3F0489-12, Forwards Response to Station Blackout Rule Implementation & Description of Severe Weather Procedures Which Will Be Implemented

Forwards Response to Station Blackout Rule Implementation & Description of Severe Weather Procedures Which Will Be Implemented

ML20245B752
Person / Time
Site:	Crystal River
Issue date:	04/17/1989
From:	Widell R FLORIDA POWER CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
3F0489-12, 3F489-12, NUDOCS 8904260256
Download: ML20245B752 (13)

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April 17, 1989 3F0489-12 Wwnt Cbntrol Desk U. S. Nuclear Regulatory Cemninnion Washirgton, DC 20555

Subject:

Crystal River Unit 3 Docket No. 50-302 Operating License No. DPR-72 Station Blackout Rule Implementation

Dear Sir:

10 CFR 50.63 requires each licensee to provide a submittal describing their implementation of the rule by April 17, 1989. Attachment 1 to this letter is Florida Ibwer Corporation's response for Crystal Plver 3. The submittal is in the format rm -">+nded by the Nuclear Management and Resources Council.

Attachment 2 is a description of the severe weather procedures which will be implemented for Crystal River 3.

Should there be any questions, please contact this office.

Sincerely,

( D Rolf C. Widell, Director Nuclear Site Support AEF:

ATTAGMENIS xc: Regional Administrator, Region II Senior Resident Inspector Nuclear Management and Resources Council

%[2gggy h, g2 gg P f GENERAL OFFICE: 3201 Thirty fourth Street South

• P.O. Box 14042

• St. Petersburg, Florida 33733 * (813) 866 5151 A Florida Progress Company I

.., 4.

ATTACHMEtif 1 STATION BIACKOUl' RUIE IMPLEMEtfIATION EDR CRYSTAL RIVER 3 On July 21, 1988, the Nuclear Regulatory Cammission (NRC) amended its regulations in 10 C.F.R., Part 50. A new section, 50.63, was added which requires that each light-water-cooled nuclear power plant be able to withstand and recover from a station blackout (SBO) of a specified duration.

Licensees are cxpected to have the baseline assumptions, analyses and related information used in their coping evaluation available for NRC review. It also identifies the factors that must be considered in specifying the station blackout duration. Section 50.63 requires that, for the station blackout duration, the plant be capable of maintaining core cooling and appropriate containment integrity. Section 50.63 further requires that each licensee subnit the following information:

1. A proposed station blackout duration including a justification for the selection based on the redundancy and reliability of the onsite emet 9.ucy AC power sources, the expected frequency of loss of offsite-power, and the probable time needed to restore offsite power;

2. A description of the procedures that will be implemented for station blackout events for the duration (as determined in 1 above) and for recovery therefrom; and

3. A list and proposed schedule for any needed modifications to equipnent and associated procedures necessary for the specified SB0 duration.

'Ihe NRC has issued Regulatory Guide 1.155 " Station Blackout" which describes a means acceptable to the NRC Staff for meeting the requirements of 10 C.F.R. 50.63. Regulatory Guide (RG) 1.155 states that the imC Staff has determined that NUMARC 87-00 " Guidelines and Technical Bases for NUMARC Initiatives Addressing Station Blackout At Light Water Reactors" also provides guidance that is in large part identical to the RG 1.155 guidance and is acceptable to the NRC Staff for meeting these requirements.

Table 1 to RG 1.155 provides a cross-reference between RG 1.155 and NUMARC 87-00 and notes where the RG takes pre dence.

Florida Power Corporation (FPC) has evam sted the Crystal River 3 against the I requirements of the SB0 rule using guidance from ICMARC 87-00 except where RG 1.155 takes precedence. 'Ihe results of this evaluation are detailed below. .

(Applicable NUMARC 87-00 sections are shown in parenthesis.) )

A. Proposed Station Blackout Duration NUMARC 87-00, Section 3 was used to determine a preposed SBO duration of four hours. No modifications were required to attain this proposed coping duration category.

