ML20245J612

Proposed Tech Spec Pages 3/4 4-31,3/4 4-32 & Bases 3/4 4-08 3/4 4-10 Re Heatup & Cooldown Curves

ML20245J612
Person / Time
Site:	Vogtle
Issue date:	07/28/1989
From:	GEORGIA POWER CO.
To:
Shared Package
ML20245J601	List: ML20245J599 ML20245J612
References
NUDOCS 8908180088
Download: ML20245J612 (5)

Text

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Georgi )owerI L

ENCLOSURE 3

, V0GTLE ELECTRIC GENERATING PLANT NRC DOCKETS 50-424, 50-425 OPERATING LICENSES NPF-68, NPF-81 REQUEST. TO REVISE TECHNICAL SPECIFICATIONS INSTRUCTIONS 'FOR -INCORPORATION The proposed amendment to. the Technical Specifications (Appendix A to Operating Licensos NPF-68 and NPF-81) would be incorporated as follows:

Remove Page Insert Page 3/4 4-31 3/4 4- 31 3/4 4-32 3/4 4-32 B 3/4 4-08 B 3/4 4-08 B 3/4 4-10 B 3/4 4-10 P

. , - j s, ,.3 3000 CURVE APPLICABLE FOR THE SERVICE 4

PERIOD UP TO 13 EFPY g; , RTNDT After 13 EFPY e a.1/4 T < 110*F S b. 3/4 T< 87'F LEAK TEST I

^m LIMIT

$ CRITICALITY l LIMIT i E

a 2000 ~ UNACCEPTABLE -- FOR 60'F/hr l OPERATION HEATUP {

]

b 1

• j CRITICALITY

$ f LIMIT  !

FOR 100'F/hr

$ HEATUP O

O O

m O 60*F/hr o x HEATUP g 1000 / BASED ON INSERVICE ' i g CURVE [ HYDROSTATIC TEST o

/ TEMPERATURE (255'F)

% FOR THE SERVICE ,

y PERIOD UP TO 13 EFPY U 100*F/hr

\HEATUP ACCEPTABLE

' CURVE OPERATION 0.0 -

0.0 100 200 300 400 500 LOWEST INDICATED RCS Tcold TEMPERATURE ('F)

MATERIAL BAS!S Copper Content: Assumed . 0.10 Wt %

(Actual . 0.06 Wt %)

RT NDT Initial: Assumed 40'F (Actual . 3D'F)

RTNDT After 13 EFPY C 1/4 T *110*F

@ 3/4 T *87'F FIGURE 3.4-2a UNIT 1 REACTOR COOLANT SYSTEM HEATUP LIMITATIONS - APPLICABLE "P TO 13 EFPY V0GTLE UNITS - 1 & 2 3/4 4-31

UNIT 1 3000 g g

' CURVE APPLICABLE FOR THE SERVICE PERIOD UP TO 13 EFPY E

E

' m E 2000 a.

E

$ UNACCEPTABLE

$ OPERATION ACCEPTABLE

$ OPERATION -

5 O

O U

E '

• J E 1000 E COOLDOWN o RATE

$ (*F/hr) 6 Op I

~ EW 60 /

100 O.0 100 200 300 400 500 LOWEST INDICATED RCS Tcold TEMPERATURE ('F)

MATERIAL BASIS Copper Content: Amoumed - D.10 Wt %

(Actual . 0.06 Wt %)

RT NDT inittel: Amoumed - 40'F (Actual 30'F)

RT NDT Aftrer 13 EFPY c 1/4 Tse110'F c 3/4 Tc87'F FIGURE 3.4-3a UNIT 1 REACTOR COOLANT SYSTEM C00LDOWN LIMITATIONS - APPLICABLE UP TO 13 EFPY V0GTLE UNITS - 1 & 2 3/4 4-32 1

1 .

REACTOR COOLANT SYSTEM BASES PRESSURE / TEM _PER.ATURE LIMITS (Continued)

2. These limit lines shall be calculated periodically using methods provided below,

3. The secondary side of the steam generator must not be pressurized above 200 psig if the temperature of the steam generator is below 70*F,

4. The pressurizer heatup and cooldown rates shall not exceed 100*F/h and 200*F/h, respectively. The auxiliary spray shall not be used if the temperature difference between the pressurizer and the auxiliary spray fluid is greater than 625'F, and

5. System preservice hydrotests and inservice leak and hydrutests shall be performed at pressures in accordance with the requirements of ASME Boiler and Pressure Vessel Code,Section XI.

