ML20084N033

Forwards Rockford League of Women Voters Proposed Findings of Fact & Conclusions of Law Re Contention 106 on Seismology,Per 820818 Stipulation

ML20084N033
Person / Time
Site:	Byron
Issue date:	05/31/1983
From:	Thomas D ILLINOIS INSTITUTE OF TECHNOLOGY, CHICAGO, IL
To:	Callihan D, Cole R, Smith I Atomic Safety and Licensing Board Panel
References
NUDOCS 8306020437
Download: ML20084N033 (12)

Text

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IIT rnr.vaa LEGAL SERVICES CENTERm Director Illinois institute of Technology 77 South Wacker Drive Gary S. Laser Chicago-Kent College of Lat33 . n -1 P1 :29 Chicago, I!!inois 6%%

Co-Directors 2) 567-5050 Civil Division Vivitn Cross Robarta Strickler May 31, 1983 Co-Directors Criminal Division Marc Kadish David C. Thomas Ivan W. Smith, Esquire Dr. Richard F. Cole Faculty Administrative Judge and Administrative Judge Richard S. Kling Chairman Atomic Safety and Licensing M rvin Green Atomic Safety and Licensing Board Sarzh L. Flosi Board U.S. Nuclear Regulatory U.S. Nuclear Regulatory Commission Commission Washington, D.C. 20555 washington, D.C. 23555 Dr. Dixon Callihan

. Administrative Judge Atomic Safety and Licensing Board c/o Union Carbide Corporation P.O. Box Y Oak Ridge, Tennessee 37830 Re: In the Matter of Commonwealth Edison Company (Byron Nuclear Power Station, Units 1 and 2)

Docket Nos. 50-454 and 50-455)

Gentlemen:

Please find enclosed a copy of the League's Proposed Findings of Fact and Conclusions of Law, sent pursuant to regulation, Section 2.754 and the Stipulation entered on August 18, 1982.

Also please be informed that three copies of the enclosed document have been mailed to the Secretary, and one copy of same has been mailed to each concerned party, the names and addresses of which are indicated on the attached Service List.

Thank you.

Very truly yours, iOl$ % (MN David C. Thomas DCT:mm Enclosures 8306020437 830531 O

PDR ADOCK 05000454 0 ppg

SERVICE LIST

• Mr. Ivan Smith

• Douglass W. Cassel, Jr.

Administrative Judge and Chairman Jane Whicher Atomic Safety and Licensing Board Panel BPI Room 428 Suite 1300 East West / West Towers Bldg. 109 N. Dearborn Bethesda, MD. 20114 Chicago, IL 60602

• Dr. Richard F. Cole *

• Isham, Lincoln & Beale Atomic Safety and Licensing Board Panel Three First National Plaza U.S. Nuclear Regulatory Commission Chicago, IL 60602 Washington, D.C. 20555 Atomic Safety and Licensing Board Panel U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Chief Hearing Counsel Of fice of the Executive Legal Director U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Dr. A. Dixon Callihan Union Carbide Corporation P.O. Box Y Oak Ridge, Tennessee 37830

• Dr. Steven C. Goldberg Ms. Mitzi A. Young Office of the Executive Legal Director U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Atomic Safety and Licensing Appeal Board Panel U.S. Nuclear Regulatory Commission Washington, D.C. 20555

• Secretary ATTN: Chief, Docketing and Service Section U.S. Nuclear Regulatory Commission Washington, D.C. 20555

• Ms. Diane Chavez SAFE 326 N. Avon St.

Rockford, IL 61103 Dr. Bruce von Zellen Department of Biological Sciences Northern Illinois University DeKalb, Illinois 60115

• Federal Express

• • Messcnger

I. FINDINGS OF FACT A. League Contention 106 - Seismology

1. Pursuant to stipulation, original contention 106 was altered. Alternate contention 106, as litigated, reads as follows:

There exist serious seismic related site problems discovered subsequent to the construc-tion permit herein which indicates that the seismic design for Byron is not such that there exist assurance that these problems are adequately resolved in accordance with applicable regulations, including but not limited to 10 CFR 50.57 (a) (3) (i) , 50.57 (a) (6) and 10 CFR Part 100, Appendix A. Specifically, the Rockford League of Women Voters contends that due to the lack of reliable information regarding the causes of earthquakes which have been experienced in northarn Illinois, Edison should be required to perform strain gauge tests on faults cutting basement rock located in the northern Illinois region where earthquakes of modified Mercalli VII or greater intensity are expected to occur.

