ML17286B053
| ML17286B053 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 09/12/1991 |
| From: | Johnson P, Johnston K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | |
| Shared Package | |
| ML17286B051 | List: |
| References | |
| 50-397-91-24, NUDOCS 9110010013 | |
| Download: ML17286B053 (19) | |
See also: IR 05000397/1991024
Text
U.S.
NUCLEAR REGULATORY COMMISSION
REGION
V
Report No:
Docket No:
Licensee:
50-397/91-24
50-397
Mashington Public Power Supply System
P.O.
Box 968
Richland,
MA 99352
Facility Name:
Mashington Nuclear Project
No.
2 (MNP-2)
K.
.
o nston,
Pro'ec
Ins
ctor
Inspection
Conducted:
Jul
15
, and August 12-16,
1991
Inspector:
s-n,-~h
DDsOg
Approved by:
nson
~
le
React
Projects
Section
3
ate
sgne
~Suma r:
Ins ection on Jul
15-19
and
Au ust 12-16
1991
50-397 91-24
Areas Ins ected:
The inspector
reviewed the licensee's
system engineering
program and t e program implementation.
System walkdowns of the Division 1
and
2 Diesel
Generators
and the Containment
Instrument Air systems
were
performed to provide performance
based insight of the system engineering
program.
Inspection
Procedures
36800
and 71710 were used.
Safet
Issues
Mana ement
S stem
SIMS
Items:
None.
Results:
General
Conclusions
and
S ecific Findin
s
Although the system engineering
program expectations
appear consistent
with those typical to the industry, the program elements
necessary
for an
engineer to implement these expectations,
such
as training, procedural
requirements,
and resources,
have not been consistently provided.
Problems identified regarding
a diesel starting air system pressure
regulator (Section 3a.)
seem to indicate reduced effectiveness
of
the system engineer s.
Despite
an
NRC Information Notice discussing
the
potential for damage to diesel air start motor s as
a result of problems
associated
with this pressure
regulator,
despite
two maintenance
work
requests,
and despite
involvement of the system
and design
engineers
in
design
change
and procedure
review, the subject pressure
regulator
was in
a degraded
condition from November
1989 to the time of the inspection.
110010053 9109i3
ADOC)(I Q5QQQ397
G
I
>u
t
Si nificant Safet
chatters:
None.
Summar
of Violations and Deviations:
One violation was identified
regarding t e failure to sn tiate
a Problem Evaluation Request to address
high diesel starting air system pressures
(Section 3a.).
0 en Items
Summar
One followup item and
one enforcement
item were
opened.
4
!
I
DETAILS
1.
Persons
Contacted
Washin ton Public Power
Su
l
S stem
- J
+ R.
+*G
- J
+ D.
+ W.
+ p.
~R.
- T
+ S.
+ p.
- D
- J
- R
+OR
+ J.
+ B.
W. Baker, Plant Manager
T. Harrold, Assistant Plant Manager
L. Webring, Plant Technical
Manager
L. Gelhaus,
Assistant Plant Technical
Manager
D. Harmon, Maintenance
Manager
S.
Feldman, Assistant Maintenance
Manager
D. Shaeffer, Assistant Operations
Manager
W. Harness,
Generation
Engineering
Mechanical
Systems
Manager
G. Graybeal,
Health Physics
and Chemistry Manager
L. Neade,
Plant Technical Supervisor
L. Washington,
Plant Technical
Compliance Supervisor
D. McBurney, Lead Engineer, guality Assurance
A.
Ker lee, Principal Engineer, guality Assurance
D. Arbuckle, Compliance
Engineer
E. Fuller, .Compliance Engineer
E. Powell, Diesel
Generator
System Engineer,
Plant Technical
C. Mowery, Diesel
Generator
Engineer,
Generation
Engineering
L. Twitty, Engineer,
Technical
Assessments
The inspector
also interviewed other members of'he licensee's
operations,
maintenance,
engineering,
and quality assurance
staff.
+
Denotes
the individuals present
during the July 19,
1991 exit
meeting;
Denotes
the individuals present
during the August 16,
1991 exit
meeting.
2.
~0b'ective
The inspector
reviewed the licensee's
system engineering
program
and
program implementation.
System walkdowns of the Division
1 and
2 Diesel
Generators
and the Containment
Instrument Air systems
were performed to
provide performanced
based insight of the system engineering
program.
Inspection
Procedures
36800
and 71710 were used.
3.
S stems
Walkdown
Ins ection Procedure
71710
The inspector
performed
system walkdowns, in accordance
with Inspection
Procedure
71710, of both the Division
1 and
2 Diesel
Generators
(DGs)
and
the safety related portions of the Containment
Instrument Air system.
a.
