ML18136A246

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Discusses NRC Review of LERs & Tech Spec Requirements Re Control RPI Sys at Westinghouse Pwrs.Requests Tech Specs Review to Ensure Requirement for Rod Maint to within +/- 12 Steps Indicated & RPI Sys Verified Accurate within 12 Steps
ML18136A246
Person / Time
Site: Surry  Dominion icon.png
Issue date: 10/29/1979
From: Schwencer A
Office of Nuclear Reactor Regulation
To: Proffitt W
VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
References
NUDOCS 7912050199
Download: ML18136A246 (10)
v • d • e


Text

{

Docket Nos. 5U-2bo/

and SU-281 Mr. W. Lo Proffitt OCTOBER 2 9 197~

Senior Vice President - Power Virsinia Electric and Potver Company.

Post Office Box 2.6666 Richmond, Virginia 23261

Dear Mr. Proffitt:

The staff has recently completed a revim-, of the LER.' s and Tc:chnical Sµec"i"f;i cation requirements reL:ited to th£? Control Rod Position I ndicatiun Systems (RPI) at \\rJestinghouse Vi~Rs.

1-Je 11av2 determined that a wide varia-tion exists in the numuer of LERS received and the technicai specification requ*i rernents arid have~ tllen~fore., decided to clarify our requirements.

At tile time of development of the Standard Technical Specifications, a systematic attempt ~vas macte to clarify potentially ambiguous sp~1cifications.

One sucll specification was the control rod misal *ignment specification for West in:;ihousE:-dC!s*i ~ned reactors.

1,Jest i nghouse has performed safety analyses for control rod mis,d ignment up to 15. *inches or 24 steps (one step equals S/8 inch).

Since analysis of misalign11Ients in excess of this amount have not been submitted) vm have imposed an LCO r<::stricting continued operation

\\*Jith a litisaligrn11ent in excess of 15 inches.

Because the analou control rod position indication sy~te1,1 has an uncertainty of 7.5 inches (12 steps). 1.s1hen an indi<.:ated deviation of 12 steps exists> ti1e actual misalignment may be 15 "inc;l!es.

This is because one of the coils, spaced at 3.75 inc!ies~ may be failed \\vithout the operator knowing about it. The Standard Technical Specifications were written to dimin.:ite any confus*ion about tllis, and allm,1 a deviation of up to 12 indicated steps.

Surveillance requirements> on the inaication accuracy of 12 steps were also prepared to ensure that the 15 inch LCO is net.

There is no diffor1:mce intt:?nded in requirements *issued for any Hestinghoust, reactor.

liiest i nSJhouse has i nfornied the t4RC that all of tht~ir customers have been inform~d of this and. that an the licensees should be following the same procedures regurd1ess of the 1 anguage of tl1ei r Technical Sµeci fi cation.

That is, plants with Technical Specifications written in terms of 15 inch misalign~

merit should be considering the 12 step instrument inaccuracy \\*1!leri monitoring rod µosit i one c)}f A related probler,1 is ttiat the installed analoy control rod pos'ition indicating

~ystem equi prnent may not, in srnne areas, be adequate to maintain the control rod mi sa 1 i gnment specification requi ren1ent because of ct rift problems in the calibration curvt:s.

This is ev*idenced by numerous LER 's concerning rod position indication accuracv.

In these cases. tl"1e uncertaintv ma 1 be more than 12 steo<-.

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SURNAMEll"'-**************--*1*:................

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DATE.................... 1.............................................

\\... *... * *. * * * * * * *, * * * * * * * * * * * * * * * * * * * * * * * *

°C'I.LS. GOVERI\\Jl,1E1'1T PRINTING OFFICE: 1979-289-369

f i

Mr. w. LG Proffitt Virginia Electric and Pm,Jer Company The present ~Jestilighouse Standard Technical *Specifications (rJ-STS) require all.

full length control* rods to be positioned within +. 12 steps Tindicated position) of their group ste*p counter demand position.

Since numerous problems have deve*lopeu in S'ignal conditioning circuits for display indication of control roti position., the $taff has determined that the "indicated position" requirement may be.fulfil led by voltage measure..-nents* obtained from the position indication.

mechanism (and therefore no LER_ need be-1:'submitt&d) provided a sufficient data base has been established to ensure a co,~relati;6n between voltage and position.

A copy of'the current~ applicable ~J... STS Specifications (3/4.1.3.*1 and 3/4.1.3.2) are attached for your information und consideration.

