AECM-88-0048, Summary of Operating Experience - 1987

Summary of Operating Experience - 1987

ML20147E798
Person / Time
Site:	Grand Gulf
Issue date:	12/31/1987
From:	Kingsley O SYSTEM ENERGY RESOURCES, INC.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
AECM-88-0048, AECM-88-48, NUDOCS 8803070159
Download: ML20147E798 (12)

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Attachment I to AECM-88/0048 Summary of Operating Experience - 1987

'The following is a summary of Grand Gulf Nuclear Station (GGNS) Unit 1 ioperating ' experience for the 1987 calendar year. During 1987, the reactor was critical for 7,203.3. hours with the generator on line for 7,100.0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br />. The plant set a record for continuous operating time of a General Electric (GE)

Boiling. Water. Reactor (BWR) in the second cycle of operation by operating for 171 consecutive ~ days. The previous record of 157 days was held by Kuosheng 2.

GGNS also achieved a generator gross output of 30,930 megawatt hours (MWH) in a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period which was also a BWR record.

The first refueling outage which began on September _5,1986 continued into 1987 due to repairs to the turbine rotor and number 10 bearing that were damaged when a wrench socket was left in the unit during outage work. Following repairs.and successful completion of the turbine overspeed trip test, GGNS recommenced commercial operation on January 9, 1987. The rate of reactor power increase was limited by thennal limits and post outage testing. The plant achieved 100 percent power operation on January 19, 1987.

GGNS continued non;al plant operation, varying reactor power to support system load demands and rod pattern changes. An unplanned power decrease occurred on May 27, 1987 when both reactor recirculation pumps downshifted to slow speed apparently due to an invalid cavitation interlock trip. Operators followed the off-normal event procedures to stabilize the plant at approximately 41 percent power. GGNS returned to 100 percent power operations on May 31, 1987.

On June 29, 1987, the reactor automatically scranined on a turbine control valve fast closure signal (LER 87-009-00). An Agastat relay failed causing the main steam inlet valve to the condenser air removal system to close. The subsequent loss of condenser e cuum caused the turbine to trip and the reactor to scram on the turbine control valve fast closure signal. The relay was replaced and reactor restart coninenced on June 30, 1987. The generator was off-line for 54.2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.

On July 29, 1987, System Energy Resources, Incorporated (SERI) design engineers discovered a containment isolation design problem: two isolation valves in series in the Reactor Water Cleanup System (RWCU) were powered from the same electrical division (LER 87-011-00). The short-term correction to the problem was to place one of the valves in the isolation (closed) position which requires the RWCU system to be operated in the pre-pump mode of operation (reactor water drawn first to the RWCU pumps and then the heat exchangers instead of vice-versa as in the post-pump mode). During the second refueling outage, separate power supplies were provided for the two isolation valves. This modification allowed the resumption of RWCU operation in the post-pump mode.

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' Attachment I to AECM-88/0048 On August 6 -1987, the generator tripped and the reactor scrammed when the generator output breakers automatically opened (LER 87-012-00). Accumulated moisture in the switchyard control house had caused a backup scheme relay-to short and activate the breaker trip circuitry. Although short-term corrective actions were' taken to allow plant restart, restart was delayed when SERI engineers identified concerns over the design adequacy of certain HVAC ductwork sections (LER 87-013-01). The ductwork sections of concern included: 1) the ductwork between tornado backdraft check dampers and Control Building perimeter walls and 2) the ductwork between high energy line break check dampers and .

Auxiliary Building interior walls. Bechtel and SERI engineers determined that all suspect duct sections were acceptable except for.3 duct sections between tornado check dampers and the Control Building perimeter wall. Additional stiffeners were installed inside the ducts to make them acceptable. Plant restart commenced on August 9, 1987. The generator was off-line for 102.0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br />.

GGNS continued normal operation until the scheduled refueling outage which began on November 7, 1987. Plant coastdown began at approxitnately 0700 on October 30, 1987. ~At 1600 on November 5,1987 GGNS began reducing power to 38 percent for planned pre-outage testing and inspections. The main generator was taken off-line at 0112 on November 7,1987 and the reactor shutdown at 0222.

Mode 5, Refueling, was entered on November 10, 1987 at 1622. The.second refueling outage ended with the generator being syn.hronized to the grid at 0317 on January 6, 1988.

