ML20212B654
| ML20212B654 | |
| Person / Time | |
|---|---|
| Issue date: | 12/23/1986 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| To: | |
| Shared Package | |
| ML20212B628 | List: |
| References | |
| REF-QA-99900837 NUDOCS 8612290287 | |
| Download: ML20212B654 (10) | |
Text
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e ORGANIZATION: TOBAR INC.
TEMPE, ARIZONA REPORT INSPECTION NO.: 99900837/86-01 RESULTS:
PAGE 2 of 10 l
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A.
VIOLATIONS:
l No violations were identified during this inspection.
0 B.
NONCONFORMANCES:
No nonconformances were identified during this inspection.
C.
UNRESOLVED ITEMS:
No unresolved items were identified during this inspection.
D.
ACTION TAKEN ON PREVIOUS INSPECTION FINDINGS:
The inspectors reviewed the corrective action on the nonconformances identified durirg an inspection conducted on April 9-13, 1984 and documented in Inspection Report 99900837/84-01. Tobar's corrective actions wm outlined in their letters dated May 24 and June 7,1984.
1.
(Closed) Nonconformance Item A: The nonconformance identified that contrary to the Tobar Nuclear Quality Progran Procedures (NQPP) manual PI-2, page 5-6, Revision 0, the form " Request for Engineering Action" (REA) was baing used prior to the formal approval of the procedure. Tchar representatives stated that due to charge in ownership of the company from Westinghouse to Tobar, they were rewriting the QA manual and procedures with the new owrers name. During the transition, they were implementing the program and procedures established by Westinghouse. The irspectors determined that the REA vas approved on July 11, 1984. Review of the REA forms initiated during July-August 1986 indicates that in each instance, the raasen for action and the action taken were stated including the necessary signatures with dates.
2.
(Closed) Nonconformance Item B: The nonconformance identified that contrary to the Tobar NQPP manual PI-?, page 18-7, Revision 0, the Annual Internal Audit Report (AIAR), dated October 1983, was not signed by the Product Integrity Marager (PIM) and did not identify the General Manager as recipient. As stated in Tobar letter dated June 7, 1984, the format has been revised and the AIAR is addressed to the General Manager and signed by the PIM. Review of the AIARs corducted in 1984 and 1985 indicate that the procedure was implementad.
l 8612290287 861223 PDR QA999 E!WTOBAR 99900837 PDR
ORGANIZATION: TOBAR INC.
TEMPE, ARIZONA REPORT INSPECTION N0.: 99900837/E6-01 RESULTS:
PAGE 3 cf 10 3.
Nonconformance Item C: The nonconformance identified that contrary to the NQPP manuel PI-2, Section 18 titled Audits, page 31, Revision 1, the Tobar employee who performed the October 1983 internal audit of the areas of " Purchased Material Inspection" and
" Products Integrity Program" was not trained ir all five steps of training and was not certified. As stated in Tobar letter dated June 7, 1984, Tobar sent two empicyees in 1984 to GA Technologies in San Diego, California for training in audits. The inspectors reviewed the certificates for these two individuals and determined.them accept-able.
E.
INSPECTION FINDINGS AND OTHER COMMENTS:
1.
Background Information a.
General Tobar Incorporated (Tobar) was established in 1983 by a former employee of Westinghouse Electric Corporation (Westinghouse).
Prior to 1983 Westinghouse manufactured a complete line of panel instruments at this incation, including pressure trans-mitters which were known as Veritrak. The Veritrak line of transmitters was originally designed and manufactured by Motorola until 1971. Vestinghouse bought and manufactured the Veritrak line in 1971 and in 1983 oualified the Veritrak trans-mitters to the requirements of IEEE 323-1974 and IEEE 344-1075.
In 1983, Westinghouse transferred the lire of panel instruments to a location in Orrville, Ohio, leaving the facilities to Tcbar.
Tobar marufactures the same line of transmitters under the trade name Tobar model 32, which include gauge pressure transmitters, absolute pressure transmitters, and differential pressure trans-mitters for use in nuclear power plants. Tobar also manufactures a similar line of transmitters for non-nuclear applications and the model numbers are distinguished by the prefixes 75 or 56 (instead of 32 for nuclear).
b.
