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HomeMy WebLinkAboutBradley Lake PMC Meeting December 17, 2008 4HEA Transformer Failure Investigation Report Investigation Date: October 30, 2008 Personnel Involved: Kurt Labonte: MLP: Relay/Substation Foreman Operation) Tusi Fa’afetai CEA: Substation Technician Bob Day HEA: Power Production Manager Steve Pollack HEA: Bradley Lake Operator / Foreman Bob O'Neil HEA: Nikiski Plant Foreman / Rover Travis Kincaid | HEA: Operator / Rover / Electrician Transformer Information: Manufacturer: ABB TYPE: ONPS-XA1 Ser No. DS00858001 KVA: 750 HV: 13800 KV BIL: 9SHV/60LV LV: 1240Y/7200 LV Amp: 35 Class: AA Type: VPI Phase: 3 IMP: 5.96 HZ: 60 Config: Primary-Delta/Secondary-Y Overall Inspection Report: On October 30, 2008 an inspection was carried out on the request from Homer Electric to have a more in depth look into the cause of failure of transformer ONPS-XA1. This transformer was a replacement to the original transformer that failed catastrophically after several years in service. There were no records of the fault or any investigation report for the first transformer. This replacement transformer was in service for 15 years before it failed. The transformer serves as the source to the “Camp” distribution system, which serves the surrounding facilities and a several mile single phase run up to the dam. The load appears to be connected on C phase. The transformer is rated at 750 KVA, which equates to a little over 30 amps per phase available load current. Normal loading was reported at a few amps on A and B phase and around 5 amps on C phase. It is not sure where exactly these reading were taken at, but it’s assumed that they were taken at the ACB 30/40 circuit breakers. There have been several cable faults associated with the long single-phase run but the cause of each fault is unknown. The transformer was also reportedly exposed to some significant load swings between the two generators due to governor issues during load sharing conditions. Normally this would only affect the source voltage and happened some years ago. Listed below are some visual inspections details and photographs of the failed transformer. 1- Carbon residue observed in the inside of transformer top cover and above aluminum bus bars, core support frame, paper insulation of middle winding and red insulation barrier board between three coils/windings. 2- Excessive signs of melted varnish at the iron core bottom support frame of the center coil/Phase 2 3- Three melted cables on each transformer HV phase at terminal bus bars connection to the transformer HV winding. 4- Melted top portion of terminal bus-bar connection to the transformer three HV winding. Figure 1 AA Suy Ae In reviewing pictures of the transformer after failure, it was observed that the neutral conductor of the low side is a shielded 15KV cable. The original pictures didn’t show a bare copper ground on either side of the transformer or any mark on the ground bus where a ground had been connected. This doesn’t mean there wasn’t a ground connected but evidence of one could not be found. Relay settings information for ABC 30 and 40 that had a pick-up of 2 amps, a time dial of 1, and an instantaneous of 15 amps. There is insufficient information regarding relay protection curves and CT ratio. This setting needs to be reviewed to ensure protection is set within the mechanical and thermal damage curve for dry type three phase transformer base on IEEE Std C57.12.59 Category Il. Two tests were run to verify the signature and condition of the fault in the transformer. The unit was originally stored and well wrapped with plastic out in the container yard but was transported to the North Star Stevedoring warehouse for testing. MLP representative Kurt Labonte performed the turns ratio test and the mega-ohm resistance test and the result are listed below. Turn Ratio Test (TTR) H1 —H3 to X1- X0 = 0.4% deviation @ ratio 1.924 H2 -H1 to X2-X0 = 0.4% deviation @ ratio 1.924 H3 - H2 to X3- XO = 30% deviation @ ratio 2.498 Megger Test Result @ 5K VDC HV insulation to Gnd = PI of 1.25 @ 61 Gohm HV to LV = PI of 1.09 @ 65 Gohm LV insulation to Gnd = PI of 1.13 @ 1.52 Mohm Fluke ohmmeter resistance reading X1 winding resistance = 1.1 ohms X2 winding resistance = 1.1 ohms X3 winding resistance = 1.14 kilo Ohms The transformer was dissected to inspect the suspected area in the center LV winding. Two burned and melted open winding conductors at a quarter way in the LV winding from the top were found. This caused a lot of heat and burning of insulation in that part of the winding. It appears that there was substantial overheating as evidenced in the melting and varnish dripping from the bottom of the faulted winding. The present appearance does not indicate if the winding failed from shorted turns or if some external intrusive fault caused the winding to burn open. Collectively, present facts and visual evidence can produce scenario of no-nonsense theories that could be considered as a probability. The transformer failure is most likely due to-turn-to turn low voltage winding short and not a ground or HV winding fault. The limited transformer loading history and fault report presented did not reflect any significant effect on the fault other than gradually intensifying any existing fault in the system or transformer. An unbalance loading as reported in one phase will produce high loss (impedance) in the system and can be seen as high increase of resultant current return to ground (high ground impedance). This in fact will not affect the transformer directly but it will force the source excitation for more reactive power compensation. Normally, the transformer will experience an increase in load current and may be exposed to some degree of heating. A turn-to- turn short in the transformer will be seen as voltage drop in one phase (turn and voltage