'Ihe followirq plant factors were identified in determining the proposed station blackout duration:

1. AC Power Design Characteristic Group is P2* based on:

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a. Expected frequency of grid-related IOOPs does not exceed once per 20 years (Section 3.2.1, Part IA, p. 3-3) ;

b. Estimated frequency of IDOPs due to extremely severe weather places the plant in ESW Group 4 (Section 3.2.1, Part 1B, p. 3-4);

c. Estimated frequency of LOOPS due to severe weather places the plant in SW Group 1 (Section 3.2.1, Part IC, p. 3-7);

d. We offsite power system is in the I1/2 Group (Section 3.2.1, Part 1D, p. 3-10);

e. Plant-specific pre-hurricane procedures, which meet the intent of Section 4.2.3 of NUMARC 87-00, will be implemented. %ese procedures and their justification are discussed in detail in Attachment 2.

2. %e emergency AC power configuration group is C based on:- (Section -

3.2.2, Part 2C, p. 3-13)

a. There are 2 emergency AC power supplies not credited as alternate AC power soumes ' (Section 3.2.2, Part 2A, p. 3-15) ;

b. One emergency AC power supply is n-ay to operate safe shutdown equipment following a loss of offsite power (Section 3.2.2, Part 2B,

p. 3-15).

3. %e target EDG reliability is 0.95. A target EDG reliability of 0.95 was selected based on having a nuclear unit average EDG reliability for the last 20 demands greater than 0.90 consistent with NUMARC 87-00, Section 3.2.4.

B. Procedure Description Plant procedures have been reviewed and modified, if nemmy, to meet the gni M1ines in NUMARC 87-00, Section 4 in the following areas:

o AC power restoration per NUMARC 87-00, Section 4.2.2; (1) . System restoration is controlled by an Energy Control Department, procedure, " System Restoration Procedures - General Guidelines". his procedure directs that power be restored to the nuclear plant as quickly as possible. ,

(2) and (3) . The Energy Control Deparbnent would direct off-site power restoration to Crystal River 3 per their procedures. Other departments, including Transmission and Substation Construction, Central Division Engineering and Operations, and System Protection and Control, would work to restore equipnent to service as directed by the Energy Control Department. In addition, these departments have been directed to give highest priority to restoration of power to Crystal 1

ATTA0 M NT 1 Page 3 River 3.

(4). Transmission ard substation crews are routinely supplied with equipnent n-myy to ccxnplete repairs.

(5) . Restoration of power to plant equipment will be addressed by plant procedures. (See response to section 4.2.1, Item (1).)

1 Plant procedures have been reviewed and charges necessary to meet 10 MARC 87- I 00 will be implemented in the followirg areas:

1. Station blackout response per 1 2 ARC 87-00, Section 4.2.1; Items (1) through (7), (10) ard (11) contain rocarmndations for actions to be taken by the plant cpclators during a station blackout event. 'Ihese actions will be covered in a new proccdure specifically for that event.

Item (8) r-eds a precedure be written to assure portable lightirg is available. SP-807, Mounted and Hard Held Emergency Battery-Powered Light Units, currently ensures that the lighting required to achieve compliance with 10 CFR 50, Appendix R is operable on a monthly basis.

Item (9) ray < mords plant procedures address access to locked areas during a station blackout. SP-443, Master Surveillance Plan, currently ensures that all on-auty personnel have Pays to all security doors.

'Ihis verification is made on a daily basis.

Item (12) re)--'rds that non-Class 1E equipment used during a station blackout be included in a maintenance program. Preventive maintenance or surveillance procedures will be modified, as appropriate, to assure that maintenance of non-Class 1E equipnent relied upon to cope for the required coping duration will be addressed.

Item (13) re) mands plant procedurt.s consider the loss of heat tracirg during a station blackout. No action is nmary to compensato for the loss of heat tracing, since none of the equipment relied upon to cope with a station blackout requires heat tracing to function.

