ML17188A105
| ML17188A105 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 03/21/1998 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML17188A103 | List: |
| References | |
| 50-237-98-03, 50-237-98-3, 50-249-98-03, 50-249-98-3, NUDOCS 9803270176 | |
| Download: ML17188A105 (23) | |
See also: IR 05000237/1998003
Text
=-~-.-_ ----;* ---;:-....=..---
_-...:~- -
-* -.. -
..... --.':.'~ .
-
--,._ .. --
~- - - ....------- *-* -
. - -.-~---.-* ..
- ****
..... ,,
U.S. NUCLEAR REGULA TORY COMMISSION
Docket Nos:
License Nos:*-**
. Report No:
- .
- Licensee:
Facility:
Location:
Dates:
Inspectors:
Approved by:
9803270176 980321
' '
ADOCK 05000237
G
- -
REGION Ill
50,..237; 50-249
50-237/98003{DRP); 50-249/98003(DRP) .
Commonwealth* Edison Company
Dresqen Nuclear Station Units 2 .and 3
6500 North Dresden Road
Morris, IL 60450
. .
-
.January 12 through February 20, 1998
K Riemer, Senior Resident Inspector
B. Dickson, Resident Inspector
D. Roth, Resident Inspector
T: Pruett, Senior Resident Inspector, Clinton
M~ *Ring, Chief
Reactor Projects Branch 1
_.
. - ---
"-
- -*:. ":*:.
.:-=~..: --*-
-_-_--.-:. - .
.
- _ .. _-: __
/
EXECUTIVES UM MARY
Dresden Nuclear Station Units 2 and 3 *
NRC Inspection Report No. 50-237/98003(DRP); 50-249/98003(DRP)
This inspection was conducted from January 12 to February 20, 1998, by resident personnel and
by personnel from other sites.
- .
Operations
The operators' response to an automatic scram was correct and in accordance with
procedures. *(Section 01 ~2)
The availability and performance of the licensee's high pressure coolant injection system
continued an adverse trend during this inspector period. (Section 02.2)
- *
The inspectors were concerned that the operators were not completely in control of the
shutdown cooling evolution as evidenced by the turn of reactor pressure and temperature
parameters. The inspectors also identified that the corrective action process failed to
resolve the adverse condition adequately. (Section 03.1)
The inspectors did not identify any performance deficiencies during the Unit 2 startup
from a forced outage. Operators completed the startup of Unit 2 correctly and safely,
The inspectors concluded that the Management Review .Meeting was a positive meeting
and added value .to plant operations. (Section 07.1)
Maintenance
An inadequate procedure in use in the field severely impacted plant operators by
contributing to an automatic reactor scram from full power. (Section 01.2)
- The licensee improved the material condition of the control rod drive system by
performing maintenance that resulted in better pertormarice during the subsequent
reactor startup. Other systems, such as the feedwater system and the high pressure
coolant injection system, were observed to have minor leaks that required corrective
maintenance during the Inspection period. (Section M2.1) .
The licensee completed major diesel maintenance within the time allowed by Technical
Specifications. However,* errors in package preparation and failures of the errors to be
detected during the review cycle led to rework, damage to equipment,, and increased
unavailability of safety-related equipment. (Section M4.1)
The inspectors identified incorrectly constructed scaffolding that was in contact with
safety-related equipment. Shortly after the end of the inspection period, the licensee
identified that the safety-related standby gas treatment system was damaged and made
inoperable by incorrectly constructed scaffolding. (Section M4.2) *
2
.-.,i.
. ...::.=.:...:....:.:.:_;,;,; *. :::: .. -:-...:. .. .::.:..:._.::...:__ __
- --.*--r* ... --*-
... --** ..
- .. *-
-
Engineering
- ...__ ..
The potential to overfill the reactor vesset following a reactor trip on either of the units
required additional operator actions.** The identification of the issue showed a good
questioning attitude by engineering personnel.. (Section E2.1)
The feedwater level_control (FWLC) system response .presented a challenge to operators
follow~ng a reactor scram. The compensatory actions that operators were required to .
take following a scram constituted an operator work-around. Pending permanent
resolution of the FWLC system performance issues, the station was relyi_ng on operator .
intervention following a scram to prevent water .intrusion into HPCI system steam lines.
(Section E2.1)
. .
. . ,
, .
Plant Support
\\
.
. J*.*
' ~ , f '.
';,
I
Overall performance of.radiation protection personnel;.was*good. The radiation protection
personnel maintained up-to-date survey maps, responded correctly to potentially
contaminated personnel, and challenged plant workers' understanding of radiation
hazards and controls. (Section R 1. 1)
3
~**
_ .. : ,.::..:....::;.*;:;-.-*.....:..:-.:.*...:._
- --~=- _:;~_:___:
~---~--:*-;.~--. .....
....,.....,.~-
- -t-:-~~--- .
'
~ '*
-- ..
. *-*-*
Report Details
- . i:
Summary of Plant Status
Unit 2 started the period at full power. On January 13, the unit automatically scrammed due to a
turbine trip inadvertently.caused by.a.surveillance test. The forced outage (D2F31) ended on
January 18, but full power was not reached until January 23 because of problems with reactor
feed pump ventilation. On February 7, the load was reduced to about 300 MWe to facilitate a*
drywell entry to investigate increased drywell leakage. The leakage was found to be .from a
drywell cooler, and.the load was raised to full load by February 10. Unit 2 remained at full power
for the rest of the.:period, except for brief decreases to support tests*and equipment swaps.
Unit 3 remained at full power for the inspection period except for brief decreases to support tests,
to perform equipment swaps, and to extinguish an off-gas system fire. Unit 3 power was limited
to maintain the main turbine control valve position to below an average position of 85 percent
open with no valve greater than 90 percent open.
On both units, feedwater flow was limited to 9. 735 Mlbm/h as a result of a review of the fuel cycle
analysis performed by engineering personnel. Analyses to eliminate the derates .were being
done.
