IR 05000387/1987018
| ML18040B193 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 12/14/1987 |
| From: | Blough A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML18040A858 | List: |
| References | |
| 50-387-87-18, 50-388-87-17, GL-87-09, GL-87-9, NUDOCS 8712220064 | |
| Download: ML18040B193 (15) | |
Text
U.S.
NUCLEAR REGULATORY COMMISSION
REGION I
Report Nos.
50-387/87-18 50-388/87-17 Docket Nos.
50-387 50-388 License Nos.
NPF-14 NPF-22 Licensee:
Penns lvania Power and Li ht Com an 2 North Ninth Street Al 1 entown Penns 1 vania 18101 Facility Name:
Sus uehanna Steam Electric Station Inspection At:
Salem Townshi Penns lvania Inspection Conducted:
October
1987 - November
1987 Inspectors:
L.
R. Plisco, Senior Resident Inspector J.
R. Stair, Resident Inspector R. L. Fuhrmeister, Reactor Engineer Approved By:
A, R. Bloug, Chief, Reactor Projects Section No.
3B, DRP Date Ins ection Summar
Areas Ins ected:
Routine resident inspection of plant operations, physical security, plant events, previous inspection findings, surveillance, mainten-ance, refueling activities, and open item followup.
Results:
No violations or deviations were identified.
8712220064 871216 PDR ADOCK 05000387
TABLE OF CONTENTS 1.0 Followup on Previous Inspection Findings
.
2.0 Routine Periodic Inspections
.
2.1 Operational Safety Yerification 2.2 Station Tours 3.0 Summary of Facility Activities
.
~
~
~
~pa e
3.1 Unit 1 Summary 3.2 Unit 2 Summary 3 '
Spill in The Radwaste Building 3.4 Inactive Status SROs Supervising Refueling Operations 4.0 Licensee Reports
.
4.1 In-Office Review of Licensee Event Reports 4.2 Onsite Followup of Licensee Event Reports 4.3 Review of Periodic and Special Reports 5.0 Surveillance and Maintenance Activities 5.1 Monthly Surveillance Observations 5.2 Monthly Maintenance Observations
'6.0 Unit 1 Third Refueling and Inspection Outage 7.0 Management Meetings
13
DETAILS 1.0 Followu on Previous Ins ection Findin s
Closed Violation 388/84-19-01
B assed SRH While Loadin Fuel in 0 erational Condition
On April 10, 1984, core alterations were conducted in core quadrant
'A'ith Source Range Monitor (SRM)
Channel 'A'n bypass violating the Technical Specifications.
Despite the fact that there was annun-ciator indication in the control room that SRM 'A'as bypassed, the condition was allowed to exist through two shift turnovers, while core alterations were in progress.
An enforcement conference was held on May 7, 1984, and a Civil Penalty was issued on July 6, 1984.
The licensee responded to the enforcement action on August 3, 1984 (PLA-2250).
Corrective, action taken by the licensee included oper-ator training, personnel action, and revision of shift turnover practices.
The event was incorporated into the license operators requalification program, and all shifts completed the training.
Licensee management took appropriate personnel actions in regard to personnel conduct.
The shift turnover practices were revised to include several overlapping panel walkdowns.
In addition, the admin-istrative procedure for shift routine was revised to require the operators to record panel alarms and the reason for each alarm.
1.2 The licensee also conducted several reviews of operations performance to assess the quality of operations.
Reviews were conducted by management personnel, NSAG, an INPO assi stance visit, and an inde-pendent consultant.
A number of items identified during these reviews were incorporated into an Operations Enhancement Program.
The program has resulted in significant improvement in the operations performance and control room environment, as discussed in the pre-vious SALP report.
The inspector reviewed the violation response, the revised adminis-trative procedures, and observed control room operations since imple-.
mentation of the revised programs.
The corrective actions taken, coupled with the continuing Operations Enhancement Program, should prevent recurrence of similar events.
