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Malmberg MM, Smith C, Thakur P, Drayton MC, Wilson J, Shinozuka M, Clayton W, Inch C, Spangenberg GC, Smith KF, Cogan NOI, Pembleton LW. Developing an integrated genomic selection approach beyond biomass for varietal protection and nutritive traits in perennial ryegrass (Lolium perenne L.). TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2023; 136:44. [PMID: 36897387 PMCID: PMC10006259 DOI: 10.1007/s00122-023-04263-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 10/21/2022] [Indexed: 06/18/2023]
Abstract
Breeding target traits can be broadened to include nutritive value and plant breeder's rights traits in perennial ryegrass by using in-field regression-based spectroscopy phenotyping and genomic selection. Perennial ryegrass breeding has focused on biomass yield, but expansion into a broader set of traits is needed to benefit livestock industries whilst also providing support for intellectual property protection of cultivars. Numerous breeding objectives can be targeted simultaneously with the development of sensor-based phenomics and genomic selection (GS). Of particular interest are nutritive value (NV), which has been difficult and expensive to measure using traditional phenotyping methods, resulting in limited genetic improvement to date, and traits required to obtain varietal protection, known as plant breeder's rights (PBR) traits. In order to assess phenotyping requirements for NV improvement and potential for genetic improvement, in-field reflectance-based spectroscopy was assessed and GS evaluated in a single population for three key NV traits, captured across four timepoints. Using three prediction approaches, the possibility of targeting PBR traits using GS was evaluated for five traits recorded across three years of a breeding program. Prediction accuracy was generally low to moderate for NV traits and moderate to high for PBR traits, with heritability highly correlated with GS accuracy. NV did not show significant or consistent correlation between timepoints highlighting the need to incorporate seasonal NV into selection indexes and the value of being able to regularly monitor NV across seasons. This study has demonstrated the ability to implement GS for both NV and PBR traits in perennial ryegrass, facilitating the expansion of ryegrass breeding targets to agronomically relevant traits while ensuring necessary varietal protection is achieved.
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- A, Thakur P, Sharma R. 246P Clinicoepidemiological profile and patterns of failure in carcinoma oral cavity in Indian patients: A 6-year retrospective study. Ann Oncol 2022. [DOI: 10.1016/j.annonc.2022.10.281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2022] Open
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Walmsley A, Fares W, Clegg N, Duriez A, Singh M, Thakur P, Al-Mansoori M, Al-Arfi S, Bazuhair M, Baloushi MA, Gohary ME, El-Abd S. High Resolution 3D Electromagnetic Inversion in a Mature Carbonate Field. EAGE GEOTECH 2022 FIRST EAGE WORKSHOP ON RESERVOIR MANAGEMENT OF MATURE FIELDS 2022. [DOI: 10.3997/2214-4609.20224008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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Arumugam P, Thakur P, Sarabahi S. Changing Trends In Electrical Burns From A Tertiary Care Centre - Epidemiology And Outcome Analysis. ANNALS OF BURNS AND FIRE DISASTERS 2021; 34:351-359. [PMID: 35035329 PMCID: PMC8717909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Accepted: 03/29/2021] [Indexed: 06/14/2023]
Abstract
Electrical burn injuries result in significant mortality and morbidity. Most of these injuries are preventable. We conducted a retrospective analysis of various aspects of electrical injuries presenting to our center over a period of 1 year from September 2018 to August 2019. Demographic characteristics of patients along with burn characteristics and associated injuries were analysed. Outcomes including length of hospital stay, need for fasciotomy, amputation, renal failure and mortality were also analysed. A total of 6380 patients presented to our center during the study period, of which 471 (7.38%) had electrical burns. Total burn admissions were 1530, of which 283 (18.49%) patients were admitted with electrical burns. The mean age in our cohort was 25.31±12.76 years and mean TBSA was 29.22±23.81%. The most common cause of electrical burns was occupational (33.3%), followed by those that occurred on the rooftop of houses (31%). A historical comparison with data published from our center in 2011 showed a significant increase in occupational burns (18.72% vs. 33.3%) and rooftop electrical burns (8.21% vs. 31%), and a decrease in agriculture-related (42.46% vs. 9.1%) and domestic electrical burns (26.02% vs. 6.7%). There was also a significant rise in proportion of high voltage injuries (71.23% vs. 86.90%). Logistic regression analysis showed electric contact burn to be a risk factor for fasciotomy and limb gangrene. Risk factors for renal failure were age, percentage burn, electric contact burn and rural residence, and those for mortality were percentage burn and renal failure. Emphasis on preventive strategies, especially against occupational injuries and injuries occurring on rooftops, is necessary to prevent such devastating injuries.
