ML20203K812

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Rev 0 to Training Lesson Plan LO-LP-39205-00, Reactivity Control Sys 3/4.1
ML20203K812
Person / Time
Site: Vogtle  Southern Nuclear icon.png
Issue date: 08/08/1986
From: Brown R, Shaw J
GEORGIA POWER CO.
To:
Shared Package
ML20203K798 List:
References
LO-LP-39205, LO-LP-39205-00, NUDOCS 8608210354
Download: ML20203K812 (16)
v • d • e


Text

F

's Georgia Power POWE.1 GENERATION CEP*ATMENT

.- VOGTLE ELECTRIC GENERATING PLANT h .

TRAINING LESSON PLA,N .,.. ,

, s TITLE: REACTIVITY CONTROL SYSTEMS 3/'4, 1E NUMBER, - LO-LP-39205-00 PROGRAM: LICENSED OPERATOR TRAINING 0 REVISION:

AUTHOR: J . P . SHAW 8/7/86 DATE:

APPROVED:

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DATE:

7,/f,/g INSTRUCTOR GUIDELINES: v I. MATERIALS A. WHITE BOARD WITH MARKERS B. TRANSPARENCIES

1. LO-TP-39205-00-001 OBJECTIVES
2. LO-TP-39205-00-002 ROD INSERTION LIMIT CURVE C. HANDOUT: LO-H0-39205-00-001 D. COPY OF TECH SPECS OR SECTION 3/4.1 FOR EACH STUDENT.

II. EVALUATION: WEEKLY EXAM AND SATISFACTORY PERFORMANCE ON SIMULATOR.

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LO-LP-39205-00

l. PURPOSE STATEMEN  :

TO TEACH STUDENTS THE APPLICABILITY AND ACTIONS OF LIMITING CONDITIONS FOR OPERATION SECTION 3/4.1, REACTIVITY CONTROL SYSTEMS II. LIST OF OBJECTIVES:

1. The student will be able to determine if in violation of an LCO given a list of equipment and a given applicability condition.
2. The student will be able to give the required action statement from memory if the time limit for action is one hour or less.
3. The student will be able to look up the required action if given the applicable LCO if action required in more than one hour.
4. " State (SRO) or be familiar with (RO) the basis for each of the LCOs."

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_ LO-LP-39205-00

REFERENCES:

TECHNICAL SPECIFICATIONS SECTION 3/4.1 REACTIVITY CONTROL SYSTEMS 9

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  • LO-LP-39205-00 Ill. LESSON OUTLINE: NOTES A. Boration Control
1. Shutdown Margin
a. Read 3/4.1.1.1 Shutdown Margin T*** greater FSAR 15.4.6 than 200*F Mode 1 and 2 k/k
b. Read 3/4.1.1.2 Shutdown Margin T less than Mode 3 and 4 2.0 or equal to 200*F k/k for CVCS malfunction
c. Action is immediate consideration Mode 5 1.5 k/k
d. Bases
1) Shutdown margin insures a) Reactor can be made suberitical from all operating conditions b) Reactivity transients due to acci-dents are controlled c) Prevent inadvertent criticality at shutdown
2) Most restrictive condition a) Steam line break at EOL and T *** at Rx can become no-load critical again &

reach approx 15% PWR

, b) Minimum SDM required to control this transient c) Mode 3 and 4 - BOL, Boron dilution accident (1) Based on FSAR 15.4.6 boron dilution accident study l (2) CVCS malfunction resulting in pure water makeup to VCT (3) No operator intervention until l High Flux at shutdown alarm

! then 15 minute response time allowed.

3) At T less than or equal to 200*F cool-down* effects from steam break minimal l

a) Lower SDM limit provides adequate protection I

e. Example - McCuire 2 LER 85-014 (attached)

