ML18219D973

Letter Effect of High Burnup on Fission Gas Release and Impact of Increased Rod Internal Pressure on Safety Analyses

ML18219D973
Person / Time
Site:	Cook
Issue date:	12/28/1976
From:	Tillinghast J Indiana Michigan Power Co, (Formerly Indiana & Michigan Power Co)
To:	Rusche B Office of Nuclear Reactor Regulation
References
Download: ML18219D973 (9)

Text

U.S. NUCLEAR REGULATORYCOMI'ION NRC FORM 195 (2 76)

'4IRC DISTRIBUTION FoR PART 50 DOCKET MATERIAL DOCKET NUMBER FILE NUMBER Benar~

C. Rusche FROM: Indiana h Michigan Power Co.

New York, N.Y.

1000II John Tillinghast DATE OF DOCUMENT DATE RECEIVED LETTER

)/)ORIGINAL

~

- OCOPY QNOTORIZED

@]UNCLASSIFIED PROP SQNOT REMOVE ACKNOWIK>0<0 DESCRIPTION Ltr. Notoiize~ 12-28-76---Ref.

our 11-23-76 ltr. Trans The Following:

INPUT FORM

'NUMBER OF COPIES RECEIVED 2

8iglgw org, t

ENCI OSURE Ltr." i'rom Westinghouse Electric furnishing info op, Effect of high burnup on fission gas release 5'mpact of increase~

ro~

internal pressure on safety analyses...

COOK UNIT g 1 SAFETY

--- ASSIGNED AD:

FOR ACTION/INFORMATION cm 3.

R C

'MA E

'L C ASST

. PROJECT MANAGER>>

LIC ASST

- J3?G 3FILE.

NRC'PDR--

I &E OELD-GOSSICK & STAFF MIPC HA'RLESS PROJECT MANAGEMENT BOYD P,

COLLINS HOUSTON PETERSON MELTZ HELTEMES SKOVHOLT LPDR St Jose h M X TIC:

NSIC:

ASLB:

AC RS CYS lQiQsMWS/

INTERNALDI

.- -SYSTEMS-SAFETY

- HEINEMAN.

SCHROEDER

. ENGINEERING

','CARR KNIGHT SIHWEIL PAWL CK REACTOR SAFE ROSS NOVAK

.ROSZTOCZY CHECK AT & I SALTZMAN RUTBERG EXTERNALDISTRIBUTION NAT LAB REG V IE LA PDR CONSULTANTS.

ST Rl BUTION PLANT SYSTEMS TEDESCO-N IPPOLI 0 OPERATING REACTORS STELLO OPERATING -TECH EISENHUT B

E ULR KSON OR S

SA ERNST tv...,~

BALLARD SPANGLER

--""" ~ ~

SITE TECH GAMMILL STEPP HULMAN SITE ANALYSIS VOLLMER BUNCH J

COLLINS KREGER CONTROL NUMBER 13132 ps~ g NRC FORM 196 {2 76)

f; 0

t 0 p

0 CRStto StsttO 6~g Ot(uhtSStatt ucRSAR RS~

Nett ~'ee

'6 p

~ NDIANA IL MICHIGAN POWER COMPANY P. O. BOX 18 BOWLING GREEN STATION NEW YORK, N. Y. 10004 geguiatOry DOCket File December 28',

1976 Donald C. Cook Nuclear Plant Unit No.

1 Docket. No. 50-315 DPR No.

58 Mr. Benard C. Rusche, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C.

20555

~<8 G~0 p.+ ~Q W+ASS

%44, sS,Si CO+S Sss CP

Dear Mr. Rusche:

In Mr. Dennis L. Ziemann's letter of November 23,

1976, which we received on November 29,

1976, he requested further information regarding the effect, of high burnup on fission gas release and the impact of increased rod internal pressure on the safety analyses.

We transmitted that letter to Westinghouse Electric Corporation, asking that. they reply promptly to us for your category of plants that will reach peak local fuel rod burnups of 20,000 Megawatt-days per metric ton of Uranium prior to June 1, 1977.

We estimate that this burnup was achieved at the Donald C. Cook Nuclear Plant Unit 1 during the first wee'k of December, 1976.

'IIlit The attached letter from Westinghouse Electric Corporation, in response to our request, indicates that it is their belief that Westinghouse letter NS-CE-1302 (C. Eicheldinger to Dr. Denwood F. Ross of NRC) satisfied the staff's needs in this matter.

A copy of NS-CE-1302 is also attached hereto.

Very truly yours,

(

pr fat

(

lSworn and subscribed to before me

,this A~+day of December 1976 in New York County, Ne York n

3nn s

Vice Presiden Notary Public DAVIDG.

ME NOTARY PU8LIC, State of New York

. 31460S113 Quelified in New York County Commission Expires Merch 30, 1977

.13.l.3Z

~ 4

~

P l

Nr. B. C. Rusche December 28, 1976 JT:mam Attachment cc:

G. Charnoff R. C. Callen R. J. Vollen P.

W. Steketee R. Walsh R. S. Hunter R.

W. Jurgensen Bridgman

Ci

'l

s~

s

..r/

pe~.'jOI;So~reofrt".COrI.era!ion

'S-CE-130(-

December 2, 1976 Huctca'FrJ D;i:-e Box3'.5,

'I PitrstarghPa.~~ytaha 152Ã Ref.:

Letter D. Ross (NRC) to C. Eicheldinger (1 )

Dated ljovember 23, 197=

Dr,. Denwood F. Ross, Jr.

