ML20214S297

Application for Amend to License DPR-61,revising Tech Specs to Incorporate Guarantee That motor-operated Valves Installed During 1987 Refueling Outage Remain in Position in Order Not to Cause Adverse Effects to Eccs.Fee Paid

ML20214S297
Person / Time
Site:	Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png
Issue date:	06/01/1987
From:	Mroczka E CONNECTICUT YANKEE ATOMIC POWER CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
Shared Package
ML20214S299	List: B12544, Proposed Tech Specs,Incorporating Guarantee That New motor-operated Valves Scheduled for Installation During 1987 Refueling Outage Remain in Respective Positions,Causing No Adverse Effects to ECCS ML20214S297
References
B12544, NUDOCS 8706090218
Download: ML20214S297 (7)

Text

.

p.

CONNECTICUT YANKEE ATOMIC POWER COMPANY B E R L I N. CONNECTICUT P.O. box 270 e HARTFORD, CONNECTICUT 06141-0270 TELEPHONE June 1,1987 203 465 5000 Docket No. 50-213 B12544 Re: 10CFR50.90 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555 Gentlemen:

Haddam Neck Plant Proposed Revision to Technical Specifications Emergency Core Cooling System Pursuant to 10CFR50.90, Connecticut Yankee Atomic Power Company (CYAPCO) hereby proposes to amend its Operating License, DPR-61 by incorporating the attached proposed change into the Technical Specifications of the Haddam Neck Plant.

In general, the proposed changes will guarantee that the new motor-operated valves (MOV) scheduled to be installed during the 1987 refueling outage will remain in their respective positions in order to not adversely affect the Emergency Core Cooling System (ECCS) until the valves are electrically powered during the 1989 refueling outage. The proposed change also requires the throttle valves which will be installed in the high pressure safety injection (HPSI) lines to be locked in their proper position.

Background

On March 31, 1986,(1) CYAPCO submitted a Probabilistic Safety Study for the Haddam Neck Plant which included best estimate loss of coolant accident (LOCA) analyses for that facility. Through these analyses, CYAPCO identified a small range of break sizes in one loop of the reactor coolant system for which safety injection flow in the high pressure recirculation mode may be insufficient to provide adequate core cooling.

The temporary measures undertaken by CYAPCO and approved by the NRC to respond to this range of small break LOCAs involved revising Haddam Neck emergency operating procedures regarding LOCA responses to provide, onder prescribed conditions, an alternative flow-path for core cooling during the high pressure recirculation mode. The revision provides for establishment of the long-term recirculation mode using the HPSI pumps.

I (1) 3. F. Opeka letter to C.1. Grimes, "Haddam Neck Plant Probabilistic Safety

$ I Study - Summary Report and Results," dated March 31,1986.

8706090218 DR 870601 ADOCK 0500 3 G ceM/C g g uo

U.S. Nuclear Regulatory Commission B12544/Page 2 June 1,1987 Use of the HPSI pumps for this recirculation path requires realignment of certain valves, including two valves which do not satisfy single failure requirements.

Accordingly, CYAPCO requested an exemption from the single failure requirements for these valves, pendin which satisfied those requirements.(2)g implementation On April of permanent 28, 1986, the Staff granted themeasures requested exemption for Cycle 14.13)

On September 30, 1986,(4) CYAPCO submitted a request for an extension to the single failure exemption and provided a detailed description of the permanent modification and its implementation schedule. As previously stated, the extension is necessary because the electrical modifications for the permanent resolution cannot be completed until the 1989 refueling outage.

In December 1986, while analyzing the design for these modifications, a medium size break in the core deluge system was identified which could not be sufficiently mitigated during sump recirculation. Procedures were developed, a flow control valve (FCV) was repositioned and the technical specifications were changed to provide a temporary resolution to this problem. On December 24, 1986,t5) the Staff approved the Technical Specification change.

