IR 05000269/1979026
| ML19257D655 | |
| Person / Time | |
|---|---|
| Site: | Oconee, Mcguire, Susquehanna, McGuire  |
| Issue date: | 10/24/1979 |
| From: | Dyer J, Jape F NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML19257D636 | List: |
| References | |
| 50-269-79-26, 50-270-79-24, 50-287-79-26, NUDOCS 8002050260 | |
| Download: ML19257D655 (9) | |
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UNITED STATES
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NUCLEAR REGULATORY COMMISSION
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101 MARIETTA ST N.W., SUITE 3100 o$
ATLANTA, GEORGI A 30303
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Report Nos. 50-269/79-26, 50-270/79-24 and 50-287/79.o Licensee: Duke Power Company Post Office Box 2178 Charlotte, North Carolina 28242 Facility Name: Oconee Nuclear Station License Nos. DPR-38, DPR-47 and DPR-55 Inspection a' Oconee Nuclear Station near Seneca, South Carolina Inspector:
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Da(e Signed f
Approved by:
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yer, Ac; ing Section Chief, RONS Branch D'at'e Sffned SUM'iARY Inspection on September 4-28, 1979 Areas Inspected This routine unannounced inspection involved 61 inspector-hours onsite in tne areas of maintenance, the August 25 earthquake, plant operation and emergency power system maintenance outage.
Results Of the four areas inspected, no apparent items of noncompliance or deviations were identified in three areas; two apparent items of noncompliance were found in one area. Infraction - failure to control procurement of reactor vessel head 0-Ring (Paragraph 5) and Infraction - failure to follow maintenance procedure for installing reactor vessel head 0-Rings (Paragraph 5).
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DETAILS 1.
Persons Contacted Licensee Employees Duke Power Company
- J. E. Smith, Station Manager
- J. M. Davis, Superintendent of Maintenance
- J. N. Pope, Superintendent of Operations
- R. M. Koehler, Superintendent of Technical Services
- R. T. Bond, Licensing and Projects Engineer R. C. Adams, I&E Engineer
- J. Brackett, Senior QA Engineer H. W. Morgan, Shift Supervisor J. W. Herring, Shift Supervisor T. D. Patterson, Shift Supervisor G. B. Jones, Shift Supervisor D. W. Yoh, Shift Supervisor L. C. Evans, Assistant Shift Supervisor D. L. Gordan, Assistant Shif t Supervisor R. T. Scott, Assistant Shift Supervisor W. R. Pollard, Assistant Shift Supervisor D. F. Roth, Assistant Shift Supervisor W. A. Horton, Assistant Shift Supervisor F. E. Owens, Assistant Shift Supervisor D. J. Phillips, Assistant Shift Supervisor C. M. Sheridon, Assistent Shift Supervisor E. G. LeGette, Assistant Shif t Supervisor O. C. Kohler, Assistant Shift Supervisor P. J. Chudzik, Assistant Shift Supervisor E. A. Force, Assistant Shift Supervisor S. M. Pryor, Assistant Shift Supervisor L. L. Howell, Assistant Shift Supervisor R. Knoerr, E&E Support Engineer B. Millsaps, Mechanical Maintenance Engineer C. T. Yongue, Station Health Physicist T. Harrison, Maintenance Supervisor Other licensee employees contacted included 4 technicians, 20 operatcrs, 3 office personnel, 4 technical support personnel and 4 maintenance craftsmen.
Duke Power Compay - Lee Station
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R. Holliday, Plant Manager R. E. Hadden, Plant Engineer
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- Attended exit interview
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Exit Inte'rview The inspection scope and findings were summarized on September 7, 14 and 27, 1979 with those person indicated in Paragraph 1 above.
The Station Manager acknowledged the items of noncompliance regarding the reactor vessel head 0-Rings, but expressed the view that the 0-Rings are simply a gasket or packing.
In his view, the 0-Rings are " backed up" by a Technical Specification limit on RCS leakage.
Hence, the 0-Rings are of less safety significance than they would be if there was no leakage limit.
The inspector restated that reactor vessel head 0-Rings are safety-related and as such full compliance with the approved quality assurance program is required.
Further inspection findings were discussed without significant comment.
3.
Licensee Action on Previous Inspection Findings Not inspected.
4.
Unresolved Items Unresolved items were not identified during this inspection.
5.
