ML19354D627

Application for Amend to License DPR-53,disabling Automatic Start Feature of HPSI Pumps in Low Temp Overpressure Protection Condition

ML19354D627
Person / Time
Site:	Calvert Cliffs
Issue date:	12/20/1989
From:	Creel G BALTIMORE GAS & ELECTRIC CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML19354D628	List: ML19354D627 ML19354D629
References
NUDOCS 8912280327
Download: ML19354D627 (5)

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BALTIMORE GAS AND ELECTRIC CHARLES CENTER . P. O. BOX 1476. BALTIMOR E, MARYLAND 21203 Gromot C. CREEL December 20,1989 Vice Passiotut NuCLEAn Ehtmov (800 860 4465 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 Request: High Pressure Safety Inicalon Pumn Operability in MODE 3 REFERNCE: (a) Letter from Mr. G. C. Creel (DC&E) to Document Control Desk (NRC), dated October 27, 1989, Request for Amendment Gentlemen: The Baltimore Gas & Electric Company hereby requests an amendment to its Operating License No. DPR-53 in accordance with 10 CFR 50.90 and 50.91 with the submittal of these proposed changes to the Technical Specifications. This change supercedes Change No. 3 of Reference (a). INTRODUCTION' As part of a review of our Low Temperature Overpressure Protection (LTOP) system, we have identified the need to propose Technical Specification changes to ensure adequate protection of the reactor vessel at low temperature. The proposed changes affect High Pressure Safety injection (HPSI) pump operability while the potential for low temperature overpressurization exists. Currently, our LTOP system is enabled at 330 F, while we are in MODE 3 operation. Our Technical Specifications require that the HPSI pumps be available for automatic operation while in MODE 3. If a HPSI pump were . to inadvertently actuate while in the LTOP condition, we would overpressurize the reactor vessel. Therefore, we are proposing changes which would disable the automatic start feature of the IIPSI pumps when in the LTOP condition. We are requesting that these changes be approved prior to February 8, 1990. We anticipate entering MODE 3 around that date. LTOP is required up to 330 F, therefore,- we- must enter MODE 3 prior to disabling our LTOP system. However, an integral part of our LTOP system involves disabling the HPSis. Until these changes are approved, we cannot enter MODE 3. The remainder of the changes requested by the NRC require that we operate in a more conservative manner that the Technical Specifications allow. We will submit those conservative changes under a separate amendment request. 8912280327 891220 , i gDR ADOCK0500g7

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          ' . Document C:ntr:I Desk December 20,1989 Page 2 '

Ql6NGE NO. I Changes pages 3/4 3-11 and 5-1 of the Unit 1 and Unit 2 Technical Specifications as

            - shown on the atta:hed marked-up pages.

DISCUSSION (a) To comply with Technical Specification LCO 3.5.3, the plant is operated with at i least one llPSI pump available on an automatic start signal when in MODE 3. in addition, Table 3.3-3 requires the availability of a llPSI pump for manual start in MODES 3 and 4 for 1.a. and automatic start for MODE 3 only for 1.b and c. Ilowever, because of LTOP concerns, a llPSI pump must be placed in PULL-TO-LOCK to minimize the likelihood of spurious llPSI initiation whenever RCS temperature drops to or below the MPT enable temperature. These proposed changes would allow the OPERABLE IIPSI pump to be in PULL-TO-LOCK when RCS temperature is at or below 350 F, as long as the minimum Safety injection Tanks (SITS) pressure and volume required by LCO 3.5.1.b is maintained throughout MODE 3. his requirement would terminate upon entering MODE 4. j in support of this change, a conservative evaluation was performed to determine the SIT pressure and volume needed to refill the RPV following a LOCA and the minimum time available to initiate additional RCS make-up flow to maintain 1 core heat removal. The calculation determined - that the operator has at least 20 minutes to initiate additional injection flow (greater than approximately 200 gpm) to maintain long-term core heat removal. This evaluation was based on the following assumptions:

a. Reactor coolant temperature is less than or equal to 350 F.

b. No limitations are applied on the potential break size or location. A full spectrum of break sizes was considered. The worst case was determined to be a . large cold leg break, such that one SIT spills from the break and consequently provides no usable injection flow.

c. All the initial reactor coolant is instantaneously discharged from the break (i.e., no credit for residual inventory following blowdown),

d. Fission product decay heat is based on 110% of the 1971 ANS proposed standard, it corresponds to four hours following reactor shutdown from long-term operation at full power.

e. The core power distribution corresponds to pre-shutdown operation with a peak linear heat rate at 85% core height and at the Technical Specification limit of 15.5 kw/ft.

