IR 05000245/1979021
| ML19312E668 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 10/30/1979 |
| From: | Mccabe E, Shedlosky J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML19312E666 | List: |
| References | |
| 50-245-79-21, 50-336-79-22, IEB-79-13, NUDOCS 8006050524 | |
| Download: ML19312E668 (8) | |
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w U.S. NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT 50-245/79-21 Report No. 50.~26/79-22 50-245 Docket No. 50-336 DPR-21 License No. DPR-65 Priority Category C
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Licensee:
Northeast Nuclear Energy Company P. O. Box 270 Hartford, Connecticut 06101 Facility Name:
Millstone Nuclear Power Station, Units 1 and 2 Inspection at:
Waterford, Connecticut 06385 Inspection conducted: August 4 - September 1, 1979 Inspectors: $[bu& /w
/0/gp/79 J.T.Shedfaliky,'ResidentInspector date sighed
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date signed date signed
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Approved by:
0 0. b N h a[g,79 E. C. McCabe, Jr., Chief, Reactor Projects date signed Section No. 2, RO&NS Branch Inspection Summary:
Inspection on August 4 - September 1,1979 (Combined Report Nos. 50-245/79-21 and 50-336/79-22)
Areas Inspected:
Routine, onsite regular, backshift and weekend inspection by the resident inspector (35 hours4.050926e-4 days <br />0.00972 hours <br />5.787037e-5 weeks <br />1.33175e-5 months <br />, Unit 1; 90 hours0.00104 days <br />0.025 hours <br />1.488095e-4 weeks <br />3.4245e-5 months <br />, Unit 2). Areas inspected included the control rooms and the accessible portions of the Unit 1 reacter, turbine, radioactive waste, gas turbine generator and intake buildings, the Unit 2 enclosure, auxiliary, turbine and intake buildings, and the condensate polishing facility; radiation protection; physical security; licensee action taken to complete the examination of feedwater piping required by IE Bulletin 79-13, and the implementation of the commitments documented in the NRC letter to the Northeast Nuclear Energy Company, dated August 25, 1979; fire. protection; plant operating records; surveillance testing; calibration maintenance; core power distribution limits; and reporting to the NRC.
Results:
No items of noncompliance were identified.
Region I Form 12 (Rev. April 77)
8006050504 Q
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s DETAILS 1.
Persons Contacted The below listed technical and supervisory level personnel were among those contacted:
J. M. Black, Superintendent, Unit 3 P. Callaghan, Unit 1 Maintenance Supervisor F. Dacimo, Station QC Supervisor E. C. Farrell, Superintendent, Unit 2 J. Bangasser, Station Security Supervisor H. Haynes, Unit 2 Instrumentation and Control Supervisor P Merbert, Superintendent, Unit 1
.. Kelly, Unit 2 Operations Supervisor E. J. Mroczka, Superintendent, Plant Services J. F. Opeka, Station Superintendent R. P1 ace, Unit 2 Maintenance Supervisor R. Przekop, Unit 1 Engineering Supervisor W. Romberg, Unit 1 Operations Supervisor S. Scace, Unit 2 Engineering Supervisor F. Teeple, Unit 1 Instrumentation and Control Supervisor M. Kupinski, NUSCO Senior Engineer 2.
Review of Plant Operations - Plant Inspections The inspector reviewed plant operations through direct inspection and observation during routine operation of Units 1 and 2.
Inspection was made of the Unit 1 control room; accessible portions of the reactor, turbine, radioactive waste, gas turbine cenerator and intake buildings; the Unit 2 control room, enclosure, auxiliary, turbine and intake buildings.
During this inspection, the implementation of the licensee commitments documented in the NRC letter to the Northeast Nuclear Energy Company, dated August 25, 1979, was reviewed.
A shutdown of Unit 2 occurred on August 8 due to an non-isolable steam leak on one of the two steam supply lines to the turbine driven auxiliary feed water pump.
During this shutdown, the inspection of feedwater lines required by IEB 79-13 was conducted.
Linear circumferential indications were found in the base metal in the vicinity of two pipe to safe end welds and two pipe to first elbow welds.
These findings were documented to the NRC in letters dated August 22 and 24,1979.
The NRC reviewed this event and concluded that the facility may be returned to power operations until October 31, 1979, based on the implementation of
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seven commitments documented in the NRC letter, dated August 25, 197.
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The inspector observed operations in the control room including shift turnovers and backshift and weekend activities.
a.
Instrumentation Control room process instruments were observed for correlation between channels and for conformance with Technical Specification requirements.
No unacceptable conditions were identified.
b.
Annunciator Alarms The inspector observed various alarm conditions which had been received and acknowledged. These conditions were discussed with shif t personnel who were knowledgeable of the alarms and actions required.
During plant inspections, the inspector observed the condition of equipment associated with various alarms.
No unacceptable conditions were identfied.
c.
