ML20044D186
| ML20044D186 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 05/10/1993 |
| From: | Norrholm L Office of Nuclear Reactor Regulation |
| To: | Rossi C Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 9305170353 | |
| Download: ML20044D186 (8) | |
Text
r DDocket Nos.: 50-259 50-260 50-296 MEMORANDUM FOR:
Charles E. Rossi, Director Division of Reactor Inspection and Licensee Performance Office of Nuclear Reactor Regulation FROM:
Leif J. Norrholm, Chief l
Vendor Inspection Branch
+
Division of Reactor Inspection and Licensee Performance Office of Nuclear Reactor Regulation
SUBJECT:
MINUTES OF MEETING WITH WYLE LABS ON ITS QUALIFICATION OF PNEUMATIC CONTROL ASSEMBLIES (PCAs) FOR THE BROWNS FERRY NUCLEAR POWER PLANT (BROWNS FERRY)
REFERENCE:
HRC (Norrholm) letter to Wyle Laboratories (Smith), dated March 22, 1993 t
On April 2, 1993, the Deputy Director of the Division of Reactor Inspection and Licensee Performance and other NRC staff members met with representatives of Wyle Laboratories to discuss Revision A to the Third Party Qualification Test Report (TPQ) 30081-99 of January 28, 1993, which qualified eight PCAs for the main steam isolation valve operators for Browns Ferry by similarity to previously qualified operators.
i At the conclusion of the discussion, the NRC staff informed Wyle representatives that they had provided sufficient additional information on the referenced technical issues to satisfactorily resolve the NRC concerns.
Details of items discussed and a list of attendees are included in Enclosures 1 and 2, respectively, to this memorandum. Wyle's formal response dated April 14, 1993, addressing our comments is included as Enclosure 3 to this memorandum.
~
0EGINAL SIGNED BY:
Leif J. Norrholm, Chief Vendor Inspection Branch g51gy y @
Division of Reactor Inspection P
PDR and Licensee Performance Office of. Nuclear Reactor Regulation
Enclosures:
1.
Details of Items Discussed 2.
Meeting Attendees 3.
Wyle's Response to NRC Comments of April 14, 1993 I
p DISTRIBUTION:
WITH ENCLOSURES: VIB R/F DRIL R/F GC9ALINA S. HYTEN (WYLE)
SALEXANDER TROSS PCAMPBELL 1.1005'J HORNSTEIN DOCKET / CENTRAL FILES /PDR j fre %Lh5 (t ncuwAb l OFFICE VIB/DRIL VIB/DRIL VIB/DRIL DRIL/NRR DRIL/NRR NAME KNAIDlIk GCWALINAA LNORRHOLM RZIMMERMAN CEROSSI DATE b/ l$ /93 4/ 1'/93 4/:V/93 Miic[ 04/3/93A k/ '7/93 f-h COPY
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NO YES YES
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DOC O
V 6 &~rdcw 0FFICIAL RECORD COPY Document Name: A:\\WYLE. MIG
DDocket Nos.: 50-259 50-260 50-296 MEMORANDUM FOR:
Charles E. Rossi, Director Division of Reactor Inspection and Licensee Performance Office of Nuclear Reactor Regulation FROM:
Leif J. Norrholm, Chief Vendor Inspection Branch Division of Reactor Ir N etion and Licensee Per.%.manc a Office of Nuclear Reactor Regulation
SUBJECT:
MINUTES OF MEETING WITH WYLE LABS ON ITS QUALIFICATION OF PNEUMATIC CONTROL ASSEMBLIES (PCAs) FOR THE BROWNS FERRY NUCLEAR POWER PLANT (BROWNS FERRY)
REFERENCE:
NRC (Norrholm) letter to Wyle Laboratories (Smith), dated March 22, 1993 On April 2,1993, the Deputy Director of the Division of Reactor Inspection and Licensee Performance and other NRC staff members met with representatives mf Wyle Laboratories to discuss Revision A to the Third Party Qualification Test Report (TPQ) 30081-99 of January 28, 1993, which qualified eight PCAs for t
the main steam isolation valve operators for Browns Ferry by similarity to previously qualified operators.
At the conclusion of the discussion, the NRC staff informed Wyle f
representatives that they had provided sufficient additional information on i
the referenced technical issues to satisfactorily resolve the NRC concerns.
