ML16342B883
| ML16342B883 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 05/22/1992 |
| From: | Zimmerman R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Rueger G PACIFIC GAS & ELECTRIC CO. |
| References | |
| NUDOCS 9206020191 | |
| Download: ML16342B883 (8) | |
See also: IR 05000275/1991007
Text
~4 RECT
P
+y*~+
UNITED STATES
NUCLEAR REGULATORYCOMMISSION
REGION V
1450 MARIALANE
WALNUTCREEK, CALIFORNIA94596-5368
MAY 2 2
1992
Docket Nos.
50-275
and 50-323
Pacific
Gas
and Electric Company
77 Beale Street,
Room
1451
San Francisco,
California 94106
Attention:
Hr.
G. Rueger,
Senior Vice President
and General
Hanager,
Nuclear
Power Generation
Business
Unit
Gentlemen:
Your letter dated
August 19,
1991,
in response
to our Notice of Violation
(Inspection Report Nos. 50-275/91-07
and 50-323/91-07),
dated July 18,
1991,
contested
Violations Al and
B.
Violations Al and
B concerned
a Harch 7,
1991, failure of Emergency Diesel
Generator
(EDG) l-l to assume its required load within a Technical
Specification limit.
You classified this event
as
an invalid
EDG failure.
Violation Al and
B were issued
based
on the conclusion that the
EDG l-l
failure should
have
been classified
as
a valid
EDG failure.
Your letter
indicated that you disagreed
because
you considered
that the time required for
an
EDG to assume its required load was not to be considered
when determining
valid
EDG failures.
We notified you by letter dated October
18,
1991, that
we would take the
position of your letter under review.
We have completed
our review and, with
concurrence
from the Office of Nuclear Reactor Regulation
(NRR), have
determined that the original violations were appropriate
as written.
The
basis for retaining these Severity Level
IV Violations,
as documented
in the
Notice of Violation and Inspection
Report Nos. 50-275/91-07
and 50-323/91-07,
is that our review determined
that
EDG 1-1 failure was
a valid
EDG failure as
specified in Regulatory
Guide
1. 108.
The basis for this determination is
discussed
in Attachment
1.
We have discussed
this position with your staff in
a conference call held
on Harch
17,
1992.
Your original letter contesting
these violations included
a commitment to modify a procedure
to provide
clearer definition of valid
EDG failure criteria.
You are requested
to review
that action
and include, if necessary,
the information contained
in Attachment
1 of this letter.
We will review your corrective actions during
a future
inspection.
Should you or your staff have
any further questions,
please
contact Hr.
P. Narbut of my staff at (510) 975-0316.
920602019i
920522
ADOCK 05000275
8
gpy
2 2
3992
Your cooperation
in this matter is appreciated.
Sincerely,
Attachment:
As Stated
3/P
R.
P
mmerman, Director
Division of Reactor Safety
and Projects
cc w/attachment:
J.
A. Sexton,
PGSE
J.
D. Townsend,
Vice President/Plant
Hanager,
PGIIE
C. J. Warner,
Esq., Attorney
D. A. Taggart, Director, equality Support,
PG8E
B. Thomas,
New Services,
PGKE
T. L. Grebel,
Regulatory Compliance Supervisor,
State of California
bcc w/attachment:
H. Rood,
J. Martin,
RV
B. Faulkenberry,
RV
R.
Zimmerman,
RV
K. Perkins,
RV
B. Ang,
RV
S. Richards,
RV
P. Morrill, RV
Docket File
D.
A ker
P
Na but
R.
y
(9Z,
[RE
ST COPY]
[RE
EST
COPY]
[RE
T COPY]
f
NO
YE
NO
NO
P. Morrill
6 <~
[RE
COPY ]
[S
0
PDR]
YES
NO
NO
[RE(VEST COPY]
NO
ATTACHMENT 1
1.
Background
Diablo Canyon Technical Specification
(TS) Table 4.8-1 required that the
criteria for determining the number of valid test failures of emergency diesel
generators
(EDGs)
be in accordance
with Position C.2.e of Regulator
Guide
(RG)
1.108,
Revision
1, "Periodic Testing of Diesel
Generator Units Used
as Onsite
Electrical
Power Systems
at Nuclear
Power Plants."
During a loss of offsite power
event
on March 7,
1991, Diablo Canyon Unit
1
EDG 1-1 took approximately
19.8 seconds
to energize its emergency
bus.
TS 4.8.1.1.2.b.5
required that
an
EDG energize its emergency
bus within 10
seconds
during simulated loss of offsite power testing.
The cause of the
delay was not determined.
2.
Regulatory
Guide
1. 108
RG 1. 108 states
that:
a ~
b.
"Failure is taken
here to mean the failure to start,
accelerate,
and
assume
the design-rated
load within and for the time
prescribed
during
an emergency or a valid test."
(RG 1. 108 Par
B)
"Unsuccessful
start
and load attempts that can definitely be
attributed to spurious operation of a trip that is bypassed
in the
emergency
operating
mode, to malfunction of equipment that is not
operative
in emergency
operating
mode (e.g.
synchronizing
circuitry) or is not part of the defined diesel
generator unit
design
should not be considered
valid tests
or failures."
(RG 1.108 Par C.2.e(2))
c.
Successful
starts
followed by an unsuccessful
loading attempt
should
be considered
valid tests
and failures,
except
as noted in
(b) above."
(RG 1. 108 Par C.2.e(5))
Therefore,
based
on the quotes
from
RG 1. 108 we conclude that this event
constitutes
a valid
EDG failure since
EDG 1-1 did not "assume
the design-rated
load within... the time prescribed,"
and since this unsuccessful
start
and
load attempt cannot "definitely be attributed...
to malfunction of equipment
that...
is not part of the defined diesel
generator
unit design."
(RG 1. 108
Par C.2.e(5))