05000321/LER-1979-021-03, Radioactive Water Found Bubbling Out of Ground Near Diesel Generator Bldg.Caused by 1/2-inch Temporary Line Being Left in Ground After Tank Removed.Line Capped & Will Be Removed During Shutdown
| ML19250C058 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 10/31/1979 |
| From: | Rogers W GEORGIA POWER CO. |
| To: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| Shared Package | |
| ML19250C055 | List:
|
| References | |
| LER-79-021-03L, LER-79-21-3L, NUDOCS 7911060458 | |
| Download: ML19250C058 (54) | |
| Event date: | |
|---|---|
| Report date: | |
| 3211979021R03 - NRC Website | |
text
-.
- 7-771 Update to a previous report LICENSEE EVENT REPORT submitted March 26, 1979 CoNTnoL BLOCe<: l l
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lh (PLE ASE FRINT OR TYPE ALL hEQUIRED INFORMAllON) 1 6
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61 DOCKET NUMBER 68 69 E VE N' O ATE 74 75 REPORT OATE 80 EVENT DESCRIPTI0N AND PROBABLE CONSEQUENCES h g lDuring steady state power operation at 2384 BIT, two Chemical Radiation Technicians g lwere obtaining a water sample from Piezometer Well Pl7B near the Diesel Generator l
~
Tpr] l Building when they observed a small amount of water bubbling out of the ground nearby. l g lAn analysis of this water and the soil in the immediate area revealed small amounts of l l0 lc i l radioactivity as found in reactor steam samples. There are no significant impacts on I g lthe public health and safety because the event occurred in the Protected Area of the l
10181 Isite. the activity released is small, and the activity (excluding tritium) was l
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l 34 35 36 37 40 41 42 43 44 47 CAUSE DESCRIPTION AND CORnECTIVE ACTIONS 27 l An investigation revealed that, during construction a 4" temporary line was installed l ii O
!ii lil l to carry nitrogen for inerting to the feedwater heaters from a tank in the yard which I f
I i, i,;l was' located adjacent to Piezometer Pl7B. Afterwards the tank in the yard was removed l y l leaving a buried open line about eight inches below yard grade.
The heater end of l
iTT41 1 this temporary line was not removed after start up of the unit.
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NAME OF PREPAf1ER.
PHONc:-
Radioct.cmis t t__
Georgia Power Company Plant E.
I. Hatch Baxley, Georgia 31513 Reportabic Occurrence Report No. 50-321/1Q79-021 Event Description (cont.)
confined to the immediate point of discharge.
Cause Description (cont.)
line went undetected until the events of March 20 led to its discovery.
A valve on the temporary line near the feedwater heaters was found to be partially open.
It was immediately closed.
To prevent any possible re-occurrence, the line was broken inside the turbine building by removing a pipe coupling and the line capped.
The line was also capped at its end near Piezometer P17B.
When the unit is shut down the line will be removed from the feedwater heater connection.
Contaminated earth at the discharge point in the yard was drummed to be shipped off to a licensed burial site.
Further investigations are contemplated and are discussed in the attached Anomalous Measurement Rooort.
Also discussed in this Report is information regarding elevated tritium levels in the Piezometer Wells in the Protected Area which was reported in the Annual Environmental Report for 1977.
1
~
\\212 U2
NARRATIVE
SUMMARY s
NRC DOC"ET 50 171 OPERATION LICENSE DPR-57 EDWIN I. H ATCH NUCLEAR PLANT - UNIT 1 NONR00 TINE RADIOLOGICAL ENVIRONMENTAL OPERATING REPOR T ANOMALOUS MEASUREMENT REPORT Pursuant to Section 3.2 and 5.7.2 of' the Environmental Technical Specifications (ETS),
Appendix B of the Op e ra t in g
- License, this noncontine report describes the elevated tritium concentrations in ground water sampics cellected f rom. two locations within the protected area.
These concentrations exceed the reporting level. of 3 X 104 pCi/1 specified in Table 3.2-2 of the ETS.
A samgle taken from Piezometer No. Pl7B on December 1,
1978, showed al level of 2.6 X
105 pCi/1.
After receiving the laboratory report from this sample, a new sample was collected on January 24, 1979, to]
confirm this elevated level.
Confirmation was established on March 12 by receipt of the lab report for th e January sample; the concentration was 1.7 X 105 pCi/1.
Piezometer No.
Pl7B is a well about 11 feet deep which is located adjacent to the SE corner of the Diesel Generator Building.
The laboratory results of the previous samples at this location fall in 4
1978) were 8.5 X
- 102, 7.9 X
103 and 1.1 X
10 pCi/1 for collections on 6/18, 8/8 and 8/31, respectively.
The laboratory results for samples collected on 2/16/70 and 3/13/79 have not yet been received.
The second location from which ground water was collected with elevated concentrations of tritium was Piezomotor No. P16.
This well is also about 13 feet deep; it is adjacent to the south side of the condensate storage tank (CST).
The laboratory results received on March 12, for a
sample collected on January 26,
- 1970, showed a
concentration of 1.4 X 105 pCi/1.
Previous samples (all in 1978) were 1.4 X
- 105, 1.6 X 105, and 1.5 X. 10 5 pci/1 for collections on 6/18, 8/8, and 8/31, respectively.
The laboratory results for samples collected on 2/14/79 and 3/9/79 have not yet been received.
These previous elevated levels were not reported since there were no reporting levels for radiological environmental samples prior to an amendment to the ET S on November 16, 1978.
This amendment also eliminated the requirement of sampling for ground waten.
Prior to this amendment quarterly sampling was required only in the event of an accident or unusual circumstance; the ETS specified sampling from a background station, a 1: ell at Deen's Landing 2 miles uostream, and from an on-site control station, the subsurface drainage ditch.
This subsurface drainage network encircles the plan t yard and has two outfalls from which samples are collected; its purpose is to control the water level in the unconfined ground water table.
The U. S. Department of the, Interior in their comments dated June 98, e
\\272 $
'1977 on the Draft Environmental Statement (DESI for the Hatch Nu c l.c a r Plant Unit 2 suggested ground water sampling of the wince confined acquifer which underlies the plant.
Consequently in the 4th quarter of 1977, samples were collected from three piezometer uclls which have depths on the order of 80 feet.
Sampics from one of these wells, N7A which is adjacent to the south side of the CST, showed a level of 1.6 X 103 pCi/1; samples from the other two wells showed the tritium levels to be less than the lower limit of detection (about 102 pct /1).
Also in the 4th quarter of 1477 the sample from the north outfall of the subsurface drainage ditch showed a level of 9.5 X
102 pCi/1.
As explained in the An r.
al Environmental Surveillance Report for Calendar Year 1477, these two readings were a matter of concern since the previous maximum reading was 2.4 X 102 pCi/1.
When additional samples collected at N7A
.n February and May of 1978 showed the level to be consistent, it was decided to sample the unconfined water table.
It is questionable that the ground water samples gathered at P173 and P16 should be considered as environmental samples due to their remoteness from unrestricted areas; thus there is considerable doubt that the noncoutine reporting requirements of Sections 3.2 and 5.7.2 of the ETS are applicable in this case.
The maximum environmental impact of these elevated tritium levels in ground water may be assessed as the dose to a hvoothetical individual who regularly drinks this water where it enters the unrestricted
- area, that is, from the outfalls of the subsurface drainage ditch.
The highest quarterly average concentration from the outfalls during 1978 was 1.8 X 103 0C1/1 and the annual average concentration was 7.4 X
102 pCi/1.
Using the assumptions and constants from Regulatory Guide 1.109 Revision 1,
these constants translate to whole body and organ doses of 0.046 mrem for the maximum quarter and 0.077 mrem for the year.
The dose limits from Appendix I to 10 CFR 50 for liquid effluents are 1.5 mrom whole body and 9 mrem organ for any quarter, and 3 mrem whole body and 10 mrem organ for the y e r. r.
The MPC for tritium in unrestricted areas as given in 10 CFR 20 is 3 X 106 pCi/1.
a.
The cause of the elevated tritium levels in samples collcoted from Piezometer No.
Pl7B is believed to have been found.
During construction a
temporary line carried nitrogen to the feedwater heaters from a
tank in the yard which was located adjacent to Piezometer No.
Pl7 B.
Afterwards the tank in the yard was removed lea'ing a buried open line ab ou t 8 inches below yard grade.
The v
heater end of this temporary line was not removed after the tests were completed.
The presence of the line went undetected until the events of March 20 led to its discovery.
On March 20, 197q, "ar,er was observed to be flowing out of the ground near Piezometer Pl7B from this spot to a height of from one to two inches.
Water would flow for around 10 seconds, then stop for e
e 1272 1M
'perhaps 5 minutes or so.
This cyclic phenomenon occurred several times over a few hours.
Water samples from the flow and mud samples on the ground at this spot were collected.
Gamma scans of these samples show Xe 133 - 2.45 E-4 ue/ml, Xe 139m 7.23 E-6 u c /m l, Xe 135 - 5.90 E-5 uc/ml and Kr-85m - 1.68 E-6 ue/ml in the water and Cs 134-1.34 E-5 uc/gm, Cs 137 1.51 E-5 uc/gm.
Co 58 - 1.11 E 6 uc/gm, l%n 65 - 9.65 E-7 uc/gm. Co 60 - 1.88 X 1.06 uc/gm, Ba La 140 4.91 E-7 uc/gm, Xe 133 - 4.98 E-6 uc/gm, Xe 135 - 6.87 E-7 uc/gm isotopes in the soil.
The laboratory results of a tritium analysis is not yet available.
A check of the valve on this temporary nitrogen line at the feed water heater on March 21, 1970, showed the valve to have been partially open.
This valve was promptly closed.
The open end of this temporary nitrogen line was unearthed on March 22, 197e.
The line lies horizontal pointing north.
There was no measurable activity in the soil beyond 2
feet from the pipe's end.
The contaminated soil was placed in drums for shipment to a licensed burial ground.
The open end of this temporary line was capped off.
The line was also broken by removing a pipe coupling in the line inside the turbine building and capping the line.
The frequency of sampling has been increased at Pl7B to monitor the tritium level closely now that the probable tritium source to this area has been eliminated.
During the forthcoming shutdown of Unit I scheduled to begin in late April or early May of 1974, it is planned to disconnect this temporary nitrogen line from the feedwater heater and cap-o ff the connection.
An investigation of the clevated tritium levels in the piezometer wells has been in progress for some months.
The underground piping systems which carry high tritium levels have been identified.
Some of those piping systems have been hydrood to some extent; but the results of the hydro do not positively con firm or exclude leakage to the ground from these systems.
Dr. James R.
Wallace, a Professional Engineer and Chief Hydrologist for Law Engineering Testing Company of Atlanta, Georgia has been engaged as a consultant in planning and implementing this investigation.
A study of the piping diagrams, ground water levels and tritium levels is in progress to determine seepage paths to the source where tritium is entering the ground.
Additional surface borings are being considered; the location and the priority for these borings are being determined.
The gamma levels in the soil and ground water from these new borings may be indications of the proximity of any tritium source other than the one found at Piezometer Pl7B.
t xc:
U.
S.
Nuclear Regulatory Commission Office of Nuclear Reactor Regulation ATTN:
Director of Regulation
+
Washington, D.
C.
20555 March 26, 1074 1272 135 A
SUPPLEMENTAL NARRATIVE SUMMARY NRC DOCKET S0-321
~
OPERATION LICENSE DPR-57 EDWIN I.