01
01.1
I. Operations
Conduct of Operations
General Comments
Using Inspection Procedure 71707, .the inspectors conducted frequent reviews
of ongoing plant operations. Overall, the conduct of operations was safe and in
accordance with procedures. *
During the inspection period, some events occurred for which the licensee was
required by 10 CFR 50. 72 to notify the NRC. The events and the notification
dates are listed below:
January 13 (Unit 2) Automatic reactor scram from .100 percent power following
turbine trip during an on-line reactor vessel water level surveillance test.
January 28 (Unit 2) High pressure coolant injection (HPCI) system declared
inoperable due to rupture of a valve diaphragm for a steam supply drain valve
during standby operations.
February 19 (Unit 3) HPCI system declared inoperable due to failure to start the
gland seal leak off pump on a high level condition during a surveillance test.
4
,...;.:
_--.....,._ __
*--**
~~
--
.... **~*--*
.
- .
01.2
a. -
b.
*--
-:.:....:. *-*: * .r"'~---_ _:_;:;:~ . ....:.-..:..~-
-
.. ~--. .-;* ---~ .. -
.* --... ---
.(Unit 2) Automatic Reactor Scram.From Full Power
.
. .
~
Inspection Scope (71707) .
.. ';: *: *. *':'.***.
The inspectors conducted a detailed review of the Unit 2 reactor scram that
occurred on January 13, 1998 ..
. .. .,.
- .
Observations and Findings
. *. . , ~
. .
. -
During the per:formance of Dresden instrument surveillance test. (DIS) 0263-14,
"Local Reactor Level.Indicator (Safe Shutdown) Yarways Calibration," a m~in
.turbine trip and subsequent reactor scram occurred. The re~ctor scram was the
expected response to a turbine trip at high power.
Before the trip, the unit was at full power and instrument technicians were
performing a surveillance test.to calibrate the Yarway level indicators (LI). The
licensee recently had moved the calibration surveillance procedure from the
refueling outage to on-line. The licensee had modified the instruments to
- remove the trip functions such that the Yarway LI now performed an indication-
only function.
Although the Yarway Lis had been modified to perform an indication-only
function, the instruments shared a common-sensing line with several
instruments that performed trip functions: The surveillance procedure stated,
"Extrem*e--eaution should be exercised in valving the LI during the surveillance.
The LI shares common sensing lines with several Scram and ECCS
instruments. Sudden depressurization of the sensing lines, e.g., rapid opening
of the pressure switch instrument valve, can cause a full Reactor Scram and/or
isolation by spiking the other instruments to their trip settings."
The test summary sheet also stated, ;'Improperly valving of LI will C:ause sudden
changes in sensing line pressure. These lines are common to SCRAM and.
ECCS instrumentation." When instrument technicians performed valve
manipulations to return the firsHested instrument to service, a turbine trip and
reactor scram occurred.
The inspectors reviewed the events associated with the turbine trip and
subsequent reac::tor scram and *concluded that the operators performed correctly
and that the overall response of the plant systems was correct. The inspectors
noted that the operators successfully implemented the required compensatory
actions associated with the feedwater level control (FWLC) system and
prevented vessel level from overshooting and flooding the HPCI steam lines
(see NRC Inspection Report No. 50-237/97028; 50-249/97028 for information.
about the compensatory actions).
The licensee's investigation team determined that a false high reactor water
le~el signal caused the turbine trip that occurred while the Yarway level
instrument was being returned to service. Several causes for the event included
design deficiency, procedure inadequacy, and inadequate procedure review .
5
~..__
_,......, __ - . ---:-"""":;-:--
- ~ *' -
C.
02
02.1
a.
b.
Historically, the procedures fo perform the* LI calibration inciuded steps to bypass
the trip functions and the procedure had been performed with the reactor shut
down. The licensee's investigation team also found a lack of a questioning
attitude among the personnel involved in *the evolution:
. ,.
. '
.
The planfoperations review committee's (PORC) review of the team's results
was thorough and demanding.
'
10 CFR Part 50, Appendix 8, Criterion V, requires activities affecting quality,
such as the calibration of the level indicators, be prescribed by instructions
appropriate to the circumstance. However, Dresden Instrument
Surveillance*0263-14 ori level indiea'tor calibration was not adequate for the
circumstancein>f performance* of power because the bypass of the trip function
had been removed frorrrthe*procedure. 'As a consequence of the inadequate
- surveillance procedure, an automatic reactor scram occurred on January 13,
- 1998;*during the performance of the calibration surveillance. This was a
violation of 10 CFR Part 50, Appendix B. (VIO 50-237/249-98003-01a(DRP)).
Conclusion
The performance of an on-line surveillance test resulted in a turbine trip and
reactor scram.* The event resulted from an inadequate procedure and *
inadequate review of the plant irnpact of the surveillance test.
The licensee's root cause investigation was thorough. However, continuing a
theme documented in prior inspection reports, and discussed further in this
report, an inadequate procedure severely impacted plant operators by causing
an automatic reactor scram from full power.
Operational Status of Facilities and Equipment
(Units 2.-3) *core Spray Systems
Inspection Scope (71707)
The inspectors reviewed the status of the core spray system and the results of
recent core spray system surveillance tests.
Observations and Findings
The core spray systems were aligned according to procedure. However, the
inspectors found that the Unit 3 core spray checklist, DOP 1400-M1/E1, Rev. 16,
listed the inboard valves as capped instead of the outboard valves. The
licensee reviewed the checklist, the locked valve checklist, and the local leak
rate test (LLRT) capped valve checklists and identified and corrected additional
errors in another alignment procedure. The licensee then changed the
procedures. The inspectors noted that the personnel who documented the issue
were not informed of any reason as to why the checklists indicated the inboard
valves as capped. The licensee was continuing to pursue this issue. The
6
'i
- ---~.-.. ~:z .... ...:.:r.--.:. , __ .
. . *-=-~-**
--:-=-~
... -** - -*--
..
- ---
~--~
.
_::....;.::*_-=.....;:.. __ .
inspectors c:Onsidered the-safety significance.to be minor, and therefore no
violation was issued.
The inspectors reviewed the results of recent core spray surveillances and noted
that on January*22, the core spray system test failed because the flow test valve
(3-1402-4A) ceased moving. The licensee investigated and concluded that dirt
around the switch contacts may have c~used the failure. The switch was
cleaned and the valve and *core spray system subsequently tested successfully.*
The licensee considered the failure to be a random event, and not associated *
with any generic switch problem.
