ML20141H612

Documents 860108 Presentation to NRC Re 851226 Event. Continuation of Search for Cause of Event Requested.Reviews Will Be Conducted of Various Types of Electrical Malfunctions & Failures Leading to Similar Problems

ML20141H612
Person / Time
Site:	Rancho Seco
Issue date:	01/09/1986
From:	Tucker H BABCOCK & WILCOX OPERATING PLANTS OWNERS GROUP
To:	Eisenhut D Office of Nuclear Reactor Regulation
References
NUDOCS 8601140300
Download: ML20141H612 (28)

Text

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" OWNERS GROUP

- 1 Arkansas Power & IJght Company ANOw1 Toledo Edison Company Dawes Sesse Duke Power Company Orence 9,3. 3 7_ - VaNey Aanherty Sellefonte 9,2 1 Pterede Power t_m_ Crystal INwer 3 r-, washington Pubik Power Supp#y WNPI GPU Nuclear Corporasson Thef-9 System Sacramente htunkipal UtNesy Desertti stancho Seco Sabreck & Macos Company g gglg Working Together to Economically Provide Reliable and Safe Electrical Power Suite 220  ;

January 9, 1986 7910 Woodmont Avenue  !

m Bethesda, Maryland 20814 (301)951-3344 Mr. D. G. Eisenhut Deputy Director Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D. C. 20555

Subject:

B&WOG RRG Meeting related to 12/26/85 Rancho Seco Event

Dear Mr. Eisenhut:

The purpose of this letter is to formally document the presentation made to the NRC at your request by the B&WOG Regulatory Response Group on January 8, 1986. A copy of the information presented is attached.

The B&WOG appreciated the opportunity to meet with the NRC to present our preliminary assessment of the generic implications of the recent Rancho Seco transient. We believe the meeting was beneficial.

The actions requested of the B&WOG and agreed upon at the conclusion of the meeting were as follows:

1. Efforts are to continue to develop an understanding of the root cause of the Rancho Seco transient.

2. Review will be made of the various types of ICS and NNI electrical malfunctions and failures that can lead to problems such as the Rancho Seco transient.

3. Near-term training is to be conducted to make all operators aware of the Rancho Seco transient and to review the required actions for dealing with a similar event.

4. The B&WOG will submit by February 5, 1986, an Owners Group letter presenting the program to be followed by the operating plants as a result of the January 16, 1986 Executive Committee meeting.

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3 Mr. D. G. Eisenhut January 9, 1986 i

5. The B&WOG plans to discuss the program at the previously planned February 5, 1986 NRC/B&WOG meeting.

Consistent with the charter and intended purpose of the RRL, and as stated at the meeting, this completes the actions by the RRG relative to the Rancho Seco transient. Follow-on actions will be handled through the regular B&WOG organization and communication will be through established channels.

Should there be additional significant concerns raised by the NRC staff relative to the Rancho Seco transient between now and the planned B&WOG Executive Committee meeting, please call me prior to the meeting.

Very truly yours,

.T H. B. Tucker, C$' airman B&WOG Executive Committee J

NRC / B&WOG REGULATORY RESPONSE GROUP MEETING

~

TO REVIEW THE DECEMBER 26,1985 RANCHO SECO TRANSIENT JANUARY 8,1986 BETHESDA, MARYLAND B&WOG RRG REPRESENTATIVES:

. Arkansas Power & Light Duke Power Company Florida Power Corporation GPU Nuclear SMUD Toledo Edison

_4 A A. ._.m-__

4 B&WOG RRG MEMBERSHIP AND CHRONOLOGY OF RECENT ACTIVITIES 0 RRG MEMBERSHIP - ALL B&W OPERATING PLANTS ARE MEMBERS 0 RECENT RRG ACTIVITY CHRONOLOGY INDIVIDUAL UTILITY ACTION BEGAN AS SOON AS RANCHO SECO TRANSIENT INFORMATION AVAILABLE.

FIRST RRG TELEPHONE CONFERENCE CALL - 12/31/85; DECISION TO ACTIVATE RRG.