, 4 l

t

r LO-LP-39205-00 Ill. LESSON OUTLINE: NOTES

2. Moderator Temperature Coefficient
a. Read 3/4.1.1.3 Moderator Temperature Coefficient
b. Action requires rod withdrawal limits
1) MTC*more negative in a rodded core a) Rods require a lower boron concen-tration b) Rods increase leakage factor of MTC (More places for neutrons to leak to)
2) Still must maintain rods above RIL
c. Bases
1) Maintain MTC remains within FSAR analysis
2) Limit on most negative probable steam break a) Does no,e state in bases
d. Example - North Anna 1 LER 84-012 (Attached)
3. Minimum Temperature Criticality,
a. Read 3/4.1.1.4
b. Action within 15 minutes
c. Bases
1) Ensures reactor not made critical below MTC
2) Required to insure a) MTC within its analyzed range b) Protective instrumentation within normal operating range c) Pressurizer operable with steam bubble d) Reactor pressure vessel above RT NDT 5

L

LO-LP-39205-00 Ill. LESSON OUTLINE: NOTES B. Boration Systems

1. Read 3/4.1.2.1 Boration Flowpath Shutdown
2. Read 3/4.1.2.2 Boration Flowpath Operating
3. Read 3/4.1.2.3 Charging Pump Shutdown
4. Read 3/4.1.2.4 Charging Pumps Operating
5. Read 3/4.1.2.5 Borated Water Source Shutdown 15 . Read 3/4.1.2.6 Borated Water Source Operating
7. Bases a.- Boration injection system insures negative reactivity control available in all modes
b. Components required
1) Borated water sources
2) Centrifugal charging pumps
3) Separate flow paths
4) Boric acid transfer pumps
c. Above 200*F two flow paths ensure single

. failure criteria

1) Stored volume assures attaining 1.3% SDM for Modes 1 and 2, 2.0% SDM for Modes 3 and 4.

a) After xenon. decay I

( b) Cooldown to 200*F

2) Maximum volume requirement at EOL, full Numbers not in power equilibrium xenon bases or T.S. yet a) BAST - 18,480 gallons at 7000 ppm b) RWST - 82,000 gallons at 2000 ppm l

c) Usable volume 6

(~ , .

LO-LP-39205-00 LESSON OUTLINE:

111. NOTES

d. Less than 200*F
1) Single train adequate a) Stable reactivity condition of reactor b) Restrictions on core alterations on loss of single train
2) Volume requirement a) Provide 1.5% SDM after xenon decay and b) Cooldown from 200*F to 140*F c) BAST - 2660 gallons at 7000 ppm Numbers to be verified after T.S.

d) RWST - 11,800 gallons at 2000 ppm issuance e) Usable volume

e. RWST contained vo,lume and boron concentration
1) Limit sump pH between 8.5 and 10.5 during LOCA.
2) Minimizes evolution of iodine

. 3) Minimizes effects of CL- and caustic stress corrosion.

8. Example - Farley 1 LER 85-005 (attached)

C. Movable Control Assemblies

1. Read 3/4.1.3.1 Group Height
2. Read 3/4.1.3.2 Position Indicating Systems -

Operating

3. Read 3/4.1.3.3 Position Indicating Systems -

Shutdown

4. Read 3/4.1.3.4 Rod Drop Time 7

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LO-LP-39205-00 ll1. LESSON OUTLINE: NOTES

5. Read 3/4.1.3.5 Shutdown Rod Insertion Limit
6. Read 3/4.1.3.6 Control Rod Insertion Limit LO-TP-39205-00-001
7. Bases
a. By verifying all rods above RIL assures:
1) Minimum SDM maintained
2) F elta H within acceptable limits
3) RCCA ejection minimized
4) Core made subcritical with required SDM a) With one RCCA stuck b) In event of ejected rod with two RCCA's stuck - where one is worst ejected rod
5) Trip reactivity in accident analysis available ,
6) Dropping or misaligning RCCA will not violate DNBR
7) Uncontrolled withdrawal no more severe than analysis
8) Uncontrolled withdrawal will not result in peak power density that exceeds center line melting
b. Operability of RPI ensures compliance with control rod alignment
c. Operability of demand PI is required to ensure compliance with insertion limits
d. Action statements permit variations but have additional restrictions
1) Measure peaking factors or
2) Restrict thermal power
3) Either assures fuel rod integrity 8

