ML20244A652

Amend 20 to License DPR-34 to Revise Tech Specs to Install Eight Test Fuel Elements Into Reactor Core at First Refueling & to Install Graphite Surveillance Specimens Into Five Bottom Transition Reflector Elements

ML20244A652
Person / Time
Site:	Fort Saint Vrain
Issue date:	04/20/1979
From:	Speis T Office of Nuclear Reactor Regulation
To:
Shared Package
ML20244A651	List: ML20244A649 ML20244A652 ML20244A655 ML20244A659
References
NUDOCS 7905310171
Download: ML20244A652 (9)

Text

_ _ . _ _

ps - a UNITED STATES

'p - NUCLEAR REGULATORY COMMISSION

'{

'j',

.y c gf e

g g.;

WASHINGTON, D. C. 20666 T [h 7.. .

U

[' PUBLIC SERVICE COMPANY OF COLORADO 3 DOCKET NO. 50-267 I

l- -FORT ~ST. VRAIN NUCLEAR GENERATING STATION T:

b AMENDMENT-TO FACILITY OPERATING' LICENSE Amendment No. 20 License No. DPR-34 i

7 1. The Nuclear Regulatory Commission (the Commission) has found that:

1 _

4 A. The applications for amendment by Public Service Company of -

• Colorado (the licensee) dated January 9, 1978, and January 26, c; . 1979, comply with the standards and. requirements' of the Atomic

h- Energy Act of 1954, as amended (the Act) and the Commission's

. regulations set forth in 10 CFR Chapter I; B. 'The facility will operate in conformity with the application.

;- the provisions of the Act, and the regulations of the Commission;

.x

![ C. There is reasonable assurance (i) that the activities authorized

[ by this amendment can be conducted without endangering the health

i. 'and safety of the public, and (ii) that such activities will be conducted in compliance with the Commission's regulations; D. The issuance-of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E. The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied.

2. Accordingly, the license is amended by changes to the Technical Specifications'as indicated in the attachment to this license amendment, and paragraph 2.D(2) of facility Operating License No. DPR-34 is hereby amended to read as follows:

(2) Technical Specifications The Technical Specifications contained in Appendices A and B, as' revised through Amendment No. 20, are hereby incorporated in i the license. The licensee shall operate the facility in accordance 'with the Technical Specifications.

j , - , ~ .

( .

a

,, QMy

(%7 f o r5/o/7 / ,

, i i Da*Ns%w, ,.,g, ,

+

.,1 .,.. .-

g?

~

LO- LO

. ;p; k.

..gy l .!

xm, i 'J -J'l Thisilicense amendment 'is; effective.' a s of the date. of its issuance.

c

" 9 FOR THE NUCLEAR REGULATORI C0WIISSION

h' '

Ljl .

li). ,

- Dkti., m -

4,

%a .

Themis P; Speis, Chief.

ll ", Advanced Reactors Branch j.

Division of Project Management

Attachment:

~ Changes to thb<

. Technical' Specifications i:

Date.of Issuance: April 20; 1979

_r n

3.

],

a k

!o y.

j ,;-

i j  : u

'b

-j :

i.

g#

?

,h I

j

'

y=

2. . -

i

-t t

< .1 -

h

-c-

. >.:,;. i .

s,? _ __

p p p

's ()

. lc .

', ATTACHMENT-6 AMENDMENT NO. 20 TO

[ FACILITY OPERATING LICENSE DPR-34 Docket No. 50-267 Remove existing pages 6.1-3 and 6.1-4 of Technical Specifications, Appendix A, and replace them with the attached pages 6.1-3. through 6.1-6. The changed areas are reflected by marginal lines.

Also, add pages 5 2,-19 and 5 3-20, which add a new technical speci-fication.

4 ^'i.

i

,1.

1 l'

)*-

.,c I

. .e f") ' [

6.1-3 l

1 Each fuel element is.a hexagonal right prism with' nominal dimensions of 14.2 inches across the flats by 31.2 inches high. The fuel beds and coolant channels are distributed on a triangular array of about 3/4 inch pitch spacing with an ideal ratio of two fuel beds for each coolant channel. l l

The bottom of the fuel beds in the bottom fuel element of the control rod fuel column does not exceed a length of 23.1 inches from the top face of the fuel element.

Fuel The fuel consists of fissile uranium highly enriched (93.15%) in 235 U and fertile thorium. The initial fuel loading is about 773 Kg of uranium and 16,000 Kg of thorium. The initial core is loaded with 13 fuel compositions whose distribution within the core is designed to mock up the fuel content of the equilibrium cycle refueling regions and to shape the radial and axial power distribution. Fuel is designed for up to a six year life. Abput one-sixth of the core will be replaced at each refueling interval. The fuel loading in a reload segment will be about l

200 Kg of uranium and 2300 Kg of thorium.

All uranium and thorium in the reference fuel elements is in the form I

of heavy metal carbide and pyrocarbon, referred to as coated fuel particles.

The coatings form the primary fission product barrier. The coated fuel particles consist of two general types, fissile particles (TH:UC 2) and  ;

fertile (TH C2) Particles. The fissile particles shall contain thorittm and uranium in a weight ratio of about 4.25 to 1 of thorium to uranium.

l l The fsrtile particles shall contain only thorium.

Amendment No. 20 1

{\'- 6.1-4 In addition to the reference fuel elements, eight test fuel elements are included in'the reactor core. These eight' test elements (FTEl-8) contain y small quantities of' test fuel particles that are in various ways dif ferent

} rom the reference fuel. The description of the test fuel elements is contained in Table 6.1-1.

