IR 05000237/1992028
| ML17179A696 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 01/15/1993 |
| From: | Falevits Z, Gardner R, Winter R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML17179A694 | List: |
| References | |
| 50-237-92-28, 50-249-92-28, NUDOCS 9301250030 | |
| Download: ML17179A696 (10) | |
Text
U. S. NUCLEAR REGULATORY COMMISSION
REGION III
Reports No. 50:-237/92028(DRS); No. 50-249/92028(DRS)
Dock~t Nos. 50-237;_ ~0-249 Licenses No. DPR-19.; Nq.- *oPR-25 *
Licensee:
Commonwealth Edison company Opus West".II opus Place Downers Grove, IL * 60515 Facility Name:
Dresden Nuclear Power station.- units 2 and 3 Inspection At:
Dresden Site, Morris, IL 60450 Inspection Conducted:
October 26, 199-2, through January 4, 1993 Inspectors:
/-:/(-'f3 Date 1/:6"/is R. Winter Date Approved By:
- -Y,~_-"l.(* ~:_-_--?;*,//'..
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cJ'1 K /.:_-,:::rr--..: 1\\1"1: * Gardne i Chief Date Plant Systems S~ctio' Inspection Summary_
Insoection on octobei 26. 1992, thrdugh January 4, i993 (Reports No. 50-237/92028(DRS); No. 50-249/92028CDRS))
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Areas Inspected:* Announced inspection of previously identi-fied *
items; Licensee Event Reports LERs; fuse control program; 125Vdc *
ground detection process; design changes for physical sepaiation
. and control room annunciators; _:design basis program;. and modifications- (37700).
- Results: Of the seven areas inspected, two apparent violation~
were identified: (1) failure to follow existing procedures
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r~quiring entry l.nto an administrative LCO and _the isolation-and
- removal of 125Vdc system grounds (Paragraph 4.2); and (2) failure to promptly replace overs~zed fuses which could result in miscoordination and.damage to safety related components and circuits {Paragr~ph 4.3).
One non-cited violation was identified during reviews of cable.separation. (Paragraph 4. 5).
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. 930125'0030 930120 PDR ADOCK 05000237 G
. PDR
Inspection Summary
- ol.lring the course of the inspection, the following were noted:
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o Licensee progress io closeotit remaining EDSFI {tems was *
- .. satisfactor O Design basis program, master equipment list upgrade program and component ciassif ication program were considered good mapagement initiative *o Fuse c:ontrol program appeared to need increased management involvemen *. o Procedure~ to enter administrative LCOs, locate and isolate
. 125Vdc grounds were not consistently followed.,
O
.Proposed.design changes to control room annunciators appeared appropriate and should improve reliability of control room anriunci~tor o Modification process was detailed and comprehensive for the packages reviewed..
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DETAILS
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1.0 Principal Per~on* Contacted Cominonwealth Edisori company CCECol
- J. Kotowski, Production Superintendent H. *Massin, BWR Systems Design Superintendent
- J. Gates,* Assistant Technical Staff Supervisor
+*E. Carroll, Regulatory Assurance, NRC Coordinator
- D. VanPelt, EDSFI Director
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- B. Viehl, Nuclear Engineering Department Site Supervisor
+*R. Sparks, Technical staff.Engineer
- D. Barrett, Stiperviso~, Quality Verification s. Dileto,* CECO BWR System Design
- u. s. Nuclear Regulatory commission CNRCl W.. Rogers, * Senior R.esident Inspector
- Denotes those present during the initial exit meeting on December 11, 199 *
+Denotes thqse parti~ipating in the exit telecon on January 4,* 199.0 Licensee Event Reports CLER*> Followup (Closed) LER 249/92-004: Inadequat~ calculation to determine degraded voltage relay trip setpoint put
- plant in an unanalyzed safety c6nditio The electrical_ distribution system functional inspectio (EDSFI) team determinedthat the degraded voltage setpoint was set too.low to adequately prot~ct safety related lll.Otors during a LOCA.concurrent with a degraded vpltage condition that hovered-above the degraded
. voltage relay setpoint.. (3708 to 3784. volts) *. -
The licens.ee performed a voltage drop caiculation *for the assumed worst-case 480 volt motor load (Unit 2~
Division 2, diesel generator* cooling water*pump (DGCWP)).