Principle of Operation - Pressure Transmitters The principle components in the Tebar Model 3 EPA type pressure and absolute pressure transmitters are the measuring head and the AC amplifier. The measuring head consists of a capsule assembly and process connection flerge, both welded together as a single unit. The capsule assembly consists of a diaphram on which has been deposited a bridge network of strain sensitive
a b
ORGANIZATION: TOBAR INC.
TEMPE, ARIZONA REPORT INSPECTION NO.: 99900837/86-01 RESULTS:
PAGE 4 of 10 resistive elements. The diaphram is electron beam welded to the support and header assemblies. The header assembly con-tains hermetic feed through leads which carry the electrical g
signal from the diaphram to the amplifier.
The amplifier emplifies the measured signal received and furnishes a proportional 4-20mA output signal. An oscillator /
AC amplifier /demodulator set-up is used to provide stable operation with minimal thermal drifts.
c.
Principle of Operation - Differential Pressure Transmitters The principle components in the Tobar model 32DP type pressure differential transmitters are the measuring head and the AC amplifier. The measuring head consists of a differential pressure capsule assembly (capsule) and two process connection flanges. The capsule consists of a flexure on which has been deposited a bridge network of strain sensitive elements. The flanges are bolted together with the capsule between them. A pressure applied to each flange is transferred as a force to the respective diaphram. The capsule converts the algebraic difference between the two pressures into an electrical signal and provides it to the amplifier.
The amplifier amplifies the received signal and furnishes a proportional 4-20 mA output signal. An oscillator /AC amplifier /
demodulator set-up is used to provide stable operation with minimal thermal drifts.
2.
Review of 50.55(e) Reports a.
South Texas Project 50.55(e)
On August 1, 1986, Houston Lighting & Power (HLP) the owner of South Texas Project Nuclear Power Plant reported that Veritrak pressure transmitters manufactured and supplied by Westirghouse exhibited excessive changes in their accuracy under varying ambient tenperatures.
In a subsequent letter to the NRC dated August 29, 1986, HLP stated that Westinghouse confirmed that Veritrak transmitters which provide input for various Reactor Protection System trip functions, ESF actuation, and post-
ORGANIZATION: TOBAR INC.
TEMPE, ARIZONA REPORT INSPECTION NO.: 99900837/86-01 RESULTS:
PAGE 5 of 10 accident monitoring, are subject to excessive change in trans-mitter accuracy under varying ambient temperatures. Westinghouse provided the confirmation to HLP based on the results of tests 3
performed on Veritrak transmitters which were supplied to Seabrook Nuclear Power Plant and subsequently returned to Tobar for additional tests.
b.
Seabrook Nuclear Power Plant 50.55(e) Report On March 7,1986, Public Service of New Hampshire (PSNH), the owner of Seabrook Nuclear Power Plant (Seabrook), reported that during testing of pressure transmitters, Veritrak type 76PH2, calibration shifts due to ambient temperature changes in excess of the 1% per 100 F specified maximum were recorded.
The transmitters were returned to Westinghouse to analyze the cause and to repair the transmitters.
On June 30, 1986, PSNH reported that they installed Tobar Model 32 type pressure transmitters to replace Veritrak transmitters after performing ambient temperature compensating tests on Tobar transmitters and determining that their ambient temperature compensation shifts were within Seabrook's allowable technical specification limits.
c.
Summary of Discussions with Tobar Management The inspectors discussed the performance of Veritrak pressure and differential pressure transmitters with Tobar management personnel and determined the following.
1)
The Veritrak absolute pressure trarsmitters (APTs) and differential pressure transmitters (DPTs) installed at Seabrook and South Texas Project were manufactured by Festinghouse. During the change of ownership from Westinghouse to Tobar, Tobar complated the assembly of I
selected Veritrak transmitters which were in various stages of assembly.
2)
Tobar performed temperature compensation tests (TCTs) on 5 APTs and 20 DPTs returned by Westinghouse. These were Veritrak transmitters which had been supplied to Seabrock.
During these tests, Tobar determined that 3 APTs, with date code 8240 (manufactured during the 40th week of 1982),
exhibited a large change in the temperature coefficient
l ORGANIZATION: TOBAR INC.
