ML17286B115
| ML17286B115 | |
| Person / Time | |
|---|---|
| Site: | Columbia |
| Issue date: | 10/15/1991 |
| From: | Kirsch D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | |
| Shared Package | |
| ML17286B114 | List: |
| References | |
| 50-397-91-27, NUDOCS 9111040044 | |
| Download: ML17286B115 (75) | |
See also: IR 05000397/1991027
Text
e
U.
S.
NUCLEAR REGULATORY COMMISSION
REGION
V
Report
Number:
50-397/91-27
License
Number:
Licensee:
Washington Public Power Supply System
P. 0,
Box 968
3000 George
Way
Richland, Washington
99352
Facility Name:
Washington Nuclear Plant, Unit 2
(WNP-2)
Inspection at:
WNP-2 Site,
Benton County Washington,
and
NRC Headquarters,
Rockvi lie, Yaaryland
Inspection
Conducted:
July 30 - August 2,
1991
(WNP-2),
and
August
12 - 27,
1991
(NRC Hg)
Inspectors:
L.
F. Hiller, Jr., Chief, Operations
Section,
RV (Team Leader)
C. VanDenburgh,
Chief, Reactive
Inspection Section
No, 2,
VIB (EOP Inspection
Leader)
N, Biamonte, Training and Assessment
Specialist,
HFAB
G, Galletti,
Human Factors Specialist,
HFAB
T, Meadows,
Senior Operations
Engineer,
RV
Reviewers:
T. Walker, Senior Operations
Engineer,
RI
(EOP Review Leader)
R,
Frahm, Sr., Senior Reactor Engineer,
RSB
A. Cubbage,
Reactor
Systems
Engineer,
RSB
J. Honniger,
Reactor
Engineer,
PSB
Approved by:
. Kirsch, Chi f
Reactor
Safety
Date
Soigne
Branch
~Summa r:
.
2
27.
99
I
'
. 977
.277
Areas
Inspected:
Onsite
team inspection
and
a Headquarters
review of the licensee's
emergency
operating
procedures,
operator training,
and corrective action plan for restart,
The inspection
emphasized
a review of the technical
adequacy of the
EOPs.
In
addition,'he
inspectors
performed
an assessment
of the clarity and useabi lity
of the procedures,,
During this inspection,
Inspection
Procedures
41500
and
42001
were used,
2<<7<<9 ~!till)
None
911
$ 040044
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ADDCK 05000~~i7
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5'l.if<
4
I
Oj
Results:
The licensee
did not adequately justify several
significant technical
deviations
between their
and the
Also, the inspection
identified numerous
other- less significant examples
of inadequate
justification of deviations
between
the
EOPs and'PGs,
and
between
the
and Plant Specific Technical
Guidelines
(PSTGs).
In addition,
the inspection
identified several
examples of deviations
which were not identified by the
licensee.
.The inspection
concluded that the licensee's
EOP verification and
validation program
was flawed in its execution
and quality.
By the
end of the inspection period,
the licensee
had revised
the
EOPs further
to eliminate the most significant of these deviations,
They agreed
at
a
meeting
on August 28,
1991 to supply additional technical justification for
the balance of the deviations.
They also agreed
to provide this information
thirty days after this inspection report was received,
The licensee's
training program for operators
appeared
thorough,
Management
and peer utility participation in training evaluation
was extensive,
and
appeared
effective.
The licensee's
corrective action plan appeared
complete,
'The inspection
verified that all open restart
items were being tracked,
and
no
new restart
items were appropriate.
The licensee's
revision of the
appeared
to have significantly improved
the, clarity and useabi lity of'the
EOPs.
However, the inspection
made sev'eral
specific observations
for further improvement of their useabi lity.
~tl
Open
Item 91-27-01
was identified to track the licensee's
corrective actions.
IN
P ECT ION DETAILS
Persons
Contacted:
- A~ L, Oxsen,
Deputy Managing Director
- C, M, Powers, Director of Engineering
- D, Bouchey, Direc'tor, Licensing
and Assurance
- J. Baker, Plant Manaoer
- S. L. McKay, Plant Operations
Manager
- D. R.
Kobus, Manager,
Technical Training
- B, Barmettlor,
Manager Nuclear License Training
- D, Topley, Supervisor,
Requalification Training
D. Conserriere,
SRO on assignment
to training
B. Mixson, Communication
and Assessment
Specialist
E. Bates,
Instructor/Simulator
Evaluator
(General
Physics)
D, Rodgers,
I'nstructor
(Gener'al
Physics)
M. Elliot, Instructor (General
Physics)
M,,Williams, Peer Evaluator
(Brunswick)
R, Tate,
Peer Evaluator
(Brunswick)
B. Nunez,
Peer Evaluator (Limerick)
- C. H, McGitton, Manager,
Operations
Assurance
- D. L. Williams, Nuclear Engineer,
Bonneville Power Administration
The inspectors
also interviewed
a number of other licensed operators,
supervisors
and managers
in the operations,
training, quality assurance,
and licensing departments.
- Attended the Exit Meeting
on August 2,
1991, at WNP-2.
Summar
of Results of the Ins ection
Onsite
and Review
NRC Head uarters)
The onsite inspection
concluded that the licensee's
Plant Specific
Technical
Guidelines
(PSTGs)
did not accurately
incorporate
the guidance
of Revision
4 of the
and that the licensee
had not adequately
evaluated their deviations
from the
EPGs to provide
a clear
technical justification for numerous potentially significant deviations.
The review at
NRC Headq'uarters
concluded that
none of the individual
deviations
required
immediate corrective action by the licensee,
However,
the following significant concerns
related to the
EOP development
process
were identified:
2.
The licensee
did not identify or justify deviations
from
numerous
BWROG EPGs with sufficient quality or depth of effort,
The licensee
inappropriately applied the licensing design basis
analysis
when identifying and justifying deviations
from some
of the
3,
The licensee,
in some cases,
removed available
equipment
and
mitigation strategies
from use
based
on operator
judgement without
sufficiently analyzing
the safety significance of removing the
options.
The licensee,
in some cases,
created
PSTG steps
and
EOP flowcharts
which did not reflect the accident
management
strategy
described
in the deviation documentation,
2
These errors
were manifestations
of significant weaknesses
in the
licensee's
verification and validation program,
At the meeting
between
the licensee
and the
NRC on August 28,
1991, the
licensee
agreed
to respond to the
NRC's concerns
related
to the
specific deviations identified by the
NRC in the next revision to
the
EOPs,
They also
agreed
to withdraw Implementation Deviation 428
(from the licensee's list of design,
strategy,
and implementation
deviations)
and correct. the
EOPs in a'udicious
manner.
This deviation
restricted
the reactor pressure
vessel
vent path during containment
flooding to the main steam lines only, using the main steam isolation
valves.
In addition to the concerns
related to the
EOP development
process,
the
inspection
and review both identified several
human factors
concerns
related
to the
WNP-2
EOPs.
Open Item 50-397/91-27-01
was created
to track the licensee's
completion
ov corrective action for,all of the concerns
identified in this report.
Ins ection of Emer enc
Operatin
Procedures
(41500
42001)
a
~
~Back round
Following the Three Nile Island
(TMI) accident,
the Office of
Nuclear Reactor
Regulation
(NRR) developed
the
"TMI Action Plan,"
and
NUREG-0737) which required
licensees
of. operating
plants to reanalyze
and'ccidents
and to upgrade
(NUREG-0737 Item'.C. 1).
The plan also required the
NRC staff to
develop
a long-term plan that integrated
and expanded efforts
in the writing, reviewing,
and monitoring of plant procedures
(Item
I.C.9),
"Guidelines for the Preparation
of Emergency Operating
Procedures",
represents
the
NRC staff's long-term program for
upgrading
EOPs,
and describes
the use of
a Procedures
Generation
Package
(PGP) to prepare
EOPs,
The .licensees
formed four vendor
owners
groups
corresponding
to the
four major reactor
vendor types in the United States:
Babcock
E Wilcox, and Combustion Engineering.
Working with the vendor companies
and the
NRC, the owner's
groups
developed
generic
procedures
that set forth the desired
accident
mitigation strategy,
For General Electric plants,
the generic
guidelines
are referred to as the
These guidelines
were to be used
by the licensee
in developing their
PGPs,
"Supplement
1 to NUREG-0737 - Requirements
for Emergency
Response
Capability," required
each licensee
to
submit to the
NRC
a
PGP which included,
( 1) Plant Specific Tech-
nical Guidelines
(PSTGs) with justification for safety significant
differences
from the
(2)
a Plant Specific Writer'
Guideline
(PSWG), (3)
a description of the program to be used for
the verification and validation of EOPs,
and (4)
a description of
3
the training program for the upgraded
EOPs.
The generic letter
required
the development
of plant-specific
EOPs which would provide
the operators
with directions to mitigate the consequences
of
a'road
range of initiating events
and subsequent
multiple fai lures
or operator errors,
The upgraded
EOPs were. required to be
symptom-based
procedures
which would not require
the operators
to
diagnose
specific events.
NRC Information Notice (IN) 86-64
was issued
on August 14;
1986
and
Supplement
1,
was issued
on April 20,
1987,
alerted
the licensee
to problems
found in review and audits of
Procedure
Generation
Packages
(PGPs)
and
EOPs.
The
IN indicated
that many utilities had not appropriately
developed
or implemented
upgraded
.and identified deficiencies
in the development
and implementation of each of the four major aspects
of the upgrade
program (i,e.,
undocumented
deviations
from and inappropriate
adaptation
of
BMROG EPGs, 'failure to adhere
to the
PSWG, failure to
adhere
to the verification and validation programs,
and deficient
training programs),
Supplement
1 to IN 86-64 alerted
the
licensee
tn significant problems that were continuing with plant
EOPs.
Deficiencies
were identified in all the major aspects
of
the
EOP upgrade
program.
The licensees
were requested
to review
=
the information for applicability to their facility and consider
actions to correct or preclude similar problems
from occurring.
0~i
WNP-2 is
BWR-5 plant,
The objective of this
portion of the inspection
was to determine
whether the
revisions effectively
( 1) improved the useabi lity of the
EOPs;
(2)
corrected
the previously identified significant technical
weaknesses;
and (3) verified and validated
the
EOP changes,
The inspection
team compared
Revision
4 of the
BWR Owner's
Group
.(BWROG) Emergency
Procedure
Guidelines
(EPGs) to the Plant Specific
Technical
Guidelines
(PSTGs),
and
compared
the
PSTGs to the
EOPs.
The inspection
was
based
on
a draft of the
EOPs which incorporated
Revision
4 of the
and corrected
deficiencies
which had
been identified during
an
NRC. Emergency Operating
Procedures
Inspection
(Inspection
Report 50-397/90-20).
The latest draft version of the licensee's
EOPs were derived from
Revision
4 of the
BMROG EPGs,
This
EPG revision had incorporated
a
revised accident strategy
and calculational
methods
which were
'approved
by the
NRC in
a generic Safety Evaluation
Report
(SER)
issued
on September
12,
1988.
The inspection
team reviewed the
draft
because
the licensee
was in the final stages
of
implementing
and training the operators
on this significant
revision to their EOPs.
This revision
had iust been
made
as
a
result of unsatisfactory requalification program results
which were
partially related
to
EOPs which had
been difficult to use.
The
licensee
had scheduled full implementation of this draft of the
The previous version of the licensee's
had also derived from Revision
4 of the
BMROG EPGs.
l
','l
l
During the inspection,
the
team reviewed
a version of the
PSTG
which the licensee
provided in WYP-2 Procedure
5.0,8,
"VNP-2
Emergency
Procedure
Guidelines,"
dated 7/13/91, 'lthough this
version
was annotated "final draft," it contained
numerous
deletiors
and handwritten
changes
and
had not been
approved,
I Gl .~IG I
Twenty-s'ix deviations
were identified between
the
and
the plant-specific technical guidelines
(PSTGs).
The inspection
team identified that several-of
the differences
resulted
from one
strategy deviation which resulted
in multiple differences
from the
EPGs,
The inspection did not attempt to identify every example of
these
changes.
However, it was
an extensive
sample
comparison of
the
EPGs,
PSTGs,
and
EOPs,
Seventeen
specific strategy
devia-
tions were identified.
