IR 05000259/1989046
| ML18033B040 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 10/27/1989 |
| From: | Carpenter D, Little W, Patterson C NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML18033B039 | List: |
| References | |
| 50-259-89-46, 50-260-89-46, 50-296-89-46, NUDOCS 8911130262 | |
| Download: ML18033B040 (21) | |
Text
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Report Nos.:
UNITED STATES NUCLEAR REGULATORY COMMISSION
REGION II
101 MARIETTASTREET, N.W.
ATLANTA,GEORGIA 30323 50-259/89-46, 50-260/89-46, and 50-296/89-46 Licensee:
Tennessee Valley Authority 6N 38A Lookout Place 1101 Market Street Chattanooga, TN 37402-2801 Docket Nos.:
50-259, 50-260, and 50-296 License Nos.:
DPR-33, DPR-52, and DPR-68 Facility Name:
Browns Ferry Units 1, 2, and
Inspection at Browns Ferry Site near Decatur, Alabama t
A Accompanied by E. Chri stnot, Resident Inspector W. Bearden, Resident Inspector K. Ivey, Resident Inspector Approved by:
W.
S. Little, Section Chief, Inspection Programs, TVA Projects Division Inspection Conducted:
September 16 - October 15, 1989
"Inspector>>'.
Car'pe er, NRC Site Manager n
'.
Pat rson, RC Restart Coordinator (
>>
Date Si ned
'+7,P Date Si ed
<c
~~7 Da+ Sigrhd SUMMARY Scope:
Results:
This routine resident inspection included surveillance observations, practice emergency exercise, modifications, maintenance observations, operational safety verification, and site management and organization.
A NCV was identified concerning a field design change notice which did not correctly address the jam ratio for a cable pull.
Management action to resolve the cable pulling concerns was appropriate and should prevent future problems for the many cable pulls remaining.
8911130262 891031 PDR ADOCK 05000259
PNU
.2 Additionally the concerns associated with the frequent occurrence of spills (paragraph 8),
and the observations during the licensee's practice emergency exercise (paragraph 3), are weaknesses that should receive licensee management attention.
The inspector wi 11 be closely following the licensee's corrective action in reducing the occurrence of spills.
One positive observation was the extensive relabeling and work station upgrades in the control room that were observed which should enhance control room operation REPORT DETAILS 1.
Persons Contacted Licensee Employees:
0. Zeringue, Site Director
"G. Campbell, Plant Manager
"M. Herrell, Plant Operations Manager
"R. Smith, Project Engineer
"J. Hutton, Operations Superintendent A. Sorrell, Maintenance Superintendent G. Turner, Site Quality Assurance Manager P. Carier, Site Licensing Manager
- P. Salas, Acting Compliance Supervisor,
"J. Swindell, Plant Support Superintendent J.
Corey, Site Radiological Control Superintendent R. Tuttle, Site Security Manager R.
Young, Modifications Manager R. Martin, Assistant Modifications Manager - Field A. Chapman, Assistant Modifications Manager - Planning and Scheduling M. Caston, Quality. Engineering Manager R. Baron, Quality Control Manager R. Large, Assistant Quality Control Manager Other licensee employees or contractors contacted included licensed reactor operators, auxiliary operators, craftsmen, technicians, and public safety officers; and quality assurance, design, and engineering personnel.
NRC Attendees:
"D. Carpenter, Site Manager
"C. Patterson, Restart Coordinator
"E. Christnot, Resident Inspector
- W. Bearden, Resident Inspector
"K. Ivey, Resident Inspector
"Attended exit interview ly Acronyms used throughout this report are listed in the last paragraph.
2.
Surveillance Observation (61726)
The results of the surveillance inspections during this time period are included as part of special inspection report 89-43.
3.
Practice Emergency Exercise (82301)
a.
OSC Observation On September 20, 1989, the NRC inspector observed the licensee performance of a practice site emergency at the OSC.
The exercise
required that site personnel report to the site, assembly areas rather than evacuate the site.
The inspectors reviewed licensee procedure SDSP 22.3, Personnel Accountability and Evacuation, prior to the exercise.
