ML20027C415

Forwards Revised FSAR Section 6.2.2 Providing Justification for Excluding Inert Cover Gas on Sodium Hydroxide Storage Tank.Info Will Be Incorporated in Amend 48 to OL Application

ML20027C415
Person / Time
Site:	Seabrook
Issue date:	10/07/1982
From:	Devincentis J PUBLIC SERVICE CO. OF NEW HAMPSHIRE, YANKEE ATOMIC ELECTRIC CO.
To:	Kerrigan J Office of Nuclear Reactor Regulation
References
SBN-341, NUDOCS 8210150510
Download: ML20027C415 (4)

Text

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PUEBUC SERVICE suma summ rasi  % o sc.:

Companyof New Hampshire 1671 Worcester Road Framingham, Mossochusetts 01701 (617) - 872 - 8100 October 7, 1982 SBN- 341 T.F. B 7.1.2 United States Nuclear Regulatory Commission Washington, D. C. 20555 At tention: Ms. Janis Kerrigan, Acting Chief Licensing Branch 3 Division of Licensing Re f e re nce s : (a) Construction Permits CPPR-135 and CPPR-136, Docket Nos. 50-443 and 50-444 (b) USNRC Letter, dated August 13, 1982, " Draft Safety Evaluation Report (SER) for Seabrook Station",

T. M. Novack to W. C. Tallman

Subject:

Draf t SER Section 6.1.1

Dear Ms. Kerrigan:

The following comment appears in the Draft SER Section 6.1.1, which was forwarded in Reference (b):

"The applicant has taken exception to the SRP recommendations to provide an inert cover gas on the sodium hydroxide storage tank to prevent deterioration of the chemicals. However, the applicant has not provided the information necessary to complete our review. We wLil report the resolution of this item after we receive the necessary information."

In response to the above comment, we will revise FSAR Section 6.2.2 as indicated on the attached FSAR pages 6.2-42 and 6.2-43 to provide justification for not including an Enert cover gas on the sodium hydroxide storage tank. This information will be included in Amendment 48 to the OL Application.

Very truly yours, YANKEE ATOMIC ELECTRIC COMPANY @f A,J J. DeVincentis Project Manager ALL/dd 82iO150510 821007 Attachment PDR ADOCK 05000443 A PDR

, . SB 1 & 2 FSAR temperature of 860F, and provides cooling for a minimum of 21.9 minutes after an accident, based upon maximum pumps in operation at '

maximum flow rates. Upon a low level signal from the RWST (approximately 350,000 gallons removed), the suctions of the residual heat removal (RHR) and CBS pumps automac.ically re-align to take suction from the containment recirculation sumps. The *

, operator then manually re-aligns the centrifugal charging pumps to take suction from RHR pump P-8A discharge and the safety injection

, pumps to take suction from RHR pump P-8B discharge. All pumps continue to operate in the recirculation mode until no longer required.

b. Component Description The following are descriptions of the components in the CLS system. RHR pumps and heat exchangers are described in Sections 5.4.7 and 6.3; ECCS component descriptions are found in Section 6.3.

1. Containment Spray Pumps The CBS pumps are horizontal centrifugal pumps selected to supply the design spray flow rate at containment design pressure. The pumps are' designed to take suction from the containment sump at the most limiting NPSH condition (

(atmospheric pressure and a temperature of 2120F) and pump it back into the containment through the spray nozzles. Design pump discharge pressure takes into account containment pressure, elevation head to the highest nozzles, and piping frictional losses.

Each CBS pump is designed to deliver 3010 gpm from the lowest level in the RHR equipment vault to the highest point in the I containment building. Conservative assumptions have been made concerning piping and fitting frictional losses to assure adequate flow under actual conditions.

2. Spray Additive Tank l

The spray additive tank (SAT) is mounted adjacent to the RWST, and drains by gravity into the RWST mixing chamber.

External heaters are provided to prevent freezing or chemical

( precipitation during cold weather. The ratio of the spray additive tank area to the RWST area is such that the initial spray pH is maintained at approximately 9.5. The tank is

sized to provide the correct amount of sodium hydroxide l solution to insure that the final containment recirculation j pump pH af ter injection will be between 8.5 and Mv0=, for the j

various reactor coolant conditions. NoprovisionisQadein the design of the SAT to prevent the reaction of NaOH .with g l

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SB 1 & 2

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atmospheric carbon dioxide during long-term storage. Gte te... ;;!: 1:t:d th:t 1::: th:2 0.0155! cf the M ^M eill re::t

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3. Containment Spray Heat Exchangers The containment spray heat exchangers are shell and tube type heat exchangers with spray flow in the tube side and primary component cooling water (PCCW) on the shell side. They are sized such that one containment spray heat exchanger and one residual heat removal heat exchanger provide 100% of design heat removal capacity.

i Heat exchanger parameters, including flow rates, were selected such that one RHR heat exchanger and one CBS heat exchanger satisfy containment cooling requirements. Table 6.2-76 contains the heat exchanger performance data used for the accident adalyses.

4. Spray Headers and Nozzles The spray headers are positioned in the containment dome to maximize coverage of the containment volume. Four separate

(. headers are utilized to obtain the distribution of the-flow, two for each 3010 gym train. Each train contains 198 nozzles with each nozzle providing a flow of 15.2 gpm (see Figures 6.2-79 and 6.2-80).

5. Refueling Water Storage Tank The refueling water storage tank (RWST) is designed to store 475,000 gallons of borated water. This tank is designed to supply water both for refueling operations and to the

(. containment spray system and the emergency core cooling system l during accident operations. The RWST capacity is based on-

! accident requirements and will supply the safety injection,

the charging, residual heat removal and containment spray l

pumps for at least 21.9 minutes during the injection phase of a design base accident.

l Margin is provided to allow time for transfer of the systems l

to the recirculation mode and to account for instrument errors. Analysis is based on a minimum of 350,000 gallons of l water being injecter'. An external steam heating supply l

system is provided to protect against freezing. Tank temperature is indicated locally and alarmed in the main control room.

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l 6.2-43 j i

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INSERT FOR PAGE 6.2-43 Using extremely conservative assumptions, it has been calculated that a very small fraction (0.0133) of the NaOH would react with the CO2 during the life of the plant. The calculation assumes one complete volume change of air per day (in a stagnant tank) with complete reaction of all CO . The minimum total volume 2

of Na0li (1260 f t3) was assumed ta be present in the tank, thus maximizing the available air space (291 ft 3).

The above calculated loss of Na0li through reaction with atmospheric CO 2 would result in a reduction of NaCll concentration from 20% to 19.7% (by weight) over a forty' year period. This is well within the ' range of concentrations allowed by the plant technical specifications. This will be verified periodically by chemical analysis.

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