ML16342E180
| ML16342E180 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 07/17/1998 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| Shared Package | |
| ML16342E179 | List: |
| References | |
| 50-275-98-10, 50-323-98-10, NUDOCS 9807270006 | |
| Download: ML16342E180 (28) | |
See also: IR 05000275/1998010
Text
ENCLOSURE 2
U.S. NUCLEAR REGULATORYCOMMISSION
REGION IV
Docket Nos.:
License Nos.:
Report No.:
Licensee:
Facility:
Location:
Dates:
Inspectors:
Approved By:
.50-275
50-323
DPR-80-
50-275/98-10
50-323/98-10
Pacific Gas and Electric Company
Diablo Canyon Nuclear Power Plant, Units 5 and 2
7 1/2 miles NW of Avila Beach
Avila Beach, California
May 10 through June 20, 1998
D. L. Proulx, Senior Resident Inspector
D. B. Allen, Resident Inspector
D. G. Acker, Resident Inspector
Howard J. Wong, Chief, Reactor Project Branch E
Attachment:
Supplemental Information
9807270006 9807i7
ADOCK 05000275
9
0
-2-
EXEC TIV
S
Diablo Canyon Nuclear Power Plant, Units 1 and 2
NRC Inspection Report 50-275/98-10; 50-323/98-10
This inspection included aspects of licensee operations, maintenance,
engineering, and plant
support.
The report covers a 6-week period of resident inspection.
~Oe a ions
~
Routine operations were conducted in a professional manner, with self-checking and
effective three-way communications (Section 01.1).
aintenance
The maintenance mechanics demonstrated
good maintenance practices in replacing the
shuttle valves on the main feedwater Pump 1-1 stop valves.
Engineering provided good
onsite assistance
and assisted
in determining the proper wiring of the new shuttle
valves.
Performance of the functional test confirmed proper operation prior to returning
the main feedwater pump to service (Section M1.1).
Maintenance personnel demonstrated
poor self-verification that, combined with an
inadequate briefing and self-imposed time pressure, resulted in a violation of Technical Specification (TS) 6.8.1.a for failure to implement instructions for performing
maintenance,
in that two auxiliary feedwater (AFW) pumps were simultaneously
rendered inoperable because
oil was drained from the wrong pump.
In addition,
licensee personnel failed to take adequate immediate corrective actions in that they:
(1) failed to notify the control room in a timely manner; (2) continued to work on the
wrong component without work authorization or a clearance;
(3) failed to make timely
log entries in the control operator's log; and (4) could have decided to perform a
postmaintenance
test in a more timely manner.
The safety significance of this event
was mitigated by the relatively short period of time with two AFW pumps inoperable
(Section M1.3).
n ineerin
Temporary modifications were performed, controlled, and tracked properly.
10 CFR 50.59 safety evaluations for these temporary modifications provided good
justification as to why no unreviewed safety question existed (Section E1.1).
Plan
Su
o
~
Housekeeping was excellent throughout safety-related areas (Section 02.1).
Re ort Detai s
Summa
o
lan S a us
Unit 1 began this inspection period at 100 percent power.
On May 15, Unit 1 power was
reduced to 50 percent to test the control oil valves for the main feedwater pump stop valves.
The unit was returned to 100 percent power on May 16. On June 20, Unit 1 power was
reduced to 50 percent to replace certain control oil valves on main feedwater Pump 1-1. The
unit was returned to 100 percent power and continued to operate at essentially 100 percent
power until the end of this inspection period.
Unit 2 began this inspection period at 100 percent power.
On June 6, Unit 2 power was
reduced to 50 percent to close steam generator blowdown sample stop Valve MS-2-1048 and
install a bypass line to isolate a body-to-bonnet leak. The unit was returned to 100 percent
power and continued to operate at essentially 100 percent power until the end of this inspection
period.
I. ~Oerations
01
Conduct of Operations
01.1
n r
I Commen s
70
The inspectors visited the control room and toured the plant on a frequent basis when
on site, including periodic backshift inspections.
In general, the performance of plant
operators was professional and reflected a focus on safety.
The utilization of three-way
communications continued to improve, with operators requiring three-way
communications from nonoperations personnel.
