Metals in Groundwater and RACER

In this post I follow up on a question introduced earlier; viz., how likely is it that RACER will help the citizens of Northern New Mexico to check up on LANL's stewardship of the local environment?

In attempting again to answer this question, I first reproduce here a history of high metal concentrations in the groundwater at LANL's Technical Area 49 (TA-49), as revealed by the Water Quality Data Base. Although this history was presented in the fall of 2008 at meetings of the Northern New Mexico Citizens Advisory Board, no formal response by LANL to the problems revealed here has ever been offered.

Introduction

In two earlier white-papers I discussed (in the summer of 2008) data excerpted from the Radionuclides in Groundwater section of LANL’s online Water Quality Data Base (WQDB). These short papers were intended to serve as non-technical introductions to the WQDB for members of the Northern New Mexico Citizens Advisory Board (NNMCAB).

In this latest of an ongoing series, I describe data from the Metals in Groundwater section of the WQDB. After a few general remarks, I discuss the high levels of chromium(3) being measured in Regional Well 28 (R-28), and then react to a recent study, by geologist Bob Gilkeson, in which past high levels of lead(4) in deep wells at TA-49 were considered.

General Remarks

The data tabulated in the Metals in Groundwater section of LANL’s online Water Quality Data Base describe the results of measurements of the concentrations of approximately 24 non-radioactive metals, made at about 430 locations distributed over the DOE/LANL site, and in its immediate vicinity, during the past 40 years.

These data are a record of the concentrations of metals, measured at wells or springs, in units of mg/l (micrograms per liter). In contrast to the case of Radionuclides in Groundwater, discussed earlier(1,2), uncertainties in the measured values of metal concentrations in groundwater are not tabulated, nor are values for the estimated Minimum Detectable Amount (MDA). Even so, measured concentrations are often accompanied by a < sign, perhaps denoting that the data recorded is, in some sense, a “non-detect”(5). However, in no case do values of measured concentrations appear with a minus sign, which would indicate that the sample value was less than the value of a corresponding blank(6). In the following, we will not refer to tabulated data, if it is preceded by a < sign.

A user of the WQDB might wonder how measured values for the concentrations of individual metals translate into estimations of health risks.

In order to address this question, we consulted the EPA’s online standard for metals in drinking water, and found the following EPA benchmark information relating to health risks; i.e., the Primary Drinking water Standards(7), for metals in groundwater. These standards set values for the Maximum Contaminant Level (MCL) as:

Metal MCL (mg/L) ...... Metal MCL(mg/L)

Antimony 6 ............... Copper 1300
Arsenic 10 ................. Lead 15
Barium 2000 ............. Mercury 2
Beryllium 4 ................ Selenium 50
Cadmium 5 ................ Thallium 2
Chromium 100 ........... Uranium 30

Also, EPA’s Secondary Drinking Water Standards(8) for metals in groundwater are:

Metal MCL (mg/L) ...... Metal MCL(mg/L)

Aluminum 50 ............. Manganese 50
Copper 1000 .............. Silver 100
Iron 300 ................... Zinc 5000


Chromium (Cr)

The subject of chromium in groundwater at LANL is interesting because it appears to be almost unique. It seems that chromium may be one of only a few substances contaminating the aquifer beneath the Pajarito Plateau, for which LANL aggressively assigns itself the blame(3, 9-11). Moreover, until recently, it seems that this contamination had been found to exist, primarily, in only one deep well.

The well in question, R-28, was drilled into the regional aquifer below Mortandad Canyon at the end of 2003, and a single well-screen was installed(12). This screen was intended to sample the groundwater at depths between 934 ft and 958 ft bgs, near the top of the underlying aquifer.

The first data from this well(13) was collected on 5-20-05 and, while showing essentially normal values for the concentrations of most metals, showed a dissolved chromium (Cr(VI)) concentration of 375 mg/L, which was roughly four times the EPA’s MCL. Previously, at other deep wells located all over LANL, levels of dissolved chromium were usually no more than ~5 mg/L, and had never been found to exceed ~20 mg/L. Evidently, this data from R-28 was a very surprising circumstance, since it led, seven months later, to a report from LANL to NMED, and ten months later to a LANL(9) public announcement.

At that time, it was said that the probable source of this contamination was effluent water from a cooling tower, attached to a power plant, formerly situated at the head of Sandia Canyon. It seems that this water had contained dissolved chromate (Cr(VI)), added as a corrosion inhibitor, which had somehow found its way into groundwater at the newly drilled R-28. It was estimated that during the period of time from the 1950’s to the 1970’s, between 58,000 and 230,000 lbs of dissolved chromium had been dumped(10) into Sandia Canyon.

