ML18059A706
| ML18059A706 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 03/04/1994 |
| From: | Burgess S, Wright G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML18059A705 | List: |
| References | |
| 50-255-94-02, 50-255-94-2, NUDOCS 9403090039 | |
| Download: ML18059A706 (22) | |
See also: IR 05000255/1994002
Text
U. S. NUCLEAR REGULATORY COMMISSION
REGION II I
Report No. 50-255/94002(DRS)
Docket No. 50-255 .
License No. DPR-20
- Licensee:
Consumers Power Company
212 West Michigan Avenue
Jackson, MI
49l01
Facility Name:
Palisades Nuclear Generating Plant
Inspection At:
Palisades Site, Covert, Michigan
Inspection Conducted:
January 10 through February 11, 1994
Inspection Team:
S. Burgess, Team Leader
J. Guzman
J. * Lennartz
R. Lerch
NRC Consultants:
M. Shlyamberg, Parameter, Inc.
- Approved By:
Approved *By:
/~u-~-
\\s::JD. Burgess, Team Leader
Region III
)tc:,
I __k--**
G. c.~ief
Engineering Branch
Inspection Summary:
3-3-34
- Date *
?fy/J/
Date
Inspection on January 10 through February 11; 1994 (Repoft No. 255/94002(DRS))
Service water system operational performance inspection (SWSOPI) in accordance
with NRC Temporary Instruction 2515/118.
Results:
The team .determined that Palisad~s' servi~e water and component cooli~g water
systems were operable based on the current low lake temperature.
However, the
systems' ability to fulfill their safety related function at elevated lake
water temperatures combined with other adverse design basis conditions is in
question pending the completion of an engineering analysis.
Because of the
significance and number of design iss.ues identified during the inspection, the
team concluded that engineering did not have a clear understanding of fhe
systems design.
One apparent violation with five examples was identified
regarding inadequate or no corrective actions taken to previously ~dentified
concerns.
Three unresolved items were identified related to the lack of
overpressure protection for CCW heat exchangers (Section 5.3), the engineering
analysis that would determine service water operability margin (Section 5.4),
and the past ESS pump operability based on the integration of IST reference
values and required system performance (Section 8.1).
9403090039 940304
ADOCK 05000255
G
TABLE OF CONTENTS
--*-
EXECUTIVE SUMMARY ................................................... .
1.0
INSPECTION SCOPE AND OBJECTIVES ................................ 2
2.0
LICENSEE ACTION ON PREVIOUS INSPECTION FINDINGS ................ 2
3.0
GENERIC LETTER 89-13 IMPLEMENTATION ............................ - 3
4.0
SYSTEM DESCRIPTION................................... . . . . . . . . . . 3
5.0
MECHANICAL DESIGN REVIEW ......................... ~.*............ 4
6.0
OPERATIONS ............ , ....... _................................. 9
7.0
MAINTENANCE . .- ........... -... -.. ; .. * ........... * .................... 11
8.0
SURVEILLANCE AND TESTING ..................................... * .. 12
9.0
QUALITY VERIFICATION AND CORRECTIVE ACTIONS .................... 14
UNRESOLVED ITEMS .................. ;.................... . . . . . . . . 15
EXIT M_EETING ... _ ............... * .. .-.......................... _ .... 15
10.0
11. 0
Appendix A - Personnel Contacted
Appendi~ B :- Generic Letter 89-13 Action* Items
-*
Executive Summary
During the period January 10 through February 11, 1994, a Region III
inspection team conducted a service water system operational performance
inspection (SWSOPI) at Palisades Nuclear Generating Facility.
The inspection
scope encompassed the service water (SW) and component cooling water (CCW)
systems.
For these systems, the inspection included a mechanical design
review;
d~tailed system walkdowns; review of system operation, maintenance;
- and surveillance; and assessment of quality verification and corrective
actions requested by Generic Letter 89-13, "Service Water System Problems
Affecting Safety Related Equipment," as well as system unavailability.
The team determined that Palisades' SW and CCW systems were operable based on
the current low lake temperature.
However, the systems' ability,to fulfill
their safety related functio~ ~t elevated lake water temperatures combined.
with other adverse design basis conditions is in question pending the
completion of engineering analysis.
The team also identified the following:
(1)
Engineering lacked ari understanding of SW and CCW system design as*
evidenced by:
A previously identified; however unrecognized, single failure
vul*nerability results in the eventual failure of Engin~ered
Safeguards System pumps and loss of the required safety injection
function.
The use of SW as a backup source* of coo 1 i ng to the ESS pumps
during a LOCA condition results in draining CCW to the lake.
A potential water hammer in the SW system could potentially impact
containment integrity during a LOCA cond~tion.
The current IST program ~ould allow the SW.and CCW pumps to
degrade below minimum system f'ow requirements without being
- declared inoperable.
(2)
An apparent violation with five examples was identified where inadequate
or no corrective actions were taken to address previously identified
concerns.
(3)
Self-assessment effectiveness was hindered by inadequate corrective
actibns and lack of management involvement .
-*
DETAILS
1.0
Inspection Scope and ~bjectives
Numerous problems identified at various operating plants in the country have
called into question the service water systems' (SWSs) ability to perform
their design function.
These problems have included:
inadequate heat removal
capability, biofouling, silting, single failure concerns, erosion, corrosion,
insufficient original design margi~, lapses in configuration control or
improper 10 CFR 50.59 safety evaluations; and inadequate testing.
NRC
management concluded that an in-depth examination of SWSs was warranted based
on the identified deficiencies.
The inspection team focused on the mechanical design, operational control,
maintenance, and surveillance of the SWS and evaluated aspects of the quality
assurance and corrective action program~ related to the SWS.
