ML17352A321
| ML17352A321 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 11/18/1993 |
| From: | Casto C, Hunt M NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML17352A320 | List: |
| References | |
| 50-250-93-25, 50-251-93-25, GL-89-10, NUDOCS 9312140069 | |
| Download: ML17352A321 (24) | |
See also: IR 05000250/1993025
Text
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UNITED STATES
NUCLEAR REGULATORY COMMISSlON
REGION II
101 MARIETTASTREET, N.W., SUITE 2900
ATLANTA,GEORGIA 303234199
Report Nos.:
50-250/93-25
and 50-251/93-25
Licensee:
Florida Power and Light
9250 West Flagler Street
Miami, FL 33102
Docket Nos.:
50-250
and 50-251
License Nos.:
and
Facil ity Name:
Turkey Point 3 and
4
Inspection
Conducted:
October 25-29,
1993
Lead Inspecto
- ~ M.
. Hunt
Ii gS'y
Da e S'gned
Accompanying Personnel:
H. Miller
Other Personnel:
H. Holbrook, Consultant,
EGSG Idaho-INEL
Approved by:
asto,
hief
Test Programs
Section
Engineering
Branch
Division of Reactor Safety
Il
I FD
Date Signed
Scope:
SUMMARY
This special,
announced
inspection
was performed at the Turkey Point nuclear
plant to examine the implementation of the licensee's
motor operated
valve
(HOV) program to meet commitments in response
"Safety-Related
Motor-Operated
Valve Testing
and Surveillance."
The
inspectors utilized the guidance
provided in Temporary Instruction
(TI) 2515/109 (Part 2), "Inspection Requirements for Generic Letter 89-10,
Safety-Related
Motor-Operated
Valve Testing
and Surveillance."
As delineated
in Part
2 of TI 2515/109, this inspection
was the initial review of the
Licensee's
HOV program implementation in response
to
The inspectors
reviewed the engineering
data for six HOVs including selected
portions of design calculations, test packages,
and diagnostic signature
traces.
The inspectors
also reviewed follow-up issues
from the previous
NRC
inspection of the
MOV program (TI 2515/109,
Part
1) conducted
in March 1992,
and documented
in NRC Inspection
Report Nos. 50-250/92-08
and 50-251/92-08.
9312140069
931118
ADOCK 05000250
8
Results:
The inspectors identified the following items during the inspection.
Concerns
2.
3.
The procedures for the performance of MOV static testing
need to be
enhanced
to define clearly the acceptance
criteria and record the as-
found data.
These procedures
need to consider the
Appendix
B
criteria in the verification process
for the data collected
and
equipment/programs
used for the test.
There
was
a lack of documentation
to support the operation of MOV brake
assemblies
at less
than
90 percent rated voltages.
No margins
were
included in the stem friction coefficient calculation for stem
lubrication degradation.
The licensee
intends to conduct testing to
evaluate
the appropriate
amount of margin"required.
No margins were set aside for load sensitive
behavior (rate of loading)
in the licensee's
calculations.
The licensee
was evaluating this margin
for dynamically-tested
HOVs.
In cases
where dynamic testing
showed original thrust calculations
were
not conservative,
the licensee
changed
the method of extrapolating the
required thrust by directly measuring thrust at control switch trip.
Although no operability concerns
were noted,
no guidelines
were provided
to account for torque switch repeatibility and other uncertainities
in
the calculations.
~Stren the
1.
Aggressive
approach to
MOV differential pressure testing.
Prioritization was given to high DP/low margin
MOVs.
2.
3.
4.
5.
Performance of multiple differential pressure
testing to aid in
justifying extrapolation methodology.
The use of upstream
and downstream
pressure
transducers
to capture time
dependent
pressure
variation during
MOV dynamic testing.
The measurement
of MOV thrust
and torque during static
and dynamic
testing to allow quantification of stem friction coefficients
and aid in
the evaluation of the load sensitive behavior
phenomena.
Engineering
and maintenance
personnel
responsible for the
MOV program
are technically knowledgeable
and current in the area of ongoing
industry issues.