FURTHER INDIVIDUAL UTILITY ASSESSMENT RESULTING FROM RRG TELEPHONE CONFERENCE CALL.

SECOND RRG TELEPHONE CONFERENCE CALL -

1/2/86:

AGREEMENT ON SCOPE OF RRG ACTIVITIES.

THIRD RRG TELEPHONE CONFERENCE CALL -

1/6/86.

RRG MEETING -

1/7/86.

RRG/NRC MEETING - 1/8/86.

1

NRC/B&WOG RRG MEETING JANUARY 8,1986 AGENDA

1. Introduction H.B. Tucker /DPC (10 min) ll. Rancho Seco Transient R.J. Rodriquez/SMUD (15 min)

Ill. Plant-Specific Assessment Results

- Hardware &

Function Comparisons .C.B. Doyel/FPC (45 min)

-- Procedures, Training and J.T. Enos/AP&L (15 min)

Plant Performance IV. Preliminary Conclusions H.B. Tucker /DPC ( 5 min)

& B&WOG Actions e

e

--- .- - .=n . .. . . . .

s. .

TO OTHER OTSG h

DUAL DRIVE TURBINE BYPASS VALVES

+ b h FROM CONDENSATE STORAGE MOTOR DRIVEN NORMAL AFW CONTROL VLV bM AFW PUMP TANK l

><1 OTSG MAIN THROTTLE MFW [] ^

REGULATING MAIN VALVE BLOCK VLV CONTL ATMOSPHERIC TEAM DUMP VALVES MAIN STEAM SYSTEM PUMP STARTUP (MSS)

CONTROL FEEDWATER SYSTEM (FWS)

Rancho Seco

,; .- SEQUENCE OF EVENTS

SUMMARY

RANCHO SECO TRANSIENT 12/26/85 i INITIAL CONDITIONS: DECEMBER 26,1985 76% REACTOR POWER ICS IN FULL AUTOMATIC CONTROL IlME EVENT l

04:13:47 LOSS OF ICS DC POWER  !

VALVES MOVE TO 50% OPEN POSITION TURBINE BYPASS VALVES (TBV) i ATMOSPHERIC DUMP VALVES (ADV) 1 MAIN FEED WATER REGULATING VALVES (MFW) 1 AUXILIARY FEEDWATER VALVES (AFW)

MAIN FEED PUMPS GO TO MINIMUM SPEED 04:14:01 MOTOR DRIVEN AUXILIARY FEEDWATER PUMP (AFW)

STARTS AT 850 psig MAIN FEEDWATER PUMP DISCHARGE PRESSURE 04:14:03 REACTOR TRIPS ON HIGH RCS PRESSURE 04:14:06 TURBINE DRIVEN AUXILIARY FEED PUMP (AFW)

STARTS 04:14:11 AFW FLOW TO BOTH OTSGs l 1

04:14:25 OPERATORS INCliEASE RCS MAKEUP AS PART OF PROCEDURE E,02 " VITAL SYSTEM VERIFICATION" 04:14:30 OPERATORS SENT TO ISOLATE TBVs, ADVs, AND AFW VALVES, OPERATORS RECOGNIZE EXCESSIVE COOLDOWN RATE.

04:15:04 OPERATORS MANUALLY START "B" HIGH PRESSURE l

lNJECTION PUMP (HPI) TO FURTHER INCREASE RCS MAKEUP.

l

, SEQUENCE OF EVENTS

SUMMARY

(CONT'D.)

EME EVENT l

04.16:02 OPERATORS MANUALLY TRIP BOTH MAIN FEEDWATER PUMPS, ACTUAL MAIN FEED FLOW WAS ZERO SINCE 04:14:03.

AFW FLOW APPROXIMATELY 1100 GPM TO EACH STEAM GENERATOR.

04:16:57 SAFETY FEATURES (SFAS) AUTO INITIATION AT RCS PRESSURE OF 1600 psig 04:17:10 OPERATOR SHUTS SFAS ACTUATED AFW VALVES.

04:20:00 PRESSURIZER LEVEL OFFSCALE LOW 04:23:00 TBV AND ADV ISOLATED LOCALLY.