proportionality) which will intensify the already unbalance loading situation. This will behave in the same manner and draw more reactive compensation and more excitation current from the source. As a result of this situation, the transformer will experience more overheating to the point where the weak connection will probably be the first to give up. The disconnection of any single phase during the fault caused a high unbalance which trip the C/B on over-current or ground fault depends on what incur first with respect to the natural heating and the protection setting. The cause based on this explanation of the turn-to-turn LV winding short has some substantiated evidence that may be a possible scenario. The overheating resulted in melted bus bar HV terminal connection and a turn to turn short burning open at the LV winding. This fault happened simultaneously from overheating due to high current from the excitation source for reactive compensation due to turn to turn short. There were no signs of arching splashed across the turn to turn short to cause any further damage beside the black carbon smoke and soot from the burning winding and insulation. There was also evidence that the faulted winding had experienced some movement that was due to an unbalanced from turn-to-turn short vibration. The dissected part of the LV winding that was inspected has some interesting findings that may be linked to the winding turn-to-turn short. There was evidence of corona effect in the impregnated resin varnish insulation seen in one part of the dissected winding close to the fault. A drop of varnish in between two winding had a void with signs of burning starting to expose the two winding edges. This may be one of the events that eventually caused the turn-to-turn short in the LV winding. Recommendation: This transformer fault has resulted in awareness for the need to review the existing transformer protection scene. Since there was not much information provided on transformer protection, there is a need to review the settings to make sure that the transformer is protected from thermal and mechanical damage in respect to the current loading, rating, fault current and relay setting. These settings need to be reviewed to ensure protection is set within the mechanical and thermal damage curve for dry type three phase transformer base on IEEE Std C57.12.59 Category Il. Routine online and offline testing for fault indication is highly recommended. Infra red can be very helpful in detecting an early overheating situation. Test results must be carefully reviewed to create a baseline database of results to detect early signs of faults. Chugach Electric employs PDM (predictive maintenance) techniques to improve productivity, increase safety and reduce costs through early detection of faults. We would be willing to share our Pdm program with Homer Electric in an effort to improve their maintenance efforts. Tusi Fa’afetai CEA Sub-Tech Nuka Glacier remediation work summer of 2008 Report to the BPMC December 17 2008 Robert Day During the start of summer a USGS snow survey crew had gone to the Nuka Glacier site to service the gauging system located there. When they returned to Anchorage they provided us a short report that indicated there was a large quantity of water going over the spillway of the Nuka Diversion structure. On July 29, 2008 John Miyashiro, Bob Day Bryan Carey and John Magee took an inspection flight to visit the diversion. Upon arrival they saw the following: Photo of the water overtopping the Nuka Diversion structure taken on July 29, 2008 An effort was begun to obtain a permit to accomplish remedial work to correct the flows. Our permit requires that the first 5 CFS of flow toward Beauty Bay be allowed to continue, It is permitted to divert flows over 5 CFS toward Bradley Lake and hence through the turbines. The wooden platform in the above picture has two valve handles attached to the face of it that allows one to open or close two slide gates. The slide gates control the flow of water through two approximately 12” pipes that penetrate the diversion structure and allow the required flows to be delivered to Beauty Bay. As you can see from the photo excess water is overtopping the structure and is escaping towards Beauty Bay. By August we had received permission to fly to Nuka Glacier with some equipment and attempt to change some of the flows in order to try to capture additional water for Bradley Lake. The initial attempt involved a 4” dredge (similar to a gold dredge). The dredge proved ineffective as there was a large quantity of bigger stones present in the material and the dredge suffered from constant clogging and shutdowns. We then obtained a small tractor with a loader and backhoe attachment that was small enough to Nuka Glacier work report 2008 1 of 6 Robert Day be flown in by helicopter. That machine was effective in moving sufficient material from the drainage area that the flows over the diversion were diminished. The net flow to Bradley Lake was improved. The small Kubota tractor is working on clearing the flow path to Bradley Lake. The Diversion Structure is directly behind the tractor operator. Bradley Lake is behind the Photographer Flow over the Diversion Structure has diminished after the tractor has performed it work Beauty Bay is Behind the Photographer with Bradley Lake at the top of the photo Though the tractor was effective it became clear that it was going to take a long time to really make a big difference due to the limited capacity of the tractor. We began to look for other possible solutions. The next photograph shows the layout at the face of the Nuka Glacier. The Glacier had pushed up the glacier moraine at the terminus of the glacier and had effectively blocked the flows to Bradley Lake. The water was forced to flow across the face of the glacier back toward the Diversion