This view was supported somewhat by the fact that a number of alluvial (shallow) wells in Sandia, Pueblo, Los Alamos, and Pajarito Canyons had shown a record of sporadic high levels of chromium in filtered(14) groundwater samples. For example, in the Pueblo Canyon alluvial well APCO-1, chromium concentrations were as high as 5300 mg/L, on 3-29-95; in the Los Alamos Canyon alluvial LAO-2 the concentration was 400 mg/L, on 12-21-93; and in the Pajarito Canyon alluvial PCO-3 the concentration was 740 mg/L, on 6-7-93, all in filtered samples. However, it was also true that these high levels of chromium were neither persistent in time, nor were they spread out in space; i.e., they existed for periods of time of no more than a few months, usually did not recur, and they were observed only at isolated locations. Other nearby alluvial wells did not show these sharp chromium concentration spikes. Perhaps most importantly, in no case had such high chromium concentrations been measured in alluvial wells during the past five years.

However, it may have seemed odd that no other deep wells in the vicinity of R-28 had ever shown signs of elevated chromium levels; e.g., the old test well TW-3, in Los Alamos Canyon, had never registered high levels of chromium. Also, none of the Los Alamos County water supply wells, PM-1, PM-2, and PM-3, in place since 1977, and PM-4 and PM-5, in place since 1988, had ever shown signs of elevated chromium. These water supply wells are, in no case, more than two miles from R-28, and surround it. PM-1 and PM-3 are in Sandia Canyon itself, PM-4 is in Cañada del Buey, PM-5 sits between Tenmile Canyon and Cañada del Buey, while PM-2 is in Pajarito Canyon. These last three wells are all to the south of Mortandad Canyon.

Finally, it may have seemed odd too that no intermediate depth wells had ever shown elevated chromium levels; e.g., MCOI-8, MCOI-4, and MCOBT-4.4, all in Mortandad Canyon, and all located within 1 ½ miles upstream of R-28, had no history of high chromium concentration.

Subsequently, many studies have been performed, based on computer simulations, in an attempt to better understand this situation. LANL scientists now believe that there is a plume of groundwater, contaminated by high levels of dissolved chromium (~400 mg/L (+/-) 25 mg/L), confined to an area centered on R-28, and extending no more than one-half mile in any direction; see Fig. 4.2-1 of ref. 3. It is problematic as to how these high levels of Cr(VI) have been maintained, essentially without change, for at least the past three years.

Based upon these observations, it is reasonable to speculate that there is a large source of chromium located somewhere upstream of R-28. And, in fact, a source of sedimentary chromium is known to exist in a wetland at the head of Sandia Canyon, adjacent to, and downstream from, the site of the old power plant cooling tower; see Fig. 1.0-1 of ref. 3.

Presumably, this chromium is in its reduced state, Cr(III), which is largely insoluble in water, for values of pH near neutral. Further, evidence exists that this source of chromium is being mobilized by outfalls from a large sewage treatment plant which sweep regularly through the wetland(15).

In order to further test this hypothesis, LANL has planned for several new wells to be drilled in the immediate vicinity of R-28. The latest news(14) is that, in the first of these wells to be completed, SCI-2, perched water has been detected at a depth of 509 ft bgs, and a filtered sample of this water shows a chromium concentration of ~500 mg/L.

Lead (Pb)

The subject of lead in groundwater at LANL is also of some interest. During the period 1959-1961 LANL conducted underground weapons tests at MDA-AB (TA-49). These were the so-called hydronuclear tests, described by Bob Thorn(16). Residues of these tests included a variety of toxic materials(17), among which was an estimated 200,000lbs of elemental lead (Pb).

The tests were conducted in unlined earthen shafts, dug to depths of between 30 and 100 ft. These shafts were disrupted by the test explosions and, one assumes, toxic residues were mixed into the adjacent tufa and soil. What has become of these residues, the mobility of which has been unrestricted by any artificial barrier, over the past 50 years? I alluded to this subject in a previous publication(1). This subject has also been discussed by Bob Gilkeson, in a recent study(4).

Bob quotes data(13) taken from the WQDB, describing the history of Pb concentrations measured in the old test wells DT-5A, DT-9, and DT-10, located at MDA-AB. He points out the very large excursion in the record of Pb concentrations recorded at DT-5A, during the period 1992-1995; i.e., to a level of ~9000 mg/L, which is 90 times the MCL. It seems that DT-5A is located in the middle of a cluster of five shafts, once used for hydronuclear tests, and is no farther than 1000 ft from any one of those shafts.

Bob notes also that, during this same period, excursions were recorded in Pb concentrations from DT-9 and DT-10, although to values of less than 100 mg/L. But, those two wells are both located outside of the cluster of shafts, and at a distance of several thousand feet from the nearest shaft. Meanwhile, at the old test well TW-3, located in Los Alamos Canyon, approximately five miles distant from MDA-AB, no excursion in Pb concentration was ever seen.

Enquiring minds ask for an explanation of these phenomena. After all, if what was measured at DT-5A, DT-9, and DT-10 were Pb residues from old hydronuclear tests, residues which had somehow become mobile for a period of a few years during the early 1990’s, then such residues could become mobile again, at some future time.

