IR 05000237/1991003
| ML17202V025 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 03/08/1991 |
| From: | Burgess B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML17202V023 | List: |
| References | |
| 50-237-91-03, 50-237-91-3, 50-249-91-03, 50-249-91-3, NUDOCS 9103190005 | |
| Download: ML17202V025 (14) | |
Text
- . U. S. NUCL'EAR REGULATORY COMMISSION.*
REGION III
R~ports No. 50-237/91003(DRP); 50-249/91003(DRP)
Docket Nos. 50-237;.50-249 Li~ensee: Commonwealth Edison Company P. 0. Box 767 Chicago, IL.60690 Licen~es N6.. PPR-19; DPR-2.Facility Name:
Dresden.Nuclear Power Station, Units *2 and 3 Inspe~ti-0n At:
Dresde~ s{te~ Morris, IL
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Inspection Conducted:** December 30, 1990 through February is, 1991 Inspectors:
D. E. Hills M. S. Peck J. 0. Monninger Inspection Summary Oat~ *
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Inspection during the period of December.30 through February 15, 1991 (Reports No. 50-237/91003(DRP); No. 50-249/91003(DRP))
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Areas Inspected:
Routine unannounced resident inspection of previousl identified inspection items, plant operations, maintenance/surveillance,.
engineering/technical supper~. safety assessment/quality verificatidn,
$ystematic evaluation program items, TM! action plans requiremen~s follow~p and report review..
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Results:
One violation was identHied involving.a react.or protection system re$ponse time testing surveillance proced~re which prescribed usage of test eq~ipme~t in a fashion that resulted in measuremerits that were inconsistent with Technical Specification requirements (Paragraph.4.b.l).
One unresolved item was id~ntified which invo~ved the adequacy of design control measures regarding input parameters and.. calcul~tions for a
.modification package.* The.item is pending* a v.erbal response from the licensee
. on specific concerns that were expressed to th~ licensee (Paragraph 5.a).
9103190005 ~10308 PDR ADOCK 05000237 Q
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p l ant 0 per a"t i 0 n s..
Problems delineated*in this report are indicative of the ~ontinuation.of the declinirig trepd previously reflected in Inspection Report.No. 50-237/90027; 50-249/90026 and No. 50-237 /90023; 50-249/90023 in this fun ct fona l.are The failure to adequately utilize the drywell venting procedure or to obtain temporary_ procedure change prior to deviating from the drywel l venting
- prricedure was a commonly accepted practice~ Plant manigement did not appear to be aware Q.f.this specific practice and had taken actions.in response t previous vio~ations to ensure adhe~ence to procedure These.actions would *
~ppear to have been.ineffective (Paragraph 2).
The inspectors regarded the licensee's pr~ctice of not decliring equipment inoperable when it was rendered
. non-functional for surveillance testing to represent weak or non-existent controls (Paragraph 2).
However, the inspectors* observed the operators perform adequately during the conduct of several startu*p and shutdowns, including some in an ibnormal condition (Par~graph 3).
Maintenance/Surveillance Problems delineafed in this**area are in.dicative of the continuation of the declining trend previously reflected in Inspection Report No. 50-237/90027; 50~249/90026 and No. 50-237/90023; 50-249/9002 The basis for thii conclusion was the inattention to.detail of maintenance personnel involved. in a June 1988 surveillance procedure change.and in conduct of the surveillance since that time resulting. in a faf]ure to ensure ~he proper application of test equipment (Paragraph 4.b.l). Another.basis was the the damage to turbine co~ponents and*
resulting extension of the Unit 2 refueling outage being indi~ative of continuation of work practice proble~s enc~untered eatlier in the o~tage (Paragraph 4.a).
One item, however, reflects a strength in this functional are The inspectors
- .. regarded the licensee's identification of a failure to test Standby Gas*
Treatment System heater interlocks t~ be an~example of the effectiveness of the Procedure Upgrade Program and the diligence and attention to detail exhibite by the maintenance staff performing the review (Paragraph 4.b.2).
