IR 05000338/1993016
| ML20035F273 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 04/07/1993 |
| From: | Branch M, Hunt M NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML20035F266 | List: |
| References | |
| 50-338-93-16, 50-339-93-16, GL-89-10, NUDOCS 9304210105 | |
| Download: ML20035F273 (8) | |
Text
,
-
.
B #f CO
[(f UNITED STATES f,,
NUCLEAR REGULATORY CONMISslON n
REGION Il
$
101 MARIETTA STREET, N.W.
k g
AT LANTA, GEORGI A 30323
%, o... + f APR 8 1o93
!
,
l Report Nos.:
50-338/93-16 and 50-339/93-16 Licensee: Virginia Electric and Power Company Glen Allen, VA 23060
l Docket Nos.: 50-338 and 50-339 License Nos.:
NPF-4 and NPF-7 Facility Name: North Anna 1 and 2
,
!
Inspection Conducted: March 19 - 23, 1993
Inspector:
)ki N 1 m,--'
D' ate' S igned
- ~7 9 8 M. D. Funt
),Lv 4!7/93 Approved by:
6'
M.
Branch, Chief Date Signed Test Programs Section Engineering Branch i
Division of Reactor Safety l
SUMMARY Scope This special, announced inspection was conducted in the areas of the licensee's programmatic activities associated with the testing of motor
,
i operated valves in accordance with Generic Letter 89-10; and inspection of l
safety related check valves.
Results j
l In the areas inspected, violations or deviations were not identified. The inspector examined the licensee's actions taken to correct weaknesses identified during the Part I Motor Operated Valve Inspection (Report No. 91-09) and the inspection of safety related check valves, (Report No 92-19). The l
I actions taken by the licensee's engineering staff to correct program weakness I
were found acceptable. The licensee's diagnostic testing of MOVs was observed by the inspector and found to be well planned and executed even though the differential pressures achieved during testing were not at the design values.
The personnel involved were knowledgeable and understood the purpose of the
,
!
testing and what was required to obtain good test data.
!
l l
9304210105 930408 PDR ADOCK 05000338 G
-
--
.
,
I
!
REPORT DETAILS
!
1.
Persons Contacted
.
'
- R. Beger, Nuclear Operations Support
- D. Heacock, Superintendent, Engineering
- G. Kane, Station Manager
- J. Leberstien, Staff Engineering, Licensing
- B. Noesen, System Engineering
- Q. Parker, Maintenance Engineering
- B. Shriver, Assistant Station Manager
- J. Smith, Quality Assurance Manager
- J. Stall, Assistant Station Manager B. Standley, Senior System Engineer
- E. Thomas, Maintenance Engineering Resident Insoector
- D. Taylor, RI
- S. Lee, RI l
l 2.
Generic Letter (GL) 89-10 " Safety-Related Motor-0perated Valve (MOV)
j Testing and Surveillance" (2512/109)
The inspector observed the differential pressure (DP) testing of a selected group of Low Head Safety Injection MOVs performed as directed by Periodic Test No. 1-PT-57.13. The purpose of the tests was to operate the MOVs against design basis DP, to record VOTES data, and
'
verify proper sizing and operability to satisfy the intent of GL 89-10.
Eight MOVs were tested during this inspection.
Due to the location of the valves within the system, full differential pressure could not be developed.
Listed below are the MOVs and their functions.
1-SI-MOV-1862A, A LOW HEAD SI PUMP SUCTION FROM RWST 1-SI-MOV-1862B, B LOW HEAD SI PUMP SUCTION FROM RWST l-SI-M0V-1885A, LHSI PUMP A RECIRC VALVE l-SI-MOV-1885C, LHSI PUMP A RECIRC VALVE l-SI-MOV-1864A, LHSI PUMP DISCHARGE TO COLD LEGS VALVE l-SI-M0V-1890D, LHSI COLD LEG INJECTION VALVE 1-SI-MOV-1863A, A LHSI PUMP DISCHARGE TO CHARGING PUMPS
,
1-SI-MOV-1890D, LHSI COLD LEG INJECTION VALVE The licensee furnished the testing information for the DP testing of the oight MOVs listed. (See Table 1, Page 7) The highest actual test differential pressure was only 75% of the calculated (design) pressure for 1-SI-MOV-1890A.