04:23:10 AFW VALVE TO "B" STEAM GENERATOR PARTIALLY CLOSED.

FLOW DECREASED TO "B" STEAM GENERATOR BY 60%.

04:26:22 AFW VALVE TO "A" STEAM GENERATOR CLOSED, OPERATOR BELIEVES VALVE ONLY 80% SHUT.

04:26:47 PRESSURIZER LEVEL BACK ON SCALE 04:29:40 OPERATOR ATTEMPTS TO CLOSE AFW VALVE TO "A" OTSG FURTHER. VALVE FAILS OPEN.

04:30:30 OPERATORS BEGIN DEPRESSURIZING RCS TO MOVE OUT OF PTS REGION.

04:33 AFW VALVE TO "B" STEAM GENERATOR IS FULLY CLOSED.

ALL FEEDWATER FLOW TO "B" STEAM GENERATOR IS STOPPED.

l l 04:40:00 ICS DC POWER RESTORED. OPERATORS SHUT AFW VALVES, TBV, AND ADVs FROM CONTROL ROOM. COOLDOWN CEASES l AT 386*F.

1

. ..... . ~ . . , - - . - .

Simplified Functional Relationship.of I&C Systems t

l Safety g Non-Safety RPS NUCLEAR ,

MEASUREMENIS M NEUTRON B0P CHDCS ISOLATION DEVICE FLUX

--> AN NU N C I AT I ON NON-NUCLEAR

--D iSOLAT10N ICS M UREMENTS DEVICE CONTROL OF SELECT RC FLOW >

8 h EL EMENTS ( FW V ALV TO CRD TRIP p & PUMPS. BYP ASS ISOLATION BREAKERS VALVES. TURBINE E DEVICE CRDCS)

. ESFAS BUI LDING > p ICS INPUTS PRESSURE FROM NNI RC PRESSURE E y 4 W

TO HPl e 9 m TO BUILDlHG E

, --> ANNUNCI ATI ON. INDICATION I SOL ATION &

RECOP0 LNG SPRAY NNI .

SG LEVEL

= --> CONTROL OF SELECTED U PROCESS ELEMENTS (PRESSURIZER FW CONTROL 0F INPUT SPRAY & HEATERS, PRlHARY PUMP STATUS E N ELEMENTS EN MAKEUP..PORV)

AUTO -e -> (V ALVES, PUMPS)

CONTROL START

s ---- n - - - - --a- A-4 4 - t ae AREAS BEING EVALUATED BY RRG RELATIVE TO '

RANCHO SECO TRANSIENT O ICS POWER SUPPLIES 0 EQUlPMENT CONTROLLED BY ICS 4

0 CONTROL ROOM INDICATORS

, O BACKUP MEANS OF CONTROL i

0 PROCEDURES AND TRAINING FOR LOSS OF ICS POWER I

l l

l 1

l i

1

ea B&WOG RRG ASSESSMENT OF R/S 12/26/85 TRANSIENT 0 ICS POWER SUPPLIES COMPARED POWER SUPPLY DESIGNS EVALUATED RANCHO SECO INITIATING EVENT i

O EQUIPMENT CONTROLLED BY ICS DETERMINED COMPONENTS CONTROLLED /

AFFECTED BY lCS DETERMINED FAILURE MODES (LOSS OF ICS POWER)

COMPARED FAILURE MODES AT B&W Pi. ANTS IDENTIFIED DIFFERENCES AND POTENTIAL IMPROVEMENT i

.u , + - m- - - - --,-- a

• e ea B&WOG RRG ASSESSMENT OF R/S 12/26/85 TRANSIENT b

0 BACKUP MEANS OF CONTROL

-- AVAILABILITY OF MANUAL CONTROL OF ICS COMPONENTS IN CONTROL ROOM

-- AVAILABILITY OF OTHER BY-PASS CONTROL CIRCUlTS AVAILABILITY OF NON-ICS. COMPONENTS THAT CAN ACCOMPLISH MISSION 0 CONTROL ROOM INDICATORS EVALUATED AVAILABILITY OF DIRECT CONTROL ROOM INDICATION FOR LOSS OF ICS POWER 1

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820 System: CR-3, Davis Besse, Rancho Seco and ANO-1 IE or IE or I. BATTERY BACKED N-l N lE

2. VITAL DISTR.

l. INVERTER WI TH STATIC SW1TCH 1F

2. BATTERY BACKED

3. REG INST. BUS hMVE ER REG.

INVERTER

4. AUXil PWR. DISTR. STATIC BUS STATIC

SWITCH F -~ SWITCH .