r LO-LP-39205-00 111. LESSON OUTLINE: NOTES

e. Actions 3.1.3.1 b and c
1) Incumbent upon to verify trippability of inoperable rods a) May be verification of control system failure b) Failure in control rod stepping mechanisms
2) Otherwise assume untrippable and to to action A.
f. Rod Drop Time
1) Consistent with accident analysis
2. Measured with T,y, hot and RCP's on a) Representative of real trip from power
g. Bank demand and RPI's verified every 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />
1) More restrictive without alarm
2) Assures LCO's satisfied
8. Examples: (Attached)
a. Summer 1: LER 85-011 (3.1.3.1)
b. Davis-Besse 1: LER 81-038 (3.1.3.1)
c. Salem 2: LER 85-010 (3.1.3.3)
d. McGuire 2: LER 85-021 (3.1.3.3)
e. Davis-Besse 1: LER 85-006 (3.1.3.4)
f. McGuire 2: LER 85-014 (3.1.3.6)

D. Summary

1. Boration Control
a. Shutdown Margin
b. Moderator Temperature Coefficient
c. Minimum Temperature lar criticality 9

l

c LO-LP-39205-00 lil. LESSON OUTLINE: NOTES

2. Boration systems
a. Flow path
b. Centrifugal charging pumps
c. Borated water sources
3. Movable control assemblies
a. Group height
b. Position indication systems
c. Rod drop time
d. Shutdown rod insertion limit
e. Control rod insertion limit E. Practical Exercises
1. Shutdown Margin
a. On a routine Rx s/u you announce that the reactor is critical at 45 steps on CB "C'.

What are your actions based on Tech Specs and procedure

1) Reinsert all control banks comply with

, T.S. 3.1.1.1 and borate approximately 100 gallons to ensure adequate SDM

2) Have chemist resample RCS for boron
3) Investigate cause, write LER
b. Af ter a 15% load rejection you receive a RPI ROD DEVIATION and notice that a control

, rod in CB "D" failed to insert and is

( misaligned by greater than 12 steps. What l Tech Specs are you in and if the rod is I

unmovable due to friction what are your actions?

1) GO TO PROCEDURE 17010-1 "RPI ROD Students may go thru

( DEVIATION" " Rod Control Malf."

l Procedure before 6

2) T.S. 3.1.3.1 action discovering bound I

rod.

l a) Verify SDM satisfied per 3.1.1.1 w/in 1 hr and be in HOT STANDBY w/in 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

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.c LO-LP-39205-00 lil. LESSON OUTLINE: NOTES

3) Operator wouldn't know rod was unmovable due to friction until attempts to restore rod per 18003-1 " Rod Control System Malf" is made not that time of rod out-of-line is that which should be used to start S/D clock.
2. Boration Systems
a. During refueling the SRO notes that both CCPs are in Pull-to-Lock. Is this a violation of Tech Specs? What is the required action?
1) Per T/S 3.1.2.3 suspend all operations involving CORE ALTERATIONS or positive reactivity changes
2) Report to S.S., investigate cause.
3) Ensure at least one CCP restored to OPERABLE before resuming CORE ALTERATIONS.
b. While in Mode i during repair work on ILV-112D

" REFUELING WTR TK to CHARGING PUMP IS0" the shift chemist reports that the boron concen-tration of the Boric Acid Scorage Tank is 7750 ppa, backup samples confirmed. What actions are required?

1) Restore either the BAST concentration

. to 7000-770 w/in 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> er restore ILV-112D to service w/in 72 hrs

2) Per chemistry's recommendations add 2 or 3 " batches" of pure water to BAST per 13701-1 step 4.4.1 to restore boron concentration to normal
3) Tank will have to be recire'ed for up to 16 hrs af ter batchin; to verify proper mixing before aanpr ing.-

l 4) If actions to rette:b (; aoration l flowpaths are unsuccesstui after l

72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, be in HOT STBY w/in 6 hrs and then 7 days to restore or be in

cold shutdown within the next 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />, l

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c LO-LP-39205-00 Ill. LESSON OUTLINE:

NOTES

3. Movable Control Assemblies
a. While performing surveillances procedure 14410-1 " Control Rod Operability Test" @

100% RTP. Power Cabinet IBD fails at the time Control Bank B is inserted to 218 steps.

This causes a Power Cabinet Urgent Failure and inhibits any further rod motion. What Tech Specs LCOs are not met and what actions are necessary?