The inspectors reviewed recent *core spray system problem identification forms
(PIFs) and found no repetitive failures .. The licensee's review of core spray
instruments found out of tolerance *during 1996 and 1997 (Ref. Dresden
- ID:0005590718) showed no "adverse trends."
C.
02.2
a.
b.
Conclusions
The core spray system was correctly aligned. Apparent errors in the alignment
checklist did not result in an incorrect system alignment. The core spray system
did not have any adverse performance trends.
(Units 2. 3) High Pressure Coolant Injection CHPCI) System Availability
Inspection Scope (71707}
The inspectors evaluated the availability of the HPCI systems during thE!
inspection period.
Observations and Findings
Unit 2 Drain V~lve Failure
On January 28, 1998, the licensee declared the Unit 2 HPCI system inoperable
due to a ruptured air-operator (diaphragm) on the HPCI turbine stop valve above
seat drain valve (2-2301-64). The failed diaphragm caused the valve to close.
The Unit 2 nuclear station operator (NSO) discovered this abnormal condition
during a routine control board walkdown.
The 2-2301-64 valve was used to drain condensate accumulated between the
HPCI system steam supply shutoff valve (2-2301-3) and the turbine stop valve.
During standby operation the 2-2301-64 valve was open to a*llow the condensate
to drain to the HPCI system room sump. Upon HPCI system initiation, the
2-2301-64 valve would automatically close so the room would not become full of
steam. Due to excessive leakage of the 2-2301-3 valve (a condition reference in
Section 02.1 of Dresden Inspection Report No. 50-237/97028; 50-249/97028)
the closure of Valve 2-2301-64 would result in the introduction of a slug of water
into the turbine on an automatic initiation signal of the HPCI system .
7
c.
03
o~.1
a.
- ..-=:::..-.:...:... . _;..,,.,.,,;:.- ... :..-; ......... _
.... ,;*----:-
- .--.:~ *---~ -
..;,_
. __ ._...__ ._
--
*- *--
The licensee reported that initial investigations revealed that the .diaphragm
appeared to have failed.due to localized wear; and noted no other abnomial
indications upon disassembly ofthe air operator. The licensee reported in
PIF 1998-01055 that a similar HPCI system 64-valve diaphragm failure was
identified in June of 1995 at Quad Cities Nuclear Station. Additionally, the PIF
stated that .a manufacturing deficiency associated with the diaphragm resulted in
the diaphragm degradation and failure.
- '.~:*I '
. ,*
This was the second occurrence of the HPCI system being rendered inoperable
due to problems associated with the 2-2301-64 valve within a year at Dresden.
The first event occurred on June 16, 1997, on the Unit 2 HPCI system, and the
licensee documented this event in Licensee Event Report (LER) 50-249/97-003.
Unit 3 Gland Seal Leakoff Failure
On February,19, 1998, the licem;ee declared the Unit 3 HPCI system inoperable
due. to the failure of the gland seal leakoff (GSLO) pump to start on high level
conditions in the GSLO drain line. This event occurred during the performance
of the HPCI quarterly operability surveillance. Preliminary indication suggested
that the GSLO high level pump start control switch (3-2300-LCS-2) failed to
perform its intended function.
Since June 1997, three events oceurred that rendered a HPCI system inoperable
due to leakoff pump level switch problems (Ref. LERs 50-237/97-012,
50-249/97-009, .and 50-249/97-014): In LER 50-249/97-014 the licensee
documented that the* packing nut was loose and would not engage the threads.
The licensee also stated that the float/mechanical linkage acted sluggish when
manually actuated. The licensee replaced this switch due to the condition
mentioned above. Following the completion of the work outlined in
50-249/97-014, the licensee successfully pei"formed a functional check on the
switch. Due to recent events the inspectors were concerned with the adequacy
of the corrective actions discussed in both 50-249/97-009 and 50-249/97-014.
Conclusions
The availability and performance of the licensee's HPCI systems continued an
adverse trend during this inspection period. The inspectors were concerned that
maintenance and previous corrective actions failed to prevent additional HPCI
system failures on both units. *
Operations Procedures and Documentation
(Units 2) Reactor Shutdown Activities
Inspection Scope (71707)
The operators were delayed aligning the shutdown cooling system after the
January 13 scram .. Consequently, reactor pressure and temperature rose. The *
. inspectors reviewed the occurrence and the licensee's corrective actions.
8
--- -
. - .. -
b.
- ,
c .
04
04.1
a.
- -:::*.:.:...;__-.....:.::_::::::::..;:_ __ ~-
~-.....,.- ---
__,.,.._
,;:::
-- -- - -----*-
- - ... -
--
- ----*-- -- .
*- ----***
Observations and Findings . . ..
,_;
.:. '
The operators. encountered a 'de1ay in establishing the correct reactor building
closed cooling water (RBCCW) alignment during shutdown cooling activities
following the January 13, .1998, automatic reactor scram. Before the scram, per
procedure, one RBCCW pump and heat exchanger were in ser\\tice. To put
shutdown cooling in service, and still meet procedural limits for pump current.
and system pressure,*the 0perators were required to place an additional pump
and. heat exchanger in service. During the delay in establishing a two-pump arid
two~heat excnanger.RBCCW lineup, reactor pressure and temp~rature rose
slightly. Operators set .up alternate methods of decay heat removal until the
correct RBCCW and shutdown cooling alignment were established. While the
event had minor safety consequences (reactor temperature increased
approximately 26 degrees before the operators established the correct lineup)
the inspectors were concerned with the operators' performance in establishing
the correct shutdown. cooling lineup.
- :
,*,
'
.!
- ' -_: ! .
The licensee documented the occurrence in PIF 01998-00227. The PIF was
listed as "Issued Closed" based on the assumption that procedures would be
revised to eliminate the delay in setting up the proper lineups. However, the
inspectors identified that the* procedural changes did not occur and that the
licensee did not have a formal tracking mechanism in place to ensure the *
discrepant condition was resolv~d~ The licensee subsequently documented the
inadequate corrective actions via PIF 01998-01118.