Additional information submitted to the NRC on April 1, 1987,(6) restated CYAPCO intentions to install all necessary mechanical modifications during the 1987 refueling outage followed by the electrical modifications during the 1989 refueling outage. Therefore, in order to maintain the present method for mitigating LOCAs during Cycle 15 operation, the new valves will be required by technical specifications to be kept in their respective positions.

The permanent mechanical modifications consist of cross-connecting the residual heat removal (RHR) pump discharge, downstream of the RHR heat exchanger, to the HPSI pump suction in order for an RHR pump to feed a HPSI pump for high head sump recirculation. Manual throttle valves will be installed on each of four HPSIlines to balance flow and to prevent a HPSI pump from exceeding RHR (2) 3. F. Opeka letter to C. I. Grimes, "Haddam Neck Plant - Request for Temporary Exemption from Single Failure Requirements," dated April 22, 1986.

(3) F. 3. Miraglia letter to 3. F. Opeka," Exemption from Single Failure Criterion (GDC-35) - Haddam Neck Plant," dated April 28,1986.

(4) 3. F. Opeka letter to C. I. Grimes,"Small Break LOCA Permanent Resolution

- Request for Extension of Single Failure Exemption," dated September 30, 1986.

(5) C.1. Grimes letter to 3. F. Opeka, " Revision to Technical Specifications -

Repositioning Flow Control Valve RH-FCV-796," dated December 24,1986.

(6) E. 3. Mroczka letter to the NRC Document Control Desk, "ECCS Modifications Additional Information - Request for Extension of Single Failure Exemption," dated April 1,1987.

U.S. Nuclear Regulatory Commission B12544/Page 3 June 1,1987 design flow when operating in the sump recirculation mode. A new MOV will also replace an existing normally open manual valve in the core deluge line in order to provide redundant isolation of that line.

Discussion The individual Technical Specification requirements for each of the new valves is discussed below.

SI-MOV-854 A and B These HPSI pump suction isolation valves are replacing existing manual valves, SI-V-854A and B, which are normally open during operation. When the HPSI pumps receive flow from the containment sump via the RHR pumps, the refueling water storage tank must be isolated to prevent refilling it with potentially highly contaminated water. These two MOVs along with the existing MOV (SI-MOV-24) will provide redundant isolation. Since the new MOVs will not be energized and will be required to open during operation, the change has no effect on system configuration. The proposed change to require verification that these valves are locked in the correct (open) position once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> represents the addition of a new requirement to insure proper system configuration and is, therefore, not detrimental to safety. System configuration is essentially unchanged until the MOVs receive electrical power.

SI-MOV-901 and 902 These valves isolate the new cross-tie line and are required to be closed until the completed electrical modifications are implemented in 1989. Since the cross-tie line is new, maintaining Liese valves in the closed position eliminates flow through this line, thus resulting in no change from the present system configuration. The proposed change to require that these valves are locked in the closed position and verified once every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> ensures that these valves remain in the proper system configuration and therefore, does not impact safety.

SI-MOV-873 This valve will be located in the core deluge line and will serve as a redundant means of isolating the core deluge line once the entire modification is implemented in 1989. It is replacing manual valve SI-V-873 which is open during operation. Since the nes MOV will not be energized and will be required to open during operation, the change will have no effect on system configurati:)n. The proposed requirement to verify that this valve is locked in the correct (open) position and deenergized prior to start up from cold shutdown represents the addition of a new requirement to ensure correct system configurat}on and therefore, does not impact safety. This valve is located in containmeni and is also locked open. More frequent surveillances are, therefore, impractical, not warranted and not in keeping with ALARA.

SI-V-905, 906, 907, and 908 These manual valves, which are located in the containment loop areas are throttle valves which are set to balance flow in the four HPSI injection lines.

U.S. Nucl:ar Regulatory Commission B12544/Page 4 June 1,1987 These valves are also set to prevent HPSI flow from exceeding RHR design flow when an RHR pump is used to feed a HPSI pump during sump recirculation. The correct positions of these valves will be established by a test following completion of the modification. Blocking and locking devices will ensure that these valves remain in the proper throttled position.