It appears that LANL may actually favor an explanation of these facts based on a theory(18, 19) of “ … well sampling and well construction issues rather than from LANL contamination.” This appears to be a peculiar theory, on the one hand, because it assumes something which is not much in evidence; viz., that either the drilling fluids, or the well casing and/or the well screening materials used in the construction of DT-5A were rich in Pb, but not so for DT-9 and DT-10, and not at all so for TW-3. On the other hand, this theory is also peculiar since it does not attempt to account for the pronounced time-history of the Pb concentrations that have been observed. At the same time, LANL personnel deny the presence in groundwater of Pb residues from old hydronuclear tests at MDA-AB(19).

However, it is also true that LANL’s point of view finds support in other data found in the WQDB. These data are the records of the concentrations of other common metals, found in the groundwater at these four wells. In Figs. 1, 2, 3, and 4, I plot the histories of measured concentrations for iron (Fe), zinc (Zn), and lead (Pb), at the old test wells DT-5A, DT-9, DT-10, and TW-3, respectively.

Interestingly, excursions in Pb concentration, appearing during the 1993-1994 time period, are accompanied by excursions in both the concentrations of Fe and Zn. Moreover, at DT-9 and DT-10, the excursion in Pb concentration is much smaller than the excursions in both the concentrations of Fe and Zn. At TW-3, concentration histories show a series of fluctuations, but do not show a dominant excursion in the concentration of any metal during the 1993-1994 time period(20).

It may be relevant that LANL will report, in its soon to be released Environmental Surveillance Report for 2007(21), that elevated levels of Pb, and several other metals, have been detected recently in Water Canyon and Threemile Canyon surface water. Water Canyon borders on MDA-AB, and Threemile Canyon borders on Water Canyon. Anon!

Conclusion

We have seen that the subject of metals in groundwater at LANL is one of minor mystery; and we have seen two examples of such mystery.

The story of the high levels of chromium in the groundwater beneath Mortandad Canyon is at least curious. Hard evidence to support the prevailing theory, that the original source of chromium contamination was the old water cooling tower at the head of Los Alamos Canyon, is only now beginning to emerge(3). Earlier, the evidence seemed to be just circumstantial. Certainly, a power plant cooling tower did dump lots of chromium into Sandia Canyon, and that chromium had to go somewhere. But, the connection between that cooling tower in Sandia Canyon, and R-28 in Mortandad Canyon, was tenuous, and seemed to be confined to the histories of chromium contamination measured in samples from select alluvial wells, mostly, but not exclusively, upstream of R-28. Also, these histories showed, for the most part, an isolated excursion in chromium concentration during the period 1993-1995; and this excursion did not recur. At the same time, similar excursions did not occur in other nearby alluvial wells.

But wait! The story of the high levels of Pb, Fe, and Zn measured in groundwater beneath TA-49 is similarly strange. This is because the histories of these three contaminants, in the three deep wells DT-5A, DT-9 , and DT-10, are ones that themselves show sharp excursions in concentration during the 1993-1995 time period, which failed to recur; see Figs. 1-4.

Could all of these isolated concentration excursions, occurring at different locations, but at roughly the same time, be just a coincidence? Or was there some, as yet, unaccounted for influence on the measurements of metal concentrations made at wells distributed over a wide area on the Pajarito Plateau, during 1993-1995?

Bibliography

1) “Summary [with Commentary] of ‘Radionuclides in Groundwater’ from LANL’s ‘Water Quality Data Base’ I.”, Ken LaGattuta NNMCAB, 7-18-08.

2) “Summary [with Commentary] of ‘Radionuclides in Groundwater’ from LANL’s ‘Water Quality Data Base’ II: History of Tritium Activities”, Ken LaGattuta NNMCAB, 8-30-08.

3) D. Katzman, “Chromium Fate and Transport for Chromium Contamination from Sandia Canyon”, LA-UR-08-4702. The story of the contamination of groundwater beneath Sandia Canyon by chromium is extensive and ongoing.

4) “Comment on the Large Plume of Lead in the Groundwater Below the LANL Legacy Waste Disposal Site MDA AB and the Deficiencies in the LANL Protection Practices …” , Robert H. Gilkeson, 8-25-08.

5) See remarks in ref. 2, relating to the proper use of the MDA.

6) See remarks in ref. 2, relating to (-) Result values.

7) Office of Water (4606M), EPA 816-F-03-016, www.epa.gov/safewater, June, 2003. The Primary Drinking Water Standard defines values of the MCL beyond which serious health effects could ensue, for the general population. It should be clear that applying a drinking water standard to groundwater, which may not be used for regular drinking, is a conservative approach.

8) Ibid. The Secondary Drinking Water Standard defines values of the MCL beyond which noticeable minor health effects could ensue, for the general population.