structure (away from Nuka Glacier work report 2008 2 of 6 Robert Day Bradley Lake) and into the large pool in front of the diversion structure. The large Nuka Diversion Pool was holding the water against the Diversion Structure (out of the photo to the lower right) and letting the water go toward Beauty Bay. Aerial photo of the terminus of the Nuka Glacier Prior to opening the Bradley Drainage In the above photo the flows from the melt water of the glacier flows to the photo’s right and some limited water returns to Bradley Lake through the channel at the upper right of the photo. The remainder of the water is lost to Beauty Bay Using the Tractor, Operators Steve Pollack and Jon Klein were able to open a small drainage ditch through the area indicated in the photo. A few days later Rob Mahan and Bob Day returned to the Nuka Glacier area and were successful in opening the breech far enough that the rushing waters took out the berm of material and re-established the river channel to Bradley Lake. Nuka Glacier work report 2008 3 of 6 Robert Day The newly opened river channel to Bradley Lake Bradley Lake is directly behind the Photographer A composite shot of the Nuka Glacier after the work was accomplished The diversion structure is near the lower left corner of the composite photo. The pool that feeds the diversion structure is simply the remnant of the large Nuka Diversion Pool. The earlier picture of the tractor working was taken near the stream (now diminished) in the lower third of the photo just below the blue pools near the center. As this photo clearly shows the majority of flow is going into Bradley Lake (to the right of the photo). Nuka Glacier work report 2008 4 of 6 Robert Day John Magee inspecting the Diversion Structure On September 17" we returned to make an inspection and found the diversion structure to no longer be inundated by water. Indeed the required minimum flows were going to Beauty Bay but by in large the water from the Nuka Glacier was going to Bradley Lake. This was accomplished with the expenditure of approximately 75, 000 dollars, the largest portion going to the Helicopter rental and to the purchase of the Kubota Tractor. The tractor remains at Bradley Lake ready for future service when conditions at Nuka Glacier again change. In reviewing the history of the work at Nuka it is apparent that every few years things move and change at Nuka and work needs to be preformed in order to correct the situation. In retrospect I believe the work was a profitable endeavor. Nuka Glacier work report 2008 5 of 6 Robert Day BRADLEY LAKE LEVEL June 1992 - December 2008 To support this contention please look at the line showing lake level for the 08-09 timeframe (bright purple color). Right at the beginning of September the line suddenly turns upward and the lake level comes up approximately 22 feet in about 10 days. There were extensive rains in the upper reaches of the lake but had the diversion work not been accomplished when it was a large portion of that lake rise would have been lost. Ata worth of approximately $100 per MWH the lake increase over that time equated to about 8 Million dollars. If the Nuka work captured % to 1/3 of that water then the Nuka work conservatively was worth 2 to 3 Million dollars in energy. Nuka Glacier work report 2008 6 of 6 Robert Day Bradley Drain Report November 17-21, 2008 On November 17, we assembled at Bradley Lake to test and verify operation of the Mongoose Jetters drain cleaning system. The system consists of a trailer-mounted 1000 gallon water supply high pressure pump pumping about ten gallons per minute and 4000 psi with 1000 ft. of hose on a hydraulically driven hose reel. The Mongoose Jetters high pressure washer There are two different nozzles that go on the head of hose. The first head is a rotating spray nozzle and the other is a nozzle that sprays primarily in a backward direction. The rotating spray nozzle is used to initially clean the drains and cut through the material. The rotating nozzle has a forward jet that spins around and some backward jets that assist in making the whole thing rapidly rotate. The backward jetting nozzle (not shown) is used to clean out the debris once the rotating nozzle has been used to knock the calcite loose from the side of the pipes. Two photos of the rotating head nozzle Page | of 6 Bradley Drain Cleaning Report Robert Day December 15, 2008 On the 17" bob Day and Jon Kleine verified operation of the device. On the 18", Travis Kincaid joined us at Bradley Lake where we started cleaning the drains in earnest. As you look at the powerhouse unit 1 and unit 2, just to the right of unit 1’s TSV are drains 1 and 2 and just to the right of unit 2’s TSV are drains 3 and 4. We initially ran the rotating nozzle up drain one and got a large quantity of debris and particles out of drain 1. We found out we really had to operate the hose in a back and forth running it up and down the drain, making at least 4 passes. In between each pass, we were running a video camera from American Marine to observe the effects so we could determine the more effective technique to use. The most successful was to advance 2-3 feet, then pull the hose back about 2 feet, then advance 2-3 feet so there would be a kind of counter- flushing but yet keep working forward at a slow rate. The drain laterals where they enter the powerhouse Each of the drain laterals had a different length to the point that they joined the main drain and once you reached that point the hose would not make any further progress. On drain one we were able to penetrate in about 50 ft. before we hit an obstruction. On drain two we penetrated about 70 ft., Drain 3 about 20 ft. and drain four 72 feet before we reached either the T or some offset that stopped forward progress. We flushed all the material out of the lateral into the powerhouse on the powerhouse