The proposed requirement to verify that these valves are locked in the correct throttled position prior to start-up from cold shutdown adequately ensures that these valves remain in the correct position. Since these valves are located in containment in an area that is not accessible during operation due to radiation and in the overhead, out of reach, more frequent surveillances are not warranted and are not in keeping with ALARA.

Correct position verification for the HPSI throttle valves following maintenance or stroking will be required under the proposed technical specification change.

This ensures that these valves will be placed in their required positions following any maintenance activities. Correct positioning of RHR flow control valve RH-FCV-796 is also required to be verified within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> after surveillance activities, which will be accomplished by replacing the locking collars, and within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> af ter maintenance activity (i.e., valve disassembly) by conducting an RHR flow test. This valve was placed in the throttled position in December, 1986 af ter discovering the core deluge line break concerns. This section of the technical specification ensures that these valves will not be lef t in an improper position following maintenance activities. The proposed change requires that the ECCS subsystems be rebalanced and rethrottled following any modifications which could alter flow characteristics. This requirement is over and above inservice inspection requirements and ensures that future modifications will not result in placing the ECCS in a condition outside of its design basis.

Several editorial changes have been made to the Technical Specifications.

Changes have also been made to Final Design Safety Analysis (FDSA) references in the Technical Specifications in order to make them consistent with the updated Final Safety Analysis Report (FSAR). These changes have no impact to safety.

Safety Evaluation CYAPCO has reviewed the attached proposed changes pursuant to 10CFR50.59 and has determined that they do not constitute an unreviewed safety question.

The probability of occurrence or the consequences of a previously analyzed accident have not been increased and the possibility for a new type of accident has not been created. This change is limited to ensuring that the installation of new valves and new piping lines do not effect the present ECCS configuration.

No new failure modes are introduced with this change because the new valves will have no electrical power and will be positioned (opened / closed) such that the present ECCS functional configuration is unchanged. The proposed change does not impact the consequences to the protective boundaries and therefore does not reduce the margin of safety as specified in the basis of the Technical Specifications.

U.S. Nuclear Regulatory Commission B12544/Page5 June 1,1987 Effect on Design Basis Accident Analysis The impact of the change on the design basis large break and small break LOCAs has been reviewed and has been determined that these analyses are unaffected by the change. The affect of the new HPSI line flow balancing valves is improved mitigation for HPSI line breaks and a very slight decrease (2 per cent) in HPSI pump delivery flow when all HPSI lines are intact. With this slight flow decrease the new sum of available LPSI and HPSI flow remains greater than that assumed in the large break LOCA analysis. The slight flow decrease will not affect the small break LOCA analyses since the peak clad temperature (PCT) is governed by the loop seat behavior which produces a momentary total core uncovery for the limiting 0.075 f t2 cold leg break. Because the PCT for the 0.075 f t2 break occurs during the period of time the loop seals are clearing where total core uncovery occurs momentarily, a 2 percent decrease in HPSI flow will not affect the PCT for the limiting break. As a consequence it can be concluded that ECCS performance is unaffected by the proposed change and the present accident analyses remain bounding.

Potential for Creation of an Unanalyzed Accident As previously stated, there are no new failure modes associated with this proposed change because the new valves will have no electrical power and will be positioned such that the present ECCS functional configuration is unchanged.

No new potential accident is created because the proposed change does not modify the plant response. Neither the change nor the associated failure modes affect the normal operating conditions of the plant or the plant response. This proposed Technical Specification change ensures that the system will remain unchanged and therefore the current safety analysis remains correct.

Effect on the Margin of Safety As noted above, the proposed change does not diminish ECCS LOCA mitigation capability and thereby does not impact the consequences to the protective boundaries. The proposed Technical Specification change ensures proper system configuration and therefore is not detrimental to the public health and safety.

The proposed change does not reduce the margin of safety as specified in the basis of the technical specifications.

