ML20210C672
| ML20210C672 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon, South Texas, 05000000 |
| Issue date: | 04/22/1976 |
| From: | Parr O Office of Nuclear Reactor Regulation |
| To: | Morrissey J PACIFIC GAS & ELECTRIC CO. |
| Shared Package | |
| ML20210C503 | List:
|
| References | |
| NUDOCS 8705060263 | |
| Download: ML20210C672 (8) | |
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NUCLEAR REGULATORY Coff. MIS $10N
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_gtp-Docket Nos. 50-275 and 50-323 E "'
'I /.7.v file Pacific Cas and Electric Co:npany KITN: Mr. John C. Morrissey Vice President 4 General Counsel 77 Beale Street San Frcncisco, California 94106 Gentlemon:
Wo have completed our evaluation of your report entitled "h'estinghouse Protection Systens Naisc Tests" which was suhnitted with your letters dated January 16,1975, April 7,1975 and Novenber 24, 1975, h'c have fowr.1 that the test program is acceptabic and that it dc=onstrates acceptabic perfor.rance as impic.nonted at Diablo Canyon. Other a,plicants
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referencir.g the report will need to provide justification that t ic tests reported encon. pass the potentini clectrient faults or interference reficcting into the systems tested as n result of the particular plant's design.
Our evaluation is provided in the enclosure.
Sincercly, 0lA.e,.,,ID[sn i
O nn D. larr, Chief Light 1.'ater Reactors Liranch Na, 3 Division of Project tranagement F.ncionure:.
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Pacific Gas anxi Electric Company APA 2 0.D76 cc:
Philip A. Cranc, Jr., Esq.
Pacific Gas and Electric Company 77 Beale Street San Francisco, California 94106 Andrew J. Skaff, Esq.
California Public Utilitics Comission 350 >!cA111 ster Street San Francisco, California 94102 hfr. Frederick Eissler, President Scenic Shorelino Preservation Conference, Inc.
4623 b! ore b!csa Drivo Santa Barbara, California 93105 his. Ell:abeth E. Apfelberg 1415 Cazadero San Luis Obispo, California 93401 Fis. Sandra
. Silver 5055 Radford Avenue
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h' orth Ibilywod, California 91607 h!s. Rayc Ficming 1746 Chirro Street San Luis Obispo, California 93401 Ftr. John Forster 985 Palm Street San Luis Obispo, California 93401 h!r. William P. Cornwc11 P. O. Hox 453 bbrro pay, California 93442 E!r. W. J. l.indblad, Project Engineer Pacific Gas and filectric Company 77 Beale Street San Francisco, California N106 fir. Gordon A. Silver
, 5055 Radford Avenuo h' orth llollywod, California 91607
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EVALUATION. 0F THE WESTINGHOSUF PROTECTION SYSTEM NOISE TEST REPO T
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_ Summary of_ Report
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"The subject report was initiated as a result of our concerns relating to the qualification of electrical isolation devices, design criteria requiring elactrical and. physical separation between p rotection and control circuits and "as built" protection sya: cms immunity to cicetricci noise.
We have indicated in our Safety Evaluation Report of the Diablo Canyon Nuclear Pouer Station, Units 1 and 2 dated October 16, 1974, that during l
the CP revicus of both units the physical and electrical isolation of protection and control was not adequate and the impicmentation of the design presented in the FSAR does not meet the regnirements of Sections -
4.2, 4.6 and 4.7 of IEEE Std 279-1971.
The voltages and test methods were salected to cover the credibic voltager,
and noisc conditiens for the systems tested.
Westinghouse defined the following acceptance criteria for all tests.
Noise would net degrade the ability of the protectic.n systems to a.
provide the necessary action
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Noisc wh'ich caur.cs initiation of protective actiono, vill be reported j
and evaluated on a case by case basis.
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The test report vcs divided into threc sections covering the follouing Westinghouse supplied systems:
1 Section A Solid State Protcetien Systen (SSPS).
Appendi:t A of thir.
noction' contained isolatien vovification tests and results for the Light Emitting Dioden (LEDs) used for isolation in
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the SSPS.
.9ection_J Nucicar Instrumentation System Section_C Process Analog System 7100 Serics I
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The above identified cyntens were rubjected to the followinp testa.
4 Representative channels core energir.cd and the functional operability 1
c hecked f or each tor.t.
