ML16340C305
| ML16340C305 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 01/18/1982 |
| From: | Palladino N NRC COMMISSION (OCM) |
| To: | Panetta L HOUSE OF REP. |
| Shared Package | |
| ML16340C306 | List: |
| References | |
| NUDOCS 8202110202 | |
| Download: ML16340C305 (6) | |
Text
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CHAIRMAN UNITED STATES NUCLEAR REGULATORY COiiiMISSION P D~
VitASHIMGTOM,D. C. 20555 January 18, 1982 The Honorable Leon E. Panetta United States House of Representatives Washington, D.C.
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Dear Congressman Panetta:
'We share the concerns expressed in your October 1,
1981 let the implication of the recent seismic design errors detected at t e Diablo Canyon nuclear power plant.
The implication of these errors has been and will be thoughtfully considered by the Commission.
The timing of the detection of these errors,'o soon after authorization for low-power operation, was indeed unfortunate and it is quite understandable that the Congress'nd the public's perception of our licensing process has been adversely affected.
Had this information been known to us on or prior to September 22,
- 1981, I
am sure that the facility license would not have been issued until the questions raised by these disclosures had been resolved.
8ecause of these design errorS, on November 19, 1981, we suspended Pacific Gas and Electric Company's (PGIEE} license pending satisfactory completion of the following:
1.
The conduct of an independent design review program of all safety-related activities performed prior to June 1,
1978 under all seismic-related service contracts used in the design of safety-related structures, systems and components.
2.
A technical report that fully assesses the basic cause of all design errors identified by this program, the significance of the errors found and their impact on facility design.
3.
PGSE's conclusions of the effectiveness of the design verification program in assuring the adequacy of facility design.
4.
A schedule for completing any modifications to the facility that are required as a result of the design verification program.
In addition, the Commission ordered PGLE to provide for NRC review and approval:
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A description and discussion of the corporate qualifications of the company or companies that PG&E would propose to ca'rry out the independent design verification program, including information that demonstrates the independence of these companies.
2.
A detailed program plan for conducting the design verification program.
In recognition of the need to assure the credibility of the design verification program, NRC will decide on the acceptability of the companies proposed by PG&E to conduct this program after providing the Governor of California and Joint Intervenors in the pending operating licensing proceeding 15 days for comment.
Also, the NRC will decide on the acceptability of the plan proposed by PG&E to conduct the program, after providing the Governor of California and the Joint Intervenors in the pending operating license proceeding 15 days for comment.
Prior to authorization to proceed with fuel loading, the NRC must be satisfied with the results of the seismic design verification program and with any plant modification resulting from that program that may be necessary prior to fuel loading.
The NRC may impose additional requirements prior to fuel loading necessary to protect health and safety based upon its review of the program or any. of the information provided by PG&E.
This may include some or all of the requirements specified in the letter to PG&E dated November 19, 1981.
Responses to each of the three questions in your letter are enclosed.
A decision to permit PG&E to proceed with fuel loading will not be made until all the actions contained in the Commission's November 19, 1981 Order are fully satisfied.
Sincerely,
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Nunzio J. Palla ino
Enclosures:
1.
Commission Order, dated ll/19/81
- 2. Ltr from Office of Nuclear Reactor Regulation, NRC, to PG&E dated 11/19/81 3.
Response
to guestions
RESPONSE
TO 'QUESTIONS uestion 1:
How, specifically, did this oversight occur in the licensing process?
During the licensing process, the NRC staff conducted an extensive evaluation of the seismic design of Diablo Canyon.
The primary focus of this review is on the seismic design criteria, models, analytical techniques and design methods.
The staff concluded that the'applicant's design criteria, models, analytical techniques and design methods were reasonable and would assure an adequate seismic design for the facility.
The presently known errors in the design occurred in putting correct data into the design calculation for seismic stresses.
The oversight occurred at a point'in the seismic design process that was not the subject of explicit review by the staff.
Ultimately, the responsibility for assuring and verifying the design of the facility rests with the applicant/licensee.
guestion 2:
What assurance does the public have that further discrepancies or problems do not exist in the Diablo plant?
We share your interest and concern in assuring that this occurrence is an isolated one.
Prior to authorization to proceed with fuel loading, the NRC must be satisfied with the results of the seismic design verification program required by the Commission's
- Order, and with any plant modification resulting from that program that may be necessary prior to fuel loading.
The NRC may Impose additional requirements prior to fuel loading necessary to protect health and safety based upon its review of the program or any of the informa-tion provided by PGEE pursuant to paragraph 4 of Attachment 1 to the Commission's Order.
'guestion 3:
Will the NRC now consider undertaking the full Commission review which it decided not to undertake regarding the lower board's positive decision on Diablo's low-power licensing?
The Commission has not yet decided whether it will undertake a review of the Atomic Safety and Licensing Appeal Board's decision (ALAB-644) on Diablo Canyon seismic issues.
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