Closed Unresolved Item 388/84-28-03
- Technical S ecifications Re uire Correction to Reflect As-Built Plant In July 1984, the inspector identified that the Unit 2 Technical Specifications were inconsistent with the Unit 1 Technical Specifi-cations concerning the number of fire detectors in several common fire zone The licensee submitted Proposed Amendment 40 to License No.
NPF-22 on August 5, 1986, The proposed Amendment corrects the Fire Detec-tion Instrumentation Table 3.3.7.9-1 to be consistent with the Unit
Technical Specifications and the as-built condition.
The inspector reviewed the submitted proposed Amendment and verified the items of concern had been corrected.
Closed Deviation 388/84-34-03
Com liance With Re ulator Guide 1.47 In July 1984, the inspector identified that commitments in FSAR Sec-tion 3. 13.3 regarding Regulatory Guide 1.47,
"Bypassed and Inoperable Status Indication for Nuclear Power Plant Safety Systems" were not satisfied.
The Regulatory Guide requires automatic indication in the control room for each deliberately induced inoperable status that renders safety systems or their auxiliaries unable to perform their safety function, if this occurs more frequently than once per year.
In response to the Deviation, the licensee installed a modification which permits surveillance testing of the degraded grid voltage pro-tection relaying without disabling the automatic 4KV bus transfer to alternate power sources on loss of power.
The Unit 1 modifications were reviewed previously in Inspection Reports 50-388/85-10 and 50-388/86-11.
The Unit 2 modification, PMR-3114 was later installed during the First Refueling Outage.
The applicable surveillance procedures SM-104(204)-009-012 have been revised to include the new modification.
The inspector verified the surveillance procedure revision.
Closed Ins ector Followu Item 388/85-16-01:
RHR Checkoff Lists Did Not Reflect Status of Containment Boundar Valves In June 1985, the inspector noted that of four recently installed containment boundary valves in the RHR system, only two were indi-cated locked closed and none of the valves were indicated as contain-ment isolation valves.
The licensee revised the associated checkoff list to properly reflect the administrative controls required for these.
containment boundary valves.
The inspector verified that the checkoff lists reflected the proper status of the valves (i.e. locked closed).
Closed Viola.ion 388/85-17-01:
Not Lockin Closed RCIC Containment Isolation Valve On July 9, 1985, the inspector noted that RCIC valve 249F055, a
1-inch manual LLRT test valve which is a containment isolation valve, was closed but not locked.
Administrative procedure, AD-gA-302,
"System Status and Equipment Control", Section 6. 1.3 specified that manual containment isolation valves (including LLRT test valves)
were
to be locked.
A previous violation in 1984 had occurred for not locking closed manual LLRT test valves which are containment bound-aries.
The licensee modified the checkoff lists, locked the valve, and initiated a review of all containment penetrations.
The licensee responded to the violation on September 13, 1985 (PLA-25323.
The licensee stated that a
comprehensive review and analysis was conducted to identify containment boundary valves.
The valves were compared to the checkoff lists, and the associated draw-ings were revised to clearly identify containment boundary valves.
In addition, the licensee developed a position that while test, vent, or drain valves located on the penetration barrier are not contain" ment isolation valves in the strict sense, they should provide positive isolation of the penetration using at least two physical barriers.
Therefore, in each line which connects directly to a con-tainment penetration (i.e.,
the line is conne"ted between the two containment isolation valves, or inboard of a
single isolation valve),
there must be one locked closed valve and either a
second closed valve under strict administrative control or a threaded cap.
For those test, vent and drain valves located outboard of single con-tainment isolation valves where a closed loop is used as the second barrier, the valves are not required to be locked, but under strict
'administrative controls.
The inspector reviewed the licensee's anal'ysis of the containment isolation valves, selected checkoff lists and system 'drawings, and the revised administrative procedure, and verified the corrective action taken.
In addition, the inspector held discussions wi'th NRR staff members and Region I management and confirmed that'he licen-see's approach was acceptable.
The inspector noted that the Admin-istrative Procedure, AD-gA-302, lacked clarity in its incorporation of the position taken during the above-described review.
