The following news article originally appeared in NEI’s Nuclear Energy Overview.
The industry has submitted for NRC endorsement revised guidance for implementing the agency’s post-Fukushima order to install additional used fuel storage pool instrumentation.
The revision clarifies several points based on NRC staff comments on the initial version, which was submitted in July. In its submission, the industry reiterates its position, in line with the commission’s direction, that installing commercial-quality instruments—combined with a training and testing program to maintain their reliability—will fully comply with the order.
“It is the industry’s view that [spent fuel pool] instrumentation channel components qualified using commercial quality requirements and installed on seismic mountings in the pool fully meet the requirements of the NRC order,” said Steven Kraft, NEI’s senior director of Fukushima response coordination and strategy, in a letter accompanying the revised guidance.
Based on recommendations from its post-Fukushima task force, the NRC in March ordered all nuclear energy facilities to add a second tier of used fuel storage pool instrumentation to monitor water level. The objective is to enhance operators’ ability to monitor pool conditions should the facility experience an external event exceeding its design basis.
In several public meetings, the NRC staff has said the instruments should be nuclear-safety-grade and subject to the seismic qualification requirements provided in Regulatory Guide 1.100. However, the industry believes that goes beyond what the NRC order requires.
Kraft said the only requirement in the order that mentions seismic ground motion pertains to the mounts on which the instruments are to be placed. He cited the order, which states that “installed instrument channel equipment within the spent fuel pool shall be mounted to retain its design configuration during and following the maximum seismic ground motion considered in the design of the spent fuel pool structure.”
The order also states that the instruments themselves must be “reliable” and provides guidance on how such reliability is to be achieved. Kraft noted that the commission told the staff when it approved issuance of the order that commercial-grade instruments would be acceptable, provided they met certain conditions. “Reliable, commercial grade equipment could be an appropriate solution, so long as the expectations for ‘reliable’ are clearly outlined in the guidance documents,” the commission said in the staff requirements memorandum related to SECY-12-0025.
Kraft added that the industry guidance provides a variety of requirements to address the reliability of the used fuel pool instrumentation channels. He said an attachment to the NRC order allows for the reliability of spent fuel pool instrumentation to be maintained through the development and implementation of training, procedures, and testing and calibration.
Kraft also said that if licensees must qualify instrument channel components using other than commercial quality requirements, the schedules for complying with the order may be affected. “We expect utilities will bring any schedule effects to the NRC’s attention in either their reports due 60 days following issuance of the final guidance or their Overall Integrated Plans due February 28, 2013.”