IR 05000346/1980014
| ML19320D408 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 06/03/1980 |
| From: | Mcgregor L, Reyes L, Tambling T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML19320D404 | List: |
| References | |
| 50-346-80-14, NUDOCS 8007210327 | |
| Download: ML19320D408 (8) | |
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U.S. NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT
REGION III
' Report No. 50-346/80-14 Docket No. 50-346 License No. NPF-3 Licensee: Toledo Edison Company Edison Plaza, 300 Madison Avenue Toledo, OH 43652 Facility Name: Davis-Besse 1 Inspection At: Oak Harbor, OH Inspection Conducted: ' April 8-11, 15-25, 29-30, May 1, 2, 5-9, 1980 7. d Y
Inspectors:
L. A. Reyes 3 W
T. A.3. T o =- IM L. G. McGregor ( 3fc97.)
T.d Tn-L T. N. Tambling C [ S [ R4
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N Approved by:
T. N. Tambling, Acting CEief bf3 80 Reactor Projects Section 2-2 Inspection Summary Inspection on April 8-11, 15-25, 29-30, May 1, 2, 5-9, 1980 (Report No.
50-346/80-14)
Areas Inspected: Routine unannounced inspection of long term shutdown, IE Bulletin followup, special inspection of the April 19, 1980 loss of decay heat removal' system and instrument power; Part 21, Report and License Event Report. The inspection involved 319.5 inspector-hours-onsite by three NRC inspectors.
Results: Of the five areas inspected no items of noncompliance or de-viations were found in four areas; one item of apparent noncompliance was identified in the other area (deficiency - failure to establish a fire watch patrol paragraph 3).
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. DETAILS 1.
Persons Contacted
- T. Murray, Station Superintendent B. Beyer, Assistant Station Superintendent P. Carr, Maintenance Engineer S. Quennoz, Technical Engineer D. Miller, Operations Engineer D. Briden, Chemist and Health Physicist J. Hickey, Training Supervisor L. Simon, Operations Supervisor C. Daft, Operations QA Manager G. Grime, Nuclear Security Manager
- D. Huffman, Administrative Coordinator
- Denotes those present at the exit interview on April 25, 1980.
The inspector also interviewed other licensee employees, including members of the technical, operations, maintenance, I&C, training and health physics staff.
2.
Long Term Shutdown Inspection The inspector performed control room observations, reviewed appli-cable logs and conducted discussions with control room operators during the course of the inspection. The inspector verified that surveillance tests required during shutdown were being completed and that the tagout system was in effect. Tours of the containment building, auxiliary building and turbine building were conducted to observe plant equipment conditions, radiological controls, potential
. fire hazards, physical security, plant housekeeping and neccessary instrumentation.
No items of noncompliance or deviations were identified.
3.
Loss of Instrument Power and Decay Heat Removal a.
i'atus of Plant Prior to Loss of Power to Busses E-2 and F-2 1)
Refueling mode with RCS temperature at approximately 90 F and level slightly below vessel head flange. Head deten-sioned 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.
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K Bus A energized but not connected.
RPS and SFAS Channels 1 and 3 being supplied from YAR.
3)
Equipment-Out of Service.
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.
b.
Sequence of Events TIME EVENT CAUSE/ COMMENTS 2:00 p.m.
Loss of power to Ground Fault Flag on 13.8 KV breaker Busses E-2 and F-2 HBBF2 which caused breaker to open.
(non-essential 480 This interrupted power to busses E-2 VAC)
and F-2 which were supplying all non-nuclear instrument (NNI) power, channels I and 3 of the Reactor Pro-tection 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 (re-Two out of four logic tripped upon circulation mode)
loss of Busses E-2 and F-2.
Actua-actuation.
tion caused 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 (low Operator turned off only operating pressure safety DH pump to avoid spillage of RCS injection) flow water to containment via the tygon secured by oper-tubing for RCS level indication and ator open SG manway.
2:33 p.m.
Partial restora-Power to Bus E-2 and SFAS channels tion of power 1 and 3 restored along with one channel of NNI. This restored all power for ECCS.