Details of items discussed and a list of attendees are included in Enclosures i
I and 2, respectively, to this memorandum. Wyle's formal response dated April I4,1993, addressing our comments is included as Enclosure 3 to this memorandum.
Leif J. Norrholm, Chief Vendor Inspection Branch Division of Reactor Inspection and Licensee Performance Office of Nuclear Reactor Regulation
Enclosures:
a I.
Details of Items Discussed
+
2.
Meeting Attendees t
3.
Wyle's Response to NRC Comments of April 14, 1993 DISTRIBUTION:
WITH ENCLOSURES: VIB R/F DRIL R/F GCWALINA S. HYTEN (WYLE)
L SALEXANDER TROSS PCAMPBELL HORNSTEIN DOCKET / CENTRAL FILES /PDR 4 tce @(15t6 f_tmacatdt>
l OFFICE VIB/DRIL VIB/DRIL VIB/DRIL DRIL/NRR DRIL/NRR NAME KNAI'Dtfh GCWALINAA LNORRHOLM RZIMMERMAN CEROSSI f
4/87f93 M b[q [4fj;/93d k/ '7/93 $
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DATE
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(
NO YES NO YES OfflCIAL RECORD COPY Document Name: A:\\WYLE. MIG
/
UNITED STATES y
3, ',j NUCLEAR REGULATORY COMMISSION h
-g W ASHINGTON, D. C. 20555 p
e
,, /
May 10, 1993 Docket Nos.:
50-259 50-260 50-295 MEMORANDUM FOR:
Charles E. Rossi, Director Division of Reactor Inspection and Licensee Performance Office of Nuclear Reactor Regulation FROM:
Leif J. Norrholm, Chief Vendor Inspection Branch Division of Reactor Inspection and Licensee Performance Office of Nuclear Reactor Regulation
SUBJECT:
MINUTES OF HEETING WITH WYLE LABS ON ITS QUALIFICATION OF PNEUMATIC CONTROL ASSEMBLIES (PCAs) FOR THE BROWNS FERRY NUCLEAR POWER PLANT (BROWNS FERRY)
REFERENCE:
NRC (Norrholm) letter to Wyle Laboratories (Smith), dated March 22, 1993 On April 2,1993, the Deputy Director of the Division of Reactor Inspection and Licensee Performance and other NRC staff members met with representatives of Wyle Laboratories to discuss Revision A to the Third Party Qualification Test Report (TPQ) 30081-99 of January 28, 1993, which qualified eight PCAs for the main steam isolation valve operators for Browns Ferry by similarity to previously qualified operators.
At the conclusion of the discussion, the NRC staff informed Wyle representatives that they had provided sufficient additional information on the referenced technical issues to satisfactorily resolve the NRC concerns.
Details of items discussed and a list of attendees are included in Enclosures 1 and 2, respectively, to this memorandum. Wyle's formal response dated April 14, 1993, addressing our comments is included as Enclosure 3 to this memorandum.
i
~
fi l
Leif. tgrrholm, Chief Vendor Inspection Branch Division of Reactor Inspection and Licensee Performance Office of Nuclear Reactor Regulation
Enclosures:
1.
Details of Items Discussed 2.
Meeting Attendees 3.
Wyle's Response to NRC Comments of April 14, 1993
?
DETAILS OF ITEMS DISCUSSED DURING THE MEETING WITH WYLE LABS i
t Backaround In 1980, Wyle performed environmental qualification tests on pneumatic control assemblies (PCAs) manufactured by the Automatic Valve Company (AVC), Novi, Michigan, for a group of four licensees, Tennessee Valley Authority (TVA)
(Browns Ferry), Commonwealth Edison Company (Dresden), Detroit Edison Company (Fermi 2) and Pennsylvania Power and Light Company'(Susquehanna), to the requirements of IEEE 323. Wyle documented the results in its Report No. 17514-1, Revision A (Wyle Report). The qualification tests enveloped environmental conditions for the four plants.
l AVC fabricated the PCAs for main steam isolation valve (MSIV) operators.