Engineering/Technical Support:
The long delay* in the licensee's analys~~ of cracks found in Unit 2 reactor vessel head closure studs in January 1989 was.regarded by the inspectors to be a failure of Tec'hn1cal -Staff personnel to pursue resolution in a timely manne~. This reflected inspector concerns regarding the effectiveness of-Technica*l Staff interface with offsite groups such as the Systems Materials Analysis Department (Paragrap~ 5.b).*'
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Safety Assessment/Qual{ty*V~r1fication A ~eview of the li~ense~'s* quality~control (QC) feedback sheets indicated the QC or*ganization's initiative to go beyond requi_remerits in pursuit qf problem identific:ation and resolu~ion. (Paragraph'.6).
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DETAILS *Persons Contacted
~Commonwealth Edi~on Co~pan * Eenig~nbur~, Station Manager
- J. ~otowski, Produciion Supetint~nderit*
. G~rner, Technical Superi~tendent
E. Mantel, Services Director
- D. Van.Pelt, A~sistant Superinterident - Mafhtenance J. Achterberg, As~istant Superintendent~ Work Planning*
- G. Smith, Assistant Superintendent~Operations
- K, Peterman, Regulatory Assurance Supervisor M.. Korchynsky, Operating Enginee *
B. Zank, Operating Engineer J. Williams, Operating Engineer
. R. Stobert, Operating Engineer T. Mohr, Operating Engineer M. Strait, Technical Staff Supervisor
- l. Cartwright, Quality Control Supervisor J. Mayer, St~tibn Security Administrator D. Morey, Chemistry*Services Supervisor D. Saccomando, Health Physics Services Supervisor
- K. Kociuba, Nuclear Quality Programs Superintendent*
- D:
Lo~enstein~ Regulatory A~surance Analyst.
- B. Viehl, Nuclear Engineering Department.Desfgn Supervisor
- K. Yates, Onsite Nuclear Safet~ Administrator
- T. Gallaher, Nuclear Quality.Programs Engineer
- G. Kusnik, Quality Control
- D. Gulati, Master Instrument Mechanic
- The inspectors also talked with a~d intervi~wed several other licensee employees, including members of the technical and engineering *staffs, reactor and auxiliary operators, shift engineers a:nd foremen, electrical, mechanical and.instrument personnel, and contract security personne.
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- Denotes, those attending bne or more exit inte~views conducted informally
- at various times throughout the inspection period; * Previo~sly Identified In~pection !~em~ (92701 and 92702)
(Closed) Violation (50-237/90017-02): * Several examples of inadequate equipment outages which resulted in adverse consequence The inspector reviewed the licensee's correcfiv~ actions including ~revisions to ensure
. appropriate drawings were utilized.and development of a self check progra The inspector~ determined that measures had been taken in accordance with *licensee commitments a*nd have no other cohcerns in this area.
- (Closed) Unresolved.Item (50-237/90023-09):* -Review usage of quality control* feedback iheets. * Thi~ item is addressed in Paragrap~ The inspector has no further concerns 'in this *are (Closed) Unresolved Item (50-237/90027-04):
On December*], 1990; the irispecto~s f6und that the sefvic~ air supply~o*three of the Unit 3 *
drywe 1 J purge and vent il at icin *fan.dampers had been dfsc.Onnecte Further revie~ found that the length of time that the damp~rs were disconnected*
tould not be positively determined, due to the ~umber of procedures *
involvi~g inerti~g. deinerting~ and venting of the containment which
. specified mani pul at ion of the drywe 11 purge dampers. *However, it was
- found that venting of the drywell.was performed on December 3 and again on December 5, 1990. *
According to D~esden Operating Proced~re (DOP) 1600-1, Revision 5,
"Normal Venting *of Drywell or Torus, 11* the.air supply to the dampers was required to be disco~n~cted to cause the dampers to fail.open and then recorinected. following the evoluti-0 Di~cussions with the cognizan~
