IR 05000255/1987025
| ML18052B377 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 11/17/1987 |
| From: | Burgess B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML18052B376 | List: |
| References | |
| 50-255-87-25, NUDOCS 8711230275 | |
| Download: ML18052B377 (11) | |
Text
U.S. ~UCLIAR REGULATORY COMMISSION
- -REGlON. II I Report No~ 50-255/B7025(DRP)
Docket ~og 50-255 -
licensee: Consumers PoWi:r Company 2-12 ~st Michigan Avenire Jackson, MJ-49201 Facili"ty ~ame: l>.a1isads fWclear 6enerating**p1 ant Insvection At: Palist!d6 5ite, Cov-ert., "1ichigan ITis:pection Conducted:-
Octob£r*£ 'ttlrniJgh November 2, 1987 lns:pertors: I. R. Swanson
-
.
-
N.~. ~i13amsen
-~" *;;--"
Approved By:
B. L. Bur~ Chief Reactor Projec1:s Sertion 2A
_ 1nspction Summary License No~ DPR-20 lnspection on October 6 through November 2, 1987 (Report No. 50-255/87025(DRP))
Areas Inspected: Routine, unannounced inspection by resident inspectors of followup of previous*ins:pection findiTigs; operational safety; maintenance; surveillance; physical security; *radiological protection; engineered safety features walkdown; reportable events; and Regional request Results:
Of -til!? areils inspect-en no violations or deviations were identified.
DETAILS Persons Contacted Consumers Power Company (CPCo)
- D. P. Hoffman, Plant General Manager
- J. G. Lewis, Technical Director
- G. B. Slade, Executive Director, Nuclear Assurance
- R. D. Orosz, Engineering and Maintenance Manager
- R. M. Rice, Operations Mariager
- D. W. Joos, Administrative and Planning Manager
- C. S. Kozup, Licensing*Engineer
- D. J. Ma1one, Licensing Analyst
- R. E. McCaleb, Quality Assurance Director
- R. A. Fenech, Operations Superintendent
- R. A. Vincent, Director, Plant Safety Engineering T. J. Palmisano, Plant Engineering Supervisor K. E. Osborne, Plant Projects Superintendent
- Denotes those present at the Management Interview on November 2, 198 Other members of the Plant staff, and several members of the Contract Security Force, were also contacted briefl.
Followup on Previous Inspection Findings:
(Closed) Unresolved Item 255/87022-03(DRP)):
Diesel Generator (DG)
loading modeling studies indicated that the 1-1 DG would not be capable of maintaining the required voltage under the existing design basis accident (OBA) loadin The voltage regulator utilizes both voltage and current feedback in regulating output voltage. Unloaded voltage regulator response testing was conducted on September 4, 1987, and the time response of the voltage feedback in the voltage regulator was maximize In order to demonstrate DG operability and the acceptability of the current feedback,
. full load testing was conducted on October 31 and November 1, 198 While at a reduced bus voltage (2300 vs: 2400 volts) and loaded to the approximate OBA load, the P-8A auxiliary feedwater pump was then starte Voltage dropped about 400 volts for a brief (1.96 seconds) perio No loads were lost and the test is considered acceptable proof of the operability of the DG under the OBA loading. This event is discussed in more detail in Paragraph 3 (Open) Unresolved Item (255/87022-04(DRP)):
The reactor vessel low temperature overpressure protection system (LTOP) was found not to provide adequate protection. During most of this inspection period the primary coolant system (PCS) was depressurized with vent paths totaling greater than 1.3 square inches, in accordance with the Technical Specifications (TS).
Prior to restoring the vents and repressurizing the licensee reviewed and approved a lower setpoint for the LTOP
system which provided acceptable protectfon. Additional setpoint changes, Technical Specification changes and possibly long-term hardware changes will be required to provide vessel overpressure protection.. A licensee project team was established to resolve the issue An informational lette~ will be sent to the NRC by November 5, 1987, and proposed TS will be submitted within 60 ~ay No violations or deviations were identifie.
