ML19210E529
| ML19210E529 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 10/29/1979 |
| From: | Schwencer A Office of Nuclear Reactor Regulation |
| To: | Dunn C DUQUESNE LIGHT CO. |
| References | |
| TAC-43186, NUDOCS 7912050170 | |
| Download: ML19210E529 (7) | |
Text
Tf61 UNITED STATES 8
NUCLEAR REGULATORY COMMISSION g
E WASHINGTON, D. C. 20555
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OCTOBER 2 9 1979 Docket No. 50-334 Mr. C. N. Dunn, Vice President Operations Division Duquesne Light Company 435 Sixth Avenue Pittsburgh, Pennsylvania 15219
Dear Mr. Dunn:
The staff has recently completes a review of the Lt3As and Technical Specification requirement:, related to the Control Rod Position Indication Systems (RPI) at Westinghouse PWRs. We have deteminej 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 Standar.1 Technic 0 Specifications, a systematic attempt was made to clarify p;tentially ambiguous specifications.
One such specification was the control od misalignment specification for Westinghouse-designed reactors. Westinghousa has perfomM safety analyses for control rod misalignment up to 15 inches or 24 steps (ene 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 wera written to eliminate any confusion about this, ami allow a deviation of up to 12 indicated steps. Surveillance requirements, un 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 infomed the NRC that all of their customers have been infomed 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.
A related problem is that the installed analog control rod position indicating system equipment may not, in some areas, be adequate to maintain the control rod mi.salignment specification requirement because of drift problems in the calioration curves. This is evidenced by numerous LER's concerning rod position indication accuracy.
In these cases, the uncertainty may be more than 12 steps.
1498 224 7912050 / 7 O [
Mr. C. N. Dunn Duquesne Light Company OCTOBER a ' 1979 W-STS) require all The present Westinghouse Standard Technical Specifications (Tindicated po full length control rods to be positioned within + 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 detemined 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 infomation ind consideration.
It is requested that you review your present technical specifications to ensure that the cont.ol rods are required to be maintained within + 12 steps indicated and that the rod' position indication system is verified to Te accurate to within 12 stcps.
If your review indicates that this is not the case, you should so infom the Ccmmission within 30 days of your receipt of this letter together with your plans to correct the deficiencies.
Any needed corrective actions may take several foms; such as (1) revising your technical specification; to limit control rod misalignment to no more than + 12 steps indicated position, (2) seeking relief by performing analyses justiTying (with penalties if needed) greater misalignments, or (3) proposing i
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,
/Wbt.
A. Schwencer, Chief Operating Reactors Branch #1 Division of Operating Reactors
Enclosure:
-W-STS Specifications 3/4.1.3.1 ano 3/4.1.3.2 cc: w/ enclosure See next page e
1498 225 E
0 a
4
Mr. C. N. Dunn OCTOBER 2 9 Egg Duquesne Light Company-cc: Gerald Charnoff, Esquire Mr. James A. Werling Jay E. Silberg, Esquire Plant Superintendent Shaw, Pittman, Potts and Trowbridge Beaver Valley Power Station 1800 M Street, N.W.
P. O. Box 4 Washington, D. C.
20036 Shippingport, Pennsylvania 15077 Karin Carter, Esquire Mr. John A. Levin Special Assistant Attorney General Public Utility Commission Bureau of Administrative Enforcement P. O. Box 3265 5th Floor, Executive House Harrisburg, Pennsylvania 17120 Harrisburg, Pennsylvania 17120 Mr. Roger Tapan Stone and Webster Engineering Corporation P. O. Box 2325 Boston, Massachusetts 02107 Mr. J. D. Woodward R & D Center Westinghouse Electric Corporat:on Building 7-303 Pittsburgh, Pennsylvania 15230 i
B. F. Jones Memorial Library 663 Franklin Avenue Aliquippa, Pennsylvania 15001 Mr. Jack Carey Technical Assistant Duquesne Light Company P. O. Box 4 Shippingport, Pennsylvania 15077 Mr. R. E. Martin Duquesne Light Company 435 Sixth Avenue Pittsburgh, Pennsylvania 15219 Marvin Fein Utility Counsel City of Pittsburgh 313 City-County Building Pittsburgh, Pennsylvania 15219 1498~226
REACTIVITY CONTROL SYSTEMS 3/4.1.3 MOVABLE C0NTROL ASSEMoLIES 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 i 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 inoperable or misaligned from the group step counter demand position by more than :l: 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 confirn 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.
~
1498 227 W-STS 3/4 1-14 007 I tyg
REACTIVITY CONTROL SYSTEMS LIMITING CONDITION FOR' OPERATION (Continued) c)
A power distribution map is obtajned from the movable incore detectors and F (Z) and F are verified to be within their limits wikhin 72 hobgrs.
d)
[ither the THERMAL POWER level is. reduced to less than or equal to 75% of RATED THERMAL POWER within one hour end 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 12 steps of the inoperabl rod within one hour while maintaining the rod sequence and insertion limits of Figures (3.1-1) anc (3.1-2); the THERMAL POWER level shall be restricted pursuant in Speci-fication (3.1.3.6) during subsequent operation.
SURVElLLANCE 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 D.eviation Monitor is inoperable, then verify the group pos'tions 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.
1498 228 W-STS 3/4 1-15 MAR 15 D77
TABLE 3.1-1 ACCIDENT ANALYSES REOUIRING REEVALUATION IN THE EVENT OF AN INOPERABLE FULL OR PART LENGTH R00 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 Assembly Ejection) t 1498 229 W-STS 3/4 1-16 OCT 1 1976
REACTIVITY CONTROL SYSTEMS POSITION INDICATION SYSTEMS-0PERATING LIMITING CONDITION FOR OPERATION 3.1.3.2 The shutdown, control and part length control rod position indication system and the damand position indication system shall be OPERABLE and capable of determining the control rod positions within i 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 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 RE0VIREMENTS 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 />.
JUL 151979 W-ST5 3/4 1-17 1498 230
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