Three observations were noted at the OSC during the drill:
There appeared to be some confusion as to whether accountability requirements were met. It'as subsequently determined that they had been met.
Some confusion existed concerning the evacuation of Unit
reactor building which occurred at 9:50 a.m.
during the drill.
Several key personnel in the OSC were not aware of this event due to poor communications.
There also existed some confusion concerning the implementation of SDSP 22.3 which requires that when the three minute undulating siren for assembly and accountability occurs, personnel are to use the PREAS readers.
Several OSC personnel
were observed using the PREAS readers in the OSC prior to the sounding of the siren.
,Those same personnel did not again use the reader when the siren was sounded, b.
Control Room Observations The NRC inspector monitored the exercise from the control room with the following observations:
On one occasion, when asked by the Plant Manager the drill SOS
. forgot the reason that the reactor was being manually scrammed.
The reason was that a player message stating three times normal Offgas Post Treatment High Radiation had been provided to the
operator at the controls.
The drill scenario was not properly controlled in that one player message containing drill information concerning a
condition requiring the reactor to be manually scrammed was given to the operator early, out of sequence.
This caused confusion among control room personnel.
Although a list of v'ital or exempt personnel had been prepared prior to the start of the exercise, this information was not given to Radiological Control personnel.
Mhen a
step off pad was.set up at the reactor building turnstile, TS required fire watch personnel were prevented entry into the reactor building until the SOS authorized their entry.
There was a
significant delay associated with the new accountability reader in the control room, which required many personnel to scan their badges several times prior to the system computer accepting the informatio The above observations were discussed with the licensee for consideration in this drill critique and in preparation for the full participation emergency exercise in November, 1989.
No violations or deviations were identified in the Practice Emergency Exercise area.
4.
Modifications (37700, 37702, 37828)
The NRC inspector performed reviews of the following items involving electrical cable replacement and CRD housing supports.
a.
Electrical Cable Replacement.'he inspector reviewed procedures, interviewed personnel both craft and gC inspectors, reviewed modification documents, and observed field activities.
1).
Engineering Change Notices/Design Change Notices The inspector reviewed two ECNs and one DCN, related to the AD/DC 'calculation and ampacity
. programs for scope of change, general construction criteria',
and gC.requirements.
a)
ECN E-2-P7137, Replace 'ables due to voltage drop calculations.
This ECN was initiated by NE as part of the AC/DC calculation deficiencies.
The following WPs generated by NE as a result of this ECN were reviewed:
-
WP 2070-89 Cable replacement in the turbine building at coordinate R13, EL 565'.
-
WP 2071-89 Fabricate/install conduit supports, install supports and install new cables ES 3325, 29, 33,
II.
b)
ECN E-2-P7142, Install new raceways to facilitate the replacement. of five cables as identified by the EBASCO Ampacity Program.
The following WPs generated by NE as a
result of this ECN were reviewed:
WP 2264-88 Replace existing cables ES 141-I and ES 189-I for RHR Pumps 2A and 2C.
WP 2263-88 Install new raceways to facilitate replacement of cables and installation of new cables for Shutdown Board 3EC.
WP 2265-88 Replace undersized cable ES 2641-II, RHR Pump 2 WP 2262-88 Fabricate and install conduit supports c)
DCN W048-0A, Design of new raceways and supports and replacement of cables for the Ampacity Program.
This DCN was initiated by plant personnel to address the Ampacity Program for selected cables.
The following WPs, generated by NE as a result of the DCN, were reviewed:
WP 2387-88 Replace cables ES 2575-II, RHRSW Pump B3 and ES 2588-II, RHRSW Pump B2.
WP 2389-88 Replace cable ES 2689-II for RHR Pump 2D due to ampacity concerns.
The inspector noted during the review that the ECN/DCNs indicated the TVA General Construction Specifications G-38,
"I'nstalling Insulated Cables Up to 15,000 Volts";
and G-40,
"Installing Electrical Conduit Systems and Conduit Boxes",
were part of the installation criteria.
A review of G-38 indicated a requirement that when three single conductor cables of the same conductor size are pulled into a
conduit, the prospect of jamming is likely as the D/d ratio approaches 3.0.
