ML20034H731

Provides Specific Leak Rate Determination & Isotopic Sample Analysis Frequency for Water Sources & Outfalls Associated W/Alignment

ML20034H731
Person / Time
Site:	McGuire, Mcguire
Issue date:	03/12/1993
From:	Mcmeekin T DUKE POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9303190343
Download: ML20034H731 (11)

Text

g h.

DuDePouer Company T C hectax.

~ McGuire Nuclear Genemtion Department -

^ Vice President

_i 12700 Hagm l'erry Road (MC0!A)

Eunterwille. NC28018-8985 (TM)8754800 l

(TM)8?S-4809 fax -

3 DUKEPOWER q

itarch 12, 1993 e:

r-Document Control Desk U.S. Nuclear Regulatory Commission

' Washington,.D.C.

20555

Subject:

McGuire Nuclear Station i

Docket Nos:.'50-369-and 370

Dear ' Sir:

}

l In 1992 McGuire identified leaking tubes in the 2B Containment?

j Spray (NS) Heat Exchanger. These tube leaks allow 1 for i minimal:

' il

. concentrations of radioactive water to' be introduced-to the Nuclear-Service :(RN) water. system, and subsequently to' the Standby LNuclear?

4 Service Water. Pond (SNSWP).. Since the-2B NS. Dat Exchanger leaks '

have been identified, the associated RN train has-not been, aligned

,4

'to the SNSWP.

After careful reviewJ of-the-radioactiveL concentrations-in the RN water that,would be: ~1ntroduced ato. the' SNSWP, it is McGuire's intention ' to establish. the H RN J to D SNSWP.

alignment during -the upcoming Units l_ and.2 Refueling.utages.:This<

alignment will be necessary in order to-comply with the Cs-137'LLD.

value requirements during-the draining of the condensers-'(via:ther WWCB) forfoutage maintenance. The Unit 1 -Refueling ~ Outage.-began.

i

-today. Prior to the alignment'of the-RN' train to-the SNSWP, McGuire)

. determined that the NRC should~ be made: aware of.the' circumstances-surrounding theJ RN alignment. and.- of the:eplannedi11eak1 rate?

determination and ~1sotopic sampling analysis' criteria that will be l

performed during this alignment. The ' circumstances; surrounding.this;:

j alignment-were discussed with the NRCEin a ' conference call on March

.2,

-1993.

Attachment-

1. 11 provides the= specific. leak rate-1

.determinationiandDisotopic sample analysis. frequency forlthe waterb

~

V l sources and;outfalls associated.with this alignment.<

1

'If there are any. questions:or comments-.regarding;this; issue =

please contact Robert Sharpe'at (704) 875-4447-or.StevelMooneyhan i

cat (704)E875-4646.

1 Very truly yours,;

A q

I i

T. C. McNeekin

'j 9303190343 930312 - Yj PDR ADOCK 05000369- ~

,.. ystj P

.PDR l

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9 U.S. Nuclear Regulatory Commission March 12, 1993 Pape 2 xc:

Mr. S.D.

Ebneter Administrator, Region II U.S. Nuclear Regulatory Commission 101 Marietta St.,

NW, Suite 2900 Atlanta, Ga.

30323 Mr. Tim Reed U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Mail Stop 14H25, OWFN Washington, D.C. 20555 Mr. P.K. VanDoorn NRC Resident Inspector McGuire. Nuclear Station i

?

I 4

Attachment #1 Page 1 of 9 2B NS HEAT EXCHANGER LEAKAGE

SUMMARY

At the present time only the

'B' train of the RN system is utilized to provide the water necessary for, the SNSWP overflow. Due to problems identified with the operability of the Auxiliary Feedwater System (CA) assured makeup from RN,-the alignment of

'A' train RN to the SNSWP now results in limited CA system operability.

The RN system provides cooling to the Containment Spray (NS) Heat Exchangers. At the present time the 2B NS Heat Exchanger has some identified tube leakage which allows small quantities of radioactive water into the RN side of the NS Heat Exchanger. The c.itlet isolation valve for the RN side of the 2B NS Heat Exchanger also has a minimal leak rate (Presently 4.36 gph) that allows this radioactive water to enter the main RN system. This small amount of

~

radioactivity in the RN system is being released and accounted.for in the Condenser Circulating Water system (RC). The RC system is an approved discharge pathway. In August of 1992 Eddy Current testing and subsequent tube pluggi_ng was performed on the 2B NS Heat Exchanger.

