ML20112G472

Investigation Into Sources of Chloride in Fort St Vrain Primary Circuit

ML20112G472
Person / Time
Site:	Fort Saint Vrain
Issue date:	03/05/1985
From:	Baldwin N, Burnette R, Montgomery F GENERAL ATOMICS (FORMERLY GA TECHNOLOGIES, INC./GENER
To:
Shared Package
ML20112G466	List: ML20112G463 ML20112G472
References
907838, TAC-57248, NUDOCS 8504010133
Download: ML20112G472 (34)

Text

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k GA Technologies Inc.

c..

m.v.,.

ISSUE

SUMMARY

AMRWA M E 5 AN INVESTIGATION INIO THE SOURCES OF CHLORIDE gg y a s IN THE FORT ST. VRAIN PRIMARY CIRCUIT O DESIGN OlSCIPLINE SYSTEM 00C. TYPE PROJECT [00CUMENT NO.

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GA Technologies Inc.

,G A-1484 (REV.10/82)

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TITLE:

AN INVESTIGATION INTO THE SOURCES OF CHLORIDE IN THE FORT ST. VRAIN PRIMARY CIRCUIT Document No.

907838 Issus N/C CONTENTS 3

1.0

SUMMARY

5

2.0 INTRODUCTION

3.0 EKPERIMENTAL............................

7 3.1 Phase I - Screening......................

7 10 3.2 Phase II - Heatup/ Hydrolysis 10 8

3.2.1 Titanium Sponge f

3.2.2 Graphite........................

11 14

's g

3.2.3 Fuel Rods

.a 18 3.3 Neutron Activation of Chlorine I

25 4.0 07ERAU. CONCLUSIONS...........,.............

}

26 5.0 POSTULATED CHLORINE RELEASE SCENARIO...

y APPENDIX A: PHASE II - TEST APPARATUS AND PROCEDURE 28 j

APPENDIX B: DETAILS OF hcl RELEASE TESTS FUEL RODS...........

31 I

APPENDIX C: CALCULATIONS OF CHLORINE-36 PORMATION 32 I

FIGURE

~5 u

N 1 With red No. 25 fully out, cable corrosion / failure was just on or 21

.E below drum..............................

E

.eE E

TABLES z

6 1

Sources of chlorine in the primary circuit 8

2 Analysis of water systems at FSV......

3 Test results of water leaching of primary circuit materials 9

12 4 Results of Phase II tests on Ti sponge..

13 5 Results of heatup and hydrolysis of graphite..

5 Summaty of Phase II heatup/ hydrolysis of fuel rods..........

16 19 7 Results of chlorine 36 analysis Page 2

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0A-1484 (REV.10/82)

TITLE:

AN INVESTIGATION INTO THE SOURCES OF CHLORIDE IN THE FORT ST. VRAIN PRIMARY CIRCUIT Document No.

907838 Issue N/C 1.0

SUMMARY

The discovery of chloride stress corrosion of a Fort St. Vrain (FSV) control rod drive (CRD) cable prompted an investigation into the possible sources of the chloride.

The total chlorine plateout in the primary circuit l

1s calculated to be about 100 g, not including possible higher asounts in trevice areas.

Samples of virtually all materials of construction in the pri-mary circuit were screened for possible release of chloride either by water a

leaching or by heatup.

It was found that almost all materials tested leached chloride, presumatly es salt, with PCRV concrete leaching the most.

In heacup tests, fuel rods and some graphite samples were found to release hcl gas when heated to 1800*F. Subsequent long term heating in dry He caused no further release of HC1. Heating in wet helium caused small amounts of hcl release.

The total amount of hcl rolessed to date from fuel and graphite into the pr-inary circuit is estimated at about 300 gm.

The following is a list of major 2

observations and conclusions of this investigation:

j 1.

Chloride on the CRD cable and on the circulator bolts is more con-centrated than found on other acimary coolant surfaces. This sug-j gests concentration of Cl in crevices or stagnant areas.

.E The water ingressed into The FSV primary circuit is not a source of 2.

l l

3 i

E chlorine, except for possible leaching that it causes.

3.

The fuel releases hcl gas during initial startup; under dry condi-tions there is no continuous release, under wet conditions at oper-ating ':ss.perature the fuel will release small amounts of HC1.

4.

Because of the sheer total mass in the reactor, core graphite (R-327) and side reflector graphite (HLM) are also major sources under dry and/or wet conditions. H-451 graphite is a minor source, to date.

Y Page 3

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G A-1484 (REV.10/82)

TITLE:

AN INVESTIGATION INTO THE SOURCES OF CILORIDE IN THE FORT ST. VRAIN PRIMARY CIRCUIT Document No.

907838 issue N/C 5.

The Ti sponge in the purification system is not a major source of

~

chlorine.

It is possibly a minor transient source during initial heatup.

6.

Leaching of concrete and/or thermal insulation is not ruled out, however, leaching would yield chlorine as salt, which is nonvola-tile, and therefore may not readily circulate.

Circulation of small amounts of salt particulates entrained in the helium is, of course,

-3 g

possible.

t 7.

Multiple sources and ingresses are quite probable. The data suggest t

that about 200 g chlorine was released upon Core i startup in 1976.

k Later, " spike" releases occurred during reload startups and during 5

operation with high moisture. The total amount released into the g

j primary circuit to date is postulated to be about 300 g.

I 5

.s

.e 3

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GA-1484 (REV.10/82)

TITLE:

AN INVESTIGATION INTO THE SOURCES OF CHLORIDE IN THE FORT ST. VRAIN PRIMARY CIRCUIT Document No.

907838 Issue N/C l

2.0 INTRODUCTION

Control rod cables and some circulator bolts have experienced stress corrosion cracking accelerated by chloride. The chlorine content of the cable in the cracked region is 138 pg/gm wire.

Chlorine on circulator bolts was 1 2 for wire to 2 mg per bolt. These values equate to 11 and up to 24 uga C1/cm and bolt, respectively. These concentrations of chlorine are higher than that 2

about 2 ug/cm, or on the plateout found on a circulator (C2102) inlet duct, probe sleeve, which was f0.5 uga C1/cm2 This suggests that the chloride con-centrates on surfaces with crevices like the cable or the bolts, relative to saceth or well swept surfaces. Extrapolating 0.5 to 2 pgm C1/cm2 to all swept I

7 cm ), yields a C1 plateout of about 100 g.*

The 2

metallic surface, (7 x 10

=

f total is undoubtedly larger due to concentration in crevices or stagnant 3

areas, or on the bottom plenum floor where water may have pooled.

I 2

Tests were conducted to determine the most likely source or sources of 3

j chloride in the reactor. Materials of construction within the PCRV were

[

tested for potential chlorine content or release. These include FSV water, concrete, Ti sponge, fuel, graphite, and ceramic insulation.

The release of chlorine can potentially occur from these materials during initial heatup, and j

3 later via hydrolysis reactions during water ingress, or in the case of insula-l h

tion and concrete, by water leaching. Table 1 lists the important potential 2

i sources.

