Thermal-Hydraulic Post-Test Analysis of OECD LOFT LP–FP–2 Experiment (NUREG/IA–0049, ICSP–LP–FP–2)

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Publication Information

Date Published: April 1992

Prepared by:
J. J. Pena/Empresa Nacional del Uranio (ENUSA)
S. Enciso/Central Nuclear Valdecaballeros (C. N. Valdecaballeros)
F. Reventos/Associacion Nuclear ASCO (ANA)

Consejo de Seguridad Nuclear
Madrid, Spain

Prepared as part of:
The Agreement on Research Participation and Technical Exchange
under the International Thermal-Hydraulic Code Assessment
and Application Program (ICAP)

Office of Nuclear Regulatory Research
U.S. Nuclear Regulatory Commission
Washington, DC 20555-0001

Availability Notice


Experiment LP-FP-2 was conducted on July 9, 1985, in the Loss-of-Fluid Test (LOFT) facility located at the Idaho National Engineering Laboratory (INEL). The LP-FP-2 experiment was the final experiment in a series of eight experiments conducted under the support and direction of the objectives of the Organization for Economic Cooperation and Development (OECD). The objectives of the experiment were to obtain information on the release of fission products from fuel rods at temperatures in excess of 2100 K (3320°F), and to observe the transport of these fission products in a vapor/aerosol dominated enviroment from the primary coolant system (PCS), through a simulated low pressure injection system (LPIS) line, to a blowdown suppression tank (BST). The thermal-hydraulic conditions specified for the experiment were based on a V-sequence accident scenario. The emergency core cooling system (ECCS) injection was delayed until the specified temperature limits on the center bundle thermal shroud were reached, thereby obtaining the desired time-at-temperature condition for fission product release and transport. The reactor was then brought to a safe condition with full ECCS injection. Specially designed fission product measurements were made in the PCS, LPIS, and BST during the transient, with some measurements continuing for several weeks following the experiment. Fission products were detected at all measurement locations; however, the vast majority of the released fission product activity was contained in the PCS liquid following the experiment. In addition, it was observed that large quantities of control rod aerosol material were deposited in the lower sections of the upper plenum (near the top of the core).

This document presents the thermal-hydraulic posttest analysis of the experiment conducted at Spain by using the RELAP5/MOD2 and SCDAP/MOD1 computer codes.

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