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Noisc Susceptibility Tests These tests were run in accordan"ce with MIL-N 19900B, dated June *7, 1960, Military Specification - Nucicar Propulsion Control and Instrumentation Equip =cnt, Cencral Requirements, Paragraph 4.6.11, Susceptibility.
-Output Cabic Voltare Faults The maximum credibic voltages ('118 V AC and 250 V DC) were applied to each system output cabling to decernine the effect on the input side.
Two additional tests were conducted on the Analog Proces,s System.
A' 460 V AC fault test and a 125 V D~ test switching a 2.17h inductive lo.
to simulate the inductive componcut of the isolator output circuit.
The isolator output circuits were disconnected during tha fault tests.
The isolators and connectors have already been qualified for fault vol ages and currents which verified operability of the input side during destruction of co ponents in the output portion of the isolator.
The output cable voltage fault ccsts were to verify the adequacy of the caMd separation (input / output) of the "as built" systems.
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}!agnetic Interforence Tests l
These tests were conducted by disconnecting the output cables and j
introducing a 118 V AC powcr source and providing a 100 ohm load at t!s. !
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connector cad to allow 1 caporc to ficw in the output wiring.
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input side of the isointor was conitored for indu:qd noisa.
Since the j
input / output wiring in the Process Analog System arc closer than the j
other r.ystems the 1 aepara A0 current was routinely switched.
Light Enittine, Diode (LED) Verification Tests l
I These tests were conducted by introducing a co non mode voltaga source the isolation boardt A 2 Kv de dynamic cource and ic?pulac tests at 2K peak.
12Cu: ringing down 1:. 6 - 10 cycles applied for i uinute.
A 140 rms 6011: dynaalc sourec was applied to the output side of the isolato; i
.and the input monitored to decernine the effect of a destruct fault voltaga.
The tests ucre performed to demonstrate that potentials applied on the non-protection side are not directly (Clachover) or in-directly (induced or capacitanec) coupled into the protettinn logic side.
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Tito banis for selecting the 1 nnp value for the car,nctic interferenco tests described above were based on cn analytical study.
The calculat connidered untuistad contrci cabica running parallel for 30 caters with three-phase conductors carrying 200 a porcs.
The induced loop currcor ev calculated to ha 7.7 nicro-c.mporun in a 100 ohn 1 cad;--The 1 m.p.r. e s.an ule.:te..) La pov2e a cea.vrm.iva w tuo f or Lae LO:.t.
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3 Test Procedures Description and Results The test icport provided decciled test procedurcs and descriptions f or the tests identified above.
Westinghouse summarized the results of the tests for cach of the systems tested.
2.0 Sumnary of Regulatory Review We reviewed the detailed test procedurcs, setup, description, functional checks and test results for the systems identified in the summary of the repert.
The results of all the tests conducted indicated that the tests performed did not introduce interference or noise from the non-safety to the safety portion of the systems.
The functional verification portion of the tests indicated that the equip-ment performed as designed, beforc, during and af ter tests.
The sa'fety f unctions of the systems ucre exercised dnring the tests.
As we have indicated in the nummary of this report, the test program was initiated as a result of our concerns relating to the lack of physical separation between the protection and control cf.rcuits in the final impicnentation of the system designs which could result in interaction between control and safety functions.
Nestinghouse has indicated as part of their a:ceptance criteria that noisc which cause.s initiation of protective actionn, if any, would be acco.pcalle.
We found thin criteria u.acceptuhic.
lEEE Std 279-1971, requires that the protection synten shall, with precision and reliability, autor.atically
( }J initiate appropriate protective action whencycr a condition monitored by the system reaches a pre-set level.
The acceptance criteria uns modified indicatinc, : hat any spurious operation would be reported and evalunted on a case by case basis.
The orir,inal report did not include 460 V AC tents on the i*;o.'.ntor output viring.
We informed Gestinghouse of thir require =cnt at a meeting held February 6, 1975 (sce reference, Enclosure 2).
Uc unre later inforrced that the 460 V AC had been perforacd during the crigiral tests a nd would be documented in Supple. ment 1 of the report.
We reviewed the report through Supplement 1 and found it acceptable uith the fo11 cuing exceptions (1) the acceptance criterin must be nodified and (2) the nef sc curceptibility tests inust be nodified and repeated due to lack of justification for locating the noice source 18 inches from the equip-nent tunted.
