ML17251B074
| ML17251B074 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 04/26/1988 |
| From: | Collins T, Eapen P, Prividy L NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML17251B073 | List: |
| References | |
| 50-244-88-06, 50-244-88-6, IEIN-86-005, IEIN-86-5, NUDOCS 8805090373 | |
| Download: ML17251B074 (16) | |
See also: IR 05000244/1988006
Text
U.S.
NUCLEAR REGULATORY COMMISSION
REGION I
Report
No.
50-244/88-06
Docket No.
50-244
License
No.
Licensee:
Rochester
Gas
and Electric
Com an
49 East Avenue
Rochester
14649
Facility Name:
R.
E. Ginna
Inspection At:
Ontario
Inspection
Conducted:
March 7-11
1988
Inspectors:
Collins, Chief
Nuclear Performance
Section,
Reactor
Systems
Branch
date
/leonard J. Prividy, Reactor
Engineer
date
Approved by:
Dr.
P.
K. Eapen,
C ief
Special
Test Programs
Section,
EB,
date,
Ins ection
Summar
Ins ection
on March 7-11
1988
Re ort No. 50-244/88-06
~l
physics tests
including:
precritical tests; critical boron measurements,
moderator temperature coefficient measurements;
control rod worth measurement;
and
QA/QC role in startup physics testing.
A major portion of this inspection
involved actual test witnessing.
Licensee
responses
to
NRC Information Notice No. 86-05
and
one previous unresolved
item were also reviewed.
Results:
No violations were identified.
8805090373
880428
ADOCK 05000244
9
'
'
DETAILS
1.0
Persons
Contacted
"S. Adams,
Reactor
Engineer
'J.
Bodine, Nuclear Assurance
Manager
- S. Spector,
Superintendent,
Ginna Station
- J. Widay, Technical
Manager
C. Marschall,
Senior Resident
Inspector
N. Perry,
Resident
Inspector
- Denotes those
present at the exit interview on March ll, 1988.
The
inspector also contacted
other licensee
employees
during the course of
the inspection.
2.0
C cle
18 Startu
Testin
Pro
ram
The startup physics test
program
was conducted
in accordance
with PT-34.0,
Startup
Physics
Test Program,
Revision
16.
This procedure
outlined the
steps for the test program,
set initial conditions
and prerequisites,
specified calibration procedures
at appropriate
points,
and referenced
detailed tests
and data collections in separate
test procedures.
Initial
criticality for Cycle
18 was achieved
on March 9,
1988.
The Zero Power
Physics Testing
was completed
on March 10,
1988.
At the
end of the
inspection
on March 10,
1988, while attempting to increase
power to 25%,
the plant tripped
on low steam
generator
water level.
The inspector witnessed
several
of the startup physics tests
including
Rod Drop Measurements,
Initial Criticality, All Rods Out (ARO) Boron
Concentration
Measurement,
Moderator Temperature
Coefficient Measurement,
and Control
Rod Worth Testing.
Test results
and procedures
as well as
the Cycle
18 core management
report
and Reload Safety Evaluation were
reviewed to assess
the adequacy of the licensee's
physics test program.
The inspector
independently verified that the predicted
values
and
acceptance
criteria had been obtained
from "The Nuclear Design
and
Core Management of the
R.
E. Ginna Nuclear Reactor. Cycle 18," WCAP-
11713,
February,
1988.
The details
and findings of the inspection
are described
below.
3.0
C cle
18 Startu
Testin
- Precritical
Tests
and Reviews
The inspector witnessed
and reviewed calibration
and functional test
results to verify the following:
Procedures
were provided with detailed instructions;
Technical
content of the procedures
was sufficient to result in
satisfactory
component calibration
and test;
Instruments
and calibration equipment
used were traceable
to the
National
Bureau of Standards;
and,
Acceptance
and operability criteria were observed.
The following items were witnessed
and reviewed
as noted:
3.1
C cle
18 Reload Safet
Evaluation
The inspector
reviewed the Reload Safety Evaluation
(RSE) prepared
by the fuel vendor (Westinghouse)
and noted that the applicable
burnup
range for the analysis
was 11,600
+500
MWD/MTU, and that
a
Cycle
17 burnup greater
than
11,400
MWD/MTU was necessary
to avoid
imposition of rod withdraw limitations for Cycle 18.