floor relying on the dirty water sump and the dirty water trash pumps to remove that water through the oil water separator and into the tailrace. There were a lot of large pieces, hard particles, mud, dirt and generally dirty water that was flushed out. Page 2 of 6 Bradley Drain Cleaning Report Robert Day December 15, 2008 Some of the debris removed from the drain lateral. An example of the size and thickness of some of the debris removed. Another example of the material we were able to remove Page 3 of 6 Bradley Drain Cleaning Report Robert Day December 15, 2008 After about 4 cleanings or 4 passes with the rotating nozzle, and then a single pass with the backward jetting cleaning nozzle, we ran the video in and saw some fairly good success. There were still isolated chunks of calcite material attached to the walls but for the most part, from what we could see on the video it was clean, we estimated it was about 80% clear. There is no way to close off the clear water sump from the lateral. The prints show a valve embedded just inside the wall. This is not the case and some of this dirty water material that you wash out of the laterals ends up going down a vertical standpipe and going towards the clear water sump in the powerhouse. So at the end of cleaning we will need to come back and clean the clear water sump. The condition of a drain lateral after three successive washings After we cleaned the four laterals as far as we could reach we went to the adit and began cleaning from there. In the exit of the adit the four penstock drains are arranged in a quadrant on the bottom left hand side as you face the up the adit. With drain 1 in the lower left, 2 above it, and 3 to the upper right and 4 is in the bottom right. We were able to run the high pressure hose up drain #1 to a length of 400 ft. At 400 ft. we clearly hit and obstruction that was very well defined and further progress was halted at that point. Page 4 of 6 Bradley Drain Cleaning Report Robert Day December 15, 2008 A screen shot of the video showing the condition of Drain 1 at 200 ft prior to washing With the more limited time for passes with video in between because of the length involved we are probably not as clean in the main drains as the laterals. I would estimate that the main drains are on the order of 60-70% clean. Drain #1 was a fairly good success as we spent a good deal of our time on that drain, we were however, limited to 400 feet into that drain. To limit the amount of debris and mud going into the clear water sump we had inserted into the lateral an inflatable plug. We pushed it up into the lateral from the power house just as far as we could and then inflated it remotely. On further inspection we found that the plug had partially deflated while we were working and allowed some of the dirty material to enter into the lateral. On completion of the drain washing up to 400 ft. (the maximum we could get to) we then fitted an 8” flange with a fire hose connection to the end of the drain and backwashed the drain using fire water from the penstock systems. We initially opened the valve into the powerhouse next to TSV #1. This allowed most of the loosened material, dirt, calcite and chunks to wash onto the floor of the powerhouse. A small amount of debris was left in the piping leading to the clear water sump and that was washed clear. We let the fire hose water run until the drain started to run clear. After letting it flush onto the powerhouse floor for a few minutes we then operate the valve, closing it off to drain #1 TSV and force the fire hose water to back flush the last leg of piping between the drains and the TSV into the clear water sump. We would observe the clear water sump and run the hose until the water coming out of the standpipe at the clear water sump ran clean. It will be a good idea to go into the clear water sump Page 5 of 6 Bradley Drain Cleaning Report Robert Day December 15, 2008 during the summer outage and inspect it. If necessary we will need to muck it out. We repeated the same process with drain #3. Drain #2 and drain #4 remain to be fully flushed and backwashed because they are harder to get into with the cleaning apparatus. We contacted Mongoose Jetters and tried to get information on a root cutter, a rotating head with some blades attached. They indicated that that type of head may well take us past the obstruction at 400 feet that we encountered. They seemed to indicate that will cut through this calcite material and we can make some further progress. It will also be a lot more convenient to do drain cleaning in warmer weather. We did have some freezing issues with some of the equipment. All in all, the washing system seems to be effective. It does require multiple passes but it has been collecting calcite for about 18 years and there is a buildup. Still to be determined is whether we can reach the full length with of the 1000 ft. of hose that we have. The penstock drains are about 3000 ft. long so we are only going to be able to get to the lower third with the existing equipment. We also need a better device for inserting the camera. We did not have sufficient PEX tubing to insert the camera very far up the penstock. In addition the camera had a large junction box on its back end that interfered with our inserting it very far up the drain. The junction box made it difficult to go around and bends or turns. We should obtain some 1” PEX tubing in at least 300 ft. lengths, join them together and use that as the push tube to push the camera up the drains for further inspection. We could use that push tube to make a fire hose connection and insert the 600 ft. of 1” PEX just as far as we can up into the drain, hook the firehouse to it and flush from the top down which would be a much more effective way of flushing out the material. We could then use the fire hose connection and a flange for the final