9) “Los Alamos National Laboratory News”, James E. Rickman, March 17, 2006.

10) “Los Alamos National Laboratory News”, James E. Rickman, December 7, 2006.

11) “Los Alamos National Laboratory News”, James E. Rickman, May 3, 2007. Quoting from this news release: “Personnel in the Lab's Water Stewardship Project recently began construction of monitoring well R-35 in lower Sandia Canyon. This regional-aquifer-monitoring well is being constructed upgradient and near Los Alamos County drinking-water-supply well PM-3. The R-35 well will act as a ‘sentinel’ that can determine whether a plume of hexavalent chromium—a component of a corrosion inhibitor used from the 1950s to the 1970s—is approaching the county’s PM-3 well.” However, R-28 was installed(12) in 2003, and the discovery of high levels of dissolved chromium in this well was made(13) in May, 2005.

12) (www.wqdbworld.lanl.gov / Chemistry/ Characterization Wells/ Completion Reports.

13) (www.wqdbworld.lanl.gov / Chemistry/ Metals/ Groundwater.

14) D. Katzman (LANL), in talk presented to the NNMCAB’s EMSR Committee, Sept. 10, 2008. He emphasized the importance of obtaining filtered water samples, when attempting to measure the concentration of Cr(VI) in groundwater. Presumably, unfiltered samples would include sediments onto which insoluble Cr(III) could be adsorbed.

15) Ibid. Katzman reported that the nitrogen detected in groundwater at R-28 is in the form of nitrate, suggesting that its origin is in sewage.

16) R. N. Thorn and D. R. Westervelt, “Hydronuclear Experiments”, LA-10902-MS, Feb., 1987.

17) D. G. Levitt, etal , “Site Characterization and Monitoring of TA-49 at LANL”, in Proceedings of Waste Management ‘03 Conference, Tucson, AZ, Feb. 23-27, 2003.

18) Environmental Surveillance at Los Alamos during 2006, LA-14341-ENV.

19) Terry Morgan (LANL), during a discussion of EM issues at LANL, Aug., 2008. Present were T. Morgan, A. Simmons, L. Bonds-Lopez, and myself.

20) Unfortunately, all entries in the WQDB for metals in groundwater, prior to 1993, are for unfiltered samples; entries for filtered samples, begin in 1993. Although in Figs. 1-4, for data prior to 1993, I have recorded the values measured for unfiltered samples, beginning with 1993-1994 the recorded values are largely for filtered samples. Most importantly, the peaks appearing circa 1993-1994 are for filtered samples.

21) Environmental Surveillance at Los Alamos during 2007, (DRAFT) Executive Summary, Table ES-4, Sept., 2008.


Fig. 1

Fig. 2

Fig. 3

Fig. 4

Tritium in Groundwater and the RACER Database

The Department of Energy (DOE) has sponsored the creation of an online database and data analysis tool called Risk Analysis, Communication, Evaluation, and Reduction (RACER) located at www.racerdat.com. This tool is being administered by the New Mexico Community Foundation (NMCF) and has been publicly available since early 2009. Currently, it is said that there are approximately 7 million pieces of environmental data accessible through RACER. Presumably, most of these data pertain to contamination left by the DOE's nuclear weapons program at Los Alamos National Laboratory (LANL).

RACER is also a tentative component of the DOE's newly refurbished Environmental Justice (EJ) Program. DOE says that the its EJ program aims to assist members of economically disadvantaged communities across the United States to participate in evironmental decision-making. This would be a decision-making related to the disposition of detritus from large DOE operations; in particular, to the accumulated legacy waste from its nuclear weapons program. But, whether or not RACER will prove to be useful in this regard, remains to be seen.

Quoting from a January, 2010 letter from the NMCF to RACER users:

"RACER is the first project ever in the United States where the public has full access and full transparency to environmental data at a Department of Energy site. It's giving the public a voice in a way that it never really had before."

Continuing from the same letter (but paraphrasing somewhat):

Do you have questions about what chemical or radionuclear contaminants may be present in the Northern New Mexico environment?

For example, is the soil on the Pajarito Plateau contaminated with chemical residues from high-explosives tests conducted at Los Alamos National Laboratory?

Has laboratory analysis confirmed the presence of radionuclides along your favorite hiking trail in Bandelier National Monument?

Have tritium levels in local groundwater ever exceeded national drinking water standards and, if so, where and when did this occur? (end of paraphrase)

Prior to the appearance of RACER, much of the groundwater data that it contains could be found in LANL's Water Quality Data Base (WQDB). However, the WQDB itself was withdrawn from public access in early 2009.

In my opinion, the extent to which RACER's data will act to "give the public a voice" is doubtful. Nevertheless, as an example of the kind of questions that could be raised by perusing this data, I've copied here a white-paper which I wrote in mid-2008, while a member of the DOE-sponsored Northern New Mexico Citizens Advisory Board. The paper was concerned with tritium activities in groundwater on the Pajarito Plateau, and was based entirely on data taken from the WQDB. No response to the questions raised in this paper has ever been offered by representatives of LANL, or of the DOE.