Operational Safety Routine Inspections The inspectors observed control room activities, discussed these activities with plant operators, and reviewed various logs and other operations records throughout the inspection. Control room indicators and alarms, log sheets, turnover sheets, and equipment status boards were routinely checked against operating requirement Pump and valve controls were verified to be proper for applicable plant condition On several occasions, the inspectors observed shift turnover activities and shift briefing meetings.*
Tours were conducted in the turbine containment and auxiliary buildings, and central alarm station to observe work activities and testing in progress and to observe plant equipment condition, cleanliness, fire safety, health physics and security measures, and adherence to procedural and regulatory requirements. A portion of the inspection activities were conducted at times other than the normal work wee An ongoing review of all licensee corrective action program items at the Event Report level was performe Electrohydraulic Control System As a result of a series of electrohydraulic control (EHC) system-ruptures, the most recent on August 17, 1987, the licensee initiated a series of extensive corrective actions. Prior to the October,1987, maintenance outage, the supply tubing to the turbine control valves was redesigned including welded fittings, revised supports, and flexible hoses for connection to the valves where previous vibration induced failures have been experienced. Also before the outage, Westinghouse was contracted to perform detailed monitoring of the turbine EHC system and other components which might have caused the vibratio As a result of this diagnostic evaluation, the licensee learned that the vibrations of the number four governor valve lines were of the natural frequency for the length and size of tubing. _
The redesigned tubing and improved bracing will be monitored on plant startup to verify that this contributor has been eliminate Westinghouse also determined that worn valve components likely causing the vibratio The licensee rebuilt the number four governor valv The diagnostics also determined that the electronic turbine control system was inducing a harmonic of the failed tubing's frequenc To
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eliminate this source, the impulse pressure transducer will be replaced and a band-pass filter will be installed. Additional testing will be conducted during unit startup to verify the success of these change Finally, the licensee is confident that the installation of the flexible hoses will allow some operating margin to permit the scheduling of maintenance to repair or replace components which experience induced vibration during an operating cycl The dedicated effort and resources expended in resolving this recurring problem is indicative of the "new attitude" Palisades is striving towar Purchase Agreement As a result of negotiations to settle disputes over the cancelled Midland Nuclear Plant, an interim agreement was reached between Bechtel and Consumers Power (CMS), where Bechtel and other investors
- would purchase 2/3 ownership of Palisades for $550 million.* CMS would retain 1/3 ownership, and Consumers Power would operate the plant and purchase the powe Approvals of the NRC, FERC, SEC, and Michigan PSC are required for this agreement, which is hoped to be finalized by the end of the yea Loss of Shutdown Cooling In order to replace the leaking drain valves on the four intermediate PCS cold legs, the plant was drained to a level of 617 feet, eight inche At this level the shutdown cooling (SOC) system is provided with adequate net positive suction head (NPSH) for the pump, but due to the vortexing phenomena, the system requires operator attention to maintain proper flows and pump discharge pressure The attached drawings depict the PCS layout and elevations. Note the ledge, which is created by the primary coolant pump (PCS) bowl to loop transition, which permits the intermediate cold legs to be drained for maintenanc At 6:37 p.m. on October 15, 1987, operators stopped the operating SOC pump in response to alarms and indications_ of considerable fluctuations
- in discharge pressure. The operators then noticed one of the four loop isolation valves for SOC (M0-3008) cycling open and closed, causing the. flow variations and pump cavitation. Immediate corrective action was taken by opening the valve breaker while the valve was in the closed position. Approximately twenty-six minutes later the pump was restarted and the PCS was refilled (7:06 p.m.). Subsequent licensee investigation and review at this event determined that PCS water had intermittently overflowed the PCP ledge and ran out the PCS cold leg drain valves (open although isolable) for about fifteen minutes due to induced flow and level surges caused by the cycling valv Approximately four inches of water (1,000 gallons) was required to refill the PC Primary plant temperature increased approximately 37 degrees F (92 TO 129 degrees) during the time (26 minutes) the SOC pump was of *-
The cause of the.valve cycling was**determined*to*be incorrectly placed
- jumpers for MOVATS valve *testing. The incorrectly placed jumpers were removed at about 7:05 p.m.. All MOVATS work was suspended, and a revi~w of the work was* performed. lt was determined that an electrical drawing was read incorrectly by a contract. electrical engineer, resulting in the pl~cement of the jumpers on the wrong valve (M0-3008 vs M0-3062).
No verification or second level* review of the terminal.Selection was being performed. Verification of correct placement. was being performed as required by the licensee's work pro-cedures. All remaining jumpers installed for MOVATS testing were
. rsnoved..After.management :review, MOVATS testing,was resumed with l icens~ operators in contrDl of the valves and without the use of jumpers *.