The inspection
team was concerned
that the licensee
had not ade-
quately evaluated
the strategic deviations
from the
In
support of this inspection,
the licensee
provided
a document
titled "WNP-2 Deviations to Revision
4 of the Emergency
Procedure
Guidelines,"
Although this document
(annotated
as "Tim's Copy,")
was not dated or approved,
the licensee
indicated that it
represented
the latest version of their deviation document.
The
deviation document's
stated
purpose
was to "...identify and
document
the 'deviations'hat
WNP-2 has
taken to Rev.
4 of the
BWROG Emergency
Procedure
Guidelines
(EPGS),"
The document's
stated
scope
was to pro'vide "...a detailed
comparison of the
generic
guidance
provided in the
and the plant-specific
guidance
provided in thy WNP-2 EPGs.
Where deviations
to the
generic
guidance exist, justification is provided.
A deviation
was defined
as
a change
in intent or philosophy relative to the
actions/strategies
provided in the generic
BWROG Guidance,"
The inspection
team noted that the Justification Section for each
of the deviations listed in the deviation
document
provided the
licensee's
engineering
judgement or conclusions,
In most cases,
these
judgements
and conclusions
were not supported
by
a detailed
analytical engineering
evaluation,
Rather,
the licensee's
iustification provided
a conclusion regarding their technical
judgement of the feasibility of the different strategy
and the
consequence
of the deviations.
Specifically, the inspection
team identified the following five
significant deviations:
( 1)
Prevention of RPV Cooldnwn with Potential Recriticalit
- The
deviation document
page
39
de eted the override prior to
EPG step
RC/P-3,
This override required returning to the
pressure
control actions of step
RC/P-2 if the reactor
became
recritical during the subsequent
cooldown actions of step
RC/P-3,
In addition, the deviation
document
(page
40)
deleted
the fourth bullet of. EPG step
RC/P-.3
and
(page
45)
the third bullet of step
RC/g.
These
steps
required depres-
0
surization
and cooldown when the reactor
was
shutdown
and
no
has
been injected into the reactor
pressure
vessel
(RPV).
Based
on these deviations,
the deviation
document
(pages
43 and
156) also modified
EPG step
RC/P-5
and deleted
the fourth bullet of
EPG step
C2-2 which required verifica-
tion that 'the control
rods
have
been fully inserted
or the
reactor
was
shutdown,
or boron
has
been injected prior to
proceeding
to cold shutdown,
The
EPGs allow cooldown
and depressurization
with the reactor
subcritical with th'e possibility of recriticality, because
delaying the cooldown
and depressurization
is not necessary
unless
boron is being injected into the core.
The
RC/P steps
provide adequate
assurance
that the positive reactivity
addition of this cooldown would be slow and controlled,
The
licensee justified this deviation
becaus'e
they concluded
that the
BWROG guidance
was "not conservative,"
because
they
want to delay cooldown until subcriticality "could assuredly
be maintained,"
The inspection
team identified these
deviations
as
items
CAV-13, CAV-15 and
CAV-25 during the inspection
and concluded
that they were significant deviations.
Although the licensee
had identified it as
WNP-2 Strategy Deviation No. 2,
a
detailed
engi neering evaluation of the consequences
of this
strategy deviation
was not performed,
Dela
ed Entr
into Power/Level
Control if Two Standb
Li uid
ontro
um
s are
unnsn
-
T e deviation
document
page
1
6
added
a
new step to
EPG step
C5-2 (Level/Power
Control) to require "Less, than two
SLC pumps are injecting
into the
RPV or (emphasis
added)
reactor
power is not
decreasing,"
before
RPV water level will be lowered to
decrease
reactor
power during
an anticipated transient
without scram
(ATWS).
The effect of this deviation
was to
prevent the operator
from lowering
RPV water level during
an
ATWS to reduce reactor
power when other. actions
have not been
effective, provided
two SLC pumps were running.
The licensee justified this deviation
because
their
plant-specific
ATWS analysis
showed that if two
pumps
were running the integrity of the primary containment
would
not
be threatened.
The justification for this deviation
stated that the licensee
decided
not to lower
RPV water level
unless
the injection of boron did not occur because
con-
trolling reactor
power in this manner
was unstable,
(3)
The licensee's
justification neglected
the potential that
both
pumps
may
be running, but not injec'ting boron into
the
RPV.
The additional
step delayed
the operator's
response
to the
symptom of high reactor
power based
upon the assump-
tion that
two running
SLC pumps would'be effective in reduc-
ing reactor power., The l.icensee's
plant-specific
ATh'S
analysis
was
based
upon the assumption
of
a single-failure
analysis
which assumes
that only one of the
SLC pumps could
fai 1,
However, the actions of the 'EPG are intended
to
address
both above-
and below-design
basis
accidents,
As
a
result, this deviation prioritizes
ar
"event-based"
action
before
a "symptom-based"
response.
The inspection
team identified this deviation
as item CAY-31
durino the inspection
and concluded that it was
a signi.ficant
deviation.
Although the licensee
had identified it as
MNP-2
Strategy Deviation
No, 8,
a detailed
engineering
evaluation
of the consequences
of this strategy deviation
was not
performed.
(See Attachment
C, Strategy Deviation 8 for.
the
NRC review team's additional
concerns
with this item,').
Deletion of Hi
h Pressure
Core
S ra
HPCS)
Net Positive
Suction
Head
Limits - The deviation
document
page*8)
de eted
EPG Caution.No,
5 concerning
the
NPSH limits.
The
EPGs provide these limits in an overall caution step
so
'that the operator
could refer to them during
a subsequent
accident,
Although this information is important for all
~ pumps,
the
EPGs place the limits for the reactor core isola--
tion cooling (RCIC) and
HPCS systems
vortex
and
NPSH limits
.
in an overall caution step
based
upon the importance of
monitoring these limits during the degraded
conditions of
and drywell pressures,
temperatures
and
levels.
The licensee's justification indicated that this information
was deleted
from the caution
because
the guidance
was only
applicable
to
EPG step
RC/L-2 and at this poi'nt in the
EPGs:
( I) plant conditions
have not degraded
to the point that
operation,
irrespective of hPSH limitations,
was authorized;,
and (2) suppression
pool heatup or
a reduction in suppression
pool level
was not significant enough to threaten
the
NPSH.
Additionally, the justification concluded that the
caution is unnecessary
because
the
HPCS system
was designed
to prevent cavitation
due to pump runout.
lhe licensee's justification did not address
the possibility
that the operator
may
be required to reenter
EPG step
RC/L-2
at
a later stage of an accident
when the plant conditions
have
degraded,
In addition,
these
NPSH limits are important
because
they may form the basis for deciding which of several
available injection systems
should
be used,
The
HPCS system
may not
be the most appropriate
choice if a lower
head
pump
that would not cavitate is available.
I
I
~,
- (4)
The inspection
team identified this deviation
as item CAV-3-
during the inspection
and concluded
tha.t it was
a significant
deviation,
Although the licensee
had identified it as
WNP-2
Design Deviation No,
1,
a detailed engineering
evaluation of
the consequences
of this strategy deviation
was not performed.
(See also Attachment
C, Design Deviation No.
1 for the
NRC
review team's
additional discussion
of this item.')
Deletion of Low Pressure
Core
S ra
(LPCS)
and
Low Pressure
~ore
n ectton
t
page
22
modified t e fs t
and sixth bullets in EPG step
RC/L-2 which require ensuring that the
LPCI and
LPCS system
flows are controlled
and maintained
below curves for both the
NPSH and vortex limits.
The deviation
document deleted
the
reference
to the
NPSH limits and
removed
the curves
entirely.
The removal of these limits from the step
and the deletion of
these
curves
from the
EPGs entirely were not discussed
in the
justification section of the deviation document.
The
intend the operators
to control
LPCS flow within the
curve for the
pumps,
The
EPGs did not incorporate
these
limits in an overall caution statement
like the
limits because
the
LPCS curves
are not flat like the
HPCS curve.
The inspection
team identified this deviation
as item CAY-7
during the inspection
and concluded that it was
a significant
deviation.
Because
the licensee
had not identified it as
a
WNP-2 Deviation,
a detailed engineering
evaluation of the
consequences
of this strategy deviation
was not performed,
(See also Attachment
C, Design Deviation No,
1 for the
NRC
review team's
discussion of this item.)
Incom lete
Im lementin
Procedures
for EPGs.
The inspection
team also noted that the licensee
had not
developed all the implementing procedures
for the
EPGs,
especially
those actions that are to be accomplished
outside
the control
room.
Although the licensee
did not develop
these
emergency
support
procedures
(ESPs)
as flowcharts, they
are
an integral part of the
EOPs which must
be available to
accomplish all the
EPG actions.
For example,
the
Contingency
No,
6 (Containment
Flooding)
was not available
for review at the time of the inspection.
This concern
was identified as
CAV-16 during the inspection,
The licensee
was developing
these
procedures
during the
inspection;
therefore, it was .not identified as
a deviation.
However,
the inspectors
concluded that the absence
of these
procedures
for training
and validation was
a significant
omission
from the training of operators
which had occurred
by
that time,
Yany additional
examples
of inadequately justified EOP/EPG deviations,
as well as other deviations
were identified by the inspection,
These
are detailed in Attachment
A,
<'I
f,
The inspection
team
was concerned
that the licensee justified many
of the deviations identified based
upon the conclusion that the
licensing
and design
basis of VNP-2 precluded
taking the actions
recommended
by the
As stated
in Section
2 of the
BWROC
EPGs,
the
EPGs were developed
as
an accident mitigation strategy
that makes
the optimum use of plant equipment
and design,
regard-
less of the type of event which occurs.
All plant conditions for
which generic operational
guidance
could
be practically provided
were addressed,
irrespective of the probability of their occurrence
or whether they involved multiple failures or operator errors.
Thus,
the
address
a spectrum of conditions
more severe
than
were considered
in developing
the plant design
and licensing basis,
In this manner,
the entry conditions
and operator actions
are
keyed
.
to certain plant parameters
or symptoms.
Actions are specified
as
appropriate
to restore
and maintain these
key plant parameters
to
within limits which define safe operation.
Operator actions,
limits, and action levels
are
based
on realistically bounding
best-estimate
engineering calculations
as
opposed
to design-basis
analytical
methods
and assumptions.
Although the
were intended to provide the best possible
operational', guidance, it was not intended that the
EPGs would
extend
any design
basis
beyond that which was currently estab-
l.ished,
The
NPC staff reviewed the General Electric Topical Report
NE00-31331,
"Emergency
Procedure
Guidelines,
Revision 4," dated
March ]987,
and found the
EPGs to be generally acceptable
for
implementation,
The.SER for this report stated
that each
BWR licensee
who used
Revision
4 of the
should assure
that the
EPGs did not impact
its licensing basis.
Two possibilities could arise
'in this case,
Each
BWR plant could implement
a plant specific strategy
which
would be consistent with its safety analysis,
and provide additional
justification of such
a deviation,
Alternatively, the plant could
revise its licensing basis
and adopt the generic strategy.
Significant deviations
from the technical guidelines
should
be
supported
by engineering
analyses.
recommended
that-
these
analyses
consider
(1) the integrated
performance
of the
and balance of plant systems,
(2) the completeness
of the accidents
and transients
analyzed,
(3) the
use of appropriate
models,
calculational
methods,
and plant data,
(4) audit calculations
of selected
accidents
and transients,
(5) the adequacy
of 'the
program to develop guidelines
form the analysis of accidents
and
(6) testing thc guidelines
against
scenarios
including
multiple failures,
and (7) the information and control
needs
of the
.operators
to execute
the instruction of the guidelines,
During the inspection
and at the exit meeting,
the licensee
OuOereasoned
that deviations
from the
BWROG EPGs were justified if the
EPGs specified actions that were not within the scope of their
licensing or design
basis prior to exceeding its design or
licensing basis.
In addition, in several
cases,
WNP-2
I
W
~
'
devi.ated
from the
EPGs for beyond design
basis
events
when
they concluded that the
recommended
actions
were inappropriate
and
an alternate
strategy
was
recommended
for substitution in the
WNP-2
FOPs.
However,
WNP-2 did not provide additional
information or
perform an analytical
engineering
analysis
tc demonstrate
that the
revised
accident strategy
provided
an acceptable
or comparable
technical
guideline.