RADIONUCLIDES in GROUNDWATER: A HISTORY of TRITIUM ACTIVITIES at LANL

Introduction

In an earlier communication(1), the first of a series, I presented a brief summary of the contents of LANL’s online Water Quality Data Base (WQDB). This was intended to serve as a non-technical introduction to the WQDB for members of the Northern New Mexico Citizens Advisory Board (NNMCAB). Although no feedback was evoked from NNMCAB members, reaction to this overview from LANL staff was quick, and in the course of a long face-to-face conversation I was presented with many critical LANL thoughts(2).

In this, the latest installment in my ongoing study of the WQDB, I react to some of these criticisms, while I present a WQDB based history of tritium concentrations measured all around the LANL site, beginning in the 1960’s, and extending to the present day. I continue to hope that my efforts will help to inform the future work of the NNMCAB.

Throughout the following, some paragraphs are repeats taken, with minor modifications, from my earlier paper(1).

Data tabulated in the WQDB (www.wqdbworld.lanl.gov) is a record of the activities of specific radionuclides, at particular locations (wells or springs), usually in units of pCi/L (picocuries per liter). Uncertainties in measured values of activities are also usually tabulated, as well as the estimated(3) Minimum Detectable Amount (MDA). In many cases, the listed MDA is greater than the measured value of the activity, and its associated uncertainty. If so, then the measured activity is accompanied by a < sign, indicating that the measurement is thought to be of a “non-detect”(4). Often values of measured activities appear with a minus sign, indicating that the measured activity was less than the activity of a corresponding blank sample and, therefore, also of a non-detect(5).

Note that, generally, for activities recorded prior to 1995, no value at all for the MDA appears in the WQDB. In the following, I will not refer to data preceded by a < sign, or by a minus sign.

History of tritium activities

Keep in mind, while perusing the following, that the DOE sets the upper bound for acceptable values of tritium activity in drinking water at approximately 20,000 pCi/L.

Tritium, a beta emitter and essential to the weapons program, has been found to be widespread in groundwaters of the Pajarito Plateau. Levels in the alluvial wells of Los Alamos and Mortandad Canyons have been very high, until within the last ten years, when levels have subsided. For example, at LCAO-2 a value of 190000 pCi/L was measured on 8-13-70, but levels have decreased since then to a value of 64 pCi/L, returned on 1-15-08. At MCO-3 a level of 12000000 pCi/L was measured on 3-24-87, while the level was 5400 pCi/L on 7-12-04. Levels measured at drinking water wells have been moderately high until as recently as the 1980’s when they were found to be at 5900 pCi/L at PM-1 on 9-10-81, and 4200 pCi/L at PM-3 on 3-30-82. However, the measured levels at drinking water wells have now subsided to values of less than 1 pCi/L.

Levels measured at some wells of recent origin are also high; e.g., at the intermediate depth regional wells, such as R-6i, levels were 4300 pCi/L on 11-17-05, and 3800 pCi/L on 1-23-08. Levels measured at a few deep regional wells are a bit high. For example, a level of 195 pCi/L was returned from R-28 on 11-29-07, and a level of 28 pCi/L was returned from R-15 on 2-25-08.

Since 2001, levels returned from the Buckman wells have all been below 2 pCi/L. Prior to these recent measurements, there were only a very few measurements recorded. These occurred in 1973, and returned levels of approximately 100 pCi/L.

The highest recorded values of tritium activity are depicted in Fig. 1. Here, the history of detected tritium activity is displayed for the three sites, MCO-3, LAO-1, and PM-1. The first two of these sites are alluvial wells (shallow wells), one in Mortandad and one in Los Alamos Canyon, and the third site is a Los Alamos County drinking water well (deep well).

The similarity between these three histories is striking. The measured values of tritium activity were very low prior to 1970, jumped to high values, often suddenly, remained at a constant level for up to 2 decades and then, beginning around 1990, subsided slowly at a rate which was characteristic of the site.

In fact, this same behavior can be seen to have occurred at many other LANL locations. For example, Fig. 2 records the histories of tritium activities at the Mortandad Canyon alluvial well MCO-5, the Los Alamos County drinking water well PM-3, and the deep characterization well DT-10, located at TA-49. It seems that all these histories suggest a series of events in which some source of tritium contamination first appears around 1970, persists at a constant intensity until about 1990, and then subsides, either gradually or abruptly.

Looking back at Fig. 2, the decrease of the measured tritium activity with time, between 1987 and 2007, is very close to an exponential, with a resident half-life which I estimate to be about 7.6 years. Similarly, assuming an exponential decrease in tritium activities for the DT-10 and PM-1 histories too, I arrive at a value for the resident half-life in these two wells of about 12.3 years. Returning now to Fig. 1, I estimate the resident half-life of tritium in LAO-1 to be about 7.9 years.

