ML20195C485
| ML20195C485 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 05/28/1986 |
| From: | Devincentis J PUBLIC SERVICE CO. OF NEW HAMPSHIRE |
| To: | Noonan V Office of Nuclear Reactor Regulation |
| References | |
| SBN-1073, NUDOCS 8605300347 | |
| Download: ML20195C485 (5) | |
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SEABROOK STATION Enginzaring Offics sib \\
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May 28, 1986 Put2c Service of New Hampshire SBN-1073 T.F.
B7.1. 2 NEW HAMPSHIRE YANKEE DIVISION United States Nuclear Regulatory Commission Washington, DC 20555 Attention:
Mr. Vincent S. Noonan, Project Director PWR Project Directorate No. 5
References:
(a) Construction Permits CPPR-135 and CPPR-136, Docket Nos. 50-443 and 50-444 (b) PSNH Letter (SBN-903), dated November 27, 1985,
" Resolution of Power Systems Confirmatory Items",
J. DeVincentis to G. W. Knighton (c) PSNH Letter (SBN-1020), dated April 25, 1986,
" Resolution of Power Systems Confirmatory Items",
J. DeVincentis to V. S. Noonan (d) PSNH Letter (SBN-1066), dated May 23, 1986,
" Response to Request for Additional Information on SER Confirmatory Issue No. 25", J. DeVincentis to V. S. Noonan
Subject:
Response to Request for Additional Information on SER Confirmatory Issue No. 25
Dear Sir:
Attached is our response to the Requests for Additional Information on the analysis and test program submitted by Reference (c) on the coct-puter IRTUs and the RTD/TC Conversion Cabinets. This information is in addition to that transmitted by Reference (d).
We trust that the attached responses are acceptable and request that resolution of the above referenced confirmatory issue be reflected in the next supplement to Seabrook's SER.
Very truly yours, L 9 ~x John DeVincentis Director of Engineering Attachment ec: Ato'nic Safety and Licensing Board Service List i
B50530C3 PDR E
ADO 860528 050004 3 P
Seabrook Staten Corstruction Feld Office. P.O. Box 700
- Seabrook,NH O3874 J
Dicn3 Curran, Esquire C31 vin A. Cann:g Marinon & Weiss City Manager 2001 S. Street, N.W.
City Hall suite 430 126 Daniel Stredt Washington, D.C.
20009 Portsmouth, NH 03801 Sherwin E.1bek, Esq.
Stephen E. Merrill, Esquire Office of the Executive Legal Director Attorney General N.S. Nuclear Regulatory Comunission George Dana Bisbee, Esquire Tenth Floor Assistant Attorney General 4
Washington, DC 20555 office of the Attorney General 25 Capitol Street Robert A. Backus Seguire concor11, MN 03301-4397 114 Lowell Street P.O. Box 516 Nr. J. P. Nadeau Manchester, NH 03105 Selectmen's Office 10 Central Road Philip Ahrens, Esquire Bye, NH 03870 Assistant Attorney General Department of The Attorney General Mr. Angle Machiros Statehouse Station M Chairman of the Board of Selectmen hugusta NE 04333 Town of Newbury Newbury MA 01950 Mrs. Sandra Gavutis Chairman, Board of Selectmen Mr. William S. Lord RFD 1 - Box 1154 Board of Selectaea Kennsington, NN 03827 Town Hall - Friend Street Amesbury, MA 01913 i
Carol S. Sneider, Esquire i
Assistant Attorney General Senator Gordon J. Humphrey Department of the Attorney General 1 Pillsbury Street One Ashburton Place, 19th Floor Concord, MN 03301 l
Boston, MA 02108 (ATTN: Herb Boynton)
Senator Gordon J. Humphrey H. Joseph Flynn, Esquire U.S. Senate Office of General Counsel Washington, DC 20510 Federal Emergency Management Agencyg (ATTN: Tom turack) 500 C Street, SW Richard A. Hanye. Esq.
Hampe and Mc51cholas Paul McEachern, Esquire 35 Pleasant Street Matthew T. Brock, Esquire Concord, NH 03301 Shatnes & McEachern I
t 25 Maplewood Avenue Donald E. Chick P.O. Box 360 l
Town Manager Portsmouth, NH 03801 Town of Exetsr 10 Front Street Cary W. Holmes, Esq.
Exeter, EH 03833 Holmes & Ells 47 Winnacunnet Road i
Brentwood Board of Selectmen Hampton, NH 03841 RFD Dalton Road Brentwood, NH 03833 Mr. Ed Thomas FEMA Region I Peter J. Mathews, Mayor 442 John W. McCorinack PO & Courthouse l
City Hall Boston, MA 02109 i
Newburyport, MA 01950 Stanley W. Knowles, Chair 1 nan Board of Selectmen t
l P.O. Box 110 North Hampton, NH 03862
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r SBN-1073 ATTACHMENT 1 RESPONSE TO REQUESTS FOR ADDITIONAL INFORMATION ON SER CONFIRMATORY ISSUE NO. 25
- 1) QUESTION The report discusses a RTD that is physically attached to the Uniform Temperature Reference (Page 4).
