ML13333A446
| ML13333A446 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 10/29/1979 |
| From: | Schwencer A Office of Nuclear Reactor Regulation |
| To: | James Drake Southern California Edison Co |
| References | |
| NUDOCS 7912050187 | |
| Download: ML13333A446 (6) | |
Text
Mr. James H. Drake
- 2 The present Westinghouse Standard Technical Specifications (W-STS) require all full length control rods to be positioned within + 12 steps Tindicated position) of their group step counter demand position. Since numerous problems have developed in signal conditioning circuits for display indication of control rod position, the staff has determined that the "indicated position" requirement may be fulfilled by voltage measurements obtained from the position indication mechanism (and therefore no LER need be submitted) provided a sufficient data base has been established to ensure a correlation between voltage and position.
A copy of the current, applicable W-STS Specifications (3/4.1.3.1 and 3/4.1.3.2) are attached for your information ind consideration.
It is requested that you review your present technical specifications to ensure that the control rods are required to be maintained within + 12 steps indicated and that the rod position indication system is verified to Ee accurate to within 12 steps. If your review indicates that this is not the case, you should so inform the Commission within 30 days of your receipt of this letter together with your plans to correct the deficiencies.
Any needed corrective actions may take several forms; such as (1) revising your technical specifications to limit control rod misalignment to no more than + 12 steps indicated position, (2) seeking relief by performing analyses justifying (with penalties if needed) greater misalignments, or (3) proposing alternate or supplemental monitoring specifications to demonstrate compliance with the + 12 step indicated alignment requirement.
If you have any questions on this matter, please contact us.
Sincerely, Originfl Dennis L. Ziemann, Chief Operating Reactors Branch #2 Division of Operating Reactors
Enclosure:
W-STS Specifications 3/4.1.3.1 and 3/4.1.3.2 OFFICE 4 0OR.0 B #2 DOR:ORB #2 DOR:STS D
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NRC FORM 318 (9-76) NRCM 0240 S GOVERNMENT PRINTING OFFICE: 1979-289-369
Mr. James November 5, 1979 cc w/enclosure:
Charles R. Kocher, Assistant General Counsel Southern California Edison Company Pos.t Office Box 800 Rosemead, California 91770 David R. Pigott Samuel B. Casey Chickering & Gregory Three Embarcadero Center Twenty-Third Floor San Francisco, California 94111 Jack E. Thomas Harry B. Stoehr San Diego Gas & Electric Company P. 0. Box 1831 San Diego, California 92112 U. S. Nuclear Regulatory Commission ATTN:
Robert J. Pate P. 0. Box 4167 San Clemente, California 92672 Mission Viejo Branch Library 24851 Chrisanta Drive Mission Viejo, California 92676
REACTIVITY CONTROL SYSTEMS 3/4.1.3 MOVABLE CONTROL ASSEMBLIES GROUP HEIGHT LIMITING CONDITION FOR OPERATION 3.1.3.1 All full length (shutdown and control-) rods, and all part length rods which are inserted in'the core, shall be OPERABLE and positioned within t 12 steps (indicated position) of their group step counter demand position.
APPLICABILITY:
MODES 1* and 2*
ACTION:
- a. With one or more full length rods inoperable due to being immovable as a result of excessive friction or mechanical interference or known to be untrippable, determine that the SHUTDOWN MARGIN require ment of Specification 3.1.1.1 is satisfied within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and be in HOT STANDBY within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
.b. With more than one full or part length rod inocerable or misaligned from the group step counter demand position by more than +/- 12 steps (indicated position), be in HOT STANDBY within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
c.-
With one full or part length rod inoperable due to causes other than addressed by ACTION a, above, or misaligned from its group step counter demand height by more than +/- 12 steps (indicated position),
POWER OPERATION may continue provided that within one hour either:
- 1.
The rod is restored to OPERABLE status within the above alignment requirements, or
- 2.
The rod is declared inoperable and the SHUTDOWN MARGIN requirement of Specification 3.1.1.1 is satisfied.