Thus, it seems reasonable to conjecture that the deep wells PM-1 and DT-10, whose tritium resident half-lives I estimated to be 12.3 years, show time histories which reflect the natural decay rate of tritium (T1/2 = 12.3 yrs., for the beta decay of 3H), and suggest that the natural residence time for waters in the vicinity of the relevant well screens in these wells is much greater than 12 years. On the other hand, the shallow wells MCO-5 and LAO-1, have tritium resident half-lives which I estimated to be 7.6 to 7.9 years, suggesting that there is an exchange of waters in these wells with the surrounding area which takes place over a period of approximately 7 years.

The behavior of all of these histories of detected tritium activities is interesting, and has led to some prior well-informed speculation. In a August, 2005 paper(6), it was suggested by scientists working under contract to the DOE that this behavior could be traced to the contamination of groundwater by the Omega West reactor(7), formerly located at the head of Los Alamos Canyon. This reactor operated continuously from 1956 until 1992, when it was shut down for servicing, and soon thereafter decommissioned.

During the shut-down it was discovered that there was a leak of a significant size in a pipe buried underneath the reactor. This was a pipe which transported primary coolant water between the reactor and its external cooling tower. [Evidently, there was no provision made in the reactor design for a secondary coolant system, so that the primary coolant system could be completely contained within the reactor building, as is the case for all existing NRC licensed commercial power reactors.] At that time, it was said that it was not known for how long that the leak had existed.

[As is well-known, a fission reactor’s primary coolant should be completely isolated from the environment, since it contains a build-up of tritium produced by absorption of neutrons emitted by the 235U fuel. In cases where the fuel cladding has developed cracks or holes, highly radioactive fission products may also be released into the primary coolant. Among these is 99Tc.]

The radionuclide 99Tc, an electron(beta) emitter, is a common product of the fission of 235U, and does not occur naturally on the earth, except in the minutest of quantities. In fact, 99Tc is normally found in groundwater at activity levels as high as 1 pCi/L only in the immediate vicinity of a water cooled nuclear reactor. There, it can be ejected into the coolant during fission of the uranium fuel in the core, and may be released into the environment with coolant water effluents.

During the period 1956 to 1994 the Omega West reactor operated at the head of Los Alamos Canyon and occasionally deposited its wastes, containing 99Tc, directly into the canyon(8). Thus the presence of technetium in groundwater downstream of the now decommissioned Omega West reactor is a probable remnant of the operation of that reactor.

The high concentrations of 99Tc in the alluvial well LAUZ-1, in Los Alamos Canyon, and in the alluvial wells MCO-5, MCO-6, MCO-7, MCO-7.5, MT-1, MT-3-, and MT-4, in Mortandad Canyon, and in the intermediate wells MCOI-4, MCOI-5, and MCOI-6, in Mortandad Canyon, can be taken as evidence of contamination by effluents from that reactor. For example, 99Tc has been detected in groundwater taken from LAUZ-1 at levels of up to 38 pCi/L; in groundwater from MCO-7.5 at levels up to 23 pCi/L; and in groundwater from MCA-5 at levels up to16 pCi/L.

The regional wells R-22 and R-34 have shown the presence of 99Tc in groundwater taken from the aquifer underlying Mortandad Canyon, at levels of 5 pCi/L. However, there have been no detections of 99Tc at locations removed from the Pajarito Plateau. In particular, this radionuclide has not been detected in the Buckman wells.

Conclusion

Based upon the evidence presented, it is arguable that a major contribution to the past contamination of groundwater by tritium, beneath certain parts of the Pajarito Plateau, was made by a leak in the Omega West reactor primary coolant system, and that this source of contamination had been ongoing for as long as two decades(6).

[Oddly, during all this time, measurements of tritium activity in groundwater were also ongoing and evidence of the contamination of groundwater by tritium was persistent. It may seem difficult now to imagine how such data could not have been seen, at the time that it was being collected, as evidence for the existence of a major reactor leak. However, for as long as two decades, apparently nothing was done to put a stop to this potential hazard. Perhaps the hazard was judged to be of no great significance for the public health.

In this context, it is interesting to note that the Agency for Toxic Substances Disease Registry (ATSDR), an arm of the United States Public Health Service, issued a report(8) in April of 2005, in which they found no evidence of impacts to public health from LANL operations, over the period 1980 to 2001. However, no mention is made in this report of the very high tritium activities, recorded during the period 1980-1995, in the groundwater of alluvial wells located in Los Alamos and Mortandad Canyons. Concerning tritium, the ATSDR only reports, without comment, measurements of tritium activities in certain biota; e.g., 27,000 pCi/L in honey from Mortandad Canyon, sampled in 1980; 11,000 pCi/L in elk bone, sampled in 1994-5; and 17,000 pCi/L in “produce”, collected in 1999. The ATSDR is unalarmed by these values since the DOE sets a standard for the tritium contamination of biota at approximately ten times its standard for tritium in drinking water.]