Assistant Director for React'or Sa'fety Division of Systems Safety Office of Nuclear Reactor Regulation U. S; Nuclear Regulatory.

Commission

. l!ashington, D. C.

20555

Dear Dr. Ross:

As.indicated in the referenced letter, Hestinghouse has had several meetings (1,2) with your staff on the effect of high. burnup on fission gas release and.the impact of increased rod internal pressure on. safety analyses.

1!e l>ave already advised the Staff<3>4i5) of the results of detailed calculations perforired with a fuel rod behavior model which recognized the increased fission. gas rel ase....

These analyses demonstrated that fuel rod inter,nal pressure will not exceed system pressure in any Hastinghouse-designed fuel prior to llarch of 1977;

Further, we have recently provided a detailed'safety analysis(~) of limiting accidents which demonstrai:es that for, the lrighest rated Hestinghouse fue',

with high initial pre-pressurizaiion increased fission gas release will not have a s'ignificant adverse impact on accident consequences.

at any time in design life.

He have requested timely revierv of these analyses by your staff:

In. prior discussions with your Staff, Hestinahouse has pointed out that it.=is inappropriate to attempt to "correct" a fuel design model by simply modify',ng'ne portion of the model.

Because of feedback effects of fission gas release on such things as. cladding cr

. p ana,fuel ter,perature, an incorrect res;rl-'ill be obtairred.

!!e-also emphasized that a very extensive eftort lras gone into our overall model revision to account for recent data and high burnup effects on helium solubility and fuel swelling and densification as well as fission gas release.

Use of approxirvate correction factors to the previous design model cannot, result in a predictive capability which is comparable to our revised model.

Thus, t!estinghouse

araued, and the Staff aareed, that the suggested NRC stopgap rmeasure should not be used to assess the fission gas release for l!estinghouse fuel.

2.

C

<Mestinghouse believes that the.submittals already made to the flRC satisfy the 'needs for llestinghouse custom rs outlined in your letter.

Since l/estinghouse has experimental data and an analytical capability to deal with increased fission gas release thore is no need to utilize the JlRC

.equation.

It follows, therefore, that the date at which the fuel reaches

-~'

a'n exposure of 20,000 h! 0/TU (item "a" of you> letter) is of ro consequence

, since, the specified burnup merely. serves to trigger. the*use of the Staff ls correction fartor if the vendor does not have a better modeling capability'han that provided by the Staff model.

The meetings with your Staff and our recently-supplied safety analyses have discussed our most limiting fuel conditions of power, burnup and pre-pressurization.'herefore, our customers actual fuel conditions are bound=d by these analyses.

Consistent ivith your statement that 'such bounding calcu-lations are acceptable, we will advise each. of our customers to reference

~

this'letter. to satisfy your request (it ms b, c, and d).

Hhile these submittals are fully responsive to the Staff's request

and, therefore, th need to employ the recommended flRC correction factor does not arise, k~estinghouse believes it appropriate to re-emphasize our concern with two aspects of the Staff request.

First, the error implicit in using a correction factor to only one portion of a fuel behavior model deserves re-emphasis.

He have examined the proposed correction factor and have concluded that it leads to large predictive errors, particularly for fuel irradiated to high burnup at low temperatures.

Under these conditions, errors of a factor of 5 have been noted.

J Of even greater concern than the possib',o tcchnical inadequacies of the--

NRC's suggested correction factor is the perception that the Staff is. o'ce

. again adopting the role'f primary model developer for the industry rather than modeling solely for'the purpose of regula 'ory review.

Specifically,

.'the data ised by the Staff was publicly 'available to each of tl e vendors-

and could have been used by them,-in conjunction with.other data they.may have had, to develop. i,ndividual technical positions.

In addition to any regulatory delay which may ha~~e.b en associa.ed with the Staff waiting to develop an 'internal position prior to issue

'of= the referenced lett'er, the Staff's action has discouraged the other vendors from performing an

'in-depth.evaluation of their fission gas. rel.ease models by providing an "acceptable" correction factor.

hestinghouse strop< ly urges the staff to reconsider the appropriateness of repeated acti'ons'lo.~)

which have the ef

-

of obviating the need for individual vendor experimental and analytical ef=orts.

Very truly yours,

~..~~'~r.,~sr.. r~

C. Eicheldinger, t1anager

"'uclear Safety Department

/cls

Additional Peferences 0

r Hestinghouse/NRC heeting - September 16, 1976 2.

llestinghouse/NRC Heeting - November 4, 1976..

3.

Letter C. Eicheldinger (H) to J. Stolz (NRC)

. NS-CE-1148, August, 2, 1976, Revised Fuel Rod Internal= Pressure Design Basis

\\

4.

Letter. C. Eicheldinger

(!.') to J. Stolz (NRC)

~

NS-CE-1262, November 2, '1976, Improved Analytical Models Used in Hestinghouse Fuel Rod Design Computations

'I 5;

Letter C. Eicheldinger (ll) to D. Ross (HRC)

NS'CE-1290, November 24, 1976, Safety Analysis for.

the Revised Fuel Rod Internal Pressure Design Basis 6.

Letter D. Ross (HRC) to C. Eicheldinger (ll)

September 15,

1976, Fuelograms for L'HR Fuels 7.

NUREG-0085, Th Analysis of Fuel Densification l

r