Notice that there are two possible species, hcl gas which would be easily transported around the circuit and salt which would be less easily a

l l

transported.

The hcl gas, therefore, may be responsible for C1 contamination on virtually all swept surfaces, while leaching of salt would result in high local concentrations, particularly in the bottom plenum or other areas where i

water would accumulate.

• This extrapolation assumes 0.5 ug C1/cm2 on hot surface, 2 ug C1/cm on cold surfaces, and the hot and cold surface areas are equal, 3.5 x 107 cm2 each.

I l

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GA-1484 (REV.10/82)

I TITLE:

AN INVESTIGATION INTO THE SOURCES OF GLORIDE IN THE FORT ST. VRAIN PRIMARY CIRCUIT Document No.

907838 Issue N/C l

(

TABLE 1 SOURCES OF GLORINE IN THE PRIMARY CIRCUIT j

Species Source Released Transport Mechanisa Fuel rods hcl Heatup and hydrolysis of metal chloride H-327/H-451 graphite hcl Heatup and hydrolysis of metal chloride PGX/HLM graphite hcl Heatup and hydrolysis of metal chloride

.Ti sponge hcl Heatup and hydrolysis of metal chlor,ide Ceramic insulation Salt Water leaching due to condensation on 3

(Kaowool, Masrock, PCRV liner 2

acc. )

j Concrete Salt Water leaching of core support floor Water Salt Direct ingress with water leaks 2

a

.s E'il3 E

e e

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-GA-1444 (REV.10/82)

TITt.E:

AN INVESTIGATION INTO THE SOURCES OF CELORIDE IN THE FORT ST. VRAIN PRIMARY CIRCUIT Document No.

907838 Issue N/C 3.0 EXPERIMENTAL 3.1 Phase I - Screening The work was in two phases.

In Phase I all materials were screened by leaching in boiling water to determine which material was a likely source.

In addition, the water sources at FSV were tested (by PSco personnel) to deter-mine the chlorine content. Table 2 lists the various water sources at FSV and their chlorine content.

1 In Table 2, all of the water sources, systems 21, 22, 31, 46, and 47, are low in chlorine, i.e., chlorine is in the ppb range. The purification system, system 23, however, removes water from the primary circuit which contains a few ppa to 400 pga chlorine.

In other words, water enters the primary circuit relatively free of chlorine and comes out contaminated with chlorine.

2 Clearly, there is a source of chlorine within the PCRV.

[

Table 3 lists the Phase I screening tests on the potential sources within j

the PCRV. The results in Table 3 show that the PCRV concrete is by far the largest source of chlorine in the system. How the chlorine in the concrete 3

would get in the primary circuit is not clear, however.

Presumably, during shutdown, some water in the core support floor concrete could Isak into the i

PCRV through the support floor liner leak and carry with it salts leached from the concrete. Obviously, this source would be difficult to quantify.

The other sources all have low ppa levels of chlorine, but because they have large total masses, the total chlorina can be significant.

For example, the core and reflector graphite, total weight ~6 x 105 kg, could contain almost a kilogram of leachable chlorine. These figures do not tell the whole story, for all of these materials have a residual chlorine content that is not easily leached. The residual chlorine ranges from 10 to 100 ppm in the graph-ice and kaowool, up to 1000 ppe in the Ti sponge and concrete. The fuel rods Page 7

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TITLE:

AN INVESTIGATION INTO THE SOURCES OF CHLORIDE IN THE FORT ST. VRAIN PRIMARY CIRCUIT Document No.

907838 Issue N/C TABLE 2 ANALYSIS OF WATER SYSTEMS AT FSV(a)

No.

System ppa Calorine 21 Circulator bearing water

<0.025 22 Main steam

<0.020 to 0.193 31 Feedwater

<0.020 to 0.090 46 Liner cooling

<0.020 to 0.090 47 Purification system cooling 0.088 to 0.470 23 Drier regeneration 3.8 to 4.0 2

23 HPS front end kdockout pot 3.8 to 400

(* All data supplied by PSCo chemistry. The sys-f tem 23 values may be high because of C1 contamination e

in the sample storage drums.

2 3

i

.eE

.E E

l 3

a i

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,GA-1444 (REV.10/82)

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TITLE:

AN INVESTIGATI0t INTO THE SOURCE 9 0F CHLORIDE IN THE FORT ST. VRAIN PRIMARY CIRCUIT Document No.

907838 Issue N/C ll 4

TABLE 3 I

TEST RESULTS OF WATER LEACHING (a) 0F PRIMARY CIRCUIT MATERIALS Total hachable Mass In Chlorine in Chlorine Sodium Reactor Reactor (d)

Material (ppm)

(ppa)

(kg)

(g)

Fuel rods

<1 44,000

<44 H-327 g sphite

<1 1.0 250,000

<250 H-451 graphite

<1

<0.2 21,000

<21 PGX graphite

<1 0.3 50,000

<50 j

(loop 112,~138)

HIM graphite

<1 0.2 320,000

<320 PCRV concrete (b) 160 1.8

>106

>>1,000 (floor) u Kaowool 10(c) 27,000 270(c)

Masrock

~23 5,000 100 2

Quartz et Silice 9

400 4

Ti sponge 44 10 95 4

I (fresh)

!s

(*) Boiling crushed materials 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> in deionized water.

3 (b)The concrete also had 325 ppa sulfate and other ions including 8

nitrate, formate and acetate.

(")The specification on leachable C1 in Kaowool is 10 ppa.

One Z

" archive" sample leached as asch as 44 ppe. This value is probably not representative of that in the reactor.

(d)Errar bands or uncertainties have not been applied to these values, because they are based on leaching single samples. Obviously, the uncertainty would be large, perhaps factors of 2 to 4.

• ~

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, GA-1484 (REV.10/82)

TITLE:

AN INVESTIGATION INTO THE SOURCES OF CHLORIDE IN THE FORT ST. VRAIN PRIMARY CIRCUIT Document No.

907838 Issus N/C j

contain in the range i to 20 ppa residual chlorine.

Some of the residual chlorine may be released as hcl gas during heatup or hydrolysis at elevated temperatures. Tests to determine the amounts and sources of the gaseous form are discussed in the Phase II work.

3.2 Phase II - Heattip/ Hydrolysis Phase II work involved heating car.didate materials to their reactor oper-ating temperature.in flowing dry and wet helium. The apparatus and test g

method are shown in Appendix A.

The Jry helium step would remove volatile chlorine (or HC1) and simulates a norral heatup in the reactor. The wet helium step may cause hydrolysis of tvtal chlorides creating hcl gas by the reaction 2

j H O + MC12 = 2 HCit + MD 2

2 43 j

where M = Fe, Mg, etc.

c:!

The procedure for the Phase II heatup tests assumes the volatile species collected is HC1. This point was checked in a number of samples by measure-3 ments of pH.

These data are provided in Appendix A-3 and indicate that hcl and perhaps other volatile acids were released from the test samples.

15 a:

3.2.1 Titanitum Sponge Titanium sponge was felt to be a likely source because the control rod drive penetrations are purged with purified helium which comes directly from the Ti beds.

