ML17285A634
| ML17285A634 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 07/20/1989 |
| From: | BOUCHEY G D WASHINGTON PUBLIC POWER SUPPLY SYSTEM |
| To: | FAULKENBERRY B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| GO2-89-120, NUDOCS 8907310070 | |
| Download: ML17285A634 (24) | |
See also: IR 05000397/1989021
Text
AC CK1ZRATED DlSTKBUTION
DEMONSTRATION
SYSTEM REGULATORY
INFORMATION
DISTRIBUTION
SYSTEM (RIDS)ESSION NBR:8907310070
DOC.DATE: 89/07/20 NOTARIZED:
NO DOCKET CIL:50-397
WPPSS Nuclear Project, Unit 2, Washington
Public Powe 05000397 AUTH.NAME AUTHOR AFFILIATION
BOUCHEY,G.D.
Public Power Supply System RECIP.NAME
RECIPIENT AFFILIATION
FAULKENBERRY,B.
Region 5, Ofc of the Director SUBJECT: Provides addi info re acceptability
of five installed items.for use in safety related applications,per
Insp Rept 89-21.DISTRIBUTION
CODE: IEOID COPIES RECEIVED:LTR
J ENCL g'SIZE: I TITLE: General (50 Dkt)-Insp Rept/Notice
of Violation Response NOTES: RECIPIENT ID CODE/NAME PD5 PD INTERNAL: ACRS AEOD/DEIIB
DEDRO NRR/DEST DIR NRR/DOEA DIR 11 NRR/DREP/RPB
10 NUDOCS-ABSTRACT
OGC/HDS2 RES MORISSEAU,D
ERNAL: LPDR NSIC COPIES LTTR ENCL 1 1 2 2 1 1 1 1 1 1 1 1 2 2 1 1 1 1 1 1 1 1 1 1 RECIPIENT ID CODE/NAME SAMWORTH,R
NRR/DLPQ/PEB
NRR/DREP/EPB
10 NRR/PMAS/ILRB12
0-B,J 02 RGN5 FILE 01 NRC PDR COPIES LTTR ENCL 1 1 1 1 1 1 1 1 1 1-1~1 1 1 1 1 1 1 1 1 1 1 R I D S A NCTE'IO ALL"RIDS" RECIPIENT:
PIZASE HELP US IO REDUCE HASTE!CONI'ACT'IHE DOCUMWI'ONHRL
DESK, RDCN Pl-37 (EXT.20079)KO ELXKBRXR YOUR MHE FKH DZPHUBUTICN
LISTS FOR DOCUMEMI'8
YOU IXlNiT NEEDf OTAL NUMBER OF COPIES REQUIRED: LTTR 25 ENCL 25 D S
ti WASHINGTON
PUBLIC POWER SUPPLY SYSTEM V P.O.Box 968~3000 George Washington
Way~Richlaiid,"Wa'shinglon
99352 July 20, 1989 G02-89-120"ll: 0~Docket No.50-397 Mr.B.H.Faulkenberry
Deputy Regional Administrator
U.S.Nuclear Regulatory
Commission
Region V 1450Maria
Lane, Suite 210 Walnut Creek, CA 94396 Dear Mr.Faulkenberry:
Subject: Reference:
NUCLEAR PLANT NO.2 LICENSE NO.NPF-21 NRC INSPECTION
REPORT 89-21 ADDITIONAL
INFORMATION
1)Letter, B.H.Faulkenberry (NRC)to D.W.Mazur, dated July 3, 1989 2)Letter, B.H.Faulkenberry (NRC)to D.W.Mazur, dated July 14, 1989 Per the verbal agreement made in our telephone call on July 13, 1989 and the Reference 2)letter, we are providing additional
information
regarding the acceptability
of the five installed items for use in safety related applica-tions, This response includes specific critical characteristics
and verifi-cation methods.This additional
submittal provides details on how the current Supply System commercial
grade dedication
would be performed in accordance
with EPRI Standard NCIG-07 guidelines.
