ML17304A299
| ML17304A299 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 07/14/1988 |
| From: | Polich T, Richards S NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | |
| Shared Package | |
| ML17304A298 | List: |
| References | |
| 50-528-88-24, NUDOCS 8808030087 | |
| Download: ML17304A299 (11) | |
See also: IR 05000528/1988024
Text
U. S.
NUCLEAR REGULATORY COMMISSION
REGION
V
Report No:
Docket No:
License
No:
Licensee:
Facility Name:
50-528/88-24
50-528
Arizona Nuclear
Power Project
P. 0.
Box 52034
Phoenix,
AZ. 85072-2034
Palo Verde Nuclear Generating Station Unit 1
Inspection
Conducted:
July 5-8,
1988
Inspector:
o ~c
,
en>or
es)
ent
nspector
ate
>gne
Approved By:
7-i I-SS
~Summa r:
S ecial
Ins ection
on Jul
5 throu
h Jul
8
1988
Re ort Number 50-528 88-24
.
Areas Ins ected:
This special
inspection
reviewed the inoperability of both
trains
o
ssential
Chilled Water at Unit 1 during the period of May 20-29,
1988.
During this inspection, the following inspection
modules
were covered:
30703
and 93702.
v+
Results:
One;:.violation of: Technical Specifications
was identified in that two
trains of Essential
Chilled Water were inoperable for a period of approximately
nine days.-
8808030087
880715
ADQCK 05000528,
G
~
PNU;i~
DETAILS
Persons
Contacted:
The below listed technical
and supervisory
personnel
were
among those
contacted:
Arizona Nuclear
Power Pro ect
(ANPP
- J. Al 1 en
- W. Doyle, Jr.
- J. Driscoll
- R. Gouge
- J. Haynes
- W. Ide
- D. Karner
- J. Kirby
- R. Logan
- K. Oberdorf
- T. Schriver
- J. Sills
Plant Manager, Unit
1
Manager, Unit 2 Radiation Protection
Assistant
Vice Pres. ident,
ANPP Admin.
Operations
Manager, Unit 3
Vice President,
Nuclear Production
Plant Manager,
Unit 2
Exec.
Vice President,
ANPP Administration
Director, Site Services
Supervisor,
Central Radiation Protection
Manager, Unit
1 Radiation Protection
Manager,
Compliance
Supervisor,
Radiation Protection
Standards
The inspector also talked with other licensee
and contractor
personnel
during the course of the inspection.
"Attended the Exit Meeting on July 8, 1988.
Ins ection
Back round
The Essential
Chilled Water
(EC) system consists of two 100 percent
capacity chilled water trains.
Each train consists
of a single
100
percent capacity essential
chiller unit.
The
EC system supplies chilled
water to the Essential Air Cooling Units
(ACUs) for the Control Building,
Auxiliary Building, and Main Steam Support Structure.
At approximately
0955
MST on May 29, 1988,
a manual start attempt
was
made
on the Train "A" Essential Chiller to support surveillance testing
of the steam driven Auxiliary Feedwater
pump.
When the chiller did not
start,
an Auxiliary Operator
(AO) was sent to investigate
the chiller
breaker
and found "n'o indication of an electrical fault.
The
AO was directed
to the local annunciator
panel for further investigation
and found
a low
flow alarm indicated.
A second
attempt
was
made to start the chiller and
was again unsuccessful.
The Assistant Shift Supervisor
(A/SS) then went
to the Control Building to investigate
the valve lineup, in accordance
with
the alarm response
procedure.
The A/SS found that the root isolation valves
for the flow instrumentation
loop were closed.
The flow instrumentation
loop consists of a non-safety related flow indicator
gauge with isolation
valves;
and
a safety related flow transmitter,
which supplies
a signal to
satisfy
a compressor
"run" interlock.
The "as found" valve lineup was
contrary to the proper system lineup,
because
the safety related flow
transmitter
was isolated,
preventing the transmitter
from sensing
system
water flow and thereby satisfying the compressor
run interlock.
The
licensee 'immediately entered
Technical Specification Limiting Condition
for Operation
(LCO) 3.7.6
and concurrently
opened
the root isolation valves.
The chiller was successfully started
and the Train "A" EC system
was
declared
The operability of Train "B" was then investigated
and Train "B" was
declared
inoperable at 1022
MST.
The root isolations for the Train "B"
instrumentation
loop were also found isolated
and subsequently
opened.
The Train "B" EC system
was declared
operable at 1040
MST after
successfully starting the "B" chiller.
