ML16341G242
| ML16341G242 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 08/14/1991 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | |
| Shared Package | |
| ML16341G243 | List: |
| References | |
| 50-275-91-19, 50-323-91-19, NUDOCS 9108300034 | |
| Download: ML16341G242 (46) | |
See also: IR 05000275/1991019
Text
INITIAL SALP
BOARD REPORT
U.S.
NUCLEAR REGULATORY COMMISSION
REGION
V
SYSTEMATIC ASSESSMENT
OF LICENSEE
PERFORMANCE
INSPECTION
REPORT
NOS. 50-275/91-19
and 50-323/91-19
PACIFIC GAS 5 ELECTRIC COMPANY
DIABLO CANYON POMER PLANT
JANUARY 1, 1990,
THROUGH JUNE 30,
1991
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I.
Introduction
II.
Summary of Results
Overview
III. Performance
Analysis
TABLE OF
CONTENTS
Pa
e
s
A.
B.
C.
D.
E.
F.
G.
Plant Operations
Radiological Controls
Maintenance/Surveillance
Emergency
Preparedness
Security
Engineering/Technical
Support
Safety Assessment/equality
Verification
3-4
5-6
6-8
9-11
11-13
13-16
16-17
IV.
Supporting
Data
and Summaries
A.
B.
C.
D.
E.
Licensee Activities
Inspection Activities
Enforcement Activity
Confirmatory Action Letters
Licensee
Event Reports
18-19
20
20-21
21
21
I.
INTRODUCTION
The Systematic
Assessment
of Licensee
Performance
(SALP) is
an
integrated
NRC staff effort to col.lect available observations
and data
on
a
periodic basis
and to evaluate
licensee
performance
on the basis of this
information.
The program is supplemental
to normal regulatory processes
used
to ensure
compliance with NRC rules
and regulations.
It is intended to be
sufficiently diagnostic to provide
a rational
basis for allocating
NRC
resources
and to provide meaningful
feedback to the licensee's
management
regarding
the
NRC's assessment
of their facility's performance
in each
functional area.
An
NRC SALP Board,
composed of the staff members listed below, met on July 30,
1991, to review observations
and data
on performance,
and to assess
licensee
performance
in accordance
with NRC Manual Chapter'516,
"Systematic
Assessment
of Licensee
Performance."
This report is the NRC's assessment
of the licensee's
safety performance at
the Diablo Canyon
Power Plant for the period January
1, 1990,
through June 30,
1991.
The
SALP Board for Diablo Canyon
was attended
by:
Board Chairman
R.
Zimmerman, Director, Division of Reactor Safety
and Projects,
RV
Board Members
J. Dyer, Project Director V, Division of Reactor Projects,
K. Perkins,
Deputy Director, Division of Reactor Safety
and Projects,
RV
H. Rood, Project Manager,
PDV,
G. Yuhas, Chief, Reactor Radiological Protection
Branch,
RV
D. Kirsch, Chief, Reactor Safety Branch,
RV
S. Richards,
Chief, Reactor Projects
Branch,
RV
P. Morrill, Chief, Reactor Projects
Section I,
RV
P. Narbut, Senior
Resident
Inspector,
RV
Other Attendees
R. Huey, Chief, Engineering Section,
RV
J.
Reese,
Chief, Safeguards,
Emergency
Preparedness
and
Non-Power
Reactor
Branch,
RV
G.
Good,
Emergency
Preparedness
Analyst,
RV
B. Olson, Project Inspector,
RV
D. Schaefer,
Safeguards
Inspector,
RV
M. Cillis, Radiation Specialist,
RV
K. Johnston,
Project Inspector,
RV
H. Resides,
Radiation Specialist,
RV
A. Dummer, Reactor Inspector,
II.
SUMMARY OF
RESULTS
Overview
The licensee's
overall performance
level during this assessment
period
was
acceptable
in all areas.
Examples of particularly good performance
were
demonstrated
by relatively event-free operation,
low occupational
radiation
exposure,
completion of the
Long Term Seismic
Program,
and your performance
based audits.
The strengths
observed
in the Operations,
Radiological Controls,
Engineering/
Technical
Support
and the Safety Assessment/guality
Verification functional
areas
resulted
in these
areas
being rated
as Category
1.
The Board
deliberated
at length for the functional
area of Safety Assessment/guality
Verification as
a result of instances
where problems
were not aggressively
resolved
but concluded that the licensee's
overall performance
and corrective
actions
outweighed earlier problems.
In rating the functional area of Emergency
Preparedness
as Category 2, the
Board noted that problems
from past
assessment
periods
resurfaced
again,
resulting in five repeat findings during the October
1990 exercise.
Based
on
this and other findings, the Board reached
the Category
2 conclusion.
Likewise, the
number of enforcement
actions in the functional area of Security
did not demonstrate
superior performance.
Security was rated
as Category 2,
Improving, in recognition that the licensee
had reduced
the
number of events
involving improper entry into vital areas
in the latter portion of the
evaluation period.
Maintenance
management
appears
to need to improve the timeliness of dealing
with problems.
In rating the functional area of Maintenance/Surveillance
as
Category 2, the Board discussed
various
problems that were allowed to exist
until the plant was undesirably affected or high level management
involvement
was required to resolve
the problem.
It appeared
that Maintenance
could
improve their interaction with Engineering in an effort to reduce
the time
that problems
remain unresolved.
Overall, the Board
recommends
that problems
need to be aggressively
pursued
in
all functional areas.
This emphasizes
the continuing
need for management
involvement and oversight
when issues first develop.
The performance ratings during the previous
assessment
period
and this
assessment
period according to functional areas
are given below:
Functional
Area
Rating Last
Period
Rating This
Period
A.
B.
C.
D.
E.
F.
G.
Plant Operations
Radiological
Controls
Maintenance/Surveillance
Emergency
Preparedness
Security
Engineering/Technical
Support
Safety Assessment/equality
Verification
II
2 Improving
I
2 Improving
2 Improving
\\
2 Improving
1
2
2
2 Improving
III. PERFORMANCE ANALYSIS
A.
~PP
0
l.
A~nal sis
Evaluation of this area
was primarily based
on the results of 13 routine
inspections
by the resident
inspectors
and the observations
of the operator
licensing staff.
Twenty-nine percent of the total inspection effort was
expended
in this functional area.
The licensee's
strengths
in this area
included relatively event-free operation
and
a knowledgeable
and generally
well-trained staff.
Weaknesses
identified were associated
with untimely
and occasional
reluctance
to involve plant
management
when problems arise.
Licensee
performance
in this functional
area during the previous
SALP period
was rated
as Category I with relatively few events attributed to operational
causes.
Superior performance
on the part of operations
continued throughout
this assessment
period.
Although four Unusual
Events
were declared
during
this period, the causes
wer e not associated
with operations.
Additionally,
operators
managed
the plant well after events,
such
as
when steam
dump valves
failed open following reactor plant trips in December
1990
and April 1991.
