ML19305E763
| ML19305E763 | |
| Person / Time | |
|---|---|
| Site: | Perry  |
| Issue date: | 05/12/1980 |
| From: | Pappas H NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Davidson D CLEVELAND ELECTRIC ILLUMINATING CO. |
| References | |
| NUDOCS 8005200378 | |
| Download: ML19305E763 (1) | |
Text
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UNITED ST ATES 4
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GLEN E LLYN,lLLINOIS 60137
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IMAY ! 2 980 Docket No. 50-440 Docket. No. 50-441 The Cleveland Electric Illuminating Company ATTN:
Mr. Dalwyn R. Davidson Vice President - Engineering 4
P. O. Box 5000 Cleveland, OH 4410h 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.
i Sincerely, J
Helen Pappas, Chief Administrative Branch
Enclosure:
Attachment A to IE Information Notice No. 80-20 cc w/ encl:
Central Files Director, NRR/DPM Director, NRR/ DOR PDR Local PDR NSIC TIC Harold W. Kohn, Power Siting Commission Mr. Daniel D. Wilt, Attorney 4
Helen Evans, State of Ohio
IE Information Notice No. 80-20 1
Enclocum A i,
DAVIS-BESSE_ EVENT OF APRIL 19 1980 s
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.
Head detensioned with bolts in place.
Manway cover on top of OTSG removed.
Tygon tubing attached to lower vents of RCS hot lug for RCS level indication.
Decay heat loop 2 in service for RCS cooling.
2.
All non-nuclearfinstrument (NNI) power and Static Voltage Regulator YAR supplied from 13.8 KV Bus B via HBBf2.
13.8 K Bus A energized but not conaected.
RPS sud SFAS Channels 1 and 3 being supplied from YAR.
3.
Equipment Out of Service i
a.
Source Ra'nga 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.
SEQUENCE OF EVENTS TIME EVENT CAUSE/ COMMENTS 2:00 p.m.
Loos of power to Ground short on 13.8 KV breaker EBBF2 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 Attuation Signal (STAS).
the computer, and much of the control room i
indicators.
i 2:00 p.m.
SFAS Level 5 (recircu-Two out of four logic tripped upon loss lation ecde) actua-of Busses E-2 and F-2.
Actuation caused tion.
ECCS pump suction valves from containment 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 (Iow Operator turned off only operating DH pressure safety in-pump to avoid spillage of RCS water to jaction) flow secured containment via the tygon tubing for RCS j
by operator level indication and open SG manway.
2:33 p.m.
Yartial restoration
'of power Power to Bus E.2 and STAS channels 1 and 3 v
restored along with one channel of N51.
This restored all essential power for ECCS.
i t
. TIME 2:44 p.m.
EVENT CAUSE/ COMMENTS Attempt to reestab-Started DH pu=p 1-2 then stopped 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.
(:00 p.m.
Restoration of Busses Eusses restored sequentually as efforts r.
(480 VAC) F-2 F-21, progressed to isolate ground fault.
4:06 p.m.
F-22, and F-23 4:23 p.m.
DH flow restored DH pump 1-2 started after venting. RCS temperature at 170 F. DH flow bypassing 18 176e. '"" ' ' b * *" 8 ""k'" '"d ""***""
r 4:46 p.m.
Containment sump Precautionary 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 It ore 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 te erature at 150 F. Incore Ti rangefrom151to$580F.
9:50 p.m.
Power completely RCS temperature at approximately 115 F.
restored j
I e**
STATUS OF DAVIS BESSE 1 AFTER RECOVERY FROM LOSS OF p0WER TO BUSSES E-2 AND F-2:
l 1.
Refueling mode with RCS temperature at 135 F and level slightly below vessel he flange.
Head detensioned with bolts in place.
Manway cover on top of OTSC 1
removed.
Tygon tubing attached to lower vents of RCS hot leg for RCS level indication. Uecay heat loop 2 in service for RCS cooling.
i 2.
Bus E-2 being supplied from 13.8 KV 3us A via breaker RAAE2 and Bus F-2 being l
supplied from 13.8 KV Bus B via breaker HBBF2.
l l
3.
Decay heat loop filled, all tags clear.
Maintenance work restricted so restoration of system will be less than two hours.
i 4.
ECCS pump suction valves (DH-9A and DH-93) from containment sump closed and breakers racked ou'.
This will prevent the suction of air into the decay t
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1 3-heat loop during a level 5 actuation (recirculation mode) when there is no water in the. sump.
5.
Equip =ent out of Service:
Emergency Diesel Generator 1 - maintenance 6.
Breakers for containment spray and HFI pumps racked out.
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