The coated fuel particles are bonded together with a carbonaceous material to form fuel rods. The' fuel rods are completely surrounded and contained by graphite which forms the structural part of the fuel element

- and, in addition to .the carbon contained within the- fuel rods, also serves as the sole moderator. The reference fudl elements are fabricated from H-327 needle' coke (anisotropic) graphite, as described in the Fort St.

Vrain FSAR, Section 3.0. 'The test fuel elements are fabricated from H-451 near-isotropic graphite in anticipation of qualifying this material for future use in all reload fuel for'the reactor.

Reflector Reflector elements above, below, and immediately adjacent to the side of the active core are hexagonal right prisms with nominal dimensions of 14.2 inches across flats and 15.6, 23.4, or 31.2 inches high, as required.

The outer peripheral envelope of the reactor core reflector graphite contains boron to minimize the neutron flux leaving the reflector. The side reflector contains nominal 2.3 weight percent boron stainless steel pins l within the spacer blocks. The middle layer of lower reflector elements, excluding the central element in each core region, contains 25 weight percent boronated graphite pellets enclosed in hastalloy-X cans. The top layer of reflector above the hexagonal columns contains 1 weight percent i

Amendment No. 20

--___-.-__-______,___.m __.

) 0 ,

. ....

- /-)

3. , ) .

[ 6.' l-5 :

p N:

crushed ' boronated graphite. , ' The top layer of reflector above the .

Permanent side re flector. blocks contains 1 weight percent boronated l

graphiteLenclosed in steel cans.

Basis for:. Specification e DF 6.1- ,

o

The above specifications form the general design bases and criteria-for the overal1 design features of the reactor core which were used to

~

<b. . evaluate ,its general perf ormance. Further details concerning these design

. features are given in Section 3.0 of the FEAR and the Safety Analysis Report for Fort St. Vrhin Reload' 1 Test ' Elements FTE-1 through FTE-8, General i

Atomic Document C1;P-5494, June 30, 1977.

Amendment No. 20

'2' C

7 ) s O s E

- 1 5 U, O S 2S e T 4 hI CI B 5 c F - TR hR I . o 7 1

( T TT C 5 r 1

p V e S c t O U U F a 6 s S E E l e) I I

M ep 8 - I c -

- E t a B E T 1 O ( O nn T F 5 S sl 2S s ei P 5 , } r -

F 4 2I ue 0I u

- CRl u hR l I B P P T ee i

7 1 UT pf TT p C 5 I I I I f r l

G '

1 C C C C eu U rc t t t t O n n n n - n R 5 1 O O l

i - 5 S 2S e e e e i T E 4 2I 0I P 5 m m m m d T - CR hR l . e e e e ed 1 F 6 1 UT TT C 4 l l l l b e 1

e e e e c an E

T r r r r ne F e e e e ii p p p p mr S t O ue T 4 s S s s s s l p N - e) I d d d d ax E E t a B o o o o e M T 1 O ( O r r r r n E F 5 S sl 2S s i s L 4 2I ue 0I u P 5 8 0 6 8 a E - CRl u hR l I . 8 5 7 8 e -

5 1 UT pf TT p C 3 3 1 r s 1 T 1

un

- S co i

1 E = t

. T 3 1 O O i 6 - 5 S 2S L E 4 2I 0 I P 5 Bd 6 O I n

- E E T - CR h R I .

S C o 1 L U F 4 1

1 UT T T C 2 B F

, I c 6

A O R  ;

S ,

T ng T N I O on I

A B S 2 ii R t O I 0 t t V 2 s S 2 R h aa

- e) I 0 T T zl E t a B ,

h / i u T

T 1 O ( O O T 2 O nm S F 5 S sl 2S s S / 0 S oi 4 2I ue 0I u P 5 I O h I b s T - CRl u hRl I . R S T R r R 3 1 UT pf TT p C 1 T I / T a ,

O 1

R O cs l' 2 T S 2 e C I 0 dl F 1 1 O O )

• R ) ob y T ri O - 5 S 2S U, 0 U, c E 4 2I 0I P 5 N T - CR h P. I h x 2 h l u O F 2 1 UT ' T I

C 0 T C C T er I

1

( U U ( uc f

T e P )

I b  : et R ( s ci C g e ah S n d l p pa E i u D r l - r u s c ng n

c r i a i - ,

d e ee e e o y l rb uu p p r e y y ,

u ct t t l e f -

e e m = n p l l u i t i y e e f t s P -

t u u e I e f f f e T C r e o c I ) u t t e e n (

" b c

(

n i l i d e e h i i o d =

m p s t h i T

g a s r t s e r i e e e I S G F F M R C

5.2-19 Specification SR 5.2.'22 PGX Graphite Surveillance

-PGX 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. These 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 nondestruc--

tive examination, and compared with laboratory control specimens in evaluating oxidation rates, oxidation profiles, and general dimensional 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 shall also be utilized to modify, as necessary, the planned removal of subsequent PGX surveillance specimens.

The results of these examinations 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 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 parameters that are normally seen by the PGX core support blocks. Exam-ination and tests of the surveillance test specimens at regular intervals can readily be utilized to assess oxidation rates, 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.  ;

i Amendment No. 20

5.2-20 SR 5.2.22. PGX GRAPHITE SURVEILLANCE Table 1 TRANSITION ELEMENT ASSEMBLY WITilDRAWAL SCHEDULE Withdrawal at Refueling Reflector Region Column Number

• 25 7 2 30 3 4 24 7 6 22 6 9 27 2 17 J

• Schedule would be adjusted to remove transition element assemblies at a faster. rate should specimens at any withdrawal interval show a burnoff significantly greater than predicted.

1' l

Amendment No. 20

, - - - - - - - -__