The DGCWP critical.starting and running voltage requirements at the 4160 bus were* 3960 and-3950 vol ts, respectivel Compensatory m.easures were initiated until new degraded vo'ltage setp.oints. were established.* in early. 1992.. The new setpoint calculations.were developed using cur+ent setpoin techniques.,The inspectors reviewed the new setpoirit calculations and found them to be acceptable.. Tl) is item is considered closed. *
. (Closed) LER (237 /91-013, Revision 1):
250 VDC battery discharge voltage below acceptance valu The licensee added four additional battery cells to the 250 Vdc
.battery and conducted-a battery performance test that
- verified that the battery terminal voltage did not. drop
.. below the 210 Vdc level during the crucial first six minute period, when many large loads were adde This i tern *is considered closed.**
' * (Closed) LER (237/91-017):
Spu~{ous closure of AC
.solenoid operated primary containment isola'tion valves.
during fast bus transfer The*isolation valves close when power is removed from their solenoid~.. During fast bus transfers (approximately 83.35 msec), the spurious closing of Group II isolation valves was increasin The licensee identified that se~eral GE type 12HMA111B9 relays were dropping.out during the transfer. *Testing identified the HMA relay drop oµt *
time *was approximately 100 msec. * _
The licensee replaced the Pnit 3 JiMA relays with GE
- type 12HGA17S63 relay The measured drop out times~of the HGA relays _were greater than 300 msec> Similar
- relays in Unit *2 will be replaced during the nex refueling outage~ This item is considered cl6se.
Action on Previously tdentified Inspection Findings (Open). Unresolved Items C23i/91038-0~CDRSl and (249/91038-0GCDRSll:
Adequacy of cable ampacity of some *cables routed in safety related and balance of plant (BOP) cable trays had not been confirme Approximately 953 cable tray routing points were identified as potentially thermally overloade The licensee performed an analysis which consisted of*
taking a sampl~ of 10 (five from each unit) cable-tray routing points believed to represent the worst case thermal condition The actual full load current on power* cables was used rather thafi the origina conservative current value which was based on cable siz The control cables we~e considered as a negligible hea.t load and deenergize The thermal margin was the additional number of power cables that could b~ added without. exceeding the present SLICE
calculated ampacity value Preliminary results showed that evaluation of engineering assumptions and*
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replacing conservative assumptions with actual current values reduced the number of potentially overloaded * *
routing points but did not eliminate the potential for individual cables to be thermally overloade on November 12 ! 1992; the"' license*e-*took field *current. and
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- temperature measurements on the worst case tra The
'licensee extrapolated these external temperatures to get an estimate of the internal cable temperature However, the inspectors noted inconsistencies in the methodology used which could leave doubt whether ~he
- thermal overload conditions :could be easily resolve If cable ampacity is found. *to be inadequate, allowable conductor temperatures could be exceede Higher temperatures could degrage the cable insulation and its ability to withstand the* 40 year design life and**
accident load condition Pending licensee evaluations,_ experimental results and NRC review, this item ~ill remain ope (Closed) Open Item (237/91023-0SCDRP)):
Adequacy of cable ampacity. with thermal. overload has not been *
confirme This item. will be followed by unresolved items (237 /91038~05 (DRS) and -(249/91038...;06 (DRS)).. This-item is considered close *
(Open)
Open Item (237/91038-06(DRS):
The EDSFI team
_found the Unit 2/3.EDG room to-be excessively ho The 1 icensee * committed to_ :monitor the 2 / 3 * EOG room
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. temperature each shift.* During the period of August 17 to *september 28, 1992~ the cabinet mounted thermometer was removed arid other thermometers were used; however, 51 shift re*adings were not talce The licensee will*
evaluate whether readings taken during this second
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period were comparable to previous temperature readings and if the missed readings during this period would require more data be taken to reach an. engineering evaluatio *
No.violations or deviations-were identifie.0 'Electrical Systems Reviews-4.1 Control Room Annunciator System Design Changes The inspectors review~d the iicensee's special investigation reports for General Station Emergency Procedure (GSEP)
events and the proposed design changes and_ corrective
- actions to pr~vent recurrenc Each of the reports dealt with instances where the qontrol room annunciators were
- los No concerns were noted with the proposed-modif ications.. The inspectors were -informed that the Unit 2 * *
modification will _be comp*leted during the 1993 outage and-Unit 3 during the 1994 outag The inspectors determined that, when implemented, these actions should improve the
_design *and reliability of the *annunciator syste T
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4 ~ Review *of 125Vdc Ground* Detection and Isolation Process During the review of.past control.room annunciator failures, the inspectors noted that on September 22, 1991, all Un.it 3
- control room annunciators were lost when an undersized fuse.