Operator responses
to alarms were
observed to be prompt and appropriate to the circumstances.
02
Operational Status of Facilities and Equipment
02.1
G
a Co
e
s
1
7
The inspectors toured the facility on a frequent basis to determine ifconditions in the
facility impacted the operability of safety-related equipment.
The inspectors determined
that housekeeping was excellent throughout the safety-related areas and no adverse
conditions existed that impacted the operability of safety-related equipment.
-2-
M1
Conduct of Maintenance
M1.1
Re
I ce
en ofShu leValveson
he
ainF
e waerPu
-1Sto
Valv s
a.
ns
c ion
co e 62707
The inspectors observed maintenance
personnel replace the Racine (shuttle) valves on
the main feedwater Pump 1-1 high pressure and low pressure stop valves.
The
following documents were reviewed:
~
WO C0155937, Feedwater Pump 1-1, Install New Racine Valves, Implement
AT-MMA0444397
AT-MMA0444397, Unit 1 - Low Pressure/High Pressure Racine Stop Valves:
Replacement
~
Clearance Number 00058606-001, Main Feedwater Pump 1-1 Racine Valve
Replacement
Maintenance Procedure MP I-2.31-1, Revision 9, Functional Check of Main
Feedwater Pump 1-1 Controls
b.
Obs
rv 'and Fi d'
This maintenance activity was scheduled after it was identified that the Racine valve
associated with the low pressure stop valve would not close during testing the previous
weekend.
The inspectors found the work performed under these activities to be
accomplished
in accordance with procedures.
Allwork observed was performed with
the work package present and in active use.
The maintenance mechanics were familiar
with the equipment and competent at the required tasks.
The new Racine valves'iring
configuration was different from the previous model and the inspectors observed an
engineer at the job site assisting in the resolution of this issue.
The functional test
revealed the wiring connections were reversed on one valve. This was corrected and
the test was completed successfully.
c.
Conclusions
The maintenance mechanics demonstrated
good maintenance practices in replacing the
shuttle valves on the main feedwater Pump 1-1 stop valves. Engineering provided good
onsite assistance
and assisted in determining the proper wiring of the new shuttle
valves.
Performance of the functional test confirmed proper operation prior to returning
the main feedwater pump to service.
t
-3-
M1.2
Surveillance Observa 'on
Ins ection Sco
e
26
Selected surveillance tests required to be performed by the TS were reviewed on a
sampling basis to verify that:
(1) the surveillance tests were correctly included on the
facility schedule, (2) a technically adequate procedure existed for the performance of the
surveillance tests, (3) the surveillance tests had been performed at a frequency
specified in the TS, and (4) test results satisfied acceptance
criteria or were properly
dispositioned.
The inspectors observed all or portions of the following surveillances:
~
STP I-36-S2R10
Protection Set II, Rack 10 Channels Operational Test,
Revision 6
STP M-21C
Main Turbine Valve Testing, Revision 27
b.
bervao
s
d id'
On June 17, the inspectors observed the performance of surveillance test
Procedure (STP) l-36-S2R10, "Protection Set II, Rack 10 Channels Operational
Vest,"
Revision 6, on Unit 1. This test satisfied TS requirements for channel operational test
for pressurizer pressure Channel P-456, pressurizer level Channel L-460, and reactor
coolant loop flow Channels F-415, F-425, F-435, and F-445. The procedure allowed the
calibration of test points to be performed manually (user enters the voltage values
measured
by the meter via a screen keypad) or automatically (meter would be
connected to the rack and information entered automatically). The test was performed
using the manual calibration of test points and the test meter was within its calibration
frequency. The inspectors observed the pretest briefing, which covered the
prerequisites, precautions and limitations, effects on the channels under test, expected
alarms in the control room, and the necessary
communications and actions of the
control room operator.
The test procedure was technically adequate,
the test was
performed in accordance with the procedure, and the test results satisfied the
acceptance
criteria.
On June 20, the inspectors observed portions of the STP M-21C, "Main Turbine Valve
Testing," Revision 27, performed on Unit-1. The pretest briefing covered the necessary
prerequisites, precautions and limitations, coordination of personnel, sequence of testing
to allow maintenance
on a valve, and the potential use of the modification to the
hydraulic line, which isolated the trip pilot valve. During the performance of the test,
stop Valve FCV-1-143 did not reopen.
