ML20011A581

Forwards Response to NRC 810821 Ltr Re Pressurized Thermal Shock to Reactor Pressure Vessels.Response to Question 5 Will Be Delayed Until 811030,due to Detailed Nature of Info

ML20011A581
Person / Time
Site:	Three Mile Island
Issue date:	10/23/1981
From:	Hukill H METROPOLITAN EDISON CO.
To:	Eisenhut D Office of Nuclear Reactor Regulation
References
L1L-316, NUDOCS 8110290127
Download: ML20011A581 (4)

Text

.

s Metropolitan Edison Company g Post Of fice Box 480 Middletown, Pennsylvania 17057 Writer's Direct Dial Number October 23, 1981 LlL 336 h

Office of Nuclear Reactor Regulation \

Attn: D. G. Eisenhut, Director .

Division of Licensing -

-24 U. S. Nuclear Regulatory Commission O~

00T2 8 bib b b y,g '

Washington, D.C. ?.0555 coJ%  %

Dear Sir:

P Three Mile Island Fuclear Station, Unit 1 (TMI~1)

Operating License No. DPR-50 Docket No. 50-289 Pressurized Thermal Shock To Reactor Pressure Vessels Enclosed please find our response to your August 21, 1981 letter concerning pressurized thermal shock to reactor vessels. Because of the detailed nature of question 5, our response to that item will be supplied separately by October 30, 1031. This response is correct to the best of my knowledge and belief.

Sincerely,

1. . Iukill Director, TMI-l IIDH:CJS:vj f Enclosure cc: L. Barrett R. Jacobs 31gnedandsubscribedtobeforemethisO day of , 1981.

D 6\A f\l A s AL r ,' -

Not bEic FAMRA 30Y L!J8RL i otary N PuMc Dau; Canty, Pa nckfietown.

My Comnsson Expires August 41933 i

d 8110290127 811023

, p DR ADOCK 05000289 $1 PDR Atan Ed: con Company .s a t/ ember of the Genera l Pubhc Utit.es System I

1 Item (1) Provide the RTNDT values of the critical welds and plates (or forgiugs) in your vessel for:

(a) initial (as-built) conditions and location (e.g. , 1/4 T) and the (b) current conditions (include fluence level) at RPV inside carbon steel surface.

Response

(la) As Built Conditions Material RT "" "

NDT Base Metal C-3307-1 +40(2) T/4 Cire. Weld WF25 +20(3) T/4 Long Weld WF8 +20 T/4 Long Weld SA1526 +20 T/4 (1b) Current Conditions Material Cu/P(4}wt.% Fluence (5)n/cm 2>lMeV RTNDT( NDT(

Base Metal C-3307-1 2.3 E18 83 77 Circ. Weld WF25 2.1 E18 177 159-180 Long. Weld WF8 2.1 E18 147 160 Long. Weld SA1526 1.7 E18 170 170 (1) From BAk-1439 estimated per BAW-10046P as most conservative.

(2) BAW-1439 unirradiated surveillance base metal Charpy test result is +20.

(3) BAW-1439 unirradiated surveillance weld metal Charpy test result is -14.

(4) Refer to BAW-1511P, B&W visuals 7/28/81 presentation to NRC, NRC visuals 9/11/81 ACRS meeting.

(5) Based on BAW-1511P (geometrical fluence factors) and 9/11/81 visuals.

(6) Per R. G. 1.99 Rev.1. Where the wt.%P is greater than 0.012 the equation in R. G. 1.99 Rev. I was used regardless of the upper limit curve as this is based on 0.012 wt.%P and may not be applicable. This resulted in more conservative values of RT NDT' (7) From B&W visuals 7/28/81 presentation to NRC, NRC visuals 9/11/81 ACRS meeting.

Item

'(2) At what rate is RTNDT increasing for these welds and plate material?I

Response

(2) From the equation in Reg. Guide 1.99 Rev. 1 A= C(BF/K)b (t) where:

A= predicted adjustment of reference temperature, F C= chemistry factors = 40 + 1000 (%Cu-0.08) + 5000 (%P-0.008)

B= geometrical fluence factor F= fluence per EFPY 19

'K=10 t= time - (EFPY) f=IC(BF/K) (t)~ = rate of increase of RTNDT f

Material dA/dt* F/EFPY Base Metal C-3307-1 6.2 Cire. Weld WF25 22.8 Long Weld WF8 18.5 Long Weld SA1526 19.9 J

• dA/dt is not linear in time. These dA/dt values are good for the current condition at TMI-1.of 3.45 EFPY. As plant life (number of EFPY's) increases-dA/dt will decrease.

dA/ dt 100<

80 d 60 Cire. Weld W? 25 40 0 22.8 7 .

\

S l 3.45 10 20 30 40 EFPY

- 1 . 4 m

L ,

=

. Items (3)- What:value of RTg for the critical welds and plate material do you.

-consider appropriate as a limit for continued operation?

(4) What is the basis for your proposed limit?

Response (3&4)

-Use of RT 'as a limiting parameter for continual. operation is not con-sidered appropriate at this time. GPUNC and the B&W Owner's Group will develop and establish a set of parameters and conditions within the Phase Il response that are expected to be other than RT NDT*

1.

9 s

I t

l l'

I k

l-

j. .

F

l. -,

c .n -

+~ ,, , _ . , ~ . - , . . , , ,~..n.. . . ,, .

.e. , . , . . . . , r