2. Severe weather per NUMARC 87-00, Section 4.2.3.

Crystal River 3 currently has in place a procedure for operation during hurricane conditions. 'Ihat procedure will be enhanced to assure compliance with 10 CFR 50.63. See Attachment 2 for a detailed description of the severe weather procedures to be implemented.

3. Procedure changes associated with any modifications required after assessing coping capability per IUMARC 87-00, Sectior. 7.

(See Item C.3, belcw.)

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I ATTACHMDTI' 1 Page 4 C. Proposed Modifications and Schedule he ability of Crystal River 3 to cope with a station blackout for four hours in accordance with NLM\RC 87-00, Section 3.2.5 and as detennined in Section "A'.' above; was =canced usiry NUMARC 87-00, Section 7 with the follctrity results:

1. Condensate Inve,ntory For Decay Heat Removal (Section 7.2.1)

It has been deternined frun Section 7.2.1 of NUMARC 87-00 that 56,273 gallons of water are required for decay heat removal for four hours.

The minimum p=incible emergency feedwater tank level per technical speciD. cations provides 150,000 gallons of water, which excoeds the required quantity for copiry with a four hour station blackout.

2. Class 1E Batteries Capacity (Section 7.2.2),

A battery capacity calculation verifies tnat the Class 1E batteries have sufficient capacity to meet station birckout loads for four hours assuming loads not needed to cope with a station blackout are stripped.

These loads will be identified in plant procedures.

3. Comoressed Air (Section 7.2.3)

We following modifications and procedure changes are necessary to ensure that air-operated valves required for decay heat removal during a station blackout of a four hour duration have sufficient backup sources for operation:

o Modifications to the main steam abnospheric dump system o Associated procedural changes

4. Effects of Ioss of Ventilation (Section 7.2.4)

Se calcule' ed steady state ambient air temperature for the steam driven emergency feedwater pump room (the dominant area of concern for a pWR) during a station blackout induced loss of ventilation is 132 OF.

We steady state ambient air temperature has been calculated for the following other dominant areas of concelTu xRes momwRu i Atmospheric Dump Valve Rocxn 179 OF i Battery Clarger Room A 87 OF Battery diarger Room B 89 OF  ;

Battery Room B 103 OF  !

Battery Rocan A 102 OF  !

Control Rocan 100 OF I EFIC Room A 109 OF 1

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Page 5 AREA TD4PFPATUFC EFIC Room B 122 OF EFIC Room C 127 OF EFIC Roam D 101 OF Inverter Room A 133 OF Inverter Roam B 141 OF Relay Roam 114 OF Remote Shutdown Panel Rocxn 95 OF 4160 v Switchgear Roam A 93 OF 4160 v Switchger Roca B 93 OF 480 v Switchgeer Rxxn A 90 OF 480 v Switchgeer Rxan E 92 OF During a station bleckout event at Crystal River 3, the plant will be operated frun the reacte shutdown panel. The assumption in NUMARC 87-00, Section 2.7.1 that the remote shutdown panel rocm will not exceed 120 OF during a station blackout has been assessed. The remote shutdown panel nxxn at Crystal Piver 3 does not exceed 120OF during a station blackout. Therefore, the renote shutdown panel room is not a dominant area of concern.

Reasonable assurance of the operability of station blackout response equipnent in the above dominant areas of concern has been =W using Appendix F to IU4 ARC 87-00 and/or the Topical Report. The followiry procedure change is required to provide reasonable assurance for equipment operability; o Procedural steps will be added to assure the panel doors for Emergency Feedwater Initiation and Control (EFIC) System cabinets in Roams "B" aid "C" and EFIC auxiliary cabinets in rooms "A" and "B" are opened within 30 minutes. This will assure the equiprent within the cabinets does not exceed its rated temperature.

5. Containment Isolation (Section 7.2.5)

The plant list of containment isolatien valves has been reviewed to verify that valves which must be capable of being closcd or that must be operated (cycled) under station blackout conditions can be positioned (with indication) independent of the preferred and blacked-out unit's Class 1E power supplies. No plant modifications or associated procedure charges were determind to be required to ensure that appropriate containment integrity can be provided under SB0 ccnditions.

