IR 05000416/1993016
| ML20059B509 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 12/09/1993 |
| From: | Bernhard R, Cantrell F, Hughly C NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML20059B476 | List: |
| References | |
| 50-416-93-16, NUDOCS 9401040169 | |
| Download: ML20059B509 (12) | |
Text
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5.. E 101 MARIETTA STREET. N.W.. SUITE 2900 ' l; oy ATLANTA, GEORGIA 303234199 %*.... Report No.: 50-416/93-16
Licensee: Entergy Operations, Inc.
Jackson, MS 39205 Decket No.: 50-416 License No.: NPF-29 i Facility Name: Grand Gulf Nuclear Station ' Inspection Conducted: 0ctober 24,,1993-through November 27, 1993 . its /h/ Inspectors: J - R. H. Ber,nhard, Senior Resident Inspector Date Signed YA If/ Mc( cf lYS/N t, a/ C. A. Hughey, Resident inspector Date Signed Accompanying Personnel: M.D. Sykes, Resident Inspector (Intern) Approved by: N /![[
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/2/M73 F. S. Cantrell, Chief /- Date Signdd " . Reactor Projects Section IB Division of Reactor Projects
SUMMARY ' Scope: The resident inspectors conducted a routine inspection in the following areas: operational safety verification; maintenance observation; surveillance observation; refueling activities; action on previous inspection findings; and reportable occurrences. The inspectors conducted t ackshift inspections on
October 29 and 30, and November 11, and 22. 1993.
' Results: A new type of recirculation system jet pump holddown beam failure was identified.
Intergrannular stress corrosion cracking initiated failure in a new beam location caused plant management to conservatively extend the outage.
' . ' to replace all twenty four beams (paragraph 6.). During the restart-from the outage, a resin intrusion from the condensate i storage tank to the' vessel during a reactor core isolation cooling (RCIC) system test lead to a shutdown based upon the Electric Power Research Institute reactor water chemistry guidelines.
The shutdown was delayed for i several hours due to poor communications between the chemistry personnel and j the operations staff (paragraph 3.c.). 9401040169 931209. PDR ADDCK 05000416 G PDR- .
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i ' A Unresolved Item from last month's report (93-15) became a violation when personnel error was determined to be the cause of a loss.of shutdown cooling-(paragraph 8.b.). One con-cited violation was identified for failure to meet requirements of an LC0 prior to entering a higher operational condition. The Operations staff
did not place RCIC in an operable condition prior to allowing the reactor to exceed 135 pounds. This event was easily avoidable (paragraph 7.). . , s h .
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REPORT DETAILS
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Persons Contacted l .i Licensee Employees
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- L. Daughtery, Superintendent, Plant Licensing W. Deck, Superintendent, Security l
- M. Dietrich, Manager, Training
- J. Dimmette, Manager, Performance and System Engineering
~! C. Dugger, Manager, Plant Operations
- C. Ellsaesser, Technical Coordinator
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- C. Hayes, Director, Quality Assurance
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- C. Hicks, Operations Superintendent C. Hutchinson, Vice President, Nuclear Operations
- A. Khanifar, Manager,- Nuclear Plant Engineering
- M. Meisner, Director, Nuclear Safety and Regulatory Affairs '
- D. Pace, Director, General Manager, Plant Operations
.' J. Roberts, Manager, Plant Maintenance R. Ruffin, Plant. Licensing Specialist
- G. Vining, Manager, Plant Modification and Construction-l
, Other licensee employees contacted included superintendents,
supervisors, technicians, operators, security force members, and office
personnel.
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- Attended exit interview l
Acronyms and initialisms used throughout this report are listed in the -! ' last paragraph.
2.
Plant Status j The Unit was in a refueling outage for the inspection period. The .; outage was extended for a complete replacement of the recirculation system's jet pump holddown beams.
Plant startup was in progress at the end of the period.
Duringt@eweekofOctober 25, 1993, Region 11 personnel from the Division of Radiation Safety and Safeguards conducted an inspection in .I the areas of occupational. radiation safety and radiation controls'(NRC j Inspection Report 50-416/93-20).
i During the week of November 22, 1993, Region 11 personnel from the Division of-Radiation Safety and' Safeguards conducted a'special inspection-in_the area of radioactive wastes transportation (NRC Inspection Report 50-416/93-22).
3.
-Operational Safety (71707 and 93702) a.
