05000338/LER-1979-109-03, /03L-0:on 790906,specific Activity of Primary Coolant Exceeded 1.0 Mci/Dose Equivalent I-131 on 780923. Caused by Hourly Sampling of Primary Sys to Investigate Fuel Defect.Personnel Reinstructed

/03L-0:on 790906,specific Activity of Primary Coolant Exceeded 1.0 Mci/Dose Equivalent I-131 on 780923. Caused by Hourly Sampling of Primary Sys to Investigate Fuel Defect.Personnel Reinstructed

ML19209B642
Person / Time
Site:	North Anna
Issue date:	10/05/1979
From:	Cartwright W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19209B634	List: 05000338/LER-1979-109, Forwards LER 79-109/03L-0 05000338/LER-1979-109-03, /03L-0:on 790906,specific Activity of Primary Coolant Exceeded 1.0 Mci/Dose Equivalent I-131 on 780923. Caused by Hourly Sampling of Primary Sys to Investigate Fuel Defect.Personnel Reinstructed
References
LER-79-109-03L, LER-79-109-3L, NUDOCS 7910100265
Download: ML19209B642 (3)

LER-1979-109, /03L-0:on 790906,specific Activity of Primary Coolant Exceeded 1.0 Mci/Dose Equivalent I-131 on 780923. Caused by Hourly Sampling of Primary Sys to Investigate Fuel Defect.Personnel Reinstructed

Event date:
Report date:
3381979109R03 - NRC Website

text

NRC FORM 366 U. S. NUCLEAR REGULATORY COMMISSION D:77) ~

LICENSEE EVENT REPORT CONTROL BLOCK: l l

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8 63 bl DOCKET NUVdE R 68 63 EVENT D ATE 14 7.2 REPORT DATE 80 EVENT DESCRIPTION AND PROBABLE CONSEQUENCES h O

2 l During a review of Chemistry logs on September 6 19 79, it was discovered that O

3 1 the specific activity of the primary coolant exceeded 1.0 micro ci/ gram Dose

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0 4; Equivalent I-131 on 9/23/78.

The sample frequency of item 4a of Technical Snecifi-l cation Table 4.4-4 was met but the special report requirement was overlooked.

The 0

3 l health and safety of the general public were not affected by this event.

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40 41 42 43 44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h l A fuel defect which occurred on July 25, 1978 was being investigated and samples of l

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Virginia Electric and Power Company North Anna Power Station, Unit #1

Attachment:

Page 1 of 2 Docket No.56-338 Report No. LER 79-109/03L-0

Description of Event

On September 6, 1979, during a review of Chemistry logs, it was discovered that the specific activity of the primary coolant exceeded the limit of T.S. 3.4.8.a on September 23, 1978 while sampling the system to obtain the iodine spike af ter a shutdown.

The sampling and asalysis requirements of item 4a of Technical Specification Table 4.4-4 were satisfied but the special report requirer 2ent was overlooked.

Probable Consequences of Occurrence The health and safer.y of the general public were not affected by this occurrence because the specift: activity of the primary coolant was greater than 1.0 uCi/

gram Dose Equivalert I-131 for only 9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br /> and the unit was in Hot Standby when the event occt rred.

There are no generic implications associated with this incident.

Cause of Occurrence A fuel defect became evident on July 25, 1978.

During a September 23, 1978 shu tdown, further investigation by sampling was being conducted.

Samples of the primary coolant system were taken on an hourly basis to obtain the iodine spike af ter the shutdown and during this sampling the lodine spike exceeded 1.0 uCi/ gram Dose Equivalent I-131.

A special report was not submitted when the incident occurred because the requirement was overlooked by the personnel involved.

Immediate Corrective Action

The primary coolant was sampled and analyzed at the frequency required by item a of Technical Specification Table 4.4-4 and it was verified that the specific activity returned to acceptable limits.

Appropriate personnel have been reinstructed on requirements to ensure that discrepancies are properly reported in the future.

Scheduled Corrective Action No scheduled corrective action required.

Actions Taken to Preveat Recurrence No further actions are required.

Supplemental Information The Dose Equivalent I-131 limit of < 1.0 uCi/ gram was exceeded on September 23, 1978 as follows:

1i26 184

Virginia Electric and Power Company North Anna Power Station, Unit #1

Attachment:

Page 2 of 2 Docket No. 50-338 Report No. LER 79-109/03L-0 Time Dose Equivalent I-151 (uCi/ gram) 0100 1.18 0200 1.35 0300 1.31 0400 less than linit 0500 1.42 0600 1.38 0700 1.15 0800 1.04 0900 1.67 1000 1.04 1100 less than limit The following are the ancwers to the Action Statement of Tech. Spec. 3.4.8.

1.

September 21, 1978 - the power history for the day was 99.2% for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

September 22, 1978 - 99% until 2100 hours0.0243 days <br />0.583 hours <br />0.00347 weeks <br />7.9905e-4 months <br /> when a 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> rampdown to 0% started and finished at 0000, 9/23/7?

September 23, 1978 - 0% all day 2.

Fuel Burnup Region 1 - 5127 MWD /MTU Region 2 - 5123 MWD /MTU Region 3 - 3385 MWD /MTU 3.

Normal mixed bed demineralizer line up 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> prior to exceeding the limit.

4.

No degassing operations were performed.

5.

The duration of activity exceeding 1.0 uCi/ gram Dose Equivalent of I-131 is approximately 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br />.

I126 185