ML20215J466
| ML20215J466 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 04/27/1987 |
| From: | Ireland R, Norman D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| Shared Package | |
| ML20215J451 | List: |
| References | |
| 50-382-87-05, 50-382-87-5, IEB-85-003, IEB-85-3, NUDOCS 8705080035 | |
| Download: ML20215J466 (7) | |
See also: IR 05000382/1987005
Text
-
.
"
4
,
,,
,
APPENDIX B
U.S. NUCLEAR REGULATORY COMMISSION
REGION IV
NRC Inspection Report:
50-382/87-05
License:
Docket:
50-382
Licensee: ' Louisiana Power & Light Company (LP&L)
N-80
317 Baronne Street
New Orleans, Louisiana
70160
Facility Name: Waterford 3
Inspection At: Taft, Louisiana
Inspection Conducted:
February 9-13, 1987
Inspector:
[, 73sfem
4M3
7
D. E. Norman, Reactor Inspector, Engineering
Date
~
.Section, Reactor Safety Branch
h 98
f/F7
Approved:
R. E. Ireland, Chief, Engineering Section
Date '
j
Reactor Safety Branch.
Inspection Summary
Inspection Conducted February 9-13, 1987 (Report 50-382/87-05)
Areas Inspected:
Routine, unannounced inspection of a followup to Waterford 3
commitments.in response to IE Bulletin 85-03.
Results: Within the areas inspected, one violation was identified as a result
of a failure to perform an evaluation to assure that test requirements had'been
satisfied and that Limitorque valve operators would perform satisfactorily
during services as a result of acceptance limits permitted by test procedures
having been exceeded (paragraph 2.c(1)).
Two unresolved items
(paragraphs 2.c(2) and 2.(d)) which also require licensee action were also
identified.
S080
5
0
P
O
a-
- - -
-
1.j
-
-
-
~ -
- - -
--
-
-
- - -
. -
.~
.
. +
.
.
.
.
.
'-
,
,
-2-
_
.
DETAILS
_
,
.
,
1.
Persons Contacted-
,
Louisia' a Power -& Light Company (LP&L) '
n
!
c
- K. L. Brewster, Licensing
- R. V. Sei_dl, Nuclear Operations Engineering
'
- L.-L. Bass, Nuclear Operations Engineering,
- S. K. Shete', Nuclear Operations Engineering
-
- E. Fields, Nuclear Operations Engineering
- R. P. Barkhurst, Nuclear Operations
- N. S. Carns, Plant Manager.
- D. W. Vinci, PME
,
- T. H. Smith, Maintenance
'
- M. I. Meyer,: Nuclear Operations Engineering
- R. F. Burski, Nuclear Operations Engineering
,
- A.
S.- Lockhart,'N0SA Manager-
- *T. F. Gerrets, Quality Assurance
- J. R.:McGaha, Operations and. Maintenance
- K. L. LeBlanc, Maintenance-
G. Koehler, Operations Quality Assurance
MOVATS Incorporated
-
.
l
K. M. Eslinger, Manager, Signature Analysis
k'
'
NRC
-
- *J. G. Luehman, Senior Resident Inspector
- D. E. Norman, Reactor, Inspector
- Denotes those present=at the exit interview.
l-
2.
Inspection Summary
'
,
.
LIE Bulletin 85-03, " Motor. Operated' Valve Comon Mode Failure During Plant
,
L
Transients Due to , Improper Switch Settings," was issued as a result of
4
l
several events during which motor operated valves (MOVs) failed on demand
due to improper switch settings...The Bulletin requested that MOVs in
'
certain systems be tested for operational ^ readiness, and that licensees
~
i
develop and implement a programfto ensure that valve operator switches are
selected, set, and maintained properly to accomodate maximum differential
,
f
pressure expected during both opening and closing of the valve for both
. normal and-abnormal events within the design basis. The Bulletin requires
i
- that a report be submitted within 180 days of the Bulletin date
(November 15,1985) with the followin
(a)documentationof
design basis for each valve, and (b) g information:
l
program for complying with~the
Bulletin and a schedule for accomplishing the program. The requested
i'
,
-
.n
, - , , - . - , . - . . . . . - , . , , . - - -.,,, ,,, .--,__ -.-.- -
. . _ . . , , - - - - , , , ,
, - , , .
. - . - .
r
F.
. , - . .-
-3-
submittal was made by.the licensee on May.14, 1986, and an additional
submittal with information requested by the NRC was made on August 22,
1986.
