ML18152A845

LER 88-004-00:on 880216,reactor Coolant Dose Exceeded Tech Spec Limit.Caused by Fuel Element Defect in Reactor Core. Level of dose-equivalent I-131 Monitored at Least Every 4 H Until Level Returned to Less than 1 mCi.W/880304 Ltr

ML18152A845
Person / Time
Site:	Surry
Issue date:	03/04/1988
From:	Benson D VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
88-005, 88-5, LER-88-004, LER-88-4, NUDOCS 8803140290
Download: ML18152A845 (4)

Text

POW 28-06-01 NRC Form 366 U.S. NUCLEAR REGULATORY COMMISSION (9-831 APPROVED 0MB. NO. 3150-0104 LICENSEE EVENT REPORT (LER) EXPIRES: 8131188 FACILITY NAME (11 DOCKET NUMBER (21 PAGE (31 TITLE (41 Surrv Power Station Unit 1 !o 15 I o Io I O I? I R In , loF o I 3 Iodine Soike Due To Defective Fuel Element EVENT DATE 161 LER NUMBER (61

• REPORT DATE (71 OTHER FACILITIES INVOLVED (81 MONTH DAY YEAR YEAR { } : SE~~~~r~AL (t ~~~~~~ MONTH DAY YEAR FACILITY NAMES. DOCKET NUMBER(SI ol21IG a a sls-olol4-oloob ol4*sls OPERATING THIS REPORT IS SUBMITTED PURSUANT TO .THE REQUIREMENTS OF 10 CFR §: (Ch*ck on* or more of the follovying/ (11)

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- 60.73(111211111 60.73(11(2lliiil LICENSEE CONTACT FOR THIS LER !121

- 60.73(1112llvlll)(B) 60.73(1112llx)

"Special Report" NAME TELEPHONE NUMBER AREA CODE D. L. Benson, Station Manager 81 01 4 31 5 I 7 I - 13 I 1 I 8 I 4 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

CAUSE SYSTEM COMPONENT MANUFAC- MANUFAC-TURER SYSTEM COMPONENT TURER R~60~ltitE iif:iiiii!i!i!i!i!ii!i!ii!i:i!i!!!!!!ii!!!:!i!iii!i!: CAUSE I I I I I I I I I I I I I I I I I I I I I 1 I I I I I I SUPPLEMENTAL REPORT EXPECTED (141 MONTH DAY YEAR EXPECTED SUBMISSION I YES (If yes, complete EXPECTED SUBMISSION DATE/

DATE (151 I I I ABSTRACT /Limit ro 1400 spaces, i.e., *pproxim*tely fifteen single-spac* typ*writton lines/ (161 On February 16, 1988 at 1430 hours0.0166 days <br />0.397 hours <br />0.00236 weeks <br />5.44115e-4 months <br />, following a Unit 1 reactor trip, the specific activity sample of the reactor coolant showed a dose equivalent I-131 of 1.17 microcuries/cc. This exceeds the dose equivalent I-131 Technical Specification of less than 1.0 microcurie/cc specified in Section 3.1.d.2 and is being reported in accordance with the special reporting requirements outlined in Technical Specification 3.1.d.4.

The iodine spike was caused by a known, but not specifically located, fuel element defect in the reactor core. Post shutdown conditions enhanced the release of fission products, specifically I-131. This caused an increase in reactor coolant specific activity. The immediate corrective action was to implement the actions required by Technical Specification Table 4.1.2B. Specifically, the level of dose-equivalent I-131 was monitored at least every four hours until the level returned to less than 1.0 microcurie/cc.

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.;:, DCD NRC Farm 386 (9-831

POW 28-06-01 NRC Form 366A e U.S. NUCLEAR REGULATORY COMMISSION 19-831 LICENSEE EVENT REPORT (LERI TEXT CONTINUATION APPROVED 0MB NO. 3150-0104

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EXPIRES: 8/31/88 FACILITY NAME 111 DOCKET NUMBER 121 LER NUMBER 161 PAGE 131 Surry Power Station, Unit 1 o 1s Io Io Io I 2 I al o al a - oI ol 4 - o I n nl? oF n I -::i TEXT /If motW _ . , . io ,aquhd, u* !MldltioMI NRC Fann 31511A '1/ 1171 1.0 Description of the Event On February 16, 1988, at 1430 hours0.0166 days <br />0.397 hours <br />0.00236 weeks <br />5.44115e-4 months <br />, following a Unit 1 reactor trip, the specific activity sample of the reactor coolant showed a dose equivalent I-131 level of 1.17 microcuries/cc. This exceeds the dose equivalent I-131 limit of 1.0 microcurie/cc specified in Technical Specification 3.1.d.2 and is being reported in accordance with the special requirements outlined in Technical Specification 3.1.d.4.

