An integrated head assembly (IHA) is equipped with the missile shield to absorb the missile energy from postulated control element drive mechanism (CEDM) missile during the dynamic event of accidental conditions. Once a CEDM nozzle breaks, reactor coolant jet discharges from the broken nozzle, then it impinges at the bottom of the CEDM, and gives a thrust force to the CEDM missile until it impacts on the missile shield. After the missile impacting on missile shield, it is necessary to evaluate the structural responses on the local area of the missile shield, as well as behaviors of overall IHA structure. The jet has been previously assumed to be a single-phase flow. However, in order to reduce excessive conservatism for the jet characteristic, the jet is assumed to be a two-phase critical flow, and accordingly Fauske slip equilibrium model is applied to estimate the jet velocity. In this paper, jet impingement models are proposed to estimate the missile velocity depending on jet expansions and size of objects. With the calculated missile velocities using the jet impingement models, the nonlinear CEDM missile impact analysis is performed to investigate structural responses of the missile shield of advanced power reactor 1400. Finally, the results show that the structural integrity of the missile shield and the IHA can be maintained due to CEDM missile impact.

1.
EPRI
, 1995, “
Advanced Light Water Reactor Utility Requirement Document (URD)
,” Vol.
II
, Chaps. 4 and 7, Rev. 07.
2.
Richard
,
C. G.
, 1968, “
Missile Generation and Protection in Light-Water-Cooled Power Reactor Plants
,” Oak Ridge National Laboratory Report No. ORNL-NSIC-22.
3.
American Nuclear Society
, 1999, “
Design Basis for Protection of Light Water Nuclear Power Plants against the Effects of Postulated Pipe Rupture
,” ANSI/ANS 58.2.
4.
Fauske
,
H. K.
, 1962, “
Contribution to the Theory of Two-Phase, One Component Critical Flow
,” Argonne National Laboratory USAEC Report No. ANL-6633.
5.
U.S. Nuclear Regulatory Commission
, 2007, “
Standard Review Plan 3.5.3, Barrier Design Procedures
,” NUREG-0800.
6.
ANSYS, Inc.
, 2005, ANSYS Manual, ANSYS Release 10.0.
7.
Robinson
,
R. A.
,
Zielenbach
,
A
, and
Lawance
,
A. A.
, 1954, “
A Survey of Strain Rate Effect for Some Common Structural Materials Used in Radioactive Material Packaging and Transferring Systems
, BMI-1954, UC-71.
8.
U.S. Nuclear Regulatory Commission
, 2007, “
Damping Values for Seismic Design of Nuclear Power Plants
,” Regulatory Guide 1.61, Rev. 01.
9.
American Institute of Steel Construction
, “
American National Standard Specification for the Design, Fabrication, and Erection of Steel Safety-Related Structures for Nuclear Facilities
,” ANSI/AISC N690-1994.
10.
ASTM Committee
, 1977, “
Standard Specification for High Strength Low-Alloy Structural Steel With 50000 psi Minimum Yield Point to 4 in. Thick
,” ANSI/ASTM A588-77a.
You do not currently have access to this content.