The Bulletin requires that a written report on the completion of
the. program be made within 60 days of completion.
Followup on the licensee's actions with respect to the Bulletin was made
by performing the following inspections:
a'
Procedures Review - The following procedures, which implement the
.
provisions of the licensee's IEB 85-03 program discussed in the
submittal to the NRC, were reviewed by the NRC inspector:
ME-7-027, Revision 0, dated November 25, 1986, "Using
M0 VATS 2150 System for Testing of MOV"
ME-7-008, Revision 5, dated November 28, 1986, " Motor Operated
Valve"
MM-6-105, Revision 2, dated October 31,1986, "Limitorque Motor
Operator Maintenance"
Pertinent aspects for proper setting of the switches which were
covered by the procedures include:
Specific procedure for determining as-found and as-left switch
settings.
Setting of torque switch bypass verified by handwheel turns
after removal of any system backlash.
Setting of torque switches at valve mid-stroke position and
Belleville springs in a relaxed condition.
Additionally, the procedures presented certain acceptance criteria to
be utilized during the valve testing.-
With the exception of items montioned later in this report, the
licensee had implemented a program to~ ensure reliable operation of
MOVs, utilizing the Motor Operated Valve Analysis and Test
System (M0 VATS), a system which permits testing, adjusting; and
setting of torque and limit switches which are part of the controls
for an MOV.
MOVATS is a portable signature analysis device designed
for field use.
Parameters obtained by the system include:
Axial motion of the worm.
Actuation of torque and limit switches and the torque switch
bypass.
Motor current.
'
.
N
- . ;.; -
s ,
4
,
,
Operatorthrust. levels (stemload).
- b.-
Hardware Inspection - The valves required.to meet IEB 85-02 criteria
had been tested by the MOVATS system during the first refueling-
outage and the plant was back in operation at the time of,the NRC
' inspection;-therefore, no hardware inspections were performed,
c.
Data Review'- IEB 85-03 reported that valves failed to operate upon
demand because torque bypass switches had not been set to remain
closed long enough to provide the necessary typass function on valves
opening with differential pressure conditions across the valves.
Switches.were reportedly set for 5 percent of full stroke. Waterford
procedures require either a 5 percent setting after removal of system
backlash' or a setting determined by Engineering on a valve by valve
basis.
Twenty' valves were tested by.the licensee. . Six were tested with
design differential. pressures while the remaining were tested under
static conditions. A final analysis of test data had not been
Lcompleted by the licensee at.the time of the NRC inspection.
.
The NRC inspector reviewed both data manually collected during
testing and signature data recorded by the MOVATS 2150 system. The
following observations were made from that review.
-(1) Acceptance' Criteria Exceeded =
(a) As-found thrust limits recomended by Limitorque and as
stated in ME-7-027 had been exceeded on the following
operators:
SI-228B
SI-502A
SI-121B
MS-401A
MS-401B
SI-506B
SI-502B
(b) Possible.backseating had occurred either during operation
or during testing of following valves:
SI-506B
SI-502B
(c) Thermal overload tripped several times while testing
SI-120B.
(d) As-left motor current exceeded 130 percent of nameplate
rated current on the following operators:
~
v.
. . .
.
.
.
l
.
.
-5-
SI-225A
'
SI-226B
(e) Torque switch did not balance on operators:
SI-502A
'
SI-502B
The above conditions exceed acceptance criteria for the
operators, set by the licensee and vendors, and could affect
valve operability; however, at the time of the NRC inspection
the conditions had not been identified and analyzed by the
licensee and the plant had been restarted.
Failure to properly document and analyze the conditions
identified in paragraphs 2.c(1)(a) through 2.c(1)(e) in respect
to the capability.of valve operators to complete their
safety-related function is considered a violation of NRC
requirements (382/8705-01).
(2)
Inadequate Procedures - Paragraph 4.2.5_of ME-7-027 presents
thrust limits for SMB model operators and states that those
limits should not be exceeded. Limits actually in use, however,
are based on Limitorque correspondence dated November 24 and 28,
1986, which states that the torque switch trip may be set as
high as the published thrust rating and that the maximum thrust
(inertial) can be a maximum of 10 percent above the torque
switch set point. 'It was also stated in the letter that for a
maximum of 100 operating cycles the operator thrust may be
increased another 10 percent above the published ratings (tor
switch trip point could be 110 percent of the thrust rating) que
and
that the final thrust (inertial) could be 120 percent of the
rating. The procedure provided no means to account for the
number of valve cycles which had been made or could be made in
the future at the higher setting. There were, also no
provisions in the procedures relative to operators which were
found during M0 VATS testing to have torque switch setpoints or
inertial thrusts in excess of 110 and 120 percent respectively.