6. Reactor Ccolant Inventerv (Section 2.5)

The ability to maintain adequate reactor coolant system inventory to ensure that the core is cooled has been assessed for four hours. The generic analyses listeo in Section 2.5.2 of 10 MARC 87-00 L: re used for '

this assessment and are applicable to the specific design of Crystal River 3. The expected rates of reactor ouolant inventory loss under i

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SID conditions do not result in core uncovery in a SBO of four hours. J Therefore, makeup systems in addition to those currently available )

under SB0 conditions are not required to maintain core cooling urder natural circulation.

The modification and associated procedure changes identified in Part C above will be ocmpleted during or before the first refueling outage beginning more than 12 months after the notification provided by the Director, Office of -

Nuclear Raactor Regulation in accordance with 10 C.F.R. 50.63(c)(3) .

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SEVERE WFMHER GUIDELINES EDR CRYSTAL RIVER 3 I 1

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Florida Ruer Corporation (FPC) is implementing plant specific hurricane guidelines for Crystal River 3 (CR-3) which differ frun those outlined in IUMARC 87-00. Actions for a tornado will be implemented as r - nded. ,

l ACTIWS FOR IURRICANE l

'Ihe follwiry paragraphs detail the IUMARC guidance for actions to be taken for a hurricane and outline the procedures FPC will implement to meet the intent of the IUMARC guidance while ensurity CR-3 is safely operated during hurricane conditions.

IUMARC GUIDELINE (1)

The plant procedures should identify site-specific actions nmesary to prepare for the onset of a hurricane. 'Ihese actions should be initiated when a hurricane sarning is issued for the plant site area and should include:

(a) inspecting the site for notential missiles aM reducing this potential; (b) reviewing the adequacy of site staff to support operations and repair; (c) expeditirg the restoration of important plant systems and camponents to service; (d) warmirg and lubricating s,tardby (Class 1E) AC pwer sources; (e) determining the status of Alternate AC sources (if available) ard taking r-mry actions to ensure their availability; (f) increasirg CST inventory; (g) placirg battery chargers in service (if applicable); ard (h) start and load test EDG's.

FR: IMPLME2EATION (a) When a hurricane watch is issued for the site, the site will be inspected for loose materials and debris which could benm missiles in a strong wind. 'Ibese materials will be removed to the maximum extent possible. Areas which will be insp:cted include:

o The CR-3 protected area o 'Ihe CR-3 warehouse area o 'Ihe area around CR-1 & 2

ATIAGMENT 2 Page 2 o %e area around G-4 & 5 o % e substation switchyards o Both coal yards o Any other areas of the site where construction type activities are in progress.

(b) Staffirg levels will be reviewed and enhanced as r-vry as weather conditions charge. (See also NUMARC Guideline 2 Implementation.)

(c) Safety related equipnent status will be reviewed when a hurricane warning is issued for the site. Inoperable eg im =nt will be returned to service if possible. We turbine driven emergency feedwater pump will'be tested to assure its operability. Actions will be taken to minimize equipment out of service during the hurricane. Surveillance schedules will be reviewed. Surveillance will be performed early, if possible, to minimize equipment perturbations during the hurricane.

Other surveillance will be delayed until after storm passage if permitted by Technical Specifications.

(d) Both diesel generators at m-3 are corrtinuously warmed. Lubricating oil is also continuously circulated through the lower crankcase. No other preparatory- actions are possible without actually starting the ergine.

(e) No action to be taken because G-3 has no Alternate AC power source.

(f) When a hurricane watch is issued for the site, the condensate and emergency fepdwater tanks will be filled if needed to maximize the supply of cordensate available for the duration of the storm.

-(g) 2 e battery chargers at G-3 are in service continuously. An evaluation will be made for each battery to determine if an equalizing charge is needed to maximize battery capacity. mis will be done when hurricane warnings are issued for the site.

