ML20081B617

RO SPR-84-003:on 840206,following Trip from 100% Power, Specific Activity Sample of Reactor Coolant Showed Peak Dose Equivalent I-131 Limit of Less than or Equal to 1.0 Uci.Caused by Fuel Element Defects in Reactor Core

ML20081B617
Person / Time
Site:	Surry
Issue date:	02/24/1984
From:	Joshua Wilson VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
RO-SPR-84-003, RO-SPR-84-3, NUDOCS 8403090250
Download: ML20081B617 (3)

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} l1% *. h h viPGINiA EL(CTPIC AND POWER COMPANY

, Surry Power Station P. O. Box 315 Surry, Virginia 23883 i FEB 2 41994 Serial No: SR-84-3 Docket No: 50-280 License No: DPR-32 Pr. James P. O'Reilly

) Regional lu%inistnttor Suite 2900 101 Parietta Street, NW Atlanta, Georgiai 30303 t

Dear Pr. O'Reilly:

Pursuant to Surry Power Station Technical Specifications, the Virginia Electric and Pcwer Ccripeny hereby sumits the following Special Report for Surry Unit 1 .

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Eggert thrter Apolicable Technical Seecification SPR-84-3 T. S. 3.1.D.4

'Ihis report has been reviewed by the Station Nuclear Safety and l Operating Ccnnittee and will be reviewed by Safety Evaluation ard Ccntrol. '

. Very truly yours, M 5s%-

iJ. L. Wilson l Staticn Panager Enclesdre cc: Document Control Desk, USNRC 016 Phillips Building Washington, D. C., 20555 8403090250 840224 PDR ADOCK 05000200 OFFICIAL COPY S PDR c-Jbb, L i i

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SURRY PCNER STATION, UNIT NO.1 DOCKET NO: 50-280 REPORT NO: SPR-84-003 EVENT DATE: 2-C-84 TITLE OF T!!E EVENT: SPECIAL REPORT PURSUANT TO T.S.3.1.D.4 DOSE _EOUIVALENT, I-131 > 1.0 MICRCCURIES]cc.

Description of the Event l On February 6,1984, at 2115 hrs. , following a unit trip from 100%, the specific activity sample of the reactor coolant showed a peak dose equivalent I-131 T.S.3.1.D.2 limit of < 1.0 microcuries/cc and is reportable per the

' special reporting requirements of T.S.3.1.D.4.

Probable Consequences and Status of Redundant Equipment The limitations on the ~ specific activity of the prinary coolant ensure that t

' the resulting 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> doses at the site boundary will not exceed an appropriately small fraction of 10 CFR 100 limits following a postulated steam generator tube rupture. Since the dose equivalent I-131 peak was below the Technical Specification upper limit of 10 *aicrocuries/ce, the reactor coolant gross activity was below the value analy' zed in the FSAR for a tube rupture and 1% failed fuel. Therefore , the health and safety of the public were not affected.

cause The Iodine Spike was caused by~ known, yet not specifically located, fuel element defects in the reactor core. Post trip conditions enhanced the release of fission products, specifically I-131 which caused an increase in the coolant specific activity level.

Imediate Corrective Action The immediate corrective action was to implement the actions required by T.S.

Table 4.1.2.B. Specifically, the level dose equivalent I-131 was monitored every 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> until the icvel returned to less than 1.0 microcuries/cc.

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-6 Report No. SPR-84-03 ,

SUPPLE *' ENTAL INFORMATION The supplemental information required by T.S.3.1.D.4 "Special Report" is included as follows:

1. Reactor Power History 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> prior to the event:

February 4, 1984 - 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> at 100%

February 5, 1984 - 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> at 100%

February 6, 1984 - @ 1847 - Reactor Trip from 100%

S 2. Fuel burnup by core region - as of February 6,1984.

Fuel Batch  : S2/63: 29373 WD/MTU 4 6C: 31323 MWD /MTU 4C: 31413 WD/FrU 7At 28391 mfd /KrU 7B: 36270 mfd /MTU 8A: 25998 MWD /MTU 8B: 25805 MJD/MTU 9: 7682 MWD /MrU Cycle 7 Burnup: 6724 MWD /wrU

3. Prior to the reactor trip, the unit had established a normal letdown rate of 106 gpm.

re . No De-Gassing operations were performed.

5. Duration of I-131 Spike:

February 6, 1984 9 0015 - Routine Sanple .125 nicrocuries/cc 2115 - Post Trip Sample - 2.15 microcuries/cc 2315 - Post _ Trip Sample - 1.98 microcuries/cc February 7, 1984 9 0115 - Post Trip Saeple - 1.96 microcuries/cc 0315 - Post Trip Sample - 1.54 microcuries/cc 0515 - Post Trip Sample - 1.49 microcures/cc 0710 - Post Trip. Sample - 1.15 microcuries/cc ,

0925 - Post Trip Sample .838 microcuries/cc Duration approximately 12.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />.

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