Further, recent evidence from the central portion of the United States shows that neither the Byron designated safe shut down earthquake peak ground acceleration value of 0.20 (g) nor the operating basis earthquake peak ground acceleration value of 0.09 (g) are sufficiently conservative. Ground acceleration significantly greater than both of these values are possible at the Byron site. In addition, it is not known if the recently discovered Plum River Fault #.s a capable fault. This fault is knowr to approach the Byron site within 5.3 miles and may even be closer if the fault extends further to the east.

2. The League presented as its witnesses, the testimony of Dr. Henry H. Woodard, Ph.D. in Geology, University of Chicago and Chairman of the Geology Department of Beloit College in Wisconsin. Dr. Woodard has worked for the United States Geological Survey and has conducted extensive research into the geologic structures of Central North America.

Witnesses for the Nuclear Regulatory Commission were Dr.

Ina B. Alterman, a staff geologist in the geosciences branch in the Office of Nuclear Reactor Regulation of the NRC, and Dr. Robert L. Rothman, a seismologist in the geo-sciences branch in the Office of Nuclear Regulation of the NRC. The witnesses for the Applicant were Mr. Alan K.

Yonk, a senior geologist at Sargent and Lundy (the Byron station architect-engineer) and Dr. Anand K. Singh, a structural engineer and Assistant Division Head of the .

Dynamic Analysis Section of Sargent and Lundy.

3. At the construction permit stage of review both the Applicant and the Illinois Geological Survey, on whom it relied, failed to reveal the presence of the Plum River Fault (Alterman, Prepared Testimony, p. 3).

4. Escavation of the Byron site exposed to the Applicant to the fault structure which direct observation indicated had been analyzed incorrectly (Yonk, Prepared Testimony, p. 2; Alterman, Prepared Testimony, p. 2).

5. Sargent and Lundy and Dames and Moore, a geo-technical and environmental consulting firm examined the small faults found in the excavation site. The capability of these faults is not in dispute (Yonk, Prepared Testi-mony, p. 2).

. 6. The Applicant relied on a study conducted by the Illinois State Geological Survey (ISGS) to re-evaluate the other fault structures in the vicinity of the plant (Yonk, Prepared Testimony, p. 6).

7. The ISGS survey which re-evaluated the area around the Byron site (Alterman, Prepared Testimony, p. 2) re-vealed the presence of the Plum River Fault in the bedrock

. (Yonk, _ Prepared Testimony, p. 5; Alterman, Transcript, pp. 763, 867). .

8. Essentially, the techniques of seismic refraction and core drilling employed by the ISGS provided sufficiently accurate data to establish the presence of the Plum River Fault in the bedrock (Alterman, Tr. pp. 763, 832, 867-868; Rothman, Tr. pp. 870-871).

9. The critical information yielded by these tech-niques were the gross observations that 1) there was rock of dif ferent types on gither side of the drill holes (Alter-man, Tr. p. 832) and

2) there was considerable dlfference in the bedrock velocity which indicated some type of altera-tion in the lithography (Alterman , Tr. p. 791) .

10. The ISGS as well as the study by Dames and Moore, revealed that interglacial residual soil and glacial till, which was deposited 125,000 years ago, overlies the fault zone (Yonk, Tr. p. 461; Alterman, NRC Staff Prepared Testimony, at 8, ff. Tr. p. 753).

11. The eastern end of the Plum River Fault Zone is

-known to approach the Byron site within 5.3 miles northwest of the Byron plant site (Yonk, Prepared Testimony 5 ff, Tr.

p. 478; Alterman, NRC Staff Prepared Testimony at 3, ff.,

Tr. pp. 753, 812). Because the eastern end of the fault zone is not exposed, it is unclear as of the present whether the fault zone extends inside the five-mile radius circle drawn by the Regulation in Part 100, Appendix A. Also, no investigations were conducted to determine if the Fault does approach the five-mile regulatory limit.

(Woodard, Prepared Testimony, p. 2; Alterman, Tr. pp. 814-815).

12. Accordingly, the Board finds that the ISGS data sufficient to establish the presence of a fault in the bedrock but insufficient to establish that the fault does not fall within the five-mile regulatory limit.

13. One of the critical questions for determining whether the Plum River Fault is capable is whether the till has been offset. (Alterman, Tr. pp. 788, 794, 818; Yonk, Prepared Testimony, p. 6).