After completion of this inspection no signs of radioactivity were seen in the RN side of the 2B NS Heat Exchanger.

In September of 1992 leakage of radioactive water was again discovered in the RN side of 2B NS Heat Exchanger. Based on the problems associated with this tube leakage the 2B NS Heat Exchanger is scheduled to be replaced during the next scheduled Unit. 2 refueling outage (July 1993).

i Until the 2B NS Heat Exchanger can be replaced, anytime that the

'B' train of the RN system is aligned to the SNSWP the site would-be discharging very slight amounts of radioactive water to the SNSWP via the RN system. Based on the previous amount of activity identified in the RN side of the NS Heat' Exchanger, expected concentrations of the various isotopes that would be seen in the-SNSWP have been estimated and are. Included on pages 3 - 9 of this attachment. These estimates are based on the highest activity seen for each of the isotopes for all of the RN samples that have been analyzed. The dilution f actor utilized is based on the total SNSWP volume (1.85 E8 Gallons). The activity estimates have also been performed for varying amounts of time that the RN system would be l

aligned to the SNSWP. In all cases the amount of act ivity that is calculated to be present in the SNSWP would be well below the Lower Limit of Detection (LLD) capability of the isotopic analysis i

equipment in use at McGuire.

I

4 Attachment #1 Page 2 of 9 McGuire has not aligned the 2B RN train to the SNSWP since the leaks in the 2B NS Heat Exchanger have been discovered. While the SNSWP ooes discharge to an approved discharge pathway

,WWCB,-

additional actions are planned for the time periods that the RN alignment is made. Preliminary plans for alignment of the 2B RN train to the SNSWP include the following actions:

Prior to the overflow alignment, the RN side of the heat' exchanger would be sampled to determine the level-of radioactivity. (This is already being done twice a month) The sampling of the RN side of the heat exchanger would then be performed on a weekly basis for as long as the overflow alignment is maintained.

-l The leak rate passed the RN outlet isolation valve for the NS Heat Exchanger would be verified prior to the RN alignment.

The leak rate would then be checked monthly for as long as the overflow alignment is maintained.

The SNSWP would be sampled for isotopic analysis prior to the alignment and then on a daily basis for as long as the overflow alignment is maintained.

As there are already effluent release procedures in place _.to account for any radioactivity that is discharged via the WWCB l

no additional dose calculations are planned.

1 t

4.

s NS HEAT EXCHANGER LEAKAGE INFORMATION H-3 Co-60 Cs-134 Cs-137 Xe-133 Xe-135 RN Activity (uCi/ml) 6.93E-04 1.50E-07 1.10E-07 3.13E-07 2.00E-06

- 1.90E-07 c

RN Activity (uCl/ gal) 2.62E+00 5.68E-04 4.16E-04 1.18E-03 7.57E-03 7.19E-04 Hours Aligned Total Gallons -

Est. SNSWP Est. SNSWP Est. SNSWP Est. SNSWP Est. SNSWP Est. SNSWP To SNSWP Sent To SNSWP H-3 (uCi/ml)

CO-60 (uCi/ml) Cs-134 (uCi/ml) Cs-137 (uCi/ml) Xe-133 (uCi/ml) Xe-135 (uCi/ml)

.5 21.80 ~

8.17E-11

' 1.77E-14.

1.30E-14 3.69E-14 2.30E-13 2.24E-14 10 43.60 1.63E-10 3.54E-14 2.59E-14 7.38E-14 4.71 E-13 4.48E-14 20 87.20 3.27E-10

.7.07E-14 5.18E-14 1.48E-13 9.43E-13 8.96E-14 50 218.00 8.17E 1.77E-13 1.30E-13 3.69E-13 2.36E-12 2.24E-13 100 436.00 1.63E-09.

3.54E-13 2.59E-13 7.38E-13 4.71 E-12 4.48E-13 150 654.00 2.45E-09 5.30E 3.89E-13 1.11 E-12 7.07E-12 6.72E-13 200 872.00 3.27E-09 7.07E-13 ~

5.18E-13 1.48 E 9.43E-12 8.96E-13 300 1308.00-4.90E-09 1.06E-12 7.78E-13 2.21 E 1.41 E-11 1.34E-12 400 1744.00 6.53E-09 1.41 E-12 1.04E-12 2.95E-12 1.89E-11 1.79E-12 500 2180.00 8.17E-09 1.77E-12 1.30E-12

- 3.69E-12.

