DCL-12-080, Nonroutine Report of Planned Disturbance of Archaeological Site SLO-2

Nonroutine Report of Planned Disturbance of Archaeological Site SLO-2

ML12234A574
Person / Time
Site:	Diablo Canyon
Issue date:	08/21/2012
From:	Welsch J Pacific Gas & Electric Co
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
DCL-12-080
Download: ML12234A574 (6)

Text

Pacific Gas and Electric Company Diablo Canyon Power Plant James M. Welsch Station Director Mail Code 104/5/502 P. O. Box 56 Avila Beach, CA 93424 805.545.3242 August21,2012 Internal: 691.3242 Fax: 805.545.4234 Internet: JMW1@pge.com PG&E Letter DCL-12-080 u.s. Nuclear Regulatory Commission 10 CFR 50.4 ATTN: Document Control Desk Washington, D.C. 20555-0001 Docket No. 50-275, OL-DPR-80 Docket No. 50-323, OL-DPR-82 Diablo Canyon Units 1 and 2 Nonroutine Report of Planned Disturbance of Archaeological Site SLO-2

Dear Commissioners and Staff:

Appendix B to Facility Operating License Nos. DPR-80 and DPR-82, Diablo Canyon Nuclear Generating Station, Units 1 and 2, Environmental Protection Plan (EPP),

Section 4.2.2, indicates that the Pacific Gas and Electric Company (PG&E) shall avoid disturbances to the SLO-2 site in accordance with the Archaeological Resources Management Plan (ARMP) submitted to the Nuclear Regulatory Commission (NRC) on April 7, 1980. EPP Section 4.2.2 further indicates that should a disturbance of the SLO-2 site inconsistent with the allowable use of the site under the ARMP be necessary, PG&E shall report the planned disturbance to the NRC.

ARMP Section 4.1 indicates that PG&E will restrict its activities within the survey area to the following:

(1) Fire Protection: The groundcover may be kept short, if required, by grazing or mowing. Harrowing or the use of herbicides will be prohibited.

(2) Storage: The storage of materials will be confined to the areas protected by the fill.

(3) Traffic: Vehicular traffic and site usage shall be restricted to existing, paved or unpaved roads and to the fill area.

(4) Maintenance: Any necessary maintenance of roads shall be limited to surface treatment. Maintenance of the wastewater holding pond and buried utilities will be limited to existing disturbed areas.

Pursuant to EPP Section 4.2.2, PG&E hereby reports a planned disturbance that is inconsistent with the allowable use of the SLO-2 site under ARMP Section 4.1.

As part of PG&E's efforts to accurately map and characterize faults in proximity to the Diablo Canyon Power Plant (DCPP), PG&E plans to implement the next phase A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway

• Comanche Peak

• Diablo Canyon

• Palo Verde

• San Onofre

• South Texas Project

• Wolf Creek

Document Control Desk PG&E Letter DCL-12-080 August 21, 2012 Page 2 of the onshore seismic survey program during the fall of 2012. This phase of the survey will involve the deployment of geophone "nodes" (coffee can size geophones) and the use of an EnviroVibe MiniBuggy sound source on DCPP property.

The enclosure provides a project description of activities within archaeological site SLO-2 for the onshore seismic survey.

The onshore seismic survey has been designed to eliminate potential adverse effects to cultural resources during implementation. Of specific concern is archaeological site SLO-2, which covers approximately 47 acres adjacent to DCPP.

Under the direction of qualified archaeologists, PG&E has surveyed the SLO-2 site and the proposed location of geophone nodes within the site. Pinflags were used to mark the proposed locations to ensure that archaeological deposits within the site were not disturbed.

PG&E performed a cultural resources review to characterize the potential impact to the SLO-2 site, as well as to develop mitigation measures while operating within the site. Based on this review, PG&E determined that the seismic imaging work can be conducted without impacts to the SLO-2 site provided the following mitigation measures are implemented:

(1) Geophone nodes will be placed on the surface and secured with a small spike attached to the base of the geophone node; nodes will not be buried within the archaeological site. This requirement will eliminate the potential for mixing or unearthing archaeological materials.

(2) Deployment of nodes will be monitored by an archaeologist that has the authority to direct node placement away from sensitive features within the site. An archaeological monitor will also accompany project personnel when they return to the site to remove the nodes.

(3) Operation of the sound source, the EnviroVibe mounted on a MiniBuggy, will be restricted to operating on established roads within the SLO-2 site.

PG&E is making regulatory commitments (as defined by NEI 99-04) as indicated in the above three mitigation measures. This letter includes no revisions to existing regulatory commitments.