Uc requir ed that ned Lfied ::11.-::-199003 ::o.ius Susceptibility Tent Procrac or a new progran be initiated for the Analog precenn !;ystem uhich uill include the follouing rcquirc~.ents.
The test program uf.11 include all the provloions or cinilar iequirenentr. of ilII.-N-19900".
!!owever, the n olne coerce output cable si all run in the name cable ways, vertical and herb.onteil, es tha input /eutput cab.'en of the Analn~, Procces Syccc i
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..i r t hf' libli.ci'. t.j 8t;stcc f ren Lt i* na j ce Courrt' output d ' t 'i ' i v f;tr t he* eqttip-rien t t e:: Led in t he,* l l.-N-] (, m tes t o in t h.1t typic.nl c.'bh v.tya d'0"rd s
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4 ships are 18. inches wide.
If the installed equipment experiences noise interfer'ence problems,.the source can be detected and separated by at least a distance of 18 inches.
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Subsequent to our review, Westinghouse informed the staff that the
- s ubject tests were run in the canner identified in the Regulatory Position of our review during the original testing.
We indicated to Westinghouse that the information decuennted should be' adequate to perform an independent evaluation of the test scope, basis, procedures, impicntntation and results of the test program performed.
Supplenent 3 documents revised acceptance criteria and additional material addressing our requirements relating to the MIL-U-19900 Noise Susceptibility Test Program identified'in our evaluation of the subject report dated August 15, 1975.
(sce references, Enclosure 2).
The test results indicated that the systems. tested operated as designed before, during and after the tests.
Thn safety functions of the systems were exercised durlug the tests.
Rep,ulatory Position-Wo.have concluded that the test progran, as documented through Suppic-mont 3, is acceptabic.
The results of the test program indicate that the syster.s are n'ot degraded below an acceptabic 1cyc1 and can pc fors their cafety functions, during the faulted conditions tested, as it-plcmented at the Diablo Canycn Nucicar Power Station.
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Uc require that any applicant rcIorencing this report provide justi-fication that the tests reported encompass the potcntial electrical faults or interference reficcting into the systems tested as a result of their particular b.' lance-of-plant designs.
The requirements of Regulatory Guide 1.75, " Physical Independence of E1cetric Synters" tuct be net for any neu system desf ens and for all devi un for construe:Jon permit applicationc for which t!'c 1.isua date t
o f the Safety Evalcation Kaport in February 1, 1974, or after.
We utilized IEEE Std 279-1971, " Criteria for Protection Systens for Nuclear Power Cencrating Stations," in our revicu of this Westinghouse Test Report.
Other references used arc included in Encionure 2.
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o ENCLOSURE 2
'i REFERENCES 1.
Report of Process Instrumentation Isolation haplifiers, dated-1brch 28, 1973.
2.
Westinghouse Topical Report WCAP 7488L Solid State Protection Systen Description, dated January, 1971.
3.
Summary of Electrical Site Visit end Meeting Held on February 20-22,1E dated March 18, 1974."
4.
Summary of Meeting with Westinghouse Electric Corporation, dated August 7, 1974.
5.
Safety Evaluation Report. Diablo Canyon Nuclear Power Station Units 1 and 2, dated October 16, 1974.
6.
Summary of Mactin; Held February 6,1975 to discuss separation and qualification, dsted March 5,1975.
7.
Letter dated /.pril 7,1975, PGr.E to NP.C, trancaitting Suppleacnt 1 to the Ucstinghounc Protection Systen Noice Test R2 pert.
G.
Letter dated Septerlber 4,1975, O. Parr to J. Morrissey, transttitting
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the results of the Ecguletory Staff review of the Ucstinghounc Protection Syctem Noice Test Report.
9.
Letter dated Movember 24, 1973, PG0E to NRC, transmitting the Westinghouse letter US-!U"J-1047 including Supplen:ent-3 to the Westinghouse Protection Syste,Noiac Tent Report.
I'EE Std 279-1973, " Criteria for Protection Systens for Nuclear 10.
J Power Cencratidt; Stations."
11.
Regulatory Guide 1.75, " Physical Independence of Electric Fystccs, Revision 1", dated January, 1975.
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Westinghouse Protection Systems Noise Test Report, Revision 2, October 1975 L1/NRC/ba