ML19319C562

Submits List of Identified Substantive Deficiencies in Facility Fsar.Recommends Deferring 750630 SER Due Date Pending Resolution of Issues

ML19319C562
Person / Time
Site:	Davis Besse
Issue date:	06/10/1975
From:	Maccary R Office of Nuclear Reactor Regulation
To:	Moore V US ATOMIC ENERGY COMMISSION (AEC)
References
NUDOCS 8002190998
Download: ML19319C562 (5)

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D(v "JN 10 375 V. Score, Assistant Director for Li he 'Jacer Reactors, Group 2 S

Division of Reactor Licensing DA713 OCSSC NU': LEAR PO'.7ER STATION UNIT 1 Plant Name: Davis 3 esse No. 1 Docket No.:

50-346 Responsible 3 ranch and Project Manager: Lie ~A 2-3, L. Engle Issues to be resolved During late January and February of this year, various substantive deficiencies re.aaining in the Davis Besse-1 FSAR following the Q-2 response were discussed with the applicant, and it was understood that additional asterial would be forthcening to cover each issue. Revisions 11 and 12 have been received subsequent to these discussions and have eliminated several of the identified deficiencies, but most have not been addressed. Due to the lengthy list which is attached, it is reconuended that these be brought to the attention of the applicant for resolution and that the Safety Evaluation scheduled to be prepared-by ME3 by 6/30/75 he deferred until the applicant can respond.

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' p, y g.m R. 2. Maccary, Assistant Director for Engineering Division of Technical Review cc w/cncl:

S. H. Uanauer, DRTA F. Schroeder, TR J. P. h ip,ht, T1 A. Schwencer, IL L. Engle, RL

2. J. Bosnak, T1 cc w/o encl:

A. Giambusso, 2L

'J. G. Mcdonald, MIPC Docket Files 50-346 NRR Reading File TR:MEB File hk T

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i Davis Besse 1 - Current Status of Outstanding Items Mechanical Engineering Branch i

i 1.

Refer to question 3.6.6 - Regarding postulated pipe break locations -

In discussions during January and February 1975, the need to provide the design margin against the formation of a plastic hinge for the " pipe span method" of determining pipe break locations was discussed. It was suggested at that time that Table 6.1 of Faupel " Engineering Design" could be used as an aid in the presentation of the moment which

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is required for full plasticity versus that present in the Davis Besse 1 design to demonstrate the design margin.

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2.

Refer to questions 3.6.2, 3.6.3 and 3.6.7 regarding pipe whip f

I restraint design. During the January-February 1975 discussions the j.

following inadequacies-were discussed:

(a) Dynamic amplification factors of 1.67 inside containment and 1.5 i

f outside containment were not acceptable without additional j

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i (b) The treatment of potential gap rebound amplification by stating that i'

the structure yields plastically is not acceptable since it does not I

treat.the load that does not cause plastic yielding.

l (c) Clarification of the pipe whip restraint design criteria stated in the FSAR as "20% of ultimate strain" is required. As was pointed out in earlier discussions the stated criteria may, unless 1

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clarified, be less conservative than the NRC criteria which was l

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stated as "50% of the ultimate uniform strain". The NRC criteria is 50% of the strain at the~ point of horizontal tangency to the eugineering stress-strain curve for the material. The SAR stated criteria unless qualified could refer to 20% of the ultimate strain on a true stress-true strain curve.

l (d) The use of an increase of 20% of the specified minimum yield strength is not acceptable to account for strain rate effects unless it is justified by the development of a material stress-strain curve to L

show that the strain-rate adjusted curve is not less ductile then the unadjusted curve.

3.

Section 3.10 - Amendment 12 to Section 3.10.2 of the FSAR indicates that vital appurtenances of Seismic Category I components would be qualified by " testing or by qualification." In our January 31, 1975 telephone conversation it was indicated that all such vital appurtenances should be qualified by test. The additional wording "or by qualification" should be deleted or clarified to show the correlation to previous testing.

4.

The reference to B & W Topical 10003 without inclusion of revisiens 1 and 2 to that document is not acceptable.

5.

In discussing the required revisions to Table 3-10(a) prior to revision 11, the need to cover the design criteria for class 2 and 3 component supports was pointed out.

The present revision of the table has not incorporated e

. o such requirements. These design criteria must be provided.

6.

With regard to the design criteria for ASME Class 1 components the following areas were previously discussed during the January-February period but information has not been provided:

(a) Tables 5-12 'and 5-13 covering loading conditions and stress limits for class 1 components do not presently cover class 1 valves. The material within Sections 5.2.1.6 and 5.2.1.7 is not acceptable since it is incomplete._ Valves coverage comparable to that in Tables 5-J2 and 5-13 for the other components should be provided for valves in the FSAR. In addition, Table 5-12 should be editorially i-amended to cover class 1 pumps to agree with the response to question

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5.2-8.

- (b) Provide the loading combinations and appropriate stress limits applicable to class 1 components.

Section 5.2.1.5 is not clear as to the combination of loads due so design transients with other loads and the design stress limit which was applied.

(c) Section 5.5.J.4.1 indicates that the design loadings and stress limits for class 1 component supports appears in Section 3.6.

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There should be explicit coverage for class 1 component supports provided in the FSAR which parallels the presentation of Tables 5-12 and 5-13 modified to included the appropriate loading combinations for these supports.

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(d) Page 3-151 referring to the preoperational piping test Program should be modified to include a statement which indicates that code fatigue limits appropriate to class 1 piping will be verified in addition to the. allowable stress levels.

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