The licen-see revised the procedure on October 20, 1987.
2.0 Routine Periodic Ins ections 2.1 0 erational Safet Verification The inspector toured the control room daily to verify proper manning, access control, adherence to approved procedures, and compliance with LCOs.
Instrumentation and recorder traces were observed and the status of control room annunciators was reviewe Nuclear Instrument panels and other reactor pmtection systems were examined.
Effluent monitors were reviewed for indications of releases.
Panel indications for onsiteloffsite emergency power sources were examined for automatic operability.
During entry to and egress from the protected area, the inspector observed access con-trol, security boundary integrity, search activities, escorting and badging, and availability of radiation monitoring equipment.
The inspector reviewed shift supervisor, plant control operator and nuclear plant operator logs covering the inspec.ion period.
Sampling reviews were made of tagging requests, night orders, the bypass log, Significant Operating Occurrence Reports (SQORs),
and gA nonconform-ance reports.
the inspector observed several shift turnovers during the period and routinely attended work planning meetings.
In addi-tion, the inspector conducted midnight shift inspections on October 6, 1987 and weekend/holiday coverage on October 17, 1987.
2.2 Station Tours The inspector toured accessible areas of the plant including the con" trol room, relay rooms, switchgear rooms, cable spreading rooms, penetration areas, reactor and turbine buildings, diesel generator buildings, ESSW pumphouse, the security control center, and the plant perimeter. 'uring these tours, observations were made relative to equipment condition, fire hazards, fire protection, adherence to pro-cedures, radiological controls and conditions, housekeeping, secur-ity, tagging of equipment, ongoing maintenance and surveillance and availability of redundant equipment.
No unacceptable conditions were identified.
3. 0 Summar of Faci lit Activities 3.1 Unit 1 Summar Unit 1 continued with its Third Refueling Outage which commenced on September 12, 1987.
Core reloading commenced on October 18 and was completed on October 24 with the replacement of 524 irradiated fuel bundles and 240 new bundles.
The reactor vessel head was replaced and tensioned with Condition
being reached on November 5.
The Operational Hydrostatic Leak Test (1,000 psig)
was completed on November At 4:20 p.m.
on November 1, electrical switching to restore from the Unit 1 Refueling Outage auxiliary bus work was in progress when a
momentary half-scram from the 'B'PS side occurred and a Division II containment isolation signal was received.
At the time, the
'A'HR pump was in shutdown cooling and the 'B'PS system was aligned to its alternate power supply.
As a result of the containment iso-lation signal, the outboard shutdown cooling isolation valve (HV-151-1F008) closed and the 'A'HR pump tripped on a loss of suc-tion.
The cause of the occurrence was a
momentary voltage transient which was induced by the untieing of load centers 1B250 and 1B260 under Permit No. 1-87-2438.
The 'B'PS alternate supply is fed from 1B260, as is the isolation signal for 1F008, thus the 'B'PS half-scram and closure of 1F008.
The half-scram and isolation signals were reset and RHR shutdown cooling restored.
At 3:38 a.m.
on November 5, while conducting the 18 Month Functional Test of Primary and Secondary Containment Isolation (SE-159-200)
a Zone.III isolation occurred which caused actuation of the 'B'rain of Standby Gas Treatment, Control Room Emergency Outside Air Supply, and Zone III Recirculation Fan Systems.
Investigation by the licen-see determined that apparent personnel error resulted in the place-ment of a jumper in panel 1C611 instead of panel 1C623 as called for in SE-159-200 step 6. 10',
which placed the reactor water sample valve isolation logic switch AU/0214-522D in test.
The jumper was relocated to the correct panel, all affected systems restored to standby, and testing resumed.
At 8: 17 p.m.
on November 13, during the performance of the 18 Month Containment Instrument Gas System (CIG)
Remote Position Indicator (RPI) checks (S0-.215-015),
a blown fuse (F4-79) in the control logic for solenoid operated valve SO-12605 at'he Remote Shutdown Panel, caused it to close and trip the 'A'IG compressor.