The operators performed the on-the-spot change
per Appendix 7.1, which used the trip pilot valve isolation modification and successfully
reopened the stop valve. The procedure was technically adequate, the test was
performed in accordance with the procedure, and the test results satisfied the
acceptance'riteria.
Conclusions
The inspectors found that the surveillances observed were being scheduled and
performed at the required frequency.
The procedures governing the surveillance tests
were technically adequate and, in general, personnel performing the surveillance
demonstrated
an adequate
level of knowledge.
The inspectors noted that test results
appeared to have been appropriately dispositioned.
M1.3
OilR moved
Wo
FW Pum
s e
i n
co e 6
2902
The inspectors evaluated the licensee's response to Quality Evaluation Q0012042 and
associated Action Request A0461604 that described an event in which mechanics
removed the lubricating oil from an incorrect AFW pump.
b.
Observa io
a
Findin s
On May 14, 1998, mechanics prepared to perform Work Order (WO) R0180120 for
preventive maintenance on AFW Pump 1-2, one of the Unit 1 motor driven AFW pumps.
One mechanic was assigned to verify the clearance, another to obtain replacement oil,
and the third to obtain sample bottles from the chemistry laboratory.
Only the mechanic
assigned to verify the clearance received a prejob briefing from the foreman. The
mechanics agreed to meet at the job site following their initial assignments
before work
was to commence.
Operators correctly cleared AFW Pump 1-2, and entered the
72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> TS action statement of TS 3.7.1.2 since AFW Pump 1-2 was no longer capable
of automatic initiation.
The mechanic assigned to obtain the sample bottles believed that he could save time by
immediately proceeding to drain the oil from AFW Pump 1-1, as soon as he arrived at
the job site. This was done despite the clearance walkdown not being completed by the
first mechanic.
Because the mechanic assigned to retrieve the sample containers only
had previous experience in performing preventive maintenance
on turbine-driven AFW
Pump 1-1, he assumed that the AFW pump maintenance performed on May 14, 1998,
was also associated
with AFW Pump 1-1. The mechanic assigned to perform the
clearance walkdown had the WO in hand, so the mechanic assigned to obtain the
sample bottles could not self-check that he was working on the correct pump.
Therefore, he proceeded to drain the oil from turbine-driven AFW Pump 1-1, rather than
motor-driven AFW Pump 1-2.
-5-
Approximately 10 minutes later, a second mechanic arrived at the job site and
immediately noted that oil had been drained from the incorrect pump.
Instead of
notifying the control room immediately so action could be taken to preclude automatic
initiation ofAFW Pump 1-1, the mechanics returned the oil to AFW Pump 1-1. AFW
Pump 1-1 was without lubricating oil for approximately 10 - 20 minutes. Afterthis was
complete, the mechanics went to the shop to inform their acting foreman.
The acting
foreman had difficultyin attempting to notify the regular foreman of this incident.
Following contact of the regular foreman, the mechanics wrote an AR to document the
occurrence and then called the control room. Approximately 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> elapsed before
control room. operators were made aware of the incident.
0 era
r Res
onse
When notified of the occurrence, the shift supervisor contacted engineering personnel
on the need for a postmaintenance
test for AFW Pump 1-1, given that maintenance was
inadvertently performed.
Engineering took the position that draining and refilling of
pump oil was such minor maintenance that a post-maintenance
test was unnecessary..
The shift supervisor agreed with this assessment
and the turbine-driven AFW pump was
considered fully operable.
The control operator did not make a log entry for this event
until approximately 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> later.
On May 15, 1998, approximately 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> later, when the next shift assumed the watch,
the new shift supervisor questioned the decision of the previous shift with respect to
postmaintenance
testing.
The new shift supervisor determined that performing a
postmaintenance
test was prudent.
Turbine-driven AFW Pump 1-1 was started
manually and ran for several minutes successfully.
Licensee management
subsequently stated that the postmaintenance
test was conservative, but not a
necessary
action. Therefore, licensee management determined that the timeliness of
the postmaintenance
test was not an issue.