Operator actions following plant trips appeared
to be consistently superior.
The licensee
demonstrated
strength in their short term analysis
and review of
operating events.
The licensee's
"event response
plans" continued to provide
a formal identification of plant problems following events.
Additionally,
corporate
management
exhibited
a commitment to the assurance
of quality,
as
demonstrated
when they risked
a record Unit 2 run to reduce
power and repair
a
feedwater control valve oscillation problem.
Additional strengths
observed
in this functional
area
include the conservative
management
of plant conditions during outages,
specifically the minimization
of mid-loop operations,
and the development of equipment control guidelines
for plant equipment not covered
by Technical Specifications.
Also, during
this assessment
period,
an examination of the fire protection
program found
that there
was strong
management
support for the program.
Escalated
enforcement action was taken during the previous
SALP period
regarding the licensee's
failure to take timely corrective actions in response
to repeated
equipment lineup problems.
During this period,
the licensee's
corrective actions
have proven to be effective with only an occasional
lineup
problem: the one exception
was
when
an auxiliary operator disabled
two
residual
heat
removal
pumps
due to not following written instructions.
This
event
was immediately detected
and corrected
by the licensee.
The previous
SALP noted
some inconsistency
in the ability to recognize
and
address
problems in a timely manner.
During the current period,
some
weaknesses
were observed.
Less than
conservative
action resulted
from untimely operability decisions
pertaining to
the vibration and loose parts monitors, the auxiliary feedwater
pump steam
supply stop valve,
and the ventilation supply for the auxiliary feedwater
pump
rooms.
The concerns
regarding the operability determinations
appear to be
a
result of a lack of formality in 'the decision making process.
Another apparent
weakness
observed
during this assessment
period was
a
reluctance
on the part of shift management
to contact plant management
when
addressing
operational
problems.
This reluctance
was not widespread,
but did
occur twice on the backshift.
In one instance,
during
a plant startup,
a high
water level tripped the main,feedwater
.pumps,
The operators
restored
the plant conditions
and continued
the startup without informing
their management
of the occurrence.
In the other instance,
an
RHR pump
tripped while filling the refueling cavity.
The operators
restored
RHR and
. concluded that the event
was not reportable.
After plant management
was
informed of the event the next morning, the event
was classified
as
reportable.
The licensee's
operations training program continues
to be well-defined and
implemented with dedicated
resources.
The overall
pass
rate
on both initial
qualification and requalification
exams
was
100 percent.
While inadequate
training was rarely the cause of an event, operator
performance
during the
October
1990 emergency
preparedness
exercise,
where offsite dose
assessments
were not made in a timely manner,
demonstrated
an isolated training weakness.
Additionally, during an Unusual
Event on May 17,
1991,
a non-licensed
auxiliary operator
performed several activities in the control
room that may
require either
a license or additional training.
This is being evaluated
by
the
NRC.
This occurrence
late in the
SALP period may point to the
need for
increased
operating
crew training and coordination.
The single violation in this functional
area during this assessment
period
concerned
a lack of administrative controls to ensure operability of the
positive displacement
charging
pump.
Five of the
14 Licensee
Event Reports
(LERs) attributed to operations
involved personnel
errors associated
with
either poor communications
or not following procedures.
Three of the
LERs
pertained to equipment failures.
The remaining
LERs did not point to any
single concern.
2.
Performance
Ratin
Performance
Assessment
- Category -
1
3.
Recommendations
Management
should ensure that their operations staff involves
them in complex
decisions
and should increase
the formality and timeliness with which
operability decisions
are made.
Operations staff should involve management
when equipment is not performing properly or is inoperable,
such
as the
vibration and loose parts monitor and the feedwater regulating valves.
Operations
management
should raise
these
issues
to a higher level
when they
persist.
Operating
crew training and coordination should
be assessed
to
ensure
operational
effectiveness.
B.
It di~li
1
C
l.
A~nal sis
Inspections
conducted
during this
SALP, period. found that the. licensee
has
been
proactive in assuring quality and innovative in their approach
to reducing
occupational
dose
and radioactive effluents.
Approximately five percent of
the total inspection effort was devoted to this functional
area
by the
regional
inspectors
during this assessment
period.
The licensee's
performance
in this functional area during the previous
period
was
a Category
1.
The previous
SALP board
recommended
that the
licensee
continue their aggressive
approach
towards
ALARA and improve the
quality of health physics
and work practices
during outages.
Management
has
been consistently
involved in assuring quality.
They
implemented
a positive incentive program which included time off for achieving
ALARA goals.
The 1990 site occupational
dose
was
352 person-rem.
The volume
of solid radioactive waste shipped for disposal
was reduced
to 2935 cubic feet
in 1990,
and liquid and gaseous
effluents were maintained at
a small fraction
of the Technical Specification limits.
These
are substantial
improvements
over previous years'ctivities.
Corporate
involvement
was evidenced
by frequent site visits and thorough
reviews of outage activities.
Decision-making
has
involved appropriate
levels
of management
as noted in the licensee's
response
to leaks in the letdown
piping, containment entries at power,
and
a major upgrade of radiation
monitoring and analytical
support equipment.
Radiation protection
and
chemistry policies were well documented,
goals
were realistically established
and well publicized,
and workers were familiar with management
expectations.
Some minor weaknesses
were identified.
These
involved the number of personnel
contamination events,
the backlog of fixed and portable radiation detection
instruments
needing calibration, maintaining administrative control of keys
providing access
to very high radiation areas,
and training of dosimetry
clerks
and those
personnel
involved in the preparation of radioactive waste
for shipment.
The licensee's
approach to the resolution of technical
issues
was
conservative,
timely, and technically sound.
Examples
included proactive
efforts to minimize corrosion in the steam generators
by removal of ionic
impurities in the steam generator
tube crevices,
testing the use of hydrazine
to further reduce dissolved
oxygen in the condensate
and feedwater
system,
and
the installation of an on-line ion chromatograph
as well as
an on-line sodium
monitor to immediately identify which polisher
beds
have high sodium
and
sulfate content in their effluent.
Another technical
issue involved the
development of methods
to improve the effectiveness
of the liquid radwaste
processing
system
(LRM) to reduce effluent activity. Failure of a
solidification process
to produce
a stable product that met burial site
criteria was thoroughly researched
and the root cause
was identified as
a
manufacturing defect.
Another project taken
on by the licensee
involves
a
comprehensive
program to upgrade
the radiation monitoring system
(RHS).
This
very significant effort is expected
to take approximately
two years to
complete.
The first channel of the
new
RMS is scheduled for installation in
the fall of 1991.
Detailed analysis of each
outage
by the licensee
has
revealed opportunities for additional
dose reductions
and improved goals.
Licensee
management
has
supported training programs for the chemistry
and
radiation protection technicians,
supervisory personnel,
and the technical
staff with state-of-the-art
training facilities and dedicated
resources.