2.0 Safety Consequences and Implications The limitations on*the specific activity of the reactor coolant ensures that the resulting two hour dose at the site boundary will not exceed a small fraction of the 10CFR100 limits following a postulated Steam Generator Tube Rupture (SGTR). Since the dose-equivalent I-131 peak was below the Technical Specification upper limit of 10 microcuries/cc, the reactor coolant gross activity was below the value analyzed in the UFSAR for a SGTR with 1% failed fuel.

T~erefore, the health and safety of the public were not affected.

3.0 cause The iodine spike was caused by a known, but not specifically located, fuel element defect in the reactor core. Post shutdown conditions enhanced the release of fission products, specifically I-131. This caused an increase in reactor coolant specific activity.

4.0 Immediate Corrective Actions The immediate corrective action was to implement the action*s required by Technical Specification Table 4.1.2B. Specifically, the level of dose-equivalent I-131 was monitored at least every four hours until the level returned to less than 1.0 microcurie/cc.

NRC FORM 366A 19-83)

• U.S.GPO: 1986-0*624-538/455

NRC Form 3841A e U.S. NUCLEAR REGULATORY COMMISSION (9-831 LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVED 0MB ND. 3150-0104 EXPIRES: B/31 /88 FACILITY NAME (11 DOCKET NUMBER (21 LER NUMBER (61 PAGE 131 Surry Power Station, Unit 1 TEXT /If_,,._.. b ,eqund, ,,_ ~itioMI NRC Farm .-...**J 1171 Supplemental Information:

The following supplemental information required by Technical Specification 3.1.d.4 11 Special Report 11 is included:

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 14, 1988 @ 0000 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> 100% power.

February 14, 1988 @ 1200 hours0.0139 days <br />0.333 hours <br />0.00198 weeks <br />4.566e-4 months <br /> 100% power.

February 15, 1988 @ 0000 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> 100% power.

February 15, 1988 @ 1200 hours0.0139 days <br />0.333 hours <br />0.00198 weeks <br />4.566e-4 months <br /> 100% power.

February 16, 1988 @ 0000 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> 100%power.

February 16, 1988@ 1143 hours0.0132 days <br />0.318 hours <br />0.00189 weeks <br />4.349115e-4 months <br /> - Reactor Trip.

2. Fuel burnup by core region as of February 16, 1988.

Fuel Batch Burnup S2/8A 36102 MWD/MTU Sl/8B 31644 MWD/MTU Sl/9A 35453 MWD/MTU Sl/9B 35472 MWD/MTU S2/9B 35028 MWD/MTU Sl/lOA 34103 MWD/MTU Sl/llA 17705 MWD/MTU Sl/llB 17137 MWD/MTU Cycle 9 Burnup: 14572 MWD/MTU

3. Prior to the reactor shutdown, the unit had normal letdown rate of 105 gpm.

4. No degassing operations were performed prior to the event.

5. Duration of I-131 Spike:

February 16, 1988@ 0455-Routine Sample: .0420 microcuries/cc February 16, 1988@ 1430-Post Shutdown Sample: 1.17 microcuries/cc February 16, 1988@ 1725-Post Shutdown Sample: 0.75 microcuries/cc Event Duration: Approximately 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />.

NRC FORM 386.A (8,831

• U.S.GPO: 1988*0*1124*538/455

VIRGINIA ELECTRIC AND POWER COMPANY Surry Power Station P. 0. Box 316 Surry, Virginia 23883 March 4, 1988 U.S. Nuclear Regulatory Commission Serial No.: 88-005 Document Control Desk Docket No.: 50-280 016 Phillips Building Licensee No. : DPR-32 Washington, D.C. 20555 Gentlemen:

Pursuant to Surry Power Station Technical Specifications, Virginia Electric and Power Company hereby submits the following Licensee Event Report for Surry Unit 1.

REPORT NUMBER 88-004-00 This report bas heen reviewed by the Station Nuclear Safety and Operating Committee and will be reviewed by Safety Evaluation and Control.

Very truly yours, David L. Benson Station Manager Enclosure cc: Dr. J. Nelson Grace Regional Administrator Suite 2900 101 Marietta Street, NW Atlanta, Georgia 30323