ML20012B708

Application for Amend to License DPR-53,revising Tech Specs Re Low Temp Overpressure Protection Sys,Per 10CFR50,App G

ML20012B708
Person / Time
Site:	Calvert Cliffs
Issue date:	03/02/1990
From:	Creel G BALTIMORE GAS & ELECTRIC CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20012B709	List: ML20012B708 ML20012B711
References
NUDOCS 9003160143
Download: ML20012B708 (8)

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il 3m s BALTIMORE F GAS-AND ,

ELECTRIC H CHARLES CENTER . P. O. BOX 1475. BALTIMORE, MARYLAND 21203 Gconot C. CREEL Vict Passierwt March 2,1990 l Noctran Engnov (200 eso 44ss  ;

U. S. Nuclear. Regulatory Commission Washington, DC 20555 ATTENTION: Document Control Desk

SUBJECT:

Calvert Cliffs Nuclear Power Plant Unit No..1; Docket No. 50-317 ,

Technical Specification Change. -

Low Temperature - Overpressure Protection System }

REFERENCE:

'(a) Letter from G. C. Creel (BG&E) to Document Control' Desk, dated

-March 2,1990, Clarification of the Low Temperature Overpressure Protection System Description l 1

(b) Letter from G. C. Creel (BG&E) to Document Control Desk (NRC),

dated October 27, 1989, Request for Amendment -

-(c) ' Letter from G. C. Creel (BG&E) to Document Control Desk (NRC),

' dated February 7, 1990, Description of-- Calvert Cliffs Low Temperature ' Overpressure Protection System i (d) Letter from G. C. Creel (BG&E) to Document Control Desk (NRC), e dated February 14, 1990, Technical: Specification Change - llPSI Pump Operability in' MODE 3 (TAC No. 75562)

(e) Letter from - S. A. McNeil (NRC) to J. A. Tiernan (BG&E) dated 4

, m February 4, 1987, Projected Values of Material ' Properties for L Fracture Toughness Requirements for Protection Against Pressurized Thermal Shock Events

. Gentlemen; i

On . November 27, 1989, a meeting was held with Nuclear Regulatory Commission (NRC) b . representatives to discuss our - current Low' Temperature Overpressure Protection (LTOP) system. As a result of that meeting, the Baltimore Gas and Electric Company hereby requests an Amendment to its Operating License No. DPR-53 for Calvert Cliffs Unit No. I with . the. submittal of the attached proposed changes to the Technical Specifications.

The ; purpose of this amendment request is to bring the Technical ~ Specifications into conformance 'with the current .LTOP system established in accordance with 10 CFR 50, Appendix .G. This system is described in Reference (a). These changes would establish more . conservative operating limits than exist in the current Technical Specifications.

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DISCUSSION in 1976,. the Nuclear Regulatory Commission (NRC) required commercial nuclear power plants to institute automatic and administrative controls to prevent exceeding the 10 CFR 50, Appendix G operating limits (Pressure-Temperature Limits) for the reactor vessel during operations at low temperature. The Unit I Low Temperature Overpressure Protection (LTOP) controls were based on Pressure-Temperature (P-T) limits for the reactor vessel that were applicable for the first 10 Effective Full Power Years (EFPY) of operation (Figure 3.4-2a in the Technical Specifications). Operation has now shifted to the P-T limits that are applicable for 10-to-40 EFPY of operation (Figure 3.4-2b in the Technical Specifications). Using the 10-10-40 EFPY P-T limits as a basis for LTOP controls, however, would severely impact plant operation at low temperature since an insufficient pressure band would be available for operation of reactor coolant pumps, t

in 1987, we reviewed the draft revision to Regulatory Guide 1.99 which addressed a

-change in the potential for brittle fracture of the reactor vessel at low temperatures.

We realized that our reactor vessels might be affected by the material property changes described in the draft Regulatory Guide. Because of these concerns, which reduce our operating window, we requested Southwest Research Institute (SwRI) to provide 10 CFR 50, Appendix G heatup and cooldown curves for 12 EFPY, The method described in the draft Regulatory Guide was used to generate these curves. The SwRI report that describes the initial' results has been provided to the NRC as Attachment 2 to Reference (b). The final analytical results were accepted by BG&E in early 1989. ,