Shift Manning The operating shifts were observed to be staffed to meet the operating requirements of Technical Specifications, Section 6, both to the number and type of licenses.
Control room and shift manning were observed to be in conformance with Techncial Specifications and site administrative procedures.
d.
Radiation Protection Controls Radiation protection control areas were inspected.
Radiation Work Permits in use were reviewed. and compliance with those documents, as to protective clothing and required monitoring instruments, was inspected.
There were no unacceptable conditions identified.
e.
Plant Housekeeping Controls Storage of material and components was observed with respect to preven-tion of fire and safety hazards.
Plant housekeeping was evaluated with respect to controlling the spread of surface and airborne conta-mination. There were no unacceptable conditions identified.
f.
Fire Protection / Prevention
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The inspector examined the condition of selected pieces of fire fighting equipment.
Combustible mate-ials were being controlled and were not found near vital areas. SelecccJ cable penetrations were examined j
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and fire barriers were found intact.
Cable trays were clear of debris.
g.
Control of Equipment During plant inspections, selected equipment under safety tag control were examined.
Equipment conditions were consistent with information in plant control logs.
h.
Instrument Channels Instrument channel checks were reviewed on routine logs.
An independent comparison was made of selected instruments.
No unacceptable conditions were identfied.
i.
Equipment Lineups The inspector examined the breaker position on all switchgear and motor control centers ir. accessible portions of the plant.
Equipment conditicia, were found in conformance with Technical Specifications and operating procedure requirements.
3.
Review of Plant Operations - Logs and Records During the inspection period, the resident inspector reviewed operating logs and records covering the inspection time period against Technical Specifications and administrative procedure requirements.
Included in the review were:
Shift Supervisor's Log 8/4 to 9/1/79
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Plant Incident Reports
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8/4 to 9/1/79 Jumper and Lifted Leads Log
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all active entries Maintenance Requests and Job Orders
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all active entries Safety Tag Log all active entries
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Plant Recorder Traces daily during control room
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surveillance Plant Process Computer Printed Output
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daily during control room surveillance Key Control Log 8/4 to 9/1/79
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Night Orders dailydggingyyntrglroom
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Plant Incident Reports
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daily during control rocm surveillance
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The logs and records were reviewed to verify that: entries were properly made; entries involving abnormal conditions provide sufficient detail to communicate equipment status, deficiencies, corrective actione restoration and testing; records are being reviewed by management; operating orders do not conflict with the Technical Specifications; logs and incident reports detail no violations of Technical Specifica'.:on or reporting requirements; logs and records are maintained in accordance with Technical Specification and Administrative Control Procedure requirements.
Several entries in these logs were the subject of additional review and discussion with licensee personnel.
No unacceptable conditions were identified.
4.
Licensee Event Reports (LER's)
The inspector reviewed the following LER's to verify that the details of the event were clearly reported, including the accuracy of the description of cause and adequacy of corrective action.
The inspector determined whether further information was required, and whether generic implications were involved. The insrector also verified that the reporting requirements of Technical Specifications and Station Administrative and operating procedures had been met, that appropriate corrective action had been taken, that the event was reviewed by the Plant Operations Review Canmittee, and that the continued operation of the facility was conducted within the Technical Specification limits.
Unit 1:
79-04, Updated report, jammed control rod drive mechanism, control rod location 22-07, due to a price of a previously failed neutron source holder becoming wedged between the drive guide cap and indr~ tube.
79-18, Standby liquid control system, low concentration of sodium pentaborate solution' caused by a calculational error and degraded reagent.
79-19. Excessive leak rate of ten primary containment isolation valves found during local leak rate testing.
79-20, Set point drift of one of four reactor vessel low water level instruments which initiate a Group 1 primary containment isolation.
79-21, Failure of one of four reactor vessel low water level instru-ments which initiates ECCS logic to trip caused by foreign metalic particles binding the magnet shaft assembly of the Yarway Model 4418C differential pressure instrument.
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79-22 and 23, Failure of primary containment isolation valve to close.
The valve, the two-inch pressure suppression chamber vent bypass valve, was shut manually.
At a later time the valve was disassembled and foreign material removed from the valve internals.
79-24, Set point drift, one of two refuel floor high radiation monitors.
Unit 2:
79-14 Thrcugh wall crack in the valve block of one of three charging pumps.
79-15, Unt /entified leakage into the containment exceeded one gallon per minute due to body to bonnet leakage on the isolation valve for one of the two power operated pressurizer relief valves.
79-16, Set poir' drift of pressurizer pressure channel actuating one c
of two pressurizer power operated relief valves.
79-17, Inoperability of one of two motor driven auxiliary feedwater pumps due to the failure of a pump bearing.
Bearing failure was caused by the contamination of bearing oil with water.
79-18, Inoperability of the Control Element Assembly Motion Inhibit interlock due to the drift of the out of sequence scanner power supply.