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Document C:ntr:1 Desk December 20,1989 Page 3

f. Adiabatic heat-up of the fuel hot-spot (i.e., no credit for steam cooling) once the collapsed liquid level in the core drops below the hot-spot location.

g. At least 3975 cubic feet of water available in the SITS.

l; L The evaluation shows that adequate time for operator action is available for manual initiation of IIPSI pump flow following a LOCA event while at an RCS temperature of 350 F or less. The acceptance criteria for system performance is the same as that given in Chapter 14 of the Final Safety Analysis Report. DETERMINATION OF SIGNIFICANT llAZARDS l These proposed changes have 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 Administrative controls are being revised to prevent the occurrence of events in which automatic protection is not sufficient to prevent exceeding i the LTOP limits. _The evaluation performed shows that, by utilizing SIT l- availability in lieu of automatic HPSI pump starting, adequate protection i against the effec.t of a LOCA is still provided until operator action can manually initiate llPSI flow. Therefore, the proposed change does not significantly increase the probability of an accident previously evaluated. Furthermore, this change will not result in a significant change to the configuration or operation of the plant, and thereforc, would not significantly increase the consequences of an accident previously analyzed. (ii) Create the possibility of a new or different type of accident from any accident previously evaluated; or This proposal would disable the automatic HPSI pump start capability at and below 350 F, but an adequate substitute (SITS) as demonstrated by the i evaluation, will be provided. No significant plant configuration or operation changes are required. Specifically, no new hardware is being added to the plant, no existing equipment is being modified, nor are any new or different types of operations being introduced. Therefore, the possibility of a new or different type of accident from any accident previously evaluated would not be created.

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            " Document C;;tr:I Desk December 20,1989 PPge 4 (iii)                                   Involve a significant reduction in the margin of safety.

Administrative controls have been added to reduce the likelihood of inadvertent ' mass addition accidents. The reactor vessel integrity limits will not be challenged when the described administrative controls are applied. The proposed Technical Specification change substitutes the SITS for automatic HPSI pump start in the event of a LOCA at 350 F and i below. The evaluation performed shows that adequate flow would still be available with the conservative assumptions listed in the discussion. Adequate protection against the effect of a LOCA is still provided until operator action can manually initiate llPSI flow, if the SITS are used as described in this submittal. Therefore, the proposed changes would not ' significantly reduce the margin of safety. SAFETY COMMITTEE REVIEW These proposed changes to the Technical Specifications and our determination of  ; significant hazards have been reviewed by our Plant Operations and Off-Site Safety l Review Committees, and they have concluded that implementation of these changes will i not result in an undue risk to the health and safety of the public.

          Document Control Desk
               . December 20,1989

[ Page 5 Very truly yours

                - STATE OF MARYLAND                 :
                               /)                   :     TO WIT :

f) thaAn Y CLlht-{ -  : I hereby certify that on the NO S day of ^W ,19N, before, me, the subs 9 tiber, a Notary ' Public of the State of Maryland in and for 14 M1Lo r3

                      / m..t3m            , personally appeared George C. Creel, being duly s' worn,(/and states that he is gice President of the Baltimore Gas and Electric Company, a corporation of the State of Maryland; 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, information, and belief; and that he was authorized to provide the response on behalf of said Corporation.

WITNESS my-fland and Notarial Seal: th /LM

                                  -                                          /          otar'y Public My Commission Expires:                                        ILA> !s sate

[ GCC/ PSF /bjd Attachment cc: D. A. Brune, Esquire J. E. -Silberg, Esquire R. A.Capra, NRC S. A.McNeil,NRC W. T. Russell, NRC J. E. Dealt, NRC T. Magette, DNR}}