REPORT DETAILS
Persons
Contacted
- C. Bible, Supervisor,
Site Engineering
- R. Bleaker, Electrical Supervisor,
Nuclear Engineering
- J. Cook, Site
MOV Coordinator,
Plant St.'ucie
- R. Gianfrancesco,
Supervisor,
Maintenance
Support Services
- 0. Hanek,
Engineer,
Licensing
- J. Hoffman, Mechanical
Supervisor,
Nuclear Engineering
- H. Johnson,
Supervisor,
Operations
- J. Knorr, Analyst, Licensing
- R. Kundalkar,
Manager, Site Engineering
- S. Lankford, Site
HOV Coordinator,
Plant Turkey Point
- J. Hanso,
Principal
Engineer,
Site Engineering
- D. Osborn,
Nuclear Assurance
- L. Pearce,
Plant General
Manager
- H. Pearce,
Supervisor,
Electrical
- T. Plunkett, Site Vice President
- D. Powell, Manager,
Technical
Support
- J. Price,
Corporate Specialist
Other licensee
employees
contacted
during this inspection
included
engineers,
technicians,
and administrative personnel.
Other Personnel
- J. Colvin, Mechanical
Engineer,
ABB Impell
NRC Resident
Ins ectors
- T. Johnson,
- B. Desai,
RI
- Denotes personnel
that attended
the exit meeting.
Acr onyms
and initialisms used throughout this report are listed in the
l.ast paragraph.
GENERIC LETTER (GL) 89-10
"SAFETY-RELATED MOTOR-OPERATED VALVE [HOV]
TESTING AND SURVEILLANCE"
(2515/109)
On June
28,
1989, the
NRC issued
GL 89-10, which requested
licensees
and construction permit holders to establish
a program to ensure that
switch settings for safety-related
HOVs were selected,
set,
and
maintained properly.
Subsequently,
five supplements
to the
GL have
been
issued
and
one issued for comment.
NRC inspections of licensee
actions
implementing commitments to
and its supplements
had
been
conducted
based
on guidance
provided in Temporary Instruction
(TI)
2515/109,
"Inspection Requirements for Generic Letter 89-10,
Safety-Related
Motor-Operated
Valve Testing
and Surveillance."
TI 2515/109 is divided into Part 1,
"Program Review," and Part 2,
" "
"Verification of Program Implementation."
The TI 2515/109 Part
1 program review was conducted
March 16-20,
1992
and documented
in NRC Inspection
Report 50-250/92-08
and 50-251/92-08.
The principal focus of this inspection
was to select
and review in depth
sev'eral
HOVs from the
111 safety-related
NOVs within the
program at Turkey Point Units 3 and 4.
Valves were selected
from an
data information matrix and
NOV Testing Status
Report provided at the
request of the inspectors.
The
HOV selection
was
made to examine
various systems,
valve sizes,
and differential pressure
conditions, to
the extent practicable.
For the
HOVs selected,
the inspectors
reviewed the licensee's
Motor Operated
Valve Plant Program,
piping. and instrumentation
drawings,
the design-basis
calculation results of the expected differential
pressure,
the sizing and switch setting calculations,
the diagnostic
test data
package,
and the
HOVATS software generated
diagnostic traces.
The following HOVs were selected
for review:
MOV-8788
MOV-3-1405
HOV-3-1420
High Pressure
Safety Injection
Pump
Discharge Disconnect
Valve
Pump Steam
Supply Valve
Feedpump
Discharge
Isolation Valve
HOV-4-843A
HOY-4-869
Boron Injection To Reactor Coolant
System Cold Leg Valve
Reactor Coolant System Hot Leg
Safety Injection Stop Valve
MOV-4-1420
Feedpump
Discharge
Isolation Valve
I
Based
on the review of the
HOVs sampled,
the inspectors
determined that
the licensee
was implementing
an effective
NOV program.
In response
to
GL 89-10, the review of the
MOV documentation verified that the design-
basis capabilities
were being met.
The inspectors
concluded that the
licensee's
implementation of its HOV program addressed
the
recommendations
and the licensee's
commitments to the generic letter.
.r
The inspectors
reviewed the licensee's
design-basis'to
determine
and
verify its adequacy for the six sampled
HOVs examined during this
inspection.
In addition, the recommended
action "a" of GL 89-10 that
requested
the maximum differential pressure
and flow expected for both
normal
and abnormal
(accident)
conditions
was examined to verify that
maximum parameters
were used.