flush. The drain plug for the laterals needs to be investigated as to why it would not hold pressure, possibly a small leak in the tubing we used to inflate it from a remote distance. Activities to be completed in the spring: Obtain a root cutter Try to penetrate further up drains 1 and 3 Place the drain plug in the drain lateral Clean and flush of drains 2 & 4 Injection washing (flushing) using the PEX tubing reaching in as far as we can Back flushing the dirty water in the lateral to the clear water sump for drains 2 and 4 e This could all occur in May when the weather conditions improve. We secured the area on the 18". Brian Carey made a visit here on the 19" and observed the operation. Also in attendance was John Magee for R&M Engineers. Page 6 of 6 Bradley Drain Cleaning Report Robert Day December 15, 2008 MA INTAIN 24 INCHES IN FRONT ANY VENTILATED SURFA CE ENCLOSURE BRADLEY LAKE PROJECT COSTS 7/1108 TO 12/15/08 NUKA REPAIR LABOR 24,664.98 PER DIEM 570.00 TRANSPORTATION-EXPENSE 666.72 FREIGHT EXPENSE 293.64 OUTSIDE SERVICE 500.00 SUPPLIES 1,204.18 MATERIALS 2,748.80 TRACTOR wiBACKHOE & LOADER 23,500.00 HELICOPTER EXPENSE 35,899.66 TOTAL 90,047.98 POWER TUNNEL DRAIN CLEAN & INSPECT MONGOOSE PRESSURE WASHER 47,471.68 MATERIALS & TOOLS 1,488.22 TUNNEL DRAIN CAMERA INSPECTION (approx. cost) 10,000.00 TOTAL 58,959.90 TRANSFORMER FIRE LABOR 17,488.30 TRANSPORTATION-EXPENSE 2,027.52 FREIGHT EXPENSE 3,305.57 EMPLOYEE MEALS 415.53 AVIATION TO BRADLEY LAKE 1,704.00 GENERATOR RENTAL 13,611.56 BOAT LEASE 5,600.00 TRANSFORMER 31,850.00 TOTAL 76,002.48 *Note - $20,486.47 was paid during previous FYO8& Bradley Lake Transformer ONPS-XA1 Failure On October 30, 2008 I traveled to Homer to try and shed more light on the cause of failure of transformer ONPS-XA1. A brief history of this transformer is that it was a replacement to the original transformer that failed violently several years after energization. I don’t have record of the fault investigation of that occurrence. This replacement transformer was in service for a number of years before it failed. The transformer serves as the source to the “Camp” distribution system which serves the surrounding facilities, and a several mile single phase run up to the dam which appears to be on C phase. The transformer is rated at 750 KVA which equates to a little over 30 amps per phase available load current. Normal loading was reported at a few amps on A and B phase and around 5 amps on C phase. I am not sure where these reading were taken at, but I assume that they were taken at the ACB 30/40 circuit breakers. There have been several cable faults associated with the long single phase run. I am unaware of the number or cause. The transformer was also subjected to some significant load swings between the two generators due to, I believe, governor issues during out of step conditions. This would only affect the source voltage, and happened some years ago. In reviewing pictures of the transformer after failure, I observed that the neutral conductor of the low side utilized a shielded 15KV cable. I did not see a bare copper ground on either side of the transformer, nor did I see marks on the ground bus where a ground had been connected. This doesn’t mean there wasn’t a ground connected; I just couldn’t find evidence of one. I also received relay settings for ABC 30 and 40 that had a pick-up of 2 amps, a time dial of 1, and an instantaneous of 15 amps. I’m not sure of either the curve type or the CT ratio. If the CT ratio is in excess of 100:5, these settings need to be reviewed. Tusi Faafetai from CEA and I performed some testing on the transformer in Homer at the North Star Stevedoring terminal. The high and low side winding leads had been cut but we were able to figure out orientation and perform a turns ratio test and mega-ohm resistance tests. The H1-H3 to X1-X0 and H2-H1 to X2-X0 windings tested within 0.4% deviation at a ratio of 1.924. The H3-H2 to X-3 to XO winding tested at a ratio of 2.498 or 30% deviation. The megger test was performed at SK VDC. I did a Polarization Index on the High side insulation to ground (PI of 1.25 at 61 giga-ohms), High to Low (PI of 1.09 at 65 giga-ohms), and Low to ground (PI of 1.13 at 1.52 mega-ohms). A winding resistance test would have been nice, but the flight down limited the amount of test equipment I could bring. A simple Fluke ohm-meter across the low voltage winding showed winding resistances of; X-1 of 1.lohms, X-2 of 1.1 ohms, and X3 of 1.14 kilo-ohms. We “dissected” the faulted area and found that the low voltage winding had burned open in at least one place. This caused a lot of heat and burning of insulation in that part of the winding. It was impossible to tell if the winding failed from shorted turns, or if some defect caused the winding to burn open. Statistically, I would say that the “open” began as a shorted turn, and escalated due to the local heating. It appears that there may have been substantial heat associated with this problem as we observed what looked like recent varnish drippings (pic.0021) from the bottom of the faulted winding. Conclusions: The low voltage winding of this transformer failed turn to turn and did not fail to ground or to the high voltage winding. The smoke and soot (pic 0022) from the burning winding caused a phase to phase “flash over” on the high voltage “Delta” winding leads and bus. It appears that the phase to phase fault ran towards the primary cable connections where it created a three phase fault (pic.0026) before being cleared. The cause leading to the failure is more elusive. There was evidence that the faulted phase winding had experienced some vertical movement (pic.0019) at some time. The low voltage winding blocking was smashed against the core. This could have been from the through faults associated with the cable failures. This transformer has a very limited amount