The licensee
stated
during the inspection
and at the exit meeting
that many of their deviations
were analyzed
and justified by an
internal technical
memorandum,
At the request of the
NRC Project
tlanager,
the licensee
provided
a partial
copy of Technical
Memorandum
(TN-2005, dated
December 4,
1990) titled, "Engineering Basis for
Justifying Deviations to
NRC Approved
EPG Rev.
4 Strategies."
The
inspection
team reviewed this document,
and concluded that it did
not support
the deviations
which had
been taken,
The inspection
team concluded that the licensee's
PSTGs did not
accurately
incorporate
the guidance of Revision
4 of the
and that the licensee
had not adequately
evaluated their deviations
from the
The licensee failed to provide
an adequate
enoineering
analysis
to demonstrate
the acceptability of their
alternate
accident mitigation strategy.
d,
Results of PSTG/EOP
Com arison
The inspection
team also identified se'ven differences
between
PSTG
steps
and their
EOP equivalents,
This implied that, either the
PSTG, or the
EOP,
was incorrect.
The
and the
PSTG must
be
consistent
with each other.
Further licensee
action is'ecessary
to either revise the
EOPs or the
PSTG,
as appropriate,
so that both
are consistent with the
EPGs,
These
PSTG/EOP differences
are detailed in Attachment
B.
4.
Review of Emer enc
0 eratin
Procedure
Deviations
In response
to the major scope
and depth of the inspection
team's
findings in the
EOP area,
a followup review by
a second
NRC team
was
conducted
August 12-27,
1991 at
NRC Headquarters.
A meeting
was held
with the licensee
on August 28,
1991 to further discuss
the
deviations,
The results of that review are discussed
in the next
paragraph,
The purpose of this review was to further assess
the technical
adequacy
of 'the licensee's
deviations
from the
BWR Owners
Group
(BWROG) Emergency
Procedure
Guidelines
(EPGs).
The review did not assess
the overall
technical
adequacy
of the
WNP-2 Emergency Operating
Procedures
(EOPs).
This review focused
on the deviations identified by the licensee
in their
"deviation document."
It did not include
a complete
EPG to
PSTG
comparison
or
a comparison, between
the
PSTG
and
EOPs,
except
when
necessary
to understand
the intent of the deviation.
"
l
.1
l
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f
. 10
The licensee
withdrew
a
number of the deviations following the onsite
inspections,
The licensee's
withdrawal of several
deviations following
the onsite inspection indicated to the
NRC the licensee
recognized
these
deviations
to
be undesirable.
The licensee
provided additional information
to support the remaining deviation justifications.
This information was
used
along with the draft "deviation document" during the review of the
MNP-2 deviations
from the
Descriptions
of the specific deviations that
WNP-2 has
taken from the
.
are provided in .Attachment
C.
The following findings are
supported
by examples of deviations
referenced
to the licensee's
three
lists of design,
strategy,
and implementation deviations,
respectively.
The documentation
of the justifications for many of the deviations
between
the
and the
MNP-2
PSTG -.in the "deviation document"
was
not adequate.to
assess
the technical
adequacy
of, the deviation.
The
additional
information provided
by the licensee
subsequent
to the onsite
inspection
to support
the deviations
was more complete,
but was still
insufficient in many cases.
For example,
the justification for deletion
of the primary containment
vent valve closure
pressure
in the Primary
Containment
Pressure
Limit (PCPL) calculation did not address
the
consequences
of attempting to close the valve above its .rated closure
pressure
(Implementation Deviation ¹32).
Discussions
with the licensee
concerning the, deviations that did not have
adequate
technical justification indicated that the quality and depth of
effort associated
with analysis of the deviations
was lacking,
For
example',
the licensee
specified that multiple level instruments
must
be
available, prior to termination of RPV Flooding rather than
a single level
instrument without consideration of the negative effects of RPV Flooding
( Implementation Deviation ¹26),
The licensee
also took
a deviation in
allowing bypass
of main steam tunnel
high temperature
isolation
interlocks without adequate
assessment,
of the
EPG bases
for
restricting the action
( Implementation Deviation ¹35),
In addition to the withdrawal of deviations,
and the deviations
between
PSTGs
and
EOPs which were not adequately justified, the
NRC identified
several
differences
between
the
BMROG EPGs
and the
WNP-2
PSTGs that were
not identified
as deviations
in the "deviation document,"
For example,
the licensee
deleted
(SLC) test tank as
an
injection source,
but failed to identify and justify the deviation,
It
is important to identify and justify all deviations
from the
that result in logic or strategy
changes
to ensure that the overall
effectiveness
of the
BMROG
EPG accident mitigation strategy is not
diminished,
This is another indication of poor quality in the
development
process.
Further,
a
number of deviations
were noted
by the
NRC that were
identified in the "deviation document,"
but were not included in the
licensee's list of deviations.
Additionally, the list of deviations
often did not reference all of the applicable
steps
in the
PSTG affected
fj
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!
11
by the deviatioh,
For example,
the 'deviation to utilize RCIC suction
from the suppression-pool
did not reference
the applicable
section of the
Flooding contingency
procedure
(Strategy Deviation
¹I). It is important to assess
the effect of
a deviation
on the entire
accident mitigation strategy.'herefore, it is necessary
to ensure that
all sections
of the
EPGs affected
by the aeviation
are addressed,
The licensee
based
the justification for
a number of deviations
on design
basis
analyses.
'Ihe'licensee
made conclusions
based
on the results of
analyses
for specific accident
sequences
without consideration of other
potential malfunction or adverse
conditions.
,For example,
WNP-2
EOPs did
not lower level to control reactor
power in an anticipated transient
without scram
pumps
were operating
and
reactor
power was decreasing
(Strategy Deviation ¹8).
The justification
for this deviation
was
based
on
a design
basis
ATWS analysis that
, indicated that the reactor will be shutdown
and the containment integrity
will be maintained with the
SLC pumps operating
as designed.
The licens-
ee did not consider
the adverse effects
on the containment
from the
additional'heat
input if the
pumps were to subsequently fail.
As
discussed
in the previous section,
the
are designed
to
mitigate the consequences
that can occur
as
a result of multiple
failures.
The
EPG strategy to lower level in addition to boron
injection with SLC prov'ides
a "defense
in depth" strategy that assures
continued
safe operation of the plant under
degraded
conditions.
Some of the deviations
tal en by WNP-2 removed options
and mitigation
strateqies
that are specified in the
For example,
WNP-2
deleted
the direction to bypass
drywell cooling isolation interlocks to
allow drywell cooler operation for drywell temperature
control
(Design
Deviation ¹6),
They also
removed the option to rapidly depressurize
the
RPV to the main condenser
when Emergency Depressurization
is anticipated
(Design Deviation f4),
These actions
were deleted without an adequate
assessment
of the consequences
of deleting the strategy or option.
WNP-2
deleted
several
mitigation strategies
without clearly demonstrating
the
negative
consequences
of -implementing the strategy,
or compensating
for
removal of the strategy.
In several
cases,
the
WNP-2
EOPs did not reflect the logic presented
in,
the
PSTG,
For example,
the
PSTG directed termination of steam cooling if .
an injection source
was lined up while steam cooling was in progress.
The
WNP-2
EOPs did not direct termination of steam cooling until level
dropped
below -205" regardless
of injection system lineup,
Termination
of steam cooling when
an injection source is lined up is
an integral part
of the analysis
used to justify the deviation to delete
the
low pressure
override from the Alternate Level Control Guidelines
(Strategy Deviation
¹6).
The technical
adequacy of the
PSTG is dependent
on accurate
implementation of the
PSTG logic into the
EOPs.
The
EOP verification and
validation
(VSV) program should
ensure
that the
PSTG logic is accurately
reflected in the
EOPs.
~
l
12
In conclusion,
during review of the deviation justification documentation,
NRR identifiea several
concerns
related to the
EOP development
process.
'The quality and depth of effort associated
with identification and
justification of deviations
from the
was 'not adequate.
The
documentation
of the justifications did not provide sufficient information
to evaluate
the technical
adequacy
of the deviation in many cases.
Application of the licensing design basis
analysis
was inappropriately
applied
when identifying and justifying deviations.
Conclusions
were
based
on
a design
basis
analysis for specific accident
sequences,
excluding consideration
of other malfunctions or adverse
conditions,
Deviations were taken that removed available
equipment
and mitigation
strategies
for use
based
on operator
judgement without sufficient
analysis of the safety significance of removing the option.
Some
PSTG
steps
and
EOP flowcharts did not reflect the accident strategy
described
in thedeviation documentation
indicating deficiencies
in the licensee's
V&V program,
Each of the discrepancies
identified was
an indicator of significant
EOP verification program weakness.
Human Factors
Review of EOPs
a
~
~Summa r
A human factors review of the revised
WNP-2 Emergency Operating
Procedures
(EOPs)
was conducted
in accordance
with Inspection
Procedure
42001,
"Emergency Operating
Procedures,"
and the criteria
outlined -in the
WNP-2 restart inspection plan.
The inspection
plan
criteria
used
was:
have
been revised to eliminate siginificant human factor
errors,
such that
and supporting
procedures
could
be
physically and correctly performed.
The
WNP-2 Symptomatic
Emergency Operating
Procedures
Writer'
Guide, Plant Procedure
Manual 5.0.2 (P.P.H. 5.0.2),
WNP-2 Emergency
Operating
Procedures
User's
Guide, Plant Procedure
Manual 5.0.7
(P.P.H, 5.0.7),
and
a selection of EOPs were reviewed for
consistency
with human factors principles described
in NUREG-0899,
and
Generally,
the licensee's
revised
EOP development
guidelines
incorporated
human factors principles described
in these
and the
were developed
in
a manner consistent
with the
WNP-2
EOP development
guideline criteria.
However,
the review identified
a number of human factors
concerns
including:
( 1)
inconsistent
and excessive
use of transitions,
(2)
embedded
logic/decision steps,
1
(3)
lack of definitive
EOP development criteria
on the use of color-
coding
and override decision steps,
and
(4)
a lack of guidance
on placekeeping
and the intent of contingency
statements'The
licensee
was apprised of these
findings and committed to review
the
EOPs to ensure
these
concerns
were addressed.
Inconsistent
Use of Transitions
Transitioning within and
between
procedural
flowpaths
and support
procedures
can cause
confusion,
delay accident mitigation,
and
contribute to operator error.
Because
of these
concerns,
definitive .criteria should
be established
to ensure consistent
development
of transition steps
in procedures.
Additionally, the
development of EOPs
should focus
on minimizing the
need for
transitioning within and between
procedures
where possible.
The
MNP-2
EOPs contained
several
examples
of concerns
associated
with transition points including:
(I)
the inconsistent
use of exit arrows following contingency
statements,
(2)
excessive
transitions
based
on the use of contingency
statements
and associated
overrides (in some instances
the
transition from
a contingency
statement
-to an override
statement
and then to the appropriate
contingency flowpath
introduced
an unnecessary
intermediate transition),
(3)
the lack of any demarcation
(or grid) pattern
on the
flowcharts to aid the operator in transitioning to the
appropriate
entry point(s) of another flowchart or flowpath,
(4)
the lack of definitive color-coding criteria for match-mark
symbols
used to aid the operators
in transitioning
between
flowpath segments
on individual flowcharts,
and
( 5)
the lack of definitive criteria for the implementation of
override steps
and subsequent
actions
associated
with these
override steps
when they have
been
reached
through
a
contingency
statement.
EGP transition steps
should
be structured consistently
because
there is the potential for degradation
of decision
making under
highly stressful
conditions,
Additionally, decision
steps
should
be incorporated into the procedural
structure in
a manner which
ensures
that they are perceived
and evaluated
appropriately.
I
II
Imbedded
Lo ic Ste
s
The
WNP-2
EOPs contained
several
decision
steps
(e,g, logic
statements)
which were
embedded
in tables
referenced
from the steps
in the
EOP flowpaths.
In several
instances
these
decision steps
contained
an override condition, which if present,
required
an
additional transition to an entry point on another flowpath (e.g.
RPV-Control, Table 13),
Where practical,
these
logic statements
should
be incorporated
into the flowpath structure directly,
In
instances
where these logic statements
pertain only to the table
information, they should
be emphasized
appropriately
to ensure
they
are perceived
and evaluated
by the operators,
Im recise
EOP Develo ment Criteria
The
EOP Writer's Guide (P,P,N. 5,0.2)
and the
EOP User's
guide
(P,P.N, 5,0;7)
lacked defini tive guidance
in several
areas
including:
( 1) color-,coding for match-mark transition symbols,
(2)
override decision steps,
and (3) placekeeping,
This lack of
guidance
may contribute to inconsistencies
in th'e development of
the
and their subsequent
use
by operators.