Nuclear Station Operators (NSOs) indicated that the NSOs were venting the drywell on December 3 and 5-through what they believed were closed dampers* iri order to gradually reduce pressure in the primary containmen They did not ~tilize that portion of DOP 1600-1 to fail open and then restore the dampers and therefore did not identify that the dampers were already in the failed open p6sition. It was foftuitous that the dampers were already open for undeiermin~d reasons such that* venting was conducted with open dampers as prescribed in the procedur Therefore, this was riot considered to be a vi6lation of procedural req4irement The specific safety significance of having the dampers disconnected was
- minimal due to primary" containment isolation valves upstream of the process flow and reactor_ buildi~g ventilation*system which provided isolation capabilitie Of greater conce~n was apparent operator*attitude toward
procedure adherenc Interviews with other operating personnel indicated that performance of this ~volution without ~isconnecting ~nd reconnecting the dampers was not limit_ed to the _involved individuals:
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In one case, knowl~dge of the procedure upgrade p~ogram was used as a contributing rational The use of this program by selected individuals within the licensee's organization as a basis.for not pursuing needed procedural changes was considered inappropriate by the inspectors.. Th December 3 and 5 occurrences of venting of the drywell were not the only cases of procedural adherence problem A tecent violation involving operator failure to follow procedure resulting in a reactor cav-ity overflow event and a recent non-cited violation involving maintenance-failure to follow procedure res~lting in draining of the reactor cavity are additional example The licensee's corrective actions involved inclusion of the first event in* a meeting with supervisors on October.17,. 1990 and instructions give~ t~ Shift Engineers regarding procedure adherence on October 24; 1990. _*These corrective actions appea *to have been ineffectiv The licensee 'further emphasized adherence to
procedures to all licensee personnel during meetings conducted February 26~27, 1991, and recent inspections have not *identif1ed additional ~roblems in this area.: Therefore, the inspectors have no further concerns in this are *
(Closed) Unreso~ved Item (50~237/90027~07):
On *November 18, 1990, the inspector noted that a temporary vacuum pump ahd hose assembly wer ~tili~ed td augm~nt th~ filterfng capability of the fuel pool cleanup system quring *refueling operation A review of the Updated Final Safety
' Analyii~ Report (UFSAR) indicated that this did not ~onstitute a change
- in. the facility as described in the UFSAR and therefore did not require a 10.CFR 50.59 safety *evaluation to be performe Following identification of *this issue by the* inspectors, the licensee determined that any potential adverse effects from this.evaluation were bounded bY existing analyse Therefore, the inspectors have no further concerns in this are (Clrised) Unresolved Item (50-237/90027-12):
Complete review of.
licensee's overtime policy in regards to Generic Letter 82-1 The licensee's program met formal commitments. in this are However, some instances were identified in which the licensee's program did.not appear
'to meet the intent of the generic l~tter; these were delineated in inspection report 50-237/90027; 50-249/90026 and forwarded to NRC management for review. Thi~. item is closed.. *
(Closed) Unresolved Item (50~237/90023-05): Review licensee's practice of not declaring equipment.inop~rable when rende~ing* it n6nfunctional for th_e purpose of conducting Technical Specification required surveillance testin During this rev~ew, the following specific examples were identified:
Hi9h Pressure Coolant Injection (HPCI) ~ystem - Performance of the low pressure trip functio~~l test resulted in the isolation of the HPCI steam supply valve:
In the test.configuration, the HPCI system would fail to respond to an ~utomatic initiation signa Isol~tion Condenser (IC) System - The IC functional test inhibited automatic; system initiation* by disabling of one of the two required logic th~n~el_s (Initiation logi~ was t~o out of two).
The IC high*
f]ow isolation test prevented the IC from automatically initiating by the closure of the steam supply line,.