(h) The emergency diesel generators will be determined operable by performance of the monthly surveillance load test when hurricane warnings are issued for the site. %e test will be performed sequentially on each EDG except that the diesels will not be loaded on the grid if severe weather conditions exist.

NUMARC GUIDELINE (2)

Utility procedures should identify additional plant support staff and the method of contacting them once a Purricane notice has been issued by the National Weather Service.

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FPC IMPUEENTATION Hurricane support staff will be identified in plant pro dures, including methods to contact them. 'Ihe procedure will re311re individuals to be contacted, and their availability determined, when a hurricane watch is issued for the plant site. 'Ihe procedure will also require that if a hurricane warning is issued, arrangements shall be made for optors and support staff to be transprted to the plant site should the plant access road become impassable by passengcr car. .

i NUMARC GUIDEIJNE (3)

Plant procedures should specify actions m sery to ensure equipnent required for station blackout response is available.

FPC IMPIINENTATION Plant procedures will contain a list of station blackout response active equipnent (e.g., pumps, valves, instrumentation, etc.) which will be verified to be operable when a hurricane warning is issued for the plant site. Other I equipnent and supplies needed to ensure safe plant operation urder hurricane conditions will be verified to be available when a hurricane watch is issued.

Additional actions to protect the plant frun the effects of the storm will be taken shen a hurricane warning is issued.

NUMARC GUIDEIJNE (4)

Plant procedures should address the following items prior to a hurr.icane arrival at the site:

(a) the site-specific indicator should ensure that the plant would be in safe shutdown two hours before the anticipated hurricane arrival at the site (i.e., sustained wind speeds in excess of 73 mph);

(b) operator review of station blackout procedures; and (c) operator review of procedures to line up and operate the switchyard spraydown system (if installed).

FPC IMPUMENTATION (a) While a hurricane warning is in effect, appropriate FPC management will confer following the issuance of each hurricane advisory by the National Hurricane Center. 'Ihis management conference will specifically consider the safety benefits gained by taking protective actions (including plant shut-down) in light of the current situation, and forecast changes in that situation. 'Ihe decision to take protective actions will be based upon the significance of the threat of the storm to CR-3 considering the possibility of wind damage i to the plant and the off-site power supply, ard radical charges in tides. All relevant storm information will be taken into account,

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ATTAQ EENT 2 Page 4 including:

o the ability of CR-3 to continue to run in a stable manner; o the availability of normal and emergency equipment to support normal operation, anticipated transients, and accident conditions; o storm intensity and forecast chi Jes; o storm moverTnt (speed and direction) ard forecast changes; o tidal conditions and forecast maximum and minimum; o status of the off-site pwer supply, as determined by discussions with the Energy Control Center and the Crystal River 1 & 2 and Crystal River 4 & 5 control rooms; and o the urgency of the need for pwer fram CR-3 to maintain service to customers.

(b) Operators will review station blackout procedures when a hurricane warning is issued for the plant site and at the beginning of each shift while the hurricane warning remains in effect.

(c) 'Ihe Crystal River site has no installed switchyard spraydwn system.

JTEFIFICATICE OF ADBJUACY OF IK1RRICANE PRO DURE INTRODUCTIOLi Both Crystal River 3 and the entire Florida Power Corporation service area are located in an area which experiences hurricanes occasionally. Because of this, the design of all substations, transmission lines, power plants and other important structures includes specific criteria to assure the ability of the system to operate under most hurricane conditions. 'Ihis makes the FIC grid more able to survive under hurricane conditions than that of a utility where hurricanes are rarely experienced. It also means that the likelihood of a hurricane induced loss of off-site pwer is less for Crystal River than for scxne other plants. 'Ihis section will detail those design features which provide this system ruggedness.

PIANT DESIGi Crystal River 3 safety related systems are designed to operate urder probable maximum hurricane conditions. 'Ihe safety related equipnent is also protected fram.the tidal surge that would result frun that probable maximum hurricane. 'Ihe CR-3 Technical Specifications contain limits on maximum and minimum allowable tide levels which assure that the plant will be safely shutdown if a hurricane produces high or low tide levels which could adversely affect plant operation.