This item is considered unresolved (382/8705-02)-
(3) Noncompliance With Procedures
'
(a) Torque Bypass Switch Settings - Torque bypass switch
settings detailed in ME-7-027 and ME-7-008 were based on
the ratio of handwheel turns at which the switch dropped
out to the full-stroke turns, allowing for system backlash.
,
Data reviewed by the NRC inspector showed a bypass switch
setting calculated from the MOVATS signature.
It was based
on the time at which the switch dropped out and the total
valve stroke time but did not consider the time prior to
valve unseating (backlash). This method did not comply
. - - _ .
_
,
.
.. .
-
'
-f.
with approved procedures and appears to result in an
apparent switch setting (bypass ratio) which is25-400 percent greater than the actual setting based on the
handwheel method.
This could result in bypass switch
settings which would permit a bypass switch trip prior to
valve unseating.
It was explained by the licensee that
emergency actuation of certain valves is accomplished by
bypassing both the torque switch _and the bypass switch;
therefore, the bypass switch setting would be of no
consequence during an emergency.
however, addresses both normal and abnormal events;
therefore, the licensee should address both conditions in
his submittal to IE Bulletin 85-03.
The bypass switch settings of valves MS-401A and MS-401B
appear marginal (1.5 and 1.9 percent respectively based on
MOVATS signature and considering system backlash) and could
trip prior to valve unseating.
It was explained to the NRC
inspector that this. situation exists because the valve
position indicator lights and the bypass switch share the
same limit switch rotor, and adjusting the switch would
result in an erroneous position indicatiori.
This problem
was solved on all other operators by replacing two rotor
limit switches with four rotor switches and placing the
indication lights and bypass switch on different rotors.
This could not be done on the above valves since four
rotors were already in use and served different functions.
The adequacy of bypass switch settings for compliance with
IEB 85-03, for both normal and abnormal events, and the
apparent deviation of switch setting method from
established procedures will be further reviewed when the
final licensee report is submitted and by a subsequent NRC
inspection if necessary.
This is considered an open item
requiring additional NRC review (382/8705-03).
(b) Limit Switch Setting - The limit switch setting method
outlined in ME-7-027 and ME-7-008 was based on the number
of handwheel turns at the switch trip point and the number
of full-stroke turns; however, data reviewed _by the NRC
_.
inspector based the trip point on the MOVAT,S signature.
It
could not be demonstrated conclusively,' fro'm the data
reviewed, at what valve position the limit switch,
activated; nor could it be determined whether' valves were,
or had been, backseating.
This item is considered an open'
item and will receive additional review when the licensee
report is submitted and by a subsequent NRC inspection if
necessary (382/8705-04).
,
. . .
.
-
. .
.
. .
.
. .
. . . . .
s
-7-
.
d.
Q. A. Program Implementation
'
,
During the course of this inspection, the IEB 85-0'3 program committed
'
to by the licensee and its implementation was reviewed.
As mentioned
previously in this report, acceptance criteria had been exceeded in
.
~
several areas and there was no evidence that the items had been-'
'
reported or were to be reported and appropriate corrective action
-
taken.
It was also observed, during the course'of.the' inspection',"
.
that Quality Assurance Program requirements of 10 CFR-50 Appendix B,J -
~
Criterion II, had not been applied to the IEB 85-03 program.
This:
conclusion was reached by the NRC inspector because of a lack'o.f.
evidence that verification of quality had been performed by reviewing ~
program procedures, reviewing conduction of inspection or, tests,~and
reviewing test results or final as-left condition of'the valves.
The
apparent lack of training of QA personnel in the valve testing and
inspection program adds to the concerns expressed for this program
and to question possible generic implications involving the QA
program implementation.
This is considered to be an unresolved. item
'
pending further review by the NRC.
(382/8705-02)
-
3.
Exit Interview
The NRC inspector met with the licensee representatives denoted in
paragraph 1 and Mr. J. G. Luehman, NRC senior resident inspector on
February 13, 1987,- and summarized the scope and findings of the
inspection.
4