TEMPE, ARIZONA REPORT INSPECTION NO.: 99900837/86-01 RESULTS:
PAGE 6 of 10 between the tinie of shipment (as shipped) and the time of tests'(as received). The temperature ccefficient is the change in calibration setpoint with the change in
)
ambient temperature. The date code refers to the manu-facturing date of the sensing capsule. Tobar determined from the records that 3 other Veritrak APTs with date code 8240 had been shipped to Braidwood Nuclear Power Station.
Tobar arranged for their return and performed similar tests to ascertain whether they also exhibited a large change in temperature coefficient between the as shipped and the as returned condition. The test results indicated that these APTs did exhibit a shift, but not as large as the ones returned from Seabrook.
3)
Tobar performed TCTs on 2 pts, 5 APTs and 8 DPTs manufac-tured by Tobar. The 5 APTs were manufactured during the 15th, 16th and 17th week of 1984. The accuracy ranged from -1/2% to +1/8%. The accuracy of all the pts and DPTs were within the specified accuracy for operating tempera-tures (80 F to 130 F) and accident corditions (280 F).
The accurecy was above the 6% margin at accident condition (320 F).
3.
Tests Performed on Transmitters Tobar perforced TCTs on Veritrak transmitters returned to them by Vestinghouse and on Tobar transmitters. After the unit was stabi-lized at the temperature, the reference accuracy was established for each transnitter at 80*F, by adjusting the cutputs at 0, 50% and 100%
of the input per rango. The accuracies were verified subsequently at 130*F, 280"F, and 320*F. At each of these temperatures, the unit was soaked for at least 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> to attain thermal stabilization. The temperature cycle used to verify the accuracy for each unit was 80 F-130 F-80 F-130*F-80'F-280 F-320 F-80 F.
The deviations from the reference accuracy were recorded. A sunrary of the results are as fellows:
a.
The deviations from the reference accuracy in a population of 25 Veritrak transmitters manufactured and stored over 1 year exhibited a standard deviation of approximately 5%.
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ORGANIZATION: TOBAR INC.
TEMPE, ARIZONA REPORT INSPECTION N0.: 99900837/86-01 RESULTS:
PAGE 7 of 10 b.
The above test results were compared with the test results recorded during the environmental qualification tests performed in 1983 to qualify Veritrak transmitters to IEEE 323-1974. The O
final test results obtained after the Veritrak transmitters were artifically aged, irradiated, and subiected to loss of coolant accidert (LOCA) also exhibited a 5% standaro deviation.
It must be noted that the 5% standard deviation is a statistically derived deviation and individual units may exhibit a larger deviation.
For instance, the output of one of the units prepared for environmental qualification test exceeded the permissible 6%
deviation at 320 F stabilized temperature. However, the outputs of all transmitters were within 6% deviation during the entire LOCA simulation.
c.
Three of the Veritrak APTs returned by Westinghouse with manu-facturing date code 8240 exhibited a large change in temperature coefficient between the time of shipment and the time of testing.
d.
The deviation from the reference accuracy in a pcpulation of 13 Tobar transmitters manufactured and stored for more than one year exhibited a 1% standard deviation. At 280 F stabilized temperature, for all transmitters, the outputs were within the 6% deviation limits. At 320"F stabili::ed temperature, one unit exhibited a 6.5% deviation. The original test records indicate that the deviation was balnw 6%.
e.
Recently manufactured Tobar transmitters exhibited a 1% stardard deviation in steady state accuracy at 4 different ambient temperatures.
f.
The inspectors observed that there is no correlation between the results obtained during stabilized condition at 320 F elevated temperature ard the output results during a simulated LOCA.
During LOCA, the 320*F plevated temperature is brief (only a few seconds) after which the temperatura drops. There-fore, the output deviation beyond 6% cbserved during the 320'F steadystate temperature should not affect the performance of the transmitters under LOCA conditions.
Furthermore, the calibration of the units in place are not verifiable at 320 F, because 320"F steadystr.te temperature cannot he generated and maintained inside the containment.
ORGANIZATION: TOBAR INC.
TEMPE, ARIZONA REPORT INSPECTION NO.: 99900837/86-01 RESULTS:
PAGE 8 of 10 4.
