1 BROOKHAVEN SCIENCE ASSOCIATES Part 851 & Vacuum Systems W.R. Casey NSLS-II Project Brookhaven National Laboratory August 12, 2008 Office of Science Accelerator Safety Workshop

2 BROOKHAVEN SCIENCE ASSOCIATES Vacuum System Design Issue Part 851 defines a vacuum system as a pressure system because of the potential for back-pressurization which invokes ASME Pressure Vessel Code, Section VIII Discussed at length at SC sponsored Accelerator Safety Workshop held 8/07 Uncertainty was expressed regarding interpretation and implementation of requirement Potential impact to design of NSLS-II and other new accelerators was noted

3 BROOKHAVEN SCIENCE ASSOCIATES Approach to Addressing Pressure System Requirements for Vacuum Systems Developed during break-out session at Accelerator Safety Workshop ORNL, BNL, ANL, LANL, TJNL, and others Prevent pressure differential greater than 15 psig through use of pressure relief devices (prevent over-pressurization if accidentally backfilled) Develop guidance that defines the design, fabrication, inspection, & test requirements for a vacuum vessel.

4 BROOKHAVEN SCIENCE ASSOCIATES Approach to Addressing Pressure System Requirements for Vacuum Systems (cont.) Form a working group to further develop this guidance. Issue guidance as an Office of Science document, most likely as an attachment to the Implementing Guidance for the DOE Accelerator Safety Order 420.2B.

5 BROOKHAVEN SCIENCE ASSOCIATES Status of Effort Working Group was formed Jan Technical issues were discussed during 6 conference calls from January to April. Six drafts of consensus standard were reviewed Final draft issued 6/17/08 Edited version issued 7/17/2008

6 BROOKHAVEN SCIENCE ASSOCIATES Members of Working Group Argonne National Laboratory Jeffrey T Collins William F Toter Brookhaven National Laboratory Robert Casey (Chair) Edwin Haas Dick Hseuh Steven Kane Edward Lessard Sushil Sharma Fermi National Accelerator Laboratory Daniel R Olis David R Pushka Oak Ridge National Laboratory Peter Ladd Stanford Accelerator Center R. Keith Jobe

7 BROOKHAVEN SCIENCE ASSOCIATES Summary of Standard Key features of standard Defines design requirements for all vacuum vessels Requires ASME code compliance for vacuum vessels subject to over pressurization > 15 psig Defines requirements for equivalent level of safety when ASME code does not apply (because of pressure range, vessel geometry, use of special materials, etc) Provides exemption for vacuum vessels with energy less than 100,000 joules or vessels with small dimensions (cross-sectional area less than 28.5 in 2 )

8 BROOKHAVEN SCIENCE ASSOCIATES Summary of Standard (cont.) Defines Authority having jurisdiction Engineering evaluation Independent design professional Pressure Safety Committee Responsible vacuum system design engineer Vacuum systems –Category I –Category II –Category III

9 BROOKHAVEN SCIENCE ASSOCIATES Summary of Standard (cont.) Defines responsibilities and qualification requirements for the responsible design engineer, independent reviewer, authority having jurisdiction, and Pressure Safety Committee Establishes requirements for Design Design review Fabrication –Welding –Inspection –Testing Pressure Relief Records

10 BROOKHAVEN SCIENCE ASSOCIATES Summary of Standard (cont.) Two Appendices Appendix A defines “ Engineering Evaluations ” Appendix B defines independent review requirements for Category III vacuum vessels

11 BROOKHAVEN SCIENCE ASSOCIATES Current Status The working group is very satisfied with its product – there was a true consensus. Definitions and requirements are being incorporated into BNL Pressure Safety requirements (other Labs are doing the same) However – we need for this standard to be recognized by the Office of Science and incorporated into the Accelerator Safety Order (or other appropriate documents)

12 BROOKHAVEN SCIENCE ASSOCIATES Next Step Review standard at break-out session Incorporate any additions, deletions, modifications to standard Identify responsibility and process for moving the document into the Office of Science Establish time line for official recognition of standard