Conclu.sions .
The inspectors were concerned. that the operators were not completely in control
- of the shutdown cooling evolution as evidenced by the tum of reactor pressure
and temperature .parameters. The inspectors also concluded that the initial
corrective action process failed to resolve the adverse condition.
Operator Knowledge and Performance
(Units 2. 3) Routine Operator Performance
Inspection Scope CT1707)
The inspectors performed frequent observations of operator performance and
compliance with procedures.
. Observations and Findings
Routine observations and review of operating logs showed the operators to be
following procedures and practicing good communications.
However, on February 18, 1998, the inspectors identified a disconnect between
th~ NSOs and the unit supervisor (US) regarding the operation of torus cooling.
The NSOs and USs gave the inspectors two different values for the length of
time Valve 3-1501-38A was throttled open (one said 18 seconds, the other
9
- ~:;:= ~-::.:.;...: __ ,,;;~ ;o:....:.....__ *- :~--
- ;-.....
-- --
-,~--- -
-~-
-
-
- ----~--*--
- !-
c.
04.2
a.
b.
c .
.,;.-
- -***-- ..
24 seconds). This was *significant because Procedure DOP 1500-02, Rev. 34,
stated: '
- * "
"Due to the limitations* of the LOCA analysis, the LPCI system is required to be
declared inoperable IF: Valve 2(3)-1501-38A(B) is throttled open more than 36
seconds WHILE valve 2(3).;.1501-20A(B) is open."*
The procedure was weak because it *did not mandate recording the valve throttle
time.
An example of poor crew communications was found during the same evoluti.on.
The inspectors identified that the US thought an operating surveillance
procedure (DOS) was in use to control torus cooling, while the NSOs were
actually using an operating procedure (DOP). *
Conclusions
\\ :=
Operators performed according to procedures and practiced good
communications. However, some examples of poor communications and weak
procedures were identified.
.(Unit 2) Operator Performance During Startup .
Inspection Scope (71707)
The ins.pectors conducted observations of startup activities from forced outage
D2F31. Procedures and documents reviewed included Dresden *General
Procedure (DGP) 01-01, "Unit Startup," and "Unit 2 Startup Plan (D2F31)."
Observations and Findings
During the Unit 2 startup; the inspectors noted that the operators performed
startup activities- in a careful and controlled manner. Good communications*
were evident, and the operators were knowledgeable of the plant conditions and
issues. The NSO maintained a heightened awareness of the plant status. The
shift manager and* us maintained correct command and control during the
.
startup and held crew briefs as necessary. The inspectors noted that the NSOs
appropriately referenced Dresden Annunciation Procedures in response to
various control room alarms ..
Conclusions
The inspectors did not identify any performance deficiencies during the Unit 2
startup from a forced outage. The operators completed the Unit 2 startup safely
,
and correctly .
10
_-::.;;...:._ *-
---
--;-=-. -.-*.
- ,
..
07
07.1
Quality Assuranc~ _in Operations
.
.
- '. * ..
Management Review Meeting
. a.
b.
c.
Inspection Scope (71707. 40500)
-- - -- -----* -The *in'specto*rs observed a Management Review Meeting (MRM) conducted on
Febn.1a,.Y*f1,'1998'. :: **
- ** -
.
.
- .
- * * .
.
.
. ,
. . .
. .
Observations and *Finding's * '*
. ,,,
... '
The topics'for the ~MRM ihcf udec(general. plarit status, plant material condition
assessment, human performance assessment, maintenance work backlogs,
ref~eling outage plans, arid 'Quality Eind Safety Assessment (Q&SAnssues. Site
managers presented the topics to a panel of licensee senior executives. * The
inspectors observed the panel members ask probing and in-dept!") questions of
the presenters. *)he panel provided feedback and criticism to the panel
presenters during the dis-~u_ssions.
Conclusion
The panel asked probing questions and did not accept easy answers from -the
presenters. The inspectors concluded that the MRM was a positive meeting. and
added value to plant operations.* *
II. Maintenance
M1'
Conduct of Maintenance
M1 :1
- Surveillance Testing
.b.
The inspectors observed portions of inst~ment maintenance surveillance tests
performed during the inspection period. The inspectors observed the following
procedures:
Dresden Instrument Surveillance (DIS) 0700-06, Average Power Range Monitor
(APRM) Flow Biased Scram, Rod Block and Downscaled Calibrations, Rev. 20.
DIS 0250-01, Main Steam. Line High Flow Isolation Switch Calibration, Rev, 15.
DIS 1500-09, Low Pressure Coolant_ Injection (LPCI) Loop Select, Reactor
Recirculation Pump Differential Pressure Switch Calibration.
Observations and Findings
The inspectors noted that these activities were performed in a careful and
- controlled manner. When questioned on issues regarding procedural
acceptance criteria, cautions and limitations, the instrument mechanics
appeared knowledgeable of the scope of their assigned activities. Additionally,
11
. ---.-.~* --
- "*
. c.
M2
M2.1
a.
b.
- :. *-=-~.:_.~.=---.:._
. ,--~* *--** --~*
- -**
. -
.
- ----..
the insj)ectors noted that the maintenance per$onnel used three-way
communication. 'Self.:.CJieeking and independent verifications were also evident
throughout the portions of each surveillance activities witnessed by the
inspectors.
Conclusion
.......
--*~~-- _: ~.._~ :- ( ;._; ,*,
The inspector concluded that instrument maintenance personnel performed
maintenance activities in a *professional and controlled manner. Maintenance
personnei appeared knowledgeable and self-checking and independent
verifieations were. evident .
Maintenance and -Material Condition of Facilities and Equipment
(Units 2. 3) General Plant Conditions
. .. .
. ' ' .. ' .. ' .
' ' : ;~ .
( .
-: ..
' ' . '
Inspection Scope <71'707)
The inspectors performed routine tours of both Units 2 and 3 and assessed
maintenance and material condition of plant facilities and equipment.
Observations and Findings .