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Torus to.Reactor Building Vacuum.Breaker (TVB) - The*.TVB circuit card functional test, prevented initiation of the vacuum breaker by interrupting the torus differen.tial pressure transmitter (DPT)
signal to the valve actuation logi The TVB DPT calibration procedure prevented the TVB function due the ma~ual isol~tion of the
. DPT from the torus; Diesel ~enerator (DG) - The DG monthly surveillance test manually loaded the. DG and rendered the load sheddi n'g feature* nonfunctiona In the c~se of a loss 6f coolant accident coincident with a loss of
offsite power d~ring.th~ surveillance performance, the diesel generator would attempt to pick u~ all the non-vit~l loads which we~e powered from the bus prior.to ~he e~ent in addition to the emergency load These loads could be in_ex~ess of the design capacit~ o( the OG;
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- No.discussion.exists in Technical Specifications regarding the
. definition of operability as it applies specifically to systems u~dergoing surveill~h~e testin In addition~ h~ving personnel available to manually perform normally required automatic actions,.if needed, was'*
not credited in the Updated F{nal Safety*Analysis Report {UFSAR), and therefore cannot be used* to justify an :operability determinatio Whenever a system, subsystem; train, component, or device is not capable of performing its spec.ified safety function(s), for any reason, including surveillance testing, that *equipment is inoperable f6r Technical.
Specification pur~oses and appropriate Technical Specification action
. statements appl The licensee d{d.not provide tracking to ensure Technical Specification action statements were not exceeded for equipment inoperable due to surveillance testing:
However, the* inspectors rev{ew of surveillance test intervals did not identify.any instances in which a Technical*
Specification action statement ~as i~advertently exceeded under the~e circumstances and, therefore; no violations of NRC requ~~ements were
. identified in this area*;. T_his was undoubtedly due to the short duration of most survei.11 ances in comparison *to the required action statement time dur~tions. In light of the failure to pro~ide such trackin~ mechanisms and the potential applicabilit~ of Technical Specification action itatements to such circum~tances, the inspecto~s considered the licehsee controls to b~ we~k or nonexisten The other* portion o.f this i tern dealt wi.th the 1 i cen see' s. delay of investigation of control rod drive iccumul~tor alarm A revie~ of Technical Specifications indicated that no action ~tatement could be exceeded unless.more than one accumulatcir in the nine-rod array were inoperabl The alarm ~espons~ procedure required that the nine-rod array be s,peciffoally checked.* Therefore, two inoperable atcumulators
- would be ident{fiable and higher pri.or~ty*could be placed upon resolving th~ problem. *As no specific case~ were identified where this was not done and no Technical Specificati'on* action statements were identified as having been exceeded, the inspectors have no further concerns.in this are (Open) Open Item (50~237/90027-14): Perform sample ins~ection of Systematic Evaluation Program (SEP) topic resolution Additional* items cpnfirmed by the inspectors are listed in Paragraph This item will remain op~n pending completion of licensee confi~mation of topic closures and completion of the NRC sample ihspection~
No violations or*deviatioris were identified in this area.
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- Plant Operations (71707, * 71711 *and 93702)
The inspectors obser.ved*contro"l-room,operations, reviewed.applicable logs arid conducted disc~ssions with tontrol room operators during this perio The inspectors verified the operability of selected emergency systems,*
reviewed tagout records and verified proper ~eturn to service of affected componerit Tours of Units~ and 3 reactbr buildings *and turbine
builpings were conducted to observe pJant equipment condit.ions~*-including pbtenti~l.fi~e hazards, fluid leaks, and excessive vibrations, and to verifythat maintenance requests had been initiated for equipment in need of maintenanc *During the inspection peri.od, several s*tartups and shutdowns were conducted on both units.. Several startups and shutdowns* on Unit 3. were conducted *in an off-normal tondition, in that, only one* recirculation pump
~as cipe~ating. The inspectors observed that the operators effectively
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dealt with this condition and performed ad~qu~tely du~ing these evol~tion Each:week during routine activities or tours, the inspectors monitore the licensee's security program ~o ensure that observed actions were being implemented according to their approved iecurity pla The ihspectors noted that persons within the protected *area dis~lay~d proper photo-identification bad~es and tho~e indJiiduals requiring escorts were properly e*scorte The inspectors also verified that vital areas were locked and alarme Additi6nally, ~he inspectors also verified that *
personnel and packages entering the protected area were searched by appropriate equipment or by hand. *
Th~ inspectors ve~ified that the.licens~e's radiological p~ot~ction program was implemented in accorqan_ce with facility policies and programs and was in compliance with regulatory requirement.
