ML12037A056

E-mail from D. Decker to M. Khanna, NRR; Subject: Follow-up Question from Congressional Staffer

ML12037A056
Person / Time
Site:	North Anna
Issue date:	09/16/2011
From:	David Decker Office of Congressional Affairs
To:	Meena Khanna Plant Licensing Branch 1
References
FOIA/PA-2011-0357
Download: ML12037A056 (3)

Text

DE FOIA Resource From: Decker, David H \ "

Sent: Friday, September 16, 2011 11:34 AM To: Khanna, Meena Cc: Li, Yong; Manoly, Kamal

Subject:

RE: Follow-Up Question from Congressional Staffer Meena.

I sent the staffer the updatedinfo you sent to me below, and here is a follow-up e-mailfrom her aboutthe seismicmeasurhig equiment at North Anna. Iopeful/ the USGS statementabout better equ~pmentbeing available was talkhig about the kkbematic equipment, but / wanted to check A/so, Is there anything we can say abouthow confident we are about the readings,a the staffer Is worriedabout? Thanks. -David Follow-Up E-mail Thanks for the hifo. but i'n sill a bit confused Is the hinemetric equoment the tye of equipment USGSis recommendihg?

The witness made it sound ike there was better equIpment that wasn t being usedyet /i plants. A/so, if the two tes of equiment didn 'tprovidethe same readings,how do we know which is/orif eitheris correct? Couldthe earthquakehave been worse than Dominion thoughtbecause their equimentdidn t recorditproperly?

-Orghial Message-Frm-/ anna, leena \

Sent: Thursday. September 15.20/1 /0:50 Pill To." Decker, David Cc: Lt Yong: Manoly, Kamal Subject-FW. Follow-Up Oueton from CongressionalStaffer Importance: /igh David p/s use this response in lieu of what I sentyou earlier.thanks Rinemetrics seismometers arerelativeS reliablebecause they providegroundmotlbn thie historiesandthe corresponding responsespectrum can be calculated. however. EngdahlScratchplates on4i record *pek acceleratkonsanddue to unknown reasons.the scratch plates atthe North Anna plantdid not registeranygroundmotoin from the earthquakeatcertain frequencies. The resonsespectra from Engdahland Kinemetricsseismometersshowed sgmni/fcant inconsistency inboth frequencies andamplitudes eventhough the two seinometersare locatedat the same location/elevation. However, it should be noted thatboth types of recordingsindicatedthe exceedance of OfE andDBE at the North Anna site.

from.- Khanna, illeena Sent: Thursday, September /5, 2011 635 Pil To: Decker. David Cc. Manoly, Kamal It: Yong: Wilson, George

Subject:

FW- Follow-Up auestion from CongressionalStaffer

David,here is a responseto your question...

Yes. Kmiemetric recordingsare more rel/able because they provide time histories andthe correspondingresponsespectracan be calculated EngdahlScratchplates onti recordpeak accelerationsandcouldmiss accelerationsatcertain frequencies, thus.

one would be erpectedto see some inconsistency inrefleching the frequency vs. amplitude of vlbrat'ons. However, it shouldbe noted thatboth Oypes of recordingsindicate the exceedance of OBE andDBE at North nna.

Thanks; Meena From:. Decker. David To: Munson, Clifford Cc. Wilson, George Sent: Thu Sep 15 09:55..48 2011

Subject:

RE: Follow-Up Question from CongressionalStaffer Thanks Cliff Knowing that we also have data from seismometers (do we know how many there are at theplant)is good George - anything more that we can say about where we got datato evaluate the eartquake' inpact (other than the scratchplates)would be much appreciated.

From:Munson, Clifford Sent: Thursday, September 15. 2011 8:01 *t4 To: Decker, David cc.. Wilson. George

Subject:

RE&Follow-Up Question from CongressionalStaffer 811/Leith of U1SGS was referring to the 'scratchplate "readouts; Dominion also has seismometers which give a complete recordof the earthquakemotions so they aren 'tjustrelying on the scratchplates. which are fairly crude (1970s technology).

Maybe George Wilson can amplify more on the accuracyof the scratchplatessince he has experience with them.

Clif From: Decker. David Sent: Wednesday. September 14. 20115:25PM To: Wilson. George.: Munson. Clifford' Croteau. Rick: dones. Wili'am Subject. Follow-Up Ouestion from CongressionalStaffer 2

We receivedthe following quemton from Kathy Dedrick (one of our Senate oversightstaffers who we 'e talked with on the phone 1wice recently), after she watched the Task Forcepub/ic meet'g tody. Thanks foryour help in respondingto the quest/on below. -David T'ZOn anyone eW/lain to me what the rami/cationsareof the USGS test'nony today which saidthat the measurementsat North Anna were probablynot accurate within 10 or 20 percent. Does thatmean they are less sensitive and the ground mot'on could have been much more? Or what does thatmean? It sounds like those instrumentsare the only source of information,so Pomkinon wouldbe basingdecisionson something thatisn t veiy accurate. "

3