ML20024C750

Pages 53 & 54 to Testimony of Tl King & ET Rumble Re Adequacy of DBA Spectrum

ML20024C750
Person / Time
Site:	Clinch River
Issue date:	07/11/1983
From:	King T, Rumble E NRC, Office of Nuclear Reactor Regulation
To:
Shared Package
ML20024C747	List: ML20024C746 ML20024C750
References
NUDOCS 8307130215
Download: ML20024C750 (2)

Text

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licensing contributes to the Staff's conclusion than CDAs need not be included in the DBA spectrum.

Q79. How will the results of the Reliability Assurance Program be utilized by the Staff?

A79. (King, Rumble) The Staff considers the Program to be a systematic method for reviewing and enhancing the CRBR design. As such, the Staff will ensure that the results of the Program are applied in a fashion which will result in design and procedure changes to improve reliability, where such improvement is judged desirable. Based upon experience with 1.WR PRAs, these improvements are not expected to be of such a magnitude as to cause a total redesign of the safety systems since the deterministic criteria applied to the design are,

expected to result in highly reliable systems. However, certain specific improvements in design or operating procedures to enhance reliability may be identified and factored into the plant.

In any event, whatever changes are identified as necessary will be implemented.

Q80. What is required by the Staff's criteria to be in the Program?

A80.(King, Rumble) Tne Staff's criteria require that the following three elements be included in the Program:

(1) reliability information gathering; (2) feedback to design, operation, surveillance, and maintenance; and (3) traceability and auditability.

8307130215 830711 PDR ADOCK 05000

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Q81. What is reliability information gathering?

A81. (Rumble) The following activities will generate reliability information and are considered the information gathering activities for the Program:

(1) component level evaluations (2) system level evaluations (3) accident sequence level evaluations (4) common cause failure analyses (5) system interaction analyses (6) equipment testing (7) equipment qualification (8) failure evaluation Performance of the above activities in appropriate depth will ensure a thorough review of those CRBR systems and features which perform the safety functions of preventing or mitigating CDAs, and will provide sufficier.t information to identify areas for improvement in the design. Evaluation of the component, system and overall acci-dent sequence levels helps ensure that potential malfunctions at all _

levels (including human error) are examined. The common cause failure analyses help provide assurance that built-in design redundancy, diversity, independence and protective functions are not defeated by common environmental factors, common support systems, or connon initiating malfunctions. System interaction analyses help to identify system malfunctions, which may be acceptable by themselves, but which could propagate to other systems with unacceptable l

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