ML19210E532
| ML19210E532 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 10/29/1979 |
| From: | Schwencer A Office of Nuclear Reactor Regulation |
| To: | Goodwin C PORTLAND GENERAL ELECTRIC CO. |
| References | |
| NUDOCS 7912050183 | |
| Download: ML19210E532 (7) | |
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OCTOBER 2 9 1979 Docket No. 50-344 Mr. Charles Goodwin, Jr.
Assistant Vice President Portland General Electric Company 121-S.W. Salmon Street Portland, Oregon 97204
Dear Mr. Goodwin:
The staff has recently completed a review of the LER?.s and Technical Specification requirements related to the Control Rod Position Indication Systems (RPI) at Westinghouse PWRs. We have determined that a wide varia-tion exists in the number of LERS received and the technical specification requirements and have, therefore, decided to clarify our requirements.
At the time of development of the Standard Technical Specifications, a systematic ' ttempt was made to clarify potentially ambiguous specifications.
a One such specification was the contrcl rod misalignment specification for Westinghouse-designed reactors. Westinghouse has perfomed safety analyses for control rod misalignment up to 15 inches or 24 steps (one step equals 5/8 inch). Since analysis of misalignments in excess of this amount have not been submitted, we have imposed an LC0 restricting continued operation with a misalignment in excess of 15 inches. Because the analog control rod position indication system has an uncertainty of 7.5 inches (12 steps), when an indicated deviation of 12 steps exists, the actual misalignment may be 15 inches. This is because one of the coils, spaced at 3.75 inches, may be failed without the operator knowing about it. The Standard Technical Specifications were written to eliminate any confusion about this, and allow a deviation of up to 12 indicated steps. Surveillance requirements, on the indication accuracy of 12 steps were also prepared to ensure that the 15 inch LCO is met.
There is no difference intended in requirements issued for any Westinghouse reactor. Westinghouse has informed the NRC that all of their customers have been informed of this and that all the licensees should be following the same procedures regardless of the language of their Technical Specification. That is, plants with Technical Specifications written in tems of 15 inch misalign-ment should be considering the 12 step instrument inaccuracy when monitoring rod position.
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A related problem is that the installed analog control rod position indicating system equipment may not, in some areas, be adequate to maiatain the control rod misalignment specification requirement because of drift problems in the calioration curves. Tnis is evidenced oy numerous LER's concerning rod position indication accuracy.
In these cases, the uncertainty may be more than 12 steps.
1498 267
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7912050
Mr. Charles Goodwin OcTaeER : 9 1979 Portland General Electric Company
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The present Westinghouse Standard Technical Specifications (Tindicated posit W-STS) require all full length control rods to be positioned witisin i 12 steps 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 attacn, ea for your infonnati~on and consideration.
It is requested that you review your present technical specifications to ensure that the control rods are required to be maintained wi*.hin + 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 infonn the Commission within 30 days of your receipt of this letter together with your plans to correct the deficiencies.
Any neeaed corrective actions may take several fonas; 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 justi7ying (with penalties if needed) greater misaligraents, or (3) proposing alternate or supplemental monitoring specifications ta demonstrate compliance with the 112 step indicated alignment requirement.
If you have any questions on this matter, please contact us.
Sincerely, J
bkHW&
y A. Schwencer, Chief Operating Reactors Branch #1 Division of Operating Reactors Enc 1osure:
W-STS Specifications 3/4.1.3.1 and 3/4.1.3.2 cc:
w/ enclosure See next page 1498 268
Mr. Charles Goodwin, Jr.
OCTOBER 2 9 1979 Portland General Electric Company cc: Mr. H. H. Phillips Robert M. Hunt, Chairman Portland General Electric Company Board of County Commissioners 121 S.W. Salmon Street Columbia County Portland, Oregon 97204 St.. Helens, Oregon 97051
. Warren Hastings, Esquire Counsel for Portland General Electric Company 121 S.W. Salmon Street Portland, Oregon 97204 Mr. Jack W. Lentsch, Manager Generation Licensing and Analysis Portland General Electric Company 121 S.W. Salmon Street Portland, Oregon 97204 Columbia County Courthouse Law Library, Circuit Court Room St. Helens, Oregon 97501 Director, Oregon Department of Energy Labor and Industries Building, Room 111 Salem, Oregen 97310 Richard M. Sandvik, Esquire.
Counsel for Oregon Energy Facility Siting Counsel and Oregon Department of Energy 500 Pacific Building 520 S.W. Yamhill Portland, Oregon 97204 Michael Malmrose U. S. Nuclear Regulatory Commission Trojan Nuclear Plant P. 0. Box 0 Rainier, Oregon 97048 Mr. Donald W. Godard, Supervisor Siting and Regulation Oregon Department of Energy Labor and Industries Building, Room 111 Sal em, Oregon 97310 1498 26.9
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REACTIVITY CONTROL SYSTEMS 3/4.1.3 MOVABLE CONTROL ASSEMBLIES GROUP HEIGHT LIMITING CONDITION FOR OPERATION 3.'l. 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 212 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 inoperable or misaligned from the group step counter demand position bv more than 12 steps (indicated position), be in HOT STANCBY within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
I 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 />.
S ee Special Test Exceptions 3.10.2 and 3.10.3.
1498 2Z0 W-STS 3/4 1-14 OCT I 1c,,3
REACTIVITY CONTROL SYSTEMS LIMITING CONDITION FOR OPERATION (Continued) c)
Apowerdistributionmapisobtajnedfromthemovable incore detectors and F (Z) and F a
withintheirlimitswikhin72hobYs.reverifiedtobe d)
[ither 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 high 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 i 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 RE0VIREMENTS 4.1.3.1.1 The position of each full and part length 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.
i498 27i W-STS 3/4 1-15 MAR I5 D77
TABLE 3.1-1 ACCIDEN1 ANALYSES REOUIRING REEVALUATION IN THE EVENi 0F AN INOPERABLE FULL OR PAR'.
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) i.bior Secondary System Pipe Rupture Ruptu. e of a Control Rod Drive Mechanism Housing (Rod Cluster Control Assemt'y Ejection) 4 1V)3 15E W-sTs 3/4 1-16 0CT 1 1975
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 : 12 steps.
APPLICABILITY:
MODES 1 and 2.
ACTION:
a.
With 'a maximum of one red position indicator per bank inoperable either:
1.
Determine the position of the non-indicating rod (s) indirectly by the movable incere 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 />.
15 D79
-W-STS 3/4 1-17 1498 273
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