The D/d ratio is the ratio of the inside diameter of the conduit and the outside diameters of the three individual conductors.
Three single conductor cables of the same conductor size shall not be pulled in a conduit when the D/d ratio ranges between 2.8 and 3. 1.
WP 2387-88 was approved for field activity.
However, FDCNs F1607A and F2025 were subsequently issued resulting in the use of MK No.
WNF-2 cable rather than MK No
~
WNF-4 without revising the design input.
As a result of this change, the diameter of the new cable caused the cable jam ratio to fall within the unacceptable range specified in the construction specification.
The licensee initiated CAQR BFN890578 to document this violation of the jam ratio requirement of G-38.
TVA provided the NRC a
copy of the CAQR.
The inspector considers the actions taken by the licensee to be appropriate.
A violation for failure to implement adequate design controls required by
CFR
Appendix B, Criteria III is not being cited because criteria specified in section Y.G. 1 of the NRC enforcement policy were satisfied.
This licensee identified violation is identified as NCV 259, 260, 296/89-46-01, Cable Pull Exceeds Jam Ratio, and requires no response.
The NRC inspector s will continue to monitor TVA activities in this area.
2).
Field Activity The inspector observed the field activities involved 'in WP 2387-88.
These activities included a
cable replacement, in
trays of six separate conductors, from the Unit 2 and 3 reactor building entrances, through the RHRSW cable chase tunnel, and to the basement of the intake structure, a distance of approx-imately 500 feet.
The inspector noted that the old cables, which were sprayed with flamastic, were covered with plastic so that the new cables would not be damaged.
During this pull, the licensee utilized approximately two dozen electrical craft, foreman and general foreman as well as eight QC inspectors to accomplish this activity in, a deliberate controlled manner.
The pull was accomplished by the hand feed and hand pull method with a
craftsman located approximately every
feet.
No deficiencies were identified during the cable pulling activities.
3).
Conduit Installation The inspector observed that the.
new cables for the RHRSW pumps B2 and B3 were routed into the Unit 2 reactor building through previously installed buried conduit.
The licensee informed the inspector that for this run of approximately 60 feet, the cables would be in violation of the jamming ratio.
However, by ensuring that the three conductors were fed into the buried conduit in a triangular manner, jamming would not be a factor for'hat portion of the pull.
The inspector, also observed that the new cables were installed in new raceways inside the Unit 2 reactor building.
b.
Control Rod Drive Housing Restraints On October 4, 1989, the inspector toured the Unit 2 reactor building and observed fitup work in preparation for adding the CRD housing restraint.
The fitup work consisted of identifying centerlines for position of the restraint beams.
This job is being performed by General Electric and managed by TVA.
Plans for the job include building an onsite mockup to train personnel performing the work.
As result of the reviews and field observations the NRC inspector determined that the ECNs,'CNs, and WPs were written
'.n accordance with approved procedures, the work in the field was performed in a controlled manner, and with the exception of the jamming ratio no significant problems were identified.
The inspector will continue to followup on the licensee's activities in the cable replacement and the CRD housing restraint modification areas.
In the cable replacement area, the identical activity will be performed for RHRSW Pumps D2 and D3 as was performed for RHRSW Pumps B2 and B3.
One NCV was identified in the modifications are Unit 2 Control Air Leakage (62703)
An inspector held discussions with various licensee personnel for the purpose of determining the status of repairs associated with known air leaks from the Control Air System/CRD HCUs.
Many of these leaks are on air line connections which represent an interface between these two systems.
The unit has had a history of leakage with limited effective corrective action until now.
During April 1989, the NRC inspector had walked down portions of the CRD and Control 'Air Systems and met with licensee personnel and determined that although man'y leaks had been repaired, many remaining deficiency tags were hung identifing other leaks which were awaiting parts or required Control Air System outage for repairs'he extent of the Control Air System leakage on Units
and
were and remain indeterminate since those CRD and Control Air Systems have not been in service for an extended period of time.
Based on the recent.discussions with licensee personnel the NRC inspector determined that many of the leaks including all identified gross leaks had been repaired.
A portion of the identified leaks are being repaired during the ongoing work associated with replacement of the Inlet and Outlet Scram Valve diaphragms in accordance with SIL No.
