Jones River Watershed Association (JRWA) sent a letter yesterday, Feb. 11th, to the Nuclear Regulatory Commission (NRC) asking the NRC to require Entergy to carry out an updated, accurate site survey and flood assessment at Pilgrim before Entergy’s Hazard Reevaluation Report for flooding is submitted on March 12, 2015.

JRWA, in conjunction with Northeastern Geospatial Research Professionals, Inc., recently developed an Elevation Analysis of the Pilgrim site. The analysis and accompanying maps clearly raise valid concerns related to flooding and storm impacts on the Pilgrim site.

In the Feb. 11th letter, JRWA asks points out that Entergy will not be able to provide a valid Hazard Reevaluation Report to the NRC on March 12th without first carrying out a proper site survey. The site survey needs to use the most updated methodology and data, as well as the most current information about sea level rise, and influences by tides, storms, waves and wind.

Information and maps that Entergy has provided to the NRC and the public to date, have been misleading and inaccurate and seem to be copied and pasted from plans developed by Boston Edison (the original owner of Pilgrim) in the 1970s. We have concern that Entergy’s Hazard Reevaluation Report for flooding that is due on March 12, 2015 will be useless in preventing an accident due to flooding, if the information is carried over from outdated plans and no new site-survey is completed.

Read the full letter HERE. Here are the attachments to the letter:

The same request was made to Entergy on Feb. 10th. Read that letter HERE.

JRWA, in conjunction with Northeastern Geospatial Research Professionals, Inc., recently developed an Elevation Analysis of the Pilgrim site. The analysis and accompanying maps clearly raise valid concerns related to flooding and storm impacts on the Pilgrim site.

Here are some highlight from the Elevation Analysis report. The maps are also included below.

Introduction:

The Pilgrim Nuclear Power Station (PNPS), located in Plymouth County, Massachusetts on the shores of Cape Cod Bay was commissioned on December 9, 1972. The power station design included development of near-shore revetments and other engineered reinforcements intended to protect the site from wave action emanating from Cape Cod Bay. Over the operational history of the power station, there have been dredging operations to ensure that the water intake and outlet remain operational and that engineering design meets current standards.

Resulting from a perceived shortfall in response to global climate change and sea-level rise evidence on the part of PNPS, it has come to the attention of the Jones River Watershed Association (JWRA) that the Pilgrim Nuclear Power Station site and its assets may be at risk. Specifically, with the advent of outdoor storage of high-level radioactive waste in the form of spent fuel rods contained in casks engineered for such containment in close proximity to Federal Emergency Management Administration (FEMA) flood zones.

This elevation analysis has been conducted using the best available, civilian accessible geospatial data in a comparative study to determine where the location of spent fuel casks are in regard to FEMA modeled flood zone data.

Conclusion:

The Pilgrim site map shows several surveyed locations that do not match current modeled elevation data. Although the survey locations on the PNPS map are in a known, disparate vertical datum and are compared to the current modeled elevation data, in some cases, there is a discrepancy in elevations that is too great to determine precisely where the modeled FEMA flood zone impacts the site. The data collected and produced by Entergy have been referenced to and modeled for the NGVD29 datum while all other data are referenced and modeled to the newer NAVD88 datum. Although it is possible to convert between NGVD29 and NAVD88 datums, it is standard practice to use data that are all modeled to the same datum (horizontal and vertical, respectively). This eliminates potential misrepresentation of a given location on site plans, and other planimetric data (including flood hazard data), which may also be projected in a different datum. While it appears that the top of engineered elevation per the PNPS site map is nearly identical to the modeled LIDAR elevation data, the discrepancy in vertical elevations when survey data are compared to the FEMA flood zone data confounds the analysis.

Recommendation:

The recommendation based on this analysis is to undertake a site survey of PNPS grounds using known, measured benchmarks. Additional reference locations should also be plotted and measured throughout the PNPS site for an accurate elevation data set that is surveyed to the NAVD88 datum. This will provide the public (regulators, residents, etc.) with a clearer picture of how sea level rise resulting from our changing climate impacts current, potentially hazardous conditions at PNPS. Further, a new data set will enable decision-makers the ability to more accurately assess on-site assets and contingencies for future planning.

Read the full Elevation Analysis Report HERE.

Links to the high-resolution maps:

Shoreline Profile Sections_2

Flood and Lidar Elevations_2

PNPS_USACE2FtCtourMap_Rev002_10feb2015

SurficialGeoandMonitorWells_3

 

Additional maps and images:

FFandLIDAR

3D_1

 

3D_2