained in gentainment, opened Incore TC's range from 161 to 164 F.
5:40 p.m.
Computer returned to Incore TC's range from 158 to 160 F.
service.
6:24 p.m.
DH flow directed RCS cooldown established at less than 25 F through cooler per hour. RCS temerature at 150 F. Incore Ti ra. ige from 151 to 1580F.
~ 9:50 p.m.
Power completely RCS temperature at approximately 115 F.
restored STATUS OF DAVIS.BESSE 1 AFTER RECOVERY FROM LOSS OF PORER TO BUSSES E-2 AND F-2:
1.
Refueling mode with RCS temperature at 115 F and level slightly below vessel he flange. Head detensioned with bolts in place.
Manway cover on top of OTSC i
removed.
Tygon tubing attached to lower vents of RCS hot leg for RCS level indication.
Decny heat loop 2 in service for RCS cooling.
l l
2.
Bus E-2 being supplied from 13.8 KV 3us A via breaker HAAE2 and Bus F-2 being supplied from 13.8 KV Bus B via breaker HBBF2.
3.
Decay heat loop filled, all tags clear.
Maintenance work reetricted so restoration of system will be less than two hours.
4.
ECCS pump suction valves (DH-9A and DH-9B) from containment sump closed and breakers racked out.
This will prevent the suction of air into the decay
~
3-heat loop during a level S actuation (recirculation mode) when there is no water in the. sump.
5.
Equipment out of Service:
Emergency Diesel Generator 1 - maintenance 6.
Breakers for containment spray and HFI pumps racked out, i
e e
1
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