14. The critical information which would resolve the question of till displacement with the greatest degree of accuracy can only be obtained through direct observation of the interface between the fault and till overlying it (Woodard, Tr. pp. 567-568). These critical observations have not been made (Woodard, Tr. p. 567; Alterman, Tr.

p. 830).

15. One of the most reliable means of directly ob-serving the till-fault interface is by excavation with a backhoe across the Plum River Fault (Woodard , Tr. p . 5 94 ) .

This method is certainly a feasible exercise because the

excavation need only extend a few tens of feet to reach the bedrock (Woodard, Tr. p. 574).

16. In addition, no evidence has been adduced to I

l indicate an overburden sufficiently deep on the Plum River Fault, at least at a juncture 5.3 miles near the Byron site, which would obscure the Plum River Fault and f

thus make the measure proposed by the League either im-possible or unpractical.

17. The Applicant chose indirect methods over direct observation for determining whether the till was dis-l

1 turbed once in the past 35,000 or in a recurring pattern in the past 500,000 years. The Applicant contends that the techniques employed to determine the presence of the fault in the bedrock are sufficiently accurate to conclude i

that there has been no movemet:t of the till in the last 35,000 years and that there has been no recurring fault movement in the past 500,000 years (Yonk, Prepared Testi-mony, pp. 6-8; Tr. p. 418).

18. The' techniques of core drilling and seismic refraction are not sufficiently accurate to make the determination that there has been no displacement of the till (Woodard, Tr. p. 571). Core boring cannot determine the dating of the fault (Alterman, Tr. p. 867). The use-fulness of seismic refraction is limited to identifying the presence of the fault in the top of the surface of the bedrock (Alterman, Tr. p. 869). The NRC does not dispute that seismic refraction data cannot yield data of a significant degree of accuracy to determine if the Plum River Fault is capable or not. (Rothman, Tr. p.798.)

19. These techniques are inadequate for at least two major reasons. First, displacement in the till of only a few inches, which if it had occurred in the last 35,000 years would demonstrate a capable fault, would in ,

all probability fail to show up through either of these methods. (Rothman, Tr. p. 798.) Second, If there had been a horizontal movement along the fault neither method 2

would isolate that movement. (Woodard, Tr. 572.)

20. Even accepting the Applicant's conclusion of

125,000 years of no movement, the Board can find no support for the contention that there has been no recurring motion within the past 500,000 years. (Woodard, Tr. 599, Alterman,

p. 756.) The Applicant has provided no evidence to esta-blish his contention that there has been no recurring move-ment in the past 500,000 years. (Yonk, Prepared Testimony,

p. 7.)

21. The Board finds that the Applicant has failed to perform the feasible and most accurate form of inves-tigation to determine the capability of the newly discovered Plum River Fault. In addition, the Board finds that the indirect methods of analysis relied on by the Applicant are insufficiently accurate to conclusively resolve the question of whether the Plum River Fault is Capable.

22. Accordingly, the Board is unable tr find that the Plum River Fault is noncapable.

23. The NRC's regulations, as set forth in 10CFR Part 100, Appendix A, require that the safe shutdown earthquake, also commonly referred to as the design basis earthquake, is that earthquake which is based upon an evolution of the maximum earthquake potential considering the regional and local geology and seismology and specific characteristics of local subsurface material. It is the earthquake that pro-duces the maximum vibratory ground motion which the structures, systems, and components that are necessary to enable a reactor to shut down and avoid major offsite exposures are designed to withstand. (Singh, Applicant Prepared Testimony, at 3, f f . T' . 451.)

24. . The operating basis earthquake:is that earthquake I which, considering the regional and local geology and i

seismology and specific characteristics of local subsurface material, could reasonably be expected to affect the plant site during the operating life of the plant. It is the i earthquake that produces the vibratory ground motion for which those features of the nuclear power plant necessary for continuous operation without undue risk to the health 1

, and safety of the public are designed to remain functional.

1 If the vibratory ground motion exceeding that.of the oper-ating basis earthquake occurs duri.ag the life of the plant, the Commission's regulations require that the plant be i shut down and that, prior to resuming operations, it must be demonstrated that no functional damage has occurred to 4

those features of the plant necessary for that continued

operation without undue risk to the health and safety of the public. (Singh, Applicant Prepared Testimony, at 3-4, i ff. Tr. 431.)