Considering that a mistake had been made,
that the mechanics did not notify the control room until 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> after the event, and that
work continued on the pumps, the inspectors concluded the postmaintenance
test was
appropriate.
Based on the safety significance of two auxiliary feedwater pumps
inoperable simultaneously, the decision to perform the postmaintenance
test could have
been more timely.
The inspectors noted that a number of barriers were broken that led to this event.
Additional errors were made upon discovery.
Prior to the Inciden
Personnel failed to follow Procedure OP2.ID1 "Clearances and Administrative
Tagouts," Revision 8, Section 5.2.2, in that work commenced prior to the
maintenance walkdown of the clearance, or reporting on the clearance for work.
-6-"
Personnel failed to have the WO at the job site while work was in progress,
which did not meet management's
expectations.
1
Personnel failed to self-check prior to work commencement,
which did not meet
managements'xpectations.
~
. Personnel failed to followWO R0180120 that directed the user to drain the oil
from AFW Pump 1-2.
Personnel did not inform the control room in a timely manner that the oil had
'een
drained from AFW Pump 1-1 so that operators could take action to
preclude automatic initiation of the pump to prevent possible damage.
, Upon recognizing that the oil had been drained from the wrong pump, mechanics
refilled.the oil; however, this was an unauthorized maintenance activity on AFW
Pump 1-1, done without a clearance required by Procedure OP1.DC18,
"Authorization for Equipment Operation and Maintenance," Revision 3.
Section 5.3 of Procedure OP1.DC18, states that whenever plant equipment is
removed from service for maintenance, written authorization from the Unit shift
foreman shall be obtained prior to removal from service.
~
When informed of the incident, the operator failed to log the event in the control
operator's log until 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> later.
Licensee management was not informed of the event until the next day.
~
-
Postmaintenance
testing could have been performed in a more timely manner.
The licensee's failures to: (1) implement WO R0180120; (2) implement the clearance
procedure; and (3) perform work on safety-related components without proper
authorization are three examples of the failure to follow procedures as specified by
TS 6.8.1.a (Violation 50-275/98010-01).
Although this violation was discovered by the licensee, the immediate corrective actions
upon discovery were inadequate,
resulted in further, violation of procedures,
and could
have resulted in equipment damage.
Therefore, the inspectors concluded that
enforcement discretion was not warranted.
Safe
Si
ificance
AFW pumps were credited in the licensee's safety analysis for removal of decay heat
during several design basis scenarios.
The turbine-driven AFW pump was designed to
remove 200 percent of the postulated decay heat following a reactor trip and design
basis accident.
The turbine-driven AFW pump discharges to all four steam generators.
-7-
Each motor-driven pump was capable of removing 100 percent of the postulated decay
heat.
Each motor-driven AFW pump discharges to two of four steam generators.
Because one motor-driven pump was available throughout this incident, the inspectors
concluded that the licensee had adequate means to remove decay heat.
The licensee also evaluated this incident with respect to overall risk. The instantaneous
risk of having one motor-driven and the turbine-driven AFW pumps inoperable
simultaneously would result in an approximate increase in core damage frequency of
3000 percent (ifboth pumps were inoperable for the entire year).
However, this risk was
mitigated by the fact that both pumps were inoperable for only a short period of time.
Therefore, the increase in core damage frequency per reactor year was increased on
the order. of 1 E-8, a minimal increase.
The inspectors reviewed the licensee's risk
assessment
and agreed that this incident was potentially risk significant, but was
mitigated by the fact that the configuration lasted a short period of time.
In addition, the licensee complied with the TS Action Statement because the TS
required 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> to be in hot standby with 2 AFW pumps inoperable.
The licensee's analysis concluded the causes of the event was attributable to human
error with the following factors present:
~
A mind set that AFW Pump 1-1 was the component to be sampled caused the
wrong component error. The mechanic had only worked on Pump 1-1 previously
and assumed
it was the pump to be sampled.
This error could have been
prevented by self-verification that was not properly executed.
~
Time pressure, which was self-imposed, to complete the task expediently for the
purpose of minimizing critical component outage time caused the mechanic to
rush the job and commence work prior to the work package being available at
the job site.