Daily discussions were held with plant management and various members of the plant operating staff. The inspectors made frequent visits to the control room to review the status of q
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I ! equipment, alarms, effective LCOs, temporary alterations, instrument readings, and staffing. Discussions were held as appropriate to understand the significance of conditions observed.
Plant tours were routinely conducted and included portions of the control building, turbine building, auxiliary building, radwaste building and outside areas. These observations included safety > related tagout verifications, shift turnovers, sampling programs, housekeeping and general plant conditions. Additionally, the . ' inspectors observed the status of fire protection equipment, the control of activities in progress, the problem identification systems, and the readiness of the onsite emergency response facilities.
No deficiencies were identified.
b.
The inspectors performed observation of control room activities - during the startup performed at the end of the period.
The reactor mode switch was placed in startup on November 26, 1993, at 7:32 am.
Rod movement started about a half hour later.
Rod movement was performed with much attention to detail.
Personnel' were rotated pe'iodically to avoid fatigue. Rod control movement was performed in accordance with 17-S-02-400, Revision 5, Control
Rod Sequences and Movement Control, and Attachment 1-07-000CO-A2-01. The inspector reviewed the new limits on core operations with , respect to core instability with the on shift personnel. The new core power / flow map was finalized November 8,1993. The new map ' - includes a " Region III, Controlled Entry", that requires fraction of Core Boillag Boundary to be calculated. The current computer display has this value.
Also,'" Region II, Exit", has.been enlarged. The on shift staff was knowledgeable of the changes.
c.
On November 27, 1993, during a reactor startup from the refueling l outage, Grand Gulf's reactor coolant sulfate concentrations ! exceeded the EPRI action level 3 recommendations of 200 ppb.
Concentrations reached 391 ppb for. sulfates and conductivity reached 3.8 mho/cm. Administrative procedures written to enforce the EPRI guidelines required an immediate orderly shutdown of Mr.: , plant. About sixteen hours af ter commencing shutdown, sulfate concentrations and conductivity were brought back into l' specifications and the unit was scheduled for--restart on November 28, 1993. The licensee suspected that a resin intrusion . occurred during operational surveillance' testing of the RCIC l system at 150 psi. Resin fines were apparently agitated.from the- ' bottom cf the CST when the RCIC pump was pumping CST to CST.
After about one hour.of recirculation, RCIC was lined up to the jl vessel and injected'for about 2 minutes at 800 gpm.
Vessel water-chemistry samples drawn after the injection showed abnormal
readings.
RWCU was not available for clean up of the reactor-i coolant during a large portion of the event, due tc an P_WCU isolation and normal system realignments during startup.
During a review of the sequence of events, the inspectors noted that greater than two hours passed between the availability of the I -
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chemistry results from the 4:00 a.m. samples and the chemistry department notifying operations of the results. This resulted in an unnecessary delay while reactor coolant chemistry sulfate concentrations were well in excess of EPR:/ Administrative procedural guidelines requiring plant shutoewn. Further investigation by the inspectors revealed weaknesses in the chemistry procedures regarding notification of the control room when chemistry results require operator actions. The licensee initiated a quality deficiency report to further address these concerns.
d.
The inspectors observed a simulator training session on the new digital feedwater control system. The session consisted of'a lecture on the updated System Operating Instruction 04-1-01-N21-1, Feedwater System, and hands-on training with the new feedwater controls.
Emphasis was placed on the lowered response time (60 seconds to 15 seconds) for full travel of the turbine governor valve, startup and shutdown of the pumps, and startup of a second feed pump. Comments were received from students for procedural enhancements. The session was comprehensive, informative and well presented.
e.
Prior to startup after the outage the inspectors reviewed the status of items committed to be closed prior to the end of RF06.
A summary follows: 1.
The response to LER 91-005-00, LER 91-005-01 commits to inspect, maintain and test 500kv switchyard breakers on a routine basis, including gas compressor oil analyses.
The licensee has replaced breaker J5232 and plans to replace breaker J5228 during the next refueling outage. These are tha only Siemens breakers of this type tied to the main generator, and are the only ones scheduled for replacement at this time. -The replacement breakers are Mitsubishi designed breakers. Oil samples were taken from J5228 and other similar Siemens breakers and were sent to an MP&L contractor for analysis.
2.
Lic. Cond. 2.C(26) requires that the licensee ultrasonically inspect bores and keyways of LP turbines prior to exceeding 50,000 hrs, of operation.