2:44 p.m.
Attempt to re-Started DH pump 1-2 then stopped it establish DH flow when it was determined that air was in suction line. Pump secured to prevent damage.
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3:34 p.m.
Source Range
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Channel 2 energized
'4:00 p.m.
. Restoration of Busses restored sequentually as
,to Busses (480 VAC)
efforts progressed to identified
'4:06 p.m.
F-2, F-21, F-22, and isolate ground fault.
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 cooler.
Incore TC's being taken and maximum is 170*F.
4:46 p.m.
Containment sump Precautionary measure to assure con-pump breakers tainment sump water from BWST re-opened mained in containment.
Incore TC's range from 161 to 164*F.
5:40 p.m.
Computer returned Incore TC's range from 158 to 160 F.
to service 6:24 p.m.
DH flow directed RCS cooldown established at less than through cooler 25 F per hour. RCS temperature at 150*F.
Incore TC's range from 151 to 158 F.
9:50 p.m.
Power completely RCS temperature at approximately restored 115 F.
c.
Status of Plant after Recovery from Loss of Power to Busses E-2 and F-2 1.
Refueling mode with RCS temperature at 115 F and level slightly below vessel head flange. Head detensioned with-bolts in place. Maaway 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.
Bus E-2 being supplied from 13.8 KV Bus 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 restricted so rectoration 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-4 -
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suction of air into the decay heat loop during a level 5
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actuation (recirculation mode) when there is no water in the sump.
5.
Equipment Out cf Service:
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Emergency Diesel Generator 1 - maintenance 6.
Breakers for containment spray and HPI pumps racked out.
d.
'Immediate Corrective Action Taken by Licensee To increase the reliability of decay removal during the refuel-ing outage the licensee, 1) closed and electrically disabled the isolation valves to the containment emergency sump, 2) is keeping the second decay heat loop in standby until the refuel-ing canal is filled and 3) will review future electrical dis-tribution system maintenance, modification and testing to pro-vide maximum diversity to the 120 vac instrument power buses.
e.
Internal Communications During the loss of instrument power, the Gaitronics System
.(internal communications system) was without power for approxi-mately 33 minutes.
Corrective actions to this problem will be verified as per the actions requested on IE Circular 80-09 (Problems with Plant Internal Communications Systems).
f.
Fire-Detection Instrumentation Power to the detection instrumentation was lost at 1400 hours0.0162 days <br />0.389 hours <br />0.00231 weeks <br />5.327e-4 months <br /> on April 19, 1980. A fire watch patrol was not established until approximately 1700 hours0.0197 days <br />0.472 hours <br />0.00281 weeks <br />6.4685e-4 months <br />.
T.S. 3.3.3.8 requires the fire detection instrumentation to be operable in all modes, or to establish within one hour a fire watch patrol. This is an item of noncompliance of the deficiency level.
g.
Source Range Nuclear Instrumentation During the loss of instrument power, indication that high voltage was being supplied to the source range instrumentation was lost.
Source channel I was operable throughout the event.
It was determined by the licensee that if power to YBU (uninterruptable instrumentation channel B) is lost the high voltage indication is lost'.
The license has informed the operations personnel of this condition.and instructed them to observe the source range analog meter to determine if the source range channels are
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operable'when power to YBU is lost. The inspector interviewed i
several reactor operators and determine they were knowledgeable l
in the actions to.take during a loss of high voltage indication.
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Company' Nuclear Review Board (CNRB) Review of the Event.
The CNRB reviewed the events that occurred April 19, 1980. This review resulted in several recommendations, namely:
(1) In future alignments only one 13.8 KV bus or one 4.16 KV bus in one train would be taken out of service at one time.
(2) Power Engineering,-(PE) was requested to investigate cur-
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rent cautions in the switching procedure which called for the essential inverters not to be connected to their as-sociated batteries / charger without the associated regulated rectifier in service also.
(3) PE was requested to perform an overview of electrical system
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for additional cautions and/or guidance that can be provided.