Programs
include training to further develop'the
knowledge
and skills of staff
members
by participating at onsite
and offsite educational
opportunities
such
as:
owners
group meetings,
EPRI conferences,'ow-level
radwaste
user group meetings,
and periodic rotational
assignments
of the
radiation protection technician staff at other nuclear facilities.
Examples
also include
a five week supervisory
development
course for foremen
and
supervisory
personnel
and participation of the training staff in outage
activities
as
a means of determining
areas
that can
be improved in the
training program.
The licensee
has initiated training for their staff on the
new
10 CFR Part 20 requirements.
The licensee
has well staffed site
and corporate
chemistry
and radiological
protection groups.
Staffing includes
an active
and experienced
chemistry
and
radiation protection
ALARA work planning group.
,Authorities and
responsibilities
were defined
by management
and understood
by the staff.
Key
positions were generally filled on
a priority basis.
All site departments
communicate effectively with the health physics
and chemistry organizations.
One Severity Level IV violation and six Licensee
Event Reports
(LERs) were
identified in this functional
area during the assessment
period.
The
violation concerned
a failure to perform leak checks of two licensed
sources.
Neither the violation nor the
LERs indicated
a programmatic
breakdown of the
radiation protection
program.
The licensee's
root cause
and corrective
actions
were prompt and effectively implemented
as evidenced
by lack of
repeated
events.
2.
Performance
Ratin
Performance
Assessment
- Category -
1
3.
Board Recommendations
Management
should continue to provide their full support to site and corporate
staff initiatives to maintain
and improve the present
performance level.
Some
- additional
emphasis
seems
appropriate
towards correcting
minor weaknesses
in
controlling personnel
contamination,
reducing the backlog of non-Technical
Specification radiation monitoring equipment
needing calibration,
and training
of dosimetry clerks
and radioactive waste handlers.
C.
Maintenance/Surveillance
l.
A~ns1
s is
The maintenance
and surveillance functional area
was observed routinely during
the assessment
period
by resident
and regional
inspection personnel.
. Twenty-
one percent of the inspection
resources
were devoted to this functional area.
Licensee
performance
in the maintenance
and surveillance functional area
during the previous
SALP period
was rated
as Category 2, Improving.
The
previous
SALP recognized
licensee
advancements
in proceduralization,
control
of backlog,
and effective outage
management.
The previous
SALP also noted
that the licensee
was slow to address
some concerns,
including plant material
condition,
such
as the intake structure.
The previous
SALP recommendations
to
licensee
management
included
a need for stronger
management
oversight.
The
major issues
of the previous
SALP included the use of excessive
overtime
without management
awareness
and improper maintenance
of the .containment
and the auxiliary feedwater
pump trip valve.
The maintenance
and surveillance
area during this
SALP period
has
been
slow to
show consistent
improvement.
This conclusion is based largely on examples
of a lack of management
aggressiveness
in the resolution of problems
and
examples
of a lack of maintenance
management
oversight.
The most notable
indication of lack of oversight
was the failure to resolve long-standing
mechanical
maintenance
measuring
and test equipment
problems.
These
problems
were the subject of several
licensee
audits
and surveillances.
Subsequently,
the
NRC made this area
the subject of three special
inspection reports,
including an enforcement
conference.
The end result of this problem was that
the licensee
decided to close their mechanical
maintenance
measuring
and test
equipment
shop
and assign
these duties to the instrument
and control shop.
A
second
example dating back to the previous
SALP was water intrusion and
component corrosion in the intake structure.
Conditions in the intake
have
continued to worsen
and
now include concrete spalling, reinforcing bar
co'rrosion,
and component corrosion wastage.
Management of maintenance
and surveillances
to minimize equipment out-of-
service
times
has
been
improving.
Several
errors
were
made in taking
equipment out of service,
but were identified by the licensee.
Likewise,
outage
management
has generally
been superior
and
has minimized mid-loop
operations
while maximizing the availability of electrical
power supplies.
Management
assurance
of quality has generally
been
shown to be acceptable
in
attributes
such
as prior planning,
assignment of priorities,
and procedures
for the control of activities.
These policies are adequately
stated
and
generally understood
but not always practiced.
For example,
maintenance
personnel
signed off work steps
before they were performed during the
installation of an auxiliary feedwater
pump governor, maintenance
personnel
failed to follow administrative
procedures
by not identifying spring pack
relaxation of important motor operated
valves,
and
a fire pump was repeatedly
misassembled.
Decision-making
appeases
to
be. done at
a level which ensures
management
review, but that review is sometimes
non-conservative.
A March 7,
1991, loss of offsite power event
was
caused
by maintenance
personnel
using
a
crane in close proximity to high voltage energized electrical lines despite
the licensee's
specific review of a similar event at the Vogtle power plant.
Other examples of a lack of conservatism
and inquisitive attitudes
were
shown
by followup after the December
24,
1990, reactor trip and safety injection in
which
a pressurizer
spray valve failed open
due to
a missing locking device,
and
a steam
dump valve failed open
due to
a broken stem.
Licensee
maintenance
management
did not thoroughly investigate
the steam
dump valve problem prior
to restarting.
Subseouently,
during
a plant trip, on Nay 17,
1991,
another
steam
dump valve failure caused
a safety injection and excessive
reactor
cooldown.
After this event adequate
attention
was given to resolve
problems
with the steam
dump valves.
Staffing in maintenance
appears
to be adequate
although work hour
changes for maintenance staff have left Mondays
and Fridays
more lightly
staffed.
Training and qualification in the maintenance
area
appear
to be well
defined
and implemented.
Licensee
audits
have identified, however, that
untrained
and uncertified personnel
have
sometimes
been utilized due to
a lack
of discipline by supervisory maintenance
personnel
in assigning
work.
In
'January
1991, Instrumentation
and Controls
(18C) personnel
removed the wrong
Unit's power range nuclear instrument
due to not following self-verification
policy.
In Nay 1991, the wrong power range instrument
was
removed again,
resulting in a reactor trip.
These
examples
show that although the licensee
has
adequate
training, procedures,
and policies in the maintenance
area,
they
have not been consistently followed by working and middle level management
personnel.
Naintenance
management
does
not appear to have
emphasized
these
issues sufficiently.
During the
SALP period,
the licensee
has
improved visibility in some
pump
rooms through painting the
rooms white.
In general,
the licensee
has
instituted
an energetic
painting program which is an important element in
maintaining plant material condition.
In response
to industry and
NRC
initiatives, the licensee
has started
to trend important safety equipment
out-of-service
times
and
has started
to consider
programs for utilizing
to perform risk evaluations
of preventive
maintenance activities.
Additionally, a predictive maintenance
group has
been
formed,
and the licensee
is moving towards
a reliability centered
maintenance
program.
The licensee's
surveillance test
program
has generally
been adequately
conducted.
Procurement
control
and storage of components
has
been
examined
and found to be well controlled
and executed.
Likewise inservice. inspection
and testing
have
been
examined
and found to be generally well performed.