The inspection's
primary objectives were to:
assess SWS performance through an in-depth review of mechanical systems
functional design and thermal-hydraulic performance; operating,
maintenance, .and surveillance procedures and their impfomentation; and
operator training on the SWS,
verify that the SWS's functional designs and operational controls are
capable of meeting the thermal and hydraulic performance requirements
and that SWS components are.operated in a manner consistent with their
design bases,
assess the licensee's planned and completed action~ in response io
.Generic Letter 89-13, "Service Water System Problems Affecting Safety
Related Equipment," July 1989, and
assess SWS unavailability resulting from planned maintenance,
surv~illanc~, and component failures.
The areas reviewed and the concerns identified are described.in Sections *2.0
through 9,0 of this report.
Conclusions are provided after each section.
Personnel contacted and those who attended the exit meeting on February 11,
1994, are identified in Appendix A.
Details pertaining to Generic Letter (GL) 89-13 action items are attached as Appendix B.
2.0
Licensee Action on Previous Inspection Findings
(Open)
Unre~olved Item 50-255/92028-03CDRS):
Use of firewater to backup water
supply for auxiliary feedwater (AFW).
The NRC's concern was based on the lack
of an analysis or testing to verify the fire water system's capability to
provide backup water to*the AFW system.
The licensee committed to complete an
analysis to document the fire water system adequacy under action item request
(AIR) A-PAL-92-098.
This item is considered open .
2
3.0
Generic Letter 89-13 Implementation
The NRC issued GL 89-13, "Service Water System Problems Affecting Safety
Related Equipment," requesting that licensees take certain actions rel~ted to
their SWS.
These actions included establishing the appropriate frequencies
for testing and inspecting safety related heat exchangers over three operating
cycles to ensure the operability of SWSs that are credited for cooling safety
related equipment.
-
The team considered Palisades' response adequate in addressing GL 89-13
concerns.
See Appendix B for details pertaining to each GL 89-13 Action Item.
4.0
System Description
The safety related service water was co~prised of the SW ahd CCW system.
The SW system passes codling water to the following major s~fety related
components:
CCW heat exchangers' tube side that provided heat removal from the CCW
system,
- .emergency diesel generators (EOG) jacket water and lube oil coolers,
containment .air coolers (CAC) that provided*containment heat removal,
engineered safeguards.system (ESS) room coolers that provided heat
removal from the equipment and piping housed in the ESS rooms, and
condensers for control rocim air conditioners.
The SWS is a once-through system that supplied cooling water to the heat
exchangers listed above and provided an emergency water source for the AFW and
backup to CCW system for ESS pump cooling.
The SWS also provide cooling for
the nonsafety related loads, which were automatically isolated d~ring accident
conditions.
The system consisted of common piping network with redundant
. components instead of the traditional "two independent trains." A limited
"train independence" was achieved by grouping the essential compc:rnents into*
two critical headers.
Critical headers A and B provided redundant cooling to th~ EOG jacket water
and lube oil coolers, ESS room air coolers, backup supply for the AFW and ESS
pump cooling and the nonsafety related plant air compressors.* C~itical header
A provided redundant cooling to the CCW heat exchangers, whereas critical
. header B provided redundant cooling to the CACs.
There were three SW pumps,
each rated for 8,000 gpm at 140 feet.
Depending on the accident event, one or.
two pumps were-required.
Also, there were two CCW heat exchangers and four
CACs.
The CCW system recirculated cooling water to the following major safety
related components:
3
CCW heat exchangers' shell side that provided the heat transfer to the
SW system,
shutdown cooling heat exchanger (SDCHX) that provided the decay heat
removal,
seal cooling and lubricaticin heat removal for the ESS and make-up pumps,
and
spent fuel pool (SFP) cooling.
- CCW is a closed loop system that provided cooling water to the heat exchangers
listed above as well as nonsafety related loads.
The nonsafety related loads
located outside containment and the SFP cooling were automatically isolated
during the accident conditions. Similar to SW, CCW was also comprised of the
common piping network with redundant components instead of two independent
trains." However, unlike SWS, the essential components were not separated
into two critical headers,
There were three CCW pumps, each ~ated for 6,000
gp~ at 164 feet.
Only one pump was required to provide the safety related
flow in the event of an accident.
5.0 .
Mechanical Design Review
The mechanical design review of Palisades' SW and CCW systems included
determination of whether the systems' design bases, design assumptions,
calc~lations, analyses, boundary conditions, and models met licensin~
- commitments and. regulatory requirements.
This review also included an
assessment of a single failure impact on the ability to perform required
safety function.
Al~o reviewed were the SW and CCW systems' capability to
meet the thermal and hydraulic performance specifications during accident or
abnormal conditions.
The team also reviewed the systems' seismic
qual.ification, design vulnerabilities, floodin~ mitigation characteristics,
a~d selected modification packages.
The significance and humber of design issues identifi~d during this
inspection, illustrated that not only was.the system design not clearly
understood but there also appeared to be no clear understanding of system
design responsibility betwe~n system and design engine~ring.
5 .1
Single Failure Vulnerabilities
Two potential new single active failures were identified for SW and CCW
configuration for supplying cooling water for seal coolirig and lubrication
heat removal for the ESS pumps.
The first failure could lead. to the loss of
all ESS pumps.
The second failure could lead to a complete loss of CCW during.
a LOCA.
.
5.Ll
Loss of all ESS Pumps
One possible scenario, which exemplified the first failure is a LOCA with a
loss of offsite power (LOOP) and a single. active failure of normally closed
4
isolation valves CV-0913 or CV-0950 to open on receipt of a safety injection
(SI) signal (See Figure 1).
