IR 05000295/1990006
| ML20042G506 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 05/04/1990 |
| From: | Sands S NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20042G503 | List: |
| References | |
| 50-295-90-06, 50-295-90-6, 50-304-90-06, 50-304-90-6, NUDOCS 9005150008 | |
| Download: ML20042G506 (18) | |
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U.S. NUCLEAR REGULATORY COMMISSION
REGION III
Report Nos. 50-295/90006(DRP); 50-304/90006(DRP)
l Docket Nos. 50-295;:50-304 License Nos. DPR-39; DPR'-48 E
Licensee: : Commonwealth Edison Company
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P. 0. Box 767 Chicago, IL 60690
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Faciliti'Name: -Zion Nuclear Power Station, Units 1 and 2
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Inspection'At: ~ Zion, IL
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, Inspection Conducted: March 11 through April 14, 1990 E
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Inspectors:. J. D. Smith i
R. J. Leemon
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A. M. Bongiovanni J
~F. A. Maura j
L E. Murphy (NRC Consultant)
l Approved By:
nds, Acting Chief
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React Projects.Section 1A Date/-
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Inspection Summary Ins)ection from March 11 through April 14, 1990 (Report Nos. 50-295/90006 TUR)); 50 304/90006(DRPJ)-
Areas Inspected:
Routine, unannounced resident inspection of licensee action
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- on previcas inspection findings; summary of operations; safety.' verification
and engineered safety features system; monthly surveillance; monthly mdintenance; engineering and' technical support; emergency preparedness; training;' quality program effectiveness; and fuel moves.
LResults: 0f the 11~ areas inspected, no violations or deviations were 11dentified. During the previous inspection, a violation was issued-that l identified four examples in the failure to follow procedures. Similar problems.have_been identified during this inspection period in the area of surveillances and out-of-services. Since the-corrective action to the violation has not-been in place for a sufficient length of time to measure
- the effectiveness of the actions, an unresolved item was identified.
The performance of the Unit 1 control' room operators during a reactor startup was
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considered good. The startup was performed with operators-in-training:and
potential distractions in the Unit 2 control room area were halted by the
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Unit ~1 operators.. Good ALARA practices were noted by the inspectors with use of TV cameras to monitor work activities in the containment. The assessment of the licensee's thermal performance and maintenance activities by the offsite corporate assessment organization appeared effective in the identification of strengths and weaknesses.
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DETAILS 1.
Persons Contacted
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- T.. Joyce, Station Manager
- T. Rieck, Superintendent, Services-j E...
- W..Kurth, Superintendent, Production
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P. LeBlond, Assistant Station Superintendent, Operations-R. Johnson, Assistant Station Superintendent, Maintenance
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,J.; LaFontaine, Assistant Station Superintendent, Planning R. Budowle, Assistant Station Superintendent, Technical Services N. Valos, Unit'2.0perating Engineer-N W. Demo, Unit 1 Operating Engineer
- M. Carnahan, Unit 1 Operating Engineer E. Broccolo, Jr., Director of Performance Improvement
- E. Fuerst, Project Manager, Engineering and Construction
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.T. -Vandevoort, Quality _- Assurance Supervisor-
- C. Schultz, Quality Control Supervisor
- W. Stone, Regulatory Assurance Supervisor
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j W. T'Niemi,-Technical Staff Supervisor
R. Smith,' Security Administrator
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T. -Saksefski, Regulatory-Assurance W. Mammoser, PWR Projects
' *L..~ Bush, Regulatory Assurance
R. Abboud, Electrical Grou Leader n
J. Ceis, Systems Engineer DieselGenerator)
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' D. Cook, Master Mechanic
iG. Fanning,-Lead: Engineer,: Power Group
'I l7 J, T. O'Brien,. Engineer, Nuclear Engineering Department US NRCs
- M. C. Thompson, Human Factors Analyst
- Indicates persons present at the exit interview.
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The-inspectors also contacted other licensee personnel including members of the, operating, maintenance, security, and engineering-staff.
b 2.-
Licensee Actions on-Previous Inspection Findings (92701, 92702)
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a.
'information= Notice No. 89-77, Debris in Containment Emergency Sumps l
and Incorrect Screen Configurations q
On March 15, 1990, in response to Information Notice 89-77, the i
111censee conducted an inspection of the Unit 2 recirculation sump j
to determine if the screens and covers were installed and intact in
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accordance with the design drawings. The inspection, determined that all external covers and screens were installed according to the.
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design and the appropriate fasteners were in place.
The inspection revealed some slight damage to two of the screens. The wire mesh-
had bee.n' dented and slightly deformed with the space between the'
i mesh about 3/4 in square in one spot.
The design drawing specified
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1/2 in, square wire mesh.
The NRC resident inspectors were shown
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photographs and were satisfied that the external portions of the
. sump screens were acceptable.
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On March 17 and 19,1990, an inspection of:the internal areas of.
the sump was performed. No. debris was found in the sump and all
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internal screens were in place.
However, two fasteners designated
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'on the design drawing were found not. installed. Also, spaces-
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about 1 inch between the' individual screens were identified. The:
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y design drawings specified a space no larger than 1/8 inch. A work i
. request:was issued to correct the deficiencies. prior to the end of.
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- the outage..The inspectors determined that the licensee's actions
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were adequate.
