IR 05000010/1980023
| ML19350A238 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 02/02/1981 |
| From: | Jordan M, Key W, Reimann F, Spessard R, Tongue T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML19350A236 | List: |
| References | |
| 50-010-80-23, 50-10-80-23, 50-237-80-25, 50-249-80-30, NUDOCS 8103130245 | |
| Download: ML19350A238 (10) | |
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U.S. NUCLEAR REGULATORY COMMISSION
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OFFICE OF INSPECTION AND ENFORCEMENT
REGION III
Reports No. 50-10/80-23; 50-237/80-25; 50-249/80-30 Docket Nos. 50-10, 50-237, 50-249 Licenses No. DPR-02, DPR-19, DPR-25 Licensee:. Commonwealth Edison Company Post Office Box 767 Chicago, IL 60690 Facility Name: Dresden Nuclear Power Station, Units 1, 2 and 3 Inspection At: Dresden Site, Morris, Illinois November 15 - December 31, 1980 Inspection Conduct
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Inspectors:
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Approved By:
R. L. Spe / ard, Chief M / f/
Reactor Projects Section 1 Inspection Summary Inspection on November 15 - December 31, 1980 (Reports No. 50-10/80-23; 50-237/80-25; 50-249/80-30)
Areas Inspected: Routine, unannounced, resident inspection of operational safety verification, montbly maintenance observation, monthly surveillance observation, plant trips, IE Bulletin followup, Immediate Action Letter followup, inspection during long-term shutdown, preparation for refueling, Licensee Event Reports, and a special inspection of Scram Discharge Volume Continuous Monitoring System. The inspection involved a total of 192 inspector-hours onsite by four NRC inspectors, including 45 incy
.or-hours onsite during off-shifts.
Results: Of the ten areas inspected, there were no items of noncompliance in nine areas. There was one item of noncompliance (Severity Level VI -
failure to follow procedure, paragraph 5) in one area.
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DETAILS Section I 1.
Persons Contacted Licensee
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Scott, Station Superintendent
- R. Ragan, Operations Assi-tant Superintendent J. Ecingenburg, Maintenance Assistant Superintendent
- D. Farrar, Administrative Services and Support Assistani Superintendent
- J.
Brunner, Technical Staff Supervisor
- C. Sargent, Unit 1 Operating Engineer
- J. Wujciga, Unit 2 Operating Engineer
- M. Wright, Unit 3 Operating Engineer
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Holland, Engineer D. Adam, Waste Systems Engineer G. Myrick, Rad-Chem Supervisor B. Sanders, Station Security Administrator B. Zank, Training Supervisor H. Cobbs, QA Inspector Nortec Corporation R. Sinclair, QA Manager The inspector also talked with and interviewed several other licensee employees, including members of the technical and engineering staffs, reactor and auxiliary operators, shift engineers and foremen, electrical, mechanical and instrument personnel, and contract security personnel.
- Denotes those attending one or more exit interviews conducted on November 26, December 17, and December 31, 1980.
2.
Operational Safety Verification The inspectors observed control room operations, reviewed applicable logs and conducted discussions with control room operators during the period of November 15 - December 31, 1980. During one discussion, the inspector determined that the operator had no knowledge of the activities of two Commonwealth Edison Company non-station staff elec-tricians who were performing electrical work on the back panel portion of panel 8 while the unit was operating. Further inspection into the activities revealed that no apparent violation of work controls had occurred and that one member of the shift engineer's shift staff was following the work as it progressed. During subsequent discussions of this situation with station management, it was agreed that the unit operator should have knowledge of ongoing work which could affect his unit, and that increased awareness would be achieved.
