PIPE-FLO Nuclear

Millstone Power Station. Image via www.nrc.gov

Now that PIPE-FLO Nuclear is nearing its release, one of our new employees asked me how someone in a nuclear power plant could use the new program. That got me thinking about my first job after getting out of the Navy. In 1975, I was hired by Northeast Utilities as a start-up and test engineer at Millstone Unit 2 in Waterford Connecticut. I was assigned to a group of five engineers involved in a pre-operation test in which we balanced the component cooling water system. The component cooling water system is a safety related system and must be operational after a postulated accident.  
This involved test went on 24 hours a day for about two weeks. It started when the engineers at Bechtel in Gaithersburg, Maryland (the EPC for the plant) sent us a datasheet with the prescribed valve position as the initial “guess” for balancing the system. 

During the second shift, the plant operators placed the component cooling water system in the proper configuration for the test. The team of test engineers would place the throttle valves to the prescribed valve position. Once this was done, we would then record the pressures and flow rates using the installed plant instrumentation. We would compile the information into a report; type in onto a report and by about 5:00 AM, would finally fax the results to Bechtel in Gaithersburg.
 
During the day, a group of engineers at Bechtel evaluated our test data from the night before, and after a day of calculations, compiled a new set of valve positions. They would then type a report with the new valve positions and fax it to us by 7:00 PM, so we could repeat the process. This was an iterative process and after each round of test data and new valve positions, the flow rates to each load in the cooling water system got closer to the design values. This process continued for about two week until the results were within the prescribed value outlined in our Final Safety Analysis Report (FSAR for short).

Image from the 1999 movie "Office Space", where
disgruntled workers obliterated their fax machine.

As you can see this was a team effort with about ten engineers in two location working around the clock to balance a critical system in a nuclear power plant. Even the FAX machine required two full time operators, using a Xerox Magnafax Telecopier, one at Millstone the other in Gaithersburg. Let me quickly describe this arduous process and this is such old technology I could not find a picture of one anywhere on the internet, but try to imagine with me. The fax machine was a hefty 46 pounds and was connected to a standard telephone buy inserting the phones handset into an acoustic coupler. The operator sending the fax would place a call on a POT (Plain Old Telephone) to the operator on the receiving end. The sending operator would then place the page on a drum, to start the process the drum would rotate, the machine would screech and once the two machines were talking to each other the receiving operator would flip a switch and the Fax would come through line by line. After six minutes, a single page was done and the operators would then manually reload the paper on each end and start the process for the next page in the report. With two good operators, we could transmit a six-page report in an hour! 

As you can see, technology has come a long way. About 10 year ago, I met up with one of the test engineers from Millstone. He was now in plant management and said that they used PIPE-FLO to calculate the valve positions needed to balance his plants cooling water system. I asked him how long it took with PIPE-FLO, and he said once the model was validated, the valve positions were calculated within seconds. The operators then set the valves to the prescribed position and then took the pressure and flow readings just like before. Now they would compare the calculated values with the observed values. If the results were within the prescribed values, the test is signed off. He said from start to finish they were able to balance their equipment cooling water system in less than a day. 

In 2005, the NRC granted Millstone 2 and 3 a 20-year extension on their operating license after an extensive 22-month review process. I find it remarkable that after 40 years, the plant that I helped start up is still running and has another 10 years of operation. 

One of the reasons that the US civilian nuclear power program has been so successful and safe is because of the quality requirements placed on the equipment, and the training requirements of the plant personnel.


Our soon to be released PIPE-FLO Nuclear program comes with an extensive Commercial Grade Dedication in which we document the engineering methods used, outline our development and testing programs, along with an extensive set of test procedures that we developed. To automate the testing process we use PIPE-FLO’s DataLink feature to export design data and calculated results from the PIPE-FLO model to any ODBC capable program like Microsoft ® Excel® or Access®. 

Using the Excel spreadsheets included in the PIPE-FLO Nuclear, one is able to compare PIPE-FLO’s calculated results with the results calculated using Excel. The Excel Verification Worksheets utilize conditional formatting to automatically highlight any values greater than those specified in the Acceptance Criteria. By using Excel, anyone can review the formulas use in the spreadsheets and validate our check calculations.

Nuclear power plants have used PIPE-FLO for over 20 years, but until the release of PIPE-FLO Nuclear, each of our utility customers had to develop their own Commercial Grade Dedication, which may take months to develop. Since a Commercial Grade Dedication needs to be performed for each new version of PIPE-FLO, and the cost is so high for them to perform the work, many use older versions of PIPE-FLO. 

By making PIPE-FLO Nuclear available to our nuclear customers, they will benefit from the latest versions of the software much more quickly. They will still need to run their own commercial grade dedication, but using our supplied templates, they will be able to do their own CGD in a fraction of the time.

Now that is progress.