-An alert was rleciared UTirler the emergency plan at 7:49 p.m. for that period when the operators din not have control of the SOC system du to the cycling valve. Tilt! licensee is pursuing clarification of their emergency ~lan cla~sification of SDC~loss event,.he license is planning additional corrctive actions to deal with the issue of s-econd level technical revi£w in work order planning and has ulso requested an INPO assist visit. Dperator training is being conducterl to focus on lessons* learned during the event."* Pl ant
- management has also*convned a Management Review Board and determined 1:hat broader Beneric issues TIed to be.addressed including: formalized v-erifi cation of _important... f..u~;tiDns,....su.ch.~..as~--.Pn~par..atiDn._.,of.taggJng
- .-~}Dri:fers.5and:tt:Erta::in:i:*engineen:ng.:;'1Jr.D.cesses:;:.;*ithanges*;111:~:1evels"~*of,/revi-ew required during major outages: and procedural and hardware related iluman factors issue e. *fitness for Duty Jn the licens-ee's continuing program of verifying fitness for duty, an unannounced drug test was given on October 20, 1987, to 155 people,
.virtually all.of them contractor personnel.. On October 28, 1987, the results.were,comnu.micated.to the licensee: six personnel, all of them
"WDrking*for* contractors11*:had:t-est-ed:~pcsitive. --One -of *thefive had
- been tenninated earlier and access was immediately tenninated for the
- rsnaining fiv ihf! licens~ has reviewed the projects.that "these six*:-entployees worked
"*on to determine if any corrective-action was*-necessar Certain safety related work activities. were identified.and will.f>e verified i:orrect*:by inspecticn.and/or.. retest.prior to plant restar * Diesel ~rator'Loau Test Duri~ S£°ttll' *for.lJerfonnance.bf the special :ns test 1-256 tin October 31,
.. 1987 *. severa 1 problems were.encounterrl. After 1 oadi ng* ttie~ 1-1 DG to carry the startup transfonner loads, the startup transfonner.breaker was,tripped *at.11:35 a.m_
A voltage-drop t>ccurrerl*on 1:1le lC vital bus,
-5
L then being carried by the DG, and a brief undervoltage condition was experienced which caused the auto~atic starting of the 1-2 D A four hour*non-emergency reptirt of this actuati-0n was reported to the NRC at 1:43 Subsequent to this event, while measuring load parameters, a ground-alarm was received on vital bus IC and indication of decaying machine voltage in the control roo The operators attempted to restore the
.voltage, stripped loads* from the bus and then tripped the 1-1 DG at 1:06 The bus was then reenergized from station powe It was later determined that the output of the bus potential transformer was grounded through a high impedance path in the test instrumentation hookup, causing the ground alar The X-phase metering fuse then blew causing the speed controller to lose voltage control from.the control roo The test equipment was reconnected properly and the fuse replace Another effect of the bus voltage fluctuation was a blown fuse in the control scheme for the shutdown cooling flow control valves (CV-3025 and CV-3006).
Since the valves remained in their throttled positions, it was not until 2:45 p.m. that the inoperative valve controls were discovered. It was then verified that the valves were controllable from the remote shutdown panel C-3 At 3:30 p.m. the fuse was replaced and valve control verifie No continuing operability concerns exist in relation to the blown fuses since they both were associated with known causes, ie, a ground and an unusual voltage perturbatio No violations or deviations were identifie Maintenance The inspectors reviewed and/or observed the following selected work activities and verified whether appropriate procedures were in effect controlling removal from and return to service, hold points, verification testing, fire prevention/protection, radiological controls, and cleanliness where applicable: Replacement of Auxi"liary Feedwater Turbine (K-8) trip lever (FWS-24704276). Repacking of valve CV-0749 (FWS-24702213). Rebuilding of valve M0-3072 (ESS-24702584). Clean and inspect coupling on Auxiliary Feedwater Pump P-8H (FWS-24704648). Preventive maintenance on P-8A (FWS-2475940). Addition of local/remote transfer switch (SPS-24703933, FC-687).
- g; Removal of Snubbers and replacement with rigid struts (MSS~24704731, SC-87-203). Instrument loop checks for panel C-150 (PCS-24706007). Primary Coolant Pump P-500 work (PCS-24703588, 24706102). Drawing verification for configuration control of Service Water Pump
.breaker (SPS-24706244).
No violations or deviations were identifie.
Surveillance The inspectors reviewed surveillance activities to ascertain compliance with scheduling requirements and to verify compliance with requirements relating to procedures, removal from and return to service, personnel qualifications, and documentatio The following test activities were inspected: R0-32-41 Containment Local Leak Rate Testin Total "as found" leakage was 31,889 SCCM which is less than half the allowable leakage of 65,200 SCC The licensee program to improve containment isolation valve reliability is credited with the 16%
improvement in results over the last test in early 198. T-FC-627-1-01 Test of replacement meters on DG 1-1 (T-FC-627-1-01).