Color-coding
was not used consistently in
the
WNP-2 EOPs,
Color coding was
used to aid the operator in identifying
override conditions which are applicable
when specific
contingency
statements
are encountered,
By design,
objects
of "like" color were related to one another (e.g,,
emergency
depressurization
contingency
and override statements
are
coded "green").
However, color-coding
was also
used for
match-mark
symbols which represent
connections
between
flowpaths
on
a specific flowchart,
The
EOP Writer's Guide described
in detail
the color-coding
conventions for override
and contingency statements,
but did
not contain
any additional
information on the color-coding
conventions for the match-marker
symbols.
As
a result,
several
match-mark
symbols
used
the
same color-coding
conventions
as override
and contingency
statements
and
additional match-mark
symbols,
This practice could lead to diluting the effectiveness
of
color-coding
used in the flowcharts (e.g.,
adding "visual
noise" to the flowcharts)
and create
a condition where the
operator falsely establishes
relationships
between flowchart
symbols which are not intended,
Definitive criteria should
be established
for the color-coding
corventions
used for match-marks
in the
EOP flowcharts.
I
15
'2)
The
WNP-2
EOPS did not have
a consistent orientation for
the
Y/N (Yes/No) exit points from decision steps,
1
'ecision
steps
are inherently difficult to deal with under
stressful
s itua tions.
Therefore,
where practical,
deci s i on
steps
should
be developed
which are simple
and consistent.
In doing so', operators
can'develop
expectations
based
on the
fact that
a decision
step
has
been encountered
and take the
appropriate
actions
based
on predefined
established
rules.
By providing consistency with respect
to the direction on the
flnwpath to be taken from a decision point, the operator
can
implement these
rules which may aid in navigating through
a
complex network of procedural
paths,
If practical,
the primary direction of movement
should
be
based
on the actions
and decisions
operators
need to make
and
not on the arbitrary placement of Y/N exit points to avoid
operator
expectancies
as described
in the
EOP Writer's Guide.
If the development of
a consistent orientation for the
Y/N
exit points requires
rephrasing
the decision
steps
in such
a
way that it introduces
confusion (e.g.,
using double-negative
phrases),
then it may
be more appropriate
to vary the
orientation of the
Y/N exit points
and retain the original
format,
(3)
,'Placekeeping
provides
the operator with
a mechanism for
tracking pr'ogress
through the complex network of procedural
paths,,and
helps
ensure
that the Control
Room Supervisor
maintains situational
awareness
throughout transient
mitigation.
The
EOP Writer's Guide
and
EOP User's
Guide did
not describe
the development of placekeeping
or define
any
method for implementing placekeeping,
Because
nf the benefits
provided
by establishing
placekeeping
methods,
guidelines for the use of placekeeping
should
be
provided,
and operators
should
be trained to implement these
methods.
Ins ection of 0 erator Trainin
Effectiveness
a,
Overview
A total of 22 interviews were conducted
from July 29 through
August 1,
1991.
The interviews were used to determine
the
effectiveness
of the licensee's
corrective actions related to
training and evaluation of operators
on the revised
EOPs,
Included
in those
interviewed were licensed
operators
with various
success
histories
on the requalification
exams
and operating evaluations,
operations
managers,
training managers,
operations
instructors,
and
peer evaluat'ors,
Interviewees
were
asked to comment
on three
specific areas:
EOP training content
and quality; management
expectations
of and participation in the training process;
and
operator
feedback
on training
and recent.
EOP revisions,
I)
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4
lt
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'16
Classroom Trainin
Classroom training to prepare
the operators
to use revised
was
not derived using
a systems
approach
to training,
However,
the
training content
was derived conservatively,
with all operators
. receiving the
same
leve'l of classroom training on the
EOPs.
The
lesson
plans
used to present
the classroom portion of the training
were not in the standard
WNP-2 format but contained
adequate.detail
for successful
presentation
of the topics.
Contract instructors
presenting
the classroom trainino were viewed by the operators
as
being
knowledgeable
in the
EOPs.
The two days of classroom
training consisted
of
a step-by-step
review of each of the
EOP flow
charts with emphasis
on the basis for each step,
The training was
well received-and
the operators
performed well on the written
evaluation
given at the
end of the training,
On the basis of interviews
and
a review of the lesson
plans,
the
methods
used to develop
and present
the classroom portion of the
EOP training for the operators
were effective in preparing
the
operators
to use the revised
EOPs,
Simulator Trainin
The team observed
two crews trainino on the
EOPs in the WNP-2.
simulator
.
.The team noted that the operating
crews worked effec-
tively with the training staff to establish
an understanding
of the
revised
EOP flowcharts
and to identify potential
procedural
deficiencies,
The licensee
stressed
three
areas
during the
exercises:
improving crew communications
during transient mitiga-
.tion, ensuring
the operators
understood
any revisions to the
EOPs,
and using the
EOP flowcharts in their intended
manner.
Procedural
deficiencies identified during the exercises
were noted
by the
trai ning staff for input to the procedural
development staff.
Host operators
interviewed described
current simulator training as
having increased
in pace
and complexity when compared
to training
before the requalification program
was declared, unsatisfactory.,
The operators
noted
an increase
in the formality and professionalism
required for
a successful
evaluation in the simulator.
Increased
emphasis
on communication
was consistently identified as
a change
in management
expectations
that was reflected in the simulator
training and evaluation.
Nest of the operators
interviewed
specifically cited recent revisions to the plant procedure
on
conduct of operations
as providing more detailed
standards
for
communication,
Peer evaluators
from other utilities were being
used to evaluate
instructors
and crews during the conduct of simulator trainino.
The peers
were asked
by the licensee
to provide frank feedback
in
the areas
of crew communication,
command
and control,
and in-
structor critiques,
Interviews with the peers
indicated that their
comments
were being well received
by the licensee,
The peers
also
.
e
0
f)
N
II
17
noted that they felt confident their suggestions
were being given
appropriate
attention
due to the level of management
interaction
with them,
They specifically noted
the involvement of training
management,
the operations
manager,
and the Deputy Nanaginq
Director. in their daily debriefing sessions.
A strength identified by the oper'ators
during several
interviews
was the specificity of the feedback
on their performance
in the
simulator being provided
by the training staff and operations
management.
The operators
indicated that they
knew what~standards
their performance
was being evaluated
against
and felt comfortable
that the standards
were being consistently applied.
A strength
identified by the inspector
was the licensee's
efforts to develop
detailed
standards
of performance for evaluating
the
command
and
control
and communication skill of the Control
Room, Supervisor
and
the communication
and
teamwork skills of the Control
Room Operator.
On the basis of interviews
and observations
of simulator training,
the training and evaluation of crews
had improved,
Performance
standards
for both the operators
and instructors
was being
established
at appropriate
levels.
Mana
ement
Ex ectations
Licensee
management
oversight of training had increased
over the
past
two months,
Operators
consistently
mentioned that the
Operations
Yianager
and the Assistant
Operations
Yianager
had taken
an active role in setting
standards
and evaluating
crews in the
simulator,
Management
had established
desired
operator
performance
levels to be achieved prior to retesting.
The operators
wer'e
familiar with the expected
standards
and consistently felt that
their opinion on readiness
for retesting
would be considered
in
making that determination,
Although the interviewed operators
currently in training were
familiar with the evolving standards
and changing training methods,
the interviewed operators on-shift were not.
Of particular note
was the on-shift operators'ependence
on the "grapevine" for
information about the changes
they would be experiencing.
The
operators on-shift were less
knowledgeable
than their counterparts
in training about management
expectations.
Licensee training and operations
managers
discussed
the reasons
for
incr easing
management
involvement in and changing
management
expectations
for operator requalification training.
The managers
consistently
mentioned
the
need to maintain
an awareness
of
evolving training and testing trends
in the industry in order to
maintain
a successful
requalification program.
On the basis nf interviews
and observation
of managers
in crew
briefings
and training critiques,
the level of management
in-
volvement
had increased
and
had resulted
in improvements
to the
training program,
However,
management
involvement with keeping the
0
)
t
H
0'
on-shift operators
informed about the events
in training to reduce
their dependence
on less reliable information sources
was weak;
Both the operators
and the managers 'indicated in interviews that
they expect
the level of management
involvement to remain high
after restart,
e,
Feedback
Feedback
was being actively collected
from the operators
in the
areas
of training and
EOPs.
The
EOP feedback
included both
technical
and useabi lity issues,
Operator
comments
and questions
were being reviewed.
Responses
to these
issues
were being .compiled,
and distributed to the operators,
During interviews, operators-
'onsistently
stated that their feedback
was being satisfactorily
addressed.
An SRO/Shift Manager
had
been
assigned
to the training
department
to compile the responses
and coordinate
the distribution
of the information to the operators,
On the basis of interviews
and
a review of operator
feedback
and
responses,
the feedback
mechanism
appeared
adequate
to ensure that
operator
comments,
concerns,
and questions
were reviewed
and
resolved.
Conclusions
In summary, this portion of the inspection
concluded that:
.The methods
used to develop
and present
the classroom portion
of the
EOP training for the operators
were effective in
preparing
the operators
to use
the revised
EOPs,.
The training and evaluation of crews
had improved.
(3)
Performance
standards
for both the operators
and instructors
were being established
at appropriate
levels.
The level of management
involvement
had increased
and
had
resulted
in improvements
to the training program.
The feedback
mechanism
appeared
adequate
to ensure that
operator
comments,
concerns,
and questions
were reviewed
and resolved,
(6)
Management
involvement with keeping the on-shift operators
informed about the events
in training, to reduce their
dependence
on less reliable information sources,
was
weak
at the time of this inspection.
N
I
~,i
'19
Ins ection of Corrective Action Plan
The licensee's
Corrective Action Plan, Revision',
was reviewed. All
items which were
on the list appeared
appropriate',
No items which
were identified to be non-restart
appeared
misclassified.
The licensee
Training Manager
agreed that the Corrective Action Plan would be placed
on the docket to update
the previous submittal
which had .been
made ir.
Nay,
and which was out of date at the time of the inspection.
The only concern identified during this review was that the licensee
had
not collected closure information for each
item so that it was readily
retrievable for review.
However, several
items of closure
documentation
were requested,
and were retrieved
by the licensee
by the completion of
the inspection,
ATTACHMENT A
In addition to the most significant examples identified in Paragraph
3 of the
inspection report,
the inspection identified the following deviations
which
were not adequately justifieo:
Deletion of the Condensate
Stora
e Tank
(CST)
as
the Preferred
Suctior
or t e
eactor
ore
so ation
oo in
stem -
e
eviation
document
page
22
modified the third and fourth bullets of EPG step
RC/L-2 which specified using the
RCIC and
HPCI systems
with suction from
the
CST instead of the normal suction from the suppression
pool-(SP).
The revision deleted
the action to take suction from the
CST and
incorporated
a
new action to observe vortex limits when using
RCIC or
HPCS with suction
from the
SP,
The deviation document
(pages
87
and
192) also
made similar modifications in the fourth bullet of
EPG step
RC/P-2
and
EPG step
C5-3 of Contingency
No,
5 (Power/Level Control),
The licensee's justification for this deviation indicated that the
elimination of the
SP suction
as
a water source for RPV injection was
not justified because it was of lower quality than the
CST and might be
at higher temperatures
than the
CST under certain conditions.
The
licensee
also believed that these deviations
preserved their licensing
basis
because
RCIC operation with suction from the
SP was allowed.
The licensee's justification did not address
one important aspect of the
EPG's
basis for initially using
Specifically,
the
EPGs specify starting with CST suction
because
in the event'of
a
station blackout transfer to the
CST suction
may not be possible.
Also',
the
SP (i,'e,, primary containment) will heat
up faster if RPV injection
is from the
SP rather than from the
CST.
e
2
The inspection
team identified these
items
as
CAV-6, CAV-12, and
CAV-32
during the inspection.
Although the licensee
had identified them
as
WNP-2 Strategy Deviation No,
1
and Design Deviation No, 5,
a detailed
engineering
evaluation of the consequences
of this strategy deviation
was not performed.
(See also Attachment
C, Strategy Deviation No.
1 for
the additional technical
review of this deviation
by the review team.)