The Palisades cooling sy~tems' desig~ relied on the operator initiated backup
of SW for ESS pump cooling.
However, SW could not provide backup pump cooling
for a LOCA/LOOP scenario because it required opening normally closed, air-to-
open, valves CV-0879 or CV-0880, and CV-0951.
This evolution required an
- instrument air supply, which is nonsafety related and, hence, cannot be used
to mitigate the accident consequences.
The unavailability of instrument air
is further exacerbated by the fact that these valves do not have a safety
related air backup and do n6t have handles.
The failure to provide coolin9 water for ESS pump seal cooling and lubrication.
heat remova 1 could result in eventua 1 ESS pump fa i 1 ure, s i nee the pumps w*ere
not qualified to perform without cooling when they pump hot water from the
containment sump~ Ess*pump failures would lead to a loss of the required
safety injection and containment cooling functions.
Even if the failure was.
limited to the pump seals, such failure could lead to uncontrolled releas~
from containment.
This vulnerability was previously identified by the licensee's Safety System
Design Confirmation (SSDC) report on May 25, 1989; however, its s1gnificance
had not b~en recognized and no corrective actions were taken~ Failure to take
prompt corrective actions to this previously identified single failure
vulnerability is an example of an apparent violation of 10 CFR Part 50,
Appendix B, Criterion XVI .
5 .1. 2
One possible scenario, which exemplified the second failure is a LOCA without
LOOP and a single active failure of one normally closed isolation valve CV-
0913 or CV-0950 to open on rece'ipt of an SI signal (See Figure 1). *
In this ~cenario, *instrument a~r would be availabl~ for ppening normally
closed valves CV-0879 or CV-0880, and CV-0951 .. However, the control circuits
for isolation valves CV-0913 and CV-0950 have a *"seal-in" feature.
These
valves could not be reclosed during an SI actuation, until the SI signal was
reset. As discussed in Section 6.1, bperating procedures prohibited SWS and
CCW valves to and from the ESS pumps to be open at the same time.
Thus,
during this scenario the operator is faced with two following choices:
(1) do
not initiate the SW backup, which results in the loss of ESS pumps, or (2)
violate procedures and initiate the SW backup.
If SW backup cooling was initiated with an SI signal still in; opening valve
CV-0951 created a direct path for draining CCW to the lake, which would result
--*in the loss of shutdown cooling.
The current FSAR containment analysis
credited the use of shutdown cooling in all cases and, thus, relied ri~ CCW
availability .. The loss of shutdown cooling placed the required containment
cooling function outside of Palisades' current licensing bases .
5
5.2
Leak Testing Important SW Valves
The team questioned the Category B designation of SW non-critical ~eader
isolation valve, CV-1359, the SW containment return isolation valve, CV-0824,
and the SW containment supply isolation valve, CV-0827.
Category B meant that
seat leakage was inconsequential for fulfillment of the valves' safety
function.
The team determined that an evaluation should be made to determine
if a Category B designation was appropriate since valve leakage was
consequentiil, based 0n the following:
Test results and engineering evaluations were inconclusive and could not
be used to determine if the SWS would fulfill its safety related
function at elevated lake water temperatures as discussed in Section
5.4. Therefore, the leakage impact of valves CV-0824 and CV-1359 on. SW
system margin could not be presently determined.
As discussed in Section 5.5, leakage of valves CV-0824 and/or CV-0847
could result in a water hammer that had a potential to challenge
containment integrity during a LOCA.
Leakage of valve CV-0847 could lead to an.uncontrolled intr~as~ of the
post-accident maximu~ containment sump levels~
Deviation report (OR) O-PAL-93-272 initiated corrective actions to review the.
need to leak test valves CV-0824, CV-0847, and CV-1359.
the licensee's SW SSDC i~ehtified the importance of incorporating the SW: .
non-critical header isolation ~alve, CV-1359, into a leak~ge test* program on*
May 17, 1990.
The lic~nsee attempted to resolve this issue under action item
req~est (AIR) A-PAL-90-089 and subsequ~ntly under* E-PAL-90~002. However, an
evaluatiorr of leak testing CV-1359 was not completed and t~e issue was never
resolved.
Failure to provide prompt corrective actibns to incorporate SW
valve CV-1359 into a leakage test program is an example of an apparent
violation of 10 CFR Part 50, App~ndix B~ Criterioh XVI.
5.3
Lack of Overpressure Protection for CCW Heat Exchangers
The team identified the lack of overpressure protection for CCW heat
exchangers (HX)
E~54A and E54-B.
The concern involved overpressure due to
thermal expansion stemming from SW valve isolation.
Pali~ades' ASME Code of
record required each vessel to be protected from any conditions of pressure or
temperature that was in excess of design conditions specified in the certified
design specification.
The Code further required to document the degree of
overpressure protection in a summary technical report.
The licensee was
- unable to retrieve the summary technical report that justified the lack of
overpressure protection prio~ to completion of thi~ inspection;
The licensee
co~~iftea t6.16~ate the report or~erform the technic~l analysis to show Code
compliance.
Pending the licensee's action to resolve the lack of overpressure protection
for the CCW HXs and the subsequent review by NRC, this is considered an
unresolved item (50-255/94002-01) .
6
.,
.--**
5.4
Operability Margin of SWS
The re5ults of tests, calculations and engin~ering evaluations were
inconclusi~e and could not be used to determine if the SWS would fulfill its
safety related function at elevated lake water temperatures combined with
other adverse design basis conditions.
The licensee concluded that the SW and CCW systems were currently operable
because current lake water temperatures were less than.50 °F.
This
temperature provided significant margin to account for all issues impacting
the SW operability margin;
The licensee co~mitted to resolve the following
issues, documented in DR D-PAL-93-272, by mid April 1994.
