ML19319D767

Proposed Tech Spec 3.5.2 Re Locking of Control Rod Drive Patch Panels at All Times W/Limited Access to Be Authorized by Superintendent & Rod Position Limits

ML19319D767
Person / Time
Site:	Rancho Seco
Issue date:	10/23/1974
From:	SACRAMENTO MUNICIPAL UTILITY DISTRICT
To:
Shared Package
ML19319D764	List: ML19319D763 ML19319D767
References
NUDOCS 8003250768
Download: ML19319D767 (2)

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RANCHO SECO UNIT 1 Fgu%iF -

NC7

.O TECHNICAL SPECIFICATIOP' O

. Littiting t.onditi'ons for Operation

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3. 5. 2. 7 ' The cont'rol red drive ' arch lancis sha.11 be locked at all times with limited access to be authori:cd by the superintendent.

. Bases The power-i=balanec envelope defined in figure 3.5.2-2 is based on LOCA

- 28 rate (sce figure 3.5.2-3) analyses which have defined the maximum linear heat o such that the =aximu.t clad temperaturc will not exceed the Interin' Acceptance Criteria.

Operation outside of the poTer imbalance envelope alone does not 24 constitute a situation that would cause the Interin' Acceptance Criteria to be exceeded should a LOCA occur.

The power imbalance envelope represents the boundary of operation limited by the Interia. Acceptance Criteria only if the 28[ control rods are at the position l'i=1ts as defined by figure 3.'5.2-1 and if a 4 percent quadrant power tilt exisrs.

Additional conserv'atism is introduced by application of:

A.

Nuc1 car uncertainty factors.

3 M, g q. 7 f

", 24 B.

Thermal calibration uncertainty.

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C.

Fuel densification effects.

D.

Hot rod =anufacturing tolerance. factors.

The 30 percent overlap between successive control rod groups is allowed since the worth of a rod is lower at the upper and lower part of the stroke.

Control rods are arranged in groups or bcnks defined as follows:

Group Function

'* Safety '

l 2

. Safety Safety 3,.

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4 Safety 5

Regulating

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Regulating 6

7 Regul-a' ting APSR (axial power shaping bank) 8 Control rod groups are withdrawn in sequence beginning with group 1.

Group 5 is ~ overlapped 25 percent with groups 6 and 7, which c.perate in parallel.

The norEal position at power is 'for groups.6 and 7 to,be partially inserted.

The minimum available rod worth provides for achieving hot' shutdown by reactor trip at' any ti=c assuming the highest worth contiol rod remains in the full out positics.(U Inserted rod groups during power operation will not contain single rod worths greater than 0.65 perecnt a k/k. This value has been shown to be safe by the safety analysis of the hypothetical rod ejections accident.(2)

A single inserted control worth of 1.0 percent Ak/k at beginning of life, hot, =cro 29 power would result in a lower peak thercal power and therefore less severe environmental. consequences than a 0.65 percent a k/k ejectcd rod at rated power.

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Amendment 29 3-33a

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10 0 94.5_

' 177.7,94.5 200. 3 90 175.9,87.I 87.1 80 166.8,7 6.0 Restricted Region 50 a

122.3, 46,3 40 o

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Pemi ssi bl e 30

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. Operating N

Reg.nen

- 80, 15 10 49, 0 0

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20 40 60 80 100 1 20 140 160 ISO 20 0 Rod Index, % Withdrawn 0

25 50 75 10 0 i

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O 25 50 75 10 0 Group 6.& 7 I

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Group E Rod Index is the percen'tage su:a of the withdrawal 1.

of control rod groups 5,6 & 7 ROD POSITION LiHITS

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Figure 3. 5. 2-1

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