H ATCH NUCLEAR PLANT - UNIT 1 NONROUTINE RADIOLOGICAL ENVIRONMENTAL OPERATING ANOMALOUS MEASUREMENT REPORT This report supplements the previous report submitted with L ER 50-321/1979-021 Rev.
1 by providing updated and additional information on the elevated tritium concentrations in ground water samples collected from piezometers within the protected (restricted to the public) area of the plant site.
There has been no significant impact on the public health and safety since the previous submittal date of this LER; any release to unrestricted areas through the pathways describcd in this summary would be minuscule and results in insignificant doses to the public.
Additional surface borings are now underway.
As of April 30, 1979, nine additional piezometers to the unconfined water table have been made in the vicinity of the affected piezometers.
It is planned to install up to a total of 20 piezomoters.
These new borings will serve as aids in establishing flow pathways in the ground water in the vicinity of the affected piezometers, in order to be assured that there are no sources of tritium, other than previously reported.
These piezometers w ill also inform us of where tritium is being confined in the plant yard.
The analyses being done with samples from the new surface borings will consist of meacuring temperature, and tritium levels in the ground water.
Also, gamma levels are being measured in ground soil and water to determine if any activity measured is above normal background and can be attributed to plant operation.
The history of tritium levels at each of three piezometers is provided in Table 1;
this history - began in June 1978.
Both Piczome te r P16 an d Piezome te r Pl7B are about 13 feet deep; they are respectively located adjacent to the south side of the condensate storage tank (CST) and adjacent to th e S.
E.
corner of the diesel generator building.
Piezometer N9B, a 17 f ort deep hole, is located adjacent to the N.
E.
corner of the turbin e building and is approximately 120 feet from Pl7 B,
which is adjacent to where the temporary nitrogen line was found buried.
The tritium levels at Pl7B a f ter having built up rather d raraa tic ally over a six month
- period, then becoming m ere or less stable for several months, now seem to be decreasing af ter having eliminated the tritium source from the temporary nitorgen lime.
The levels at N9B were steady in 1978, begam a rise early in 1979, and now seem to be approaching a plateau.
The activity level in this Supplement page 1 1272 136 Apr11 30, 1979
piezometer execeded the reporting level fer offsite environmental samplen of 3
X 103 pCi/1 specified in Table 3.2-3 of the Environmental Technical Specifications on Ma rc h 20, 1979.
The highest level found in the piezometer to date (April 10) is 2.3 percent of the maximum permissible concentration (MPC) allowed for unrestricted areas.
It is speculated that the recent increases at this location are due to migration of ground water f rom 'the vicinity of P17B since the two piezometers are close to one another.
The levels of P16 seem to be slowly but steadily decreasing; this could be construed to mean that the input of tritium to this location has stopped or has been significantly reduced.
To check the extent of tritium migration in the plant yard, on March 13 and 16, 1979, ground water samples were collected from 10 other piezometers which tap the unconfined water table.
These piezometers encircle the complex of the main plant buildings Service, Turbine (2), Reactor (2), Radwaste (2), and Control Buildings.
None of these samples had detectible levels of tritium.
It is questionable that the ground water gathered from any of the on site piezometern should be considered as environmental samples due to their remoteness from unrestricted areas; thus, there is considerable doubt that the noncoutine reporting requirements of Section 3.2 and 5.7.2 of the ETS are applicabic in this case.
The maximum environmental impact of the elevated tritium levels is assessed as the dose to a
hypothetical individual who regularly drinks the water from the outfalls of th'e subsurface drainage network.
The highest quarterly average concentration of tritium from the outfalls was 1.8 X 103 pci/l and occurred in the 3rd quarter of 1978; this concentration is equivalent to a whole body or organ dose of 0.0386 mrem.
The quarterly dose limits from Appendix I to 10 CFR 50 due to liquid releases are 15. mrom for the whole body and 5 mrem for any organ.
The MPC for tritium in unrestricted areas as given in 10 CFR 20 is 3 X 106 pci/1.
Note that this dose estimate is very conservative as drinking water is not obtained from this source.
c 1272 137 Supplement page 2 April 30, 1979
TABLE 1 IIISTORY OF THIT!UM LEVELS III oCl fl _ AT AFFECTED P I E 7.OM F.T E :.S DATE 119 3
~P16 Pl73 JUtib 18 1.4 (5)a 8.5 (2)
AUG.*G 3.6 (3) 1.6. (5) 7.9 (3)
AUG. 31 3.5 (3) l'..S (5) 1.1 (4)
SEPT. 29 37 (3)
DEC. 1 4.5 (3) 2.6 (5)
J A!!. 24 1.4. (5) 1.7 (5)
J Ali. 26 FEB. lll 1.3 (5)
FEB. 16 9.6 (3) 30 (5)
HAR. 9-1.2 (5) li A R. 13
- 2. 8 -( 4 )
2 3 (5) li A R. 20 4.6 (4) 1.1 (5)
~
2.9 (5)
MAR. 27 5.4 (4)
- - APR. 4 6.0 ( '! )
1.1 (5) 2.3 (5)
APR. 10 C.8 (4) 1.1 (5) 2.4 (5)
APR. 17 6.7.(4) 1.1 (5) 8.5 ( !! )
APE. 24 6.6 (4) 9.52 (4) 1.66 (5)
F0,0T 0TE:
(a) 1.4 (5) Indi. cates 1.4'X 105 1272 138' Supplement page 3 April 30, 1979 l
SU P P L E!!E!!T A I, ll ARR ATIVE SUf!M ARY lilic DOCE ET %0-U1 OP ER ATIO!! LICE!!SE DPR-57 C
EDUIll I. !! ATCil !JUl ti AR PLA:!T - U!!IT I NOli ROUTI !E R ADIOLOGICAL E!! VIRO !ME: ITAL O PER ATI!!G ANO:!ALOUS ME ASURE:-:E:!T REPOP.T 7
The report which f ollors - sup pleme nt s-the provioun su bci t t tals of LER 50-321/1979-021.
The report is-written in the format or the Annual En v i ron= c n ta l Surveillance Report and will be submitted in the near future as a
supplement to the Annual. Environme'ntal Surveillance Report for 1978.
1272 139
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. 'g t
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S U P y L E:1 E.': T June 27, 1079
(
.g s
t o IINP ANNUAL REPORT 2.4 DISCl!ARCES TO THE GROUND Pursuant to Sections 3.2 and 5.7.2 of the new ETS, a nonroutine report (Reportable Occurrence No. 50-321/1979-021) with subsequent revisions was filed with the NRC in March and April 1979 to inform them of high tritium concentrations in grcund war.er samples collected in the plant yard.
There has been no significant impact.on the public's health and safety due to these high tritium levels as the releases to vnrestricted areas have been miniscule and have thus resulted in insignificant doses.
In order that the reader may appraise this problem, a wealth of back-ground and historical information is provided.
As a result of the interest aroused by this norroutine report, data and activities related to this problem are reported subsequent to 1978 up until the time of this writing.
Some extraneous sources of tritium have been identified.
Actions have been or are being taken to eliminate these.
Other possible sources of extraneous tritium are being checked or will be checked as necessary.
An investigation of the seepage pathways is in progress.
An assessment of the current status of this problem and a prognosis of its eventual solution are also provided.
1272 14.0 4
Supplement 1 2.4-1 6/79
UNp ANNUAL REPORT 2.4.1 BACKGkOUND AND HISTORY There are three distinct water zones underlying the site:
a water tabic, a local squifer and a regional aquifer.
Aquicludes separate and hydraulically isolate these zones from each other.
The vast regional aquifer whose top is a few hundred feet below plant grade is not hydrau-lically connected to surf ace waters in the vicinity of the site.
The shallow local aquifer is separated from the regional acquifer by an aquiclude which is about 100 f'cet thick; the top of the local aquifer is roughly 65 feet below the grade of the plant yard; it is hydraulically connected to surface waters in the UNP environs.
The foundations for some of the buildings at the plant enter but do not rupture the aquielude between the local aquifer and the water tabic; this aquiclude is 40 to 50 feet thick.
The water table which is charged by the percolation of precipitation through the soil is unconfined.
In the plant yard the water tabic more or less extends from 10 to 20 feet below grade.
Two separate subsurface drainage ditches, whose outfalls are at about 25 feet below grade, provide a system for controlling the icvel of the water table.
Roughly 70% of the yard area in drained by Ditch No. 1, the subsurface ditch whose outfall is north of the plant; Ditch No. 2, the subsurf ace ditch whose outfall is cast of the plant, drains the remainder of the plant yard.
This network of subsurface ditches encircles the plant buildings.
During preoperation between January 1972 and September 1974, ground water samples were taken from three indicator and one control station.
The indicator stations were all on-site.
They consisted of two deep wells and Ditch No. 2.
The deep wells tap the regional aquifer.
The subsurface drainage ditch taps the water table. The control station is a well located near the bank of the Altamaha River approximately 2 miles west (and upstream) of the plant at Deen's Landing.
According to the owner, this well is'535 feet deep; thus water is apparently drawn from the regional aquifer.
During preoperation, gross alpha, gross beta, gamma spectral and tritium analyses were performed on the ground water. samples. Traces of raden daughter products were detected occasionally by the gamma scans.
The samples were analyzed for tritium by a gas enrichment process which provides a LLD on the order of 100 pCi/1.
Detecta' ale icvels of tritium were found in only two of the seven samples collected.
These were 240 and 130 pCi/l from Deep Well No. 1 and No. 2, respo:tively.
The old Unit 1 ETS required tritium and gamma spectral analyses at one indicator station and one control station.
Since initial criticality of Unit 1 in September 1974, the gamma spectral analyses of ground water samples have never shown detectable levels of activity for any radio-nuclide.
The indicator and control stations were established as an on-site subsurf ace drainage ditch and the well at Ieen's Landing, respectively.
The deep wells are not considered as good environmental 1272 141 Supplement 1 2.4-2 6/79
HNP ANNUAL REPORT monitoring stations because of the isolation and remoteness of the regional aquifer from the plant.
However, due to the importance of the regional aquifer, sampics are occasionally drawn from the deep wells.
The general location of all of these ordinary stations are shown in Figure 2.4-1.
These are referred to as ordinary stations because they were either used during preoperation or were referred to in the old Unit 1 ETS; they were the only stations utilize,d until November 1977.
Furthermore, the old ETS required activation of this phase pf the radio-logical environmental monitoring program only in the event of accidental or unusual circumstances.
Ccnsequently, regular collections were stopped when operations began in September, 1974.
Collections were made, however, in the 1st quarter of 1975.
Ditch No. 1 had not yet been utilized as a sampling station in early 1975.
Then sometime later Ditch No. 2 was blocked off for a period of time due to construction work on Unit 2; it was subsequently reopened.
Collections from Ditch No. I were initiated on a temporary basis in the 3rd quarter of 1976 to provide a comparison with previous data obtained from the samples gathered at Ditch No. 2; concurrently, sampics were taken from the control station.
At least one sample each quarter has continued to be collected to this date f rom the control station and from at least one of the outfalls of the subsurface ditch; samples were also occasionally drawn from one or both of the deep wells.
A complete listing of the laboratory results of the tritium analyses for all samples collected at the ordinary stations is given in Table 2.4-1.
It is seen from this table that, since operations began through the end of 1977, the tritium Icvels in all samples collected from these ordinary stations, except one, were no higher than those found during preoperation
~~
of UNP-1.
