ML19260D908
| ML19260D908 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 02/05/1980 |
| From: | Utley E CAROLINA POWER & LIGHT CO. |
| To: | Ippolito T Office of Nuclear Reactor Regulation |
| References | |
| NO-80-197, NUDOCS 8002120583 | |
| Download: ML19260D908 (8) | |
Text
.
February 5, 1980 File: NG-3514(B)
SERIAL NO: N0-80-197 Office of Nuclear Reactor Regulation ATTN:
Mr. T. A. Ippolito, Chief Operating Reactors Branch No. 3 United States Nuclear Regulatory Commission Washington, D. C.
20555 BRUNSWICK STEAM ELECTRIC PLANT UNIT No. 2 DOCKET No. 50-324 LICENSE NO. DPR-62 ADDJ.TIONAL INFORMATION ON END-OF-CYCLE RECIRCULATION PUMP TRIP
Dear Mr. Ippolito:
Your August 17, 1979 letter requested additional Ic."armation con-cerning the B.unswick Steam Electric Plant (BSEP) Unit No. 2 end-of-cycle Recircularion Pump Trip (EOC-RPT) system.
In response to your requests, Carolt.a Power & Light Company (CP&L) hereby submits the requested informa-tio,as attachments to this letter. Copies of your " Requests for Additional I.iformation" are also attached for reference.
As requested in your August 17, 1979 letter, CP&L does commit to implement design improvements in the area of ambiguous indications as resolved by Ceneral ElsnttLc in their generic investigation.
Yours very truly,
% g >n n g d
E. E. Utley Executive Vice President Power Supply and Customer Services RMP/DCS/jc (1678)
Attachments 1950 270
\\c\\
0
\\
\\
i 3 0 0.31 f!O 58
REOUEST FOR ADDITIONAL INFORf% TION BRUNSWICK 2 END OF CYCLE RECIRCULATION CUMD TRIP (RPT' l.
Docuren; in a:pr:priate de ail that -he end-of-cycle RET systers will De par cf -he reactor prote::icn system, will fully ::nform : IEEE 279-1971, anc will be appropriately qualified as Class IE epui; ment.
2.
In order nat compliance witn the single failure criterion can be verified, provide :ne control logic diagrams, P&ID's, and scheratic ciagrams for -he RPT systems (including sensors,
- era-ing bypasses, anc maintenar.ce typass features).
2.
Relative : IEEE 279 Section a.20, cescribe :ne rip s atus in:ica:icns for :ne EPT systems.
2 Relative : IEEE 270 Section a.12, anc a.20, cescribe ne :ycass s atus incica icns for ne RPT system.
E.
Relative to IEEE 279 Section 4.17, discuss ne provisiens for manual initiation of :ne RCT sys em.
6.
The GE re:cr-NE00-24179 Revision i discusses the testability Of the RPT system.
Mcwever, scme aspec s of One licensee's sa:mi tai remain of concern.
a.
Relative to IEEE 279 Section 4.11, describe the bypass capabilities that are provided to f acilitate on-line testing.
b.
Relative to IEEE 279 Section 4.14, describe ne means provided to control access to bypass capability.
c.
Propose new wording for the Technical Specifications which makes clear :na only one of the two RPT systems may be bypassed for testing at one time, d.
Prc::se a Technical Specification which pr0 vices for ; erit:ic es-ing cf the res:cnse time cf the RPT sys er.
becifically, such tes-i ; shcuid demonstrate ina ne sys s
- 1-te --i r a te
-he :ur-en- : :ne :u : c rs i
'.ess : nan 2 0
'M issc:r:s n':e - e -e:ei:
- f ne senser signal.
April 30,197; 1950 271
REOUEST FOR ADDITIONAL INFORMATION BRUNSWICK UNIT NO. 2 END-OF-CYCLE RECIRCULATION PUMP TRIP Aoril 30, 1979 CP&L Responses The following information updates the CP&L responses to NRC's April 30, 1974 requests:
1.
The response to this question is adequately covered in a CPSL letter from E. E. Utley to T. A.
Ippolito dated April 27, 1979 (Serial No. GD-79-1143).
2.
The information requested was provided to the NRC staff at an April 30, 1979 meeting as documented by a CP&L letter from E. E. Utley to T. A. Ippolito dated May 29, 1979 (Serial No. GD-79-1418).
3,4.
The RPT annunciators will be revised such that there are separate annunciators for RPT System A Trip, RPT System B Trip, RPT System A Out of Service, and RPT System B Out of Service. The Out of Service annunciators indicate both loss of power and system bypass.
5.