These evaluations
also demonstrate
the acceptability
of the previous dedication
efforts by the Supply System.Both this submittal and the previous submittal concluded that the actions taken by the Supply System were acceptable'e
conclude that the items procured and installed are accep-table and of a quality level commensurate
with the items importance
to safety.The Supply System has determined
that some of the items under review were produced and supplied under 10CFR50 Appendix B gA programs.The application
of these gA programs as accepted by the Supply System ensures that characteristics
affecting form, fit and function are controlled
to a design standard and that quality of the item can be verifi'ed.
These items are now essentially
bei ng treated as guality Class I items and do not require dedication.
Additionally, both submittals
were reviewed by our consultant
of CYGNA Energy Service.They have reached the same conclusion.
CYGNA has been involved in development
of the EPRI standards for commercial
grade dedication
and in the NUMARC training for industry personnel.
~>07:<<i070
Sg0720 PDR AGGCK 05000397 0 PDC~~H'
Page Two NRC INSPECTION
REPORT 89-21, ADDITIONAL
INFORMATION
Commercial
grade dedication
activities
have been evolving as.an area of grow-ing concern with the NRC and Utilities over the past several years..The guidance that has been available to Utilities for commercial
grade dedication
is only now evolving.This is demonstrated
by the issuance of the EPRI/NCIG-07
Standard dated June 8, 1988, the NRC conditional
endorsement
of the methods developed by this standard in March of 1989 (the same time as the SSOMI per-formed by the NRC at HNP-2)and by NUMARC endorsement
of.this standard in March of 1989 with utili ty implementation
planned to be complete by December of 1989.For all of the five items of concern the original dedications
were performed in advance of issuance of the EPRI Standard, the NRC Generic Letter (89-02)and the NUMARC endorsement
of the EPRI Standard.These dedications
were done by qualified engineers to assur e acceptability, and the judgements, conclusions
and basis for dedication
were reviewed by qualified engineers'n
conclusion, it is the Supply System's position that improvements
can and have been made to our dedication
process to provide added assurance and documentation
of acceptability.
It is also our position that these items are acceptable
for use, that the dedications
were acceptable
as prepared based on existing acceptance
criteria and that none of these items represent a violation of NRC regulations.
Should you have fur ther questions regarding these items we suggest a meeting would be the appropriate
format to allow full exchange and resolution
of con-cerns.Very truly your s, G.D.Bouchey,, Directo Licensing 8 Assurance SHP/bk Attachment
cc: JB Mar tin-NRC RV NS Reynolds-BCP8R RB Samworth-NRC Document Control Desk-NRC DL Hilliams-BPA/399 NRC Site Inspector-901A
Page 1 of 12 ATTACHNENT
1 ITEN NO.1: POTTER 8(BRUNFIELD RELAYS Item Description
-Relay, control 8PDT contacts rated 0.8 amp 125VDC resistive, 125VDC continuous
duty coil, NIL-R-19523A(SHIPS), operating voltage general service (80 to 110K), endurance category A, ambient temperature
65 degrees C, shock class 1 Additional
Su 1 S stem Res onse These relays are"like for like" replacements
for the origina'1 installed relays.Critical Characteristics
Determination
Function of the Item-Active electrical, this relay is energized on a"loss of offsite power" signal.Hhen picked-up it enables/causes
a diesel auto start.Failure Nodes/Effects
-1)Coil short circuit/failure
of diesel to start.2)Coil open circuit/failure
of diesel to star t.3)Coil short to ground/failure
of diesel to start.4)Contact failure to change to energized state/failure
of diesel to start.5)Contact failure to change to de-energized
state/makes, it difficult to stop DG, use of"emergency
stop" switch will stop DG.Returning switch to normal would cause DG ,to star t, (acceptable, DG running is safe condition).
6)Contact chatter in energized state/could
cause air start motors to stop operating.
This is not considered
a credible failure as the K16 relay which is in series with the K52 and K54 relays would also have to drop out and then air start motors (pneumatic)
would stop.7)Contact chatter in de-energized state/could
cause diesel start (acceptable-
DG running is safety condi ti on).Cri ti cal Characteri
sti cs 1)Relay operation'al-endurance
-500,000 operati ons 2)Relay operation frequency-10 cycles per minute (minimum)3)Ambient temperature
-65 degrees C 4)Seismic capability
5)Coil rated voltage-125 VDC 6)Coil operating voltage-80 to 1105 of rated 2)Coil pick-up voltage-80%of rated (maximum)8)Coil duty-continuous
9)Contact configuration
-8PDT 10)Contact rating-0.8 amp continuous
at 125 VDC resistive
,/
Page 2 of 12 r Verification
Method The manufacturer
has a gA program which has been audited by Wisconsin Electric Power Company (audit A-Y-88-20).