Bibliography

(1) “Summary [with commentary] of “Radionuclides in Groundwater” from LANL’s “Water Quality Data Base”, K. LaGattuta, NNMCAB, 7-18-08.
(2) Meeting called at LANL by Lorrie Bonds-Lopez to inform me of my errors: in attendance, besides myself, were Ms. Lopez, Ardyth Simmons, Terry Morgan, and Mike McLaughlin (briefly present), Aug., 2008.
(3) As pointed out by LANL’s Terry Morgan, the Minimum Detectable Amount (MDA) or, Minimum Detectable Activity, is the result of a “calculation”. It seems to me, however, that this calculation is only an approximation to some exact theory of error, and must be problematic to some degree. Therefore, it is fair to refer to it as an “estimate”. Note that, prior to ~1995, Results appearing in the WQDB are unaccompanied by any value at all for the MDA.
(4) The level at which the recorded activity of a particular radionuclide is said to be a “detect” is somewhat arbitrary. In fact, at various times this level has been set at the MDA plus one standard deviation (SD); at other times, a “detect” has been assigned as the MDA plus two SD’s; and at still other times, a “detect” has been set at the MDA plus three SD’s. For cases in which a measured activity is close to the MDA, it is necessary to ask: Is this value, returned by some analytical laboratory, a real measure of the activity of a particular radionuclide, or a measurement error of some sort? The answer can best be couched in terms of probabilities. Generally, as a measured value approaches the MDA from above, the probability of its being a real value and not an artifact should approach zero. But, the probability of a measured value of activity at, or even below, the MDA, being a real measure of activity, with non-zero probability, depends upon one’s estimation of the reliability of the precise value of the MDA. (The SD is an accepted measure of the most probable variation from the mean found in a lengthy data series. For the data recorded in the WQDB, the SD could be taken as the tabulated Uncertainty.)
(5) If the measured activity of a sample (S), inside a container, is less than the apparent measured activity of the empty container (C), then a negative value appears in the Results column of the WQDB; i.e., since Result = S-C. The data errors accumulated over the course of a lengthy series of sample measurements are partly due to the variable influence of the individual sample containers upon the measurement process.
(6) In, “A Vadose Zone Flow & Transport Model for Los Alamos Canyon, Los Alamos, New Mexico”, by Bruce A. Robinson, etal, published online, August 26, 2005. In this numerical simulation of tritium transport beneath the Pajarito Plateau, the authors estimate the source concentration of tritium in the Omega West reactor’s primary coolant water to be ~18 x 106 pCi/L. They also describe the history of detected tritium activities from LAO-1, and from LAO-3, both alluvial wells in Los Alamos Canyon.
(7) “Lab completes Omega West reactor decommissioning”, LANL Public Affairs, July 30, 2003.
(8) In, “LANL Public Health Assessment”, ATSDR/US-HHS, April 26, 2005. It seems that the ATSDR undertook this study, in part, because of worries expressed to it by members of the general public, living around Los Alamos, about possible deleterious health effects arising from past LANL operations. It is interesting to note a passage appearing on p94 of this Assessment: “Three underground storage tanks were used to hold liquid radioactive wastes produced when the Omega West reactor was active. Usually, when the tanks were full, their contents were emptied and transported to the TA-50 Radioactive Liquid Waste Treatment Facility. Occasionally, when the tanks were full, liquid waste water was discharged directly into Los Alamos Canyon.”



Fig. 1

Fig. 2

National Park Status for Los Alamos?

The U. S. National Park Service has recently announced its intent to conduct a study for the preservation and interpretation of four historic sites associated with the Manhattan Project. One of these four is the Los Alamos National Laboratory and townsite (for more info see the website: parkplanning.nps.gov/mapr.) It seems that national pride in the singular product of the Manhattan Project may soon be reburnished.

On the other hand, some months ago (on June 25, 2009, in a public meeting at the Buffalo Thunder Hotel) members of the Centers for Disease Control's "Los Alamos Historical Document Retrieval and Assessment Project" (LAHDRA) presented their draft final report. Much interesting information was conveyed during the approximately two hours allotted to the summarizing of this report.

For example, quoting directly from the LAHDRA final report’s chapter 22, under the heading, “Early airborne releases of Plutonium”:

“Plutonium was processed in crude facilities in D Building during World War II, and many roof-top vents were unfiltered and unmonitored. After DP West Site took over production late in 1945, there was some filtering of releases, but poor monitoring practices caused releases to be underestimated. Documents indicate that DP releases for 1948-1955 alone were over 100 times the total reported by the Lab for operations before 1973.”