Reactor Vessel Head 0-Rings:
Unit 1 On August 28, 1979, Unit I was shutdown due to RCS leakage in excess of Technical Specificat. ion limits.
Leaking valves were repaired and on September 2, 1079, a leak was noted at the reactor head flange during inspection prior to returning to power. The vessel head was subsequently removed and the 0-Rings were inspected on September 8, 1979.
The inspection revealed that the clips that hold the 0-Rings in place were improperly installed.
See Figures 1 and 2.
Because of the improper installation of the clips, the screw heads extended below the 0-Rings when compressed. This resulted in some coining on the reactor vessel flange.
Both B&W and Duke Power Company personnel concluded that the coining was not significant enough to warrant repair.
Further investigation revealed that incorrect 0-Rings were installed. The discrepancies were :
1) the 0-Rings had 16 slots for the retainer clips instead of 12, and 2) the OD of the 0-Ring was 0.500 inches instead of 0.455 inches.
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l871 339 Procurement of Incorrect 0-Rings a.
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The incorrect 0-Rings were purchased by Duke Power Company through purchase order No. C 60920, dated July 12, 1979. The order was placed with United Aircraft Products (UAP) in 1977.
UAP supplied DPC a
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s-3-drawing, No. U 701307-1,2, for verification. The drawing was approved by DPC on September 12, 1976 and returned to UAP for manufacture of the 0-Rings.
The approved drawing was incorrect in that it stated that 16 equally spaced slots (correct dimensions of each slot war given) were to be provided for both the inner and outer 0-Rings.
An 0-Ring with 16 equally spaced slots will align with only 4 of the 12 retainer clips.
Also, the drawing specified that the OD of the 0-Rings was to be 0.500 inches instead of 0.455 inches.
The material speci#ied for the 0-Rings was silverplated nuclear grade Inconel 718.
The original 0-Rings, supplied by B&W were silverplated SA-213 type 304 stainless steel, and were 0.500 inches OD. When the material was changed to Inconel, the OD was also reduced to 0.455 inches.
The operational quality assurance program, described in DUKE-1, and implemented by Section 4.5 of the Administrative Policy Manual (APM)
requires measures to be taken to ensure accuracy of purchase orders and that the procured materials, parts, or components, as delivered, are of the quality required for the intended service.
The failure to exercise the necessary measures to ensure accuracy of this purchase order is considered to be an infraction against 10 CFR 50 Appendix B, Criterion V, Instructions, Procedures, and Drawings (50-269/270/280/
79-26-01).
b.
0-Rings Installation in Unit 1 The 0-Rings were installed September 24, 1978 under Work Request 53791 using maintenance procedure MP/0/A/1150/09.
The reactor vessel head was installed September 26, 1973 under Work Request 53799 using main-tenance procedure MP/0/A/1150/2A. The inspector reviewed these records and found that MP/0/a/1150/09 contained the following statement:
11.1.5 Lift and hold 0-Ring against seal surface and slide clips into perforation in o-rings.
Tighten retaining screws.
Repeat for the other o-ring.
This step in the procedure was signed-off.
However, on September 8, 1979 an inspection of the 0-Rings and the reactor vessel flange, made by B&W and DPC personnel revealed the 0-Rings were improperly installed.
Of the 12 retainer clips on the outer 0-Ring, one was missing, one was inserted into the slot correctly, see Fig.
I and the remaining 10 were incorrectly installed under the 0-Ring (see Fig 2.).
The inner 0-Ring had 2 clips installed correctly in the slots, one was tissing and the other 9 were installed under the o-ring, incorrectly.
A licensee representative explained that the three clips that were missing were not installed during the outage. The screws that support the clips had been broken-off some time ago.
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Technical Specification 6.4.1 e.
requires maintenance to be accom-plished using written procedures with appropriate check-off lists and instructions. Failure to follow MP/0/A/1150/09 is considered to be an infraction.
(50-269/79-26-02) The improper installation of the 0-Rings is believed to be the cause of the reactor coolant leak that was detected on September 2, 1979.
The licensee reported to the inspector that all of the improper 0-Rings onsite have been destroyed to alleviate a future problem.
Also the inspector questioned the status of 0-Rings on the other Oconee Unit.
Licensee management reported that the 0-Rings on Unit 2 are uncertain. However, the reactor coolant system is not leaking and therefore the 0-Rings are considered acceptable. Unit 3 is believed to have 0-rings of the origingal design.
These were installed in May 1979.
The inspector interviewed the maintenance foreman respon-sible for the Unit 3 0-Rings.