This audit determined
that the manufacturer's
program was acceptable.
The manufacturer
is an approved vendor of these NIL Spec.Relays by listing on Federal ()ualified
Products List (APL 19523-13).
The manufacturer
has a ()A program which has been audited by Washington
Public Power Supply System.This audit determined
that the manufacturer
is acceptable
for the supply of commercial
grade items for use in safety applications.
The audit specifically
covered the manufacturing
of NDR relays to the requirements
of NIL-R-19523A(SHIPS).
This audit gives us reasonable
assurance, that state-ments made by the manufacturer
with respect to the design, testing and inspec-tion of the relay are correct..MIL-R-19523A(SHIPS)
requires qualification
testing of the following critical characteristics
and assurance that the above defined acceptance
criteria are.met.It also requires periodic testing and testing after"...any change in design which.affects performance
characteristics." LNote that the following critical characteristics
are considered
performance
characteristics
by NIL-T-19523A(SHIPS)].
Relay Operational
Endurance Relay Operational
Frequency Ambient Temperature
Coil Operating Voltage Coil Pick-up Voltage Coil Duty Contact Rating Seismic capability
was originally
established
for the relay by testing.The applicable
test report is Wyle Labs.Report 43735-.1, dated 9/20/78.This test qualified the relay as part of the panel E-CP-DG/EP1.
MIL-R-19523A(SHIPS)
requires vibration testing of the relay after"...any change in design which affects performance
characteristics." The test requires that the relay's resonant frequency be determined
by test.This test requires a 0.010 single amplitude vibration applied for 15 seconds at 1 Hz.steps from 4 to 33 Hz.The relay is then vibrated from 4 to 50 Hz.(in 1 Hz.steps)for.5 minutes at each frequency[amplitude
as specified in MIL-R-19523A(SHIPS)].
The relay is then vibrated at its resonant frequency[amplitude
as specified in MIL-R-19523A(SHIPS)3
for two hours.Although the amplitude/frequency
combina-tions required by the tests do not attain the levels required by the OID (assuming that the relays ar e not rigidly mounted)the NIL tests are of such extended duration that is it our judgement that the NIL testing imposes suffi-cient design constraints
such that similarity
is established
to the relays tested by.Wyle.Acceptance
criteria in MIL-R-195523A(SHIPS)
is no mechanical
damage, contact chatter or failure to operate to either the energi zed or de-energized p'osition.
Operation will be checked at each frequency.
Page 3 of 12 Coil rated voltage is specified in the purchase document and is stated on the relays nameplate.
It is normal procedure for the receipt inspection
to verify by comparison
that the received item's nameplate data matches the purchase documents description.
The audited manufacturer's
()A program gives us reason-able assurance that the correct nameplate is attached to the relay.MIL-R-19523A(SHIPS)
requires routine testing of each relay subject to MIL-R-19523A(SHIPS).
This testing includes: o Visual and mechanical
examination
to verify the materials, design, con-struction, dimensions, weight, marking and workmanship.
o Measuring the coil resistance
to determine if it is within 10K of the value required by the design.o Measuring of the insulation
resistance
to determine if it is within design limits.o Measure of the pick-up and drop-out voltages at maximum operating tempera-ture to determine that they are within specified limits.o A dielectric
test.The routine testing gives us reasonable
assurance that the relays supplied are of high quality and that-the problem documented
by Palo Verde Unit 3 LER, Docket Number 50-530, does not exist for the supplied relays.Control over relays with know deficiencies
identified
by specified data code has been estab-lished to assure none are installed, available for installation
or procured by the Supply System.Post maintenance
testing would also reveal this problem.Contact configuration
is verified at time of installation
by post maintenance
testing.Per the INPO NPRDS records on 968 MDR relays there have been 35 failures based on records fr om 12/8$to 10/88.The failure rate for this relay type is approximately
3 X 10.This is considered
by the Supply System to indicate a high reliability
factor.The Supply System has obtained certification
that the relays supplied through Newark Electronics
were manufactured
by Potter 8 Brumfield to the purchase order requirements
and the Potter 8 Brumfield gA program as verified by serial numbers on relays.A Supply System ()A Auditor has verified that the tests and inspections
required by the MIL Spec.were accomplished
on 2/10/87 or 2/12/87.Conclusion
The Supply System concludes that all critical characteristics
of the relay have been verified by a combination
of manufacturer's
testing/inspection (Method 1*), Supply System testing/inspection (Method 1), audit of manufacturer (Method 2), performance
history (Method 3)and approved'vendor certification.