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The inspector verified the operability of selected emergency systems, reviewed tagout records and verified proper return to service of affected components. Tours of Units 2 and 3 reactor buildings and turbine buildings were conducted to observe plant equipment conditions, including potential fire hazards, f.uid leaks, and excessive vibrations and to verify that maintenance requests had been initiated for equip-ment in need of maintenance. The inspectors by observation and direct interview verified that the physical security plan was being implemented in accordance with the station security plan. One security guard forwarded allegations to the inspect (<
that certain security plan requirements were not being properly observed. The inspector reported these allegations to Region III security specialists, who will followup on these allegations.
The inspector observed plant housekeeping / cleanliness conditions and verffied implementation of radiation protection controls. During the period of November 15 through December 31, 1980, the inspectors walked down the accessible portions of the Unit 2 and 3 Core Spray and LPCI systems to verify operability. During these tours it was noted that there were no working lamps in the local valve operators in the Unit 2 east ECCS pump room. Subsequent review of licensee requirements and discussions with licensee management established that, although there are no apparent regulatory requirements to maintain these lamps oper-able, maintainir.g their operability does constitute good engineering practice. The licensee has stated that increased efforts will be applied to relamping of local valve controls.
These reviews and observations were conducted to verify that facility operations were in conformance with the requirements established under Technical Specifications, 10 CFR, and administrative procedures.
No items of noncompliance were identified.
3.
Monthly Maintenance Observation Station maintenance activities of safety related systems and com-ponents listed below were observed / reviewed to ascertain that they were conducted in accordance with approved procedures, regulatory guides and industry codes or standards and in conformance with technical specifications.
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The following items were considered during this review:
the limiting conditions for operation were met while components or systems were removed from service; approvals were obtained prior to initiating the work; activities were accomplished using approved procedures and were inspected as applicable; functional testing and/or calibrations were performed prior to returning components or systems
'.o service; quality control records were maintained; activities were ascomplished by qualified personnel; radiological controls were implemented; and, fire prevention controls were implemented.
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Work requests were reviewed to determine status of outstanding jobs and to assure that priority is assigned to safety related equipment maintenance which may af fect system performance.
The following maintenance activities were observed / reviewed:
Unit 3 B LPCI Heat Exchanger Unit 3 Diesel Generator Unit 2/3 Diesel Generator Following completion of maintenance on the Unit 3 Diesel Generator, the inspector verified that this system had been returned to service ptsperly.
No items of noncompliance were identified.
4.
Monthly Surveillance Observation The inspector observed technical specifications required surveillance testing on the Units 2 and 3 HPCI Auto Isolation and verified that testing was performed in accordance with adequate procedures, that test instrumentation was calibrated, that limiting conditions for operation were met, that removal and restoration of the affected components were accomplished, that test results conformed with technical specifications and procedure requirements and were reviewed by personnel other than the individual directing the test, and that any deficiencies identified during the testing were properly reviewed and resolved by appropriate management personnel.
The inspector also witnessed portions of the following test activities:
Unit 2 SRM and IRM's and Unit 3 LPCI valve operability.
No items of noncompliance were identified.
5.
Plant Trips On December 2, 1980, Unit 2 tripped automatically as a result of a turbine trip which was caused by a turbine high vibration signal. The licensee is still determining the cause of the high vibration signal.
No apparent adverse safety concerns were identified as a result of this trip.
I On December 4, 1980, three trips of Unit 2 occurred as described below:
a.
The unit tripped automatically as a result of valid Intermediate Range Monitor (IRM) Hi Hi alarms during startup. The cause of the Hi Hi condition was an unplanned increase in power level induced by a decrease in moderator temperature. The modera'.or temperature decrease resulted from the operator opening several bypass valves to supply transient steam supply requirements for conducting a HPCI turbine surveillance (bypass valves are opened to balance
steam flow without necessitating power level changes to maintain-4-
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stability of pressure regulator control).
It appears that the bypass valves were ramped open quickly enough to induce a power change which tripped the IRM's before remedial operator action could stabilize power level. The cause of the trip is operator error. No apparent adverse safety concerns were identified as a result of this trip.
b.