Furthermore the manufacture of Ti sponge involves the reduction of tic 14 by Mg metal.

The final product can contain up to several thousand ppa of chlorine as MgCl. The MgCl2 is subject to hydrolysis via the above 2

chemical reaction, however, it is difficult to create a scenario whereby Page 10

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u-1484 mev. io/s2)

TITLE: AN INVESTIGATION INTO THE SOURCES OF CHLORIDE IN THE FORT ST. VRAIN PRIMARY CIRCUIT Document No.

907838 Inue N/C moisture contacts the sponge while at operating temperature. The results of the Phase II tests on the sponge are listed in Table 4.

Table 4 shows that during initial heatup of the Ti sponge about 0.6 to 3 g of chlorine (tests 1 and 5) could have been released from the 210 lb get-ter bed at FSV. Upon longer heating times, the amount released would trickle down to ~0.0005 g/hr (average of tests 2 and 7) or in fact to zero (based on the used FSV sponge tests No. 9 and 10). If the sponge were somehow subjected to weter vapor, the rate of chlorine release could be about 0.01 g/hr (test 4) or virtually zero (test 12 on FSV sponge).

It is concluded that initial heacup of the sponge can release a few grams of chlorine (probably less than 3 g) but prolonged heating and/or exposure ta moisture has little effect on chlorine release.

Furthermore, while short exposures to water vapor may be possible, it is difficult to imagine a long term exposure of the sponge to 3

j water vapor.

It may be concluded that the Ti sponge is not the major source j

of chlorine in the primary circuit.

l 3.2.2.

Graphite

~S Graphite can become contaminated with chlorine in two ways. First, the C

}

high purity grades, H-327 and H-451 were purified by treatment at high temper-f ature with chlorine gas.

It is possible therefore that some of the as manu-S factured logs contain some residual C1.

Also, all of the graphite, including the nonpurified PGI and EM grades could become contaminated during storage due to salt or chlorine in the air (rain water, for example, contains ppe levels of Cl).

+

Accordingly, EM, H-451, and H-327 graphites were coarsely crushed and subjected to heatup in dry helium followed by wet helium. The EM was heated to 1300* to 1800*F, simulating the side reflector temperature while the H-327 and H-451 were heated to 1800*F, the fuel element temperature. The results are shown in Table 5.

Page 11

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,GA-1484 (REV.10/82)

TITLE:

AN INVESTIGATION INTO THE SOURCES OF CHLORIDE IN THE FORT ST. VRAIN PRIMART CIRCUIT 1

Document No.

907838 Issue N/C i

TABLE 4 RESULTS OF FHASE II TESTS ON TI SPONGE (Temperature All Tests = 700*F)

Chlorine Released at FSV Initial Continuous N M ne hieased Test Weight Time Heatup Release No.

Material (g)

(hr)

Gas (a)

(ug)

Ug/hr (g)

(g/hr)

Blank Empty 17 He 21 1.2 tube g

1 Fresh Ti 80.0 5.5 He 2698 3.2

.3 sponge j

2 Fresh Ti 80.0 63.5 He 99 1.5 0.0004 sponge 3

Fresh Ti 80.0 6

He/H O 138 23 0.025 2

}

sponge 4

Fresh Ti 80.0 18.5 He/H O 157 8.5 0.009 2

sponge E

5 Fresh Ti 78.6 2

He/

497 0.6

)

H (*)

sponge 2

l 6

Fresh Ti 78.6 17.5 He/H2 57 3

0.002 3

sponge j

7 Fresh Ti 78.6 24.5 He/H2 41 1.7 0.0006

.g sponge j

8 Used FSV 46.8 3.75 He/H2 41 10.9 0.02 l

3 sponge 9

Used FSV 46.8 67.25 He/H2 44 0.65(b) o sponge 10 Used FSV 46.8 46.25 He/H2 36 0.78(b) 0 sponge 12 Used FSV 46.8 72.5 He/H /

32.8 0.45(b) o 2

HO 2

sponge l

(a)In Run 5 the gas was changed from pure He or helium containing 25,000 ppe water vapor to a mixture of He and 1000 ppm H2 or He/100 ppm H /25,000 ppm 2

H 0.

The addition of H2 was thought to simulate H2 in the reactor and to 2

i maximize the production of hcl gas.

l Less than background or blank run.

l Page 12

Notations in this column indicate where changes have been made e @

-4 1

1ABLE 5 r

RESULTS OF HEATUP AND HYDROLYSIS OF CRAPHITE h

x Total ppe hcl N$

Time hcl Furnace hcl Released E

ga Sample Core (b) g g' Test Weight Temp At Found Bign Released Fros No.

Sample (g)

Cas

(*F)

(hr)

(py pg ON 16(a)

HIR 66.8 He/H2 1300 24 34 40 ND(c) pg He/H /H O 1300 23 29 40 ND p

17(a) 2 2 do*

23(a)

H-327 145 He/X2 1800 3

40 40 ND 8833-Il3(b)

H-327 150 He/H2 1800 2

95.8 0.8 0.64(d) 2 8.8 0.8 0.05 2

4.8 0.8 0.03 200 N"

16 24.2 3.2 0.14 74 21.4 14.8 0.04 8

b He/H /H O 1800 4.7 5.5 0.9 0.03 18 5.9 3.6 0.015 11 F

0 7

2 2 l

23 5.2 4.6 0.004

.3 8833-115 HIM 151 He/H2 1800 3

17.3 0.6 0.11 4

12.5 0.8 0.08 96 f

h g

42 24.6 8.5 0.11 He/H /H O 1800 4

11.1 0.8 0.07 ts 2 2 42 0.48 8.0 ND o5 Y

O 8833-117 H-451 155 He/H2 1800 3

38.2 0.6 0.24 6

h 4.4 7.2 0.9 0.04 He/H /H O 1800 5

30 1.0 0.19 4

g 2 2 i'I I*ITests 16,17, and 23 had a furnace blank of 40 pga total based on 0.8 ppe C1 in 7

the water used.

Te st s 113, 115 had a furnace blank of 0.2 pge/hr.

(b) hcl released from core calculated by: ppe Het x total a6 se graphite, g, x 10-6 Graphite masses are: HIR = 320 Hg,11-327 - 250 Hg, X-451 = 21 Hg.

(# None detected af ter 40 pga blank subtotal.

g n

(d)0.2 pg/hr background subtracted.

GA Technologies Inc.

.GA-1484 (REV.10/82)

TITLE:

AN INVESTIGATION INTO THE SOURCES OF CHLORIDE IN THE FORT ST. VRAIN PRIMARY CIRCUIT Document No.

907838 Issue N/C l

t The resuits of Table 5 show two sets of data.

In tests 16, 17, and 23, hcl release from the graphite was not apparent af ter the furnace blank or background of 40 uge was subtracted.