A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway. Comanche Peak. Diablo Canyon

• Palo Verde

• San Onofre

• South Texas Project

• Wolf Creek

Document Control Desk PG&E Letter DCL-12-080 August 21,2012 Page 3 Should you have any questions regarding this letter, please contact Mr. Jearl Strickland at (805) 781-9785 (email: LJS2@pge.com).

Sincerely,

~ -~~

Jam~. ~e~sch Interim Site Vice President gwh2/50506177 Enclosure cc: Diablo Distribution cc:/enc: Elmo E. Collins, NRC Region IV Michael S. Peck, NRC, Senior Resident Inspector Joseph M. Sebrosky, NRR Senior Project Manager A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway

• Comanche Peak

• Diablo Canyon

• Palo Verde

• San Onofre

• South Texas Project

• Wolf Creek

Enclosure PG&E Letter DCL-12-080 Page 1 of 3 ONSHORE 2 DIMENSIONAL AND 3 DIMENSIONAL HIGH*RESOLUTION SEISMIC REFLECTION SURVEYS PROJECT DESCRIPTION ACTIVITIES WITHIN ARCHAEOLOGICAL SITE SLO*2

1.0 INTRODUCTION

The following project description was prepared in support of the onshore seismic surveys occurring within Diablo Canyon Nuclear Power Plant (DCPP) property located on the central coast of San Luis Obispo County, California. This project description focuses on the activities occurring within the California archaeological site known as SLO-2.

Proposed activities within the SLO-2 site boundary include the use of a sound-generating source and a sound-recording device.

1.1 PURPOSE AND OBJECTIVES The purpose of the proposed survey is to conduct additional seismic studies within DCPP.

The objectives of the proposed seismic survey are to:

(1) Provide additional information on the deformation rates of the bedrock underlying DCPP; (2) Obtain images of steep shallow structures and faults.

The seismic surveys are being undertaken due to public concerns with operating a nuclear power plant in a seismically active area of California following the Fukushima Daiichi accident.

1.2 PROJECT LOCATION The proposed seismic survey will be conducted on DCPP property along the central coast of California, between Point Buchon and Point San Luis.

1.3 SCHEDULE The duration of the seismic survey will take place from approximately late summer to early fall 2012.

Enclosure PG&E Letter DCL-12-080 Page 2 of 3 2.0

SUMMARY

OF ACTIVITES WITHIN SLO-2 2.1 SEISMIC (SOUND) SOURCES The onshore sound source activities within the SLO-2 site boundary will include the use of an EnviroVibe mounted on a 'Minibuggy' (see Figure 2-1) because of its low source generated ground pressure, low vehicle generated ground pressure, and reduced operational noise. EnviroVibe activities will be confined to existing .

roadways within the SLO-2 site boundary.

Figure 2-1. Typical EnviroVibe Mounted on a Minibuggy 2.2 SOUND-RECORDING DEVICES Within the SLO-2 site boundary, arrays of geophones, cables, and seismographs (Figure 2-2) will be laid out along the ground by crews on foot to minimize ground disturbance. Small 2.5-3 inch spikes attached to the base of the geophones will be used to secure the cabled geophone system in place. Prior to deployment, pinflags will be used to mark the proposed geophone locations to ensure that archaeological deposits are not disturbed. The geophones will passively record sound generated by the EnviroVibe. Geophone arrays will consist of approximately 31 lines with approximately 33 channels per line. The channels will be spaced at 10 meters (m)

(33 ft) intervals. The lines and channels will be spread over an area of 320 m by 300 m (1,056 ft by 990 ft). Once deployed, the cabled geophones will remain in place for approximately 2 months. On completion of the surveys, all geophones, cables, seismograph arrays, pinflags, and any other associated materials placed into SLO-2 during the planned activity will be entirely removed.

Enclosure PG&E Letter DCL-12-080 Page 3 of 3 Figure 2-2. Example of the Primary Components of a Cable-based Recording System 2.3 ARCHAEOLOGICAL MONITORING The following measures will be implemented to mitigate potential impacts to the SLO-2 site:

(1) Geophone nodes will be placed on the surface and secured with a small spike attached to the base of the geophone node; nodes will not be buried within the archaeological site. , This requirement will eliminate the potential for mixing or unearthing archaeological materials (2) Deployment of nodes will be monitored by an archaeologist that has the authority to direct node placement away from sensitive features within the site. An archaeological monitor will also accompany project personnel when they return to the site to remove the nodes (3) Operation of the sound source, the EnviroVibe mounted on a MiniBuggy, will be restricted to operating on established roads within the SLO-2 site