L... - .!

1 r IP 120 VAC 120 V AC BACKUP PREFERRED POWER POWER SYSTEM CABINET AC CIELD LOADS o o ABT SI - --

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-24  ! ++

+24 VDC l VDC

-- ., u POWER MONITOR T0:

RECO RDERS

-24 6 + I N DI C ATORS V DC g( ,

y H/A STATIONS AUX RELAYS f__  %

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-24 V0C +24 VDC BUS BUS

721 System TMI-1 ES RE

= . - - - , INVERTER REG.

BUS.

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BUS.

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1 SW r _. _ L _ _q 5e il NSTRUMEN TAT 103 ICSF CONTROLS lNNI L__7__J I

721 System Oconee I

125 VDC BUS 125 VDC BUS l l

ISOLATING & TRANSFER 118 VAC REGULATED BUS i DIODES i

INVERTER TRANSFER SWITCH e b N.C.

ELECTR0 /HECHANICAL TRANSFER SWITCH N.C. MANUAL SW

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L__ 5 P CONTR0tS 11MSTRUMENTATIO ICSF CONTROLS lNNI L - T-i

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EQUIPMENT CONTROLLED BY ICS (ORIGINAL DESIGN) l TURBINE BYPASS VALVE (TBV) 1 ATMOSPHERIC DUMP VALVE (ADV)

EMERGENCY FEEDWATER CONTROL VALVE STARTUP FEEDWATER VALVE (SUV)

MAIN FEEDWATER VALVE (MFW)

MAIN FEEDWATER PUMP TURBINE GOVERNOR -

CONTROL RODS MAIN TURBINE GOVERNOR l

l

\

b

POSITIONS OF KEY VALVES AND SYSTEMS .

FOLLOWING: LOSS OF ICS DC POWER

~. .

RANCHO DAVIS CRYSTAL SECO BESSE RIVER ANO-1 OCONEE TNI-l EQUIPMENT BAILEY BAILEY BAILEY TYPE 820 820 BAILEY BAILEY BAILEY 820 820 721 721 TBPV 50% 0% 0% 50% N/A N/A ADV 50% On N/A N/A N/A N/A EFW CONTROL 50% N/A N/A VALVES N/A N/A N/A STARTUP FW 50% 50% 50% 50%

FLOW PATH N/A N/A MAIN FW 0% 0% 0% 0%

FIDW PATH N/A N/A MF PUMP 2600 RPM 4690 RPM 4200 RPM GOVERNOR MIN SPEED N/A N/A ROD CONTROL TO MANUAL TO MANUAL TO MANUAL TO MANUAL N/A N/A MAIN TURBINE AS IS AS IS AS IS AS IS coVERNOR N/A N/A DOES PLANT NO YES YES YES HAVE MSIVs? NO YES eps e-d

POSITIONS OF KEY VALVES AND SYSTEMS  ?

FOLLOWING LOSS OF ICS AC POWER RANCHO DAVIS CRYSTAL '

SECO BESSE RIVER ANO-1 OCONEE TMI-1 EQUIPMENT CAILEY BAILEY BAILEY TYPE 820 820 BAILEY BAILEY BAILEY 820 820 721 721 TBPV 50% 0% 0% 50% 0% 0%

ADV 50% 0% N/A N/A N/A N/A i

EFW CONTROL 50% N/A VALVES N/A N/A N/A

• 50%

STARTUP FW 50% 50% 50%

i FLOW PATH 50% 50% 50%

MAIN FW 0% 0%

FLOW PATH 0% 0% 50%' 0%

MF PUMP AS-IS AS-IS GOVERNOR AS-IS AS-IS AUTO TRIP 4100 RPM ON LOSS OF

~

ICS POWER RCD CONTROL AS-IS AS-IS AS-IS AS-IS AUTO TRIP ON AS-IS TRIP OF MF PUMPS MAIN TURBINE AS-IS' AS-IS AS-IS AS-IS AUTO TRIP ON AS-IS TRIP OF MF PUMPS DOES PLANT NO YES YES HAVE MSIVs? YES NO YES