The cycle 3 fuel reload consisted of replacing 288 GE fuel assemblies with Advanced Nuclear Fuels assemblies. On November 19, 1987 during core alterations, a load limit trip at 1200 pounds was received for the refueling platform main hoist while attempting to remove peripheral fuel assembly LJSO47. Subsequent attempts to remove the assembly were also unsuccessful. The fuel assembly was found wedged beside the support casting rather than resting in the support casting. After verbally receiving a discretionary enforcement waiver on November 24, 1987, the fuel assembly was freed at approximately 1600 pounds. A subsequent inspection by GE personnel revealed no evidence of assembly or reactor internal damage. The reload including core verification was completed on November 28, 1987.

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Attachment'II to:

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.AECM-88/0048.

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1. '. GGNS Unit'17 Annual Report.'

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- Man-REM-Exposure'--1987; , .

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i This :section!contains-la tabulation c' t$e~ number offstation, utility,: and . '

other personnel receiving exposures greater lthan.100 mrem /yr'and their . ,

. associated man-rem exposure according to work ~and job' function. :Alsogincluded

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is'a; tabulation.of.the' number of personnel by exposure rangen v.

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Attachment II to

' AECM-88/0048 Systen Ensrgy Resources, Inc.

Grand Gulf Nuclear Station Post Office Box 7S6 Port Gibson, Mississippi 39150 1:58 PM THU., 31 DEC., 1987 ANNUAL REPORT NUP.BER OF PERSONNEL AND MAN-REM BY WORK AND JOB FUNCTION

' Total Man-Ren Nanber of Personnel ( ) 100 nren 1 Contractors Station Utility Contractors Station Utility Employees Employees and Others Work & Job Fonction Employees Employees and Others i

Reactor Oper & Surveillance 74 2.97 0.00 17.85 Maintenance Personnel 20 0 0.00 65 0 0 26.46 0.00 Operatino Perscnnel 37 34.86 0.00 15.97 Health Pftysics Personnel 42 0 1.10 5 2 7 .83 1.06 Supervisory Personnel 0 0 .11 0.00 0.00 Engineering Personnel i l

Routine Maintenance 260 32.92 0.00 146.00 Maintenance Personnel 99 0 0.00 .54 0 0 2 0.00 Operating Personnel 0 3 0.00 0.00 .55 Health Physics Personnel 0 4 0.00 0.00 1.24 0

Supervisory Personnel 0 0 i .59 0.00 .11 Engineering Personnel i l

inservice Inspection 61 .39 0.00 33.90 Maintenance Personnel 3 0 0.00 0 0 0 0.00 0.00 Operating Personnel 0 0.00 0.00 0.00 Health Physics Per nnnel 0 0 0 17 .16 0.00 7.82 Supervisory Personnel i 3 0.00 0.00 2.01 0

Engineering Personnel 0 l

Special Maintenance 145 7.00 0.00 42.33 Maintenance Personnel 24 0 1.02 0 2 0.00 0 . 0 ')

Operating Personnel 0 1 0.00 0.00 44 Health Physics Personnel 0 0 0 7 0.00 0.00 1.87 Supervisory Personnel 0 3 .61 0.00 1.40 4 0 Engineering Personnel i

Uaste Processino 0 18 3.31 0.00 5.65 Haintenance Personnel 18 .89 Operating Personnel i 0 2 .i2 0.00 0 0 0.00 0.00 0.00 Health Physics Personnel 0 0 0.00 0.00 0.00 0

Supervisory Personnel 0 0 0 0.00 0.00 0.00 Engineering Personnel 0

l Refueling 0 15 0.00 0.00 6.71 Haintenance Personnel 0 .39 0 2 0.00 0.00 Operating Perstnnel 0 0.00 l 0 0.00 0.00 Health Physics Personnel 0 0 0.00 0.00 .32 0 2 Svpervisory Personnel 0 2 0.00 0.00 .65 0

Engineering Personnel 0 TOTAL 573 46.60 0.00 252.44 164 0 2.83 l Haintenance Personnel 8 26.58 0.00 Operating Personnel 66 0 0.00 16.96 I

42 0 41 34.86 Health Physics Personnel .99 1.06 12.34 l Svoervisory Personnel 6 2 37 0.00 4.16 i

6 0 9 1.31 En'ineering g Personnel 668 110.34 1.06 288.73 284 2 _

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Attachment II'to

^ Syo'tsm Energy Resources, Inc. AECM-88/0048-Grand Gulf Nuclear Station Post Office Box 756 s