The exception was for the November 16, 1977 sample from Ditch No. I which had a measured level of 950 pCi/1.
This established a new maximum tritium level detected in ground water samples; but, an even higher level was found in a sample collected 5 weeks later from a new sampling location.
Sampling at some new locations came about as follows:
The U. S. Depart-ment of Interior in their comments dated June 28, 1977 on the Draf t
. Environmental Statement for HNP Unit 2 suggested ground water sampling of the local aquifer as its top is about 5 feet below the foundation of the UNP-2 radwaste building.
It should be noted that the local aquifer had not been monitored previous to this time.
Consequently, in the 4th quarter of 1977 sampics were collected from three piezameter holes (identified as N7A, NSA, and Pl7A).
Each of these test holes (or wells) has a depth on the order of 80 feet.
The tritium Izvel in the sample taken from N7A which is located about 15 feet south of the Unit 1 Con-densate Storage Tank (CST-1) dyke was 1550 pCi/1. The tritium concentra-tion in the samples from the other two holes was be3ew the level of detection. All three holes lie within several huna:ed feet of each other.
The locations of these holes (as ec11 as the other piezometer holes discussed in subsequent paragraphs) are shown in Figure 2.4-2.
1777 142 Supplement 1 2.4-3
~
6/79
TABLE 2.4-1 TRITIUM LEVELS FROM ORDINARY STATIONS PC1/1 E
Deen's Deep Wells Subsurface Ditch Qj Date Landing No. 1 No. 2 North (#1)
East (#2)
S
',Preoperation)
<8.00 (1)n
<7.00 (1) 1.30 (2)
<7.00 (1) 1/72 - 9/74 )
<7.00 (1) 2.40 (2)
<7.00 (1)
S 3
2/17/75
<7.00 (1)
<1.00 (2) <1.00 (2)
<1.00 (2) 9/02/76
<1.00 (2) 2.30 (2) g 11/19/76
<1.00 (2) 2.40 (2) 2/23/77
<9.00 (1)
<9.00 (1) 5/16/77
<1.00 (2) 1.40 (2) 8/24/77
<1.00 (2) 2.20 (2) 11/16/77
<1.10 (2) 1.30 (2) 1.20 (2) 9.50 (2)b 1.00 (2) 12/20/77 g
2/17/78 1.00 (2)
<1.00 (2) 2.50 (2) 1.80 (2) e
$g 5/28/78
<1.30 (2) 1.90 (2) 3.80 (2) 1.80 (2) r*
D3 7/20/78
<1.00 (2) 3.10 (2)
<9.68 (2) pl 7'
8/08/78 8/31/78 1.82 (3)
<6.64 (2) gl 9/06/78
<1.10 (2) 2.41 (3) 2.70 (2) gj 9/29/78 1.70 (2) 2.70 (2) 1.06 (3) 2.90 (2) d 9/29/78
<7.01 (2)
<7.01 (2)
<7.01 (2) 11/15/78
<1.10 (2)
<1.30 (2) 7.50 (2)'
3.30 (2) 12/01/78 2.60 (2) 1.26 (3) 2.80 (2) 1/24/79 3.12 (3) 1.40 (2) rs;
~a 1/25/79 1.00 (2) rs) 1/26/79 1.20 (2) 2/13/79 1.10 (2) n u
m D
e 1
a) indicates < 8 x 10 b) recount 1.08 (3) c) Teledyne d) APT
I l-TABLE 2.4-1 (Cont'd)
TRITIIDI LEVELS FROM ORDINARY STATIONS pCi/1 Decn's Deep Wells Subsurface Ditch L
Date Landing No. 1 No. 2 North (#1)
East (#2)
~
0 2/20/79
<1.10 (2) 1.00 (3)a i
3/09/79
<1.45 (3)
<1.45 (3) 3/20/79
<1.50 (3)
<1.50 (3) 3/27/79 2.72 (3)
<1.64 (3) 4/04/79 2.10 (3)
<1.45 (3) 4/10/79
<1.58 (3)
<l.58 (3) 4/17/79
<1.48 (3)
<1.48 (3) 4/24/79
<1~. 40. ( 3)
<1.40 (3)b p
5/02/79
<1.50 (3)
<1.50 (3) 5/08/79
<1.70 (3)
<1.80 (3)
<1.70 (3)
P 5/09/79c
<1.70 (3) h 5/17/79
<1.70 (3)
<1.70 (3) y w
L 5/23/79
<1.70 (3) 5/24/79
<1.70 (3) h 0
il e
- e f
a) indicates 1.00 x 103 b) split < 1.50 (3) c) <1.70 (3) at }2!18 y
N-ij N
N}
)
n Il
'i
e.
HNP ANNUAL REPORT TABLE 2,4-2 TRITIUM LEVELS IN LOCAL AQU1FER pCi/1 P17A N8A
.N7A Date_
<1.10 (2)"
11/16/77 1.55 (3)b
<1.10 (2)
<1.00 (2) 2.50 (2) 2.90 (2) 12/20/77 1.66 (3)
<1.10 (2) 2/17/78 1.57 (3) 5/28/78 1.46 (3) 7/20/78 1.02 (3) 8/08/78 1.55 (3)
<1.10 (2) 8/31/78 1.70 (3) 9/06/78 1.33 (3)C 3.60 (2) 1.80 (2) 9/29/78 1.27 (3) 11/15/78 1.20 (3)
<1.10 (2) 7.90 (2) 12/01/78 2.82 (3) 1/24/79 1.84 (3)
<1.64 (3) 2/14/79
<1.64 (3) 3/28/79 2.12 (3) 4/10/79d 5/09/79 2
a) indicates < 1.1 x 10
~
b) recount 1.71 (3) c) splits 9.85 (2) and 1.49 (3) d) <1.70 (3) at P102B and P108B 6/79 2.4-6 Supplement 1 1272 145
..-- - ;.... ~.
llNP ANNUAL REPORT O
Recounts of the 4th quarter sampics taken from Ditch No.1 and piezometer The 4th quarter sampic from well N7A confirmed their icvels to be high. Ditch No. I was abou the 4th quarter sample from Piezometer N7A was more than six times Thesc higher than the icvel found in any sample from previous i
the icvels were still quite innocuous.
1272 146 1
6/79 2.4-7 Supplement 1
HNP ANNUAL REPORT 2.4.2 MONITORING FOR 1978 AND EARLY 1979 Analyses of samples taken from Ditch No. 1 returned to normal in the 1st quarter of 1978, but the icvel at piezometer well N7A persisted at around 1600 pCi/1.
It was then decided to take ground water samples from the water table in the plant yard fror ceteral piezometers; this was carried out in mid June of 1978.
The tritium levels at N8B and N10B were 180 and 200 pC1/1, respectively; these icvels are considered as only slightly above minimum de,tection levels.
The icvel in.P17B, a 13 foot deep test hole which is located adjacent to the southeast corner of the Diesel Generator Building, was 850 pCi/1.
Piezemeter P16, anotacr 13 foot deep test hole, was of special interest since, as can be seen from Figure 2.4-2, its surface location is only about 8 feet from the errant N7A which is 75 feet deep.
The level at P16, however, was 1.44 x 105 pCi/1 which is about two orders of magnitude above the previous maximum reading at N7A.
All of the readings up to mid-June 1978 were associated with Unit 1 not only because an Operating License for Unit 2 was not issued until June 13, 1978, and initial criticality was not actieved until July 4, 1978, but also because all the piezometers which hid been sampled were on the north side of the plant yard which is physically in the proximity of Unit 1 and relatively remote from Unit 2.
The ordinary sampling sta-tions, however, would serve to monitor each of the units more or less equally.
It should be pointed out, however, that ground water sampling is not required by the Unit 2 ETS.
A nonroutine report on the discovery of the high tritium :cvels at P16 was not required by the old Unit 1 ETS since this did not involve a significant environmental impact.
The environmental impact was not considered significant as this location was well within the protected area, the water was not being used, there were no planned usages of this yater, and its movement through the ground is rather slow.
The old Unit 1 ETS did not specify reporting levels for radiological environmental sampics.
The high reading at P16, however, did spark ef forts to obtain laboratory results sooner, and th'e initiation of actions that might lead to the discovery of the cause of the high readings; it also brought about an increase in the intensity of sampling.
All of the ground water samples collected through July of 1978 had been analyzed by Tcledyne Isotopes, Inc. of Wes twood, New Jersey.
A gas enrichment process was used to determine the tritium level of each sampic.
Although the LLD was very low, nominally about 100 pCi/1, the results were generally not forthcoming for 6 weeks or so; someti es the wait was in excess of 2 months.
To obtain quicker results, the services of a closer laboratory were procured through Applied Physical Technology (APT) of Smyrna, Ccorgia; it was also decided to use a liquid scintillation detector in the laboratory analysis for tritium.
Although results were obtained quicker (from several days to several vecks), the LLD was much higher (ranging from about 700 to 1700 pCi/1).
The old Unit 1 ETS did not specify detection capabilitics for radiological environmental samples.
The Unit 2 ETS specify an LLD of 330 pCi/l for tritium analyses of wster samples.
The services of Telodyne continued to be employed also.
1272 147 6/79 Supplement 1 2.4-8 A
ilNP ANNUAL REPORT The investigation of the high tritium readings began slowly and informally in August of 1978.
The underground piping systems which carry high levels of tritium were identified from a study of the piping diagrams.
}bny of these piping systems were hydrostatically tested to some extent; results were generally inconclusive, neither positively confirming nor excluding leakage to the ground from these systems.
The sampling was intensified by an increase not only in the frequency of collections but also in the ndsber of sampling locations.,17ua results of the tritium analyses for the ordinary stations are listed in Table 2.4-1.
The tritium levels for sampics taken from the local aquifer are given in Table 2.4-2.
The tritium levels in the test holes which have been the most af fected, at least until very recently, are provided in Tabic 2.4-3; these three piezometers N9B, P16 and P17B, tap the water tabic. The levcis of tritium found at other piezcmeters tapping the water table were not found to be high; these are tabulated in Tabic 2.4-4.
Samples were also taken from selected catch basins and the outfalls of the surface drainage ditches; these are presented in Tabic 2.4-5.
From Table 2.4-1, it is seen that the readings from Decn's Landing, the control station, are usually below the LLD, and when positive only slightly above detection.
There appeared to be an exception to this for the co13cetion on September 28, 1978, when camples taken from this station and from other stations were split and sent to Teledyne end APT for laboratory analyses.
Teledync found a level of 170 pCi/1 which is consistent with the levels found previously while APT found a level of 2020 pC1/1 from the "same" sample.
It is believed that APT's results are erroneous; this could result from mislabeling, contamination, instru-ment crror, etc.
Since this is the only control station and all other stations may be considered as indicator stations, it is to be noted that nearly all positive readings of the indicator stations are more than twice the control station readings.
Also from Table 2.4-1, it is seen that the readings from the deep wells have continued to be low.
The positive readings for Ditch No. 2 have slowly increased from 100 pCi/1 on December 20, 1977 to 1000 pC1/1 on February 20, 1979.
There was, however, a reading.of 8340 pCi/1 (not in table) by APT for the collections on August 8,1978; this reading is believed to be erroneous as the readings from this location around that time were less than 300 pCi/1.
The icvcis from Ditch No. 1 are generally a few times higher than those from Ditch No. 2.
The readings at Ditch No. 1 have been somewhat crratic.