In later tests No. 8833-113, 115, and 117 a more sensitive technique was used in which tne furnace blank was reduced to 0.2 uga/hr. Extrapolating the H-327 results (in test No. 113) to the core H-327 inventory (250,000 kg), 200 g hcl would be released and test 115 (HIR, 320,000 kg) extrapolates to 96 g.

Seventy percent of this total would be released in the first 2 he of bestup. When the H-327 graphite was exposed to water vapor an additional 0,05 ppe hcl was released or 7 g released from the core when extrapolated to the total H-327 inventory. Of course, the results b

of samples 16,17, and 23 should not be totally discounted.

If it is assumed that in those tests 10 ug hcl could have been detected (i.e., 50 uga total -

40 uga furnace blank) then the hcl released was less than 0.1 ppa hcl. This shows that the hcl contamination of the graphite is quite variable. Without performing a large number of tests to obtain some statistical relevance, it j

may be concluded that all graphite in the core may have released in the range of 50 to 500 g HC1, corresponding to 0.1 to 1 ppa HC1. Comparing this amount

}

of hcl release with the estimated amount in the primary circuit ~100 g (plus i

an additional snount in crevice or stagnant areas) shows that graphite could have been a major contributor to the total C1 burden.

.E I

l 3.2.3 Fuel Rods

$z l

It was surmised that fuel rods could be a source of chlorine for the i

following reasons.

During fuel manufacture, particles are coated with sic by thermal decomposition of methyl trichlorosilane, which results in some resid-ual chlorine in the fuel particles.

In addition, fuel rods are leached with hcl gas af ter the hot press and carbonization steps to remove tramp or uncoated uranium sad thorium. The hcl leaching is accomplished during the final high temperature anneal step at 2900* co 3300*F,.-hich effectively removes most of the hcl from the rod.

Some residual chlorine remains, i

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GA-1484 (REV.10/82)

TITLE:

AN INVESTIGATION INTO THE SOURCES OF CHLORIDE IN THE FORT ST. VRAIN PRIMARY CIRCUIT Document No.

907838 Issue N/C however, typically in the low ppa range, as allowed in the fuel manufacturing specification.

At GA, as part of fuel production, QA testing, and qualification, fin-ished fuel rods are routinely heated in the high temperature mass spectrometer to measure the chlorine vapor pressure above the rod, and therefore the poten-tial for chlorine release into the primary circuit. When rods are heated up in vacuum in the mass spectrometer they invariably release about 1 to 50 ug of hcl gas per rod at around 1000*F (this is from 0.1 to 5 ppe in the rods).

b Since the rods were annealed at up to 3300*F during the hcl leach step, the release of hcl gas during the modest heatup in the mass spectrometer was puzzling.

It was concluded that either the leach /high fire process contami-natied the rods or that the hcl gas was formed during storage in air due to j

hydrolysis of metal chlorides.

Furthermore, if the latter occurred it was expected that hydrolysis in the reactor should also occur during normal opera-tion where a few ppa moisture are available or during shutdowns where large E

amounts of water are sometimes present.

.e 1ll To verify the results of the hcl observation in the mass spectrometer and a

j to determine the effect of hydrolysis, a number of fuel rods have been heated I

in the Phase II apparatus. The rods included archive specimens from the ini-

• !i tial core loading and rods from each of the reload segments 7, 8, and 9.

The a:

results are summarized in Table 6.

Details of these results including all background or blank determinations are given in Appendix B.

The results of Table 6 show that the initial core fuel rods averaged L

about 0.5 ppe based on averaging 19 mass spectrometer tests.

In 4 tube fur-nace tests, on 24 fuel rods, the average hcl found was 1.8 ppm which converts l

to 100 g released from the initial core.

The mass spectrometer results are known to be non-quantitative on the total amount released. The tube furnace t

results are much lesc ambiguous and are more quantitatively correct.

l I

I

+

l l

Page 15 l

L

Notations in this column indicate where chaeges have been made

-! S TABLE 6

d 1

SUMMARY

OF PHASE II HEATUP/ HYDROLYSIS OF FUEL RODS

!" h b

hcl Released From Core (b)

Hass spectrometer (s) hcl Tube Furnace (g) i hcl No.

Dry He Wet He No.

Tube Qd Test Fuel ppe hcl Rods ppe hcl (pps/

Rods Mass Furnace 58 p No.

Segment Released Tested Released hr)

Tested Spec (b)(c) hy "E

3 I

1 0.28 3

3.7 2

2 0.71 5

o g

3 3

0.70 5

3.2 0.03 6

4 4

0.5 5

0.75 2

5 6

0.67 1

0.33 6

20 100(d)(e) 6 7

0.5 1

0.26 0.04 6

3 2

E O

7 8

3 g

g O_

1 7

8 0.10 6

1 h

8 9

0.4 6

2 O

o 0

up l

es (a)Hass spectrometer data unambiguously indicate presence of hcl gas.

The absolute values 8

y 89 4

in the table, however are uncertain.

y g

p i ppe hcl = ~50 g hcl released, calculated by 10-6 g/g x 4.4 x 106 rods x 11 g/ rod.

N g

(c)The total released from the tube furnace was divided by 0.79, which was the collection efficiency, prior to calculating the total amount released.

See Appendix A for details.

N (d) Uncertainties or error bands have not been assigned. A factor of ~2 uncertainty may be O

appropriate.

The overall release would be to 50 to 200 g C1.

3

(* The average hcl released from core 1 fuel was 1.8 ppe. This was arrived at by assigning

[

2' a value of 3 ppa to the segment 2 fuel (which was not tested) and 0.33 ppa to fuel segment 5.

4 E

cb o

GA Technologies Inc.

GA-1484 (REV.10'/82)

TITI.E:

AN INVESTIGATION INTO IHE SOURCES OF CHLORIDE IN THE FORT ST. VRAIN PRIMAR'.". CIRCUIT Document No.

907838 issue N/C l

In tests where hydrolysis was tried two rod batches showed small hcl I

releases equivalent to about 2 g per hour from the core. This could be impor-tant during high-temperature reactor operation and high moisture coccentra-lj

'I tions. Normally, the reactor is shut down when moisture ingress occurs, therefore hydrolysis is not an important steady state release mechanism.

It could be a transient mechanism, however.

i It is apparent from the table that the initial core fuel may have released about 100 g hcl upon startup in 1976. Heatup of each reload contrib-uted an additional few grams.

Short term operations with water vapor present may have sdded a few grams. This snount of release is consistent with that speculated to be in the primary circuit, 2100 g.

It may be concluded that hcl gas released from the fuel is a major contributor to the total C1 burden.

A list of conclusions of Phasa II Heatup and Hydrolysis Tests is given below:

1.

Initial heatup of fael rods in the initial core released about 100 g HC1. Prolonged heating under dry conditions did not increase the j

release.

1 E

2.

Titanium sponge released 1 to 3 g hcl on initial heatup. Prolonged g

M hasting or hydrolysis did not increase the release.

3.

Heat up of graphite may have released an additional 100 g HC1.

4.

Hydrolysis of fuel and graphite at operating temperature and high moisture would cause small release of hcl gas, up to about 3 g C1/hr, depending on moisture concentration and temperature.

