ML25196A280
| ML25196A280 | |
| Person / Time | |
|---|---|
| Issue date: | 09/14/1977 |
| From: | Bender M Advisory Committee on Reactor Safeguards |
| To: | Hendrie J NRC/Chairman |
| References | |
| Download: ML25196A280 (1) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION ADVISORY COMMITTEE ON REACTOR SAFEGUARDS WASHINGTON, D. C. 20555 September 14, 1977 Honorable Joseph M. Hendrie Chainnan U.S. Nuclear Regulatory Conmission Washington, DC 20555 SUB.JECI':
REPORI' ON PARI'IAL REVIEW OF THE SITE FDR THE SAN JOJIQUIN PROJECT
Dear Dr. Hendrie:
During its 209th meeting, September 8-10, 1977, the Advisory Conmittee on Reactor Safeguards corrpleted a partial review of the suitability of a sitP on which the Los Angeles Department of Water and Power (Applicant) pro-poses to construct two or nore nuclear power plants. Members of the ACRS Subconmittee visited the site on August 15, 1974. Subcorrmittee rreetings were held on August 15, 1974 and June 24, 1977 at Bakersfield, California.
On September 1, 1977, in conjunction with the Seismic Activity Subconmittee, a m:eting was held in San Francisco, California. During its review of the San Joaquin site, the Cormnittee had the benefit of discussions with mem-bers of the Nuclear Regulatory Conmission (NRC) Staff and the United States GE!ological Survey (USGS), and with representatives of the Applicant and its consultants. The Corrmittee also had the benefit of the documents listed.
The San Joaquin site review was limited in scope as permitted by 10 CFR Part 50, Appendix Q.
Specifically, the scope was limited to evaluating the suit-ability of the site with respect to: (1) hydrology: (2) geology and seismol-ogy, including seismic input criteria: and (3) stability of subsurface materials as to the potential for subsidence.
The San Joaquin site is located in Kern County, California, in the southern San Joaquin Valley, approximately 10 miles northwest of Wasco and approxi-mately 33 miles northwest of Bakersfield, the nearest population center, which had a 1970 population of 69,515.
The site and its environs consist primarily of unimproved and improved farm lands located on the floor of the San Joaquin Valley. The total area of the site is approximately 2500 acres.
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Honorable Joseph M. Henck ie September 14, 1977
.l'he maximtml probable flood, including wave run-up, is estimated to resuic in a water level of 9 ft. above the existing site level. The ACRS agrees
~ith the Staff's position that a nuclear plant can be designed to protect against this water level. Further NRC review will be necessary at the Construction Permit stage to validate plant design for this condition.
A substantial depletion of the underlying aquifer, primarily for agri-cultural use, has caused approximately four feet of subsidence at the site. This subsidence is anticipated to continue at a rate of about 0.1 ft. per year. The nDnitoring program suggested by the Applicant is considered adequate for measuring subsidence, nonuniform settling or surface fissuring. With proper plant design such subsidence is not considered to be a problem.
The Applicant, the NRC Staff, and the U&;S have agreed that horizontal ground accelerations of 0.45g and 0.225g at the site are appropriate de-sign v.alues for the safe shutdown earthquake (SSE) and the operating basis earthqt~e, respectively. The SSE value was based on a postulated 8.5 magnitude (Richter) earthquake on the San Andreas Fault at a distance of 35 miles. For the Pond-Poso Creek Fault, the Applicant postulated an earthquake-of magnitude 7.0 at a location 11 miles from the site. The NRC Staff, the U&;S and the Applicant believe this magnitude is extrenely conservative, based on further reviews of fault length and echeloned con-figuration. The ACRS agrees that a maximum seismic event on this fault should lead to less than 0.45g. Questions have arisen concerning the Greeley Fault. The ACRS agrees with the position of the NRC Staff and the the U&;S that this fault is not capable.
The NRC Staff has underway a program of review and reevaluation of several generic matters related to soil-structure interaction and the appropriate response spectrum for use at foundation levels of nuclear power plants.
Canpletion of this reevaluation may result in some change in the develop-ment of the appropriate design response. The Conmittee believes this matter can be resolved prior to conpletion of the review for a construc-tion permit for use at this site.
The Comnittee believes that the San Joaquin site is acceptable uooer the guidelines of 10 CFR Part 100 with respect to the specific site-related itens noted above.
1425 Sincerely,
'1YI (J~
M. Bender Chairman
Honorable Joseph September 14, 1977
REFERENCES:
- 1. Los Angeles Department of Water and Power:
"San Joaquin Nuclear Project, Early Site Review Report" (April 1974) with Arneooments 1 through 19.
- 2. U.S. Nuclear Regulatory Cornnission:
"Limited Site Review by the Office of Nuclear Reactor Regulation for the San Joaquin Nuclear Project, Project No. 499," NUREG-0284, June 1977.
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