ML20087B777

Submits Info Re Evaluation of Flow Test Which Could Have Been Performed on Safety Injection Sys After Completing Mod, in Response to Request from NRC

ML20087B777
Person / Time
Site:	Robinson
Issue date:	07/01/1971
From:	Utley E CAROLINA POWER & LIGHT CO.
To:	Morris P US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20087B779	List: ML20087B777 ML20087B788 ML20087B813 ML20087B838
References
NUDOCS 8403090363
Download: ML20087B777 (3)

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'O Division of Reactor Licensing  %.Q' U. S. Atomic Energy Commission ro l Washington, D. C. 20545 ^

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Dear Dr. Morris:

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We described in our letter of April 13, 1971, the testing which; was performed on the modifications to the Safety-Injection System at-our H. B. Robinson Unit No. 2. The modifications were previously discussed with your Staff on January 22, 1971, and documented in our Ictter to you .

of January 25, 1971. In response to a subsequent request from your Staff regarding our evaluation of the flow tests which could have been performed on the Safety Injection System af ter completing the modification as well as additional submit details information:

the following of the flow test which was actually performed,'we A preoperational flow test was performed on'the Safety Injection-System to verify that the system fulfilled the design requirements. The. .

preoperational test verified that the Safety Injection System fulfilled the performance requirements documented in the FSAR and revised by Mr. J. A.N Jones' letter of August 12,.1970 ~

to you regarding rc-ovaluation of .the safety injection pump performance.. Subsequent to the preoperational test,'it was determined that the flow resistance of-2'-inch high head safety injection piping was underestimated. The flow resistance error was factored into the calculation of system line losses. Subsequent systemi flowtesting'b7 Westing-house at the Ginna nuclear Power Plant has verified their. calculational mode for determining line losses and system delivery capability based on pump per-

' formance. The modified flow configuratio' n of tite ' Robinson Safety Injection :

' System was used with the Westinghouse calculational model in the reJanalysis of the system documented in the January 25, 1971 Ictter referenced-above. ,

Therefore, a system-flow capacity test was not required on the modified Safety Injection' System. The only flow. test required was one to ensure that no block- ~

age of the modified-flow paths had been incurred.

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Ur. Peter A. mom July 1, 1971 On February 5,1971, a flow test was performed on the Safety Injec-tion System following the piping modification. The purpose of the test ,was to ensure that unobstructed safety injection flow paths had been maintained af ter tho' addition of valves SI-870A and 870B and the hot leg cross-connection

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line.

'Ihe initial conditions for the flow test were as follows:

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1. Reactor Coolant System (RCS) vented to the pretsure relief tank (PRT) through the pressurizer with both power relief valves and their respective isolation valves open.

2. Pressurizer Icyc1 at about 507. as read on icyc1 transmitter LT-462.

3. RCS temperature was belew 200 F.

4. Safety Injection System (SIS) temperature at ambient temper-ature. ,

5. Boron concentration in the SIS suction and discharge headers and the boron injection tank were verified to be equal to that in the refueling water storage tank. ,

6. All accumulator test and fill lines were isolated. ,

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7. Relief valve 842 set at 1750 psig. ,

- k For the flow test, Residual llcat Recoval System (RIIR) pump "D" was run to supply water to safety injection (SI) pumps "A" and "C". To Q0y verify that the cold leg injection path was open, the following flow path gku was set up with all other possibic flow paths valved out: n Reactor coolant water at 200 F was taken from RCS loop 2 b hot Icg t:1 rough RilR valves 750, 751, 752B, RHR pump "B", RilR valves 754B, 7573, RIIR heat exchanger "B", SI valves 863B, 887, Q(th L

s 886A, 8860, SI pumps "A" and "C", 888A, 888C, 878A, 878B, 867A, S F1 Boro'n Injcction Tank, SI valves 870A or 870B, 868A, 868B, and g j{

8680 to the cold 1 cgs. t U

. 3 Valves SI-870A and 870B were apened one at a time. Flow element s FT-943 verified that flow through both the valves was about 880 gpm at a s 4 mat leg pressure (PT-943) of about 740 ipsig.

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D hi Co t.0 s For verification that the hot icg injection path through the hot g t.

icg crossconnec tion line was open, the following flow path was set up with g 1

all' otl}cr l ossibic flow paths valved out- N , C

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Dr. Peter A. Mor9 July 1, 1971

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Reactor coolant water at 200 F was taken from RCS loop .

2 hot leg through Rl!R valves 750, 751, and 752B, RllR pump "B",

RllR valves 75'4B, 757B, RIIR heat exchanger "B", SI valves 863B, 887, 886A, 886C, SI pumps "A" and "C", 888A, 888C, 878A, 878B, 869, 866A or E66B to loops 2 and 3 hot 1 cgs.

Valves SI-866A and 866B were opened one at a time. Flow clement FT-940 verified that flow through both valves was about 670 GPM at a hot leg pressure (PT-940) at 1060 psig. A con 6act pyromoter was used in each cu: to verify flow through the hot Icg cross-connection line by detecting an increase in the injection fluid temperature from ambient 4:onditions to the reactor coolant temperature.

This flow test was designed to verify that no flow blockage existed following the Safety Injection System modification. The test was not designed to be a system capacity check. The preoperational test was run to ensure that the safety injection pumps deliver adequate injection flow during accident conditions. Therefore, it was not necessary to radically change plant condi-tions to verify system flow capacity again.

The Safety Injection Systen modification provided for the installa-tion of two new valves (SI-870A and 870'B). The valves were functionally tested and opening and closing times at 807. and 1007 rated voltage were measuicd. The measured opening and closing times at the apecified voltages for the valves'are listed bcita:

Valve Voltage (volts) Opening Time (sec) Closing Time (sec) 870A 480 7.5 7.5 870A 385 7.5 7.5 870B 480 8.0 8.0 870B 385 .

8.2 8.2 These measured opening and closing times were within the 10.0 seconds specified for the valves.

We hope that this information .will allow your staff to complete their review of this-matter.

Yours very truly, A-E. E. Uticy Manager

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Generation & System Operations RLM/lef^

'cc: 1Mr. J.' A. Jones

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