He participated in the work and is familiar with the correct installation procedure.
The inspector concurs with the belief that the 0-Rings in Unit 3 are correctly installed.
6.
Temblor A tremor was experienced on August 25, 1979 that was felt by personnel at the Oconee Nuclear Station.
The control operators and shift supervisors logs noted that at 2132 hours0.0247 days <br />0.592 hours <br />0.00353 weeks <br />8.11226e-4 months <br /> on August 25 a slight earth tremor was felt.
EP/0/A.1800/9, Earthquake, was implemented.
Results were negative, no visible damage to the facility was identified.
The seismic instrumentation, located in Unit 1 tendon gallery and the Unit 1 cable spreading room was examined.
The equipment appeared to be in good condition. Results of recently performed periodic tests listed below were reviewed and the equipment is considered to be operable.
Test Title Date Tested IP/1/B/125/1, Strong Motion Accelerograph 8/20/79 IP/1/B/125/2A, 2G Peak Recording Accelerograph 7/05/79 7/09/79 8/22/79 8/22/79 IP/1/B/125/2B, 2G Peak Recording Accelerograph 7/03/79
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1P/1/B/125/3, Seismic Trigger (0.05G)
8/20/79
'ine trigger for the strong motion accelerograph is set to actuate the recording equipment at 0.01G or 3.34 on the Richter scale.
This system was not actuated by the tremor.
7.
Plant Operations The inspector reviewed plant operations at ascertain conformance with regulatory requirements, technical specifications and administrative 1871 341
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-5-directives.
The control room logs, shift supervisors logs and the removal and restoration record books for all three units were reviewed.
Interviews with a number of plant operations personnel were held on the day and night shifts.
Supervisor and control room operator actions were observed during the shift and at a shift change.
The actions and activities were conducted as pre-scribed in Section 3.08 of the Station Directives.
The number of licensed personnel on each shift met or exceeded the minimum required by Technical Specification C.l.1.3.
Operators were responsive to annunciator alarms and appeared to be cognizant of plant status.
The following areas were toured by the inspectors:
a.
Penetration Room, Unit 1 b.
Turbine Building c.
Auxiliary Building d.
Electrical Equipment Rooms Units 1, 2 and 3 Cable Spreading Rooms, Units 1, 2 and 3 e.
f.
Keowee Hydro Station Observations were made during the tours of housekeeping and cleanliness, ongoing activities, security, equipment status and radiation control prac-tices.
In general, housekeeping and cleanliness were found to be satisfac-tory.
Security and radiation control practices were adhered to during the periods of observation.
Fluid leaks were observed in the turbine building on secondary, non-safety related equipment.
Lock out tags on equipment required to be tagged were found as specified by Station Directive 3.1.1.
Within the areas inspected, no fire hazards were observed.
Also, during periods of observation the inspector verified the presence of an operator at emergency feedwater (EFW) pumps as required depending on the number of Units in operation. The inspector verified, through interviews, that the operator had been trained on the operation of the pump and that a direct communication link to each control room was available.
Communications checks are being performed on a shiftly schedule and appeared satisfactory.
A test is conducted twice each shift and results are docu-mented in the routine surveillance test procedure.
The training program for the EFW watchmen was reviewed and found satisfac-tory.
The men have a troubleshooting guide available to them at the watch station and a copy of the operating procedure.
8.
Keowee Maintenance Outage A planned maintenance outage for both Keowee Hydro Units (emergency power source for Oconee) was initiated at 0721 hours0.00834 days <br />0.2 hours <br />0.00119 weeks <br />2.743405e-4 months <br /> on September 22, 1979.
Technical Specification (TS) 3.7.2 authority is a 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> outage provided a Lee Station gas turbine generator is in operation providing emergency power to Oconee through the 100KV transmission circuit, separated from the grid and non-safety related loads.
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Following this outage, Keowee Unit I was to return to service while Keowee unit 2 would remain out-of-service for scheduled weld repair on the rotor.
TS 3.7.4 authorizes this outage for a maximum of 45 days. A Lee Station gas turbine generator plus the operable Keowee unit must remain in service during this outage. During this period the 4160 volt standby buses are to be energized from the Lee Station gas turbine generator and the operable Keowee unit is connected to the underground feeder.
The resident inspector visited the Lee Station on September 24, 1979 to verify compliance with the TS conditions.