It l
uses solenoid operated valves (SOVs) manufactured by Airmatic Allied i
Incorporated (AAI). The Five Star Company (FSC) and Quality Coils Company (QCC) supply the coils to AAI for assembling the SOVs.
j I
In 1991, Wyle prepared Third Party Qualification (TPQ) Report No. 30081-99, documenting its qualification of eight.AVC PCAs for TVA's Browns Ferry nuclear power plant (Browns Ferry) based on similarity to the PCAs previously qualified by the Wyle Report. One of the anomalies documented in the Wyle i
Report was that some AVC SOVs failed the aging test.
_ yle-unsuccessfully W
attempted to determine which of the two coil manufacturers supplied the coils that failed. The staff was concerned that AVC may have used coils similar to the ones that failed during the Wyle tests in the PCAs intended for Browns Ferry.
During an inspection at Wyle in May 1992, the NRC issued a notice of nonconformance to Wyle for certifying the eight AVC PCAs supplied to Browns t
Ferry without adequately demonstrating similarity to the ones qualified in the i
Wyle Report. On September 29, 1992, Wyle notified the NRC pursuant to 10 CFR Part 21 that Report 30081-99 does not provide sufficient evidence that the eight AVC PCAs are qualified by similarity to Wyle Report 17514-1, Revision A.
l In a letter dated February 12, 1993, Wyle informed the NRC that, based on its revised similarity analysis provided in Revision A to TPQ 30081-99, it is closing the 10 CFR Part 21 notification of September 29, 1992.
t The NRC staff reviewed the revised TPQ and requested Wyle to provide t
additional information for eight items related to the revised TPQ. Wyle i
agreed to meet with NRC staff on April 2,1993, to discuss the eight items.
Minutes of the Meetino 4
Wyle informed the NRC that some of the SOVs failed during the latter stage of the aging tests because they were exposed to higher than anticipated temperatures. However, the S0Vs did not fail to exhaust during the 3 t
simulated loss of coolant accident environmental conditions.
1 i
i
Wyle presented slides showing the various components of the PCA that successfully withstood the environmental qualification tests (1980) and explained the functions of each component. Wyle stated that the S0Vs that failed during the aging tests had been exposed to higher than expected temperatures because the temperature was measured inaccurately.
Initially, Wyle used thermocouples around the SOVs to measure the temperature. After discovering that this method inaccurately measured the temperature of the S0V coil, Wyle used variations in the resistance of SOV coil magnet wire to measure the temperature. With a known resistance-temperature coefficient of the magnet wire, this method gave a more accurate indication of the actual temperature of the coil.
Wyle stated that it issued the 10 CFR Part 21 on September 29, 1992, after it determined that its personnel had not adhered to established procedural requirements after an NRC inspection during May 1992 identified a nonconformance with the similarity argument used in its TPQ.
Earlier, the NRC staff had expressed a concern regarding Wyle's use of Houghton H-620 type lubricant used in PCAs. Wyle responded that it had used Houghton H-620 type lubricant on the aluminum manifold during the tests and
-showed specimens (on which H-620 was used) in the slides to confirm that those components did not exhibit deterioration after about 13 years.
Because Wyle reported that it had used Houghton H-620 type lubricant without deleterious effects during the qualification tests, Susquehanna Steam Electric Station (Susquehanna) instructed AVC (in 1985) to use the same lubricant in PCAs being supplied to them. On December 10, 1986, Susquehanna experienced common-mode failures on all the AVC supplied MSIV operators. The lubricant had corroded i
the unanodized aluminum manifolds in the PCAs. AVC reported this matter to the NRC pursuant to 10 CFR Part 21. The staff was concerned that, unaware of its incompatibility to unanodized aluminum, a licensee may inadvertently use Houghton H-620 to lubricate the PCA solely because the Wyle Report documents it as an acceptable lubricant.
During the meeting, Wyle provided the following additional information in response to the eight items addressed in the referenced NRC letter, dated March 22, 1993.
1)
Para. 8.6.2 of the test report, page 7, states, in part, "The dimensions of the springs, Line Nos. 9 and 10... varied slightly and they have shown to have no effect on the operability of the SOVs as demonstrated by their functional tests..."
The staff was concerned that at elevated temperatures, such as might be expected at a nuclear power plant, changes in spring dimensions may cause interference and impede the operation of the SOVs.