The response to this question is adequately covered in CP&L letter from E. E. Utley to T. A. Ippolito dated April 27, 1979 (Serial No. GD-79-1143).
1950 272
April 30, 1979 6(a)
There is no bypass required for on-line testing purposes; however, a bypass is provided for maintenance purposes as noted in the proposed technical specifications.
6(b)
The bypass switch provided is of the keylock type with the key required to actuate the bypass. The key is maintained under the administrative control of the shift foreman.
6(c),(d) Proposed Technical Specifications will be provided to NRC on or about February 12, 1980.
1950 273 7:07
REQUEST FOR ADDITIONAL INFORETION BRUNSWICK NO. 2 END-OF-CYCLE RECIRCULATION PUMP TRIP 1.
Being part of the Protection System, each division of RPT logic should include timely status indication with regard to loss of Operability.
Since the RPT logic requires electric poder to provide a functional output, a blown fuse, for example, can cause less of Operability of a division.
Describe the design feature (s) of each RPT logic division which will provide timely indication to the reactor operator of loss of Operability.
2.
The RPT logic and pump breakers are required to respond to sensor signals by disconnection of the pump motor current within 165 milli-seconds (i.e.,10 cycles). We understand that the planned response time testing will detennine the interval from sensor signal to receipt of a breaker open position switch signal.
This measurement does not inc.lude the time required to extinguish the load current arc.
Include the circuit breaker manufacturers information on how much of the 165 milliseconds must be reserved for reducing pump current to an acceptable level, i.e., trip.
Considering this, restate the time available for operation of the logic and breaker motion.
3.
The RPT logic includes wiring within each division which runs between redundant RPS panels P609 and P611.
State the separation criteria and the means provided to satisfy these criteria, i.e., distance, barriers, for the newly installed circuitry.
4.
Within each division of the RPT logic, safety signals (breaker trip) and control signals (breaker close) receive electric power from the same source.
Discuss the fuse scheme and relative fuse sizes with regard to providing adequate separation between the safety circuits and control circuits, with particular attention to assuring that no control system " fault" can render the safety circuit inoperable due to loss of power to the breaker trip scheme.
August 17, 1979 1950 274
REQUEST FOR ADDITIONAL INFORR\\ TION BRUNSWICK UNIT NO. 2 END-OF-CYCLE RECIRCULATION PD!P TRIP Aucust 17, 1979 CP&L Responses 1.
Each RPT logic division has system status indicating lights on a back panel in the Control Room to monitor loss of operability, including loss of power. An annunciator will be installed on the main control board to also indicate this status for each division.
2.
Based on information provided by Generrl Electric, the EOC-RPT pump breakers require a maximum time of 5 cycles from the receipt of its trip signal to the time current is removed from the load.
Since this time is less than that required for the breaker to fully open and since the response time will be measured from initial valve movement to the breaker full open position, the overall response time should be j:,175 milliseconds.
3.
The separation criteria for wiring within each division vhich runs between panels P609 and P611 is as follows:
a.
The raceway network will provide required channel and/or division separation by means of physically separated paths including ".
. intervening metal barrier between the divisional or redundant raceways (e.g.,
rigid steel conduit)."
1950 275
August 17, 1979 b.
Wiring for the reactor protective system outside of the main protection system cabinet shall be run in rigid steel conduit used for no other wiring.
All wiring within each division which runs between redundant RPS panels P609 and P611 is run within rigid steel conduit.
4.
A common 25A fuse is being provided for the two recirculation pump trip control circuit branches labeled Bkr. "A" and Bkr.
"B" rather than a single 15A fuse for each circuit. This will minimize further the probability of control circuit faults resulting in loss of power to the safety circuits (refer to the attached Figure 1).
1950 276 397-173
- BkIA~)
'"I j Tr 'y shel t
= RK J c:n.:hy n
(*\\
g a N
30 A I Ru,c. Pg N
12 f VDC (-b^
go4 -
=
A vt. Tr o.p i
i
'e O
Cocos'lry in v
y P609 i
DIV.t S lO h '
P(6 g?g
- 5
' 10 A.
EL4 Ctf.
M 15 A I BKR CLOSE
=-
x l, A,,
(lreo;frf In *.N BKR R'P tin.,;t r y y
DIV I PdO gd'q".g#
- H IoA,
x Elee CM.
110 A H lf A l
- 7 BKR CLOSE
[d J cu'I'/
,15 A,
y Mart BKR TRIP C;tev;ity
~
DIV f I.
F,yce Rec.,<. L p G.e Sp /--
C (rol /-se S/,e-m/;.
'