Port Gibson, Mississippi 39150 1:58 PM THU., 31 DEC., 1987 Number of1 Personnel By-Exposure. Range BADGES l EXPOSURE RANGE l l  ;

I 1677- I LESS THAN .010 REM i

l. 523 ) .010 TO .099 REM i 327 l .100 TO .249 REM l l

242 l .250 TO 499 REM l l

l 144_ l .500 TO .749 REM ]

48 l .750 TO .999 REM [

l l 71 I i.000 TO i.999 REM l 3 l 2.000 TO 2.999 REM l l 3.999 REM i l O' l 3.000 10 l 0 l 4.000 TO 4.999 REM i 0 l 5.000 TO 5.999 REM l 1

0 l 6.000 TO 6.999 REM i l i 1 0 l 7.000 TO 7.999 REM l 0 l 8.000 TO B.999 REM l 0 9.000 10 9.999 REM l l 1 i

l 0 l 10. 0 00 10 10.999 REM l 0 l 11.000 TO 11.999 REM l 0 l 12.000 OR MORE REM l l '

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., AECM-88/0048.

2 GGNS Unit 1 Main Steam Safety Relief Valve-Challenges - 1987'

.This section.contains a . summary of main steam line safety-relief valve

~ challenges which occurred during 1987 as' reported in the GGNS Monthly _

0perating Reports for that period. The' summaries were originally included in:

the following. monthly reports:

Ja:,6ary,~'1987 Report - AECM-87/0035 dated February'13. 1987

~ August,'1987 Report - AECM-87/0182 dated September 15, 1987 October, 1987 Report'- AECM-87/0216 dated November 13, 1987 r M 7

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LAttachmentIII*to

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y. -MAIN STEAM SAFETY RELIEF VALVE CHALLENGES Date of Occurrence: ' January 23, 1987

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Plant-0perating-Condition:

lRx' Power (MWT) 3825 'Rx Pressure 1013 .Rx Mode ~ 1 Rx Power (MWE) 1280 Rx-Temperature 528 F

. Number of main steam SRVs: 20 Number of.SRVs affected by event: 6 Narrative:

_On January 23,1987 at 0843, safety relief valves B21-F0510, B21-F0518, B21-F0470, B21-F047G, B21-F051A, and 821-F051F-inadvertently lifted while the plant was' operating at 99.9 percent power.- Operators reclosed,all of_the valves within 2 minutes. Reactor water level was maintained above 20 inches-

-(187 inches above the top of active fuel) without the use of ECCS systems.

The safety relief valve actuation was the result of a voltage spike produced by a transmation test unit which was being used to adjust current to a trip unit for performance of the SRV High Pressure Trip / Low Low Set Relief monthly.

functional surveillance. The "B" and "F" trip channels are powered by a comon power supply in the DivNon 1 trip system. The "gross failure" logic was being tested.only in.the "B" channel. The voltage spike caused trip units in the "F" channel, which was not under test,'to_ trip and actuate the safety relief valves.

The surveillance-was changed to require the valve control switches to be placed to the "off" position to prevent inadvertent logic actuation during the surveillance.

In addition, Grand Gulf implemented a design modification during the 1987 refueling outage to reduce the probability of spurious actuations. Suppression diodes were installed across the coils of relays associated with trip logic that are normally energized but are de-energized during system calibration or circuit card removal. These diodes reduce the amount of electromagnetic interference induced into the power supply circuit during relay de-energization.

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MAIN STEAM, SAFETY RELIEF VALVE CHALLENGES ,

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Date of Occurrence: Auaust 6, 1987' '

a Plant Operating Condition:

Rx Power (MWT) .3818 -Rx Pressure 1033 psig Rx Mode 1 -

0 Rx Power (MWE) .1204 Rx Temperatures 531 F Number of main. steam SRV's: 20 Number of SRV's 'affected by event:. 6

^ Narrative:

'As a result of-the automatic reactor scram on August 6, 1987, the safety relief

-valve low-low set logic actuated to control reactor pressure, lifting valves-B21-F0510, F0518, F047G, F051A, F0470, and F051F. Reactor pressure. reached a maximum'of:1107 psig with a minimum reactor water level ~ of 168 inches above the

. top of active fuel. The low-low set logic functioned properly to lift all 6

. safety relief valves associated with the low-low set function.

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Attachment.IIInto.