The blown fuse was'pparently caused by a momentary short to ground when the cover was removed from the solenoid operator.
The fuse was replaced, the valve reopened, the compressor restarted,.
and testing resumed.
The inspector concluded that the licensee responded to the above events by implementing appropriate immediate corrective action and restoring safety systems in a timely manner, Safety systems func-tioned as designed for the initiating signal( s)
and reporting requirements of
CFR 50.72 were met.
Licensee Event Reports (LERs), detailing the licensee's evaluation of root. causes and long-term corrective actions are required for these events.
These reports are routinely reviewed by the inspector.
3.2 Unit 2 Summar Unit 2 operated at or near full power for most of the inspection period.
Scheduled power reductions were conducted throughout the period for control rod pattern adjustments, surveillance testing and scheduled maintenanc At 8:30 a.m.
on October 28, an internal electrical arc-over of the
'A'uxiliary boiler caused an overcurrent trip of its 13.8 KV supply breaker and resultant electrical transient on the T-10 startup trans-former.
As a result, the Division I Containment Atmosphere Control (CAC) valves received a spurious signal to close.
In addition, the Reactor Building Chiller switched from the 'A'o '8',
the reactor building particulate-iodine-noble gas monitor tripped and the
'A'eactor feedwater pump speed controller switched to manual.
Follow-ing the event, all affected systems were returned to normal service.
Cause of the arc-over was determined to be due to a
combination of low boiler pressure and high conductivity.
The inspector concluded that the licensee responded to this event by implementing appropriate corrective action and restoring safety sys-tems in a timely manner.
Safety systems functioned as designed for the initiating signal and the reporting requirements of
CFR 50.72 were met.
3.3 S ill in The Radwaste Buildin During the Unit I Third Refueling Outage, the instrument air system was removed from service in order to perform preventive maintenance and the service air system used as its normal backup source.
At 6:20 a.m.
on October 5,
the licensee was preparing to precoat the
'8'iquid radwaste (LRW) filter.
Fluctuations in service air pressure caused the low air pressure alarm to annunciate on the radwaste con-trol panel.
This alarm originates from a pressure switch in the air supply to the valve operators which also causes air operated valves HV-06227A
&
to drive close when low air pressure is sensed.
HV-06227A
&. 8 are
inch, 4-way solenoid air operated knife gate valves at the outlet of the A & 8 LRW filters in line to the A & 8 waste mixing tanks.
Prior to precoating the filter, the filter cake discharge valve is opened to allow backflushing to the waste mixing tank.
The valve is then shut prior to precoating the filter to pre-vent draining the precoat to the waste mixing tank.
During this event, the operator completed backflushing the '8'ilter but did not return the HV-062278 control switch to the close position since upon observation the valve was already in the close position.
The oper-ator, although aware that low air pressure existed due to the alarm, did not connect the fact that HV-062278 was closed due to the low air pressure and not due to control switch position.
The operator then commenced precoating the '8'adwaste filter.
During the precoat operation, Instrument Air was returned to service, air pressure
increased, and as a
result HV-06227B opened allowing the filter medium to flow to the 'B'aste 'mixing tank.
The waste mixing tank overflowed to floor drains which backed up on the 646 foot elevation of the Radwaste Building inside the personnel decontamination room, resulting in approximately 400 square feet of area becoming contam-inated to levels of 22 mR/hr and 25 mRad/hr.
No personnel were con-taminated.
The overflow was stopped immediately upon receipt of the high level alarm on the 'B'aste mixing tank by terminating the pre-coat and closing HV-06227B.
Decontamination ac.ivities were promptly initiated and access to the area restored.
The licensee elected to issue a press release describing the spill and made an ENS notification due to the press release.
In addition, a
Significant Operating Occurrence Report (SOOR)
(1-87-279)
was issued to,investigate and resolve the event.
3.4 The licensee has taken action to assure that the operators are aware of the effect of air pressure fluctuations on these valves and has instituted a
policy that directs the operators to terminate any processes in operation if a
low air pressure alarm is received.