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- Bulletin No. 89-02, Stress Corrosion Cracking of High-Hardness Type 410 Stainless Steel Internal Preloaded Bolting in Anchor Darling
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Model 5350W Swing Check Valves or Valves of Similar Design
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On April 7,1990, the retaining block stud broke during-disassembly of the residual heat removal (RHR) Loop C cold-leg injection-outboard
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[ Anchor Darling]- check valve, 2SI-90028. The: licensee noted pitting Idnd possible evidence of stress Corrosion cracking in the block i
stud.- 'On April 9,'during a subsequent inspection-of the RHR Loop D j
cold leg-injection inboard [ Anchor Darling] check valve, 2SI-9001C, e
the retaining block stud was found broken ~ Again, possible evidence of stress corrosion cracking was present. To date a total of
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seven inspections have been completed and two failed block studs
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-have been identified. The licensee originally committed to
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'l performing : inspections of' ten Anchor Darling check valves ~ each refueling outage;-however, due-to the two failed block studs, the licensee decided to~ inspect all 24 Unit 2 Anchor Darling check valves-during the present refueling outage.
The licensee also committed to complete inspections of five check valves on Unit 1-
-during.the current forced outage.
The five valves selected would
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not impact mid Loop operations or require full core off-load. This
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is'consideredanOpenItem(295/90006-01(DRP);304/90006-01(DRP))-
i pending the results of the remaining inspections.
1; 3.
Summary of Operations.
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Unit 1-a The unit was in cold shutdown to repair the "0" emergency diesel.
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. generator.(EOG). On March _1, 1990, the licensee had declared'an Unusual Event because of the inoperable "0" EDG'.
On March 12, 1990, at approxi-
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ma tely1 5:00 p.m. (CST), the licensee terminated the. Unusual Event when Unit 2 also reached cold shutdown.
On March'29, 1990, at approximately'
L12:15 p.m., Unit 1-was taken critical in preparation for returning the unit to service after repairs to the
"0" EDG were completed. During the outage, the 1A Main Steam Isolation Valve (MSIV)'was furmanited to E
eliminate steam leakage around the shaf t.
While at hot standby, the-
1A failed to meet the Technical Specification (TS) stroke time of five
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The reactor was manually shut down on March 30 at approximately 12:38 p.m. to test and troubleshoot the MSIV. Repairs to the 1A MSIV
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included lubrication and-packing adjustments.
The 1A MSIV was stroked successfully subsequent to the repairs while the unit was in hot shutdown
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(Mode 4). On April 3,1990, at approximately 12:53 a.m., Unit I was taken
critical.
The 1A MSIV again failed t.o stroke within five seconds. The
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' licensee made adjustments to the hydraulic bleed valve; however, the t
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1A MSIV did not meet the TS' stroke time, In addition to the MSIV-j F
problems a body to bonnet leak of approximately two drops per second t
was identified on the reactor coolant system (RCS) Loop D hot leg stop u
valve. -The unit was manually shut down at 6:10 p.m. on April 3,1990,
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and was placed'in cold shutdown to repair the 1A MSIV-and the RCS
Loop D stop valve. The unit remained in cold shutdown for the remainder F
of,the inspection period. The 1A MSIV and the RCS Loop D stop valve problems are further discussed in Paragraph 6.
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Unit 2 p
The unit' entered this inspection period in cold shutdown due to the a
inoperability of the "0" EDG.
On March 21,1990, the cycle 11 refueling outage officially started when the "0" EDG was declared operable.
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licensee completed a full core off-load on April 3,1990, and remained
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defueled for the remainder of the inspection period.
4.
Operational Safety Verification and Engineered Safety Features System Walkdown (71707 & 71710)
The inspectors observed control room operations, reviewed applicable
logs and conducted discussions with control room operators. - During i
these discussions and observations, the inspectors ascertained that the operators were alert, cognizant of plant conditions, attentive to. changes
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..in those conditions, and took prompt action when appropriate. The inspectors > observed two approaches to criticality on Unit 1 that were conducted by a trainee under direct observation of licensed operators..
The licensed operators reviewed the procedures, 'and actions to be taken L-for the evolution with~ the operators-in-training. The licensee's
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operators had good control of reactor startup as evidence.by one licensed
'i operator that requested the DCRDR modification work to stop on Unit 2 due
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to the potential distraction for the operator-in-training.
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The inspectors verified the operability of selected emergency systems, reviewed.tagout records and verified proper return to. service of. affected _
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components; Tours of the auxiliary and turbine. buildings were conducted to observe' plant equipment conditions, including potential fire' hazards, c
fluid leaks,_ and excessive vibrations and to verify that maintenance-
requests had been initiated for. equipment in need;of maintenance.
The
' inspectors by observation and direct interview verified that selected-physical security activities were being implemented in accordance with
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the station security plan.
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The inspectors observed plant housekeeping / cleanliness conditions and i
verified implementation of radiation protection controls. The inspectors walked down the accessible portions of the AC: electrical power system; DC electrical power system; reactor protection system; residual heat removal system;. containment and support system; engineered safety features system, radiation monitoring system; service water system; component cooling water system; main and auxiliary steam system; condensate, feedwater system; process sampling system; circulating water system; main generator system; diesel generator and auxiliaries system;
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plant air: system;' plant compressed gas system; plant heating, ventilation.