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Thakur P, Ward AL. 210Po in the environment: insight into the naturally occurring polonium isotope. J Radioanal Nucl Chem 2019. [DOI: 10.1007/s10967-019-06939-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Thakur P, Ward AL. An Overview of Analytical Methods for in Vitro Bioassay of Actinides. HEALTH PHYSICS 2019; 116:694-714. [PMID: 30908319 DOI: 10.1097/hp.0000000000000982] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The bioassay of urine and fecal samples has been used since the 1940s to determine an individual's uptake of uranium and actinide elements such as americium and plutonium. Over the years, several analytical separation methods and techniques have been employed for these types of analyses. Analytical separations, ranging from solvent extraction and anion exchange to chromatography, and analytical techniques, ranging from autoradiography to kinetic phosphorescence to fission-track analysis and high-resolution solid-state alpha spectroscopy, have been used at one time or another. Over the last few decades, there have been significant advances in radiochemical separations, as well as an increased use of mass spectroscopy, to determine trace and ultratrace levels of actinides in urine and fecal samples. This review summarizes and discusses developments in radiochemical separation methods and advancements in analytical techniques for actinide bioassay since the early 1940s to the present, followed by a recent development and trend in the bioassay of actinides-particularly in urine and fecal samples.
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Thakur P, Ward AL. 241Pu in the environment: insight into the understudied isotope of plutonium. J Radioanal Nucl Chem 2018. [DOI: 10.1007/s10967-018-5946-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Lemons B, Khaing H, Ward A, Thakur P. A rapid method for the sequential separation of polonium, plutonium, americium and uranium in drinking water. Appl Radiat Isot 2018; 136:10-17. [PMID: 29448060 DOI: 10.1016/j.apradiso.2018.02.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 12/10/2017] [Accepted: 02/05/2018] [Indexed: 10/18/2022]
Abstract
A new sequential separation method for the determination of polonium and actinides (Pu, Am and U) in drinking water samples has been developed that can be used for emergency response or routine water analyses. For the first time, the application of TEVA chromatography column in the sequential separation of polonium and plutonium has been studied. This method utilizes a rapid Fe+3 co-precipitation step to remove matrix interferences, followed by plutonium oxidation state adjustment to Pu4+ and an incubation period of ~ 1 h at 50-60 °C to allow Po2+ to oxidize to Po4+. The polonium and plutonium were then separated on a TEVA column, while separation of americium from uranium was performed on a TRU column. After separation, polonium was micro-precipitated with copper sulfide (CuS), while actinides were micro co-precipitated using neodymium fluoride (NdF3) for counting by the alpha spectrometry. The method is simple, robust and can be performed quickly with excellent removal of interferences, high chemical recovery and very good alpha peak resolution. The efficiency and reliability of the procedures were tested by using spiked samples. The effect of several transition metals (Cu2+, Pb2+, Fe3+, Fe2+, and Ni2+) on the performance of this method were also assessed to evaluate the potential matrix effects. Studies indicate that presence of up to 25 mg of these cations in the samples had no adverse effect on the recovery or the resolution of polonium alpha peaks.
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Thakur P, Seam R, Gupta M. Will doublet chemotherapy and radiation improve outcome as compared to standard treatment in carcinoma cervix IIIB? Long term results of a prospective randomized phase III trial. Ann Oncol 2017. [DOI: 10.1093/annonc/mdx663.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Sharma A, Surya M, Upadhyay M, Sharma M, Fotedar V, Gupta M, Vats S, Thakur P, Sharma M, Tuli D, Sharma S, Seam R. Bone health in cancer survivors. Ann Oncol 2017. [DOI: 10.1093/annonc/mdx668.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Thakur P, Khaing H, Salminen-Paatero S. Plutonium in the atmosphere: A global perspective. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2017; 175-176:39-51. [PMID: 28432864 DOI: 10.1016/j.jenvrad.2017.04.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 04/06/2017] [Accepted: 04/09/2017] [Indexed: 06/07/2023]
Abstract
A number of potential source terms have contributed plutonium isotopes to the atmosphere. The atmospheric nuclear weapon tests conducted between 1945 and 1980 and the re-entry of the burned SNAP-9A satellite in 1964, respectively. It is generally believed that current levels of plutonium in the stratosphere are negligible and compared with the levels generally found at surface-level air. In this study, the time trend analysis and long-term behavior of plutonium isotopes (239+240Pu and 238Pu) in the atmosphere were assessed using historical data collected by various national and international monitoring networks since 1960s. An analysis of historical data indicates that 239+240Pu concentration post-1984 is still frequently detectable, whereas 238Pu is detected infrequently. Furthermore, the seasonal and time-trend variation of plutonium concentration in surface air followed the stratospheric trends until the early 1980s. After the last Chinese test of 1980, the plutonium concentrations in surface air dropped to the current levels, suggesting that the observed concentrations post-1984 have not been under stratospheric control, but rather reflect the environmental processes such as resuspension. Recent plutonium atmospheric air concentrations data show that besides resuspension, other environmental processes such as global dust storms and biomass burning/wildfire also play an important role in redistributing plutonium in the atmosphere.