Neither test results or design basis calculations accounted for
instrument uncertainties.
The analyses that develop required flow rates to HXs served by the SWS
used only the original design fouling.
No calculations had been
performed to evaluate degraded HX performance resulting f~om fouling
beyond the original design value.
-
.
The most limiting system lineup may not have been tested.
The imp act of increased* SW temperatures and reduced 'SW fl ow rates on the
SW and CCW design pressures and temperatures and systems' operation wa*s
not evaluated.
The root cause of declining flow rates to control room. chillers VX-10
and vx~11 had not been determined.
.
As discussed iri Section 8.1, the SW pump IST reference values and pump
degradation was not coupled to the required system performance.
The elevated lake water temperature was not incorporated into the
maximum allowable SW system degradation. *
Pending the licensee's completion of all the actions impacting SWS margin
documented in DR O-PAL-93-272 and review _by the NRC, this is ~onsidered an
unresolved item (50-255/94002-02).
5.5
Potential Water Hammer Event
The team identified a potential water hammer in the SWS that could challenge
containment integrity during a LOCA condition.
One possible scenario that
could result in such an event ts a LOCA with LOOP, and the single active
failure of EOG 1-2.
Since EOG 1:2 powered the CAC fa~s, a~ operator would
close the SW CAC outlet isolation valve tV-082~ per Off Normal
Prti~edure (ONP)
6.1, "Loss of Service Water."
Since this valve was not leak tight, as
discussed in Section 5.2, it is possible, that an operator would close the CAC
inlet isolation valve CV-0847 to assure total CAC isolation. This isolation
could lead to a depressurization of SWS in containment and formation of air
pockets in the 16 inch containment penetrations since that was the SWS high
7
point in containment.
The cause of the depressurization could be preexistent
leaks in the CACs.
When po~er to the CAC fans was restored, an operator would
try to restore water flow to the CACs in order to maximize contatnment
cooling.
Air pockets in the containment penetration would cause a water
hammer.
The licensee agreed with the team's water hammer concern and committed to
provide procedural guidance to eliminate the inadvertent restoration of the
containment SW header that may cause a water hammer.
The licensee failed.to
identify this SWS water hammer susceptibility in their prior review.
The team
considered this an example where the system d~si~n was not clearly understood.
5.6
Use of SW as Alternative Source ~f Cooling for SDCHXs
The licensee was unable to determine the basis for the use of SW as an
alternate source of cooling for the SDCHXs.
Off Normal Procedure (ONP) 17,
"Loss of Shutdown Cooling," Revision 16, required the* alignment of SW to the
SDCHXs in the event CCW supply to the HXs was lost. Since the alternate
supply was estimated to yield only 250 gpm of service water, the effectiveness
of this cooling was questionable. Also, the combination of this small flow
rate and SW pressures being lower then CCW could lead to a potential for vapor
locking of .sw backup cooling for ESS *pumps. *
Since the licensee could not determine why the evol.ution was incorporated into
pl ant' procedures, they committed to evaluate the need and safety of this event
miti~ati-0n strategy..
5.7
Bent Instrument Tubing*
Instrument tubing routed in front of the CCW HXs was bent ~nd had the
appearance of being repeatedly stepped on.
Likewise, the unistrut supports
for the instrument lines were bent.
The team questioned if this configuration
was analyzed and met the seismic support requirements.
The licensee's review
determined that the stresses in the tubing met the allowable values for
operability, but were in excess of the FSAR Section 5.7 committed stress
values based on the tubing specification.
The licensee identified th~ bent tubing on Januaty 4, 1994, with tag# 12553.
Corrective actions on the tag indicated "r.epafr or replace."
The licensee
failed to appropriately question the seismicity of the condition until asked
by the team on January 27, 1994.
Failure to take prompt corrective actions to
address the instrument tubing and unistrut support seismicity is an example of
an apparent violation of 10 CFR Part 50, Appendix B, Criterion XVI.
.5.8
Lack of Isolation of Plant .Air Compressors from SW
Crinirary to the description provided in Section 9.1 of Palisades' FSAR the
nonsafety related air compressors were not automatically isolated from the
critical portion of SW.
The licensee committed to correct this FSAR
discrepancy during the next FSAR revision .
8 ..
. ..
.-.-.
5.9
Conclusions
The significance and number of design issues identified during this
inspection, illustrated that not only was the system design not clearly
understood but there also appeared to be no clear understanding of system
design responsibility between system and design engineering.
Signiffcant
issues included unidentified and/or unrecognized single active failures,
valves with critical shutoff functions were not leak tested, and the SW and
CCW .systems' ability to fulfill their safety related function at the elevated
lake water temperatures was pending the completion of engineering analysis.
6.0
Operations
The team reviewed plant operations to assess operator knowledge and the
accuracy and completeness of procedures and training with regard to the SW and
CCW systems.
The team performed system walkdowns; reviewed procedures for
normal, abnormal, and emergency .conditions; assessed conduct of operations in
the field and control room; and evaluated training manuals, .lesson plans, and
operator actions on simulated SWS/CCW malfunctions.
Overall the team determined that operator response to the simulated SWS
malfu~ctions and the crew's knowledge of SWS operation and SWS role in
accident mitigation were ~dequate.
6 .1
Operation Scenarios
The first scenario required the crew to isolate SWS crjtical .header A tri stop
a leak.
Header A provided cooling to both CCW HXs; therefore, CCW was
The ESS pumps were running due to an SI s1gnal and were needed to
provide cooling to the feactor core.
Operator actions_~enerated the following
concerns:
The crew identified the loss of CCW with the resultant loss of cooling
to the ESS pumps; however, CCW system design ~equired the crew to
violate procedural guidance to maintain cooling to the ESS pumps with
SWS.