Wyle representatives stated that they had determined that the coefficients of linear expansion of the spring, the seats, and the stem of the 50V are larger than that of the plunger and are therefore compatible. The clearance between the spring and the plunger was measured in an 50V (including manufacturing tolerances) and found to be very close to the test specimen.
2
f t
.l l
2)
Para. 8.6.2 of the test report, page 8 - states, in part, "The travel of the plungers, Line No. 22...were different and were shown to have no effect on the operation of the SOVs as demonstrated by their. functional
(
testing..." The staff was concerned that at elevated temperatures such j
as might be expected at a nuclear power plant, the travel of the plunger i
is impeded.
?
Wyle's response to this question was the same as in No. 1.
In addition, Wyle stated that its technicians had measured the travel distance and found the difference to be negligible.
j 3)
Para. 8.6.2 of the test report, page 8, addresses, "The calculated j
relative position between the bottom of the coil and the top of the r
mani fol d... " The report notes that the measured value for the qualified i
manifold assembly is lower than those measured for the'new SOVs. The report provides several possible sources for the differences.
In light of the fact that manufacturing techniques and tolerances can result in dimensional differences, and that the spring dimensions and plunger j
travel have changed, the staff had requested Wyle to provide further i
justification that design changes do not adversely affect the S0V operation at elevated temperatures.
Wyle responded that the calculated coil to manifold dimension' in the new i
S0V is only 0.101-inches greater than the qualified 50V. Therefore, there will be no significant change in the closing time.
4)
Para. 8.6.2.1 of the test report, page 9, states that the new S0V small l
Exhaust Adapter 0-ring (line 19) is made of Viton A.
Please provide justification for your conclusion that the use of the Viton A 0-ring "does not impact the qualification of the manifold assembly" when the actuator is exposed to elevated temperatures and a radiation i
environment.
Wyle indicated that the Viton A type small Exhaust Adapter 0-rings used in the current SOVs were similar to those that successfully withstood exposure to the radiation environment documented in the Wyle Report.
l 5)
Para. 8.6.2.1 of the test report, page 9, indicates that the large Exhaust Adapter 0-rings (Line No. 20) are also made of Viton A.-
The staff requested Wyle to justify the use of Viton A in an elevated
[
temperature and radiation environment.
Wyle indicated that the Viton A type large Exhaust Adapter 0-rings used in the current SOVs were similar to those that successfully withstood exposure to radiation environment documented in the Wyle Report.
6)
Para. 8.6.2.3 of the test report, page 10, states that.the originallyL qualified Molded Bobbin for the 120 V ac coils (Line No. 34) "was shown to be ' extremely degraded material which may once have been similar' to the new one."
The staff had requested Wyle to justify the similarity argument in light of the fact that the originally qualified bobbin was l
extremely degraded and could not-be accurately analyzed.
3 l
Wyle did not consider the coil bobbin safety-related.
Further, Wyle also stated that, even though the epoxy was degraded, it was still possible to compare the two bobbins.
7)
Para. 8.6.2.3 of the test report, page ll, stated that the 750 V ac Molded Bobbin (Line No. 35) was "polyphenylene so;ffde with some dimethyl silicone. The silicone could be contamination ~from the 0-ring lubricant..." The staff had requested Wyle to verify the source of the silicone contamination and to identify the silicone grease (manufacturer, type and qualification).
Wyle identified the lubricant as Super-0-lube grease but could not determine the reason for its presence. Wyle postulated that the grease came from the hands of the technician who performed the disassembly.
8)
In the past, many of the S0Y coils open circuited because of separation of the leads to the coil. The staff had asked Wyle if it had reviewed the sequence of operations to clean the joint where the leads are soldered to the 50V coil.
Wyle stated that it experienced only one such coil failure which occured while thermal aging the specimen. Because it had not inspected the coil manufacturer, Wyle did not know how the coil is attached to the lead wire. However, as a result of the failure, Wyle lowered the qualified life from ten years to five years.
In addition to the above, Wyle provided information to the NRC which showed the results of tests that it had recently conducted on AVC SOVs. The tests confirmed that AVC SOVs remained operable when exposed to elevated temperatures and accident environmental conditions.
Further, by additional disassembly and testing, Wyle stated that coils manufactured by both suppliers had successfully withstood the testing.
