ML20076E695

Application to Amend License DPR-28,consisting of Proposed Change 107,revising Tech Spec Figure 3.6.1 Re Reactor Vessel Pressure Temp Limitations to Permit Reactor Operation to Power Output of 1.330E8 Mwh(T)

ML20076E695
Person / Time
Site:	Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date:	05/26/1983
From:	Heider L VERMONT YANKEE NUCLEAR POWER CORP.
To:	Eisenhut D Office of Nuclear Reactor Regulation
Shared Package
ML20076E697	List: ML20076E695 ML20076E700
References
FVY-83-45, NUDOCS 8306010246
Download: ML20076E695 (4)

Text

.

VERMONT YANKEE NUCLEAR POWER CORPORATION PROPOSED CHANGE NO. 107

. RD 5, Box 169 Ferry Road, Brattleboro, VT 05301 7, x

y May 26, 1983 ENGINEERING OFFICE 1671 WORCESTER ROAD

+ FRAMINGHAM, MASSACHUSETTS 01701

• TELEPHONE 617-872-8100 United States Nuclear Regulatory Commission FVY 83-45 Washington, D. C. 20555 2. 2C. 1 Attention: Office of Nuclear Reactor Regulation Mr. Darrell G. Eisenhut, Director Division of Licensing Reference s: (a) License No. DPR-28 (Docket No. 50-271)

(b) SIL No. 14, Supplement 1, " Reactor Pressure Vessel Surveillance Program", General Electric Company, dated June 9, 1980 (c) Figure 4.2.3, " Change in NDTT Versus Neutron Exposure, VYNPS Final Safety Analysis Report", dated July 1982 (d) General Electric Company Licensing Topical Report NEDO-21778-A, " Transient Pressure Rises Affecting Fracture Toughness Requirements for Boiling Water Reactors", dated December 1978

Subject:

Reactor Vessel Pressure Temperature Curves

Dear Sir:

Pursuant to Section 50.59 of the Commission's Rules and Regulations, Vermont Yankee Nuclear Power Corporation hereby proposes the following modifications to Appendix A of the Operating License.

PROPOSED CHANGE A change is proposed to page 111, Figure 3.6.1, " Reactor Vessel Pressure Temperature Limit ations for Operation Through 1.15E8 MWH(t)", f the Vermont Yankee Technical Specifications. The change, included as an enclosure to this letter, depicts the revised allowable heatup curves for reactor operation through a power output of 1.330E8 MWH(t ). Because 10CFR50, Appendix G is currently undergoing revision and approval is anticipated in the near future, a second version of Figure 3.6.1 is attached. This figure incorporates the requirements of the proposed revision to Appendix G and is labeled accordingly. Revised bases page 117 is also provided to reflect this change.

REASON FOR CdANGE This change will permit the continued operation of Vermont Yankee to a power output of 1.330E8 MWH(t). Upon the issuance of the next revision to Appendix G to 10CFR50, approval of the curves marked " Adjusted Per Revised 10CFR50, Appendix G," will allow the use of nuclear heat at lower temperatures. The lower criticality temperature will decrease both vessel heatup start time during start up and heatup time to reach the temperature 8306010246 830526 AD Cb PDR ADOCK 05000271 b d 0%I fSB P PDR g* nsfy OCpo9' tas%q D G

3 I$Oq $.

) o$f

United States Nuclear Regulatory Commission May 26, 1933 Attention: Mr. Darrell G. Eisenhut Page 2 needed for operational hydrostatic leak tests, thereby improving plant availability.

BASIS FOR CHANGE This change adjusts the curves of the attached Figure 3.6.1 to compensate for the ef fects of increased neutron exposure to permit operation to a power of 1.330E8 MWH(t). This adjustment is necessary because existing curves are limited to a power output of 1.15E8 MWH(t); a value which will be reached during January,1984 Neutron fluence calculations for determination of RTNDT shift are based on a "K value" from Reference (b). This value is:

K=

1000 MWD (t)

The RTNDT shif t numbers utilized are based on FSAR curves, Reference (c).

The FSAR curves are more conservative than those curves included in Regulatory Guide 1.99, as the Regulatory Guide 1.99 curves are not applicable to the low fluences (less than 3.0E17n/CM2 ) which will be seen by the Vermont Yankee reactor vessel.