One area that requires
improvement is
a reduction in the backlog of radiation
detecting
instruments
that require calibration.
The backlog appears
to have
developed
as
a result of ISC not fully supporting
the health physics
organization.
There were nine Level IV violations
and
16 Licensee
Event Reports
(LERs)
associated
with this area.
Fifteen of the
LERs were. attributed to personnel
error and point out,
as previously discussed,
that training, procedures,
and
policies are not always consistently followed.
Performance
Assessment
- Category - 2
3.
Recommendations
Nanagement
should provide more timely attention to preventing
and correcting
degradation of the plant material condition.
The licensee
should ensure that
maintenance
management
develops
an inquisitive attitude
toward plant hardware
anomalies
such that root causes
of hardware
problems
are identified and
resolved.
The timeliness of dealing with problem areas
should
be improved.
The licensee
is encouraged
to continue to develop their initiatives regarding
preventive maintenance
risk assessment,
predictive maintenance,
and outage
'anagement
strategies.
0. ~EP
d
l.
An~al sis
The licensee's
performance
in this functional area during the previous
period
was rated
as Category
1.
The previous
SALP Board
recommended
that
problems related to emergency
preparedness
(EP)
be corrected in a more timely
manner,
and that licensee
management
take the necessary
steps
to strengthen
the engineering
support in the Technical
Support Center
(TSC)
and
Emergency
Operations Facility (EOF).
During the current
SALP period,
weaknesses
were
identified in the effectiveness
of the licensee's
EP corrective action
program,
the control of the drill program,
and the effectiveness
of the
training program
as demonstrated
by performance
during drills and exercises.
The licensee's
actions to address
NRC concerns
about on-shift dose
assessment
capabilities
and their initial actions to address
recurring inspection
findings was considered
to be
a strength.
The licensee's
EP program
was
observed
by both the regional
and resident
inspectors
during three routine
inspections,
an annual
emergency exercise,
and several
operational
events.
Approximately five percent of the total inspection effort was devoted
to this
functional area.
Inspections
conducted
during this
SALP period identified weaknesses
in
licensee
management's
oversight
and control of the implementation of the
corrective action program,
and the drill and exercise portion of the
training program.
Many of these
weaknesses
were reflected in the licensee's
declining performance
during the October
1990 annual
exercise.
During the
1990 exercise, five issues
were identified as repeat findings from prior years
( 1987-1989).
These
issues
involved:
1) the coordination of protective action
recommendations
at the
EOF, 2) the failure to establish
measures
to control
contamination within the TSC, 3) the ability of the
TSC engineering staff to
support the Control
Room (CR), 4) the identification of inconsistencies
in
General
Emergency 'class
requirements
in procedures
used to classify emergency
events,
and 5) the potential missile hazard associated
with storage of
unsecured
iodine monitors in the
TSC ventilation room.
The repeat findings
demonstrated
that the licensee
did not have
a corrective action program fully
effective in preventing the recurrence
of issues
identified during drills,
exercises,
and
NRC inspections.
Once the repeat findings were identified by
the
NRC at the conclusion of the
1990 annual
exercise,
the licensee initiated
a nonconformance
report
(NCR) to track the resolution of the matter.
The
licensee's
actions
in response
to the
NCR appeared
thorough;
however,
the
effectiveness
of the licensee's
corrective actions
could not be determined
since they were initiated toward the end of the
SALP period.
Additional
findings from the
1990 exercise that indicated
a decline in performance
are
discussed
in subsequent
paragraphs.
The inspections
also
showed that the licensee
did not have sufficient
procedural
controls to govern the implementation of its drill program.
As
a
result,
some drills did not fully meet the scope of the emergency
plan
requirements.
For example, radiological
(environmental) monitoring drills
were conducted,
but environmental
samples
were not collected.
Air samples
were simulated during
some inplant health physics drills and post accident
sampling system drills were conducted,
but samples
were not analyzed.
As described
above,
one exception involving the effectiveness
of the
licensee's
EP corrective action program
was identified.. The licensee's
10
approach
to the resolution of technical
issues
from a safety standpoint
was
generally sound,
thorough,
and timely.
Based
on the CR's inability to
demonstrate
that offsite dose calculations
could be completed in a timely
manner to support
emergency classification during the
1990 annual
exercise,
the licensee
immediately initiated dose calculation training for onshift
CR
staff members
and incorporated
dose calculations
into recurring operator
training.
The licensee
implemented its emergency
plan
on several
occasions
during this
SALP period.
All of the events
were correctly classified
as
Unusual
Events.
The most notable
example occurred
as
a result of the March 7, 1991, loss of
offsite power during Unit 1's refueling outage.
In general, all of the events
were classified in a timely manner;
however,
the timeliness of the March 7,
1991,
Unusual
Event declaration
was slow.
Notifications to local offsite
authorities
were
made in
a timely manner.
Staffing for the
EP program appeared
sufficient during this
SALP period.
Due
to rotational
assignments
and
a reorganization,
several
changes
have occurred
in EP's
management
reporting chain at the site during the current
SALP period.
The licensee
has established
a new,
permanent position to provide management
oversight for EP, safety,
and health.
The management
position above
and the
position below the newly established
permanent position are considered
to be
rotational
assignments.
During this
SALP period, the individuals in these
two
positions
were changed
due to
a shift in rotational
assignments.
Both of the
new individuals have strong
EP backgrounds
which should benefit the management
of the
EP program.
Establishing
the permanent position was viewed
as
a
positive step to maintain stability.
The effectiveness
and continuity of the
management
could not be fully determined
because
two of the position changes
occurred
toward the end of the
SALP period.
Organizational
changes
to the
emergency
response staff (engineering
support) at the
EOF were made
as
a
result of NRC concerns
identified during the
1989 exercise.
Several
weaknesses
in the effectiveness
of the licensee's
EP training program
were identified during this
SALP period.
The most significant example
was the
inability of the
CR staff to complete
dose calculations
in a timely manner to
support accident classification during the
1990 emergency
exercise.
Although
the licensee
took prompt corrective action,
as previously described,
the
problems experienced
during the exercise
indicated that the previous level of
training/practice
was not adequate
to accomplish
the assigned
responsibilities.
The weakness
in the level of training/practice
was also evident during the
1990 exercise
as indicated
by the findings discussed
earlier
and the
observation that personnel
from the Operations
Support
Center
(OSC) did not
fully adhere
to radiation protection
procedures
during simulated
emergencies.
Toward the end of the
SALP period,
the licensee initiated steps
to improve its
EP training program.
More drills were scheduled
and drill/exercise findings
will be incorporated into the training.
The effectiveness
of these
actions
could not be determined
since they were initiated toward the end of the
period+
An in-office inspection
was conducted to evaluate
changes
to the licensee's
emergency classification
procedure
and the emergency action levels
(EALs)
t
contained therein.
A change
to the Diablo Canyon emergency
plan was also
reviewed during this appraisal
period.
The changes
to the emergency
plan
and
EALs were acceptable
and continued to meet
NRC requirements.