It is requested that you review your present techrrlca1 specifications to ensure that the control rods are required to be maintained within + 12 steps indicated

and that the rod position indication systew is verified to be ac;curate to within
  • 12 steps.

I.f your review indicgtes that this is not the case,, you should so i nfonn the Cornmi ssi on within 30 days of _your receipt of this letter together

~vitil your plans to*correct the.deficiencies~

Any needed correct i vc.: act ions may take severa 1 forms; such as (.l) revising your teehnioa'i spec'ifications to limit control rod n1isal ignment to no more than.:!:. "12 steps indicated position., (2) seeking relief by perfonning analyses*

justifying (with penalties if needed) greater misalignments, or (3) proposing alternate or supplemental monitoring specifications to demonstrate compliance.

with the.::. 12 steµ indicated alignment requirement.

If you have any quest"ions on this matter 3 please contact uso_

Sincerely,

Enclosure:

w.. srs Specifications

- 3/4. 1.. 3. 1 *.and

. 3;,1.1.:3.2 A. Schwencer:i Chief Operating Reactors Branch #1 Division of Operating Reactors

  • \\ '

. cc:

\\1/t:tnclosure See next page orn~,~_DOR~

QOR:ORB1 suRNAME~I.JDNijshb.ors.:.J. ASc.h.w~nG~r....

1 DATE~j*l* 9/9"°\\/}~........ J.Q... !}_.~..... *I*............................................................. *_:_~

-*"i'.:ru.s: GOVE-RNMENT ~RINTING.OFFICE, 1979-289*369

e UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 OCTOBER 2 9 1979 50-338

,\\

Mr. w. L. Proffitt Senior Vice President - Power Virginia Electric and Power Company Post Office Box 26666 Richmond, Virginia 23261

Dear Mr. Proffitt:

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 detennined 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 attempt was made to clarify potentially ambiguous specifications..

One such.specification was the control rod misalignment specification for Westinghouse-designed reactors. vJestinghouse has perfonned 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 LCO 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 LCD is met.

There is no difference intended in requirements issued for any Westinghouse reactor. Westinghouse has infonned the NRC that all of their customers have been infonned 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 tenns 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 misalignment specification requirement because of drift problems in the cal ibr9tion curves. This is evidenced by numerous LER',s concerning rod position indication accuracy.

In these cases, the uncertainty may be more than 12 steps.

  • e e

Mr. W. L Proffitt

  • Virginia Electric and Power Company OCTOBER

" ?.1S79 The present Westinghouse Staqdard Technical Specifications (W-STS) require all full lengt_h 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 detennined that the 11 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 ~stabl.ished.to ensure a correlation between voltage and position.

A copy of the current, applicable W-STS Specifications (3/4.1.3. l and 3/4.1.3.2) are attached for your infonnation and consideration.

It is reques-ted *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 be 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 needed corrective actions may take several fonns; such as (1) rev1s1ng your technical specifications to limit control rod misalignment to no more than+ 12 steps indicated position, (2) seeking relief by perfonning 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.

Enclosure:

W-STS Specifications

- 3/4. 1.3. 1 and 3/4.1.3.2 cc:

w/ enclosure See next page Sincerely,

()

A. Schwencer, Chief Operating Reactors Branch #1 Division of Operating Reactors

e Mr. W.*L. Proffitt Virginia Electric and Power Company cc:

Mr. Anthony Gambardella Office of the Attorney General 11 South 12th Street - Room 308 Richmond, Virginia 23219 Richard M. Foster, _Esquire 1230 A Pearl Street

  • Denver, Colorado 80203 Michael W. Maupin, Esquire Hunton, Williams, Gay and Gibson P.O. Box 1535 "Richmond, Virginia 23212 Mrs. June Allen 412 Owens Drive Huntsville, Alabama 35801 Mr. Jame.s Torson 501 Leroy Socor~o. New Mexico 87801
  • Mrs. Margaret Dietrich Route 1, Box 568 Gordonsville, Virginia 22042 Ellyn R. Weiss, Esquire Sheldon, Harmon, Reisman and* Weiss 1725 I Street; N.W., Suite 506 Washington, D. C.

