ML060410057

Comment (5) of Emily G. Lewis Opposing the Vermont Yankee Uprate

ML060410057
Person / Time
Site:	Vermont Yankee
Issue date:	02/07/2006
From:	Lewis E - No Known Affiliation
To:	NRC/ADM/DAS/RDB
References
%dam200606, 71FR1774 00005
Download: ML060410057 (1)

Text

'RUIE-s CTIVES Chief, Rules and Directives Branch M Ad 7 I 9:16 FE-Division of Administrative Services Office of Administration U.S. Nuclear Regulatory Commission Washington, DC 20555 0001 [ \ /

page 1774 Federal Register / Vol. 71, No. 7/ Wednesday, J0*ry 11, Dol

Dear Chief:

I am very concerned about the Vermont Yankee uprate.

The risk assessments in the draft Safety Evaluation (SE) released by the NRC are based on the assumption that the reactor is brand new. But.. .the plant-is NOT brand new, so the design basis safety margins NO LONGER APPLY. The vast number of reduced safety margins on every page of the SE add up to a SIGNIFICANT and very possibly DANGEROUS REDUCTION IN SAFETY MARGINS. They have no idea what safety margins should apply to an aged, embrittled, cracked plant, because they refuse to do an ISA to actually inspect the degree to which components are leaking, degraded, cracked or left in the wrong position.

This is irresponsible.

The fatal flaw and limitation of probabilistic risk assessment is that it does not consider consequences and is based on theoretical design standards and not real experience. In the ACRS hearings NRR staff admitted there were better methods to evaluate system integrity under uprate conditions, but NRC is not using them.

All of the above argue that the NRC is wrong in its ruling, and should revisit its decision after performing an Independent Safety Assessment and a real risk and consequence.

Nuclear plant risk assessments are really not risk assessments because potential accident consequences are not evaluated. They merely examine accident probabilities - only half of the risk equation--and the probabilities they use do not take into account actual experience of failures in the nuke industry overall, only probabilities based on the design basis.

In other words, the accident probability calculations are seriously flawed. They rely on assumptions that contradict actual operating experience.

Sincerely, Emiy G Lwis 19 Salem Place Amherst, MA 01002

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