These follow-up reviews were conducted to
determine if changes
were implemented after the first NRC
MOY GL 89-10
Part
1 inspection
conducted
March 1992.
During that inspection,
the
licensee's
design-basis
documentation
and the electrical calculations
for degraded
voltage were reviewed.
However, the licensee
had not
completed the design-basis
HOV calculations for all ill HOVs.
The
licensee
had completed calculations for 30
MOVs with 81 calculations
remaining that were not complete.
During that inspection,
the
inspectors
concluded that the design-basis
was adequately
addressed
the
recommendations
in GL 89-10.
Since that Part
1 inspection,
the licensee
had received additional information that required further evaluation of
the design-basis
documentation.
During this inspection the inspectors
reviewed the licensee's
design-
basis calculations
and documents to verify that the remaining
81
HOV
calculations
were completed.
Since the Part
1 inspection,
many
calculations
and documents
were revised.
All of the revised
documents
and calculations
were reviewed to determine
and verify that design-basis
differential pressure
and flow conditions,
design temperature,
and other
design parameters
for the
HOV selected for review met the
recommendations
of GL 89-10.
The degraded grid calculations
were
reviewed to ensure that the lowest motor terminal voltage
commensurate
with design-basis
conditions
was factored into the
HOV electrical
calculations.
The closure control for all six valves
was by torque
switch in the closing position
and by limit switch in the opening
position.
Design-basis
documentation
was reviewed for the selected
HOVs
that were configured
as
shown in Appendix A.
The following design-basis
documentation,
calculations,
drawings,
and
procedures
were reviewed:
System Description
No. 021,
Emergency
Core Cooling Systems
(MOV-878B, MOV-4-843A, and MOV-4-869)
1
System Description
No. 112,
Condensate
And Feedwater
System
(HOV-3/4-1420)
System Description
No.
117, Auxiliary Feedwater
System
(HOV-3-1405)
Design Basis
Document,
Volume 1,
DBD No. 5610-062-DB-002,
Revision 3. Auxiliary Feedwater
System
Design Basis
Document,
Volume 2,
DBD No. 5610-062-DB-002,
Revision 3, Safety Injection System
PTN-BFJH-90-076,
Revision
4 dated July 20,
1993,
MOV Design Basis Differential Pressure
Determination"
1) Attachment
12, HOV-3/4-843A/B
2) Attachment
20, HOV-3/4-869
3) Attachment
22,
HOV-878-A/B
4) Attachment
25, MOV-3/4-1403,
1404,
1405,
5) Attachment 27, HOV-3/4-1420,
1421
PTN-BFJM-92-039,
Revision
0 dated
November 24,
1992,
Determination
Of Revised
Design Basis Differential Pressure
And Thrust Requirements
For HOV-3/4-1420.And HOV-3/4-1421
PTN-BFJH-90-077,
Revision
5 dated July 22,
1993,
HOV Thrust Calculation
PTN-BFJE-92-022,
Revision
0 dated
March 9,
1992,
PSB-1
Voltage Analysis For Electrical Auxiliary Systems
PTN-BFJE-90-006,
Revision
6 dated August 2,
1993,
Motor
Operated
Valve Voltage Drop Calculations
PTN-BFJE-91-015,
Revision
3 dated August 2,
1993,
Motor
Operated
Valve Voltage Drop Calculations
Based
On
EDG 3A And
3B Test Results
PTN-BFJH-93-019,
Revision
0 dated
June
28,
1993,
Evaluation of HOV Output Torque Capability Considering
The
Effects Of Derated Motor Starting Torque
PTN-BFJH-93-003,
Revision
2 dated July 14,
1993,
Calculation
To Determine
The Starting Torque,
Current And
Voltage Of AC Valve Actuator Motors At Elevated
Temperatures
PTN-BFJE-92-032,
Revision
0 dated July 13,
1992,
125
VDC
Valve Actuator Motor Voltage Drop Calculation -
Revision
4 dated August 22,
1991, Existing Stationary
Battery Cell Sizing And Voltage Drop Calculation (Verified 105
VDC
was minimum DC voltage)
EBASCO Services
Incorporated
FL0-53-20.5009,
Revision
0 dated
January
31,
1992, Unit 4 Emergency Diesel
Generator Units Dynamic
Load Study (Verified degraded grid was worst case
minimum voltage
for Unit 4)
Electrical
Elementary
Drawings
1) 5610-E-25,
Sheet
35B
2
5613-E-26,
Sheets
12G,
and 36A
3) 5614-E-10,
Sheet
1
4) 5614-E-25,
Sheets
27K and 28P"
5) 5614-E-26,
Sheet
36A
Mechanical
Process
Diagrams
1) 5613-H-3074,
Sheet
1
2) 5613-M-3075,
Sheet
1
3) 5614-H-3062,
Sheets
1 and
2
4) 5614-H-3074,
Sheet
1
JPN-PTN-SEHP-93-021,
Revision
0 dated
June
28,
1993,
Reduced Starting Torque Capability For Limitorque
Supplied Motors Located
In High Temperatures
Environments
(This document is classified
as
a
Substantial
Safety Hazards
Evaluation)
- Denotes revision since Part
1 inspection in March 1992.