The unit tripped automatically during plant startup when the mdde switch was inadvertently placed in the RUN mode, rather than the STARTUP/ HOT STANDBY mode. The cause of the trip was that the supervised operator in training who was conducting the startup was not familiar with the mechanical resistance of the mode switch.
At the appropriate time in the startup, the operator in training attempted to place the mode switch in STARTUP/ HOT STANDBY from the REFUEL position. He apparently applied excessive torque to the mode switch causing it to rotate through STARTUP and into RUN position. No apparent adverse safety concerns resulted from this trip.
c.
The unit was tripped during normal startup from approximately 250 psig reactor pressure. The manual trip was initiated to terminate water level and power level instabilities resulting from the uncontrolled cycling from full closed to full open, of the turbine bypass valves which resulted from failure to follow the requirements of Dresden Startup Procedure DGP l-1.
Subse-quent investigation of the events leading up to the trip with operating personnel involved revealed that shift personnel assigned to the unit startup became involved in numerous startup and outage related activities and that several changes of responsible personnel were made for meal reliefs during complex startup evolutions. As a result of these activities, the initial pressure regulator setpoint was not maintained 50 psig greater than reactor pressure, as required by DGP l-1.
At approximately 250 psig, a repair outage on the main condenser mechanical vacuum pump was cleared and an unidentified individual started the pump.
When the main condenser vacuum increased to 7" Hg vacuum, the turbine bypass valve close interlock cleared. Because the initial pressure regulator was left at its low setpoint (150 psig) a 100 psi pressure error signal caused operation of all nine bypass valves. Successive actuation and clearing of the 7" Hg vacuum interlock appears to have caused the rapid bypass valve cycling which occurred. The operators attempted to diagnose the cause of the problem, and, when the cause was not immediately apparent, a manual trip was initiated. The failure to follow approved Startup Procedure DGP l-1 as previously described is a violation of the unit Technical Specifications.
(237/80-25-01)
Manual trips of Unit 2 were initiated on December 11 and 12,1980,
'in response to valid alarms from the newly installed Scram Discharge Volume Continuous Monitoring System (CMS). The CMS alarms, although valid considering the design and installation of the system, were apparently not indicative of a condition adverse to safety. The system o-5-
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design required that the control room alarm actuate at ik" of water accumulation in the SDV. The combined effects of the conservative selection of Ik" as the alarm setpoint and the placement of the CMS sensors on a low point in the SDV piping resulted in indications of excessive water accumulation in response to small amounts of leakage into the SDV from leaking scram valves. The licensee and NSSS vendor re-analyzed the alarm setpoint requirements, and reset the CMS high level alarm to 2\\".
No apparent adverse safety concerns resulted from these trips. CMS operability is further discussed in Details,Section II of this report.
6.
IE Bulletin Follownp, During the inspection period, the inspector verified that the requirements of IE Bulletin 80-17, including Supplements 1, 2 and 3 were complied with during those periods when the Scram Discharge Volume Continuous Monitoring System was not in service (as described in paragraph 8 below).
7.
Regional Information Request The inspector responded to a regional request for failure information on certain canned rotor type pumps used in applications important to safety, and which may pose generic concerns. Although the Dresden Station uses canned rotor pumps in applications important to safety, the pumps employed are not of the same design as those of concern.
Additionally, no evidence of recurring failures of the nature cited in the request were apparent.
No items of noncompliance were identified.
8.
Immediate Action Letter On December 4,,1980, Region III issued an Immediate Action Letter to the licensee which provided the basis upon which Units 2 and 3 could continue to operate in view of operational difficulties experienced with the newly installed Scram Discharge Volume (SDV) Continuous Monitoring System (CMS), which was required by the NRC Confirmatory Order, dated October 2, 1980.
The causes of the CMS malfunctions have been addressed in Supplement 4 to IEB 80-17 and IE Information Notice 80-43, which was prepared by IE Headquarters with the assistance of Region III personnel. The inspector reviewed the licensee's actions in response to the Immediate Action Letter and has determined that the licensee is complying with its requirements with the exception of Items 4 and 5.