blew~.The potential cause.for this.event was attributed to *
intermittent grounds in the 125Vdc syste Further NRC review of groun~ detector* charts revealed that o September 26, 1992, the Unit 3 125Vdc ground detector recorder indicated a full 125Vdc ground on the syste This ground -was_ present for approximately 7 hour8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> The
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Operator's Log also documented the 125Vdc battery groun * Proc,edure DOP 6900-07, Revision 9,
-"1~5 Vdc ground..
detection", required that at DC grounds above 60Vdc,* the procedure be immediately implemente For a ground above
- * 115Vdc, the procedure required that a 14 day time clock (administrative LCO) be entered and actions be taken-_ to
_locate the ground and remove it. *. The procedure further stated that-if the ground' c'ould not be loc~ted within. 14 days or if it was located but could not be isolated to permit repair, a Justification for Continued Operatiori- (JCO)
be prepare In addition, Procedure. OAP 07-05, Revision 9,
"Operating Logs and Record~", *Paragraph B.5, required that when a Limiting con!iition for Operation (LCO) entry..
_condition.occurs, *the event will be.logged *in the LCO Lo However*, no entry for this ground condition on unit 3 was made on the LCO Log and no Work Request was w~itten to identify and, remove the groun *
- The. inspectors also noted that on November 3,. 1992, 125Vdc grounds werepresent in both.Units 2 and-3 for approximately 7 hour8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> Work Requests (WRs) 013806(U2) and D13836(U3) were written and the event was logged in the LCO Log for unit 3 on). The Unit 3 WR and the LCO Log indicated.that tl)e ground was ori bus 3A-2, circuit #1 ~he LCO ~as exited on November 6; * 1992; however,- the licensee could not provide'
evidence that Procedure DOP 6900-07, Revision 9, was performed or that _actions were taken to identify and remove the grounds.
On November 12, 1992,.a 125Vdc ground was present ~n Unit 3 as.evidenced by the LCO Log entry that indicated that the ground was again on bus 3A-2, circuit #1 The. ground
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detection procedure was not performed and no.* WR was. issued. * *
to locate and remove this groun On Nove_mber 16, 1992, *
.work request Dl4l29 was written to document a 90Vdc ground -
- on Unit The "Work Performed" section of the WR did no indicate that ~ction was taken to :identify and remo~e the ground.-. ( ***
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The inspectors considered the failure to follow plant procedure reqUirements to (1) locate, isolate and.remove the 125Vdc grounds, (2) enter-an administrative,LCO, and -(3)
issue a JCO when appropriate, to be an example of a violation of 10 CFR 50, Appendix *a, criterion v (237/9~028-0l(DR$); 249}9202&-0l(DRS)).
Fuse Control/Upgrade Program In early.1992, the licensee initiated a Fuse.Controi/Upgrade Program foilowing EDSFI findings, issuance of NRC
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Information Notice 91-51 and an INPO initiative-to properly size *and classify all. installed fuse As of December 1992, *
the licensee completed walkdowns of* approximately 65% of the.
known.safety related fuses~* The licensee established a fuse
- list,* is.sued a fuse control procedure and document~d various fu_se *discrepancies* in Technical Problem Reports (TPRs).