The report then goes on to test, out of its environment, a RTD mounted in motor windings (Page 10).
Explain the discrepancy and its effect on the report.
RESPONSE
The purpose of the RTD/TC-CC analysis and test was to demonstrate that any failures within the RTD/TC-CC wayld have no detrimental ef fect on field devices supplying input to the RTD/TC-CC.
Fo r RTDs, the field device la a motor where the RTD monitors winding t em pe rat ur e.
Since it was impractical to test an RTD actually mounted in a motor, the RTD was tested in free air with an acceptaace criteria of no catastrophic failure, i.e.,
if the RTD does not catastrophically fail, there could be no motor damage. This acceptance criteria was met with much margin since not only was the RTD not physically damaged but the current flow through the RTD during the test was only slightly above normal.
This shows that testing the RTD "out of its environment" had no effect on the test results.
As explained on Page 4, the RTD on the Uniform Temperature Reference (UTR) plate assembly is only used for processing the Thermocouple (TC) signal as part of the input to the computer.
Since the computer is non-safety related, potential degradation of this RTD was not specifically addressed.
However, even if there was a concern, the test results could be applied to this RTD since an RTD is just a resistor and the test results showed that the current through the RTD from the test was only slightly above normal.
- 2) QUESTION The " Analysis" section of the report,Section III, takes credit for fuses and circuit breakers. This invalidates the analysis.
RESPONSE
The statement on protection devices in Section III.C.1 (Page 5) was not intended to actually take credit for the protective devices preventing degradation of field devices but really was simply a
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statement of the circuit's response to a short circuit, i.e.,
protective devices will operate.
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SBN 1073 RESPONSE (CONT'D)
A short circuit at this point in the circuit (on the 120 volt side of the low voltage power supply or in the low voltage power supply circuit) presents no potential for field device degradation because the f ault current would flow directly back to the source through the short without going through the field devices.
Even if the protective devices do not operate, the short circuit current would flow until some component (wire, terminal, etc.) burns open with no impact on field devices because the fault current does not flow through the field device. Any damage to the RTD/TC-CC (for example, burned open components) as a result of the short circuit or the protective devices not operating is of no concern since the RTD/
TC-CC performs a non-safety related function. Therefore, the con-clusion is still valid that a short or short circuit to ground will not cause any detrimental impact on the RTD input devices.
- 3) QUESTION j
The rationalization used to eliminate technician errors on Page 8 is not acceptable for the following reasons:
a)
The method and type of splices is not defined.
Splices can separate.
l b)
There appears to be exposed connections on the 120 Vae cir-cuits and on the field circuit cennections - and both in the back of the rack.
c)
No credit may be taken for the OBVIOUS (Page 8).
RESPONSE
a)
The splices used for the 120 Vac terminations are qualified Raychem heatshrink splices.
b)
There are no exposed signal terminations directly on the back of the card rack. The signal terminations use enclosed connectors (ref erence Photograph No. 3) with a wire handle connecting to terminal blocks at the back of the cabinet.
The only exposed 120 Vac terminations on the card rack uas at the power supply transformer and filecr. Although these terminations were not reallp access!Sle, we did splice these terminations utilizing qualified 3aychem splices, to eliminate any concern with exposed terminations.
c)
Since the 120V power terminations were spliced to eliminat e expoacd terminatlen, there is now no aaed to take credit for the abvious signal cable termination points.
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SBN-1073
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- 4) QUESTION No credit for tie-wraps (Page 9).
They are always cut to make nods and other changes and then are not replaced.
RESPONSE
Good workmanship practices will ensure that tie-wraps are rein-stalled af ter modifications are completed to properly train and support the wiring within the cabinet. Even if one assumes the tie-wraps are not reinstalled, this would not present a problem since there are no expoced 120 Vac terminations which the signal wires could contact because of the splices and the protective metal grating around the ac control panel.
- 5) QUESTION Due to the possibil_ity of technician error, the outgoing field wiring should also be tested with the MCVF.
RESPONSE
As explained on page 8 and in Item 3.above, there is no credible technician error which could result in the 120 Vac being applied directly to the field cables because there are no exposed 120 Vae terminations.
This part of the analysis was reviewed and accepted by the Staff as shown by the fact that their test program request did not include a request to test 120 Fac applied directly to the field cables.
- 6) QUESTION le appears, from the report, that the teet setup and the operating environment of the devt.ces undet teat were not t he same and that the protective devices for which dredit is being taken wern not in-volved in the test.
Therefore, it was not shown that with the protective devices shorted-out the acceptance criteria had beca met or the Train "A" Class IE bus had not becu degraded.
RESPONSE
As explained in item 2, credit is not really being taken for the prott.ctive devices protecting the field devices.
Even though no credit is being taken, a 20A circuit breaker was included in the test setup, at the guidaace of the Staff, to simulate as best possible the actual field setup.
l As explained in Section IV.E (Pages II,13, and 14) the test 120 V;c was lef t Applied to the circuit f or greater than five minutes.
Since the input prctective device (20A circuit breakor) did not operato, it had no effect on the test results, i,c.,
the test results would have been the same even if the protective device had shorted out.
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