Overall, the inspectors noted that housekeeping throughout plant was good;
however,_a few areas needed additional licensee attention.*. The inspectors also
noted continuing material condition improvement efforts. For example, during
the forced outage (D2F31) the licensee performed maintenance on several
control rod drives (CRDs). As a result, during the subsequent startup, the
performance of the CRD system significantly improved over the past
perforrilance of the CRD system noted during the Unit 2 startup from D2F30 *
(Ref. Section 01.3 oflR 97-028). Despite this, other material condition issues,
such as the HPCI system issues,. continued to challenge the operations staff.
Unit 2 Reactor Feed Pump (RFP) Room
The inspectors identified packing leaks on Unit 2 RFP discharge vent
. Valve 2-3299~79. The US dispatched a non-licensed operator to adjust valve *
packing.
..
Additionally, the licensee noted that the RFP discharge check valves for both 28
- and 2C RFPs were leaking, resulting in condensate traversing back through
pumps while the pumps were in standby.
Unit 3 East Emergency Core Cooling System (ECCS) Room Cooler
The licensee identified that the East low pressure cooling injection/core spray
(LPCl/CS) pump room cooler was auto starting very frequently. Investigations
revealed that the reactor building heating steam sub-cooler and several steam
traps were passing flow. Discussions with cognizant licensee personnel
indicated that the heating steam to the sub-cooler was greater than 180°F which
caused elevated temperature in the LPCl/CS comer room, which in tum resulted
.12
--* .. -..... -:------ ~-: -
- -
C.
M4
M4.1
a:
b.
.~::.Le* .. ::::.
in the continuous *auto starts of equipment needed for long term containment
cooling. . .
.. .
.
.
- . .
.
Unit 2 LPCl/Core Spray (CS) Room Sump Pump
The licensee identified that the 2A East LPCl/CS sump pump was separated
from its discharge piping because the pipe had completely rusted through.
Additionally; the licensee noted that the 2A West LPCl/CS sump pump was
thermally tripping after it initiated due to high sump levels .. Both conditions
resulted in poor 'performance of the Unit 2 comer room_'s sump system .
.
'
'
'
- .. *.
.
.
.
'
'unif2 Control Rod Drive.Hydraulic Control Units (HCUs)
The inspectors identified a packing lea*k on Unit 2 inlet scram valve on
HCU 14.:.15 (0-4). *The inspectors also noted several other packing lea.ks on
scram valves that the licensee had already identified, each varying in severity.
.
. . .
Conclusions
The inspectors concluded that the licensee was improving the plant material .
condition. These efforts resulted in sustained plant operation and improved *
performance of safety- related equipment. * However, some areas were observed .
to be in poor condition. Corrective maint~nance documents were initiated, or
already existed, to correct the notec:t'deficienCies.
Maintenance Staff Knowledge and Performance.
(Units 2. 3) Emergency Diesel Generator Maintenance
Inspection Scope (62707. 71707. 61726)
. . The inspectors monitored the licensee's execution of planned maintenance on
the 2/3 EOG. The inspectors assessed the effectiveness.of the work performed
and the licensee's responses-to problems.
Observations and Findings
The maintenance included six-year inspections, trip checks, calibrations, and
some modifications. The licensee activated its "Outage Control Center" and
assigned a dedicated maintenanc_e task owner to coordinate the work.
Limiting Conditions for Operations and Work Scheduling.
The licensee had five days of work planned for the 2/3 EOG to be completed
within the seven-day LCO without the 2/3 EOG. The licensee planned to shut
down both units eight hours before the end of the LCO.
The licensee completed the work within the required time. However, the work
was completed behind schedule due to problems described below .
13
- ... ,_: __ .. .:,_ - ._
- *.
- -: .:-*- ,r *. :..:._
-*:"" :
- ..-*--"::". __
- ----
.
.'
-. *.
- .
- **-*- ,._ -* ---
_,,.,.___ -~~ ---
- -
--~---
Work Package Preparation
- * *
The work on the 213* EOG was performed using a combination of work requests
(WR) and existing procedures. Some WRs were not prepared with sufficient
thoroughness to perform the work.
In PIF 01998-006006, the licensee documented the discovery that the work
. instructions for replacing the turbo oil circulating pump were mistakenly written
for replacement of the continuous lube.oil pump. The error was noted by an
alert mechanic preparing to begin work, who remembered that turbo oil
circulating* pump work was planned, and not continuous lube oil work . .The*
licensee concluded .the error was caused by a .planner who was confused about
the two pumps (ref. NTS #237-260-98-15101).<- .*
~ : ..
In PIF 0 1998-00715, the licensee documented the discovery, on February 5,
- 1998, .that the 213 EOG turbo lube oil pump was rotating in the wrong direction.
The system had been returned to service about three hours earlier. The
incorrect rotation was found by mechanics checking the system for leaks. The
licensee noted *that the proce(jures and work instructions used did not eall for
verification of pressure or pump rotation, and no bump check was done after
installation. Also, when the pump was started, no one verified the expected plant
response by checking the local pressure gage.
- .. r' '. 1
,
- 1
In PIF o 1998-00698, the licensee documented that when the 2/3 EOG vent fan
was started on MCC 28-1, it auto swapped to MCC 38-1. The licensee
investigated and found that the door to the cubicle was open and the inside
charred.--The cause for the damage was the incorrect replacement of the MCC's
480-V coil with 120-V coil. The licensee found that the work package specified
the incorrect part, and concluded that the incorrect coil was specified because
the planner performed an inadequate walk-down.
In various other PIFs, the licensee' documented problems related to parts. For
example, the licensee found wrong auxiliary contacts installed
(ref. PIFs D 1998.;.00681, D 1998-00727), and found problems ordering the
correct parts (ref. PIF D 1998-00652). -
Some problems resulted from inadequate parts. The licensee modified the fuel
oil filter system and installed a duplex fuel filter with the capability to select which
filter was in service. When the licensee attempted to run the 2/3 EOG, the
engine had to be tripped because it was not receiving enough fuel. The *ucensee
found that the fuel filter select valve was incorrectly oriented, and had been
shipped that way from the vendor. Furthermore, the installati'on instructions were
not sufficient to detect the condition before the requirement to trip the 2/3 EOG
(ref. PIF D 1998-00763). Also, the vendor of the fuel filter valve informed the
licensee. (post EOG trip) that a similar problem occurred at a different nuclear
site. The licensee was pursuing additional investigation
(NTS #237-260-98-20801 ):
Criterion V, "Instructions, Procedures and Drawings," of Appendix B to
10 CFR Part 50 required that activities affecting quality be prescribed by
instructions appropriate to the circumstances. Contrary to this, the instructions
14
f
--*----*-*--*-.