Page 17

GA Technologies Inc.

, G A-1484 (R EV.10/82)

TITLE:

AN INVESTIGATION INTO THE SOURCES OF CHLORIDE IN THE FORT ST. VRAIN PRIMARY CIRCUIT Document No.

907838 Issus N/C 3.3 Neutron Activation of Chlorine Chlorine 35 has a large neutron capture cross section (20 barns) creat-ing Cl-36, which has a half-life of 3 x 105 yr and is a pure beta emitter (0.7 MeV).

It was surmised that if chlorine found on the cable (or elsewhere in the primary circuit) contained Cl-36, then it would prove that either the source of the chlorine was the core, or at least, the chlorine had circulated in the primary circuit, becoming activated, prior to placing out in the system.

1 Accordingly, a utnaber of samples from the primary circuit were analyzed for C1-36 and total C1 concent. The results are given in Trble 7.

I The results in Table 7 clearly show that the chlorine found on the cor-

,j roded cable, the moisture moniter valve, the circulator duct, and the circula-tor bolts has been subjected to a degree of activation equivalent to 100 to 200 days in core at 70% power. Ihe chlorine found on the cable above the cor-

[

rosion failure and on the plateout probe and in the HPS knockout pot has j

apparently been subjected to substantially less activation. The following is j

offered in explanation. The water obtained from the HPS knockout pot in late E

October 1984 contained 3.8 ppa total C1 and a C1-36 ratio of 10.2 uci C1-36/g E

C1.

This low ratio suggests that this water sample contains chlorine which is g

j not representative of that in the primary circuit, or possibly, it was contam-insted with stablo C1.

The contamination could have come from the sample storage drtna.

Or, it could have leached from non activated locations inside the primary circuit, since the water sample was obtained 3 to 4 months af ter reactor shutdown.

The C1 found in the platsout probe diffusion tube and on the outer sleeve also have low Cl-36 contents.

Either these samples were contaminated by han-dling or storage since November 1981, or, it suggests the major C1 ingress Page 18

GA Technologies ince GA-1434 (REv.10/82)

TITLE:

AN INVESTIGATION INTO THE SOURCES OF CHLORIDE IN THE FORT ST. VRAIN PRIMARY CIRCUIT Document NO.

907838 issue N/C TABLE 7 RESULTS OF CELORINE 36 ANALYSEE 5eutroe Tire la Activation Service Cl-36 uci 36/

Days at Sample (gFFD)

Found usm/cm2 Total am 35 701 Cable wire 664 120 is. free rod 138 ug/g(a) 11 23 aci/g 167 92 142 is. from rod 10 mg/g 0.8 0.23 aci/g 24 13 178 La. from rod 24 ug/g 1.8 0.16 fv.1/g 7

4 Plateout probe 408 Sleeve, top 18 cm2 9 us 0.5

<0.01 nei

<1

<1 E

Tube sections 5. BE, 6 us 0.7 0.07 aci 11 6

g M. M

.a Tube section 313 8 us 2

0.11 nci 14 8

Circulator C2102(b) 5 or 352 Inlet eset (234 cm2) 110 us 2(c) 23 nei 212 116 Belt (70 cm )

921 us 13 309 nei 335 184 2

Moisture monitor valves 659 502 us 2

V118 M (C2104 outlet) 502 us 128 256 141 V11868 (C2101 outlet) 627 us 2

V11867 (return to 19,700 us inlet pleem)(*)

Circulator C2104(d) 659 e

Bolt A (70 cm2) 250 us 3.6 340 nei/ bolt 136 75 Bolt 3 120 vs 1.7 110 oci 92 92 g

[

Bolt C 1708 ug 24 320 187 103 5

Belt D 1313 us 19 232 177 97

.5 solt E 963 us 14 132 189 104 Bolt F 608 ug 9

147 242 133 Bolt G 703 us 10 156 222 122 j

RFS 30 FOT water 6/84 ingress 3.8 ppe 0.039 oci/mi 10.2 6

ISS balls 664 Mid. 21 8 ug/ ball 0.0006 nci/

0.08 0.04 ball sott. 21 7 us/ ball 0.005 nei/

0.8 0.4 ball I*I33 us sulfate /gs wire also found.

(b)C210*, wee in service for 3 months, 5 EFFD prior to shutdown on June 23, 1984. The totsi service time wee 352 EFFD.

(*IAnalysis of wipe increased by 14 reflecting decon factor of 0.24, determined by gessna counting the wipes for fission products and coopering with direct gaans scan of the duct.

IIC2104 wee in service for 659 EFFD psior to removal on January 20, 1984. The efft-ciency of decon efforts (if any) on the bolts is ur.known.

(V11867 wee in the return line from all noisture monitors, including the bypass line; therefore the flow rate wee higher than the other valves. This valve contained some black

• crud

• vhich could have estained chloride.

Page 19

GA Technologies Inc.

GA-1484 (REV.10/82)

TITLE:

AN INVESTIGATION INTO THE SOURCES OF CHLORIDE IN THE FORT ST. VRAIN PRIMARY CIRCUIT Document No.

907838 issus N/C into the primary circuit occurred af ter the probe was removed on November 9, 1981 which was 54 days into cycle 3 operation.

The RSS balls from hopper 21 had low Cl-36 contents. This shows that the water that leaked into the hopper did not carry chlorine from the primary circuit.with it.

2 Chlorine on the plateout proba sleeve, f0.5 ug/cm, and on the circulator (C2102) duct, ~2'ug/cm, are the only samples from the % wept" primary cir-2 cuit. These data extrapolated to all surface area 7 x 107 cm2 yields about 100 g total pleted out on swept surfaces.* Chlorine in crevice areas, i.e.,

bolts, valves and cable strands is obviously higher in concentration. The 8

total C1 burden, therefore, probably exceeds 100 g.

E j

The variability of total C1 and Cl-36 on the cable required explanation j

and prompted further innstigations. A 36 in. section of the cable which was

'j located 10 in. above the corrosion failure was gamma counted and leached for l

chlorine.

The result of taose analyses are listed in Fig. I which is a sche-3 matic of the CRD and penetration. The location of the corrosion failure was 120 in. above the top of the control rod. Referring to Fig. 1, with the rod i

inserted, the corrosion occuremd just inside the penetration. With the rod C

j fully out, the corroded cable was just on or a few inches below the enble drum. In order to reconstruct the corrosion / ingress scenario, it is important co know whether the rod was in or out and the fraction of time spent in each of those positions.

This rod (No. 25) was in region 14 during all reactor cycles.

During cycle 1, region 14 wac totally unrodded.

In cycle 2 the rod was inserted about 75% of the time and in cycle 3 it was inserted about 40% of the time.

• This extrapolation assumes 0.5 ug C1/cm2 on hot surface, 2 ug C1/cm on cold surfaces, and the hot and cold surface areas are equal, 3.5 x 107 cm2 each.

Page 20

G Technologies Inc.