A yellow plastic caution sign
was mounted
near both sets of root
isolation valves.
The sign read
"CAUTION valves to remain closed
except
when reading gauge."
The licensee initiated
a four hour notification to the
NRC Operation
Center
and initiated an internal report, Potentially Reportable
Occurrence
(PRO)
No. 1-88-065.
Subsequently
the licensee initiated
a Special
Plant Event Evaluation
and submitted Licensee
Event Report
(LER) 1-88-017 to the
NRC, which describes
the above event in detail.
Ins ection Findin s
The inspector
performed
a review to determine
the circumstances
which
led to this event.
Valve alignment procedures
and 410P-IEC02
were revised
on
May ll, 1988, to include
a note indicating the importance of assuring
that non-class
flow indicators are isolated
from the class flow transmitter
loop.
The valve alignments
were properly performed in all three units
when the revision was
implemented.
A Unit 3 Shift Supervisor,
in response
to the procedure revision,
had
a
set of yellow laminated plastic signs
made for all three units.
The
signs read,
"CAUTION valves to remain closed except
when reading gauge."
'he Shift Supervisor did not inform his management
or the management
of
the other units of his decision to make or install the signs.
When the
signs were made, Unit 3 installed the signs
near the flow
indicators'solation
valves
and delivered the remaining signs to Units
1 and 2.
On May 19,
1988,
both Essential
Chillers were operated satisfactorily.
On May 20,
1988, Unit I received
two signs
and
a note with the flow
indicator numbers
and
no additional instructions
as to their intended
use.
The Assistant Shift Supervisor
(A/SS) did not inform the Shift Supervisor
of the signs,
but directed
a Reactor Operator
(RO) to research
the
appropriate
Operating
Procedures
for more information.
The
RO found the
appropriate
procedure
pages
in 410P-1ECOl
and 410P-lEC02
and copied those
pages.
The
RO also looked
up the valves that were located nearest
the
flow instrument valves
on the system drawing and wrote those valve numbers
on the note containing the flow indicator numbers that accompanied
the signs.
The numbered valves were the flow instrumentation
loop root isolation valves,
which are the last valves
shown
and numbered
on system drawings.
The
licensee
does not label local instrumentation isolation valves.
The
then called
a relief shift Auxiliary Operator
(AO) to hang the signs.
When the
AO arrived in the Control
Room he was given the signs,
the note
containing flow indicator and valve numbers,
and the appropriate
pages
from the valve alignment procedures.
The
RO told the
AO to hang the
signs
on the flow indicators.
A phone call then interrupted the
RO, and
when
he finished the phone conversation,
the
AO was
gone
and
had not
taken the copies of the valve alignment procedure
pages.
Since the
was reading the information when the phone rang,
the
RO assumed
the
understood
the instructions
and didn't need
the valve alignment procedure
pages.
The
AO proceeded
to the Control Building and located the
instruments
and valves
on the note
and installed the signs next to the
valves which he observed
to be root isolation valves.
When the
installed the signs,
he also noted that the valves
were
open
and closed
them to correspond
to the directions
on the signs.
The
AO traced
the
valves to the flow indicators to ensure
that the valves did, in fact,
isolate the flow indicator.
He also observed that the valves isolated
a
flow transmitter.
The
AO returned to the Control
Room and informed the
A/SS that
he
had hung the 'signs,
shut the valves,
and asked if there
was
any paper work to fill out;
The A/SS assumed
that the
AO had installed
the signs correctly,
and that the valves the
AO closed were the local
instrumentation isolation valves
and not the instrumentation
root valves.
In an interview with the AO, he stated that at the time,
he
had
made
a
statement,
not specifically directed to the A/SS,
as to how stupid
he
thought it was to isolate all flow indication.
The A/SS was not aware
of the AO's comment
and did not respond.
The
AO stated to the inspector
that since
he did not get
a response
and it was not his normal crew,
he
did not feel free to pursue
the matter any further.
Thus, the valves
remained
closed
and the signs installed at the incor rect location until
the discovery
by the licensee
on May 29,
1988.
Licensee
Followu
The licensee
has described
the event in Licensee
Event Report
(LER)
88-017-00,
dated
June
28,
1988.
The
LER classified the event
as
a condition prohibited by Technical Specifications,
a condition which
could have resulted in the plant being in an unanalyzed
condition that
significantly compromised plant safety,
and
an event that could have
prevented
the fulfillment of the safety function of a system
needed
to
mitigate the consequences
of an accident.