At the conclusion of the meeting, the staff informed Wyle that it had provided sufficient additional information on the above technical issues to satisfactorily resolve the NRC concerns. Wyle agreed to provide this information in a formal response.
4
MEETING ATTENDEES Wyle tabs l
l Sherwyn D. Hyton, General Manager i
Jim Gleason, Consultant Jim Anderson, Sr. Staff Engineer Nuclear Reaulatory Commission I
R. P. Zimmerman, Deputy Director, DRIL L. J. Norrholm, Branch Chief, VIB/DRIL G. C. Cwalina, Section Chief, RIS-2, VIB/DRIL K. R. Naidu, Sr. Reactor Engineer, RIS-2, VIB/DRIL H. L. Ornstein, Sr. Reactor Engineer, AEOD, NRC S. D. Alexander, RIS-2, VIB/DRIL T. M. Ross, Sr. Project Manager, NRR P. Campbell, Mechanical Engineer, NRR/DE/EMEB i
TVA l
Roger Huston, Manager, Rockville Office /TVA Hubert McCall, Elec. Eng., Browns Ferry /TVA f
s
i r
j ENCLOSURE 3 i
WYLE i
unau wse weercee=vces s wous onw Apdl 14,1993 a
Mr. IJef Norholm Division of Reactor & Inspection & Safeguards
[
Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission MS-9 D4 Chief, Vendor Inspection Branch I White Flint North i
11555 Rockville Pike Rockville, MD 20852 l
Subject:
Wyle Response to NRC Comments on Potential Part 21 on AVC Solenoid Manifold Assemblies Supplied To TVA
Dear Mr. Norholm:
I L
Wyle Laboratories appredated the opportunity on Apr0 2 to hi== our responses to i
your questions after which you indicated all questions had been antamfactorDy answered. This letteris our fonnal response and we trust it will serve as closure to the matter. Some general comments, before speciSc answers, are appropriate.
During the IOCA, the only safety function is to assure closure of the MSTV by allowing an exhaust path through the AVC Manifold Ameembly, since it is the AVC Manifold i
Assembly that is supplying the air pressure, which is Mwi off the MSfV piston. The l
solenoid coils are normally energised and have to i m@ to pedorm the safety
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function. The solenoids are in two out of two logic, and thus both safety ralated j
solenoids' plungers have to change state for the air to==haust. A faDure of one aclenoid in service, not dudng an accident, does not emua* a transient by inadvertent I
closure of the MSIV.
l The AVC Solenoid Manifold anaemblies were tested for all functions throughout the original qualiScation program, but only the safety related function was d*=ana'ated during LOCA, which is per the requirements of the IEEE Standmed 323 and the NRC's regulations including 20CFR50.49, NUREG 0588, DOR OnM*1=*= and Reg. Guide 1.89.
(
The original test program (Wyle Report 17514) was a generic r"#W br four l
utilities,1VA, CECO, PP&L and DE. Wyle actually found the initial problem with excess amounts of Parker's Super-O-Lube that caused operahuity problems after j
exposure to high radiation. Wyle then quah6ed Eve options (Super-O-laabe, Houghton 620, DC 200 DAG 156, and unlubricated), from which each utility could deade for themselves that was e y..y hte for them within the quahfication umbrella. Wyle r
qualified Super-O-Lube, using minute amounts and the application procedure in the test report. The Houghton 620, which has been the focus of the problem at PP&L did not cause a problem in Wyle's tests. As was seen by a March 1993 inspection of the l
original test specimen, it is relatively clean, has very light sorrosion, is still operational, even after surviving radiation, thermal aging, cycle aging, pressurisation cycle agmg, a severe seismic test medes, and six LOCA profiles in two different series.
i Since then it has been exposed to normal aging in Almha=='s weather in an unair-conditioned and unheated warehouse for four years and Class B storage for approximately four years.