457.
This control activity is discussed in more detail in paragraph 6.
Additionally, air system tubing is being walked down by the licensee for the purpose of identification of any other leakage.
The remaining known leaks associated with Unit 2 require the associated portions of the Control Air System to be depressurized and are scheduled to be repaired during an upcoming outage associated with DCN W2146C.
This design change replaces the Backup Scram Valves inorder to comply with 10 CFR 50.49.
The licensee system engineer for the CRD system stated that all identified air leaks will be repaired prior to the SPOC of the CRD system.
The licensee does not classify the Control Air System as safety related.
Only those portions of the CRD System associated with the RPS scram function or maintenance of the primary system boundary are considered as safety related.
Since the licensee considers the air supply to the CRD HCUs as serving a
power generation function to maintain adequate air pressure to hold the scram valves closed during power operation, reactor startup or shutdown, the leakage was not considered to impact reactor safety.
The actual safety scram function depends on pneumatic pressure contained in the individual HCU scram accumulaters rather than the Control Air System pressure.
Either the loss of RPS trip logic electrical power or a loss of control air pressure would result in the individual scram valves opening causing control rod insertion into the reactor core.
The licensee system engineer stated that although a significant number of leaks had existed for some time leakage had not exceeded the capability of the Control, Air System pressure regulator since the valve has never been observed completely full ope Although the NRC inspector concurs with the licensee's evaluation that the condition does not impact safety, an excessive'mount of time has been allowed to pass without repairing the leaks.
This time included extended periods when the system was depressurized prior to Unit 2 core reload.
However, there does currently exist adequate ongoing corrective action to support resolution of the problem prior to restart of Unit 2.
No.violation or deviations were identified.
Maintenance Observations (62703)
Plant maintenance activities of selected safety-related systems and components were observed/reviewed to ascertain that they were conducted in accordance with requirements.
The following items were considered during this review:
the limiting conditions for operations were met; activities were accomplished using approved procedures; functional testing and/or calibrations were performed prior to returning components or systems to service; quality control records were maintained; activities were accomplished by qualified personnel; parts and materials used were properly certified; proper tagout clearance procedures were adhered to; Technical Specification adherence; and radiological controls were implemented as-required.
Maintenance requests were reviewed to determine the status of outstanding jobs and to assure that priority was assigned to safety-related equipment maintenance which might affect plant safety.
The inspector observed portions of ongoing activities associated with the replacement of all Unit 2 inlet and outlet scram valve diaphragms in accordance with GE SIL No.
457.
This effort is intended to prevent possible future diaphragm failures during plant operation.
Recent failures of these non-safety'elated diaphragms which had been in service for nine to eleven years at another BMR resulted in the issuance of the SIL which recommended replacement with new diaphragms on all BMR/4 units prior to 12 years total, material lifetime.
In the worst case, with failure of an inlet scram valve diaphragm during a plant startup, the resultant control rod insertion and static pressure could damage CRD internals.
On September 27-28, 1989, the NRC inspector observed replacement of outlet scram valve diaphragms in HCUs 54-39 and 34-51.
At the time of the inspection approximately half of a total of 370 Unit 2 scram valves had their diaphragms replaced.
The inspector noted that mechanical gC personnel were at the job location performing inprocess verification of material condition, inspection of scram valve operator internals, valve cleanliness, valve actuator spring setting, and valve cover bolt torquing in accordance with MCI-0-085-VLV003 Rev.4,
"Outlet Scram Valve Disas-sembly, Valve Packing Replacement, Actuator Replacement, Valve Seat Replacement, and Valve Reassembly."
Several old diaphragms removed from scram valve actuators were available for examination by the NRC inspecto Of those available none appeared to be deteriorated.
The mechanical gC inspector stated that of those replaced so far only
had any noticeable damage (1 with surface bubble, 1 tom)
~
The NRC inspector reviewed-RWP 89-2-02279-00 Rev.
1, which documented radiological protection measures required for this work and noted that although there were no specified requirements for the survey of the scram valves or associated internal components, radcon personnel were'hecking the valve actuators for contamination prior to work and immediately after removal of cover.