TECIINICAL SPECIFICATION CIIANGES The following proposed changes to the Technical Specifications would incorporate the 12 EFPY P-T heatup rates for the Unit I reactor vessel, as developed from the draft Revision 2 to Regulatory Guide 1.99. In addition, the proposed changes would adjust the LTOP controls as required to ensure the 12 EFPY P-T limits (based on the draft Regulatory Guide) are not ' exceeded. Reference (c) describes how the various setpoints and administrative controls were derived. New 12 EFPY heatup and cooldown curves are under development to replace the existing 10-40 EFPY heatup and cooldown curves. The basis for these curves will be the final Revision 2 to Regulatory Guide 1.99.- The use of the final Regulatory Guide 1.99, Revision 2 will have some impact on three of the parameters presented in these proposed changes. It is expected the MPT enable temperature, the PORY pressure setpoint, and possibly the IIPSI pump flow will need to be adjusted slightly. The changes to these parameters are expected to be minimal, and should have no impact on the overall LTOP system configuration. The 12 EFPY curves and the above-mentioned adjustments will be submitted in a separate license amendment request by May 15,1990. Unit I is currently scheduled to return to operation in March 1990 for a short period of time. In April, 1990, Unit I will be shutdown for an outage of approximately 90 days duration.

Change pages 3/4 1-8, -10, 4-2a, -23, -26, -26a, -26b, 5-4, 5-6, B3/4 4-1 and 5-2 of the Unit i Technical Specifications as shown on the marked-up pages attached to this transmittal.

11 .i I?ocument OIntrol Desk

. March 2,1990 Page 3 Changes ' proposed to incorporate 12 EFPY P-T heatup rates:

a. Limiting Condition for Operation (LCO) 3.4.9.1 currently provides a heatup rate based on 0-to-10 and 10-to-40 EFPY of operation. We need to incorporate heat-up rate based on 12 EFPY of operation. Therefore, BG&E proposes to change the existing maximum allowable heat-up rate of.100 F in any one hour period to the following:

Maximum Allowable Heatuo Rate RCS Temocrature 700 F in any one hour period RCS> 2500F l 400F in any one hour period RCS s250 F In addition, the ACTION STATEMENT for LCO 3.4.9.1 should be changed to bring it into conformance with the 10-to-40 EFPY P-T curves (Figure 3.4-2b). The ACTION STATEMENT currently requires a cooldown to less than

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2000 F and 500 psia. When compared to the 10-to- 40 EFPY cooldown curve, this - ACTION STATEMENT violates the P-T curve. To correct the ACTION STATEMENT, we propose a cooldown to less than 2000F and 300 psia,

b. Changes to the ACTION STATEMENT- of Technical Specification 3.4.9.2 are proposed to ensure that cooldown actions required - are consistent with the  ;

10-10-40 EFPY P-T curves. These cooldown actions are consistent with the  !

proposed ACTION STATEMENT in Technical Specification 3.4.9.1. (See a.)

Changes proposed to adjust the LTOP controls:

c. LCO 3.4.9.3 currently requires two PORVs be: operable with a lift setting j of s 450_ psig, or a reactor coolant system vent of ;>. 1.3 square '

0 inches when one or more RCS cold , leg temperature is .s' 275 F. - This proposed change would lower the required PORV lift setting to s '

422.7 psia and require system vents equivalent to the number of PORVs not available. The proposed change would also require two of three llPSI pumps to be disabled, and the HPSI loop motor-operated valves be prevented from automatically aligning IIPSI pump flow to the RCS. If a f IIPSI pump is to be used, the total flow will be throttled or a vent equivalent to two PORVs will be required, i

The temperature at which this Technical Specification is applicable has -

been raised to s 319 F in conformance with the analysis described in i Reference (c). The controls of ' this proposed Technical Specification are not applicable if a system vent greater than 8 square inches exists. A system vent greater than 8 square inches has a greater flow area than six PORVs (7.8 square inches). Every two PORVs can handle the full flow of a IIPSI pump and the full flow of three charging pumps. Therefore, a vent of this size will handle the injection from any operable set of pumps.

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' ACTION STATEMENT changes are proposed to provide appropriate actions based I on the requirements proposed for the LCO. Proposed ACTION STATEMENT (a) l' maintains the same venting requirements found in the existing' ACTION STATEMENT, however, the action times have been changed. The current action times are 7 days to restore a PORY to OPERABLE status or the RCS must be vented within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. The proposed change would only allow 5 days to restore the PORY to OPERABLE status and would increase the- time permitted to vent the RCS to 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />. This change is proposed because it is '

impractical to attempt to depressurize and vent the RCS within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. If the RCS were at 3190F and 422 psia (LTOP entry conditions), BG&E has determined that a cooldown of- the RCS to less than 200 F and depressurization within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> is practicable. In addition, the proposed H

'? change does not increase the total time a PORY could be out of service (7 days) before a vent is established in the RCS. ACTION STATEMENT (b) l' currently requires that a a 1.3 square inch vent be established within 8  !

hours if both PORVs are inoperable. The proposed change would increase the vent size to a 2.6 square inches (equivalent 'o two PORVs) or allow entry into LCO 3.4.9.3.a.2. The action time has been increased from 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> to 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> for the reasons mentioned above. ACTION STATEMENT (c) has not i

been changed. ACTION STATEMENT (d) has been relabled as ACTION STATEMENT

'(g).