The TPRs were then. submitted to Sargent & Lundy (S&L) for.
evaluation and analysis to determine whether the fuses were correctly sized and coordinated and to provide proposed'
corrective actio _NED then evalu.ated S&L' s analyses prior to sen_ding the. TPRs to Dresden system engineers for fie_ld implementatio *
The inspectors reviewed-five of sixteen-licensee-Nuclear Engineering Department (NED) and S&L evaluations_ issued to resolve field identified fuse discrepancies~ The inspectors reviewed the-*safety related fuse circuit discrepancies
documented in ~P~s DF-014j, 0147, Oi49, 0184 and 0186, where the* installed fuses did.not correspond with vendor desig * *.and drawing requirement The fuse discrepancies were identified in *February and April 199 The design
. analysis/evaluation which *included vendor input was completed in. *June l992 when the licensee and Sargent & Lundy engineers concluded that, under a fault.condition, the.
currently installed fuses would not provide adequate circuit protection or coordination and could result in damag~ to
safety relai;.ed co_mponents and circuit The proposed corrective action was to replace the discrepant fuses with the.correct size.and typ The following observations were made during the- _review of the TPRs:
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TPRs DF.-0147 and DF-0186 docuriiented that the currently installed fuses in the excitation and control circuits
- of EDGs 2 and 3 were JOA and 40A-fuses rather than the vendor specified 25A fuse The engineering evaluation stated-that the currently installed fuses did not
provide adequate circuit and component protectio Under.a fault condition, these fuses could cause a loss-of -power -to*-excitation--and-control-- circuits for* the---
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. 0 standby die.sel generator The licensee Is. evaluation '
relied on the redundant EOG to provide power if a fault occurred on one EO The engineering evaluation
.recommended that the ex_i~ting. fuses *be replaced wit the 25A fuses specified by the vendo.The_ inspectors_
determined that a TPR was not issued for the oversized*
fuse*in the*unit 2/3 EOG circuitry; neither wereWRs issued to replace the oversized fuses on all three EDGs until *questioned by th_e inspectors on.December 12, 199 In addition, a replacement-schedule had not been established to replace the improperly sized fuse The replacement fuses and fuse holders were hot ordered until November 199 *
TPR *DF"".'0143 documented a discrepancy in* the Unit 3.
Uninterruptible Power Supply '(UPS) _circuitry,- where an sooA fuse was installed instead 'of the required 500 fuse.. The UPS provides 120Vac to the lE ESS bus*.
The inspectors questioned the licensee whether Unit 2 was inspected to verify if the appropriate fuses were
.installed in similar UPS circuit The inspector was informed that this was not accomplished yet, even though the Unit 3. fuse discrepancy was identified on February 14, 199 The inspectors noted that Work
- Request (WR)* 010349 was. issued on June 30, * 1992; :to replace-the_Unit 3 fus However, as of this *
inspe~tion, the WR has not been *assignec:l a work:
priority, nor had_it been processed for field implementatio on January 4, 1993,-during a telephone conference requested by the licensee, the inspectors were informed that.while attempting to replace the SOOA fuse during a short outage on December 28, 1992, the licensee noted that the installed fuses were actually 500A rather_ than the SOOA noted during the walkdown performed in Fepruary 199 The licensee replaced the fuse with a like~for-like fus Incorrect identification of fuse sizes is considered to be a weakness in the licensee'~ fuse inspection progra O TPR DF-0149 and DF~Ol84 documented that the installed fuses in the* RWCU demineralizer solenoid arid.LPCI valve 1501-25A circuits were oversized and did.-- not coordinate with the upstream -circuit breaker The licensee's evaluation recommended that these fuses be replaced~
No docUiilentation was available for review to ind-icate that corrective action was initiate.
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The inspectors noted that since May 1992, the licensee had several.opportunities to replace the oversized fuses' on both uni t However,.the l*icensee had not developed a schedule to replace the incorrect fuses i:ioted during the February through April 1992,walkdown, ~ -, ___,-- -., ~ --
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- The-licensee's failure to take corrective actions to replace improperly sized fuses used to, protect safety related_
components and circuits is coni:;;idered a *violation of 10 CFR so, *Appendix B, Criter.ia XVI {237 /92028-0*2 {DRS); 249/92028-0 2 {DRS)) * -
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The inspectors per!ormed field inspections* of selected fuses installed in safety related panel ~ost of the fuse ty'pes and sizes could not be verified without removing the fuses because original labeling infopna~ion.was*not present on the fuse One oversized fuse was discovered during* inspector walkdowns {FU16, a.SA fuse was installed rather than t;.he 3A fuse shown on draw1ng 12E-6811AP,- Revision 1).