During discussions with the licensee, the inspector addressed pre-vious problems with these valves and requested the licensee consider other potential long-term corrective actions which may be appro" priate.
The licensee's corrective actions will be reviewed in a subsequent inspection (387/87-18-01).
Inactive Status SROs Su ervisin Refuelin 0 erations On September 18, the licensee discovered that two assistant unit supervisors (AUS's) with SRO licenses, assigned to fuel handling operations did not meet the requirements of
CFR 55.53(f)(2)
in that AUS's do not normally perform the functions of an SRO to main-tain active status per
CFR 55.53(e).
The two AUS's had performed fuel handling operations from 3:23 a.m. to 3:00 p.m.
on September 18.
This also was a violation of the requirements of Technical Specifi-cation 6.2.2.d in that no active SRO was directly supervising core alterations during this period.
Although Technical Specification 6.2.2.d does not specifically state that the SRO must be in active status, that is the intent of this specification.
The licensee stated that prior to the latest revision of
CFR 55, dated March 31, 1987, the AUS was considered to be actively licensed for fuel handling operations only.
The AUS position was routinely assigned to refueling operations and the two individuals involved have extensive.
operating experience on the refuel bridge as both RO's and SRO' The licensee took prompt action to place an active status SRO on the refueling floor to supervise and observe the AUS's for an
hour shift before they were allowed to resume the duties of a refueling SRO.
Prior to this event, the licensee had initiated consolidation of the procedures governing
"Return to Shift" raining in an effort to simplify and clarify the
"Return to-Shift" process.
This, in addition to operator training on the event should help to prevent a
recurrence.
The licensee also stated that they are considering a
program which would assure that all AUS's with SRO licenses maintain an active status.
The inspector reviewed the Significant Operating Occurrence Report (SOOR) (1-87-257)
and its resolution and discussed the event and its significance with the licensee.
This occurrence was promptly iden-tified and corrected by the licensee.
The licensee also evaluated this event for reportability per
CFR 50.73.
The licensee init-ially determined that no LER was required.
He based this determina-tion on NUREG-1022, Supplement I, (February 1984), which provides NRC guidance on reportabi lity.
The licensee charac erized this event as a violation of an administrative requirement of Technical Specifica-tions, which is not reportable per NUREG-1022, Supplement 1.
The inspector stated that the event more closely apjroximates a violation of shift manning requi rements, for which the NUREG recommends sub-mitting an LER.
On November 25, 1987, the licensee agreed to submit an LER by December 25, 1987.
This item is unresolved pending review of the licensee's submittal of the followup Licensee Event Report (387/87-18-02).
4.0 Licensee Re orts 4.1 In-Office Review of Licensee Event Re orts The inspector reviewed LERs submitted to the NRC:RI office to verify that details of the event were clearly reported, including the accur-acy of description of the cause and adequacy of corrective action.
The inspector determined whether further information was required from the licensee, whether generic implications were involved, and whether the event wairranted onsite followup.
The fo'llowing LERs were reviewed:
Unit
87-026 Reactor Building Heating, Yenti lating and Air Conditioning Zones I & III Cross-tied
"87-027 Entry Into L.C.O. for Modification Implementation
"Further discussed in Detail Primary Containment Isolation Valve Closure Due to Spurious High Shutdown Cooling Flow Signal Rev.
1, Division I LOCA Isolation When 'A'eactor Protec-tion System Bus Power Lost Unit 2
""87-009 Reactor Water Cleanup Isolation From High Room Differential Temperature Signal
- "87-010 Auxiliary Boiler Arc-Over Causes Primary Containment Isola-tion Valve Closure 87-011 Common Loads on 125 VDC Battery Were Not Transferred Per Procedure I
"Further discussed in Detail 4.2
""Previously discussed in Inspection Report 50-387/87-16; 50-388/87-16 4.2 Onsite Followu of Licensee Event Re orts For those LERs selected for onsite followup (denoted by asterisks in Detail 4. 1),
the inspector verified that the reporting requirements of
CFR 50.73 had been met, that appropriate corrective action had been taken, that the event was adequately reviewed by the licensee, and that continued operations of the facility was conducted in accordance with Technical Specification limits.
