ML20196A564

Provides Info Re Util Use of Four Previously Irradiated LGS, Unit 1,GE11 Assemblies in Unit 2 Cycle 6.Encl 990518 GE Ltr Provides Objective of Lead Use Assemblies Program & Outlines Kinds of Measurements That Will Be Made on Assemblies

ML20196A564
Person / Time
Site:	Limerick
Issue date:	06/15/1999
From:	Geoffrey Edwards PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9906220250
Download: ML20196A564 (4)

Text

3

( - .

4

,- l PECO NUCLEAR ee w e - c - eev ocs enesterexook souievard i

A Unit of PECO Energy Wayne, PA 19087-5691 June 15,1999 Docket No. 50-353 License No. NPF-85 U. S. Nuclear Regulatory Commission

' Attn: Document Control Desk Washington, DC 20555

{

Subject:

l Limerick Generating Station, Unit 2

{

Use of Lead Test Assemblies in Operating Cycle 6 '

Gentlemen:

The purpose of this letter is to provide Information regarding PECO Nuclear's use of four previously irradiated Limerick 1 GE11 assemblies in Limerick 2 Cycle 6 (commenced May 1999). These four assemblies have been classified as Lead Test Assemblies (LTAs).

These assemblies were irradiated for three cycles beginning with Limerick 1, Cycle 5 in July 1992, and achieved a peak bundle average exposure of approximately 52 Gigawatt-Days per Metric Ton Uranium (GWd/MTU) by the end of Cycle 7 (April 1998). It has been determined that the continued irradiation of these assemblies will cause some of the fuel pellets to exceed the licensed peak pellet exposure (PPE) limit of 70 GWd/MTU. The 70 GWd/MTU is a monitoring limit. These assemblies, however, did not use the maximum allowable Peak Pellet Power during their previous use. Therefore, General Electric Nuclear Energy (GENE) was able to recalculate a new PPE using the actual histories for these four assemblies. The new PPE, 86 GWd/MTU, will allow operation of these four assemblies without exceeding any of the original GE11 GENE licensing criteria which are protected by the PPE limit. The operating ,

limits associated with these assemblies are documented in the Limerick 2, Cycle 6 Core Operating Limits Report, which was submitted to the Nuclear Regulatory Commission (NRC) on May 20,1999.

The analysis supporting the use of these assemblies was performed by GENE using NRC-approved, standard methodologies (Reload Licensing Topical Report, " General Electric Ii Standard Application for Reactor Fuel *, NEDE 24011-P-A-13, August 1996 and 'GE11 Compliance with Amendment 22 of NEDE-24011 P-A (GESTAR ll)", NEDE-31917P, April 1991"). In addition, PECO Nuclear personnel performed an audit of the GENE analysis and are satisfied that the work was completed using existing NRC approved methodologies and that no existing licensing criteria were violated. The enclosed letter from J. A. Baumgartner (GENE) to J. M. Carmody (PECO), "GE11 Lead Use Assemblies," dated May 18,1999, provides the objective of the Lead Use Assemblies program and c:tlines the kinds of measurements that will be made on the assemblies.

d o

9906220250990I15 33 <

PDR ADOCK 05 P

in

June 15,1999 Page 2 Shonid you need additional information or have any questions regarding the information contained in this letter, please do not hesitate to contact us.

Sincerely,

'b h lf#ft Garrett D. Edwards Director- Licensing

Enclosure:

As stated cc: H. J. Miller, Administrator, Region I, USNRC A. L. Burritt, USNRC Senior Resident inspector, LGS l

l

.Q Mun-

', ~

e w

.= . uc. mr 1:wrw May 18,1999 cc: K. W. Hunt {

JAB:P99-033 J. L. McHale G. A. Potts

]

J. D. Stephen i i

Mr. J. M. Carmody Fuel & Sersices Division PECO NUCLEAR 965 Chesterbrook Boulevard Wayne, PA 19087-5691

SUBJECT:

- Gell Lead Use Assemblies

References:

1. R. E. Engel (GE) letter to T. A. Ippolito (NRC), Lead Test Assembly Licensing, August 24,1981

2. T. A. Ippolito (NRC) letter to R. E. Engel (GE), Lead Test Assembly Licensing, September 23,1981

Dear Jim:

References (1) and (2) established the simplified procedure for approving Lead Use Assemblies (LUA) in reloads. GE has accepted the provisions in Reference (2). This letter provides the objective of the LUAs, and outlines the kinds of measurements that will be made on them Four Limerick 1 Reload 4 gel 1 assemblies (YJ1432, YJ1436, YJ1437, and YJ1470) have been designated as LUAs. These LUAs have completed three cycles of operation. An examination was conducted at ~52 GWd/MTU bundle average exposure after the third cycle. The bundles are acceptable for continued operation for a fourth cycle to >60 GWd/MTU.

The objective of this LUA program is to quantitatively confirm acceptable fuel performance at the elevated exposures. To that end, it is anticipated that an examination will be conducted after discharge of the LUAs. The examination will include both detailed visual examination of the integral bundle and individual fuel rods and measurements of key indicators of bundle irradiation growth, fuel rod thermal-mechanical behavior, and corrosion. Measurements, such as length of

- the bundle and bundle components, rod-to-rod spacing within the bundle and fuel rod diameter and cladding oxide thickness along the length of the rod, will be made. These measurements will

. GJD i -

. ear ineniv JAB: P99-033 Page 2 be compared with the performance projections made with the existing design methods, and thereby' provide a validation of design methods in addition to a confirmation of acceptable performance.

Very truly yours, h_ d u

./J. A. Baumgartner {

Fuel Project Manager l I

PECO Nuclear i