The NRC inspector was informed by onshift radcon personnel that the RWP was written for dose control only and that no radcon problems had been expected duiing the work.
At the time of the inspection no internal or external contamination had been found on or in any scram valve, actuator during disassembly.
On October 3,
1989, the NRC inspectors were notified that the diaphragm replacement work had been stopped due to a problem associated with the new diaphragms.
The recently replaced diaphragms were experiencing air leakage from the scram valve actuators via the nylon reinforcing threads located between the two layers making up the diaphragm material. Although the components were not considered safety related, vendor assistance was requested, and the scram valve manufacturer, Hammel Dahl Corporation, was on site.
Based on discussions between licensee personnel and the vendor representative it was determined that the new diaphragms were of a
different design than those used in the original installation.
Although both designs utilize nylon reinforcing threads, the orininal design did not allow the threads to extend all the way into the center hole provided for the actuator stem and therefore did not provide a leakage path.
The vendor has agreed to reproduce a limited set of 12 diaphragms of the original design for trial use by TVA.
Pending receipt of the
diaphragms and determination of long term corrective actions, the licensee has decided to discontinue work associated with replacement of the diaphragms.
No violations or deviations were identified.
Operational Safety Verification (71707)
The inspectors were kept informed of the overall plant status and of any significant safety matters related to plant operations.
Daily discussions were held with plant management and various members of the plant operating staff.
The inspectors made routine visits to the control rooms.
Inspection observations included instrument readings, setpoints and recordings; status of operating systems; status and alignments of emergency standby systems; onsite and offsite emergency power sources available for automatic operation; purpose of temporary tags on equipment controls and switches; annunciator alarm status; adherence to procedures; adherence to limiting conditions for operations; nuclear instruments operability;
'
temporary alterations in effect; daily journals and logs; stack monitor recorder traces; and control room manning.
This inspection activity also included numerous informal discussions with operators and supervisors.
General plant tours were conducted.
Portions of the turbine buildings, each reactor building, and general plant areas were visited.
Observations included valve positions and system alignment; snubber and hanger conditions; containment isolation alignments; instrument readings; housekeeping; proper power supply and breaker alignments; radiation area controls tag controls on eqQipment; work activities in progress; and radiation protection controls.
Informal discussions were held with selected plant personnel in their functional areas during these tours.
a.
Unit Status All three units remained in an extended outage as part of the BFNP recovery plan.
Units
and
are defueled with Unit 2 in cold shutdown with fuel loaded.
The licensee has identified a series of milestones for returning groups of systems to service for restart.
The second and third milestones were completed during this report period.
The second milestone was plant auxiliary systems.
The third milestone was turbine auxiliary systems, completed on October 2,
1989.
While these milestones are on schedule for restart, projected at Hay 15, 1989, more difficult milestones are forthcoming.
b; Control Room Tours Efforts to enhance control room operations were observed during this period.
Extensive relabeling was noted especially for the annunciator windows.
The windows are now clear and easy to read.
Several new operator aids have been put in place.
Red and green colored carpeting has been placed throughout the Units
and
combined control room.
Work has begun on an elevated work station for the SOS.
The licensee was responsive to a
concern that the height of the work station walls might restrict the operators view.
Walls lower in height were ordered and installed.
These efforts should help to enhance control room operations once the unit is restarted.
Shutdown Boards Systems The NRC inspector walked down the portions of the BFNP shutdown board system required for Unit 2 restart.
The system consists of eight 4160 volt and two 480 volt distribution boards.
The normal shutdown power for the 4160 volt boards is through the switch yard grid system.
The standby power for the 4160 volt boards is supplied by eight D/Gs, with each 0/G feeding a respective 4160 volt system via stepdown transformer The inspector utilized the following drawings for the walkdown:
0-15E500" 1 Units 1 and 2 Key Diagram of Standby Auxiliary Power System.
3-15E500-3 0-45E742-2 0-45E724-3 2-45E749-3 Unit 3 Key Diagram of Normal and Standby Auxiliary Power.
Wiring Diagram 4160V Shutdown Board B Single Line.
Wiring Diagram 4160V Shutdown Board C Single Line.
