DCL-06-097, Groundwater Questionnaire

Groundwater Questionnaire

ML062280577
Person / Time
Site:	Diablo Canyon
Issue date:	07/31/2006
From:	Becker J Pacific Gas & Electric Co
To:	Richards S NRC/NRR/ADRO/DIRS
Sakai, S, DIRS/NRR, 415-1884
References
DCL-06-097, FOIA/PA-2010-0209
Download: ML062280577 (3)

Text

Pacific Gas and Electric Company' James R.Bechcer Diablo Canyon Power Plant Vice President P.0. Box 56 July31, 2006July31, 006Station Diablo Canyon Operations and Director Avila Beach, CA 93424 805.545.3462 Fax: 805.545.4234 PG&E Letter DCL-06-097 Mr. Stuart A. Richards, Deputy Director Division of Inspection and Regional Support Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Docket No. 50-275, OL-DPR-80 Docket No. 50-323, OL-DPR-82 Diablo Canyon Units 1 and 2 Industry Groundwater Protection Initiative - Voluntary Data Collection Questionnaire

Dear Mr. Richards:

The nuclear industry, in conjunction with the Nuclear Energy Institute, has developed a questionnaire to facilitate the collection of groundwater data at commercial nuclear reactor sites. The objective of the questionnaire is to compile baseline information about the current status of site programs for monitoring and protecting groundwater and to share that information with the NRC. The completed questionnaire for Pacific Gas and Electric, Diablo Canyon Power Plant, Units 1 and 2 is enclosed.

This submittal contains no new regulatory commitments.

Please contact Mr. Mark Somerville of my staff at (805) 545-4007 if you have questions about the enclosed information.

Sin rely, James R. Becker ddm/3649/A0671649 Enclosure cc: Document Control Desk Ralph Andersen, Nuclear Energy Institute Edgar Bailey, California Department of Health Services Terry W. Jackson, NRC Senior Resident Inspector Bruce S. Mallett, NRC Region IV Alan B. Wang, NRR Project Manager Diablo Distribution A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway

• Comanche Peak

• Diablo Canyon

• Palo Verde o South Texas Project o Wolf Creek

Enclosure PG&E Letter DCL-06-097 Industry Groundwater Protection Initiative Voluntary Data Collection Questionnaire Plant: Diablo Canyon Power Plant, Units I & 2

1. Briefly describe the program and/or methods used for detection of leakage or spills from plant systems, structures, and components that have a potential for an inadvertent release of radioactivity from plant operations into groundwater.

Response

Diablo Canyon Interdepartmental Administrative procedure RPI .ID 11, "Environmental Radiological Monitoring Procedure", describes locations from which environmental samples, representative of areas which could be affected by plant operations, are obtained. Diablo Canyon has added additional sampling locations to the Radiological Environmental Monitoring Program (REMP). These sample points include but are not limited to the Unit I and Unit 2 containment foundation sumps (monitoring wells 1 and 2),

the auxiliary building french drain system (drywells), Diablo Creek, and near site beach samples. Additional control sampling locations have also been added. These locations would be sensitive to leakage or spills from plant systems, structures, and components.

2. Briefly describe the program and/or methods for monitoring onsite groundwater for the presence of radioactivity released from plant operations.

Response

Onsite sub-surface and ground waters are sampled and sent for analysis as part of the REMP. Waters are collected and sent to an independent, off-site vendor with LLDs specified at levels well below those required by federal guidance. Diablo Canyon does not have groundwater in the conventional sense. There is no potable groundwater at the plant site.

Those portions of the site that contain radioactive materials are within a watershed that proceeds to the ocean. Ocean water is sampled as part of the REMP program and the effluents program calculates the impact of sampled effluents in the discharge process. However, runoff waters that have been identified are monitored based on industry experience. These waters are sampled as mentioned in the response to item 1.

3. If applicable, briefly summarize any occurrences of inadvertent releases of radioactive liquids that had the potential to reach groundwater and have been documented in accordance with 10 CFR 50.75(g)..

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Enclosure PG&E Letter DCL-06-097 Industry Groundwater Protection Initiative Voluntary Data Collection Questionnaire

Response

Diablo Canyon has had a single, known occurrence of a significant, inadvertent release of radioactive liquids. This occurrence was in November of 1993 and was captured in the Diablo Canyon corrective action program. An investigatory report was written. This occurrence was an inadvertent release of less than 4,000 gallons of water containing tritium and carbon-14 to an inappropriate floor drain that was routed to the outside areas and not to plant liquid processing systems. This water was routed to asphalt covered area north of the auxiliary building, but did not go beyond the protected area and evaporated rapidly. This event was documented in accordance with 50.75(g) to ensure that this area is properly characterized and investigated at the time of decommissioning.

4. If applicable, briefly summarize the circumstances associated with any onsite or offsite groundwater monitoring result indicating a concentration in groundwater of radioactivity released from plant operations that exceeds the maximum contaminant level (MCL) established by the United States Environmental Protection Agency (USEPA) for drinking water.

Response

To date, Diablo Canyon has found no water with tritium concentrations or concentrations of other radionuclides that exceeds the USEPA MCLs.

These results are applicable to non-potable waters since no potable waters exist in the protected area or in the non-restricted areas adjacent to the power plant.

5. Briefly describe any remediation efforts undertaken or planned to reduce or eliminate levels of radioactivity resulting from plant operations in soil or groundwater onsite or offsite.

Response

Diablo Canyon has not undertaken any remediation efforts to reduce or eliminate radioactivity in the environment to date. This is because no such repositories in soil or in sequestered water have been discovered or are known to exist. To date, no system leaks, occurrences, or events that have the potential for releasing radioactive materials into the soils or waters around Diablo Canyon have been identified. Sampling as part of the REMP program will continue to be used to monitor for potential unintended leakage pathways.

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