Three new ACTION STATEMENTS have been added to reflect the additional controls added to the LCO. Proposed ACTION STATEMENT (d) requires placing at least two HPSI pump handswitches in Pull-to-Lock within 15 minutes and disabling two HPSI pumps within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> if less than two pumps are disabled. Psoposed ACTION STATEMENT (e) addresses the disabling of the automatic alignment feature of the HPSI pump flowpath, it requires that the HPSI loop MOVs be closed and disabled or the affected IIPSI header t,e isolated _ within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. in addition, because .a llPSI header may now be isolated, the ACTION STATEMENT directs the operator to erter applicable HPSIflowpath ACTIONSTATEMENTS Proposed ACTIONSTATEMENT(f) addresses ,

actions to be taken if IIPSI- pump flow exceeds 350 gpm while an RCS vent 5 2.6 square inches exists. Flow must be immediately reduced to within limits and the pressure must be verified to have remained- within limits.

if the RCS pressure exceeded the limits given on the = 10-to-40 EFPY curve, then a Special Report will Se submitted in accordance with ACTION STATEMENT (c).

This change will ensure that appropriate ovupressure protection is -

provided in the low temperature region. The - basis for this LCO will be changed at a later date.

d. Surveillance Requirement 4.4.9.3.3 is added to verify the new conditions -

proposed in paragraph (c), above, for overpressure protection.

Specifically, the proposed change requires verification that the motor circuit breakers are removed for the two inoperable HPSI pumps or their discharge valves are locked shut. It would also require that the automatic opening feature of the HPSI loop motor operated valves be verified disabled. These verifications would be done at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

Document C:ntr:1 Desk

- March 2,1990 Page 5. -

These proposed surveillances and their associated times are consistent with similar - previous surveillances (Technical Specification 4.5.3.2).

Therefore, Surveillance Requirement 4.5.3.2 is deleted due to redundancy with the above changes. ,

Changes proposed to modify RCP controls:

e. Proposed footnote ("') is appended to the APPLICABILITY of LCO 3.4.1.3 and requires that a reactor coolant pump not be started when RCS cold leg temperature is less than or equal to 275 0F unless (1) the pressurizer water j volume is less than 600 cubic feet or (2) the secondary water temperature '

of each steam generator is less than 460F (34 F when measured by a surface  ;

contact instrument) above each' of the RCS cold leg temperatures. The I proposed change would require that a reactor coolant pump not be started when the RCS cold leg temperature is less than or equal to 319 F0unless (1) pressurizer - indicated water level is less than 170" (609 cubic feet) and (2) the secondary water temperature of each steam generator is less than 1500F above the RCS temperature. This proposed change will ensure that a reactor coolant pump is not started while the RCS is water solid and the energy addition caused by starting a reactor coolant pump _ will not cause pressure to exceed the 12 EFPY P-T limits.

f. The basis for LCO 3.4.1.3 is changed to reflect the above restrictions.

Changes proposed to modify IIPSI pump controls l g, Currently, LCOs 3.1.2.1 and 3.1.2.3 allow the use of a IIPSI pump to l provide a source of boron injection in MODES 5 and 6. The proposed change - would add a footnote (*) which defines an operable llPSI pump as being in pull-to-lock 'and states that FIPSI pump manual use is in accordance with approved procedures under the restrictions outlined in u change (c). This footnote will provide assurance that the use of a llPSI L pump while borating will not overpressurize the RCS.

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h. LCO 3.5.3 requires one operable FIPSI pump in MODE 3 (with pressurizer pressure < 1750 psia) and MODE 4. Footnote (#) to this LCO states that a maximum of one IIPSI pump shall be operable when the temperature of L one or more RCS cold legs is s 27.5 F. The proposed change increases the

! applicable temperature to 3190F. Additionally, the footnote will now state that the operable pump may be in pull-to-lock and can be manually operated in accordance with approved procedures (from Reference (d)). This change will also assure appropriate overpressure protection is provided in the low temperature region.

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i. A foctnote has been proposed for the surveillance requirements of Technical -

l Specification 4.5.2. The note allows full flow testing of a IIPSI pump to I be conducted at RCS temperatures s 319 F as lon8 as the llPSI pump is L recirculating RCS water. This prevents a mass addition to the RCS from

! other water sources, if a llPSI pump is to be tested without recirculating

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c. _ Document C=tr:1 Desk  !