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Cao M, Schulze C, Gardner R, An Q, Thakur P, Thompson J, Boehmer J. P1577Device-measured third heart sound predicts heart failure events better than auscultated third heart sound. Europace 2017. [DOI: 10.1093/ehjci/eux158.203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Yadav B, Sharma S, Bansal A, Thakur P, Yadav B, Bhusan P, Ghoshal S, Kapoor R, Kumar N. Risk Factors for Breast Cancer – How Much Weightage for Weight? Clin Oncol (R Coll Radiol) 2017. [DOI: 10.1016/j.clon.2016.10.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Miriyala R, Bansal A, Dracham C, Thakur P, Ghoshal S. 567P_PR Diagnostic delay in oncology: Is there a need for increasing cancer awareness among primary care physicians of developing countries? Ann Oncol 2016. [DOI: 10.1093/annonc/mdw603.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Thakur P, Kumar N, Miriyala R, Ghoshal S. 144PD Cranio-Spinal irradiation - is acute hematological toxicity. Ann Oncol 2016. [DOI: 10.1016/s0923-7534(21)00302-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Thakur P, Kumar N, Miriyala R, Ghoshal S. 144PD Cranio-Spinal irradiation – is acute hematological toxicity under-reported? A single institutional experience. Ann Oncol 2016. [DOI: 10.1093/annonc/mdw578.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Chakravarti A, Roy P, Malik S, Siddiqui O, Thakur P. A study on gender-related differences in laboratory characteristics of dengue fever. Indian J Med Microbiol 2016; 34:82-4. [PMID: 26776124 DOI: 10.4103/0255-0857.174106] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Studies have reported significant gender-related differences in serological tests for detection of NS1 antigen and IgM antibody used for diagnosing dengue fever. However, no such study has been undertaken in India though dengue fever is endemic in this country. Therefore, this study was planned to study the association of serological findings with gender in 700 patients suspected to be suffering from dengue fever in the Indian setting. Haematological parameters of seropositive patients were also studied. Seropositivity and haemorrhagic findings were significantly associated with the female gender. Positive NS1 antigen and IgM antibody results were significantly associated with females and males, respectively.
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Thakur P, Lemons BG. Source and long-term behavior of transuranic aerosols in the WIPP environment. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:19645-19656. [PMID: 27394421 DOI: 10.1007/s11356-016-7155-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 06/26/2016] [Indexed: 06/06/2023]
Abstract
Source and long-term behavior transuranic aerosols ((239+240)Pu, (238)Pu, and (241)Am) in the ambient air samples collected at and near the Waste Isolation Pilot Plant (WIPP) deep geologic repository site were investigated using historical data from an independent monitoring program conducted by the Carlsbad Environmental Monitoring and Research Center and an oversight monitoring program conducted by the management and operating contractor for WIPP at and near the facility. An analysis of historical data indicates frequent detections of (239+240)Pu and (241)Am, whereas (238)Pu is detected infrequently. Peaks in (239+240)Pu and (241)Am concentrations in ambient air generally occur from March to June timeframe, which is when strong and gusty winds in the area frequently give rise to blowing dust. Long-term measurements of plutonium isotopes (1985-2015) in the WIPP environment suggest that the resuspension of previously contaminated soils is likely the primary source of plutonium in the ambient air samples from WIPP and its vicinity. There is no evidence that WIPP is a source of environmental contamination that can be considered significant by any health-based standard.