Air Start Motor Air Pressure
Control Valve Settin
The inspector
observed
a deficiency tag which indicated that
Division
1
DG air start motor air pressure
control valve DSA-PCV-1A
had not performed
as designed
since
November
1990.
Pressure
downstream of DSA-PCV-1A was
260 psig, equivalent to the upstream
I
l
I
I
pressure.
The downstream
pressure
should
have
been regulated at 190
psig with the upstream
pressure
regulated at 250 psig.
NRC
Information Notice IN 89-94 identified that high air pressures
were
a contributor to the failure of air start motors at another plant.
The inspector
developed
several
concerns
based
on the presence
of
this condition.
o
This condition had existed since at least
December
1989
and
possibly earlier
and
had not been recognized
as
a condition
requiring prompt licensee action.
o
NRC Information Notice IN 89-84 did not receive
a complete
review.
As
a result,
the licensee
missed
an opportunity to
correct this condition.
Plant surveillance
procedures
did not have appropriate
acceptance
criteria to prevent starting air system pressures
from exceeding
the air start motor design pressure
despite
opportunities
during the design
change
process
to make these
changes.
Startin
Air S stem Desi
n
For the Division
1 and
2 DGs, there are
two diesels for each
generator.
Each diesel
has four air start motors,
two on each side
of the diesel flywheel.
There are two banks of four starting air
receivers for each
DG.
One bank of receivers
supplies starting air
to the air start motors
on one side of the
DG (i.e. four air start
motors,
two on each diesel).
The starting air receivers
are maintained at 250 psig by pressure
switch controlled air compressors.
A pressure
regulator associated
with each receiver
bank reduces
the starting air pressure
supplied
to the air start motors to 190 psig.
On a
DG start signal, solenoid
operated
valves
open
and supply air which engages
the air start
motors to the flywheels.
When the motors are engaged,
stop- valves
open to supply air to the motors.
"The motors operate until 150 rpm
is achieved,
and then shut off.
Maintenance
Work Re uests
Voided and Dela
ed
The inspector
reviewed the the work history of DSA-PCV-1A and found
that inadequate
reviews
had inappropriately delayed corrective
maintenance.
Specifically;
o
A 1989
MWR documenting
the problem was "voided" based
on
a
flawed assumption of the function of DSA-PCY-1A.
o
Corrective maintenance
was delayed from November
1990 to the
refueling outage
and again
postponed
to the
1992 outage without
an engineering
review.
1
ll
~;
On November 21, 1989, Maintenance
Work Request
MWR AS 3191
was
initiated by Operations to document that the pressure
downstream of
DSA-PCV-lA was
250 psig.
According to the Operations
monthly D/G
inspection
procedure
(PPM 7.4.8.1.1.2.1),
this was the upper limit
'of 'the downstream
pressure.
The licensee
did not recognize this as
a significant problem requiring them to initiate
a root cause
and
corrective action review.
Additionally, no work was performed.
During the review process,
the
MWR was determined to be void and
work was cancelled.
The basis for voiding the
MWR was documented
as follows:
"The purpose of the pressure
regulating valves
DSA-PCV-1A 5 2A
is to maintain diesel starting air pressure
from going below
190 psig during the start cycle.
Air receiver pressure
is
maintained
by the diesel air start compressor
pressure
control
switches."'he
reasoning
in the first sentence
was flawed.
The purpose of the
pressure
regulating valves
was to maintain downstream starting air
pressure
from going above
190 psig, not to maintain the downstream
or upstream 'pressure
from going below 190 psig.
On November 18, 1990, Operations
personnel
initiated
a second
MWR
(AR 1719).
A Problem Evaluation Report
(PER), the licensee's
document which initiates root cause
review and corrective action
decisions for significant problems,
was not initiated.
Work was
scheduled for the April 1991 refueling outage without an engineering
review of the effects of the higher
downstream air start pressure
on
DG operability.
Instrumentation
and Controls (IEC) personnel
tested
DSA-PCV-1A in
May 1991.
They determined that, although with an air demand
DSA-PCV-1A regulated properly, without air demand
downstream
pressure drifted up, indicating valve seat
leakage.
The
MWR was
passed
on to mechanical
maintenance for disposition.
Parts for the
valve were subsequently
ordered.
In June, prior to the necessity of
an extended
outage,
the
MWR was deferred to the
1992 outage for
completion.
The parts for the valve were received during the inspection
and
DSA-PCV-1A was repaired in August 1991.
