ML20211L067

Forwards Synopsis of 860904 Meeting Between NRC & Aslab Re Jan 1986 State of Oh Earthquake,In Response to . Meeting in Question Was Not Ex Parte Since Issue of Seismicity Ceased to Be Contested Issue in Proceeding

ML20211L067
Person / Time
Site:	Perry
Issue date:	12/02/1986
From:	Malsch M NRC OFFICE OF THE GENERAL COUNSEL (OGC)
To:	Hiatt S OHIO CITIZENS FOR RESPONSIBLE ENERGY
References
NUDOCS 8612150291
Download: ML20211L067 (4)

Text

'

/"Y o,, TA1.:s k s P n tiUCLEAR REGULATORY COMMISSION

; WASHINGTON, D. C. 20655 g g - k/ 4 0, L/ 'f /

I,s ..... jf December 2, 1986 Susan L. Hiatt Ohio Citizens for Responsible Energy 8275 Munson Road Mentor, Ohio 44060

Dear Ms. Hiatt:

In your September 19, 1986 letter to the Commissioners, you expressed the view that the meeting between members of the NRC staff and Dr. W. Reed Johnson of the Atomic Safety and Licensing Appeal Board to discuss his concerns about the January 1986 Ohio earthquake constituted an illegal' ex parte communication. You also requested that the persons present at the meeting prepare a summary of the meeting and serve it on the parties.

As a legal matter, the meeting in question was not ex parte, because the issue of seismicity had ceased to be a contested issue in the proceeding with the issuance of the Commission's order of April 18, 1986, which denied OCRE's motion to reopen the record. There was accordingly no legal obligation to memorialize the discussion and place it on the public record. Nevertheless, in response to your request for a summary of the discussion, the staff and Dr. Johnson have together developed a synopsis of the meeting, which we are herewith providing to you and the other parties.

Sincerely,

$?' '

s Martin G. Malsch Deputy General Counsel Attachment A:

Synopsis of September 4, 1986 meeting cc: Service List 8612150291 861202 PDR ADOCK05000gO P

o 0

ATTACHMENT A synopsis of September 4, 1986 Meeting The meeting between Dr. Reed Johnson and the staff was convened on September 4, 1986 in Mr. V. Ste11o's office. The purpose of the meeting was to clarify the staff's formal responses to his questions on the Perry earthquake. The meeting was informal and no minutes were recorded.

In summary, the discussions focused on: (1) the methodology ,.

used by the staff and its consultants in independently evaluating the integrity of the plant's structures and components in the aftermath of the earthquake, and how the design allowable value calculations permitted in the ASME Code were applied in determining the adequacy of structural integrity; and (2) the s

significance of high frequency elements witnessed in recent i Eastern U.S. earthquakes, and the generic studies being undertaken by the NRC to reassess seismic design criteria

. currently specified in Chapter 10 of the U.S. Code of Federal

. Regulations. The information, which Dr. Johnson alluded to

.t having received, during the September 5, 1986 Commission briefing on Perry full power licensing (see Transcript at p. 76) pertained to the items noted above; i.e., the information was verbally communicated to Dr. Johnson at the September 4, 1986 meeting.

One item that was discussed was the relevance of the duration of strong motion (Response at p. 6) when high frequency motion is involved. Dr. Johnson expressed his view that under l

l

o l

~

l such circumstances equipment with high natural frequencies would reach maximum excitation in a short time. As a result, he questioned the worth of calculations of " longer duration events" that merely repeated the same time history of motion several times.

There was a discussion of whether at the foundation level of the Reactor building and the Auxiliary building earthquake motion should be considered equivalent to free field ground motion, or that there could be some degree of amplification. The staff ,

presented an argument as to why there would be no expected tau-effect reduction in the high frequency motion at the Perry site.

I The odd, rich-in-high-frequency-motion nature of the 1986 Ohio earthquake was discussed, and Dr. Johnson was told of a staff study under way which was exploring this phenomenon, which was apparently a characteristic of other eastern earthquakes. A decision was yet to be made as to the need for changing the seismic regulatory requirements to account for this behavior.

Dr. Johnson noted his concern at the relatively large number of calculated stress ratios which were larger for the 1986 Ohio event than for the SSE (Response, Item :3). In this regard, it was emphasized by the staff that design allowable stresses are calculated using clastic behavior of equipment and that in reality its capability would be much increased if the expected inelastic behavior of materials was considered. This factor would provide a margin to failure, even in the case of an

3 i

earthquake having a spectra shape similar to the 1986 Ohio event and a greater intensity.

I