1) Although testing is allowed by 3.1.3.6

" Control Rod Insertion Limit", where the surveillances is interrupted for an extended time due to repair, it would seem that the action of 3.1.3.6 would apply and either the rods are restored to 228 steps w/in 2 hrs or power lowered with boration to less than 25% RTP which is the insertion limit of CB "B' @ 218 steps.

2) SDM is verified per 4.1.1.1.1 a. with an increased allowances for the Bank that is stuck @ 218 steps (immediate boration would not be warranted in this case)
3) Restoration would require repeat of surveillance on rod and proper overlap

, and sequencing restored,

b. ERPI indication is lost for a shutdown rod in Bank "B" while in mode 3. What are your actions?
1) 3.1.3.3 leaves little room for inter-pretation.
2) Open the Reactor Trip Breakers immediately.

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.- IV. PRACTICAL EXERCISES.

SDM (also 3.1.3.6)

[161} MCGUIRE 2 DOCKET 50-370 LER 85-014 REACTOR CRITICALITY WITH CONTROL RODS BELOW MINIMUM INSERTION LIMITS.

EVENT DATE: 051785 REPORT DATE: 062885 NSSS: WE TYPE: PWR (NSIC 195243) ON MAY 17, 1985 AT 0609, THE REACTOR WAS MADE CRITICAL WITH BANK "C" CONTROL RODS BELOW THE MINIMUM TECH SPEC INSERTION LIMITS. OPERATORS REINSERTED ALL CONTROL RODS IN ACCORDANCE WITH OPERATING PROCEDURES, SHUTTING DOWN THE REACTOR. MAXIMUM POWER LEVEL WAS ABOUT 10(-8) AMPS ON THE INTERMEDIATE RANGE NEUTRON DETECTOR WITH CONTROL R0D BANK "C" WITHDRAWN 26 STEPS. THIS EVENT IS CLASSIFIED AS A PROCEDURAL DEFICIENCY BECAUSE THE COEFFICIENTS IN THE XENON PREDICT COMPUTER PROGRAMS WERE INCORRECT. THIS PROGRAM WAS USED BY OPERATORS TO PREDICT THE CONTROL R0D POSITION AT WHICH THE REAt'"Od WOULD GO CRITICAL.

MTC

[213] NORTH ANNA 1 DOCKET 50-338 LER 84-012 POSITIVE MODERATOR TEMPERATURE COEFFICIENT.

EVENT DATE: 092584 REPORT DATE: 100484 NSSS: WE TYPE: PWR (NSIC 193654) ON 9-25-84, NORTH ANNA POWER STATION, UNIT 1, FUEL CYCLE 5'S MODERATOR TEMPERATURE COEFFICIENT WAS DETERMINED TO BE MORE POSITIVE THAN 0 DELTA K K/F. A POSITIVE MTC WAS EXPECTED. THE NEW FUEL LOADING HAS A HIGH POTENTIAL BURNUP OF 16000 MWD /MTU. THIS HIGH BURNUP REQUIRES A HIGH INITIAL CRITICAL BORON CONCENTRATION WHICH PRODUCES A SLIGHTLY POSITIVE MTC WITH ALL RODS OUT AT ZERO POWER. INTERIM CONTROL R0D WITHDRAWAL LIMITS HAVE BEEN IMPLEMENTED TO PREVENT OPERATING WITH A POSITIVE MTC. A CORE BURNUP OF 600 MWD /MTU IS EXPECTED TO BE NECESSARY TO RESTORE THE MTC TO WITHIN ITS LIMIT FOR ALL RODS WITHDRAWN CONDITION. THIS EVENT IS REPORTABLE PURSUANT TO TECH SPEC 6.9.2 (SPECIAL REPORTS).

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- I IV. PRACTICAL EXERCISES B0 RATION SYSTEMS I

[110] FARLEY 1 DOCKET 50-348 LER 85-005 ALL CHARGING PUMPS WERE INOPERABLE.