The licensee's
failure to initiate
a
PER to address
the apparent
failure of DSA-PCV-1A, identified in
MWRs in November
1989
and
November
1990, is an apparent violation (Enforcement
Item
50-397/91-24-01).
Inade uate
Review of NRC Information Notice IN 89-84
IN 89-84 described
a condition at another facility where it was
believed that starting air pressure
greater
than the air start motor
design pressure
contributed to the failure of two
DG air start
motors.
The WNP-2 air start motors were
a different model
made
by
l'
the
same vendor.
The inspector
reviewed the licensee's
review of
the Information Notice
(OER 83-0250).
OER 83-0250, initiated January
16, 1990, recognized that high
starting air pressure
could damage
the air start motors-.
The
evaluation established
that "...the starting air pressure ... is
normally maintained at 200 psi" and that the vendor "...stated that
operation
using 200 psi starting air was within the design limits of
the motor."
However, the
same evaluation failed to adequately
address
the potential for starting air pressures
to exceed
the
design rating of the
DG air start motors.
o
At the time the evaluation for OER 83-0250
was performed;
DSA-PCV-1A was malfunctioning,
as discussed
in NMR AS-3191.
The evaluating
engineer
did not perform
a walkdown of the
system to verify an overpressure
condition did not exist.
Had
a walkdown been performed,
the overpressure
condition would
have
been identified.
o
Even though the evaluation
determined
the design pressure
was
200 psig, procedures
were not reviewed to determine if this
value
was routinely inspected
and maintained.
The monthly
surveillance of the Division
1 and
2 DGs,
PPN 7.4.8. 1.1.2.1,
required
a verification that the starting air pressure
down-
stream of the DSA-PCV-lA was less
than
250 psig.
A change to
this procedure
would have prompted
a review of the condition
which existed at DSA-PCV-lA.
As
a result of the failure to perform on adequate
analysis of IN 89-84, the licensee
missed
an opportunity to identify and correct
the problems with DSA-PCV-1A.
Desi
n Chan
e Not Thorou
h
During the initial installation of the diesel starting air (DSA)
system,
a non-conforming condition was identified (Startup
Problem
Report
SPR M-1121, Nay 22, 1981).
It was discovered that the design
pressure
of the air piping downstream of the pressure
reducing
valves
was
200 psig while upstream
the pressure
was rated at 250
psig.
Although relief valves were
shown
on the downstream piping on
the vendor drawings,
none were installed.
The licensee
subsequently
determined that the relief valves
were required
by the applicable
code
~
The resolution of SPR N-1121 was to install relief valves, set at
205 psig,
downstream of the pressure
reducing valves.
This was
subsequently
accomplished
under Project Engineering Directive (PED)
215-N-A894.
Problems
occured during diesel
generator starts; fluctuations in the
air start
system pressure
would cause
the relief valves to lift.
A
design
change
was issued
(DCP 85-719-OA) to remove the relief valves
and qualify the downstream
equipment to 250 psig.
This involved the
replacement
of the starting air solenoid valves with valves
qualified to the higher pressure.
'The air start motors were not
reviewed for the higher pressure
since they were not considered
a
pressure
boundary.
As discussed 'previously,
DG surveillance
procedures
included
starting air system pressure
acceptance
criteria which allowed
downstream
pressures
up to 250 psig.
A thorough design
change
would
have evaluated
the reduced air star t motor overpressure
protection
resulting from the removal of the relief valves
and recognized that
the surveillance
procedures
provided inadequate
protection.
The
failure to evaluate existing surveillance
procedures
during the
design
review process
represents
a missed opportunity to prevent the
high starting air system pressures.
Corrective Actions
On July 17, 1991, the licensee initiated
a problem evaluation
reouest
(PER 291-601)'to
address
the inspector's
findings.
The
initial corrective actions
were to:
o
Repair the pressure
control valve.
o
Evaluate the potential for air start motor damage.
o
Reevaluate
(1)
Re air of DSA-PCV-1A
Naintenance
was completed
on DSA-PCV-1A on August 9, 1991.
The
inspector
reviewed the associated
NWR and discussed
the work
with the mechanical
maintenance
engineer
and the mechanical
maintenance
engineering
supervisor.
The inspector
noted that the completed
NWR did not include
a
description of the as-found condition of DSA-PCV-1A.
The
maintenance
en'gineer stated that
he had observed
portions of
the work performed
and observed that
a degraded
rubber seating
surface
and corrosion products in the valve had contributed to
the valve leakage.
The inspector
observed that the lack of an as-found review
indicated that there
was
no intention of reviewing the root
cause of the failure of DSA-PCV-1A.