The rod
withdraw limits, if necessary,
would be
imposed to assure
that the
Moderator Temperature
Coefficient (MTC) remains within Technical
Specification Limits at all operating
power levels.
The inspector
determined that the actual
Cycle
17 burnup level
was
11,500
MWD/MTU
by reviewing the detailed core management
report (WCAP-11713).
This
burnup level (11,500
MWD/MTU) is both within the range of the
RSE
and greater
than the minimum burnup necessary
to avoid rod withdraw
limitations due to
MTC ~
The
RSE was forwarded
by the licensee's
offsite engineering staff
to the plant staff by memorandum
dated
February 2,
1988.
The Plant
Operations
Review Committee
(PORC) approved
the
RSE at Meeting
No.
024 on February
10,
1988.
No unacceptable
conditions were identified.
3.2
Control
Rod Checks
and Tests
The rod drop measurements
were performed in accordance
with procedure
RSSP-7.0,
Revision
12.
The inspector witnessed
the test performed
on March 8,
1988 and reviewed the test results.
The inspector deter-
mined that the
Rod Cluster Control Assembly drop times were well
below 1.8 seconds,
required
by the
TS.
The inspector
reviewed
several
visicorder traces
and verified that the drop times were
interpreted correctly.
'
The recently modified Microprocessor
Rod Position Indication (MRPI)
System
was being calibrated
and checked
per Procedure
No. SM-3797.7,
Revision 0,
on March 8,
1988.
The
MRPI system
was recently modified
to eliminate electrical
noise
problems.
The inspector
reviewed the
test data
and noted that it was satisfactory.
3.3
S stem
RTD Calibration
RTDs were cross calibrated
in accordance
with
Procedure
RSSP-8.0,
Revision
10,
on March 9,
1988.
The inspector
reviewed the calibration data
and noted that all calibration checks
were satisfactory.
4 '
C cle
18 Startu
Testin
- Postcritical
Tests
The inspector
reviewed selected
tests
and verified the following:
The tests
were
implemented
in accordance
with Cycle
18 Startup
Physics
Test Program;
Stepwise instructions of test
procedures
were adequately
provided
including Precautions,
Limitations and Acceptance Criteria in
Conformance with the requirements
of the Technical Specifications.
Appropriate measures
were taken if a test condition and/or test
result acceptance
criteria was not met;
Methods
and calculations
were clearly specified
and the tests
were
performed accordingly;
Review, approval,
and documentation
of the results
were in accordance
with the requirement of the
TS and the licensee's
administrative
controls;
and,
equality control
was active during test
and review.
4. 1
Initial Criticalit
and Critical Boron Measurements
End
Points
Prior to achieving initial criticality, the licensee
performed
a
reactivity computer checkout.
This was done by comparing the reacti-
vity computer outputs with established
curves of reactivity versus
period from a series of predefined
Control
Bank 0 movements.
The
licensee
measured
the All Rods
Out (ARO) critical boron concentra-
tions in accordance
with test procedure
PT 34. 1.
The boron
end point
for Banks
A+B+C+D inserted
was measured
in accordance
with procedure
PT 34.4.
The inspector witnessed
the conduct of the tests
and
reviewed the data'
The
ARO Boron
End Point was determined
as follows:
The reactor
was
brought to
a just critical state with only the
D rod bank not fully
withdrawn.
(The
D bank was withdrawn to about the
204 position in
this configuration.)
The reactivity worth of the
D bank at this
position
was then determined
by withdrawing the
D bank fully and
monitoring the flux increase
and startup rate.
The
D bank was then
'reinserted
to return the flux level to within the normal startup test
range.
Finally, the
D bank was returned to the 204 position
and the
reactor
was brought again to just critical, and the boron concentra-
tion was measured.
The boron concentration
was then adjusted
for the
equivalent
boron worth of the
D bank at position
204 and the
ARO
boron concentration
established.