The licensee
was awaiting completion of the
NRC staff's reconsideration
of the need for
PWR licensees
to address
valve mispositioning
as part of
their
GL 89-10 program.
Besides
reviewing the
HOV documentation,
the inspectors
conducted plant
walkdown inspections to examine the
HOVs for stem lubrication and
'nstalled
strain gages.
The motor control centers
(MCCs) were inspected
to verify the installed electrical configuration agreed with design
drawings.
No concerns
were identified.
The inspectors identified no concerns with the performance of the
design-basis
review for the selected
HOVs and concluded that the
licensee
has adequately
addressed
the design-basis
review for the HOVs.
2.2
MOV Sizin
and Switch Settin
The inspectors specifically reviewed
PTM-BFJN-90-077,
MOV Thrust Calculation,"
PTM-BFJN-90-077,
HOV Actuator Evaluation,"
and the documentation for
determination of thrust
and torque requirements
for the six selected
valves.
The licensee's
gate valve thrust equation typically used
a valve factor
of 0.30 for flex wedge gate valves
when tested
at static conditions.
A
valve factor of 0.50 for wedge gate valves
was
used for dynamic (flow)
testing.
Similar choices
using 0.20 static
and 0.40 dynamic were
selected for double disk gate valves.
A valve factor of 1. 10 was used
for all globe valves.
The licensee
had revised their valve factor
assumptions
for the
18 inch Malworth flex wedge gate valves to
approximately 0.76.
The value of 0.76 was
based
on in-situ dynamic test
results.
The licensee
assumed
a stem friction coefficient of 0.20 for those
HOVs
that were located inside containment,
or that experienced
high operating
temperatures.
A stem friction coefficient of 0.15 was used for the
balance of HOVs in the program.
The licensee
had not included
a
specific margin in its
HOV calculations for stem lubrication degradation
that might increase
the stem friction coefficient over the lubrication
int'erval.
The licensee
intends to conduct
some as-found testing to
determine
an appropriate
margin to account for degradation of the
lubricant.
Minimum thrust requirements
were adjusted to account for
diagnostic
equipment
inaccuracy
and torque switch repeatability.
The licensee
had not set aside
a margin for load sensitive
behavior
(also
known as "rate of loading" ).
The licensee
was assessing
load
sensitive
behavior for specific dynamically-tested
MOVs, but had not
identified margins necessary
for MOVs that will only be tested
statically.
The licensee
intends to review their test data to justify
appropriate
margins for these valves.
The inspectors
noted that the licensee
had addressed
Potential
10 CFR 21 condition, "Reliance
3 Phase
L. C. Actuator Motors
(Starting Torque at Elevated Temperatures),"
dated
Hay 13,
1993, which
dealt with the effect of elevated
temperature
on the output of AC
motors.
In response
to the issue,
calculation
PTN-BFJM-93-019,
"Evaluation of HOV Output Torque Capability Considering the Effects of
Derated Motor Starting Torque," dated
June
28,
1993,
was developed to
assess
the impact of derating
The licensee
concluded that all affected
HOVs were capable of functioning under
design basis conditions.
However,
HOV-3-6386 and MOV-4-6386 were
evaluated
as having
a small margin
and were identified by the licensee
as
a candidate for future modification to improve actuator torque
capability.
The inspectors
agreed with this conclusion.