Therefore, the relay installed by MNR AV1684 is acceptable
for its application.
- Exception
methods as defined in NCIG-07
Page 4 of 12 ITEM NO.2: ANCHOR DARLING VALVE PARTS Item Descriptions-
Item 2-1-stem, yoke ASTM A-564 Gr 630 HT 1150 F, with collar (P/N 19-2-01)for 12" 900 lb.Anchor Darling double disc gate valve.Part No.94-13401-19-2, Dwg.No.94-13401, item 19-2.Item 2-2-wedge, upper yoke ASTM A-216 Gr WCB with Stellite for 12" 900 lb.Anchor Darling double disc gate valve.Part No.94-13401-14-5, Dwg.No.94-13401, item 14-5.Item 2-3-wedge, lower ASTM A-216 Gr WCB with Stellite for 12" 900 lb.Anchor Darling double disc gate valve.Part No.94-13401-15, Dwg.No.94-13401, item 15.Item 2-4-pin, wedge ASTM A-108 Gr 1018 (AISI 1018)for 12" 900 lb.Anchor Darling double disc gate valve.Part No.94-13401-82-14, Dwg.No.94-13401, i tern 82-14.Additional
Su 1 S stem Res onse The Supply System re-evaluation
of these items has concluded that the items are available and were originally
manufactured
under the Anchor-Darling
()uality Assurance program.We have revised this evaluation
to require these parts to~~~be supplied as equality Class I.Anchor Darling has provided certification
under a r evision to the original purchase order that the items supplied meet the requirements
of this program.The Supply System has audited the Anchor Darling equality Assurance Program and its implementation
on numerous occasions.
Anchor Darling is maintained
on the Supply System's Evaluated Suppliers List (ESL)as a 10CFR50 Appendix B ()uality Class I supplier.The current full audit was performed in June of 1987, six (6)months before the subject parts were procured.This audit was the basis for inclusion of Anchor Darling on tHe Coordinated
Agency of Supplier Evalua-tions (CASE)list of approved suppliers.
Additional
inspections
to assure implementation
of their program occurred in February of 1988, April of 1988, June of 1988, October of 1988, December of 1988 and January of 1989.These inspections
pr ovide additional
assurance of supplier performance
history.Anchor Darling was audited by a team of auditors from 3 utilities on October 11 13, 1988 as a Nuclear Supplier equality Assurance Committee joint utility audit.This audi t also concluded that Anchor Darling's OA Program"was evaluated as effective and satisfactory".
This audit specifically
addresses piece parts supplied, including commercial
grade parts.The Supply System concludes these items'are acceptable
as installed
,/
Page 5 of 12 ITEM NO, 3: FUSES (600 VOLTS AND LESS)Additional
Su 1 S stem Res onse Standard Procurement
and Use Policy No.6,"Fuses (600 volts and under)" was issued on 6/30/87 to define procurement
and dedication
requirements
for these items.This policy was prepared by an engineer from the Supply System design engineer-ing organization, reviewed by an engineer matrixed to Plant Technical from design engineering, and approved by the Supervisor
of Plant Technical Electri-cal Group and the Manager of Electrical/18C
group of design engineering.
