[Federal Register Volume 78, Number 120 (Friday, June 21, 2013)]
[Notices]
[Pages 37591-37592]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2013-14875]
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NUCLEAR REGULATORY COMMISSION
[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
accident.
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
detonations.
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
licensee.
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
Regulation.
[FR Doc. 2013-14875 Filed 6-20-13; 8:45 am]
BILLING CODE 7590-01-P