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and air conditioning 1 system; make-up demineralizer system; plant fire'
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protection system; fuel. handling system; and control room system to
. verify operability. The' inspectors also witnessed portions of the radioactive waste system controls associated with' radwaste shipments and barreling.
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'These reviews and observations were conducted to verify that facility
. operations were-in conformance with the requirements established by the-
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.TS, 10 CFR,'and administrative procedures. The inspectors had the j
following observations:
-a.
Improvements in Outage ALARA Practices During -the Unit _2. refueling outage, health physics (HP) technicians utilized TV. cameras to monitor work activities in the containment.
The cameras reduced radiation exposure to the HP staff, verified
that ALARA concepts were practiced during work activities, and i
provided assistance to the worker, when required.
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S@rtage of-Health Physics (HP) Technicians.
Due to a nationwide strike of some HP technicians in the nuclear-industry, the' station experienced a shortage of HP technicians.
'Although the HP' technicians at the Zion. station did not participate
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in the strike, the. station had planned for thirty HP technicians
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to support the' Unit 2 outage; however,~only twenty HP technicians were available. Since both units were currently in an outage, additional >HP. support was required.
Due to the shortage, the HP technicians were on twelve hour shifts with the possibility of 70 hour8.101852e-4 days <br />0.0194 hours <br />1.157407e-4 weeks <br />2.6635e-5 months <br /> work weeks. The residents are' monitoring the impact, performance, and effectiveness of'the technicians during the outage periods,
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c.
Out-of-Services
On March 15, 1990, anout-of-service-(00S)was'initiatedto isolate ~ the pressurizer liquid space sampling system to repair a packing leak.on valve, 1A0V-SS93508. The licensed shift L
supervisor (LSS) and-the auxiliary operator ~ (B-man) entered the Unit I containment to locate the necessary four valves.
While performing the 005 activity, valve locations designated on the 00S were noted as incorrect.
The B-man found the i
K location for the valves, however, did not correct the 00S card.
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sheet to identify the actual location of the valves. Unable to find the remaining two valves, the LSS and the B-man exited containment and reviewed the piping and instrumentation diagrams and the system line-up procedure. The review identified that one of the 00S valves, ISS-0602, was located
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in the Unit 2 horizontal pipe chase area. The LSS and the
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B-man entered the pipe chase area to continue the 00S'line-up.
The LSS located a sample system valve rack and alerted the
B-man.that valve ISS-0602 had been found. Neither the LSS nor the B-man read the valve tag completely and did not
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realize that the. valve was actually valve 2SS-0602. The
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B-man, closed volve 2SS-0602 and hung the 00S tag.- The.last
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valve for the 00S was found and placed in the 00S position.
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Later during the next shift, valve IA0V-SS9350B was identified
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as not isolated and subsequent investigation determined that
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valve ISS-0602 was not closed as required by the 00S.
The. root cause of this event was personnel error compounded.
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by an inadequate procedure.
The sample system racks for both
units were in close proximity and not-clearly labeled; however, i
the valve identification. tags clearly designate the appropriate f
unit. The LSS and the B-man failed to verify the valve'
Ji identification prior to manipulating the valve. The independent
verification, required by the 00S procedure was not properly accomplished since the LSS that located the valves also signed off as the independent reviewer. Another contributing factor
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was that the 005'did not list:the correct locations for the-
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valves. The LSS and the B-Man failed to correct the 00S sheets.
s upon identifying the discrepancies.
The licensee conducted a personnel error review board to
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determine the root cause and corrective actions. The corrective
. actions proposed by the licensee included an assessment for the use of an out-of-service editor. establishment of a data-base for valve locations, improved labels on components,.
lighting, and unique paint designation for each_ unit horizontal Jpipe chase and reemphasized the purpose of-independent'verifica-
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tion'during.00S activities.
On _ April 6,1990, at approximately:1:45.a.m., the 2B EDG
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auto-started due to a bus-undervoltage' caused when Bus 249 was taken out-of-service (00S). Unit 2 was defueled at the time of the event. The 2B EDG auto-started'when Bus'249 was de-energized with the DC control power still energized.
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The Emergency Notification System call was made at 2:15 a.m.
to the NRC.
The Bus 249 and the 2B EDG were being taken out-of-service for maintenance and. modification work involving the. installation of a synchronization checking relay
'The 00S did not include opening the knife switch that would have disabled the auto
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start feature-of the 28 EDG due to a bus undervoltage condition.-
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The 00S tags for the bus outage were written one shift prior to de-energizing the bus and 00S cards were placed on the EDG control switch and on the EDG output breaker in the Control Room without a second 00S authorization signature. The
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oncoming control room shift assumed that the 2B EDC was adequately' tagged out-of-service and four more DOS tags were i
prepared for the OSS on Bus 249.
The subsequent control room
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shift was not satisfied with the out-of-service job that was
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prepared by the previous shift and added ten more tags to the OSS and also assumed that the 28 EDG was adequately tagged out-of-service. The out-of-service was then initiated by 6 _
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- de-energizing Bus 249.- Therefore, when Bus 249 was.
.de-energized, the 2B EDG auto-started on a Bus 249 under-
- i voltage condition since the DC start control power.'for the 28 EDG was.still energized.