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Thakur P, Lemons BG, White CR. The magnitude and relevance of the February 2014 radiation release from the Waste Isolation Pilot Plant repository in New Mexico, USA. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 565:1124-1137. [PMID: 27261427 DOI: 10.1016/j.scitotenv.2016.05.158] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Revised: 05/20/2016] [Accepted: 05/22/2016] [Indexed: 06/05/2023]
Abstract
After almost fifteen years of successful waste disposal operations, the first unambiguous airborne radiation release from the Waste Isolation Pilot Plant (WIPP) was detected beyond the site boundary on February 14, 2014. It was the first accident of its kind in the 15-year operating history of the WIPP. The accident released moderate levels of radioactivity into the underground air. A small but measurable amount of radioactivity also escaped to the surface through the ventilation system and was detected above ground. The dominant radionuclides released were americium and plutonium, in a ratio consistent with the known content of a breached drum. The radiation release was caused by a runaway chemical reaction inside a transuranic (TRU) waste drum which experienced a seal and lid failure, spewing radioactive materials into the repository. According to source-term estimation, approximately 2 to 10Ci of radioactivity was released from the breached drum into the underground, and an undetermined fraction of that source term became airborne, setting off an alarm and triggering the closure of seals designed to force exhausting air through a system of filters including high-efficiency-particulate-air (HEPA) filters. Air monitoring across the WIPP site intensified following the first reports of radiation detection underground to determine the extent of impact to WIPP personnel, the public, and the environment, if any. This article attempts to compile and interpret analytical data collected by an independent monitoring program conducted by the Carlsbad Environmental Monitoring & Research Center (CEMRC) and by a compliance-monitoring program conducted by the WIPP's management and operating contractor, the Nuclear Waste Partnership (NWP), LLC., in response to the accident. Both the independent and the WIPP monitoring efforts concluded that the levels detected were very low and localized, and no radiation-related health effects among local workers or the public would be expected.
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Khaing H, Lemons BG, Thakur P. Concentration of uranium in the drinking and surface water around the WIPP site. J Radioanal Nucl Chem 2016. [DOI: 10.1007/s10967-016-4825-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Miriyala R, Thakur P, Singh A, Gupta A, Yadav B, Kumar N, Rattan R, Ghoshal S. EP-1451: Workflow Management: Impact on the ergonomics of a Radiotherapy department in a developing country. Radiother Oncol 2016. [DOI: 10.1016/s0167-8140(16)32701-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Thakur P. Source term estimation and the isotopic ratio of radioactive material released from the WIPP repository in New Mexico, USA. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2016; 151 Pt 1:193-203. [PMID: 26492395 DOI: 10.1016/j.jenvrad.2015.10.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Revised: 10/07/2015] [Accepted: 10/08/2015] [Indexed: 06/05/2023]
Abstract
After almost 15 years of operations, the Waste Isolation Pilot Plant (WIPP) had one of its waste drums breach underground as a result of a runaway chemical reaction in the waste it contained. This incident occurred on February 14, 2014. Moderate levels of radioactivity were released into the underground air. A small portion of the contaminated underground air also escaped to the surface through the ventilation system and was detected approximately 1 km away from the facility. According to the source term estimation, the actual amount of radioactivity released from the WIPP site was less than 1.5 mCi. The highest activity detected on the surface was 115.2 μBq/m(3) for (241)Am and 10.2 μBq/m(3) for (239+240)Pu at a sampling station located 91 m away from the underground air exhaust point and 81.4 μBq/m(3) of (241)Am and 5.8 μBq/m(3) of (239+240)Pu at a monitoring station located approximately 1 km northwest of the WIPP facility. The dominant radionuclides released were americium and plutonium, in a ratio that matches the content of the breached drum. Air monitoring across the WIPP site intensified following the first reports of radiation detection underground to determine the extent of impact to WIPP personnel, the public, and the environment. In this paper, the early stage monitoring data collected by an independent monitoring program conducted by the Carlsbad Environmental Monitoring & Research Center (CEMRC) and an oversight monitoring program conducted by the WIPP's management and operating contractor, the Nuclear Waste Partnership (NWP) LLC were utilized to estimate the actual amount of radioactivity released from the WIPP underground. The Am and Pu isotope ratios were measured and used to support the hypothesis that the release came from one drum identified as having breached that represents a specific waste stream with this radionuclide ratio in its inventory. This failed drum underwent a heat and gas producing reaction that overpowered its vent and lifted its lid to allow release of waste into the underground air.