Additionally, porcelain fuse holders located in control room.
.. HVAG panei, and shown on wiring drawing 12E-6811AP, Revision i, were stamped_ "withstand rated 10, 000 Amps: rms-"; however, some of the fuses installed in these holders were rated. at 200,0dO Amps. rms *. The licensee was. in the process 'of evaluating this findin Pending*licensee action and NRC review,* this matter is cons'idered -to be an Open* Item
{237/92028-03{DRS); 249/92028-03{DRS)) *.
Walkdowns for Design Basis Program The licensee's ongoing Design Basis Program was rev.iewed to determine the progress and direction taken by CECo to
~rovide retriev~ble desi~n basis infor*atio Design bases for four systems were being 'finalized.* The program was con*iderea to be a positive managemerit initiativ.S Physical separation Between*Electrical Divisions
- on November 26, 1991, the licensee discovered that the. power feed cables t6_480V MCCs 28-2, 28-3; 29~2, arid_ 38-2 for Units 2-and 3 were misclassified as BOP feed cables and
.consequently not physically separate(j.between electrical divisions {LER-91-042). * This condition was con_trary to the licens*ee's design criteria for divisional*. separatio The -
affected cables were promptly rerouted in safety related
- trays and identified with the c_orrect segregation cod The licensee's ongoing Master Equipment List Upgrade Program and
.the. component Classification Program may :id~ntify if additional cable segregation inconsistencies exis These programs are considered positive management 'initiativ_e The NRC considers the licensee's failure to originally install arid maintain these c~bles ~s safety related to be_ a violation 10 CFR so, Appendix B, criterion III, and of the licensee's separation.criteria wh1ch states, "a safety-
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related cable shall be only routed within the.raceway system of the division to which it;. is assigned", as well as
Regulatory Guide 1.97 and IEEE 279 guideline However, the liqensee _identifi_ed,this violation<and--it -is not-- being~ cited* -
because the criteria specified in Section VII.B.(2) of.the
"Gerieral st~tement of Policy and Procedures foi NRC Enforcement -Actions,n (Enforcement Policy, io CFR Part 2,-
Appendix c ( 1992)), were satisfied.*
4.~ Design Control/Modification Revie~
The inspectors evaluated the licens~e's performance and programs relating to-design changes and modification The inspectors reviewed two modification package Areas verified included review and approval process, post modification test requirements and execution, training, 10 CFR 50.59 reviews, and.satisfactory completion of design -
,requirements. *The following mod~fications were r_eviewed:
{a)
M12-2-91-022, High Pressure Coolant Injection (HPCI)
Val~e 2301~10. Interposi~g R~lay Additio (b)
M12-~-~1-021, Addition of 4 C~lls to Unit 2 250Vdc Batter The modification packages were compreh~nsive and detaile The inspectors concluded the licensee ~as adequately implementing the.design control process for these
modifications.. Open*Items Open i terns are matters which have been d.iscussed with t_he licensee, which will be. reviewed further by the inspector,*
and which involve some action on the.part of the NRC or licensee or bot Open items disclosed during this
- in_spection are discussed in Section 4. 2 of this repor ; O.Exit Interview
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The inspectors met with licensee representatives (denot~d in Paragraph 1) at.the conclusion of the inspection on
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December*11, 1992.* The inspectors summarized the scope and findings of-the inspection activities. -The license acknowledged the inspection finding The inspectors.also discussed the*likely informational* content of the inspection*
report with regard to documents or processes reviewed by the inspector.during the inspection~. The licensee did not identify any *such document/processes as.proprietar Subsequent to_the*ihitial exit, the inspector conducted an
- additional.exit with tbe licensee by telephone on.January 4,
- 1993, after the licensee, uncovered additional information which affected one of the violations. -
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