GA-1484 (REV.10/82)

TITLE:

AN INVESTIGATION INTO THE SOURCES OF CHLORIDE IN THE FORT ST. VRAIN

-i PRIMARY CIRCUIT Document No.

907838 issus N/C R00 IN R00 QUT b

b-

b. w.h :..

Igg. h!,

.:..MMcM%

x, nil'f ts.~.

~9 X y i:.Arg.;6,Qj.

yCQRR0$10N/

s

. k%:y' :h: gy;:p=Mf. $$- g.;;Rr4't

a. -

s

.b**?~.

.G r

• • de hI Isi 2NEY

{r%>y$~ly.'k)'

tEh

• CRV h 3 p%,b.fy;g f

Wih'g

.h y m;q;w4 3

i8M8i

-v

- a%

,..Y,A 5^

W wv- '-

njG..Q yf'y 5:53.yg

i8%:

ig

;ipp Q $HIELD-,i ?~-

tg n

g3PLUGg$ ]g;;p g

Nf8.M.,vM. D l

w r-k..:,

$Ah.K,3;.33,

..?'t-<h-Q: !$

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%:4.+ k5&.~&.Ch::

Z

...yf.7 e

e j

M?:p:.

%yl(jf. 6.9h sy

3..

.:..s

. [.

E173f.h.u.. !-d

[

~

s

%y.,Ws.h;%

i~g,

Il[gg s u s s m a s M.;$

E

r. t d

4

$e

.

g s

-;:k%=.e weh gn:a.:t D

l M010 ACTIVITY (nCI/g)

CI

$C d

i Co-60 Cs-137 Cl-36 g (uCf/q b e j

%g 't[j s

3;L)((p.YOff h.MgdhEaW^

N4 5

3 0.03 0.16 24 7

' g.

e A N <rp g

36 1

e; gypw;;;y:gs;pg'jg7f g,g a

c q; 2C 0 33 0.23 10 24 j

j+pp3;g g

m3d.m,$qy.

gd. w 10,g:

-QMCCRROSIONS gpr ypg93 l

WWE::.a 23 138 167 12L-1 X+se.wh:e

,' Q i

FAILURE m

3s l

l

.s e

.---Gul 0E TUBE--e, E:s 1

-au j

g 120

.E E

O t

2 1

l liimmummmumimillllilillVllillHlilIll0lil!!Illlllllll!I L

! ll l

l

-l e

T0e a:FtsCTon/pt.ENUM ELEMENT 5i l

l 1 '

N N OFY C N N ORE h

\\

Fig. 1.

With rod No. 25 fully out, cable corrosion / failure was just on or below drum

+

l Page 21 1

GA Techn logies Inc.

G A-1484 (R EV.10/82)

TITLE:

AN INVESTIGATION INTO THE SOURCES OF CHLORIDE IN THE FORT ST. VRAIN PRIMARY CIRCUIT Document No.

907838 issus N/C 1

during cycle 4 it was fully inserted at startup and was slowly withdrawn as power increased. By June 22 at 38% power rod 25 was half out of the core.

This means that the total time the rod has spent inserted was about 260 EFPD or about 39% of the total reactor power time. Af ter the shutdown on June 23, 1984, the rod was removed for refurbishment.

It was reinstalled in region 7 in late August. At this time, during reactor shutdown when exercising the i

rod, the cable failed, due to hangup of some of the outer frayed cable strands in the pulleys or orifice. The rod was removed and samples of the cable were removed for metallurgical and chemical analysis.

t The concentration of Cs-137 on the 36 in. cable section varied by a fac-4 t

tor of 10 from one and to the other. This was puzzling since Cs-137 on the f

cable can only be explained by decay of the parent Xa-137 (t 1/2 3.9 min).

),

The Cs-137 data are in qualitative agreement with the Cl-36 data which shows a j

factor of about 100 ti2nes more total C1 and Cl-36 at the corrosion / failure j

location compared to just 22 in. higher up.

Both the Cl-36 and Ca-137 data j

suggest that access to primary coolant helium was more restrictive above the failure.

If the contamination occurred while the rod was fully withdrawn the cable failure location was in the CRD mechanism housing, a few inches on the n

E drum. Since the drum has a metal cover, the cable underneath may have been

=

]

protected from chlorine intrusion. There also could have been restricted j

access to xenon within the drum housing, which may explain the low Cs-137 concentration therein.

If the contaminaton occurred while rod 25 was inserted, then a different and more plausible explanation is offered.

Referring to Fig. 1, with the rod in core, the contaminated / corroded cable section was just inside the penetra-tion. We may assume that condensed water dripped down the length of the cable until it reached a tenperature where evaporation was rapid. The water would have dissolved the water soluble contamination, C1 and Cs, from the upper part of the cable and transported them down where evaporation occurred.

At the 1

Page 22

GA Technologies Inc.

GA-1484 (REV.10/82)

TITLE:

AN INVESTIGATION INTO THE SOURCES OF CELORIDE IN THE FORT ST. VRAIN PRIMARY CIRCUIT Document No.

907838 Ime N/C i

point of evaporation, the salt and Cs content would be the highest, due to the concentration effect of the evaporation process.

The chlorine found on the corroded cable and on the circulators experi-enced neutron activation equivalent to an average 112 days in core at 70%

power. This means that most of the chlorine was not continuously released from the core, because tasch of it would have experienced up to 1000 days of neutron activation (the average activation in core is 745 days).

It is cer-tainly possible that the chlorine found in the circuit is a mixture of that g

which was released frca core 1 and a smaller amount released asch later, which would be highly activated.

a Another extreme possibility is that a large portion of the chlorine is in k

constant circulation. For example, the residence time in the core is about j

0.2 seconds which is 2% of the total cycle time of 10 seconds. If all of the j

chlorine had circulated continuously for 1000 days of reactor operation, it

]

would exhibit a C1-36 ratio equivalent to an activation of 1000 x 0.02 =

l 20 days. This degree of activation is less than what was found on the cable 8

and on the circulator. This proves that most of the chlorine came from the

.eE core where it was activated before it was released. Futhermore, if there had C

}

been continuous circulation of C1, there would have been continuous cleanup by j

the HPS, and the chlorine removed would be many times that in the primary cir-cuit, or several thousand grams. This is considered to be rather unlikely.

It is concluded that only a small fraction of the Cl is circulating, the 1arger portion being plated out or concentrated in crevices.

Conclusions of Cl-36 analysis:

1.

The Cl-36 concentrations in the primary circuit show that a major source of chlorine is the active core.

Page 23

GA Technologies Inc.

GA-1484 (Rev.1o/s23 TITLE:

AN INVESTIGATION INTO THE SOURCES OF CHLORIDE IN THE FORT ST. VRAIN PRIMARY CIRCUIT Document No.

907838 Issue N/C 2.

The core does tot continuously release C1, otherwise the " equivalent activation" would be several hundred days.

3.

The Cl-36 ratics in the primary circuit are consistent with a mix-ture of chlorine activation times:

a large fraction of relatively t

I nos-activated C1 (either released from the core on initial startup or from leaching of concrete or insulation) and a smaller fraction of highly activated C1, such as might have been released later.