The positive results in pC1/1 for each station are summarized belew by quarter:
1272 id Supplement 1 2.4-9 6/79
.....__._...y,......__,...-....~.._......
ANNUAL REPORT TABLE 2.4 -3 TRITIUM LEVELS IN EFFECTED TEST HOLES pC1/1 Date N9B P16 P17B 6/18/78 1.44 (5)3 8.50 (2) 8/08/78 3.55 (3) 1.64 (5)b 7.88 (3) 8/31/78 3.48 (3) 1.51 (5) 1.05 (4)
~
9/29/78 3.67 (3)c
~
12/01/78 4.49 (3) 2.64 (5) 1/24/79 1.66 (5) 1/26/79 1.37 (5) 2/14/79 1.32 (5) 2/16/79 9.63 (3) 2.97 (5) 3/09/79 1.21 (5) 3/13/79 2.80 (4)d 2.32 (5) 3/20/79 4.56 (4) 1.12 (5) 2.49 (5) 3/27/79 5.40 (4)f dry dry E
4/04/79 5.97 (4) 1.09 (5)U 2.29 (5) 4/10/79 6.79 (4) 1.07 (5) 2.36 (5)h
~
4/17/79 6.67 (4)1 1.14 (5) 8.47 (4) 4/24/79 6.60 (4)J 9.52 (4) 1.66 (5) 5/02/79 6.89 (4) 9.55 (4) 7.88 (4) 5/09/79 8.64 (4) 1.11 (5) 5.69 (4) 5/17/79 7.68 (4) 7.78 (4) 2.88 (4) 5/23/79 8.99 (4) 8.20 (4) 4.71 (4) 6/05/79 7.66 (4) 3.06 (4) 1272 149 5
a) indicates 1.44 x 10 b) recount 1.51 (5) c) split 2.95 (3) d) recount 2.95 (4) c) split 5.13 (4) f) split 5.73 (4) g) split 1.01 (5) h) split .21 (5)
~
i) split 6.90 (4) j) split 6.93 (4)
Suppleme at 1 2.4-10 6/79
..,,g....
.....,....,...,,.,...m..._._,....,.,...,,.-.
TABLE 2.4-4 TRITIUM LEVELS IN OTHER TEST HOLES TAFPING WATER TABLE
~
pC1/1
+
E Date NSB N10B N123 P15B k
~
?.3 g
6/14/78 1.80 (2)a 2.00 (2) 8/08/78
<9.68 (2)
<9.68 (2) n b
9/29/78 1.10 (2)
H 9/29/78c
<7.01 (2) 12/01/78 3.00 (2) 1/24/79 1.70 (2) 2/15/79
<1.00 (2) 2/16/79 2.10 (2) d 3/13/79 3/16/79e
<1.45 (3) dry
<1.45 (3) g 3/28/79 dry E
, 1.58 (3) p g
~
4/10/79
<1.58 (3) y f
g 5/09/79
<1.70 (3) g m
w O
W
,pe N
i w
2 a) indicates 1.80 x 10 b) Teledyne c) APT d) <1.45 (3) at A1, A3, N113 e) <1.45 (3) ar. A2, N2B, N3B, N5B, P133
~
f) <1.70 (3) at N13B, N14B, N15B, P102A, and P108A e3 e
a g
4
3LE 2.4-5 TRITIUM LEVELS IN SURFACE DRAINAGE pCi/1 o
vs Outfalls Catch Basins E
Date North (#1)
East'(#2)
PY24 PY12 PY16 3
8/08/78a 2.75 (3)b 2.40 (3) 1.22 (3) 8/31/78 dry dry dry 1.54 (3) dry 9/29/78c 2.40 (2) 1.52 (3) 1.63 (3) 9/29/78d
<7.01 (2)
<7.01 (2) 1.34 (3) 12/01/78 6.80 (3) 5.00 (2) 2/22/79 6.32 (3) 2.50 (2) 3/09/79 8.73 (3)
<1.45 (3) 3/13/79
<1.45 (3) 3/16/798 dry.
dry 3/20/79 dry dry g
3/28/79 dry dry 2.82 (3)
Eg p-@
4/10/79
<1.58 (3)
<1.58 (3) -
u 5/02/79 dry dry b,
5/17/79 d'ry dry h
5/23/79 dry.
dry g
6/04/79 dry dry 6/14/79 dry dry
.I s
N N
~
O
~
a) <7.89 (2) at PY17, MFrr4 and CBR63; <9.68 (2) at CER61 3
b) indicates 2.75 x 10 mD' c) Teledyne f
d) APT e) 1.91 (3) adjacent to } Dill 1
HNP ANNUAL REPORT Quarter n
Max Min Avg-s Ditch No. 1 1st 78 1
250 250 250 2nd 78 1
380 380 380 3rd 78 4
2410 310 1400 913 4th 78 2
1260 750 1005 361 1st 79 3
3120 110 1933 1635 2nd 79 1
2100 2100 2100 Ditch No. 2 1st 78 1
180 180 180 2nd 78 1
180 180 180 3rd 78 2
290 270 280 14 4th 78 2
330 280 305 35 1st 79 2
1000 140 570
.603 This summary indicates a general upward trend of the tritium levels in the subsurface drainage network.
From the data presented in Tabic 2.4-2 it appears that the levels in the local aquifer on the whole have not varied greatly.
An exception is seen for P17A where the readings have increased froa < 100 pCi/1 in February 1978 to 790 pci/1 in January 1979.
The bulk of the data in this table is for N7A; its positive results in pC1/1 are summarized below by quarter.
Quarter n
Ibx FHn Avg s
4th 77 1
1630 1630 1630 1st 78 1
1660 1660 1660
'2nd 78 1
1570 1570 1570 3rd 78 5
' 1700 1020 1412 257 4th 78 2
1270 1200 1235 50 1st 79 2
2820 1840 2330 693 2nd 79 1
2120 2120 2120 It might be postulated that P16 is tapping tritiated water that has accumulated in a pocket.
If the input of tritium to such a " pool" were to stop, the tritium level would diminish due to radiological decay (the half life of tritium is 12.3 years) and due to the dilution afforded by precipitation.
AsmaybeseenfromTabic2.4-3,t.helevcisatPighave slowly but steadily decreased from a maximum reading of 1.64 x 10 pCi/1 in August 1978 to 7.66 x 104 pCi/1 in early June 1979.
Thus this can be construed to mean that the input of tritum to this location has stopped or has been significantly reduced.
Supplement 1 2.4-13 6/79 1272 152 A
ENP ANNUAL REPORT The levels at Pl?B as shown in Tabic 2.4-3 af ter having built up rather dramatically over a six-month period from 853 pCi/l on June 18, 1918 to 2.64 x 105 pci/1 on December 1, 1978, then f.ecame more or less stable for several tanths with a maximum reading or 2.97 x 105 pCi/l on Feb-ruary 16, 1979, but have since decreased to 2.88 x 104 pCi/1 on bby 17.
The decrease resulted from the stopping of the discharge of radioactive water to the ground at a point adjacent to.this location on March 21, 1979.
The details of the discovery of this source and its punctual termination are provided in subecquent paragraphs.
It can be seen from Tabic 2.4-3 that the levels at N9B, a 17 foot deep test hole located adjacent to the NE corner of the Turbine Building were not low when first sampled on August 8,1978.
The level seemed to hover at around 3600 pCi/l for a few conths then began to rise.
The rise was vigorcus early in 1979.
The readings during April indicated that a plateau of around 6.7 x 104 pC1/1 had been reached, but subsequent readings show further increases.
The tritium levels in other test holes tapping the water table are provided in Table 2.4-4.
The activity of each of the samples was less than the LLD afforded by a liquid scintillation detector.
When the gas enrichment process was employed, positive results ranging from 110 to 300 pC1/1 were found.
These very low levels give assurance that con-tamination in the water table is pretty much confined to the proximity of the three effected test holes listed in Table 2.4-3.
The results of sampics taken in.the surface drainage system are listed in Tabic 2.4-5.
The outf alls were rearly always dry; the only positive result gave a very low level of 240 pCi/1.
Rather high icvels, however, were found in a few catch basins, especially PY24 which is near P16.
It was postulated in a previous paragraph that water contaminated with tritium may have accumulated in a pocket in this proximity.
After periods of considerabic precipitation, the water tabic will rise and ti.creby cause an overflow from such pockets.
Should the water table rice to the level of the surface drainage system, an easy path for horiz,ntal movement would be provided.
It appears then, there may be a relatively easy pathway from this postulated pocket in which tritiated water is lodged to this catch basin.
Af ter precipitation stops and horizontal movement stops, some tritiated water becc_tes trapped in t he catch basin.
Any water which is transported from this catch basin would be greatly diluted as this stream of water is combined with a number of other streams on its way to the outfall.
In the second week of May 1979, a group of samples were taken and split with the NRC as per their suggestion.
Included in this group were sampics taken from outlying test holes which were a few hundred to about 13 hundred yards away.
These were taken to provide assurance that ground water tritium had not migrated offsite.
The outlying test holes tapping the water tabic were N13B, N14B, N15B, P102A and P108A; those tapping L'ie Supplement 1 2.4-14 6/79 L272.151
ilNP MURIAL REPORT local aquifer were P102B and P103B; the locations of these test holes are shown in Figure 2.4-3.
The tritium icyc1 in each of there outlying test holes was less than the LLD.
Previously, on March 16, 1979, in order to determine the extent of tritium migration in the plant yard, samples were collected from 10 test holes which tap the water tabic.
These test holes ent.ircle the compicx of main buildings - Service, two Turbine, two Reactor, tt-Padwaste, and Control Buildings.
None of these sampics hau detectable icvels of tritium.
e 4
1272 154 4
Supplement 1 2.4-15 6/79
.w..
HNP ANNUAL REPORT 2.4.3 NONROUTINE REPORT an amendment to Appendix B of the Unit 1 Operating On November 16, 1978, License was issacd whereby the old ETS were replaced with the new ETS, that is, those issued with the Unit 2 Operating License in June 1978.
Although these new ETS do not require ground water sampling, they do specify that if a confirmed measured radionuclide concentration in an environmental sampling medium averaged over any quarterly sampling period should exceed the reporting 1cvel given in Tabic 3.2-3 of the ETS, then a written report shall be submitted to the NRC within 30 days from the end of the quarter or af ter confirmation, wlyicheve.r is later.
pCi/1.
The ETS The reporting icvel for tritium in water is 3.0 x 104 defined " confirmed" as a confirmatory reanalysis of the original, a duplicate, or a new sample as appropriate.
that this reporting icyc1 should apply to any There was some doubt then, It of the ground water samples, even those from the ordinary stations.
was indeed questionable that a nonroutine report should be made for any subsequent high tritium levcis such as those found at N9B, P16 and Pl7B.
Due to the inaccessability of these locations to the generel public, sampics gathered here probably should not be considered as radiological environ-mental sampics.
On December 1,1978, sampics were collected at a number of locations The including P17B; these were shipped to Tcledyne on December 4,1978.
results were roccived on January 24; the tritium IcVel for P17B was 2.64 The previous maximum reading at this station had been 1.05 x 105 pCi/1.
A new sampic was collected from Pl7B on January 24 to 4
x 10 pCi/1.
confirm this new maximum reading; it was shipped to Tcledyne on January 27; the laboratory report was received on March 12; the tritium level 5 pCi/1.