EVENT DATE: 041585 REPORT DATE: 050985 NSSS: WE TYPE: PWR (NSIC 194770) AT 0237 ON 4/15/85, DURING CORE ALTERATIONS, IT WAS RECOGNIZED THAT THE TECH SPEC 3.1.2.1 REQUIREMENT FOR A BORON INJECTION FLOWPATH THROUGH AN OPERABLE CHARGING PUMP AND THE TECH SPEC 3.1.2.3 REQUIREMENT FOR AN OPERABLE CHARGING PUMP WERE NOT MET BECAUSE ALL OF THE CHARGING PUMPS HAD BEEN TAGGED OUT. A BORON INJECTION FLOW PATH VIA THE RESIDUAL HEAT REMOVAL PUMP WAS AVAILABLE. UPON DISCOVERY, TECH SPEC ACTION STATEMENTS WERE COMPLIED WITH IN THAT CORE ALTERATIONS WERE SUSPENDED IMMEDIATELY. ON 4/14/85, IN ACCORDANCE WITH TECH SPEC REQUIREMENTS, ONLY ONE CHARGING PUMP (THE 1A CHARGING PUMP) WAS OPERABLE. THE SHIFT SUPERVISOR AUTHORIZED A TAGGING ORDER FOR REPAIR OF SEVERAL VALVES ON THE CHARGING LINE WHICH, AT 2242, MADE THE 1A CHARGING PUMP INOPERABLE. FUEL MOVEMENT BEGAN AT 2303. AT APPROXIMATELY 0200 ON 4/15/85, THE SHIFT SUPERVISOR REQUESTED A REVIEW OF TAGGING ORDERS AFFECTING THE BORON INJECTION FLOW PATHS. AT 0237, THIS REVIEW DETERMINED THAT NO CHARGING PUMPS WERE OPERABLE. ACTIONS WERE TAKEN TO RESTORE THE 1A CHARGING PUMP TO OPERABILITY AND THESE WERE COMPLETED AT 0424 ON 4/15/85. THIS EVENT WAS CAUSED BY PERSONNEL ERROR. THE SHIFT SUPERVISOR FAILED TO PERFORM A SUFFICIENTLY DETAILED REVIEW OF THE TAGGING ORDER BEING AUTHORIZED. THE SHIFT SUPERVISOR INVOLVED IN THIS INCIDENT HAS BEEN COUNSELED.

3.1.3.1 MOVABLE. CONTROL ASSEMBLIES (305] SUMMER 1 DOCKET LER 85-011 ROD CONTROL SYSTEM FAILURE.

EVENT DATE: 041885 REPORT DATE: 051785 NSSS: WE TYPE: PWR VENDOR: WESTINGHOUSE ELECTRIC COMPANY (ELEV. DIV)

(NSIC 194849) AT APPROXIMATELY 0147 HOURS ON APRIL 18, 1985, CONTROL RODS POWERED BY ROD CONTROL SYSTEM CABINET 2AC FAILED TO MOVE. THE AFFECTED RODS WERE DECLARED INOPERABLE, AND THE PLANT ENTERED ACTION STATEMENT (B) 0F TECH SPEC 3.1.3.1, " MOVABLE CONTROL ASSEMBLIES."

DURING SYSTEM TROUBLESHOOTING, AN INADVERTENT ROD DROP OCCURRED JUST PRIOR TO STARTING A CONTROLLED SHUTDOWN OF THE PLANT. THE ROD DROP CAUSED A REACTOR TRIP FROM 100% POWER AT 0629 HOURS ON POWER RANGE NEGATIVE RATE. THERE WERE NO ADVERSE CONSEQUENCES FROM THIS EVENT. THE REACTOR PROTECTION SYSTEM FUNCTIONED PER DESIGN. DUE TO A PREVIOUS STEAM GENERATOR TUBE LEAK, THE STEAM SUMPED FROM THE AFFECTED STEAM LINE TO ATMOSPHERE AND FROM THE TURBINE-DRIVEN EMERGENCY FEEDWATER PUMP EXHAUST RESULTED IN AN UNMONITORED RELEASE.

THE RELEASE WAS CONSERVATIVELY CALCULATED TO BE A SMALL FRACTION OF THE ALLOWABLE RELEASE l LIMITS. THE ROD CONTROL SYSTEM FAILURE WAS DETERMINED TO BE A DEFECTIVE SLAVE CYCLER l COUNTER CARD. THE CARD WAS REPLACED AND A PLANT RESTART MADE AFTER A FORCED OUTAGE OF 19.3 l HOURS. TO PREVENT A POTENTIAL RECURRENCE, THE LICENSEE HAS ESTABLISHED A PREVENTIVE MAINTENANCE PROGRAM FOR THE ROD CONTROL SYSTEM CABINETS.

