ML20087B618

RO SPR-84-2:on 840118,specific Activity Sample of Reactor Coolant Showed Peak Dose Equivalent I-131 Level of 1.89 Uci,Exceeding Tech Spec Limit.Caused by Fuel Element Defects in Reactor Core.Dose Level Monitored

ML20087B618
Person / Time
Site:	Surry
Issue date:	02/17/1984
From:	Joshua Wilson VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
RO-SPR-84-2, SR-84-2, NUDOCS 8403090223
Download: ML20087B618 (3)

Text

s g: 53 VIRGINIA ELECTRIC AND POWER COMPANY Surry Pcwer Station P. O. Box 315 Surry, Virginia 23883 FEB 17 gg4 Serial No: SR-84-2 Docket No: 50-280 License No: DPR-32 Mr. James P. O'Reilly Regional ddninistrator Suite 2900 101 Marietta Street, hW Atlanta, Georgia, 30303

Dear Mr. O'Reilly:

Pursuant to Surry Power Station Technical Specifications, the Virgirda Electric and Power Co@any hereby subnits the followira Special Report for Surry Unit 1.

Report Number Applicable Technical Scecification SPR-84-2 T. S. 3.1.D.4 This report has been reviewed by the Staticn Nuclear Safety and Operating Carmittee and will be reviewed by Safety Evaluation and Ccntrol.

Very truly yours, 5/14

.T. L. Wilson taticn Manager Enclosure cc: Document Control Desk, USNRC 016 Phillips Building Washington, D. C., 20555 OFFICIAL COPY .,

8403090223 840217 PDR ADOCK 05000280 g y [._ d Z S PDR '

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SURRY POWER STATION, UNIT NO. 1 DOCKET NO: 50-280 REPORT NO: SP R-84-2 EVENT DATE: 1-18-84

- TITLE OF THE EVENT: SPECIAL REPORT PURSUANT TO TECH. SPEC. 3.1.D.4 DOSE EOUIVALENT I-111 >l.0 MICR0 CURIES /CC.

Description of the Event On January 18, 1984 at 1125, following a reactor trip fron 100%, the Specific Activity Sample of the reactor coolant showed a peak dose equivalent I-131 level of 1.89 microcuries/cc. This exceeds the dose equivalent I-131 liriit of < 1.0, microcuries/cc specified in Tech. Spec. 3.1.D.2 and is being reported in accordance with the Special reporting requirenents outlined in Tech. Spec. 3.1.D.4.

Probable Consequences and Status of Redundant Equipment The limitations on the specific activity of the primary coolant ensure that 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 microcuries/ce, the reactor coolant gross activity was below the value analyzed in the FSAR for a tube rupture and 1% failed fuel. Therefore, the health and safety of the public were not af fected.

- Canse The Iodine Spike was caused by known, but not specifically located, fuel o element defects in the reactor core. Post trip conditions enhanced the release of. fission products, specifically I-131. This caused an increase of the reactor coolant specific activity.

Immediate Corrective Action The immediate corrective action was to implenent the actions required by Tech. Spec. Table'4.1-2B. Specifically, the lev-l of the dose equivalent I-131 was monitored at least once every 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> until the level returned to less than 1.0 microcuries/cc.

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• Report No. SPR-84-2 SUPPLEMENTAL 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; January 16, 1984 - 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> at 100%

January 17, 1984 - 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> at 100%

January 18, 1984 - 0834 Reactor Trip from 100%

2. . Fuel Burnup by core region as of January 18, 1984; Fuel Batch  : S2/6B: 29,141 MWD /MTU 6C: 30,727 MWD /MrU 4C: 30,973 MWD /MTU

.7A: 28,104 MWD /MTU 7B:- 34,740 MWD /MTU 8A: 25,509 MWD /MTU 8B: 25,126 MWD /MTU 9: 6,995 MWD /MTU Cycle 7 Burnup:

.6125 MWD /MTU

3. Prior to the . trip, the letdown flowrate had been established at 107 gpm.

4. De-gassing operations were not being performed.

S'. Duration of I-131 spike:

January 18, 1984: 0015 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br /> - Pre Trip Sample 0.121 microcuries/cc.

1125 hours0.013 days <br />0.313 hours <br />0.00186 weeks <br />4.280625e-4 months <br /> - Post Trip Sample 1.89 microcuries/cc.

1330 hours0.0154 days <br />0.369 hours <br />0.0022 weeks <br />5.06065e-4 months <br /> - Post Trip Sample 1.84 microcuries/cc.

1530 hours0.0177 days <br />0.425 hours <br />0.00253 weeks <br />5.82165e-4 months <br /> - Post. Trip Sample 1.60 microcuries/cc.

'1930 hours0.0223 days <br />0.536 hours <br />0.00319 weeks <br />7.34365e-4 months <br /> - Post Trip Sample 1.23 microcuries/cc.

2130 hours0.0247 days <br />0.592 hours <br />0.00352 weeks <br />8.10465e-4 months <br /> - Post Trip Sample 0.997 microcuries/cc.

Duration of the event was approximately 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br />.

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