No cited
violations or Licensee
Event Reports
wer e identified in this functional
area
during this appraisal
period.
2.
Performance
Rating
Performance
Assessment
- Category -
2
3.
Board Recommendations
Licensee
management
should ensure that
an effective corrective action plan for
drill and exercise
findings is established
and carried out.
Licensee
management
should evaluate
the adequacy of classroom training provided to
emergency
response
personnel
and ensure that personnel
are given an adequate
number of opportunities to practice their assigned
tasks
during periodic
drills.
The additional
dose
assessment
training provided to
CR personnel
should continue.
The need to adhere
to radiation protection procedures
under
simulated
emergency
conditions
should also
be stressed
during classroom
training and during drill conduct.
Administrative procedures
should
be
enhanced
to ensure that drills and exercises
consistently
meet emergency
plan
requirements.
Simulating sample collection during drills and exercises
should
be avoided to enhance
realism
and increase
the training value.
E.
S~ecucit
l.
A~nal sls
During this assessment
period,
Region
V conducted
three physical security
inspections
which comprised
approximately four percent of the total inspection
effort.
In addition,
Region
V conducted
one enforcement
conference
pertaining
to an escalated
enforcement action.
Further, the resident
inspectors
provided
continuing observations
in this area.
The previous
SALP report rated the licensee
as Category 2, Improving, and
recommended
that licensee
management
resolve
the identified weakness
with the
closed circuit television
(CCTY) alarm assessment
capability, plus finalize
measures
to correct identified inadequacies
with portions of vital area
barriers.
As discussed
below, these
issues
are scheduled for completion, or
have
been completed.
During this
SALP period,
the licensee's
weaknesses
pertained to an escalated
enforcement action that primarily focused
on
personnel
access
control to vital areas,
plus additional
enforcement
actions
involving failed compensatory
security measures.
The 'strengths
identified
this
SALP period included the licensee's
construction of a
new Central
Alarm
Station,
and their improvements
related to strengthening
the readiness
posture
of the security contingency
response
force.
The previous
SALP report encouraged
the licensee
to resolve the identified
weakness
in CCTV alarm assessment
capability, involving the manner in which
the integrated security systems
(barrier, perimeter
alarms
and
CCTV cameras)
are used.
To resolve this weakness,
the licensee
has
scheduled
installation
. of a video-capture
system
by September
1991.
This
new system,
in conjunction
with the
CCTV cameras
and security alarms,
should provide the capability for
12
instant assessment
of the cause for perimeter alarms.
The previous
report also encouraged
the licensee
to finalize measures
to correct identified
inadequacies
with portions of vital area barriers at the Units'
and
2 pipe
galleries.
This action
has
been completed.
'The licensee's
approach
to the
resolution of these
two technical
issues
has
been
sound,
and thorough.
With regard to management's
involvement in assuring. quality, corporate
and
plant management
continued to review the operation of the overall security
program.
They have
implemented generally
sound
and thorough remedial
measures
to correct deficiencies
and weaknesses
identified in the course of both
internal
and
NRC security inspections.
During this
SALP period,
the licensee
reported
seven incidents in which
unauthorized
employees
had gained
access
to plant vital areas.
In most of
these
instances,
the unauthorized
employee
had
been previously authorized
access
only to the protected
area,
and
had entered
the vital area
based
upon
the card-key authority of another
employee.
The.licensee's
corrective actions
have
emphasized
to plant employees
the importance of following required
procedures
when seeking
access
to vital areas,
thus the frequency of these
incidents
have
been
reduced
by approximately
80 percent.
Additionally, multiple incidents of failed compensatory
measures
were
identified by the licensee
during this
SALP period.
In each instance,
an
officer had
been
assigned
the required duty of monitoring
a degraded
piece of
security equipment,
and for one of several
reasons,
the equipment
was not
properly monitored.
In two instances,
the compensatory officer was discovered
and in other instances,
the compensatory officer had either
been
provided inadequate
instructions
by his supervisor,
or had
been involved in
a
miscommunication with other members of the security force.
The majority of
these
incidents involving failed compensatory
measures
occurred during the
second half of the
SALP period,
and the overall effectiveness
of the
licensee's
corrective actions
have not been evaluated
by the
NRC.
During this period, the licensee's
overall security program
has
been
enhanced
in several
areas.
A newly constructed
Central
Alarm Station provides
an
improved "nerve center" for security operations.
The licensee's
responsiveness
to the design basis threat
has
been
increased
- through implementation of defensive
choke-point positions,
prepositioning of
response
equipment to expanded
locations
throughout the plant,
and improved
weaponry
and uniforms for members of the security force.
Additionally, the
licensee effectively upgraded
the capability of their security emergency
power
supply.
The enforcement history for this period includes
issuance
of one Level-III
violation, four Level-IV violations,
and ten non-cited violations.
The
Level-III violation, plus
one Level-IV violation focused primarily upon the
entry of unauthorized
employees
into plant vital areas.
Two of the Level-IV
violations, plus three of the non-cited violations pertained
to situations of
failed compensatory
security measures.
A separate
portion of the aggregate
Level-III violation, plus
one non-cited violation pertained to situations
involving the licensee's
failure to properly protect safeguards
information.
In response
to these
enforcement actions,
the licensee's
corrective actions
have
been thorough
and generally effective.
t~
13
During the
SALP period,
each of the licensee's
fourteen
safeguards
events
were
reported
in the Licensee
Event Report
(LER) format.
These
events
related to:
failed compensatory
measures(5);
problems
encountered
with the security
power
system(3);
and miscellaneous
events(6).
Nine (64K) of these
safeguards
events
were caused
by personnel
errors
and were attributed to causes
under the
licensee's
control.
The five LERs pertaining to failed compensatory
measures
were caused
by: inadequate
compensatory
instructions to security officers,
miscommunication
between security personnel,
and inattentive security
officers.
During the previous
SALP period, the greatest
number of LERs pertained
to
degraded
operation of the alarm stations,
and Region
V determined that the
alarm station operators
had
been rarely observed
during the performance of
duty by their supervisors.
To correct this situation,
the licensee
required
each shift supervisor to visit both alarm stations
once per shift.
This
appears
to have
improved the overall operation of the alarm stations.
Key positions
and responsibilities
within the Security
Department
were well
defined.
The licensee's
security training program supported
the overall
increased
readiness
posture of the security for ce.
The licensee's
Fitness-For-Duty
(FFD) program appears
to meet the requirements
of 10 CFR Part 26.
Though not formally inspected
during this
SALP period,
reviews of required
FFD reports plus informal reviews of FFD staff and
facilities indicate that the
FFD program is comprehensive
and well understood
by the general site population.
Performance
Assessment
- Category - 2, Improving
3.
Board Recommendations
Licensee security
management
should reduce the
number of situations
involving
failed compensatory
security measures.
Licensee
management
should emphasize
adherence
to site security procedures
in order to reduce
the types of
enforcement
actions
and reportable
events identified during this
SALP period,
or licensee
management
should
implement other. techniques for positive control
over door entries.