The above exa'mples of inadequate 00Ss indicate _ lack of
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j attention to_ detail by operations shift personnel.- Previous L
. inspection report 50-295/90003; 50-304/90003 identified a s
violation that also pertained to personnel error due to lack
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of attention to detail. 'Since the' licensee's corrective action has not been implemented for a sufficient duration to assess effectiveness, the weaknesses identified.in the 00S i
program identified above and :in the surveillance program
' described in paragraph 5:of this report are considered a
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- unresolved item pending further NRC review. (295/90006-02(DRP);-
F 304/90006-02(DRP))
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d.
Inadequately. Monitored Release During-Unit 1 Reactor Head Venting On April-11, 1990, at approximately 6:00 p.m., the -licensee noted -
that the. Unit I reactor head vent-activities were conducted with.
the containment purge exhaust stack gas monitor, IRT-PR09A,
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inoperable., The vent activities were performed in accordance with y
a procedure that allowed a containment purge with monitor 1RTJN9A
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inoperable and the general redundant containment monitor operable.
The redundant monitor, IRIA-PR40, sampjes the air pior to entry
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into the= purge duct. The reactor head was vendd_to the-purge duct via tygon tubing and was not monitored by the containment.
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radiation'. monitor 1RIA-PR40. Prior to the release a sample was
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obtained, as required by procedure, and determined to be below the-
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10 CFR 20 Appendix B concentrations. The licensee reported'the
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event as a 10 CFR 50.72(b)(2)(iii)(C) notification on. April 11, 1990.
However, the notification was rescinded.by the licensee on April 12, 1990, based on the belief that monitor 1RT-PR09A was considered nonsafety-related.. Investigation by the resident-
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1RT-PR039A, was to close the purge exhaust valves on high ra'diation.
' Based on discussions with the inspectors, the licensee reinstituted
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the original notification on April 12, 1990. A regional inspector
will continue to monitor the licensee's corrective actions.
e.
Security Drills c
On March 11, 1990, a consultant conducted a series of security
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drills to. assess the licensee's new program on identifying,
tracking nd communicating intruder movements. 'Overall, the
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license <'s performance was adequate. Areas that needed improvement
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inc M ed' maintenance of existing equipment, equipment upgrading ar.J communication.
- One.part of a violation was identified, and all the other areas inspected i
were adequate.
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5.
Monthly Surveillance' Observation _ (61726)
The inspector. observed required TS surveillance tests on the. main steam, auxiliary feedwater, reactor coolant, safety injection, and fuel
' handling systems and verified that the tests were, performed in accordance-with the following: adequate procedures, test instrumentation was calibrated, limiting conditions for operation were met, removal and
restoration of the affected components were accomplished, test results conformed with TS and procedure requirements, test results were reviewed by personnel other than the individual directing the test', and that any.
deficiencies identifieo during the tests were ' properly reviewed and
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Jresolved by appropriate management personnel..
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The ' inspector also witnessed portions of the following test activities:
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PT-2A Safety Injection System Tests PT-2T Power Operated: Relief. Valve (PORV) Accumulator Check-Valve -
Leakage Test
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PT-7A Starting Procedure for Auxiliary Feedwater Pump Lube 011 j
Pumps
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PT-21 Reactor Coolant System-Leakage Surveillance-PT-23-Main Steam Isolation Valves Refueling / Cold Shutdown Ll Surveillance
q TSS 15.6.107: MSIV/Mainsteam Check Valve Leak Test The fol. lowing observations were noted:
On March 14, 1990, during the review ofLthe result.of surveillance,
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PT-2T, "PORV Accumulator Check Valve -Leakage Test performed on 1'
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March 6, 1990, the-Operating Engineer determined that the accumulator-
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to the pressurizer PORV,1PCV-45SC, did not satisfy -the acceptance criteria of ze/o leakage. PORV,:1PCV-455C was then declared inoperable. At the time the Unit.was in cold shutdown, Mode 5.
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The licensee entered the action statement-for TS'3.3.2.G.1, low-a temperature overpressure protection. On March 14, 1990, the-A
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licensee again performed surveillance test, PT-2T, for both PORV j]
accumulators to, verify operability. During PT-2T, both accumulators
had a 0.5 psig pressure drop during a 15 minute interval and failed
to meet.the acceptance criteria of zero leakage. With-two inoperable o-PORVs, the. action statement for.TS 3.3;2.G.3.b required the licensee to depressurize the RCS to less than 100 psig and lower i
the pressurizer level to less than'25%.
The licensee initiated actions to comply with the TS ' action statement and also initiated an engineering evaluation to review the bases for the zero leakage acceptance criteria. Review of the TS and design criteria indicated
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-i that the accumulators, were sized to provide the required number of PORV open/close cycles for ten minutes with the loss of instrument
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air.
The engineering evaluation concluded that a minimum accumulator pressure of 95 psig was acceptable to assure the required cycles.
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-The' surveillance ~ performed on March 14, 1990, resulted in accumulator
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pressures at or above 98 psig after instrument air was isolated for
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15 minutes. The onsite review of the design evaluation-for the PORV air accumulator determined that the accumulators were operable and
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that the_ acceptance criteria for PT-2T was too conservative.