20006 Mr. James C. Dunstan State Corporation Commission Commonwealth of Virginia Blandon Building Richmond, Virginia 23209 Mr. A. D. Johnson, Chairman Board of*Supervisors of Louisa County Treviilians, Virginia 23170 e

OCTOBER-2 9 1979 Mr. ~ichael S. K,dd u.* s *. Nuclear Regulatory Comr.iission P. O. Box 128 Spotsylvania, Virginia 22553 Director, Technical Assessment Division Office of Radiation Programs (AW-459)

U. s. Envirormental Protection Agency Crystal Mall #2 Arlington, Vitginia 20460 U. S. Environment.al Protection Agency Region III Office ATTN:

ElS COORDINATOR Curtis Building 6th and Walnut Streets Philadelphia, Pennsylvania 19106 Aldennan Library Manuscripts Department University of Virginia Charlottesville, Virginia 22901 Mr. Edward Kube Board of Supervisors Louisa County Courthouse P.O. Box 27 Louisa, Virginia 23093 Mr. J. B. Jackson, Jr.

Commonwealth of Virginia Councfl on the Environment 903 Ninth Street Office Building Richmond, Virginia 23129 Mr. Paul W. Purdom Environmental Studies Institute Drexel University 32nd and Chestnut Streets Philadelphia, Pennsylvania 19104

e Mr. W. L. Proffitt Virginia Electric and Power Company cc:

Alan S. Rosenthal, Esquire Atomic Safety and Licensing Appeal Board U. *s. Nuclear Regulatory Commission Washington, D. C.

20555 Michael C. Farrar, Eiquire Atomic Safety and Licensing Appeal Board U~ S. Nuclear Regulatory Commission Washington, D. C.

20555 Dr. John H* *.

  • Buck Atomic Safety and Licensing Appeal Board U. S. Nuclear Regulatory Commission Washington, D. C~

20555

=Atomic Safety and Licensing Board Panel U. S. Nuclear Regulatory Commission Washington, D. C.

20555 e

OCTOBER 2 9 1979

e e

REACTIVITY CONTROL SYSTEMS.

3/4. 1.3 MOVABLE CONTROL ASSEMBLIES GROUP HEIGHT LIMITING CONDITION FOR OPERATION

3. 1.3. l All full length (shutdown and control) rods, and all part length rods which are inserted in' the core, shall be OPERABLE and positioned within+/- 12

-~teps ~indicated position) of.their group st*p counter demand position.

APPLICABILITY:

MODES l* 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 untrippabl*, determine that the SHUTDOWN MARGIN require-ment of Specification 3. 1. 1. l is satisfied within l hour 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 rnore*than one full or part length rod inoperable 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 co~nter demand height by more than+/- 12 steps (indicated position),

POWER OPERATION may continue provided that within one hour either:

1.

The rod is restored ~o OPERABLE status within the above a 1 i gnm*ent requirements, or

2.

The rod is declared inoperable and the SHUTDOWN MARGIN requirement of Specification 3. 1. 1. l is satisfied.

POWER OPERATION may then con~inue 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.l 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 1 1976

e REACTIVITY CONTROL SYSTEMS LIMITING CONDITION FOR ~PERATION (Continued) c)

A power distribution map is obta~ned from the movable incore detectors and F0(Z) and F6 H 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)

~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 equat to 85% of RATED THERMAL POWER, or*

~)

The remainder of the rods in the group with the inoperable fod are aligned to* within+/- 12 steps of the inoperabl~ rod within one hour while maintaining the rod sequence and insertior:i limits of Figures (3.1-1} and (3. l-2); the THERMAL POWER level shall be restricted pursuant to Speci-fication (3.l.3.6) durfng subsequent operation.

SURVEILLANCE REQUIREMENTS 4,].3.1.l The poJition of each full and part length rod shall be determined t~ 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 1 ength 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.

'n'-STS 3/4 1-15 MM? 1 S 1977

e TABLE 3. 1-1 ACCIDENT ANALYSES REQUIRING REEVALUATION IN THE EVENT OF AN INOPERABLE FULL OR PART LENGTH ROD Rod Cluster Control Assembly Insertion Characteristics Rod Cluster Control As~embly_Misalignment *

,Major Reactor Coolant System Pipe Ruptures (Loss Of Coolant Accident)

~ajor Secondary System Pipe Rupture Rupture of a*Control Rod Drive Mechanism Housing (Rod Cluster Control Ais~mbly Ejection)

W-STS 3/4 1-16 OCT i 1976

e 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 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 1 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 indi~ation 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 0 inoperable, then compare the demand ~osition 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 JU~ 1 S 1979

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