March 2,1990 Page 6 - . J RCS ' water, the controls of LCO 3.4.9.3 apply. These controls, discussed in change (c), limit the mass addition from a HPSI pump or require an appropriate vent to exist. This prevents overpressurization of the RCS due ,

j; to a mass addition transient.

J. The basis for LCO 3.5.3 have been changed to reflect the new restrictions on HPSI operation imposed by the above changes, 4

DETERMINATION OF SIGNIFICANT HAZARDS This proposed change has been evaluated against the standards in 10 CFR 50.92 and has.

been determined to involve no significant hazards considerations, in that operation of the facility in accordance with the proposed amendment would not: -

(i) involve a significant increase in the probability or consequences of an accident previously evaluated; or The Unit i 12 EFPY P-T limits were conservatively developed in accordance with the fracture toughness requirements of 10 CFR 50, Appendix G as supplemented . . by the ASME Code Section 111 - Appendix - G. The mechanical properties and chemical composition of the reactor vessel beltline materials used in the analysis were the same as those used to evaluate the Pressurized Thermal Shock (PTS) concern in January 1986.

These ' material characteristics have been reviewed and accepted by the NRC (Reference (e)). The peak reactor vessel fluence was calculated using ,

Discrete Ordinate Transport (DOT) calculations with a DOT IV.3 computer code. The analysis of the reactor vessel material irradiation surveillance specimens was used to verify the validity of-the fluence calculations. The Adjus".1 RTNDT values were based on- the conservative methodology provided 4 Regulatory Guide 1.99, Revision 2 (Draft).

The LTOP controls . have been revised to ensure compliance with the 12 EFPY P-T limits as described in this submittal. Administrative controls have been revised to prevent occurrence of events for which automatic protection - is insufficient. The PORY low pressure setpoint has been reduced from 450 psig (464.7 psia) to 422.7 psia to ensure protection is provided during solid plant conditions. The revised P-T limits provide conservative limits on reactor coolant system pressure to minimize the likelihood of a rapidly propagating fracture due to pressure - transients at low temperature.

The revised LTOP controls provide adequate assurance that the P-T limits will not be exceeded during normal operation and anticipated operational occurrences in - the low temperature region. Therefore, the proposed amendment does not involve an increase in the probability or consequences of accidents previously evaluated.

(ii) create the possibility of a new or different type of accident from any accident previously evaluated; or

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9 The P-T _ limits and revised LTOP controls do not represent a significant change in the configuration or operation of the plant. Specifically, no new hardware is being added to the plant as a result of these proposed l changes, no existing equipment is being modified, not. are any significantly

- different types of operations being introduced. Therefore, the proposed amendment would not create the possibility of a new or different kind of >

accident from those previously evaluated.

(iii) involve a significant reduction in the margin of- safety.

The 12 EFPY curves provide an adequate margin of safety as required by 10 CFR 50, Appendix G, as supplemented by ASME Code Section Ill, Appendix G. The conservative methodology of Regulatory Guide 1.99, Revision 2

. (Draft) also provides an adequate margin of safety for the prediction of reactor vessel neutron embrittlement. The revised LTOP administrative  ;

controls provide adequate protection assuming failure of the most limiting i single active component. Therefore, the proposed amendment .would not significantly reduce the margin of safety.

SAFETY COMMrITEE REVIEW The attached proposed changes to the Technical Specifications and our determination of significant hazards have been reviewed by our Plant Operations and Off-Site Safety Review Committees, and they have concluded that implementation of these changes will not result in an undue risk to the health and safety of the public.

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Y Very truly yo

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., j STATE OF MARYLAND  :  ;

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I ' hereb> er y that on the day of' , 19 k ore me, the subs 9tjiber. a N ry Public of the State of Maryland in and for ;. > L+0 I

/ 'A us_ , personally.. appeared George C.l Creel, being d'uly sworn, angstates f that he is Vifc jPresident of the Baltimore Gas and Electric Company, a corporation: of :

the State of IWhryland; that he provides the foregoing response for the purposes therein' ,

. set ' forth; that- the statements made . are true and correct to the best of his knowledge,.

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information, and- belief; and that he was authorized to prov' e the response on, behalf of said Corporation, ,

. WITNESS my liand and Notarial Scal: "

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N ry Public My Commission Expires: / >>  !

GCC/ PSF /bjd -

6' F J Attachment .

cc: D. A. Brune, Esquire J, . E. Silberg. Esquire R. A.Capra, NRC D. G. Mcdonald, Jr., NRC W. T. Russell, NRC J. E. Beall, NRC

'l'  : T. Magette, DNR ,

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