POWER OPERATION may then continue provided that:
a) A reevaluation of each accident analysis of Table 3.1-1 is performed within 5 days; this reevaluation shall confirm that the previously analyzed results of these accidents remain valid for the duration of operation under these conditions.
b) The SHUTDOWN MARGIN requirement of Specification 3.1.1.1 is determined at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
'See Special Test Exceptions 3.10.2 and 3.10.3.
w-sTs 3/4 1-14 OCT 6
REACTIVITY CONTROL SYSTEMS LIMITING CONDITION FOR OPERATION (Continued) c) A power distribution map is obtained from the movable incore detectors and F (Z) and FAH are verified to be within their limits within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
d) either the THERMAL POWER level is reduced to less than or equal to 75% of RATED THERMAL POWER within one hour and within the next 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> the hich neutron flux trip setpoint is reduced to less than or equal to 85% of RATED THERMAL POWER, or
- e) The remainder of the rods in the group with the inoperable rod are aligned to within + 12 steps of the inoperable rod within one hour while maintaining the rod sequence and insertion limits of Figures (3.1-1) and (3.1-2); the THERMAL POWER level shall be restricted pursuant to Speci fication (3.1.3.6) during subsequent operation.
SURVEILLANCE REQUIREMENTS 4.1.3.1.1 The position of each full and part leng:h rod shall be determined to be within the group demand limit by verifying the individual rod positions at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> except during time intervals when the Rod Position Deviation Monitor is inoperable, then verify the group positions at least once per 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.
4.1.3.1.2 Each full length rod not fully inserted and each part length rod which is inserted in the core shall be determined to be OPERABLE by movement of at least 10 steps in any one direction at least once per 31 days.
W-STS 3/4 1-15 MAP 1 5 1977
TABLE 3.1-1 ACCIDENT ANALYSES REOUIRING REEVALUATION IN THE EVENT OF AN INOPERABLE FULL OR PART LENGTH ROD Rod Cluster Control Assembly Insertion Characteristics Rod Cluster Control Assembly Misalignment Loss Of Reactor Coolant From Small Ruptured Pipes Or From Cracks In Large-Pipes Which Actuates The Emergency Core Cooling System Single Rod Cluster Control Assembly Withdrawal At Full Power Major Reactor Coolant System Pipe Ruptures (Loss Of Coolant Accident)
Major Secondary System Pipe Rupture Rupture of a Control Rod Drive Mechanism Housing (Rod Cluster Control Assembl\\ Ejection)
W-STS 3/4 1-1E OCT 1 1976
REACTIVITY CONTROL SYSTEMS POSITION INDICATION SYSTEMS-OPERATING LIMITING CONDITION FOR OPERATION 3.1.3.2 The shutdown, control and part length control rod position indication system and the demand position indication system shall be OPERABLE.and capable of determining the control rod positions within t 12 steps.
APPLICABILITY:
MODES 1 and 2.
ACTION:
- a. With -a maximum of one rod position indicator per bank inoperable either:
- 1. Determine the position of the non-indicating rod(s) indirectly by the movable incore detectors at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> and immediately after any motion of the non-indicating rod which exceeds 24 steps in one direction since the last determination
-of the rod's position, or
- 2.
Reduce THERMAL POWER TO less than 50% of RATED THERMAL POWER within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.
- b.
With a maximum of one demand position indicator per bank inoperable either:
- 1. Verify that all rod position indicators for the affected bank are OPERABLE and that the most withdrawn rod and the least withdrawn rod of the bank are within a maximum of 12 steps of each other at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, or
- 2.
Reduce THERMAL POWER to less than 50 of RATED THERMAL POWER within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.
SURVEILLANCE REQUIREMENTS 4.1.3.2 Each rod position indicator shall be determined to be OPERABLE by verifying that the demand position indication system and the rod position indication system agree within 12 steps at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> except during time intervals when the Rod Position Deviation Monitor is inoperable, then compare the demand position indication system and the rod position indica tion system at least once per 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.
W-STS 3/4 1-17 JUL 15 1979