The UT inspection of the No. 3 LP turbine was completed during RF06.
Indications were observed on both No. 4 rotor discs but the vendor.has released the rotor for. unrestricted operation.
(See Inspection Report 50-416/93-15) 3.
In response to IN 93-70 the licensee agreed to load freshly discharged spent fuel in Boraflex surveillance are. . .
Discharged fuel assemblies were loaded into the surveillance area where coupons will be checked in 10-14 months.
(See Inspection report.50-416/93-14).
4.
In the Bulletin 90-01 response, the licensee committed to replace numerous Rosemount transmitters at earliest ' opportunity.
. The five transmitters the licensee committed to replace in RF06 were replaced.
5.
LER 92-017 committed the licensee to install DC to DC , converter between power supply and primary water tank level transmitters (main generator).
The converter was installed and a 10 second time constant was inserted into the level logic to prevent spurious generator / turbine trips.
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The licensee agreed to verify increased SFP system flow rates and report results prior to end of RF06 (Augmented SFP cooling) to address an NRR commitment (TAC No. M2836).
Verification of increased standby service water and fuel pool cooling flow rates were completed prior to and during
the outage for worst case spent fuel pool decav heat loads.
Results were reported by letter to NRC dated M9 timber 8, 1993.
7.
The licensee's response to NRC Bulletin 93-03 required the implementation of hardware modifications to Reactor level instrumentation.
, . Installation and off-line testing of the modification has been completed. On-line testing is scheduled for after, completion of ILRT and during power ascension.
8.
The licensees response to NRC Bulletin 93-02 stated they would ensure cleanliness of drywell.and suppression pool prior to restart from RF06.
- Drywell walkdowns were performed for cleanliness and for fibrous material by the licensee. Divers and general cleanup crews performed cleanup activities. The residents performed independent walkdowns of the drywell and i
suppression pool area prior-to drywell closeout.
Discussions were held with the licensee on their findings with respect to materials with the potential to foul ECCS strainers. The licensee had a technical basis for. verifying adequacy of the type and quantity of material used in the j drywell. Divers were used to provide suppression pool .l cleanup. The inspectors could not visually identify
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material in the supprecsion pool with the potential to foul the strainers. Suppresrion pool water clarity was good at i the end of the outage.
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Completed this outage as part of the lightning protection
modifications to reduce plant scram rate, but not outage-commitments were: The licensee replaced the current vol'. age
suppression diodes used on the front end of the APRM t channels with a high speed type diode to dissipate lightning induced voltage spikes. The licensee also placed ferrite .; beads in signal cable penetrations to provide-additional
shielding for noise suppression.
Panel chassis ground busses in the control room panels that contain trip units were strapped to instrument ground bus.
No violations or deviations were identified.
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-Maintenance Observation (62703) ' During the report period, the inspectors observed portions of the maintenance activities listed below. The observations included a review ,' of the MW0s and other related documents for adequacy; adherence to procedure, proper tagouts, technical specifications, quality controls, and radiological controls; observation of work and/or retesting; and specified retest requirements.
MWO DESCRIPTION , i' TSTI IN21-93-005-0-N RFPT A(B) Power Ascension Test 108912 Remove turning _ vanes from , circulating _ water pump A 97713 Disassemble circulating water pump B to determine cause of excessive vibration.
19931094 Replace APRM diode with Schottky diodes STI IB21-93-008-0-S, Rev. O Reference Leg Purge Preoperational
Test TSTIs above are the post modification-retest's for the reactor feed pump turbine control replacement and for the reactor water level instrument ' backfill modifications. The reactor feed pump low pressure hydraulic- . mechanical control system was replaced with a high pressure hydraulic system with digital controls. The new system has proven to be quite , stabla at the low flow conditions seen this inspection period. The new . systeni has redundant hydraulic systems and control systems. The l I , w
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inspectors reviewed the TSTI and it duplicates the testing performed in the original startup testing for the plant. The inspectors will review the results of higher power testing in a future report.
The testing of the installed reference leg backfill system has shown the ' worst transient to be when the backfill system is valved into the reference leg without the normal pressure equalization. A change of indicated level of six to seven inches was observed. The system was , stable for CRD movement and SRV lifting. The residents will review high power test results in a future report.
No violations or deviations were identified. The results of the observations in this area indicated that maintenance activities were effective.
5.