Several meters did not respond properl An appropriate change was implemented and verified proper by a subsequent tes R0-27 Low Temperature Overpressure Protection System Functional Tes DW0-1 Daily Control Room Surveillanc SH0-1 Operators Shift Surveillanc No violations or deviations were identifie Physical Security The inspectors observed physical security activities at various locations throughout the protected and vital areas including the Central and Secondary Alarm Stations. Periodic observations.of access control activities including proper personnel identification, badging *and searches of personnel, packages and vehicles were conducte The inspectors verified appropriate security force staffing and operability of search equipmen Protected and vital area boundaries were toured to verify maintenance of
integrit Illumination was verified to.be adequate to.support patrol and Closed Circuit Television (CCTV) monitor observation CCTV monitor clarity and resolution were also observed. The inspectors periodically verified that appropriate compensatory measures Wf!re taken for degraded or inoperable equipment and breached boundari-e No violations or deviations were identifi~.
Radiological Protection The inspectors made observations and had**,tfiscussicns i:onc-erni.ng.r.adio1Dgi.ca1 safety practices in the radiation controlled areas including: verification of radiation levels and proper posting; accuracy and currentness of area status sheets; adequacy of and compliance with selected Radiation Work Permits and high radiation procedures; and "the ALARA (As Low AS is Reasonably Achievable) program. Implementation of.dosimetry requirements~
proper personnel survey (frisking) and contamination control (step-off-pad)
practices were observe Health Physics logs and *dose records were routinely reviewe No violations or deviations were identifie.
Engineered Safety Feature Walkdown The inspector performed a walkdown of the.Low Temperature Ovefllressure Protection system and.verified: that __ each.. aa:ess1b1e.. v.alve.tn.th£!
fl owpath was in its required pos itton'*:and:.::nperab1:e~'.'::that*;:power'::was aligned for components that actuate on JJ.n initilltion signal, i:hat essential instrumentation was operable, and that no conditions existed which could adversely affect system operation. The inspector also reviewed the implementation of a more conservative~ lower setpoint under SC-87-32 No violations or deviations were identifie.
Licensee Event Reports Through direct observations, discussions witti.-*lit:ensee, personnel, and review of records, the inspectors examined the following ri>ortable events to determine whether:
reportability r-equirernerrts were met; inunediate corrective action was accomplished as appropriate; and corrective action to prevent recurrence has been accomplished.per the Technical Specification (Closed) LER 255/87-031_:
Diesel Generator {DG) 1_;1. was. declared
- inoperable on September 3, 1987 due.tD".potential*Ifeficiencies:.;n:tile exciter voltage regulato As documented in *Paragraph 3~f of this report, subsequent testing performed on September-lkand November 1, 1987, flas demonstrated the acceptable performanc~ of tht! D6. The computer load model which predicted voltage collapse will,.be-*updated*.
0tort!flect th actual performance recorded during the rer:art tes B
-The handling of this event from a management and technical standpoint-represent the level of excellence the licensee should strive.toward in all area No violations or deviations were identifie. Regional Requests An investigation regarding pos.sibly excessive ambient temperatures in areas containing electrical equipment and instrumentation (especially
- during the summer months) was requested by Region III, by memorandum to
- Resident Inspector staffs dated June 27, 1987. Specifically, the request asked whether a program was in existence to monitor temperatures in such D.reas, and whether appropriate limits on such temperatures had been established by the licensee. Presently, the Palisades Nuclear Generating Plant program consists of three ceiling-mounted ambi~nt temperature monitors which alarm in the Control Roo These monitors are located in the cabie spreading room and in the 1-C*and 1-D electrical switchgear room Calibration is done biennially, to an alarm temperature of 104 degrees f ahrenhei *1ne licensee also periodically reviews ambient temperatures from the
- standpoint of adjusting the heating, ventilating, and air-conditioning
.. system (HVAC) balanc One such review of ambient temperatures was done
.. wi.th... the.HVAC turned off and resulted in some changes being made, such as
'.),~3;;:am:Ji_ng!'.f,ims~:**:so that even if the HVAC were i noperab 1 e, with a few manua 1 actions the temperatures would still be acceptable for a reasonable tim As a result of their changes, the licensee states that excessive ambient temperatures have not been a proble. Management Interview
- A management interview was conducted on November 2, 1987, following the conclusion of the inspectio The scope and findings of the inspection
.. were*-discusse The inspector also discussed the likely information content of the inspection report with regard to documents or processes
'reviewed by the inspectors during the inspection. The licensee identified the.Westinghouse report on the EHC system as proprietary, but discussions with Westinghouse determined that the results noted in Paragraph 3.b of this-report were not proprietar I
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