Summary and Conclusions Based on the foregoing assessment, the change proposed herein is considered safe and does not represent an unreviewed safety question as defined in 10CFR50.59 since it does not:

1. Increase the frequency of occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated in the safety analysis report;

2. Create the possibility of an accident or malfunction of a different type than any evaluated previously in the safety analysis report;

O U.S. Nucisar Regulatory Commission B12544/Page 6 June 1,1987

3. Reduce the margin of safety as defined in the basis for any Technical Specification.

Significant Hazards Consideration in accordance with 10CFR50.92, CYAPCO has reviewed the attached proposed change and has concluded that it does not involve a significant hazards consideration. The basis for this conclusion is that the three criteria of 10CFR50.92(c) are not compromised; a conclusion which is supported by our determinations made pursuant to 10CFR50.59. The proposed change does not involve a significant hazards consideration because the change would not:

1. Involve a significant increase in the probability or consequences of an accident previously evaluated. As stated above, these changes ensure that the present system configuration is maintained, therefore, the probability of occurrence of the design basis accidents is unchanged.

Since adequate LOCA mitigations is maintained, the consequences of the design basis accidents are not impacted.

2. Create the possibility of a new or different kind of accident from any previously evaluated. There are no new failure modes associated with this proposed change. No new systems or designs are introduced by these proposed changes; therefore, no new failure modes are created. In addition, operating characteristics are unchanged. Thus, no new accident possibilities are created.

3. Involve a significant reduction in a margin of safety. As stated above, the proposed change does not diminish ECCS LOCA mitigation capability and thereby does not impact the consequences to the protective boundaries. Thus, these changes will not reduce the margin of safety as defined in any Technical Specifications.

Moreover, the Commission has provided guidance concerning the application of standards set forth in 10 CFR 50.92 by providing certain examples (March 6, 1986, F_RR 7751) of amendments that are considered not likely to involve .

significant hazards consideration. The change proposed herein is most closely enveloped by example (ii), a change that constitutes an additional control not presently included in the Technical Specifications. The proposed change imposes periodic surveillance requirements to ensure valves are in the correct position, post-maintenance surveillance requirements for the throttle valves and retest requirements following significant modifications to any ECCS subsystem.

Since the proposed change provides added assurance that the ECCS system configuration will be maintained, the probability of occurrence of the design basis accidents is unchanged. Since the proposed change will not diminish ECCS LOCA mitigation capability, the safety margin as specified in the basis of the technical specifications remain valid and thus the consequences of the design basis accidents are not impacted. Therefore, the proposed change would not involve a significant hazards consideration.

The Haddam Neck Plant Nuclear Review Board has reviewed and approved the attached proposed revision and concurs with the above determinations.

U.S. Nuclear Regulatory Commission B12544/Page 7 June 1,1987 In accordance with 10CFR50.91(b), CYAPCO will provide the State of Connecticut with a copy of this proposed amendment.

Pursuant to the requirements of 10CFR170.12(c), enclosed with this amendment request is the application fee of $150.00.

Very truly yours, CONNECTICUT YANKEE ATOMIC POWER COMPANY

. cJ E. 3.'Mf6czka //

Senio/Vice President cc: Mr. Kevin McCarthy Director, Radiation Control Unit Department of Environmental Protection Hartford, Connecticut 06116 W. T. Russell, Region I Administrator F. M. Akstulewicz, NRC Project Manager, Haddam Neck Plant P. D. Swetland, Resident Inspector, Haddam Neck Plant STATE OF CONNECTICUT )

) ss. Berlin COUNTY OF HARTFORD )

Then personally appeared before me E. 3. Mroczka, who being duly sworn, did state that he is Senior Vice President of Connecticut Yankee Atomic Power Company, a Licensee herein, that he is authorized to execute and file the foregoing information in the name and on behalf of the Licensees herein and that the statements contained in said information are true and correct to the best of his knowledge and belief.

Abstin b 17?/ W

$otary Pyc My Commission Expires March 31,1988

-_ __