All other test DPs were much less and in two tests we only 26% of the calculated value. The licensee's engineers will use the guidance in North Anna Site Engineering Services (NASES)
Procedure 3.10, CONTROLLING PROCEDURE OUTLINING AND PROVIDING GUIDELINES
-
.
.
.
-
--....s-
.,.s
- -.
w a
--
.a
.
....
!
-!
.
'
FOR ADDRESSING MOV DESIGN ISSUES, Section 6.8, EVALUATION OF DP TEST l
RESULTS, to evaluate the test results. It was noted that 1-SI-M0V-1862A
and B were suction valves for the A and B Low Head SI Pumps and the only j
DP available was the head of water in the RWST. The higher DPs could
'
not be developed because the reactor vessel was not closed and the water l
pumped was into the reactor cavity. The engineering evaluation of the j
testing of these MOVs will be reviewed during the Part 2, GL 89-10 l
inspection.
!
!
The inspector reviewed the diagnostic data'for the eight MOVs to verify
,
that the thrust data recorded by the test equipment was within the-l calculated margins for both the static and the dynamic tests. Table 2,
Page 8, depicts the data taken from the diagnostic records as compared
to the calculated thrust requirements and margins. The diagnostic test j
results for MOV l-SI-MOV-1862A. indicates'that the thrust at torque
switch trip (TST) for the DP test was less than the minimum thrust j
margin. The licensee issued Deviation Report No. N-93-534 denoting the
condition. The inspector was advised that a work order was later issued
!
to troubleshoot and retest the MOV. Additionally, there was a sensor
'
.
failure during the DP testing of 1-SI-M0V-1863A and no thrust value was
!
recorded. The licensee plans to retest the valve.
l l
3.
Generic Letter 89-10, Part 1 Inspection Followup i
The inspector reviewed the actions'taken in response to the concerns
!
identified in Inspection Report 50-338,339/91-09. The licensee
!
submitted a response to this inspecticn report by letter dated September 3, 1991. Although the actions taken by the licensee appear adequate, NRC will require further review during subsequent inspections.
Listed below are the concerns and the licensee's actions taken.
i A.
Four RHR inlet isolation valves were excluded from the program
!
based on the limited duration of time the valves are actuated.
l The four valves are in the program and have been set up using
!
diagnostic equipment and will continue to be evaluated i
diagnostically-during corrective and preventive maintenance.
The inspector reviewed thrust calculation SWEC 01040.3610-M-12, GL-89-l 10 MINIMUM REQUIRED TARGET THRUST AND MAXIMUM TARGET THRUST
!
DEVELOPED for MOVS 1-RH-MOV-1700, 1701, 1720A, 1720B AND 2-RH-MOV-
)
2700, 2701, 2720A, 2720B which used the Limitorque.15 coefficient (
of friction chart in determining the valve stem factor.
It was also assumed that the valve's seat, packing and threads have not
,
been altered and have been maintained. The inspector also reviewed the static test results for the Unit 2 valves and verified that there was adequate thrust margin.
These valves will not be differential pressure tested because:
1.
These valves are not required to operate for accident mitigation,
..
.
--.-
.
.
'
>
'
l
,
II.
They are in their safety position, closed and their
,
breakers de-energized during normal operations, and
!
III.
System configuration makes it impractical to perform design
'
differential pressure testing.
l The inspector reviewed the licensee's logic regarding the decision i
to not test these valves and considered the reasoning acceptable.
'
B.