Procedure violations resulted in draining CCW to Lake Michigan
with a resultant loss of shutdown ~ooling cap~bilities.
The crew attempted to close the inlet and outlet CCW valves (CV-0913 an~
CV-0950) to the ESS pumps, and without verifying valve response, opened
SWS valves_(CV~0879 or CV-0880, and CV-0951) to the ESS pumps.
The CCW
valves d{d not close due to a sealed in open signal received from the SI
signal that was still active. This resulted in draining the CCW system
to Lake Michigan via th~ SWS.
The CCW surge tank low level annunciator
energized and the crew responded by securing CCW pumps but failed to
-diagnose that the loss of. CCW was .due to the valve manipulations just
performed.
After the scenarip was terminated the crew recognized that
the CCW valves did not close even though the handswitches were in the
close position.
The crew then recognized that the CCW valves could not
be closed until the SI signal was reset .
9
6.2
Station Operating Procedures (SOP) 16, "Component Cooling Water System,"
Revision 11, section 5.0, and SOP 15 section 4.0, contained requirements
that SWS and CCW valves to and from the ESS pumps shall not be open at
the same time.
These procedure sections were not followed by the crew
during the scenario.
However, given the same scenario circumstances and
khowing the valve manipulation precautions and limitations, the crew
indicated that they would again violate the procedure because cooling to
the ESS pumps was essential to operate the pumps so cooling to the
reactor core could be maintained.
The crew then indicated that the
expected loss of CCW would result in a loss of cooling to the SDCHXs,
which would preclude shutdown cooling system operation.
The SWS critical header A leak, which was located in the CCW pump room,
was not isolated until 30 minutes after the event was identified by the
crew.
This created the potential for flooding the CCW pump room.
Because procedure ONP 6.1, "Loss of Service Water," Revision 5, di.d not
contain any specific guidance to isolate the leak, operator aid (OA) 136
was used to determine which valves should be closed to determine leik
location.
QA .136 was a SWS simplified schematic that was attached to
the control panel. Although the crew successfully isolated the SWS
leak, identified leak location, and determined the impact on plant
operation*, the team considered the delay to.coniplete leak isolation
actions a weakness.
Operations Procedures
The team identified the following weaknesses in the licensee's operating
procedures:
SOP 16, steps 5.1.2 and 7.6 prevented initiation of backup cooling from
the SWS to the ESS pumps if normal cooling from CCW was lost concurrent
with an SI signal.
Procedure compliance would prohibit opening the SWS
valves to the ESS pumps with the CCW valves open.
The CCW valves would
remain open until the SI signal could be reset. Current procedur*a1
compliance results in loss of cooling water to the ESS pumps ..
The licensee indicated that the procedure would be revised to allow
opening the SWS.valves to the ESS pumps if the CCW valves were open and
an SI signal was present. A CAUTION preceding step 7.6 would also be
added to a 1 ert the operator that CCW would drain to Lake Mi chi gan w_ith a
resultant loss of CCW system functions, if SWS cooling to the ESS pumps
was aligned with either CCW valve open.
SOP 15, "Service Water System," Revision 7, step 4.1.2 contained a
similar statement as described above .. The licensee indicated that this
procedure would also be revised.
-
Annu.nciator Response Procedure (ARP) 7, window 29, "Service Water Bay Lo
Level," did not provide guidance regarding what level SW pumps should be
tripped if SW bay level was decreasing.
This item was previously
identified during the licensee's SSDC conducted in May 1990.
The
10
licensee indicated that the procedure would be revised to provide
clearer direction on when to.trip the SW pumps based on basin level and
other control room and local indications.
ONP 6.1, Revision 5, Attachment 1, "Alternate Method of Supplying the
Intake Structure," required tripping the SW pumps if warm water
recirculation pump (P-5) was used to supply water to the intake
structure. This did not coincide with SOP-14, "Circulating Water and
Chlorination Systems, Revision 16, step 7.13.1, which provided stepi to
supply the intake structure from P-5 but did not require tripping the SW
pumps.
The licensee indicated that guidance for tripping the SW pumps would be
incorporated into the appropriate ARP and removed from ONP 6.1,
Attachment 1.
No revisions to SOP 14 were deemed necessary.
The team considered a 11 the proposed procedur_e changes acceptable.
6.3
Operations Training
Overall, the team determined that operations training was
adeq~ate with one
exception.
The CCW system design feature of a sealed in open signal from an
SI signal to CCW valves CV-0913 and CV-0950 was not identified in the training.
lesson plans.
As demonstrated during the simulator scenarios, this design
feature could cause serious complications with event mitigation strategies _and
should be included in the training material .
An operations representative, assigned to the training staff during simulator_
training, provided operational based input to the training session when
responding to "in plant" actions.
The individual was a licensed Nuclear
Control Operator, licensed AO, or non-licensed AO and received training as a
simulator operator.
This practice added realism to the training and was
considered a strength.
6.4
Conclusions
Operator tesponse to the s~mulated SWS malfunctions and the crew's knowledge
of SWS operation and SWS role in accident mitigation wer~ adequate.
However,
it was not recognized that the use of SWS as- a backup source of cooling to the
ESS pumps during a tOCA condition could result in draining CCW to the lake,
7.0
Maintenance
The team reviewed maintenance procedures, work history, completed work request
-packages,-.. LERs, DRs, preventive maintenance (PM) tasks for selected
components, performed detailed system walkdowns and observed _selected
maintenance activities to determine if the SW and CCW components and.piping_
were adequately maintained and system equipment that required frequent -
maintenance was identified.