of short circuit current (590 amps secondary) and is lightly blocked against winding movement. Suggestions: I am unaware of the coordination of primary breakers and secondary fusing, but it should be reviewed if it hasn’t been. I could not see were there was any metering equipment on the load side of this transformer. Knowing the actual phase and neutral loading through all loading conditions would be beneficial. I am not sure if any of your Camp distribution is overhead, but if so, some surge arrestors at the load side terminals of the transformer won’t hurt. Also, ensuring proper grounding of the transformer ground bus to the ground grid and connecting the X0 to the ground bus is advisable. The best advice I can offer is to get accurate baseline electrical test data and then perform routine retesting in an attempt to predict and prevent a repeat. Kurt Labonte Substation Foreman Municipal Light and Power labontekm@muni.org (907)263-5404 MEMO: To: Date: Members of Bradley Lake Management Committee 12/15/2008 From: Robert Day, Power Production Manager, HEA Thru: Charlie O’Hare, Director of Power Production and Transmission, HEA Subject: Bradley Lake Power Plant Operators Report for December 2008 Since the last time we reported on activities at Bradley Lake in June of 2008 the following significant events have transpired: The annual outage was completed with no significant issues remaining The annual gate testing was accomplished. The annual FERC visit was completed. Noted by FERC is the issue of continuing corrosion in the Gate and Diversion shafts. A trip of the Plant resulted when the gate was caused to go closed due to a fault in the inverter at the Gate house. This was not immediately noticed due to a failure (due to corrosion) of a snap switch on the gate. The turbines were tripped on Low penstock pressure. It took approximately 1 day to diagnose and correct the problem. Nuka glacier work was completed. Middle Fork was inspected and appears to be in good shape. The transformer serving the camp facilities failed. It was subsequently replaced. Please see the additional reports attached to the BPMC package. Mike Teinert, Bradley Lake Superintendent, resigned. While performing transmission line maintenance the chartered helicopter struck the line. The resulting wreck destroyed the helicopter and severed a conductor on the line. Fortunately the Pilot escaped relatively unscathed. We began work to try to modify the Fish Water release permit conditions e The initial drain cleaning was accomplished. e Successfully tested the fire pressure regulating valve at flow. The valve needs servicing because it overpressures the fire water system and lifts the pressure relief valve. e Aaron Remer, the new Bradley Lake Superintendent joined HEA in December. All things considered the Plant is in relatively good shape and continues to operate smoothly. Lake levels are at the average for this time of year. During certain loading conditions we have seen an oscillation of the entire power grid (usually with light loads and the Kenai exporting to Anchorage. BRADLEY LAKE HYDROELECTRIC PROJECT PROJECT SITE WORK RULES Hydroelectric Project (the “Project”), you will be provided furnished living quarters. The following guidelines are provided to explain the various duties and responsibilities for living at the project site in a fair, equitable and nondiscriminatory manner. While the information offered here is intended to be comprehensive, it is not all-inclusive, is subject to change and may be updated or revised from time-to-time at the direction of the Bradley Project Management Committee (BPMC) Executive—Directer-and/orthe Director/Facilities-Operations-andEngineering. For these reasons, please check with the Plant SuperintendentSenior-Operations-Engineer for verification prior to taking any questionable action. The following guidelines are separated into two main sections: 1) Project Residency Guidelines and 2) Project Employment Guidelines. PROJECT RESIDENCY GUIDELINES (: Moving Expenses/Logistics To and From Site. Upon assignment to the Project, the-Energy—Authority-wiltmeve up to 3,000 pounds of personal household belongings on ad eps 7 Mdsabiacd % no expense to ine Bethe the-Energy Authority poley-as_drected by the Executive Director The move will be coordinated through the Plant Superintendent. Genera In addition, *he—Energy—Autherity-wit transport ee 3,000 ii of ae belongings will be transported between the Project site and Homer at the commencement and the termination of employment at the Project. Such costs shall be reimbursed to the Project participants if employment is terminated prior to one year of service. 2 Housing Provided. At no cost to the employee, the—EnergyAutheritywil} provide a two bedroom furnished housing unit at the Project site will be provided for use by each employee, their family, and visitors. On-call employees will be required to be on-site continuously throughout their normally scheduled workshifts. Major appliances, maintenance equipment and normal kitchen, living room, and bedroom furniture are provided by-the-Energy—Authority in the housing units. Small appliances, cooking utensils, bedding, entertainment devices, personal belongings and other furnishings are the responsibility of the employee and are not supplied by the employer. The Plant Superintendent Generatfereman/Bradiey will provide employees with a list of the provided furnishings and household goods and their condition both at the commencement of employment and at the end of employment at the Project. ATTACHMENT 1 3. Utilities. FheEnergyAuthoritywiltprevide Electricity, heat, sewer, and water will be provided at no cost to the employee. Employees will be responsible for and pay for their personal telephone calls and any service charges for telephone and television. 