Thhroot.causeofthiseventwaspersonnelerror.
Although the acceptance criteria stated that the final accumulator tank pressure ashall be equal to the initial pressure, the LSS concluded that-the small. pressure drop was insignificant and did not notify the technical staff ~or the shift supervisor of the surveillance.
results.
Zion administrative procedure General Surveillance-Program, ZAP 3-52-6, states.that the corrpleted surveillance should be reviewed-for technical accuracy and compliance with the
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accep.tance criteria.
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On March 28, 1990, dur ing the review of the results-of-surveillance
~g PT-2A, _" Safety. Injection Systems Tests", performed on March 26, 1990,c the_0perating-Engineer determined that the 1A safety injection:
-pump failed to meet the acceptance criteria for minimal recirculation flow. The' surveillance results had been previously accepted by-- the.
LSS. The pump was retested on March 28, 1990, with satisfactory
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results of a recirculation flow of greater than 27 gpm.. The
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technical staff reviewed inservice test data for,the previous year and' verified that no negative performance trend was evident.
The pump.was then declared operable, j
The:above examoles were caused by inadequate reviews of. surveillance'
results by shift; personnel.- The : licensee conducted personnel: error review boards to ascertain the-root causes and corrective actions.
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- The : licensee -bas: re-emphasized to the plant staff the importance of q
compliance to surveillance requirements.and the subsequent actions -
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- if the criteria is not; met.- The licensee plans to review all TS--
surveillance procedures (pts)' for appropriate acceptance criteria.
The review will also-include an assessment of the methods utilized
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in:the identif.ication of acceptance criteria _in~the surveillance.
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-M nthly Maintenance Observation-(62703)
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-Station maintenance activities for safety related-systems and components were observed or reviewed to ascertain compliance with -approved-procedures, regulatory guides,1ndustry codes or standards, and with, TechnicalSpecifications(TS).'Considerationwas(givento:
the limiting
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conditions for operation while components or systems were removed from:
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service; approvals prior to initiating the work; use.of approved
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procedures and functional testing and/or calibrations prior to returning _
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components or systems to service.-
-i The following maintenance activities were observed or reviewed:
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On March 26,1990} during a routine surveillance on the 18 EDG, the
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high pressure fue line between the jerk pump and the injector for
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the 3R' cylinder failed and fuel oil was sprayed in the room.
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event was caused by a loose ferrule on a compression fitting on
~a the fuel line.
The Cooper Bessemer representative informed the_
licensee that the fuel; line-on the jerk-pump would develop a leak i
prior to a rupture. The licensee inspected all.EDGs and identified -
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a minor leak on the 2L cylinder jerk pump for the 1A EDG. The-licensee ' completed repairs to-the-fuel lines on the 1A and IB EDG
~by March 28, 1990.
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On March 16 1990, the licensee identified a missing ei ht inch ^
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retaining pin from the 1A feedwater pump discharge chec valve during a preventive maintenance activity.- The licensee initiated
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'aClion.tO' search for the retaining' pin and on March 19, 1990, the retaining pin was found in the feedwater recirculation line.
Inspectioniof the-retaining pin, identified that approximately 10%
of-the 1/2 in, diameter by 3/4 in, length pin was not-found. The licensee performed an engineering evaluation and ascertained-that the missing piece would not hinder operation of the feedwater system.
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The Unit 1, IA MSIV failed the TS stroke test. The. probable causes include a 3/16 in, bent shaft, a scored shaft, and possible adverse affects of furmanite.
Unit I was shut down to replace the valve
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shaft.
The resident staff will monitor the repair and post
maintenance test on the-1A MSIV.
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On March 21, 1990, the licensee commenced a: Unit-2, Cycle 11, refueling' outage. During the forced. outage-period, March 2, 1990, through March 21, 1990,.many refueling outage activities-were-completed that-~ included the-following: MSSV tests, RCS cooldown, j
breaking containment integrity, air tests and depressurization of
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-the main generator,-securing condensate and circulating water, and a
the hanging of many out-of-services. The return to service for.
J Unit 2.is scheduled for the end of May 1990.
' Refueling maintenance activities on safety related systems and components were observed or reviewed to; determine compliance with approved procedures,_ regulatory guides,' industry codes or standards.
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and with TS.
Consideration was given to the control of contract'
l work,l involvement of quality assurance organizations, radiological t
control, personnel l qualifications, functional testing and use of g
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proper procedures.
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Major.' activities _ include-steam generator tube eddy current. testing, steam ger.erator tube sleeving and plugging, inspection of girth
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' welds, detailed control room design review (DCRDR) modifications, aE main turbine generator maintenance, and overhaul of the 2A EDG.
On March 29,_1990, a contractor notified the resident office with a concern regarding the installation of an insulator in the Unit 2
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cable spreading room. The individual was. concerned that the workers
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were using a Serafiber, a _ very fine particle insulator, without wearing masks or gloves as recommended on the product label. The
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inspector discussed the issue with the station Safety Industrial Hygiene coordinator. The Material Safety Data Sheet (MSDS)
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handling _this-product. The licensee stopped work in-the cable spreading room and issued the necessary safety equipment to the s
- personnel' performing the work.
During the period. of_ February 20 to March 2,1990, the "0" diesel-
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- generator experienced 10 failures to start as follows:
_5 failures to start within 13-15 seconds eventually determined
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to be caused by the lube oil pressure not reaching 20 psig.