E 3

4.

Circulation of Cl would increase the Cl-36 content by an insignifi-cant amount.

t i

k 5.

The high Cl-36 content of the circulator samples relative to the low 3

Cl-36 content of the plateout probe sleeve and diffusion tube sug-j gests that chlorine releases from the core have occurred af ter 2

November 1981.

E li

.ef

.5 E

.e 3

5 Page 3

GA-1484 (REV.10/82)

TITLE:

AN INVESTIGATION INTO THE SOURCES OF CHLORIDE IN THE FORT ST. VRAIN PRIMARY CIRCUIT Document No.

907838 luus N/C 4.0 OVERALL CONCLUSIONS (CONSISTENT WITH Cl-36 ANALYSIS AND HEATUP TESTS) 1.

The fuel is not a continuous source of C1 rather it is a transient source upon initial heatup. The initial core could have released about 100 g C1.

2.

Graphite is a source of hcl, possibly ~100 g, on initial heatup.

3.

Exposure of fuel and graphite to high water vapor at operating tem-g peratures causes a relatively maall release of C1, up to 3 g/hr, from the core, depending on water vapor conceEtration.

Ia h

4.

Titanian sponge is a minor transient source, up to 3 g, on inicial heatup.

g 5.

Leachable sources such as concrete or insulation could lead to high salt levels locally but would not necessarily contribute to the circulating inventory.

-8 j

6.

The major chlorine release (~200 g C1) occurred during initial E

reactor startup.

During all subsequent reactor operation to date, e

j approximately 100 g additional has been released, about 50 g from j

fuel reload startups, and another 50 g due to reactor operation in relatively high moisture.

This latter 50 g of C1 was highly acti-vated, and when mixed with the nonactive C1 in the circuit, caused the C1-36/Cl-35 ratio in the circuit to increase dramatically. This postulated event sequence is described in detail in the next section.

Page 25

' G A-1484 (R EV.10/82)

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AN INVESTIGATION INTO THE SOURCES OF CHLORIDE IN THE FORT ST. VRAIN PRIMARY CIRCUIT Document No.

907838 luus N/C 5.0 POSTULATED CHLORINE RELEASE SCENARIO The data obtained from primary circuit samples (Table 7) shows that the C1-36/35 ratio has increased with time.

For example, in late 1981 (408 EFPD) the ratio was about 13.

At the and of cycle 3, January 1984, the ratio was about 100 to 200 and in June 1984, af ter only 5 EFPD into cycle 4, the ratio was 200 to 300. This suggests that the core released small amounts of highly active C1 in cycles 3 and 4.

These data may be explained by the following 3

sequence of events.

E 8

I 1.

Upon initial startup in 1976, about 200 g of hcl was released from I$

the core (including fuel and graphite).

P 5

2.

Operations through 1981 contributed to this total, by heatup of j

reloads and/or by leaching of concrete and ceramic insulation.

2, Assume the total C1 burden is 250 g.

This C1 was relatively non-activated having a 36/35 ratio of around 13 uci 36/g C1 consistent with the plateout probe C1.

(See Table 7.)

~8 j

3.

Sometime af ter the plateout probe was removed (November 1981), the 8

reactor was operated with moisture in the helium. During the latter e

j part of cycle 3, the reactor was operated at 70% power for several j

months at I to 3 ppm H O and, on June 22, 1984, the beginning of 2

cycle 4, the reactor was operated at from 10% to 50% power with grencer than 1500 ppm H O for 12 hr.

2 4.

According to the fuel rod hydrolysis tests in Table 6, at high mois-ture, on June 22 the release of C1 could have been about 3 g/hr, and extrapolating down in water vapor pressure the release may have been of the order of 10 mg/hr during cycle 3.

Page 26

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TITLE: AN INVESTIGATION INTO THE SOURCES OF CELORIDE IN THE FORT ST. VRAIN PRDIARY CIRCUIT Document No.

907838 issue N/C 5.

Therefore, during latter cycle 3 operation the hcl release was about 20 g and in cycle 4 on June 22, 1984, the release was about 30 g HC1.

6.

These Cl releases would be highly activated, the 20 g hcl released from the core in cycle 3 would have an average 36/35 ratio of about 1500 while the 20 g released in June 1984 would have an average ratio of about 1400 taci Cl-36/g C1 (see Table C-1 in Appendix C).

E

[

7.

By mixing small amounts, 20 and 30 g, of highly activated C1, with a larger amount (~250 g) of relatively nonactivated C1, results in apparent 36/35 ratios of about 120 for the end of cycle 3 (consis-k tent with the C2104 bolts) and a ratio of about 250 (consistent with a

y the C2102 samples).

8.

Therefore, the total Cl released from the ' core to date was about j

]

300 g.

Most of this total was released during startup. Some of l

this C1, about 50 g, was released from the older fuel later in life

~S (cycles 3 and 4) which caused the apparent C1 36 content to increase

.!l!

with time.

.E E

.e

%3z t

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GA Technologies Inc.

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AN INVESTIGATION INTO THE SOURCES OF CHLORIDE IN THE FORT ST. VRAIN 9

PRIMARY CIRCUIT Document No.

907838 issue N/C l

APPENDIX A PHASE II - TEST APPARITUS AND PROCEDURE The apparatus for determining the release of hcl gas from FSV materials is shown in Fig. A-1.

The method is to place the samples in a silica boat in the quartz furnace tube, establish helium flow, turn furnace on to desired temperature (950*C for

.g fuel rods and H-327 and H-451 graphite, 800*C for HLM and PGX graphite, 370* C E

for Ti sponge), remove and replace, hcl collection flask at I to 5 hour5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> inter-E u

2 vals, continuing to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> total.

If hydrolysis is required, moisture j

saturator is valved in for additional 24 to 100 hour0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> periods.

Furnace back-g ground or blank values are determined by performing tests using empty furnace l

tube prior to addition of the sample, and also by running for long times af ter I

the hcl is release from the sample.

1 I

.2 Collection flasks are submitted to analytical chemistry for chlorine mea-1

'E surements by means of ion chromatography, the sensitivity of which is below E

.g 0.1 ppm chlorine.

pH measurements of selected samples were performed. These data are listed in Appendix A-2.

l

.5 A number of standards were run in which known amounts of hcl were added i

to the furnace, hcl collected in the above method and submitted to analytical z

chemistry.

The results of those calibrations are shown in Table A-1.

l l

l l

l

+

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GA Technologies Inc.

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AN INVESTIGATION INTO THE SOURCES OF CHLORIDE IN THE FORT ST. VRAIN PRIMARY CIRCUIT Document No.

907838 issue N/C l

m I

FURNACE nnn.

)

X

(

f//

x x

/[

FUEL RODS g

l DE10NIZED o*

~ - -

d' WATER I

o**

hcl COLLECTION He/

MolSTURE FLASK s

1000 ppm H2 SATURATOR

]

TANK I

g Fig. A-1.

