ML19259D112

From kanterella
Jump to navigation Jump to search
RO 50-29/79-18:errors Discovered in Transient or Accident Analysis of Exxon Fuel Rod pre-pressurization.GAPCON-THERMAL Computer Calculations Performed.Concludes Pin Pressure Increase Permissible
ML19259D112
Person / Time
Site: Yankee Rowe
Issue date: 07/30/1979
From: Moody D
YANKEE ATOMIC ELECTRIC CO.
To: Grier B
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
RO-50-29-79-18, NUDOCS 7909100112
Download: ML19259D112 (2)


Text

s.,

yg E'_;t=

en7 346-9011 ree YANKEE ATOMIC ELECTRIC COMPANY s

20 Turrspoke Road Westborough. Massot.husetts 01.381

%xmn July 30, 1979 Mr. 5. H. Crior Director U. S. Nuclear Hagulatory Consaission Of fice of Inspect. ion and Enforceament Region 1 631 Park Avenue Xiag of.Pruem14, PA 19406 Subjects Licensas Event Report 50-29/79-18 P-=

Fuel Wad Pre-t'raseucization Error Desc He. Criers Pursuant to the requirevients of Technical Specification Section 6.9.4.a. (8) the following is x perzed am Reportable occurrence 59-29/79-18.

The occurrence involves "erroca discovered in the traumient or accident analysis or in che methods used for such an=1ysis as described in the MISR oc in the Bases for the Tech-alcal Specifications that have oc could have pen rred cemetac

,eperation in a manner less consarvative.than ammuned in the.ana-lysie."

YanW Atamic Electric Company was infor:med about a deviation in the fuel pin preamuse trona its specirted value by its fumi amanutmecure r.

Ezzon Nuclear, Inc.

The nominal value of the pin prannoce is 1251 5 peig, -huc a refined ammsuremenc oc the archieved pins abowed a preeauce of up to a ~i-value of 143.1 pois.

'Ih= pin pseanute impacts LOCI calcuir.tions in two wayuz (1) thu average fuel r==p-erature at egercating conditions may change and (2) the -11 ing and rupture response during the accident my alter.

To masene the impact, CaPCD:(-THERMAL-2 computer calculation was per-formed for che high (as-built) mand leu (design) prep-ressuricacica levels.

It da pe>edicted that at the present operating core aveerage buruup condition of 6867 WD/Mr. the as-built fuel average M P r_

ture is about 73 F (3.1%) lower than that of the design case ad the pressure ia about 1.7 pai or 0.2% highet.

It in also predicted that at the end-of-cycle conditions, the mm-built fuel ave.rmge temperature is about 111 F (-6.1%) lower than th.er of the desigu came and the presuure la about 74 pai or -6.6% lower.

Wace, it is concluded that the pin pressure increase tram ira specified value of 1251

.I 7 909100 l[

bbI_a

,,. r ;, s...

.s, Licanase Evenc Report 50-29/79-18 Ruwan Fual 1 Lad f re-Preewarization Error Fase two 5 pais shasuld have no adverse affect on.Pemi Clad Tanparacuee experienced as a resulc of a LOCA and that the plant may concinue to operate withouc adverasely impacting the health and ausfacy of the pubile.

Very truly yours, YANKEE ATOMIC ELECTRIC COMPAMT D

D.

E., N ody Manager of Operacions JKT/sec cc:

Direct.ot, Office of Inspectiett and Enforcecnenc U.

S., Nuclear Wmgulatory Commimmion Washington, n. C.

20555 Dicdctor Office of Manstement Information & Programa Cancsv1 U. S. helear Regulatory Commalmeion Washington, D. C. 20DS r\\P

' O, q fl,I. O"iu' -l b -

' 6 l

o