Calculation
PTN-BCJH-93-005,
"MOV GL 89-10 Diagnostic Test Data
Evaluation," dated
September
7,
1993, contained
the static test results,
and dynamic test packages
for the selected
valves:
VALVE
HOV-4-843A
HOV-4-869
HOV-878B
HOV-3-1405
MOV-3-1420
HOV-4-1420
CLOSE MAX.
D/P
1715
sid
1715
sid
1715 psid
1118
sid
312
sid
312 psid
CLOSE TEST
D/P
1489
sid
1474
sid
425 psid
290
sid
330
sid
298
sid
HAX D/P
87%
86%
25%
26%
106%
96%
The inspectors
reviewed the licensee's
dynamic test data that used the
industry standard
equation,
the valves'rifice diameters,
and the
dynamic test conditions.
Gate valve factors for the closing direction
ranged
from 0.16 (double disk) to 0.71 (flex wedge)
(see Appendix A).
The licensee's
test method identified load sensitive
behavior
as high as
24 percent.
The licensee's
valve factor assumption for gate valves
was
not always bounding.
However, the licensee
had increased their valve
factor assumption for their 18" Walworth flex wedge gate valves to 0.76.
Stem friction coefficients for the sample valves
(determined at flow
isolation) were
as high as 0. 14.
To determine
the operability of an
HOV, the licensee
used linear
extrapolation for the thrust necessary
to overcome differential pressure
to design basis conditions.
The licensee
was conducting multi-point
dynamic tests to develop
a justification for their extrapolation
methods.
Until the licensee
completes their justification, the
inspectors
consider the licensee's
extrapolation to be in the first
stage of a two stage
approach,
where the valves are setup using the best
available data,
as discussed
in GL 89-10.
The licensee
would be
expected
to justify its method of extrapolation
by the schedule
commitment date for the completion of their
GL 89-10 program.
During review of the dynamic test packages,
the inspectors
noted that
the test acceptance criteria only determined if the assumptions
made in
the original calculation were conservative.
No extrapolations
(where
necessary)
or margin assessments
were made prior to returning the valve
to service.
However, the licensee
had completed
a detailed review of
all dynamic test data conducted
before the inspection
and no operability
concerns
were identified.
In JPN-PTN-SEHP-032,
"Engineering Evaluation
for
HOV Static
and Dynamic Test Results,"
Rev.
0, dated October
15,
1993, the licensee identified that
a more
comprehensive
review was required before returning the
HOV to service.
This document
contained specific recommendations
for the revision of
dynamic test acceptance
criteria.
The licensee
indicated that computer
software
was being developed to allow the test evaluations to be
performed in a timely manner.
The licensee's
engineering
evaluations typically compared the
extrapolated
required thrust to the minimum control switch trip (CST)
thrust specified in the original calculation.
These evaluations
provided assurance
that sufficient margin existed to account for
uncertainties
(e.g.,
torque switch repeatability).
However, in those
cases
where the original thrust calculation
was not conservative,
the
licensee
used
a different approach,
in that the extrapolated
required
thrust was compared directly to the thrust measured
at CST.
In these
cases,
the licensee did not have guidelines specifying the amount of
margin that was required to account for torque switch repeatability
and
other uncertainties.
No operability concerns
were identified with the
use of this approach for the sample
MOVs.
However, the licensee is
developing this guidance for future operability judgements.
During review of the static test
package for HOY-4-843A, the inspectors
noted that the technician
signed off procedure
steps.
The technicians
answered
"yes" to questions
on
a check list that the available thrust
was within the specified
window when the measured
available thrust
was
less than the minimum required available thrust, corrected for
uncertainties.
The condition was not identified at the
end of the
static test,
but was later identified by the
HOV coordinator after the
dynamic test
was completed.
The valve performance
was acceptable
during
the dynamic test.
The licensee
performed
an additional static test
where the torque switch was set higher to allow for additional
margin
and to bring the measured
available thrust in conformance with the
requirements
of the thrust calculations.
The licensee
stated that the
test procedures will be enhanced
to improve the acceptance
criteria,
and
their independent verification process.
The inspectors
noted deviations in the HOV-4-843A engineering
evaluation's
"corrected target" values
as
compared to the values
used in
the dynamic test package.
Licensee
personnel
stated that
a
communication error between
maintenance
and engineering
was the cause of
the deviation.