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'within. the 10-20 seconds control system lock out period during t
engine startup (bypassed during a safeguards start of the
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engine)
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5 failures to stort within 5 seconds due to an improperly installed '20s' solenoid valve during the. troubleshooting for the cause of the 13-15 seconds failure to start.
The root cau'se of the five 13-15 seconds failures to start was determined by the licensee to be the failure.to vent the turbo-charger lube oil filter housing on December 10, 1989, following m
lube oil system draining and refilling for engine maintenance.
The maintenance procedures had not specified the venting of the turbocharger lube oil filters.
The procedures have subsequently been upgraded to ensure proper venting is-performed following maintenance..
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The inspectors reviewed the licensees' troubleshooting process, the. identified root cause of=the five failures'to start within 13-15 seconds, and the corrective actions taken or planned.
The results were:
a.
.The intermittent nature of the trips, the complexity of the
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pneumatic control system, and' the unreliability'of the pneumatically activated first-out ancuntiator panel (only..
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"Overspeed" and " Normal Panel Shutdu n" n re tripped; " Low; Lube Oil Pressure" _never annunciated) oeioyed the identi-fication of the cause of the diesel trips.
b.
.The licensee's initial reluctance to instrument the diesel j
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control system and instead depend on the staff's expertise plus the first-out panel alarms delayed the identification 1 <*
.of the cause of-the intermittent trips as their effort
shif ted from troubleshooting the pneumatic control' system to the electrical, and back to the pneumatic.
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The root cause was finally identified by the licensee as an
air bubble in the turbocharger lube oil filters -(high point
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in the lube oil system) caused by the failure to vent the l
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system following maintenance performed on December 10,1989.-
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The inspectors agree with the licensee that the most probable
cause of the "0" diesel generator trips was the failure vent the turbocharger lube oil filters (found 50% full).to
because:
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Numerous variables can affect the lockout period
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(specified by the vendor to be 10-20 seconds) for the
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low lube ~ oil trip signal during engine:startup.
Q, The low lube' oil shutdown sensor is located downstream -
of the turbocharger filters, therefore, a significant^ air-
'pocketTin the filters had a measurable effect on the lube-oil pressure increase rate at the-sensor.
L-Testing performed on March 3 demonstrated that venting
the turbocharger lube oil filter reduced the. oil circuit:
pressurization time =(to 20 psig) from 11.2 to 6.9-4" J
seconds.
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Measurements of oil circuit pressurization time.for.
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diesels.1A, 2A, and 2B ~ ranged from approximately 4-6 seconds.
I No additional failures to start in 13-15 seconds have
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E occurred since.the venting of the filter housing.
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The question of why the. start failures did not-occur shortly -
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after the' introduction of the unvented air on December 10,
1989, may never be answered.
One possible explanation.is'that-initially the air bubble was not large enough to delay the oil circuit pressurization time.: That implies an additional source'of air exists in the lube oil system which has not-been identified.- The licensee has incorporated periodic-turbocharger lube oil filter housing venting into its
' Technical Staff surveillance procedures'to monitor for the c
buildup of an air pocket which would indicate the' existence
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of air inleakage.
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= Another possible explanation assumes the.. air pocket' remained '
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constant)(, but the lockout period was beingsreduced over constant lube. oil circuit pressurization. time remained
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time until on February 20,:1990, the two-values coincided.
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- W'111e this-question 'may never be answered,E the licensee's'
-corrective. actions. should prevent. a repetition of thefproblem.
In addition'to the --immediate procedural corrective. actions.
taken'so far (post maintenance'and periodic venting of
,
turbocharger lube oil filters)- the licensee plans to
implement the following long' range corrective actions:
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. Complete replacement of the start air system to improve the quality of the delivered air (moisture,. dirt and oil
'l were found during disassembly of some components).
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Replacement of the first out annunciator with a more
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reliable monitoring system. This will be part of the
planned control / monitoring system upgrade which may
include the relocation of the lube oil low pressure i
trip sensor.
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On March 5,1990, the '"0" diesel generator experienced a main
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bear.ing (No. 7) high temperature trip (bypassed during safeguards ~
starts). As a result, the licensee inspected the bearing and
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decided'to replace all 10 main bearings.
The NRC inspected all the removed main bearings and determined that:-
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a.
' All lower bearing halves had-an area of significant primary
wear (averaging.approximately6-7inchesinlength).
b.
Varying amounts of bronze were exposed in the primary wear area
of all= lower bearings, with numberL10 and 7 lowers having the most'babbitt wear and exposed bronze.
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A secondary wear area was also observed on the lower bearing o
half. This secondary wear area-was in the. form of. grooves.or gouges 'in the babbitt layer running from the primary wear area n
to the tabbed edge of~the lower bearing, d.
Damage:to the' upper bearing halves, when present, was in the
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form of scoring-to the babbitt layer, presumably from bronze
. wear metal ~ carried over from the lower bearing half. The degree-of scoring on the; upper bearing halves increased proportionately with the lower bearing half wear rate.
According to the licensee all journals were in excellent condition and no metal transfer had occurred.