• CAVITATING VENTURI

POSITIONS OF KEY VALVES AND SYSTEMS FOLLOWING, LOSS OF ICS DC POWER RANCHO DAVIS CRYSTAL-SECO BESSE RIVER ANO-1 OCONEE TMI-1 EQUIPMENT BAILEY. BAILEY BAILEY TYPE 820 820 BAILEY BAILEY 820 820 721- BAILEY TBPV-- 721 50%' '0% 0% 50%

• N/A N/A ADV 50% On N/A N/A N/A

._ N/A EFW CONTROL 50% N/A VALVES N/A N/A N/A N/A STARTUP FW 50%*** 50% **

FIAW PATH 50% *** 50 % *** N/A N/A MAIN FW 0% 05 FLOW PATH 0% 0%

N/A N/A MF PUMP 2600 RPM GOVERNOR 4690 RPM 4200 RPM MIN SPEED- N/A N/A ROD CONTROL TO MANUAL TO MANUAL TO MANUAL TO MANUAL N/A N/A QURBINE AS IS AS IS AS IS R AS IS N/A N/A D 1 NO YES YES YES NO YES *

• MSIV CIOSURE __

• • SFRCS MAIN FEED PUMP TRIP

. . _ , . , _ A , _ -_ - - - - w CONTROL ROOM INDICATIONS

FOR LOSS OF ICS POWER RANCHO DAVIS INDICATION SECO BESSE CR-3 ANO-1 OCONEE TMI-1 ANNUNCIATOR X X X X X X LOSS OF llGHTS X X X X X X ON HAND / AUTO STATIONS 4 PLANT X X -- --

X --

COMPUTER POWER STATUS LIGHT -- --

X X --

X BLOWN FUSE --

X X --

X --

INDICATOR EVENTS -- --

X -- -- --

RECORDER i- ICS INVERTER X X --

X X X

POSITIONS OF KEY VALVES AND SYSTEMS FOLLOWING LOSS OF ICS DC POWER RANCHO DAVIS CRYSTAL SECO BESSE RIVER ANO-1 OCONEE- TMI-1 EQUIPMENT BAILEY BAILEY BAILEY TYPE 820 820 BAILEY BAILEY BAILEY 820 820 721 721 TBPV 50% 0% 0% 50% N/A N/A ADV 50% On N/A N/A N/A N/A EFW CONTROL 50% N/A. N/A VALVES N/A N/A N/A STARTUP FW 50% 50% 50%

FLOW PATH 50% N/A N/A MAIN FW 0% 0% 0%

PLOW PATH 0% N/A N/A MF PUMP 2600 RPM 4690 RPM GOVERNOR 4200 RPM MIN SPEED N/A N/A ROD CONTROL TO MANUAL TO MANUAL TO MANUAL TO MANUAL N/A N/A MAIN TURBINE AS IS AS IS AS IS ,

GOVERNOR AS IS N/A N/A DOES PLANT NO YES YES HAVE MSIVs? YES NO YES

~~

4 Q

, ANTICIPATED RESPONSE TO LOSS OF ICS POWER ANO-1 T=0 LOSS OF ICS DC POWER

-- TBV GOES TO 50% .

-- STARTUP FEEDWATER VALVE GOES TO 50%

-- MFW PUMP RUNBACK TO MINIMUM SPEED

-- MFW BLOCK AND LO-LOAD BLOCKS GO TO 0%

-- ADV REMAIN AT 0%

O PLANT RESPONSE MFW FLOW DECREASING RCS PRESSURE INCREASING

-- SG LEVEL DECREASING T=8 sec. RX TRIP ON HIGH PRESSURE TURBINE TRIP ONE MFW PUMP TRIPS (OPERATOR CLOSES MSIVs PER PROCEDURE)*

0 PLANT RESPONSE RCS TEMPERATURE DECREASING RCS PRESSURE DECREASING STM GENERATOR PRESSURE INITIALLY INCREASING STM GENERATOR LEVEL DECREASING  ;

(WILL GET EFIC EFW ACTUATION ON l LO-LEVEL IN ~ 30 SEC.)