The Supply System policy and acceptance
of the fuses in questions is based on an understanding
of the manufacturer's
processes, Underwriter's
Laboratory (UL)activities
and our experience
with fuses.To confirm our, policy we contacted the manufacturers
in question on 6/27/89.These conversations
provided the following:
o Bussmann 1)Bussmann fuse production
quality is governed by the Bussmann ()uality Assurance Manual.2)The ()A Manual includes: a.Physical checks to verify compliance
to design requirements
and workmanship, b.100K resistance
checks, and c.UL specified tests.o Gould 1)Gould production
testing is governed by their (}A Manual.2)UL listed fuses are subjected to quarterly testing at the factory by UL.Additionally, Supply System, Procurement
QA made contacts with the QA'Manager of Bussmann in June of 1985 to ascertain their testing requirements.
The contact concluded that"in-process
testing consisted of gaging for length and DC resis-tance testing at 100K of rated amperage".
Also"On a random basis, ()C con-ducts audits of the in-process
manufacturing.
-During these audits, fuses are sele'cted for destructive
testi ng;i,e., subjected to anywhere from 130-500K of rated amperage.All Bussmann fuses are subjected to these tests."
Page 6 of 12 On 3/16/88 Gould-Shawmut
was added to our"commercial
grade" suppliers list based on review of a ()A audit performed by American Electric Power on 9/17/86., This audit concludes: "Gould, Inc.is an established
manufacturer
of circuit protection (fuses).Although Gould does not claim to do nuclear work, their'()A program is written to 10CFR50 Appendix B, ANSI N45.2 and 10CFR21.In general, Gould's OA program and implementation
is adequate for the manufacture
of fuses.Both of these manufacturers
produce UL listed fuses.UL independently
tests these fuses to assure'acceptability.
The performance
of these tests was audited.by Niagra Mohawk in April of 1988 and concluded UL listing was a"cri tical characteristic" of a listed product.Our review of this audit and UL standards concludes that UL activities
constitute
a significant
quality assur-ance effort involving certification
by an independent
'laboratory
that the products meet the published industry standard.Observance
of the requirements
of the UL Standards by a manufacturer
i.s a condition of continued listing of the product.UL Standards specify requirements
for, construction, dimensions
and performance.
Performance
testing is completed on samples of eacH type of material (or design).Tests include: 1).Capacity test-fuses must carry 110K of rating indefinitely.
i 2)Temperature
test-fuse temperature
must not exceed specified temperature
limits when subjected to 110K rated current.Clearing time current test-fuses must clear (open)within specified time limits when subjected to'a combination
of current values.Test values are 135%, 1505, 200$and 500K based on fuse type.4)Other design verification
tests (i.e.interrupting
ability, m~ximum energy, maximum threshold ration, let-through
current and clearing I t.).~The Supply System's use of fuses is controlled
by procedure (PPM 1.3.47)which requires evaluation
of the fuse log and identification
of repeated failures of fuses..This evaluation
would reasonably
b'e expected to identify a concern with fuse quality.PPM 1.3.47 requires: 1)Inspection
of fuses for evidence of overheating.
2)Replacement
of fuses wi th like in kind fuses.3)Requirement
to replace known incorrect fuses with the proper fuse as found.
Page 7 of 12 4)Requirement
to log fuses as replaced to provide a record of fuse replace-ments.5)6)Requirement
to replace all fuses when one fuse is replaced in the circuit, i:e., both sets of isolation fuses, all three fuses in three phase appli-cations, both fuses for DC applications.
This practice limits the possi-bility of fuse again causing a problem of inadvertent
opening.Requirement
for checking fuse integrity after installation.
7)Requirement
for a technical review of replacements
every three months to assure fuse configuration
is being maintained
and to identify recurring failures or other design problems.Critical Characteristics
Oetermination
Functions of the Items-Fuses are used in safety related equipment electrical
circuits to prevent severe equipment damage in the event of faults or shorts, to protect 1E motors and transformers
from overloads and to provide isolation of non-1E circuits from 1E circuits.The fuses have been sized with the consi-deration for the total loads the fuse would be expected to experience
under all conditions.
This sizing is done in a conservative
manner (at least 125K of full load current)to preclude the event of a fuse opening in any condition other than a real fault or overload, and minimize impact of commercial
product tolerances.
