ML20206J552
| ML20206J552 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 06/23/1986 |
| From: | Bechhoefer C Atomic Safety and Licensing Board Panel |
| To: | HOUSTON LIGHTING & POWER CO., NRC OFFICE OF THE EXECUTIVE LEGAL DIRECTOR (OELD) |
| References | |
| CON-#286-706 OL, NUDOCS 8606270195 | |
| Download: ML20206J552 (5) | |
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s UNITED STATES OF AMERICA (U
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NUCLEAR REGULATORY COMMISSION ATCMIC SAFETY AND LICENSING BOARD A C N 9~
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l Before Administrative Judges
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Charles Bechhoefer, Chairman Dr. James C. Lamb 1
Frederick J. Shon WED JUEffes
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In the Matter of
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Docket Nos. STN 50-498 OL
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STN 50-499 OL HOUSTON LIGHTING AND
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(South Texas Project Units 1 and 2)
June 23, 1986 MEMORANDUM AND GRDER (Board Ouestions Concerning Design of Nonconformi'ng Structures to' Withstand Hurricanes and Tornados)
In our Partial Initial Decision dated June 13,1986(LBP-86-15),we declined to grant summary disposition of Contention 4 (design of safety structures to withstand hurricanes) insofar as it dealt with the design to withstand hurricane-generated missiles of three structures or portions thereof--(1) the Isolation Valve Cubicle (IVC) roof area; (2) certain Mechanical Electrical Auxiliary Building (MEAB) HVAC openings; and (3) certain diesel generator exhaust stack openings (hereinafter collectively referred to as nonconforming structures). Under normal circumstances, these structures must be designed to provide adequate protection for various types of safety-related equipment (hereinafter collectively referred to as protected equipment). We stated that we would issue certain questions to the parties; and that, after responses l
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2 were received, we would evaluate whether summary disposition might then be granted or whether further hearings may be required.
Following are questions directed to both the Applicants and NRC Staff. Where applicable, each party should respond on the basis of the probability calculations for which it has previously submitted affidavits.
1.
Define the particular MEAB HVAC openings which have been identified as not designed to withstand tornado-or hurricane-generated missiles.
2.
Define the particular diesel generator exhaust stack openings which have been identified as not designed to withsta.nd tornado-or hurricane-generated missiles.
3.
Define the protected equipment which each nonconforming structure would normally protect.
4.
For each of the ncnconforming structures, what are the externally generated missiles (or the spectrum of missiles) used by the Applicants or Staff to determine the probability of a tornado-or hurricane-missile strike?
5.
For these nonconforming structures, how were the above-specified missiles factored into the probability figures set forth by the Applicants and Staff, respectively? Provide details as to particular types of missiles, velocities assumed, definition of and probabilities for storms utilized and the rationale for any limits applicable to any facets of the probability calculations.
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6.
Are there externally generated missiles other than those listed in response to question 4 that could conceivably strike any of the nonconforming structures or protected equipment during a tornado or hurricane? If so, specify what missiles, or range of missiles, could strike any or all of the nonconforming structures and/or protected equipment.
7.
What damage, if any, might be foreseen to result to nonconforming structures or protected equipment if any of the missiles identified in response to questions 4 and 6 were to strike any of the nonconforming structures or protected equipment? If differing degrees of damage are dependent upon the type of missile, please explain.
8.
State the combined probability of any of the missiles identified in response to questions 4 and 6 striking each of the nonconforming structures or the equipment protected by each in the event of a hurricane and/or tornado.
9.
In his affidavit dated March 11, 1986, Mr. R. Bruce Linderman states that Category I structures (with a specified exception) have been designed to withstand a spectrum of missiles that is said to envelope missiles which could be generated from non-Category I structures (Linderman Aff., 5 22). Are any or all of such missiles included in the category of missiles set forth in response to either question 4 or 6 above? Have any or all been included in calculating the probabilities of missile strike set forth by the Applicants or Staff, respectively?
a.
If either answer is affirmative, please explain the trechanism by which such missiles were included (i.e., the particular
4 missiles, the velocities assumed, and the manner in which probabilities were determined).
b.
If either answer is negative, please explain.
- 10. State whether any or all of the nonconforming structures or protected equipment have been designed to withstand any of the missiles identified in response to questions 4, 6 and 9.
Please provide explanations as to how, and the degree to which, the nonconforming structures or protected equipment are protected against missiles, if that be the case. For structures which provide no effective protection against missiles (eg., the open IVC roof area), explain what additional protection, if any, is currently proposed to protect. safety related equipment or components located within the nonconforming structures.
Please provide details concerning any such protection.
- 11. Assuming a strike of an external missile on any of the nonconforming structures or protected equipment, what is the probability of a release of radiation in excess of-the limits in 10 C.F.R. Part 100?
Provide answers for each nonconforming structure, item of protected equipment and, as applicable, for different types of missiles.
- 12. What is the feasibility of providing missile protection, as required by General Design Criterion 4, for each of the nonconforming structures or protected equipment? Explain which type (s) of protection (eg., barriers conforming to the standards of SRP, 9 3.5.3 (NUREG-0800)), if any, are feasible for each nonconforming structure or item of protected equipment. Also specify which type is the least costly (or the type which, if required, would be preferred by the
5 Applicants or Staff to be installed). Provide a full explanation why the chosen alternative would be preferable to others which may be available.
The Applicants and Staff are directed to answer the foregoing questions under affidavit by July 14, 1986. Other parties may do so (or 4
provide comments) if they wish.
If the Applicants and Staff were to agree and advise us that their positions could better be presented at an evidentiary hearing, we would be prepared to schedule such a hearing at an early date.
If the Applicants or Staff need more time to respond, we would be prepared to grant extensions of time, but we prefer simultaneous filings by all parties on these questions.
If we were to determine, on the basis of the Applicants' and Staff's responses, that summary disposition of the remaining design aspects of Contention 4 appears to be warranted, we will provide parties an opportunity to comment on thosE responses or to submit further information bearing on whether a grant of sammary disposition would be warranted. Cf. 10 C.F.R. 5 2.749(a).
FOR THE ATOMIC SAFETY AND LICENSING BOARD 8o Rl{luw j
Charles Bechhoefer, Chairman ADMINISTRATIVE JUDGE Dated at Bethesda, Maryland this 23rd day of June, 1986.
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