F.
~En lnee~rln /Technical~Su
nrt
l.
A~nal sis
This functional
area
was examined
by regional
and resident
inspectors
and was
also
examined
by
NRC headquarters
evaluators.
Approximately 18 percent of the
inspection resources
were used in evaluating this functional area.
The previous
SALP rated licensee
performance
in this functional area
as
Category 2, Improving. The licensee
was encouraged
to place
emphasis
on the
system engineering
and configuration management
programs
and to focus
on the
formal resolution of plant problems.
The licensee
was also encouraged
to be
self-critical, to promote early identification of problems,
and to establish
aggressive
schedules
for corrective actions.
The licensee
received
a specific
14
board
recommendation
to aggressively
assess
the issue of plant material
condition.
Generally, during this
SALP assessment
period, engineering/technical
support
at Diablo Canyon
has
been very good in, the areas
where attention
has
been
focused.
Engineering
involvement at the site
has noticeably increased
and
has generally
had
a positive effect on operations
and the quality of
modification work.
In addition, licensee
management
involvement
shows
consistent
evidence of prior planning
and assignment
of priorities.
Host
engineering evaluations
have
been
found to be technically adequate.
The licensee's
design basis
reviews
were productive in identifying problems in
the original construction.
The licensee
has
been for thright in addressing
these
problems
as
nonconformances
and dealing with them appropriately.
One
design
problem that was quickly resolved
involved
a 'seismic
concern
regarding
water that had not been drained
from containment
spray piping.
Plant
and
corporate
personnel
worked closely together to resolve the problem.
Likewise,
corporate engineering's
setpoint reverification program was productive in
identifying problems with electrical
thermal
overload design margins
throughout the plant.
Corporate engineering
established
a proactive
program with Westinghouse
to
maintain up-to-date
communications with Westinghouse's
study of potential
generic issues.
This program enabled
PGKE to respond to Westinghouse
Part
21
reports very quickly.
In addition there were cases
wher e corporate
engineering interest
and involvement in long-standing plant problems resulted
in comprehensive
action
and correction of problems.
Such
was the case in the
investigation of breaking
steam
dump valves
and in the case of determining
why
the steam admission valve to the auxiliary feedwater
pump was sticking closed.
Currently, the quality of engineering
work on masonry walls is good.
Towards the end of the assessment
period,
an electrical distribution system
functional inspection
(EDSFI) was conducted.
The inspection,
conducted
by
NRC
regional
and headquarters
staff members,
found the engineering
technical
performance
to be generally very good.
In particular,
the team found that the
licensee
had implemented
a number of proactive measures
to address
problems at
Diablo Canyon
based
on their own review of EDSFI findings at other facilities.
Also, the team noted that Diablo Canyon
had
implemented
an aggressive
vendor
interface
program to maintain up-to-date
information on equipment installed at
the plant.
The primary engineering
weaknesses
noted
by the team involved
several
instances
of incomplete technical
work and
a weak sense of ownership
of some plant problems.
This latter concern
appeared
to manifest itself in
the form of a lack of timely identification and resolution of some problems.
Engineering
personnel
were found to be well qualified in a January
1990
team
inspection of the corrective action program.
The staffing levels,
both at the
site
and in the corporate office are very good.
The licensee is currently
developing
comprehensive
training initiatives including
a job task analysis
for engineers.
Despite the previous observations,
improvements
can still be made in the
thoroughness
of engineering activities.
One example involves
a design
change
to remove the boron injection tank in Unit 2.
The planned
design
change
was
aborted
when licensee
gA audits
found that additional
equipment qualification
was required.
Likewise, engineering
exhibited other examples
where work could
g~
15
have
been
more thorough
such
as providing improper blowdown settings for Unit
2 relief valves, utilizing the wrong unit steam
dump data for justification of
a technical specification
change,
and providing inaccurate wiring schematics
for a diesel
generator
droop relay design
change.
Some examples
where
engineering
personnel
did not always promptly. assess
si.te occurrences
were
observed.
Equipment
problems like motor operated
valve spring pack
relaxation, out-of-service
hardware,
and frequent alarms
on the reactor
vibration and loose parts monitor received little attention
by responsible
plant engineering
personnel.
Additionally, about
50 minor deviations
to the
licensing basis for fire protection
have not been fully resolved.
The results of a Vendor Branch assessment
of PGSE's
procurement
practices
indicated that
PGSE
had
made
a significant effort to upgrade its
commercial-grade
program since its inception in July 1986,
and that
their program description
was generally consistent with the dedication
philosophy described
by the Electric Power Research
Institute (EPRI).
PGSE's
engineering
and technical
support related to commercial-grade
was
seen
as
a strength
by the assessment
team.
Personnel
related to the program
were found to be knowledgeable
and
aware of current issues
and concerns.
PGSE's
involvement in industry groups
has benefited
both the engineering staff
and the overall commercial-grade
program.
Especially noteworthy
was the fact that
PGSE's
commercial-grade
program
was initiated
16
months prior to the initiative commitment date of January
1, 1990.
One
negative
aspect of the procurement
and dedication
program was that
a licensee
internal audit found that communication
and interaction
between site
and
corporate
personnel
appeared
to be lacking.
During the
SALP period,
the
NRR staff was involved in a number of in-depth
reviews pertaining to engineering activities.
Principal
among these
was the
staff's review of the Long Term Seismic
Program
(LTSP).
The material
presented
demonstrated
thorough
and comprehensive
engineering analysis.
Overall, the staff found that the geological, seismological,
and geophysical
investigations
and analyses
conducted
by the licensee
for the
LTSP were the
most thorough
and complete ever conducted for a nuclear facility in this
country and have
advanced
the state of knowledge.
As part of the
LTSP, the
licensee
developed
a comprehensive,
Level
1
PRA model for the plant which
includes external
accident initiating events
such
as fires and earthquakes,
as
well as internal
events
such
as
The engineering staff expects
to use
the
PRA as
a tool to assist
the maintenance,
operations,
and planning
organizations
in scheduling
outages
and preventive maintenance activities.
The violations
and Licensee
Event Reports
associated
with this functional
area
did not point to any single concern.
2.
Performance
Ratin
Performance
Assessment
- Category -
1
3.
Board Recommendation
The licensee
should provide additional
emphasis
in early identification,
effective engineering
involvement,
and timely correction of plant problems.
The licensee
should continue to build a strong interface
between corporate
and
plant engineering
and consider continued
involvement of corporate
engineering
16
in a leadership
role in plant problem resolution.
The licensee is encouraged
to continue to develop their innovative corporate
engineering
training
program.
/. l~/A
/IL 1/
/
l.
Analysis
Evaluation of this functional
area
was
based
on regional
and resident
based
inspections.
Eighteen
percent of the
NRC's inspection effort at Diablo Canyon
was
used in this functional area.
