ML20024C076

Testimony of Tl King on ASLB Question 14 Re Operation W/ Leaking Fuel Pins.Sodium Entry Into Fuel Pin May Cause Increased pellet-to-clad Gap Conductance,But Would Not Adversely Affect Fuel Performance.Prof Qualifications Encl

ML20024C076
Person / Time
Site:	Clinch River
Issue date:	07/08/1983
From:	King T Office of Nuclear Reactor Regulation
To:
Shared Package
ML20024C019	List: ML20024C022 ML20024C024 ML20024C038 ML20024C043 ML20024C050 ML20024C062 ML20024C076
References
NUDOCS 8307120232
Download: ML20024C076 (4)

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UNITED STATES OF AMERICA NUCLEAR REGULATORY COPNISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of ll l

UNITEDSTATESDEPARTMENTOFENERGYl>l Docket No. 50-537 PROJECT MANAGEMENT CORPORATION TENNE 3SEE VALLEY AUTHORITY ll

.I (Clinch River Breeder Reactor ll Plant)

,1 NRC STAFF TESTIMONY OF THOMAS L. KING ON BOARD QUESTION 14, CONCERNING OPERATION WITH LEAKING FUEL PINS Q1. Mr. King, please state your name, by whom are you employed, and the nature of your responsibilities regarding the Clinch River Breeder Reactor ("CRBR")?

A1. My name is Thomas L. King.

I am employed by the U.S. Nuclear Regu-latory Commission as Chief of the Technical Review Branch, Clinch River Breeder Reactor Program Office, in the Office of Nuclear Reactor Regulation.

I am responsible for direction of the Technical Review Branch's review of the fast sodium-cooled-related aspects of the CRBR safety review.

Q2. Have you prepared a statement of professional qualifications?

A2. Yes. A copy of my statement is attached to this testimony.

Q3. What is the purpose of your testimony?

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A3. My testimony addresses the concern raised by the Atomic Safety and LicensingBoard(" Board")inBoardQuestion14,whichstatesas follows:

Operation with leaking fuel pins could conceivably offer the opportunity for these ains to " inhale" some amount of sodium whenever t1e reactor is shut down. Should this occur, subsequent return to operation at power might then result in a signifi-cant increase in pellet-to-cladding gap conductance with an attendant off-nornal performance of the fuel.

The Staff is requested to comment upon whether it sees this as a problem requiring resolution and the reasons for its answer.

Q4. Has the Staff considered operation of CRBR with leaking fuel pins?

A4. Yes. The results of our review are discussed in the CRBR Safety EvaluationReport("SER"),NUREG-0968,Section 4.2.1.3.2.6 (pgs. 4-20 and4-21).

Q5. Would sodium entry into a fuel pin result in increased pellet-to-clad gap conductance with subsequent off-normal performance of the fuel?

A5. Sodium in contact with fuel inside a pin would may result in increased pellet-to-clad gap conductance, depending upon the degree of gap closure. However, it is the Staff's judgment that if increased conductance between fuel and cladding results, it would not adversely affect fuel performance, for the following reasons. First, an increased conductance would reduce the potential for fuel melting by reducing the stored energy in the fuel. Secondly, an increased conductance would result in faster transfer of stored fuel energy to the coolant in a transient event. This could lead to a mildly

. a adverse effect on the peak coolant temperature within the fuel assembly during such an event, but would not be of practical conse-quence unless the major portion of an assembly were so affected.

However, even if the major portion of an assembly was affected by sodium entry into fuel pins, fuel performance would not be adversely affected by increased gap conductance.

Q6. Are there other concerns regarding sodium entry into a fuel pin?

A6. The Staff's primary concern with regard to sodium ingress to the pin is the reaction between sodium and the fuel, the reaction product being less dense than the fuel and causing local swelling with the potential for flow restriction. This concern is discussed in the CRBR SER, Section 4.2.1.3.2.6.

The Staff has determined that restrictions on CRBR operation should be imposed upon the detection of fuel failure, which would require removal of the fuel assembly containing the failed pins at the next reactor shutdown 6e at the exceeding of a predetermined delayed neutron signal, whichever i

occursfirst(seepgs.4-20and4-46oftheCRBRSER). These restric-tions should minimize the potential for operation after the ingress

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of sodium. Tests are currently being ccnducted at EBR-II to evaluate operation with failed fuel; if data from these tests indicate that these restrictions should be changed, appropriate changes will be considered by the Staff.

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Thomas L. King PROFESSIONAL QUALIFICATIONS I am presently Chief, Technical Review Branch in the CRBR Program Office, Office of Nuclear Reactor Regulation, U.S. Nuclear Regulatory Commission.

In this capacity, I am responsible for the direction of the Branch's Review of those aspects of CRBRP related to a fast, sodium cooled reactor. This includes direction of the Branch's review of CRBRP sodium systems, fuel handling systems, CDA analysis, support systems, reliability program, safety criteria and analysis.

I received a Bachelor of Science degree in Mechanical Engineering from Drexc1 University.

I also received a Master of Science degree in Mechanical Engineering from Stanford University.

I have over fourteen years of professional experience in the nuclear field.

while I worked for the Department of Energy (DOE), I held various positions in the Division of Reactor Research and Technology. These included positions as a Reactor and Nuclear Engineer in the Core Design Branch, the Liquid Metal Systems Branch, and the Components Branch where I worked on the FFTF Project, the EBR-2 project and Facilities at the Engineering Technology Center in Santa Susana, California.

In 1975 I was assigneo to the DOE FFTF Project Office in Richland, Washington where I held positions as a Reactor Engineer in the Operational & Experimental Safety Division and Branch Chief for FFTF Engineering until April 1982 at which time I joined the NRC as a Reactor Engineer.

List of Publications 1)

"FFTF Reactor Characterization Program" T. L. King (DOE) & J. Rawlins (HEDL)

ANS invited paper - 1981 Winter Meeting - San Francisco l

2)

" Reactor and Plant Performance During FFTF Nuclear Startup" T. L. King & C. E. Moore - DOE Ans Topical Meeting - September 1981 - Newport} RI (Technical Basis for Nuclear Fuel Cycle Policy t>. -

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