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r The "0" diesel replaced bearings were the unit's original bearings,
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approximately 18 to 20 years old. As of March 8,.1990, the unit-had -2444 hours of. operation. _ A-review of. the Diesel Generator-Start'
g Log from January 1984 thru March 1990 showed approximately 600-starts for the 61 : years. A conservative extrapolation would place the :
. number of starts for the removed bearings at approximately' 2000.
The observed " damage" to the main bearings removed from the "0"
. diesel.should not be considered excessive based on.the number of
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transitions (approximately 2000 starts) through the semifluid or; mixed. lubrication-condition before sufficient hydrodynamic pressure
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-is developed to float the journal and carry the load applied to it, i
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As part of the corrective action the licensee, in consultation with the vendor.. plan to develop a bearing replacement schedule which will.take-into account the number of starts'and the wear found'in
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the."0" diesel and the other four diesels. During April 1990, the licensee was in the-process of replacing the main bearings of the 2A and 28 diesels.
~ 7..
Engineering and Technical Support
a.
' Thermal Performance Assessment by the Offsite Quality Assurance An assessment of Zion's thermal performance was conducted by i
the Commonwealth Edison corporate Quality Assurance department.
Strengths were identified in the Cycle Isolation Monitoring methodology and in interdepartmental communication.
The Cycle
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Isolation Monitoring method,has improved in the identification
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ofBalance.ofPlant(B0P)1 leaks, which in the past would not have been identified. The thermal engineer identified the-leaks,
l initiated work requests, and input the priority to maintenance
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planning / scheduling ~ based on the estimated energy loss. The
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monitoring occurs before and after each outage. This practice
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allows for-corrective maintenance during the outage and verifi-
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cation of the effectiveness of maintenance following the outage.
The communication channels were determined to be well established for flow of information between the technical staff. thermal
- engineer, the planning department, operating personnel, and station management.-
The assessment identified one deficiency in the portion of the program that monitors the cor. denser performance. The station currently monitors: condenser performance once every two weeks
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<instead of_ the-required frequency of once every week. The
. assessment concluded that weekly monitoring of the condenser was
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appropriate'to ensure-identification of concerns in condenser performance in a timely _ manner.
-- b.
Inadequate Cable Separation for' Containment Area High Radiation Monitors-
On March 30,1990,.during a walkdown of Unit 2 cable trays conducted as part of-the corrective actions to a SS0MI finding (see' Inspection
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Report 295/88003), the: licensee determined that-the high range.
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containment area radiation monitors, 2RI-AR02 and 2RI-AR03 did'not
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have the adequate cable separation'
The cables for the monitors
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were tie wrapped together and were routed through the same fire
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barrier penetration. The technical staff inspected the cable runs
'for Unit 1 and determined that the:same condition existed for Unit T
1.
The licensee declared all of the affected monitors inoperable.
'On April 2,-1990, the licensee repositioned the Unit 1 monitors'
cables to establish the required cable separation. The licensee will correct the cable separation on Unit 2 monitors prior to the-need for> operability.
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Unit 2 Reactor Trip Breakers -(RTB)' Failure to Close
'On AprilI3, 1990, during a bench test described in " Reactor Trip Breaker Maintenance Testing," E0015-1, the Unit 2 Train B reactor Etrip and bypass breakers failed to manually close. The breakers had operated successfully during reactor protection system tests.
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The RTBs are Westinghouse Model 08-50 breakers. The Westinghouse-breaker specialist was sent to the site and diagnosed the problem as a defective manual actuation roller that had. not returned to its
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neutral rest position. Several manual closures repeated the failure mode.
Further inspection identified one breaker's rollers had'a bad bearing. The' other breaker's roller had a bad shaf t weld.
Westinghouse was previously aware of the failure mode and had a replacement bearing with a larger roller and a better bearing and roller surface. The other RTBs on site were inspected and the results are as follows.
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Unit 1 -- four new rollers, two spare new rollers and
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Unit.2 -- four old rollers, spare two old rollers;-
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All RTBs will have the upgraded roller before either unit is
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--returned to service, e
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No violations of deviations were identified.
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,a.
Zion Station Relocation Center
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In March 1990, the licensee designated the Antioch High School as-I
- the relocation center for station personnel during a site emergency, a
The school can accommodate an expected 1,200 persons (using normal
. station compliment-with a Unit in an outage and contractors on-site)-
during a. Zion site evacuation.
Once in the school, all personnel are required to sign in and assemble in the gymnasium. Vehicles will also be-surveyed for the presence of. contamination. The
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licensee plans to evaluate.the relocation center during the annual GSEP exercise scheduled on July 18, 1990, b.
Possible Flooding due to Heavy Rains 0n March 13, 1990, heavy rains raised concerns of possible' flooding in'the area that'could impact site and general evacuation routes.
-The Emergency Preparedness supervisor contacted the Lake and'Kenosha
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county officials who stated that there was= no immediate threat of a
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1 flooding.
If a threat of flooding developed, the counties would
' call the station and the station would notify the NRC. Alternate.
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routes'to-evacuate-the site and to facilitate vital personnel access to'the site were also reviewed by the licensee. The actions plans appeared-to be: adequate.
No violations of deviations were' identified.
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- 9.