Heatup and hydrolysis apparatus for measurements of hcl release h

~

8

.e TABLE A-1 hcl CALIBRATION STANDARDS

.E E

S Furnace Chlorine hcl Added Temp Time Removed Recovery Z

(uga)

(*C)

(hr)

(pga)

(%)

465 950 4.25 336 72 i

l I

3550 950 4

2924 80 l

l 20.6 3033 83 l

785 950 4

518 66 19.75 584 74 l

Note:

Average recovery: 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> = 73%; 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> - 79%.

l Page 29

GA Technologies inca 11A-1484 (REV.10/82)

TITLE: AN INVESTIGATION INTO THE SOURCES OF CHLORIDE IN IHE FORT ST. VRAIN PRIMARY CIRCUIT Cocument No.

907838 inus N/C APPENDIX A-2 MEASUREMENTS OF pH OF PHASE II CHLORIDE COLLECTION FLASKS A tacit assumption in the Phase II heatup tests is that the chlorine species released was hcl gas. This point was checked on a number of samples by measurement of pH of the water solutions given in Table A-2.

TABLE A-2 pH OF PHASE II CHLORIDE SAMPLES E

PH k

Sample Chloride Other(s)

No.

Sample Heated (uga)

(uga)

Measured Calculated (b) r

.c 105-A Fuel rods 120 3.7 4.1 a

I' f

105-F Fuel rods 13 4.1 5.1 2

111-A Fuel rods 54 3.9 4.5 111-D Fuel rods 6.6 4.2 5.5 2

.9 115-B HLM graphite 0.7 13 (SO4-)

3.8 4.2

,]

42 (F-)

115-F HIM graphite 17 10 (F-)

4.1 4.7 3

3 RW-1 Rainwater 34 4.9 4.5

.eE

.E y

• In most cases, other anions were found, but not always quantified.

j (b) Calculated pH based on assuming all anions found are derived from a

acids, i.e., hcl, H SO, HF.

2 4 1

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AN INVESTIGATION INTO THE SOURCES OF CHLORIDE IN THE FORT ST. VRAIN f

l PRIMARY CIRCUIT I

Document No.

907838 laus N/C APPENDIX B-1 MASS SPECTROMETER RESULTS OF hcl RELEASED FROM FUEL RODS Rod No.

Fuel Segment hcl Imached(s) ppe BC1 CR1420012-21 2

IX 0.51 C11420024-19 2

11 0.26 CR1430001-0029(1) 3 11 0.77 CR1430001-0029(2) 3 1X 1.81 CR1430001-0029(3) 3 IX 0.38 CR1430010-0027 3

1X 0.31

)

CR1430019-0026 3

IX 0.20 j

CR14-40014-0032 4

II 0.50 CR14-2001-24(1) 3 1X 0.69

.g C1142001-24(2) 3 IX 0.66 CR142001-24(3) 3 IX 1.41 CR14-10125-1 1

1X 0.34 C116-10125-1 1

2X 0.40 CR18-10125-1 1

3X 0.10 E

C114N-60078-2 6

1X 0.67 CR14N-10311-17-00 7

1X 0.52

.n6

.E

(*) Number of hcl leaches during manufacture.

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AN INVESTIGATION INTO THE SOURCES OF CKLORIDE IN THE FORT ST. VRAIN i

PRIMARY CIRCUIT l

Document No.

907838 issue N/C APPENDIX B-2 DETAILS OF hcl RELEASED FROM FUEL RODS USING IHE TUBE EURNACE METHOD Dry Helium Purge Wet Helium Furnace Furnace Blank hcl RCl(b)

Blank hcl hcl (b)

Fuel Before 4 hr 20 hr After 4 hr 20 hr Rod No.(a)

Segment ug (pg)

(pg) ug (pg)

(ug) 2 es CR1430048-1S 2 ea CR1430051-1N 3

0.46 173.0 236.0 22.5 48.4 3

2 en CR1430053-1N E

l 2 ea CR1460078-2 2 es CR1460080-2 6

1.8 29.5 56.0 1.46 j

2 es CR1460089-6 h

2 es CR14-10046-1 3

2 es CR14-10050-13 1

3.0 270.0 3.0 e

2 ea CR14-10066-2 h

2 ea CR14-10300-00 g

2 ea CR14-10318-16 7

1.8 21.01 44.2 1.8 11.5

~

j 2 ea CR14-10335-17 e

l 2 ea CR14-20001-24 3

2 ea CR14-20024-19 8

1.86 10.22 21.8 1.0

.e 2 ea CR14-20012-21 E

E 2 en CR14-30001-0429 E

2 ea CR14-30010-0027 9

1.45 24.5 39.0 0.72

'il 2 ea CR14-30019-0026 5z (a)All tube furnace rod samples totaled 72 g.

(b)This column is the total released.

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3 H 8UIWsw as av.

GA-1484 (REV.10/82)

TITLEf AN INVESTIGATION INTO THE SOURCES OF GLORIDE IN THE FORT ST. VRAIN Y

PRIMARY CIRCUIT Document No.

907838 Issus N/C l

APPENDIX C CALCULATIONS OF GLORINE-36 FORMATION Calculate the formation of Cl-36 (t 1/2 = 3 x 105 yr) from I ga of stable C1 by neutron activation in FSV at 70% power.

uciCl-36/gC$=-AN35$oc/3.7 x 104 dps/uci where N35 - atoms Cl-35 = 1 ga x 6 x 1023 x 0.75/35 g/ mole = 1.3 x 1022, g

E 0.75 = fraction 35 in stable C1, g

2 4 = neutron flux at 70% power = 4 x 1013, j

1 = 7.5 x 10-14 s-1, g

a = C1-35 cross section, 20 x 10-24 em2 (HTGR neutron spectrum),

4 j

t = time, see assume 1 day = 8.64 x 10.

!!3 In one day at 70% power in core a gram of stable C1 yields 3

i 8.64 x 10 /3.7 x 104 = 1. d 4

7.5 x 10-14 1.3 x 1022 4 x 1013 20 x 10-24 y

E 5

The cable wire leach found E

Oj 167 uci 36/g C1 + 1.8 = 93 days activation at 70% power E

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taA I W U H H U I U S I L" 5 III U.

G A-1484 (REV.10/82)

-TITLE!

AN INVESTIGATION INTO THE SOURCES OF GLORIDE IN THE FORT ST. VRAIN PRIMARY CIRCUIT Document No.

907838 Isst.d I;/C

~l 1

TABLE C-1 CALCULATED ACTIVATION OF Cl-36 IN CORE 8"

~

End of Se ts Cycle Cycle Total in Core Minimum (b)

Maximum (b)

Average (b) 1 175 175 1-6 450 450 450 2

180 355 2-7 470 920 850 3

309 660 3-8 800 1,700 1,500 4

5 665 4-9 13 1,700 1,400 E

g

(*)1 uci C1-36/gm C1 = atos ratio 35/36 = 25,772.

j (b) Minimum ratios obtained from newest fuel segment. Maximum E

ratios obtained from oldest fuel segment.

b a

s i

=

.I!

.5 E3 iiz e

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