ML20196D097

Forwards Request for Addl Info Re Proposed Changes to Tech Specs & FSAR Concerning Nuclear Svc Water Sys.Response Requested within 30 Days

ML20196D097
Person / Time
Site:	Catawba
Issue date:	01/22/1988
From:	Jabbour K Office of Nuclear Reactor Regulation
To:	Tucker H DUKE POWER CO.
References
TAC-66403, TAC-66404, NUDOCS 8802170017
Download: ML20196D097 (4)

Text

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I January 22, 1988

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Docket No.:

50-413 DISTRIBUTION 50-414 Dochet FU e.

NRC & Local PDRs PDII-3 Rdg.

W. LeFave Mr. H. B. Tucker, Vice President S. Varga J. Wermiel Nuclear Production Department G. Lainas J. Craig Duke Power Company K. Jabbour 422 South Church Street M. Rood J. Partlow Charlotte, North Carolina 28242 OGC Bethesda E. Jordan

Subject:

Catawba Nuclear Station, Units 1 and 2 - Request for Additional Information on Nuclear Service Water System (TACs 66403/66404)

By letter dated October 16, 1987, you provided infonnation concerning proposed changes to the Technical Specifications and Final Safety Analysis Report (FSAR) related to the Nuclear Service Water (RN) System at Carawba Nuclear Station Units 1 and 2 The proposed FSAR changes revise the design bases of the RN system by deleting the assumption of a simultaneous LOCA and seismic event.

As a result, the NRC staff disagrees with your conclusion that the proposed changes would not

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involve an increase in the probability or consequences of any previously evaluated accident. Thus, you should revise your submittal to address this matter.

Also based on its review, the staff finds that additional information, identified in the enclosure, is required to evaluate the proposed changes.

Your response to the enclosure is requested within 30 days from the date of this letter.

Please contact me at (301) 492-7367 if you have questions regarding the enclosure or are unable to meet the requested response date.

Sincerely, Kahtan N. Jabbour, Project Manager Project Directorate II-3 Division of Reactor Projects, I/II

Enclosure:

As stated cc:

See fext page d3

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PDII-(3/PM PQW/LA PDII-3/ Acting PD KJabbour MRood KJabbour 1/2.t/88 1//8(88 1/tV88 8802170017 880122 DR ADOCK 050 3

Enclosure t

PLANT SYSTEMS BRANCH pE0llEST FOR ADDITIOUl INFORMATION PROPOSED TECHNICAL SPECIFICATION AND FSAP CHANGES P.FLATED TO THE NUCLEAR SFPVICE WATER SYSTEM CATAWPA, NUCLEAR STATION UNITS Ui? DOCKET NOS. 50-413/414 1

In Technical Specification Tables 3.3-3, and 4.3-2 Item 14.0, the Applicable Mode is identified as Modes 1,2,3,4 This should be revised to identify that it applies when either unit is in Fodes 1,2,3,4 because even for sirgie unit operation, both pump pits must be operable.

P.

The proposed revision to the Bases B3/4.7.4 identifies that one RN pump has sufficient capacity to maintain a unit indefinitely in COLD SHilTDOWN (conmencing 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> following a trip from full power) while supplyina the post-LOCA loads on the other unit.

However, the proposed Specification 3/4.7.4 for the RN system does not consider the 36 hour4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> time period.

For example, Specification 3.7.4 discusses "both units in MODE 1,2,3 or 4."

It should discuss either both units in MODE 1 ?,3 or 4 er-one unit in MODE 1,2,3 or 4 plus the other unit in MODE 5 or 6 for less than 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. Revise your proposed specification to reflect this 36 hour4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> period.

3.

The proposed surveillance reouirements for the standby nuclear service water pond (SNSWP) under Technical Specification 3/4.7.5 added a requirement to measure the RN terperature in the discharoe path of an operating RN pump during the months of July, August and September while the RN systen is aligned to Lake Pylie. Phile this may be a recessary operatien, it does not appear to effect the operability of the SNSWP as implied by the location of the requirement.

Revise the proposed specifications to identify why this measurement is recessary and place it in the proper location.

4 In the proposed FSAR amendment the RN flows to the containment spray (CS) beat exchanger and component coolino water (CCW) heat exchanger have been decreased from 4500 gpm to 3800 gpm and 6500 ppm to 5200 gpm, respectively. Consequently the design heat transfer capability has been correspondingly decreased. Provide the following related infometion:

a. Explain the reason for this decrease in RN flows and discuss why no other RN cooled components are affected, i.e., is there a corresponding flow reduction to other components cooled by the RH system?

b. Why is there no corresponding change in the post - LOCA containment pressure / temperature profiles? If there is a charge l

then the FSAR should be revised accordingly.