1 p
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lW 7800 Govemors Dnve. P.O. Boa 077777
- Huenevme. Ateneme 35e07 7777. (ass) 837 4411
ENCLOSURE 3 1
j her.1MNorhoin,NRC
)
y Pase 2 1
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The solenoid coils are manufactured to an AVC drawing operine= dan, which identi6es the materials of construction, which are the anme for both vendora. The cons are kom third tier suppliers, Quality Coils and Five Star, through the mat =ald vendor Airmatic/ Allied / Snap-Tight to AVC.
i At the time of quali6 cation, we were aware of multiple con vergdors and attesapted to have representation in the test specimens, however, lookirs back at the spedmens that have been through all of the aforementioned testing, we definitely know that we had at least the Five Star coil as a test specimen, which had a unique marking. Other i
test specimen coils do not have the Five Star marking, but the location where the l
Quality Coil marking may have been is obliterated try the app 9-h_ of epony and the aged condition of the coils, since Quality cod marked the outer tape, prior to encapsulating Thus Wyle has relied on chemical and physical tests, supplemented with a series of -
temperature and temperature and steam tests to d*=an-trate that the AVC antmata Manifold assemblies are quali5ed. The eh*=le=1 and physical tests provide the evidence that the materials of construction are as anW'-d and thus, whGe not being exactly the same, are indicative of what was speci6ed in the drawings, 'd=+iA=d in the quali5 cation plan and are consistent in the test specimens and samples of the new TVA lot. Since the evidence does not show that materials are di5erent, it is concluded that they are essentinDy the same and are quah5ed.
Wyle's responses to the eight questions are as follows:
h 1.
Under accident conditions, the normally energised cons are de-energised and the return spring (Item 10) forces the plunger down and seals the puot seat ptem 4).
l The compensating spring (Item 9) loads the stem seat seal Stem 7) which performs no function during the safety related operation of the SOV. Therefore, only the temperature effects on the return spring wG1 be investigated.
j t
The return spring is made from 302 SS which has an average thermal aa-8ident of expansion of 9.9 (micro in/in/'F) over the temperature range of 32 to 572'F.
l The plunger is saade from 430F SS with a coefEcient of ewpanaian of 6.1.
[
Increasing temperature will increase the clearances between the spring and the plunger since the opnng will be incremaing in aise at a greater rate than the l
2 plunger. Therefore, an increase in temperature wul not adverne}y efect the
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relative movement of the spring and the plunger.
The stem (Item 12) has an ID of 0.688" where the spring amats and the OD of the spring (large end) is 0.578 which gives a total clearance of 0.110*. The stem is made of 304 SS which has the same coefEcient as 302 SS and 430F SS. In the worst came, going from 75'F to 3550F (peak accident temperature) the total clearance would be reduced about 0.0004 to 0.0006*. It is judged by Wyle that this OA to 0.6% reduction in the clearance has no measurable afIect on the i
relative motion of the spring and the stem.
The above calculations were based on two conservative assumptions. Phrst, that the internal components of the SOVs are at the " hot spot" temperature of the coil. Second, that there is no thermal delay during the aeddent transient and the internal connponents of the SOVs actually see these peak conditions.
k l
i
EMLOSURE 3 i
i her.WarNorhohn,NRC Page 3 i
Therefore, Wyle concludes that operational testing of the SOVs at aardd*at I
temperatures would have resulted in the same condations as experienced at
{
ambient temperatures.
t i
2.
The plunger travel (Item 22) of the quali5ed plunger was calculated as 0.0343*
and the new ones were 0.0372* which is s serence of*0.0029" which is well within the manufacturing tolerances for this type of assembly which is usually
+/.005- (based on conversations with several manufacturers). Variations j
caused by normal manufacturing tolerances are accounted for by the snarsms added to the acciden? test conditions. A change from ambient to accident conditions will have no effect on the diference in plunger travel. Wyle concludes j
that this difference will have no measurable e5ect an the operahuity af the SOVs i
under accident conditions.
i 3.
The dastance tom the bottom of the cod to the top of the manifaki (Item 48) is inversely proportional to the snagnetic force azerted on the plunger. Under accident conditions the normaDy energised mous. are de-energised and the plungers seal the puot seats Smee the new con was alightly further away hasa 1
the top of the snanifold than the quali5ed one, the restraining force as the plunger will be less. Therefore, as the snagnetic 5 eld decays, the return spring will be able to overcome the magnetic Seld slightly sooner and therefore close l
ever ao alightly sooner.
l The average thermal coef5eient of expansion of the armiale== steels used sanges from 6.1 to 9.9 (micro in/in/'F) over the temperature range of 32 to 572*F.