Dela
in@
RPV In'ection if a
Low ualit
Water Alternate In'ection
Subs
stem
Becomes Available, when
RPV Level can
be Maintained
at- 2/3
il
Cl-3 and Cl-4 and
added
new steps
Cl-6 and Cl-7 to Contingency
No,
1
(Alternate Level Control).
EPG Steps
Cl-3 and Cl-4 required injecting
the
RPV with low quality water injection subsystems
when the
RPV=
pressure
dropped
below the highest
RPV pressure
at which the shutoff
head of
a low quality water alternate
injection subsystem
(excluding
SLC) was reached,
New steps
Cl-6 and Cl-7 added
a
new override to delay
proceeding
to Contingency
No.
2 (Emergency depressurization)
or Contin-
gency
No.
6 (Containment
Flooding) if RPV water level
can
be maintained
above 2/3 core height
and
combined
and
RPV injection is above
6000 gallons
per minute (gpm),
S
1
A2
The
EPGs direct the
use of Contingency
No,
1 (Alternate Level Control)
when
RPV water level cannot
be maintained
above the top of active fuel
(TAF):
Contingency
No. 1'ttempts
RPY injection with all the injection
subsystems
to maintain
RPV water level
above
the TAF, irrespective of
the systein's
NPSH and vortex limits.
With RPV pressure
above the
maximum shutoff head of the alternate injection subsystems,
Contingency
No,
1 requires
entry into Contingency
No.
2 (Emergency Depressurization)
or Contingency
No.
3 (Steam Cooling) when
RPV water level drops to the
TAF.
When
RPY pressure
decreases
to the
maximum shutoff head of the
alternate
injection systems,
Contingency
No.
1 requires injection by all
alternate
injection systems
(low quality water systems).
With RPY
.pressure
below the maximum shutoff head of alternate
injection systems,
Contingency
No,
1 requires
entry into Contingency
No.
2 (Emergency
.Depressurization)
or Contingency No,'6 (Containment
Flooding) when
RPY
water level drops to the TAF.
In this manner,
when the
RPV water level falls to the TAF, the
requi re emergency
depressurization if any iniection system is available.
In addition,
the
EPGs allow the
RPV water level to fall below the
and,enter
a steam cooling mode if the high
RPY pressure
prevents
the use
of an alternate
injection system,
When the
RPV pressure
decreases
sufficiently, the
then require using the low quality water systems
to control the
RPY water level to the TAF,
When
RPV water level cannot
be restored
and maintained
above
the
TAF by the. use nf alternate
injection systems,
the
EPGs require containment flooding.
The licensee's justification for deleting
EPG steps
Cl-3 and Cl-4 .
indicated that this deviation allowed the use of the steam cooling mode
(i.e.,
RPY water level
below the
TAF) until either
an injection subsys-
tem becomes
available or until the minimum zero injection level (2/3
core height)
was reached.
The justification indicated that this
approach
maximized the time for operator action to establish
an injec-
tion system while maintaining adequate
core cooling prior to proceeding
to Contingency
No.
6 (Containment
Flooding).
The justification also
indicated that the
EPG strategy
had tied the effectiveness
of steam
cooling to the shutoff head of the high pressure .alternate
injection
systems
(excluding
SLC).
The licensee
believed that this approach
allowed
a significant variation
in this pressure
based
on
a given plant's
design (e,g,,
some plants
may
have
a 350 psig system while others
have only
a 90 psig system).
The
justification indicated that there
was
no 'relationship
between
the pres-
sure at which steam cooling may become ineffective and the physical
limitation of
a plant's alternate
injection system.
However, the
licensee
had not performed
a detailed analytical engineering
evaluation
of the consequences
of this strategy deviation.
The licensee's justification*for adding
new steps
Cl-6 and Cl-7 indicat-
ed that the deviation
was necessary
to preserve
the integrity of their
design basis for the double-ended
loss of coolant accident
(LOCA),
Their design
basis
indicates
that the
RPY water level will recover to
the elevation of the top of the jet pumps (2/3 core height)
and that
adequate
core cooling will be achieved
by
a combination of steam cooling
and core spray,
The licensee's justification indicated that the
0
0'i
i)
h
A3
performance
of the containment'looding
contingency" when
RPV water level
cannot
be maintained
above
the
TAF would result in direct venting of the
RPV and the containment
to the environment while still within the licen-
see's
design basis,
In addition,
the licensee's
justification indicates
that the
BWROG's
basis for requiring containment flooding when RPV'level cannot
be
maintained
above
the
TAF is inadequate.
The justification indicates
that the
EPGs did not credit spray cooling due to the possibility
that the spray pattern might be affected
by the steam
environment to the
extent that, adequate
core cooling is jeopardized.
Even if the core
spray pattern is not significantly affected,
spray cooling requires
con-
tinuous reliance
on core spray
pump operation.
The
assumed
that core cooling is immediately threatened
in this mode
due to the
potential fai lure of the operating
pump.
The licensee's
justification indicated that their design basis,
as 'represented
by the
WNP-2 Final Safety Analysis Report
(page 6.3-24),
shows that. the core
will remain covered to .at least
the jet pump suction elevation
and that
the uncovered
region is cooled
by spray cooling
as calculated
by
Generic Analysis
(NEDO 20566P).
The inspection
team identified these
items
as
CAV-21 and
CAV-23 during
the inspection.
Although the licensee
had identified them
as
WNP-2
Strategy Deviation No. 6, Strategy Deviation No.
9 and Design Deviation
No. 15,
a detailed engineering
evaluation, of the consequences
of this
strategy deviatioh
was not performed,
(See also Attachment
C, Design
Deviation No. 15
and Strategy Deviation No. 6, for a related discussion
of the review team's findings,)
Deletion of Emeroenc
De ressurization
Usin
the Vain Turbine
B
ass
Va ves - The deviation
document
page
29
de eted the second
bul et of
the override statement
following EPG step
RC/P,
This override required
the operator to rapidly depressurize
the
RPV with the main turbi,ne
bypass'valves if emergency
depressurization
is anticipated
to be needed
and either (1) all control rods
are inserted
or (2) it has
been deter-
mined that the reactor will remain
shutdown
under all conditions without
The licensee's justification indicated that this override
and its
associated
caution (i.e,,
EPG Caution
No, 5) was not implemented
because
it may cause violation of WNP-2's Technical
Specifications
when the
plant may still be within its licensing basis.
The inspector's
noted
that although this justification indicated that
EPG Caution
No,
5 had
been deleted,
the caution
appeared
in the licensee's
Plant Specific
Technical
Guidelines
and
was not identified in the deviation document
as
being 'deleted.
However, the caution
was not incorporated into the
flowcharts.
(This was identified as item CAV-9 during the inspection.)
The justification also indicated that the
EPG's
basis for this step
was
to preferentially deposit
the energy in the
RPV to the main condenser
rather
than the suppression
pool to the extent that this will not result
in
a low RPV coolant inventory or the release
of fission products.
Therefore,
the
EPGs did not authorize
bypassing
the main steam isolation
A4
valve (NSIY) isolation interlocks.
The justification indicated that the
three main criteria that require
emergency
depressurization
were (I)
inability to maintain
RPV level
above
the TAF, (2)
an unisolable
primary
system discharging into an area
outside of the primary containment,
and
(3) exceeding
one of the primary containment structural limits (i.e,,
PSPL,
HCLL,
etc'
)
The iustification concluded that these criteria for using the NSIYs to
emergency
d'epressurization
were not applicable for the following.
reasons.
b.
The NSIVs isolate at -50 inches
RPY level
and the interlocks are
not authorized to be overridden; therefore,
when
RPV level reaches
TAF the NSIVs will not be available.
However, this rationale
neglected
the fact that the
EPGs direct emergency
depressurization
using the NSIVs when the operator anticipates
the need.
There-
fore, the NSIYs could
be used prior to their isolation
on low RPY
water level.
As an additional
argument,
the justification indi-
cated that the
have not defined,nor
provided guidance
on how
to anticipate
emergency
depressurization.
(For further discussion
of this point,
see
Attachment
C, Design DEviation No. 4.)
If the primary system is discharging
to an area outside primary
containment with
a fuel element failure, the HSIVs will isolate
on
high radiation; therefore,
the HSIYs will again not be available.
However,
the
EPGs specifically preclude
emergency
depressurization
in this circumstance,
Although the justification indicated that
a
discharge
outside
the primary containment without
a fuel element
failure is
a valid situation requi ring the use of the YiSIVs, the
justification specifically states
that:
"...the qualifiers necessary
to correctly implement
(this
EPG step)
would be overly complex
and difficult
for the operators
to use.
Therefore, for ease of
implementation
and operator
use, this action is not
'llowed."
e
c
~
Finally, the justification concluded that the only two credible
events that might pose
a threat to the primary containment limits
were
an inability to remove
long term decay heat
and
a
LOCA with
a
failure of the pressure
suppression
function of the primary
containment.
The justification concluded that long term decay
heat
removal would allow sufficient time for reestablishment
of
the main condenser
as
a heat sink and that
a
LOCA with.a pressure
suppression
fai lure would result in either
a low RPY water level
(and associated
NSIV isolation) or an immediate depressurization.
Th'erefore,
rapid depressurization
to the main condenser
could not
be accomplished
or it is unnecessary.
Again, this justification
neglected
the fact that the operator is required to anticipate
the
need for emergency
depressurization
prior to the isolation of the
-HSIVs. 'ore importantly, this iustification addressed
only two
"credible events,"
when the basis for the
BMROG EPGs
are for the
I
A5
mitigation nf the
symptoms of all credible
and non-credible
events.
The inspection
team identified this item as
CAV-10 during the inspec-
tion',
Althouoh the licensee
had identified it as
WNP-2 Design Deviatior:
No, 4, the inspectors
concluded that
a detailed engineering
evaluation
of the consequences
of this strategy deviation
was not performed.
Addition of an Inside Shroud
In 'ection
S stem Durin
Outside
Shroud
In ection Ste
s - The deviation
document
pages
191,
197,
and
168
added
the
hs,.g
pressure
system
(HPCS)
as
an alternate for the
high pressure
core injec'tion system
(HPCI) in
EPG steps
C5-3
and C5-3.2
in Contingency
No.
5 (Level/Power Control) and in
EPG step C4-1.3 in
Contingency
No.
4
(RPV Flooding).
These
EPG steps
specified the plant
systems
which are available to inject outside the
RPV shroud (i,e,, the
Group
I systems).
The
do not specify injecting with the systems
that inject inside the shroud (i.e,, the Group II systems) until after
the Group
I systems
have not been successful
in controlling
RPV water
level.
The
EPG basis for this selection is to prevent disruption of the
steam cooling occurring in the
RPV and to prevent
a positive reactivity
addition caused
by adding cold moderator to the top of the core
when at-
tempting to control reactor
power during
an
ATWS with:lowered
RPV water
level.
The licensee's
iustification indicated that
was
allowed during the time of bo~on injection by the
SLC pumps
because
WNP-
2 had
a plant-specific
ATWS analysis
to support its operation
under
these conditions.
The justification indicated that
HPCS injection
inside the shroud provides
increased
boron mixing.
The inspectors
noted
that this
ATWS analysis
was not referenced
by the justification,
Further evaluation is necessary
to ensure
that the
ATWS analysis
provided
a detailed analytical engineering
evaluation of the consequenc-
es of this strategy deviation,
The inspection
team identified these
items
as
CAV-33 and CAV-26,during
the inspection,
Although the licensee
had identified them
as
WhP-2
Design Deviation No.
16,
a detailed
engineering
evaluation of the conse-
quences
of this strategy deviation
was not performed,
(See also
Attachment
C, Design Deviation No.
16 for additional discussion of this
item,)
Deletion of the
Head Vent as
an Alternate
De ressurization
S stem-
The deviation
document
page
154
deleted
the
head vent as
an alternate
RPV emergency
depressurization
system from EPG step C2-1.4 in Contingen-
cy No,
2 (Emergency
RPV Depressurization),
This
EPG step lists every
available
system that can
be used to help depressurize
the
RPV if less
than the minimum number of safety relief valves
(SRVs) are
open
and
pressure
is 50 psig
above
the minimum
SRY reopening
pressure.
t
The licensee's justification indicated that venting steam directly to
the drywell may aggravate
conditions 'in the primary containment,
This
path is not specified
because
venting steam directly to the drywell will
tend to pressurize
the drywell and
have the adverse
impact of increasino
I
0
l'
I'l
f
t
A6
the
SRY's
back pressure
which may affect the ability to maintain the
SRVs open in the power-actuated
assist
mode,
The justification neglected
that
EPG step C2-1,4 only allows the use of
the listed systems if the
RPY pressure
is high enough to allow opening
the
SRVs,
Therefore,
the
EPG would require termination of head ventinc
if the back pressure
increased, 'n addition,
the justification neglects
the potential that the head vent may be the only depressurization
system
available,
The operators
would not, use the
head vent unless all other
methods of depressurization
were unsuccessful.