~
The pretask briefing by the maintenance foreman did not sufficiently identify
each mechanic's role and responsibilities related to the task at hand.
Subs
n Co r
iv Ac ion
The issues related to this event were reviewed with mechanical maintenance personnel
during weekly safety meetings on May 19 and on May 26. The first issue was the
selection of the wrong component for oil sampling.
The second issue was the fact that
one mechanic verified the clearance while another started work on the component
without positive confirmation that the component was cleared.
The third issue was not
notifying the control room in a timely manner.
Management's
expectations for each of
these issues was discussed
and emphasized.
The need to be self-critical as an
organization and learn from others'istakes
was also emphasized.
0
-8-
DCPP Case Study 66 was developed from this event and reviewed with essentially all
maintenance services personnel.
The lessons learned discussed
in the case study
included:
(1) the importance of good pretask briefings; (2) time pressure can result in
unnecessary
hurry or short cuts; (3) self checking to verify the right unit, train and
component should be used prior to work on any component and requires the work
documentation be in hand; (4) mind.set can be an incorrect preconceived idea;
(5) assuming everything is OK, in this case that the component was cleared, can have
an adverse safety impact; and (6) the necessity for timely reporting to operations.
These reviews were completed by June 23 and completed the planned corrective
actions for this event and actions to prevent recurrence.
Conclusions
Maintenance personnel demonstrated
poor self-verification which, combined with an
inadequate briefing and self-imposed time pressure,
resulted in a violation of TS 6.8.1.a
for failure to implement instructions for performing maintenance.
This resulted in two
AFW pumps simultaneously rendered inoperable because
oil was drained from the
wrong pump.
In addition, licensee personnel failed to take adequate immediate
corrective actions in that they: (1) failed to notify the control room in a timely manner;
(2) continued to work on the wrong component without work authorization or a
clearance;
(3) failed to make timely log entries in the control operator's log; and
(4) could have decided to perform a postmaintenance
test in a more timely manner.
The safety significance of this event was mitigated by the relatively short period of time
with two AFW pumps inoperable.
The inspectors'eview of the licensee's reason for the violation and subsequent
corrective actions determined they were adequate.
MS
Miscellaneous Maintenance Issues (92700)
M8.1
Closed
I ic
se
v
50-275 323/95008-:
Control Room Ventilation
System was outside of its design basis due to a programmatic deficiency in the
operation and maintenance of the filters and charcoal adsorber system.
This LER
described situations in which both trains of the control room ventilation system were
rendered inoperable because of maintenance activities. On four occasions, from 1986
to 1990, the charcoal adsorbers were removed and replaced without isolation. Because
there was no isolation provided for these replacements,
the boundary of the control
room envelope was breached.
For corrective actions, the licensee proposed to: (1)
provide a local operator aid to alert personnel not to perform work on the filter units
unless the filter units are properly isolated, (2) a shift order was provided to the
operators to ensure that the control room ventilation system is properly cleared prior to
work, (3) the design criteria memorandum associated with the control room ventilation
system was revised to alert personnel to concerns with breaches of the envelope, and
(4) revise procedures associated
with maintenance and operation of the control room
ventilation system.
These corrective actions were previously reviewed during closeout
of Revisions 0 and
1 of this LER. Revision 2 changed the safety analysis to note that
-9-
the total dose to the operators following a design basis event would not exceed the
limits of 10 CFR Part 50, Appendix A, General Design Criterion 19. The inspectors
reviewed the licensee's corrective actions and new safety analysis and determined them
to be satisfactory.
This item is closed.
l'1
Conduct of Engineering
E1.1
Tem ora
Modifica io s
3 551
The inspectors reviewed the temporary modifications log for Unit 1. The inspectors
noted that each temporary modification was properly installed and independently
verified. The inspectors also reviewed the 10 CFR 50.59 evaluations and screenings
and determined that these evaluations appeared
to be satisfactory.
None of the
modifications were in place for an excessive period of time.
E8
Miscellaneous Engineering Issues (92700)
E8.1
Clos
d LER50-275/96006-
0: BaslerBE1-50/51Bovercurrentrelaysfailedtomeet
instantaneous
current pickup acceptance
criteria during preinstallation testing.