The followihg find-ings relate to the LERs reviewed on site:
4.2.1 LER 87-027:
Entr Into LCO 3.0.3 for Modification Unit
On September 10, 198?, with Unit 1 operating at 100 percent power, Technical Specification LCO 3.0.3 was entered inten-tionally for 23 minutes.
This was a planned evolution for the purpose of performing wiring modifications which in-cluded temporarily declaring the Division I 4KV busses inoperable due to deenergization of control power through their degraded grid voltage protection circuitry.
The licensee subsequently recognized that an alternate method of performing the modifications could have precluded entry into the LCO.
The modifications were performed to increase the reliability of the LOCA load shed logic circuitr ~ ~
Following the event, the inspector discussed the intended application of LCO 3.0.3 with sta-.ion management.
LCO 3.0.3 is not intended to be used as an operational conveni" ence which permits redundant safety systems to be out of service for a limited period of time.
Its intended purpose is to provide guidance on the time limits for an "orderly" shutdown when the individual LCO or Action Statements in other specifications cannot be complied with.
Generic Letter 87-09 was recently issued to clarify the basis and intent of LCO 3.0.3.
The inspector provided the licensee with a copy of Part 9900 of the NRC Inspection Manual con-cerning STS Section 3.0.3.
In the LER, the licensee stated that they recognized that LCO 3.0.3 was not intended to be used as an operational convenience in lieu of other alternatives that would not result in redundant systems or components being inoperable.
The licensee's corrective action consisted of the compli-ance group preparing a
summary of the basis and intended use of LCO 3.0.3 and reviewing it with senior station managers and PORC
~
4.3 Review of Periodic and S ecial Re orts Upon receipt, periodic and special reports submitted by the licensee were reviewed by the inspector.
The reports were reviewed to deter-mine that they included the required information; that test results and/or supporting information were consistent with design predictions and performance specifications; that planned corrective action was adequate for resolution of identified problems; and whether any information in the report should be classified as an abnormal occurrence.
The following periodic and special reports were reviewed:
Monthly Operating Report -
September 1987, dated October 14, 1987.
Monthly Operating Report - October 1997, dated November 11, 1987.
The above reports were found acceptabl.0 Surveillance and Maintenance Activities 5.1 Surveillance Observations The inspector observed the performance of surveillance tests to determine that:
the surveillance test procec re conformed to Tech-nical Specification requirements; administra
.ve approvals and tag-outs were obtained before initiating the test; testing was accom-plished by qualified personnel in accordance with an approved sur-veillancee procedure; test instrumentation was calibrated; limiting conditions for operations were met; 'test data was accurate and com-plete; removal and restoration of the affec=ed components was pro" perly accomplished; test results met Techn:=al Specification and procedural requirements; deficiencies noted were reviewed and appro-priately resolved; and the surveillance was co..pleted at the required frequency.
These observations included:
SM-102-C03,
Month Channel
'C'D630 125 VDC Battery Elec-trical Parameter Test and Inspections, Ba:tery Service Discharge and Battery Charger Capability Test, pe formed on October 15, 1987.
S0-151-002, Quarterly Core Spray Flow Verification, performed on October 7, 1987.
No unacceptable conditions were identified.
5.2 Maintenance Observation The inspector observed portions of selected maintenance activities to determine that the work was conducted in a"cordance with approved procedures, regulatory guides, Technical Speci=ications, and industry codes or standards.
The following items were =onsidered during this review:
Limiting Conditions for Operation we-.e met while corn'ponents or systems were removed from service; required administrative approvals were obtained prior to initiating the work; activities were accomplished using approved procedures and QC.:".old points were estab-lished where required; functional testing was performed prior to declaring the particular component operable; a"tivities were accom-plishedd by qualified personnel; radiological c."ntrols were implemen-ted; fire protection controls were implemented; and the equipment was verified to be properly returned to servic These observations included:
WA S63545, Reinstallation of Standby Liquid Control System (SLCS) Squib Valves 148F004A
B, performed on October 17, 1987.