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The inspectors reviewed new procedures and changes to procedures that were imple~ented dur~ng.the insp~~tion perio The review consisted of-a verification for accuracy, correctness, and compliance with regulatory require!11ent These reviews 'and observations were conducteq to verify that faci 1 i ty
~perations were in tonformance with the requirements est~blis~ed under technital specifications, 10 CFR,,and administrative procedure The following operational occurrence was also reviewed:
On February 13, 1991, Una 2 automatically scrammed from 60 percent rated thermal power due to an automatic Group 1 (main steamline) primary containment isolatio The isolation was caused.by a spike or:i the main steamline radiation monitors due to resin intrusion frdm the ~eactor water cleanup (RWCU) syste Control room operators responded*
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appropriately tQ the scra The resin intrusion result~d from* a leaking RWCU demineralizer isolation valve While changing out the resin bed on a demineralize The lea~age was caused by the manual.valve being slightly 7..
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open*although.the remote valve posit,ibn indicating pointer (on the other side' of.~ Valve gallery wall) indicated the valve was fully ciosed. *The licensee postulated th.:! _discrepancy wa_s due to long *term.. loosening of valve operator components.. The.licensee planned to perform future resin
- bed change outs with the ent1re RWCU system isolate The licensee did not plan to immediately repair the. yalve due to high radiatio~ levels in the are The inspectors nbted that licensee managemeHt's investigation of the scram was extensive and comprehensive.*
No vfola-tions or deviations were identlfied'in this *area..
4. * Maintenance and Surveillances (6270j~ 61726, and 93702) Maintenance Activities
. Station mairitenanc~ activities of systems and compohehts listed below were observed.or reviewed to-ascertain that they were
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conducted in accordance with approved procedures, regulatory guides and industry codes or standard$ and in *confor*mance with Technical Specifications.*
The following items were considered. during *this review:
The Limiting Cond~tions for Operaii6n (lCOs) were met ~hile components or sy_stems were removed from service; approvals were obtained priot to initiating the work; activities were aqcomplishe using.approved procedures and ~ere.inspected as applicable; functicinal testin~ and/or calibrations ~ere performed prior to returning components or systems to service; quality control records*
were maintained; activities were accomplished by qualified personnel; parts a~d materia}s used were properly certified; radiological.controls.were implemented; and, fire prevention controls were impleme~ted.. Work requests were reviewed to determine status of. outstanding jobs and to.assure that priority is assigned to safety-related equip~ent maintenance which may affect system performanc *
Reactor Recirculation Pump 38 Seal Replacement Reactor Recirculation Pu~~ 38 Bearing Replacement
- A Unit 2 startup was commenced on January 4, 1991, following a refueli.ng outage that began on September 23, 1990, which was originally scheduled to end on December 4, 199 The delay was attributed to recirculation piping overlays, valve *work, Source Range Monitor (SRM) problems during fuel reload. and a main gene~ator hydrogen seal l_ea Problems -were encountered while rolling the main turbine which. necessitated tripping the turbin Subsequent licensee inspection identified extensive damage to turbine components.. Damage was caused by lube' on blockage due to a blank
- being left in a lube oil st~ainer'following maintenanc Although the work p'ackage prescribed* remova_l... of the blanks, this one was
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missed by maintenance per~.onnel.*
The ins.pectors regardeq this error, which resulted in ari additional one month delay for repairs, to be~indicative of the type of *w9rk practice problems encountered during the first half of the refueling outag However, the error*
involved balance of p.lant equipment with no safety signifiCance and did not present a.direct challenge to safety system *. Surveillance Activities The inspectors observed s~rv~illance iesting, inclu~ing req~ired Technical Specification sufveillance testing, and verified for actual activities observed that testing was* performed in accordance with ~dequate procedure The tnspect6rs also verified that test instrumentation wa~ calibrated, *that Limiting Conditions for Opera~ion were met, that removal and restoration of 'the affected components were accomplish~d and that test results conformed with Technical Specification and Procedure.requirement AdditionalJy, the inspectors ensured that the tes~ results were revie~ed by
personnel other than the individual directing*the test, and that any deficiencies* identified during the testing were properly reviewed
- .. and resolved by.appropriate manage.ment personne *
The inspectors witnessed *or reviewed portions of th~ following test activities:
~eactor Protection System Response Time Testing
- Service Water Outlet Radiation Monitor Calibration*
'Generator Load Reject Instrument Response Time Surveillance New Fuel Receipt Inspection Turbine Control Valve Pressure.Switch Calibration Containment Cooling Service Water Pump Test..