The licensee had included only differential pressure in its design-basis reviews. The licensee should also address other design-basis parameters outlined in Supplement I to GL 89-10.
The inspector reviewed GL 89-I0 TESTING BASIS AND RESULTS DOCUMENT N0. NAPS-2-GL8910-SI-1 FOR DIFFERENTIAL PRESSURE TESTING (92-ST-91), MOVS: 2-CH-MOV-2275 A/B/C, 2-SI-MOV-2836, 2867 A/B/, 2869 A/B, D/P and flow test results.
These results verified that the actual measured D/P flows were within 4% of the DBA most limiting condition. The licensee defines the most limiting condition, in this case, as the maximum head the safety injection pump developed under zero or near zero flow conditions. This is the basis for most of this licensee's D/P testing. The MV engineer's evaluations show that with well maintained valves the maximum i
thrust is required during the closing stroke at seating contact
,
and the effect of flow will be less than the seating contact thrust. These actions appear acceptable.
C.
Recently published industry test data indicates the valve factors used by the licensee in analytical determinations of MOV thrust i
may yield non-conservative results.
The licensee's MOTOR-0PERATED-VALVE SIZING & CALCULATIONS STANDARD GN-0002 directs the use of an Engineering Safety Factor which is intended to account for variations in valve factors.
Since there is no consensus on the use of.2 or.3 valve factors, either will be used but a 15% margin will be initially added to the i
calculated minimum total thrust required for the gate valves.
.
D.
No provisions had been made in the program to correct analytical thrust determination for the " rate of loading" effects.
The licensee is currently evaluating the " rate of loading" by verifying that the difference between torque switch trip (TST) at the static test and the TST at differential test is within the range of the equipment accuracy.
E.
The degrading effects of high ambient temperature on the output of the MOV motors had not been considered.
The licensee has a Motor Operated Valve Program Master Integrated Action Plan which contains a list of all open items in the program and assigns responsibility for closure of the items.
Item 23
r
~
.
contains the assignment for follow up on the high ambient temperature effects on MOV motor output. This method of follow up
,
is acceptable for handling this issue.
'
F.
The licensee's written evaluation of the NRC Information Notice 90-72 (November 28,1990), TESTING OF PARALLEL DISC GATE VALVES IN EUROPE," appeared inaccurate.
The licensee has revised their evaluation of NRC IN r
90-72 to remove the statement implying NRC approval of the GL 89-10 program. The issue regarding the use of the less conservative i
valve factor is discussed in the Concern No. C corrective action.
G.
The licensee is changing from MOVATS to VOTES equipment for their
'
MOV diagnostic testing and will need to provide assurance that the equipment accuracies are considered in determining torque switch
.
setting and available thrust margin.
The inspector reviewed portions of the Set Point document and
,
determined that the licensee has incorporated the test equipment
-
inaccuracies in the evaluation process. These documents were issued by Engineering Work Request 92-124 which directed that i
engineering, " Provide torque switch settings for GL
89-10 MOVs which reflect current Stone & Webster Engineering Corporation (SWEC) calculations, VOTES equipment accuracies, j
torque switch accuracies, and current Liberty Part 21 considerations". The thrust requirement settings are reflected in
-
the margins listed in Table 2 and appear adequate.
H.
The licensee has an ongoing evaluation of recent failures of motor-operated butterfly valves in the Service Water system. The result is an increased torque requirement to accommodate valves that are installed in the reverse position.
The inspector reviewed the licensee's PART 21 REPORTABILITY I
ASSESSMENT, for valves 1-SW-MOV-103C,104B, and 104D which had torqued out during DP testing and were later found to have been installed in the non-preferable flow direction. The documents reviewed by the inspector revealed that torque switches settings i
had been lowered during the refueling outage of February 1991.
Prior to that time the torque switch settings had been set at a higher setting and there had been no problem.
The evaluation presented good reasoning for the condition not being a safety problem. The licensee filed a special report with the NRC on May 31, 1991, which adequately covered the situation.