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e LO-LP-39205-00

.- IV. PRACTICAL EXERCISES

[ 79] DAVIS-BESSE 1 DOCKET 50-346 LER 81-038 REV 1 UPDATE ON FAILURE OF CONTROL ROD DRIVE LEAF SPRING ANTI-ROTATIONAL DEVICE.

EVENT DATE: 062581 REPORT DATE: 121784 NSSS: BW TYPE: PWR VENDOR: BABCOCK & WILCOX COMPANY (NSIC 195162) ON 6/25/81 DURING A ROUTINE RECOVERY FOLLOWING A REACTOR TRIP, A CONTROL ROOM OPERATOR DISCOVERED THAT CONTROL ROD (CR) 5-8 WAS NOT MOVING WHILE WITHDRAWING GROUP 5.

CR-58 WAS DECLARED INOPERABLE AT 0530 HOURS, PLACING THE UNIT IN ACTION STATEMENT (A) 0F TECH SPEC 3.1.3.1. THE UNIT WAS IN THE HOT STANDBY MODE AT THE TIME OF THE EVENT, AND THE EXISTENCE OF AN ADEQUATE SHUTDOWN MARGIN WAS VERIFIED. THE CAUSE WAS A COMPONENT FAILURE.

THE LEAF SPRING ANTI-ROTATIONAL DEVICE OF THE LEADSCREW NUT ASSEMBLY HAD FRACTURED INTO SEVERAL FRAGMENTS, CONSEQUENTLY, PREVENTING THE LEADSCREW FROM RISING. THE LEADSCREW NUT ASSEMBLY WAS REPLACED, AND ALL FRAGMENTS WERE RETRIEVED. CR 5-8 WAS DECLARED OPERABLE ON 7/17/81 AT 1020 HOURS. ALL LEAF SPRINGS WERE INSPECTED DURING THE 1984 OUTAGE AND NO PROBLEMS WERE FOUND.

3.1.3.3 (215} SALEM 2 DOCKET 50-311 LER 85-010 FAILURE TO OPEN REACTOR TRIP BREAKERS WITH AN INOPERABLE ROD POSITION INDICATOR.

EVENT DATE: 070785 REPORT DATE: 080685 NSSS: WE TYPE: PWR VENDOR: MAGNETICS DIV SPANG INDUSTRIES, INC.

(NSIC 195748) UNIT 2 TECH SPEC 3.1.3.2.2, (0UR 3.1.3.3) APPLICABLE IN MODES 3, 4 AND 5, REQUIRES THE REACTOR TRIP SYSTEM BREAKERS TO BE OPENED IN THE EVENT OF AN INOPERABLE INDIVIDUAL ROD POSITION INDICATION (IRPI). ON 7-7-85, DURING UNIT STARTUP OPERATIONS, WITH THE UNIT IN MODE 2. IT WAS DISCOVERED THAT THIS ACTION REQUIREMENT WAS NOT COMPILED WITH EARLIER IN THE DAY WHEN THE IRPI FOR CONTROL ROD 2SA2 WAS FOUND TO BE DEVIATING FROM THE GROUP DEMAND INDICATION BY GREATER THAN 12 STEPS. THE ROOT CAUSE OF THE EVENT WAS ATTRIBUTED TO THE FAILURE TO FULLY REVIEW ALL APPLICABLE TECH SPECS. CONTRIBUTING TO THIS OCCURRENCE IS THE FACT THAT THIS TECH SPEC IS UNIQUE TO UNIT 2; UNIT 1 TECH SPECS DO NOT CONTAIN A SIMILAR REQUIREMENT. BECAUSE THE TECH SPEC ACTION REQUIREMENTS WERE NOT COMPLIED WITH, THE EVENT IS REPORTABLE IN ACCORDANCE WITH 10 CFR 50.73(A)(3)(I)(B). THE INDIVIDUAL INVOLVED WAS COUNSELLED, AND A DISCUSSION OF THIS EVENT IS BEING INCLUDED IN THE APPROPRIATE TRAINING /REQUALIFICATION PROGRAMS. A LICENSE CHANGE REQUEST, PREPARED PRIOR TO THIS OCCURRENCE, IS BEING SUBMITTED TO THE COMMISSION TO MODIFY BOTH UNIT 1 AND 2 TECH l SPECS RELATING TO CONTROL ROD POSITION INDICATION.