Surveillance Observation (61726) The inspectors observed the performance of portions of the surveillance listed below.
The observations included a review of the procedure for technical adequacy, conformance to Technical Specifications and LCOs; . verification of test instrument calibration; observation of all or part of the actual surveillance; removal and return to service of the system or component; and review of the data for acceptability based upon the acceptance criteria.
06-0P-1C71-V-0002, Rev 29 Refueling Interlock Check One-Rod-l Out Interlock ' No violations or deviations were identified. The observed surveillance test was performed in a satisfactory manner and met the requirements of the Technical Specifications.
6.
Refueling Activities (60710) During the last inspection period (see IR 50-416/93-15) the jet pump ' holddown beam from the number ten jet pump had not been located. A ' review was made of the video tapes taken during the prior searches for the beam, and a systematic search found the beam near the number six jet _ pump. The beam was retrieved, and after an on site visual examination, sent to General Electric's hot cell for examination.
Initial results - ' indicated the failure mechanism was IGSCC crack initiation and propagation with possibly some fatigue contribution through the last 20% , of the crack.
Due to the reduced cross section in the vicinity of the crack, the licensee could not prove that from the time the crack was of detectable size by UT or VT, that failure of the beam would not occur by the next outage. The plant management conservatively chose to perform a complete jet pump beam replacement. As found measurements were taken of , the replacement beams and a considerable amount of variance was found in ! some dimensions.
Beams with thicker cross sections were used.
- , The crack location on the number ten beam was in an area not previously ' found to crack. The inspectors reviewed videos from RF05 and indications of a crack on the beam were not visible.
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The inspectors observed the decision making process used for determining plant actions to be taken as more information became available on the , mode of the beam failure. The inspectors found the decision to be e conservative and based upon technical information aggressively. collected by the licensee.
Independent consultants and General Electric provided input.
' During the period, the inspectors periodically and routinely observed activities on and around the refueling floor and spent fuel pool area.
Fuel movements observed were conducted in a controlled and deliberate manner and were tracked and documented per P&SE Instruction 17-S-02-300, SNM Movement and Inventory Control. On duty supervisory personnel were aware of the status of ongoing activities when questioned by the ? inspectors. Jet pump beam replacement activities were well planned and executed, and were completed well ahead of schedule.
Radiological controls and general housekeeping were good.
In addition, the inspectors observed portions of core verification activities, non-destructive examination of the new jet pump beams, and the in-vessel visual inspection of reactor internals. No deficiencies were observed.
No violations or deviations were identified.
7.
Reportable Occurrences (90712 and 92700) The event report listed below was reviewed to determine if the information provided met the NRC reporting requirements.
The determination included adequacy of. event description, the corrective i action taken or planned, the existence of potential generic problems and the relative safety significance of the event. The inspectors used the NRC enforcement guidance to determine if the event met the criterion for
licensee identified violations.
' On November 26, 1993 at 7:00 p.m., a licensee operator determined that a higher operational condition had been entered while the requirements for an LC0 had not been met and continued noncompliance with the LC0 would result in a shutdown. Technical Specification 3.7.3 requires that RCIC be operable in operational conditions 1,2, and-3 with reactor steam dome j pressure greater than 135 psig. During plant startup from RF06, reactor
steam dome pressure increased to 138 psig for approximately 8 minutes with the RCIC system inoperable.
Licensee operators took immediate action to reduce dome pressure and declared RCIC operable within 10 minutes of decreasing dome pressure to less than 135 psig.
This item was licensee identified. and corrective actions were taken ! prior to the end of this report period. The safety significance of this event is low because all ECCS system were operable and would.have f performed their design functions. Plant management is aware of the inspector's concerns with the recent mistakes made by operations while performing activities.
Plant management has stressed increased attention to detail in the performance of duties. This violation is not j i i , - -
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being cited because the criteria specified in Section VII.B of the NRC
Enforcement Policy were satisfied and is identified as NCV 50-416/ 93-16-02, Failure to meet Shutdown LC0 Requirements Prior to Entering a ! Higher Operational ~ Condition. This item is closed.
j " One non-cited violations was identified.
! 8.
Action on Previous Inspection Findings (92701 and 92702)
! a.
(Closed) Inspector Followup Item 50-416/93-14-03, Implementation of hardware modifications to Reactor Vessel Level Indicating System.
Installation and offline testing of the modification was completed during RF06 per DCP 93-0011.