During the previous
SALP period, this functional area
was rated
as Category 2,
Improving.
Licensee
strengths
in performance
based Quality Assurance
(QA)
inspections
were recognized.
The Board recommendations
encouraged
the
licensee
to maintain emphasis
on performance
based
audits
and to increase
emphasis
on the identification of problems.
The general
conduct of QA audits continued to be performance
based
and
effective.
When necessary,
expert technical
personnel
were called in to
augment
the audit team.
In addition, the licensee
formulated
a group called
the Nuclear Excellence
Team
(NET) to evaluate
problem areas
as requested
by
senior management.
One product of the
NET was
a meaningful
examination of
fire protection
program implementation.
The licensee
has also demonstrated
committed involvement and leadership
in the area of industry initiatives.
During the
SALP period the licensee
reorganized
the
QA organization.
The
organization
now reports directly to the Senior Vice President
and General
Manager for the Nuclear
Power Generation
Business
Unit instead of the
corporate President.
No adverse effects
from the
QA reorganization
were noted
during the reporting period.
Near the middle of the
SALP period, the Senior Vice President
required that
an
event investigation
team (EIT) be conducted
to address
NRC concerns
related to
the timeliness
and ownership of actions following an auxilary feedwater
pump
event
and
a weld crack in the positive displacement
charging
pump
piping.
The EIT concluded that the untimely problem resolution
was caused
by
(1)
a lack of problem ownership
and (2)
a lack of requirements
for the allowed
time to initiate a nonconformance
report.
The licensee
implemented
organization
and procedural
changes
as
a result of the EIT.
These actions
appeared
to provide
some
improvement in the assignment
of responsibility for
multi-department
problems.
The licensee
also
began to monitor the time limits
for nonconformance
decisions.
The decision level for nonconformance
resolution
was also elevated
to the plant manager
when necessary.
It was observed
during the first part of the assessment
period that
organizations
such
as Quality Assurance,
Quality Control,
(QC) and the Onsite
Safety
Review Group performed little critical assessment
of Operations.
Problems identified by the
NRC through the review of control
room logs
had
been overlooked.
In response
to this assessment,
Quality Control
began to
perform critical reviews of control
room logs with some positive results.
In
the area of Radiological Controls,
the licensee
'developed
a program to perform
thorough reviews of radiological protection using peer experts.
J
17
As discussed
in the maintenance
area of this
SALP report, in one significant
case
when
a problem area
was recognized
by oversight groups their actions to
pursue
and resolve the problem was not sufficiently aggressive.
Such
was
the case
when inadequate
control of measuring
and test equipment
had
been
identified by both
QC and
QA but had not been resolved,
even
though the
problem
had
been elevated
to upper management.
In some instances,
the licensee's
organizations
were slow to understand
and
solve repetitive
component failures
and problems.
For example,
steam
dump
valves
have
had internal failures since
May 1990
and were not systematically
addressed
unti 1
May 1991.
Likewise, letdown welds
have
been cracking in Unit
l2 since June of 1989
and the root cause
was not aggressively
pursued
and
resolved until 1991.
Finally, the repetitive
NRC findings from Emergency
Preparedness
exercises
also indicate the
need to aggressively
correct
problems
before they recur .
Once the licensee's
attention
was focused
on these
problems, resolution
appeared
thorough
and timely.
Licensee staffing in the quality oversight groups
appears
good.
It was noted
that the licensee utilizes outside expertise
when determined
to be necessary
and
has
extended this policy to include
a non-PGSE expert
member
on its
General Office Nuclear Plant Review and Audit Committee
(GONPRAC).
During this assessment
period, it was observed that when the Vice President,
Diablo Canyon Operations
and Plant Manager
was
away from the site,
a
department
head
was designated
to act as the Plant Manager.
The effect of
this was that department
heads,
with their specific areas
of responsibility,
may not have the broad
scope perspective
necessary
when designated
as acting
plant manager.
An example of this situation
was the Maintenance
Manager'
decision to restart
from the pressurizer
spray valve event
(on December
24,
1990) without fully investigating the problem.
During the
SALP period the
NRR staff reviewed
a large
number of safety
analyses
performed
by the licensee.
The licensee
replies to generic letters
and bulletins were timely, responsive,
and of generally high quality.
The
submittals for licensee
.amendment
requests
were technically adequate
and
generally complete.
The most significant violation attributed to this functional area pertained
to
the control of mechanical
maintenance
measuring
and test equipment.
The
Licensee
Event Reports in this area
did not point to any significant concern.
2.
Performance
Ratin
Performance
Assessment
- Category -
1
3.
Board Recommendations
The licensee
should promptly deal with emerging technical
issues
to prevent
them from affecting the plant as
was the case with steam
dump valve failures
and cracking of charging piping.
Management
should involve themselves
in
timely resolution of outstanding
issues
to prevent the slow action that
occurred in addressing
concerns with measuring
and test equipment.
Increased
attention
should
be focused
on repeat
problems.
~ '
18
IV.
SUPPORTING
DATA AND SUMMARIES
A.
LICENSEE ACTIVITIES
UNIT
1
Diablo Canyon Unit
1 was at
100'X power at the start-of this reporting period.
On February 6,
1990,
an Unusual
Event was declared
when
a moderate
seismic
event
was detected,
but an inspection of both units indicated
no
abnormalities.
On February 20, 1990, Unit
1 was manually tripped due to a loss of flow from
both main feedwater
pumps.
Two logic cards
from the
SSPS
were tested
and
replaced.
The cause of this event
was unknown.
Unit 1 was returned to
100%
power on February
22,
1990.
On June
14,
1990, Unit
1 tripped
on
a
Power
Range Nuclear Instrument high
positive rate trip signal
due to an increase
pump speed
caused
by a loss of load.
Unit
1 entered
Mode
1 on June
19,
1990.
On July 26, 1990,
the
NRC Senior Resident identified
a through wall crack
on
a
four-inch diameter piping elbow, upstream of the suction stabilizer for the
positive displacement
charging
pump.
The licensee
calculated that as
a result
of the crack, control
room radiation
doses
could have exceeded
the
10 CFR Part 50 requirements for control
room habitability in the event of a
LOCA.
Compensatory
measures
were taken to allow continued operation,
and: a weld
repair of the crack
was performed
on August 1, 1990.
On December 5, 1990,
a reactor trip followed
a turbine trip.
The turbine
tripped after
a runback did not reduce generator
load below
a required limit.
The licensee
discovered
that the
r unback limit setpoint
was improperly set.
The runback
was caused
by a stuck low flow switch for the main generator
stator cooling water system.
After repairs,
Unit
1 returned
to
lOOX power
on
December 9, 1990.
On December
24,
1990,
an Unusual
Event was declared after
a reactor trip and
safety injection occurred
due to low pressurizer
pressure,
caused
by the
~ failure of a pressurizer
spray valve.
Following the reactor trip, the
Technical Specification
maximum cooldown rate of 100'
in one hour was
exceeded.