ATTACHMEtTf 2 Page 5 SUBSTATION DESIG1 Five transanission lines from three different substations feed the 230 kv substation at Crystal River. The substation, which is the off-site power source for CR-3, is designed to withstand 90 mph sustained wirds with 117 nph gusts without adverse affect. Similarly, other 230 and 500 kv substations which form the core of FPC's transmission grid aro designed to at least as high a wird loadirg. This assures ' hat significant numbers of hurricane induced substation failures will not occur.

TRANSMISSION SYSTEM DESIGi The 500 kv and 230 kv lines which rnke up the most important part of FPC's transmission system are designed to withstard wiMs of at least 135 mI 21 sustained winds with an additional safety factor for wiM gusts. The major tie lines and internal transmission lines of the utilities with which FPC is interconnected are similarly designed. FPC's 500 kv and 230 kv transmission lines are suspended from steel towers on cleared rights-of-way. This assures that falling trees will not adversely impact these lines and high wirds will not result in a significant number of line failures.

OTHER GENERATING UNITS IDCATED AT THE SITE Crystal River 3 shares the energy complex site with Crystal River 1 (372 mw),

Crystal River 2 (468 mw) , Crystal River 4 (697 mw) and Crystal River 5 (697 mw) . These five units comprise 61% of FPC's steam generating capacility makirg this site the hub of FPC's generation system. Crystal River units 1, 2 aid 4 are all connected to the 230 kv bus which is the off-site power source for CR-3. This assures that, short of a complete state-wide blackout or total destruction of the 230 kv substation, CR-3 will not be subjected to a sustained loss of off-site power. If one of these events were to occur, highest priority would be given to restoration of power to the site since it is so vital to the survival of FPC's system.

MATGINAL SHUPDOWN BENEFITS Despite the emphasis put on shutting down nuclear plants prior to the arrival of a hurricane, the safety benefits gained are minimal. The shutting down of a nuclear plant should only be done when there is a clear safety benefit.

Besides degradirg the reliability of the grid, it causes the plant to go through an additional operating transient. The major safety benefits resulting from being in a shutdown condition when a station blackout occurs are the avoidance of a reactor trip at power ard a lower decay heat load at the beginning of the blackout event. While it is desirable to avoid a reactor trip frun power, the systems which trip the reactor are very reliable ard the station blackout transient, as described in NUMARC 87-00, Section 2, is initially similar to other reactor trip transients. The initial power level at the time the blackout event begins will have little affect on the event as it proceeds.

The reduction in decay heat load achieved by shutting down before the

ATTA W MENT 2 Page C commencement of the event will serve mainly to reduce the demand for condensate which cannot be recovered after condenser vactann is lost. This provides virtually no saiety enhancement since the plant is requirtd by Technical Specifications to maintain over two and one half times the condensate inventory needed to cope with a four hour station blackout event.

In addition, other sources of wter are always wallable which could support i

decay heat removal operation for as long as two weeks should the normal i

source be depleted. Thus, a reduction in decay heat level will produce little, if any, safety benefit fee a station blackout. event.

CDtK1USION As demonstrated above, the Crystal River generating complex is unique in the diversity of sources available to supply off-site power to CR-3 and in the ruggedness to withstand hurricane force winds. This uniqaeness justifies the use of plant-specific criteria fcT actions during hurricanes at Crystal River.

The protective actions outlined in this attachment provide assurance that CR-3 will be safe urder all hurricme induced corditions.

The prompt and frequent asm-nt by FPC management, using all relevant information, assures that CR-3 will be shut down or other actions will be taken as needed during hurricane conditions. The effectiveness of FPC's actions during hurricane Elena was applauded in a letter dated September 16, 1985, from Dr. J. Nelson Grace, then Regional Administrator of NRC Region II, to FPC. With the enhancements outlined above, even greater assurance is provided that a hurricane will not cause a station blackout event at CR-3, and if it did, the plant will be ready to safely hardle the event.

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