The team also evaluated implementation of GL 89-
13 commitments in the maintenance area .
11
Overall, the team concluded that maintenance performed on SW and CCW
components was effectively accomplished and that maintenance problems were
properly addressed and, where necessary, corrected.
7 .1
lhe team identified non-seismically conitructed scaffolding, installed in the
west safeguards room over safety-related equipment.
The licensee performed an
engineering analysis, which concluded that the scaffolding did not meet the
requirements of procedure MSM-M-43, "Scaffolding," Revision 0, but was not a
safety concern.
The licensee removed the scaffolding and initiated a revision
to MSM-M-43 that provided additional instructions for scaffolding in safety
telated areas.
The revision would include walkdown inspections, supervisor
sign~off for installation, clarification of requir.ements, and approval and
justification by the system or assigned engineer for deviations from the
procedure.
The team considered this action acceptable. *
7.2
Containment Spray Pump Ground Strap
The team identified that a ground strap was not connected on a recently
replaced containment spray pump motor.
DR D-PAL-94-017 evaluated the problem
and concluded that the work package instructions lacked* the detail necessary
to ensure the ground strap connection.
The package al~o contained other .minor
discrepancies as well.
The licensee connected the ground strap and was
developing corrective actions for the other minor deficiencies .. The ~earn
considered this action acceptable .
'
7.3
SWS Instrument Lines Maintenance
.The team found that the licensee had not full~ evaluated the susceptibility of
SWS instiument line fouling.
Specific flushing requirements had only been
implemented for instruments that had been clogged i~ the past; however,
walkdowns of SWS pump discharge lines found that. instrument lines to pressure
switches for standby pump starting had long stagnant horizontal runs that
might be subject to fouling.
These lines were not checked by periodic
maintenance or surveillance. Also omitted were stagnant lines to and from the
former control room air conditioners; This was not consistent with the GL
intent, which recommended licensees establish routine maintenance rif SWS
piping and components to ensure that silting and biofouling could not degrade
system performance.
The licensee committed to review the maintenance of these
and other instrument lines.
7.4
Conclusions
Overall, the. team concluded that maintenance performed on SW and CCW
components was effecti~ely accomplished.
Weaknesses were identified in the
scope of instrument lines in the GL flushing program, scaffolding installed in
safety related areas, and incomplete maintenance on a containment spray pump.
8.0
Surveillance and Testing
The team reviewed preoperational test procedures, surveillance procedures, and
12
the licensee's inservice test (IST) program and implementing procedurei to
determine if sufficient testing had been conducted to confirm system design
requirements and system operability.
Overall the team determined that the IST program was adequate.
However,
concerns with the SWS pump testing were identified.
8 .1
Uncertainty in IST Pump Acceptance Criteria
DR D-PAL-93-272 identified that the IST acceptance criteria for allowed pump
degradation for all ESS pumps were inadequately tied to the systems' accident
analysis flow rates and differential pressures. Although the acceptance
criteria for the pumps was based on ASME Section XI code limits, the design
requirements for the pumps may be more limiting.
The licensee'~ preliminary
operability assessment indicated that currently all ESS pumps could deliver
the required design.flows.
The team agreed with .the preliminary analysis .
. The SW pump IST reference values and the allowed pump degradation was also
inadequately tied to the required system functional performance.
The allowed
degradation for the SWS pumps did not conside.r that the SW system flow *
balancing tests may have imposed additional restrictions on flow degradation.
This created the potential for the SW pumps to be allowed to degrade below
minimum system flow requirements without being declared inoperable.
On May 4, 1990, the licen~ee's SW SSDC identified that the SW IST pump
reference values were not coupled to the SW flow bal~ncing test.* However, the
licensee fafled to recognize the issues' significan'ce and took no corrective
actions.
Failure to take prompt correctiv~ actions to previously identified*
deficiencies is an example of an apparent violation of 10 CFR Part 50,
Appendix B,. Criterio'n XVI.
Corrective actions in response to DR D-PAL-93-272 will couple the deveiopment
of SWS pump testing reference values and required system performance.
Additionally, the licensee intended to review the basis fo~ IST reference
values and allowed degradation for all Section XI pump t~sts to ensure that
they were adequately coordinated with safety analysis performance criteria.
This issue is considered an unresolved item pending the* licensee's review to
determine impact on the IST reference values a~d the possible effect on past
ESS pump operability ( 50-255/94002-.03).
8.2 *
- System Testing Deficiencies
SWS test T-216, "Service Water Flow Verification," Revision 4, balanced'flow
.to the CCW HXs at or very near their required flow rates,and did not allow for
pump degradation.
This concern was identified in the SWS SSDC on May 4, 1990.
The licensee dispositioned the issue by stating that n~ margin in flow rates
actions taken.
Failure to take prompt corrective actions to previously
identified deficiencies is an example of an apparent violation of 10 CFR Part
50, Appendix B, Criterion XVI .
13
- 8.3
Conclusions
Although the IST program was adequate, concerns with the SWS pump testing were
identified.
Concerns included allowable IST pump degradation criteria that
was not compared to design requirements that may be more limiting and SW flow
balance testing that did not include flow margins for allowed SW pump
degradation.
9.0
Quality Verification and Corrective Actions
The team reviewed SW and CCW systems and GL 89-13 program implementation
assessments, technical audits, corrective action tracking system to ensure
adequate treatment of related items, and SW and CCW system operational history_
to assess the adequacy of root ca~se analysis ..
Three documents were considered to be "se l f-as.sessments":
the 1990 SWS and
1989 CCW SSDCs, a SWS testing assessment completed December l, 1993, and .an
Nuclear Performance Assessment Department (NPAD) assessment of SW completed
January 12, 1994.