~--* *~*
- c
used on February'4, 1998, to perform work on the safety-related MCC 28-1 were
not appropriate because *the instructions specified the installation of an incorrect
coil. As a consequence, the coil overheated when energized and damaged the
cubicle (VIO 50-237/249-98003-01b(DRP)). In a second example, the work
- instruction used on .February 5, 1998, were inadequate because proper rotation
direction for the pump was* not checked. This led to the turbo lube oil pump
being run backward fdr several hours (VIO 50-237/249-98003-01c(DRP)). The
inspectors noted that during the work on a 2/3 EOG, the licensee identified
various other procedure and work request problems that were not detected
, during the normal revi~w process.
.
Work *Execution
- *
- The executio'n of work directly observed by the inspectors was aceomplished
according to the work instructions. Some workers displayed good attention to
. detail and good questioning attitudes that lead to the discovery of errors in work
packages such as the incorrect turbo oil pump specification.
In other work, however, some inattention to detail or lack of questioning attitude
was displayed when workers did not note or question non-like-for-like parts
replacements in the 480 V to 120 V coil replacement, and did not verify expected
actions following energization of turbo lube oil pump. The inspectors noted that
the coils were clearly labeled, arid. that local indication was available to
determine correct pump operaticm.
Proble_m_ Identification and Self Assessment
The workers wrote PIFs to document the problems encountered during the
diesel maintenance. However, some workers did not write PIFs immediately,
but only after being prompted by management. Reluctance or failure to generate
PIFs has been ongoing.
The licensee performed a good critique of the work .. The critique lead to the
entry of the problems into the station's corrective action process. The licensee
planned to issue a formal root cause* report that consolidated the PIFs and
implemented corrective action.
Conclusions
The licensee completed major diesel maintenance within the time allowed by
technical specifications.: * .:
Errors in package preparation and failure to detect the errors during the review
cycle led to rework, damage to equipment, and increased unavailability of safety-
related equipment. Additionally, a faulty part used in a modification was not
discovered until the 2/3 EOG was running, and the part forced the diesel to be
tripped.
The performance of workers in the field was generally correct. However, in
some cases, workers did not note changes in parts or verify expected actions
.after manipulation of equipment.
15
-* ...:...-:....:..--.:-::.::.:::.....-:-.;:::....:. .. ~*--= -==
-*-*.*
...
-~-*
- --- -.----
-- ----
--
I 4
At" the end of the inspection period, 'the licensee was pursuing root cause
report #237-:200-98.;.00100 to determine the sources and appropriate corrective
actions for the errors that occurred during the maintenance.
. . -:.
~: ~ .
M4.2
(Unit2. 3) Scaffolding
a.
Inspection Scope (62707)
The inspectors perfe>imed an inspection of erected scaffolding during this
inspection period. The inspectors reviewed Dresden Maintenal"!ce Procedure
(DMP) 0018-!)8, Rev .. 03,.dated October 3,.1997.
b.
Observations and Findings
-.!t.
- . ..
During a walkdown of the containment cooling service water (CCSW) pump
- .
vault room, the inspectors identified that a section of scaffolding erected around
the CCSW room cooler was positioned against pressure indicator isolation
Valve 2-1599-82C. This valve is found on the discharge side of the 2C CCSW
pump. Attachment D of Section 5.2 of DMP 0018-08 contains requirements that
address the horizontal and vertical clearance requirements between scaffold and
safety-related equipment. The inspectors promptly reported the issue to the
licensee. The inspectors followed .up this issue by verifying that the licensee
- -
adjusted the scaffolding to comply with requirements of DMP 0018-08. After. the
inspectors' identification of the scaffolding concerns, the licensee also identified
additional scaffolding erection and inspection deficiencies and appropriately
docume*nted the issue with problem identification forms. For example, following
. the end of the inspection period, the licensee identified some da*mage to the
safety-related standby gas treatment system ductwork which rendered the
system inoperable. The damage appeared recent and the licensee suspected
that banging a scaffold into the ductwork caused the damage.
- 10 CFR Part 50, Criterion .V, requires activities affecting quality be prescribed by
appropriate instructions and accomplished in accordance with those instructions.
" '*
f
Failure to.ensure that scaffolding was constructed in accordance with the
'
. requirements of DMP 0018-08 was a violation of these requirements
(VIO so..;237/249-98003-01d(DRP)).
c.
Conclusions
~
- ~-
Failure to follow procedures governing the erection and inspection of scaffolding
resulted in a violation. After the inspectors' identification of scaffolding
deficiencies, the licensee noted additional examples of scaffolding concerns,
including an instance where safety-related standby gas treatment system
ductwork appeared to have sustained minor damage from scaffolding.
M4.3
Parts and Package Preparation
The licensee identified that a nonsafety-related motor shaft nut was installed on
the safety-related 2D LPCI pump motor. A supervisor who was not involved with
16
M8
M8.1
the-installation of the nut identified the discrepancy ... The licensee concluded that
the error came from poor work package preparation. In re.sponse, the licensee
- conducted a one-day standdown of work package preparation and discussed the
procedural requirements for parts and -packag~. pre~~ration.
' ..
No violation was iss~ed because a violation *for poor work package preparation
and use of.the correct parts was already discussed in Section M4.1 of this *
report.
Miscellaneous Maintenance Issues
~ *.;
- ~.; ~-~ .. ~: :~!~* ... :
-
Breaker Maintenance Issues (97203) *
- .* : ' '*
! *
' : . r: 1
l ;* : '.
~ ;
I
l
- ~
~ !
.
. . ::
The inspectors reviewed several historical 4-kV breaker events, the corrective
actions, and the effectiveness reviews.