The fracture toughness properties of the ferritic materials in the reactor vessel are determined in accordance with the NRC Standard Review Plan, ASTM E185-82, and in accordance with additional reactor vessel requirements. These properties are then evaluated in accordance with Appendix 6 of the 1972 Summer Addenda to Section III of the ASME Boiler and Pressure Vessel Code and the calculation methods described in WCAP-7924-A, " Basis for Heatup and Cooldown Limit Curves," April 1975.

The heatup and cooldown limit curves shown in Figures 3.4-2a and 3.4-3a are applicable to Unit 1 for up to 13 EFPY and are based on Westinghouse- l developed generic curves which were developed assuming a 40*F initial RTNDT and a copper content of 0.10 WT% for the most limiting material. These curves are applicable to Unit 1 since its most limiting material (Table B 3/4.4-la) has both a lower initial RTNDT (30*F) and a lower copper content (0.06 WT%).

These curves, however, are not applicable to Unit 2, since its most limiting material (Table B 3/4.4-lb) has a higher initial RTNDT (50 compared to 40*F). Separate heatup and cooldown limit curves were developed based on the actual material properties of the most limiting material for Unit 2 up to 16 EFPY. The Unit 2 curves are shown in Figures 3.4-2b and 3.4-3b.

Heatup and cooldown limit curves are calculated using the most limiting value of the nil-ductility reference temperature, RTNDT, at the end of the Effective Full Power Years (EFPY) of service life. The EFPY service life period is chosen such that the limiting RTNDT at the 1/4T location in the core region is greater than the RTNDT of the limiting unirradiated material. (

)

The selection of such a limiting RTNDT assures that all components in the Reactor Coolant System will be operated conservatively in accordance with applicable Code requirements.

}

YOGTLE UNITS - 1 & ' B 3/4 4-8

o .. .

-' REACTOR COOLANT SYSTEM BASES PRESSURE / TEMPERATURE LIMITS (Continued)

The reactor vessel materials have been tested to determine their initial RTMDT; the results of these tests are shown for Units 1 and 2 in Table B 3/4.4-la and b, respectively. Reactor operation and resultant fast neutron (E greater than 1 MeV) irradiation can cause an increase in the RTNDT. There-fore, an adjusted reference temperature, based upon the fluence, copper content, and phosphorus content of the material in question, can be predicted using Figure B 3/4.4-1 and the largest value of ARTNDT computed by either Regulatory Guide 1.99, Revision 2, "Ef fects of Residual Elements on Predicted Radiation l Damage to Reactor Vessel Materic15," or the Westinghouse Copper Trend Curves shown in Figure B 3/4.4-2. The heatup and cooldown limit curves of Figures 3.4-2a and 3.4-3a (Unit 1), Figures 3.4-2b and 3.4-3b (Unit 2) include predicted adjustments for this ghift in RTNDT at the end of 13 (Unit 1) and 16 (Unit 2) l EFPY as well as adjustments for possible errors in the pressure and temperature sensing instruments.

Values of aRTNDT determined in this nenner may be used until the results f rom the material surveillance program, evaluated according to ASTM E185, are available. Capsules will be removed in accordance with the requirements of ASTM E185-82 and 10 CFR Part 50 Appendix H. The surveillance specimen with-drawal schedule is shown in Table 16.3-3 of the VEGP FSAR. The lead factor represents the relationship between the fast neutron flux density at the loca-tion of the capsule and the inner wall of the reactor vessel. Therefore, the results obtained from the surveillance specimens can be used to predict future radiation damage to the reactor vessel material by using the lead factor and the withdrawal time of the capsule. The heatup and cooldown curves must be recalculated when the ARTNDT determined from the surveillance capsule exceeds the calculated ARTNDT for the equivalent capsule radiation exposure.

Allowable pressure-temperature relationships for various heatup and cooldown rates are calculated using methods derived from Appendix G in Sec-tion III of the ASME Boiler and Pressure Vessel Code as required by Appendix G to 10 CFR Part 50, and these methods are discussed in detail in the following paragraphs.

The general method for calculating heatup and cooldown limit curves is based upon the principles of the linear elastic fracture mechanics (LEFM) tech-nology. In the calculation procedures a semielliptical surface defect with a depth of one-quarter of the wall thickness, T, and a length of 3/2T is assumed to exist at the inside of the vessel wall as well as at the outside of the vessel wall. The dimensions of this postulated crack, referred to in Appendix G of ASME Section III as the reference flaw, amply exceed the current capabilities of inservice inspection techniques. Therefore, the reactor operation limit cur-ves developed for this reference crack are conservative and provide sufficient safety margins for protection against nonductile failure. To assure that the radiation embrittlement ef fects are accounted for in the calculation of the V0GTLE UNITS - 1 & 2 B 3/4 4-10

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