The boron
end point for A+B+C+D banks inserted configuration
was
performed after determination of the individual bank worths discussed
in Section
4.3
~
The boron
end points are
summarized
below:
Confi uration
All Rods Out (ARO)
'+B+C+D Banks In
Predicted
Value
ppm)
1552 (+75)
1126 (+75)
Measured
Value
ppm
1560
1139
Ho unacceptable
conditions were identified.
4.2
Moderator
Tem erature Coefficient
The Moderator Temperature
Coefficient (MTC) was determined
in accord-
ance with the procedure
specified in
PT 34.2,
Revision 9.
The test
was witnessed
by the inspector
and involved
a slow heatup
and cool
down ( 10 degrees
F per hour) of the reactor coolant
system
and meas-
urement of the change
in reactivity as
a function of temperature.
The licensee
maintained
boron concentration
at
a constant
level
throughout
the test.
The parameter actually measured
is the Iso-
thermal
Temperature Coefficient (ITC).
ITC is defined
as the change
in reactivity for a unit change
in the moderator temperature
as well
as clad and fuel pellet temperatures.
Since
change
in reactivity at-
tributable to a change
in fuel
and cladding temperatures
is repre-
sented
by the Doppler (or fuel temperature)
coefficient, the
moderator
temperature coefficient can
be inferred from the
measurement
by subtracting
the value of the Doppler Coefficient from
the measured
ITC.
The measured
ITC at hot zero
power
(HZP) with all rods out (ARO) was
+2.8 pcm/degree
F at
547 degrees
F.
This is in reasonable
agreement
with the predicted
value of +2.93 pcm/degree
F.
The Doppler Coeffi-
cient (taken
from the fuel design report) is -1.9
pcm per degree
F
and the
MTC is therefore
+4.7
pcm per degree
F which is within the
Technical Specification
requirement of less
than +5.0
pcm per
degree
F at less
than
70% power.
The inspectors
noted that there
was
no lower bound acceptance
criteria
for the
MTC and
no acceptance
criteria on the difference
between
predicted
and measured
value of the
ITC (and therefore
MTC).
The
inspector discussed
how the licensee
assures
that the value of MTC
determined
from ITC measurement
is bounded
by that used in the Safety
Analysis for the Main Steam
Line Break (MSLB).
The concern
in the
MSLB analysis is that too negative of an
MTC can result in recriti-
cality due to the cooldown effects of the blowdown.
The licensee
indicated that the margin between
the analysis
value
and that pre-
dicted for the most negative point in cycle
(EOC) is large
enough
and
that the difference
between
the measured
and predicted
ITC would be
scrutinized.
The inspector
agreed that the margin was large
enough
for the current cycle.
The inspector also discussed
the lack of
acceptance
criteria for the difference
between
predicted
and measured
value of ITC or the lowerbound for the
MTC.
Inclusion of either of
the
above
acceptance
criteria will adequately
address
the
concern.
The licensee
agreed
to modify test procedure
PT-34.2 for
future testing
by including
a lower limit in the
MTC acceptance
criteria'he
inspector
had
no further concerns.
4.3
Control
Rod Worth Measurement
The control rod reactivity worth measurements
were performed in
accordance
with test procedure
PT-34.3,
Revision 9.
The
following'esults
were noted:
Rod Bank
Predicted
Worth
pcm
Measured
Worth
Difference
~Pc IA
Control Bank
D
782 (+15%)
Control
Bank
C (D in)
1123
(+15%)
Control
Bank
B (C+D in)
788 (+15%)
Subtotal
(D+C+B)
2693
(+10%)
Control
Bank A (B+C+D in)
1535
(+15%)
Subtotal
(A+B+C+D)
4228 (+10%)
708
1005
692
2404
1522
3925
- 9.5
-10.6
-12.3
-10.8
- 0.9
- 7.7
As noted previously,
the predictions continue to be
on the low end
of the acceptance
criteria.
The inspector
had
no further questions.
'
5.0
Control
Room Observations
and
A/
C Role in
C cle
18 Startu
Ph sics
~Teetin
The inspector
observed
good coordination of operations,
testing,
reactor
engineering
and
IKC personnel
during startup physics testing.
