ML19095A709

LER 1975-005-00 for Surry Power Station, Unit 1, Ventilation Vent Gaseous Release

ML19095A709
Person / Time
Site:	Surry
Issue date:	11/04/1975
From:	Stallings C Virginia Electric & Power Co (VEPCO)
To:	Moseley N NRC/IE, NRC/RGN-II
References
Serial No. 764 LER 1975-005-00
Download: ML19095A709 (5)

Text

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• • . *e-*.. .*.' :_*,

Mr. Norriia.n .C~

• Moseley.; . Director *. Serial No. 7M

.*. Off ice. of Inapect:io~ *arid _Enfor~emen~ .* * '.f .~

• PO&M/ JTB; clw .

U.S.* Nuclear *Regulatory* Commission; Regioij. iI ~ .Suite eia *_ ; * .. -Docket .No. 50-280

.230 Peaclitree . Streat,: Northwest_. License No. D~R-32

. Atlanta, . Georgia .-_ ' 30303 : . . .

Dear Mr *. Moseley:

" .* :_ ( *

.,1 * , ' i:, ..

Pursuant to Surry Power Station .T~~hnicai Specification 6. 6. B. 3 ,- the Virginia Electric': ariq J;>ower Coinpa.ny hereby submits forty . (40) copies of Spe_cial* Rep9rt: No~ SR_;Sl-75~05~ * * * **! *.* .

• * 'c.. * ,, * .' ' * ' ' *

. Ti~e: s~b;uincie ;:~£,' tJ:i:;l.~ep~r~ *-*~a~\ .b;een r~viewed by the Statton Nuclea~

• *Safety *.and Operating Commi,ttee an~; will be placed .on. ~he agenda for the..

ne~t II!Geting of the. .

System*"Nu~lear>*Saf~ty arid' Op,erating Connnittee *

.. Very *truly *yours,-.

• Enclosure cc:.

...... ,,,., * .. \ '

e SPECIAL REPORT SR-Sl-75-05 VENTILATION VENT GASEOUS RELEASE DOCKET NO. 50-280 LICENSE NO. DPR-32 OCTOBER 29, 1975 SURRY POWER STATION VIRGINIA ELECTRIC AND POWER COMPANY

e e I. I_NTRODUCTION In accordance with Technical Specification 6.6.B.3 for Surry Power Station, this report describes the release of gaseous wastes in excess of 4 per cent of the Technical Specification limits established by Technical Specification 3.11.B.1.

II.

SUMMARY

OF OCCURRENCE On September 29, 1975, routine sampling of the ventilation vent gaseous activity revealed an Iodine-131 activity in excess of 4 per cent of the Technical Specification limit, This condition has lasted until October 23, 1975, as summarized in Attachment A of this report.

This condition has been attributed to a number of operational cir-cumstances. During normal Unit No. 1 operation prior to the current refueling outage, contaminated-liquid had accumulated on the basement floor of the containment as a result of a leaking equipment as reported in AO-Sl-75-18. This water apparently got into the containment iodine filters in the basement and saturated some of the charcoal which greatly reduced the efficiency of these filters. Also a factor is the fact that the "B" bank of the auxiliary building filter banks was not functioning at maximum efficiency, as determined from results of the routine periodic test of these filters. As a result of these filter problems along with the processing of contaminated liquids from both the containment and auxiliary building basements and through purging operations of Unit No.

1 for refueling, the Li per cent of Technical Specification limit was exceeded.

....:1-

e The charcoal in the auxiliary building filter banks and the con-tain~ent iodine filters is being replaced during this outage. Also to avoid the problem of flooding the containment iodine filters in the future, a design change is in progress to construct a flood control dike for this filter and should be completed during the current out-age. During the current outage portable iodine filters have been placed in the Unit No. 1 containment to minimize the ventilation vent release rate condition.

III. CONCLUSION The ventilation vent Iodine-131 activity exceeded 4 per cent of the Technical Specification limit from September 29, 1975 to October 23, 1975 due to Unit No. 1 containment purging operations, filter problems, and leakage and subsequent treatment of radioactive water which had accumulated in the containment basement. Applicable limits contained in Technical Specification 3.11.B were not exceeded.

The Iodine-131 activity from the ventilation vent should decrease below the 4 per cent of Technical Specification limit in the near future as the replacement of filter charcoal and the processing of contaminated liquids is completed.

The,health and safety of the general public was not adversely effected by this occurrence.

• ATTACHMENT A sufNARY OF GASEOUS RELEASES AS A PERCENT OF :*lPC SEPTEMBER 29, 1975 to OCTOBER 23,. 1975

% of HPC DATE 15.6 9-29-75 27 .4 9-30-75 28.l 10-1-75 34. 6.

10-2-75 22.5 10-3-75 16.7 10-4-75 16.7 10-5-75 18.7 10-6-75 17.8 10-7-75 15.l 10-8-75 8.78 10-9-75 43.5 10-10-75 23.9 10-11-7 5 34.5 10-12-75 17 .4 10-13-75 26.0 10-14-75 33.3 10-15-75 30.4 10-16-75 16.5 10-17-75 10.5 10-18-75 12.1 10-19-75 9.7 10-20-75 12.5 10-21-75 11.4 10-22-75 24.0 10-23-75 16. 7 10-24-75 12.5 10-25-75 <4.0*

10-26-75 <4.0*

10-27-75 5. 4.

10-28-75 4 .1 10-29-75

,':flow reduced because of maintenance activity in containment.