5.

Because the revised design results in a situation where following an accident, the RN system might very well continue to draw from Lake Wylie instead of the SNSWP, the maxinum temperature of Lake Wylie should also fall within the Technical Specification.

Revise your Technical Specifications accordingly.

(Refer to Ouestion 3 above)

J

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6.

Do crossover valves between SW trains still receive close signals on a safety iniection signal (SIS) or containment isolation signal?

It was the staff's understandino that only the switchover from Lake Vylie to the SNSWP would be eliminated following an SIS.

Specifically identify these valves whose operation on an STS or containmert isolation sigrel will te different followino the proposed changes.

The staff's concern is that all possible scenarios are considered, especially if the proposed changes involve more than the switchover between Lake Wylie and the SNSWP.

In your response specifically identify wbother you still have autonatic isolation between trains and discuss when such isolation i

would occur.

7.

If automatic cressover isolation or isolation of nonessential loads does not occur until loss o# Lake Wylie, then you should reevaluate various scenarios other than LOCA during different rodes of operation to i

ensure that the proposed Technical Specifications are acceptable.

For example, evaluate a diversion of RN flow through a faulted nonessential portion of the system under different possible accident scenarios.

3.

The safety injection pumps' and CCW punps' heat exchanger inlet velves were previously identified as interlocked to open when their respective pump started. The proposed amendment deletes this from the FSAR.

Explain why this change was made and justify deletien of this interlock.

9.

On page 9.2-1 of the FSAR, it was previously stated that "should Lake Wylie be lost due to a seismic event..... the SNSWP contains l

sufficient water to bring the station safely to a cold shutdown condition following a single loss of coolant accident".

Your proposed FSAR amendnent deletes "following a single loss of coolant accident." Even though your proposed change is to delete a simultaneous LOCA and seismic event as a design basis, the SNSWP still must be capable of handling a LOCA upon loss of Lake Vylie.

You should revise the subject FSAR statement to state that the SNSVP contains sufficient water to bring the station safely to a cold shutdown condition under all normal, transient and accident conditions. The automatic switchover on low pump pit level should assure this function.

10. On page 8.?-9 of the FSAR, you deleted the statement that "the operation of any two purps on either or both supply lines is sufficient to supply all cooling water requirements for the two unit plant for post-accident operation". Your revision does not include "post-accident operation."

Does this deletion / revision freen that two pumps cannot bandle all accidert situations, or are you implying that one pump is sufficient under all accidert conditions.? The reason for this change should be made clear. Also, if you are saying one pump is sufficient, then supporting analysis should be provided such that the sta#f can make its ovr independent evaluation.

11.

In a similar vein, on revised FSAR page 9.2-5 it is stated that "bearing lube oil injection flow is maintained to all RN pumps at all times, ever though only one pump is reouired to meet all the r,creal and accident flow requirements of both units." Previously, this was considered to be applicable only under nomal conditions.

You should clarify what the

.3 design bases for the RN system is, one pump or two pumps.

From the i

Technical Specification bases if appears that one pump is sufficient for accident situations only after one unit has been shutdown for greater than 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />.

12. On page 9.2-7 of your proposed FSAR revision, you have deleted the fact that the RN system is designed to handle a LOCA in one unit with a sinultanecus shutdown of the other unit plus the lost of Lake Wylie.

This is unacceptable. The staff reouires that this remain a design basis for the PN system and the ultinate heat sink, the standby nuclear service water pond. Although simultaneous LOCA and seismic loads do net have to be considered, reliance on Lake Wylie which is not designed to seismic Category I requirements is not acceptable under LOCA conditions i.e. General Design Criterion 2 and 10 CRF part 100.

13. Additionally, on the revised Safety Evaluation Section of the FSAR (page 9.2-7) you state that upon complete channel separation, both units are assured of beving a source of water and et least one pump. This is not as clear as in the original FSAR where it is stated that each unit will have at leest one 100 percent cap 3 city pump.

Revise this preposed change to identify whether each Unit is assured of having at least one pump or not. If you intend to rely en a single pump for both units then the appropriate analysis should be provided.

14.

In the original FSAR, Section 9.2.1.3, you stated that any one diesel gererator can be down for maintenance and the RN system can still shut the plant down safely assuming a LOCA, seismic event, blackout, and single failure.

In your proposed amendment you have eliminated the seismic event.

Identify the bases for this elimination as you apparently have made no design changes that certradict this design basis. At any rate, the loss of Lake Wylie should be considered as part of the design basis in conjunction with a LOCA. (refer to Question 11 above).

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