2.36E-11 2.24E-12 600 2616.00 9.80E-09 2,12E-12 1.56E-12 4.43E-12 2.83E-11 '

2.69E-12 700 3052.00 1.14E-08 2.47E-12 1.81 E-12 5.16E-12.

3.30E-11 3.13E-12 800=

3488.00' 1.31E-08 2.83E-12 2.07E-12 5.90E-12 3.77E-11 3.58E-12 900

-3924.00 1.47E-08 3.18E-12 2.33E-12 6.64E-12 4.24E-11 4.03E-12 1000 4360.00-1.63E-08 3.54E-12 2.59E-12.

7.38E-12 4.71 E-11 4.48E-12 '

1100 4796.00 1.80E-08 3.89E-12 '

2.85E-12 8.11 E-12 5.18E-11 4.93E-12 1200.

5232.00 1.96E-08 4.24E-12 3.11 E-12 8.85E-12 5.66E-11 5.37E-12 ATTACHMENT #1 PAGE 3 OF 9

-.s-4 NS HEAT EXCHANGER LEAKAGE INFORMATION H-3 RN Activity (uCi/ml) 6.93E-04 RN Activity (uCi/ gal) 2.62E+00 Hours Aligned Total Gallons Total Concentration With SNSWP Estimated SNSWP To SNSWP Sent To SNSWP (uCl)

Dilutulon uCi/ gal Concentration uCi/mi 5

21-80 57.18 3.09E-07 8.17E-11 10 43.60 114.36 6.18E-07 1.63E 20 87.20 228.73 1.24E-06 3.27E-10 50 218.00 571.82 3.09E-06 8.17E-10 100 436.00 1143.63 6.18E-06 1.63E-09 150 654.00 1715.45-9.27E-06 2.45E 200 872.00 2287.26 1.24E-05 3.27E-09 300 1308.00 3430.89 1.85E-05 4.90E-09 l

400

.1744.00 4574.52 2.47E-05 6.53E-09 500 2180.00 5718.15 3.09E-05 8.17E-09 600 2616.00-6861.78 3.71 E-05 9.80E-09 700 3052.00 8005.41' 4.33E-05 1.14E 800 3488.00 9149.04 4.95E-05 1.31 E-08 900 3924.00 10292.67 5.56E-05 1.47E-08 1000 4360.00 11436.30.

6.18E-05 1.63E-08 1100-4796.00 12579 93 6.80E-05 1.80E-08 1200--

5232.00 13723.56 7.42E-05 1.96E-08 ATTACHMENT #1 PAGE 4 OF 9 l;

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NS HEAT EXCHANGER LEAKAGE INFORMATION CO-60 RN Activity (uCi/ml) 1.50E-07 RN Activity (uCi/ gal) _

5.68E-04 Hours Aligned Total Gallons Total Concentration With SNSWP Estimated SNSWP To SNSWP Sent To SNSWP (uCi)

Dilutuion uCi/ gal Concentration uCi/ml 5

21.80 0.01 6.69E-11 1.77E-14 10 43.60 0.02 1.34E-10 3.54E-14 20 87.20 ~

0.05 2.68E-10 7.07E-14 50 218.00 0.12-6.69E-10 1.77E-13 100 436.00 0.25 1.34E-09 3.54E-13 150 654.00 0.37 2 01 E-09 5.30E-13 200 872,00 0.50 2.68E-09 7.07E-13 300 1308.00 0.74 4.01 E-09 1.06E-12 400 1744.00 0.99 5.35E-09 1.41 E-12 500 2180.00 1.24 6.69E-09 1.77E-12 600 2616.00 1.49 8.03E-09 2.12E-12 l-700 3052.00 1.73'-

9.37E-09 2.47E-12 800 3488.00 1.98 1.07E-08 2.83E-12 900 3924.00 2.23

- 1.20E-08 3.18E 1000 4360.00 2.48

- 1.34E-08 3.54E-12

-1100-4796.00 2.72 1.47E-08 3.89E-12 1200 5232.00 2.97 1.61 E 4.24E-12 ATTACHMENT #1 PAGE 5 OF 9 l

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NS HEAT EXCHANGER LEAKAGE INFORMATION Cs-134 RN Activity _(uCi/mi) -

1.10E-07 RN Activity (uCi/ gal) 4.16E-04 Hours Aligned Total Gallons Total Concentration With SNSWP Estimated SNSWP To SNSWP.

