ML19312D852

Forwards Response to Part I of NRC 800502 Request for Addl Info Re Restart After 800226 Accident.Util Is Installing Redundant Indicators Above Intercommunication Sys Section of Control Board.Part II Responses Will Follow

ML19312D852
Person / Time
Site:	Crystal River
Issue date:	05/02/1980
From:	Richard Bright FLORIDA POWER CORP.
To:	Reid R Office of Nuclear Reactor Regulation
References
3--1-A, 3-0-1-A, IEB-79-27, TAC-12961, TAC-42664, NUDOCS 8005050237
Download: ML19312D852 (7)

Text

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8005050 P

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M Power C O M Po re a i so es May 2, 1980 3 File: 3-0-1-a l

Mr. Robert W. Reid Branch Chief Operating Reactors Branch /14 Division of Operating Reactors U.S. Nuclear Regulatory Commission Washington, DC 20555

Subject:

Crystal River Unit 3 Fc ty bperat ng License No. DPR-72 b

Dear Mr. Reid:

1 Enclosed are responses to Part I of your request for addition-i al information to Florida Power Corporation of May 2, 1980.

The responses to Part II: " Areas Not Yet Addressed by Florida Power Corporation" will be submitted as expeditiously as possi-ble to support your preparation of the Safety Evaluation for the restart of Crystal River Unit 3.

! If you would desire further discussion on this ' subject, please contact this office.

Sincerely, FLORIDA POWER CORPORATION W

onald M. Bright Acting Manager Nuclear Support Services RMBekcF13(D1)

Enclosure l

General Office 3201 Thirty fotrth street south e P O Box 14042, St Petersburg. Floruta 33733 813 866 5151 i-

k STATE OF FLORIDA l COUNTY OF PINELLAS R. M. Bright states that he is the Acting Manager, Nuclear Support Services Department of Florida Power Corporation; that he is authorized on the part of said company to sign and file with the Nuclear Regula tory Commission the infonnation attached hereto; and that all such statements made and matters set forth therein are true and correct to the best of his knowladge, infonnation and belief.

LBMLYJ R.14. Mrir/ht J

Subscribed and sworn to before me, a Notary Public in and for the State and County above named, this 2nd day of May, 1980.

RO* t l, /, j - **~

Notarypublic Notary Public, State of Florida at Large, My Commission Expires: February 3, 1981.

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CRYSTAL RIVER UNIT 3 REQUEST FOR ADDITIONAL INFORMATION RESTART AFTER 2/26/80 INCIDENT Part I: Areas Addressed by Fla. Power Corp.

ITEM I.1 Your March 12, 1980, response states that the only sure way to de-termine which indicators or recorders are good (following a power loss) is by observing their operation and response to transient conditions. This situation is unacceptable. Describe those plant modifications to be made to provide positive and obvious indication of the validity of information presented by indicators and record-ers for partial, total, AC, and DC power loss situations.

RESPONSE

FPC is installing redundant indicators above tne ICS section of the control board with corresponding power indicating lights. These lights infonn the operator which set of redundant indicators are valid. In addition, the annunciator windows have been modified to inform the operator when NNI(X), NNI(Y) or ICS power is lost. Ad-ditional details concerning this modification are contained in Item 34 of Enclosure B in our May 2,1980 letter to the Director, Office of Nuclear Reactor Regulation.

ITEM I.2 Your March 12, 1980, response indicates that the control circuitry for the PORY will be modified to include an interlock which will preclude PORV opening on loss of 24 VDC power. Does this interlock depend upon the operation of the NNI Power Monitor? Will the in-terlock prevent automatic operation of the PORV between the time of a loss of either the positive / negative DC power and the time of the tripping of the DC supplies (i.e., S1 and S2)? Confirm that this interlock will not interfere with the manual operation of the PORV.