Wiring Diagram 480V Shutdown Board 2A Single Line.
The NRC inspector noted that the 4160V Breakers were tagged with a label which stated:
THIS BREAKER WAS OVERHAULED BY GENERAL ELECTRIC TO BE USED AS ASSIGNED CABINET ONLY and additional labels such as:
CORE SPRAY PUMP 2B 4KV SD BDC COMPARTMENT 7, S/S-0224A8058-023 1200 AMP and RHR PUMP 2B 4 KV SD BD C
COMPARTMENT 18, S/S-0224A8085-005 1200 AMP Each 4160 V circuit breaker was labeled for a specific item of equipment as well as the cabinet number.
The NRC inspector noted that the circuit breakers for the 480V shutdown board were labeled as follows:
MG SET
DN NORMAL FEEDER FOR 480V REACTOR MOV BD 2D NORMAL FEEDER 480V REACTOR MOV BOARD 2A In addition to the labels on the individual breakers, lenses and escutchians were also adequately identified.
The system was aligned to support current plant activities, all boards were clean and well maintained.
No violations or deviations were identified in the Operational Safety Verification are Site Management and Organization (36301, 36800, 40700)
The NRC staff is concerned about the continued number of events involving spills of water from closed piping systems.
During the period of September ll 21, 1989, at least five separate water spills occurred.
Similar events have occurred at frequent times since the beginning of 1989.
One such event resulted in a severity level IV violation which is documented in NRC inspection Report 259, 260, 296/89-35.
Although four of the five more recent events resulted from equipment failures such as hose ruptures or gasket fai lures and did not involve potentially contaminated water, one event resulted in the contamination of 50 sq. ft. of floor.
This event also occurred due to a
component failure but would have been less severe had operations personnel conducted close monitoring of the system.
The NRC inspectors discussed this concern with members of licensee management, who stated that the site had recently implemented a
program to emphasize greater accountability in this area, which should correct the problem and totally eliminate the frequent occurrences of spills.
Mr.
Max Harrell has recently joined TVA-BFN as the Plant Operations Manager.
He will be reporting to the Plant Manager and have Plant Operations, Work Control, and the.Chemistry Department reporting to him.
This reorganization is designed to reduce the number of people reporting directly to the Plant Manager and to redistribute the work load.
Mr.
Harrell comes from SMUD where he was the Training Manager at Rancho Seco.
He was a licensed SRO at the Salem Nuclear Plant.
No violations or deviations were identified.
Exit Interview (30703)
The inspection scope and findings were summarized on October 13, 1989 with those persons indicated in paragraph
above.
The inspectors described the areas inspected and discussed in detail the inspection findings listed below.
The licensee did not identify as proprietary any of the material provided to or reviewed by the inspectors during thi s inspection.
Dissenting comments were not received from the licensee.
One non-cited violation was identified:
259, 260, 296/89-46-01 NCV, Cable Pull Exceeds Jam Ratio, paragraph.
Acronyms BFNP BWR CAQR CRD DC DCN ECN ESF FDCN GE HCU LIV MR NCV NE NRC OSC PSC PORS PREAS QC Rad Con RHR RHRSW RPS SDSP SED SI SIL SOS SPOC SRM SRO TS TVA USQ VIO WP Browns Ferry Nuclear Plant Boiling Water Reactor Condition Adverse to Quality Rep Control Rod Drive Direct Current Design Change Notice Engineering Change Notice Engineered Safety Feature Field Design Change Notice General Electric Hydraulic Control Unit Licensee Identified Violation Maintenance Request Non-Cited Violation Nuclear Engineering Nuclear Regulatory Commission Operation Support Center Primary Suppression Chamber Plant Operations Review Section Personnel Radiological Emergency Quality Control Radiological Controls Residual Heat Removal Residual Heat Removal Service Wa Reactor Protection System Site Directors Standard Practice Site Emergency Director Surveillance Instructions Service Information Letter Shift Operations Supervisor System Preoperabi lity Checklist Source Range Monitor Senior Reactor Operator Technical Specifications Tennessee Valley Authority Unreviewed Safety Question Violation Work Plan ort Accounting System ter