A Hydrologic Perspectiveof Waste Storage at VYNP

Presentation to the Senate Committee on Natural Resources and Energy,Vermont Legislature

Leslie Kanat, Ph.D.Johnson State Collegeles.kanat@jsc.edu12 March 2008

Use of Historical DataInterpretations of the ancient are based on observations of today natural laws do not change with time.Use evidence preserved in the ancient (record) as one indication of what might occur in the future. The conditions of today will not be the conditions of tomorrow conditions do change with time.

Probabilitiesrecurrence intervalprobability =110-year flood (10% chance of occurring each year)100-year flood (1% chance of occurring each year)200-year flood (0.5% chance of occurring each year)500-year flood (0.25% chance of occurring each year)

Connecticut RiverHistoric flooding (1927 at 229 feet, 1936 at 231.4 feet, 1938 at 226.6 feet) is now controlled by construction of five flood control dams.Battelle (1991) reports: 100-year floodplain at 227 feet 500-year floodplain at 232 feet

Probable Maximum FloodA defensible, worst case scenario, describing a flood that can be expected from the most severe meteorological and hydrologic conditions that are reasonably possible.

Results:discharge (cubic feet per second)stage (elevation in feet)probability (percent chance per year)

John Hoffman, an employee of VYNP, reports the probable maximum flood could reach a stage (elevation) of 252.5 feet (PSB 2005).

VYNP Interim Spent Fuel Storage Installation pad is 254.0 feet (PSB 2005).Probable Maximum Flood

The conditions continue to change;New England is getting wetter.(Holdren 2007)moreless

National Flood Policy ForumThe National Flood Policy Forum at the National Academies reports (ASFM 2004):Floods appear to be getting bigger and causing more damage than anticipated. The calculated expected flood depths and the extent of flood reach as depicted on maps are regularly demonstrated to be inaccurate.

Some ObservationsPrecipitation is increasing in New England, thus determination of recurrence intervals is unreliable.Class C Low-Level Radioactive Waste must have 300-year waste stability near surface and a 500-year intruder barrier (US NRC 2008).The Interim Spent Fuel Storage Installation pad is only 1.5 feet above the probable maximum flood (PSB 2005).

ConclusionBattelle (1991, p. 1.0-5) recommended that further characterization of the VYNP facility as a low-level radioactive waste site be suspended and that the VT Low-level Radioactive Waste Authority consider other alternatives.

RecommendationsReassess the probable maximum flood before moving the Interim Spent Fuel Storage Installation pad.

Do not use the Interim Spent Fuel Storage Installation pad for long-term storage.

ReferencesAssociation of State Floodplain Managers (ASFM), 2004. Reducing Flood Losses: Is the 1% Chance (100-year) Flood Standard Sufficient? Retrieved 24 Nov 07 from http://www.floods.org/Foundation/Files/2004_Forum_BackgroundPapers.pdf. Battelle, 1991. Site Characterization Data Report for the Vernon/Vermont Yankee Site. Prepared for the Vermont Low-Level Radioactive Waste Authority.Holdren, J., 2007. Realities of Energy and Climate Change: Science, Technology, Economics, Politics. UN 60th Annual DPI/NGO Meeting, United Nations, NY.Public Service Board (PSB), 2005. Petition of Entergy Nuclear Vermont Yankee. Pre-filed Testimony of John Hoffman on 16 June 2005.US Nuclear Regulatory Commission (US NRC), 2008. Part 61 Licensing Requirements For Land Disposal Of Radioactive Waste, 10 CFR, Part 61.7, Section 5. Retrieved on 9 March 2008 from http://www.nrc.gov/reading-rm/doc-collections/cfr/part061/full-text.html.

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