ML20214L180

Requests Addl Info Re 860613 Application & 0722 Suppl.Info Needed Re Average Spacing During Double Batching & Nonconservative Aspects of Safety Analysis Re Neutron Leakage

ML20214L180
Person / Time
Site:	07000371
Issue date:	09/03/1986
From:	Bidinger G NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS)
To:	Kirk W UNC NUCLEAR INDUSTRIES
References
NUDOCS 8609090480
Download: ML20214L180 (2)

Text

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SEP 0 31986 FCUP:GHB 70-371 SNM-368 UNC Naval Products

• Division of UNC Resources Inc.

ATTN: Mr. William F. Kirk, Manager Nuclear and Industrial Safety 67 Sandy Desert Road Uncasville, Connecticut 06382 Gentlemen:

We have reviewed the June 13, 1986, application and the July 22, 1986, supplement. As a result, we require additional information to continue our review.

Proposed Item 10 of Table 3.9.5.1 has been revised to accept two types of elements on a cart. The justification in proposed Section 3.40.2, Part II, evaluates the double batch situation by decreasing the average spacing so as to use the analysis referenced in proposed Table 3.39.1.2. Proposed Table 3.39.1.2 (actually proposed Table 3.39.1.2 Part II), which is discussed below in connection with proposed Table 10.0-I, Part I, on Page 10.0-7e, is in error. Even if Table 3.39.1.2, Part II, were correct, it would be an inappro-priate reference since the cart design does not permit " average spacing" in the double batch situation. A realistic mode should be used for the double batch situation.

Concerning the proposed additions to Table 10.0-1, Part I, on Page 10.0-7e, the following comments apply:

a. The preposed S.Q. limits for item 7.a. are based en the analysis in Section 3.39, Part II. The placement of the elements for the analysis in Table 3.39.1.1 did not minimize neutron Icakage which must be done if one is attempting to calculate a maximum subcritical number of elements in a unit. For example, the cross-section area of the unit for KEN 01.D.

3.39.1.1 more nearly approximates a slab rather than a cylinder. This non-ccmervatism must be eliminated from the safety analysis.

b. The pi,v sed unlimited height for item 7.b. assumes geometry control. No such c.".rol is provided in the application and so the proposed limit is quite non-conservative. In addition, the parametric survey of k-effective as a function of separation shows two peak valves. This phenomenon is unknown in criticality safety and should be further evaluated.

0609090400 860903 PDH ADOCK 07000371 C PDR

o UNC Naval Products 2 SEP 0 31986

c. The footnote for Items 7.c - 7.e. seems to assume that the core types are identical or nearly identical. We have no basis for this comparison of core types. Please provide justification.

Upon receipt of this information, we will proceed with our review.

Sincerely.

Op6 sinal Signed By:

George H. Bidinger Uranium Process Licensing Section Uranium Fuel Licensing Branch Division of Fuel Cycle and Material Safety DISTRIBUTION:

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