Engineering incorrectly assumed that the strain gage
had
been calibrated with the
HOVATS torque thrust cell (which would allow
use of a smaller uncertainty),
when the strain
gage
had not been
calibrated.
This error led to the development of thrust limits that did
not adequately
account for diagnostic
equipment uncertainty.
After
review of the remaining
sample
HOVs, it was found that this was
an
isolated occurrence.
The licensee
stated
they will conduct
a review to
ensure that similar errors
have not occurred,
and will develop ways to
prevent
a recurrence
of the event.
2.4
During review of test
packages for HOV-3-1420, the measured
torque at
CST exceeded
the maximum allowed
by 39 ft-lb.
The licensee
dispositioned
the condition on the basis that the torque limit was not
a
structural limit.
However, the torque limit was
based
on the actuator's
output capability under degraded
voltage conditions.
This means that
the actuator would be unable to generate sufficient output torque to
open the torque switch during
a degraded
voltage condition and could
cause
the actuator to stall.
The licensee
reevaluated
the
maximum
allowed torque limit using
an application factor of 1.0 that resulted in
a corrected
maximum allowed
CST torque of 1004.4 ft-lb, which was 64.4
ft-lb greater
than the measured
The licensee
also noted that
their standard
methodology
used
a more conservative pullout efficiency
for the closing direction.
The licensee
conducted
a review and
determined that no other conce} ns were dispositioned
using this basis.
The inspectors
performed
a detailed review of diagnostic traces
using
the
HOVATS 3000 software for the sample
MOVs.
The licensee
used the
highest force including hard seat contact
as the force used in their
extrapolation for design-basis.
No concerns
were noted in this area.
HOV Motor Brakes
In Maintenance
Update 92-2, Limitorgue Corporation
informed the nuclear
industry that there
was
a concern with motor brakes.
Limitorque stated
it had discovered
through operating experience
and testing that motor
brakes
do not minimize the thrust load caused
by inertia when closing
HOVs.
Limitorque also stated it did not qualify motor brakes
through
its nuclear qualification program.
Limitorque warned that voltage
variations
(low voltage)
may render the brakes inoperative.
In
addition, disconnection of the electrical
does not render the
brake inoperative,
the friction pads
need to be removed.
The inspectors
discussed this motor brake concern with the licensee.
The licensee
informed the inspectors
they were aware of the motor brake
issue
and
had already
implemented partial corrective action.
Six HOVs
with motor brakes,
HOV-3-865A, B,
& C and HOV-4-865A,
B 5
C were locked
open to prevent valve failure due to the motor brakes.
These six
valveswere
scheduled
to have the motor brake assemblies
removed during
the next refueling outage.
The licensee
also identified twelve
additional
HOVs with motor brakes installed.
These
HOVs are listed as
follows:
HOV-3-716A
HOV-3-716B
HOV-3-730
MOV-3-872
MOV-3-880A
HOV-3-880V
HOV-4-716A
HOV-4-716B
MOV-4-730
HOV-4-873
MOV-4-880A
HOV-4-880B
The licensee
calculated
the minimum voltage at the
HOV motor brake
assembly terminals for brake equipped
HOVs in both Units.
The 90
percent voltage rating of 460 volts for the brake assemblies
is 414
volts.
The inspectors verified that the calculated
voltages for Unit 4
MOV motor brakes
assemblies
were above the 90 percent voltage rating at
degraded grid voltage.'owever,
the
HOV motor brake assembly terminal
voltage for Unit 3
HOVs was below the 90 percent rating at degraded
10
grid.
(Degraded grid is the setpoint where the emergency diesel
generators
start
and pick-up load.)
The licensee
addressed
this concern
through discussions
with other licensees
that had
HOVs with motor
brakes.
However, they had not contacted
the
MOV brake vendor.
The
inspectors
informed the licensee that
MOV motor brake concern
was under
review by the
NRC staff.
The licensee
advised the inspectors that the
vendor would be contacted
and appropriate corrective action taken.
The
inspectors
requested
that the licensee
keep the
NRC informed of their
actions.
The inspector
concluded that the licensee
was addressing
the
MOV motor
brake concern in a satisfactory
manner.
'.5
Schedule
In GL 89-10, the
NRC staff requested
that licensees
complete all design-
basis
reviews,
analyses,
verifications, tests,
and inspections that were
initiated to satisfy the generic letter recommendations
by June
28,
1994, or three refueling outages after December
28,
1989, whichever is
later.