Quarterly LPCI System Pump Operability Test
{l) While reviewing Dresden Iristrument Surveillance (DIS) 500-9 11 Rea~tor Protection System (RPS) Functional Time Re$ponse Tests the inspector noted a discrepancY*between the procedure
. and Technical Specifica~ion requirement A scram signal was
- prot~ssed through the RPS logic beginning with the opening of the ?ensor contacts followed by th~ de-energization (and subsequent contact opening) of the HFA.relay Thi.s was followed by the de-energization (and subsequent contact opening)
of the scram* relays (108s) resulting in the de-energization of *
the scram pilot solenoid (SPS) and o~ening of the scram valves~
Technical *specification 3.1.A *required the response times *from the opening of the sensor cont~cts. (108.rela~s), to be verified
. less than 50 mil1isec.onds (msec).
On June:3, 1988,, DIS 500... 9 incorporated a Double P6~er Systems Timer (DPST), a *portable solid state.electronic 'instrument, to measure the RPS response tim Per DIS 500-9, the DPST w~i co~figured such that the*
ti~er start gate was connected.in par~llel _across the*.
HFA relays and the stop gate was connected in* parallel across the SPSs.. The test was i nHi at~d by the *
sim~la.ted opening of*the.sc'ram sensor contact by the_ removal of*
.the fuse in:.the HFA relay.circui Plant personnel believed the DPST start and stop gates would be triggered on a plus or minus 0.5 volt change*(from 120.Volts AC pre-trip value) across
. both,seti of relay coils and capture the response time of both the HFA and scram (108) relay *
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The inspector identified, from a review of the vendor manua1,-
- .the.DPST would not trigger until voltage across the HFA relays
- dtopped to an absolute value of 0.5 volts, not ju~t a change of 0.5 v6lt Based on the review of RPS response *time relay voltage. plots gerierated on a Gould recorder, a delay may occur between th~ opening of the scram sensor contacts and voltage decay to 0.5 volts across the HFA rela Additionally, because the DPST stop gate was_also connected in parallel to the SPSs, the ending._signal was also.delayed as a function* of the circuit time constant for the SPSs:
Because of the test configuration specified in DIS 500-9, the DPST unnecessarily included the
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- response time between the scram relays (108s) and SPSs, and omitted' measuring the response of the HFA There was no evidence that the ~onservatism on the back*end of the logic timing would always outweigh the nonconse~vatism on the. front en *
The licensee bench tested two HFA relays, configured similar. to the RPS logic, to.better understand the effect of.
. the voltage decay tjme across the relays, *and *to assess the safety significance of**the "DPST whe*n used 1n conjunction with DIS ~00~9. *Based on lhe results of the bench testing, no conclusion could be co~related that the DPST, when connected across the relay coils pe~ DIS 500-9, provided equivalent response time as required by Techn.ical Specification However, testing did indicate, that if properly configured constant with the manufacturer's r~commendations and within the physical limitations 6f the device, the DPST could be a valuable tool for measuring.RPS -response time in the futur The failure of~DIS 500~9 t6 ~dequately pre~tribe steps to measure the RPS response time in accordance with Technical Specification requirements is considered to be a violation (50-237/91003-0l(DRP)) of 10 CFR 50, Appendix B, Critetion V~
Following identiffcation of the pr6blem; and prior to startup, the ~icensee rep~ated RPS r~sp6nse time testingi on both units, using a multichannel chart rec6rder which timed* the cortect compone~ts. Review of results indicated all RPS circuits were found to be within the 50 msec requiremen The licensee planned to revise DIS 500-9 prior. t6 utilizing the procedure for sub~equerit surveillance testing. The root cause of the
~vent was attributed to inattention to detail of plant person~el. in writing and conduct{ng the surveillance procedure in regard to ensuring the proper applications of test
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equipmen The importance at atte~tion to detail was emphasized to all plant personnel in licensee meetiri'gs conducted on February 26-27, 199 The 1nspectors reviewed portions of the _immediate cor~ective actions and ~ampled planned corrective actions to prevent reoccurenc Based on this review the inspectors cbnsidered the lit~nsee's actio~s thorough-and have ~o furthe_r concerns in this area.