Complete compli-ance with Items 4 and 5 requires completion of the testing requirements of Supplement 4 to IEB 80-17.
Closeout of the requirements of Items 4 and 5 of the IAL will be addressed in a future inspection report which closes out the licensee's response to Supplement 4.
(237/80-25-02; 249/80-30-01)
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In addition to the above actions, NRC dispatched a consulting expert in the field of UT testing to the site on December 15, 1980, to evaluate the theoretical and engineering aspects of the "as installed" CMS, to aid in determining the capability of the system to perform its intended function. At the conclusion of his interviews with the licensee, the inspector was informed that the as installed system should be capable of performing its design function provided that the testing requirements of IEB 80-17, Supplement 4 could be successfully accomplished.
No items of noncompliance were identified.
9.
Inspection During Long Term Shutdown The inspector observed control room operations, interviewed operations personnel and the Unit 1 Operating Engineer, and toured accessible areas and portions of the unit exterior area to assess equipment condi-tions, plant conditions, and radiological controls including potential environmental releases. The inspector, by observation, and direct interview verified that the physical security plan was being implemented in accordance with the station security plan.
No items of noncompliance were identified.
10.
Media Interest in Dresden Operations Media interest in the status of the Unit I decontamination project, including public hearings and NRC safety evaluation, were received from a local newspaper correspondent. Questions regarding the Unit I reactor vessel inservice inspection were also received. The questions were referred to the regional Public Affairs Office for disposition or answered by the inspector with regional concurrence.
The inspector also received media questions regarding Scram Discharge Volume Continuous Monitoring System operability problems via the region.
The inspector supplied the requested information.
11.
Preparation for Refueling The inspector, through direct observation and interviews with refueling and management personnel, verified that new fuel inspection activities were being accomplished in accordance with approved procedures and NSSS vendor requirements, that the new fuel was being received, handled, and stored according to approved procedures, and that cleanliness requirements were being adhered to when handling and storing new fuel.
Interviews were conducted to verify that refueling personnel were familiar with refueling procedures.
While observing new fuel inspections, the inspector noted hand written changes had been added to the New Fuel Inspection checklist. There was no indication of onsite review (D.O.S.R.) authorizing the changes, plus the foreman in charge and QC inspector present were unaware of any such approval. The procedure was not available at the job site.
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Subsequently, the inspector found that the New Fuel Inspection pro-cedure had been modified and approved (D.O.S.R.) which included the check off list prior to the inspection.
Immediate licensee action was to attach a copy of the onsite review (D.O.S.R.) approval sheet to each check off list for each fuel element. Later discussions with the QC inspector and foreman indicated that they were aware of these changes; however, this was not the case on the day the NRC inspector made the inquiry. This is not a noncompliance item; however, it is of concern to the inspector since it is incumbent upon first line supervisors and QC and QA inspectors to be cognizant of the most recent procedures, especially those which have hand written changes to ensure their validation by proper approval.
This matter was discussed with licensee management personnel during the exit meeting on December 31, 1980, and the inspector suggested that all supervisors be reminded of their responsibilities to be knowledgeable of the most recent procedures when performing a job and, especially, with respect to properly approved changes. Additionally, the inspector suggested that supervisors have the most recent proce-dures available at the job site in the event of problems or questions which could arise. This matter is unresolved and will be reviewed during a future inspection.
(237/80-25-03)
No items of noncompliance were identified.
12.
Licensee Event Reports Followup The inspector conducted a special inspection with respect to the causes and circumstances surrounding the unplanned heatup and repressurization of Unit 3 that occurred on December 20-21, 1980 while the unit was in cold shutdown. The results of this inspection will be oocumented in IE Inspection Report No. 50-249/80-29.