~~Failure Nodes and Effects-Fuses have two failure modes of concern: I)inad-vertent opening with no fault or overcurrent
condition and 2)fai lure to open when a fault or overload exists.Inadvertent
opening could result in loss of downstream
safety related equipment operability.
.Random loss of a fuse in one division and subsequent
loss of downstream
safety related equipment would not affect the ability of the redun-dant division's
equipment to perform the required safety fuctions.In all cases this loss of function would be repairable
by fuse replacement
in a mini-mal amount of time.Failure to open on a fault or overcurrent
condition could cause the upstream circuit protection
devices to open potentially
resulting in loss of additional
safety related equipment operability
of the same division but would not affect the ability of the redundant divisions equipment's
ability to perform the required safety functions.
Critical Characteristics
Critical characteristics
for fuses include manufacturer's
part number and.current rating, and UL listing where fuse is UL listed.
Page 8 of 12 Yerification
Methods Industry Standards govern the manufacture
of fuses.These controls provide an acceptable
level of assurance that the items have sufficient
quality.Audi,ts of UL activities
described above provide further assurance of product accep-tabi lity (Method 2).Historical
performance
of fuses provide an additional
level of assurance (Method 4).Receipt inspection
verifies proper rating, part number, and UL listing where fuse is UL listed by comparison
with procurement
requirements (Method I).Controlled
application
of fuses and fuse trending program provide further assurance of fuse acceptability.
Conclusion
Our acceptance
of fuses has not been based solely on installation
checks to verify fuse quality.Tests at the time of installation
verifies that the fuse replacement
has restored circuit integrity.
Testing which will.verify that a fuse wi 11 perform in a manner consistent
with its design parameters
will generally result in destroying
the fuse.We are further unaware of any industry consensus concerning
receipt testing of fuses.Fuses are relatively
simple devices which operate on physical principles
that are well characterized.
We know of no basis for doubting that modern designs can perform their intended function.Application
of specific fuses by design engineers includes adequate margin to account for production
tolerances.
Our experience
with these fuses has not identified
a quality concern.~~The Supply System is aware of a utility doing extensive inspection
of procured fuses and'are rejecting significant
levels of fuses based on failure to pass a load test.These failures have primarily been with non UL listed fuses.We have been in contact with this utility and are reviewing their program to see if a similar or joint effort is warranted.
We are also aware that these tests are difficult to perform without a controlled
environment
and the results of this testing may be questionable.
The Supply System concludes the installed Fuses are acceptable
as installed'
Page 9 of 12 ITEN NO.4: PRESSURE SWITCH Item Description
-Switch, pressure, range 10-250 psi, differential
23-25 psi, maximum allowable pressure 300 psi.double pole double throw contacts rated 10 amps at 600 VAC, with form W-1 (NENA 4 watertight
enclosure).
Square D Part number 9012 ACW-29.Additional
Su 1 S stem Res onse These switches were procured as commercial
grade because the Supply System understood
the manufacturer
no longer offered them as (}uality Class I.We have subsequently
learned that the manufacturer
always offered these'tems as (}uality Class I but was accepting orders only for replacements.
We expect to revise our procurement
evaluation
to a (}uality Class I purchase, audit the manufacturer
and add them to our ESL.The manufacturer's
(}uality Assurance department
stated that these switches were made under the same (}A program even while not offered as (}uality Class I.Critical Characteristics
Determination
Function of the Item-These pressure switches monitor the air pressure in the Division I and 2 diesel generator air receivers.
Their function is to start and stop the non safety related air compressors
to maintain a specified range of air pressure in the air receivers and provide low air pressure alarms.The switches perform a passive mechanical
integrity function (prevent air leakage from the air receiver due to switch leak).Failure Nodes and Effects-In the event of loss of mechanical
integrity of the switch the switch will provide a start signal to the compressor
upon reaching the low setpoint.The makeup capacity of the compressor
is greater than the leakage capacity through the switch so this is of minor significance.
In the event of failure of the pressure switch to start the compressor
at the low pressure setpoint due to contact seizure, binding or other causes, the pressure switch will provide a low pressure alarm to the control room which will allow the operator to manually start the air compressor.
.Nechanical
integrity is the only concern for seismic qualification, contact chatter does not pose a problem in this application.