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oO LO-LP-39205-00 l

.- IV. PRACTICAL EXERCISES (155] MCGUIRE DOCKET 50-370 LER 85-021 MANUAL REACTOR TRIP DUE TO R0D POSITION INDICATOR FAILURE.

EVENT DATE: 072985 REPORT DATE: 082885 NSSS: WE TYPE: PWR VENDOR: WESTINGHOUSE ELECTRIC CORP.

(NSIC 195466) ON 7-29-85, THE REACTOR WAS MANUALLY TRIPPED WHEN CONTROL BOARD POSITION INDICATION WAS LOST FOR SHUTDOWN BANK E. ROD D-8. THIS ACTION WAS TAKEN AS SPECIFIED BY TECH SPEC 3.1.3.3. ON 7-26-85, CONTROL BOARD INDICATION WAS LOST FOR THE SAME ROD, BUT ROD POSITION WAS DETERMINED USING THE OPERATOR AID COMPUTER AND THE REACTOR WAS NOT TRIPPED.

THE UNIT WAS IN MODE 3 HOT STANDBY, WHEN ROD POSITION INDICATION WAS LOST ON BOTH OCCASIONS. THE ROD POSITION WAS DETERMINED OR THE REACTOR TRIPPED SO SAFETY WAS NOT AFFECTED. THIS INCIDENT IS ATTRIBUTED TO COMPONENT FAILURE BECAUSE THE DIGITAL ROD POSITION INDICATION (DRPI) DATA A ENCODER CARD (WESTINGHOUSE MODEL NO. 1047F28G01, CARD 0606) FAILED, CAUSING A LOSS OF INDICATION FOR ROD D-8. THE FAILED CARD WAS REPLACED.

3.1.3.4

[ 97] DAVIS-BESSE 1 DOCKET 50-346 LER 85-006 FAILURE OF CONTROL ROD DRIVE E-3 TO MEET TRIP TIME.

EVENT DATE: 032385 REPORT DATE: 041985 NSSS: BW TYPE: PWR VENDOR: DIAMOND POWER SPECIALTY CORP.

(NSIC 194809) DURING ROD DROP TIME TESTING ON MARCH 22, 1985, THE CONTROL ROD AT CORE LOCATION F-3 FAILED TO MEET THE TECH SPEC REQUIREMENT OF 1.58 SECONDS. SUBSEQUENT DISASSEMBLY OF THE CONTROL ROD DRIVE MECHANISM REVEALED A SETSCREW FRAGMENT HAD JAMMED INSIDE, PREVENTING DISENGAGEMENT OF THE LATCHING ASSEMBLY. THIS SETSCREW WAS DETERMINED TO HAVE FALLEN FROM A CONTROL ROD DRIVE MECHANISM HANDLING TOOL. A LEAF SPRING INTERNAL TO THE CONTROL RCD DRIVE MECHANISM WAS FOUND TO BE EROKEN. THIS FAILURE DID NOT AFFECT THE DRIVE'S OPERATION, ALTHOUGH IT COULD POTENTIALLY HAVE CAUSED A FAILURE SIMILAR TO THE SETSCREW. THE MOST PROBABLE CAUSE OF THIS LEAF SPRING EREAKAGE IS MECHANICAL INTERFERENCE WITH THE CONTROL ROD DRIVE MECHANISM INTERNALS. INDICATIONS ON A DRIVE COMPONENT, AND INSPECTIONS WHICH REVEALED FIVE LEAF SPRINGS TO BE IMPROPERLY SEATED, SUPPORT THIS CONCLUSION. CORRECTIVE ACTION TAKEN INCLUDES REPLACEMENT OF THE E-3 CONTROL ROD DRIVE MECHANISM, INSPECTION AND EXERCISING OF THE REMAINING LEAF SPRINGS, INSPECTION OF CONTROL ROD HANDLING TOOLS, AND MODIFICATIONS TO CONTROL ROD DRIVE MECHANISM TOOLS AND PROCEDURES.

FURTHER ANALYSIS IS BEING CONDUCTED.

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