Procurement Document Control The NRC inspectors verified the implementation of the established procurement document control by review of 5 perchase orders relating to transistors, resistors, capacitors, sensing elements, and printed circuit boards used in manufacturing Tobar transmitters. The NRC inspectors determined that Tobar purchased material from manufac-turers listed on the Approved Vendor List, that applicable quality requirements including revision levels were referenced, and that the manager of product integrity signed and dated purchase orders after the review cycle.
5.
Document Control The NRC inspectors verified the implementation of document control by reviewing 5 drawings pertaining to transistors, capacitors, sensing elements, resistors, and printed circuit boards used in manufacturing Tabar transmitters. The inspector determined that the drawirgs were reviewed and approved; that drawing changes were approved and that the master drawing file including status records, revision notices, and the original drawing was being maintained in accordance with established procedures.
The NRC inspectors also reviewed the established procedures for preparing and controlling the Product Integrity Nuclear Quality Program Procedures Manual. The NRC inspectors determined that the manual was being distributed, controlled, reviewed, and approved in accordance with established procedures.
6.
Control of Purchased Material, Equipment and Services The NRC inspectors verified the implementation of the control of purchased material by reviewing records such as purchase orders, drawings, inspection plans, data cards, test reports and certi-fications relating to transistors, resistors, capacitors, sensing elements and printed circuit boards. The NRC inspector verified that the vendors were on the Approved Vendor List, that the inspection plan listed the attributes to be inspected such as visual, dimensional, testing as determined by the drawing, that the inspector annotated acceptance /rejecticn of the material on the inspection plan, that a sampling plan was used, the proper revision of the drawing was used, that material certification was on file, and that the test data was in the file when required.
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ORGANIZATION: TOBAR INC.
TEl4PE, ARIZONA l
REPORT INSPECTION NO.:
99900837/86-01 RESULTS:
PAGE 9 ef 10 The inspectors determined that the sensors are manufactured in West L
o Germany. Tobar sends the parts for the diaphrams (for pts) and i
)
flexures (DPTs) and the manufacturer returns the material with the F
depcsited strain guage.
Specifically, for a DPT, the netal volume filler and header made of, stainless steel are sent to Germany. A molybdenium 138 flexure beam is welded to the header and the volume filler is welded to the header.. Both welds are perfortned by electron beam. A printed circuit is applied to the volume filler, lead bonds are attached from the deposited flexure to the printed circuit and connections are made to the header pins. The manufacturer performs electrical tests to determine acceptability. Tobar, verifies the operability during receipt inspections.
N 8.
Nonconformino Materials, Parts, or Components
(
The NRC inspectors verified the implementation of nonhinforming inater!al by reviewing Discrepant Material Disposition Reports s
(DMDR) initiated at receivingJnspection. Of the DMDRs reviewed, the NRC inspectors ~detarmined 'that proper ci: position of the material was taken by Tobar, ttat the DMDRs were concurrently V
signed by the appropriate personnel, that appropriate corrective action was taken, and that control of nonconformirg material was being implemented.
s 3
9.
Inprocess Inspections The inspectors observed work in progress and partially completed' in-process travellers on which in-process inspection results are documented. Selected trav'allers were verified to have traceability to the partially assembled parts. The inspectors observed the following ir-process inspections that were being performed on differential pressure capsules and that the Tobar QC inspector signed-off indicating that the workmanship was acceptabla.
The formed diaphrams which enclose the capsule were visually a.
inspected for deformities, b.
The wire leads soldered to the helder pin and the flexure essembly were inspected for workmMship, c.
A leak chack test was performed on the flange /diaphram assembly.
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d.
The serial number of the assembly was recorded,
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ORGANIZATION: TOBAR INC.
TEMPE, ARIZONA E
REPORT INSPECTION NO.: 99900837/86-01 RESULTS:
PAGE 10 of 10 e.
The solder on the header wirirg was visually inspected.
1 f.
A leak check test was perforned on the header / body tube g
and body tube / base.
g.
The capsule assembly was to be electrically tested for zero balance and activity.
A traveller was available with similar inspection attributes for inprocess inspections for pressure capsules.
F.
EXIT INTERVIEW:
The inspectors ret with individuals identified in section G and discussed the scope and findings at the conclusion of the inspection.
G.
PERSONS CONTACTED:
T. R. Fisher, President and General Manager E. J. Miller, Vice President Engineering J. H. Murphy, Product Integrity Assurance Manager
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