The licensee
determined
the root cause to be
a cognitive personnel
error
on the part of the Auxiliary Operator
(AO) and Reactor Operator
(RO), in
that they did not take adequate
measures
to ensure that the signs were placed
properly.
First, inadequate
communication occurred
between
the two
operators
in that the direction given was not sufficient to ensure that
the tags were properly placed.
Second,
the
AO repositioned
the flow
transmitter
val,ves without proper valve position documentation
and
verification as required
by Operating
Department Guidelines.
Finally,
the
AO and Assistant Shift Supervisor did not ensure that appropriate
actions
were taken
upon closing of the valves
due to inadequate
communications.
The licensee
is conducting
an evaluation to determine
the effects of the
loss of essential
chillers.
Based
on this evaluation
the licensee will
provide
a supplement to LER 88-017 describing
the safety
consequences
and
implications of the event.
The licensee's
immediate corrective actions consisted of returning the
chillers to service
and placing the caution signs in the correct location.
The corresponding
valves at Units
2 and
3 were checked
and found to be
properly positioned.
As an interim corrective action, warning labels
will not be installed without the Plant Manager's
approval.
Management
directives
were issued requiring all Unit
1 operations
personnel
to
review administrative
requirements
governing valve manipulation,
and for
all Unit 1 personnel
to be more formal in communications
when discussing
plant status
and to adopt
a more conservative
approach
when plant conditions
or indications are off normal.
As long term corrective action
a policy regarding
the installation
and
control of warning tags will be developed
and implemented.
The
administrative controls for conduct of Shift Operations will be revised
to delineate
communications
standards.
Additionally, a
Human Performance
Evaluation
System
(HPES) review is being performed.
The specific
corrective actions which result from HPES will also
be included in the
supplement
to the
LER.
The licensee
conducted
a Special
Plant Event Evaluation to determine
why
the Essential
Chilled (EC) water flow instrumentation
loop root valves
were closed, contrary to the valve alignment procedures.
The results of
the evaluation
are documented
in Special
Plant Event Evaluation Report
(SPEER)
number 88-01-007.
This report was approved
by licensee
management
on June 30,
1988.
The
SPEER noted the following three concerns
as
a result of the
investigation.
1.
The
EC system
was rendered
when the flow instrumentation
loop root valves were closed instead of the flow indicator isolation
valves.
The valves were closed during the installation of a laminated
information tag.
No guidance is provided for control of these
tags
within the plant.
2.
The communications
between
the individuals performing the installations
of the tags
was not adequate.
3.
The flow transmitter root valves were repositioned without proper
valve position verification notification per Operating
Department
Guidelines.
The resolution
and analysis of each
concern
were discussed
in the
SPEER,
as well as
the* recommended
corrective actions.
The corrective actions
for concern
1 are scheduled
to be complete within 90 days
from the
approval of the
SPEER.
And the corrective actions associated
with
concerns
2 and
3 are to be completed within 60 days.
Conclusions
Unit 1 was operating in Mode
1 for the entire period that the Essential
Chilled Water Trains "A" and "8" were rendered
This is
a
violation of Technical Specification 3.7.6, which requires
both trains
of Essential
Chilled Water to be operabld in Modes 1, 2, 3,
and
4
(50-528/88-24-01).
The
AO showed
a disregard for Administrative Controls
and Operations
Department Guidelines
concerning manipulation of safety
system valves
and
the tracking of those manipulations.
Ineffective communication
was noted
between
the Unit 3 Shift Supervisor
and Unit I, with regard to the purpose
for placement of the warning signs;
between
the Unit I
RO and
AO as to
the instructions to install the signs
and not manipulate valves;
and
between
the Unit
1
AO and the A/SS as to the safety
system valve
manipulations
that took place
and the documentation
required for their
manipulation.
Additionally, the inspector
was concerned with the relief
shift AO's apparent
reluctance
to clearly stress
to the A/SS his concern
that isolation of all flow indication was improper.
As mentioned in paragraph
4, the licensee's
investigation
appears
to have
encompassed
the inspector's
concerns
and conclusions,
with the exception
of the information which will be obtained
by further licensee
evaluations
and included in a supplement
to LER 88-017.
The inspector
met with licensee
management
representatives
periodically
during the inspection
and held an exit on July 8, 1988.
During the exit
meeting,
the inspector
discussed
recent operating
experiences
involving
personnel
error, emphasizing
the
need for greater attention to detail
and
.
management
attention.
A
I'