NATIONAL NUCLEAR SECURITY ADMINISTRATION
October 7, 2004
The Honorable John T. Conway
Defense Nuclear Facilities Safety Board
625 Indiana Avenue, N.W.
Washington, D.C. 20004
Dear Mr. Chairman:
In my May 14, 2004, letter to you, I outlined a path forward for addressing your concerns about leak path factor calculations for the Lawrence Livermore National Laboratory’s (LLNL) Plutonium Facility, Building 332. To address these concerns, the Livermore Site Office (LSO) commissioned a new leak path factor analysis for an accidental radiological release from Building 332 in the absence of electrical power.
The new leak path factor analysis has been completed and the results show leak path factors significantly higher than those contained in the draft Documented Safety Analysis (DSA) submitted by LLNL. The higher leak path factors alone do not drive the decision as to whether certain systems should be safety class or safety significant. However, LSO maintains that these new calculations, along with other concerns associated with the source term calculation in the DSA, do not support a reclassification of the Building 332 emergency power system (EPS) from safety class to safety significant. Accordingly, in the interest of defining a clear path forward to complete a rule-complaint DSA and Technical Safety Requirements (TSR) as soon as practicable, LSO has directed LLNL to revise the draft Building 332 DSA and TSR to retain Building 332 EPS and portions of other systems that preserve the active ventilation system as safety class and to submit these revisions by January 15, 2005.
Linton F. Brooks