After the meeting Joe Shonka of Shonka Research Associates, a contributing author of the report, said that LAHDRA was intended to be a historical study: “Almost everybody is already dead,” he said. “How many people do you know who were alive in the ’40s?”

Shonka noted that the “hapless civilians”, who were caught up in fallout from the first atomic explosion at Trinity Site in New Mexico, “had not been fully evaluated.” Moreover, “There is a lot of distrust and some of this [LAHDRA report] may help the public to trust that scientists know what goes on.”

However, quoting from the LAHDRA final report’s, chapter 22, under the heading
“Public exposures from the Trinity test”:

“Residents of New Mexico were not warned before the 1945 Trinity blast, or warned of health hazards afterward, and no residents were evacuated. Exposure rates in public areas from the world’s first nuclear explosion were measured at levels 10,000 times higher than currently allowed. Residents reported that fallout ‘snowed down’ for days after the blast, most had dairy cows, and most collected rain water off their roofs for drinking. All assessments of doses form the Trinity test issued to date have been incomplete in that they have not addressed internal doses received after intakes of radioactivity through inhalation or consumption of contaminated water or food products.”

In my view, it is questionable that a careful reading of the LAHDRA final report will do much to rebuild trust in activities having to do with nuclear materials. In this context, that a contributor to the LAHDRA study (J. Shonka), should refer to people who lived within approximately 30 miles of the Trinity blast, and who were all unwarned and thus unsheltered at the time, as “hapless civilians” seems disturbing.

According to Webster, “hapless” means “unlucky.” But, these people were not just unlucky. Rather, they had had their vital interests deliberately subordinated to national interests, as a part of the culmination of the then top secret government program.

Concerns of Northern New Mexico Citizens Probed

In this post I contrast the "Community Survey Report for Northern New Mexico" (CSR), available on this blog, with the "Los Alamos National Laboratory Community Leaders Study" (CLS), available at www.lanl.gov/cpo/. Both of these works first appeared in late 2009.

The former is an unfunded survey performed by myself, with 225 respondents. The latter is a DOE-LANL funded survey conducted by Research & Polling, Inc. of Albuquerque, NM, with 224 respondents. The former survey attempts to assess the feelings of ordinary local community members toward DOE-LANL and is driven by a personal curiosity, fueled by two years of frustrating service on the DOE's Northern New Mexico Citizens Advisory Board (NNMCAB). The latter study attempts to explore the question of how DOE-LANL is perceived by local community leaders, and is inspired by a need of DOE-LANL administrators for programmatic feedback.

Here are a few lines from the CSR:

"A survey was conducted of the attitudes of citizens of Española and Santa Fe toward DOE operations in NM.

Results show that worries about legacy waste, as well as wastes generated by present and possible future DOE operations, are combined with an appreciation for the economic benefits brought to NM by DOE operations."

"Based on these survey results, it is plausible to say that money and jobs brought to Northern NM by the DOE are considered to be very important to many of Northern NM’s citizens. At the same time, concerns about pollution caused by the DOE’s operations are very worrisome. Often, feelings of gratification due to economic benefit, and worries about pollution, appear within the same individual."

"There is evidence of ambivalence toward the DOE’s ongoing nuclear weapons program. Although strong opinions pro and con about nuclear weapons do not appear within the same individual, uncertainty about this issue can still be seen in the views of individual respondents."

"It seems fair to say that suspicion about the DOE’s operations in northern New Mexico is widespread. The fact that many DOE employees live and work in Northern New Mexico is not seen as a reason to be sanguine about the DOE’s operations here."

Here are a few lines from the CLS:

"This tracking study (CLS) was commissioned by LANL. The objective was to measure the Lab’s perceived progress in maintaining community relationships and listening and responding to the needs of the communities in Northern NM ... . The study measures changes in Community Leaders’ awareness and satisfaction levels with specific Lab programs and activities over the past year. The results of the research will help to better shape and direct ... contributions to the region in the ... future."

"Over the past two years, LANL has improved its overall image among Community Leaders throughout Northern NM. LANL’s persistent efforts to be involved with, and support, a variety of community programs have clearly helped its overall standing in the region. The Community Leaders’ positive opinion of LANL is reflected in their overall impression ratings. Approximately three-fifths (61%) of Leaders have a favorable impression of the Lab, which has grown from 52% in the previous year, while unfavorable ratings have dropped from 13% to 6% currently."

The difference in emphasis between the CSR and the CLS is clear enough. However, both works attempt to address legitimate concerns regarding the relationship between DOE-LANL and the Northern New Mexico community.

The completed CSR was first presented publicly on Nov. 18, 2009, at Northern New Mexico University, to NMED's Community Radiation Monitoring Group. It had been previously summarized at November, 2009 meetings of the NNMCAB.

(A discussion of LANL employee attitudes, as reflected in a 2009 LANL internal survey, has been blogged recently at LANL-the-rest-of-the-story.blogspot.com.)