(4) The station was encouraged to apply good / safe practice beyond.the requirments of the Technical Specifications.
(5) PE was requested to investigate the communication system and recommend improvements.
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Loss of Decay Heat Removal Emergency Procedure EP 1202.32 The inspector reviewed and noted that EP 1202.32 had been revised February 1,1980, to include alternate means to refill and cool the primary system in the event both decay heat trains were loss when the plant is in the refueling mode. Operator response times had also been revised to provide guidance on how soon the reactor would have to be refilled in the event boiling took place in the core.
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Long Term Corrective Actions IE Information Notice 80-20 and IE Bulletin 80-12 have been issued to all LWR licensees. These documents delineate the actions to be taken by the licensees to improve decay heat
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removal availability.
t No additional items of noncompliance or deviations were identified.
4.
.IE Bulletin Followup For the IE Bulletins listed below the inspector verified that the i
written response was within the time period stated in the bulletin, that the written response included the information required to be reported, that the written response included adequate corrective action' commitments based.on information presentation in the bulle-
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tin and the licensee's response, that licensee management forwarded-6 -
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copies of the written response to the appropriate onsite management
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representatives, that information discussed in the licensee's written response was accurate, and that corrective action taken by the li-censee was as described in the written response.
" Temperature Effects on Level Measurements".
No items of noncompliance or deviations were identified.
5.
Review and Followup on Licensee Events Reports Through direct observations, discussions with licensee personnel, and review of records, the following event reports were reviewed to
. determine that reportability requirements were. fulfilled, immediate corrective action was accomplished, and corrective action to prevent recurrence had been accomplished in accordance with Technical Specifications.
LER 79-48 The following LER's were reviewed and closed out on the basis of an in-office review and evaluations.
LER's 79-13, 79-15, 79-16, 79-17, 79-21, 79-22,78-111, 78-113 and 78-105.
No items of noncompliance or deviations were identified.
6.
Part 21 Report - Auxiliary Feedwater Pushup Turbine (AFPT) Exhaust Line The licensee report September 6, 1980, in accordance with 10 CFR Part 21.21(b) a design deficiency in the exhaust line for the AFPT's.
Modification was scheduled during the first refueling which started April 8, 1980.
The inspector reviewed supplements 1 through 10 of Facility Change Request 79-421 to verify that the design modifications were reviewed and approved in accordance with the licensee procedures. A visual inspection was conducted of the current progress on the two new exhaust lines being installed.
The new AFPT exhaust consists of two completely separate 8 inch steel lines that are routed through seismic class I structures to the south side of the Auxiliary Building.
In the previous design a common exhaust line was partially routed through the Turbine Building and in close proximity to non-seismic class I feedwater lines.
In the exit interview, the inspector noted that the present ten supplements to Facility Change Request 79-421 do not address post installation operational testing of the exhaust lines. The repre-sentative of the licensee stated that additional supplements will
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be issued to cover testing. The inspector stated that final in-
-stallations, post installation testings, operating procedure re-visions and training will be covered in a subsequent inspection.
7.
Exit Interview (30703C)
The inspector met with licensee representatives (denoted in Paragraph
1) throughout the month and summarized the scope and findings of the inspection activities.
In addition to the normal exit interviews, a telephone conversation between Region III and the Vice President, Nuclear, and members of his staff was held May 5, 1980, to discuss the chain of events that have occurred during the current refueling and maintenance outage.
While the specific corrective action for each event has been reviewed, Region 171 expressed concern that the loss of decay heat and instrument pue
, the overexposure of per-sonnel and security access control proi.lems represent a possible breakdown in management controls and planning for the outage.
The representative of the licensee acknowledge the Regions concern and stated that these events were getting full attentions of manage-ment..The Company Nuclear Review Branch is reviewing the events to-increase management controls over plant activities to prevent pos-sible recurrence of similar events. The licensee also stated that they have told and will continue to emphasis to both contractors and plant management that personnel and plant safety comes first.
The licensee was informed that Region III will continue to review and assess current activities during this outage.
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