The inspectors observed portions of on-line testing per Temporary Special Test Instruction , 1821-93-008-0-S, Rev. O, which included monitoring vessel level indication response during 1 notch rod movement, securing of a CRD pump and swap over from the B CRD pump to the A pump.
There were no significant level deviations observed during these induced transients.
In addition, a Region based specialist was scheduled for a special inspection of this modification during the week of November 29, 1993. This item is closed.
b.
(Closed) Unresolved Item 93-15-02, Loss of Shutdown Cooling. On - October 4, 1993, at 4:36 p.m., an automatic isolation of the common suction piping for shutdown cooling occurred. The isolation was caused by a failed voltage regulating and current limiting card in one of the battery chargers. On October 7, 1993,
at 3:13 p.m., operators opened the alternate supply breaker to inverters 1Y96 and 1Y87 and caused a Division I half scram, SBGT A initiation, control room standby fresh air auto start, and multiple isolations of equipment, including the closure of IE12-F009 due to a high reactor pressure signal.
Closure of F009 . caused the RHR B pump to trip, resulting in the loss of Shutdown cooling for fifteen minutes.
The operators were hanging clearances and failed to properly verify all indications that the ' inverters were on their normal power supplies prior to opening the alternate supply breakers.
Instructions on the tagout requested i verification of the normal power source. A URI was opened on ~ ' these items because the licensee had not yet verified the root cause of the incidents.
An incident review board for these events met on November 3,1993.
! Apparent causes and contributing factors for the incidents were discussed.
The-first incident was attributed to equipment i failure, and the second to personnel error.
Based upon the ! board's review of the events, and the inspector's-independent review, this URI is closed. Corrective actions were discussed in ' IR 50-416/93-15, paragraph 3e.
In addition, an EER was generated , to evaluate placing a trouble alarm in the control room for the , ESF inverters, to indicate when they are on their alternate load.
Because the second incident was the result of an operator's l failure to adequately verify the special instructions on the
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, tagout, this is being cited as violation 93-16-01, Failure to , follow instructions on clearance.
9.
Exit Interview ! The inspection scope and findings were summarized on November 30, 1993, , with those persons indicated in paragraph 1.
.The inspectors described ~; in detail the inspection results indicated below.
Dissenting comments were not received from the licensee.
Proprietary information is not ' contained in this report.
i Item Number Typ_e Descriotion and Reference 50-416/93-16-01 VIO Failure to follow instructions on clearance (Paragraph 8.b.)
. l 50-416/93-16-02 NCV Failure to meet shutdown LC0 requirements prior to entering a higher operational condition ' , (Paragraph 7.)
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Acronyms and Initialisms l Alternating Current AC - ARI - Annunciator Response Instruction APRM - Average Power Range Monitor > BWR - Boiling Water Reactor CFR - Code of Federal Regulations Control Rod Drive CRD -- > Condensate Storage Tank
CST - Design Change' Package ' DCP - Emergency Core Cooling System ECCS - EDG - Emergency Diesel Generator EER - Engineering Evaluation Request - i Electric Power Research Institute EPRI - Engineered Safety Feature ESF ' - gpm - Gallons per minute .- HPCS - High Pressure. Core Spray ! IGSCC - Intergranular Stress Corrosion Cracking
Integrated Leak Rate Testing .I ILRT - IN - Information Notice
101 - Integrated Operating Instruction IR -
Inspection Report
' kv - kilovolt. LCO - Limiting Condition for Operation . , ' LER Licensee Event Report- - Low Pressure -LP - MCP - 1 Minor Change Package MWO - Maintenance Work Order NCV - Non-Cited Violation , NRC - Nuclear Regulatory Commission l NRR - Nuclear. Reactor Regulation , q i )
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parts per billion ! ppb - psig - pounds per square inch - gauge , RCIC - Reactor Core Isolation Cooling
Refueling Outage _ RF0 - - RFPT - Reactor Feedpump Turbine
R0 Reactor Operator - Reactor Pressure Vessel RPV ' - RWCU - Reactor Water Cleanup SBGT - Standby Gas Treatment ! SDC - Shutdown Cooling . SFP - Spent Fuel Pool ! SNM- - Special Nuclear Material 50I - System Operating Instruction
SRV - Safety Relief Valve , ' TSTI - Technical Special Test Instruction URI - Unresolved Item i UT - Ultrasonic Testing ' J .i ' i i } i i r i
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