4. Food/Supplies/Mail. Employees will be responsible for the purchase and preparation of their own food. Food and mail will be transported from Homer to the Project on a space-available basis on scheduled flights by the contracted flight operator. Delivery of food and mail to the contracted flight operator will be the responsibility of the employees. All transportation of employee food, supplies and mail must be coordinated for transportation through the Plant Superintendent Generalt-Fereman/Bradiey or his designee designated representative. 5. Condition and Maintenance of Housing. Employees are responsible for maintaining the original condition of housing with the exception of normal wear and tear. Employees are responsible for damage to their housing unit and/or common areas or any equipment thereon which may be sustained by reason of carelessness, negligence or intentional acts of employee or his/her relatives and visitors to the project site. Routine maintenance, housekeeping and repair of the provided housing is the responsibility of the employees. Employees are expected to keep their housing units repaired and maintained in good sanitary order and condition. 6. Damages. Employees are not required to pay an up-front damage deposit for their housing unit. Damages to the housing unit determined to be caused by the employee or family/friends of the employee, other than normal wear and tear, may be deducted from the employee's pay. 7. Personal Property. Neither the employer, the Project Owner nor Participants are responsible for damages by wind, fire, water, theft, earthquakes or natural disaster, etc., to personal effects located within the housing units or stored at the Project. Employees will be responsible for maintaining their own personal property insurance for their personal belongings. 8. Rental. Employees are not allowed to rent out any portion of the Energy Autherit-provided housing, or permit its use by individuals not approved by the Plant Superintendent as visitors. 9. Alterations. Structural alterations are not allowed to the housing units nor are additions or alterations to the common areas. Outside installations such as antennas, basketball hoops, etc. are prohibited unless approved in writing in advance of installation by the Plant Superintendent. GeneraltForeman/Bradley—orthe—Senior Operations Engineer. 10. Owner/Access. The Plant Superintendent or other Prpject Management personnel $ n H m BRADLEY LAKE HYDROELECTRIC PROJECT PROJECT SITE WORK RULES Page 2 Energy-Authority-managementofficial, may authorize entry to an employee-occupied housing unit in an emergency if there is reason to believe there may be imminent danger to life or property. Such entry may be authorized whether or not the employee is present at the time. The Plant Superintendent or other Project Management personnel Energy Authority also maintain the right, in times of non-emergency, to conduct unit inspections, usually after a 24 hour notice, to ensure the health and safety of all residents, to protect the Project EnergyAuthoritys property and for general maintenance of the facility. 11. Drugs/Alcohol. 4aA—keeping—with—Energy—Autherity-pelicy, The Project shall remain drug-free and alcohol-free. 12. Noise/Offenses. Employees and their guests may not cause a nuisance to other resident employees. This includes, but is not limited to, noise, noise producing activities and noxious or other offensive activities. No improper, offensive or unlawful use shall be made of any part of the Project. 13. Trash. Employees will deliver trash from the housing units to the site incinerator. No storage of trash will be permitted in or outside of any residence in such a manner as to permit the spread of fire or encouragement of vermin. 14. Pets. One dog or cat or other non-exotic pet per family is allowed. The Plant Superintendent GerneratFereman/Bradiey may authorize exceptions to this guideline for birds, fish, gerbils, etc. No kennels, dog teams, livestock, horses and/or other exotic pets are allowed. Owners of pets are responsible and liable for injury, damage or loss caused by their pets; it is their responsibility to ensure that pets are not nuisances and that they do not create unsanitary conditions in/around living quarters. Pets must be leashed or under the owner's control while on Project EnergyAutherit-ewned—or controled premises. 15. Storage. Common areas in and around housing units and Project facilities shall not be obstructed or littered. Explosives or illegal products shall not be kept in the housing units. Paint, stain or other inflammable products should be stored in approved containers. Personal property storage, with the exception of firewood piles, is not permitted outside of the employee’s housing unit or assigned yard space. Outside property storage will be in a designated area as approved in writing by the Plant Superintendent. General Foreman/Bradley. 16. Firewood. If employees so desire, they may store firewood for use in their fireplaces. Wood piles shall be allowed in common areas around the housing units at a location, or locations, specified by the Plant Superintendent. General Foreman/Bradiey. Wood shall be neatly stacked, and shall not touch the common area walls. BRADLEY LAKE HYDROELECTRIC PROJECT PROJECT SITE WORK RULES Page 3 17. Gardens. Upon approval of the Plant Superintendent General Foreman/Bradiey, garden plots may be permitted. 18. Education. Education for school age dependent children of employees is the sole responsibility of the employees. 19. Voting. Voting privileges will be by means of absentee ballot and will be the responsibility of the employee. 20. Firearms. Storage of firearms will be permitted in the housing units only. Use of firearms will be in accordance with local and state law. Discharge of firearms will not be permitted within one-half (1/2) mile of the Project facilities. 