Sotera Health committed to Safeguarding Global HealthTM with Nordion’s increased
focus on global gamma technologies business

BROADVIEW HEIGHTS, OH – April 17, 2018 – Sotera Health LLC, the world’s leading, fully
integrated protector of global health, today announced that it has entered into a definitive
asset purchase agreement to sell the Medical Isotopes segment of its Nordion business to a
subsidiary of BWX Technologies, Inc. (BWXT). This transaction will create a platform that will
accelerate growth for both companies.

“The world’s need for gamma technology has expanded dramatically as the demand for
sterilization of medical and non-medical applications has accelerated in response to increasing
global regulatory demands and growing healthcare needs” said Michael Petras, Chief Executive
Officer of Sotera Health. “The sale will enable BWXT to enter the medical isotope field with
highly skilled employees and specialized facilities that are recognized as the best in the
business. As the world’s only fully integrated provider of mission-critical services to the
healthcare industry, Sotera Health is excited about the additional value Nordion will bring to
our gamma customers, and our other best-in-class businesses, Sterigenics and Nelson Labs.”

Through the agreement, BWXT will acquire essentially all of Nordion’s medical isotope assets,
including the radiochemical operation and contract manufacturing services in Kanata, and the
medical isotope operation in Vancouver, British Columbia.

Both companies will continue to operate from Nordion’s state-of-the-art licensed facility in
Kanata, Ontario. Approximately 150 employees will transition to BWXT at the close of the sale.

“Nordion will continue to focus on accelerating growth in gamma technologies, including
industrial and medical cobalt-60 which fits perfectly with Sotera Health’s broader mission of
Safeguarding Global Health™,” said Kevin Brooks, President of Nordion.

About Sotera Health:
Sotera Health LLC, along with its business entities, is the world’s leading, fully integrated
protector of global health. With over 500 years of combined scientific expertise, the company
ensures the safety of healthcare by providing mission-critical services to the medical device,
pharmaceutical, tissue and food industries. Sotera Health operates more than 61 facilities in 13
countries. The company has over 2,600 employees globally and touches the lives of more than
180 million people around the world each year. Sotera Health serves more than 5,000
customers worldwide including 75 of the top 100 medical device manufacturers.

Sotera Health goes to market through its three best-in-class companies – Nelson Labs™,
Nordion® and Sterigenics® – with the mission of ensuring the safety of healthcare each and
every day. Nelson Labs offers microbiological and analytical testing and consultancy to assist
customers in developing and maintaining sterilization solutions in medical devices,
tissue/implantable products, and the pharmaceutical and biologics fields. Nordion is the
world’s largest provider of Cobalt-60 used in the gamma sterilization process as well as medical
isotopes used in the diagnosis and treatment of various diseases and cancers. Sterigenics
provides comprehensive contract sterilization and ionization solutions for the medical device,
pharmaceutical, food safety and high-performance materials industries.

Sotera Health LLC is owned by private equity firms Warburg Pincus and GTCR. Learn more
about Sotera Health at soterahealth.com, about Nelson Labs at nelsonlabs.com, about Nordion
at nordion.com and about Sterigenics at sterigenics.com.

Contacts: Paul Monlezun
Public Affairs Advisors
613-222-7184
paul.monlezun@publicaffairsadvisors.com

Kristin A. Gibbs
Chief Marketing Officer
Sotera Health LLC
kgibbs@soterahealth.com
440-262-1412