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MAIN STEAM SAFETY RELIEF: VALVE CHALLENGES i- ,

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-" ;Date of Occurrence: ' October 4, 1987

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~ ' Plant OperatingiCondition:

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-Rx' Power (MWT)' Goe9 ' Rx Pressure - 1029- psig .Rx Mode 1 Rx Power,(MWE) 1233. Rx Temperatures 532 F iNumber-of main steam SRV's: -20:

Number of SRV's.affedted'by event: 2 Narrative::

During the performance of an unrelated surveillance procedure on.the Rbd

-Pattern. Control. System in panel.1H13-P629, a spurious' seal-in of the safety-f relief. valve low . low set logic . occurred for channels' "A"'cnd "E". This logic-1 actuation caused' safety relief valves 1821-F051B and 1821-F051D to open one L time 'each'. The operator manually closed both safety relief valves by taking

_their respective handswitches to "0FF". There-were no adverse consequences-to

reactor, pressure or levelldue'to the short' time the valves were open. The.

spurious actuation was due to the common power supply for the two chant.als in each< trip system being' susceptible to disturbance. , Corrective actions are discussed in.the' preceding January 23,.1987 occurrence of similar safety relief valve actuations.

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Attachment'IV to'

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-AECM-88/0048 failed' Fuel Indications / Inspections - 1987

'There was one irradiated fuel assembly visual-inspection performed during.the 1987. reporting period. During the second refueling outage core shuffle,

_ peripheral fuel assembly LJS047 was discovered wedged beside the support casting. ' Removal of'the assembly re

-(verbally received Novembr 24,.1987)to quired exceed a discretionary enforcement the 1200 pound load limit trip waiver for ;the refueling platfonn main hoist. The fuel. assembly was freed at approximately 1600 pounds. The subsequent inspection by General Electric revealed no indication of fuel assembly damage.

-Although there were no other fuel examinations during the reporting period, 1 plant chemists observed the presence of a small fuel failure through Offgas Pretreatment.and Reactor Coolant Iodine analysis. The failure stabilized at levels well .below Technical Specification limits. Plant chemists closely monitored the abnormality by increased analysis frequency. Current analysis

, indicates that the fuel assembly was removed during the 1987 refueling operations, s

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.p EVETEMEADERGY RE90tJRtEE, ItUC.

Ottse D. KtGREY.JR gg, February 29, 1988' O. S. Nuclear Regulatory Commission Washington, D. C. 20555 Attention: Document Control Desk Gentlemen:

SUBJECT:

Grand Gulf Nuclear Station Unit 1 Docket No. 50-416 License No. NPF-29 Annual Operating Report - 1987 AECM-88/0048 System Energy Resources, Incorporated (SERI) is transmitting, with this letter, the Grand Gulf Nuclear Station (GGNS) Unit 1 Annual Operating Report for 1987. This report is sent in compliance with the requirements of Grand Gulf Technical Specifications 6.9.1.4 and 6.9.1.5. This report is in accordance with the reporting program described in Regulatory Guide 1.16, Revision 4, Part C.1.b as modified by the NRC letter to SERI dated May 25, 1987 (MAEC-87/0131).

Provided as attachments are:

I. A narrative summary of operating experience during the year 1987, II.- A tabulated annual report of personnel exposure greater than 100 mrem /yr.,

III. A summary of main steam line safety relief valve challenges for the year 1987, and IV. A summary of failed fuel indications / inspections.

Yours truly,

% N ev-l s ODK:rg Attachments ,

cc: See next page p o ourrs j mm umn msrc l ecuwao s . m s_, .m # '

J12AECM88021901 1

AECM-88/0048

Page.2 cc: .Mr.T.H.'Cloninger(w/a)-

M6;R.~B.<McGehee_(w/a) i Mr..'N. S. Reynolds (w/a)

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-Mr. H. L. Thomas ~(w/o) -i

'Mr. R.:C.' Butcher (w/a)

.Dr. 4 : Nelson Grace, Regional.' Administrator (w/a).

.U. S. Nuclear. Regulatory Connission:

Region II

, 101 Marietta St., N. W.,; Suite 2900 Atlanta, Georgia ~ 30323 Mr. L. L. Kintner, Project Manager-(w/a)

Office of Nuclear Reactor. Regulation

-V. S. Nuclear Regulatory Comission Mail Stop 14B20 Washington,LD.C. 20555 5

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