Without a root cause
review, the licensee
would be limited in its ability to assess
the generic implications of the failure.
The inspector
discussed
this with the mechanical
maintenance
engineering'upervisor
who indicated it was standard
practice to provide
an
as-found description
and that
he would review the completed
NWR;
(2)
Potential
For
Dama
e to the Air Start Notors
The licensee's initial evaluation of the potential for damage
to the air start motors determined that pressures
above
200
psig could have
been
achieved at the inlet of the air start
motors
and therefore,
an inspection of the motors
was necessary
to determine if any
damage
had occured.
The suspect
motors
were removed from the diesel
on August 9, 1991,
and replaced
with warehouse
spares.
At the end of the inspection,
an
examination of the motors
was scheduled
to be performed.
(3)
Evaluation of the Licensee's
Failure to Identif
and Take
Correct>ye
ct>ons
The
PER required
a review of the failure of the licensee to
identify and take corrective actions prior to identification of
the issue
by the inspector.
This evaluation
was underway at
the time of the inspection.
b.
Diesel
Lube Oil Pressure
The inspector
observed that the procedures
addressing
what is
,
adequate
diesel
lube oil pressure
were inconsistent
and did not
match field conditions.
c ~
o
For the four diesel
engines,
lube oil pressures
(under
standby
conditions)
on July 16,
1991 were 25, 37, 46,
and
60 psig.
o
'he preperation for startup portion of
PPM 2.7.2,
step
4 c.
requires that oil pressure
be verified to be between
34 and 38
ps ig.
o
The annunciator
response
procedure for the diesel
panel
lube
oil pressure
alarm requires
lube oil pressure
to be greater
than
40 psig.
These inconsistencies
were discussed
with the licensee,
who
committed to review the criteria and make appropriate
changes
to
procedures
to ensure
consistency.
The plant technical
engineer
indicated that it was his understanding
that any pressure
greater
than
10 psig was sufficient.
However,
he concurred that before
changes
to procedures
were made,
a verification of the origin of the
existing criteria and
a review of the effects of operating with
different lube oil pump configurations
was necessary.
Diesel Startin
Air Receiver
Ca acit
The licensee's
Final Safety Analysis Report
(FSAR), Chapter 9.5,
states
that each
bank of diesel starting air receivers
has the
capability of- a minimum of seven
engine starts.
During a review of
diesel
design
documents,
the inspector
noted that during startup,
a
significant modification had
been
made to the diesel starting air
system.
Specifically, the original design
was to cycle between
the
air start motors
on either side of the engine every two seconds.
This design would have
had half as
much air supplied to the
DGs at
any time.
Subsequently,
a modification was performed to have all
air start motors operate
simultaneously.
This modification would
have required greater air capacity to achieve
the
same
number of
starts.
The inspector questioned
whether this change
had
been
factored into the licensee's
FSAR committment.
h'
0
l
I,'I
The design engineer stated that this was
an issue currently under
review.
He stated that he had not found the, documented
bases
to
support the
FSAR committment and that
he needed
to address
the
following issues:
The basis for the committment for seven starts.
Was it defined
as
seven start attempts of five seconds
apiece
or seven starts
to the air start motor l50 rpm cutout, approximately two
seconds?
o
The basis for the licensee's
conclusion that the committment
could be met.
Mere there startup tests or calculations that
supported
the conclusion
and were the assumptions
made in the
tests
or calculations still valid?
The design engineer
demonstrated
in an informal calculation that the
air receivers
could support
seven stat t of two seconds
and concluded
that this was not an immediate operability issue.
This is
considered
an open item pending the licensee's
resolution
(Open Item
50-397/91-24-02).
d. 'iesel
Generator
Room Paintin
Both the Divion
1 and Division 3
DG rooms
had
been recently painted.
The Division 2
DG room had not been.
The difference
between
the
painted
and unpainted
rooms
was marked.
The clean
rooms
gave
a
sense of a pride of ownership.
Nuisance
leaks
appeared
more easily
identifiable and cleaned
up.
The inspector
encouraged
the licensee
to continue with their painting program..
e.
Containment
Instrument Air S stem
The inspector walked
down the safety related portions of the
containment
instrument air system.
No findings were identified.
One violation and
no deviations
were identified.
4.
The
S stem
En ineerin
Pro
ram
The inspector
reviewed the licensee's
system engineering
program with the
Plant Technical
Manager
and discussed
the program implementation with
system engineers.
a ~
~Pro ram
The inspector discussed-the
system engineering
program
and the use
of overtime with the Plant Technical
Manager.