RESPONSE

FPC is modifying the PORV control circuitry to prevent opening on loss of 24 VDC power. This interlock does not depend on the opera-tion of the NNI power monitor. The actuation of this interlock is accomplished by auxiliary relays upon loss of either NNI +24 or -24 VDC power sources. This circuit has been evaluated by B&W and will prevent opening of the PORV upon loss of 24 VDC power. Manual con-trol of the PORV remains available to the operator and is not changed by this interlock modification.

ITEM I.3 Your March 12, 1980, response indicates that procedures will be re-vised, as necessary, to cover methods of recognition of loss of AC Klein(NRCQues)D55

ITEM 1.3 (Cont'd) vital bus power to the NNI/ICS. Confirm that these procedures will cover also the loss of any DC bus to the NNI/ICS. Describe the automatic means to alert the operator to a loss of vital AC or a NNI/ICS bus. If one considers the loss of such a bus as the

" event-initiator" and a " single failure" elimirates the main annun-ciator panel (as has occurred at other facilities), what automatic means will directly identify the bus failure for the operator?

RESPONSE

Plant procedures will be revised to add specific instructions to the operator for recognition of loss of AC or DC power to the NNI or ICS. Loss of any DC power supply, any DC bus, or any AC feed to either the NNI or ICS will be annunciated by the main annunciator panel and al so indicated by the new indepenent power indicating lights on the redundant indicator panel.

Additionally, loss of NNI(X) or NNI(Y) power will move 22 of the redundant indicators of one row to midscale and the RC pressurein-dicator which fails low. The other row of indicators will be indi-cating normally. This provides quick verification of NNI power failures.

ITEM I.4 Confirm that the training provided for operators and I&C techni-cians prior to plant restart will include a control room demonstra-tion of the loss of various AC/DC power supplies, confirming the loss of certain instruments and the availability of alternate instruments.

RESPONSE

Florida Power's training program prior to restart for operators and I&C technicians will include a detailed description of the CR-3 in-cident of February 26, 1980. The description will include a com-plete list of instruments that were unavailable due to the loss of power, and a list of redundant instruments that were not affected by the failure in NNI(X). The training will describe the chcnges made to NNI/ICS to preclude a similar occurrance, including a com-plete description of the 23 indicators to be installed above the control board annunciators for further redundancy. Instructions to recognize loss of AC or DC power to the NNI or ICS will be included in the training program. The new Automatic Transfer Switch that will supply AC power from a redundant source will be discussed.

The preferred switch lineup will also be presented in detail.

A demonstration test will be performed to demonstrate the loss of various AC/DC powers confirming the loss of certain instruments and the availability of alternate instruments. The operators and I&C technicians will be informed as to what to expect from loss of pow-er, but they will not be required to observe the demonstration test.

Klein(NRCQues)D55

ITEM I.5 Your March 12, 1980, response states that redundant NNI indicators will be provided on the main control panel. We understand that, prior to plant restart, these indicators will be " control grade."

Confirm that this classification means that no single failure of an active component can cause the loss of both redundant indicators.

Provide the design criteria to which this set of instrumentation is being designed, installed, tested, etc. I

RESPONSE

FPC is installing redundant indicators above the ICS section of the control board for the main plant parameters deemed necessary by the plant operators. These indicators are control grade and will be installed by startup. One set of indicators are powered by the NNI (X) and the other set are powered by the NNI (Y) source. No single failure of an active component will cause the loss of both indicators.

The design criteria are:

1. Independence of one set of indicators from the other set of indicators from transmitter thru conditioners to indicator.

2. Location visible from normal operators position.

3. Compatability with existing installed NNI equipment.

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4. Indicators arranged according to a physical mimic as much as possible.