During the visit, Lee Station Unit 6C was in operation, energizing the Oconee 4160 volt standby buses.
Lee Station Units 4C and SC were on standby, manually available if needed.
The operators at Lee Station had a current copy of the Oconee procedure OP/0/14/1/107/03, "10CKV Power Supply".
There were no items of noncom-pliance or deviations identified during this visit.
On September 25, 1979, at 0438 hours0.00507 days <br />0.122 hours <br />7.242063e-4 weeks <br />1.66659e-4 months <br />, Keowee Unit I was returned to ser-vice. An operational test was performed satisfactorily. An inspection of Keowee Unit 2 revealed that leakage through the wicket gates was too ex-cessive for the maintenance repair on the rotor.
Therefore, at 0922 hours0.0107 days <br />0.256 hours <br />0.00152 weeks <br />3.50821e-4 months <br /> on September 25, 1979 both Keowee Units were again removed from service to seal the Unit 2 wicket gates. During this outage, the Lee Station gas turbine generator tripped off-line as follows:
Elapsed Time-Event Date Time Tripped Time Recovered Minutes
9/26 0627 0653
2 9/26 0845 0930
3 9/26 1443 1501
On the first event, invoking TS 3.7.8 Oconee Power was not reduced.
On the second and third events, reactor power on Oconee Units 1 and 2, was reduced at 10% per hour.
(Oconee 3 was at coldshutdown during these events).
Events 1 and 2 were caused by a reverse power relay actuating the trip circuitry.
Event three occurred when the generator field ground detector relay initiated the generator lockout. The cause for these relays to actuate is under investigation by the licensee.
The inspector discussed the corrective action with licensee management following the first event. A procedure change was issued to require shut-down at normal rate (10% per hour) if the Lee Station gas turbine generator trips. This action was verified on the second and *hird event. Also, the licensee maintained a second Lee Station gas turbine generator on standby to pickup the 4160 volt standy buses if needed.
Keowee Unit I was returned to servicc at 2145 hours0.0248 days <br />0.596 hours <br />0.00355 weeks <br />8.161725e-4 months <br /> on September 27, An operational test was satisfactorily performed for this unit.
Inspection of Ke'; wee Unit 2 again revealed excessive leakage through the wicket gates, preventing the planned maintenance.
Both Keowee units were again removed
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-7-s from service at 1040 hours0.012 days <br />0.289 hours <br />0.00172 weeks <br />3.9572e-4 months <br /> on September 28, 1979. The licensee decided to delay repair on the Keowee Unit 2 rotor until a better me'. hod for sealing the wicket gates could be arranged.
So the third outage of both Keowee Units was to remove scaffolding and prepare both units for service.
At 0859 hours0.00994 days <br />0.239 hours <br />0.00142 weeks <br />3.268495e-4 months <br /> on September 29, 1979 the Lee Station gas turbine generator tripped off-line.
It was restored at 0909 hours0.0105 days <br />0.253 hours <br />0.0015 weeks <br />3.458745e-4 months <br />, for a 10 minute outage.
Reactor power at Oconee was reduced at 10% per hour during this 10 minute outage.
This trip was caused by the reverse power relay actuating the trip circiutry.
Both Keowee units were returned to service at 1209 hours0.014 days <br />0.336 hours <br />0.002 weeks <br />4.600245e-4 months <br /> on September 29, 1979.
Both were tested satisfactorily.
Within the areas inspected, no items of noncompl'.nce or deviations were identified.
9.
Liquid Waste Released Withcut Dilution Flow Concident with the Keowee Hydro unit outages, discussed in paragraph 8 of this report, the resident inspector discovered four liquid radiation waste releases were_made without the attendant dilution flow normally available through Keowee leakage. Discovery of these events came about during dis-cussions of the Keowee Hydro Station outages with licensee operations personnel on the evening shift of September 25, 1979.
Upon discovery, licensee personnel increased flow through the Keowee spill gates to provide dilution.
The event was immediately investigated by licensee management and a news release was issued by Duke Power Company on September 26, 1979.
The resident inspector ir formed licensee management that this event will be followed up by a radiation specialist inspector.
Attachnent:
Figures 1 and 2 1871 344
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I Figure 1 CORRECT 0-RING INSTALLATION REACTOR VESSEL HEAD
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m CLIP SLOT 0-RING
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Figure 2 INCORRECT 0-RING INSTALLATION REACT 0h VESSEL HEAD
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CLIP SLOT U-RING
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