13. Offsite Activities On November 20, 1980, the inspectors attended a public hearing at the Grundy County Court House in Morris, Illinois. The inspectors were requested to attend this hearing to support NRC staff activities as required in the hearing which was held to consider several petitions
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filed by intervenors in regard to the safety of proposed spent fuel pool storage expanded storage capability by adding high density spent fuel storage racks.
During the inspection period, the resident inspectors attended separate two-week training courses at the NRC Training Center in Chattanooga, Tennessee.
14. Exit Interview The inspectors met with licensee representatives (denoted in Para-graph 1) throughout the month and at the conclusion of the inspection on December 31, 1980 and-summarized the scope and findings of the inspection activities. The licensee acknowledged the inspectors findings.
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Section II Prepared by W. J. Key Reviewed by D. H. Danielson, Chief
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Engineering Support Section 2 Installation of Continuous Water Level Monitoring System for Scram Discharge Volume (SDV)
On December 1, 1980, the licensee completed installation of an ultrasonic continuous monitoring system (CMS) on the scram discharge volume (SDV) of Units 2 and 3.
On December 2, 1980, following a reactor scram of Unit 2, it was discovered that the installed CMS had failed to alarm as expected on a high, 1.25" water level.
On December 4, 1980, as Unit 2 was heating up, another reactor scram occurred, again the high water level alarm failed to sound in the ccatrol room; however, the alarm sounded about 10-15 minutes later as the SDV header was draining.
Prior to installation of the CMS, no procedures had been developed, nor had any in position testing been performed.
Following each alarm failure, the licensee investigated the cause and deter-mined that the transducers were inadequately coupled to the SDV headers.
The licensee contacted the instrument manufacturer, Nortec Corporation, for personnel to assist with the installation, calibration, and testing of the monitoring system.
On December 5, 1980, an NRC RIII staff inspector was dispatched to the site i
to examine the installed system and observe corrections being made. During his examination, the inspector observed the following.
a.
The instruments are located approximately 200' from the transdacer placement.
b.
The transducers were located approximately 4-5' apart on the SDV headers.
c.
The transducers were coupled to the SDV headers with hose clamps.
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The coaxial cables were coiled around the piping and run together to the instruments; excess cable was coiled and hung in front cf the irstruments.
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A meeting between the licensee and the instrument manufacturer with NRC inspectors present, was held to determine what acticns should be taken to make the installed equipment operable and dependable.
It was determined that the following actions were to be taken.
Shorten all coaxial cable, remove all loops around piping and hanging a.
in front of instruments.
b.
Separate coaxial cable leading from transducer placement.
Design a new method of coupling the transducers to the reference c.
standard, and the SDV headers.
d.
Peak the installed equipment as found and final.
Check correlation of maximum back wall reflection from the pipe and e.
the water reflection.
f.
Perform heat and vibration test on the reference standard, and in place on the SDV.
Licensee and manufacturers personnel examined the installed equipment and started checking the 2.25 Mhz x 3/8" transducers installed.
It was deter-mined that better results were obtained by using 5 Mhz x.5" transducers.
All coaxial cables were run to the instruments without loops and by the most direct route, and all excess cable removed. The Rep-Rate switches of both installed instruments were synchronized by manufacturer personnel.
These corrections removed most of the spurious signals and crosstalk experienced with the earlier installation. The instruments were calibrated on a section of piping material the same as the SDV headers used as a reference standard, and trouble alarm and high water level alarms set in the control room.
The transducers were coupled to the SDV headers by using u-bolts and a 6" square x 1/4" plate with rubber backing in contact with the transducer.
With the instruments calibrated and the alarms in the control room set, the licensee conducted some single rod tests to check the control room alarms.
On December 10, 1980, following a reactor scram of Unit 2, the installed CMS alarm was sounded in the control room as expected.
In accordance with IE Supplement No. 4 to Bulletin No. 80-17, the licensee is developing operating, periodic, and calibration procedures, and collecting other information requested by the bulletin.
No items of noncompliance were identified.
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