On January 26, 1979, a sampic was collected at was 1.66 x 10 P16 amongst other locations; these were shipped to Teledyne on January the tritium 1cvel for P16 was 27; the results were roccived on March 12; 1.37 x 105 pci/1.
There were also A wet spot on the ground near P17B had been noticed.
wet spots on the ground adjacent to the condensate transfer pumps which are near P16.
On February 16, 1979, wet soil samples were collected from these two locations; on February 22 these samples were shipped to Toledyne for tritium and gamua spectral analyses; in early April 1979 the results were received; the results are presented in Table 2.4-6.
The icycls f or the soil samples from the wet spot acar Pl7B are on the order of that f ound in reactor water except for Ra-226 and Th-228 which Although the levels found in the soil occur in the soil naturally.
collected near P16 are generally a few orders of =agnitude lower, they too indicate some local contamination.
Af ter receiving the laboratory analysis reports for the tritium icvels at P16 and Pl7B on March 12, 1979, it was decided that despite the doubts regarding the reporting requircuents, a nocroutine report would However, before the writeup of the report was completed, be submitted.
The the cause of the high tritium levels at P17B revealed itself.
report was filed on March 26 which was bef ore the laboratory reports on the two soil shoples were roccived.
6/79 2.4-16 Supplement 1
=.,.
ANNUAL REPORT During construction of Unit 1 a half inch temporary pipe carried nitrogen from a tank in the yard adjacent to Pl7B to the feedwater heaters in order to keep them from corroding before the plant was put in service.
Af ter Unit 1 was put into servica, the tank in the yard was removed leaving an open line buried cbout eight inches below the yard grade; the end of this line was roughly 10 feet SW of Pl7B.
The heater end of this temporary line was not removed af ter startup of the unit.
On March 20, 1979 water was discovered bubbling out of the ground to a height of several inches from the very spot ~where a soil sample had been gathered on February 16.
Wate'r would flow out for around 10 seconds, then stop for perhaps 5 minutes or so.
This cyclic phenomenon occurred several times over a few hours; it may have been caused by changes of pressure in the feedwater heater at that time.
Water samples f rom the flow and mud samples from the ground at this spot were collected for tritium and gamma spectral analyses.
The results are-E ven in Table 2.4-7.
Where comparabic, these 1cvels are seen to be i
generally higher than those found in Table 2.4-6.
On Fbrch 21, 1979, a check of the valve on this temporary nitrogen line at the feeduator heater showed the valve to have been partially open.
The valve was promptly closed.
To prevent any possible reoccurrence, the line was severed inside the turbine building by removing a pipe coupling.
Caps were then placed on both the line and the heater connection.
It may be advanced that the valve was cracked open by vibration or by someone inadvertently bumping into it.
In any regard, the tritium 1cvels in Pl7B indicate leakage. to the ground probably did not begin very long before first sampling this well on June 18, 1978.
On Fbrch 22, 1979, the open end of this temporary nitrogen line was unearthed.
The line lay horizontal pointing north.
A portable radiation detcetor showed activity in the soil near the end of the pipe.
There
'was no measurable activity in the soil beyond 2 feat from the end of the pipe. Hence it may be concluded that all activity except tritium was confined to the immediate point of discharge. The contaminated soil was placed in drums f or shipment to a licensed low icvel burial ground.
The open end of this temporary line was capped off.
On March 26, 1979, the events of March 20, were rcyorted to the NRC as a Licensec Event Report (LER).
Attached to this LER was an Anomalous Measurement Report which revealed the high tritium levels at P16 and Pl?B.
On March 28 a revision was issued to correct three errors in the report.
As has been mentioned in Section 2.4.2 above and as. shown in Tabic 2.4-3, the IcVel at N9B was undergoing a vigorous rise during the winter of 1978-1979.
The first sample to exceed the reportin; icvel was collected on March 20; its icvel was 4.56 x 104 pCi/1.
By m5d April the level 4
seemed to have more or less reached a plateau of around 6.7 x 10 pCi/1.
All of the tritium levels measured from sauples taken from N9B, P16 and Pl7B through April 1979 were reported to t3e NRC on April 30, 1979 as a second revision to the previous reporr.
12/2 156 6/79 Supplement 1 2.4-17
- g 3
UNP ANNUAL REPCRT TABLE.2.4-6 TRITIUM AND GAMMA SPECTRAL ANALYSES OF WET SOIL SAMPLES COLLECTED ON FEBRUARY 16, 1979 Radionuclide Near P16 Near P17B H-3 1.91 (3)^ pCi/1 1.03 (6) pC1/1 Ma-54
<4.00 (1) pC1/kg dry. 7.70 (1) pC1/kg dry Co-53
<5.00 (1) pci/kg dry 7.44 (2) pCi/k,g dry Co-60 1.36 (2) pCi/kg dry 9.37 (2) pC1/kg dry Zn-65
<9.00 (1) pCi/kg dry 3.49 (2) pC1/kg dry I-13 1
<7.00 (2) pci/kg dry 3.93 (3) pCi/kg dry Cs-134 8.52 (1) pCi/kg dry 1.78 (3) pCi/kg dry Cs-137 1.61 (2) pCi/kg dry 1.75 (3) pCi/kg dry Ra-226 2.05 (3) pCi/kg dry 1.52 (3) pC1/kg dry Th-228 1.08 (3) pCi/kg dry 6.02 (2) pCi/kg dry l272 157 f.
a) indicates 1.91 x 10 Supplement 1
- 2. 4'<-18 6/79
~
IINP ANNUAL REPORT TABLE 2.4-7 TRITIUM AND CATIA SPECTRAL ANALYSES OF WATER FLOWING FROM GROUND ON MARCll 20, 1979, NEAR P17B; CAMMA SPECTRAL ANALYSIS OF MUD FROM T!!IS LOCATION ON SAME DATE Radionuclide Level Sample No. 1 Sample No. 2 WATER (pCi/1) 11-3 1.05 (6) 1.08 (6)
Kr-85m 1.79 (3) 1.68 (3)
Xe-133 2.46 (5) 2.45 (5)
Xe-133m 7.30 (3) 7.23 (3)
Xc-135 5.10 (4) 5.90 (4)
MUD (pCi/kg dry)
Co-58 3.40 (3) 1.11,(3)
Co-60 4.07 (3) 1.88 (3)
Zn-65 2.10 (3) 9.65 (2)
Xe-133 1.50 (4) 4.98 (3)
Xe-135 1.60 (3) 6.87 (2)
Cs-134 2.90 (4) 1.34 (4)
Cs-137 3.27 (4) 1.51 (4)
Ba-La-140 9.88 (2) 4.51 (2) 1 1272 158 Supplement 1 2.4-19 6/79 k
+
.=
m g
a
HNP ANNUAL REPORT 2.4.4 INVESTIGATION CF HIGil LEVELS As mentioned fu Section 2.4.2, a tentative investigation of the high' tritium 1cvels began in August of 1978, and although many of the piping systems which carry water with high concentrations of tritium were hydrostatically tested to some extent, there were no conclusive results.
Six months later Dr. James R. Uallace, a Professional Engineer and Chief liydrologist for Law Engineering Testing Company of Ibrietta, Georgia, was engaged as a consultant ih planning and impic=cnting this investi-gation; his work was initiated on February 16, 1979.
In order to determine the scepage pathways to the source points uhere cxtraneous tritium is entering or has entered the ground, a study was made of the piping diagrams, ground water levcis (in conjunction with precipitation records), and the tritium levels.
It was decided that about twenty test holes should be drilled (to depths of around 20 feet) in the vicinity of the three test holes (which tap the water table) with the high tritium 1cvels.
The following information was to be sought from cach of these new test holes in hopes of determining if an extraneous source exists:
a) the gamma spectral analysis of soil sampics at various depths, b) the gamma spectral and tritium analyses of the ground water
- campics, c) the conductivity of the ground water samples, and d) the temperature of th'c ground uater samples.
The designation of the test holcs actually drilled, the date of installa-tion, the hole depth, and the depths at which the cquielude was reached are listed in Table 2.4-8.
The locations of these test holes are shown
'in Figure 2. 4-2.
The contour of the aquielude in the proximity of CST-1 seems to form sort of a trough running under CST-1 and aligned in a more-or-less NNE-SSW direction with the southern end of the trough being slightly deeper.
Piezemeter P16 appears to lie in this trough.
The aquiclude contours in the area a little cast of the Unit 1 Recombiner Building (as judged by T5, T4 and T8) show a downward slope in a south to southeasterly direction.
This suggests that the discharges of process water that took place through the open half-inch liae near Pl7B would tend to flow to the vicinity of N9B.
While constructing each of the new wells, soil sampIes were generally co11ceted at five foot intervals and at intermediate depths in some cases. A gamma scan employing a GeLi detector was run on each sampic.
Gamma spectral analyses were also run on ground watr samples from each of the new test holes which was not dry.
In a few inraances naturally, occurring radionuclides were detected; there were nr. other positive results.
The soil acts as both a filter and a demireralizer whose efficacy was demonstrated by the virtual elinination within 1 f ew feet of all of the gamma activity being discharged from an open 11,c as was noted in Section 2.4.3.
Thus, the detection of gamma activity in a soil sampic would have likely meant that an extraneous source cristed within a few feet.
1272 159 6/79 Supplement 1 2.4-20 e
m
e p
IINP ANNUAL PIPORT TABLE 2.4-8 NEW TEST 110LES IN WATER TABLE Designation Installation Depth Acquiclude*
1978 (ft)
(ft)
T2 5/04 21.5 21 T3 5/03 17.5
>17.5 T4 4/24 20.3 17 TS 4/24 20.0 12 T6 4/27 20.0 12.5 T7 4/26 20.0 13.5 T8 5/02 23.0
>23 T10 4/20 18.5 18 Til 4/19 20.0 18 T12 4/19 23.5 20 T13 4/20 18.0 15 T14 5/01 15.0 13 T15 5/01 22.5 20 T16 4/27 20.0 18 T18 5/02 18.0 13 T19 5/03 19.0 16 T20 5/04 23.0 21 1
1272 160
- Approximate depth to aquielude Supplement 1 2.4-21 6/79 s
11NP ANNUAL IEPORT The results of the tritium analyses for the new test hoics are presented of the wells were dry from a few in Table 2.4-9.
It is seen that most Seven days to a few weeks following installation; a few are still dry.4 pCi/1; all others test hoics show tritium icvels in excess of 1.0 x 10 ble.
show levcis which are less than detectable or are only marginally detecta Due to their locations it seems plausibic to associate three of thesei seven test holes (T3, T4, and T8) with the same extrancous source caus ng the high readings at N9B and to associate.the oth readings at P16.
Piezometer T3 was dry for 3 weeks before a water sampic could be co l
the two readings taken in late Fby 1979 from this location were near y l
an order of magnitude less then those taken from N9B wh 1cycis less than the LLD, a collection at T8 on June 1,1979, showed a proximity.
pCi/1, which is nearly the'same as that 4
positive 1cvel of 1.06 x 10None of the readings at T4 have been low, it took littic more than a veck for the icycls to become about the sa found at T3.
N9B.
are increasing.
It took about a week and a half for the icycls at T12 to reach what hird appears to have been an equilibrium level which is a fourth to a t the readings of the icycls at P16; in the latter half of May, however,The inital suddenly dropped below the LLD nnd have remained there.
lla-collection at P18 was made in mid-May 1979, 2 weeks af ter its insta h as those tion; the readings are f airly consistent and are nearly as The equilibrium which is less than those at P16 by a factor of 4 to 5.they are a at P16.
readings at T20 have been steady from the start, of those found at P16.