The inspection
team identified this item as
CAV-24 during the inspec-
tion.
Although the licensee
had identified'it them
as
WNP-2 Strategy
No. 7,
a detailed engineering
evaluation of the consequences
of this
strategy deviation
was not performed.
Failure to
S ecif
Defeatin
Dr well Cool'in
Isolation Interlocks - The
eviation
ocument
page
70
de eted t e
ast part of
EPG step DW/T-l,
This step provides
guidance
to defeat
the isolation interlocks if neces-
sary. to operate all the available drywell cooling when drywell tempera-
ture is high.
The licensee's justification indicated that it was inappropriate
to
provide this direction in an "symptomatic procedure"
and that this
direction violates
the
WNP-2 design basis.
However, the justification
did not identify in what manner this direction violated their design
basis,
The justification indicated that this didn't mean that ".;.this
direction could not
be given to the operator after verification that
a
LOCA has not occurred,
but rather that .this can not be provided
as
symptomatic guidance."
This logic is incor rect.
The verification that
a
LOCA has
not occurred is, in itself,
an event-based
vice symptom-based
action,
In addition, the purpose of the
was to provide the best
operational
guidance
based
on all the equipment available for use rather
than to withhol.d this guidance until after the operators
had verified
that
an event
has occurred.
The inspection
team identified this item as
CAY-41 during the inspec-
tion.
Although the licensee
had identified it them
as
WNP-2 Design
Deviation No. 6,
a detailed
engineering
evaluation of the consequences
of this strategy deviation
was not performed,
(See also Attachment
C,
Design Deviation
06 for additional discussion
of this item.)
Termination of RPV Floodin
Dela
ed Until Multi le
RPV Water Level
Instruments
Become
vai
a
e -
e .deviation
document
page
180
modified t e
irst
u
et
o
EPG step
C4-4 in Contingency
No,
4
(RPV
Flooding) to require multiple level instruments
to be available
and
deleted
the second bullet which ensured
reference
leg temperatures
were
below 212 degrees
F,
The purpose of this
EPG step is to terminate
the
flooding of the
RPV when the operator
concludes
that any
RPY water level
instrument is available
and boiling is not occurring in its associated
reference
leg.
The justification indicated that the licensee's
".. Aesired
and standard
operating practice (especially in
a situation where you are preparing to
,
~
'~
'
drain, the water out of the reactor!)"
was to require that multiple level
instruments
be available for use,
The justification also indicated that
the precaution
on verifying that the reference
legs are not boi lino was
removed
because
the effects of temperature
on the level instrument's
variable
and reference
legs
have
been
implemented
by two "event-based"
abnormal
procedures '(i.e,, fire and high energy line break).
Although normal reactor operations
would normally require
independent
level instrumentation,
the licensee's
justification for these deviations
overlooked
the primary purpose for'PV flooding, namely,
the loss of
level instrumentation,
If the operators
should conclude that any one
system is available
and its reference
leq doesn't boil, the
EPG strategy
is to terminatethe
abnormal
condition of flooding the
RPV.
In addition,
as
a separate
comment,
the inspectors
could not determine
how the
=.
licensee's
use of event-based
abnormal
procedures
for identifying high
reactor building temperatures
met the EPGs'ntent
to implement
symptom-
., based operator
guidance,
(See also Attachment
C, Implementation
Devia-
tion
19 for additional discussion.)-
The inspection
team identified this item as
CAV-29 during the inspec-
tion.
Although the licensee
had identified it them as
WNP-2 Implementa-
tion Deviation No. 26,
a detailed
engineering
evaluation of the conse-
quences
of this strategy deviation
was not performed.
Unnecessar
Emer enc
De ressurization
of the
RPV When
RPV Mater Level
n ication is Lost -
e
eviation document
pace
a
ed
an
a dition-
a
step in t e override step after
EPG step
RC/L-1.
This
new step
requires
emergency
depressurization
by Contingency
No,
2 (Emergency
Depressurization) if RPV water level cannot
be determined
and less
than
seven safety relief valves
(SRVs) are open,
The, licensee's
justification indicated that this
new step provided the
same
guidance that was provided in the pressure
control section for the
situation where
RPV water level cannot
be determined
and less that seven
SRVs are
opens
Therefore,
the justification concluded that this
directi,on is technically the
same
as what was intended
by the
EPGs, only
this deviation provided it in clearer
terms.
The licensee's justification neglected
the fact that the pressure
control actions of EPG step
RC/P only direct the operator
to Contingency
No.
2 (Emergency
RPV Depressurization) if there is
a problem with
opening
seven
SRVs.
If seven
SRVs are already
open,
then
RC/P directs
the operator to enter Contingency
No.
4
(RPV Flooding) immediately.
If
RPV water level cannot
be determined,
the
do not direct entering
Contingency
No,
2 (Emergency
RPY Depressurization)
from RC/L-1.
This
deviation would delay the accomplishment
of the actions of Contingency
No,
4
(RPV Flooding) concerning injecting water into the
RPV to estab-
lish and maintain four SRYs open
and
PPV pressure
above the minimum
alternate
reflooding pressure
while the operator
attempted
to accomplish
the actions of Contingency
No.
2 (Emergency
RPY Oepressurization)
concerning depressurizing'he
RPY with other systems,
The net result of
the deviation is to delay responding
to the
symptom of
a loss of RPV
level control while the operator
attempts
pressure
control actions,
A8
The inspection
team identified these
items
as
CAV-5, CAY-19, and
CAV-30
during the inspection.
Although the licensee
had identified it them
as
WNP-2 Implementation Deviation No. 8,
a detailed engineering
evaluation
of the consequences
of this strategy deviation
was not performed.
The inspectors
also identified the following deviations
which the licensee
had
not identified as deviations:
9
10.
Deletion of the Standb
Li uid Control
SLC) Test
Tank as
an Alternate
RPV Floodina
S stem - The deviation document
pages
24 and
176~ deleted
the
SLC Test
Tank as
an alternate
RPV injection system in
EPG step
RC/L-
2 and
as
an alternate
RPV flooding system
from .EPG step
C4-3, 1 in
Contingency
No.
4
(RPV Flooding).
These
EPG steps list every available
system that. can
be used to help inject or flood the
RPV.
The licensee
did not identify these deletions
as
a deviation.
The inspection
team identified these deviations
as
items
CAY-8 and
28
during the inspections
Deletion of the Alternate Boron In'ection
S stems
- The deviation
ocument
page
54
de eted
the contro
rod drive system,
high pressure
core spray system,
system,
and
pump from EPG
step
RC/Q-6
as possible alternate
methods
to inject boron into the
during
an
ATWS.
This
EPG step lists every available
system that can
be
used to help inject boron into the
RPV.
The inspection
team identified this deviatio'n
as item CAV-17 during the
inspection,
Reference
to an Incorrect Caution - The deviation document
(page
60)
has
a
new reference
to Caution
No.
7 in
EPG step RC/g-7.2 which de-energizes
the scram solenoids
during attempts
to insert the control rods during an
ATWS.
However, Caution
No.
7 concerns
the simultaneous
operation of
drywell and suppression
pool sprays
and is unrelated
to this actions of
this
EPG step.
The inspection
team identified this as item CAV-18 during the inspec-
tion,
Because
the licensee
had not identified this deviation, it was
not identified,. nor justified,
as
a deviation.
However,
the inspection
team verified that this
new caution reference
was not incorporated into
the
EOPs.
The following discrepancy
between
the deviation
document
and the
was also
identified:
12,
Addition of
a
New Caution into the
EPGs - The deviation
document
had
a
new,
unnumbered
page
ocated
etween
pages
13 and
14 that indicated that
EPG Caution
No,
8 concerning
operation of HPCI or RCIC turbines with
suction temperatures
above
225 degrees
F or above the
NPSH limit,
whichever is more limiting, may result in equipment
damage.
Although
the deviation
document indicated that this Caution is not incorporated
into WNP-2's
EOPs,
the inspection
team noted that Caution
No.
8 does
not
exist in Revision
4 of the
I'
'
A9
The inspection
team identified this
as item CAY-4 during the inspection.
Because
the caution
v.as not incorporated, it did not represent
a
deviation,
However,
the inspection
team
was concerned
that its inclusi.on
in the
EPGs indicated that further unidentified deletions
or inclusions
into the
EPGs might exist.
~,i
j'
ATTACHMENT
B
The inspection identified the following EOP/PSTG differences,:
PSTG step
C2-1,1
(pa'ge
234) of Contingency
No.
2 (Emergency
RPV Depress-
urization) required preventing injection of the low pressure
(LPCS) system
and those residual
heat
removal
(RHR) systems
not needed
for ensuring
adequate
core cooling if a high drywell pressure
emergency
core cooling system
(ECCS) signal is present.
These
emergency
depressu-
rization actions
were accomplished
in
EOP 5. 1,.3 (Emergency
RPV Depressu-
rization)
and
EOP 5, 1,5
(Emergency
RPV Depressurization-ATWS),
EOP'.
1.3 incorporated this step
as the first decision block; however,
5.1.5 did not incorporate
the
PSTG step.
(The inspection
team identi-
fied this item as
CAV-36 during the inspection.)
2)
3)
PSTG step
C2-2 (page
241) of Contingency
No,
2 (Emergency
RPV Depressur-
ization) required entering
the pressure
control actions of PSTG step
RC/P-4
when the reactor is shutdown.
However,
EOP 5. 1.5
(Emergency
Depressurization-ATWS)
incorrectly directed
the operator to transition
point 48 in
EOP 5. 1.2
(RPV Control-ATWS).
This transition to the
procedure after the operator
has determined
the reactor is shutdown
was
confusing.
(The inspection
team identified this item as
CAV-36A during
the inspection.)
PSTG step Cl-3 (page
222) of Contingency
No.
1 (Alternate
Level Control)
required
emergency
depressurization if any system,
injection-subsystem,
or alternate
injection system is lined up to the
RPY with at least
one
pump running,
However, in the
second
path of,level control in EOP. 5. 1. 1
(RPY Control) the operator
was directed
by the "emergency depressurizat-
ion required" contingency action to refer to the active
"emergency
depressurization"
override statement
in the pressure
control path.
Before the transition to the emergency depressurization
actions of
either
EOP 5. 1.3
(Emergency
RPV Depressurization)
or
EOP 5, 1.5 (Emergen-
cy
RPV Depressurization-ATWS),
EOP 5. 1. 1 had
an additional decision step
to determine if seven
SRVs are open.
This additional
step
was not in
the
PSTG,
and delayed
or prevented
going directly to the emergency
depressurization
actions.
(The inspection
team identified this item as
CAV-35 during the inspection,)
The override prior to
PSTG step
RC/P-2
(page
82) required
opening the
HSIYs to re-establish
the main condenser
as
a heat sink.
However,
5. 1.2
(RPV Control-ATWS) had incorporated this action in
a different
location than specified in the
PSTG,
The
PSTG
had this override
directly preceding
step
RC/P-2;
the.EOP
has this override
two steps
ear-
lier before the verification that the suppression
pool's heat capacity
temperature limit and the safety relief valve tail pipe level limit are
exceeded,
(The inspection
team .identified this item as
CAY-38 during
.the inspection.)
5)
PSTG step
RC/L-2 (page
68) required preventing
automatic
RPV depressuri-
zation
by resetting
the automatic depressurization
system
(ADS) timer if
RPV water level
can
be maintained
above the
TAF and the
ADS timer has
initiated.
However,
EOP 5. 1. 1
(RPV Control)
had incorporated this step
in
a different location.
The fourth block in the level control actions
~,
.1
li'
I
B2
had the operator reset
the
ADS timer before the water level cannot
be
maintained
above the TAF.
(The inspection
team identified this item as
CAY-34 during the inspection,)
PSTG Caution
No.
