ML19289E104
| ML19289E104 | |
| Person / Time | |
|---|---|
| Issue date: | 02/28/1979 |
| From: | Arlotto G NRC OFFICE OF STANDARDS DEVELOPMENT |
| To: | NRC OFFICE OF STANDARDS DEVELOPMENT |
| Shared Package | |
| ML19289E105 | List: |
| References | |
| RTR-REGGD-01.XXX, RTR-REGGD-1.148, RTR-REGGD-1.XXX, TASK-OS, TASK-SC-704-5 NUDOCS 7904020216 | |
| Download: ML19289E104 (2) | |
Text
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February 28, 1979 REGULATORY GUIDE DISTRIBUTION LIST (DIVISION 1)
Draft Regulatory Guide " Functional Specification for Safety-Related Valve Assemblies in Nuclear Power Plants," Division 1, Task SC 704-5, describes a method acceptable to the NRC staff for complying with those requirements of Section III, " Design Control," of Appendix B to 10 CFR Part 50 relating to the correct translation into specifications for valve assemblies whose operability must be assured.
This draft guide was initiated prior to the formulation of new procedures that seek public involvement in the early stages of development of a guide. As a result, it had progressed through the previous development process that included two NRC interoffice staff reviews, a public ACRS subcommittee meeting, and discussion at two Regulatory Requirements Review Committee meetings.
It was decided at the second Regulatory Requirements Review Committee meeting that this proposed guide should (1) be issued as a draft guide for public comment under the new proce-dures and (2) identify inconsistencies in definitions of " active" com-ponents and identify the definition the staff plans to use with this draft regula tory guide.
With reference to the provisions of Section D, " Implementation," of the guide, the NRC intends to implement this guide for all nuclear power plants, but only to those valve assemblies included in the valve opera-bility assurance program. Such valve assemblies are referred to as
" active" valves.
It is apparent that the process for defining " active" has become an evolutionary procedure based on understanding the interre-lationships between plant design and individual system safety functions.
Therefore, differing definitions of " active" appear in current and planned revisions to NRC documents.
The documents and definitions of " active" are as follows:
A.
Regulatory Guide 1.48, May 1973, " Design Limits and Loading Combina-tions for Seismic Category I Fluid System Components" Active Pumps and Valves - Components that must perform a mechanical motion during the course of accomplishing a system safety function.
B.
Standard Review Plan, Section 3.9.3, "ASME Code Class 1, 2, and 3 Components, Component c.upports, and Core Support Structures," Fa mmber 24, 1975 Subsection II.2, " Pump and Valve Operability Assurance Program" - The operation of ccrtain pumps and valves is relied upon to shut down the plant 79040202
. or mitigate the consequences of an accident. These are termed " active" pumps and valves.
C.
Proposed revision to the Standard Review Plan, Section 3.9.3 (Item Babove)
Active Pumps and Valves - A pump or valve which must perfonn a mechanical motion in order to shut down the plant or mitigate the conse-quences of a postulated event. Safety and relief valves are specifically included.
The NRC staff plans to use the definition of " active" proposed in Item C above with this guide. Therefore, we specifically solicit public com-ment, discussion, or suggested alternative definitions for " active" valve assemblies.
Si
. rely, Guy A \\rlottc, Director Divisio i of Engineering Standards Office f Standards Development