These actions appear acceptable.
I.
After initial testing of MOVs under differential pressure and/or flow, the licensee plans to use static diagnostic testing to ensure MOV capabilities are maintained.
l
.
.-
-
-
-
-
!
i
,
"
,
!
.
This licensee has written and approved D/P test procedures that
can be performed as needed to support further program testing, post maintenance / modification testing and periodic testing. The
inspector was advised that additional D/P testing would be performed as necessary but conservative judgements will be made in
the amount of D/P testing that will be performed.
l 4.
!
'
The inspector reviewed the licensee's action regarding a weakness identified in a check valve inspection conducted August 17-21, 1992, and reported in the details of Inspection Report 50-338,339/92-19. The
,
inspector reviewed an approved Procedure Action Request which was dated December 10, 1992, to revise procedure MDAP-0013, CHECK VALVE MAINTENANCE PROGRAM which added responsibilities for Maintenance Engineering to:
r A.
Ensure that all check valves in the maintenance program database
,
are submitted to Mechanical Maintenance which will enter them
,
into the PM program, and B.
Determine the frequency of check valve inspections.
l l
These actions appear to be adequate to correct the indicated weakness.
[
i
,
i 5.
Exit Interview l
The inspector met with the licensee representatives denoted in Paragraph 1, at the conclusion of the inspection of r
March 23, 1993. The inspector summarized the purpose and scope of the
_;
inspection and the findings.
Proprietary information is not contained
in this report. No violations or deviations were identified and no t
dissenting comments were received from the licensee.
!
t I
i
,
r l
i I
i TABLE 1 MOV Mk #
AP (psi)
AP (psi)
Flow Size Type actual Calc (gpm)
1-SI-MOV-1862A
51
12" DD Gate 1-SI-MOV-1862B
51
12" DD Gate 1-SIMOV-1885A
222 155 2"
Globe 1-SI-MOV-1885C
222 155 2"
Globe 1-SI-MOV-1864A 158 223 3900 10" Split W Gate 1-SI-MOV-1890D 160 223 3900 10" DD Gate 1-SI-MOV-1863A 154 223 200 8"
FW Gate 1-SI-MOV-1890A 167 223 3700 10" DD Gate
,
- - - _ _ _
_
-
.
TABLE 2 VALVE CALCULATED MARGINS STATIC DP MAX THRUST NUMBER THRUST REQD THRUST THRUST MIN MAX
@ TST
@ TST STATIC DP 1-SI-1862A 2744 7207 11411 8546 6296 9785 7416
^
(6515.9)
(12764)
l-51-1862B 2744 7187 11449 9717 9421 10799 10373 1-SI-1863A 5415 6949 13829 8683 Data 8683 Data (6227.25)
(14000)
Lost Lost 1-SI-1864A 7148 9124 22535 13794 12916 14118 13508 (8220)
(24000)
1-SI-1885A 2174 2467 20344 8674 7936 11657 10960 (2174)
(14000)
1-SI-1885C 2174 2467 20344 7832 9078 10795 12424 (2174)
(14000)
1-SI-1890A 5533 7031 38831 15196 15853 19964 21093 (6363)
(43387)
1-SI-1890D 5533 703)
38831 18329 19026 23103 23544 NOTE; The values enclosed in parenthesis in the maximum and minimum thrust columns are the calculated thrust values before instrument accuracies, torque switch repeatability and other safety factors are incorporated.
The DP thrust values for 1-SI-1863A were lost due to a thrust sensor failure.
<
The maximum thrust margin for MOVs 1-SI-1885A & C is limited by the actuator rating of 14000 lbs. The use of the higher margin value is documented in the calculations and is based on the Kalsi Engineering, Inc. Document No.1707c, " Thrust Rating Increase of Limitorque SMB-000, SMB-00, SMB-0, and SMB-1 Actuators."
l j