.On February 8, 1991, 'an i ristrument ma 1ntenance staffer, while reviewing an instrument surve*il i ance procedure.in accordance with.the Procedure.Upgrade Program, identified that the procedure did not test the Standby Gas Treatment System (SGTS)
heater interlock. This was identified during the licensee review which compared of electrical schematics to the procedur The SGTS heaters ensured that the system humidity was not great enough t_o adversely affect system.efficienc The heater interlock automatically initiated the standby train_upon f~ilure of the heater in the operating trai Altho~gh the*heaters were mentioned and credited in the Updated Final Safety Analysis Report (UFSAR), the existence of *the heater interlock was not mentione Although the inspectors considered it important to periodically test this interlock, this was not considered to be a violation of NRC requirements due *to the licensee's plant specific licen~ing b~sis. The licerisee subsequently tested the interlock and verified it to function correctl The inspectors regarded this as positiv~ examples of the eff~ctivene~s of the Procedu~e Upgrade Program and the diligence and attention to detail exhibited by the individuaJ *performing the revi_e Orie violation and no deviations were.identified in this are~.
Engineering/Technical Support (37828 arid 93702) The in~pectors ~eviewed ~everal ~ecent. plant modification package During this review, numerous concerns ~r6se regarding the appropriatenes~ of design iriput parameters and calculations for the_
Diesel Generator Cooling W~ter Pump Discharge Piping Modification (M12-2-90-18).
As these concerns cbuld indicate possible design control problem~. this is consider~d an unresolved ~tern (50-237/91003~02(DRP)) pending the licensee's response to these concern On January 10, 1991, the licensee informed the resident inspectors of the results of a failure analysis performed on a Unit 2 reactor vessel head closure stud which had been replaced during a previous refueling outage in January 198 At.the time, inservice inspection
.ultrasonic testing had detected cracks in the.lower -threaded portion -
of two of the g2 head closure stud The analysis concluded that
the cracking was the result of stress corrosion possibly d~e to the exposure to oxygenated water during unit outage In addition~ the mechanical test results indicated that the stud material had a higher stren~th and lower toughness than reported in the original certification
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material test repor The caus.e of this discrepancy was -postulated to be long term aging at operating temperatur Specifics of the technical aspects were ~eviewed and resolved between the licensee and th~ Office of Nuclear Reacto~ Regulation (NRR).
The lJcensee attribute-d the two year delay in the analysis to problems
- . with sample ~econtamination. and higher priorities at the contfact *
- laboratory. *It was apparent based on discussions-with involved technical staff personnel that the.lic~nsee failed to pur~ue re~o~~tibn in a timely mann~r and that this issue was considered to be the responsibility of the licensee's Systems Ma.terials Analysis Department~ The inspect6rs considered the delay excessive for such a potentially safety significant issue w.ith possible generi applicability. This Concern was d.i.scussed with the licensee at the exit interview:
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. On January 16, 1991, the licensee*informed the resident inspectors of the discovery of an error ifr _the. Unit 3 Cycle 12 Reload Analysis dated August 1989, for the spent-fuel storage pool reactivit The licens~e's ~ontractor, Advanced Nuclear Fuels (ANF), had set a flag incorrectly in the computer cod The error was discovered *while
- performing the analysis for the next cycl T.he Cycle 12 analysis indicated that the peak assembly reactivity in a reactor lattice distribution would be less than the Technical Specification limit
- for k-inf of 1;27 for ANF 9 x 9 assemblie Recent calculations