Since conductivity of the de-ionized process water is nominally less l
than 1 p mbo/cm whereas the conductivity of water obtainabic from norma d
ground water sources nearby is generally about two orders of magnitu e higher, a very low conductivity found in a ground water sample would indicate that such a sample was likely to have been collected close to umhos/cm Typical conductivity values in some Icak of the process water.from nearby water sources are about 23 Since generally the from the Altamaha River and around 50 for rain.
run tcmperature of the water in the piping systems of interest does n many degrees above ambient, f rom the temperature of sampics.
Listed in Tabic 2.4-10 are the conductivity and temperature measuremen 10, 1979.
None of for sampics collected from the new test holes on thrf h
h riation the conductivity measurements are low, some are rasher hig ; t e va
' in values probably reflects the variation in the udacral content of the The test holes with the hi her temperatures are t
located where there are more piping systems which may provide slight soil at cach 1ccation.
The highest temperature higher tcmperature'to the ground water in that arcrn.
Although was found at T12 which also had a relatively low c nductivity.
6/79 2.4-22 Supplement 1 1272 16i
TABLE 2.4-9 TRITIUM LEVELS IN NEW TEST HOLES pC1/1 m
^
T5 T6 T7 T8 T10 til Date T2 T3 T4 j
dry 3
4/19/79 a
3 4/20/79 dry 4/23/79 a
<1.59 O)b a
4/24/79 a
4/26/79 6.27 (3)c dry a
dry dry
<1.38 (3) 4/27/79 2.41 (4)
<1.38 (3) 4/29/79 dry
<1.48 (3) 4.77 (4) dry
<1.48 (3), dry
<1.48 (3) 4/30/79 5/01/79 dry dry a
5/03/79 dry" 7.33 (4) dry
<1.50 (3) dry dry
<1.50 (3)
<1.50 (3) 5/02/79 5/04/79
. dry dry dry dry dry 5/07/79 dry dry dry dry dry
<1.50 (3)
<1.50 (3)
{
a c
<1.70 (3) h '5/10/79
- 7. 7'4 " (4) dry dry
<1.60 (3)
<1.60 (3) w p/09/79
- e.
g 5/14/79
<1.70 (3) 7.17 (4) 1.75 (3)
<1.70 (3) 1.82 (3) o 5/13/79 S
5/16/79
<1.60 (3) dry dry dry dry 5/17/79 dry 4.66 (4) dry dry dry
<1.70 (3) 5/21/79
<1.70 (3) 8.76 (4)
<1.70 (3) 5/24/79
<1.70 (3) 1.08 (4) 1.15 (5) 5/28/79
<1.70 (3) 1.03 (4) 1.34 (5)
<1.70 (3)
<1.70 (3)
<1.70 (3) 5/31/79 1.06 (4)
N 1.34 (5)
N 6/01/79 1.41 (5) r0 6/05/79 W
S a) instc11ed w
3 b) indicates <1.59 x 10 c) split 6.72 (3) i.
- w
TA1}LE 2.4-9 (Cont'd)
TRITIIDI 1.EVELS IN NEW TEST HOLES pCi/1
+
Date T12 T13 '
T14 TIS T16 T18 T19 T2C 5'
4/19/79 a
M 4/20/79
<1.20 (3) a 5
4/23/79 2.50 (3)
~
4/24/79 4.76 (3) dry
~
4/26/79 1.46 (4) 4/27/79
<1.59 (3) a 4/29/79
<1.38 (3) 4/30/79 2.21 (4)
<1.48 (3)
<1.48 (3) 5/01/79 a
a 5/02/79
<1.33 (3) a 5/03/79 2.42 (4)
<1.33 (3)
<1.33 (3)
<1.62 (3) dry drya S/04/79 dry dry 5/07/79 2.26 (4)
<1.62 (3)d 2.62 (4)
F 5/09/79 2.12 (3)
- - i 5/10/79 3.13 (4)
<1.60 (3)
<1.60 (3)
<1.60 (3)
<1.60 (3)
<1.60 (3) 2.20 (4) 5/13/79 2.27 (4) 5/14/79 2.14 (4)
<1.70 (3)
<1.57 (3)
<1.57 (3)
<1.57 (3) 1.57 (3) 5/16/79
<1.60 (3) 6.07 (4) 5/17/79
<1.60 (3) 1.24 (4) 2.00 (4) 5/21/79
<1.70 (3)
<1.70 (3) 7.88 (4) 1.86 (4) 2.23 (4)
N 5/24/79
<1.70 (3)
<1.70 (3) 1.91 (4) 1.92 (4)
N 5/28/79
<1.70 (3)
<1.70 (3)
<1.70 (3)
<1.70 (3) 6.82 (4) 1.88 (4) 1.78 (4)
N 5/31/79
<1.70 (3) 6.91 (4) 1.98 (4) 1.E4 (4) 6/01/79 6/05/79
<1.70 (3) 6.49 (4) 1.88 (4) 1.87 (4) i u
a) installed 3
D b) indicates <1.20 x 30 c) split <1.48 (3) d) approximate date v
9 Ig
IINP ANNUAL REPORT TABLE 2.4-10 CONDUCTIVITY AND TEMPERATURE MEASUREMENTS FOR GROUND WATER SMfPLES COLLECTED FROM NEW TEST IIOLES ON MAY 10, 1979 Well Conductivity Temperature No.
(pmhos/cm)
( F)
T2 T3 T4 126 71.6 T5 T6 T7 T8 T10 204 79.2 Til 236 80.6 T12 99 82.4 T13 296 72.5 T14 181 71.6 T15 81 70.7 T16 92 75.2 T18 T19
+
79.7 T20 114 73.4
- dry
+ sample t_.: too small for measuring e^paratus 1272 164 Supplement 1 2.4-25 6/79
~
- ~ ~ ~ * -
~ * -
litlP ANNIJAL REPORT the tritium icvels have been high at T12, no particular significance is There scens to be no particular significance seen in this happenstance.
to any of the conductivity and temperature values as no correlation was established between these values and the tritium Icycis.
12.72 165 1
Supplement 1 2.4-26 6/79
liNP ANNUAL REPORT 2.4.5 CRITIQUE An explanation and prognosis of the tritium 1cycis at each of the key locations is advanced in this section.
Where it seemed needed, an attempt was made to bring these levels into perspective by showing their enviror. mental impact and their relation to the regulatory limits.
Appropriate actions either taken or being, considered which are associated with these locations are also reported.
The following locations are discussed herein:
the areas in the water tabic associated,with Piczo-meters N9B, P16, and P17B; the outf alls of the subsurface drainage network; and Piczometers N8A and Pl7A in the local aquifer.
1272 166 r
Supplement 1 2.4-27 6/79
llNP ANNUAL REPORT 2.4.5.1 Area About Piezometer P16 It has been suggested at several places above, that a " pool" of water contaminated with tritium in trapped in the water table in a pocket on the south side of CST-1.
Furthermore it appears that Piczometer P16 provides a tap to this " pool" near its center.
As explained in sub-sequent paragraphs this contaminated water is believed to have accumulated from leaks associated with the condensate. transfer pumps.
Da the south side of the SE corner of the dyke surrounding CST-1 is a small concrete slab (roughly 6 to 8 feet on a side) on which the con-densate transfer pumps are mounted.
The soil on the west side of this slab has occasionally been wet, sometimes soaked.
These pumps have occasionally had leaking seals and valves.
Pump repairs are made in a routine manner.
In addition to the ordinary repairs, shicids were mounted on the pumps to direct any spraying from such Icaks to the slab where a drain to rndwaste is installed.
As mentioned in the 1977 Environmental Surveillance Report these leaks were considered in trying to determine the primary cause of the clevated tritium levcis at N7A.
Af ter some daliberation that notion was discarded since at that time these Icaks.are thought to be much less than they presently appear to have been.
Leakages from these pumps and associated fittings if they should occur in spurts might go unnoticed for some time since t-mally no one is in this areas.
On thy 2,1979, however, the engineer supervising the installation of the new test holes noticed that just as operation was switched from one of the condensate transfer pumps to the otber, there was a momentary small release of water to che ground at the point where a pipe covered with insulation enters the ground.
Subsequently, the insulation was remoted and was found to have been completely soaked.
The check valve for the pump, when not operating, was found to have been the principal source of the concealed Icakage.
The check valve was repaired punctt ally.
Af ter the observation of the leaks on thy 2,1979, the area was surveyed with a portabic radiation monitor to determine the extent of contamination.
Camma spectral analyses were performed on soil samples which were col-lected at various points in order to confirm the radiation measurements taken with the portabic monitor.
Near the middle of May 1979, the contaminated soil was placed in drums for shipment to a licensed low level burial ground.
Over the past oso years gamma spectral analyses ha'e from time to tLac heen performed on soil samples which were collected from near these condensate transfer pumps.
Typical results were presented in Table 2.4-6 (for imor Plo").
The insulation on the pipes adjacent to the condcasate transfer pumps has provided a mask which could have allowed persistent leakage to the ground to go unnoticed.
The downward trend of the tritium 1cvels at P16 since last summer (1978) indicates that there had occurred a stoppage of or a great reduction to the input of extraneous tritium to this " pool" about P16.
It seems likely then that this leakage which was observed on May 2,1979, and believed to have. occurred in the past, had been much greater than previously thought.
Supplement 1 2.4-28 1272 167 6/79
l!NP ANNUAL REPORT Since repairing of the pumps, and the installation of shicids may have not been sufficient actions to entirely preclude releasce of contaminated water to the ground, it has been proposed to move the condensare transfer pumps inside the dyke of the CST.
A Design Change Request CDL.) has been submitted and is new being studied.
With the cessation of contaminated water to this " pool", the icvels will clowly diminish.
In addition to radiological d cay, lower tritium concentrations will result not only from the direct dilutfor. afforded by precipitation but also as a renuit of the horizontal transfer it will promote.
Some of the tritium from this " pool" may reach the river via the cast outfalls of the subsurfacc ditti - (Ditch No. 2) and of Yard Drain No. 2.
Levels at Ditch No. 2 and Catch Basins PY12 and PY24 indicate that this is indeed happening.
However the two orders of magnitude difference between the Icvels in the " pool" and at the out-falls indicates that such migration is slow and such levels present no hazard.
The highest Icycis for the " pool" are found at P16; the highest measured value at P16 was 1.64 x 105 pci/1 or August 8, 1978; currently the icvels are about half this maximum.
The MPC for water to unrestricted areas from 10CFR20 is 3.0 x 106 pCi/1.
Typical tritium levels found in the CST, the reactor water, the reactor steam, and in the hotwells of the condensor are cach about 9 x 105 pCi/1.
There are no current or planned usages of water from the water table here or at any other place on site.
The highest positive icvel found in Ditch No. 2 was 1.00 x 103 pCi/1 on February 20, 1979; it seems probable that this high came about as a result of migratich from the " pool;" Icvels with th', order of mrenitude can be expected to continue in Ditch No. 2.
It is believed that quarterly sampling at P16 and monthly sampling at.
T12, T18, T19, and T20 should be adequate to nonitor this " pool."
Since
, the levels are gancrally high, a liquid scintillation detector should provide sus __.ent accuracy for the tritium analyses.
Adjustments to the sampling frequency will be made as warranted.