9 .1
The SSDCs were effective in identifying credible design concerns; however,
inadequate corrective actions resulted in the similar concerns during this.
inspection.
Previously identified conce~ns included:
the single failure that.
resulted in the loss of all fSS pumps, not leak-testing the SW non-critical
header isolation valve, uncertainty in IST pump acceptance criteria, and
system testing defi.ciencies.
Because the SSDC concerns were issued ~s low priority action item requests
(AIR), management's involvement and knowledge in the issues was minimal.
Management became aware of concerns if elevated to a DR.
9.2
SW Testing Assessment
The SW testing assessment identified numerous deficiencies that resulted in
questioning the SWS ability to perform its function at elevated lake
temperatures.
As discussed in Section *s.4, the licensee issued DR
D-PAL-93-272, which will address the SW margin issues.
This assessment again identified many of the same issues from the SSDCs. *Most
si~nificant was the determination that the disconnect between analysis inputs
and the system functional requirements questioned the operability of all
Section XI pumps, as discussed in Section 8.1.
9.3
NPAD SW and GL 89-13 Assessment
The NPAD SW assessment was considered to be an improvement from previous
assessments.
Technical engineering issues were identified;* however,
significant issues such as the single failure vulnerabilities or the water
hammer susceptibility were npt identified. The assessment only reviewed the
14
---~
plant's compliance with the GL 89-13 response to the NRC in lieu of addressing
program adequacy in meeting the GL requirements.
The assessment also did not identify the broader issues of the lack of system
design understanding and the "gray" responsibility issues when it came to
system design basis.
9.4
Conclusions
While organizations conducted effec;tive audits on the SW and CCW systems,
inadequate corrective actions and the lack of management's knowledge of the
issues hindered the effectiveness of the self-assessments.
The NPAD
assessment, although improvedl lacked the broad perspective on engineering's
design knowledge.
10.0
Unresolved Items
An unresolved item is a matter requiring more information in order to
ascertain whether it is an acceptable item, a violation, or a deviation.
Unresolved ite~s are identified in Sections 5.3, 5.4, and 8.1.
11.0
Exit Int~r~iew
The team conducted an exit meeting on February 11, 1994, at Palisades Nuclear
Generating Plant to discuss the major a~eas reviewed during the inspection,
. the strengths and weaknesses observed, and the inspection results.
License.e
representatives and NRC personnel in ~ttendance at this exit meeti.ng are
documented in Appendix A.
The team also discussed t~e inspection report's
likely informational content with regard to documents reviewed by the team
during the inspection.
The licensee did not identify any documents* or
processes as proprietary.
--
15
TO LAKE
TO CCW PUMP
SUCTION
CV-0950
. "'
CV-0951
CONT
SPRAY
CONT
SPRAY
CON.T
SPRAY
FROM CCW
HEAT EXCHANGERS
CV-0913
CV-0947
CV-0949
CV-0948
FIGURE 1 - COMPONENT COOLING. WATER SYSTEM
CV-0879
CV-0880
BACKUP
APPENDIX A
Consumers Power Company
D. Joos, Senior Vice President, Nuclear
W. Binnington, System Engineer
.J. Blewett, Project Engineer, Configuration Control Program (CCP)
K. Chao, Staff Engineer, Nuclear Performance Assessment Department (NPAD)
D~ Crabtree, Senior Engineer
T. Duffy, Supervisor, Safety Analysis
H. Esch, Adminiitrative Manager
O. Fitzgibbon, Operations Specialist (NPAD)
G. Freeman, Operations
R. Frisch, Outage Planning & Scheduling
- D. Galle, Sargent &Lundy
. R. Gerling, Man~ger, Reactor & Safety Analysis
P. Gire, Supervisor, Engineering Safeguards Systems
J. Griggs, Director,* Human Resource
B. Harshe, Supervisor, Configuration Control
D. Hoffman, Vice President, Nucl~ar Operations
R. Jenkins, Supervisor, Civil/Structural Engineering
R. Kasper, Manager, Maintenance
D. Malone, Acting Manager, RSD
T. Marz, Engineer
..
R. Mccaleb, Performance Specialist.
R .. Orosz, Manager, Nuclear Engineering & Construction
K. Osborne, Manager, Systems Engineer
T. Palmisano, Manager, Operations & Outage Planning
E. Pearstein, Sargent & Lundy
J. Pomaranski, Manager, Project Management Construction & Testing
R. Rice, Manager, NPAD.
-W. Roberts, Licensing Engineer
D. Rogers,
Dire~tor, Safety & Licensing
G. Slade, General .Manager, Palisades
D. Smedley, Staff Licensing Engineer
G. Szczotka, Assessment Coordinator, NPAD
R. Vincent, Manager, Plant Safety Engineering
U.S. Nuclear Regulatory Commission
J. Martin, RIII Administrator
S. Burgess, Team Leader
G. Grant, Director, Division of Reactor Safety
J. Guzman, Reactor Inspector
J. Lennartz, Reactor Engineer.
L. Miller, Branch Chief, Division of Reactor Projects
D. Passehl, Resident Inspector, Palisades
M. Shlyamberg, Consultant
APPENDIX B
Generic Letter 89-13 Action Items
I.
Biofouling C6ntrol and Surveillance Techniques
Action I of GL 89-13 requested that licensees implement and maintain an
ongoing program of surveillance and control techniques to significantly reduce
the incidence of flow blockage problems as a result of befalling.
The actfon
requ~sted included intake structure inspections, chemical treatment of service
water systems, and periodic service water system flushing/flow testing.
The team reviewed the actions taken by the licensee to address the GL request.
Jntake structure and service water bay inspections were conducted each
refueling outage using Periodic and Predetermined Activity Controls (PPACs).