The Second Figure 3.6.1, marked, " Adjusted Per Revised 10CFR50, Appendix G", depicts lower criticality limits to allow heatup with nuclear heat. Approval of this Figure is requested upon issuance of the pending revision to 10CFR50, Appendix G. Based on Reference (d), the Appendix G Revision is the result of a conclusion which states that the probability of a reactor solid preesure transient concurrent with a control rod drop accident, is sufficiently low such that current vessel pressure / temperature criticality limits may be lowered to allow heatup with nuclear heat.

SAFETY CONSIDERATIONS The curves to accommodate a higher output limit are based on a neutron fluence determination factor contained in Reference (b). This value is more conservative (higher) than originally calculated values for Vermont Yankee by a factor of 4.3. Additionally, the ultimate RTNDT shift values were derived f rom FSAR curves which are more conservative than these curves contained in Regulatory Guide 1.99. Fluence values seen by the reactor vessel at a power output of 1.330E8 MWH(t) are below the range of Regulatory Guide 1.99 applicability.

The lowered criticality temperature limit (second figure) is based on the information contained in Reference (d), which states that this change is acceptable based on the lower probability of a water solid pressure transient and the negligible effect of lowering the criticality limits.

One positive aspect of the proposed lowering of the criticality limits is the reduction in time spent at temperatures where fracture is of concern.

Such a reduction of time spent in this region would imply less chance of occurrence of a maintenance or testing operation that might inadvertantly flood up and pressurize the vessel.

United Strtes Nuclear Regulatory Commission May 26, 1983 Attention: Mr. Darrell G. Eisenhut Page 3 This change has been determined not to involve a significant hazards consideration as defined in 10CFR50.92(c).

This change has been reviewed by the Vermont Yankee Nuclear Safety Audit and Review Committee.

FEE DETERMINATION This proposed change required an approval that involves a single safety issue and is deemed not to involve a significant hazards consideration. For these reasons, VYNPC proposes this change as a Class III Amendment. A payment of $4,000.00 is enclosed.

SCHEDULE OF CHANGE This proposed change, indicated by the first version of Figure 3.6.1 attached to this letter, must be approved no later than September, 1983 in order to assure continued operation within the bounds of Technical Specifications. Vermont Yankee also requests that the second version of Figure 3.6.1 marked, " Adjusted Per Revised 10CFR50, Appendix G", be reviewed and approved as soc,.i as the proposed revision to 10CFR50, Appendix G becomes effective.

We trust that this information is acceptable; however, should you have any questions in this matter, please contact us.

Very truly yours, V .NT YANKEE NUCLEAR POWER CORPORATION

%6/w U L. H. Heider Vice President JBS/dd cc: Richard Saudek Vermont Department of Public Service 120 State Street Montpelier, VT 05602 COMMONWEALTH OF MASSACHUSETTS)

)ss MIDDLESEX COUNTY )

Then personally appeared before me, L. H. Heider, who, being duly sworn, did state that he is a Vice President of Vermont Yankee Nuclear Power Corporation, that he is duly authorized to execute and file the foregoing request in the name and on the behalf of Vermont Yankee Nuclear Power Corporation and that the statements therein are true to the best of his knowledge and belief. , , , , ,

f 4,7..S.!.M %g L du/

[ hh k$ .'. V. B . Sinclair Notary Public

!N:3-My Commission Expires June 1, 1984 i4 .

{ '?.* g .s 5.$lQ Agj*

y.I

_A-, - "'

O 9

6 s

=

d 4

g.

't k

'tirs . . .

y0 '

r i ,

3/ lct '

pajou

' I s~ -

i. - ,

s s

c1/

,s,- .

g s' Yb'!l ' "

N s:-  ;

r 1 s

• * -

• g 1

t

-* 3 ., '

i'.,- ,

m

• t ,

j

\*s

(

s

's i

4 j k s ,Tj [

h/

t

-l -

t

• t

> . & g , b".

j (i , 4

\_ '

V '\ . l l

s ~ ,-

t, .

l>  : ~

l 't b j

'\\ t -e s_ .

k \-r ,

s l '

I <

+

I r l s

! i ,

(

I I

i t. . A t

i ( ,

l

- (, l\ l

[. ..

s

\. ,

?$ \

t s i I.-

i I t t l

I 'e '

i s

n - e .

I i

--- --. - . - _ , t. -3