}2)
Supplement 1 2.4-29 0/?q
~
UNP ANNUAL PSPORT Area About Piezometer P17B 7B (the discharge of process 2.4.5.2 The cause of the high tritium levels at Pla point about 10 feet from taken to permanently remove water through an open half inch line towell), how it r this extraneous source, etc.
No further explanations are warranted here.order of magnitude since l
The tritium level at P17B hss f allen near y aness water to this proxi i
tronger
~
the termination of the leakage of procThe rate of reduction here is A rather large l
lse.
i function of the amount of rainfall than anyth ng ef m It seems safe to predict March 21, 1979.
21, 1979.
amount of rain has fallen since March d
that the IcVel will drop another or er o he north outfall of the i
i Some of the tritium may reach the river v a t The levels in Ditch No.1 attes
- 1).
subsurface ditch (Ditch No.
i h the rather modest levels in this is indeed slowly happening.
ery caml1 fraction of the at N9B and at T3, T4, and T8 coupled w tDitch N tritiated water from the Pl7B areais migrating to the N9B area.
that the vast majority of this water nearly 3.0 x 10 pCi/l on 5
d r of magnitude below the The highest tritium level measured at P17B was this level is exactly an or e As indicated above the current l 16, 1979; February MFC for unrestricted areas.
No. I was 3.12 x 10 pCi/1 on about an order of magnitude b.clow the apt to continue to occur The highest positive icvel found in Ditchicvels of this mag 24, 1979; January in Ditch No. 1.
Within a year, Quarterly sampling at Pl7B seems adequate at present When the tritium fficient.
alysis method should
annual sampling will probably be more than su 1cyc1 drops below several thousand pCi/1, t e anllation det h
switch from the use of a liquid scinti
- - ment technique.
1272'169 6/79 2.4-30 lement 1
IINP ANNUAL REPORT 2.4.5.3 Area About Piezometer N9B It wasn't until the latter part of March 1979 that the levels in this area reached the reporting level.
While the levels in the other two effected areas of the water table (about P16 and Pl7B) are now diminishing, the levels here (about N9B) are on the rise.
A set of readings taken in the 4th week of Iby show that of these three areas the highest tritium levels are now found in the arca about N9B.' In addition to,N9B, Piezemeters T3, T4, and T8 are associated with the N9B area.
It is postulated that the high and rising levels here are caused by the influx of much of the process water which was discharged through the open-ended half inch line near N17B.
In Section 2.4.4 it was pointed out that in the aren just east of the Of fgas Recombiner Building, there appears to be a south to southeasterly slope to the upper surf ace of the aquiclude separating the water tabic from the minor acquif er.
This suggests that the above-mentioned process water would indeed generally tend to migrate from its point of discharge which was roughly 10 feet SW of N17B to the vicinity of N9B.
Piezometer N9B is roughly 120 feet SSE of this point of discharge.
It is estimated that the ground water in the water table will migrate between 0.1 to 0.5 feet per day depending upon the soil media and the driving force (difference in water levels between points along the path).
Thus 8 to 40 months would be required for ground water to traverse this distance.
In Section 2.4.3 it was adduced that effective leakage to the ground near Pl?B probably began in June 1978.
The natural flow paths in thL water table at the site have been complicated by the construction of the plant, particularly by die layout of numerous underground piping systems crisserossing the yard. Typically the pipes are buried 10 to 15 feet below the yard grade.
Sand was used as a backfill for the piping systems.
It can therefore be expected that groundwater migration will follow the piping beds which provide paths with relatively very low resistance to flow.
Thus migration times may be relatively short to points accessibic via the pipe beds.
It was pointed out in Section 2.4.4 that the tritiun level at T4 was now greater than that at N9B. Piczometer T4 lies between two piping systems running in a north-south direction.
The higher leral at T4 conforms with the postulate that the high icvels in the N9B area are due to migration f rom the P17B area in that this point would be reached first.
The levels at T4 may thus be foreshadowing the levc3s that misSt be expected at N9B in a few months.
Dctcetable levels of tritium have very recently beca cbtained in sampics from T3 and T8 for the first time.
The icvel at czch of these locations was about 1.1 x 104 pCi/1 which is well above detecelon. Piczometers T3 and T8 are respectively due west and due cast of BBB.
The rather abrupt oppearance of these levels seems to indicate the enrival of the " wave" of migrating tritiated water to these points.
I272 170 6/79 Supplement 1 2.4-31
/diNU/J., REPORT If this postulate to account for the high levcis in this area is correct, the levels at S9B, T3, T4, and T8 will probably continue to rise for a year or so.
Levels perhaps in excess of 3 x 105 pCi/l are envisioned should the migrating tritiated water become trapped in this area in a manner similar to that supposed for the P16 area.
If the tritiated water is merely being held up in a less permanent manner as it migrates elsewhere, the peak levels here are apt to be lower and to be reached sooner.
In 6 months or so the invels should begin to'show slower rates of increase, then after peaking with migration having been essentially completed, a
. gradual decrease in the levels is expected largely as a r~csult cf dilution afforded by precipitation.
Any migration of the tritiated water from this area is apt to be at lower 1cvels as it spreads itself over a wider area.
Another possible contribution to the levels about N9B could be from the break which occurred in the offgas line at the point ~where it entered the ground as it exited from the Turbine Building (which is perhaps 80 feet or so west of N9B).
This break which became known in May 1978 (and which was punctually fixed af ter having been properly reported) resulted from the settlement of the Turbine Building.
The gases in this line are laden with tritium; it is not highly unlikely that a significant quantity of the gaseous tritum would have escaped and would have been subsequently condensed and deposited in the ground; such leakage may have been happen-ing for some indefinite period of time before the discovery of this break.
The contribution (if any) of this leakage to the present and future levels about N9B is uncertain.
~
It seems plausible to conclude that the high tritium levels in the N9B area are caused by the migration of tritiated ground water from the vicinity of Pl?B where it had been deposited.
Also the leakage from the offgas line may possibly have also contributed significantly to the tritium levels in this area.
The input to the ground water from both of
,these sources has been terminated.
The highest tritium level yet to be found in the area was 1.41 x 105 pCi/l at T4 on June 5, 1979.
This is Icss than one twentieth of the MEC for unrestricted areas as given in 10CFR20.
The general public does not have access to this ground water.
There are piping systems in this area transporting relatively high 1cvels of tritium which might also be considered as potential sources.
Consideration is being given to hydrostatically testing each of these.
These are:
(a) the condensate return line from the recombiner.:ondenser to the hotwells of the main condenscr; (b) the drain lines to radwaste from the floor drain and the equipment sumps in the Offgas Recombiner Building; and (c) the discharge line from the Radwaste Building to the dilution line prior to discharge to the river.
4 Supplement 1 2.4-32 6/79 1272 171
llNP ANialAI. REPOP.T Such hydrostatic tests would be very difficult to perform on these lines due to the absence of valves at strategic points.
In view of the plausi-bility of the migration postulate, the difficulty in performing such tests and the improbability of leaks in such lines, the more pragmatic course of action is to postpone these tests while their need is being evaluated.
Such need will depend upon the future behavior of the tritium icvels in this area which shou 13 confirm or reject the migration postulate.
Semimonthly sampling at T3, T4, T8 and N9B seems to be sufficient at this time.
Since the icvels at each of these locations is high,' a liquid scintillation de'tector may be used for the tritium analyses.
Adjustments to the sampling frequency and the method of laboratory analysis will be made as warranted.
1272 172 r
~
Supplement 1 2.4-33 6/79 g
4 y,
w
=*
g
- - wee
HNP ARNUAL REPORT 2.4.5.4 Outfalls of Subsurface Drainage Network In the above subsections it was alleged that tritium appears to be slowly migrating from the areas in the water table where the levels are high to the subsurf ace drainage network.
The adjacency of these areas to this network coupled with many higher than usual levels and some elevated levels in the subsurface ditches attest to such an allegation.
The higher and more erratic levels in Ditch No. 1 indicate that a greater amount of tritium is finding its way to this ditch; the erratic behavior of the levels are believed to reficct the "off and on" nature of the migration which has an "off and on" motivator, namely precipitation.
It was also stated above that some elevated levels can be expected for some time.
At present, semimonthly sampling seems to be adequate.
The tritium analyses of these samples ought to employ the gas enrichment process so that a positive level might likely be ascertained.
The sampling frequency might be changed to monthly or quarterly if the read,ings become consistent or approach the LLD.
The vast majority of the tritium which might reach the river will pass through the outfalls of the subsurface drainage network enroute.
The maximum environmental impact due to all of the tritium in the ground water in the plant yard is assessed as the dose to the hypothetical individual who drinks water only from the outf alls of the subsurface drainage network.
(The average concentrations from the outf alls of the yard drains are much lower than those from the subsurface drainage ne twork. )
The highest measured quarterly average concentration of tritium from an outfall was 1.69 x 103 pCi/1 for Ditch No. 1 in the 1s t quarter of 1979; this concentration is equivalent to a whole body or organ dose of 0.044 mrem.
These dose esti=ates are very conservative as drinking water is not obtained from the outfalls.
The quarterly dose
,. limits resulting from liquid releases as established by Appendix I to 10CFR50 are 1.5 mrem for the whole body and 5 mrem for any organ.
The average annual concentration of tritium for drinking water in community 4
water systems is required to be less than 2 x 10 pCi/l according to EPA's National Interim Primary Drinking Water Regulations, 40 CFR 141.16.
The highest measured concentration in an individual sample was 3.12 x 103 pC1/1 for Ditch No. 1 on January 24, 1979 which is three orders of magnitude below the MPC for tritium in unrestricted areas as given in 10CFR20.
1272 173 Supplement 1 2.4-34 6/79
4 UNP ANNUAL REPORT 2.4.5.5 Local Aquifer The tritium icvels at N7A have persistently been about an order of magni-tude higher than what might reasonably be expected.
This test hole passes through the postulated pocket of tritiated ground water near P16 which was referred to above.
It may be advanced that a hydraulic connection exists between the water table and tlye local aquifer.
Such would provide a plausible explanation for the.clevated levels at N7A.
To preclude leakage to the local aquifer by way of the test holes tapping same, a good scal around the screen must be provided from the ground surf ace down some distance into the aquiclude separating the water table
~
and the local aquifer.
If the seal was not properly installed or if the scal were to be damaged subscquent to its installation, leakage could develop. During construction with a lot of movement of heavy equipment about the plant yard, damage was not highly unlikely.
It is therefore suggested that some scepage to the local aquifer from the water table is taking place at N7A.
Since the tritium levels in the water table in this arca are one to two order of magnitude greater than the levels at N7A, it can be expected that the levels at N7A will increase so long as the high levels in the water table are maintained.
As the input of extrancous tritium to the water table is stopped or greatly diminished, the levels in the water table are expected to slowly decrease.
This decrease would principally be due to dilution and dispersion afforded by precipitation.
The levels at N7A can be expected to show a very slow response to reduced levels in the water table since the rate of hydraulic mo" ament in the local aquifer is much slcwer; radiological decay may be the chief mechanism by which the tritium level will be reduced in the local aquifer.
.A similar but milder situation might exist at P17A which also taps the local aquifer. The tritium levels here are quite a bit lower than those at N7A but still a bit high to occur in nature.
Piezometer P17A is adjacent to the open half inch line which discharged process water into the water table.
Some seepage f rom the water table to the local aquifer is likely to be taking place at Pl7A also.