I TO FURTHER EVALUATE TRANSIENT, IT IS ASSUMED

) OPERATOR DOES NOT PERFORM THIS ACTION.

w g-.m-, .-- ,---,w-- ,

ANO-1 RESPONSE (Cont'd) l T=12 mins: SG PRESSURE DROPS BELOW 600 PSI l

-- EFIC MSLI ACTUATION MAIN STEAM LINE ISOLATION VALVES CLOSE

-- MAIN FEEDWATER ISOLATION VALVES CLOSE i

-- ADV BLOCK VALVE OPENS '

-- ADVs CLOSED (PRESSURE LESS THAN SETPOINT) 0 PLANT RESPONSE RCS PRESSURE INCREASING RCS TEMPERATURE STABILIZES

-- SG PRESSURE INCREASING

-- SG LEVEL MAINTAINED AT EFIC SETPOINT T=20 mins: SG LEVEL RETURNS TO SETPOINT EFW VALVES BEGIN TO MODULATE TO CONTROL LEVEL

-- ADV's BEGIN TO MODULATE TO CONTROL PRESSURE O PLANT RESPONSE RCS TEMPERATURE INCREASING RCS PRESSURE STABILIZED

-- SG LEVEL STABLIZED AT SETPOINT l -- SG PRESSURE STABILIZED AT SETPOINT I

ALL PARAMETERS RETURNING TO HOT SHUTDOWN CONDITIONS.

l PRELIMINARY PROCEDURE ASSESSMENT RESULTS 0 PROCEDURES EXIST IN ALL PLANTS FOR DEALING WITH THE SYMPTOMS AND CONSEQUENCES OF LOSS OF ICS POWER.

O ABNORMAL TRANSIENT OPERATING GUIDELINES (ATOG) TECHNICAL BASIS DOCUMENT IS SOUND; PRELIMINARY ASSESSMENT OF R/S TRANSIENT DOES NOT INDICATE NEED TO REVISE.

i 0 CLARIFICATION OF CRITERIA REGARDING WHEN TO TAKE CERTAIN SPECIFIC ACTIONS MAY BE APPROPRIATE.

O FURTHER DETAILED REVIEW IS APPROPRIATE AND IS UNDERWAY.

. . a

' 'E s U '

, .s . .-

IN. A 1  %

PROCEDURE ASSESSMENT y

O' CONSIDERATION GIVEN TO:

PROCEDURES FOR DEALING WITH TRANSIENTS

,, INITIATED BY THE LOSS 'OF ICS POWER l -

s

-- THE EXPECTED, RESPONSE OF ICS CONTROLLED EQL,ilPMENT AND.THE RESULTANT EFFECT ON ON THE NSS PROCEDURES FOR DEALING WITH THE RESTORATION OF ICS POWER 3--

- ,, -ROLE OF ABNORMAL TRANSIENT OPERATING c; GUIDELINES (ATOG)

s. .

e O fdDFIRAL APPROACH:

i

' REVIEW OF PROCEDURE CONTENT ,

OPERATOR INTERVIEWS '

4 s

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--_-,e-. ..,_. ..,e xw-- , ,-

FOLLOW-ON B&WOG PROCEDURES AND TRAINING REVIEW IN

. RESPONSE TO THE 12/26/85 RANCHO SECO TRANSIENT

1. REVIEW OF TRAINING RECORDS TO ASSURE THAT OPERATORS HAVE RECEIVED TRAINING ON THE LOSS OF ICS POWER SUPPLY EVENT AND IF THE INDIVIDUAL HAS NOT, WILL SCHEDULE THE INDIVIDUAL FOR TRAINING.