3 (page
45)
showed
a reactor
core 'isolation coolino
(RC1C) turbine
speed limit of 2100 rpm,
However,'Caution
No.
3 in
5,0,,0
(EOP Cautions)
had
a speed limit of 1000 rpm,
(The inspection
team identified this item as
CAV-2 during the inspection,)
The first bullet of the first override statement prior to
PSTG step
C4-1
of Contingency
No.
4
(RPV Flooding) directed the operator to Contingency
No,
5 (Level/Power Control)
and RC/P-4, if the
RPV water level
can
be
determined while performing the
RPV Flooding actions
and the reactor is
not shutdown.
However,
the
EOPs did not properly implement this step
because -the-first override step of EOP 5. 1,4
(RPV Flooding) referenced
transitions
points
82 and
13 of
EOP 5, 1. 1
(RPV Control).
Upon entering
EOP 5, 1, 1, the first override step required entering
the first steps of
EOP 5. 1.2
(RPY Control-ATWS).
This transition would result in the
operator
being in the. correct location in
EOP 5. 1.2 for level control
(i.e., transition point C7), but the incorrect location in
EOP 5. 1.2 for
power control (i,e,, the beginning of power control vice transition
point 48).
A similar, but converse,
problem existed
when the operator
would transition
between
EOP 5, 1.6
(RPV Flooding-ATWS) and
EOP 5. 1.2
(RPY Control-ATWS) when the reactor
becomes
shutdown.
(The inspection
team identified this item as
CAV-37 during the inspection'.)
r
e
Oj
J!
ATTACHY>ENT C
The following is
a partial list of the
WNP-2
EOP deviations,
Each item
includes
a description of the deviation,
the licensee's justification for the
deviation,
and the
NRC concerns
related to the deviation.
Omission from this
list does
not imply NRC approval of the deviation,
The items are designated
using the licensee's list of deviations for ease of reference,
The page
numbers refer to the documentation for the deviation in the '"deviation
document."
Desi
n Deviation 41:
Deletion of ECCS
Pum
NPSH Limits
The
BWROG EPGs specify application of net positive suction
head
(NPSH)
and
vortex limits for operation of the
pumps.
WNP-2 has taken
a deviation to
delete
the
NPSH limits for the
pumps
(pages
8, .123,
177,
and 198).
The
basis for this deviation provided
was that the vortex limits are always
more
restrictive than the
NPSH limits.
The justification in the deviation document
was not technically adequate
to
support this deviation.
The additional
documentation
provided clarification
that the
NPSH limits were deleted
because
the vortex limits for the
pumps
bound the
NPSH limits.
This deviation is
an example of the poor quality
justification documentation
developed
by the licensee.
(See also Section
3.c.3
and 3.c.4 of this report for further discussion.)
Desi
n Deviation 04:
Deletion of Emer enc
De ressurization
Antici ation
The
control include
an override that directs rapid
depressurization
of the
RPV with the main turbine bypass
valves
(BPVs) if
emergency
depressurization
(ED) is anticipated,
the reactor is shutdown,
and
.the main condenser
is available,
WNP-2 has deleted
the override for anticipa-
tion of ED from the
(page 30).
The basis
provided for this deviation
was
that it was difficult to provide clear guidance to the operators
as to when to
anticipate
ED or how fast to "rapidly" depressurize,
WNP-2's. position was that
it was inappropriate
to allow exceeding
Technical Specification
(TS) limits
while the plant may still be within its licensing basis,
The basis in the
BMROG EPGs for rapidly depressurizing
using the
BPVs when
is anticipated is to reject heat to the main condenser
rather than to the
suppression
pool, thus minimizing the challenge
WNP-2
removed this option without adequate
evaluation of the negative effects of
deleting this strategy,
Difficulty in providing clear guidance for the
performance of
a step is not adequate
technical justification for deletion of
the step.
It is not possible to predict whether the plant will still be
within its design
basis
when. anticipation of
ED would be
an appropriate
action,
However, it is
assumed
that operators will not exceed
TS limits
unless
a significant challenge
to the safety of the plant exists
and it is
clear that
ED will be required.
(See also Attachment A, Item 3 for further
discussion
of this item,)
H
II
C2
Desi
n Deviation f6:
Deletion of Dr ell Coolin
Isolation
B
ass
The
EPGs provide direction to defeat drywell cooling isolation inter-
locks to mitigate high drywell temperatures,
WNP-2 deleted this direction
(page 70).
The basis
provided for the licensee's
deviation
was that symptom-
atic override of iso15tion interlocks
was technically incorrect
and might
cause
an unnecessary
radiation release.
Additionally, restoration of drywell
cool'ing would have
a negligible effect
on long term heat
removal
from the
containment.
The licensee's
justification related
the effects of drywell
cooling to suppression
pool temperature
increase,
but did not address
the
potential effects
on drywell temperature.
The intent of the
BWROG EPGs is -to provide the optimum strategy for mitigation
of emergencies
and to utilize all available equipment.
The authorization to
defeat interlocks recognizes
that concurrent
actions directed
by other
sections of the
may otherwise
preclude drywell cooler operation.
It is
not intended that isolation interlocks
be defeated if there is indication of a
leak in the drywell cooling system which could result in a radiation release.
It is also important to take all possible actions
to. lower drywell tempera-
tures
due to the effect on
RPY water level indication, not just for long term
heat removal.
The licensee
removed
an option for mitigation of high drywell
temperatures
without adequate
assessment
of the consequences
of deleting this
strategy,
(See also Attachment A, Item 6 for a related discussion.)
Desi
n Deviation f7:
Limitation on Primar
Containment
Ventin
The
BMROG EPGs direct venting of the primary containment
before suppression
chamber
pressure
reaches
Pressure
Limit (PCPL).
The
most limiting PCPL for WNP-2 is 49 psig.
WNP-2 modified this strategy
by
waiting -until drywell pressure
exceeds
39 psig before allowing the containment
to be vented
(pages
81
and 84).
The justification for this deviation was to
delay venting
and potential
release
of radioactivity until the accident
has
progressed
beyond the design
basis of the plant.
The modification made
by the licensee
addressed
only drywell pressure
for
venting conditions.
The
PSTG
and
EOPs did not address
when the primary
containment
should
be vented with respect
to wetwell pressure.
The
WNP-2
strategy
assumed
that wetwell pressure
is equal
to or below drywell pressure.
If wetwell pressure
increased
without
a corresponding
increase
in drywell
pressure,
the
MNP-2
EOPs would not allow venting of the containment
even if the
PCPL were exceeded.
The operators
could easily
be confused
on when to take
action to vent the containment if drywell and wetwell pressures
did not
respond equivalently to the event,
The licensee's
justification for this deviation did not indicate that the time
to initiate containment
venting
was considered
in the analysis for this
deviation.
If venting is delayed unti 1
39 psig, there
may not be sufficient
time to commence
venting prior to exceeding
the
PCPL.
Design Deviation f10;
Recombiner
Suction from the Wetwell Not
S ecified-
The
EPGs direct operation of hydrogen
recombiners
with suction from the
suppression
chamber for high hydrogen or oxygen concentrations
in the suppres-
t
1
C3
sion chamber,
WNP-2 does
not specify recombiner suction from the wetwell,
and
only bases
recombiner start permissive
signals
on drywell hydrogen
and oxygen
concentrations
(pages
104
arid 107).
The justification for this deviation
was
that the hydrogen
recombiner
system treats
as
a single
volume.
Therefore,
WNP-2 expected
that operation of the recombiners
with
suction from the drywell would control accumulation of combustible mixtures, in
either the drywell or wetwell,
The licensee's
justification did not indicate whether
an analysis
was per.-
formed to ensure that recombiner operation with suction from the drywell was
as effective
as recombiner operation with suction from the wetwell if the
source of hydrooen
was in the wetwell.
Additionally, operation of the
recombiners
with suction from the wetwell was not included
as
an option if
drywell suction
was not available,
The licensee's
justification assumed
that the vacuum breakers
would function
effectively to allow mixing of the containment
atmosphere.
The
PSTG did not
direct action to start recombiners
based
on high hydrogen or oxygen concentra-
tions in the wetwell.
This was not identified as
a deviation from the
EPGs.
The WNP-2
EOPs incorporated
the
EPG guidance
to start the
recombiners
on high hydrogen or oxygen concentrations
in the wetwell or the
drywell.
Desi
n Deviation 015:
Dela
Containment
Floodin
with
S ra
Coolin
and 2/3
Core
Submer
ence
At low RPV pressure,
the
BWROG EPGs direct Primary Containment
(PC) Flooding
if RPV water level cannot
be maintained
above the top of active fuel
(TAF)
after all attempts
to submerge
the core, with RPV injection have
been
unsuc-
cessful.
WNP-2 deviated
from this strategy
by delaying
PC Flooding if core
spray
(HPCS and/or
LPCS) is injecting it or above
6000
gpm and
RPV water level
is above 2/3 core height
(pages
148,
149,
and 150),
This is
a plant specific
analyzed condition for adequate
core cooling,
The justification for this
deviation
was to eliminate or reduce
the radiological releases
associated
with
PC Flooding.
The
(Rev. 4) do not consider
spray cooling
as
adequate
core
cooling,
This is because
of the possibility that the spray pattern
may be
affected
by the steam environment,
The
EPGs also
assume
that core
cooling in this mode is immediately threatened
due to the potential failure of
the operating
pump,
The licens'ee
did not consider this long term
operability concern for the
and
pumps
when evaluating th'is devia-
tion.
(See also Attachment A, item 2-for
a related discussion.)
The licensee's
justification indicated that
PC Flooding would be performed if
RPV water level dropped
below 2/3 core height or spray cooling capability was
lost.
However, the
do not reflect this logic,
There is
no override nr
direction to implement
PC Flooding if spray cooling conditions
are lost.
0
~
'
C4
e
Desi
n Deviation 816:
Use of HPCS
as
an Outside the Shroud
S stem with Boron
~ln 'ection
The
BWROG EPGs specify preferential
use of systems
that inject outside
the
shroud for RPV flood or fill during
an
ATWS,
WNP-2 deviated
from this strategy
by allowing use of the
HPCS system which injects inside- the shroud if boron is
being injected with the
SLC system
(pages
169,
192,
and 198). 'he justifica-
tion for this deviation
was
based
on
a plant specific
ATWS analysis that .
supports
HPCS operation
under these
conditions.
HPCS injection is said to
provide increased
boron mixing because
boron is injected through the
spray header.
The
BMROG EPGs
do not allow use of systems
which inject inside the shroud
until systems
that inject outside
the shroud
have
been unsuccessful
in
controlling
RPV water level to prevent disruption of the steam cooling and
addition of posi tive reactivity,
The licensee cited analysis that indicated
that power excursions with borated
HPCS injection are minimal.
However, they
were unable to demonstrate
that
HPCS injection would not disrupt steam
cooling, therefore,
they decided to delete
thi.s deviation during the next
revision to the
EOPs.
The original analysis
performed
by the licensee
was not
adequate
to support this deviation.
(See also Attachment A, item
4 for a
related discussion,)
Strate
Deviation Ol:
Use of RCIC
Su
ression
Pool Suction
In several
situations,
the
BWROG EPGs direct use of RCIC with suction from the
Condensate
Storage
Tank (CST),
WNP-2 allowed use of RCIC with suction from the
suppression
pool in addition to suction from the
CST (paoes
22, 38,
192,
198,
and 210),
The justification for this deviation
was to increase
availability, if the
CST was lost, or during
a Station Blackout.
The licensee's
original justification documentation
did not indicate that
suction
was the preferred
source
and that suppression
pool suction
was being
allowed only if CST suction
was not available.
This was clarified in the
additional documentation,
However, the licensee
did not address
each situation
for which the suppression
pool suction option was
added separately.
To
provide adequate
technical justification for a deviation, it is necessary
to
provide specific reasons
for each
EPG step or strategy that is deviated
from.
In this case
the deviation affected four different'ections
of the
The justification for use of RCIC with suction from the suppres-
sion pool varied for each situation,
(See also Attachment A, Item
1 for
a
a related discussion,)
Strate
Deviation II3:
Deletion of Primar
Containment Air Pur
e
The
EPGs specify purging the primary containment with nitrogen or air if
a flammable mixture exists,
h'NP-2
deleted
the direction to purge with air and
specified only
a nitrogen purge
(page
111).