The licensee's
commitment to
GL 89-10 requires that all
HOVs within the
scope of its
GL 89-10 program
be tested with their design-basis
capability verified by June
1994.
The licensee's
schedule
indicated
that this commitment will be met.
Approximately 21
HOVs remain to be
dynamically tested during Refueling Outage
5, which is scheduled
to
begin in Hay 1994.
2.6
Pressure
Lockin
and Thermal Bindin
0
The Office for Analysis
and Evaluation of Operational
Data
(AEOD) has
completed
a study of pressure
locking and thermal binding of gate
valves.
AEOD concluded
in its report that licensees
have not taken
sufficient action to provide assurance
that pressure
locking and thermal
binding will not prevent
a gate valve from performing its safety
function.
The
NRC regulations require that licensees
design safety-
related
systems to provide assurance
that those
systems
can perform
their safety functions.
In GL 89-10, the staff requested
licensees
to
review the design basis of their safety-related
HOVs.
The inspectors
reviewed several
licensee's
documents that addressed
pressure
locking and thermal binding.
FPL had performed
an evaluation
in response
to
INPO SOER 84-7 and identified 40 valves that were subject
to pressure
locking and thermal binding.
The inspectors
reviewed
a
draft list that contained
59 valves
as the result of the
GL 89-10 study.
The licensee
has modified 22 HOVs to preclude pressure
locking.
The
inspectors
reviewed engineering
evaluation
JPN-PTN-SEHJ-89-066,
Revision
I, Evaluation of Pressure
Locking of Motor Operated
Gate Valves,
dated
December
12,
1989,
which evaluated
the various valves for operability
concerns.
The licensee
has
an
on going evaluation
program to address
any additional valves that exhibit pressure
locking or thermal binding.
ll
Follow-u
of Concerns
Enumerated
in the Part I Re ort
The concerns identified in the Part I report were reviewed to verify
that the licensee
had taken actions to improve, modify, or correct
any
deficiencies
observed
by the inspectors.
The} e was concern that certain
MOVs that were practicable to test
may
not be in situ DP/Flow tested.
The licensee is evaluating the
possibility of grouping in lieu of dynamically testing
each valve and is
awaiting the results of the
EPRI testing program.
The inspectors
reviewed the licensee's list of valves that were not practicable to
dynamically test.
The justification for each non-testable
valve was
examined
by the inspectors
and found technically sound
and justified.
The licensee
has not completely developed all the procedures
necessary
to support the
MOV maintenance
and testing program.
The inspectors
reviewed various parts of the maintenance
and post maintenance
testing
procedures listed below:
gI 11-PTN-I, Test Control
gI ll-PTN-3, Post Maintenance
Tests
W
O-ADM-701, Control of Maintenance
and Constructions
Work
Activities
O-ADM-737, Post Maintenance Testing
Procedures
did not require as-found data collection
and trending
information assimilation.
Test procedures
did not fully consider
the
intent of the
10 CFR 50 Appendix
B criteria to verify the data
collection process.
EXIT INTERVIEW
The inspection
scope
and findings were summarized
on October
29,
1993
with those
persons
indicated in paragraph l.
The inspectors
described
the areas
inspected
and discussed
in detail the inspection results.
Proprietary information is not contained in this report.
No dissenting
comments
were received
from the licensee.
ACRONYMS AND INITIALISMS
D/P
ft-lb
GL
Alternating Current
Office for Analysis
5. Evaluation of Operational
Data
Charging System
Control Switch Trip
Containment
Spray System
Design Basis
Document
Differential Pressure
Electric Power Research
Institute
Florida Power
5. Light
Foot Pounds
Final Safety Analysis Report
Generic Letter
INEL
HCC
HOV
NRC
PTN
PMR
psid
TI
V
VDC,
12
Idaho National Engineering Laboratory
Institute of Nuclear
Power Operations
Hotor Control Center
Hotor Operated
Valve
Nuclear Regulatory
Commission
Nuclear Reactor Regulation
Plant Turkey Point Nuclear
Pressurized
Mater Reactor
Pounds
Per Square
Inch Differential
Rate of Loading
Significant Operating
Experience
Report
Temporary Instruction
Volts
Volts Di}ect Current