[Federal Register Volume 78, Number 120 (Friday, June 21, 2013)]
[Pages 37591-37592]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2013-14875]



[NRC-2012-0284; Docket No. 50-247; License No. DPR-26]

Entergy Nuclear Operations, Inc., Entergy Nuclear Indian Point 
Unit 2, LLC, Issuance of Director's Decision

    Notice is hereby given that the Deputy Director, Reactor Safety 
Programs, Office of Nuclear Reactor Regulation, U.S. Nuclear Regulatory 
Commission (NRC) has issued a Director's Decision on a petition filed 
by the Natural Resources Defense Council, Inc., (hereafter referred to 
as ``the petitioner''). The petition, dated April 16, 2012 (available 
as Agencywide Documents Access and Management System (ADAMS) Accession 
No. ML12108A052), concerns the operation of Indian Point Nuclear 
Generating Unit No. 2 (Indian Point 2), owned by Entergy Nuclear Indian 
Point 2, LLC, and operated by Entergy Nuclear Operations, Inc.
    The petitioner requested that the NRC order the licensee for Indian 
Point 2 to remove the passive autocatalytic recombiners (PARs) from the 
containment building and replace them with electrically powered thermal 
hydrogen recombiners because the PAR system could have unintended 
ignitions in the event of a severe reactor accident, which in turn 
could cause a hydrogen detonation. The petitioner stated that 
experimental data demonstrates that Indian Point 2's two PAR units 
could have at least one unintended ignition on their catalytic surfaces 
following a severe reactor accident.
    As the basis for the request, the petitioner stated, in part, that:
     The PAR systems are simple devices consisting of catalyst 
surfaces where spontaneous catalytic reactions occur in the presence of 
hydrogen and oxygen to form water vapor. PARs are passive systems and 
do not need external power supplies or operator

[[Page 37592]]

action to function. As a consequence, control room operators cannot 
deactivate them or remove them from service.
     The PARs at Indian Point 2 are capable of controlling 
hydrogen generated from the NRC's design-basis accident as described in 
the Indian Point 2 updated final safety analysis report. The focus of 
the petition regards the behavior of PARs following a severe reactor 
     Following a severe reactor accident, hydrogen generation 
rates could overwhelm the PARs at Indian Point 2. As a result, the 
containment atmosphere could have elevated concentrations of hydrogen 
gas approaching eight to 10 percent or greater.
     The petition cites data from tests, including work 
sponsored by the NRC at the Sandia National Laboratory's Surtsey test 
facility, where PARs were observed to have unintended ignitions in 
environments containing elevated levels of hydrogen gas (i.e., eight to 
10 percent). According to the petitioner, ignitions could lead to 
     The NRC has not published any documentation indicating 
that the issue of PAR ignitions has been studied and resolved.
     Removal of the PARs at Indian Point 2 will lead to a safer 
post-accident condition because a potential source of ignition would be 
removed. Furthermore, if the PARs are replaced by electrically powered 
hydrogen thermal recombiners, control-room operators would have the 
option of deactivating them because electrically powered hydrogen 
thermal recombiners can also have unintended ignitions.
    The NRC sent a copy of the proposed Director's Decision to the 
petitioner and the licensee for comment on March 29, 2013. The 
Petitioner and the licensee were asked to provide comments within 30 
days on any part of the proposed Director's Decision that was 
considered to be erroneous or any issues in the petition that were not 
addressed. Comments were not received from either the Petitioner or the 
    The Deputy Director of the Office of Nuclear Reactor Regulation 
denied the petitioner's request to order the removal of the two PAR 
units from the Indian Point 2 containment building and replace them 
with electrically powered thermal hydrogen recombiners. The NRC staff 
has reviewed the petition and does not agree that the presence of PARs 
represents a sufficient risk to warrant their removal by order. 
Following a severe reactor accident, multiple ignition sources, besides 
PARs, would be present in containment to initiate combustion at lower 
flammability limits, which would be expected to keep hydrogen 
concentrations below detonable levels. Furthermore, the NRC staff 
believes that the presence of PARs could prove beneficial in the event 
of an extended station blackout.
    The Director's Decision (DD-13-01) under part 2.206 of Title 10 of 
the Code of Federal Regulations, ``Requests for Action under This 
Subpart,'' explains the reasons for this decision. The complete text is 
available in ADAMS under Accession No. ML13128A436 for inspection at 
the Commission's Public Document Room located at One White Flint North, 
Public File Area 01 F21, 11555 Rockville Pike (first floor), Rockville, 
Maryland, and online in the NRC library at http://www.nrc.gov/reading-rm.html.
    The NRC will file a copy of the Director's Decision with the 
Secretary of the Commission for the Commission's review in accordance 
with 10 CFR 2.206. As a provision of this regulation, the Director's 
Decision will constitute the final action of the Commission 25 days 
after the date of the Decision unless the Commission, on its own 
motion, institutes a review of the Director's Decision in that time.

    Dated at Rockville, Maryland, this 7th day of June 2013.

    For the Nuclear Regulatory Commission.
Jennifer L. Uhle,
Deputy Director, Reactor Safety Programs, Office of Nuclear Reactor 
[FR Doc. 2013-14875 Filed 6-20-13; 8:45 am]