The justification for this
deviation
was that purging with nitrogen
was more effective than purging with
air.
C5'he
licensee's
justification for this deviation did not address
any poten-
tially negative effects cf purging with air,
The WNP-2
EOPs did not include
air purge
as
an option if nitrogen
purge
was unavailable.
The licensee
deleted
an option for mitigating an emergency without adequate
analysis of the
negative
aspects
of deleting this strategy,
Strateo
Deviation <<6:
Deleticn of Low Pressure
Override for Termination of
team
Coo
sn
The
BWROG EPGs direct emergency depressurization
drops
below the shutoff head of a
l'ow quality alterna'te injection system during
alternate
level control.
This results
in termination of steam cooling
irrespective
of whether
an injection system is lined. up.
WNP-2 deleted
the
override to terminate
steam cooling
on low pressure
(pages
144
and 147),
The
justification provided for this deviation
was to prevent unnecessary
termina-
tion of steam cooling when
no injection systems
were lined up with pumps
running,
The original justification documentation
did not indicate that
an analysis
had
been
performed to verify that steam cooling is effective at low RPV pressures,
The additional
documentation
provided
by the licensee
referenced
an evaluation
performed
by
NUSCO that indicated that steam cooling was effective at low
pressures.
The effectiveness
of steam cooling at low pressures
is currently
an
open item beino evaluated
by the
BWROG.,
The licensee's justification for this deviation indicated that steam cooling
will,be terminated
and the
EPGs will be followed as
soon
as
an injection
system is lined up,
Additionally, the
WNP-2
PSTG for steam cooling contained
an override that directed
ED if an injection system is lined up while steam
cooling is in progress,
However,,the
WNP-2
EOPs did not reflect this logic,
The
EOPs did not contain
an override to direct
ED if an injection system
was
lined up while steam cooling is in progress.
(See also Attachment A, Item 2
for further discussion.)
Strate
Deviation <<8:
Deletion of Level/Power Control Strate
if SLC is
~ln 'ectin
The
EPGs direct actions to lower
RPV level to control reactor
power if
reactor
power is above the
APRYi downscale trip setpoint,
suppression
pool
temperature
is above
the Boron Injection Initiation Temperature
(BIIT), and
an
SRV is open or drywell pressure
is above
the scram setpoint.
WNP-2 has
added
an additional condition that less
than
two
SLC pumps are running or reactor
power is not decreasing
to the conditions for lowering
RPV level
(pages
18"
and 188),
The justification for this deviation
was
based
on plant specific
ATWS analysis
that indicated that reactor
power will be rapidly red'uced
when
boron is injected via the
II
N~
j
C6
The licensee's
justification stated
that they have
chosen
the "preferred"
- method for reactor
power control.
However,
the
BWROG EPGs direct both methods
(injection of boron
and lowering
RPV level) for reactor
power control,
and
do
not indicate which method is preferred,
The licensee's
justification is based
on
an event
based
analysis
that
assumes
the
SLC pumps will continue to inject
until the reactor- i s 'shutdown,
Their analysis
does not'ddress
the potential
for additional
heat input to the suppression
pool resulting from not lowering
level, If the
SLC pumps subsequently trip; this additional
heat input results
in
a greater
challenge
The licensee's
justification is based
on an analysis of the effect in
a five
minute delay in SLC injection on suppression
pool heatup.
This analysis
has
no correlation to the deviation of not lowering
RPV level.
The power reduc-
tion rate from boron injection is not equivalent to that from lowering
water level.
With the deviation,
lowering
RPV water level is not delayed for
a short period (i.e., five minutes),
but indefinitely,
while SLC is inject-
ing.
The licensee's
justification that "allowing a delay in reducing water level is
not expected
to have
any adverse
consequences
and avoids the complications
(terminating injection sources,, reducing'vessel
inventory) associated
with
reducing reactor water level" is inadequate.
The deviation
does
not result in
a delay in reducing water level, but removes
a mitigation strategy specified
by the
Removing
an action to avoid. complications is not adequate
technical justification for deviating from the
(See also Section
3.c,2 of this report for further discussion of this item.)
Review of the
EOP flowcharts indicated that the presentation
and wording of
the level/power control conditions
was very confusing.
Several
negatives
'were
used
along with
a string of "ands" and."ors" in
a table that is referred to by
a decision step,
This unclear direction could result in operator error in an
emergency situation.
Im lementation Deviation 04:
Use of Dr ell Avera
e
Tem erature
The
a caution that .restricts
use of RPV level'nstruments
based
on temperatures
near the instrument
runs.
. WNP-2 used
average
drywell
temperature
rather
than temperatures
near the instrument
runs in implementing
this caution
(page 3).
The justification for this deviation
was that drywell
temperatures
near the instrument
runs were not specifically monitored.
The licensee's justification for this deviation did not indicate that the
potential difference
between
local
and average
drywell temperatures
was taken
into consideration
when performing the calculations
for this caution.
It is
important to ensure
that the values specified in the caution are conservative
with respect
to drywell temperature,
The licensee's
justification was not
sufficient to ensure that this deviation is technically adequate.
C7
Im lementation Deviations (13, 414,
and
418:
Modification of Su
ression
Pool
Leve
ction Leve
s
The
BMROG EPGs specify initiation of suppression
chamber
sprays
only if
suppression
pool level is-below the elevation of the suppression
pool spray
,nozzles.
WNP-2 specified initiation of wetwell sprays
only if suppression
pool
level
was below'the
top of the indicating range for the suppression
pool level
instruments
(pages
77, 110,
and 115),
The
EPGs specify initiation of
drywell sprays only'if, suppression
pool level is below the elevation of the
bottom of the suppression
chamber to drywell vacuum breakers
less
vacuum
breaker
opening pressure,
WNP-2 has modified this action by specifying
initiation of drywell sprays
only if suppression
pool level
was below the top
of the indicating range for the suppression
pool level instruments
(pages
72,
79, 95, 112,
and 116).
The
BMROG EPGs specify venting the suppression
chamber
if suppression
pool level is below the elevation of the bottom of the suppres-
sion chamber vent.
MNP-2 has modified this action by specifying venting the
wetwell if suppression
pool level
was below the top of the indicating range
for the suppression
pool level instruments
(page
112).
The justification for
all of these deviations
was that the
maximum indicated level
was nearly the
same level
as the level specified
by the
and that it was conserva-
tive to limit the action to the
maximum indicated level,
The licensee's
claim that the maximum indicated level
was "nearly the
same
level" as that specified
by the
BMROG EPGs did not provide sufficient detai l
for
a technically adequate justification.
" Without specifying the plant
. specific value for .the level specified
by the
BMROG EPGs, it is not possible
to ensure that the deviation is conservative.
Additionally, the. licensee
did
not compare
the benefits of using alternate
means
to determine
suppression
pool level with the mitigation lost due to the limitations imposed
by
suppression
pool level indication availability.
Im lementation Deviation 419:
Deleted Start of Secondar
Containment
The
BMROG EPGs direct action to operate
available
secondary
containment
if radiation levels are below the isolation setpoint to control secondary.
containment
temperatures.
WNP-2 deleted
the direction to operate available
secondary
containment
HVAC (page
123),
The justification for this deviation
was that it was redundant
to previous direction given in the Secondary
Con-
tainment Control guideline.
The
EPG direction to operate
available
secondary
containment
HVAC ensures
that
ventilation is operating if it is available.
This direction was different
than the previous override which directed restart of ventilation if the system
isolated
and the isolation signal
has cleared.
The WNP-2
PSTG
and
EOPs did not
ensure that venti lation,.was operating if it was not running for any reason
other than
an isolation,
The licensee
did not perform a,thorough
technical
evaluation prior to deleting this direction.
l
lk
I
C8
l
Im lementation Deviation 826:
Multi le Level Instruments
Re uired
The
BMROG EPGs direct action to terminate
RPV Flooding when
RPV water level
instrumentation
is available,
temperature
near the instrument
runs is below
212 degrees
F,
and the Minimum RPV Flooding Pressure
(HRFP)
has
been established
for
the Yinimum Core Flooding Interval,
.MNP-2
specified that multiple
RPV level
instrunients
must
be available prior to termination of RPV Flooding (page
180).
The justification for this deviation
was that use of multiple instruments
was
the desired
and .standard
operating practice,
The
and
PSTGs
both terminate
RPV Flooding so that
RPV water level
indication can
be restored..
The
BMROG EPGs state that restoration of RPV
water level indication is achieved
when
a consistent'hange
in an instrument
reading is observed
or
a trend between
instruments is'stablished.
This
implies that it is not necessary
to have multiple instruments
available prior
to termination of RPV Flooding,
RPV Flooding is not
a desirable
condition due
to the hydraulic loads placed
on the
RPV and primary systems.
The deviation
taken
by the licensee
could result in unnecessary
delay in termination of RPV
Flooding.
The licensee
did not consider
the potentially negative
aspects
of
RPV Flooding in their analysis of 'this deviation.
(See also Attachment A,
item 7 for further discussion.)
Im lementation Deviation 428:
RPV Vent Paths
Restricted
The
vent paths for venting the
RPV when performing
Containment
Flooding,
MNP-2 restricted
RPV venting to only the main steam
lines
(YiSLs) (page 211),,
The justification for this deviation
was that only
the
YSLs had the capacity to remove
the decay heat expected
ten minutes after
shutdown.
In the additional
documentation
provided
(between
the onsite inspection
and the
NRR review), the licensee
stated
that they had misinterpreted
the vent
path requirements.
They recognized that the decay heat criterion was not
applicable to all conditions that require
RPV venting.
They withdrew this
deviation
and committed to correct the
PSTG
and
EOPs in the next
EOP revision
(or earlier),
While the licensee
recognized their mistake,
the original
justification for this deviation
was not technically adequate,
providing
another
example of poor quality in the
EOP development
process,
Im lementation Deviation 432:
Deletion of Valve Closure
Pressure
from Primar
Containment
Pressure
Limit Ca
cu ation
The
BMROG EPGs specify use of the pressures
at which the primary containment
vent valve can
be opened
and closed in calculating the Primary Containment
Pressure
Limit (PCPL).
WNP-2 did not use the pressure
at which the vent valve
can
be closed in calculating the
PCPL (Calculation MS-9).
The reason for this
deviation
was that the closure
pressure
was too limiting.
The closure
pressure
(45 psig)
was too close to the design
basis
pressure
(39 psig) limit
for vent initiation (Design Deviation,47),
'0
II
~,
C9
The
BMROG EPGs specify use of the closure
pressure
for the vent valve in
determining the
PCPL to ensure
that the valve can
be closed after it is open
to vent,
Venting should
be secured
as
soon
as possible after pressure
is
reduced
below the
PCPL to minimize the offsite release.
MNP-2 did'not consider
that attempts
to close
the valve at pressures
higher than the closure pressure
could
damage
the valve
and prevent closure.
The MNP-2
PSTG and
EOPs did not-
ensure
that venting
was not secured until pressure
is below .the closure
pressure
for the vent valve.
The jus'tification for this deviation
was not.
technically adequate,
Im lementation Deviation 435:
Addition of Hain Steam Tunnel
Hi
h Tem erature
Iso ation Bypass
The
BMROG EPGs allow bypass of the low water level isolation interlock to
allow opening or prevent closure of the NSIVs under certain conditions.
WNP-2
allowed bypass of the high steam tunnel
temperature
isolation interlock in
addition,to the low level isolation interlock (pages 35'nd 187),
The basis
for this deviation
was that steam tunnel cooling would be lost due to LOCA
load shedding
on low RPV water level,
Loss of steam tunnel cooling could
potentially cause
a high steam tunnel
temperature
isolation,
The
BMROG EPGs
do not allow bypass of interlocks that provide protection for
'onditions
whe're reopening of the HSIVs is not appropriate,
High steam tunnel
temperature
could
be indicative of
a
NSL break, in which case
the YSIVs should
not be. opened.
The licensee's
position was that protection would still be
provided for
a
HSL line break
by high steam flow isolation logic and steam
tunne'1
temperature
indication,
The
BMROG EPGs specifically discuss
the
difficulty in determining whether
a main steam line break exists with the
HSIVs closed
and
do not allow bypass of the, high steam flow and high tempera-
ture isolations
based
on this difficulty in diagnosis.
The licensee
did not
adequately
address'he
potential
concerns
associated
with bypassing this
interlock in the deviation documentation.