In June of 1996, a failure of a low pressu_re coolant injection system breaker
occurred. Investigation revealed that DES 6700-03 provided inadequate
instructions and led to hardened grease in the safety-related 4-kV breakers.
Section M2.1 of Report 96006 noted that the June 1996 breaker failure caused
the licensee to shut down Unit 3, and to delay startup of Unit 2, until compietion
of a significanLbreaker refurbishment project. Violation 50-237/96012-02 was
issued because DES 6700-03, Rev. 7; '*'Inspection and Maintenance of General
Electric 4-kV Magne-Blast Circuit Breakers Types AM-4.76-250-0D (Horizontal
Drawout)," was inadequate. Violation 50-237;249/96002-0SA was issued for.
inadequate corrective actions for 4-kV breaker problems .
The licensee has completed effectiveness reviews (ERs) for the breaker issues
and concluded the corrective actions were collectively effective:
The inspectors reviewed the ERs and identified no concerns. Therefore, the
- inspectors concluded that.the following LERs and inspection-follow up items (IFI)
could be closed:
(Closed) LER 237/93012-02: April of 1993 Failure of Unit 2 Emergency Diesel
Generator Output Breaker to Close due to Mechanical Failure. The LER and its
supplements described how the 4-kV diesel generator output breaker failed
during a refueling outage emergency core cooling system integrated functional
test. The LER stated that how the linkage was bent to the point where it failed
to operate was "indeterminable," and it noted that "damage to the alignment
guide assemblies is evident in almost all of the breaker cubieles in the plant."
The corrective actions taken in the summer of 1996 addressed the failure.
{Closed) IFI 237/249-'95002-03(0RP): February of 1995 Failure of Unit 2 Diesel
Generator Breaker. The inadvertent breaker closure was attributed to failure of
the close latch monitoring switch (CUMS) coupled with binding of *the closing
linkage. The CUMS failure was a result of rapid breaker cycling during
me\\'intenance an.d the linkage binding was attributed to lubrication practices
during maintenance. The intent of the CUMS was to inhibit the charging motor
from operating during the presence of a close signal.
17
- E2
E2.1
a.
b.
~:..::..---,,,_ .. _. -
__ ...
Section 3.4 of Report 95002 listed that the inspection follow up item was a
review of the operability evaluation performed to confirm the operability of the
Unit 3 breakers and the results of the Unit 2 inspectiQns.
The operability evaluation concluded that the 4-kV Susses 23, 24, 23-1, 24-1,
34, 33-1, and 34-1 were operable. The evaluation was based on the fact that
the Unit 3 breakers had passed their surveillance tests and on the fact that the
type of failure was easily detectable.
l
~ .
,.
Eight out ofthirty 4-kV breakers failed Unit 2 and Unit 3 testing. Most o_f the
failures were for failed close latch monitoring switches. The licensee concluded
that the breaker preventive maintenance procedure, DES 6700-03, Rev. 3, was
inadequate and led to the failure of the close .. latch monitoring switches.
Review of the operability determi_nation and the results of the testing performed
in 1995 identified no newjssues.
- (Closed) LER 237/96001-00 and-01: January 13, 1996; Failure of the Diesel
Generator Output Breaker to Close during Testing due to Inadequate Technical
Documentation. This LER determined that the root cause was the improper
alignment of the auxiliary contact linkage due to inadequate preventive . *
maintenance. The corrective actions taken in summer of 1996 addressed the
failure.
Ill. Engineering
Engineering Support of Facilities and Equipment
(Units 2. 3) Potential Overfill of Reactor Vessel Following Reactor Scram
Inspection Scope (71707. 37551)
The inspectors reviewed a licensee-identified issue concerning the potential to
overfill the Unit 3 r.eactor vessel following a reactor scram from high power.
Observations and Findings
The licensee identified the potential for the Unit 3 feedwater level control
(FWLC) system to overfill the reactor vessel following a reactor scram from high
power and flood the HPCI steam lines with water. The issue is similar to a
concern documented in NRC Inspection Report No. 50-237/97024(DRP);
50-249/97024(DRP) concerning the response of the Unit 2 FWLC system.
Licensee personnel documented the concern via PIF D1998-00907. The*
potential response of the FWLC system required Unit 3 operators to perform the
same compensatory actions following a reactor scram as the Unit 2 operators.
The inspectors will track licensee resolution of the issue via normal inspector
review of the licensee's problem identification and corrective action program .
18
) +
, .... _ *-. --
~---
c.
E4.:. *
E4.1 .*
EB.1
___ ._........__..___.
- .:~---~- :. _ _;_ ___ -_: __ _
. ---- --.--
Conclusions
The identification of the issue showed a good questioning attitude by
engineering personnel. However, the inspectors were concerned with the
potential for overfilling the reactor vessel following a reactor trip on either of the
units.
- -*.
-
. -
The FWLC system response presented a potential challenge to operators
following a reactor scram. The compensatory actions that operators are
required to take following a scram on either unit constitute an additional operator
work-around. Pendi.ng permanent resolution of the FWLC system issues, the
station was relying on operator intervention following a scram to prevent water
intrusion into HPCI *steam lines. *
,
Engineering Staff Knowledge and Performance
Core Spray System Information (37551)
As part of the core spray system review, the inspectors discussed system
monitoring with the system engineer. The engineerwas monitoring the core
spray system and documenting periodic walkdowns. However, the inspectors
noted that the system engineer _did not assure that the system notebook
contained the current lesson pl~n and was free of obsolete information. This
observation was similar to findings of a Q&SA review done in -September of*
1996. The system notebookswere not procedurally required, but were useful in
assurini;rthe correct system information was available and readily accessible to
backup system engineers. The inspectors concluded that the fallure to maintain
up-to-date information showed inattention to detail.
Miscellaneous Engineering Issues
(Closed) IFI 249/95002-02CDRP): Acceptance criteria for the* sediment and
water in the diesel fuel, The licensee found water and sediment in the Unit 3
diesel fuel oil storage tank samples, but had not established limits for the
acceptable amounts of sediment or water in the samples. The IFI was to review
the licensee's research into acceptance criteria.