Training (41400)
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During the inspection period, the inspectors reviewed abnormal events j
and unusual occurrences which may have'resulted, in part, from training deficiencies.. Selected events were evaluated to determine whether the classroom, simulator, or on-the-job training received before the event f
was. sufficient to have either prevented the occurrence or to have
,
mitigated _its effects by. recognition and proper operator action.
Personnel qualifications were also evaluated.
In addition, the Linspectors determined whether lessons learned from the events were
incorporated into the training program.
In addition, LERs were
- routinely evaluated for training impact.
The events reviewed this period were found to have no significant training deficiencies as contributors, t
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One training session was. attended by the resident. inspectors. On
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March 14, 1990, the inspectors attended an on-shift lecture on-t E
calculating off-site release rates. Discussions with the senior
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creactor operators indicated that the lecture was well presented and provided beneficial information for the operations staff.
.
No violations or deviations were identified.-
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l 10. Qualily Program Effectiveness
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m A corporate assessment on the implementation of eight: chapters of_the
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- Conduct of: Maintenance (COM) directive was conducted at the Zion i
Station. The assessment reconfirmed the areas,the station personnel
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f perceived as weak..In 1989, the Work Practices' and Work Packages
Committees drafted action plans that would enable Zion: Station to meet
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the maintenance standards expected in the nuclear industry.
These plans were incorporated-into the Performance Improvement Program (PIP)..
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~ However, not.all the plans have been completely implemented at this t
time.
Strengths and weaknesses were observed by the assessment team in the completed PIP action plans The weaknesses included:
j Maintenance memos need updating to reflect the current. licensee
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organization.
Detailed mechanical maintenance procedures need to be developed.
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Day-to-Day planning needs to be formalized.
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Approve the new revision of the Work Request ZAP 3-51-1.
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Engineering and construction work packages are-not -prepared under
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the same Conduct of Maintenance requirements as the Station's.
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Some post maintenance test requirements _ were not always specified
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or_ performed.
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-Mechanical maintenance work analysts need to review completed
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work packages for lessons learned.
Problems Analysis Data System program needs to become more of a
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station program.
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Strengths were noted in the following areas:
7 Scheduling of preventative maintenance work was performed through.
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a master operating tracking schedule, that allowed. corrective work ~
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to be scheduled within the same out-of-service boundaries.
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Station and Maintenance management had conducted tours to observe
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problems encountered by personnel in the field, aq
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The assessment concluded that Zion Station is on the right_ track,.but
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implementation of some tasks are somewhat slow. The assessment team
-provided lists of areas to'prioritize the issues and where action plans d
should be drawn up to improve the station's efforts to resolve the ' issues.
.j No. violations or deviations were identified, l
11.
FuelMoves-(60705)
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a The inspectors observed the off_-core loading of Unit 2, reviewed
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applicable logs and instructions, and conducted discussions'with fuel-
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_ handling. personnel. During these discussions:and observations, the b
inspectors ascertained that the-removal of the fuel assemblies from the.
reactor cavity storage in the fuel racks were in conformance with
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a) proved. instructions. On April.1,1990, while removing an assembly, the
"11 flux at shutdown" alarm was received.
The Unit 2 operator warned thei containment personnel and initiated a containment evacuation as required
.
by! control board response procedures. Apparently, the assembly contained
a a source which caused the monitor to alarm. The licensee readjusted the hi= flux setpoint, verified no risk existed and then continued with defueling operations.- The personnel handling the fuel were knowledgable, qualified, and appropriately supervised. ' All activities' observed were conducted in a satisfactory manner, 12. 0 pen Items
_
-Open Items are matters which have been discussed with the_ licensee which
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willibe= reviewed further by the inspector and which involve some. action j
on the'part of the-NRC_or licensee or both. One_Open Item disclosed
during this' inspection is discussed in paragraph 2.b.
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- 13. -Unresolved Items
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Unresolved items are matters about which more information is required in order to_ ascertain whether they are acceptable items, violations,-
or deviations. An unresolved item disclosed during the inspection is discussed in paragraph-5.b.-
~ 14. Management Meetings (30703)
~.
Illinois Department of Nuclear Safety Meeting.
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a On March 28, 1990, inspectors from the Illinois Department of Nuclear Safety (IDNS) met with licensee personnel to discuss future inspections of low-level waste treatment and transportation. The NRC inspector attended the meeting and verified that no violations or deviations of federal rules and regulations were identified.
b.
NRC Nanagement Meeting On April 6,1990, Mr. J. Zwolinski, Assistant Director, Nuclear Reactor Regulation; Mr. W. Shafer, Branch Chief, Reactor Projects,
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~ Section 1, and-other NRC management personnel met with Mr. T. Voyce,
. Zion' Station _ Manager and other Zion Station management-at the Zion
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site'to discuss the status of the Performance Improvement Program.
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15. Exit Interview (30703)
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The-inspectors met withi. licensee representatives(denoted in Paragraph.1)-
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- throughout the inspection-pericd and at the conclusion of the inspection 1 s
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on April 18, 1990, to summarize the scope and findings of the inspection l a
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i cactivities.- Theclicensee acknowledged thet-inspectors'icomments.
The?
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P-inspectors:also discussed lthe. likely informational content of the :
inspection report with regard to documents orl processes; reviewed by the i
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inspectors during the inspection. The licensee did not identify any such
' documents or processes._ as: proprietary.
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