ML20148H867

Hazards Analysis Supporting Proposed Change 38 to Tech Specs

ML20148H867
Person / Time
Site:	Yankee Rowe
Issue date:	10/18/1963
From:	Bryan R US ATOMIC ENERGY COMMISSION (AEC)
To:
Shared Package
ML20148H864	List: ML20148H858 ML20148H867
References
NUDOCS 8011200060
Download: ML20148H867 (2)

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UNITED STATES ATOMIC ENERGY COMMISSION :W p

HAZARDS ANALYSIS BY THE RESEAROI AND P0 PIER REACTOR SAFETY BRANCH y DIVISION OF LICENSING AND REGULATION  :

IN THE MATTER OF' E9 YANKEE ATOMIC ELECTRIC COMPANY PROPOSED OIANGE NO. 38 DOCKET NO. 50-29 .

Introduction i:

Pursuant to the provisions of Section 50.59 of the Commission's regulations, _

Yankee Atomic Electric Company in Proposed Change No. 38, dated June 28, as 1963, requested authorization of revisions of certain sections of the Plant Maintenance Instructions which are incorporated by reference as part of the ..

Technical Specifications for the reactor. ="

These revisions would permit con-

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ducting the Primary Plant Cold Leak Test with spent fuel in the core and the  ;

reactor vessel isolated from the heat removal system. The revisions would also permit increasing the minimum temperature at which the Icak test vay he i performed to compensate for the shift in nil ductility temperature of the reactor pressure vessel resulting from neutron irradiation during reactor ,

operation.

Di s cus sion

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Y:nkee has proposed that Condition 4 of Maintenance Instruction 506B3 be chnn;cd from:

"4 Isolation of the reactor vessel and connecting pressurizer system from the heat removal system may be established for the cold Icak test period, provided there is not substan-tini decay heat present in the reactor fuel." to "4 Isolation of the reactor vessel and connecting pressurizer system from the heat removal system may be established for the cold leak test period provided the coolant temperature -

in the vessel does not increase at a rate exceeding 50* F ,

per hour and that the maximum temperature increase during the test period does not exceed 100* F. Temperature moni- s toring shall be accomplished by means of the in-core thermo-  :

co tple s . "

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I Precautions 1, 3, and ~4 of Maintenance Instruction 506B3 would be changed as follows:

1. When the nuclear core is in place, the maximum-allow-able leak _ test pressure 2,485 psi gage at a m nii mum temperature of 90' F." to ,

1 When the nuclear core is in place, the maximum allow-able Icak test pressure is 2,485. psi gage at a tempera-ture 60' F in excess of the estimated vessel nil ductility.tenperature."

3. hbtal-water' temperature equilibrium must be obtained .

in the main coolant system." to .

3. Full pressurization shall not be effected until the coolant and metal temperatures have reached the test  :

temperature,"- ,

4 The main coolant system pressure must not exceed 500 -

psi gage until the temperature of the main coolant is at a minimum of 90' F." to .

4 The coolant pressure must not exceed-500 psi gage -

until the coolant is at the test temperature."

We believe that temporary isolation of the reactor vessel from the heat removal system under the conditions proposed would not present any signifi-cant change in the safety of performing the cold leak test. Should it become .

desirable for any reason during the test, the main coolant system stop valves can be automatically opened by the facility operator to reconnect the reactor vessel water with the reactor heat removal system. Further, if a power fail- 1 ure occurred during the test, these valves could be opened manually to allow heat removal from the reactor core.

Yankee has reported that the proposed requirement that the test tempera-ture be at 1 cast 60' F above the estimated reactor vessel nil ductility temperature will result in a minimum test tenperature of 120' F for the Core III refueling. This minimum temperature would be increased during subsequent,. core loadings to compensate for the increase in nil ductility te perature caused by the neutron irradiation of the reactor vessel. In a our opinion, the proposed new temperature limit is more conservative from a safety stancpoint than the present one, and we believe that it provides  !

cn adequate safety margin to prevent damage to the vessel during future  !

cold Icak tests.

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Conclusion

• Ne have concluded that Proposed Change No. 38 does not present significant kazards considerations not described or implicit in the hazards summary

.eport. We have further concluded that there is reasonable assurance that he acalth and safety of the public will not be endangered.

Olliinal signed by Robert H. Bryan Robert II, Bryan, Chief .

Research 6 Power Reactor Safety Branch Division of Licensing 6 Regulation Date: cci 1 8 1953 e-(.4 t:

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