Reinstallation of Steam Separator and Torqueing of Shroud Head Bolts, performed on November 2, 198?.
No unacceptable conditions were identified.
6.0 Unit 1 Third Refuelin and Ins ection Outa e
6.1 Underwater Re air Weldin of Unit 1 Steam Dr er Repairs to the Unit
steam dryer began on October 6 to the crack discovered on September 18 in a type 308 weld joint between the 1/8 inch thick curved drye~
hood and 1/4 inch thick end plate at 215 azimuth.
Welding was performed underwater to minimize irradiation effects on eight diver/welders from Global Co.,
Louisiana using the manual shielded metal arc process (WPS-GWPS-SMAW).
After repair of the seam, the area was reinforced by welding a 3/16 inch thick plate to the hood and end plates as in the repairs performed in 1983 on the
weld seam location and on all four locations on the Unit 2 dryer.
Instrumentation placed on the Unit 1 dryer following the 1983 failure exhibited stresses which exceeded the design endurance limit of 10 KPSI to
KPSI without the stiffener plate; however, stresses were reduced to
KPSI with the stiffener plate installed.
Stiffener plates were also added to the other two susceptible weld seams at 130'nd 310', thus providing stiffness to all four identical joints.
Underwater repairs were completed on October 11.
The inspector discussed the problem with the licensee and reviewed the analysis previously performed by G;E. for repairs instituted dur-ing the outage in 1983.
The inspector had no further questions on this subject.
6.2 Main Steam Isolation Valve 1F0280 Failed Leak Rate Tests and Rework Unit
On October 12, the licensee performed Local Leak Rate Tests (LLRT)
(SE-159-021, 022, 023, and 024)
of the Main Stqam Isolation Valves (MSIVs),
as required by Technical Specification Section 4.6. 1.2.f, during the unit's third refueling outage.
The MSIVs are
inch ATWOOD and MORRIL pneumatic-operated WYE-type valves.
Excessive
leakage was exhibited through the 'O'ain Steam Line (MSL) penetra-tion X-7D, which is bounded by the inboard and outboard MSIV valves 141F022D and 141F028D and the 'D'nboard MSIV Leakage Control System (LCS) blower outboard isolation valve 139F001P.
As-found leakage was measured at 24.7 Standard Liter s Per Minute (SLM) at 23.1 psig.
The
.
valves were then stroked several times with resulting leakage of 16.9 SLM at 22.6 psig, still above acceptable limits.
The licensee deter-mined tha:
the majority of leakage was through the outboard HSIV (141F028D)
and then removed the valve'
internals and machined the seat and disk of the main valve.
Subsequent testing on October
continued to show excessi ve leakage.
As a
r esul t the licensee disassembled the pilot valve, checking for alignment and machined the pilot sea..
The following LLRT on November 10 failed grossly.
On November 12, the licensee commenced disassembly of the valve for the third time checking the seating of the main disk with a different tool then previously used and discovered a depressed area in the seat where the disk was not making contact.
In addition, the holddown tool used for pretesting the valve was checked for proper operation and determined that it was exerting a
force of approximately 8,000 pounds in excess of that which the valve would see if it had to close.
This caused the pretest to appear satisfactory by forcing the disk into the depressed area in such a way that dye tests showed the disk making contact on the complete seating area.
Valve repairs and reassembly were completed on November 17, with the final LLRT performed on November 18 exhibiting a leak rate of 3.45 SLM at 22.6 psig.
The inspector discussed the problem and the licen-see's act:on with the licensee and reviewed the results of the various leak rate tests performed on penetration X-70.
The inspector had no fur:her questions.
7.0 Mana ement Meetin On December 4,
198?,
the inspector discussed the findings of this inspec-tion with station management.
Based on NRC Region I review of this report and discussions held with licensee'epresentatives, it was determined that this report does not contain information subject to
CFR 2.790 restrictions.