The pressurizer
spray valve failed open
due to the feedback
linkage
becoming disconnected
because
of a missing elastic stop nut.
Failure of a
steam
dump valve also contributed to the overcooling.
Following repairs,
Unit
1 returned to power operation
on December
28,
1990.
On January
18,
1991, Unit
1 commenced its
End of Life (EOL) coastdown for the
fourth refueling outage
(IR4).
On February
1, 1991, the reactor tripped
due to steam generator
low level
coincident with steam flow/feedwater flow mismatch after the feedwater
regulating valves to two steam generators
closed.
This occurred
when
instrument air was accidentally isolated during scaffolding erection.
On
February 2, 1991, it entered
Mode 5.
On February 6, 1991, Unit
1 entered
Mode
6 and fuel unloading
commenced.
On February
10,
1991, fuel unloading
was
f
19
completed,
and
on March 6,
1991, Unit
1 re-entered
Node
6 and
commenced
refuel ing.
On March 7, 1991,
a loss of offsite power to Unit 1 occurred
when
a mobile
crane
approached
too closely to the
500
kV power lines,. causing
an arc to
ground.
Following the loss of offsite power, the emergency
diesel
generators
started
and loaded to the vital buses.
Offsite power was restored five hours
later.
An Unusual
Event was declared
as
a result of the loss of offsite
power,
and
an
NRC Augmented Inspection
Team (AIT) investigated
the event.
Also on March 7, 1991,
the fuel reloading
was completed;
and the reactor
entered
Mode
5 (cold shutdown)
on March 12,
1991.
On March 27,
1991, Unit 1 entered
Mode 4, and
Mode
3 was entered
on Yiarch 29,
1991.
Unit 1 entered
Mode
2 on April 2, 1991,
and
on April 4, 1991, entered
Node 1.
On April 23,
1991,
a reactor trip resulted
from a high steam generator level.
The level transient
was caused
by
a loss of the main feedwater
pump 1-1 due to
a speed controller fai lure.
Operator action
was required to mitigate
an
unanticipated
primary cooldown due to
a failed open main condenser
steam
dump
valve.
On April 24, 1991, during
a reactor startup,
a manual reactor trip was
initiated following a rod control urgent alarm.
The alarm was
due to
a failed
fuse in the rod control
power supply.
On April 25, 1991, Unit 1 re-entered
Node l.
On May 17,
1991,
a reactor trip occurred after an
18C technician inadvertently
deenergized
a second
power range instrument while performing
a surveillance
test
on
a different instrument.
Subsequent
to the trip, two main condenser
steam
dump valves failed open, resulting in low pressurizer
pressure
and
a
safety injection.
Additionally, the Technical Specification
maximum cooldown
rate of 100
F in one hour was exceeded.
An Unusual
Event was declared
as
a
result of initiating safety injection.
The unit returned
to 100K power on May
21,
1991,
and remained at power through the end of this assessment
period.
Unit 2
Diablo Canyon Unit 2 was at
100K power at the start of this reporting period,
and remained in Node
1 until March 3, 1990,
when it commenced
a ramp down in
power in preparation for the third refueling outage.
On March 9, 1990, Unit 2 entered
Node 6,
and completed fuel off-loading on
March 14,
1990.
On March 26,
1990, Unit 2 re-entered
Yiode 6 and completed
fuel reloading
on March 31,
1990.
On April 4, 1990, Unit 2 entered
Mode 5,
and on April 22,
1990,
Mode 4 was entered.
Unit 2 entered
Mode
3 on April 23,
Node
2 on April 28,
1990,
and
on April 30,
1990, returned
to power operation.
Unit 2 remained at power through the end of the assessment
period,
a record
run of greater
than
400 days at power.
~,
20
B.
Ins ection Activities
Fifty-two routine
and special
inspections
were conducted
during this
assessment
period (January
1,
1990,
through June
30, 1991). Significant
inspections
are listed in Section IV.B.2.
1. ~l<<i
D
Facility Name: Diablo Canyon Units
1
& 2, Docket numbers:
50-275
& 50-323,
Inspection Reports:
89-33, 89-34,
90-01 through 90-09,
90-11 through 90-32,
91-01 through 91-14,
91-16 through 91-18,
91-21
and 91-23.
Five of these
reports
summarized
management
meetings,
two reports
documented
enforcement
conferences,
and
one documented
a meeting about the guality Assurance
program.
2.
S ecia1
Ins ection~Sumnar
a.
From January
1 through February 2, 1990,
a special
inspection
was
conducted
to assess
the effectiveness
of the licensee's
corrective action
program.
( Inspection
Report 50-275
& 50-273/91-01)
b.
From April 17 through
May 25, 1990,
a special
inspection
was conducted
to
review licensee activities in response
to spring pack relaxation in
Limitorque actuators for certain
YiOVs.
(Inspection
Report 50-275
&
50-323/90-16)
c.
From November
27,
1990, through January
11,
1991,
a special
inspection
was conducted
to review the licensee's
mechanical
maintenance
measuring
and test equipment
program.
( Inspection
Report 50-275
& 50-323/90-29)
d.
From February ll through February
14,
1991,
a followup inspection
was
conducted to review the licensee's
mechanical
maintenance
measuring
and
test equipment
program.
(Inspection
Report 50-275
& 50-323/91-04)
e.
From March 8 through Yiarch 13, 1991,
an Augmented
Inspection
Team (AIT)
was formed to review the licensee's
actions in response
to the loss of
offsite power to Unit 1. (Inspection
Report 50-275
& 50-323/91-09)
C.
From April 22 through
May 24,
1991,
a special
inspection
was conducted
to
perform an electrical distribution system functional inspection.
(Inspection
Report 50-275
& 50-323/91-07)
Enforcement Activit
Unit I
The inspections
during this assessment
period identified
16 cited violations,
1 deviation,
and
13 non-cited violations.
One of the cited violations was
a
Severity Level III with no civil penalty,
and
was issued for failing to
prevent unauthorized
access
to vital areas,
not properly recording entries
into vital areas,
and for failing to protect safeguards
information
( Inspection
Report 50-275/90-02).
4
C
0
21
UNIT 2
The inspections
during this enforcement
period identified 4 cited violations,
1 deviation,
and
1 non-cited violation.
All of the cited violations were
D.
Confirmator
Action Letters
None
E.
Licensee
Event
Re orts
Unit
1
LERs
Unit 1
83-38,
90-10,
(91-10
issued
49
LERs during this reporting period.'he
LERs were:
83-37,
84-42 through 84-45, 89-15, 89-16, 89-17, 89-19,
90-01 through 90-07,
90-12 through 90-15,
90-17 through 90-19,
and 91-01 through 91-10
was
a voluntary LER).
Fourteen security
LERs were issued.
Unit 2 LERs
Unit 2 issued
13
LERs during this reporting period.
The
LERs issued
were:
88-27, 89-11, 89-12,
and 90-01 through 90-10 (90-08 was
a voluntary LER).
0
g
l'