PPAC SWS-091, Inspection of SWS Pump Intake Bay and.Mixing Basin inspected
for sediment buildup, asiatic clams, zebra mussels -and collected sa~ples of
silt/sediment for analysis.
At the time of their in~tial response to GL 89-
13, the licensee had an established program of SWS chlorination to mitigate
the effects .of b~ological fou)ing.
Since the original response the plant has
experienced the spread -0f zebra mussels into their intake ~tru~ture. To
address this, the SW system was treated periodically with a molluscicide for
Zebra Mussel control. Also, the plant's discharge permit was modified to
allow continuous .chlorination. Additionally, SW system corrosion coupons were
evaluated 6n a regular basis to monito~ the chemical treat~ents affects on
corrosion rates.
The SWS treatments appeared to be effective.
The team found
no c6ncerns with the intake structure inspection and chemical treatment of the
SW system.
In their initial response to GL 89-13 the licensee identified fo~r p1p1ng
sections where possible pipe fouling could take place due to infrequent use:
SW cross ties with fire water, CCW, AFW, and SW supply tri VC-10 and VC-11.
Additionally, the licens~e initially committed to evaluat~ modifiing the
piping to permit periodic flushing of the SW/CCW and SW/AFW cross-ties without
exceeding discharge limits. All four piping sections were initially inspected
and flushed.
After the tests, the licensee withdrew their commitment to
modify piping based on the test results. The SW to fire water cross-ties would
be tested for unrestricted flow every refueling outage and the SW supply lines
to VC-10 and VC-11 would be flushed every 12 months under PPAC X~OPS471.
Based on a test result review, the team considered the current flushing and
flow testing of infrequently used piping to be _adequate.
II.
Monitoring Safety Related Heat Exchanger Performance
Action II of GL 8~-13 requested that licensees implemenf a*test program to
periodically verify the heat transfer capability of all safety* related heat
exchangers cooled by the SWS.
The test program should consist of an initial
test program and a periodic retest program.
Palisades' test program consisted in some cases of both inspecting/cleaning
and performance testing of safety related heat exchangers.
Performance
testing was limited to the CCW heat exchangers since testing the CACs and ESS
room coolers was unsuccessful and did not yield meaningful results.
Inspection/cleaning was conducted on all heat exchangers except the east ESS
room coolers, which will be conducted during the next refueling outage .
lhe performance testing portion of this program was flawed with technical and
.instrumentation errors and exhibited a lack of preplanning and understanding
of the instrumentation accuracy's limitations and its impact on test results.
Neither test results or design basis calculations accounted for the instrument
uncertainties. This condition was further exacerbated by a lack of definitive
values for the minimum required design flows.
Since all the safety related heat exchangers were included in the inspection
- program the team concluded that the licensee's response to GL 89-13, Action II.
was adequate.
With the revision to improve*CCW heat exchanger performance
test's reliability and with continued implementation of inspection, cleaning
and periodic mainten~nce of safety related heat exchangefs, the GL intent will
be met.
III.
Routine Inspection and Maintenance
Action Ill of GL 89-13 requested that licensees implement a routine inspection
and maintenance program for open-cycle SWS piping and components.
This
program should ensure that corrosion, erosion, protective coating failure,
silting, and biofouling cannot'degr~de the performance of the safety related
systems supplied by the SWS.
The GL inspection and cleaning program was accomplished by use of PPACs.
The
PPACs proceduralized the visual inspection of each heat exchanger pnd provided
for the chemical analysis of scraped samples from within the heat exchangers
for biofouling, MIC, scaling and chemical deposition.
Overall, the team considered the SW PM implementation p~ogram in response to
GL 89-13 effective.
As discussed in Section 7.3, the licensee planned to
review ~ll *instrument and stagnant lines for possible inclusion in the flush
program.
IV.
Design Function Verification and Si~qle Failure Analysis
Action IV of GL 89-13 requested that licensees confirm that the SW and CCW
systems will perform their intended function in accordance with the licensing
basis for the plant. This confirmation should include a review of the ability
to perform required safety functions .in the event of a single active component
failure.
The team reviewed the SW and CCW
sy~tems' ability to perform theit intended
function in accordance with the lic~nsing basis for the plant.
The review
included system configuration, flood and tornado protection, sei~mi~ design,
emergency power supply, and functional logic evaluation. Specific
consideration was given to identify failure of any single component that cou.ld
potentially affect the performance of safety related systems served by either
2
3
The team determined that Palisades' SW and CCW systems were Operable ba~ed -0n
the current low lake temperature.
However, the systems' ability to fulfill
their safety related function at elevated lake water temperatures combined
with other adverse design basis conditions is pending the completion of
engineering analysis. This issue is discussed further in Section 5.4.
As identified in Section 5.1, two potential new single active failures were
identified for SW and CCW configuration fo~ supplying cooling water for seal
cooling and lubricatiori heat removal for the ESS pumps.
The first failure
could lead to the loss of.all* ESS pumps.
The second failure could lead to a
c6mplete loss of CCW during a LOCA.
. ,
V.
Training
Action V of GL 89-13 requested that licensees confirm that maintenance
practices, operating and emergency procedures, and training that involves the
SW and CCW systems wer~ adequate to ens~re that safety related equipment
cooled by the SW system will function as intended and that operators of this
equipment will perform effectively.
Based on *the team's review of maintenance practices, operating and emergency*
procedures, and training documentation, the team concluded that overall,
Action V was adequately a~complished. One weakness was noted in the l~ck of
training on the sealed in open signal from an SI signal -to the CCW supply and
discharge valves to the ESS pumps.
This*~S further discuss~d in Section 6.3 .