Summary Report of the EPRI Standard Radiation Monitoring Program Dennis Hussey, EPRI Asian Technical Center ALARA Symposium Yuzawa, Japan October 11-13, 2006

Overview History of Standard Radiation Monitoring Program (SRMP) Standard Radiation Monitoring Program Goals Plant Types and Survey Points Current Results US Responses Summary statistics of loop piping channel head surveys Difference of cold leg and hot leg measurements Conclusions and Recommendations

History of Standard Radiation Monitoring Program (SRMP) Started in 1978 to study radiation fields in Westinghouse-designed plants Program expanded to include Combustion Engineering (CE) designs In 1996, program was suspended because of a lack of industry interest and funding In 2003, NEI/INPO/EPRI developed the RP2020 Dose Reduction initiative Take Radiation Off the Table EPRI was charged to take the technical lead for source term reduction First goal was to benchmark PWR performance

Standard Radiation Monitoring Program Goals Maintain the history of the program Much data have been acquired already Locations should not be change Make the procedure simple, focused, practical, and routine North American Technical Center recommendation Help HP staff so that HP staff can help us Organize the data to allow correlation to chemistry events and plant design PWR Monitoring and Assessment Database Encourage consistent sampling techniques

SRMP Monitoring Points Workshop held in Charlotte March 7-9, 2006 to discuss Selection of B&W points Required vs Recommended points Procedure clarifications Marker Discussions Emergency Core Coolant System strainers limit markers with vinyl New markers made that are etched stainless steel Discussed further SRMP plans Pre-oxidation points Auxiliary system monitoring Possible smears

Westinghouse Monitoring Points Loop piping Steam Generator Channel Head

Combustion Engineering Monitoring Points Loop piping Steam Generator Channel Head

Babcock and Wilcox Monitoring Points Steam Generator Channel Head Loop piping

Current US Survey Results  Parameter/Plant Type W CE B&W Total Plants 33/48 5/14 5/7 43/69 Total Number of Outages 982 275 180 1437 Loop Dose Rate Measurements 733 60 48 841 Channel Head Dose Rate Measurements 538 27 42 607 % Loop Measurements Received 74.6 21.8 26.7 58.5 % Channel Head Measurements Received 54.8 9.8 23.3 42.2

Summary Statistics: Loop Piping—Hot Leg and Cold Leg

Summary Statistics: Channel Head Center

Summary Statistics: Channel Head, Cold Leg - Hot Leg Difference

Conclusions The Standard Radiation Monitoring Program has been re-instated The procedures have been simplified for the HP staff Babcock and Wilcox plants are now included in the program The historical measurement points have been maintained for reference The data variability is quite large over time Westinghouse-designed plants have largest limits, and longest history Summary stats are not enough for a quantitative analysis of dose rates The trend of the cold leg having higher radiation fields than the hot leg has been confirmed for Westinghouse and CE plants Unexpected results obtained for the B&W plants

Recommendations Analyze the data to evaluate the change in radiation fields over time Time-based data will help understand transient changes in radiation fields Effects of system changes will be observable Compare the plants by chemistry operations, steam generator materials, and core duty SRMP database is combined with the EPRI PWR Chemistry Monitoring and Assessment Database Combined database also includes Steam generator information Limited core duty

Acknowledgements EPRI Solutions Sam Choi, Cara Libby PWR ALARA Group Leonard Rollins, Dan Stoltz North American Technical Center David Miller, Scott Schofield Romain Bouchacourt