Sent To SNSWP (uCl)

Dilutuion uCilgal Concentration uCi/ml.

5

'21.80 0.01 4.91 E-11 1.30E-14 10

-43.60 0.02 9.81 E-11 2.59E-14 20 87.20 0.04 1.96E-10 5.18E-14 50 218.00 0.09 4.91 E-10 1.30E '

100 436.00 0.18 9.81 E-10 e

2.59E-13 150-654.00 0.27 1.47E-09 3.89E-13 200 872.00 -

0.36 1.96E-09 5.18E-13 300 1308.00 0.54 2.94E-09 7.78E-13 400 1744.00 0.73 3.92E-09

' 1.04E-12 500 2180.00 0.91 4.91 E-09 1.30E-12 600 2616.00 1.09 5.89E-09

- 1.56E-12 700 3052.00 1.27 6.87E-09 1.81 E-12 800 3488.00 1.45 7.85E-09 2.07E-12 900 3924.00 1.63 8.83E-09 2.33E-12

-1000 4360.00 1.82 9.81 E-09 2.59E-12 1100 4796.00 2.00 1.08E-08 2.85E-12

.1200 5232.00 2.10 1.18E-08 3.11 E ATTACHMENT #1 PAGE 6 0F 9

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6-NS HEAT EXCHANGER LEAKAGE INFORMATION Xe-133 RN Activity (uCi/ml) 2.00E-06 RN Activity (uCi/ gal) 7.57E-03 Hours Aligned Total Gallons Total Concentration With SNSWP Estimated SNSWP To SNSWP Sent To SNSWP (uCl)

Dilutuion uCligal Concentration uCi/ml 5

21.80 0.17 8.92E 2.36E-13 10 43.60-0.33 1.78E-09 4.71 E-13 20' 87.20 0.66 3.57E-09 9.43E-13 50 218.00 1.65 8.92E-09 2.36E-12 100 436.00 3.30 1.78E-08 4.71 E-12 150 654.00 4.95 2.68E-08 7.07E-12 200 872.00 6.60 3.57E-08

- 9.43E-12 300 1308.00 9.90 5.35E-08 1.41 E-11 :

g 400 1744.00 13.20 7.14E-08 1.89E-11 l

500 2180.00 16.50 8.92E-08

' 2.36E-11 600 2616.00 19.80 1.07E-07 2.83E-11 700 3052MO 23.10 1.25E-07 3.30E-11 l

- 800 3488.00 26.40-1.43E-07 3.77E-11 i

900 3924.00-29.70.

1.61 E-07

- 4.24E-11 l

1000 4360.00-33.01 1.78E-07 4.71 E-11 1100 4796.00 36.31 1.96E-07 5.18E-11

' 1200 5232.00 39.61 2.14E-07 5.66E-11 l

ATTACHMENT #1 PAGE 8 OF 9 l

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NS HEAT EXCHANGER LEAKAGE INFORMATION Xe-135 RN Activity (uCi/mi) 1.90E-07 RN Activity (uCl/ gal) 7.19E-04 Hours Aligned Total Gallons Total Concentration With SNSWP Estimated SNSWP To SNSWP Sent To SNSWP (uCi)

Dilutuion uCl/ gal Concentration uCl/mi 5

21.80 0.02 8.47E-11 2.24E-14 10 43.60 0.03 1.69E-10 4.48E-14 20 87.20 0.06 3.39E-10 8.96E-14

- 50 218.00 0.16 8.47E-10 2.24E-13 1.69E-09 e

4.48E-13 100 436.00 0.31 150 654.00 0.47 2.54E-09 6.72E-13 200 872.00 0.63 3.39E-09 8.96E-13 300 1308.00 0.94 5.08E-09 1.34E-12 400 1744.00 1.25 6.78E-09 1.79E-12 500 2180.00 1.57 8.47E-09 2.24E-12 600' 2616.00 1.88 1.02E-08 2.69E-12 700' 3052.00 2.19 1.19E-08 3.13E-12 800 3488.00 2.51 1.36E-08 3.58E-12 900 3924.00 2.82 1.53E-08 4.03E-12 1000 4360.00-3.14 1.69E-08 4.48E-12 1100 4796.00 3.45 1.86E-08

' 4.93E-12 1200 5232.00 3.76 2.03E-08 5.37E-12 ATTACHMENT #1 PAGE9OF9

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