~

2. CONFIRMATORY REVIEW OF THE ATOG TECHNICAL BASES DOCUMENT WILL BE PERFORMED. '

3. REVIEW OF THE PLANT-SPECIFIC PROCEDURES FOR ,

IMPLEMENTING ATOG.

L

4. REVIEW PLANT-SPECIFIC PROCEDURES FOR RESTORATION OF ICS POWER.

l

5. ISSUE INFORMATION TO FAMILIARIZE OPERATORS WITH THE RANCHO SECO EVENT.

l l

i

. . . - , . - - - - , - - . . - - , . , - . . _ _ - . - . . - - - - - , - - - . - . . . . . - - . - - - ~ - - - - - - . - - - , - - ~ . - - - - - - , , - -

• ^

4 CONCLUSIONS OF RRfa ,

0 DUE TO PLANT DIFFERENCES, A TRANSIENT INITIATED BY LOSS OF' POWER TO ICS, SUCH AS THE RANCHO SECO EVENT, AT ANY B&W PLANT OTHER THAN RANCHO SECO WOULD RESULT IN MUCH LESS SEVERE TEMPERATURE CHANGES.'

O

-DUE TO SIM,1LARITIES, THE RRG HAS CONCLUDED THAT ADDITIONAL REVIEW OF THE RANCHO SECO EVENT SHOULD BE UNDERTAKEN AS MORE COMPLETE INFORMATION IS MADE AVAILABLE FROM INVESTIGATIONS BY NRC, SMUD, OR OTHER SOURCES. THE INTENT OF THIS REVIEW SHOULD BE TO IDENTIFY ACTIONS TO BE TAKEN BY B&WOG MEMBERS TO REDUCE THE FREQUENCY AND MAGNITUDE OF TRANSIENTS.

/

0 THEREFORE, AS CHAIRMAN OF THE B&WOG EXECUTIVE COMMITTEE, I HAVE INSTRUCTED THE CHAIRMAN OF THE B&WOG STEERING COMMITTEE TO DEVELOP A PROPOSED PROGRAM OF REVIEW AND PRESENT THAT TO.THE B&WOG EXECUTIVE COMMITTEE AT A MEETING JANUARY 16,1986.

l j AT THAT MEETING WE WILL DETERMINE THE SCOPE AND l SCHEDULE OF REVIEW WITH THE INTENT OF INCORPORATING THE ACTIONS STEMMING FROM THE RANCHO SECO TRANSIENT INTO THE REVIEWS AND ACTIONS CURRENTLY UNDERWAY AS A RESULT OF THE DAVIS BESSE L EVENT OF JUNE 9,1985.

+

f

• f l

.(

r . _ . - . _ . . _ .. __

i .

l CONCLUSIONS OF RRG (Cont'd) 0 THE GENERAL DIRECTION OF B&WOG PROGRAMS FOR l REDUCING TRANSIENTS AND SCRAMS IS SOUND AND WILL l CONTINUE. EMPHASIS IS BEING GIVEN TO THE SECONDARY l PORTION OF THE PLANTS. BOTH THE RECENT DAVIS BESSE AND RANCHO SECO TRANSIENTS RE-EMPHASIZE THE IMPORTANCE OF THIS DIRECTION. THE RELATIVE PRIORITY l

AND SCHEDULE OF THESE EXISTING PROGRAMS IS BEING '

RE-EVALUATED.

~~

O INCREASED NRC FAMILIARITY WITH EXISTING AND .

PLANNED B&WOG ACTIONS RELATIVE TO TRANSIENT REDUCTION IS APPROPRIATE. ALTHOUGH MUCH OF THIS ACTIVITY INVOLVES THE NON-SAFETY RELATED PORTIONS .

OF THE PLANT, THE B&WOG INVITES NRC INPUT ON THESE .

l PROJECTS. THE ESTABLISHED MODES OF COMMUNICATION REGARDING B&WOG PROGRAMS ARE APPROPRIATE FOR THESE INTERACTIONS.

r.

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. . _ . . . - . . . - . _ _ . ,-._-_ - _ ._- .. . . _ _ - . . - . _ - . _ _ _ _ . . _ _ . _ - _ . _ _ _ - . - , . _ .