The prognosis here at Pl7A is like that for N7A, namely: the future level in the local aquifer at Pl7A is a f unction of the level in the water table at Pl7B, but the, reduction rate at Pl7A is expected to be much less than that at Pl78.
lugration in the local aquifer is very slow, about 5.65 feet /yr (see Section 2.4 of the FSAR f or RNP-2).
The direction of flow is toward the river and at this rate it would take about 200 years to reach the river.
By that time the tritium would effectively be non-existent due to radio-logical decay.
The tritium concentration would also be greatly reduced as it spreads througn a larger volume.
It is presently planned to perform tritium analyses using the gas enrich-The ment process on samples from F7A semiannually and from Pl7A annually.
sampling f requency is likely to change as warran:cd by the results of these analyses.
j}/} }[4 6/79 Supplement 1 2.4-35
i HNP
~
ANNUAL REPORT 2.4.6 FINALE A complete account of the tritium problem in ground water in the plant yard has been described - its history was narrated; all data were pre-the actions sented; key areas were identified; explanations were offered; taken, planned or considered were related; the monitoring program to be followed has been stated; prognoses were provided; the icvels were shown to be well within the various regulatory limits; and the environmental impact was shown to be miniscule.
A grip has been obtained on this problem; its resolution is progressing satisfactorily.
Reports to the NRC will be rude as warranted.
1272 175 f.
2.4-36 6/79 Supplement 1
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Supplement 1 2.4-39
a JULY 30, lQ79 SUPPLE!!Cf1T AL !! ARR ATIVE SU!iM ARY 11R C DOCKET 50-321 OPERATIt!G LICEllSE DPR-97 EDNIN I.
HATCH NUCLEAR PLAllT UllIT 1 C..-
Il0!!ROUTIllE R ADIOLOGIC AL EllVIRO!! MENTAL OPER ATING AN014ALOUS MEASUREME!!T REPORT
=
=-
=
The fol. lowing report which supplements t.he previ.ous submittals of LER 50-321/1979-021. is necessary pursuant to Section 3.2 of, the ETS to report within 30 days the tritium levels in groun.dwater samples collected at certain stations where the level averaged over the 2nd quarter of 1979 exceeded the reporting icvel of 30 x 10'3 pCi/l as given in Table 3.2-3.
There continues to be no significant impact on the public health and safety due to these readings which exceed the report levels.
As reported previousiv any releases to unrestricted areas are through the outfalls of the ' drainage systems; such releases are minuscule and result in insignificant doses to the public.
The release rates and dose rates are no greater than those reported
.p re v i ou s ly.
There are five s ta t i.on s from which the tritium levele in the Groundwater aamples are reportable.
Each of these stations il a test hole uhich caps the water tahic.
The history of cach of t'ese stations through the end of the 2nd quarter of 1Q7Q is provided in either Table 1 or Table 2.
There are only a few values in these tables which have not teen reported in a previous submittal of this
(,
LER.
o 1272 99 s
g, SUPPLE!1ENT July 30,1979
TABLE 1 HISTORY OF TRITIUM LEVELS IN EFFECTED TEST HOLES pCi/1 C
DATE N9B P16 P17B 6/18/78 1.44.(sia 8.60 (2) 3/08/78 3.55 (3) 1.64 (5)b v.88 (1) 8/31/78 3.48 (3) 1.51 (5) 1.05 (4) 9/29/78 3.67 (3)c 2.64 (5) 12/01/78 4.44 (3) 1.66 (5) 1/24/79 1/26/70 1.37 (5) 2/14/79 1.32 (5) 2/16/70 9.69 (3) 2.97 (5) 3/09/79
- 1. 21- ( 5 )
~
^
3/13/70 2.80 (4)d 2.92 (5)
,3/20/79 4.56 (4) 1.12 (5) 2.40 (5) l
~
3/27/70 5.40 (4)e dry dry 4/04/7A 5.07 (41f 1.04 (518
'2.24 (5) 4/10/7Q 6.79 (4) 1.07 (5)
'2.36 (s)h 11/17/79 6.67 (411 1.14 (5)
'8.47 (4) 4/24/70 6.60 (4)3 q.52 (h) 1.66 (5) i 5/02/74 6.84 (4) 4.55 (4) 7.88 (4) 5/0o/70 8.64 (4) 1.11 (R) 5.60 (hi l
5/17/79 7.68 (4) 7.78 (4) 2.88 (4) 5/23/70 8.00 (4) 8. P_0 (4)
' ll. 71 (4) 6/04/79 1.06 (5) 6/05/79 7.66 (4) 9.06 (4) f(.
6/13/79 1.02 (5) 6/26/74 1,43 (5)
~
e.
W al indicates 1.4h x 105 b) recount 1.51 (5) c)
critt 2.45 (3) d)
recount 2.45 (4) c)
split 5.13 (4) f)
spli-t 5.73 (43 -
C) split 1.01 (5) h)
solit 2.P1 (5) i)
sp1.it 6.00 (4) j)
split 6.93 (4) 1272 180 SUPDLE"?"~'
July 30,1979
~
TABLE 2 HISTORY OF TRITIU!! LEVELS IN EFFECTED TEST 110LES pC1/1 C'
DATE D
T18 4/24/74 a
~
4/27/70 4/29/74 6.27 (3)c~
2.41 (4)b 5/01/79 4.77 (4) 5/02/79
'a 5/0t/70 7.33 (4) dry 5/04/79
~dry 5/10/79 7.74 (4) 5/14/70 7.17 (4) 5/16/79 6.07 (4) 5/17/79 4.66 (4) 5/21/79 8.76 (4) 5/24/79 7.88 (4) 1.15 (5) 5/28/70 1.34 (5) 5/31/70 6.82 (4)
- - 6.01 (4) 6/01/79 1 34 (5) 6/05/74 6.44 (4) 1.41 (si 6/11/79 1.56 (5) 7.02 (4) 6/13/7t<
1.63 (5)d 6.55 (4) 6/26/79 1.79 (5) 5.71 (4)
~
1 a) installed b) indicates 2.41 x 104 c) split 6.72 (3) d)
split 1.60 (5)
C 1272 181 SUPPLEMEf1T July 30,1979
...c.:......._..a OCTOBER 31, 1970 SUPPLEMENT AL N ARR ATIVE SUMM ARY NRC DOCKET 50 321 OPERATING LICENSE DPR-57 PLANT - UNIT 1 EDWIN I. II ATCH NUCLEAR G
NONROUTINE R ADIOLOGIC AL ENVIRONME ANOMALOUS MEASUREMENT REPORT submittals of LER the previous This
- report, which supplements on tritium levels in ground water samples taken from test holes N9B, P16, Pl7 B The additional data 50-321/1979-021, provides tritium levels in these holes had exceeded the rep reported in 10 ;p Ci/l as given in Table 3 2-3 of the ETS a.n d uere significant impact to be no on the public health and safety due to these readin 2
There continues the previous submittals.
to any releases l ev e l.
As reported previously the reporting through the outfalls of the drainage system; insignificant doses to the unrestricted areas are than those minuscule and result in The release rates and dose rates are no greater such relcases are public.
reported previously.
Each of these stations is a test hole which taps the The history of each of these stations through the of 197^ is provided in either Table 1 or Table 2.
The vast majority of the values in these tables have been reported in a
quarter of this LER.
previous submittal A dye was of these high tritium levels continues.
injected in test holes Pl7B and T18 (each of whic The investigation of tritiun).
Subsequent monitoring for samples from test holes and other points in the ex-sources or known sources tion.
in determining the pattern of underground migra the dye in should aid 1272 182 Supplement October 31, 1
TABLE 1 llISTORY OF TRITlUM LEVELS IN EFFECIED TEST 110LES pCi/1 Date N9B P16 P17B 6/18/78 1.44 '(5)a 8.50 (2) 8/08/78 3.55 (3) 1.64 (5)b
.7.88 (3) 8/31/78 3.48 (3) 1.51 (5) 1.05 (4) 9/29/78 3.67 (3)c 12/01/78 4.49 (3) 2.64 (5) 1/24/79 1.66 (5) 1/26/79 1.37 (5) 2/14/79 1.32 (5) 2/16/79 9 63 (3) 3/09/79 2.97 (5) 1.21 (5) 3/13/79 2.80 (.4)d 2.32 (5) 3/20/79 4.56 (4) 1.12 (5) 2.49 (5) 3/27/79 5.40 (4)c dry dry 4/04/79 5.97 (4)f 1.09 (5)E 2.29 (5) 4/10/79 6.79 (4) 1.07 (5) 2.36 (5)h 4/17/79 6.67 (4)i 1.14 (5) 8.47 (4) 4/24/79 6.60 (4)3
- 9. 52 (.4) 1.66 (5) 5/02/79 6.89 (4) 9.55 (4) 7.88 (4) 5/09/79 8.64 (4) 1.11 (5) 5.69 (4) 5/17/79 7.68 (4) 7.78 (4) 2.88 (4) 5/23/79 8.99 (4) 8.20 (4) 4.71 (4) 6/04/79 1.06 (5) 6/05/79 7.66 (4)
- 3. 36 (4) 6/13/79 1.02 (5) 6/26/79 1.43 (5) 7/11/79 1.37 (5) 7.62 (4) 3.46 (4) 7/26/79 1.47 (5)k 8/09/79 1.43 (5) 6.07 (4) 5.31 (4) 8/24/79 1.28 (5)1 6.62 (4) 7.12 (4) 9/05/79 7.66 (4) 9/06/79 1.34 (5),
2.33 (4) 9/18/79 1.42 (5)-
7.44 (4) 5.18 (4) a) indicates 1.44 x 105 b) recount 1.51 (5) c) split 2.95 (3) d) recount 2.95 (4) c) split 5.13 (4) f) split 5.73 (4) g) split 1.01 (5) h) split 2.21 (5) i) split 6.90 (4) j) split 6.93 (4) k) cplit 1.41 (5) 7}
jg}
- 1) split 1.28 (5)
Supplement October 31, 1979 z..
.s
TABLE 2 IIISTORY OF TRITIUM LEVELS IN EFFECTED TEST 110LES pCi/1 Date T4 T18 4/24/79 a
4/27/79 6.27 (3)C 4/29/79 2.41 (4)b
~
5/01/79 4.77 (4) 5/02/79 a
5/03/79 7.33 (4) dry 5/04/79 dry 5/10/79 7.74 (4) 5/14/79 7.17 (4) 5/16/79 6.07 (4) 5/17/79 4.66 (4) 5/21/79 8.76 (4) 7.88 (4) 5/24/79 1.15 (5) 5/28/79 1.34 (5) 6.82 (4) 5/31/79 6.91 (4) 6/01/79 1.34 (5) 6/05/79 1.41 (5) 6.49 (4) 6/11/79 1.56 (5)d 7.02 (4) 6/13/79 1.63 (5)
'6.55 (4) 6/26/79 1.79 (5) 5.71 (4) 7/11/79 1.72 (5) 6.57 (4) 7/26/79 1.87 (5)'1 8.83 (4) 8/09/79 2.05.(5) 8.08 (4) 8/24/79 1.81 (5) 8.27 (4) 9/05/79 7.18 (4) 9/06/79 9.22 (4)f 9/18/79 1.51 (5)E 6.70 (.4) 1 a) installed 4
b) indicates 2.41 x 10 c) split 6.72 (3) d) split 1.60 (5) c) split 1.75 (5) f) split 8.94 (4) g) split 1.52 (5) 1272 184 Supplenent Octaber 31, 1979