ML20214E281

Proposed Tech Specs Re Reactor Pressure Vessel Neutron Fluence Projection

ML20214E281
Person / Time
Site:	Pilgrim
Issue date:	02/28/1986
From:	BOSTON EDISON CO.
To:
Shared Package
ML20214E276	List: BECO-85-024, Application for Amend to License DPR-35,consisting of Proposed Change 86-06,revising Tech Specs Re Reactor Pressure Vessel Neutron Fluence Projection.Fee Paid ML20214E281
References
NUDOCS 8603070242
Download: ML20214E281 (3)

Text

-

. FIGURE 3. 6.1 PILGRIM REACTOR VESSEL PRESSURE- TEMPERATURE LIMITS HYDROSTATIC AND LEAK TESTS si  ! t i

i  :

j  !!  !

i _. _,*_ _. -

t I '

i 1

i i

' _' .q _

1200 4.w. .j + + . , .__. y. o

x. _

fg i .

P u-- .__.. .___

~

-__. . ._ - y. -.

-l000 '

/, '

! e i s_ j _

l-A pc /~-  :~

u) , '

g -

j g___ __.__

g 6

~

i  !:

800 _ _ _ _ _ ,

?

! 1 i

w g

D u) 600 ,

i i

u) ' -

w

! L_. RPV WALL l

$ l ,

E FPY* FLUENCE (dT) 2.8 x lolin/cm21 400  ; , ,

8.0 ,

--- 10.0 I 2

! l' l 3.4 x 10 n/cm i ,

! I __

200 -

~~~ ~~~~~~-

t

• PNPS EFFECTIVE FULL F0WER

--~ --

YEARS (EFPY) AS OF 12/83 END OF CYCLE 6 IS 6.68.

M. 4 . }._4.hg_ .lll[ l 40 80 12 0 16 0 200 ~

240 l TE MPER ATURE (*F) l AMENDMENT N O. 860307o242 e60228 12 8 PDR ADOCK 05000293 p PDR

. . , FIGURE 3.6.2 PILGRIM REACTOR VESSEL PRESSURE- TEMPERATURE LIMITS SUBCRITICAL/ CRITICAL HEAT UP & COOL DOWN RPV WALL 335'E FPY

• FLUENCE (dT)

III I 8.0 2.8 x 10 n/cm 2 r  ;

1200 1' 3 4

• IU "/C" ~~~~~~

l, ,

h,

~ ~'

; i

1 / / o a i o

~~ ~ ~~

-1000 .

• PNP 5 EFFECTIVE FULL POWER '

o

YEARS (EFPY) AS OF 12/83 f o- r r g ---

END OF CYCLE 6 IS 6.68. / /a/p / -/

c. r .,

f 800

'r u i c: ,

1 i

D m

600 1 f 1 g SUBCRITICAL- --

r W HEAT UP B COOL i

$ DOWN ,

)

f '

% CRITICAL

~2II 400 l CORE r l~ ~~~ OPERATION :::

, ,1 l l f i r

200  ! >

9 I J

r'  !

F I 1' 1 1 0 ' ' l 40 80 120 16 0 200 240 TE M PER ATURE (*F)

AMENDMENT N O. 128A

Bases:

3.6.A and 4.6.A Thermal and Pressurization Limitations (Cont'd)

The reactor coolant system is a primary barrier against the release of fission products to the environs. In order to provide assurance that this barrier is

maintained at a high degree of integrity, restrictions have been placed on the operating conditions to which it can be subjected.

Appendix G to 10CFR50 defines the temperature-pressurization restrictions for 4

hydrostatic and leak tests, pressurization, and critical operation. These L limits have been calculated for Pilgrim and are contained in Figures 3.6.1 and  !

3.6.2.

1 For Pilgrim pressure-temperature restrictions, two locations in the reactor  ;

i vessel are limiting. The closure region controls at lower pressures and the

]t beltline controls at higher pressures.

! The nil-ductility transition (NDT) temperature is defined as the temperature .

below which ferritic steel breaks in a brittle rather than ductile manner.  !

! Radiation exposure from fast neutrons (>l mev) above about 10 nyt may shift the NDT temperature of the vessel metal above the initial value. Impact

' tests from the first material surveillance capsule removed from the reactor  ;

vessel have established the magnitude of the RTuor shift for the beltline.

1 The shift, which is greatest for the weld metal, is tabulated below for various i fluence levels:

3 RPV Wall

, Fluence (1/4T) RTuor 2.8 x 10 n/cm 2 61*F i 3.4 x 10 n/cm' 68'F i Neutron flux wires and samples of vessel material are installed in the reactor vessel adjacent to the vessel wall at the core midplane level. The wires and  :

samples will be periodically removed and tested to experimentally verify the l values used for Figures 3.6.1 and 3.6.2. The withdrawal schedule of Table i 4.6.3 has been established as required by 10CFR50, Appendix H. l The pressure-temperature limitations of Figures 3.6.1 and 3.6.2 appilcable to i the beltline reflect an initial RT=or of O'F. This initial value is based f

! I i

r Amendment No. 139

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