79-19, Inoperable Emergency Diesel Generator 120 due to the inability to remotely trip the generator output breaker because of a loose line connection in serias with the breaker trip coil.
79-19/3X, Inoperable Emergency Diesel Generator 13U due to a leaking fuel injection pump.
79-20, Failure to monitor linear heat rate as a surveillance due to the plant process computer being taken out of service resulting in the incore detector monitoring system being inoperable.
Reactor power was reduced and linear heat rate surveillance was monitored by one power ratio calculator utilizing the excore detector system.
79-21. Inoperable RPS, Channel A, Reactor Coolant Flow Low Trip due to intermittently high signal.
79-22, Inoperable position indication CEA 64 due to erratic indication caused by a loose cable connector.
CEA top limit indication remained operable.
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79-23, Station Cattery 2018 made inoperable when seismic bracing was removed for the replacement of two cells.
5.
Review of Periodiu and Special Reports Upon receipt, periodic and special reports submitted by the licensee pursuant to Technical Specification 6.9.1 and 6.9.2 were reviewed by the inspector.
This review included the following considerations:
the report includes the information required to be reported by NRC requirements; test. results and/or supporting information are consistent with design predictions and performance specifications; planned corrective action is adequata for resolution of identified problems; determination whether any information in the report should be classified as an abnormal occurrence; and the validity of reported information. Within the scope of the above, the following periodic reports were reviewed by the inspector:
Monthly Operating Reports - July,1979.
6.
Steam Line Leak and Repai*s During plant operation on August 8,1979, a leak was feand on a 4-inch steam line which supplies a turbine driven auxiliary feedwater pump.
The break occurred at a location where a 4-inch weldolet is welded to the 12-inch steam dump line.
The steam dump line is supplied from the 34-inch main steam line and could not be isolated.
This made it necessary to shut the plant down for repairs. The shutdown commenced at 0600 hours0.00694 days <br />0.167 hours <br />9.920635e-4 weeks <br />2.283e-4 months <br />, August 8,1979, the plant was in Mode 5 at 0500 hours0.00579 days <br />0.139 hours <br />8.267196e-4 weeks <br />1.9025e-4 months <br />, August 9, 1979.
The repair was made by removing approximately two feet of the 12-inch schedule 60 steam dump piping containing the crack in the weld joining tne weldolet to the pipe.
A visual inspection shows the crack to be located on or near the heat affected zone at the top of the weld where it joins the 12-inch pipe.
It appeared that the crack initiated at the heat affected zone and propagated downward in an angular direction to the inside of the pipe resulting in a thru-wall fracture approximately 6-inches long.
The licensee is making arrangements for metallographic examination of the failure.
Prior to the failure, the licensee had monitored vibration in this section of pipe.
It was detertined that the vibration could be significantly reduced by draining the condensation from the steam line low point.
An investigation into the original design called for a piping run which continuously sloped to the system low point, the steam driven auxiliary feedwater pump.
A design change to relocate a steam isolation valve called for lowering that valve.
This caused a loop seal in the steam line.
Condens; on in this loop seal may resanate with steam
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line flow causing the vibration.
The licensee's analysis indicated the loop seal may be kept dry by blowing it down once an operating shift.
The licensee's analysis and corrective action will be reviewed during future inspection.
7.
Steam Generator Feedwater Nozzles and Piping During the August 8 plant shutdown, the licensee inspected the steam generator nozzle to safe end and safe end to feedwater pipe welds by radiography as required by IE Bulletin 79-13.
Cracking was found in the heat affected zone of the two safe end to pipe welds and the next pipe to 90 elbow welds.
This cracking was described in a letter to the NRC dated August 22, 1979.
By letter dated August 25, the NRC allowed the reactor to be returned to operation provided that seven licensee commitments documented in that letter were implemented.
The inspector verified the installation of monitoring equipment described in licensee letters (2), both dated August 24, 1979.
The installation and monitoring procedures used during plant startup are contained in a test procedure dated August 27, 1979.
This procedure implemented comitments numbers 1, 2, 6, and 7 of the August 25 NRC letter.
Special precedure 79-2-11, Revision 0, Char.ge 2, dated August 29, 1979, provides for plant operation of the reactor steam generating system modified by the addition of the monitoring instrumentation installed on feedwater lines.
This procedure implements comitments numbers 2, 3, and 7 of the August 25 NRC letter.
Work control procedures, Job Orders 2-466-79, 2-468-79, and 2-469-79, involved with the installe. tion of this instrumentation was inspected.
The implementation of requirements for monitoring leak detection equipment required by commitments 3 and 6 of the August 25 NRC letter and procedure 79-2-11 was verified by the inspector.
No unacceptable items were identified.
8.
Exit Interview At periodic intervals during the course of this inspection, meetings were held with senior facility management to discuss inspection scope and findings.
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