On
March 8, 1996, the licensee determined that approximately 40 percent (37 out of 94) of
the rela'ys (purchased commercial grade and dedicated to allow wholesale changeout of
the relays in the vital 4 kV system) failed to meet the instantaneous
current acceptance
criteria during preinstallation testing.
Discussions with the manufacturer revealed the
manufacturer knew of the problem and recommended
replacement with a newer model,
Revision "K". Relays with the same revision as the failed relays (primarily Revision "H")
were returned to the vendor. The dedication process for these relays was revised to
incorporate lessons learned from this event.
An INPO network entry was made to
provide this information to the industry. The licensee determined that the root cause of
this event was manufacturing/design error in that the relays were manufactured and sold
with a high probability of random failures when used in the higher end of the current
range advertised as being satisfactory for this relay. Procedures
controlling
preinstallation testing discovered the high failure rate before any relays were installed in
the plant. A review of records by the licensee indicated that there were no Revision "H"
relays installed in either unit. The inspectors performed an onsite review of the
corrective actions and found them to be appropriate. This item is closed.
0
-10-
N.
R1
Radiological Protection and Chemistry Controls
R1;1
General
omm
n
71750
The inspectors evaluated radiation protection practices during plant tours and work
observation.
The inspectors determined that personnel donned protective clothing and
dosimetry properly, and that radiological barriers were properly posted.
P1
Conduct of Emergency Planning Activities
The inspectors conducted a tour of the technical support center.
The inspectors
determined that the technical support center was in an adequate state of readiness for
response to emergencies.
S1
Conduct of Security and Safeguards Activities
S1.1
Ge
e a
o
e
s 71750
During routine tours, the inspectors noted that the security officers were alert at their
posts, security boundaries were being maintained properly, and screening processes
at
the Primary Access Point were performed well. During backshift inspections, the
inspectors noted that the protected area was properly illuminated, especially in areas
where temporary equipment was brought in.
V. Mana ement Meetin s
X1
Exit Meeting Summary
The inspectors presented the inspection results to members of licensee management at the
conclusion of the inspection on July 1,'1998.
The licensee acknowledged the findings
presented.
The licensee stated that they were very concerned about the draining of oil from the
wrong AFW pump, and recognized the potential safety significance.
However, while the
postmaintenance
test was performed, they did not believe that it was required due to the small
amount of oil that was removed.
The management's
expectation for notification was that the
event was not significant enough for a call in the middle of the night and could wait until the
beginning of the next day shift. The inspectors acknowledged the licensee's comments.
The inspectors asked the licensee whether any materials examined during the inspection
'hould
be considered proprietary.
No proprietary information was identified.
TTACHMENT
SUPPLEMENTA
INF
RMATION
PARTIALLIST OF PERSONS CONTACTED
Licensee
W. G. Garrett, Director, Operations
M. A. Crockett, Manager, Nuclear Quality Services
R. D. Gray, Director, Radiation Protection
T. L. Grebel, Director, Regulatory Services
D. T. Miklush, Manager, Engineering Services
J. P. Molden, Manager, Operations Services
D. R. Oatley, Manager, Maintenance Services
R. P. Powers, Vice President and Plant Manager
L. F. Womack, Vice President, Nuclear Technical Services
INSPECTION PROCEDURES (IP) USED
IP 61726
IP 71707
IP 92700
Onsite Engineering
Surveillance Observations
Maintenance Observation
Plant Operations
Plant Support Activities
Onsite Followup of Written Reports of Nonroutine Events at Power Reactor
Facilities
Followup - Maintenance
-2-
Qp~en
ITEMS OPENED AND CLOSED
50-275/98010-01
Mechanics drained oil from wrong AFW Pump
(Section M1.3)
Qlo~e
50-275;323/
LER
0 en
and
lo ed
5Q-275/96006-00
LE R
Control Room Ventilation System Outside of Design Basis
(Section M8.1).
Basler BE1-50/51B overcurrent relays failed to meet
instantaneous
current pickup acceptance
criteria during
preinstallation testing (Section E8.1)