Aluminum alloys average about 13.5 over the same temperature range. Since i
the new and old designs use the same saetallic materials there would be no additional diference between these deagns due to the elevated temaperature during an accident.
4/5. It is Wyle's position that all the Vitan anals in the===ifald amoembly are j
subjected to the anme basic operating and mer4 dent conditions. Therefore, it is t
acceptable to qualify the small exhaust adapter e ring (Item 19) by counpering it j
to the stem o-ring (Item 13) and to quahfy the large exhaust adapter e-ring (Item
- 20) by comparing it to the puot acat meal (Item 6).
Both TGA and IR tests were performed on the test specimen e-rings and a esmple from the new not. The only diferences between the TGA testa perforsned, i.e. TGA 6 for the small e-ring and TGA 4 for the stem e-ring, is a 2% diference j
in the location of the Erst let derivative point (which is web within our normal
+/- 5% range) and 6% difference in the ash content which is only 1% outside our normal +/- 5% range. The addition of 1% additional amineral EDer will' i
alightly increase the e ring's resistance to radiation, aging and temperature.
Wyle judges that the Viton materials in the new lot are essentiaDy the same as j
the original test specimen and thus the uninor differences noted wD1 have no i
measurable effect on the operability of the SOVs under accident eendations.
l The only diferences between TGA 10 for the large e-ring and TGA T for the puot d
acat mealis a 3% difference in the location of the Erst let derivative point (which is well within our normal +/- 5% range) and an additional let derivative point at 1
the 83% point. This difference occurs at approximately 600*C (1100*F) which is i
1 J
f
m
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.l ENCLOSURE 3 i
l i
bir.1Jef Norholm.NRC j
page 4 l
about 7000F above the accident conditions in the plant. Wyle concludes that this diference will have no measurable efect on the operabDity of the SOVs l
under accident conditions.
l 1
On the basis of the above TGA data and the IR analyses that show the analysed o rings are Viton, Wyle concludes that all the seals are mande of the amme banc j
material.
l 6.
The bobbin is not safety related. It was degraded during the original -uam-
-i program, but still used in the anaembly to demonstrate that its inDure would not cause failure of the Manifold amoembly and it did not The meanifald man *=hly functioned properly dunng the accident tests.
7.
The source of auicone can only be from one of two places, the aoD lead wire, unhkely, or the Super-O-Lube from the e rings, most lutely. Wyle surmined that i
it most likely occurred during the dianamambly procedure which eBowed some j
i crose conta=tandan. The e-rings were removed Arst and the aiheene
(
j was thus inadvertently transferred to the bobbin when k was dinamammhtad. -
j 8.
Wyle only experienced one cod that had a solder joint inDure and k happened l
during thermal aging for this specimen that was attempting to qualify it for 10 years Wyle assumed that this was common mode _ inDure and lowered the qualihcJ i!fe goal to 5 years. Another test specimen was then aged to a 5 year equivalent life and completed the testing with no Aarther events.
Wyle did not inspect the solderjoints of the cons in the new order for TVA eince i
the coils were already potted by the time we asw them at AVC. Since we had i
a successfully tested multiple sets of cous in the 1751410CA alanula*iaan. this one fauure may in fact be random, or Aadic=dve of a reliabGity problema, but since
(
EQ only addresses common mode proble==.. It doesniinapact EQ.
j in further conErmation of the above responses, which we feel in themselves proposty answer your questions, Wyle has recently tested three Quality Cons (one AVC aal-aaid assembly), sampled from the same lot shipped to TVA to a series of temperature testa.
1 These testa were of the same sevesity and durations of the peak tesaperature r
conditions as the ensinal Test Report 17514 test including dry heat tests and stemma j
tests in a 1DCA chamber. Additional tems were also pedermed at values greatly in ancess of the original pro $le. A proprietary Wyle test report is avaBable at Wyle, which
[
documents these tests. The operating times were consistent in these tests and wen within the expected duration. These tests, therefore, provide additional conErmation l
of the Wyle position that the AVC assemblies supplied by Wyle to TVA met all j
4 requirements.
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1 Sincerely,
'I Wyle Laboratories Easte pe tions i
1 ward W. S cetor
-l Contracts and Purchaatng i
ES/bs l
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