The licensee's
system engineering
program
has
been in place since
plant startup, with many of the startup engineers
becoming
system
engineers.
The program
has
had l,ittle personnel
turnover since
startup.
At the time of the inspection there were over 30 system
engineers.
I'j l
The Plant Technical
Manager stated that the program description
was
contained in a mission
book which was distributed to the responsible
first line supervisors.
However,
he observed that the document
was
out of date
and revisions
were in progress.
At the time of the
inspection,
a draft revision tothe system engineer responsibilities
document
was in routing and was provided to the inspector for
review.
The responsibilities
covered the following areas:
o
System
knowedge
o
System. monitoring
o
Maintenance
support
o
Operations
support
o
Technical
reviews
o
Plant modifcation
The inspector, found these
system engineering responsibilities
to be
typical of other plants.
The inspector
reviewed overtime use with the plant technical
manager.
The licensee
requires that plant technical
engineers
conform to Technical Specification
(TS) requirements for overtime
(16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> in one day,
24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> in two days,
and 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> per week)
which require Plant Manager approval if the limits are exceeded.
The inspector found that the licensee
had met TS overtime
requirements.
In those
instances
where
an individual exceeded
TS
limits, appropriate
reviews
and approvals
were documented.
Additionally,
the licensee
was establishing
a 60 hour6.944444e-4 days <br />0.0167 hours <br />9.920635e-5 weeks <br />2.283e-5 months <br /> per week administrative
limit.
Over the six months prior to the inspection, at its lowest point,
overtime usage
was at around
8 percent in a one week period.
Approaching the outage,
overtime averaged
16 percent.
At times
during the outage,
overtime for the Plant Technical staff reached
37
percent.
The Plant Technical
Manager stated that these
overtime
numbers
were consistent with his expectations
and
he did not plan
adjustments
in the future.
Im lementation
P
In addition to the system walkdowns discussed
in section 3, the
inspector interviewed system engineers
to determine
the extent to
which management's
expectations
of the system engineering
program
were implemented.
The inspector
concluded that although the
licensee
had provided
an acceptable
system-engineering
program
description,
several
of the tools necessary for system engineers
to
implement the program
had not been provided.
These
included
training of new engineers
on information systems
which enable
engineers
to maintain
an understanding
of their systems
and
programatic
requirements for system engineers
to document
system
walkdowns.
Additionally, the routine use of overtime may inhibit
the performance of routine tasks
and prevent the licensee's
engineering staff from addressing
emergent
issues
such
as the
problems with the
DSA pressure
control valve.
The inspector
observed that, although the system engineer
program
expectations
were consistent with those typical to the industry, the
program elements
necessary
for an engineer
to implement the
expectations
were not always provided.
For example:
Training was not provided to a newer engineer
on, how to access
the maintenance
history and scheduled
maintenance
data bases.
This limited the engineer's ability to recognize
repeat
problems,
develop trends,
and maintain
an understanding
of
current system status.
In addition, it reduced
engineer
efficiency.
At the time of the interview, this engineer
was
developing
an independent
data
base
which appeared
to duplicate
aspects
of an existing plant data
base.
Although the licensee's
program
recognized
the need for system
walkdowns, it lacked procedural
or administrative requirements
to emphasize their priority. As a result, in some instances
routine walkdowns were not performed.
The inspector
reviewed with the system engineers their typical work
load.
In general,
system engineers
spent the majority of time
reacting to problems
and less
time reviewing system condition.
In summary, while the inspector
found the system engineers
to be
.well qualified, program expectations
were not being met.
This was
demonstrated
by the findings in Section 3, which could have
been
identified by the system engineer.
Had
a system engineer
reviewed
NWR AS 3191, it is possible the
flawed argument supporting the decision to void the
MWR would
have
been questioned.
Had detailed
system walkdowns
been performed, it is possible
that the system engineer
would have questioned
the condition of
DSA-PCV-lA and prompted timely corrective action.
A system engineer with time to address
emergent
issues
could
have identified the inconsistencies
between plant procedures
and existing lube oil pressures,
discussed
in section 3b.
The failure to provide the supporting
program elements
necessary for
a system engineer to meet program expectations
appears
to have
reduced
the effectiveness
of the system engineering function.
Exit Yieetings were
on July 19,
1991
and August 16, 1991, with the
licensee
representatives
identified in Paragraph
1.
The inspector
suamarized
the inspection
scope
and findings as described
in the Results
section of this report.
The licensee
did not identify as proprietary
any
of the information provided to or reviewed
by the inspector during this
inspection.