ML19305C339

Inservice Insp & Testing:Proposed Tech Spec Surveillance Requirements:Prestressed Concrete Reactor Vessel Internals, Draft Revision 2

ML19305C339
Person / Time
Site:	Fort Saint Vrain
Issue date:	02/27/1980
From:	PUBLIC SERVICE CO. OF COLORADO
To:
Shared Package
ML19305C332	List: ML19305C331 ML19305C333 ML19305C337 ML19305C339 ML19305C341
References
P-80034, PROC-800227-02, NUDOCS 8003260576
Download: ML19305C339 (6)

Text

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Enclosura (3 ) to P-8003& l t

FORT ST. VRAIN INSERVICE INSPECTION AND TESTING 1

PROPOSED TECHNICAL SPECIFICA' TION SURVEILLANCE REQUIREMENTS PCRV INTERF ' S l

8 003c 6063G *.:-

Draft Rev. 2 February 27, 1980

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'. 5.2-19 Draft Rsv.2'

' Specification SR 5.2.22 PGX Graphite Surveillance-PCX graphite surveillance specimens shall.be installed into-five'(5) bottom transition reflector elements of the Fort St. Vrain-core to provide a means' for assessing the condition of the PCX graphite >

support blocks during operation of the reactor. Thesa specimens (16 per

reflector element) will be installed in reflector elements as indicated in Table 1 and will be removed at subsequent refueling intervals, as indicated in Table 1, unless the progressive examination of the specimens dictate otherwise. .

Upon removal, these specimens will be subjected to examination, and compared with laboratory control specimens in evaluating oxidation rates, oxidation profiles, and general dimensional l characteristics.

The results of these tests and examinations shall be utilized to assess the condition of the PGX core support blocks in the reactor and chall also be utilized to modify, as.necessary, the planned removal of subsequent PGX surveillance specimens.

The results of these examinati s shall be submitted to the NRC staff for review. .

Basis for Specification SR 5.2.22

The PGX graphite specimens will be placed in modified coolant ,

l channels in five (5) transition reflector elements in the hottest columns of regions 22, 24, 25, 27,and 30. -The surveillance test specimens will be subjected to the primary coolant conditions as well as other reactor ,

l p'arameters that are normally seen by the PGX core support block's. Exam-ination and tests of the surveillance test specimens at regular intervals can readily be utilized to assess oxidation races, oxidation profiles, as well as general degradation of the PGX core support blocks to adequately predict the structural integrity of the core support blocks over the operating life of the reactor.

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Amendment No. 20

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1. 5.2-20 Draft R:v.2 l e

SR 5'.2.22 PGX CRAntITE SURVEILLANCE

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. TRANSITION ELEFENT ASSEMBLY WI'HIDRAWAL SCllEDULE

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Withdrawal ~ at -

• Refueling N umber *

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Pun 1 Re gion Column 7 2 25 '

3 4 30 7 6 24 6 9 22 2 17 27

• Schedule would be adjusted to remove tranuition clement assem blies at a faster rate should specimens at any withdrawal interval show .

a burnoff significantly greater than predicted.

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Draft.Rav 2 5.2-23 Specification SR 5.2.25 - Core Support Block Surveillance The top surface of the core support block for fuel regions fitted with PGX graphite specimens shall be visually examined by remote TV for indication of cracks, in particular in areas where analysis shows the highest tensile stresses exist, at the refueling shutdown when the PGX graphite spe-cimens are scheduled to be removed from the core in accordance with Technical Specification SR 5.2.22.

Basis for specification SR 5.2.25 Visual examination of the core support blocks in those regions chosen for insertion of PGX graphite specimens will .

provide additional assurance that integrity of the core support blocks does not degrade due to p'. ant operating conditions, since those regions were selected because of their higher potential for PGX graphite burnoff. Analysis shows that the highest tensile stresses occur on the top surface of the core support blocks, at the keyways and at the web between reactor coolant channels.  ;

1 Specification SR 5.2.26 - Region Cor.straint Devices Surveillance I

(NOTE: Since the region constraint devices will be permanently installed only after confirmation that they actually eliminate j core temperature fluctuations, this technical specification is submitted as a preliminary draft only.)

The region constraint devices (RCD's) shall be inspected at each refueling shutdown using the fuel handling machine from those regions being refueled as follows:

l Draft R@vo 2 l

5.2-24 l The upper core plenum- shall be visually examined by remote TV to verify that RCD's within visible-range are i'n place on top of the core.

As RCD's are removad. the fuel handling machine location coordinates and lifting force shall be monitored to verify that the RCD pins were engaged in the fuel columns and that they disengage as expecte'd.

Selected RCD's shall be visually examined in the fuel handling machine after removal to verify their structural integrity.

As RCD's are reinstalled, the fuel handling machine loca-tion coordinates shall be monitored to verify that the RCD pins have engaged in the fuel columns.

Basis for Specification SR 5.2.26 Region ccistraint devices, located on top of fuel columns of generally three adjacent fuel regions, restrain region movements in relation to one another by means of centering pins inserted in the handling hole of the upper plenum elements.

Visual examination of the upper core plenum and comparison of the as-installed /as-found RCD coordinates will assure that the RCD's remain in place and that no phenomenon is occuring which could cause them to disengage from the fuel columns.

Comparison of RCD coordinates will require correction to account for changes in fuel column height due to irradiation of graphite and coordinate changes which will occur when RCD's are removed from a different refueling penetration thar. the one from which

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they were instal 1ed.

_ Drcft Rsv 2 5.2-24a-Checking the lifting force to remove the RCD's with the fuel handling machine will provide early indications, should a phenomenon' occur over time which might eventually prevent them from moving with the fuel columns or prevent their re-moval from the reactor. Removal and reinstallation will act as go/no-go dimensional test of the region constraint devices.

Visually examining and photographing selected RCD's in the fuel handling machine will assure that there are no unacceptable deformations, loose or missing parts, or other visible defects.

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