U.S. Nuclear Regulatory Commission
Sampling Drywell Atmosphere Before a Release
Title: Sampling Drywell Atmosphere Before a Release
See the memorandum from L. J. Cunningham to R. B. Samworth
dated November 3, 1988. Sampling drywell atmosphere is
required before each and every purging or venting.
Furthermore, methodology and parameters in TS referencing
the ODCM, should accurately represent the contents of the
Region V requested assistance in interpretation of two
current Washington Nuclear Plant - Unit 2 (WNP-2) Technical
Specifications (TS): TS 3/220.127.116.11, and TS 3/18.104.22.168.
Specifically, Region V asked: "Does TS Section 4.11.21 and
Table 4.11.2 require a sample of drywell atmosphere be
taken and analyzed prior to each vent and/or purge
operation through the Standby Gas Treatment (SGT) system?"
Region V also asked: "If prior-to-release samples are
required, should this be reflected in the ODCM, along with
an appropriate decontamination factor to account for SGT
NRR reviewed the Inspection Report documenting the
positions of both the inspector and the licensee in regard
to the subject question. NRR agreed with the position
expressed by the licensee's Corporate Nuclear Safety Review
Board (CNSRB) member at the November 27, 1985 meeting of
their Plant Operations Committee (POC) recorded on pages 10
and 11 of the Inspection Report. WPN-2 TS 22.214.171.124.2 with
its Table 4.11.2 requires that a grab sample be taken prior
to each purge and vent from primary containment. TS
126.96.36.199.3 provides additional requirements for the case of
purging or venting through other than the SGTS, but says
nothing about when the SGTS is used. The applicability of
TS 3/188.8.131.52 is "At all times." Therefore, the answer to
the first question of Region V is "yes."
In regard to the second question, TS 3/184.108.40.206.2 ties the
sampling and analysis program of Table 4.11.2 to dose rate
determinations "in accordance with the methodology and
parameters in the ODCM." Thus, statements regarding these
determinations should be incorporated in the ODCM.
Regulatory references: Technical Specifications
Subject codes: 7.3
Applicability: Reactors (BWR)