A method of determining enclosure pressure in the event of a reactor rupture is presented and a sample calculation is shown. This method was used in calculating the design pressure of the Dresden Nuclear Power Station enclosure.

The work described in this report represents progress toward an agreement signed by the United States and the European Atomic Energy Community which provides a basis for cooperation in programs for the advancement of peaceful applications of atomic energy.

GE is amending its application of 6/5/57 to construct and operate the Nuclear Test Reactor in order to incorporate changes in procedure and equipment.

A digital computer program, FORE, which calculates transients for a fast reactor, has been coded for the TRANSAC 2000 computer. Its purpose is to provide understanding of the dynamics of fast reactors with particular emphasis on large ceramic-fueled fast reactors. The program calculates reactor power and temperatures of fuel, coolant, clad, and structure.

This report is a supplement to GEAP-3759, Plastic Strain In Thin Fuel Element Cladding Due to UO2 Thermal Expansion. Cladding growth results are reported for repetitively irradiated, UO2 pellet-filled, annular capsules: for two UO2 powder-filled, annular capsules: and for six solid cylindrical pellet-filled capsules. Dimensional changes of the capsules irradiated during the entire program were analyzed, and the relationship of these results to the over-all fuel development program were evaluated.

This report summarizes progress on investigation into improving the technological limits of boiling water reactors, Vallecitos Boiling Water Reactor and other facilities.

The Big Rock Point Reactor of the Consumers Power Company went critical for the first time on September 27, 1962. Summarized here are objectives and accomplishments of the pre-operational period as well as an indication of work scope remaining.

Development of nuclear reactor cores having high power density, long fuel life, and low fabrication costs is the objective of this program sponsored by the AEC. It will be achieved by extensive development and testing carried out in conjunction with the design, construction and operation of the Big Rock Point plant of the Consumers Power Company in Michigan. This second quarterly report describes the progress achieved from July through September 1960.

The Fuel Cycle Program is an integrated program of investigation in the Vallecitos Boiling Water Reactor (VBWR) and other facilities to improve the technological limits of boiling water reactors.

Methods for analyzing chemical impurities in sodium metal samples are presented. Chemical analysis was used to determine the following impurities: Calcium, Carbon, Chromium, Iron, Lithium, Nickel, Oxygen, Potassium, and Zirconium. Spectrographic analysis was used to determine many other impurities. Sodium samples obtained from experimental apparatus operated as part of the work being conducted for Atomics International were analyzed by these methods.

Experimental results on the effect of periodic acceleration on a natural circulation, 1000 psia, two-phase flow loop are presented, and related to the topic of marine reactor design. The initial results of this work were given previously in GEAP 3397.

Work has continued on the development of accurate nuclear fuel burnup analysis. Work performed by the third quarter of 1962 is summarized.

Three thin-wall stainless steel fuel specimens made using fabrication processes and materials similar to the Consumers Big Rock Plant research and development fuel rods were power cycled 3000 times between 500,000 and 75,000 BTU/hr-ft2 in the General Electric Test Reactor (GETR) Trail Cable facility. The fuel specimens were exposed to 1000 psi boiling water. All of the fuel specimens withstood the test without failing or without any significant changes in the clad characteristics.

The primary purpose of this joint USAEC-Euratom program is to obtain a better understanding if the maximum achievable operating characteristics of UO2 as a reactor fuel. During the program work will be performed in two areas that have been of concern to reactor core designers for a long time, namely fission gas release and central melting in fuel rods.

Work performed during the quarter is summarized by; direct measurement of fission gas pressure, loop operations, performance of UO2 fuel, UO2 grain growth and melting studies.