25. The selection of ground acceleration values is connected to the determination of the intensity of the .

earthquake for which a facility is designed. (Singh, Ap-plicant Prepared Testimony, at 4, ff. Tr. 431.)

26. Seven earthquakes have occurred in northern j

Illinois between 1804 and 1972 with, according to P.C.

Heigold, Modified Mercalli intensities ranging from IV i

to VI. (Yonk, Tr. 4 66 ; Woodard, Tr. 551, 553-556, 558.)

27. The seven earthquakes depicted by Heigold have

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been interpreted as having Modified Mercalli intensities as high as VII, (Yonk, Applicant Prepared Testimony, at 10, ff.; Tr. 446-447, 478.)

28. The controlling earthquake for the Byron plant is the 1937 Anna, Ohio (which is also located in the Central Stable Region) Modified Mercalli intensity VII-VIII earth-quake. (Singh, Applicant Prepared Testimony, at 5, ff. Tr.

p. 431).

29. The SSE for Byron is based upon an earthquake with a Modified Mercalli intensity of VIII, which is greater than any earthquake ever recorded in either northern Illinois or the entire Central Stable Region. (Singh, Applicant Prepared Testimony, at 5, ff. Tr. p. 431; Rothman, Tr. p. 849).

30. The Applicant reviewed studies which considered the intensity versus magnitude and earthquakes experienced in the Central United States and selected a magnitude value of 5.8. (Singh, Applicant Prepared Testimony, p. 5).

31. The Applicant did not, however, compute a site specific response spectrum to arrive at an appropriate ground acceleration value. (Singh, Applicant Prepared i'

Testimony, p. 5: Tr. p. 480). Instead, the Applicant re-viewed a site specific response spectrum calculated for the Tennessee Valley Authority's Sequoya Nuclear Power Plant, (Singh, Applicant : Prepared Testimony, p. 5; Tr. p. 480) and adopted the value of 0.29 computed for sequoyah site.

32. The Applicant changed its approach when it calculated a ground accelerating value for the operating basis earthquake. For the safe shutdown earthquake it justified the selection of 0.2g surface ground motion by postulating sufficiently conservative estimate of earth-quake intensity. (Singh, Applicant Prepared Testimony, p. 5).

33. For reaching an appropriate ground acceleration for the operating basis earthquake, the Applicant began its calculations by first selecting a modified Mercalli intensity VI---value and determined the ground acceleration value from that (Singh, Applicant Prepared Testimony, p. 6).

34. The Applicant justifies its adoption of .09 which is less thai the regulatorily required value of .1 (Singh, Tr. p. 489) because of the probabilistic study of the recurrence interval that was calculated without any site-specific basis.

35. Modified Mercalli intensity values are calculations done after an event; they are not the same as instrumental measurements (Yonk , Tr. p . 4 57-8 ) .

36. The Applicant has ignored the only instrumentally measured data available for determining ground accerlation values. (Woodard, Tr. p. 601 ff.) Data from an earth-

quake swarm from the central United States was collected in 1982 near Conway, Arksansas. Thedatasuggeststhatthe MM intensities on which the Applicant based its calculations I

i are not conservative enough (Woodard Prepared Testimony,

p. 3 ff.; Tr. pp. 601-604).

37. This data revealed that in similar kinds of t

basement rock that are present at or around the Byron site an earthquake of a magnitude (3.8) significantly less than l that postulated for the operating basis earthquake (5.8) l l generated an acceleration value (.59) almost three times i _

the ground acceleration value determined for the safe shutdown earthquake. The other value recorded at Arkansas

(.19) is also significantly in excess of the ground acceleration value calculated for the Byron generating basis earthquake (Woodard Prepared Testimony, p. 4 ;

Rothman NRC Staff Prepared Testimony, p. 6).

38. There is no satisfactory explanation for the dis-i crepancy (Rothman, Prepared Testimony, p. 4). The fact

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that the shed in Arkansas containing the records was not damaged was irrelevant because this was an earthquake of extremely short duration which released little energy (Rothman, Prepared Testimony, p. 6)..

1 39. Based on the presence of instrumentally measured ground motion in rock similar to Byron the Board finds that the selection of the Modified Mercalli intensity value is l not conservative enough. The evidence prescribed does not justify waiving the 1/2 regulatory requirement for the relationship between the OBE ground acceleration value and the SSE ground acceleration value.

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