nuclear-news

Widespread concern about Nuclear Reactor Baffle Bolt Problems

Nuclear Reactor Baffle Bolt Problems Are Widespread Concern, POWER, 05/04/2016 | Aaron Larson Public Service Enterprise Group (PSEG) anticipates extending Salem Nuclear Generating Station’s Unit 1 refueling outage, which began on April 14, so it can inspect, repair, and replace damaged baffle bolts within the plant’s reactor vessel, according to information presented in the company’s first quarter earnings announcement.

A PSEG spokesperson told POWER that visual inspections at Salem had identified 18 of the metal insert liner’s 832 baffle-former bolts exhibit degradation, which means they had at least some indication of cracking. The news comes roughly a month after inspections at the Indian Point nuclear plant determined that 227 of its Unit 2 baffle-former bolts were degraded.

“As part of our license renewal commitments to the Nuclear Regulatory Commission [NRC], Salem Unit 1 was scheduled to conduct ultrasonic testing of the baffle bolts in 2019. Based on the visual inspections, we made the decision to conduct ultrasonic testing of the bolts now to determine the full extent of condition and to make appropriate repairs,” the PSEG spokesperson said.

Problems in Europe

It’s the first time that Salem has identified any problems with baffle bolts on either unit, but it is far from the first time for the industry. As far back as the 1980s, cracking was identified in French pressurized water reactor (PWR) baffle bolts.

In March 1998, the NRC issued an Information Notice to alert U.S. PWR license holders of the cracking found in reactor vessel internal baffle-former bolts at “several foreign PWRs.” The intent of the notice was to inform recipients of the problem so they could consider actions to avoid similar troubles. The suggestions in the notice were not necessarily requirements, however.

Are There More Potential Problems?

Neil Sheehan, public affairs officer for NRC Region I, told POWER that all U.S. PWRs—of which, there are currently 65 licensed to operate—utilize baffle plates as part of their reactor core internals. The baffle plates help direct water up through the nuclear fuel assemblies………

The NRC is still weighing the significance of the recent inspection findings. It expects analysis performed by both Entergy and PSEG will help in its assessment. http://www.powermag.com/nuclear-reactor-baffle-bolt-problems-are-much-more-widespread/?pagenum=2

May 9, 2016 - Posted by Christina Macpherson | EUROPE, safety, USA