Technical Specification 4.9.A.5 now states that fuel storage tank samples must
meet the applicable ASTM standards for water and sediment. This IFI is
therefore closed.
IV. Plant Support
R1
Radiological Protection and Chemistry (RP&C) Controls
R1 .1.
- General Comments (Inspection Procedure 71750)
The inspectors assessed the performance of radiation protection through routine
observations. The observations included maintenance of survey maps,
19
~-:*: ---*--*--
---
.... -
~-
F8
F8.1
X1
X2
-* .=---.--.. _.__T'_--:::::;..;::,.*:'....'L-.' .*
.
-
.
- *-*-
-**-~
-~*-*-** *-;""'-'- ~--:---;.-
- ..,,.'.
~. :l'.-..
-.;.~ '"..........:~ .. : . ..:~; **-
. :'!!
. ~* * .J :
. . " .* . resp~~~~s to personn~*i :contamina'tion monitor alarms*: and 6ontrol of the
- radiologically controlled area. * ,
- * *
The licensee continued to use a greeter to verify radiation worker readiness
before entry into the radiologically controlled area. This was a good practice.
Th~nadiation protection personnel performed monitoring and responded to*
_ alarms correctly. Oyerall performanc_e was good .
.. ~ . .
Miscellaneous Fire Protection Issues
- (Closed) IFI 50-237;249/97019-03: Review of the seismic requfr~ment~ for the
emergency lights. This issue was discussed in Section F2.1 of Report 97024 ..
The inspectors concluded-no* additional follow up was necessary.** Therefore,
- this:IFI 'is closed.
'*.
V. Management Meetings
- *Exit Meeting Summary
The inspectors presented the inspection results to members of licensee
management at the conclusion of the inspectiqn on February 20, 1998. The
licensee-acknowledged the 'findi'ngs presented. The inspectors asked the -
licensee whether any materials examined during the inspection should .be
consid~_!:~d proprietary. No proprietary information was identified.
Management Meeting Summary
On January 16, 1998, the NRC Region Ill Regional Administrator and the
Director of the Division of Reactor Projects met on the site with senior licensee
management. to present the result of the 151h systematic assessment of licensee *
performance.
20
,..
..
'* .. ~ . . . ....
- . :
- ..::..
- -
- * : =:
. ., .l'.: ., j ;\\'
1 ~
'!. : ; I' *
__ .,-_,
'1,**
' ... (
PARTIAL LIST OF PERSONS CONTACTED*
j *.
- Licensee
~L Aldrich, Acting RP Manager
- *S. Barrett, OPS Manager
- M. Gallaway; MMD Supervisor
- J. Heffley, Site Vice President
- *E. Hrbac, Construction Manager .
- S. Kuczsynski, OPS Staff
- VV. Liscomb, Site Vice President Staff
- *R. Peak, Engineerin*g Rapid Response Team
- *P. Planning, Plant Engin*eering Superintendent
- C. Richards, Q&SA Audit Supervisor
- D. Schupp, OPS Staff
. *'""'
- F. Spangenberg, Regular Assurance Manager
- P. Stafford, Station Manager
.
- B. Stoffles, Construction Supervrs*or
- D. Willis, EMO Superintendent
- D. Winchester, Q&SA Manager
- K. Riemer, Senior Resident Inspector
- M. Ring, Branch Chief --
- D. Roth, Resident Inspector
- Denotes those attending the meeting on February 20, 1998 .
21
I.
..
--
- .:..:::::.___~;
- . ---* . ----. -- . -*-
--~-* ............ _ *--*--***
--
- - ...
~ -----**-*-*"""-'-------*
- --.:.-.,.--
- ---'.'-- *-*---,.--
INSPECTION PROCEDURES USED
IP 37551:
Onsite Engineering
IP 40500:.
Effectiveness of Lice.nsee. 9ontrol.s in Identifying, Re~olving, and Preventing
Problems
IP 62707:
Surveillance Observations
Maintenance Observations _
IP 71707:
Plant Operations
IP 71750:
Plant Support Activities
Opened
~37-249/98003-01a *
237-249/98003-01 b.
237-249/98003-01 c
237-249/98003-01 d
Closed
237/93012-02
249/95002-02
2371249-95002-03
237196001-00-01
2371249-97019~03
Discussed
237~249/96004-01
237-249/97019.
237-249/970'28
!'
ITEMS OPENED, CLOSED, AND DISCUSSED
VIO *
LER
IFI-
IFI
LER
IFI
Failure to have appropriate surveillance instructions
Failure to have adequate maintenance instructions
Failure to have adequate maintenance instructions
Failure to follow maintenance instructions
Failure of U2 EOG Output Breaker to Close due to
.Mechanical Failure
No limits established for accepted amounts of sediment in
samples
- Closing lat~h monitor switch found stuck
Failure of DG Output Breaker to Close During Testing due
to Improper Configuration of Auxiliary Contact Linkage
Review of the seismic requirements of the emergency lights
- Checklist Corrective Action
Violation of Inadequate procedures
Failure to follow PIF process
22
__ ,_. ___ _
-
-::::-::;::--::----. ;:- .
ccsw
DGP
_DIS
DOP_
EOG
EMO
IFI
IMO
kW
kV
LER
Li.
MMD
NSO
NTS
psig
us
- --~- -..,=--* .. ~*----:~;.::;.:__
-.-:----:- ---,-
.. -
---.------*
LIST OF ACRONYMS USED
Containment Cooling Service Water
, Dresden Ge:ne~al P,roc~dur~
.
Dresden 1.nstrumer;it Surveillance
Dresden Operations Procedure
Dresden Operations Surveillapce
Electrical Maintenance Department
High Pressure Coolant Injection.
Inspector Followup Item
. .
Instrument Maintenance Department
Kilowatt
Kilovolt
Licensee Event Report
Level Indicators
Loss Of Coolant Accident.
Motor Control Center
Mechanical Maintenance Department
Megawatt
Nuclear Station Operator"
Nuclear Tracking System*"
Problem Identification Form
Pounds Square Inch Gage
Updated Final Safety Analysis Rep'ort
Unit Supervisor
23
f
.,