ML19241A558

Identifies Concerns Re Hypothetical B & B Fault as Derived from Hearing Testimony & Subsequent Talks with Nrc/Usgs Review Staff.Requests Response from NRC Before 790418 Meeting If Util'S Interpretation Is in Error

ML19241A558
Person / Time
Site:	Skagit
Issue date:	03/29/1979
From:	Mecca J PUGET SOUND POWER & LIGHT CO.
To:	Stolz J Office of Nuclear Reactor Regulation
References
PLN-214, NUDOCS 7904040179
Download: ML19241A558 (4)

Text

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ATTACHMENT TO ENCLOSURE 3 p #m y ~.7dI March 29, 1979 J Uhj b *~*[ PLN-214 Director of Nuclear Reactor Regulation Attention: Mr. John F Stolz, Chief Light Water Reactors Branch 1 Division of Project Management U. S. Nuclear Regulatory Commission Washington, D.C. 20555 Subj ect : Puget Sound Power & Light Co=pany Skagit Nuclear Pcwer Project, Units 1 & 2 Docket Numbers30-522 and 50-323 Clarificatica of the pending April 18, 1979 meeting between Puget and the NRC on the hypothetical "3 & 3 Fault"

Dear Mr. Stol:

s In order that the meeting scheduled for April 13, 1979 referenced abeve be cost productive, we feel it is Lmportant to define the concerns. The purpose of this transmissicn is to put forth our understanding relative to concerns associated with the hypothetical "3 & S fault" as derived from hearing testi-cony and subsequent conversations with =e=bers of the NRC/USGS review staff.

The questien of the hypothetical "3 & 3 fault" first arose during the March, 1978 hearings before the Atomic Safety and Licensing Board. At that time, a USGS witness, Dr. William Hays, hypothesized a fault west of the plant site.

The hypothesired fault was, for discussion purposes, labeled the "3 5 3 fault".

In his testimony, Dr. Hays emphasized that he was not stating that the "3 5 3 fault" existed, but rather that he considered it to be a conceivable fault.

Dr. Hays described the hypothetical fault as lying i==ediately to the west of Iu=mi Island, centinuing to the southeast through Sacish Bay and across the Skagit River flood plain, then curving eastward acrcss Walker 'v' alley and through the Table Mountain area and then finially curving more to the southeast and joining the Devil's Mountain fault zone a short distance east of Lake Cavanaugh.

During the hearings, Dr. Hays drew the southeastern trace of the hypothetical fault on a topographical cap which had been labeled Exhibit 132. Additional discussion with Dr. Hays and other reviewers indicated that the hypothetical fault if it existed would exhibit Quaternary displacement.

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Mr. John F. Stolz, Chief March 29, 1979 PLN-214 g The basis for Dr. Hays postulation of the "3 s 3 fault" as we under;tand from t

review of the test 1=ony and discussions with hi= are as follows:

, 1. The suggestion by Dr. Peter Ward, an assistant professer n Ohio State University in a letter dated Dece=cer 3, 1977 ta the USGS that there =ay be a northwesterly trending f ault between Lu==i Island and two small islands (3arnes and Clark Islands) to the west of Lu==1 Island. The apparent reasons for inferring a fault between Lu==i and Clark Islands are:

a. Nanai=o sediments on 3arnes and Clark Islands which were deposited in deep =arine water are located near Chuckanut sedi=ents on Lu==i Island which were deposited either on land or in shallow, fresh water; and,

b. These sedi=entary =aterials are coeval - i.e.,

were deposited at about the sa e ti=e.

2. During Dr. Hays' testi=ony, he noted that the Table Mcuntain area is a highly sheared i=bricated area with a tectonic inter =ixing of lithologies. He said it was possible to inter-pret this information as being related to a structure such as he hypothesized.

Since the March 1978 hearings our consultant, 3echtel, has embarked upon an extensive ceinvestigation of the site area involving field =apping, aerc=ag-P3 notic surveying and interpretation, =agnetics, re-review of i=agery studies and other investigative progra=s as appropriate to respond to the NRC's questions on Gilligan and Day Creeks. The sa e infor=ation as it =ight relate to the hypothesized "3 & 3 fault" has been reviewed together with infor=ation frc= seis=ic profiles to define if a structure as hypothesized by Dr. Hays exists. A substantial amount of the infor ation under consideratica has been available to all parties for quite some ti=e.

It is our intention to discuss with the NRC/USGS on April 18, 1979 all inf o r=a-tion which possibly could relate to the hypothetical "3 & 3 fault" as defined above. 'We would expec t to leave with the reviewers copies of any data and evidence presented. %e would further expect to carry on dialog with the review-ers so that our forthec=ing geology report can provide the basis for resolving this issue.

If we are in error regarding our interpretation of the NRC/USGS concerns regarding the hypothetical 3 & 3 structure, the basis for it, additional basis not noted, or objectives for the April 13, 1979 =eeting please infor:

us as soon as possible.

Very truly yours, h[. M

'J. I. Mecca, Manager Nuclear Licensing & Safety r: V 4 ey e, JEM/bv LSL3 E3J.O()

cc: Correspondence List ASL3 Corresponcence List