All per-
sonnel
interfaced well with licensee contractor
personnel.
Communications
among the reactor operator,
reactor engineering
and
contractor
personnel
concerning
rod movements
were clear.
QA/QC involvement
was evident in the precritical testing concerning
MRPI
testing
and rod drop measurements.
QA/QC involvement was confined to an
administrative role during post-critical testing
due to lack of expertise
in this area.
However,
the inspector
was advised
by the Nuclear Assurance
Manager that
an individual with prior SRO qualifications
was scheduled
to
be in the
QA/QC organization
by April 1988.
No unacceptable
conditions were identified.
6.0
Licensee
Res
onse to IE Information Notice No. 86-05
Main Steam Safet
Valve
Test Failures
and Rin
Settin
Adjustments
IE Information Notice No. 86-05 describes
a potentially .significant issue
concerning
MSSV ring settings.
The inspector
met with a lead engineer
in
the Mechanical
Engineering
group to determine
the licensee's
response
to
this issue.
The inspector determined that the eight (8)
MSSVs at Ginna
Station are Crosby type
6R10 safety valves which are the
same type
referred to in IE Information Notice No. 86-05.
The licensee
has conducted
an ongoing evaluation
concerning this issue
since shortly before their initial correspondence
to Crosby
on November
14,
1986.
In this correspondence,
the licensee
advised
Crosby of the
current ring settings for the eight (8) MSSVs.
The upper (guide) ring
setting
was +100 for six (6) valves
and +150 for the other
two (2) valves.
The lower (nozzle) ring setting
was -20 on all MSSVs.
Also, Crosby was
requested
to confirm the acceptability of these
settings
or provide
new
settings
which will ensure that the Ginna
MSSVs can achieve full capacity.
A series of correspondence
followed between
the licensee,
Crosby and
which resulted
in a recommended
change
to the current ring
settings.
For the eight, (8) MSSVs, the upper
(guide) ring setting
was
adjusted
to -50 and the lower (nozzle) ring setting
was adjusted to -100.
The licensee
is currently active with a Westinghouse
Owners
Group sub-
committee to perform testing
and confirm the adequacy of these settings.
No unacceptable
conditions were identified.
'
7.0
Licensee Action on Previous
Ins ection Findin
s
(Open) Unresolved
Item (50-244/85-09-01)
Predictions of Control
Rod Worth.
During
a Reactor
Physics Startup Test inspection for Cycle
15 (IR 85-09),
the inspector
noted that the individual bank worth measurements
were
on
the low end of the acceptance
criteria.
The licensee
experienced
the
same
anomaly during its cycle
16 and cycle, 17 startups.
The licensee
indicated that its engineering staff has
been working with Westinghouse
for the past
3 years to determine
the cause
of the relatively poor rod
worth predictions.
representatives
assisting
in the
Cycle
18 startup testing
suggested
that the concern
may be attributable
to the boron dilution rate
(40 gpm) used during the previous
rod worth
tests,
which may have
been
too high.
The licensee,
therefore,
modified
his Cycle
18 rod worth test strategy to reduce
the boron dilution rate
by
a factor of 2.
The control
rod reactivity worth measurements
were
performed in accordance
with test procedure
PT-34.3,
Revision 9.
During
the course of the rod worth tests,
the boron dilution rate
was reduced
even .further (.to about
14 gpm).
However,
as
can
be
seen
from the results
given in Section
4 '
of this report,
the predictions continue to be
on the
low end of the acceptance
criteria.
i
Since the errors
have continued for several
cycles,
the licensee staff
postulated that the Westinghouse
model
may include inaccuracies
for some
core configurations particularly with regard to the weaker control banks.
This item continues
to remain unresolved
and will be reviewed in a future
inspection.
~Efl
The inspector discussed
the inspection findings at an exit meeting
on
March ll, 1988.
(See
paragraph
1 for attendees.)
No written material
was provided to the licensee
by the inspector at any
time during this inspections
The licensee
representatives
did not indicate
that this inspection
involved any proprietary information.
I