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Thakur P, Lemons BG, Ballard S, Hardy R. Environmental and health impacts of February 14, 2014 radiation release from the nation's only deep geologic nuclear waste repository. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2015; 146:6-15. [PMID: 25880461 DOI: 10.1016/j.jenvrad.2015.03.034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 03/26/2015] [Accepted: 03/29/2015] [Indexed: 06/04/2023]
Abstract
The environmental impact of the February 14, 2014 radiation release from the nation's only deep geologic nuclear waste repository, the Waste Isolation Pilot Plant (WIPP) was assessed using monitoring data from an independent monitoring program conducted by the Carlsbad Environmental Monitoring & Research Center (CEMRC). After almost 15 years of safe and efficient operations, the WIPP had one of its waste drums rupture underground resulting in the release of moderate levels of radioactivity into the underground air. A small amount of radioactivity also escaped to the surface through the ventilation system and was detected above ground. It was the first unambiguous release from the WIPP repository. The dominant radionuclides released were americium and plutonium, in a ratio that matches the content of the breached drum. The accelerated air monitoring campaign, which began following the accident, indicates that releases were low and localized, and no radiation-related health effects among local workers or the public would be expected. The highest activity detected was 115.2 μBq/m(3) for (241)Am and 10.2 μBq/m(3) for (239+240)Pu at a sampling station located 91 m away from the underground air exhaust point and 81.4 μBq/m(3) of (241)Am and 5.8 μBq/m(3) of (239+240)Pu at a monitoring station located approximately one kilometer northwest of the WIPP facility. CEMRC's recent monitoring data show that the concentration levels of these radionuclides have returned to normal background levels and in many instances, are not even detectable, demonstrating no long-term environmental impacts of the recent radiation release event at the WIPP. This article presents an evaluation of almost one year of environmental monitoring data that informed the public that the levels of radiation that got out to the environment were very low and did not, and will not harm anyone or have any long-term environmental consequence. In terms of radiological risk at or in the vicinity of the WIPP site, the increased risk from the WIPP releases is exceedingly small, approaching zero.
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George J, Thakur P, Bindra KS, Oak SM. Demonstration of CW mode locked Cr:forsterite laser using self-shortening and transverse mode degeneracy driven mode locking. APPLIED OPTICS 2014; 53:7749-7752. [PMID: 25403000 DOI: 10.1364/ao.53.007749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This paper reports a nearly Fourier transform limited CW mode locked Cr:forsterite laser at 1282 nm, with 131 fs pulse duration, based on self-shortening and transverse mode degeneracy (TMD) driven mode locking, operating near the point of fourth-order TMD. The cavity employs a combination of instantaneous intensity driven self-shortening, and operation on the right side of the fourth-order TMD, to generate the self-amplitude modulation necessary for self-mode locking.
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Thakur P, Ballard S, Hardy R. Radiation release at the nation's only operating deep geological repository--an independent monitoring perspective. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:12698-12705. [PMID: 25313463 DOI: 10.1021/es503649y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Recent incidents at the nation's only operating deep geologic nuclear waste repository, the Waste Isolation Pilot Plant (WIPP), resulted in the release of americium and plutonium from one or more defense-related transuranic (TRU) waste containers into the environment. WIPP is a U.S. Department of Energy mined geologic repository that has been in operation since March, 1999. Over 85,000 m3 of waste in various vented payload containers have been emplaced in the repository. The primary radionuclides within the disposed waste are 239+240Pu and 241Am, which account for more than 99% of the total TRU radioactivity disposed and scheduled for disposal in the repository. For the first time in its 15 years of operation, there was an airborne radiation release from the WIPP at approximately 11:30 PM Mountain Standard Time (MST) on Friday, February 14, 2014. The radiation release was likely caused by a chemical reaction inside a TRU waste drum that contained nitrate salts and organic sorbent materials. In a recent news release, DOE announced that photos taken of the waste underground showed evidence of heat and gas pressure resulting in a deformed lid, in material expelled through that deformation, and in melted plastic and rubber and polyethylene in the vicinity of that drum. Recent entries into underground Panel 7 have confirmed that at least one waste drum containing a nitrate salt bearing waste stream from Los Alamos National Laboratory was breached underground and was the most likely source of the release. Further investigation is underway to determine if other containers contributed to the release. Air monitoring across the WIPP site intensified following the first reports of radiation detection underground to ascertain whether or not there were releases to the ground surface. Independent analytical results of air filters from sampling stations on and near the WIPP facility have been released by us at the Carlsbad Environmental Monitoring & Research Center and confirmed trace amounts of 241Am and 239+240Pu, at ratios reflecting the suspect waste stream. The highest activity detected offsite was 115.2 μBq/m3 for 241Am and 10.2 μBq/m3 for 239+240 Pu. These concentrations in air were very small, localized, and below any level of public health or environmental concern.
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