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showed the value to act~ally ~e 1.272, which was above the Tech~ical Specificatiun limi The li~ensee ihdicated that the same error had not been made on.any other. previous or current reload analyses for either Units 2 or 3.. The approximately 168 assemblies involved were in the spent fuel storage pool for 79 days prior to being loaded into the c.ore in January 1990.~-.The* cai'culations for the 1985 amendment, which establi'shed -the Technical Specification limit, actually concluded a k-inf limit of 1.27 The last digit had been truncated (purposely ro~nded in the con5ervative direction) in the amendment submittal, cor~esponding NRC safety evaluation report, and Technical Spec.ification As *the vµlue* from the.original calculations could be verified, a review by the Office of Nuclea~
Reactor Regulati~n (NRR) indicated that this was not considered to be a violation of Technical Specificati6ns. *However, the inspectors were concerned with the degree of licensee oversight regarding ANF and consider this an open item (50~237/91-003-03(DRP)) pending furthe revie0 of this area including the catise qf the error and corrective action *
No violations or deviations wer~ identifie~ in this are Safety Assessment/Qua Hty Ver if i cation ( 35502)
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The inspectors reviewed the licensee's usage of the quality control feedback sheets which were prescribed in an internal departmental memorandum to address identified concerns that were of lower significance than required by more formal mechanisms and the Quality Assurance Manua The inspectors regarded.this process to be effective and beneficial with
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- _< *.,
r~spect to ~nhancing the quality over~ight 6f programs. *It r~flecied the unilateral initiative of the quality control organization to go beyond the plant and regulatory requirements.in the pursuit of problem identification and re~olutio No:violatio~s: or deviations were identifled in this area; 7 *. Safety* Assessment/Q~ali'ty*Verification (35502).
- 'NUREG 1403, "Safety Evaluation Report. related to the full,..-term ope.rating license for Dresden Nuclear Power'Statio~,
11 table 2.1 identified SEP fotegrity Plant SafetyAssessment' Report (IPSAR) topic resolutions to be confirmed by the NRC Region I-II offic The fo'llowing items in that
- report were confirmed as closed_ by the inspectors:
Item 17 - Topic VI~~. 4.18.2-~nd 2.i~ (Supp. l}
I~em 20 - Topic VII*l.A, 4.24.1 and 2.13.1 (Supp. 1)
Item 21 Topi~ VI~~l.A, 4.24.2 and 2~13.2 (S~pp. 1).
No violations or deviations were.ident,Hied in this are TMI Action Plan Re.quirements Followup '(2515/065-01)
(Closed) TMI Item Ii.F.1.2.F (Onits 2 and 3):
This ite~ required
. addition of.drywe 11 post-accident hydrogen monitoring instrumentatio The inspectors verified the existence of this instrumentatio TMI Item Il;F.1.2.f (Units 2 and 3) is closed:'
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- No violations or deviations were ident.ified in this area..
Report. Rev1 ew D~r~ng the inspection_~erjod, th~ inspector reviewed the 1icensee 1 s Monthly Operating Report for *December 1~90.. The inspector confirmed that the information provided met the requfrem.ents_.of Technica'l Speci.fication 6.6.A.3 and Reg_ulat'ory Guide 1.16,
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1 Unresolved Items Unresolved items are matters about.which more information.is required in order to ascertain whether it is an acceptable item, an open item, a deviation or a violatio Unresolved items disclo~ed during this inspection are discussed in Paragraph.. -Open Items
- Open items are mattefs which have ~eeri discussed *w~th the licensee whith will be further reviewed by the inspector and*which involved some actions on the part of the NRC or license~ or bot Open items disclosed d~rin~
the inspection are di~cus~ed in Paragraph 5.c:
1 Ex1t fnterview The i~spectors met with licen~ee representatives (denoted in Paragraph 1)
c:in February 15, 1'991, arid informally throughout the inspection period, and summafized the scope and fihdings of the inspection activiti~ T~e inspectrirs also.discussed the likely information~l content of ~he inspection report with l'.'egard to documents or* processes reviewed by the
- inspectqr during the inspection.* The licensee did not identify any such documen*ts/processes as proprietar The licensee acknowledged the findings of the irtspectio *
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