..

February 5, 1980

File: NG-3514(B) SERIAL NO: N0-80-197

Office of Nuclear Reactor RegulationATTN: Mr. T. A. Ippolito, Chief

Operating Reactors Branch No. 3United States Nuclear Regulatory CommissionWashington, D. C. 20555

BRUNSWICK STEAM ELECTRIC PLANT UNIT No. 2DOCKET No. 50-324LICENSE 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-cycleRecircularion 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 AdditionalI.iformation" are also attached for reference.

As requested in your August 17, 1979 letter, CP&L does commit toimplement design improvements in the area of ambiguous indications asresolved by Ceneral ElsnttLc in their generic investigation.

Yours very truly,

% g >n n gd E. E. Utley

Executive Vice PresidentPower Supply and Customer Services

RMP/DCS/jc (1678)Attachments

1950 270

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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 willDe par cf -he reactor prote::icn system, will fully ::nform : IEEE279-1971, anc will be appropriately qualified as Class IE epui; ment.

2. In order nat compliance witn the single failure criterion can beverified, provide :ne control logic diagrams, P&ID's, and scheraticciagrams 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 atusincica icns for ne RPT system.

E. Relative to IEEE 279 Section 4.17, discuss ne provisiens for manualinitiation of :ne RCT sys em.

6. The GE re:cr- NE00-24179 Revision i discusses the testability Of theRPT system. Mcwever, scme aspec s of One licensee's sa:mi tai remainof 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 tocontrol access to bypass capability.

c. Propose new wording for the Technical Specifications which makesclear :na only one of the two RPT systems may be bypassed fortesting at one time,

d. Prc::se a Technical Specification which pr0 vices for ; erit:ices-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

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REOUEST FOR ADDITIONAL INFORMATIONBRUNSWICK UNIT NO. 2

END-OF-CYCLE RECIRCULATION PUMP TRIPAoril 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 2737:07

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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 shouldinclude timely status indication with regard to loss of Operability.Since the RPT logic requires electric poder to provide a functionaloutput, a blown fuse, for example, can cause less of Operability ofa division. Describe the design feature (s) of each RPT logic divisionwhich will provide timely indication to the reactor operator ofloss of Operability.

2. The RPT logic and pump breakers are required to respond to sensorsignals by disconnection of the pump motor current within 165 milli-seconds (i.e.,10 cycles). We understand that the planned responsetime testing will detennine the interval from sensor signal to receiptof a breaker open position switch signal. This measurement doesnot inc.lude the time required to extinguish the load current arc.Include the circuit breaker manufacturers information on how muchof the 165 milliseconds must be reserved for reducing pump currentto an acceptable level, i .e. , trip. Considering this, restate thetime available for operation of the logic and breaker motion.

3. The RPT logic includes wiring within each division which runs betweenredundant RPS panels P609 and P611. State the separation criteriaand 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 thesame source. Discuss the fuse scheme and relative fuse sizes withregard to providing adequate separation between the safety circuitsand control circuits, with particular attention to assuring that nocontrol system " fault" can render the safety circuit inoperable dueto loss of power to the breaker trip scheme.

.

August 17, 1979

1950 274

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REQUEST FOR ADDITIONAL INFORR\ TIONBRUNSWICK UNIT NO. 2

END-OF-CYCLE RECIRCULATION PD!P TRIPAucust 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

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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 276397-173

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