ML19312E060

Admits & Corrects Error in NRC 800519 Proposed Findings of Fact & Conclusions of Law on Control Bldg Mod,Stated in Footnote 34 on Page 134

ML19312E060
Person / Time
Site:	Trojan File:Portland General Electric icon.png
Issue date:	05/30/1980
From:	Gray J NRC OFFICE OF THE EXECUTIVE LEGAL DIRECTOR (OELD)
To:	Mccollom K, Mark Miller, Paxton H Atomic Safety and Licensing Board Panel
References
TAC-11299, TAC-13152, NUDOCS 8006030135
Download: ML19312E060 (3)

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May 30, 1980 Marshall E. Miller, Esq., Chainnan Dr. Kenneth A. McCollom, Dean Atomic Safety and Licensing Board Division of Engineering, U.S. Nuclear Regulatory Coninission Architecture & Technology Washington, D.C.

20555 Oklahoma State University Stillwater, Oklahoma 74074 Dr. 5 Jgh C. Paxton 1223 41st Street Los Alamos, New Mexico 87544 In the Matter of Portland General Electric Company, et al.

(Trojan Nuclear Plant)

Docket No. 50-344 (Control Building)

Gentlemen:

In the course of its review of the "NRC Staff's Proposed Finding's of Fact and Conclusions of Law on Modification to the Trojan Control Building" (Staff's Proposed Findings), filed on May 19, 1980, the Licensee discovered and brought to the Staff's attention a possible error and lack of clarity in a portion of the Staff's Proposed Findings. Specifically, the matter in question is footnote 34 on page 134 of the Staff's Proposed Findings which states:

i An additional concern with regard to displacements arises from the fact that, under certain conditions, Control J

Building displacement is necessary to develop the capa-cities required to resist the factored OBE (Staff Exh. 17A, l

pp. 28-29, As. 19H, 191). There is one elevation at the interface between the Control and Turbine Buildings where the clearance will not be changed by the proposed modifi-cations but where that clearance will only accommoda'te a factor of 9.52 times the STARDYNE calculated Control Building displacements.

However, the factor of 9.52 provides ample margin so that even with a factor of 9.52 times the STARDYNE displacements (and additional factors to account ft.r the factored OBE and uncertainties resulting in a total factor of 7.5), the necessary displacements to develop,the required capacity can take place without building contact (Staff Exh. 17A, pp. 28-29, As. 19H, 191; PGE Exh. 33, A.21; Tr. 4618-19 (Herring)).

(emphasis added) h 8006030I

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o The Licensee pointed out that the " total factor" of 7.5 in the underlined portion of footnote 34 is not identified in the record.

From the Staff's review of the record and the derivation of the " total factor," it has become clear that the " total factor" of 7.5 set forth in footnote 34 is in error and also that, while the " total factor" may be derived from evidence in the record, that " total factor" itself is not presented on the record.

Accordingly, the Staff herewith submits a correction to its proposed findings in the fonn of a corrected footnote 34 as set forth below. This revised footnote changes the " total factor,"

correcting it from 7.5 to 8.86, and explains its derivation from evidence on the record (note that a licensing board may draw conclusions by applying known engineering principles to, and making mathematical calcu-lations from, facts in the record whether or not any witness purported to attempt this exericse.

Vermont Yankee Nuclear Power Corp. (VermontYankee Nuclear Power Station), ALAB-229, 8 AEC 425, 437, rev. on other grds.,

CLI-74-40, 8 AEC 809 (1974)).

Footnote 34 on page 134 of the Staff's proposed findings filed on May 19, 1980 should be replaced with the following corrected footnote 34:

34/ An additional concern with regard to displacements arises from the fact that, under certain conditions, Control Build-ing displacement is necessary to develop the capacities required to resist the factored OBE (Staff Exh. 17A, pp. 28-29, As. 19H, 19I).

There is one elevation at the interface between the Control and Turbine Buildings where the clearance will not be changed by the proposed modifications but where that clearance will only accommodate a factor of 9.52 times the STARDYNE elastically-calculated Control Building displace-ments (PGE Exh. 33, A.21, p. 1 of 2; Staff Exh. 17A, p. 29, A.19I).

The Turbine Building displacement at this point is 2.4 inches and the available gap between the Control and Turbine Buildings is 3.0 inches (Tr. 4618 (Herring)).

This leaves a reduced gap into which the Control Building can deflect of 3.0 - 2.4 or 0.6 inches. Since this space can accommodate 9.52 times the STARDYNE calculated displace-ment for the Control Building (PGE Exh. 33, A.21, p. 1 of 2; Staff Exh. 17A, p. 29, A.191), such STARDYNE calculated displacement at this point is 0.6

= 0.063 inches.

9.52 The actual Complex displacement at this point (in contrast to the STARDYNE elastically-calculated displacement) under factored OBE conditions and accounting for uncertainties and stiffness degradation is 0.41 inches (Tr. 4618 (Herring)).

Combining this with the Turbine Building displacement of 2.4 inches gives a combined displacement for the Control and Turbine Buildings for a factored OBE of 2.81 inches.

Under Technical Specification 5.7.2.2(c) (PGE Exh. 33, Atth. 21-1), which will be imposed as a condition of the modifications (see paragraph 263 infra), changes to the

facility after completion of the Control Building moditi-cations will be limited such that no more than a 5% increase in combined interstructure displacements between the Control and Turbine Buildings will occur. This could result in an increase in combined Control and Turbine Buildings displace-ments of 0.05 x 2.81 = 0.14 inches. Since, under Technical Specification 5.7.2.2, all of this could be displacement of the Complex, total Complex displacement at the point of minimum clearance could increase to 0.41 + 0.14 = 0.55 inches.

In addition, Technical Specification 5.7.2.2 will allow an increase in equipment weight, which is 3% of the weight of the Complex (Tr. 4619 (Herring)), of 10% (PGE Exh. 33, Atth.

21-1), resulting in an increase in Complex displacement of 0.10 x 0.03 x 0.55 or about 0.002 inches.

The Complex displacement of 0.552 inches (0.55 inches plus 0.002 inches) could be further increased by 1% to 1.01 x 0.552 or about 0.558 inches since Technical Specification 5.7.2.2(a) and (b) allow a 1% increase in lateral shear forces in the modified Complex or a 1% decrease in the lateral resistance of the modified Complex (PGE Exh. 33, Atth. 21-1).

Thus, the maximum Complex displacement for the factored OBE, accounting for stiffness degradation, uncertainties, and changes to the modified Complex permitted by Technical Specification 5.7.2.2., is 0.558 inches.

This actual ultimate displacement is a factor of 0.558 = 8.86 0.063 times the STARDYNE elastically-calculated displacements at this point.

Since a factor of 9.52 times the STARDYNE calcu-lated displacement is available (Staff Exh.17A, p. 29, A.19I),

the necessary displacement of the Complex to develop the required capacity can take place without building contact.

(Staff Exh. 17A, pp. 28-29, As. 19H, 19I; PGE Exh. 33, A.21,

p. 1 of 2).

The Staff respectfully requests that its Proposed Findings be considered corrected in accordance with the above.

Sincerely, f

.t.o J sep R.Graf ou 'el for NRC St ff cc: Service List e

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