5. Indicators to correspond with location of existing board indicators as much as possible.

6. No changes to existing control board or indicators.

7. No change to NNI/ICS interface.

8. Indication to be provided without operator action upon loss of power.

The development and institution of a test program for these redun-dant indicators is governed by existing Compliance Procedure CP-114, " Procedure for Preparation and Control of Permanent Modifica-tions, Temporary Modifications, Deviations, and MAR Functional Test Procedures." CP-114 will be the controlling document in developing and performing the functional test for redundant instrument modifi-cations. MAR 80-3-64 is the specific MAR package detailing the modifications to be made on the redundant instruments for major plant parameters.

Specific test procedures will be developed, issued, and approved as part of the construction work package authorizing and detailing the installation once the system modifications / redesigns have been finalized.

Klein(NRCQues)D55

ITEM I.6 Your March 12, 1980, response describes redundant indicators to be provided. Describe the means to be provided to record certain key parameters in the event of a loss of AC from either vital bus to the NNIs. Identify which parameters will be recorded.

RESPONSE

In event of a loss of AC vital power to NNI(X) a new Automatic Transfer Switch will supply AC power from a redundant source, i.e.,

regulated instrument bus power. Therefore, on loss of vital bus power to the NNI, the following signals are available for recording by switch selection.

a) Pressurizer Level b) Unit Average Temperature c) RC Hot Leg Temperature d) RC Wide Range Pressure e) Main Steam Header Temperature f) Steam Generator Outlet Pressure g) Turbine Header Steam Pressure h) Full Range Feedwater Flow (Loop A) i) Steam Generator Operate Level A&B j) Makeup Tank Level These will be recorded by existing recorders. Surveillance Procedure SP-300, " Operation Daily Surveillance Log", requires checking these indicators at least once per shift.

ITEM I.7 (a) Prior to the February 26, 1980 event, did the plant have the design capability and adequate procedures as to what safety-grade instrumentation and equipment should be used in the event of postulated transients and accidents (including loss 1 of power to non-safety grade instrumentation) to follow the  !

course of the event and to maintain a stable hot shutdown condition?

(b) ... cold shutdown?

(c) List the minimum plant variables that must be monitored to safety reach and maintain hot shutdown;... cold shutdown.

l (d) Describe any modifications you would propose that would pro- l vide safety-grade instrumentation and procedures to follow the course of transients and maintain hot shutdown;... cold shutdown.

RESPONSE

(a) At the time of the event on February 26, 1980, the plant's

& design capability and procedures were within the license (b) requirements and, in general, gave the operators information Klein(NRCQues)DN55

ITEM 1.7 (Cont'd)

RESPONSE

as to what instrumentation and equip .ent should be used to follow the course of an event and maintain a stable hot shut-down and/or cold shutdown. No useable emergency procedure can go into detail as to list exactly which instrumentation and equipment is available for use in the event of every postulat-ed transient and accident (including loss of power to non-safety grade instrumentation).

Operator training in Emergency and Abnormal Procedures reviews postulated transient and accidents and the actions which the operators must take to mitigate those events.

(c) The following is a list of plant variables that are necessary to safely reach and maintain a hot shutdown condition, and to continue on to cold shutdown:

Letdown Flow Makeup Flow Makeup Tank Level Main Feedwater Flow Loop AaB Startup Feedwater Flow Loop A&B OTSG Pressure A&B OTSG Operating Level A&B OTSG Startup Level A&B Cold Leg Temperature (Tc) Loop A&B RC Sys. T Loop A&B Hot Leg Temperature Loop A&B Wide Range Pressure Low Range Pressure Pressurizer Level Pressurizer Temperature (d) FPC is installing redundant indicators above the ICS section of the main control board for the MAIN PLANT PARAMETERS deemed necessary for safe hot / cold shutdown. One set of indicators are powered by the NNI(X) and the other set is powered by the NNI(Y) source. Operating procedures are being revised to in-struct operators on the actions to be taken for a loss of pow-er to NNI(X) or NNI(Y). Prior to plant startup training will be provided on these modifications and procedures to instruct operators on these changes and the February 26, 1980, transient.

l I

Klein(NRCQues)DN55