21. Medical Emergencies. The Plant Superintendent General Fereman/Bradiey or designated authority will arrange for and coordinate assistance or evacuation to treatment facilities for medical emergencies pursuant to the facility emergency action plan or evacuation plan. The Plant Superintendent GeneratFereman/Bradiey or designated authority should be contacted immediately concerning any Worker's Compensation-related illnesses or accidents. The Plant Superintendent Genera! Foererman/Bradiey will provide and complete the necessary forms regarding the Worker's Compensation incident(s) to the Human Resources Department Ernergy—Autherity PersonnetOffiser within 72 hours of the accident/illness report. 22. Personal Vehicles. Employees may not store or operate motorized personal wheeled vehicles on the Project roads. Petroleum products for personal use may be purchased from the Project at the current price paid by the Project to the vendor. Purchases may be made through the Plant Superintendent General Fereman/Bradiey or designated authority. 23. | Recreational Vehicles. Snowmobiles, four wheelers, and other motorized off- road vehicles including trail bikes, jeeps and other four wheel drive vehicles not used in Project maintenance are prohibited on Project roads per stipulations of the FERC license. 24. Private Boats. Private boats are allowed to the extent that they do not interfere with Project operations. Private boats on the site must be approved by the Plant Superintendent. S HA B 25. Private Aircraft. The Project landing strip may be used by employees who own aircraft. Use is governed by Federal Aviation Administration rules and regulations and is to be used as Visual Flight Rules only. A State liability waiver will be required for its use. Only aircraft meeting requirements of the State Division of Risk Management to use a State facility will be allowed to use the air strip. All aircraft services precured-by the-EnergyAuthorityand utilized by employees and their guests must be logged and BRADLEY LAKE HYDROELECTRIC PROJECT PROJECT SITE WORK RULES Page 4 coordinated through the Plant Superintendent. General Foreman/Bradiey. No personal aircraft storage is provided. Employees are liable and responsible for their personal equipment on site. 26. Parking. Project vehicles may not be parked in such a manner as to block access to Project facilities, fire hydrants, designated fire lanes; they may not be parked on lawns or in such a manner as to damage yards or yardwork. 27. Project Vehicles. Project vehicles are not to be used by persons other than employees except in the case of emergency. In the case of emergency use by non- employees, the Plant Superintendent General Foreman/Bradiey, or his/her designee will be immediately notified. Project vehicles may be used only in the conduct and support of Project business. 28. Speed Limit. The speed limit on the Project site is as posted and as is reasonable for current conditions. 29. Transportation to and from Project. Transportation to and from Homer will be provided through the Employer’sEnergy-Authority’s contract carrier as scheduled by the Plant Superintendent or his designee Senier-Operations-Engineerand/erthe-General Foreman/Bradley for the employee at the start and finish of each workweek schedule. On-site persons residing with the employee will be accommodated on a space-available basis on these flights. Those persons involved in a medical emergency will have first priority. Transportation for employee and dependants other than scheduled flights will be arranged and paid for by the employee. Only approved air carriers meeting the requirements of the State Division of Risk Management to use a State facility will be allowed to utilize the air strip. 30. Visitors. Project visitation by relatives or friends will be permitted. Transportation will be by private boat or on a space available basis on the scheduled contracted flight operator or other approved charter. It is the employee’s responsibility to have their guests/invitees sign in and out with the Plant Superintendent or his designee General Foreman/Bradiey upon arrival to and departure from the Project. Visitors will abide by these Work Rules while at the Project site. The Employer Energy Authority reserves the right to ask guests to leave the Project site for safety reasons or disobeyance of site rules. 31. Energy Authority Project Management Personnel Project Visitations. When Project Management EnergyAuthority personnel visit the Project they shall be housed in the visitor's quarters and shall abide by all the guidelines and regulations for the Project. During their stay, they are responsible for their own meals and shall do their own house cleaning, including washing any dishes and bed linens used. BRADLEY LAKE HYDROELECTRIC PROJECT PROJECT SITE WORK RULES Page 5 32. Project Facilities. Spouses, other residents or Project guests are not allowed unaccompanied in Project facilities except in housing units. Project facilities includes the powerhouse, maintenance building, crews quarter's, and dam site. 33. Project Equipment/Workspaces. Project materials, supplies, equipment and workspace and other Project properties EnergyAuthority- belongings are not available for employees’ personal use. If Project facilities are needed to be used, prior approval shall be received from the Plant Superintendent. Sernior-Operations—Engineer-orthe GeneratForeman/Bradley. 34. Policies Not Covered in these Guidelines. All existing practices for the benefit and welfare of EnergyAutherity employees assigned to the Project presently in effect and not specifically covered by the terms of this Agreement shall be continued until superseded by a future revision to these work rules memeranduntordirective. 35. Project Description and Definition. As described in FERC exhibits A & G to project license. BRADLEY LAKE HYDROELECTRIC PROJECT PROJECT SITE WORK RULES Page 6