The switch can easily be serviced without declaring the DG inoperable, there is a totally redundant system in service which provides sufficient
air for multiple start attempts.This switch has minor safety significance
due to the failure effects and the redundancy
provided.
Page 10 of 12 Critical Characteristics
1.Range 10 to 250 psi 2.Contact rating-10 amps 600 YAC 3.Part No.-9012 ACH-29 4.Contact Configuration
-DPDT 5.Differential
-23-25 psi 6.Seismic integrity Yerification
Methods Items 1, 2, 3, and 5 were verified by comparison
of nameplate/tag
data with the procurement
requirements, as part of standard receipt inspection
and have been reverified
on installed switches (Method 1).Item 4 was verified as part of installation
checks, calibrations
and post maintenance
operability
tests (Method 1).Installation
included QC inspection
of the work performed.
Item 6 is assured by the switch being a like for like replacement.
The manufac-turer has stated that no significant
design changes occurred which would effect the mechanical
integrity of these switches.Original switches were qualified by Supply System in Qualification
Information
Documentation (QID)file 256015.Additionally'he
switches have a pressure rating such that a safety margin greater than two times exists.The Supply System has contacted Stoneway Electric and obtained a copy of their invoice for the switches supplied by Square D Company which provides trace-ability to the manufacturer.
These verifications
provide adequate assurance the switches are acceptable.
Conclusion
The Supply System concludes tha't the switches as installed are acceptable.
Page 11 of 12 ITEN NO.5'ETAL 0-RINGS Item description-
Item 5-1-O-ring, metallic, 2.262" OD (as measured prior to plating)0.125" free height 0.010" wall thickness, Inconel X-750 w/0.001" minimum silver plate, American Engineering
P/H 2262-125X010
-AMS5582Ag.
Item'5-2-O-ring, metallic, 1.656" OD (as measured prior to plating)0.125" free height 0.010" wall thickness, Inconel X-750 1656-125X010
-ANS5582Ag.
Addi ti onal Su 1 y S stem Res onse Dedication
requirements
are stated in Design Change Package DCP 83-0056-OA
dated 4/22/85.A CNTR was not required for the metal O-rings-, but was received.with the purchase as it is that vendor's practice to always provide the CNTR from the material supplier as a courtesy to the purchaser.
Generation
engi neering has determined
that the effects of temperature
cycling on these 0-ring seals are negligible
in this application.
These 0-rings are specifically
exempted as pressure boundary parts by the ASNE Code.However to assure all possible safety functions are evaluated the Supply System provided the following evaluation.
Critical Characteristics
Determination
Function of the Item-, These 0-ring seals constitute
a part of the containment
pressure boundary between ECCS system relief valves and the containment
suppression
pool.The discharge strainer in the suppression
pool is below the water level.The sole safety function of the 0-rings is to provide a pressure tight seal at the discharge flange of RHR-RV-18.
Failure Modes/Effects
-Seal leakage or failure is the only plausible failure mode.1)'elief Valve Opera'tion
Seal failure would cause a small leak in the RHR heat exchanger room if any of the various system relief valves sharing.the common discharge path to the suppression
pool were to'ift.The leak would stop as the valve re-seats.2)LOCA Event The containment
pressure that would be required to push suppression
pool water from 466'-3/4" elevation to a relief valve height of 585'-9/16" is approximately
51.4 psi, which is higher than the 45 psi containment
design pressure and significantly
higher than the highest postulated
accident pressure in containment.
The water seal would therefore mai ntai n containment
integrity.
If the water seal were lost, the effects would be insignificant
due to the small size of the leak.
Page 12 of 12 Cri ti cal Char aeter i sti cs 1)The 0-ring diameter must be of correct size to properly fit into the associated
groove on the flange.2)The 0-ring height (tube diameter)must be of correct size to provide a seal when installed.
Verification
Method DCP 83-0056-OA
required a"Type 8" leak test in accordance
with'0CfR50
Appendix J t'o determine adequacy of installed material and workmanship (Method 1).This was performed at installation
and documented
on the installing
MWR.Seal integrity is tested periodically
pursuant to 10CFR50 Appendix J.Conclusion
The Supply System concludes that the 0-rings are acceptable, as installed.
1 t II~